Academic literature on the topic 'Availability coefficient'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Availability coefficient.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Availability coefficient"
1
Groenevelt, P. H., C. D. Grant, and R. S. Murray. "On water availability in saline soils." Soil Research 42, no. 7 (2004): 833. http://dx.doi.org/10.1071/sr03054.
Full textAbstract:
We present a formulation for the effect of the osmotic pressure of the soil solution on the availability of soil water for plant uptake in the extreme case that the reflection coefficient of root-cell walls is always unity. We also present a new equation to fit the water retention curve, which allows for an inflection point and is solidly anchored at both the wet end (saturated water content) and the dry end (water content at 150 m head, the permanent wilting point). By differentiating the fitting-equation one finds the differential water capacity, which is subsequently multiplied by a weighting function to account for the impediment caused by soluble salts. The weighted differential water capacity is then integrated over the entire range of the matric head from zero to infinity. This produces the integral water capacity and constitutes the total amount of water the soil can hold and release to a hypothetical plant that behaves like a perfect osmometer. We illustrate the approach using data found in the literature for a wide range of soil textures. In this paper the lower boundary of water availability in the presence of soluble salts is defined and calculated as would be registered by a perfect osmometer (reflection coefficient of unity). The upper boundary of water availability is found by setting the weighting coefficient at unity at all times, which implies a reflection coefficient of zero, and in turn that the salts in the soil solution have no influence on the availability of water (as would be registered by a tensiometer). The upper and the lower boundaries constitute the envelope within which the actual availability of water to real plants occurs, and implies a variable reflection coefficient plus the occurrence of active plant osmo-regulation. This establishes a framework within which water availability to real plants experiencing real osmo-matric conditions can be evaluated.
2
Baikov, I. R., S. V. Kitaev, and O. V. Smorodova. "Set of indicators for dependability evaluation of gas compression units." Dependability 18, no. 4 (December 5, 2018): 16–21. http://dx.doi.org/10.21683/1729-2646-2018-18-4-16-21.
Full textAbstract:
The paper is dedicated to the improvement of the evaluation methods of one of the most important operating characteristics of gas compression units (GCUs), i.e. dependability, under the conditions of decreasing pipeline utilization rate. Currently, the dependability of units is characterized by a set of parameters based on the identification of the time spent by a unit in certain operational state. The paper presents the primary findings regarding the dependability coefficients of GPA-Ts-18 units, 41 of which are operated in multi-yard compressor stations (CSs) of one of Gazprom’s subsidiaries. The dependability indicators (technical state coefficient, availability coefficient, operational availability coefficient) identified as part of the research are given as well. GCUs were classified into groups depending on the coefficient values. The feasibility of using integral indicators in the analysis of GCU groups’ dependability was examined. It was proposed to use confidence intervals for identification of the integral level of dependability of the operated GCU stock and the ways of maintaining the operability of units under the conditions of decreasing main gas pipeline utilization rate. The Gini index was suggested for the purpose of generalized estimation of GCU groups’ dependability. It is shown that the advantage of the Gini coefficient is that is allows taking into account the ranks of the analyzed features in groups. The graphic interpretation of the findings was executed with a Lorenz curve. The paper implements the sigma rule that characterizes the probability of the actual coefficient value being within the confidence interval, i.e. prediction limits (upper and lower), within which the actual values will fall with a given probability. The confidence intervals were identified by the type of coefficients distribution and a standard deviation, ć. A histogram of an interval range of technical utilization coefficient distribution is given as an example. Testing of the hypothesis of the distribution type at confidence level 0.95 showed that the distribution of coefficients is normal. Using the moment method, the mathematical expectation and mean square deviation for the distribution of the values of each type of dependability indicators were established. Using the sigma rule, all extreme outliers among the GCUs in terms of the level of factor attribute were excluded from the body of input data. All units whose factor attribute value does not fall in the interval were excluded. According to the three sigma rule, 3 and 2 GCUs did not fall in the confidence interval (µ±3σ) in terms of the utilization factor and availability factor respectively. The performed analysis of causes of low availability coefficients of the above GCUs showed that the systems had been long in maintenance. The paper sets forth summary data on the maximum allowable value of the Gini index of dependability coefficients (CTU, CA, COA) depending on the sample size (the complete sample of 41 units and samples with the interval of 1, 2, 3 sigma). In case of higher values of Gini index it is recommended to adopt measures to individual units in order to improve the dependability of the operated GCU stock.
3
HEMINGWAY, R. G., E. R. PARKER, J. J. PARKINS, G. FISHWICK, and N. S. RITCHIE. "Bioavailability assessments of granular calcined magnesites derived from magnesite rocks and of magnesium hydroxide powder in sheep." Journal of Agricultural Science 131, no. 2 (September 1998): 229–35. http://dx.doi.org/10.1017/s0021859698005772.
Full textAbstract:
Granular calcined magnesites originating from Spain, China and Greece and magnesium hydroxide powder were evaluated in a series of balance experiments conducted with wether sheep (c. 42 kg liveweight) given a basal ration of dried grass at Glasgow University Veterinary School between 1989 and 1994. Four Spanish ‘Agma’ products and three Spanish ‘Navarras’ products contained less material (0–104 g/kg)>1000 μm diameter than four Chinese and four Greek materials 178–483 g/kg). The Spanish products had lower (18–45 g/kg) losses on ignition compared with the Chinese and Greek materials (53–112 g/kg). A fifth Greek product contained only 4 g/kg>1000 μm diameter. In three experiments comparing supplementation of the basal diet with 2·0 g Mg as either magnesium hydroxide or as one of the three separate purchases of the commercial calcined magnesite sources, the powdered magnesium hydroxide had the highest mean apparent availability coefficient (0·30) (faecal increase method). The corresponding values were 0·24 (Agma and Navarras), 0·20 (Chinese) and 0·15 (Greek) (pooled s.e. 0·014, d.f. 10). Powdered magnesium hydroxide also had the highest (0·18) mean availability coefficient (urinary increase method) compared with 0·12 (Agma), 0·13 (Navarras), 0·14 (Chinese), 0·10 (Greek) (pooled s.e. 0·005, d.f. 10). In two subsequent experiments, Agma had a superior apparent availability coefficient (0·26) (faecal method) than either the Chinese (0·14) or the Greek materials (0·19). A finer grade of Greek calcined magnesite (0·25) was equivalent to Agma. For the 12 calcined magnesites evaluated in the three main experiments, significant (P<0·05) correlations (r) were found between the magnesium availability coefficient (faecal method) and loss on ignition (−0·65); particle size proportions (<250 μm, 0·59; and >1000 μm, −0·65) and tended towards significance for rumen solubility in 24 μm nylon bags in hay-fed cows over two days (r=0·54, P=0·07) and rate of reaction with citric acid (0·57, P=0·055). No correlations were found with magnesium availability coefficients (urinary increase method). This confirms the limitations of both in vitro predictions and in vivo (faecal) estimates of magnesium availability for different calcined magnesites. The mean magnesium availability coefficient (faeces) of the 17 calcined magnesites was 0·21 (s.d. 0·05). If this were to be confirmed by other observations, it would have implications for the amounts of dietary calcined magnesite required to meet recommended dietary magnesium allowances for ruminants.
4
Basmanov, Vladislav, and Valerii Kholmanskikh. "Features of Forecasting Reliability of 6—10 kV Overhead Electric Lines According to Statistics of Their Failures and Reconditionings." Problems of the Regional Energetics, no. 4(52) (November 2021): 1–12. http://dx.doi.org/10.52254/1857-0070.2021.4-52.01.
Full textAbstract:
This work is aimed at forecasting justification of the failure time of the 6—10 kV overhead electric lines (OEL) during the normalized period in its operation based on comparison with the statistics of failures and reconditionings on the previous intervals with the use of the OEL availability function, statistical availability coefficient, normalized forecasting interval and the accepted values of the availability coefficient on the forecasting interval. To achieve the goal set the OEL is described as an object of a multiple action, its failure and reconditioning flows are accepted as the simplest Poisson, and for the theoretical analysis of the variation character in the availability coefficient, the probability theory methods along with a mass service were used. The most significant result is justification of the use for the forecasting of the OEL failure time of a new convenient exponential expression of its availability function on the normalized period of time being forecasted. Unlike the accepted in the theory of reliability the availability function with two parameters T and Tr.av (average times of work and reconditionings), the proposed expression uses one parameter of distribution (virtual non-failure operating time). The significance of the results obtained consists in that controlling the dynamics of the variation in the statistical coefficient of availability of the OEL on the previous time intervals makes it possible to forecast its failure time during the forthcoming normalized periods of operation.
5
Nakatsu, Kanji. "Limitation of theophylline elimination by reduced oxygen availability in mouse hepatocytes and rat isolated livers." Canadian Journal of Physiology and Pharmacology 63, no. 8 (August 1, 1985): 903–7. http://dx.doi.org/10.1139/y85-149.
Full textAbstract:
The effect of oxygen availability on theophylline metabolism by mouse hepatocytes and rat isolated livers was examined. The elimination of theophylline by mouse hepatocytes and the metabolism of theophylline to dimethyluric acid by isolated, perfused rat livers was seriously impaired when the gas mixture supplied contained less than 28% oxygen. The correlation coefficients relating oxygen supply and the concentration of theophylline remaining in mouse hepatocyte suspensions were −0.74 to −0.84. In the isolated, perfused rat liver experiments, the correlation coefficient relating oxygen availability and dimethyluric acid production was 0.87. These observations are interpreted as supporting the hypothesis that oxygen availability per se is an important factor in determining the rate of theophylline metabolism.
6
Banjarnahor, Astri Rumondang. "Effect of Fleet Availability and Controlling on Delivery Accuracy." JURNAL MANAJEMEN BISNIS 8, no. 1 (February 24, 2021): 112–22. http://dx.doi.org/10.33096/jmb.v8i1.720.
Full textAbstract:
This study aimed to determine the effect of fleet availability and control on the smooth delivery of PT. Cardig Logistics Indonesia. The survey method is used as a way to collect primary data. The population is taken from employees who work in the operational section and get a sample of 30 people. The writer used a descriptive statistical analysis method, multiple linear regression, correlation coefficient, determination coefficient, or determination to test the research hypothesis to conduct this research. The results showed that the availability of the fleet (X1) and controlling (X2) on the smooth delivery (Y) of PT. Cardig Logistics Indonesia has a positive and significant effect. From the research result, the more dominant is the variable of fleet availability.
7
Vinogradova, A. D., and M. A. Demidova. "The Problem of Economic Availability of Anticoagulants in COVID-19 Outpatient Treatment." Medicina 9, no. 4 (2021): 21–30. http://dx.doi.org/10.29234/2308-9113-2021-9-4-21-30.
Full textAbstract:
An assessment of the economic availability of direct oral anticoagulants for COVID-19 outpatient treatment was carried out. For each anticoagulant, the average cost of the package and treatment course were determined, the coefficients of availability in relation to the average wage and the minimum living wage were calculated. Based on the results of the study, an ABC analysis was carried out. The costs of dabigatran, apixaban and rivaroxaban were found to be in category A (high cost) in relation to the minimum living wage. The most accessible of the investigated anticoagulants is apixaban 5 mg in a package of 60 tablets, the coefficient of availability of this drug in relation to the average wage was 21.7, in relation to the living wage – 66.1. The low availability of anticoagulants for the course treatment of COVID-19 in outpatient settings justifies the need for the formation of drug programs for COVID-19 outpatient with at the expense of the federal budget.
8
Kuznetsov, N. Yu. "Computing the availability coefficient of a repairable system by the analytical-statistical method." Cybernetics 21, no. 5 (1986): 682–90. http://dx.doi.org/10.1007/bf01074727.
Full text
9
Chu, Kunmo, Sung-Chul Lee, Sangeui Lee, Dongearn Kim, Changyoul Moon, and Sung-Hoon Park. "Smart conducting polymer composites having zero temperature coefficient of resistance." Nanoscale 7, no. 2 (2015): 471–78. http://dx.doi.org/10.1039/c4nr04489d.
Full textAbstract:
We developed a hybrid conducting composite having zero temperature coefficient of resistance. A major feature of the composite is the availability of heating units that show no change in resistance, and this study is one of the first of its kind to attempt to realize zero-TCR polymer-based composites.
10
Колесникова, T. Kolesnikova, Пышный, and V. Pyshnyy. "ANALYSIS OF AVAILABILITY OF ROUTING PASSENGER TRANSPORT NETWORKS IN DUSHANBE." Alternative energy sources in the transport-technological complex: problems and prospects of rational use of 3, no. 1 (March 16, 2016): 417–21. http://dx.doi.org/10.12737/17915.
Full textAbstract:
The article touched upon one aspect of actual problems concerning of the evaluating of passenger transport public network performance, namely the availability of the route network. In particular, the questions of the calculation of the public network density, range approach to stopping points, distances between stopping points and route coefficient, are touched
Dissertations / Theses on the topic "Availability coefficient"
1
Волотка, В. С. "Mathematical Modeling for Reliability of Infocommunication Networks." Thesis, 2014. http://openarchive.nure.ua/handle/document/2186.
Full textAbstract:
A model of information and communication system is presented in the form of 4 main states: serviceable and unserviceable, each of them may be both in operative and standby modes. The main object of analysis is failure and appropriate parameters: mean time between failures, availability coefficient, reliability probability, probability of survivability, an average total risk of failure probability.
Books on the topic "Availability coefficient"
1
J, Van Wie Bernard, and National Institute of Standards and Technology (U.S.), eds. Evaluation of data availability and quality for interaction second virial coefficients of use to the gas industry. Gaithersburg, MD: U.S. Dept. of Commerce, National Bureau of Standards, 1988.
Find full textBook chapters on the topic "Availability coefficient"
1
Nair, Kodoth Prabhakaran. "Quantifying the Effective Diffusion Coefficient (or Buffer Power) of Soils and Testing Its Effect on Soil Nutrient Bio Availability." In Thermodynamics of Soil Nutrient Bioavailability, 17–39. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-76817-1_4.
Full text
2
Odongtoo, Godfrey, Denis Ssebuggwawo, and Peter Okidi Lating. "Water Resource Management Frameworks in Water-Related Adaptation to Climate Change." In African Handbook of Climate Change Adaptation, 1–14. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-42091-8_24-1.
Full textAbstract:
AbstractThis chapter addresses the use of partial least squares–structural equation modeling (PLS-SEM) to determine the requirements for an effective development of water resource management frameworks. The authors developed a quantitative approach using Smart-PLS version 3 to reveal the views of different experts based on their experiences in water-related adaptation to climate change in the Lake Victoria Basin (LVB) in Uganda. A sample size of 152 was computed from a population size of 245 across the districts of Buikwe, Jinja, Mukono, Kampala, and Wakiso. The chapter aimed to determine the relationship among the availability of legal, regulatory, and administrative frameworks, public water investment, price and demand management, information requirements, coordination structures, and analytical frameworks and how they influence the development of water resource management frameworks. The findings revealed that the availability of legal, regulatory, and administrative frameworks, public water investment, price and demand management, information requirements, and coordination structures had significant and positive effects on the development of water resource management frameworks. Public water investment had the highest path coefficient (β = 0.387 and p = 0.000), thus indicating that it has the greatest influence on the development of water resource management frameworks. The R2 value of the model was 0.714, which means that the five exogenous latent constructs collectively explained 71.4% of the variance in the development. The chapter suggests putting special emphasis on public water investment to achieve an effective development of water resource management frameworks. These findings can support the practitioners and decision makers engaged in water-related adaptation to climate change within the LVB and beyond.
3
Odongtoo, Godfrey, Denis Ssebuggwawo, and Peter Okidi Lating. "Water Resource Management Frameworks in Water-Related Adaptation to Climate Change." In African Handbook of Climate Change Adaptation, 993–1006. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-45106-6_24.
Full textAbstract:
AbstractThis chapter addresses the use of partial least squares–structural equation modeling (PLS-SEM) to determine the requirements for an effective development of water resource management frameworks. The authors developed a quantitative approach using Smart-PLS version 3 to reveal the views of different experts based on their experiences in water-related adaptation to climate change in the Lake Victoria Basin (LVB) in Uganda. A sample size of 152 was computed from a population size of 245 across the districts of Buikwe, Jinja, Mukono, Kampala, and Wakiso. The chapter aimed to determine the relationship among the availability of legal, regulatory, and administrative frameworks, public water investment, price and demand management, information requirements, coordination structures, and analytical frameworks and how they influence the development of water resource management frameworks. The findings revealed that the availability of legal, regulatory, and administrative frameworks, public water investment, price and demand management, information requirements, and coordination structures had significant and positive effects on the development of water resource management frameworks. Public water investment had the highest path coefficient (β = 0.387 and p = 0.000), thus indicating that it has the greatest influence on the development of water resource management frameworks. The R2 value of the model was 0.714, which means that the five exogenous latent constructs collectively explained 71.4% of the variance in the development. The chapter suggests putting special emphasis on public water investment to achieve an effective development of water resource management frameworks. These findings can support the practitioners and decision makers engaged in water-related adaptation to climate change within the LVB and beyond.
4
Amoo, Oseni Taiwo, Hammed Olabode Ojugbele, Abdultaofeek Abayomi, and Pushpendra Kumar Singh. "Hydrological Dynamics Assessment of Basin Upstream–Downstream Linkages Under Seasonal Climate Variability." In African Handbook of Climate Change Adaptation, 2005–24. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-45106-6_116.
Full textAbstract:
AbstractThe impacts of climate change are already being felt, not only in terms of increase in temperature but also in respect of inadequate water availability. The Mkomazi River Basins (MRB) of the KwaZulu-Natal region, South Africa serves as major source of water and thus a mainstay of livelihood for millions of people living downstream. It is in this context that the study investigates water flows abstraction from headwaters to floodplains and how the water resources are been impacted by seasonal climate variability. Artificial Neural Network (ANN) pattern classifier was utilized for the seasonal classification and subsequence hydrological flow regime prediction between the upstream–downstream anomalies. The ANN input hydroclimatic data analysis results covering the period 2008–2015 provides a likelihood forecast of high, near-median, or low streamflow. The results show that monthly mean water yield range is 28.6–36.0 m3/s over the Basin with a coefficient of correlation (CC) values of 0.75 at the validation stage. The yearly flow regime exhibits considerable changes with different magnitudes and patterns of increase and decrease in the climatic variables. No doubt, added activities and processes such as land-use change and managerial policies in upstream areas affect the spatial and temporal distribution of available water resources to downstream regions. The study has evolved an artificial neuron system thinking from conjunctive streamflow prediction toward sustainable water allocation planning for medium- and long-term purposes.
5
Mbwambo, Naza A., and Emma T. Liwenga. "Cassava as an adaptation crop to climate variability and change in coastal areas of Tanzania: a case of the Mkuranga district." In Climate change impacts and sustainability: ecosystems of Tanzania, 23–33. Wallingford: CABI, 2020. http://dx.doi.org/10.1079/9781789242966.0023.
Full textAbstract:
Abstract This study was carried out in two villages, Kizapala and Kazole, of the Mkuranga District, in the Coast Region of Tanzania. The objective of the study was to establish the role of cassava as an adaptation crop to the changing climate and household food security. Primary data were obtained using household questionnaires and different participatory rural appraisal (PRA) techniques which included focus group discussions (FGDs), key informants and expert meetings. Secondary data were collected through a literature review, whereas temperature and rainfall data from 1984 to 2014 was obtained from the Tanzania Meteorological Agency (TMA). In each village, a sample size of 10% of all households was interviewed. Findings showed that 96% of respondents from Kazole village and 90% from Kizapala linked climate change with major climatic extreme events such as prolonged droughts and occasional abnormal floods. Analysis of temperature data for the last 30 years (1984-2014) revealed that temperature had significantly risen by a correlation coefficient of R2 = 0.4936 for maximum and R2 = 0.777 for minimum temperature. The field survey results closely correlated with findings from the analysis of TMA rainfall and temperature data. Findings revealed a decline in crop production which resulted in food shortages and livelihood insecurity in the study villages. The respondents in both villages consider cassava as a crop that is least affected by climate and environmental extremes, thus serves to ensure food availability and security in their households. As a result, growing cassava should be considered as an adaptation strategy to climate change and variability now and in the future. Improving cassava production, processing, marketing and value chain infrastructures is, therefore, crucial for enhancing sustainable adaptation in the district.
6
Santos Sánchez, Antonio, Maria João Regufe, Ana Mafalda Ribeiro, and Idelfonso B.R. Nogueira. "Sustainable Energy Management of Institutional Buildings through Load Prediction Models: Review and Case Study." In AI and Learning Systems - Industrial Applications and Future Directions. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.93425.
Full textAbstract:
Institutional buildings need smart techniques to predict the energy consumption in a smart grids’ framework. Here, the importance of dynamic load forecasting as a tool to support the decision in smart grids is addressed. In addition, it is reviewed the energy consumption patterns of institutional buildings and the state-of-the-art of load forecast modeling using artificial neural networks. The discussion is supported by historical data from energy consumption in a university building. These data are used to develop a reliable model for the prediction of the electric load in a campus. A neural network model was developed, which can forecast the load with an average error of 6.5%, and this model can also be used as a decision tool to assess the convenience of supplying this load with a set of renewable energy sources. Statistical data that measure the availability of the local renewable sources can be compared with a load model in order to assess how well these energy sources match the energy needs of buildings. This novel application of load models was applied to the campus where a good correlation (Pearson coefficient of 0.803) was found between energy demand and the availability of the solar resource in the campus.
7
Rayapandi, Thiraviam, and Suresh P. "An Overview of Welding Methods for Advanced Materials." In Advanced Manufacturing Techniques for Engineering and Engineered Materials, 198–225. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-7998-9574-9.ch012.
Full textAbstract:
Recent developments in the engineering industry require joining of like and unlike materials with different properties such as melting point, coefficient of thermal conductivity, solubility, difference in electrochemistry, etc. as part of machines, tools, and more specific applications. Materials including those similar and dissimilar in nature are successfully joined by fusion and solid-state welding processes. In accordance with ASME Sec IX and AWS D1.1 codes and API 1104 standard, welding procedures specifications (WPS) through procedure qualifications (PQR) are required prior to commencing any fabrication work pertaining to pressure vessels, piping and pipeline, storage tanks, offshore platform structural parts, and so on. A specific welding process must be chosen based on the design of the component, the material, thickness, production, availability of equipment, people, and other factors. Weldment testing, including destructive and non-destructive examinations, are crucial during procedure qualification, welder qualification, and the production welding process.
8
Glaveli, Νiki. "“My Regular Pharmacy”." In Interdisciplinary Perspectives on Operations Management and Service Evaluation, 177–91. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-5442-5.ch009.
Full textAbstract:
The objectives of this chapter are (1) to develop an instrument that incorporates the core attributes of evaluative criteria that are used by patients/customers in selecting and repeatedly visiting a community pharmacy, (2) to analyze the proposed attributes in order to put forward valid dimensions of evaluative criteria, and (3) to assess the reliability of this instrument. The selection criteria incorporated in the final list were selected based on an extensive literature review and on experts' and customers' opinions. To collect the data, a survey was conducted in the area of Macedonia, Greece. In total, 223 questionnaires were collected. Confirmatory factor analyses revealed a four-factor structure of the proposed instrument namely: price, availability of products, staff competence, and pharmaceutical care services. Moreover, reliability was assessed through Cronbach's alpha coefficient and average variance extracted. The current study outcomes can guide pharmacists' strategic actions in boosting customer patronage behavior in the highly competitive pharmaceutical sector.
9
Chand Verma, Kuldeep, and Manpreet Singh. "Processing Techniques with Heating Conditions for Multiferroic Systems of BiFeO3, BaTiO3, PbTiO3, CaTiO3 Thin Films." In Thermoelectricity [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.101122.
Full textAbstract:
In this chapter, we have report a list of synthesis methods (including both synthesis steps & heating conditions) used for thin film fabrication of perovskite ABO3 (BiFeO3, BaTiO3, PbTiO3 and CaTiO3) based multiferroics (in both single-phase and composite materials). The processing of high quality multiferroic thin film have some features like epitaxial strain, physical phenomenon at atomic-level, interfacial coupling parameters to enhance device performance. Since these multiferroic thin films have ME properties such as electrical (dielectric, magnetoelectric coefficient & MC) and magnetic (ferromagnetic, magnetic susceptibility etc.) are heat sensitive, i.e. ME response at low as well as higher temperature might to enhance the device performance respect with long range ordering. The magnetoelectric coupling between ferromagnetism and ferroelectricity in multiferroic becomes suitable in the application of spintronics, memory and logic devices, and microelectronic memory or piezoelectric devices. In comparison with bulk multiferroic, the fabrication of multiferroic thin film with different structural geometries on substrate has reducible clamping effect. A brief procedure for multiferroic thin film fabrication in terms of their thermal conditions (temperature for film processing and annealing for crystallization) are described. Each synthesis methods have its own characteristic phenomenon in terms of film thickness, defects formation, crack free film, density, chip size, easier steps and availability etc. been described. A brief study towards phase structure and ME coupling for each multiferroic system of BiFeO3, BaTiO3, PbTiO3 and CaTiO3 is shown.
10
"Basic Principles for Substantiation of Working Pair Choice." In Technology Development for Adsorptive Heat Energy Converters, 25–42. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-4432-7.ch002.
Full textAbstract:
The chapter is devoted to basic principles for substantiation of working pair choice. Principles for substantiation for selection of adsorbate and adsorbent are considered. The main requirements to adsorbate are formulated as follows: low cost, easy of obtaining, small molecular size to facilitate the adsorption effect; high latent heat of evaporation and small volume in liquid state; high thermal conductivity; low viscosity, thermal stability with adsorbent in the operating temperature range; chemical stability in the working temperature range; non-toxicity for animals and human, non-aggressiveness and incombustibility; low pressure saturation (slightly above atmospheric pressure) at normal operating temperature; the absence of environmental problems. Water is shown to conform to these requirements. The crucial requirements to adsorbent are the ability to adsorb large amounts of adsorbate when cooled to environment temperature and give a high cooling effect; high values of maximal adsorption; desorption of the major portion of adsorbate (ideally all) when heated by an accessible source of heat; low heat capacity; good heat conductivity, short cycle time; no deterioration and loss of adsorption capacity over time or use; non-toxicity, non-aggressiveness; chemical physical compatibility with the selected adsorbate; low cost and wide availability. Properties of various types of adsorbents were compared. Composites ‘salt inside porous matrix' are shown to be promising media for heat storage and transformation. Characteristics of thermodynamic cycles of heat conversion were analysed. The ways to improve the coefficient of performance were analysed and shown to be affected by a proper choice of an adsorbent.
Conference papers on the topic "Availability coefficient"
1
Tootaghaj, Diman Zad, Farshid Farhat, Mohammad-Reza Pakravan, and Mohammad-Reza Aref. "Risk of attack coefficient effect on availability of Ad-hoc networks." In 2011 IEEE Consumer Communications and Networking Conference (CCNC). IEEE, 2011. http://dx.doi.org/10.1109/ccnc.2011.5766445.
Full text
2
Shapiro, J. D., and M. E. Taslim. "Experimental Heat Transfer and Discharge Coefficients for Single Confined Jet Impingement Normal to a Surface at Close Distances." In ASME Turbo Expo 2008: Power for Land, Sea, and Air. ASMEDC, 2008. http://dx.doi.org/10.1115/gt2008-50080.
Full textAbstract:
Heat transfer and flow discharge coefficients for confined jet impingement are being investigated for a single round jet impinging normal to a target surface less than one hole diameter from the jet origin. A search of open literature resulted in the availability of no discharge coefficient information, and limited heat transfer information, especially for the configuration of a confined jet in close surface impingement. The experiment has been conducted for a developing jet and utilizes liquid crystal thermography for heat transfer measurements. Nusselt numbers were obtained for jet Reynolds numbers between 15000 and 30000 with a gap to hole diameter ratio of 0.3 to 3. Discharge coefficient data were obtained for jet Reynolds numbers between 11000 and 59000, with a gap to hole diameter ratio of 0.2 to infinity. The heat transfer data obtained shows a secondary Nusselt number peak and similar trends to those seen in other close surface impingement studies. The data also show a crossover of Nusselt number at increasing radial distance from the jet stagnation point with increasing gap size which could be indicative of ambient air entrainment. The discharge coefficient data obtained show a decrease in discharge coefficient for a decrease in gap size. At constant pressure ratio conditions a large decrease in discharge coefficient is observed between pressure ratios of 1.05 and 1.11. The results of this study are applicable to many industrial applications. However, a discussion of close surface impingements applicability to gas turbines has been included, as well as a comparison of the experimental and numerical results.
3
Macoretta, Giuseppe, Bernardo Disma Monelli, Paolo Neri, Federico Bucciarelli, Damaso Checcacci, and Enrico Giusti. "Full-Scale Vibration Testing of Nozzle Guide Vanes." In ASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/gt2021-59356.
Full textAbstract:
Abstract An increasing number of turboexpanders are equipped with Nozzle Guide Vane (NGV) as the first stator stage. By varying the throat area of the first stator vane the NGV enables an additional control methodology to the line-up power output allowing higher operational flexibility and higher efficiency at partial load and partial speed. The design of this component might become critical for enabling high expander availability considering its exposure to high temperature, thermal loading, and fluid induced vibrations. This is especially true also considering that the vibration frequencies of this sub-assembly are influenced by internal clearances and by the value of the friction coefficient, which leaves a relevant margin of error when using numerical methods (such as FEM) for predicting the actual structural behavior of this component. In this paper, the design of a full-scale test bench for the determination of both friction coefficients and modal behavior of a nozzle guide vane geometry is described. The bench enables us to simulate the pre-load due to aerodynamic forces on the NGV airfoil simulating the actual working conditions of bushes and bearings.
4
Riofrío, José A., Chad Woodrow, and Jennifer Mallory. "Modeling, Simulation and Experimental Validation of a Servo-Pneumatic Control System With Off-the-Shelf Components." In ASME/BATH 2015 Symposium on Fluid Power and Motion Control. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/fpmc2015-9519.
Full textAbstract:
Industrial applications of servo-pneumatics have seen rapid growth in the past few decades due to the recent availability of sophisticated high-speed proportional valves, particularly in the five-ported, “four-way”, center-closed, bidirectional configuration. This paper offers a simple and effective dynamic model and simulation of a complete servo-pneumatic system using off-the-shelf valves and standard PID control, which remains the industry standard. The model combines piston dynamics, thermodynamics of the working fluid (air), mass-flow inlet and exhaust dynamics through the valve, valve dynamics, and a control system. The simulation results are experimentally validated through various closed-loop position control arrangements. The simulation model parameters are for the most part easily measurable, except for the damping coefficient of the moving mass and the discharge coefficient of the valve. A simple approach to effectively estimating each of these is shown. An experimental setup was built using off-the-shelf components: Bimba standard round-line air cylinders, Enfield Technologies high-speed proportional valves, Balluff non-contact magnetostrictive displacement transducer, and pressure sensors from Omegadyne. It is intended that this work can be easily recreated by industrial and academic designers who are considering servo-pneumatic systems.
5
Cherkashyna, A. V., and E. F. Sotchenko. "Dry matter yield of forage corn in the late milk stage of development depending on the planting dates in the steppe zone of the Crimea." In РАЦИОНАЛЬНОЕ ИСПОЛЬЗОВАНИЕ ПРИРОДНЫХ РЕСУРСОВ В АГРОЦЕНОЗАХ. Federal State Budget Scientific Institution “Research Institute of Agriculture of Crimea”, 2020. http://dx.doi.org/10.33952/2542-0720-15.05.2020.36.
Full textAbstract:
Dry matter yield is an objective indicator of assessing the productivity of corn hybrids grown for silage and green fodder. The aim of the work was to identify optimal planting dates to obtain maximum yield of dry matter at the late milk stage of development for hybrids of corn depending on groups of maturity under rain-fed conditions of the Crimean steppe zone. The sowing dates of the field experiment were on April 5th, 15th, and 25th. We studied hybrids of corn of different groups of maturity. Soil – chernozems southern low-humus. Meteorological conditions in 2016 were characterized by increased moisture availability (Selyaninov Hydrothermal Coefficient (HTC) 1.46). In 2017, severe drought was noted (HTC 0.34). Moisture availability was insufficient in 2018 and 2019 (HTC 0.79 and 0.78, respectively). In 2016-2019, the best planting date for hybrid ‘Nur’ was April 15th; the dry matter yield in the late milk stage was 6.69 t/ha. For the medium- early hybrid ‘Mashuk 220 MV’, the best sowing dates were April 15th and 25th; dry matter yield was 5.95 and 5.78 t/ha, respectively. Hybrid ‘Mashuk 355 MV’ demonstrated higher dry matter yield on April 5th and 15th (7.12 and 6.99 t/ha). However, the planting date of April 25th led to significant yield decreased (to 6.1 t/ha).
6
Reid, Don R., and Jerry Taborek. "Selection Criteria for Plain and Segmented Finned Tubes for Heat Recovery Systems." In ASME 1993 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1993. http://dx.doi.org/10.1115/93-gt-131.
Full textAbstract:
Heat recovery heat exchangers with gas as one of the streams depend on the use of finned tubes to compensate for the inherently low gas heat transfer coefficient. Standard frequency welded “plain” fins were generally used in the past, until the high frequency resistance welding technology permitted a cost-effective manufacture of “segmented” fins. The main advantage of this fin design (Fig. 1) is that it permits higher heat flux and hence smaller, lighter weight units for most operating conditions. While the criteria which dictate optimum design, such as compactness, weight and cost per unit area favor the segmented fin design, a few other considerations such as fouling, ease of cleaning and availability of dependable design methods have to be considered. This paper analyzes the performance parameters which affect the selection of either fin type.
7
Sapronov, Dmitry, Michael Mezencev, Telman Karimbaev, Sergey Reznik, and Pavel Prosuntsov. "Complex Design Method of Ceramic Blades and Metal Disk Connection." In ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gt2019-90875.
Full textAbstract:
Abstract This paper presents a complex approach to designing ceramic blades dovetail joints. Two ceramic materials were considered: diamond reinforced silicon carbide and hot pressed silicon nitride (only in contact testing). The model blades were made from diamond reinforced silicon carbide due to its availability and mature technology. Part 1 describes the models of mechanical and thermal contact and contains experimental data on contact strength and thermal contact conductance. Part 2 investigates the effect of stress concentration and scale factor on the fracture of ceramic test pieces. Part 3 proposes a theoretical-experimental method to estimate friction coefficient in a dovetail joint. We also investigated the character of the ceramic blades fracture during the rotor spin-up. Part 4 deals with automating the design process of the ceramic blades dovetail joints using experimental data.
8
Koring, Reinhard. "Industrial Application of Research Results of Packings on Safety Relevant Valves in Nuclear Power Plants." In ASME 2006 Pressure Vessels and Piping/ICPVT-11 Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/pvp2006-icpvt-11-93700.
Full textAbstract:
In a NPP approximately 380 safety relevant valves are installed. The main requirements are the safety and operational availability as well as a adequate leak tightness of the sealings and stem packings. Based upon the research results of the MPA-Stuttgart, Germany on packing features specific procedures for handling, assembly and maintenance of packings and analytical inputs for the design calculation have been developed. Depending on the valve size, especially on the stem diameter, the packing influences the necessary stem force for the closing and opening function due to the amount of friction force. The complying equations of the valve calculation guideline were derived from the research results and rely on covering material characteristics of the approved packing rings such as friction coefficient and the vertical/horizontal force transfer factor of the stressing force. The industrial application often requires a more detailed calculation and handling of the actually installed packing configurations especially if existing valves are considered for redesign measures and recalculation. Therefore additionally mock-up tests of existing packing configurations have been performed in cooperation with the packing manufacturer in order to get very specific material coefficients as input data for the calculations. This paper presents the application of research results to design calculation of safety relevant valves as well as the development of procedures for the packing assembly and maintenance.
9
Sourbron, Maarten G., and Nesrin Ozalp. "Determination of Heat Transfer Characteristics of Solar Thermal Collectors as Heat Source for a Residential Heat Pump." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-51461.
Full textAbstract:
One of the best ways of making efficient use of energy in residential units is to use heat pump. Heat pump performance can be further enhanced by integrating a solar thermal unit to provide hot water and subsidize space heating. This paper presents numerically examined energy feasibility study of a solar driven heat pump system for a low energy residence, where a flat plate solar collector served as the sole low temperature heat source. A parametric study on the ambient-to-solar fluid heat transfer coefficient has been conducted to determine the required solar collector heat transfer characteristics in this system. Solar collector area and storage tank volume were varied to investigate their impact on the system performance. A new performance indicator availability was defined to assess the contribution of the solar collector as low temperature energy source of the heat pump. Results showed that the use of a solar collector as low temperature heat source was feasible if its heat transfer rate (UA-value) was 200 W/K or higher. Achievement of this value with a realistic solar collector area (A-value) required an increase of the overall ambient-to-solar fluid heat transfer coefficient (U-value) with a factor of 6 to 8 compared to the base case with only natural convection heat exchange between solar collector cover and ambient.
10
Xing, Chang, Penghua Qiu, Li Liu, Wenkai Shen, Yajin Lyu, Zhuo Zhang, Jingyi Sun, Shaohua Wu, and Yukun Qin. "Effects of Equivalence Ratio on the Off-Design Combustion Performance of Adjustable Fuel Feeding Combustor for a Micro-Gas Turbine." In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-63885.
Full textAbstract:
To improve off-design operation performance of micro-gas turbine, we proposed an adjustable fuel feeding combustor (AFFC), and it employed the lean premixed swirling combustion technology and the adjustable fuel feeding method (AFFM). The AFFM was achieved by switching the various working groups of main fuel tube, and represented by its unique characteristic number (U). To verify the availability of adopted models, the AFFC combustion performance was investigated numerically at different equivalence ratios (ϕ) in ANSYS CFX. The results indicate that NO emission has various trends with the rising U under different ϕ due to the coupling influence of fuel flow and jet velocity in each working main fuel tube. Although the AFFM has almost no effect on the distribution of outlet temperature and the length of primary recirculation zone, the maximum and non-uniform coefficient of outlet temperature increase with the rising U.
Reports on the topic "Availability coefficient"
1
Van Wie, Bernard J. Evaluation of data availability and quality for interaction second virial coefficients of use to the gas industry. Gaithersburg, MD: National Bureau of Standards, 1988. http://dx.doi.org/10.6028/nbs.tn.1249.
Full text