Дисертації: "Efficiency coefficient"

1

Rizzo, Giuseppe, Antonino Bonanno, Giorgio Paolo Massarotti, Luca Pastorello, Mariarosa Raimondo, Federico Veronesi, and Magda Blosi. "Energy efficiency improvement by the application of nanostructured coatings on axial piston pump slippers." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-200187.

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Axial piston pumps and motors are widely used in heavy-duty applications and play a fundamental role in hydrostatic and power split drives. The mechanical power losses in hydraulic piston pumps come from the friction between parts in relative motion. The improvement, albeit marginal, in overall efficiency of these components may significantly impact the global efficiency of the machine. The friction between slipper and swash plate is a functional key in an axial piston pump, especially when the pump (at low rotational speed or at partial displacement) works in the critical areas where the efficiency is low. The application of special surface treatments have been exploited in pioneering works in the past, trying different surface finishing or adding ceramic or heterogeneous metallic layers. The potential of structured coatings at nanoscale, with superhydrophobic and oleophobic characteristics, has never been exploited. Due to the difficulty to reproduce the real working conditions of axial piston pump slippers, it has been made a hydraulic test bench properly designed in order to compare the performance of nano-coated slippers with respect to standard ones. The nano-coated and standard slippers have been subjected to the following working conditions: a test at variable pressure and constant rotational speed, a test at constant pressure and variable rotational speed. The comparison between standard and nanocoated slippers, for both working conditions, shows clearly that more than 20% of friction reduction can be achieved using the proposed nano-coating methodology.

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2

Bubnova, Olga. "Thermoelectric properties of conducting polymers." Doctoral thesis, Linköpings universitet, Fysik och elektroteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-87476.

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According to different sources, from forty to sixty percent of the overall energy generated in the world today is squandered in waste heat. The existing energy conversion technologies are either close to their efficiency limits or too costly to justify their implementation. Therefore, the development of new technological approaches for waste heat recovery is highly demanded. The field of thermoelectrics can potentially provide an inexpensive, clean and efficient solution to waste heat underutilization, given that a new type of thermoelectric materials capable of meeting those requirements are available. This thesis reports on strategies to optimize a thermoelectric efficiency (ZT) of conducting polymers, more specifically poly(3,4-ethylenedioxythiophene) (Pedot). Conducting polymers constitute a special class of semiconductors characterized by low thermal conductivity as well as electrical conductivity and thermopower that can be readily modified by doping in order to achieve the best combination of thermoelectric parameters. Conducting polymers that have never previously been regarded as hypothetically compatible for thermoelectric energy conversion, can exhibit promising thermoelectric performance at moderate temperatures, which is a sought-after quality for waste heat recovery. A rather substandard thermoelectric efficiency of Pedot-Pss can be markedly improved by various secondary dopants whose addition usually improves polymer’s morphology accompanied by a drastic increase in electrical conductivity and, consequently, in ZT. In order to enable further enhancement in thermoelectric properties, the optimization of the charge carrier concentration is commonly used. The oxidation level of Pedot-Pss can be precisely controlled by electrochemical doping resulting in a tenfold increase of ZT. In contrast to Pedot-Pss, another conducting polymer Pedot-Tos exhibits superior thermoelectric performance even without secondary doping owning to its partially crystalline nature that allows for an improved electronic conduction. With the aid of a strong electron donor, positively doped Pedot-Tos gets partially reduced reaching the optimum oxidation state at which its thermoelectric efficiency is just four times smaller than that of Be2Te3 and the highest among all stable conducting polymers. The downsides associated with chemical doping of Pedot-Tos such as doping inhomogeneity or chemical dopants air sensitivity can be surmounted if the doping level of Pedot-Tos is controlled by acidity/basicity of the polymer. This approach yields similar maximum thermoelectric efficiency but does not necessitate inert conditions for sample preparation. Optimized Pedot-Tos/Pedot-Pss can be functionalized as a p-type material in organic thermogenerators (OTEG) to power low energy electronic devices. If printed on large areas, OTEGs could be used as an alternative technique for capturing heat discarded by industrial processes, households, transportation sector or any natural heat sources for electricity production.

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Joseph, Jyothis. "Improving Photovoltaic Panel Efficiency by Cooling Water Circulation." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1404617/.

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This thesis aims to increase photovoltaic (PV) panel power efficiency by employing a cooling system based on water circulation, which represents an improved version of water flow based active cooling systems. Theoretical calculations involved finding the heat produced by the PV panel and the circulation water flow required to remove this heat. A data logger and a cooling system for a test panel of 20W was designed and employed to study the relationship between the PV panel surface temperature and its output power. This logging and cooling system includes an Arduino microcontroller extended with a data logging shield, temperature sensing probes, current sensors, and a DC water pump. Real-time measurements were logged every minute for one or two day periods under various irradiance and air temperature conditions. For these experiments, a load resistance was chosen to operate the test panel at its maximum power point. Results indicate that the cooling system can yield an improvement of 10% in power production. Based on the observations from the test panel experiments, a cooling system was devised for a PV panel array of 640 W equipped with a commercial charge controller. The test data logger was repurposed for this larger system. An identical PV array was left uncooled and monitored simultaneously to compare the effect of cooling, demonstrating that the cooled array provided up to an extra 132W or 20% of maximum power for sunny weather conditions. Future expansion possibilities of the project include automated water level monitoring system and water filtration systems.

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4

Shen, Sumin. "Contributions to Structured Variable Selection Towards Enhancing Model Interpretation and Computation Efficiency." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/96767.

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The advances in data-collecting technologies provides great opportunities to access large sample-size data sets with high dimensionality. Variable selection is an important procedure to extract useful knowledge from such complex data. While in many real-data applications, appropriate selection of variables should facilitate the model interpretation and computation efficiency. It is thus important to incorporate domain knowledge of underlying data generation mechanism to select key variables for improving the model performance. However, general variable selection techniques, such as the best subset selection and the Lasso, often do not take the underlying data generation mechanism into considerations. This thesis proposal aims to develop statistical modeling methodologies with a focus on the structured variable selection towards better model interpretation and computation efficiency. Specifically, this thesis proposal consists of three parts: an additive heredity model with coefficients incorporating the multi-level data, a regularized dynamic generalized linear model with piecewise constant functional coefficients, and a structured variable selection method within the best subset selection framework. In Chapter 2, an additive heredity model is proposed for analyzing mixture-of-mixtures (MoM) experiments. The MoM experiment is different from the classical mixture experiment in that the mixture component in MoM experiments, known as the major component, is made up of sub-components, known as the minor components. The proposed model considers an additive structure to inherently connect the major components with the minor components. To enable a meaningful interpretation for the estimated model, we apply the hierarchical and heredity principles by using the nonnegative garrote technique for model selection. The performance of the additive heredity model was compared to several conventional methods in both unconstrained and constrained MoM experiments. The additive heredity model was then successfully applied in a real problem of optimizing the Pringlestextsuperscript{textregistered} potato crisp studied previously in the literature. In Chapter 3, we consider the dynamic effects of variables in the generalized linear model such as logistic regression. This work is motivated from the engineering problem with varying effects of process variables to product quality caused by equipment degradation. To address such challenge, we propose a penalized dynamic regression model which is flexible to estimate the dynamic coefficient structure. The proposed method considers modeling the functional coefficient parameter as piecewise constant functions. Specifically, under the penalized regression framework, the fused lasso penalty is adopted for detecting the changes in the dynamic coefficients. The group lasso penalty is applied to enable a sparse selection of variables. Moreover, an efficient parameter estimation algorithm is also developed based on alternating direction method of multipliers. The performance of the dynamic coefficient model is evaluated in numerical studies and three real-data examples. In Chapter 4, we develop a structured variable selection method within the best subset selection framework. In the literature, many techniques within the LASSO framework have been developed to address structured variable selection issues. However, less attention has been spent on structured best subset selection problems. In this work, we propose a sparse Ridge regression method to address structured variable selection issues. The key idea of the proposed method is to re-construct the regression matrix in the angle of experimental designs. We employ the estimation-maximization algorithm to formulate the best subset selection problem as an iterative linear integer optimization (LIO) problem. the mixed integer optimization algorithm as the selection step. We demonstrate the power of the proposed method in various structured variable selection problems. Moverover, the proposed method can be extended to the ridge penalized best subset selection problems. The performance of the proposed method is evaluated in numerical studies.
Doctor of Philosophy
The advances in data-collecting technologies provides great opportunities to access large sample-size data sets with high dimensionality. Variable selection is an important procedure to extract useful knowledge from such complex data. While in many real-data applications, appropriate selection of variables should facilitate the model interpretation and computation efficiency. It is thus important to incorporate domain knowledge of underlying data generation mechanism to select key variables for improving the model performance. However, general variable selection techniques often do not take the underlying data generation mechanism into considerations. This thesis proposal aims to develop statistical modeling methodologies with a focus on the structured variable selection towards better model interpretation and computation efficiency. The proposed approaches have been applied to real-world problems to demonstrate their model performance.

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5

Støvne, Eivind Myklebust, and Isak Søgaard Vallinder. "Energy efficiency in glass buildings : A study about the energy efficiency of glass buildings in Stockholm and how related demands are met." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-278157.

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The building and property sector stands for one third of the final energy usage in Sweden and this should be diminished, in order to reach goals within environmental sustainability. Glass is a poor thermal insulator but nevertheless a popular choice of material when constructing new buildings. The contradiction between need of energy efficiency and the wish for “glass buildings” led to the subject of this report. This Bachelor’s thesis examines how demands on energy efficiency is met in nine glass buildings in Stockholm. Glass buildings and the current legislation is discussed from a perspective of environmental sustainability. This was done by investigating the demands stated by Boverket from a historical perspective, executing quantitative measurements of heat transfer on elected objects, and interviewing stakeholders linked to the buildings and the Swedish legislation. The study shows that the construction of glass buildings has been possible due to a restructuring of the demands on energy efficiency and technical development. It was found, in most cases, that the shares of glass were in fact lower than apparent. A larger share of glass in the building envelope required creative measures to achieve energy solutions, within legislative demands. Nevertheless, the inlet of solar radiation heat is the greatest challenge. Despite the challenges, the desire for glass is rooted in well-being and aesthetic values, which insinuate that glass buildings will be included in the cityscape henceforth. The conclusions drawn from these results are that the energy performance of glass buildings is still weaker than conventional “solid wall buildings”. Enhancement regarding insulation abilities and improvements of excluding solar radiation must be realized to strengthen the environmental sustainability of this category of buildings.
Bygg- och fastighetssektorn står för en tredjedel av den slutliga energianvändningen i Sverige, vilken måste minimeras för att nå miljömässiga hållbarhetsmål. Att bygga i glas är populärt bland moderna byggnader, trots att glas har relativt låg termisk isolationsförmåga. Motsättningen mellan behovet av energieffektivitet och efterfrågan på “glashus” skapade ämnet för denna rapport. Detta kandidatexamensarbete utforskar hur energieffektivitetskrav möts i nio olika glasbyggnader i Stockholm. Glashus och nuvarande lagstiftning diskuteras ur ett miljömässigt hållbarhetsperspektiv. Detta gjordes genom undersökningar av Boverkets krav ur ett historiskt perspektiv, kvantitativa mätningar av värmeflöden, samt intervjuer med aktörer kopplade till byggnaderna och svensk bygglagstiftning. Studien visar att byggnation av glashus har blivit möjlig på grund av en omstrukturering av energieffektivitetskraven samt teknisk utveckling. Det visade sig att andelen glas i de undersökta byggnaderna oftast var lägre än det såg ut. Större andel glas i klimatskalet krävde kreativa åtgärder för att uppnå energilösningar inom lagstiftningen. Det visade sig också att solinstrålning var den största energiutmaningen för glasbyggnaderna. Trots utmaningarna finns värden anknutna till estetik och välmående som skapar en efterfrågan på glashus, och detta leder till att glashus fortfarande kommer inkluderas i stadsmiljön framöver. En slutsats från arbetet är att energiprestandan i glasbyggnader är svagare än för konventionella “tätväggsbyggnader”. Förbättringar av glaskonstruktionen gällande isolationsförmåga och utestängning av värme från solinstrålning måste realiseras för att stärka den miljömässiga hållbarheten för denna byggnadskategori.

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6

Šumić, Mersiha. "Thermal Performance of a Solarus CPC-Thermal Collector." Thesis, Högskolan Dalarna, Energi och miljöteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:du-14526.

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The aim of this master thesis is an investigation of the thermal performance of a thermal compound parabolic concentrating (CPC) collector from Solarus. The collector consists of two troughs with absorbers which are coated with different types of paint with unknown properties. The lower and upper trough of the collector have been tested individually. In order to accomplish the performance of the two collectors, a thorough literature study in the fields of CPC technology, various test methods, test standards for solar thermal collectors as well as the latest articles relating on the subject were carried out. In addition, the set‐up of the thermal test rig was part of the thesis as well. The thermal performance was tested according to the steady state test method as described in the European standard 12975‐2. Furthermore, the thermal performance of a conventional flat plate collector was carried out for verification of the test method. The CPC‐Thermal collector from Solarus was tested in 2013 and the results showed four times higher values of the heat loss coefficient UL (8.4 W/m²K) than what has been reported for a commercial collector from Solarus. This value was assumed to be too large and it was assumed that the large value was a result of the test method used that time. Therefore, another aim was the comparison of the results achieved in this work with the results from the tests performed in 2013. The results of the thermal performance showed that the optical efficiency of the lower trough of the CPC‐T collector is 77±5% and the corresponding heat loss coefficient UL 4.84±0.20 W/m²K. The upper trough achieved an optical efficiency of 75±6 % and a heat loss coefficient UL of 6.45±0.27 W/m²K. The results of the heat loss coefficients are valid for temperature intervals between 20°C and 80°C. The different absorber paintings have a significant impact on the results, the lower trough performs overall better. The results achieved in this thesis show lower heat loss coefficients UL and higher optical efficiencies compared to the results from 2013.

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7

Gaidys, Vytautas. "Aukštadvario, Sukončių ir Pabradės hidroelektrinių darbo efektyvumo tyrimai." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2009. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20090114_153935-74229.

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Žinome, kad Lietuva didelių vandens išteklių neturi.Todėl racionalus jų naudojimas, kai nedaroma žala gamtai, arba ji visiškai nereikšminga, – kiekvieno hidroenergetiko rūpestis. Neišnagrinėjus visų, su tuo susijusių reiškinių, klaidingai apskaičiavus ir įvertrinus sukauptus duomenis mažose hidroelektrinėse, ne tik bus neefektyvus vandens panaudojimas, bet ir gali būti katastrofinės pasekmės, galinčios neigiamai paveikti gamtinę aplinką. Esami šalies vandens ištekliai – brangus mūsų turtas, todėl reikia stengtis, kad hidroenergetikoje panaudotas kiekvienas kubinis metras vandens, atneštų kuo didesnę naudą visuomenei. Trijose mažosiose Lietuvos hidroelektrinėse: Aukštadvario, Sukončių ir Pabradės buvo atliekami tyrimai, kiek vandens sunaudoja kiekviena elektrinė atskirai, kokia pratekančio vandens energija, esant skirtingiems patvankų aukščiams, bei kaupiami duomenys, kiek kiekviena elektrinė pagamina elektros energijos (kW). Pradėjus sisteminti elektrinėse sukauptus duomenis, buvo sudaryta pro turbinas pratekančio vandens ir išgaunamos elektros energijos kiekio (kW) skaičiavimo metodika. Iš gautų duomenų išvedamos hidroelektrinių efektyvumo kreivės, kurios palyginamos su kitų gamintojų hidroagregatų efektyvumo duomenimis. Prasminiai žodžiai: racionalus naudojimas, naudingumo koeficientas, efektyvumas.
The problem considered in this paper is that there aren’t many natural water resources in Lithuania. That’s why, rational consumption of water with any or very insignificant harm to the nature done, is a matter of great concern of every hydroenergetic. All matters should be taken into consideration. However, without bearing in mind all the concerning matters, having incorrect technical data or its incorrect evaluation may lead to ineffective usage of water resources in little water-power stations and even catastrophic consequences, that may affect natural environment. Available water resources are precious. So, it is important to strive to use every cubic metre of water in hydroenergetics to be of the greatest benefit for the society. Three small hydropower plants in Aukstadvaris, Sukonciai and Pabrade were tested for amount of water consumption and for flowing water energy with different water head. Also there was collected data about produced electrical energy in every water- power station (kWh). After having organized all the data, was worked out technique how to count amount of water flowing through turbines and also amount of electricity (kWh) generated by those turbines. The facts make the output graphs that are compared with other producers aggregates’ data of efficiency. Keywords: rational usage, coefficient of efficiency, efficiency.

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Heppell, Neil James. "Continuous-flow sterilization processes : a comparison between predicted and measured sterilization efficiency in homogenous liquid foods and measurement of the solid-liquid heat transfer coefficient in the sterilization." Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303072.

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Jackevičiūtė, Neringa. "Lietuvos bankininkystės plėtra ir jos intelektiniai ištekliai." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2009. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20090204_110400-95423.

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Magistrinio darbo tema yra aktuali, nes vis labiau didėja neatitikimas tarp organizacijos rinkos vertės ir tikrosios vertės, o tradiciniai pelningumo skaičiavimo būdai nebegali tiksliai atspindėti esamos situacijos, kadangi jie skaičiuoja tiktai pelną, o ne pridėtinę vertę. Temos naujumas akivaizdus, nes magistriniame darbe yra ieškomas ryšys tarp tradicinių pelningumo skaičiavimo metodų ir nefinansinių intelektinių išteklių efektyvumo skaičiavimo metodų, siekiant nustatyti, ar nefinansiniai rodikliai gali pateikti informacijos apie sėkmingą banko veiklą. Tyrimo objektas – intelektinių išteklių panaudojimo efektyvumas. Tyrimo dalykas – intelektinių išteklių svarba bankininkystės tolesniame vystymesi. Tikslas: nustatyti intelektinių išteklių svarbą bankininkystės vystymuisi ir numatyti bankininkystės tolesnius plėtros etapus. Formuluojami tokie uždaviniai: 1. Apibūdinti intelektinių išteklių sąvoką ir išanalizuoti jos apibūdinimus literatūroje; 2. Atskleisti intelektinių išteklių svarbą organizacijai; 3. Išnagrinėti intelektinių išteklių skaičiavimo metodus ir lyginti juos su tradiciniais pelningumo skaičiavimo metodais; 4. Apibrėžti intelektinių išteklių svarbą bankininkystei; 5. Numatyti bankininkystės tolesnio vystymosi gaires, naudojantis intelektinių išteklių skaičiavimo metu sukaupta informacija. Šiame darbe panaudoti mokslinio tyrimo metodai: • lyginimo metodas – atskleidžiami įvairių autorių samprotavimai apie intelektinius išteklius ir jų svarbą organizacijoje; •... [toliau žr. visą tekstą]
The theme of Master’s Work is actual today because it has been generally noticed that there is a growing difference between the organization’s market value and the real value, traditional measurements of profit are no longer able to reflect the current situation correctly as they calculate only a profit and not – the added value. The new point in this theme is being carried out by the relation between traditional profit measurements and non-financial calculations of intellectual assets efficiency, which is being analysed in order to reveal whether non-financial indicators are capable to represent the information about the successful activity of a bank. The object of the research – the effective use of intellectual assets. The subject of the research – the importance of intellectual assets in further development of banking sector. The goal formulated for this work is to define the importance of intellectual assets in growth of banking sector and also to foresee further stages of development. The tasks that are formulated for this work: 1. To define the concept of intellectual assets and to analyse its definitions in literature; 2. To reveal the importance of intellectual assets for an organization; 3. To analyse the measurement methods of intellectual assets and compare them to traditional profit measurement methods. 4. To foresee further development stages of banking sector, by using the information which has been collected via calculations of intellectual assets. The... [to full text]

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10

Kohout, Jiří. "Tepelné čerpadlo s akumulací." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-318652.

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This diploma thesis deals with the assessment of SCOP of the heat pump installed in the selected building and with the determination of optimal size of accumulation which should help to heat pump work with higher temperature and higher SCOP. Annual savings of operating cost and return of investment from installation of accumulation tank are evaluated in this thesis. In the research part of this thesis are described the main components of heat pump, sources of low-potential heat and types of heat pump.

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Sahiner, Halit. "Hydraulic Characteristics Of Tyrolean Weirs Having Steel Racks And Circular-perforated Entry." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614247/index.pdf.

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Tyrolean type water-intake structures are commonly used on mountain rivers to supply water to hydropower stations. The amount of water to be diverted from the main channel is the major concern in these kind of structures and should not be less than the design discharge. In this study a physical model of a Tyrolean type water-intake structure was built at the laboratory and the diverted flow from the main channel through the intake structure having steel racks and perforated plates of different types were measured. The experiments were conducted in two stages. In the first stage the tests were carried out with only steel racks having three different bar openings and slopes, and in the second stage, perforated screens of three different circular openings and screen slopes were used. Applying dimensional analysis to the related parameters of the system the dimensionless terms were defined for the water capture efficiency and discharge coefficient of the system, and their variations with the relevant parameters were plotted. Using these diagrams one can determine the amount of water to be diverted by a Tyrolean weir of known geometry and main channel discharge.

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Joubert, Rita. "Solid-liquid mass transfer in trickle bed reactors." Diss., Pretoria : [s.n.], 2009. http://upetd.up.ac.za/thesis/available/etd-06242009-140938/.

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13

Girdvainis, Voldemaras. "Asinchroninių variklių su sinusinėmis trifazėmis apvijomis tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20100618_134306-12927.

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Darbe įvertintos aštuonių tipų trifazių asinchroninių variklių statoriaus apvijų elektromagnetinės savybės, atlikus jų kuriamų sukamųjų magnetovarų harmonines analizes ir pagal jų rezultatus apskaičiavus elektromagnetinio efektyvumo koeficientus. Gauta, kad geriausius elektromagnetinius parametrus turi didžiausio vidutinio ir sutrumpinto žingsnio sinusinės trifazės apvijos su optimizuota sukamąja magnetovara. Eksperimentiškai išnagrinėtas gamyklinis trifazis asinchroninis 1,5 kW galios variklis su viensluoksne formine ir tas pats pervyniotas variklis su sinusine statoriaus apvija. Gamyklinio asinchroninio variklio su viensluoksne formine apvija ir pervynioto variklio su sinusine trifaze apvija visi energetiniai rodikliai apskaičiuoti atlikus jų tuščiosios veikos ir apkrovos bandymus bei panaudojus atskirų galios nuostolių metodą. Gauta, kad pervynioto asinchroninio variklio su sinusine trifaze apvija prie nurodytosios apkrovos statoriaus apvijos fazinė srovė sumažėjo 8,2 %, imama iš tinklo galia sumažėjo 5,3 %, galios nuostoliai sumažėjo 10,4 %, naudingumo koeficientas padidėjo 1,9 % ir galios koeficientas padidėjo 3,4 %, lyginant su gamyklinio asinchroninio variklio, esant tai pačiai apkrovai, atitinkamais energetiniais rodikliais. Nustatyta, kad asinchroninis variklis, turintis trifazę apviją su didesniu elektromagnetinio efektyvumo koeficientu, turi ir geresnius energetinius rodiklius.
The paper assesses the electromagnetic properties of stator winding of eight types of three-phase asynchronous motors, by performing harmonic analyses of the rotary magnetomotive forces they generate and using these results to calculate the electromagnetic efficiency coefficients. It was established that the best electromagnetic parameters are those of the sinus tri-phase winding with the largest medium and shortened step with optimised rotary magnetomotive force. Experimental analysis of a factory-made three-phase asynchronous 1,5 kW motor with a single layer form winding and the same rewound motor with sinus stator winding was performed. All energetic indicators of the factory-made asynchronous motor with a single layer form winding and the rewound motor with sinus three-phase winding were calculated after performing their no-load and load testing, and using the method of separate power loss. It was established that the phase current of the stator winding of the rewound asynchronous motor with a sinus three-phase winding, deceased by 8,2 percent at the indicated load, the power from the mains decreased by 5,3 percent, the power loss decreased by 10,4 percent, the efficiency coefficient increased by 1,9 percent and the power coefficient increased by 3,4 percent as compared to the respective indicators of the factory-made asynchronous motor at the same load. It was established that the asynchronous motor which has the three-phase winding with the larger electromagnetic... [to full text]

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14

Bártů, Marek. "Energetická účinnost tepelných čerpadel." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-241708.

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This diploma thesis deals with the energy efficiency of heat pumps, especially efficiency of air/water system. In the this thesis is simply described the principle of the heat pump and function of each component. It shows the issues of determining the parameters of performance of the heat pump and also describes verification in according to applicable standards. The diploma thesis gives an analysis of determining the energetical efficiency and calculation of coefficient of performance, in other words, the seasonal heating coefficient of performance. Seasonal energy efficiency of selected samples of heat pumps for the heating season is designated for specific climatic conditions.

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15

Luke, Mark Elden. "Predicting Drag Polars For Micro Air Vehicles." Diss., CLICK HERE for online access, 2003. http://contentdm.lib.byu.edu/ETD/image/etd297.pdf.

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16

Dragan, Urošević. "Razvoj modela za vrednovanje složenih kogenerativnih postrojenja." Phd thesis, Univerzitet u Novom Sadu, Fakultet tehničkih nauka u Novom Sadu, 2014. https://www.cris.uns.ac.rs/record.jsf?recordId=87685&source=NDLTD&language=en.

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Predložen je i testiran model za energetsko vrednovanje kogenerativnih postrojenja pri čemu se proračun koeficijenta gubitka električne snage obavlja pomoću postupka koji je posebno naveden i predložen.Sam model može i treba da predstavlja snažan alat prilikom kreiranja energetske politike, u delu koji se odnosi na kogeneraciju, s obzirom na to da pruža mogućnost jasnog energetskog vrednovanja postrojenja u smislu efikasnosti i uštede primarne energije kao i definisanja koji deo i koliko kogeneracija treba da bude stimulisana, odnosno potencijalno zastupljena u okviru nekog energetskog sistema.Predloženi model je testiran na složenom kogenerativnom postrojenju snage 150 MW.
A model for energy evaluation of a cogeneration plant is proposedand tested with the calculation of electric power loss done by meansof a procedure which is particularly specified and proposed.The model itself can and should be used as a powerful tool for thecreation of energy policies in the part regarding cogeneration since itgives opportunities for a clear energy evaluation of a plant in terms ofefficiency and primary energy saving, as well as for defining whichpart and to what extent cogeneration should be stimulated, that is,potentially represented within a specified energy system.The proposed model has been tested on a cogeneration plant withthe capacity of 150 MW.

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17

Aggarwal, Kajal. "Impact of preclinical PET scanner characteristics on the overall image quality." Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAE028.

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La tomographie par émission de positrons (TEP) est l’une des techniques d’imagerie nucléaire utilisées dans les domaines de l’oncologie, de la cardiologie et de la neurologie en tant que modalité d’imagerie fonctionnelle. Au cours des trois dernières décennies, les progrès de la modalité PET et le développement de modèles animaux de maladies humaines ont conduit au développement de la technologie PET dédiée aux petits animaux. En raison de la différence de taille entre l’homme et la souris, les scanners pour petits animaux nécessitent une résolution spatiale améliorée. En raison de l’amélioration de la résolution spatiale, la taille du voxel diminue de manière significative, réduisant ainsi le nombre de signaux d’un voxel. Plus le nombre détecté est élevé, plus le rapport signal sur bruit (SNR) est élevé ; l’amélioration de l’efficacité de la détection joue donc également un rôle important. Notre objectif est d’étudier l’impact des caractéristiques du scanner PET sur la qualité globale de l’image. Pour ce faire, nous avons simulé quatre modèles de scanneurs différents. L’idée des conceptions de scanner sélectionnées dans cette thèse est d’ajouter progressivement une dimension supplémentaire dans la position estimée de l’interaction du photon gamma, c’est-à-dire en passant de la détection 2D à la détection 3D. Nous avons démontré qu’il était possible de découpler la résolution spatiale et l’efficacité de la détection, en améliorant les deux simultanément. En outre, nous avons caractérisé le fait que l’amélioration de la résolution spatiale entraîne l’amélioration du coefficient de récupération (RC). L’efficacité de la détection a un impact sur le RSB, ce qui a également un impact sur l’erreur estimée dans les valeurs de RC. Cependant, d’autres facteurs, tels que l’approche de reconstruction d’image et les corrections de normalisation, dégradent ces valeurs d’erreur. Il est donc important non seulement d’améliorer les paramètres de performance des scanners, mais également de mettre en œuvre avec précision le processus de reconstruction d’image, afin de quantifier correctement l’amélioration de la qualité de l’image
Positron Emission Tomography (PET) is one of the nuclear imaging techniques, used in the field of oncology, cardiology and neurology as a functional imaging modality. During the last three decades, advancement of PET modality and the development of animal models of human disease have lead to the development of PET technology dedicated to small animals. Due to the size difference between humans and mice, small animal scanners require improved spatial resolution. Due to the improved spatial resolution, the voxel size decreases significantly thereby, reducing the number of signals from a voxel. Higher the detected counts, higher the signal-to-noise ratio (SNR), thus improvement in the detection efficiency also plays an important role. Our objective is to study the impact of PET scanner characteristics on the overall image quality. To achieve this, we have simulated four different scanner designs. The idea behind the selected scanner designs studied in this thesis is to progressively add an extra dimension in the estimated position of interaction of the gamma photon, i.e., going from 2D detection to 3D detection. We demonstrated that it is possible to decouple the spatial resolution and detection efficiency, improving both simultaneously. Further, we characterized that improving spatial resolution results in improved Recovery Coefficient (RC). Detection efficiency impacts the SNR, which further impacts the estimated error in the RC values. However, there are other factors such as image reconstruction approach and normalization corrections that degrade these error values. Thus, it is important to not only improve the performance parameters of the scanners but also to accurately implement the image reconstruction process, so as to correctly quantify the improvement in the image quality

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18

Akil, Fabiana. "Avaliação da estratégia de coleta de células progenitoras hematopoiéticas em dias subsequentes para transplante autólogo em pacientes com patologias hematológicas." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/17/17155/tde-08012019-145413/.

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Nesta dissertação foi proposta a avaliação da estratégia de coleta de células progenitoras hematopoéticas por aférese ocorridas no Hemorio no período de julho de 2004 a julho de 2015 com o objetivo de verificar se a eficiência ou a eficácia de coleta se deterioram nos dias subsequentes. Os resultados desse estudo podem indicar que há um dia mais favorável para a coleta, no qual o processamento de maiores volumes de sangue poderá aumentar a chance de sucesso, reservando os dias subsequentes como exceção e não como regra, reduzindo os riscos e os custos associados às coletas múltiplas. INTRODUÇÃO: Nos dias de hoje o transplante de medula óssea tem papel relevante no tratamento de diversas neoplasias não hematológicas e hematológicas como o mieloma múltiplo e o linfoma. O processo de coleta dessas células através de múltiplas punções na medula óssea é um limitante para seu uso. As células progenitoras hematopoiéticas do sangue periférico coletadas por aférese automatizada representam a principal fonte para o transplante de medula óssea, quer pela facilidade do método, quer pela recuperação hematopoiética mais precoce ou pelo baixo risco de eventos adversos. Embora essa metodologia apresente diversos benefícios, ainda é necessário buscar alternativas para melhorar sua eficácia. MATERIAL E MÉTODOS: Foram estudados 109 procedimentos de aférese em 47 pacientes mobilizados apenas com G-CSF e com coleta iniciada no D5 de mobilização. Foi feita a análise da eficácia e eficiência desses procedimentos nos pacientes submetidos ao menos a 2 procedimentos em dias subsequentes, com comparação dos resultados do dia 1 com dia 2 e, deste com o 3. Também foram avaliadas as variáveis células CD34+ pré coleta e volemias processadas. RESULTADOS: Houve diferença estatisticamente significante entre as eficácias dos dias 1, 2 e 3. A eficiência e as volemias processadas não apresentaram diferença e, a contagem de células CD34+ pré coleta só foi relevante na comparação do 2° dia de coleta com o 3°. A média institucional do coeficiente de eficiência foi de 50.51 %. DISCUSSÃO: A eficácia do procedimento de aférese depende de fatores físicos e biológicos. A maior eficácia no 1° dia de coleta em relação ao 2° e 3 °dia sem que haja alteração dos fatores físicos nos leva a sugerir que o comportamento biológico do paciente é responsável por esse resultado. Este depende da quantidade das células CD34+ pré coleta e do recrutamento intra aférese. Como não houve variação expressiva das células CD34+ pré coleta acreditamos que o recrutamento foi o responsável por esses resultados. Portanto sugerimos que a planejamento da coleta de células progenitoras hematopoéticas do sangue periférico seja feito de modo a atingir a meta em um único dia, eventualmente utilizando o dia 2 e 3 para complementação. Assim sendo os procedimentos de aférese com o manejo adequado da toxidade ao anticoagulante, devem permitir o processamento de maiores volumes de sangue, visando, quando possível, atingir a meta de coleta em um único procedimento.
In this dissertation, the evaluation of the hematopoietic progenitor cell collection strategy for hematopoietic stem cells at Hemorio in the period from July 2004 to July 2015 was proposed, in order to verify if the collection efficiency or efficacy deteriorates on subsequent days. The results of this study may indicate that there is a more favorable day for collection, in which the processing of larger blood volumes may increase the chance of success, reserving the subsequent days as an exception rather than as a rule, reducing the risks and associated costs collection. INTRODUCTION: Bone marrow transplantation has a relevant role in the treatment of several non-hematological and hematological malignancies such as multiple myeloma and lymphoma. The process of collecting these cells through multiple punctures in the bone marrow is a limiting factor for their use. Peripheral blood hematopoietic progenitor cells collected by automated apheresis represent the main source for bone marrow transplantation, either by the ease of the method, by the earlier hematopoietic recovery or by the low risk of adverse events. Although this methodology has several benefits, it is still necessary to seek alternatives to improve its effectiveness. MATERIALS AND METHODS: A total of 109 apheresis procedures were studied in 47 patients mobilized with G-CSF alone and with collection initiated in D5 of mobilization. The efficacy and efficiency of these procedures were analyzed in patients submitted to at least 2 procedures on subsequent days, with a comparison of the results from day 1 to day 2 and from day 2 to day 3. Also, the variables CD34+ pre-collection and volemia processed were analyzed. RESULTS: There was a statistically significant difference between the efficacy of days 1, 2 and 3. Efficiency and volume of processed blood volume did not show any difference, and pre-collection CD34 + cell count was only relevant when comparing the 2 nd day of collection with the 3rd. The institutional average of the coefficient of efficiency was 50.51%. DISCUSSION: The efficacy of the apheresis procedure depends on physical and biological factors. The greater efficacy in the 1st day of collection in relation to 2nd and 3rd day without changes in physical factors leads us to suggest that the biological behavior of the patient is responsible for this result. This depends on the amount of pre-collection CD34+ cells and intra-apheresis recruitment. As there was no expressive variation of pre-collection CD34+ cells, we believe that recruitment was responsible for these results. Therefore, we suggest that the planning of collection of hematopoietic progenitor cells from the peripheral blood be done in order to reach the goal in a single day, possibly using day 2 and 3 for complementation. Therefore, apheresis procedures with appropriate anticoagulant toxicity should allow the processing of larger volumes of blood, aiming to reach the collection goal in a single procedure.

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19

Parment, Rasmus. "En jämförelsestudie av värmeväxlare : Värmeöverföring för värmeväxlare i korrosiva miljöer." Thesis, Mittuniversitetet, Avdelningen för kemiteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-34948.

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Det finns stora vinningar att göra inom både transport- och industrisektorn genom att effektivisera materialanvändningen i produkter. Denna vinning återfinns i både materialkostnader och energieffektivisering. Scandymet AB är ett företag som tillverkar värmeväxlare och elektriska doppvärmare för ytbehandlingsindustrin. Denna rapport syftar till att utvärdera hur väl ett kalkylark som används som underlag för dimensionering av värmeväxlare hos företaget stämmer överens med verkligheten. En testrigg har därför konstruerats för att undersöka kalkylarkets validitet gällande temperaturer under 46 grader Celsius. I rapporten redovisas resultaten av tester på fyra olika värmeväxlare och resultaten har jämförts med företagets kalkylark. Undersökningarna visar att två av dessa värmeväxlare är överdimensionerade och två värmeväxlare stämde väl överens med kalkylarket. I samtliga tester används vatten som media, men då Scandymet AB värmeväxlares huvudsakliga användningsområde är korrosiva vätskor dras slutsatsen att fler undersökningar med andra fluider skulle behövas för att ytterligare fördjupa kunskapen inom värmeväxlarnas korrekta dimensionering.
There are huge gains in both the transport and industry sectors by making material use more efficient in products. This gain is found in both material costs and energy efficiency. Scandymet AB is a company that manufactures heat exchanger and electric immersion heaters for the surface treatment industry. This report aims to evaluate how well a spreadsheet used as basis for the dimensioning of heat exchangers at the company is consistent with reality. A test rig has therefore been designed and constructed to investigate the validity of the spreadsheet. The report presents the results of tests on four different heat exchangers and the results have been compared with the company’s spreadsheet. In all tests water has been used as the media to be heated, but since Scandymet AB’s heat exchanger’s main application is corrosive liquids, therefore I consider that a deeper investigation with additional fluids would be necessary to further deepen the knowledge in the area.

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20

Krukas, Donatas. "Žemaičių Naumiesčio anaerobinės nuotekų valyklos veikimo efektyvumo įvertinimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2007. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2007~D_20070808.113514-22519.

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Lietuvoje, tvarkant nedidelius nuotekų kiekius iškyla nemažai sunkumų. Labai svarbu parinkti tokią technologiją, kurią taikant nuotekos būtų išvalomos iki nustatytų normų, ji būtų nesudėtinga ir pigi.. Anaerobinėse nuotekų valyklose nenaudojama elektra. Tai yra šių nuotekų valyklų privalumas, tačiau jose iškyla problemų valant nuotekas iki leistinų koncentracijų. Magistrantūros baigiamąjame darbe apibendrinti 2004 – 2006 m. atlikti Šilutės r. Žemaičių Naumiesčio nuotekų valyklos veikimo efektyvumo tyrimai ir analizuojamos priežastys, dėl kurių nepakankamai išvalomos nuotekos. Nustatyta nuotekų išbuvimo anaerobiniame hibridiniame įrenginyje trukmė ir apskaičiuotas jo tūrio panaudojimo koeficientas. Gauta, kad panaudojama tik maža įrenginio tūrio dalis dėl netolygaus nuotekų pasiskirstymo anaerobinio įrenginio talpykloje.
In Lithuania the problem of low wastewater treatment efficiency in anaerobic hybrid reactors also rised. It was determined that one of main reasons of bad wastewater treatment quality in anaerobic hybrid reactors was insufficient volume of equipment and the equipment would be cheap and not complicated. In anaerobic wastewater are not used an electricity. And it is an advantage of wastewater, but there are also problems in cleaning wastewater until permissible concentrations. In the article are generalized 2004-2006 year researches Silutes area in Zemaiciu Naumiestis about wastewater treatment efficiency and analysed reasons for which are insufficient cleaned wastewater treatment. In anaerobic hybrid reactor the efficiency of wastewater treatment depends on volume load. There are found, that are used just small part of volumetric load because of uneven wastewater repartition in anaerobic reactor repository.

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Ethier, Jonathan L. T. "Antenna Shape Synthesis Using Characteristic Mode Concepts." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23464.

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Characteristic modes (CMs) provide deep insight into the electromagnetic behaviour of any arbitrarily shaped conducting structure because the CMs are unique to the geometry of the object. We exploit this very fact by predicting a perhaps surprising number of important antenna metrics such as resonance frequency, radiation efficiency and antenna Q (bandwidth) without needing to specify a feeding location. In doing so, it is possible to define a collection of objective functions that can be used in an optimizer to shape-synthesize antennas without needing to define a feed location a priori. We denote this novel form of optimization “feedless” or “excitation-free” antenna shape synthesis. Fundamentally, we are allowing the electromagnetics to dictate how the antenna synthesis should proceed and are in no way imposing the physical constraints enforced by fixed feeding structures. This optimization technique is broadly applied to three major areas of antenna research: electrically small antennas, multi-band antennas and reflectarrays. Thus, the scope of applicability ranges from small antennas, to intermediate sizes and concludes with electrically large antenna designs, which is a testament to the broad applicability of characteristic mode theory. Another advantage of feedless electromagnetic shape synthesis is the ability to synthesize antennas whose desirable properties approach the fundamental limits imposed by electromagnetics. As an additional benefit, the feedless optimization technique is shown to have greater computational efficiency than traditional antenna optimization techniques.

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22

Abebe, Yibekal Alemayehu. "Managing the soil water balance of hot pepper (Capsicum annuum L.) to improve water productivity." Thesis, University of Pretoria, 2010. http://hdl.handle.net/2263/25257.

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A series of field, rainshelter, growth cabinet and modelling studies were conducted to investigate hot pepper response to different irrigation regimes and row spacings; to generate crop-specific model parameters; and to calibrate and validate the Soil Water Balance (SWB) model. Soil, climate and management data of five hot pepper growing regions of Ethiopia were identified to develop irrigation calendars and estimate water requirements of hot pepper under different growing conditions. High irrigation regimes increased fresh and dry fruit yield, fruit number, harvest index and top dry matter production. Yield loss could be prevented by irrigating at 20-25% depletion of plant available water, confirming the sensitivity of the crop to mild soil water stress. High plant density markedly increased fresh and dry fruit yield, water-use efficiency and dry matter production. Average fruit mass, succulence and specific leaf area were neither affected by row spacing nor by irrigation regimes. There were marked differences among the cultivars in fruit yields despite comparable top dry mass production. Average dry fruit mass, fruit number per plant and succulence were significantly affected by cultivar differences. The absence of interaction effects among cultivar and irrigation regimes, cultivars and row spacing, and irrigation regimes and row spacing for most parameters suggest that appropriate irrigation regimes and row spacing that maximize productivity of hot pepper can be devised across cultivars. To facilitate irrigation scheduling, a simple canopy cover based procedure was used to determine FAO-type crop factors and growth periods for different growth stages of five hot pepper cultivars. Growth analysis was done to calculate crop-specific model parameters for the SWB model and the model was successfully calibrated and validated for five hot pepper cultivars under different irrigation regimes or row spacings. FAO basal crop coefficients (Kcb) and crop-specific model parameters for new hot pepper cultivars can now be estimated from the database, using canopy characteristics, day degrees to maturity and dry matter production. Growth cabinet studies were used to determine cardinal temperatures, namely the base, optimum and cut-off temperatures for various developmental stages. Hot pepper cultivars were observed to require different cardinal temperatures for various developmental stages. Data on thermal time requirement for flowering and maturity between plants in growth cabinet and open field experiments matched closely. Simulated water requirements for hot pepper cultivar Mareko Fana production ranged between 517 mm at Melkassa and 775 mm at Alemaya. The simulated irrigation interval ranged between 9 days at Alemaya and 6 days at Bako, and the average irrigation amount per irrigation ranged between 27.9 mm at Bako and 35.0 mm at Zeway.
Thesis (PhD)--University of Pretoria, 2010.
Plant Production and Soil Science
unrestricted

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23

Marcos, Pedro de Almeida Fernandes Murta. "Um contributo para a análise da importância de alguns parâmetros na classe energética de edifícios." Master's thesis, Universidade de Évora, 2012. http://hdl.handle.net/10174/11555.

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A aplicação do Decreto-Lei 80/2006, de 4 de Abril, Regulamento das Características de Comportamento Térmico dos Edifícios [RCCTE, 2006] trouxe uma nova dinâmica à indústria da construção, na medida em que, exige uma análise térmica rigorosa aos edifícios em fase de projeto com relevantes contributos da solução de arquitetura, das soluções construtivas, bem como dos equipamentos utilizados para a climatização e produção das águas quentes sanitárias. Pretende-se através deste estudo, analisar a importância de alguns parâmetros do RCCTE e a relevância destes no cálculo das necessidades energéticas e na atribuição da classe energética dos edifícios. Os parâmetros escolhidos são: • perdas referentes a pontes térmicas lineares nas perdas totais da envolvente; • classe de inércia térmica; • coeficiente de transmissão térmica médio da envolvente em frações de arquitetura com percentagem normal de envidraçados (PNE) e percentagem elevada de envidraçados (PEE). Para o efeito procedeu-se à escolha e análise de cem casos de estudo, todos eles com declaração de conformidade regulamentar (DCR); ### ABSTRACT: CONTRIBUTION TO THE ANALYSYS OF SOME PARAMETERS IN THE IMPORTANCE OF ENERGY BUILDING CLASS The implementation of Regulation of Thermal Behavior Characteristics in Buildings (RCCTE), brought a new impetus to the construction industry, as it requires an accurate thermal analysis of buildings design phase, which have important inputs either in architecture design or in the engineering solutions. The aim of this study is the analysis of some important parameters of the Portuguese regulation and their relevance to the thermal calculus results and energy class. The studied parameters are: • percentage of heat loss related to linear thermal bridges in the total heat loss of a building; • thermal inertia in the main indicators of the thermal calculation; • overall heat transfer coefficient of constructive solutions in standard window percentage architecture and high window percentage designs. It was analyzed a sample of one hundred projects (architecture and engineering) with thermal design certification.

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24

Ostanovkaitė, Aurelija. "Daugiafazių elektromechaninių keitiklių tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2013. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2013~D_20130621_140322-75409.

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Tiriamajame darbe elektromagnetiniu požiūriu palyginamos viensluoksnė forminė trifazė ir to pačio tipo šešiafazė apvijos. Atlikta šių apvijų kuriamų sukamųjų magnetovarų harmonė analizė ir pagal gautus rezultatus apskaičiuoti elektromagnetinio efektyvumo koeficientai. Gauta, kad viensluoksnė forminė šešiafazė apvija turi geresnius elektromagnetinius parametrus. Šios šešiafazės apvijos efektyvumo koeficientas yra 8,7 % didesnis nei viensluoksnės forminės trifazės apvijos. Atliktas eksperimentinis tyrimas su 1,5 kW asinchroniniu varikliu su viensluoksne formine trifaze apvija ir su tuo pačiu pervyniotu varikliu su ta pačia šešiafaze apvija. Asinchroninio variklio su viensluoksne formine trifaze apvija ir to pačio pervynioto variklio su ta pačia šešiafaze apvija visi energiniai rodikliai apskaičiuoti atlikus tuščiosios veikos ir apkrovos bandymus. Atlikus asinchroninio variklio eksperimentinius bandymus prie nurodytosios apkrovos trifaziam ir šešiafaziam asinchroniniam varikliui, buvo gauti tokie skaičiavimo rezultatai: pervynioto šešiafazio variklio statoriaus apvijos fazinė srovė sumažėjo 25 %, imama iš tinklo galia sumažėjo 10 %, galios suminiai nuostoliai sumažėjo 38 %, galios faktorius padidėjo 4 %, naudingumo faktorius padidėjo beveik 15 %, sukimosi momentas padidėjo apie 5 %. Nustatyta, kad asinchroninis variklis su viensluoksne formine šešiafaze apvija turi geresnius energinius rodiklius nei asinchroninis variklis su to paties tipo trifaze apvija.
In this research electromagnetic properties of single-layer former three-phase winding and the same type six-phase winding are assessed and compared. Harmonic analyses of magnetomotive force was carried out on the rotary forces they generate and, according to final results, the electromagnetic efficiency coefficients were calculated. It was established that electromagnetic parameters of the single-layer former six-phase winding are better. The efficiency coefficient of the single-layer former six-phase winding is 8,7 % higher compared to the same three-phase winding. The experimental analysis of a three-phase asynchronous 1,5 kW motor with a single-layer three-phase winding and the same rewound motor with the same six-phase winding was performed. All energetic indicators of the asynchronous motor with a single-layer former three-phase winding and rewound motor the same six-phase winding were calculated after performing a no-load and load tests. Performing a load testing of the asynchronous motor for single-layer three-phase winding and the same six-phase winding it was established that the current of the stator winding of the rewound asynchronous motor with a single-layer six-phase winding decreased by 25 % at the indicated load, the power from the network decreased by 10 %. Moreover, the power loss decreased by 38 %, the power factor increased by 4 %, the efficiency factor increased almost by 15 %, and the torque increased by 5 %. It was established that the asynchronous... [to full text]

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25

Frigo, Jiam Pires. "CONTROLE ESTATÍSTICO DA QUALIDADE NA IRRIGAÇÃO POR ASPERSÃO." Universidade Estadual do Oeste do Parana, 2014. http://tede.unioeste.br:8080/tede/handle/tede/208.

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Made available in DSpace on 2017-05-12T14:47:09Z (GMT). No. of bitstreams: 1 Jiam Pires_ Frigo.pdf: 2243207 bytes, checksum: 76a818d3ba4a98ecda459c13486050ca (MD5) Previous issue date: 2014-06-02
The sprinkler irrigation system is widely used because of the possibility of high uniform distribution and to adapt itself to different crops and soils. On the other hand, the water uniform application in irrigation is affected by meteorological factors that decrease the system efficiency. There has always been some concern about the quality of products and services in human history, since all products should have desirable characteristics to be accepted by consumers. Currently, development, improvement and monitoring of new management models quality during the production process have become essential for many organizations. Thus, inspection control has enhanced by statistical techniques, losses have been decreased and it was possible to stimulate some trading competition. In this context, this study aimed at evaluating the irrigation system in a conventional sprinkler using the Christiansen Uniformity Coefficient (CUC) and the index Process Capability (CP) to correlate techniques with the system efficiency as well as verify the wind influence on irrigation by Shewhart control chart and compare the results of Shewhart control charts use with the EWMA and tabular CUSUM control charts, applied in quality control of the conventional sprinkler irrigation. In this study, 60 essays were carried out on a four irrigation sprinklers system, Xcel-Wobbler model, 1.0 m height above soil and 6.0 x 6.0 m spaced. The collectors were 1.0 m spaced apart with 0.5 m height from soil. The service pressure was monitored and appropriate to the sprinklers specifications, while wind was monitored in situ by a 2.0 m high digital anemometer. In order to evaluate the system, Christiansen Uniformity Coefficient (CUC), the index Process Capability (CP), Shewhart charts (Xbarra) and the charts of exponentially weighted moving average (EWMA) and cumulative sum (CUSUM) were used. The irrigation sprinkler system showed the best performance and was under control when the average wind speed was less than 1.0 m s-1. The use of individual Shewhart control charts visually allowed affirming that wind has a direct influence on CUC. Night irrigation showed less variability on the studied data, when compared to daytime ones and this has resulted in greater efficiency in irrigation. The CPi index showed great similarity with the Christiansen Uniformity Coefficient (CUC). It proved to be very sensitive to efficiency sprinkler (Ea) variation and able to indicate the quality of sprinkler irrigation. The EWMA chart, when compared to the control charts, was susceptible when used in autocorrelated data, according to the occurrence of false alarms. But, to the residue data without autocorrelation (the ARIMA model), the CUSUM tabular chart was more sensitive to detect variations in irrigation due to wind speed, when compared to EWMA and Shewhart charts for the same data. In sprinkler irrigation, when there is a relation between CUC and wind speed, the Shewhart chart was more indicated by simplicity, reliability and ease of interpretation, even in the presence of autocorrelated data.
O sistema de irrigação por aspersão é muito utilizado, devido à possibilidade de elevada uniformidade de distribuição e por adaptar-se às diversas culturas e solos. Porém, a uniformidade de aplicação de água nas irrigações é afetada por fatores meteorológicos que diminuem a eficiência do sistema. A preocupação com a qualidade de produtos e serviços oferecidos sempre esteve presente na história da humanidade, pois para que os produtos fossem aceitos, deveriam possuir características desejáveis pelos consumidores. Atualmente, com o surgimento de novos modelos gerenciais, a melhoria e o monitoramento da qualidade durante o processo de produção tornaram-se uma necessidade para muitas organizações. Assim, aprimorou-se o controle da inspeção por meio de técnicas estatísticas, reduziram-se perdas e foi possível competir no mercado. Neste contexto, o objetivo deste estudo foi avaliar a irrigação em um sistema por aspersão convencional, utilizando o Coeficiente de Uniformidade de Christiansen (CUC), o índice de Capacidade do Processo (CP) para correlacionar as técnicas com a eficiência do sistema, verificar a influência do vento na irrigação pelo gráfico de controle de Shewhart e confrontar os resultados da utilização dos gráficos de controle de Shewhart, com os gráficos de controle MMEP e CUSUM tabular, aplicados no controle de qualidade da irrigação por aspersão convencional. Neste estudo, foram realizados 60 ensaios em um sistema de irrigação por aspersão convencional. O sistema era constituído de quatro aspersores, modelo Xcel-wobbler, altura de 1,0 m em relação ao solo e espaçamento de 6,0 x 6,0 m. Os coletores foram espaçados em 1,0 m entre si com altura de 0,5 m do solo. A pressão de serviço foi monitorada e adequada às especificações dos aspersores, e o vento monitorado in loco, por um anemômetro digital com 2,0 m de altura. Para a avaliação do sistema, foram utilizados o Coeficiente de Uniformidade de Christiansen (CUC), o índice de Capacidade do Processo (CP), gráficos de Shewhart (Xbarra) e os gráficos de média móvel exponencialmente ponderada (MMEP) e de soma cumulativa (CUSUM). O sistema de irrigação por aspersão convencional teve melhor desempenho e esteve sob controle, quando a velocidade média do vento esteve menor que 1,0 m s-1. O uso dos gráficos individuais de controle de Shewhart possibilitou afirmar visualmente que o vento tem influência direta sobre o CUC. A irrigação noturna apresentou menor variabilidade nos dados, quando comparados aos dados do período diurno e isso resultou em maior eficiência na irrigação. O índice CPi teve grande similaridade com o Coeficiente de Uniformidade de Christiansen (CUC); mostrou-se bastante sensível à variação da eficiência de aspersão (Ea) e capaz de indicar a qualidade da irrigação por aspersão. Em comparação aos gráficos de controle, o gráfico MMEP mostrou-se suscetível quando utilizado em dados autocorrelacionados, pelas ocorrências de alarmes falsos. Para dados de resíduos, sem autocorrelação (pelo modelo ARIMA), o gráfico CUSUM tabular foi mais sensível ao detectar as variações ocorridas na irrigação devido à velocidade do vento, quando comparado aos gráficos MMEP e Shewhart para os mesmos dados. Na irrigação por aspersão, relacionando CUC com velocidade do vento, o gráfico de Shewhart foi mais indicado pela simplicidade, confiabilidade e facilidade de interpretação, mesmo na presença de dados autocorrelacionados entre si.

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Wang, Xuechao. "Critical Transmission Sectors of Energy-Water-GHG Nexus." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-433461.

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Využití vody, spotřeba energie a emise skleníkových plynů (GHG) jsou rozhodujícími ukazateli a do značné míry souvisí s udržováním nebo dosahováním environmentální a sociální udržitelnosti. Tato práce prezentuje vyvinuté metodiky. Představuje také provedené případové studie, které prozkoumaly a identifikovaly Water-Energy-GHG Nexus (WEGN) z pohledu dodavatelského řetězce. Pro analýzu a návrh sítě WEGN jsou navrženy tři metodiky, které jsou založeny na nové aplikaci a integraci modelu vstup-výstup (IO), geografického informačního systému (GIS) a sítě dodavatelského řetězce (SCN), a zároveň řeší výzvy, které dříve neumožňovali praktické implementace. Použitelnost těchto metod je prokázána třemi komplexními případovými studiemi zaměřenými na odvětvovou environmentální účinnost, regionální environmentální účinnost a kritické přenosy WEGN. Mezi mé příspěvky v této oblasti patří: i. Nový nástroj pro hodnocení založený na IO pro identifikaci regionální environmentální účinnosti z hlediska WEGN, zejména pro regiony, které jsou úzce propojenyobchodem. ii. Pokročilá integrace metodik GIS a IO (GIS-IO) za účelem odhalení a mapování sítě WEGN, sledování kritických meziregionálních a sektorových toků WEGN, vyjasnění regionálních, odvětvových a celosvětových vzorců sítě WEGN a určení souvisejících výhod pro různé regiony. iii. Efektivní metoda hodnocení založená na IO a SCN pro kvantifikaci sektorových koeficientů WEGN. Navrhované metodiky, s podporou sady komplexních základních rovnic, transformují komplikované výzvy identifikace a analýzy sítě WEGN do snadno srozumitelného formátu, z čehož vznikají robustní řešení pro zlepšení posuzování environmentální udržitelnosti a zmírnění environmentálních tlaků. Například v jedné z případových studií ukazují výsledky nového přístupu GIS-IO zjevné rozdíly mezi různými zeměmi v rámci EU27, mezi různými sektory a také pokud srovnáme EU27 jako blok zemí, s ostatními státy světa. Analýza ukázala, že země EU27 přispěly o 1.4 Gt nižšími emisemi CO2, o 64.5 Gm3 menší spotřebou vody a 4.9 × 104 PJ nižší spotřebou energie ve srovnání se zbytkem světa, přičemž generovaly ekvivalentní ekonomickou produkci. To má dramatický dopad na globální prostředí. Největší úspěch v CWE mezi zeměmi EU27 měly Německo, Francie a Itálie. Práce doporučuje, aby EU27 poskytovala více technické podpory zemím, které těchto výsledků nedosahují, aby se zvýšila účinnost využívání zdrojů.

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El, Ghouli Salim. "UTBB FDSOI mosfet dynamic behavior study and modeling for ultra-low power RF and mm-Wave IC Design." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAD015/document.

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Ce travail de recherche a été principalement motivé par les avantages importants apportés par la technologie UTBB FDSOI aux applications analogiques et RF de faible puissance. L'objectif principal est d'étudier le comportement dynamique du transistor MOSFET du type UTBB FDSOI et de proposer des modèles prédictifs et des recommandations pour la conception de circuits intégrés RF, en mettant un accent particulier sur le régime d'inversion modérée. Après une brève analyse des progrès réalisés au niveau des architectures du transistor MOSFET, un état de l’art de la modélisation du transistor MOSFET UTBB FDSOI est établi. Les principaux effets physiques impliqués dans le transistor à double grille avec une épaisseur du film de 7 nm sont passés en revue, en particulier l’impact de la grille arrière, à l’aide de mesures et de simulations TCAD. La caractéristique gm/ID en basse fréquence et la caractéristique ym/ID proposée pour la haute fréquence sont étudiées et utilisées dans une conception analogique efficace. Enfin, le modèle NQS haute fréquence proposé reproduit les mesures dans toutes les conditions de polarisation y compris l’inversion modérée jusqu’à 110 GHz
This research work has been motivated primarily by the significant advantages brought about by the UTBB FDSOI technology to the Low power Analog and RF applications. The main goal is to study the dynamic behavior of the UTBB FDSOI MOSFET in light of the recent technology advances and to propose predictive models and useful recommendations for RF IC design with particular emphasis on Moderate Inversion regime. After a brief review of progress in MOSFET architectures introduced in the semiconductor industry, a state-of-the-art UTBB FDSOI MOSFET modeling status is compiled. The main physical effects involved in the double gate transistor with a 7 nm thick film are reviewed, particularly the back gate impact, using measurements and TCAD. For better insight into the Weak Inversion and Moderate Inversion operations, both the low frequency gm/ID FoM and the proposed high frequency ym/ID FoM are studied and also used in an efficient first-cut analog design. Finally, a high frequency NQS model is developed and compared to DC and S-parameters measurements. The results show excellent agreement across all modes of operation including very low bias conditions and up to 110 GHz

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恭平, 坂上, та Kyohei Sakagami. "金属Vベルト式CVTの摩擦伝動限界の予測に関する研究". Thesis, https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB13071664/?lang=0, 2018. https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB13071664/?lang=0.

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駆動プーリ上の回転変動が金属Vベルトを介して従動プーリへと伝達される際には，摩擦力が飽和状態に近づくにつれ，従動プーリへ伝達される回転変動は減衰する．この回転変動の変化に着目して滑り状態を指標化した．
When fluctuations in the speed of rotation of the drive pulley are transmitted to the driven pulley via the metal V-belt, the transmitted fluctuations become attenuated as friction force approaches a state of saturation. The research discussed in this paper focused on these fluctuations in the speed of rotation and developed an index for the slip state between the belt and the pulleys.
博士(工学)
Doctor of Philosophy in Engineering
同志社大学
Doshisha University

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Tang, Lin. "Efficient Inference for Periodic Autoregressive Coefficients with Polynomial Spline Smoothing Approach." University of Toledo / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1449770216.

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Mobiglia, Andrea de Mello. "Digestibilidade aparente da dieta de touros da raça nelore selecionados pelo consumo alimentar residual." Universidade Federal de Goiás, 2014. http://repositorio.bc.ufg.br/tede/handle/tede/3494.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Owing to the potential of utilization of residual feed intake as tool for genetic selection becomes indispensable the studies that looking for understand the variables influence RFI, principally data from cattle of Nellore breed, consist with Brazilian reality. The aim of this study was to evaluate the apparent digestibility of diet of Nellore bulls classified by residual feed intake (RFI). One hundred and twenty Nellore bulls were used , with body weight (BW) of 392.5 ± 47.15 kg. The animals were maintained in a feedlot with individual pens and fed with the same diet for 83 days. The animals were fed ad libitum and the diet was composed of sorghum silage, sugarcane bagasse and concentrate, in relation 33:67 (V: C) in dry matter. The animals were weight at the beginning of the trial and every 28 days after the solid feed restriction. The refused and offered fed were weight to measure the daily feed intake. RFI was calculate by difference between the observed intake and estimated intake what was obtained through a multiple regression equation of feed intake, average daily gain (ADG) and metabolic body weight (MBW) of the animals. On eighth week was realized a digestibility assay. To estimate the fecal production was used indigestible neutral detergent fiber (NDFi) as internal marker. The randomized design was used for statistical analysis. The ADG and BC were the same for different RFI groups (P>0.05), despite of low RFI animals showed lower feed intake (P<0.05) than medium and high RFI. However, the digestibility coefficient did not differ between the RFI groups (P>0.05). In contrast, the apparent digestibility of NFC was negative correlated (– 0,23) with the RFI.
Tendo em vista o potencial de utilização do consumo alimentar residual como ferramenta para seleção genética torna-se imprescindível estudos que procuram entender as variáveis que influenciam o CAR, principalmente dados com bovinos da raça Nelore condizentes com a realidade brasileira. O objetivo deste estudo foi avaliar a digestibilidade aparente da dieta de touros da raça Nelore classificados pelo consumo alimentar residual (CAR). Foram utilizados 120 touros da raça Nelore, com peso corporal (PC) de 392,5 ± 47,15 kg. Os animais foram mantidos em confinamento com baias individuais e alimentados com a mesma dieta por 83 dias. Todos os animais foram alimentados à vontade e a dieta era composta de silagem de sorgo, bagaço de cana e concentrado, na relação 33: 67 (V: C) na matéria seca. Os animais foram pesados no inicio do experimento e a cada 28 dias após jejum de sólido. Diariamente foram pesadas as sobras e o fornecido para determinar o consumo diário. O CAR foi calculado pela diferença do consumo observado e estimado, o qual foi obtido por uma equação de regressão entre consumo, o ganho de peso diário e peso corporal médio metabólico dos animais. Na 8ª semana do experimento foi realizado ensaio de digestibilidade. O marcador interno utilizado para estimar a produção fecal foi a fibra em detergente neutro indigestível (FDNi). Para as análises estatísticas, foi utilizado delineamento inteiramente casualizado. O ganho médio de peso diário (GMD) e PC foram os mesmos para as classes de CAR (P>0,05), apesar dos animais de baixo CAR apresentar menor ingestão de nutrientes (P<0,05) que os animais de médio e alto CAR. Entretanto, os coeficientes de digestibilidade não diferiram entre os grupos (P>0,05). Em contraste, a digestibilidade aparente dos CNF apresentou correlação negativa de -0,23 com o CAR.

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Юр'єв, Е. В. "Удосконалення нафтогазового сепараційного обладнання газорідинних сумішей". Thesis, Івано-Франківський національний технічний університет нафти і газу, 2011. http://elar.nung.edu.ua/handle/123456789/1947.

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Теоретично обгрунтовано й експериментально підтверджено доцільність та ефективність сепарації газорідинної суміші в сепараторах вихрового типу, в конструктивну схему яких введено внутрішні елементи. Математично описано рух газорідинної суміші на вході та виході із сепаратора, а також при її русі крізь його внутрішні робочі елементи. Здійснено комп’ютерне моделювання вихрювих потоків суміші при їхній взаємодії з дефлектором та елементами сепараційного пакета. Запропоновано математичну модель руху газорідинної суміші в сепараторі, з використанням якої, а також багагокритеріальної оптимізації визначено раціональні конструктивні параметри його елементів і коефіцієнтів ефективності сепаратора. Розроблені конструкції сепараторів захищено патентами на винаходи і корисні моделі У країни та Росії. Загальний економічний ефект отримується за рахунок зменшення габаритних розмірів в 3,5-4 рази, маси в 10 разів та знатного підвищення ефективності сепарації.
In theory is explained and expedience and efficiency of separating of gasliquid mixture is experimentally confirmed in tie separators of vortical type, internal elements are entered in tie structural chart ofwhich. Motion of gasliquid mixture is mathematically described on tie entrance and exit from a separator, and also at its motion through his internal workings elements. The computer design of vortical streams of mixture is carried out at their co-operation with deflectorom and elements of separating package. The mathematic model of motion of gasliquid mixture h a separator, with the use of which, and also multicriterion optimization, is offered tie rational structural parameters of its elements and coefficients of efficiency of separator are certain. The developed constructions of separators are protected by patents on tie inventions and useful models of Ukraine and Russia.

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Ainegren, Mats. "Roller skis' rolling resistance and grip characteristics : influences on physiological and performance measures in cross-country skiers." Doctoral thesis, Mittuniversitetet, Institutionen för teknik och hållbar utveckling, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-16446.

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The aim of this thesis was to investigate roller ski characteristics; classical and freestyle roller skis’ rolling resistance coefficients (μR) and classical style roller skis’ static friction coefficients (μS), and to study the influence of different μR and μS on cross-country skiers’ performance and both physiological and biomechanical indices. The aim was also to study differences in skiing economy and efficiency between recreational skiers, female and male junior and senior elite cross-country skiers.The experiments showed that during a time period of 30 minutes of rolling on a treadmill (warm-up), μR decreased significantly (p<0.05) to about 60-65 % and 70-75 % of its initial value for freestyle and classical roller skis respectively. Also, there was a significant influence of normal force on μR, while different velocities and inclinations of the treadmill only resulted in small changes in μR.The study of the influence on physiological variables of a ~50 % change in μR showed that during submaximal steady rate exercise, external power, oxygen uptake, heart rate and blood lactate were significantly changed, while there were non-significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests showed that time to exhaustion was significantly changed and this occurred without a change in maximal power, maximal oxygen uptake, maximal heart rate and blood lactate, and that the influence on ratings of perceived exertion was non-significant or small.The study of classical style roller skis μS showed values that were five to eight times more than the values of μS reported from on-snow skiing with grip-waxed cross-country skis.The subsequent physiological and biomechanical experiments with different μS showed a significantly lower skiing economy (~14 % higher v̇O2), higher heart rate, lower propulsive forces coming from the legs and shorter time to exhaustion (~30 %) when using a different type of roller ski with a μS similar to on-snow skiing, while there was no difference between tests when using different pairs of roller skis with a (similar) higher μS.The part of the thesis which focused on skiing economy and efficiency as a function of skill, age and gender, showed that the elite cross-country skiers had better skiing economy and higher gross efficiency (5-18 %) compared with the recreational skiers, and the senior elite had better economy and higher efficiency (4-5 %) than their junior counterparts, while no differences could be found between the genders.
Syftet med denna avhandling var att undersöka fristils- och klassiska rullskidors rullmotståndskoefficienter (μR) och klassiska rullskidors statiska friktionskoefficienter (μS) samt effekter av olika μR och μS på längdskidåkares prestation vid rullskidåkning på rullande band. Syftet var även att undersöka s.k. åkekonomi och mekanisk verkningsgrad mellan motionärer och kvinnliga och manliga junior- och seniorlängdskidåkare på elitnivå.Experimenten visade att under en period av 30 minuters kontinuerligt rullande, på rullande band, så sjönk μR signifikant (p<0.05) till 60-65 % och 70-75 % av initiala värden, för fristils- respektive klassiska rullskidor. Undersökandet av olika normalkrafter, hastigheter och lutningars påverkan på μR resulterade i en signifikant, negativ korrelation för μR som funktion av normalkraft, medan olika hastigheter och lutningar endast medförde små förändringar av μR.Studien som undersökte fysiologiska effekter av olika μR visade, vid submaximala konstanta arbetsbelastningar, att yttre effekt, syreupptagning, hjärtfrekvens och blodlaktat förändrades signifikant vid ~50 % förändring av μR. Försökspersonernas frekvens och sträcka per frekvens samt skattning av upplevd ansträngning resulterade dock i mestadels icke signifikanta eller små förändringar. Protokollen med successivt ökande arbetsbelastning (maxtest) resulterade i signifikant förändrad tid till utmattning, vid ~50 % förändring av μR. Detta inträffade utan signifikant skillnad i maximal syreupptagning, hjärtfrekvens och blodlaktat, vilket även mestadels gällde för skattning av upplevd ansträngning.Experimenten som undersökte klassiska rullskidors μS visade att dessa erhöll värden som är fem till åtta gånger högre än vad som rapporterats från studier av μS på snö med fästvallade skidor.Den efterföljande studien som undersökte fysiologiska och biomekaniska influenser av olika μS visade, vid submaximala konstanta arbetsbelastningar, att åkekonomin försämrades (~14 % högre syreförbrukning), hjärtfrekvensen ökade, den framåtdrivande kraften från benen på rullskidorna minskade samt att det blev kortare tid till utmattning (~30 %), vid maxtest, när skidåkarna använde rullskidor med en μS i likhet med vad som rapporterats för skidåkning på snö. För arbetsförsöken med olika rullskidor av olika fabrikat med en högre, och likartad, μS förelåg ingen skillnad i de undersökta variablerna.Studien som undersökte åkekonomi och mekanisk verkningsgrad som funktion av prestationsnivå, ålder och kön, visade att elitskidåkarna hade bättre åkekonomi och verkningsgrad (5-18 %) i jämförelse med motionärerna, att seniorerna hade bättre åkekonomi och verkningsgrad (4-5 %) än juniorerna och att ingen skillnad kunde konstateras mellan könen.

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Hamade, Firas Nadim. "Sediment removal from urban runoff using seep berms and vegetative filtration." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50271.

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Previous field demonstration projects in metro-Atlanta have shown that seep berms, which are elongated sedimentation basins at the outlet of a disturbed land area, can provide high suspended sediment trap efficiencies with respect to coarse sediments on construction sites having drainage areas greater than five acres. Previous literature has shown that vegetative filter strips are efficient traps for fine suspended sediment in stormwater runoff. A combination of a seep berm and vegetative filter in series was studied in this thesis as an erosion control measure with quantification of its flow resistance and sediment removal efficiency. First, a field demonstration project was implemented to evaluate seep berms as a viable erosion control measure through a side-by-side comparison with the more commonly-used silt fences on construction sites with drainage areas less than five acres in metro Atlanta. High suspended sediment trap efficiencies were recorded for the seep berm on two separate sites, and the seep berm was shown to be superior to silt fences with respect to sediment control in the site runoff. Then a vegetative filter was studied in the laboratory in a specially-built flume for that purpose. The relationship between vegetative drag coefficient and various parameters reflecting flow conditions and vegetation density in steady, uniform open channel flow was studied in the flume. Both rigid, emergent vegetation and submerged, flexible vegetation were studied at two different plant densities. The application of porous media flow concepts to open channel flow through vegetation resulted in a collapse of data for vegetative drag coefficient for the various vegetation types and densities into a single relationship when plotted against vegetative stem Reynolds number. Point velocity and turbulence intensity profiles at different locations in the vegetative filter were recorded with an acoustic Doppler velocimeter to observe the turbulence structure of the flow and its effects on vegetative drag and settling of sediment. A sediment slurry consisting of a suspension of fine sand was fed into the flume, and an automated sampler was used to measure suspended sediment concentrations along the vegetative filter length for a series of discharges from which sediment flux and trap efficiency could be determined. Experimental data for trap efficiency were plotted against a dimensionless settling efficiency for each type of vegetation and density. These relationships, along with the one developed for the coefficient of drag, were applied in a numerical design technique that allows designers to determine the flow depth, velocity and trap efficiency of a vegetative filter of known dimensions for a given flow rate, sediment grain size distribution, slope, and vegetation density. In a typical design example, the combined trap efficiency proved that a seep berm followed by a vegetative filter can be a very effective erosion control measure.

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Santos, Henrique Zenker dos. "Determinação do coeficiente e expoente de escoamento em esquadrias nacionais, para análise de infiltração de ar em edificações." Universidade do Vale do Rio dos Sinos, 2016. http://www.repositorio.jesuita.org.br/handle/UNISINOS/6018.

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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Países desenvolvidos apresentam crescimento contínuo nas taxas globais de consumo de energia. Um dos fatores preponderantes está relacionado ao uso de condicionadores de ar para manutenção das condições de conforto no interior de edificações, onde tal parcela já atinge valores de consumo superiores aos dos setores de indústria e transporte. Sabe-se que o consumo devido ao condicionamento de ar afeta diretamente o desempenho energético e ambiental de uma edificação e, por conseguinte, a qualidade de habitação e de vida dos usuários. No Brasil este processo ocasiona um vertiginoso incremento nos gastos públicos, com inúmeras consequências de ordem econômica e social. Dados do Ministério de Minas e Energia indicam que 20% da energia consumida no país é destinada ao abastecimento de residências. Cenário este que tende a evoluir devido aos constantes lançamentos do mercado imobiliário, derivativos de planos habitacionais estimulados pelo governo federal (como o Minha Casa Minha Vida), em decorrência do déficit habitacional registrado no país. Atrelado a isso observa-se o baixo padrão construtivo das edificações e o emprego de materiais e esquadrias de qualidade igualmente diminutas, que acarretam em ineficiências de carga térmica. A taxa de infiltração em uma edificação é regida pela relação estabelecida por uma equação de lei de potência, caracterizada pela presença de um coeficiente de escoamento “C” e um expoente de escoamento “n” (geralmente da ordem de 0,667 [-]). Esta dissertação apresenta, para uma esquadria de alumínio, modelo de correr, o coeficiente de escoamento C = 0,028 [dm³/s.m.Pan] e o expoente de escoamento “n” 0,552 [-]. Para uma esquadria de PVC, modelo integrado, o coeficiente de escoamento C = 0,022 [dm³/s.m.Pan] e o expoente de escoamento “n” 0,605 [-].
Developed countries have continued growth in global energy consumption rates. One of the most important factors is related to the use of air conditioners to the comfort conditions inside buildings’ maintenance, which such a part already reaches consumption values higher than the industry and transportation sectors. It is known that consumption due to air conditioning directly affects the energy and environmental performance of a building and therefore the house’s quality and the people’s life. In Brazil, this process leads to a big increase in public spending, with many consequences of economic and social order. Information from the Ministry of Mines and Energy indicate that 20% of the energy consumed in the country is used for supplying homes. This scenario tends to evolve due to the constant housing market releases, derived from housing plans stimulated by the federal government (such as “Minha Casa Minha vida”), in consequence of the housing deficit registered in the country. Related to this, it is observed the low construction standards of buildings and the use of materials and frames of low quality that lead to thermal load inefficiencies. Engineers and architects spend a part of their activities in creating scenarios for evaluating the thermal load calculation and vulnerability due to the influence caused by air infiltration into the environment. The infiltration rate of a building is managed by the established relationship by a power law equation, which is characterized by a flow coefficient "C" and a flow exponent "n" (usually on the value of 0.667 [-]). This work shows for an aluminum window, sliding template, the flow coefficient C = 0.028 [dm³/s.m.Pan] and the flow exponent "n" 0.552 [-]. For PVC window, integrated model, the flow coefficient C = 0.022 [dm³/s.m.Pan] and the exponent flow "n" 0.605 [-].

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35

Barbosa, Fernando da Silva. "Produtividade de cana-de-açúcar irrigada por gotejamento: Interações entre variedades, lâminas e intensidade do déficit hídrico na fase de maturação." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/11/11152/tde-09042015-131434/.

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O setor sucroenergético enfrenta atualmente uma crise industrial e agrícola, carecendo de pesquisas para reverter este quadro, dependendo de matéria-prima a custos competitivos, e isso, passa obrigatoriamente pelo aumento de produtividade no campo. A irrigação é uma das alternativas para o aumento de produtividade, mas exige investimentos consideráveis para se irrigar de forma profissional. Além disso, a crescente demanda por alimentos e a competição por recursos hídricos em todo o mundo são uma realidade que impulsiona o uso mais eficiente da água em todos os setores, principalmente na agricultura. Assim, com a hipótese de que, para cada variedade de cana-de-açúcar, existe uma combinação mais adequada entre a lâmina de irrigação e a intensidade do déficit hídrico na fase de maturação, de modo a maximizar a produtividade, o objetivo deste trabalho foi avaliar o efeito de quatro lâminas de irrigação e quatro intensidades de déficit hídrico na fase de maturação, para oito variedades de cana-deaçúcar irrigadas por gotejamento, analisando as variáveis relacionadas à qualidade e à produtividade por unidade de área, bem como, quantificando a produtividade por unidade de água (evapo)transpirada (produtividade da água). O experimento foi conduzido em estufa na Escola Superior de Agricultura \"Luiz de Queiroz\" (USP), em Piracicaba-SP. Os tratamentos foram distribuídos em esquema fatorial (4x4x8) com parcelas sub-subdivididas com 3 repetições, totalizando-se 128 tratamentos e 384 parcelas experimentais, sendo as parcelas experimentais compostas de um vaso com aproximadamente 330 litros de solo contendo duas plantas. As lâminas avaliadas (L50, L75 L100 e L125) foram variações na fração aplicada ao longo do tempo tomando como referência o tratamento L100, em que se manteve a umidade do solo próxima à capacidade de campo (θcc) ao longo de todo experimento. Cada variedade testada teve sua própria referência L100. As intensidades do déficit hídrico para maturação avaliadas foram M1 (déficit hídrico moderado de longa duração), M2 (déficit hídrico intensivo de longa duração), M3 (sem déficit hídrico) e M4 (déficit hídrico severo de curta duração). A produtividade de colmos (TCH) foi favorecida pela combinação L100 e M3, independente da variedade estudada, com valor médio estimado de 232,2 t ha-1. Entre as variedades, a V4 apresentou a maior TCH, com média de 250,4 t ha-1 para L100. O rendimento bruto de açúcar (RBA) está diretamente ligado à produtividade de colmos, sendo igualmente favorecido pela combinação de L100 e M3, com valor médio de 23,4 t ha-1. As variedades V1, V2, V4 e V6, na lâmina L100, não diferiram significativamente entre si para RBA e tiveram a maior média, 23,9 t ha-1. A produtividade da água em açúcar e biomassa foi diferenciada em 4 e 2 grupos de variedades, respectivamente, e foi independente da lâmina de irrigação e do manejo para maturação adotados. Este resultado para a produtividade da água é característico da irrigação por gotejamento, onde as perdas por evaporação são minimizadas e a retenção de água nas folhas inexiste. Desta maneira, recomenda-se a irrigação plena de cana-de-açúcar caso a opção econômica seja pelo sistema de gotejamento.
The sugarcane industry is currently facing an industrial and agricultural crisis, lacking research to reverse this situation, depending on the raw material at competitive costs, and this inevitably entails the increase in productivity in the field. The use of irrigation systems is imposed as an alternative, but requires considerable investments to irrigate professionally. In addition, the growing demand for food and competition for water resources worldwide, are a reality that drives the more efficient water use in all sectors, especially in agriculture. Thus, with the hypothesis that there is for each variety of sugar sugarcane, a more appropriate mix between irrigation depth and intensity water deficit during ripening, in order to maximize productivity, the aim of this work was to evaluate the effect of four irrigation depths and four levels of water stress during ripening, for eight drip irrigated sugarcane varieties, analyzing the variables related to quality and productivity per area unit, as well as quantifying productivity per unit of evapotranspired water (water productivity). The experiment was conducted in a greenhouse at the \"Luiz de Queiroz\" College of Agriculture (USP) in Piracicaba-SP. Treatments were arranged in a factorial design (4x4x8) with split-split-plot with three replicates, totaling 128 treatments and 384 plots, and the plots consist of a box with about 330 liters of soil containing two plants. The evaluated irrigation depths (L50, L75 and L100 L125) were variations in the fraction applied over time, relative to the treatment L100, where soil moisture remained close to field capacity (θcc) throughout the experiment. Each tested variety had its own reference L100. The intensities of water deficit during maturation were evaluated for M1 (moderate water deficit of long duration), M2 (intensive water deficit of long duration), M3 (no water deficit) and M4 (severe water deficit of short duration). The sugarcane yield (TCH) was favored by the combination L100 and M3, regardless of the studied variety, with an estimated average value of 232.2 t ha-1. Among the varieties, V4 had the highest TCH, with average of averaging 250.4 t ha-1 for L100. Sugar yield (RBA) is directly linked to sugarcane yield and is also favored by the combination of L100 and M3, with an average value of 23.4 t ha-1. The V1, V2, V4 and V6 varieties, for irrigation depth L100, did not differ significantly for RBA and had the highest average, 23.9 t ha-1. The water productivity in sugar and biomass differed in 4 and 2 variety groups, respectively, and was independent of the adopted irrigation depth and maturation management. The result for water productivity is characteristic of drip irrigation, where losses by evaporation are minimized and water retention in the leaves does not exist. Thus, one should consider the possibility of full drip irrigation, instead of the deficit one, for sugarcane.

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Костюк, Сава Андрійович. "Технологічне забезпечення підвищення працездатності пальців сферичних шарнірів статико-імпульсною обробкою". Diss., Тернопільський національний технічний університет ім. Івана Пулюя, 2021. http://elartu.tntu.edu.ua/handle/lib/35992.

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Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.02.08 «Технологія машинобудування». – Тернопільський національний технічний університет імені Івана Пулюя, Тернопіль, 2021. У дисертації вирішено науково-прикладну задачу підвищення працездатності пальців сферичних шарнірів статико-імпульсною обробкою за рахунок формування покращених властивостей зміцненої поверхні. Розроблено теоретичні передумови та проведено ряд експериментальних досліджень, на основі яких запропоновано спосіб біполярного статико-імпульсного зміцнення зовнішніх неповних сферичних та циліндричних поверхонь тіл обертання. Проведено обґрунтування та вибір конструктивно-технологічних параметрів устаткування для статико-імпульсної обробки. Розглянуто вплив технологічних параметрів на величину подачі деформуючого інструмента та побудовано математичні залежності для визначення режимів обробки з врахуванням коефіцієнта перекриття пластичних відбитків. Запропоновано конструкцію генератора механічних імпульсів біполярної дії та проведено розрахунки конструктивно-технологічних параметрів устаткування. Розглянуто цикл роботи генератора механічних імпульсів та побудовано математичну модель його роботи. Розглянуто вплив параметрів процесу статико-імпульсного зміцнення на формування мікропрофілю поверхні. Запропоновано технологічне устаткування та технологію виготовлення деталі типу «палець СШ», річна ефективність від впровадження якої складає 208460 грн у порівнянні з базовою. В результаті проведеної роботи для біполярної статико-імпульсної обробки зовнішніх неповних сферичних та циліндричних поверхонь запропоновано машину модульного типу з числовим програмним керуванням, яка дозволяє варіювати технологічними параметрами обробки.
Ph. D. thesis in Engineering Science by specialty 05.02.08 “Mechanical Engineering Technology”. – Ternopil Ivan Puluj National Technical University, Ternopil, 2021. The dissertation solves the scientific and applied problem of increasing the working capacity of the fingers of spherical joints by static-impulse processing due to the formation of improved properties of the hardened surface. In modern mechanical engineering, spherical sliding hinges are widely used to improve the performance of which it is recommended to harden the working surfaces of the fingers with the possibility of forming a geometrically defined oil-retaining profile. Therefore, the creation of special technological equipment for bipolar static-pulse hardening, the substantiation of the parameters and operating modes, in fact, forms a scientific and applied problem that requires a solution and is relevant for various branches of mechanical engineering. The scope of application and various design options for the execution of spherical hinges, their life cycle is considered, and a classification of factors that affect its performance is presented. A comparative analysis of the requirements for materials for the manufacture of spherical hinge pins is presented. The existing options for the formation of an oil-retaining profile on the outer incomplete spherical surface are considered. The analysis of methods of hardening of spherical surfaces is carried out on the basis of which scientific directions of research are determined and recommendations for the creation of technological equipment of bipolar action are developed. Theoretical prerequisites have been developed and a number of experimental studies have been carried out, on the basis of which a method and scheme of bipolar static-pulse hardening has been proposed. A schematic diagram of the process of bipolar static-pulse processing of incomplete spherical surfaces has been developed, which was taken as the basis for the design of technological equipment. The influence of technological parameters on the value of the deforming tool feed is considered and mathematical dependences are derived to determine the processing modes taking into account the coefficient of overlapping of plastic imprints.

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Weerasekara, Aruna Bandara. "Electrical and Optical Characterization of Group III-V Heterostructures with Emphasis on Terahertz Devices." Digital Archive @ GSU, 2007. http://digitalarchive.gsu.edu/phy_astr_diss/16.

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Electrical and optical characterizations of heterostructures and thin ﬁlms based on group III-V compound semiconductors are presented. Optical properties of GaMnN thin ﬁlms grown by Metalorganic Chemical Vapor Deposition (MOCVD) on GaN/Sapphire templates were investigated using IR reﬂection spectroscopy. Experimental reﬂection spectra were ﬁtted using a non - linear ﬁtting algorithm, and the high frequency dielectric constant (ε∞), optical phonon frequencies of E1(TO) and E1(LO), and their oscillator strengths (S) and broadening constants (Γ) were obtained for GaMnN thin ﬁlms with different Mn fraction. The high frequency dielectric constant (ε∞) of InN thin ﬁlms grown by the high pressure chemical vapor deposition (HPCVD) method was also investigated by IR reﬂection spectroscopy and the average was found to vary between 7.0 - 8.6. The mobility of free carriers in InN thin ﬁlms was calculated using the damping constant of the plasma oscillator. The terahertz detection capability of n-type GaAs/AlGaAs Heterojunction Interfacial Workfunction Internal Photoemission (HEIWIP) structures was demonstrated. A threshold frequency of 3.2 THz (93 µm) with a peak responsivity of 6.5 A/W at 7.1 THz was obtained using a 0.7 µm thick 1E18 cm−3 n - type doped GaAs emitter layer and a 1 µm thick undoped Al(0.04)Ga(0.96)As barrier layer. Using n - type doped GaAs emitter layers, the possibility of obtaining small workfunctions (∆) required for terahertz detectors has been successfully demonstrated. In addition, the possibility of using GaN (GaMnN) and InN materials for terahertz detection was investigated and a possible GaN base terahertz detector design is presented. The non - linear behavior of the Inter Pulse Time Intervals (IPTI) of neuron - like electric pulses triggered externally in a GaAs/InGaAs Multi Quantum Well (MQW) structure at low temperature (~10 K) was investigated. It was found that a grouping behavior of IPTIs exists at slow triggering pulse rates. Furthermore, the calculated correlation dimension reveals that the dimensionality of the system is higher than the average dimension found in most of the natural systems. Finally, an investigation of terahertz radiation efect on biological system is reported.

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Мейріс, Антон Жанович. "Теплообмін та теплогідравлічна ефективність пучків труб з поверхневими заглибленнями". Thesis, Інститут технічної теплофізики НАН України, 2018. https://ela.kpi.ua/handle/123456789/38181.

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Робота виконана в Національному технічному університеті України «Київський політехнічний інститут імені Ігоря Сікорського» МОН України на кафедрі фізики енергетичних систем і в Інституті технічної теплофізики НАН України у відділі високотемпературної термогазодинаміки. Захищена в Інституті технічної теплофізики НАН України.
Дисертація присвячена експериментальному та теоретичному дослідженню теплообміну та гідродинаміки при поперечному обтіканні одиночної труби та пучку труб із поверхневими заглибленнями. Теоретично досліджено теплообмін та гідродинаміку при поперечному обтіканні одиночної труби із поверхневими заглибленнями у формі усіченого конусу за допомогою комп’ютерного пакету ANSYS CFX. Проведено верифікацію моделей турбулентності. Наведено результати досліджень вихрової структури потоку, точки відриву потоку, зони зворотних течій, коефіцієнту лобового опору, коефіцієнту теплообміну. Проведено експериментальні та теоретичні дослідження теплообміну та гідродинаміки при поперечному обтіканні п’ятирядного пучку труб із поверхневими заглибленнями. Отримані дані щодо коефіцієнтів гідравлічного опору пучка та коефіцієнтів теплообміну по рядах та для пучка в цілому. Проведено верифікацію комп’ютерної моделі по експериментальним даним. Розроблено інженерну методику розрахунку рекуператора газотурбінної установки та проведено оцінку зниження його маси за рахунок нанесення заглиблень.
The dissertation is devoted to the experimental and theoretical study of heat transfer and hydrodynamics at the cross-flow of a single tube and a tube bundle with surface indentations. Heat transfer and hydrodynamics were studied theoretically at the cross-flow of a single tube with surface indentations in the form of a truncated cone using the ANSYS CFX computer package. Verification of turbulence models is carried out. The results of studies of the vortex structure of the flow, the point of separation of the flow, the zone of reverse flows, the coefficient of the frontal resistance, and the heat transfer coefficient are given. Experimental and theoretical investigations of heat transfer and hydrodynamics are carried out at the cross-flow of a five-row tube bundle with surface indentations. The data on the coefficients of the hydraulic resistance of the bundle and of the heat transfer coefficients for rows and for the whole bundle are obtained. Verification of the computer model by experimental data is carried out. An engineering method for calculation of the gas turbine plant recuperator was developed and an estimation of the decrease in its mass due to the application of depressions was made.

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39

Kronsbein, Cornelia [Verfasser], and Oleg [Akademischer Betreuer] Iliev. "On selected efficient numerical methods for multiscale problems with stochastic coefficients / Cornelia Kronsbein. Betreuer: Oleg Iliev." Kaiserslautern : Technische Universität Kaiserslautern, 2013. http://d-nb.info/1030521409/34.

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40

Leskovec, Martin. "Method Development for Heat Transfer Predictions in Channel Flows : An efficient CFD approach for ribbed stationary channels." Thesis, Linköpings universitet, Mekanisk värmeteori och strömningslära, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-132166.

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Gas turbines are today used in numerous industrial and aeronautical applications. To increase the specific power output and efficiency, a high turbine inlet gas temperature is desired. The high temperature leads to the need of cooling critical components in the hot gas path. Siemens Industrial Turbomachinery AB, SIT AB, in Finspång manufactures gas turbines where the internal cooling of critical components is done through serpentine channels. To utilize the cooling air as efficiently as possible, vortex creating objects are placed inside the channel which result in higher heat transfer. To compute the heat transfer in the channel, correlation based approaches that will give a uniform value for an entire channel are often used. This thesis contains two parts. First, investigating how an automated CAE process can be developed that is able to be incorporated into the SIT AB CAE process of today and with a future vision of a, basically, "one-click-CFD" approach for non-generic geometries. Secondly, how CFD simulations for predicting heat transfer levels inside the cooling channels with high accuracy and that captures local features of heat transfer can be performed. The suggested CAE approach involves the CAD-tool NX for geometry creation and for managing an entire CFD project the ANSYS software Workbench, combined with ANSYS Meshing for generation of computational grid, CFX-pre and CFX for pre-processing and solving and CFD-post for post-processing. This approach is suggested for generic geometries due to the simplicity in incorporating it into existing CAE processes. For the future vision of non-generic geometries, the inhouse developed project manager Concept is suggested. It allows for customized coupling between a broader range of available software tools. To validate the CFX model and to investigate how the CFD calculations should be performed, two cases were set up, one where the CFD model and the inhouse code was compared to experimental data of a generic geometry and one where the CFD model and the inhouse code were compared at engine-like conditions. The results for the experimental case resulted in heat transfer coefficients from the CFD model that were 30% off from experimental data, and the inhouse code maximum deviation was 10%. Compared to previous numerical studies this was considered to be of acceptable accuracy, and the location of data extraction points were considered to cause the deviation in the CFD model. For the engine-like case both CFD and inhouse code predicted the heat transfer level as expected. The simulations were performed in steady state mode on automatically generated meshes with the SST-Reattachment turbulence model. The Reynolds number varied from 10 000 to 80 000 and the meshes were around 4-10M elements in size.

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Saulich, Sven. "Generic design and investigation of solar cooling systems." Thesis, Loughborough University, 2013. https://dspace.lboro.ac.uk/2134/13627.

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This thesis presents work on a holistic approach for improving the overall design of solar cooling systems driven by solar thermal collectors. Newly developed methods for thermodynamic optimization of hydraulics and control were used to redesign an existing pilot plant. Measurements taken from the newly developed system show an 81% increase of the Solar Cooling Efficiency (SCEth) factor compared to the original pilot system. In addition to the improvements in system design, new efficiency factors for benchmarking solar cooling systems are presented. The Solar Supply Efficiency (SSEth) factor provides a means of quantifying the quality of solar thermal charging systems relative to the usable heat to drive the sorption process. The product of the SSEth with the already established COPth of the chiller, leads to the SCEth factor which, for the first time, provides a clear and concise benchmarking method for the overall design of solar cooling systems. Furthermore, the definition of a coefficient of performance, including irreversibilities from energy conversion (COPcon), enables a direct comparison of compression and sorption chiller technology. This new performance metric is applicable to all low-temperature heat-supply machines for direct comparison of different types or technologies. The achieved findings of this work led to an optimized generic design for solar cooling systems, which was successfully transferred to the market.

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42

Voisin, Laurent. "Nitration du mononitrochlorotertiobutylbenzene en reacteurs diphasiques liquide-liquide." Paris, ENMP, 1988. http://www.theses.fr/1988ENMP0102.

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43

Vích, Pavel. "Účinnost rozvodů tepla." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227296.

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This diploma thesis focuses on the analysis of heat loss of heating distribution in the industrial area. The aim of this labor is to determine heat loss heat distribution kept in non manholed canal and evaluate economic return to build a local source of heat for the office building. For this building is in two variants resolve the reconstruction of the existing heating system. For the first variant is designed the local gas condensing boiler and for second variant existing central heat source. The experimental part of this labor compares the measured and calculated values of boundary conditions of hot-water pipes kept in non manholed canal.

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44

Vidlák, David. "Využití absorpčních systémů v teplárenství." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-378742.

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Main goal of this work is familiarization with basic features of absorption heat pumps and it’s growing importance on the market. In the first part of the work there is a research for clarifying facts associated with such pumps. In the introduction there are descriptions of basic information from the field of heating industry and its connections to our systems. Next there is a brief analysis of price changes in electricity and heat in the last five years. Main part of the analytical section is a description of the used absorption system. Second part of the work is focused on the calculation of the absorption system itself. First there is calculated internal and external part of the device according to the parameters from GE Power s.r.o. After this step there are parametric studies based on changes of key parameters of the default device for a demonstration of the behavior of a heating pump. In the end of the work there is a integration of the unit into the heating cycle for variations including flue gas condenser and using a cooling water from the turbine condenser.

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45

Holeček, Dominik. "Studium užitných vlastností termoreflexních izolací pro stavebnictví." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392345.

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The diploma thesis is partly dedicated to energetic efficiency of buildings and describes possibilities how to evaluate energetic efficiency of buildings in the Czech Republic. We also get to know with distribution of thermal insulators by material base and use in construction. There are also mentioned methods how to determine thermal insulations characteristics of heat insulations, so called heat conductivity coefficient. The last and the crucial chapter of theoretic part is dedicated to thermal-reflective insulations. There are mentioned some of the basic characteristics of insulations, material composition and heat transfer mechanism in their structure as well. Practical part describes measurement of thermal resistance of chosen samples of thermal-reflective insulations per measuring device on the principal of Hot Box method. In the next step was determined emissivity of aluminium foils which forms the surface of chosen samples of thermal-reflective insulations. In the end of thesis are defined possibilities of use thermal-reflective insulations in building structures especially in passive and low-energy buildings in climatic conditions of the Czech Republic.

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46

Horák, Aleš. "Návrh experimentu pro řešení inverzní úlohy vedení tepla." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-233977.

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this thesis complex inverse heat transfer problem, which is focused on optimal design of experiment, is studied. There are many fields and applications in technical practice, where inverse tasks are or can be applied. On first place main attention is focused on industrial metallurgical processes such as cooling of continues casting, hydraulic descaling or hot rolling. Inverse problems are in general used to calculate boundary conditions of differential equations and in this field are used to find out Heat Transfer Coefficient (HTC). Knowledge of numerical approximation of precise boundary conditions is nowadays essential. It allows for example design of optimized hot rolling mill cooling focused on material properties and final product quality. Sequential Beck’s approach and optimization method is used in this work to solve inverse heat transfer problems. Special experimental test bench measuring heat transfer intensity was developed and built to full fill specific requirements and required accuracy. There were four different types of thermal sensor applied and studied. Those sensors are in usage in Heat Transfer and Fluid Flow laboratory (Heatlab) at various experimental test benches. Each specific sensor was tailored in Heat Transfer and Fluid Flow Laboratory to specific metallurgical application. Fist type of sensor was designed to simulate cooling during continuous casting. Second sensor is used for experiments simulate hot rolling mill cooling, while third sensor is designated for experiments with fast moving hot rolled products. Last sensor is similar to sensor type one, but thermocouple is located parallel to cooled surface. Experimental part of this study covers series of measurements to investigate Heat Transfer Coefficient (HTC) for various types of coolant, cooling mixtures and spray parameters. Results discovered in this study were compared with published scientific articles, and widely extend the knowledge of cooling efficiency for commonly used

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47

Поталіцин, Сергій Юрійович, Сергей Юрьевич Поталицын та S. Yu Potalitsyn. "Розробка науково-технічних основ впровадження компактних люмінесцентних ламп в системи зовнішнього освітлення". Thesis, Тернопільський національний технічний університет ім. Івана Пулюя, 2016. http://elartu.tntu.edu.ua/handle/123456789/16241.

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Роботу виконано в Тернопільському національному технічному університеті імені Івана Пулюя Міністерства освіти і науки України. Захист відбувся 2016 р. на засіданні спеціалізованої вченої ради К 58.052.04 у Тернопільському національному технічному університеті імені Івана Пулюя Міністерства освіти і науки України за адресою: 46008, м. Тернопіль, вул. Білогірська, 50, корп. 10 (зал засідань). З дисертацією можна ознайомитись у бібліотеці Тернопільського національного технічного університету імені Івана Пулюя Міністерства освіти і науки України за адресою: 46001, м. Тернопіль, вул. Руська, 56.
Захист відбудеться " 23 " червня 2016 р. о 1000 годині на засіданні спеціалізованої вченої ради К 58.052.04 у Тернопільському національному технічному університеті імені Івана Пулюя Міністерства освіти і науки України за адресою: 46008, м. Тернопіль, вул. Білогірська, 50, корп. 10 (зал засідань).
Дисертація присвячена проблемі енергозбереження в зовнішньому освітленні за рахунок використання СП із КЛЛ. Розроблено методику розрахунку світлового приладу із заданими розмірами світного тіла джерела світла та на її основі спроектовано світловий прилад з КЛЛ. Побудовано модель освітлення для різних категорій вулиць і на її основі проведено розрахунки якісних та кількісних показників установки вуличного освітлення та розроблено рекомендації для практичного впровадження КЛЛ в системи зовнішнього освітлення. Проведено експериментальні дослідження характеристик компактних люмінесцентних ламп при зміні температури навколишнього середовища. Проведено дослідження показників якості електричної енергії в системах зовнішнього освітлення із компактними люмінесцентними лампами та їх вплив на відносну похибку індукційного та електронного приладів обліку.
Диссертация посвящена проблеме энергосбережения в системах внешнего освещения периферийных районов городов и сельской местности за счёт использования световых приборов с компактными люминесцентными лампами. Использование в СП для внешнего освещения типа ГКУ11У, ЖКУ11У, РКУ11У и ЖКУ, РКУ Helios 21 нетипичных источников света в том числе и КЛЛ снижает их ККД на 14…17 %. В роботе проведено моделирование светового поля КЛЛ, в котором учтены геометрические размеры светового тела источника, что позволило увеличить точность полученных результатов на 40…60 %. Предложена математическая модель расчёта оптической системы СП с источником света заданных геометрических размеров, в которой учтено экранирующее действие светового потока источником света. Разработана методика и алгоритм расчёта СП с компактной люминесцентно лампой. Разработана модель освещения улиц разных категорий, на основе которой проведен расчет светотехнических параметров осветительной установки со световыми приборами с лампами Realux 55 Вт. Показано, что для достижения нормативных показателей освещения для категории улиц М4 и М5 максимальное расстояние между СП – 37 м, а для категории М3 – 33 м. Оптимальный угол наклона оптической оси СП относительно вертикали – 31°. Представлены результаты исследования влияния температуры окружающей среды на светотехнические параметры как отдельно взятой КЛЛ, так и помещённой в световом приборе. Установлено, что для ламп мощностью от 36 до 65 Вт при изменении температуры внешней среды от -25 °С до +25 °С температура ЭПРА не превышает допустимую температуру +80 °С, при этом световой поток изменяется от 0,92 до 1,0 относительно номинального значения. Проведены исследования влияния ОУ с СП с КЛЛ на показатели качества электрической энергии и относительную погрешность её учета. Показано, что амплитудные значения высших гармоник тока ламп превышают нормативные значения в 3 – 5 раз, что вызвано недостаточным уровнем коррекции коэффициента мощности ЭПРА КЛЛ. Это приводит к превышению относительной погрешности учёта электрической энергии на 3 – 4 %.
The thesis is dedicated to the problem of energy efficiency in outdoor lighting through the use of a fixture with a compact fluorescent lamp. The development of calculation methodology of a fixture with the target size of the luminous body of the light source has been done and on its basis a fixture with a compact fluorescent lamp has been projected. A lighting model for different types of streets has been constructed and on its basis calculations of qualitative and quantitative indicators of street lighting installments have been done as well as recommendations for the practical implementation of compact fluorescent lamps into outdoor lighting systems have been developed. Experimental studies of characteristics of compact fluorescent lamps during the change of the temperature of the environment have been done. The calculation of the thermal regime of a closed-type fixture with a compact fluorescent lamp Realux 55 W has been conducted. Research of quality indices of electricity in outdoor lighting systems with compact fluorescent lamps has been done as well as their impact on relative error of induction and electronic metering instruments.

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Сніткіна, І. А., та I. A. Snitkina. "Аналітичне забезпечення управління платоспроможністю підприємства". Diss., Одеський національний економічний університет, 2019. http://local.lib/DIS/disSytnikova.pdf.

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ДОСТУП ДО ДОКУМЕНТУ ТІЛЬКИ НА ТЕРИТОРІЇ БІБЛІОТЕКИ ОНЕУ. Для доступу натисніть на посилання ⬇️
У дисертації розкрито теоретичні, методичні та практичні засади аналітичного забезпечення управління платоспроможністю, а також сформульовано висновки та рекомендації, спрямовані на застосування методики в діяльності підприємств у сучасних умовах. Проаналізовано етимологічне значення, наукові підходи до розуміння сутності таких понять, як «платоспроможність», «банкрутство», «криза», «дефолт», визначено їх співвідношення та взаємозв’язок. У межах аналізу доведено, що оцінка платоспроможності та прогнозування ризику банкрутства підприємства стає тим інструментом, який дозволяє виявити ті чи інші недоліки у його діяльності, врахувати ендогенні та екзогенні фактори впливу, а також своєчасно вжити заходи для уникнення небажаних ситуацій. Сформульовано аргументи на більш широке застосування поняття платоспроможності як здатності суб’єкта господарювання своєчасно і в повному обсязі розрахуватися за своїми поточними борговими зобов’язаннями за рахунок наявних ресурсів із збереженням безперебійного здійснення основних процесів функціонування підприємства і підвищення ефективності діяльності, що дозволило систематизувати взаємозв’язки між категоріями платоспроможності, неплатоспроможності та банкрутства.
The theoretical, methodical and practical principles of analytical support of solvency management are revealed in the dissertation, as well as conclusions and recommendations aimed at applying the methodology to the activity of enterprises in modern conditions are formulated. Etymological meaning, scientific approaches to understanding the essence of such concepts as "solvency", "bankruptcy", "crisis", "default" are analyzed, their relationships and interrelation are determined. The analysis shows that the solvency and bankruptcy risk assessment of an enterprise becomes the tool that allows to identify certain gaps in its activity, to take into account endogenous and exogenous factors of influence, as well as to take in time measures to avoid undesirable situations. Arguments for broader application of the concept of solvency as the ability of an entity to timely and fully pay for its current debt at the expense of available resources, while maintaining the smooth implementation of the basic processes of enterprise functioning and improving the efficiency of activities, which allowed to systematize the corelation between the categories of solvency, insolvency and bankruptcy are given and proved. It is proposed to expand the classification of solvency factors of an enterprise depending on the consequences of manifestation and interdependence, which will allow to model the process of ensuring solvency management further on, to carry out a comprehensive search of reserves in order to maintain or enhance it.

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Micard, Diane. "Dissipation et mélange en turbulence stratifiée : une approche expérimentale." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEC041/document.

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Le climat de la Terre dépend en grande partie des échanges énergétiques entre les masses d’eau chaudes et froides de nos océans. Afin de prédire et de comprendre les variations de notre climat, les modèles numériques globaux de l’océan doivent pouvoir déterminer quelle fraction d'énergie est convertie en mélange irréversible dans un écoulement turbulent et stablement stratifié. Il apparaît que cette fraction est sensible aux paramètres de l’écoulement, ce qui a récemment conduit les océanographes à remettre en question la paramétrisation d'Osborn pour le coefficient de diffusion turbulente kz, qui utilise une efficacité de mélange constante et fixée à ŋ=0,17. Ceci nous a poussé à réaliser au laboratoire de Mécanique des Fluides et d'Acoustique (LMFA) des mesures conjointes de ŋ et kz, afin de mieux comprendre leur inter-dépendance. Cette étude est avant tout expérimentale et se base sur plusieurs dispositifs permettant de quantifier le mélange dans différents types d'écoulement. Trois de ses expériences ont été réalisées au LMFA : une expérience de lock-exchange dans laquelle le mélange est issu du cisaillement à l'interface de deux courants de gravité se déplaçant en sens opposés, une expérience de grille tractée dans un fluide stratifié et une expérience d’injection de stratification dans la grille d’un canal hydraulique. Ce travail a été complété, d'une part par une collaboration sur la plateforme Coriolis du LEGI à Grenoble, permettant d’atteindre de plus grands nombres de Reynolds ; et d'autre part par une campagne de mesure in situ dans le fjord du Saguenay au Canada en collaboration avec l'ISMER, visant à estimer le mélange turbulent conduisant au renouvellement des eaux profondes du fjord, à partir de l'analyse de transects successifs de densité. Dans ces différentes configurations, l'évolution temporelle des profils verticaux de densité ont permis d'analyser la dépendance du coefficient de diffusion turbulente et de l'efficacité de mélange avec les nombres de Reynolds et de Froude. Nos résultats ont permis de quantifier la décroissance de l'efficacité de mélange avec l'augmentation du nombre de Froude dans un écoulement turbulent, ainsi que la sensibilité du coefficient de diffusion turbulente aux nombres de Froude et de Reynolds de flottabilité. L'utilisation de trois dispositifs expérimentaux différents permet de montrer qu'au-delà de ces lois dites universelles, la variabilité propre à chaque géométrie influence fortement les valeurs de l'efficacité de mélange. Ceci est particulièrement mis en lumière dans la configuration de lock-exchange, pour laquelle la valeur limite de ŋ=0.25 prédite par la physique statistique n'est atteinte que dans une configuration fortement tri-dimensionnelle, jusqu'alors peu utilisée dans la littérature. Enfin, toutes les méthodes d'analyse développées pour les expériences de laboratoire ont pu être utilisées pour l'analyse des données in situ, permettant de clore ce travail de thèse sur une étude environnementale
Our climate partly depends on energy exchange between warm and cold water masses in the ocean's interior. In order to understand and forecast the climate variations, numerical models of the ocean must estimate the amount of energy converted into irreversible mixing in turbulent stably stratified flows. It seems that this quantity depends on the flow parameters. This assertion challenges the famous Osborn model for turbulent diffusivity kz which uses a fixed mixing efficiency of ŋ=0.17. This motivated us to measure separately kz and ŋ in order to obtain a better understanding of their inter-dependencies. The present work is an experimental study based on set-ups which enable to quantify the mixing in different types of flow. Three of those experiments are held in our lab (LMFA) and consist respectively in a lock-exchange experiment where mixing is generated by the shear at the interface of two opposite gravity currents, a stratified towed grid experiment, and a hydraulic channel experiment where the stratification is injected directly by the grid. This study has been complemented with two international collaborations. The first one, on the Coriolis platform (LEGI) consisted in a stratified towed grid experiment in a rotating tank allowing to broaden our parameter spectrum. The second one is a series of in situ measurements led in collaboration with ISMER in the Saguenay fjord (Canada) aiming at measuring density transects over time in order to quantify the turbulent mixing that participates in the renewal of the fjord's deep water. In all of those configurations, dependencies of mixing efficiency and turbulent diffusivity along with the Froude and the Reynolds numbers are extracted from the time evolution of density profiles. In our results, we were able to quantify the decay of the mixing efficiency with the increase of the Froude number. We also highlighted the sensitivity of turbulent diffusivity on the buoyancy Reynolds number. We used three different experimental setups to show that beyond the so called universal turbulence laws, the flow geometry has a huge impact on the mixing efficiency values. This is especially true in the lock-exchange configuration where the asymptotic value of ŋ=0.25, predicted by statistical physics, can only be reached in a set-up which allows 3D flows. Such investigations are still scarce in the literature. Finally, all the data analysis methods developed for the lab experiments were of great help for the analysis of in situ data and thereby enabled us to consider a real-life environnemental flow

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Zipplies, Daniel. "Effizienzsteigerung des Kunststoffblasformprozesses durch Optimierung des Drucklufteinsatzes." Universitätsverlag Chemnitz, 2020. https://monarch.qucosa.de/id/qucosa%3A70808.

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Die ökologischen und ökonomischen Anforderungen der heutigen Zeit verlangen energieeffiziente Verarbeitungsverfahren. Vor diesem Hintergrund befasst sich diese Arbeit mit dem Kunststoffblasformprozess, der neben dem für die Kunststoffverarbeitung typischen hohen Energiebedarf zusätzlich ein hohes Maß an energieintensiv zu erzeugender Druckluft erfordert. Ausgehend von einer ausführlichen Energiebilanz des Extrusionsblasformprozesses wurde der zur Formgebung (Blasluft) und zur inneren Blasteilkühlung (Spülluft) benötigte Drucklufteinsatz als eine energetische Schwachstelle identifiziert. Zur Reduzierung des erforderlichen Druckluftaufwands bei der Formgebung wird die Prozessrückführung der Blasluft detailliert betrachtet. Weiterhin wird ein Speichersystem vorgestellt, das eine sekundäre Nutzung der bei der inneren Blasteilkühlung kontinuierlich anfallenden druckbehafteten Prozessabluft ermöglicht. Abschließend wird ein Ansatz zum effektiven Drucklufteinsatz bei der inneren Kühlung flaschenförmiger Blasteile aufgezeigt, der durch gezieltes Ausnutzen von für den Wärmeübergang günstiger Strömungsverhältnisse eine Kühlzeitverkürzung sowie eine Reduzierung des Druckluftaufwands verspricht.:1 Einleitung 2 Prozessanalyse des Blasformverfahrens 3 Motivation, Zielstellung und Aufbau der Arbeit 4 Energetische Bilanzierung des Extrusionsblasformverfahrens 5 Reduzierung des Druckluftaufwands bei der Formgebung 6 Sekundärnutzung der zur inneren Blasteilkühlung verwendeten Druckluft 7 Effektive Druckluftnutzung bei der inneren Kühlung flaschenförmiger Blasteile 8 Zusammenfassung und Ausblick
Today's ecological and economic requirements demand energy-efficient processing methods. Against this background, this thesis deals with the plastic blow moulding process, which, in addition to the high energy demand typical for plastics processing, requires a high degree of energy-intensive compressed air. Based on a detailed energy balance of the extrusion blow moulding process, the use of compressed air required for forming (blow air) and for internal cooling of the blowing parts (purge air) was identified as an energetic weak point. In order to reduce the amount of compressed air required for forming, a feedback process used to recycle the blowing air is investigated in detail. Furthermore, a storage system will be presented which allows a secondary use of the pressurized process exhaust air, which is continuously generated during the internal cooling of the blowing part. Finally, an optimization approach for the effective use of compressed air for the internal cooling of bottle-shaped blow-moulded parts is presented, which promises a shortening of the cooling time and a reduction of the compressed air required through the targeted use of favourable flow conditions for heat transfer.:1 Einleitung 2 Prozessanalyse des Blasformverfahrens 3 Motivation, Zielstellung und Aufbau der Arbeit 4 Energetische Bilanzierung des Extrusionsblasformverfahrens 5 Reduzierung des Druckluftaufwands bei der Formgebung 6 Sekundärnutzung der zur inneren Blasteilkühlung verwendeten Druckluft 7 Effektive Druckluftnutzung bei der inneren Kühlung flaschenförmiger Blasteile 8 Zusammenfassung und Ausblick

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