Heat Balance Studies Research Articles

Heat Budget of Sub-Mediterranean Downy Oak Landscapes of Southeastern Crimea

This article presents the findings of a research endeavor focused on the diurnal and seasonal dynamics of heat balance and its constituent elements within an oak forest situated in the expanse of the Karadag Nature Reserve. Computed are the values corresponding to the elements of heat balance, encompassing radiation balance, latent heat fluxes corresponding to heat consumption for evaporation, turbulent heat exchange transpiring within the atmosphere, and heat flux coursing through the soil. The features of changes in the heat balance in two key areas are considered: in the zone of growth of the downy oak forest in an open area and in the forest itself. The study discloses patterns characterizing the apportionment of radiation balance into heat and energetic fluxes within the context of the downy oak landscapes native to the southeastern Crimea. Scrutiny of the data established that a substantial proportion of radiation balance finds application in propelling turbulent heat flux, while a minor share is channeled into processes of evaporation and soil heat flux. Evidenced is that the magnitudes of heat balance components, encompassing radiation balance, latent heat fluxes corresponding to heat consumption for evaporation, turbulent heat exchange transpiring within the atmosphere, and heat flux through the soil within the sub-canopy realm, undergo modifications contingent upon the seasons of the year and the vegetative phases of the downy oak forest. The correlation between air temperature and the constituents of heat balance is subject to analysis both within the confines of the territory in the zone of growth of the downy oak forest in an open area and in the forest itself. Manifest is the constancy of the influence exerted by forest vegetation upon heat balance; nevertheless, the degree of its impact is circumscribed by the cyclical dynamics of foliage upon the trees: a well-developed canopy serves to amplify the influence exerted upon the distribution of heat and energetic fluxes. This study of heat balance and its constituents assumes significance in engendering comprehension regarding the operation of downy oak landscapes that are situated on the periphery of their habitudinal range. Also, it helps to reveal deeper patterns of climate change in forest ecosystems.

Experimental study on thermo-chemical behavior of PHWR fuel channel under slumped fuel pin condition

The safe operation of the reactor is compromised under postulated accident events. The events may originate from single or multiple failures. LOCA, along with the unavailability of ECCS, is one such multiple failure event. Phenomena like fuel heat up, fuel slumping, clad oxidation, hydrogen generation and fission product release are about to take place. However, moderator cooling to the external surface of fuel channels limits the fuel heat up. The steam starvation in the channel limits hydrogen generation. The purpose of this study is to analyze the thermo-chemical behavior of a fuel channel of PHWR, assuming that the 37 fuel elements of a bundle are collapsed and collected in a tightly packed stack at the bottom of the pressure tube of the fuel channel. The temperature distribution is obtained under a pseudo-steady-state for the various components of the simulated fuel channel exposed to an oxidative environment. Experimental results have indicated that a significant temperature gradient gets established in radial, circumferential and axial directions in the fuel channel due to slumped fuel bundle configuration as well as hydrogen generation. Estimation from the heat balance studies shows that moderator functions as an active heat sink.

Increase in energy efficiency of a steel billet reheating furnace by heat balance study and process improvement

Steel is the inevitable material for the infrastructure and has the strategic importance for the growth of the country. Iron and steel making industry is one of the most energy-intensive industries, with 5% of the worlds total energy consumption. Therefore, it is required to develop suitable and efficient energy management during various processing in steel plants. Both academic and industrial research is going on worldwide to increase the energy efficiency for reducing the energy cost imparted due to application of reheating furnaces in various metallurgical process. Reheating furnaces are widely used in the Iron and Steel Industry to reheat the semi-finished products like slabs or billets to the rolling temperature at 1250°C. Reheating furnace is one of the major energy consuming equipment for rolling mills. It is also important to optimize the fuel consumption in this reheating process to avoid any overheating of the steel material which may result in the poor quality of the final product. The aim of this investigation is to conduct an analysis to explore possibilities for the improvement in the energy efficiency of an operating natural gas fired reheating furnace. Some important efficiency improvement measurements were conducted and the fuel efficiency improved by 21% along with the productivity increased by 11%. As a result of these investigations, some energy saving opportunities were ascertained. These measures culminate in the overall projected fiscal savings of INR 264 million/year. Our study not only provides efficient solutions to steel industry for proper energy utilization, but also offers ways for the self-innovation of other academic and laboratory scale research activity.

Estimation of Land Surface Temperature using Landsat Data: a Case Study of Agra City, India

Land surface temperature (LST) is an important indicator for the study of climate change, urban environment, heat balance studies, hydrological and agricultural process, and urban land use and land cover as well as user input for climate models. Landsat data is utilized for the number of applications such as environment study, digester and resource management. Land surface temperate is estimated by the help of ArcGIS through Landsat 8 and 5 satellites images. The normalized difference vegetation index (NDVI) thresholds method was used for land surface emissivity (LSE) estimation; NDVI is calculated by near infrared (NIR) and red spectral bands in its formula. NDVI = (NIR-RED)/(NIR-RED). The thermal infrared band is the source of LSE in this study area. The aim of this study is to calculate the LST and NDVI of Agra city, India, and to accomplish this task, ArcGIS Raster calculator is utilized. The empirical determine value of NDVI, LSE, and LST with appropriate accuracy help to achieve the aim of this study. In the last drive out the temperature variance in different land use and land cover area of Agra city, India. Keywords: ArcGIS, Landsat satellite images, land surface emissivity, land surface temperature, normalized difference vegetation index, raster calculator, Landsat 8

Coal Seam Gasification in Faulting Zones (Heat and Mass Balance Study)

In this article, the mass and heat balance calculations of underground coal gasification process for thin coal seams in faulting zones of Lvivskyi coal basin (Ukraine) are defined. The purpose of the research is to establish regularities of heat and mass balance changes in faulting zones influence due to usage air and oxygen-enriched blast. A comprehensive methodology that included analytical calculations is implemented in the work. The output parameters of coal gasification products for the Lvivvyhillia coal mines are detailed. The heat balance is performed on the basis of the mass balance of underground coal gasification analytical results and is described in detail. Interpretations based on the conducted research and investigation are also presented. Conclusions regarding the implementation of the offered method are made on the basis of undertaken investigations. According to conducted research the technology of underground coal gasification can be carry out in the faulting zone of stable geodynamic and tectonic activity. The obtained results with sufficient accuracy in practical application will allow consume coal reserves in the faulting zones using environmentally friendly conversion technology to obtain power and chemical generator gas, chemicals and heat.

CORP: Improving the status quo for measuring whole body sweat losses.

The measurement of whole body sweat losses (WBSL) is important to the study of body heat balance, body water balance, establishing guidelines for water and electrolyte consumption, and the study of metabolism and health. In principal, WBSL is measured by an acute change in body mass (ΔBM) in response to a thermoregulatory sweating stimulus. In this Cores of Reproducibility in Physiology (CORP) review, we revisit several basic, but rarely discussed, assumptions important to WBSL research, including the common equivalences: mass = weight = water = sweat. Sources of large potential measurement errors are also discussed, as are best practices for avoiding them. The goal of this CORP review is to ultimately improve the accuracy, reproducibility, and application of WBSL research.

Minimisation of energy consumption of a bioclimatic building based on heat balance study and stand-alone PV system sizing using LLP

ABSTRACTBioclimatic buildings are very comfortable habitats for significant savings in the consumption of daily energy. They help to protect the environment by preventing the emission of dust and pollutant gases into the atmosphere. In this paper, a sizing method is proposed that ensures a suitable internal climate with adequate comfort. First, a simple algorithm is used for the estimation of the heat balance and performance of a typical bioclimatic house in the region of Laghouat, Algeria. Second, the load demand is assured using an optimal stand-alone photovoltaic system sizing method based on the loss of load probability method (LLP) while ensuring the minimum cost of the system. The results show the effectiveness of the proposed method that can be used to develop an optimal building sizing project in all its dimensions, in particular to reduce the overall budget of the operation.

Balances de agua y calor en la marisma de Doñana

<p>Este trabajo expone los principales resultados del estudio de los balances hídrico y térmico de la marisma de Doñana. El estudio se ha basado en una amplia base de datos hidrometeorológicos tomados a intervalos de 10 minutos entre los años 2006 y 2011 por una red de seis estaciones de medida localizadas en áreas no vegetadas de la marisma. Esta información ha permitido caracterizar, a diferente escala temporal, el comportamiento térmico de la marisma mediante la modelización y análisis de los flujos de calor entre el agua y el suelo inundado, así como los procesos de transferencia de calor entre la superficie libre del agua y la atmósfera. Se ha puesto especial atención en la cuantificación de la evaporación, de la que depende en gran medida el proceso de vaciado de la marisma.</p><p class="Resumen"> </p>

Spatial impact of land use/land cover change on surface temperature distribution in Saranda Forest, Jharkhand

Land surface temperature (LST) is an important factor in global climate change studies, in estimating radiation budgets, in heat balance studies and as a control for the climate dynamics and modelling frame. This study analyses the land surface temperature distribution in the region of Gua, Chiria, Megataburu and Kiriburu. Landsat Thematic Mapper and Enhanced Thematic Mapper Plus data of the year 1994, 2004 and 2014 are used to effects of land use/land cover changes on the surface temperature distribution. The remote sensing technique is used to detect the land use changes, its impact on the land surface temperature and variation in mean LST from these hot spots. Thermal infrared remote sensing proved its capability in monitoring temperature and affecting microclimate in urban areas. Results of the study show that the LST of different land use differs significantly. This study also indicates that the external temperature has an impact on surfaces of self-heating areas. This study demonstrates that the growth of rapid mining industrial area significantly decreases the vegetation areas, hence increased the surface temperature. This analysis demonstrates the potential applicability of the methodology for climate modelling frame.

Heat Balance Characteristics of a Pressure Vessel

The study of heat balance in a pressure vessel is an important research area for energy conservation. In the present study, experiments are conducted to measure the heat input, heat energy utilized and heat loss for different volumes of water filled in a pressure vessel. Experiments are conducted on a pressure vessel of volume 0.008 m 3 (8 I) filled with 1, 2, 3 and 3.7 kg of water at 12.5%, 25%, 37.5% and 46% of its capacity respectively. Two approaches are adopted to determine the optimum condition of the pressure vessel. In the first approach, the pressure vessel is insulated and in the other approach it is non-insulated. For both cases, vessels of similar capacity, make and design are used. Outer surface of the vessel is insulated with asbestos rope, clay and cow-dung bindings. There is not much difference in heat input and heat utilization for insulated and non-insulated vessels when the water level is only about 12.5% volume. In other cases, the insulated vessel consumes more heat input than the non-insulated vessel. When the non-insulated pressure vessel is filled with 46% of its volume by water, it utilizes a maximum of 30% of total heat supplied. From the experimental results, polynomial equations are developed for the heat input (Q i ), heat utilized (Q u ) and heat loss (Q 1 ) in terms of mass of the water taken in the vessel under non-insulated and insulated conditions. The equations obtained are validated for different water levels in the same vessels with new sets of experiments.

Analysis of Temperature Field of High Speed Diesel Engine Parts and their Structural Optimization

The analysis of structure and performance of internal combustion engine is presented in this paper from the following two aspects: the thermal load of I. C. Engine and the thermal efficiency of diesel engines. Firstly, the thermal load of key parts of I. C. Engine as well as the evaluation parameters of which are introduced briefly. Furthermore, based on the factors influencing the heat transfer process of internal combustion engine, the current research situation of internal combustion engine work process and heat balance for combustion chamber components, and the whole engine using numerical simulation method is described, while the coupled study of internal combustion engine components is developing trends of internal combustion engine heat balance study in the future.

SURFACE TEMPERATURE ESTIMATION OF GANGOTRI GLACIER USING THERMAL REMOTE SENSING

Abstract. Land surface temperature (LST) is important factor in global climate change studies, for estimating radiation into heat balance studies and as a control for climate change models. The knowledge of surface temperature is important to a range of issues and themes in earth sciences, climate change and human interactions with environment. In this investigation an attempt has been made to estimate surface temperature from ASTER and Landsat Thermal Band data for the Gangotri Glacier. ASTER and Landsat Calibration had been performed to convert digital numbers to exoatmospheric radiance using published post-launch gains and offsets. The exoatmospheric radiance is then converted to surface radiance by applying the Emissivity Normalization method, assuming the emissivity of the Investigation area is constant (0.97, the emissivity of glacier ice). The surface temperature is then extracted from the surface radiance. Based on images from Oct 1990, 2001 and 2010 mean temperatures of 15.763, 15.893 and 17.154 respectively, are inferred. The extracted temperature data were compared to observed temperatures and showed a good correlation, with differences of 1–2oc.The variability of these retrieved Land surface Temperatures has been investigated with respect snout point, ELA and highest point of Gangotri Glacier determined from the Landsat visible bands and ASTER DEM. The emissivity per pixel is retrieved directly from satellite data and has been estimated as narrow band emissivity at the satellite sensor channel in order to minimize the errors in the land surface temperature estimation of study area.

Seasonal and interannual variations of upper ocean heat balance off the west coast of Australia

The Leeuwin Current, a warm, poleward flowing eastern boundary current, dominates the surface circulation off the west coast of Australia and has profound influence on regional marine ecosystem and fisheries recruitment. In this study, the seasonal and interannual variations of upper ocean heat balance in the Leeuwin Current region are analyzed by using an eddy‐resolving numerical model simulation, as a first step to quantify the climate impacts on regional ocean thermodynamics and marine ecosystem. The volume transport and heat advection of the Leeuwin Current are stronger during the austral winter on the seasonal cycle and are stronger during a La Nina event on the interannual scale. On both seasonal and interannual timescales, the mixed layer heat budget off the west coast of Australia is predominantly balanced between the variations of the Leeuwin Current heat advection and heat flux across the air‐sea interface. On the interannual timescale, the variation of the Leeuwin Current heat advection tends to lead that of the air‐sea (latent) heat flux by two months, which is likely a reflection of advection timescales of the Leeuwin Current and its eddy field. The interannual variation of the average February–April sea surface temperature off the west coast of Australia, which is crucial for the larval settlement of western rock lobster, is mostly influenced by the Leeuwin Current heat advection as well as the ocean memory from the previous austral winter, with the air‐sea heat exchange playing a buffering role.

Techniques for analyzing lead condition in visible, infrared and microwave satellite imagery

The condition of a lead or polynya, whether open, partially refrozen, or completely ice covered, is extremely important from many points of view. From a meteorological and climatological perspective the moisture and heat flux resulting from air and sea interaction over leads during cold weather periods is crucial. Enormous cloud plumes have been observed emanating from relatively small openings in leads and polynyas. Modeling studies have shown that plume development is extremely sensitive to changes in humidity, air temperature, and the nature of near‐surface atmospheric lapse rates. The studies indicate that plumes can exist, even in the refreezing process, until the new ice becomes sufficiently thick so that its temperature approaches the temperature of the surrounding ice. Heat balance studies for modeling the arctic environment depend upon knowledge of such distinctions for accurate assessment of the radiation balance over the area at any given time. This paper describes a new visible channel differencing technique shown to have some capabilities in distinguishing between open and refrozen leads and, in larger leads, distinguishing the part that is open from that which is partially or newly refrozen. Output from this technique is correlated with infrared data in two examples over the Beaufort Sea and in a polynya example with additional microwave data over the Laptev Sea. Although in situ evidence for direct documentation of lead condition is limited, the existence of cloud plumes emanating from open leads provides some verification and establishment of remote sensing parameters indicative of an open or closed condition. A logical consistency of values from independent sensors over varying conditions of open water, mixed ice and water, new ice, and first or multiyear ice also provides contributing remote sensing evidence of lead condition.

Evaporation and Bulk Transfer Coefficients on a Forest Floor during times of Leaf-shedding.

The relationship between the flux densities of sensible heat and water vapor and the mean specific concentration profile on the forest floor were examined in this study within a broad-leaved forest during the period of leaf shedding. Heat balance studies, including the energy storage term inside the litter on the forest floor were carried out and the results revealed the evaporation rates of water vapor from the litter into the atmosphere. On the forest floor, the measured sensible heat flux traveled upward and the temperature gradient indicated an upward transfer. The measured water vapor flux also traveled upward, whereas the humidity gradient indicated a downward transfer. The transfer of water vapor depicted a counter-gradient in the humidity profile within the trunk space.In this study, the dry and wet bulb temperatures both inside of and on the surface of the litter were utilized for the lower level of the gradient profile to determine the difference in temperature and specific humidity between the two different heights.Latent heat flux occupied less than 30% of the net radiation in May during periods without rainfall, except after rain events, when it occupied more than 100% of the received energy. Less than 2.0mm/day of water vapor were released after rainfall, and 0.5-0.8mm/day during the period without rainfall in May. 2.0mm/day were released after rainfall and less than 0.5mm/day during the periods without rainfall, occurring in November, in Hokkaido.It is necessary to determine the bulk transfer coefficient for scalars and momentum in order to estimate the quantity transferred from the various surfaces. The bulk transfer coefficient for sensible heat was derived using both the eddy-correlation and gradient profile methods. The coefficient for water vapor was determined through a weighing device technique and the gradient profile method. The bulk transfer coefficient for sensible heat and water vapor on the forest floor was 10 to 50 times greater than that of the snow and ocean surfaces.

Sea ice type maps from Alaska Synthetic Aperture Radar Facility imagery: An assessment

Synthetic aperture radar (SAR) imagery received at the Alaska SAR Facility is routinely and automatically classified on the Geophysical Processor System (GPS) to create ice type maps. We evaluated the wintertime performance of the GPS classification algorithm by comparing ice type percentages from supervised classification with percentages from the algorithm. The RMS difference for multiyear ice is about 6%, while the inconsistency in supervised classification is about 3%. The algorithm separates first‐year from multiyear ice well, although it sometimes fails to correctly classify new ice and open water owing to the wide distribution of backscatter for these classes. Our results imply a high degree of accuracy and consistency in the growing archive of multiyear and first‐year ice distribution maps. These results have implications for heat and mass balance studies which are furthered by the ability to accurately characterize ice type distributions over a large part of the Arctic.

How much wrapping do babies need at night?

In a longitudinal, population based study, overnight temperature recordings were made in the bedrooms of 152 babies aged 3-18 weeks and the insulation provided by their bedclothing was assessed. Outdoor temperatures for the study nights were also available. Parents applied more insulation on colder nights with lower bedroom temperatures than on warmer nights (mean 8.5 tog at 15 degrees C minimum bedroom temperature falling to 4.0 tog at 25 degrees C). For a particular temperature they also applied 2 tog more insulation in winter than in summer. The amounts of bedclothing used in the home were compared with insulation levels predicted to achieve thermo-neutrality over a similar range of environmental temperature from heat balance studies in young infants. They corresponded closely. The average amount of bedclothing chosen for babies in Avon allows them to remain in thermoneutral conditions throughout the night. These values are proposed as broad guidelines for the thermal care of young babies at night.

Snow and ice applications of AVHRR in polar regions: report of a workshop held in Boulder, Colorado, 20 May 1992

The third symposium on Remote Sensing of Snow and Ice, organized by the International Glaciological Society, took place in Boulder, Colorado, 17–22 May 1992. As part of this meeting a total of 21 papers was presented on snow and ice applications of Advanced Very High Resolution Radiometer (AVHRR) satellite data in polar regions. Also during this meeting a NASA sponsored Workshop was held to review the status of polar surface measurements from AVHRR. In the following we have summarized the ideas and recommendations from the workshop, and the conclusions of relevant papers given during the regular symposium sessions. The seven topics discussed include cloud masking, ice surface temperature, narrow-band albedo, ice concentration, lead statistics, sea-ice motion and ice-sheet studies with specifics on applications, algorithms and accuracy, following recommendations for future improvements. In general, we can affirm the strong potential of AVHRR for studying sea ice and snow covered surfaces, and we highly recommend this satellite data set for long-term monitoring of polar process studies. However, progress is needed to reduce the uncertainty of the retrieved parameters for all of the above mentioned topics to make this data set useful for direct climate applications such as heat balance studies and others. Further, the acquisition and processing of polar AVHRR data must become better coordinated between receiving stations, data centers and funding agencies to guarantee a long-term commitment to the collection and distribution of high quality data.

Snow and ice applications of AVHRR in polar regions: report of a workshop held in Boulder, Colorado, 20 May 1992

The third symposium on Remote Sensing of Snow and Ice, organized by the International Glaciological Society, took place in Boulder, Colorado, 17–22 May 1992. As part of this meeting a total of 21 papers was presented on snow and ice applications of Advanced Very High Resolution Radiometer (AVHRR) satellite data in polar regions. Also during this meeting a NASA sponsored Workshop was held to review the status of polar surface measurements from AVHRR. In the following we have summarized the ideas and recommendations from the workshop, and the conclusions of relevant papers given during the regular symposium sessions. The seven topics discussed include cloud masking, ice surface temperature, narrow-band albedo, ice concentration, lead statistics, sea-ice motion and ice-sheet studies with specifics on applications, algorithms and accuracy, following recommendations for future improvements. In general, we can affirm the strong potential of AVHRR for studying sea ice and snow covered surfaces, and we highly recommend this satellite data set for long-term monitoring of polar process studies. However, progress is needed to reduce the uncertainty of the retrieved parameters for all of the above mentioned topics to make this data set useful for direct climate applications such as heat balance studies and others. Further, the acquisition and processing of polar AVHRR data must become better coordinated between receiving stations, data centers and funding agencies to guarantee a long-term commitment to the collection and distribution of high quality data.

Energy Balance Studies and Plasma Catecholamine Values for Patients with Healed Burns

We report heat balance studies and plasma catecholamine values for 49 children and young adults with healed burn wounds (age range 0.6 to 31 years and burn range 1% to 82% body surface area burned; mean 41%). All measurements were made during the week of discharge. Heat production for patients with healed burns was not significantly different from predicted normal values. However, compartmented heat loss demonstrated a persistent increment in evaporative heat loss that was secondary to continued elevation of cutaneous water vapor loss immediately after wound closure. A reciprocal decrement in dry heat loss was demonstrated (as a result of a cooler average surface temperature, 0.84 degree C cooler than the average integrated skin temperature of five normal volunteers who were studied in our unit under similar environmental conditions). Mean values for plasma catecholamines were in the normal range: epinephrine = 56 +/- 37 pg/ml, norepinephrine = 385 +/- 220 pg/ml, and dopamine = 34 +/- 29 pg/ml. In conclusion, patients with freshly healed burn wounds have normal rates of heat production; however, there is a residual increment in transcutaneous water vapor loss, which produces surface cooling and decreased average surface temperature, which in turn lowers dry heat loss by an approximately equivalent amount.