Dissertations / Theses on the topic 'Heat balance'
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Herrero, Miriam Leire. "Heat Balance of a historical church - Solar Heat Gain." Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-17152.
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Galarraga, Maider. "Heat balance of a historical church- transmission losses." Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-17137.
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The structure of old monumental churches differs a lot from contemporary buildings. The structural materials were wood, brick and stone. In order to construct high buildings with huge spans, thick massive walls and many massive columns were needed. Originally these buildings had no heating and for centuries the outdoor temperature determined the indoor climate. As churches are considered historical heritage buildings their renovation should be thoroughly studied. In this thesis the transmission losses of Hamrånge church will be analysed. Hence, the transmission trough walls and windows as well as the heat buffering of materials will be examined. In addition, the effect of possible reformation measurements will be concluded. Finally, this project belongs to a complete study of the church, were not only transmission losses are considered but also air infiltration losses and solar heat gain. That way, a comparison between them will be carried out in order to contribute to attain the objective of the project: possible restoration for church heating system with respect to preservation, energy requirements, thermal comfort and aesthetics.Church project
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Gannon, Maureen Aine. "The energy balance of pigs outdoors." Thesis, University of Nottingham, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308769.
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Arístegui, Jesús Jaime. "Heat balance of a historical church : Air infiltration losses." Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-17150.
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James, Kelley J. "Impact of Heat Exposure on Postural Balance of Firefighters." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1397235487.
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Guastella, L. A.-M. "The sea surface heat balance in the Benguela upwelling region." Master's thesis, University of Cape Town, 1987. http://hdl.handle.net/11427/22447.
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Bibliography: pages 191-202.The surface heat balance of the Benguela upwelling area on the west coast of southern Africa is analysed. Measurements of the components of the heat balance were made in the St Helena Bay area from 14-21 October 1986. Additional long-term data was obtained from Alexander Bay and Cape Town. An average net heat gain of 227 W.m⁻² was received over the eight days of the field study. The presence of cold water determined that latent heat loss by the sea surface was small, while the sensible heat flux represented a small gain by the sea. These two turbulent heat fluxes are roughly equal and opposite and therefore approximately cancel each other. Use of a model, assuming idealised conditions, indicated that most turbulent heat exchange between the air and takes place in the nearshore region where air-sea contrasts are greatest. The net radiation was found to provide a good estimate of the total heat balance, thus the major contributing term to a high heat balance over the Benguela area is the input solar radiation. Minimal synoptic variation in the heat balance during the eight-day field programme was observed, but additional global radiation data analysed revealed that synoptic variations over the 3-6 day period are in fact more significant than the longer term seasonal variations. Both synoptic and seasonal variations in the heat balance are greater in the south than in the north. The high heat flux into the sea surface is capable of increasing the temperature of the upwelled water at a fairly rapid rate. During summer the heat exchange is capable of increasing the temperature of the upper 10 m mixed layer by as much as 0.65°C over one day. This input heat is used to realise the high biological potential of the upwelled waters.
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Knapke, Robert. "High-Order Unsteady Heat Transfer with the Harmonic Balance Method." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1427962937.
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Silva, Ana Margarida Barradinhas da. "Heat recovery from wastewater: numerical modelling of sewer systems." Master's thesis, Faculdade de Ciências e Tecnologia, 2012. http://hdl.handle.net/10362/8473.
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Dissertação para obtenção do Grau de Mestre em
Engenharia do Ambiente, perfil Engenharia SanitáriaThis thesis was carried as a collaboration of Delft University of Technology (TU Delft) and the companies Waternet and KWR. The main project aims to study the possibility of thermal energy recovery from wastewater, reducing the carbon dioxide (CO2) emissions linked to the energy sector. The present work is based on a previous computational model that was developed to simulate heat recovery from wastewater for constant flow rate and temperature of water. The first goal is to simulate a wastewater discharge. In order to achieve this, a Gaussian function was added to the boundary conditions for water flow rate and water temperature. As a second goal, this work aims to assess the significance of the terms present in the water heat balance and air heat balance equations. Binary coefficients were added in each term of both equations and then all the combinations were computed. The unsteady situation successfully simulated a main discharge and numerical predictions for water temperature and flow rate are presented. The deviations associated with the modified cases for the two equations suggest that the heat flux pipe to water (!!") and heat flux pipe to air (!!") terms are crucial for water and air heat balance predictions,respectively. In order to smooth extra oscillations, the time step (dt) was reduced and a smaller relative size of oscillations was obtained. This work concludes with a section of future developments in order to improve the results obtained. Despite of the fact that the current state of these routines does not allow us to accurately assess heat exchanges in pipes, promising results were obtained, proving that numerical modelling of heat recovery will contribute greatly to the development of the main project.
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Argyn, Aidar. "Material And Heat Balance Calculations Of Eti-bakir Plant By Computer." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/2/12609734/index.pdf.
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In this study the data taken from Outokumpu type Flash smelter of Eti-Bakir Plant (Samsun, Turkey) was used to write a computer program in Visual Basic with interface to Excel. Flash smelting is the pyrometallurgical process for smelting metal sulfide concentrates, used in Eti-Bakir plant. In this plant, copper flash smelting consists of blowing fine, dried copper sulfide concentrate mixtures, silica flux, lignite with air into the furnace and natural gas as main fuel. The molten matte is the principal product of the furnace and slag contains 0.5-2% Cu. It is sent to a slag treatment (flotation) process for Cu recovery. This flash furnace off-gas contains from 8-12 volume % SO2 which is fixed as H2SO4. Written program was used to optimize the consumption of oxygen enriched air, fuel and lignite in this Flash Smelter by making material and heat balance of the plant.
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Kim, Minsoo. "Protein Quality Control, Redox Balance and Heat Stress Tolerance in Arabidopsis." Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/217060.
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The Arabidopsis HSP101 protein belongs to the Hsp100/ClpB family of AAA+ proteins (ATPases Associated with various cellular Activities). This family of proteins, in collaboration with the Hsp70 chaperone system, has the remarkable ability to solubilize protein aggregates and refold proteins back to their native forms. Thus, their chaperone activity is necessary for acquired thermotolerance in organisms as diverse as bacteria and plants. My dissertation project focused on understanding the mechanism of HSP101 action using Arabidopsis thaliana as a model system. The first approach used genetics to screen for suppressors of a specific missense mutant allele of HSP101, hot1-4, in order to find interacting cofactor proteins or key substrates of HSP101, or other processes involved in thermotolerance. Four extragenic suppressors that can overcome the heat-hypersensitive phenotype caused by the hot1-4 mutation were isolated and one of them (shot1) was identified as a mutation in a mitochondrion-targeted protein. Although shot1 mutations do not directly interfere with HSP101 function, they reveal independent mechanisms required for thermotolerance, which involve reduced oxidative stress. The second approach used to investigate HSP101 function was to affinity-purify HSP101 and identify associated proteins. For this purpose, transgenic Arabidopsis plants were generated expressing affinity-tagged wild-type and mutant variants of HSP101. As predicted, cytosolic Hsp70s were identified as an interacting partner of HSP101. Surprisingly, 26S proteasome regulatory subunits were also identified, suggesting a possible link between the protein degradation and reactivation pathways. Further experiments were also undertaken to define the importance of different domains of HSP101, as well as the localization of HSP101. Transgenic Arabidopsis plants expressing N- or C-terminally truncated HSP101 indicate that the N-terminal domain of HSP101 is required for full activity in protecting plants from heat stress. However, in contrast to the yeast ortholog, Hsp104, the C-terminal extension of HSP101 was found to be completely dispensable for thermotolerance of Arabidopsis. Additional transgenic plants expressing an HSP101-GFP were also characterized. Initial microscopic analysis confirms nuclear/cytoplasmic localization as has been reported previously for yeast Hsp104. However, the dynamics of subcellular redistribution upon heat stress need to be further investigated to fully understand the potential significance of the observed localization.
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Norikane, Joey Hajime 1963. "An evaluation of the heat balance method for direct transpiration measurement." Thesis, The University of Arizona, 1995. http://hdl.handle.net/10150/291730.
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The measurement of sap flow has been sought after for many years. Various methods have been devised to accomplish this task, one of which is the heat balance method. This method is non-invasive and accurate, but its simplifying assumptions were questionable and needed to be critically examined. This study evaluated the heat balance method and sap flow gauges. The method yielded satisfactory results when compared to the calibration system. The satisfactory results were over a limited range, which exemplified the necessity for the gauges to be calibrated. The heat balance method's simplified heat transfer analysis does not reflect the complexity of the physical situation. Sap flow gauge improvements were suggested.
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Wallace, Scott J. "Diesel Engine Energy Balance Study Operating on Diesel and Biodiesel Fuels." Ohio University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1212586902.
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Kim, S. B. "Northwest Pacific heat balance analysed using in-situ, model and satellite data." Thesis, University College London (University of London), 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431297.
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Boyes, Haydn. "Sensitivity analysis of the secondary heat balance at Koeberg Nuclear Power Station." Master's thesis, Faculty of Engineering and the Built Environment, 2021. http://hdl.handle.net/11427/33686.
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At Koeberg Nuclear Power Station, the reactor thermal power limit is one of the most important quantities specified in the operating licence, which is issued to Eskom by the National Nuclear Regulator (NNR). The reactor thermal power is measured using different methodologies, with the most important being the Secondary Heat Balance (SHB) test which has been programmed within the central Koeberg computer and data processing system (KIT). Improved accuracy in the SHB will result in a more accurate representation of the thermal power generated in the core. The input variables have a significant role to play in determining the accuracy of the measured power. The main aim of this thesis is to evaluate the sensitivity of the SHB to the changes in all input variables that are important in the determination of the reactor power. The guidance provided by the Electric Power Research institute (EPRI) is used to determine the sensitivity. To aid with the analysis, the SHB test was duplicated using alternate software. Microsoft Excel VBA and Python were used. This allowed the inputs to be altered so that the sensitivity can be determined. The new inputs included the uncertainties and errors of the instrumentation and measurement systems. The results of these alternate programmes were compared with the official SHB programme. At any power station, thermal efficiency is essential to ensure that the power station can deliver the maximum output power while operating as efficiently as possible. Electricity utilities assign performance criteria to all their stations. At Koeberg, the thermal performance programme is developed to optimize the plant steam cycle performance and focusses on the turbine system. This thesis evaluates the thermal performance programme and turbine performance. The Primary Heat Balance (PHB) test also measures reactor power but uses instrumentation within the reactor core. Due to its location inside the reactor coolant system, the instrumentation used to calculate the PHB is subject to large temperature fluctuations and therefore has an impact on its reliability. To quantify the effects of these fluctuations, the sensitivity of the PHB was determined. The same principle, which was used for the SHB sensitivity analysis, was applied to the PHB. The impact of each instrument on the PHB test result was analysed using MS Excel. The use of the software could be useful in troubleshooting defects in the instrumentation. A sample of previously authorised tests and associated data were used in this thesis. The data for these tests are available from the Koeberg central computer and data processing system.
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Wang, Weimin. "The seasonal-interannual surface layer heat balance in the equatorial Pacific Ocean /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/11047.
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Grill, Rebecca. "Market potential for using demand response from heat pumps in multi-family buildings." Thesis, Uppsala universitet, Fasta tillståndets fysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-354873.
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More renewable energy leads to higher energy imbalances in the Swedish electric power system. In the same time, the grid capacity is almost reached in some regions which requires an extension of the current grids or a reduction of the power consumption. Demand response could be a key factor for both stabilizing the energy balances and reducing the grid congestion. The aim with this thesis is to analyze the potential incomes that demand response from heat pumps can generate for the balance responsibility parties and the grid operators and evaluate how it would affect the end-consumers. The investigated local grid that contains of 174 multi-family buildings with heat pumps could reduce its highest peak power with 2,9 MW. This peak power reduction generated a cost reduction of 483 000 SEK per year or 2800 SEK per building per year in reduced penalty fees and power subscription fees. The mFRR market and the power reserve market were determined to be the most suitable markets for using demand response from heat pumps on for the balance responsibility party in the electricity price region SE3. SE3 consists of 10146 multi-family buildings with heat pumps. The mFRR market generated an average income of 2 699 000 SEK per winter season whereas the power reserve market generated a yearly administrative compensation of 1 133 000 SEK per season and 104 000 SEK per call-off. It is important that end-consumers obtain demand-based tariffs or hourly based tariffs to enable a cost reduction from the control system.
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Gustafsson, David. "Boreal land surface water and heat balance : Modelling soil-snow-vegetation-atmosphere behaviour." Doctoral thesis, KTH, Mark- och vattenteknik, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3406.
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The water and heat exchange in thesoil-snow-vegetation-atmosphere system was studied in order toimprove the quantitative knowledge of land surface processes.In this study, numerical simulation models and availabledatasets representing arable land, sub-alpine snowpack, andboreal forest were evaluated at both diurnal and seasonaltimescales. Surface heat fluxes, snow depth, soil temperatures andmeteorological conditions were measured at an agriculturalfield in central Sweden during three winters and two summersfrom 1997 to 2000 within the WINTEX project. A one-dimensionalsimulation model (COUP) was used to simulate the water and heatbalance of the field. Comparison of simulated and measured heatfluxes in winter showed that parameter values governing theupper boundary condition were more important for explainingmeasured fluxes than the formulation of the internal mass andheat balance of the snow cover. The assumption of steady stateheat exchange between the surface and the reference height wasinadequate during stable atmospheric conditions. Independentestimates of the soil heat and water balance together with thecomparison of simulated and measured surface heat fluxes showedthat the eddy-correlation estimates of latent heat fluxes fromthe arable field were on average 40 % too low. The ability of a multi-layered snowpack model (SNTHERM) tosimulate the layered nature of a sub-alpine snowpack wasevaluated based on a dataset from Switzerland. The modelsimulated the seasonal development of snow depth and densitywith high accuracy. However, the models ability to reproducethe strong observed snowpack layering was limited by theneglection of the effect of snow microstructure on snowsettling, and a poor representation of water redistributionwithin the snowpack. The representation of boreal forest in the land surfacescheme used within a weather forecast (ECMWF) model was testedwith a three-year dataset from the NOPEX forest site in centralSweden. The new formulation with separate energy balances forvegetation and the soil/snow beneath the tree cover improvedthe simulation of seasonal and diurnal variations in latent andsensible heat flux. Further improvements of simulated latentheat fluxes were obtained when seasonal variation in vegetationproperties was introduced. Application of the COUP model withthe same dataset showed that simulation of evaporation fromintercepted snow contributed to a better agreement with themeasured sensible heat flux above forests, but also indicatedthat the measurements might have underestimated latent heatflux. The winter sensible heat flux above the forest wasfurther improved if an upper limit of the aerodynamicresistance of 500 s m-1 was applied for stable conditions. A comparison of the water and heat balance of arable landand forest confirmed the general knowledge of the differencesbetween these two surface types. The forest contributed withconsiderably more sensible heat flux to the atmosphere than thearable land in spring and summer due to the lower albedo andrelatively less latent heat flux. Latent heat flux from theforest was higher in winter due to the evaporation ofintercepted snow and rain. The net radiation absorbed by theforest was 60 % higher than that absorbed by the arable land,due to the lower surface albedo in winter. Key words:soil; snow; land surface heat exchange;forest; arable land; eddy-correlation.QC 20100614
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Molgat-Seon, Yannick. "Quantifying Heat Balance Components in Neonates Nursed under Radiant Warmers during Intensive Care." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23070.
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Thermoregulation is considered a top priority in neonatology due to the fact that relative to adults, neonates have a morphological susceptibility to excessive heat exchange with the environment, and exhibit limited physiological/behavioural responses to thermal strain. Consequently, the environmental conditions in which they are nursed must be tightly regulated to maintain body temperature stable. Neonatal intensive care units (NICU) use radiant warmers (RW) to thermally manage many newborns. However, recent evidence suggests that RW induce intermittent bouts of thermal strain that could adversely affect patients. This warrants further investigation of neonatal heat balance and the pertinent factors affecting it. Conducting an exhaustive audit of heat exchanges affecting the body during standard care under a RW could yield important information that would lead to the improvement of clinical practice in NICUs. The present thesis focuses on neonatal thermoregulatory responses, various body heat exchange mechanisms and processes during standard care under RW.
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Mohd, Sukri Nursyuhada. "Influence of hyperthermia and antioxidant supplementation on redox balance and heat shock protein response to exercise." Thesis, University of Bath, 2018. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.767577.
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Physical activity of moderate intensity and duration leads to healthy biological adaptations in humans. However, very intense and prolonged exercise may induce disruption in redox balance, potentially increasing oxidative stress. In addition, exposure to environmental heat stress and associated hyperthermia further increases oxidative stress and may induce the expression of heat shock proteins. However, antioxidant supplementation is believed to minimise the effect of oxidative stress and may therefore help reduce or limit the heat shock response to exercise heat stress. The first study (Chapter 4) examined whether exertional heat illness (EHI) casualties among military recruits may exhibit greater disturbances in redox balance following exercise compared to non-EHI controls. Nine (n=9) recruits were identified as having suspected EHI during the Loaded March (LM) on day 1, with a peak mean (SD) body core temperature of 40.1 (0.5) °C. Fifteen (n=15) recruits were identified as having suspected EHI during the Log Race (LR) on day 2, with a peak mean (SD) body core temperature of 39.7 (0.5) °C. A further twenty-one (n=21) recruits, which successfully finished both LM and LR events, were treated as controls (CON). Interestingly, the plasma antioxidant concentration was significantly elevated from pre to post-exercise (p < 0.001) for EHI and CON groups, during both LM and LR events, with no changes on lipid peroxide protein carbonyl concentrations. These data suggest there is no increase in lipid peroxide or protein carbonyl level damage in response to intense hyperthermic military exercise, regardless of acute heat illness. It is possible that military training augments the body's defence capabilities, thus reducing oxidative stress and damage induced by free radical production. To date there is a scarcity of data examining the effects of acute intake of antioxidant supplements on oxidative stress and heat shock response during continuous exercise in a hot environment. Hence, the aims of the second study (Chapter 5) were to examine the effects of acute ingestion of Quercetin (Q), Quercetin + vitamin C (QC) or placebo (P) 14 hours before, 2 hours before and every 20 minutes during trials on oxidative stress and heat shock response. In this randomised, crossover study 10 recreationally active males (age 21±2 y, V̇ O2max 54.9±8.4 ml.kg.min-1) completed three running trials at 70% V̇ O2max for 60 minutes in the heat (33.0±0.3°C; 28.5±1.8% relative humidity). Exercise heat stress significantly elevated plasma quercetin (p=0.02), antioxidant power (FRAP) (p < 0.001),plasma heat shock protein 70 (HSP70) (p=0.009) and plasma heat shock protein 90α(HSP90α) (p < 0.001) over time, but no differences were detected between trials. Also, no changes were observed in protein carbonyl concentration. Acute intake of quercetin significantly increased the level of plasma quercetin however, this did not affect the plasma antioxidant capacity or heat shock response to exercise heat stress. The increases in plasma HSP70 and HSP90α concentrations might act as supplementary antioxidants, reducing the oxidative damage reflected in the absence of changes in protein carbonyl. Exercise heat stress is effective in inducing both intracellular HSP70 (muscle and peripheral blood mononuclear cell (PBMC)) and extracellular HSP70 (plasma) concentrations. Thus, the third study (Chapter 6) tested the hypothesis that this acute quercetin supplementation would induce similar trends in plasma HSP70 and intracellular HSP70 concentrations 2 days following exercise heat stress. In this randomised, crossover study, 9 recreationally active males (age 22±2y, V̇ O2max 50.3±3.3ml.kg.min-1) completed three running trials at 70% V̇ O2max for 60 minutes in the heat (32.9±0.3°C; 28.3±1.2% relative humidity). This study demonstrated that there is no positive relationship between both intracellular of HSP70 (muscle and PBMC) and plasma HSP70 (eHSP70) 2 days following exercise heat stress. These data suggest that the release of eHSP70 could originate from others tissue or cells. Additionally, the absence of differences between trials in the expression of muscle HSP70, PBMC HSP70 and plasma HSP70 might indicate it is implausible that quercetin might inhibit the expression of HSP70 in plasma, muscle and PBMC 2 days following the exercise heat stress stimulus. Overall, the results from this thesis emphasise that the hyperthermia experienced in response to exercise and environmental heat stress could potentially influence the human redox response and heat shock response. Besides, there is reasonable evidence that acute quercetin co-ingestion with vitamin C has the potential to improve the bioavailability and bioactive effects of quercetin, however, the effects of quercetin supplementation in reducing oxidative stress in response to exercise heat stress remains to be elucidated. In addition, the anti-oxidative ability of acute ingestion of quercetin to suppress the intracellular and extracellular heat shock response remains uncertain and worthy for further investigation.
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Moregård, Daniel. "Heat Maps : En metod för att uvärdera banor." Thesis, Högskolan i Skövde, Institutionen för kommunikation och information, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-6357.
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Denna rapport har undersökt om game metrics genom heat maps kan användas för att hitta en choke point i en bana gjord till spelet Team Fortress 2. Game metrics och kvantitativa metoder erbjuder ett objektivt och nästan automatiserat alternativ till kvalitativa metoder när det kommer till balansering. En bana har konstruerats med en choke point och har speltestats för att generera en heat map. För att undersöka om det går att hitta en choke point med hjälp av en heat map så har en enkät gjorts där respondenter bads hitta choke pointen med hjälp av den heat mapen som genererades från speltestningen av banan. Alla respondenter lyckades hitta mitten av choke pointen med hjälp av heat mapen. I framtiden skulle arbetet kunna utökas genom att undersöka om användandet av bottar eventuellt skulle helt kunna automatisera balanseringsprocessen. Det skulle också gå att undersöka hur olika klasser rör sig i en bana.
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Achaaban, Mohammed Rachid. "Fluid balance and its hormonal control in the dromedary camel (Camelus dromedarius)." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299860.
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Deren, Tomasz. "An Analysis of Thermoregulatory Sweating and Heat Balance in American Football Linemen and Backs." Thesis, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/20644.
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This thesis examined why NCAA Division 1 American football “linemen” experience greater heat strain than “backs” during summer training camps. In study #1, exercise at a heat production of 350 W/m2 in a hot environment (Tdb:32.4±1.0ºC; Twb:26.3±0.6ºC) resulted in greater local sweating on the upper body (head, arm, shoulder and chest; all <0.05) and a greater core temperature (P=0.033) in linemen despite a ~25% lower heat production per unit mass (L:6.0±0.5 W/kg; B:8.2±0.8 W/kg). In study #2, greater convective and evaporative heat transfer coefficients (P<0.05) were found in backs during live summer training camp drills, but these did not lead to a greater dry heat transfer or evaporative capacity. However, the maximum metabolic rate per unit mass was lower in linemen due to differences surface area-to-mass ratio. In conclusion, the greater heat strain previously reported in linemen likely arises, in part, from differences in sweating efficiency and body morphology.
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Lund, Raymond John. "Contribution of respiratory heat loss to heat balance in Thoroughbred horses performing near maximal exercise under thermoneutral and hot-humid conditions." Thesis, University of Pretoria, 2001. http://hdl.handle.net/2263/28473.
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The purpose of the studies presented in this thesis was to develop a greater understanding of the contribution of respiratory heat loss to the thermal balance of exercising horses. In the first experiment the effect of three different warm-up regimens on the thermal balance of Thoroughbred horses was investigated. The experiments showed that a low intensity warm-up was most beneficial aiding heat dissipation during subsequent exercise. The study also showed the heat loss by sweating is not restricted by the rate of sweat production, but by the evaporation rate of the sweat. In the second experiment, horses were exercised to fatigue in thermoneutral and hot-humid environments. The evaporative heat dissipation from sweating and from the respiratory tract was severely impaired during the hot humid exercise protocol. There was a significant increase in the heart rate and the metabolic rate during the hot humid protocol, thus indicating the additional work done by the horse in an effort to dissipate the rapidly accumulating heat. The significantly shorter time to fatigue may be a mechanism to protect the horse from circulatory collapse as the circulatory demands for cardiac output exceed its capacity. In the third experiment adaptations that the horse is able to make to alleviate the compromised evaporative heat loss were identified. These experiments showed that the horse is able to shorten its stride, increase minute ventilation and the velocity of the air in the conducting airways. The results presented also indicate that the horse is able to modify the evaporative area of the airways to enhance evaporative heat loss from the respiratory tract. The experiments also showed that during exercise in hot-humid environments, small changes in the evaporating surface vapour pressure have a significant effect on the vapour pressure gradient thus having a significant effect on the evaporating heat loss. Finally, the lessons gained during the experiments presented in this thesis were used to revise and refine a mathematical model of the thermal balance of exercising horses. The resulting model is more accurate and easier to apply to use in the field.Thesis (DPhil)--University of Pretoria, 2000.
Equine Research Centre
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Moderow, Uta. "Energy balance of forests with special consideration of advection." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-71221.
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The present work was written as a cumulative dissertation based on peer-reviewed papers and is completed by yet unpublished results. The overall objective was to get a deeper insight into the role of the advective fluxes of sensible heat and latent heat in relation to the energy balance and its imbalance at the earth’s surface (typically the sum of the turbulent fluxes sensible and latent heat does not match the available energy). Data from two advection experiments at four coniferous sites across Europe served as the basis for the analysis. One was the advection experiment MORE II which took place in Tharandt (Germany) and the other advection experiment ADVEX was conducted at three different sites (Ritten/Renon, Italy; Wetzstein, Germany; Norunda, Sweden). An inspection of the available energy (AE) that is redistributed to the atmosphere by the sensible heat flux (H) and latent heat flux (LE) showed that the uncertainty of the available energy itself cannot explain the lack of energy balance closure for these four sites. The mean absolute uncertainty of the available energy was largest during midday and ranged from 41 W m-2 to 52 W m-2 (approx. 12 % of AE). During nighttime, the mean absolute uncertainty was smaller (20 W m-2 – 30 W m-2) but the relative uncertainty was much larger as AE itself is small. Among the investigated storage terms the heat storage change of the biomass was most important. The energy balance closure was improved for all investigated sites when storage terms were included. In principle, storage terms should not be neglected in energy balance studies. An investigation of the budget of sensible heat, not only including the vertical advection and the horizontal advection but also the horizontal turbulent flux divergence, was undertaken for the coniferous site at Tharandt. Inclusion of these fluxes resulted in an enlarged mean daily amplitude and suggests an improvement of the energy balance closure, at least during nighttime. The commonly determined budget (vertical turbulent flux plus storage change) was reduced by about 30 % when advective fluxes were included. Results suggest that the horizontal turbulent flux divergence is of minor importance but further studies are needed for an overall evaluation. First results for the inclusion of the advective fluxes of both sensible heat and latent heat indicate that the lack of energy balance closure is partly reduced but the imbalance still exists. Advective fluxes of sensible heat were also compared to advective fluxes of CO2. It became apparent that the advective fluxes of sensible heat and CO2 are, on average, of opposite sign during nighttime and both share large scatter. Both budgets (sensible heat and CO2) were considerably changed (although differently for different sites) when advective fluxes were included. Results further suggest that advective fluxes of H can be taken as an indicator concerning the presence and sign of advection of CO2. This points towards a coincident non-turbulent transport of heat and CO2. However, all investigated advective fluxes are site-specific. They are characterised by a large uncertainty due to uncertainties in the mean vertical velocity (vertical advection) and in the horizontal differences in scalar magnitude (horizontal advection). Obviously, they are influenced by the limitations of the experimental set-up (spatial resolution) and the local characteristics of the individual measurements. An overall evaluation of advective fluxes with respect to their representativeness and magnitude requires further studiesDie vorliegende Arbeit wurde als kumulative Dissertation verfasst, die auf begutachteten Publikationen beruht. Sie wird um bisher nicht veröffentlichte Daten zur Advektion latenter Wärme ergänzt. Ziel war es, vor allem die Rolle der advektiven Flüsse von sensibler und latenter Wärme in Bezug auf die Energiebilanz und das Problem der Energiebilanzschließung an der Erdoberfläche näher zu untersuchen. Unter der Energiebilanzschließungslücke wird im Allgemeinen das Phänomen verstanden, dass die Summe der gemessenen turbulenten Flüsse von sensibler und latenter Wärme zumeist nicht der gemessenen verfügbaren Energie entspricht. Als Datengrundlage für die Arbeiten dienten hierzu die Datensätze von zwei Advektionsexperimenten, die an vier verschiedenen Nadelwaldstandorten in Europa stattfanden. Das erste dieser Advektionsexperimente MORE II fand an der Ankerstation Tharandt (Deutschland) statt und das zweite (ADVEX) wurde an drei verschiedenen Standorten durchgeführt (Ritten/Renon, Italien; Wetzstein, Deutschland; Norunda, Schweden). Eine Untersuchung der verfügbaren Energie (AE), die über den sensiblen Wärmestrom (H) und den latenten Wärmestrom (LE) wieder an die Atmosphäre abgegeben wird, zeigte, dass die in der Bestimmung der verfügbaren Energie liegende Unsicherheit das Problem der Energiebilanzschließungslücke nicht ausreichend erklärt. Die mittlere absolute Unsicherheit der verfügbaren Energie war dabei mittags am größten (41 W m-2 – 52 W m-2; ca. 12 % der verfügbaren Energie). Nachts war diese kleiner (20 W m-2 – 30 W m-2). Jedoch waren dann die relativen Unsicherheiten deutlich größer, da die verfügbare Energie nachts klein ist. Von den betrachteten Speichertermen der Energiebilanz erwies sich die Speicheränderung von Wärme in der Biomasse als am wichtigsten. Für die vier untersuchten Standorte verbesserte sich die Energiebilanzschließung, wenn die Speicherterme mit einbezogen wurden. Grundsätzlich sollten alle Speicherterme bei der Bestimmung der Energiebilanz mit beachtet werden. Für den Nadelwaldstandort Tharandt wurde die Bilanz der sensiblen Wärme unter Beachtung der advektiven Flüsse und der horizontalen turbulenten Flussdivergenz erstellt. Die Einbeziehung der advektiven Flüsse und der horizontalen turbulenten Flussdivergenz führte zu einer Vergrößerung der Amplitude im mittleren Tagesgang und deutet auf eine Verbesserung der Energiebilanzschließung zumindest nachts hin. Im herkömmlichen Sinne wird die Bilanz für Energie oder Massenflüsse als Summe aus vertikalem turbulenten Fluss und Speicheränderung bestimmt. Die Gesamtsumme dieser Bilanz wurde um 30 % reduziert, wenn die advektiven Flüsse mit einbezogen wurden. Hinsichtlich der horizontalen turbulenten Flussdivergenz kann man noch keine abschließende Einschätzung geben. Die vorliegenden Ergebnisse deuten einen vernachlässigbaren Anteil an der Gesamtbilanz für diesen Term an. Erste Ergebnisse für die Bestimmung der Energiebilanz von Nadelwäldern unter Beachtung der advektiven Flüsse von sensibler und latenter Wärme zeigen eine teilweise Reduzierung der Energiebilanzschließungslücke, jedoch keine vollständige Schließung der Energiebilanz. Weiterhin wurden die advektiven Flüsse sensibler Wärme mit denen von CO2 verglichen. Die Bilanzen für den CO2-Fluss als auch für den Fluss sensibler Wärme änderten sich deutlich unter Einbeziehung der advektiven Flüsse, wenn auch unterschiedlich für verschiedene Standorte. Besonders nachts sind die advektiven Flüsse von sensibler Wärme und CO2 im Mittel durch gegensätzliche Vorzeichen gekennzeichnet. Diese Beziehung eröffnet die Möglichkeit, advektive Flüsse von CO2 auf der Basis von advektiven Flüssen sensibler Wärme hinsichtlich ihres Vorhandenseins und ihrer Richtung abzuschätzen. Dies deutet auf einen gleichzeitigen nicht-turbulenten Transport von Wärme und CO2 hin. Generell ist festzustellen, dass alle untersuchten advektiven Flüsse spezifisch für den jeweiligen Standort und durch eine große Unsicherheit gekennzeichnet sind. Diese ergibt sich zum einen aus der mittleren vertikalen Geschwindigkeit (vertikale Advektion) und zum anderen aus den horizontalen Differenzen (horizontale Advektion) der jeweiligen skalaren Größen. Die betrachteten advektiven Flüsse werden offensichtlich durch Einschränkungen, die sich aus dem experimentellen Aufbau ergeben (z.B. begrenzte räumliche Auflösung), in ähnlicher Weise beeinflusst. Eine abschließende Beurteilung der advektiven Flüsse hinsichtlich ihres Anteils an der Gesamtbilanz und ihrer Repräsentativität erfordert weitere Studien
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Ombu, Ebiaye Valerie. "Development of a heat-balance model for the characterization of wax blockage in flowlines." Texas A&M University, 2004. http://hdl.handle.net/1969.1/3099.
Full textAbstract:
The presence of a blockage in a pipeline will alter the fluid dynamics of a flowing
system in terms of the heat, mass and velocity characteristics. The analysis of the fluid
dynamics is based on balances taken on the overall system to qualitatively and
quantitatively assess the effects of the blockage. Pioneer work in the area of mass and
momentum effects of blockages led to the development of blockage type curves useful in
characterizing blockages from limited information. This work is an extension of
previous work and is based on the application of a simplistic energy balance approach to
characterize blockages in pipelines. The resulting heat models for the case of both a
partially and fully-blocked flowline correctly predict the effect of wax deposition.
Dimensionless temperature-based blockage maps developed here can be used in
modeling unique cases where only two of the three necessary conditions are given. The
heat model matches results from commercial software within a limited range of
restricted flow conditions.
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Fischbach, Ulf [Verfasser], and David [Akademischer Betreuer] Wharam. "Heat balance and temperature regulation in complex biological systems / Ulf Fischbach ; Betreuer: David Wharam." Tübingen : Universitätsbibliothek Tübingen, 2017. http://d-nb.info/1165578107/34.
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Alrayyes, Taleb. "The effect of ethanol-gasoline blends on SI engine energy balance and heat transfer characteristics." Thesis, University of Nottingham, 2011. http://eprints.nottingham.ac.uk/29749/.
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Ethanol is one of a group of hydrocarbon fuels produced from bio-mass which is attracting interest as an alternative fuel for spark ignition engines. Major producers of ethanol include Brazil, from sugar cane, and the USA, from com. Reasons for the growing interest in ethanol include economic development, security of fuel supply and the reduction of net emissions of carbon dioxide relative to levels associated with the use of fossil fuels. Unlike gasoline, which is a mixture of hydrocarbon compounds suited to meet a range of start and operating requirements, ethanol is a single component fuel with characteristics which make engine cold starting difficult, for example. Hence, ethanol is generally used in a blend with gasoline, accounting for <5% in EU pump-grade gasoline to 85% by volume for so called flex-fuel vehicles. Although ethanol is already available in the marketplace, there are aspects of its effects on engine behaviour that are unresolved, including its effects on engine thermal behaviour and heat transfer. These have been investigated in the experimental study presented in this thesis. The aims of this work included determining the effect of ethanol content in blends on combustion characteristics, energy balance, gas-side heat transfer rate and cylinder instantaneous heat transfer. This study covers a range of loads, speeds, spark timings, equivalence ratios and EGR levels representative of every day vehicle use, and has been restricted to fully warm operating conditions. The investigations have been carried out on a modern design of direct injection, spark ignition engine. The performance of different ethanol-gasoline blends has been compared at conditions of matched brake power output. The emissions data for NO, HC, CO and C02, which was used to calculate combustion efficiency, show a decrease in their levels proportional to the increase in ethanol content in the fuel blend. This is owing to an increase in combustion efficiency and change in chemical structure and physiochemical properties. Compared to gasoline, running on 85% ethanol produces slightly faster rates of burning in rapid burn stages of combustion. Typically, the reductions in rapid burn angle are 4%. Results show that the effects do not vary in proportion to the ethanol content in the fuel blend. This is attributable to the fact that, at low and medium ethanol content, the enhancement in combustion gained by oxygen availability is offset by its higher enthalpy of vaporisation and lower heat content. Energy balance data show an improvement in thermal efficiency proportional to the increase in ethanol ratio. This is due to improvement in combustion efficiency and a reduction in coolant and exhaust losses. Results for gas-side heat rejection show that a correlation developed for engines run on gasoline can be used without any modification. The heat rejection rate has been inferred from measurements of heat rejection to coolant adjusted to allow for the contribution of engine rubbing friction. The apparent insensitivity to ethanol content is attributed to a combination of factors. These include the increase in fuel flow rate for a given energy supply being offset in its effect on charge flowrate by a reduction in stoichiometric air/fuel ratio. Gas-side heat transfer results from both the exhaust port and the cylinder show a clear decrease when running on 85% ethanol compare to gasoline. This reduction was also observed in the total measured heat loss to coolant. The magnitude and phasing of instantaneous heat loss is not sensitive to the use of ethanol during combustion. However, as the combustion starts to terminate, lower heat loss for medium and high ethanol content was observed due to the reduction in the combustion product temperature. The results from the C 1 C2 correlation and instantaneous heat transfer are comparable.
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Dervis, Sheila. "Discerning the Influence of Total Body Weight and Pregnancy on the Contribution to Heat Balance." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42011.
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Evidence-based Canadian physical activity guidelines established specifically for pregnant women have shown to improve maternal and fetal outcomes, including prevention of adversities such as excess gestational weight gain, preeclampsia, and gestational diabetes. Unfortunately, most pregnant women fail to meet recommended guidelines for physical activity, and in many circumstances, the prevailing motive is due to a fear of overexertion and overheating harming the fetus. These concerns stem from reports of teratogenesis related to hyperthermia in several animal studies resulting in congenital fetal malformations. Although, due to disparities in thermoregulation between humans and animals, the findings are not entirely applicable to pregnant women. During exercise, the heat produced requires a given source of heat loss (i.e., skin blood flow/sweating) to maintain thermal homeostasis and a stable core temperature, preventing a continual rise in core temperature (i.e., teratogenesis). This thesis aims to separate the influence of pregnancy and body weight on oxygen consumption, heat production, heart rate, and rating of perceived exertion at rest (Study 1) and then during exercise (Study 2). On the other side of the heat balance equation is heat loss mechanisms; currently, the limited existing literature suggests that dry and evaporative heat loss increases as pregnancy progresses. Unfortunately, these findings are also based almost exclusively on animal studies. There has not been an established understanding of physiological, perceptual/behavioural responses in heat loss in pregnant women from early to late pregnancy, and the final study in this thesis sought to map the current literature in the format of a scoping review (Study 3). The findings of this thesis provide evidence that physiological measurements of oxygen consumption, heat production and heart rate are not influenced by stage of pregnancy, the responses increases/decrease according to total body mass. Additionally, both dry and evaporative heat loss responses appear to increase from early to late pregnancy.
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Stenlund, Lars. "Experimentella studier av värmeflöden och värmelagring i ett bebott flerbostadshus." Doctoral thesis, Umeå universitet, Institutionen för fysik, 1987. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-100376.
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The study is experimentally inclined, with a high target precision for performance measurement. A comprehensive programme of measurements was carried out in a two-storey building, having a massive structure and dating from 1970. Measurements were made continuously during the heating season from a total of about 70 points. Readings were taken every 30 seconds, and the mean values stored in a computer every 15 minutes. Analysis of the results have been concentrated on: * Thermal inertia, and particularly that of cooling mechanisms. * Time delays in heat flows through the building envelope in response to variations in ambient temperature. * The amount of solar input beneficially retained when operating with night setback and with normal operation. The results indicate that the building has both a long time constant, of about 200 h, and a short one, of about 1.5 h. The magnitude of the shorter time constant depends on the thermal capacity of the interior of the building (furniture, curtains etc.), and can be regarded as having some validity for other apartment building stock. Analyses of temperature gradients in the internal surfaces of the exterior walls indicate that the building's ventilation system, which was originally constructed as an exhaust air ventilation system, but with the inflow of fresh air blocked off, generates a dynamic insulation effect. Calculations indicate that this effect can provide a saving of 6 % of the total heating requirement, excluding that for domestic hot water. Investigation of the static heat requirement with and without night set-back indicate a considerable potential annual saving of heating energy, amounting to a maximum of 13 %, provided that the building is heated in accordance with a prescribed strategy. A 'comfort indoor temperature' has also been determined, being the temperature above which the occupants of the building consume excessive heating energy. Theoretical models have been derived to illustrate the short time constant and to analyse the dynamic insulation effect noted.Diss. Umeå : Umeå universitet, 1987
digitalisering@umu
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Kandel, Hari P. "Land Use /Land Cover Driven Surface Energy Balance and Convective Rainfall Change in South Florida." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/2198.
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Modification of land use/land cover in South Florida has posed a major challenge in the region’s eco-hydrology by shifting the surface-atmosphere water and energy balance. Although drainage and development in South Florida took place extensively between the mid- and late- 20th century, converting half of the original Everglades into agricultural and urban areas, urban expansion still accounts for a dominant mode of surface cover change in South Florida. Changes in surface cover directly affect the radiative, thermophysical and aerodynamic parameters which determine the absorption and partitioning of radiation into different components at the Earth surface. The alteration is responsible for changing the thermal structure of the surface and surface layer atmosphere, eventually modifying surface-induced convection.
This dissertation is aimed at analyzing the extent and pattern of land cover change in South Florida and delineating the associated development of urban heat island (UHI), energy flux alteration, and convective rainfall modification using observed data, remotely sensed estimates, and modeled results.
Urban land covers in South Florida are found to have increased by 10% from 1974 to 2011. Higher Landsat-derived land surface temperatures (LST) are observed in urban areas (LSTu-r =2.8°C) with satisfactory validation statistics for eastern stations (Nash-Sutcliffe coefficient =0.70 and R2 =0.79). Time series trends, significantly negative for diurnal temperature range (DTR= -1°C, p=0.005) and positive for lifting condensation level (LCL > 20m) reveal temporal and conspicuous urban-rural differences in nocturnal temperature (ΔTu-r = 4°C) shows spatial signatures of UHI. Spatially higher (urban: 3, forest: 0.14) and temporally increasing (urban: 1.67 to 3) Bowen’s ratios, and sensible heat fluxes exceeding net radiation in medium and high-intensity developed areas in 2010 reflect the effect of urbanization on surface energy balance. Radar reflectivity-derived surface-induced convective rainfall reveals significantly positive mean differences (thunderstorm cell density: 6/1000 km2and rain rate: 0.24 mm/hr/summer, p < 0.005) between urban and entire South Florida indicating convective enhancement by urban covers.
The research fulfils its two-fold purposes: advancing the understanding of post-development hydrometeorology in South Florida and investigating the spatial and temporal impacts of land cover change on the microclimate of a subtropical city.
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Smoljanic, Jovana. "The Independent Influence of Aerobic Fitness and Running Economy on Thermoregulatory Responses During Treadmill Running." Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31589.
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The independent influence of maximum oxygen consumption (VO2max) and running economy (RE) on thermoregulatory responses during treadmill exercise have not been isolated due to the complex interactions between VO2max, RE, body mass, body surface area (BSA), and metabolic heat production (Hprod). The purpose of the thesis is to determine whether large differences in VO2max and/or running economy independently alter thermoregulatory responses during running in a neutral environment. Seven aerobically unfit (LO-FIT: ~ 40 mlO2·kg-1·min-1) and sevn aerobically fit (HI-FIT: ~ 60 mlO2·kg-1·min-1) males, matched for body mass and BSA ran at 1) a fixed metabolic heat production of 640 W (FHP trial) and 2) 60%VO2max (REL trial). Also, seven high RE (HI-ECO: ~ 185 mlO2·kg-1·km-1) and seven low RE (LO-ECO: ~ 220 mlO2·kg-1·km-1) males, matched for body mass, BSA and VO2max (~ 60 mlO2·kg-1·min-1) ran at a 1) fixed Hprod of 640 W (FHP trial) and 2) fixed running speed of 10.5 km·h-1 (FRS trial). All trials were performed in a thermoneutral environment. The data was analyzed using a two-way mixed ANOVA, with the significance level set at an alpha of 0.05 for all comparisons. It was hypothesized that thermoregulatory responses (i.e., core temperature and sweating), during exercise will not be independently altered by VO2max, but will be altered by any differences in heat production and running economy. The FHP trial resulted in similar changes in esophageal temperature (∆Tes), changes in rectal temperature (∆Tre), and WBSL between the HI-FIT and LO-FIT groups, despite vastly different %VO2max. Whereas the REL trial resulted in greater ΔTeso, ΔTre, and WBSL in the HI-FIT group, in parallel with their greater Hprod. In groups greatly differing in RE, the FHP trial elicited similar ∆Tes, ∆Tre, and WBSL; however the HI-ECO group had to run faster to achieve the same heat production as their LO-ECO counterparts. Moreover, a FRS of 10.5 kmh-1 produced a greater Hprod, ∆Tes, ∆Tre, and WBSL in the LO-ECO group. In conclusion, thermoregulatory responses are determined by Hprod and RE, not VO2max, when differences in mass and BSA are eliminated between groups. Thus, these findings support the initially stated hypotheses.
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au, dbeatty@murdoch edu, and David Beatty. "Prolonged and continuous heat stress in cattle: Physiology, welfare, and electrolyte and nutritional interventions." Murdoch University, 2005. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20060831.144000.
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The live export of cattle is an important industry for Australia. Concerns have arisen about animal welfare and in particular heat stress which may cause production losses and death. Cattle shipped live to the Middle East from a southern Australian winter can face continuous and prolonged periods of high heat and humidity as they cross the equator and arrive into a northern hemisphere summer, leading to heat stress and excessive heat load. Some live animal exporters treat heat stressed cattle with electrolyte supplements, but no scientific data exists as to whether this is beneficial to cattle in these unique environmental conditions.
In response to industrys concerns, the experiments described here monitored the physiological responses of Bos taurus and Bos indicus to conditions similar to those experienced by cattle being shipped from southern Australian to the Middle East. Initial experiments were conducted in climate controlled rooms at Murdoch University where intensive monitoring was possible. In the Bos taurus, increases in core body temperature, reductions in feed intake, and increased water intake were measured. There were also changes in blood gas variables consistent with the observed panting causing a compensated respiratory alkalosis. Following the heating period, there were decreases in blood and urinary pH. Bos indicus showed similar responses to the heat, but the changes were less pronounced at the temperatures tested. A pair feeding experiment was conducted to separate the effects of heat from the reductions in feed intake, and this indicated that the major measured effects were due to the responses to heat. On the basis of the measured responses, an electrolyte supplement was formulated and tested on Bos taurus, in the climate controlled rooms, and then on a commercial live export vessel. Results from these experiments indicated improved buffering capacity and a weight advantage for supplemented cattle, even in the absence of extreme heat stress.
A final experiment investigated the effects of amount and quality of roughage in a pelleted feed on core and rumen temperature and feed intakes in Bos taurus subjected to hot environmental conditions in climate controlled rooms at Murdoch University. Both pelleted feeds had approximately the same metabolisable energy and crude protein but differed in content and type of roughage. There were no differences in feed intake, core temperature or rumen temperature between diets.
This work has led to a greater understanding of the physiological responses of cattle to prolonged and continuous high heat and humidity, the requirements and effects of supplemental electrolytes in these conditions, and the effect of manipulating export diets. The demonstration of advantages in weight and buffering capacity with the electrolyte supplement highlights future areas of research to investigate electrolyte doses, route and types of supplementation, and dietary manipulation.
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Arnold, Kira Brianne. "Eddy Covariance in a Tallgrass Prairie : energy balance closure, water and carbon budgets, and shrub expansion." Thesis, Manhattan, Kan. : Kansas State University, 2010. http://hdl.handle.net/2097/2362.
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Carreño, Arango Ricardo. "A comprehensive methodology to analyse the Global Energy Balance in Reciprocating Internal Combustion Engines." Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/73069.
Full textAbstract:
[EN] The main objective of this doctoral thesis is the development of a comprehensive methodology to perform and analyse the thermal balance of reciprocating engines, based on experimental and theoretical techniques. Starting from previous works carried out in the research group, which are related to combustion diagnosis and thermal management, a methodology to analyse the thermal balance from two points of view was proposed: on the one hand, the external point of view, mainly based on experimental measurements, and on the other hand, the internal point of view, based on modelling. The combination of both approaches allows the necessary model adjustment, along with a detail characterization of the different energy flows.
Apart from the thermal balance methodology, several proposals to model some internal processes have been provided, being noteworthy the sub-models for heat transfer to the chamber walls, the ports and between the oil and coolant. Besides, detailed mechanical losses model was also developed. With the aim of ensuring the models reliability and robustness, an integral uncertainty adjustment methodology is proposed, which allows determining some parameters affecting the thermodynamic properties within the chamber and the sub-models adjustment.
The analysis and calibration methodology is flexible enough to be applied in different types of engines and combustion modes, thus ensuring its generality. To demonstrate the methodology potential, it is finally applied to analyse specific parametric studies in two engines, showing its usefulness for both diagnostic and predictive applications.[ES] El objetivo principal de la presente tesis doctoral es el desarrollo de una metodología integral que permita analizar el balance de energía en motores de combustión interna alternativos, mediante la combinación de diferentes técnicas experimentales y teóricas. Para ello, partiendo de varios trabajos previos realizados en el grupo de investigación en temas relacionados con diagnóstico de la combustión y gestión térmica del motor, se ha propuesto una separación del análisis energético en dos puntos de vista: exterior, basado principalmente en medidas experimentales e interior, fundamentalmente basado en modelado. La combinación de ambos enfoques permite el necesario ajuste de los modelos, así como la caracterización completa y fiable de los flujos de energía en el motor. Junto a la metodología del balance energético, se han aportado una serie de propuestas para el modelado de diferentes procesos internos, entre los que destacan los modelos de transmisión de calor a las paredes de la cámara de combustión, a las pipas y entre el aceite y el refrigerante, así como un modelo detallado de pérdidas mecánicas. Con el fin de garantizar la robustez y fiabilidad de dichos modelos, se ha propuesto una metodología de ajuste de incertidumbres que permite obtener el valor de varios parámetros que afectan al cálculo de las condiciones termodinámicas en la cámara, así como el ajuste de los diferentes modelos propuestos. La metodología de análisis y calibración es suficientemente flexible para ser aplicada a motores de características y modos de combustión diferentes, asegurando así la generalidad de la herramienta. Para mostrar su potencial, se ha aplicado a dos motores en estudios paramétricos específicos, verificándose su utilidad como herramienta tanto de diagnóstico como para su uso en aplicaciones predictivas.
[CAT] L'objectiu principal de la present tesi doctoral és el desenrotllament d'una metodologia integral que permeta analitzar el balanç d'energia en motors de combustió interna alternatius, per mitjà de la combinació de diferents tècniques experimentals i teòriques. Per a això, partint de diversos treballs previs realitzats en el grup d'investigació en temes relacionats amb diagnòstic de la combustió i gestió tèrmica del motor, s'ha proposat una separació de l'anàlisi energètica en dos punts de vista: exterior, basat principalment en mesures experimentals i interior, fonamentalment basat en modelatge. La combinació d'ambdós enfocaments permet el necessari ajust dels models, així com la caracterització detallada dels diferents fluxos energètics. Junt amb la metodologia del balanç energètic, s'han aportat una sèrie de propostes per al modelatge de diferents processos interns, entre els que destaquen els models de transmissió de calor a les parets de la cambra de combustió, a les pipes i entre l'oli i el refrigerant, així com un model detallat de pèrdues mecàniques. A fi de garantir la robustesa i fiabilitat dels dits models, s'ha proposat una metodologia integral d'ajust d'incerteses que permet obtindre el valor de diversos paràmetres que afecten el càlcul de les condicions termodinàmiques en la cambra, així com l'ajust dels diferents models proposats. La metodologia d'anàlisi i calibratge és prou flexible per a ser aplicada a motors de característiques i modes de combustió diferents, assegurant així la generalitat de la ferramenta. Per a mostrar el seu potencial, finalment s'ha aplicat a dos motors en estudis paramètrics específics, verificant la seua utilitat tant com a ferramenta de diagnòstic com en aplicacions predictives.
Carreño Arango, R. (2016). A comprehensive methodology to analyse the Global Energy Balance in Reciprocating Internal Combustion Engines [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/73069
TESIS
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Sui, Chen. "ENERGY AUDIT of GEFLE VAPEN." Thesis, University of Gävle, Ämnesavdelningen för energi- och maskinteknik, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-6538.
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The energy audit is a very interesting and complex work. The building energy audit is defined as a process to evaluate where the energy used in the building structure and to identify the opportunities of reduce energy consumptions. In this paper, it is a first time detailed study of energy audit for me. In this research, the object is to find is it necessary to improve the ventilation systems. So the first step is to estimate how much energy consumed in the building and to find out the saving potential.The major mission in this thesis is that to make a basic energy audit which is include the heat losses from the building and the heat supply in the building. The major heat losses are transmission losses, ventilation losses, heat losses from hot tap water and infiltration losses. In this project the first three types of heat losses could be find out by some useful methods but the infiltration losses is hard to measure. On the other side, the heat supply are composed by district heating , free heating from people inside, free heating from electricity applications and sun irradiation.To make an accurate and complete energy audit is essential for finding out where the energy consumption could be reduced. And this is what I am going to do in this thesis work.
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Eriksson, Denise. "Energibalans för Norra stegvalsverket : En fallstudie på Sandvik AB i Sandviken." Thesis, Högskolan i Gävle, Energisystem, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-24070.
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Under 2014 stod industrin i Sverige för nästan 40% av den totala energianvändningen. Stål- och metallindustrin står för den näst största delen efter massa- och pappersindustrin. En stor del av energin går förlorad som restvärme och betraktas ofta som avfall. Användning av restvärme ger ett minskat behov av primär värme samt minskade utsläpp av CO2. I många fall går restvärmen att använda till fjärrvärme om den har tillräckligt hög temperatur. Det här examensarbetet har tagits form av en fallstudie på stålindustrin Sandvik. Syftet med arbetet är att ta fram en energibalans för en av byggnaderna inne på industriområdet. Ett till syfte är att undersöka om det finns möjlighet att återanvända restvärme från kylsystemet. Byggnaden som har undersökts heter Norra stegvalsverket och verksamheten som bedrivs där är stegvalsning av rör. För att nå målet med arbetet har en litteraturstudie genomförts, fallstudie som har innehållit en del mätningar av flöden och temperaturer samt en mängd intervjuer. För att ta fram en energibalans krävs det att byggandens energiflöden kartläggs. Den tillförda energin kommer i form av el, ånga och internvärme. Energin som bortförs är transmission, ventilation, kylvatten och oavsiktlig ventilation. Arbetet har begränsats till en byggnad och inga tekniska lösningar har undersökts. Resultatet från detta arbete visar att temperaturen på kylvattnet är för låg för att brukas till fjärrvärme om den inte uppgraderas till en högre temperatur. Ett annat användningsområde är att förvärma ventilationsluften med kylvattnet. Arbetet visar också att det finns för lite detaljerad information beträffande elanvändningen. Problemet upptäcktes i arbetets slutskede vilket gjorde att det inte fanns tid att göra ytterligare mätningar. Detta gör att det inte ger en rättvis bild hur energin fördelas i Norra stegvalsverket. För att utveckla detta arbete krävs en noggrann undersökning av elanvändning för att ta reda på exakt hur mycket el Norra stegvalsverket förbrukar. En studie skulle även kunna utföras om det finns tekniska och ekonomiska möjligheter att förvärma ventilationsluften med kylvattnet.In 2014, industrial operations in Sweden consumed nearly 40% of the total energy use. The steel and metal industry uses the second largest amount of energy in the industrial sector, only the pulp and paper industry uses more. A large part of the energy is waste heat and is often considered as waste. I many cases the waste heat can be used for district heating if it has sufficiently high temperature. This thesis has been taken as a case study at the steel industry Sandvik. The aim of this study is to develop an energy balance for one of the buildings at the plant. Another purpose is to investigate whether there is a possibility to reuse the heat from the cooling system. The building that has been investigated is called Norra stegvalsverket, which is a cold-pilger mill. To reach the goal with this study, a literature study has been conducted, a case study containing some measurements of flows and temperatures, as well as a variety of interviews. To generate an energy balance, it is required that the energy flow of the building is mapped. The energy that is added is electricity, steam, and internal heat. The energy that the building consumes is transmission, ventilation, cooling water, and uncontrolled ventilation. The study has been limited to one building and no technical solutions have been investigated. The result of this work show that the temperature of the cooling water is too low to be used for district heating unless it is upgraded to a higher temperature. One possible application for the cooling water is to preheat the ventilation air. The study also shows that there is too little detailed information regarding the use of electricity in the building. The problem was discovered at the end of the project, which meant that there was no time to make further measurements. Due to this problem, the study does not give a fair picture how the energy is distributed in Norra stegvalsverket. To develop this study, a thorough investigation of the electricity usage is required to find exactly how much electricity the building uses. A study could also be carried out to find out if there are technical and economic opportunities to preheat the ventilation air with the cooling water.
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Tuhovčák, Ján. "Vývoj simulačního nástroje pro semi-hermetický kompresor s cílem zlepšení účinnosti." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-369381.
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Compressors are widely used across the all technical fields and current pressure on ecology increases the demand for more effective compressor with economical operation costs. The reasons for inefficiencies must be identified during the development process of a new compressor, where simulation tools might become very useful. There are many different tools for compressor analysis and choosing the right one is mostly dependent on the level of detail that must be analyzed. Models based on energy balance seem to be appropriate when the global parameters of a compressor are demanded. These models offer quick results with reasonable degree of accuracy in terms of basic compressor characteristics. The goal of this thesis is to develop such a simulation tool for a reciprocating compressor. The tool can predict compressor behavior based on compressor dimensions and valve properties. The processes inside the cylinder and heat transfer between the components of a compressor are analyzed using energy balance equation. Simulation tools were verified and experimentally validated using two different types of compressors, therefore they might be used for any reciprocating compressor under some conditions. Mathematical solution was developed in Matlab and therefore it is possible to add new sub-models or to couple the actual model with other simulation tools. This work also contains an analysis of heat transfer models used to predict heat transfer coefficient inside the cylinder and comparison with complex numerical approach. Impact of heat transfer on the compressor efficiency was evaluated too.
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Caravello, Victor. "Total evaporative resistance of selected clothing ensembles." [Tampa, Fla.] : University of South Florida, 2004. http://purl.fcla.edu/fcla/etd/SFE0000452.
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Frank, Vojtěch. "Využití odpadního tepla z rektifikace." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-377754.
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The purpose of the thesis is to draw up a model of the energy and material balance using technical and technological analysis of the current state of production of waste heat in the process of distillation. Using these results, subsequently evaluate the energy potential of individual streams and propose optimal energy savings using waste heat. Emphasis is placed on the modelling of the process and the various proposed savings options. The result is also an evaluation of the potential of the proposed savings based on the results of the calculation.
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Krämer, Stefan [Verfasser]. "Heat Balance Calorimetry and Multirate State Estimation Applied to Semi-Batch Emulsion Copolymerisation to Achieve Optimal Control / Stefan Krämer." Aachen : Shaker, 2005. http://d-nb.info/1186588918/34.
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Quesada, Zeljkovic Joaquin. "Construction of a Heat Transfer Rig based on Energy Balance for Rapid Production of Correlations for Additively Manufactured Geometries." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-264258.
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This thesis has set the first milestones towards building a Nusselt number correlation that adapts to the current state of art designing and manufacturing processes at Siemens Industrial Turbomachinery AB, focusing on cooling mini-channels produced with Additive Manufacturing. Additive manufacturing (AM), also known as 3D printing, is a gamechanger technology that has revolutionised manufacture and design know-how, bringing down production cost, time and waste. There are techniques within AM that can be applied in the gas turbine industry. Particularly, Selective Laser Melting (SLM) can be utilised to build high-temperature-alloy components without the design constraints imposed by conventional manufacturing. However, when assessing the performance of these AM components, challenges arise due to surface roughness inherent to the SLM process. The goal is to assess SLM parts for a specific application: thermal performance of AM cooling minichannels. This thesis presents the design, construction and validation of a heat transfer experimental rig, capable of assessing the Nusselt number in SLM single mini-channel samples. The SLM samples vary in the material alloy used for its fabrication, the shape of the mini-channel, and hydraulic diameter. The results show that SLM channels have a higher Nusselt number than smooth, conventionally manufactured channels. This heat transfer enhancement comes at a cost: an increased friction factor coefficient, which was the subject of study in a parallel thesis conducted in the same facilities. The relative friction growth of an SLM sample is significantly higher than the increase in relative Nusselt number for the same SLM when compared to the smooth channel performance. These results are aligned with the expectations, matching the general trends observed in the literature. However, some contradictions with other studies were obtained: surface roughness, the key factor affecting flow performance, yielded inconclusive effects for the results obtained in the present thesis. Further assessment and validation of the heat transfer rig built is to be pursued.Denna studie är det första steget mot att bygga en test rigg för att ta fram Nusselt-korrelationer av additivt tillverkade minikaaler. Vid Siemens Industrial Turbomachinery AB anses dessa har stor potential i kylapplikationer. Additiv Tillverkning (AM) även känd som 3D-printing, är en ”gamechanger” som har revolutionerat tillverkning och design men som även har potential att minska produktionskostnader, tid och avfall. Det finns tekniker inom AM som kan tillämpas i gasturbnindustrin. Exempelvis kan Selective Laser Melting (SLM) avändas för att bygga högtemperaturkomponenter utan de konstruktionsbegränsningar som finns inom konventionell tillverkning. När man bedömer prestandan för dessa AM-komponenter uppstår emellertid utmaningar på grund av ytråheten som är ett resultat av SLM-processen. Målet för detta examensarbete var att utvärdera SLM geometrier för en specifik applikation: termisk prestanda hos AM-kylkanaler. Denna studie presenterar konstruktion och validering av en experimentell rigg för värme¨verföring som levererar Nusselt-tal för SLM tillverkade minikanaler. Tesobjekten är tillverkade i olika material och med varierande geometri. Resultaten visar att SLMkanalerna har högre värmeöverföring än släta, konvetionellt tillverkade kanaler. Denna värmeöverföringsförbättring ackompanjeras dock av en höjning av tryckförluster vilket visades i en tidigare studie vid Siemens Industrial Turbomachinery AB. Resultaten visar att den relativa friktionstillväxten för ett SLM-prov är signifikant högre än ökningen av det relativa Nusselt-talet jämfört med en ”smooth” kanal. Dessa resultat är i linje med förväntingarna och andra publicerade studier i området. Däremot hade ytråheten en överraskade liten effekt på värmeöverföringen i denna undersökning vilket innebär att ytterligare utvärdering och validering av den byggda värmeöverföringsriggen kommer att genomföras.
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Merck, Madeline F. "Variability of Water Storage and Instream Temperature in Beaded Arctic Streams." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/912.
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The purpose of this study is to investigate variation in water export and instream temperatures throughout the open water season in a beaded Arctic stream, consisting of small pools connected by shallow chutes. The goals are to better understand heat and mass movement through these systems, how this may impact chemical and biological processes, and the resulting shifts with changes in climate. This is accomplished by first examining the extent and variability of water storage and export through qualitative analysis of observational data. Further, heat fate and transport is examined through development of an instream temperature model. The model formulation, a simple approach to model calibration and validation, and information regarding residence and characteristic times of different pool layers are presented. Using temperatures measured at high spatial resolution within the pools and surrounding bed sediments as well as other supporting data (e.g., instream flow, specific conductivity, weather data, and bathymetry), various types of storage within the pools, banks, and marshy areas within the riparian zone, including subsurface flow paths that connect the pools, were found. Additionally, data illustrated that some pools will stay stratified during higher flow periods under certain weather conditions. Through modeling efforts, the dominant heat sources were found to vary between stratified layers. It was also found that potential increases in thaw depths surrounding these pools can shift stratification and mixing patterns. These shifts can further influence mass export dynamics and instream water quality. Given the amount and different types of storage within these systems and the influence of stratification patterns on the residence times in the pools, Imnavait Basin and similar beaded Arctic watersheds will likely experience delayed export of nutrients that are limiting in most Arctic systems.
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Hunt, Lindsey. "Examining the effects of caffeine ingestion on human thermoregulation during exercise in the heat in habituated and non-habituated individuals." Thesis, University of Sydney, 2020. https://hdl.handle.net/2123/23167.
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Purpose: In most thermoregulatory research, participants are asked to abstain from consuming caffeine prior to experimental trials due to an assumed confounding effect on core temperature, skin blood flow and/or sweating responses. Yet, evidence supporting this notion appears inconclusive. We aimed to rigorously assess the impact of acute caffeine ingestion on thermoregulatory responses to steady-state exercise in the moderate heat in both caffeine-habituated and non-habituated individuals. Methods: A total of 28 participants (Habituated (HAB), n=14, 4 women; Non-Habituated (NHAB), n=14, 6 women) cycled at a fixed metabolic heat production on two separate occasions: 60 minutes after ingesting i) 5 mg·kg-1 caffeine (CAF) or ii) 5 mg·kg-1 maltodextrin placebo (PLA), in a double-blinded randomised and counter-balanced order. Environmental conditions were 30.6±0.9°C, 31±1 % RH. Results: The rise in esophageal temperature from baseline (ΔTes) with CAF was greater in the HAB group (P<0.001), but not the NHAB group (P=0.34) (CAFHAB interaction: P=0.001). Skin blood flow responses on the arm and the back were attenuated with CAF in the HAB group (CAFHAB interaction: P<0.05) but not in the NHAB group (CAFHAB interaction: Arm: P>0.05). WBSL was not between CAF and PLA (P=0.18). Conclusion: A greater ΔTes with CAF was observed in the HAB group but not the NHAB group, possibly due to an attenuated skin blood flow on the forearm and back with CAF compared to PLA in the HAB group only. These findings support the practice of requesting habituated caffeine-users to abstain from all sources of caffeine prior to participating in thermoregulatory research studies. However, the restriction of caffeine intake for non-habituated individuals (from incidental sources, e.g. chocolate, tea etc) seems unnecessary.
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Kwon, Ju Youn. "Human responses to outdoor thermal environments." Thesis, Loughborough University, 2009. https://dspace.lboro.ac.uk/2134/5519.
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This thesis presents a series of studies into the responses of people to outdoor thermal conditions experienced over all seasons in the United Kingdom. The aim was to investigate practical methods for predicting human responses to outside weather conditions, which would be useful in predicting effects on human comfort and health. The studies involved both laboratory experiments and field trials. One particular aspect of outside conditions, not usually investigated in laboratory studies, is the contribution of solar radiation. Single subject and thermal manikin studies were used to determine the contribution of solar radiation to human response. In addition to this, a total of 168 subjects responses were recorded during trials at the Loughborough University weather station compound. (latitude 52.47N and longitude 01.11W). The trials were distributed between July 2007 and October 2008. This provided a comprehensive data-base for the evaluation of thermal indices. The thesis is divided into four parts. Part one provides an introduction to the subject and a comprehensive literature review. It also describes equipment, calibration procedures and methods used. Part two quantified the contribution of solar radiation to the heat load on a person. A human subject and a heated thermal manikin were exposed to outdoor thermal conditions, while in light clothing and (for the person) conducting a step test. They were then exposed to identical conditions in a thermal chamber, but without the contribution of the sun. The conditions outside were 23˚C air temperature, 42˚C mean radiant temperature and 54% relative humidity with an average air velocity of 0.75 ms-1. The difference in sweat rate (person) and heat required (manikin) between outdoor and indoor conditions were used to estimate the contribution of the sun. Using three different analyses estimates were 14 Wm-2, 35 Wm-2 and 50 Wm-2 depending upon the assumptions made. Part three describes current thermal indices that can be used to assess the effects of weather conditions on people. It also presents the results of weather station measurements over the time period considered. In chapters 8 and 9 field trials are described which capture both the thermal conditions and human physiological and subjective responses to those conditions. Chapter 10 uses the data collected to provide an evaluation of current thermal indices for predicting human responses. The range of air temperature and relative humidity (at 2 pm) over a year was -2˚C to 29˚C and 34% to 95% respectively. Wind speed varied and was greater in winter and spring than in summer and autumn. Solar radiation was influenced by the altitude of the sun which depended upon season. Mean solar radiation increased from December to June and decreased from June to December. The subjective and physiological responses for 130 people (65 males and 65 females) over a range of outdoor weather conditions are presented. Physiological responses for females generally showed a stronger relationship with environmental variables and subjective responses than those for males. The subjective and physiological responses of four groups (one in each season of the year - involving a total of 38 people), are presented. It was found that there were significant individual differences in response. Part four provides a suggestion for an improved thermal index. The PMV (Predicted Mean Vote) out of four thermal indices (WBGT, PMV, WCI/tch and Twc) had the strongest relationship with environmental variables and physiological responses but had a weak relationship with subjective responses. A PMVoutdoors index was developed to improve the prediction of subjective responses for the outdoor conditions investigated. Conclusions and recommendations for future research are provided.
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Šmarda, Marek. "Analýza efektivity využití tepla v provozu bioplynové stanice odpadů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-377751.
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This thesis focuses on the analysis of heat efficiency and effectiveness of the Vojtěchov biogas station unit. The material balances were developed in connection with biogas created in the cogeneration unit. The heat produced by the cogeneration unit is distributed to reactors and drying rooms. Pursuing the main goal of the thesis, the research of the complete heating balance for all months has been conducted. Additionally, a variety of options were assessed, to find the best solution of how to increase the effectivity of the heat. As for the final solution, two recommendations have been proposed in the thesis. The first recommendation lies in a better usage of low-level heat distributed to the secondary fermentor. The second suggestion deals with the amount of heat from cogeneration unit to the system. The result of the analysis is the final recommendation on how to increase the efficiency of the heat usage and potential impacts of the solution on the subsidy according to the KVET standards received in the given year.
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Wu, Ting. "Theoretical and physical modelling of the thermal performance of water wall systems." Thesis, The University of Sydney, 2015. http://hdl.handle.net/2123/14513.
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Water wall is an excellent passive solar strategy which can maintain thermal comfort in buildings while reducing energy consumption. Existing water wall studies are mainly based on simple heat balance models, in which convective heat transfer coefficients are assumed constant and radiation exchange is commonly neglected. Further, the application of the CFD approach to water wall research is very rare. These research gaps are addressed in this study through the development of a comprehensive transient heat balance model and unsteady CFD modelling. The thesis covers three major topics. Firstly, the turbulent natural convection with and without radiation transfer in two-dimensional and three-dimensional air-filled differentially heated cavities is numerically investigated using various RANS (Reynolds Averaged Navier-Stokes) turbulence models and the Discrete Ordinates radiation model. It is found that the shear-stress transport k-ω model has the best overall performance in terms of capturing the main features of the flow and predicting the time-averaged quantities. Secondly, a comprehensive conjugate conduction-convection-radiation model for transient analysis of a semi-transparent water wall system is developed. It is found that reducing the transmissivity of the Perspex or glass walls is the most effective, practical and economical way to improve the thermal performance of the semi-transparent water wall system. Finally, the thermal performance of an opaque water wall system is numerically investigated and compared against a conventional concrete wall system for the typical climate conditions in Sydney, Australia. The results indicate that less supplementary energy is required in winter than that in summer to maintain a comfortable interior temperature. Further, the water wall system performs significantly better than the concrete wall system of the same thickness in the winter climate of Sydney, whereas both systems have a similar performance in summer.
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Roday, Anand P. "Mathematical Analysis of One-dimensional Melting-Freezing in Finite Slabs Subjected to Convective Boundary Conditions Using the Heat Balance Integral Technique." University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1092779914.
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Bach, Aaron James Edward. "The evaluation of cooling systems to reduce heat strain in individuals wearing personal protective clothing." Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/200627/1/Aaron_Bach_Thesis.pdf.
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Personal cooling systems, worn by emergency first responders under protective clothing, are designed to minimise the risk of heat illness. This thesis reaffirms that first responder agencies (e.g. fire, police) identify heat illness as a genuine threat to worker safety. Further, it identifies that certain personal cooling systems alleviate the heat better than others, and the combination of air temperature and humidity has a direct effect on their performance. Therefore, the use of cooling systems, by first responder agencies, needs to be considered in the context of the protective clothing being worn and the environment encountered.
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Domingues, Catia Motta, and Catia Domingues@csiro au. "Kinematics and Heat Budget of the Leeuwin Current." Flinders University. SOCPES, 2006. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20060612.211358.
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This study investigates the upper ocean circulation along the west Australian coast, based
on recent observations (WOCE ICM6, 1994/96) and numerical output from the 1/6 degree Parallel Ocean
Program model (POP11B 1993/97). Particularly, we identify the source regions of the Leeuwin
Current, quantify its mean and seasonal variability in terms of volume, heat and salt transports,
and examine its heat balance (cooling mechanism). This also leads to further understanding of the
regional circulation associated with the Leeuwin Undercurrent, the Eastern Gyral Current and the
southeast Indian Subtropical Gyre.
The tropical and subtropical sources of the Leeuwin Current are understood from an
online numerical particle tracking. Some of the new findings are the Tropical Indian Ocean source
of the Leeuwin Current (in addition to the Indonesian Throughflow/Pacific); the Eastern Gyral
Current as a recirculation of the South Equatorial Current; the subtropical source of the Leeuwin
Current fed by relatively narrow subsurface-intensified eastward jets in the Subtropical Gyre, which
are also a major source for the Subtropical Water (salinity maximum) as observed in the Leeuwin
Undercurrent along the ICM6 section at 22 degrees S.
The ICM6 current meter array reveals a rich vertical current structure near North West
Cape (22 degrees S). The coastal part of the Leeuwin Current has dominant synoptic variability and
occasionally contains large spikes in its transport time series arising from the passage of tropical
cyclones. On the mean, it is weaker and shallower compared to further downstream, and it only
transports Tropical Water, of a variable content. The Leeuwin Undercurrent carries Subtropical
Water, South Indian Central Water and Antarctic Intermediate Water equatorward between
150/250 to 500/750 m. There is a poleward flow just below the undercurrent which advects a
mixed Intermediate Water, partially associated with outflows from the Red Sea and Persian Gulf.
Narrow bottom-intensified currents are also observed.
The 5-year mean model Leeuwin Current is a year-round poleward flow between 22 degrees S and
34 degrees S. It progressively deepens, from 150 to 300 m depth. Latitudinal variations in its volume
transport are a response to lateral inflows/outflows. It has double the transport at 34 degrees S (-2.2 Sv)
compared to at 22 degrees S (-1.2 Sv). These model estimates, however, may underestimate the transport
of the Leeuwin Current by 50%. Along its path, the current becomes cooler (6 degrees C), saltier (0.6 psu)
and denser (2 kg m -3). At seasonal scales, a stronger poleward flow in May-June advects the
warmest and freshest waters along the west Australian coast. This advection is apparently spun up
by the arrival of a poleward Kelvin wave in April, and reinforced by a minimum in the equatorward
wind stress during July.
In the model heat balance, the Leeuwin Current is significantly cooled by the eddy heat
flux divergence (4 degrees C out of 6 degrees C), associated with mechanisms operating at submonthly time scales.
However, exactly which mechanisms it is not yet clear. Air-sea fluxes only account for ~30% of the
cooling and seasonal rectification is negligible. The eddy heat divergence, originating over a narrow
region along the outer edge of the Leeuwin Current, is responsible for a considerable warming of a
vast area of the adjacent ocean interior, which is then associated with strong heat losses to the
atmosphere. The model westward eddy heat flux estimates are considerably larger than those
associated with long lived warm core eddies detaching from the Leeuwin Current and moving
offshore. This suggests that these mesoscale features are not the main mechanism responsible for
the cooling of the Leeuwin Current. We suspect instead that short lived warm core eddies might
play an important role.
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Henin, Riccardo. "Dynamics of Bora wind over the Adriatic sea: atmospheric water balance and role of air-sea fluxes and orography." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/8915/.
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The Bora wind is a mesoscale phenomenon which typically affects the Adriatic Sea basin for several days each year, especially during winter. The Bora wind has been studied for its intense outbreak across the Dinaric Alps. The properties of the Bora wind are widely discussed in the literature and scientific papers usually focus on the eastern Adriatic coast where strong turbulence and severe gust intensity are more pronounced.
However, the impact of the Bora wind can be significant also over Italy, not only in terms of wind speed instensity. Depending on the synoptic pressure pattern (cyclonic or anticyclonic Bora) and on the season, heavy snowfall, severe storms, storm surges and floods can occur along the Adriatic coast and on the windward flanks of the Apennines.
In the present work five Bora cases that occurred in recent years have been selected and their evolution has been simulated with the BOLAM-MOLOCH model set, developed at ISAC-CNR in Bologna. Each case study has been addressed by a control run and by several sensitivity tests, performed with the purpose of better understanding the role played by air-sea latent and sensible heat fluxes. The tests show that the removal of the fluxes induces modifications in the wind approching the coast and a decrease of the total precipitation amount predicted over Italy.
In order to assess the role of heat fluxes, further analysis has been carried out: column integrated water vapour fluxes have been computed along the Italian coastline and an atmospheric water balance has been evaluated inside a box volume over the Adriatic Sea. The balance computation shows that, although latent heat flux produces a significant impact on the precipitation field, its contribution to the balance is relatively minor.
The most significant and lasting case study, that of February 2012, has been studied in more detail in order to explain the impressive drop in the total precipitation amount simulated in the sensitivity tests with removed heat fluxes with respect to the CNTRL run. In these experiments relative humidity and potential temperature distribution over different cross-sections have been examined. With respect to the CNTRL run a drier and more stable boundary layer, characterised by a more pronounced wind shear at the lower levels, has been observed to establish above the Adriatic Sea.
Finally, in order to demonstrate that also the interaction of the Bora flow with the Apennines plays a crucial role, sensitivity tests varying the orography height have been considered. The results of such sensitivity tests indicate that the propagation of the Bora wind over the Adriatic Sea, and in turn its meteorological impact over Italy, is influenced by both the large air-sea heat fluxes and the interaction with the Apennines that decelerate the upstream flow.