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For the first time, we investigated species composition, phytoplankton community structure, and hydrochemical parameters in the artificial cooling reservoir of a major thermal power plant (TPP) in northeastern Europe located in the Pechora River basin (Komi Republic). Our research, conducted during June and August, revealed a total of 81 species of algae and cyanobacteria, with cyanobacteria predominating. Among these cyanobacteria and microalgae (Bacillariophyta and Chlorophyta), algae that serve as reliable indicators of water quality were identified. The assessment of water quality based on abundance and species composition of indicator phytoplankton species revealed that the waters of the Pechorskoe Reservoir belong to the III class (β-mesosaprobic or moderately polluted). This indicates that water quality is satisfactory, and the reservoir retains the ability to self-purify. The power plant's discharges heat the surface layers, increasing plankton communities' diversity, abundance, and biomass. Such stable warming in the upper layers throughout the season, uncommon for natural water bodies in the north, results in a slight increase in the trophic status of the studied reservoir, supported by hydrochemical analysis. These results provide valuable information about ecosystem functioning under temperature increasing for predicting changes in the phototrophic biota of small northern reservoirs facing the impacts of climate change. [ABSTRACT FROM AUTHOR]

Background. The relevance of the article is due to its practical significance for solving the problems of operational safety of ammunition located at storage facilities, when it is necessary to know the time of explosion of products. The article proposes a developed analytical model for determining the permissible exposure time for ammunition to damaging environmental factors (lightning and landscape fire). Materials and methods. Modeling of the process of emergency situations during the explosion of standard or promising ammunition with low-sensitivity explosive compositions under external thermal influence can be described by a Markov random process scheme with a countable number of states. The use of the Markov model makes it possible to apply a well-developed and proven mathematical apparatus and obtain a deliberately reliable result due to the rather strict restrictions adopted. Results and conclusions. Thus, the developed analytical model for determining the permissible exposure time for ammunition to damaging environmental factors can be used to predict the operational safety of products in storage or in the assembly and repair production of arsenals for complex storage of missiles and ammunition. The obtained algorithm for determining the permissible time of exposure to damaging environmental factors on ammunition is advisable to use in the development of promising ammunition with low-sensitivity explosive compositions.

These days, strict requirements to aeronautical equipment are imposed to enhance reliability, durability, and environmental compatibility. Aeronautical equipment operation reliability depends not only on its structural and technologic abilities, but also on the fact how aviation oils, fuels and technical fluid meet quality requirements during operation. During the aircraft engine operation, oils are subjected to the thermal impact. As a consequence, their properties and composition change which can affect the engine operation, on the whole. The most promising means of improving thermal resistance of aviation oils is developing new ones and improving available oil compositions. Therefore, it is feasible to analyze the kinetic properties of the oil thermal conversion which will make it possible to predict their resistance within the extensive temperature range. The paper investigates thermal decomposition kinetics of aviation oils MS-8P, TN-98 and TN-600 used on different types of aircraft in civil aviation of the Republic of Belarus by the method of a thermo-gravimetric analysis. The composition of oil samples has been researched into by IR spectroscopy, chromatography-mass spectroscopy methods. A comparative analysis of research results of new oils and oils drained from aircraft engines indicates that even under insignificant overheat during the operation, a change in the hydrocarbon composition occurs, and the hydrocarbon content of basic types varies to some extent. The oil thermolysis research reveals that potential overheat after engine shutdown complies with the temperatures at which the decomposition commences. Thermal conversion products of oil carbohydrates will contribute to the defect formation in friction subunits. As a result of test data processing of thermal conversion of aviation oils MS-8P, TN-98, TN-600, the principles of their decomposition as well as macrokinetic parameters, allowing us to precisely evaluate the effect of oils operation temperature conditions on their conversion rate, have been specified. It is essential while simulating the aircraft engine operation and predicting variations of oil quality properties during their operation.

PCC exhibit improved durability, chemical resistance and adhesion strength compared to unmodified variants. Commonly, the modifiers consist of thermoplastics. Despite the distinct temperature‐dependent behavior of these polymers, the properties of PCC were barely investigated within different temperatures. To make statements about the effect of different temperatures on the hardening process and therewith on the load bearing and deformation behavior of PCC, the properties of the materials have to be experimentally assessed at a defined temperature range. Accordingly, the degree of hydration, the structure development, the compressive and flexural strength as well as dynamic and static modulus of elasticity of different PCC were characterized while the samples were exposed to service temperatures of ‐20 °C, 20 °C, and 60 °C. After the specimens were thermally conditioned, the samples were tested in the proposed temperature scope. The results reveal influential changes in all tested attributes for the PCC within the applied service temperature range compared to a reference. This knowledge is essential to further investigate the temperature impact on the material and develop appropriate prediction models for the application of PCC and the integration in guidelines. [ABSTRACT FROM AUTHOR]

In this paper, the thermal effects on mechanical properties of polyvinyl alcohol fiber-reinforced engineered cementitious composites (PVA–ECC) were investigated systematically from perspective of multi-scales. At composite level, the compressive strength increases from 38 to 50 MPa as the samples were heated from 30 to 200 °C, whereas it declines to 20 MPa at 800 °C. In respect of tensile performance, at range of 30– 200 °C, the ultimate tensile stress and strain of ECC showed a decrease tendency with rising temperature, but still remained strain-hardening behavior at 200 °C. In addition, the elevated temperature exposures are adverse to multiple-cracking behavior of ECC. At micro-scale, it was found that the fiber/matrix interfacial bond reduces as exposure temperature rises, which is supposed to avail the fiber slippage, and thereby ductility of ECC. Nonetheless, through micromechanics-based analysis, the enhanced matrix toughness and severe deteriorated fiber strength prevailed over the above positive effect, which resulted in the decayed tensile properties of ECC. [ABSTRACT FROM AUTHOR]

The globalisation of the beer market forces brewers to have methodologies that rapidly evaluate the evolution of beer flavour stability. Commonly used forced ageing methods have limitations since temperature and transportation conditions (temperature, vibrations, long-distance travel, and other factors) impact beer quality. This study assessed the prediction power of a forced ageing methodology on the evolution of aldehydes during maritime transportation across four sample groups (maritime transport, storage simulation, and three ageing periods: 7, 21, and 28 days at 37 °C), which differed in their bottle-opening system (either crown cap or ring pull cap). The results revealed that forced ageing up to 28 days could estimate the evolution of phenylacetaldehyde, 3-methylbutanal, 2-methylpropanal, and hexanal during maritime transport. In contrast, the benzaldehyde content was consistently underestimated, on average, 0.8 times lower. In general, the ageing conditions significantly favoured the formation or liberation from a bound state, up to 2.2 times higher, of trans-2-nonenal, acetaldehyde, and 5-hydroximethylfurfural in comparison to the levels registered on exportation simulation beers. Moreover, forced-aged beers with ring pull caps developed quantifiable levels of nonanal and increased phenylacetaldehyde, benzaldehyde, and acetaldehyde content over time. Moreover, thermal stress induced a continuous increase in the extent of beer staling, up to seven times higher, in most samples. [ABSTRACT FROM AUTHOR]

A gas explosion can impact the roadway and cause serious damage. The thermal effect of the roadway wall is an important factor affecting the gas explosion and its impact. In view of the shortcomings of existing research studies, a basic numerical model of a pipe is established under the thermal impact effect of a gas explosion based on LS-DYNA software. The thermal conductivity coefficients of the pipe wall are set as 15, 30, 45 and 60 W/(m·K), respectively. Five measuring points A–E are set on the inner wall of the pipe, and four measuring points F-I are set in the air region. The equivalent stress distribution of the pipe wall, the pressure and displacement of each measuring point and the time history curve of shock wave velocity at the measuring point in the air region are numerically simulated under the impact of a gas explosion with different thermal effects. The research results show that the stress concentration phenomenon is more obvious and the equivalent stress distribution is more uneven, and the gas explosion intensity is greater when the pipe wall is approximately adiabatic. With an increase in the thermal conductivity coefficient, the amount of thermal dissipation through the pipe wall increases, the pressure peak value of each measuring point of the pipe wall decreases as a whole, and the radial displacement value of the arranged measuring points presents a smaller trend. With an increase in the thermal conductivity coefficient of the pipe wall, the thermal dissipation of the pipe wall increases, so the subsequent energy that drives the shock wave decreases, the impact degree on the pipe wall also decreases, and at the same time, in the pipe with a high thermal conductivity coefficient, the gas explosion energy involved in expansion work is lower, and thus the explosion intensity reduces. The shock wave velocity at a location farther away from the explosion source after a gas explosion also decreases. The research results have important practical significance for improving the theory of the wall thermal effect and the level of gas explosion prevention in confined spaces. [ABSTRACT FROM AUTHOR]

The article presents information on the processes occurring during the synthesis of cordierite ceramics produced based on clay from the Krupeisky Sad deposit; the phase composition and properties of the material were studied in detail. The influence of the clay component on the phase and structure formation features in the material during firing, as well as on the structure formation and acquisition of properties during heat treatment, has been established. [ABSTRACT FROM AUTHOR]

In the face of climate change and constantly progressing urbanization processes, so-called heat islands are observed with growing frequency. These phenomena are mainly characteristic of large cities, where increased air and land surface temperatures form an atmospheric (AUHI) or surface (SUHI) urban heat island (UHI). Moreover, UHIs have also been recognized in the underground environments of many cities worldwide, including groundwater (GUHI). However, this phenomenon is not yet as thoroughly studied as AUHI and SUHI. To recognize and characterize the thermal conditions beneath the city of Wrocław (SW, Poland), we analyze the groundwater temperature (GWT) of the first aquifer, measured in 64 wells in 2004–2005. The study aimed to identify groundwater urban heat islands (GUHI) in Wrocław. Therefore, we used a novel approach to gather data and analyze them in predefined seasonal periods. Meteorological data and satellite imagery from the same period allowed us to link GWT anomalies to the typical conditions that favor UHI formation. GWT anomaly related to the GUHI was identified in the central, urbanized part of Wrocław. Moreover, we found that the GUHI phenomenon occurs only seasonally during the winter, which is related to the city's climate zone and anthropogenic heat sources. Comparing our results with previous works from other cities showed untypical behavior of the observed anomalies. In contrast to AUHI and SUHI temperatures, the GWT anomalies detected in Wrocław are characterized by seasonal transitions from a heat island in winter to a cold lake in summer. Such a transitional character of GUHI is described for the first time. [ABSTRACT FROM AUTHOR]

With the substantial improvement of the direct ammonia fuel cells performance, it has become the key to the further development of ammonia fuel cells to deeply understand the heat and mass transfer process inside the cell and to study the thermal impacts generation mechanism during cell operation. In this paper, a whole-cell model of single tubular direct ammonia cracking solid oxide fuel cell (SOFC) is established, and the generation mechanism of thermal impacts inside the cell is analysed in a data-driven method. The model includes the coupling of chemical-electrochemical reactions, local current, local temperature, mass flow and energy transfer inside the cell. It's identified from model simulations that the key to the thermal impact optimization of direct ammonia cracking SOFCs is to reduce the effect of the excessively fast and unbalanced ammonia cracking reaction on the cell. Both introducing the ammonia pre-reforming reaction and improving the activation energy of the ammonia cracking reaction can increase the overall average temperature of the cell and improve the temperature distribution. The 96% ammonia pre-reforming SOFCs can improve the extreme temperature difference in the anode from 37.71 K to 0.52 K at the operating temperature of 800 °C. Increasing activation energy of ammonia cracking reaction by 1.5 times can also make the ammonia cracking reaction rate distribution more uniform at the fuel channel, it can improve the extreme temperature difference in the anode to 4.49 K. This study can enrich the basic theory and research methods of thermal management of direct ammonia cracking SOFCs, and provide theoretical support for further improving cell performance. • A comprehensive model of ammonia-fueled tubular SOFCs is developed. • The generation mechanism of thermal impacts in NH 3 fueled SOFC is analysed. • Effects of pre-reforming and cracking activation energy on SOFCs are discussed. • The key factors for optimizing the thermal impacts performance are revealed. [ABSTRACT FROM AUTHOR]

[Display omitted] • BIPV envelope design optimization is a complex, time-consuming process. • ANN serves as an efficient surrogate model for BIPV performance prediction. • The NSGA-II algorithm effectively optimizes multiple BIPV envelope design objectives. • The proposed framework supports rapid BIPV envelope design optimization during the detailed design phase. • Computational time is significantly reduced by the surrogate-based MOO framework while balancing energy, cost, and comfort. By integrating renewable energy systems (RESs) into buildings, Building-Integrated Photovoltaics (BIPV) reshape the demand–supply relationship, offering substantial benefits such as reduced energy usage, lower greenhouse gas emissions, improved indoor comfort, and architectural enhancement. However, designing optimal BIPV systems involves balancing multiple parameters and conflicting objectives, making it a complex, computationally intensive process. This study proposes a data-driven optimization framework to enhance BIPV envelope design during the detailed design phase. The novelties of this research lie in 1) the use of Artificial Neural Networks (ANN) as a surrogate model for rapid prediction, and 2) a multi-objective optimization (MOO)framework tailored for BIPV design at the detailed design phase. The proposed framework integrates ANN-based predictive modelling with an NSGA-II optimization component to generate optimal BIPV configurations efficiently. Implemented in Python, this approach is validated through a benchmark case study in Melbourne, demonstrating its effectiveness in reducing computational demands while achieving balanced energy, economic, and indoor comfort performance. This research advances sustainable building design by addressing gaps in current optimization frameworks and providing practical tools for architects and designers, promoting the wider adoption of BIPV solutions with significant computational savings. [ABSTRACT FROM AUTHOR]

For the first time, we investigated species composition, phytoplankton community structure, and hydrochemical parameters in the artificial cooling reservoir of a major thermal power plant (TPP) in northeastern Europe located in the Pechora River basin (Komi Republic). Our research, conducted during June and August, revealed a total of 81 species of algae and cyanobacteria, with cyanobacteria predominating. Among these cyanobacteria and microalgae (Bacillariophyta and Chlorophyta), algae that serve as reliable indicators of water quality were identified. The assessment of water quality based on abundance and species composition of indicator phytoplankton species revealed that the waters of the Pechorskoe Reservoir belong to the III class (β-mesosaprobic or moderately polluted). This indicates that water quality is satisfactory, and the reservoir retains the ability to self-purify. The power plant’s discharges heat the surface layers, increasing plankton communities’ diversity, abundance, and biomass. Such stable warming in the upper layers throughout the season, uncommon for natural water bodies in the north, results in a slight increase in the trophic status of the studied reservoir, supported by hydrochemical analysis. These results provide valuable information about ecosystem functioning under temperature increasing for predicting changes in the phototrophic biota of small northern reservoirs facing the impacts of climate change.

A classification is presented of the thermal states of the Sayano-Shushenskaya HPP and methods of identifying them by analysis of the thermal components of radial displacements obtained by the results of finite-element modeling. Based on the safety conditions of the repaired dam zones and the foundation, limit levels are presented for the entire path of filling-and-drawdown of the reservoir, depending on the thermal state of the dam. There is an evaluation of the dynamics of changes in the stress-strain state of the concrete of the dam face, based on finite-element calculation results and measurement data. Reasons are established for crack formation in the repaired zone and the effectiveness of measures taken to regulate the modes of filling-anddrawdown of the reservoir. [ABSTRACT FROM AUTHOR]

Fire is one of the most severe conditions to which buildings may be exposed. However, reinforced concrete has good resistance, which makes it one of the building materials most widely used worldwide. When reinforced concrete is exposed to high temperatures, its skeletal members undergo changes that may lead to, in many cases, inclusive cracking. Beams, columns, and slabs are the most important structural elements in any concrete construction. Structural members are generally designed to satisfy the requirements of serviceability and safety limit states for various environmental conditions. Typically, structural members are created to meet a specific fire resistance grade. The characteristics of the structure and the type of occupation are just two variables that affect fire resistance. Structural fire rating's primary goals are to enable building inhabitants enough time to leave, enough time for firefighters to put out the fire, and enough time to prevent any potential structural damage. This article overviews how various reinforced concrete building structural elements behave when exposed to high temperatures. It has been found that both concrete and reinforcing bars are adversely affected by fire. Furthermore, it has been discovered that flexibility and stiffness decrease with increasing stress or the period of fire exposure. Also, the flexibility and stiffness rise with increasing structural element cross-section; however, the maximum slab deflection non-linearly decreases during the fire test. The bottom of the concrete slab begins to cool as temperatures decrease, which increases the yield strength of the bottom reinforcing and causes it to contract along with the lower half of the slab. This article also presents a review of a set of experimental and theoretical results on the thermal behavior of reinforced concrete slabs, beams, and other structural parts under different conditions and scenarios as a historical review.

Freshwater-seawater (FW-SW) temperature contrasts widely exist in natural coastal aquifers. The significant effects of thermal forcing on water flow and salinity distributions for homogeneous aquifers have been demonstrated recently, however, the impact on heterogeneous aquifers remains unclear. This study conducted simulations of variable-density flow, and heat and salt transport with Monte-Carlo realizations of log-normally distributed permeability fields to examine such impacts. The averaged results showed that warmer freshwater could lead to a significant landward intrusion of freshwater-seawater interface in the heterogeneous aquifer. The random permeability fields increased the thermal effects of warmer freshwater and thus facilitated landward seawater intrusion. Furthermore, under warmer seawater conditions, salt dispersion was enhanced and density effects were reduced in heterogeneous coastal aquifers, thus altering the two opposing seawater circulation cells induced by double diffusion of salt and heat. The clockwise seawater circulation was strengthened whereas the anticlockwise one was weakened. Sensitivity analyses showed that an increased variance of permeability field further inhibited the anticlockwise seawater circulation cell caused mainly by heat diffusion. A larger correlation length of permeability field facilitated the thermal effect on the salinity distribution, increasing the associated uncertainty range caused by FW-SW temperature contrasts.

An alluvial fan is a good area to install open-loop geothermal heat pump (GHP) systems due to shallower aquifers, faster groundwater flow, and fewer land subsidence risks. The natural temperature change in groundwater occurs in alluvial fans due to the recharge of river water and faster groundwater flow, and the thermal impact of the open-loop system has not been studied well in such areas. The purpose of this research is to understand the thermal impact of open-loop GHP systems on an alluvial fan. A regional 3D model of groundwater flow with heat transport was created to determine the distribution of flow velocity and temperature of groundwater. After that, two local models with different groundwater velocities were constructed to demonstrate the thermal impact of an open-loop GHP system using one extraction and one injection well. The results indicated that the local model with faster groundwater flow had a smaller thermal impact. The natural temperature change in groundwater causes groundwater temperature to be lower in the summer and higher in winter during the operation in the local model, with faster groundwater flow. [ABSTRACT FROM AUTHOR]

Prolonged exposure to solar radiation can cause considerable heat stress. The application of reflective materials in garments or sunscreens is generally considered as an appropriate protective strategy. In this study, we aimed to compare a range of reflective and control fabrics on their ability to reduce the thermal impact of solar radiation. We evaluated 16 reflective and 5 control fabrics, varying in applicability for garments and/or sunscreens. Transmission of ultraviolet, visible light and infrared radiation was studied using artificial solar light. Thermal impact reduction was first studied using artificial infrared light and secondly using natural sunlight, measuring temperature right at the back and 10 cm behind the fabric after a 10-minute exposure. Most samples showed comparably low radiation transmission (

The globalisation of the beer market forces brewers to have methodologies that rapidly evaluate the evolution of beer flavour stability. Commonly used forced ageing methods have limitations since temperature and transportation conditions (temperature, vibrations, long-distance travel, and other factors) impact beer quality. This study assessed the prediction power of a forced ageing methodology on the evolution of aldehydes during maritime transportation across four sample groups (maritime transport, storage simulation, and three ageing periods: 7, 21, and 28 days at 37 °C), which differed in their bottle-opening system (either crown cap or ring pull cap). The results revealed that forced ageing up to 28 days could estimate the evolution of phenylacetaldehyde, 3-methylbutanal, 2-methylpropanal, and hexanal during maritime transport. In contrast, the benzaldehyde content was consistently underestimated, on average, 0.8 times lower. In general, the ageing conditions significantly favoured the formation or liberation from a bound state, up to 2.2 times higher, of trans-2-nonenal, acetaldehyde, and 5-hydroximethylfurfural in comparison to the levels registered on exportation simulation beers. Moreover, forced-aged beers with ring pull caps developed quantifiable levels of nonanal and increased phenylacetaldehyde, benzaldehyde, and acetaldehyde content over time. Moreover, thermal stress induced a continuous increase in the extent of beer staling, up to seven times higher, in most samples.

Concrete airfield pavements can frequently suffer from initially small and relatively shallow delamination of the subsurface concrete layer. It may be due to natural and forced temperature impact on the pavement. As a result of these impacts, thermal stresses and other phenomena are formed in the concrete slab. The significant phenomena are those related to the movement of water vapour in the slab cross-section and the associated processes leading to defects of the concrete structure. They are due to the complex interaction of various phenomena: thermal, humidity and strength that were considered damage stimulants. [ABSTRACT FROM AUTHOR]

In the face of climate change and constantly progressing urbanization processes, so-called heat islands are observed with growing frequency. These phenomena are mainly characteristic of large cities, where increased air and land surface temperatures form an atmospheric (AUHI) or surface (SUHI) urban heat island (UHI). Moreover, UHIs have also been recognized in the underground environments of many cities worldwide, including groundwater (GUHI). However, this phenomenon is not yet as thoroughly studied as AUHI and SUHI. To recognize and characterize the thermal conditions beneath the city of Wrocław (SW, Poland), we analyze the groundwater temperature (GWT) of the first aquifer, measured in 64 wells in 2004–2005. The study aimed to identify groundwater urban heat islands (GUHI) in Wrocław. Therefore, we used a novel approach to gather data and analyze them in predefined seasonal periods. Meteorological data and satellite imagery from the same period allowed us to link GWT anomalies to the typical conditions that favor UHI formation. GWT anomaly related to the GUHI was identified in the central, urbanized part of Wrocław. Moreover, we found that the GUHI phenomenon occurs only seasonally during the winter, which is related to the city’s climate zone and anthropogenic heat sources. Comparing our results with previous works from other cities showed untypical behavior of the observed anomalies. In contrast to AUHI and SUHI temperatures, the GWT anomalies detected in Wrocław are characterized by seasonal transitions from a heat island in winter to a cold lake in summer. Such a transitional character of GUHI is described for the first time.

In this paper, an advanced electrothermal model was developed in order to provide real-time information about the thermal states of the electrical components of the vehicle's powertrain and determine the evolution of losses and that of powertrain parameters versus temperature during vehicle traffic. Then, electrothermal models were introduced in order to study the impact of the thermal behavior of the motor–inverter combination on the speed control of an electric vehicle. The obtained results show that the efficiency of the adopted PI regulators with predetermined parameters is heavily affected by the variation of powertrain parameters caused by temperature change. To improve the performance of the vehicle speed control and make the PI regulators adaptable to the variation of the different parameters during a drive cycle, the fuzzy logic technique was adopted. [ABSTRACT FROM AUTHOR]

Water accumulation in permafrost regions causes a heavy thermal impact on the frozen layer, thereby leading to its degeneration. First, based on the real heat transfer process, this study proposes relevant hypotheses and governing equations for heat calculation models involving completely melted water, ice-bearing water, water–soil interface, and soil under water. The models consider the water surface as a thermal boundary on account of the natural buoyancy convection mechanism in water and the phase transition process. Second, this study verifies the accuracy of the calculation models regarding the measured water and permafrost temperatures. The four seasonal vertical temperature changes in the water according to this model are found to be consistent with the actual temperature-change trend, and the permafrost temperature under water is also consistent with the actual temperature field. This study thus provides theoretical support for the thermal impact analysis of water in permafrost regions.

Objectives This work was devoted to the research of thermal processes that occur in the reflex areas of the human body, in particular, in reflexogenic areas of the human foot, under the thermal influence under ambulatory conditions.Method A model of thermal impact on the reflex areas of the human body was developed on the basis of a semiconductor thermoelectric device. A simplified physical model was studied, which does not consider heat exchange in thermoelectric batteries (TEBs) and elements of TEBs pairing with separate reflex zones.Results Diagrams for temperature distribution throughout the foot at different values of heat flow and diagrams of temperature changes over time were obtained. The thermal influence of a TEB brought in thermal contact with the opposite surface of the foot is negligible in this case; this is due to the low thermal conductivity of foot tissues, as well as insignificant thermal flows on its surface (low-power TEBs were used for such procedures).Conclusion The developed model of a semiconductor thermoelectric device for treating the reflex areas of the human body – in particular, the foot – allows an investigation of thermal processes occurring during the thermal treatment of biologically active points of the human sole. It is established that local temperature impact on a biological object does not result in significant temperature difference over its thickness.

Abstract The use of shallow geothermal energy increasingly receives attention as a suitable alternative to fossil fuel-based space heating and cooling, warm water provision, as well as for seasonal heat storage throughout Europe. With the advent of shallow geothermal energy use on large scales, a vivid discussion of potential ecological and economic impacts has arisen but actual field data are scarce. An intensive groundwater temperature-monitoring program over a period of 3 years with consecutive measurements was, therefore, initiated at a residential neighborhood in the city of Cologne, Germany, under intense shallow geothermal use. The aim of the monitoring program was to overcome the existing data scarcity by pinpointing the effects of the intensive thermal use of the subsurface on groundwater temperatures and to foster understanding of urban groundwater temperature evolution. Results show that even though energy demands of the individual houses and energy extraction rates of the shallow geothermal systems were comparably small in this case, the accumulation of shallow geothermal users had a measurable impact on overall groundwater temperatures.

An alluvial fan is a good area to install open-loop geothermal heat pump (GHP) systems due to shallower aquifers, faster groundwater flow, and fewer land subsidence risks. The natural temperature change in groundwater occurs in alluvial fans due to the recharge of river water and faster groundwater flow, and the thermal impact of the open-loop system has not been studied well in such areas. The purpose of this research is to understand the thermal impact of open-loop GHP systems on an alluvial fan. A regional 3D model of groundwater flow with heat transport was created to determine the distribution of flow velocity and temperature of groundwater. After that, two local models with different groundwater velocities were constructed to demonstrate the thermal impact of an open-loop GHP system using one extraction and one injection well. The results indicated that the local model with faster groundwater flow had a smaller thermal impact. The natural temperature change in groundwater causes groundwater temperature to be lower in the summer and higher in winter during the operation in the local model, with faster groundwater flow.

Water temperature is fundamental to understand the functioning of aquatic systems. The objective of this study was to assess the effect of warm water discharge from a nuclear power plant on the water surface temperature (WST) of a reservoir. Using a 6-year Landsat-derived WST dataset, which includes 3 years of the power plant being in operation (2013–2015) and 3 years in which the power plant was not functioning (2016–2018), the effect of the thermal pollution was assessed. The results show that, although the warm water discharge did not reveal a statistically significant increase on the mean WST of the reservoir (p > 0.05), multi-temporal Landsat imagery revealed that the power plant generated a local thermal impact. This was the principal heat flux following a dissipation line that was wide near the cooling channel and expanding towards the rest of the reservoir. [ABSTRACT FROM AUTHOR]

This study investigates the thermal impact of using different winding topologies and different winding encapsulation materials on dual‐stator 6/4 flux‐switching permanent magnet (FSPM) machine with water jacket cooling. The thermal performance of four different design cases are compared using lumped‐parameter thermal network models. The modelling of the heat transfer in the stator slot, machine air gap and water jacket channel are presented. It is shown that FSPM machines with circumferential winding and toroidal winding have different thermal limiting components and the winding encapsulation material has a different impact on the thermal performance of the two winding topologies. Prototype motors are built and tested to validate the thermal models. [ABSTRACT FROM AUTHOR]

The dependence of the surface morphology of ion-plasma coatings on the temperature influence in vacuum was investigated. The coatings were formed by vacuum-arc method with the use of pulsed highfrequency stimulation of deposition. To compare the frictional properties, Ti-Hf metal coatings obtained in argon medium and (Ti-Hf-Si)N composite coatings were investigated. The coatings were annealed in a high temperature vacuum oven. The roughness of the coatings was investigated using a profilometer. In order to detail the structure of the surface of coatings before and after annealing, a study was carried out using an atomic force microscope. It is established that thermal influence on the surface of nanostructured coatings significantly changes the surface morphology. Such changes lead to the evolution of the structural and physico-mechanical characteristics of the coatings. The results of tribotechnical studies of Ti-Hf and (Ti-Hf- Si)N coatings are presented. The results of thermal influence on the samples of (Ti-Hf-Si)N nanocomposite coating are analyzed. The results of the study of the surface of these coatings are compared. A decrease in the (Ti-Hf-Si)N coating roughness was found by annealing and an increase in hardness to 55.7 GPa. The evolution of the surface morphology of the coatings is the result of changes in the coating structure and recrystallization processes. The studied statistical characteristics of the relief of the surface of the coatings are consistent with other experimental results. [ABSTRACT FROM AUTHOR]

Groundwater heat pump (GWHP) systems have gained attention for space heating and cooling due to their efficiency and low installation costs. Their number is growing in many countries, and therefore in some areas, dense installations are expected. This might lead to thermal interferences between neighbouring groundwater wells and a decrease in efficiency. In the presented study, three analytical formulations are inspected for the prediction of the thermal plume around such open-loop systems under various hydrogeological conditions. A thermal radial transport scenario without background groundwater flow and two advective scenarios with moderate to significant ambient flow velocities (1 and 10 m d−1) are analytically simulated and compared with numerical simulations. Two-dimensional (2D) numerical models are used to estimate the validity of analytical results for a homogeneous confined aquifer, without considering heat transfer in upper and lower layers of the aquifer. In order to represent more realistic aquifer conditions of limited vertical extension, an additional three-dimensional numerical model (3D) is deployed to account for vertical heat losses. The estimated relative errors indicate that the analytical solution of the radial heat transport is in good agreement with both numerical model results. For the advective scenarios, the suitability of the linear and planar advective heat transport models strongly depend on ambient groundwater flow velocity and well injection rate. For low groundwater velocities (1 m d−1), the planar model fits both numerical model results better than the linear advective model. However, the planar model's ability to estimate thermal plumes considerably decreases for high injection rates (>0.6 l s−1). In contrast, the linear advective model shows a good agreement with the two-dimensional numerical results for high groundwater flow conditions (≥10 m d−1). The comparison with the three-dimensional numerical models indicates that the vertical heat transfer is challenging for all of the selected analytical solutions. Despite this, there is a wide range of applicability for the provided analytical solutions in studying the thermal impact of GWHP systems. Hence, the inspected solutions prove to be useful candidates for first-tier impact assessment in crowded areas with potential thermal interferences. • Three analytical models for thermal impact assessment of GWHP systems are evaluated. • Their validity is evaluated for common hydrogeological conditions. • Analytical predictions are compared with 2D and 3D numerical model results. • For each examined scenario, an analytical model satisfactorily estimates the impact. • The analytical models are suitable for prior assessment of GWHP systems' thermal impact. [ABSTRACT FROM AUTHOR]

Although CO2 storage has been comprehensively investigated, fewer scholars have taken the effect of temperature and the dual-porosity structure of coal into account, which brought a large deviation for the study of CO2 storage. In this work, a hydraulic-mechanical-thermal coupled model of CO2 storage is established, considering the dual-porosity structure features and non-isothermal adsorption of coal. The controlled variable method was used to simulate CO2 injection into coalbed with different characteristic parameters. The results show that the CO2 storage rate follows the law of first reducing and then stabilizing. The variation of permeability is a competition result of two types of factors: one is the coal matrix shrinkage caused by pressure increase and the other is the coal matrix expansion caused by the increase of temperature and CO2 adsorption. In the process of CO2 injection into the coal seam, the matrix expansion caused by the increase of temperature and CO2 adsorption becomes the dominant role, which makes the permeability reduce with time. The higher the initial temperature of coal seam, the less the volume of CO2 adsorbed by the unit mass of coal and the smaller the CO2 storage rate; the greater the degree of coal fracture development, the greater the CO2 seepage rate, the smaller the CO2 storage rate, and the increased volume strain of coal, which can reduce the storage rate of CO2. The initial temperature of coalbed, fracture development degree, and geostress have different degrees of influence on CO2 storage. Taking CO2 storage rate as an evaluation criterion, the fracture development degree has the greatest impact on it, and the influence of geostress is the least. [ABSTRACT FROM AUTHOR]

The growing interest in shallow geothermal resources leads to dense installation areas, where interference and decrease in efficiency might occur. To optimize geothermal use in cities which prevents interference between neighbouring and future installations, we present a novel concept relying on the definition of thermal protection perimeters (TPP) around geothermal installations. These perimeters are determined by quantifying the thermal probability of capture around closed- and open-loop geothermal systems. Then, the maximal acceptable power that can be exploited in the vicinity of the installations can be continuously mapped. Existing analytical heat transport models are adapted to calculate these thermal capture probabilities. Two applications are illustrated in Lyon (France). The first application shows that adapted analytical models can help to manage multiple geothermal installations already in place in sectors of few square kilometres. In the second application, a numerical deterministic model is used to determine the TPP of one open-loop system at a local scale. The numerical approach applied for this case allows to account for flow disturbances caused by underground constructions, and thus offers a refined representativeness of the probability of capture. The presented methodology facilitates compatibility assessments between existing and planned new geothermal installations, which is otherwise not feasible by only mapping thermal plumes caused by existing installations, as done in common practice. • A novel methodology to manage multiple geothermal installations is presented. • This methodology is based on the delineation of capture zones. • Two analytical models are adapted to determine thermal probabilities of capture. • A numerical model is used to apply the methodology in a densely built environment. [ABSTRACT FROM AUTHOR]

The focus on green efficient schools is increasing globally. Both private and public-school buildings in the UAE are considered high energy consumers, using significant amounts of energy to maintain a comfortable thermal environment for students. Unfortunately, the designs of these schools have overlooked traditional passive design solutions such as courtyard design and orientation, which can improve internal thermal conditions while minimizing energy consumption. Therefore, this research aims to examine and emphasize the thermal impact of courtyard design and orientation in five existing public schools, with the goal of incorporating these considerations into future green school designs. The research utilized a qualitative approach, employing ENVI-met software to analyze the thermal effects of the schools' orientations. The findings indicated that the case studies exhibited varying temperatures based on the orientation and configuration of their courtyards. Furthermore, the research identified the optimal school building courtyard, which belonged to the UPA-fin school. This design featured north-facing, semi-opened courtyard that blocked hot winds, with rectangular shape oriented east-west, and specific proportions for courtyard area to plot area 26%, and to building area 40%. Compared to the poorest school courtyard design KAT, UPA-fin recorded temperature reductions of 1.7 °C and 1.8 °C on 21st September and March respectively. • The orientation of the schools' courtyards can affect their thermal performance. • The effect of the courtyard's orientation depends on the courtyard ratio size, courtyard type and number. • Considering the design and the courtyards orientation in vital to have better thermal performance for school buildings. • Th courtyards' orientation affects the closed courtyards less than the semi opened courtyards. [ABSTRACT FROM AUTHOR]

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Abstract What is the heat beneath our feet? There is a growing interest in the geothermal resources available at shallow depth beneath cities. However, there exists no general procedure for quantifying the low-temperature geothermal potential in urban ground and groundwater. This review categorizes previous work based on different definitions of the geothermal potential and compares the different assessment methods used. It is demonstrated that the theoretical potential of the available heat at a shallow depth is enormous, especially when not only the heat in place, but also compensating heat fluxes are considered. The technical potential describes the extractable heat by a specific technology. The methods to evaluate the extractable heat are manifold, including the use of technical performance standards, analytical and numerical simulation tools and mathematical regression procedures. These are different for groundwater well based open-loop systems and heat-exchanger-based closed loop systems, and the results depend on variable local factors, the density of systems applied and whether heat and/or cold is utilized. We contrast the published findings based on the power density and the relative contribution to the demand of a city. The broad span of the results highlights the need for a more consistent framework that distinguishes between the conceptual assumptions for calculating the technical geothermal potential and the local city-specific factors. This will be the basis for a reliable analysis of the economic geothermal potential of low-temperature geothermal applications on a local, district or city scale. This will also enhance the reliability and the trust in these technologies, and thus the public acceptance reflected in the acceptable geothermal potential. Graphical abstract fx1 Highlights • Exploration of the manifold computational concepts behind geothermal potential. • Development of a common novel framework with differently defined potential classes. • Assessment of available approaches for quantification of different potential types. • Contrasting of previous findings for the geothermal potential to the energy demand. [ABSTRACT FROM AUTHOR]

Abstract Thermal images of water bodies often show a radiance gradient perpendicular to the banks. This effect is frequently due to mixed land and water thermal pixels. In the case of the Landsat images, radiance mixing can also affect pure water pixels due the cubic convolution resampling of the native thermal measurements. Some authors recommended a general-purpose margin of two thermal pixels to the banks or a minimum river width of three pixels, to avoid near bank effects in water temperature retrievals. Given the relatively course spatial resolution of satellite thermal sensors, the three pixel margin severely restricts their application to temperature mapping in many rivers. This study proposes a new algorithm to enhance the retrieval of stream surface temperature using Landsat 8 thermal data, although it is also applicable to Landsat 7 and Landsat 5. The aim is not to perform a subpixel radiance unmixing but to refine the selection of unmixed, reliable pixels for temperature mapping. For this purpose, the spatial arrangement of native Landsat thermal pixels is approximated, and pure water pixels in the downscaled thermal band are selected accordingly. The least-favourable cubic convolution near-bank radiance mixing is simulated on image basis. Only pure thermal water pixels unaffected by the simulated worst-case resampling are selected. The algorithm allowed retrieving water surface temperature in reaches down to 120 m wide, clearly improving the existing three pixel, i.e. 300 m for Landsat 8, recommendation. The enhancing algorithm was applied to a reach in the Ebro River reach, Spain. It provided spatially distributed temperatures in narrow parts, upstream and downstream of a wide reservoir, offering new insight of the overall impact of the reservoir over the river thermal regime. Highlights • Stream temperature mapping is generally limited to reaches wider than 3 pixels. • A new algorithm is proposed to enhance temperature retrievals from Landsat data. • It refines the selection of accurate thermal data in reaches 1 to 3 pixels wide. • Enables observation of thermal gradients at regional scale in medium size rivers • Application to a river an reservoir provides new insight of regional thermal impact. [ABSTRACT FROM AUTHOR]

Building-Integrated Photovoltaic (BIPV) is a viable technology towards increasing renewable energy production and achieving low carbon footprints for buildings. Mauritius, with a daily average of 5.6 kWh/m2 of solar radiation over 2350 h annually, has been targeting at achieving its low carbon goals by focusing on photovoltaic technology including the uptake of BIPV. However, BIPV has not been well researched in terms of its overall thermal impact especially overheating on the building envelope and the resultant energy performance for buildings for the tropical climatic condition in Mauritius. This research, by means of validated simulation modelling, adopted a novel approach of coupling thermal finite element analysis (FEA) with whole building dynamic simulations to assess the heat transfer characteristics of BIPV either on facades or roof and the resultant energy consumptions of a typical office building in Mauritius. The façade scenario had two options, namely BIPV curtain wall and BIPV double-skin façade (BIPV-DSF), while the roof scenario also had two options, namely uninsulated and insulated roof BIPV membranes. Results show that roof BIPV membrane options had a better thermal performance in reducing overheating for the building compared to the BIPV façade options, with a reduction in cooling load of 8% and 15% for the uninsulated and insulated BIPV membranes, respectively. In terms of energy performance, both BIPV façade options were not capable of reducing the energy consumption of the building, as the BIPV curtain wall resulted in 1.66% more net energy consumption on a yearly basis. This shows an ineffectiveness of using vertical BIPV glazing for typical office buildings in Mauritius. Although the BIPV-DSF achieved an annual net energy saving of 5.16% benefited from the BIPV energy production, it was not as good as the net savings of 160% and 172% from the respective uninsulated and insulated roof BIPV membrane options. [ABSTRACT FROM AUTHOR]

Experimental observations have revealed the patterns of transformation of the surface of firearm toolmarks on fired bullets and spent cartridge cases caused by exposure to heat. The relationship between the nature of these changes and the temperature and period of exposure in modeled conditions has been established. The paper outlines heat exposure parameters and upper temperature limits for successful firearm identification by toolmarks on bullets and cartridge cases.

For the first time, we investigated species composition, phytoplankton community structure, and hydrochemical parameters in the artificial cooling reservoir of a major thermal power plant (TPP) in northeastern Europe located in the Pechora River basin (Komi Republic). Our research, conducted during June and August, revealed a total of 81 species of algae and cyanobacteria, with cyanobacteria predominating. Among these cyanobacteria and microalgae (Bacillariophyta and Chlorophyta), algae that serve as reliable indicators of water quality were identified. The assessment of water quality based on abundance and species composition of indicator phytoplankton species revealed that the waters of the Pechorskoe Reservoir belong to the III class (β-mesosaprobic or moderately polluted). This indicates that water quality is satisfactory, and the reservoir retains the ability to self-purify. The power plant's discharges heat the surface layers, increasing plankton communities' diversity, abundance, and biomass. Such stable warming in the upper layers throughout the season, uncommon for natural water bodies in the north, results in a slight increase in the trophic status of the studied reservoir, supported by hydrochemical analysis. These results provide valuable information about ecosystem functioning under temperature increasing for predicting changes in the phototrophic biota of small northern reservoirs facing the impacts of climate change.

Although CO 2 -enhanced coalbed methane (CO 2 -ECBM) recovery has been comprehensively investigated, fewer scholars have taken the effect of temperature into account, which brought a large deviation for the study of the influence of CO 2 -ECBM. In this work, a hydraulic-mechanical-thermal coupled model of CO 2 -ECBM is established, it combines binary gases (CO 2 and CH 4 ) infiltration and diffusion, where non-isothermal adsorption is also considered. The effect of injection pressure and reservoir initial temperature on CO 2 -ECBM was simulated by the finite element simulation software COMSOL Multiphysics, results show that: the injection of CO 2 into coalbed has a good effect on enhancing the production of CH 4 , and both the CO 2 storage rate and CH 4 production rate increase with the increase of injection pressure. The effect of initial reservoir temperature on CO 2 -ECBM is obvious. Since the amount of adsorbed gas in coal decreases with the increase of temperature, the CO 2 storage rate and CH 4 production rate decrease with the increase of initial reservoir temperature. In the gas extraction process without CO 2 injection, the variation of permeability is competition result of two types of factors: the coal matrix shrinkage caused by temperature reduction and gas desorption increase, the other is the coal matrix expansion caused by gas pressure decrease, so the permeability follows the rule of first decreasing and then increasing with the extraction time. The injection of CO 2 has a great influence on the permeability of coalbed, adsorption of CO 2 by the coal matrix causes the permeability to drop rapidly. [ABSTRACT FROM AUTHOR]

Different aspects of management policies for shallow geothermal systems are currently under development. Although this technology has been used for a long time, doubts and concerns have been raised in the last years due to the massive implementation of new systems. To assess possible environmental impacts and manage subsurface energy resources, collecting data from operating shallow geothermal systems is becoming mandatory in Europe. This study presents novel advances in the upscaling of operation datasets obtained from open-loop geothermal energy systems for an optimal integration in hydrogeological models. The proposed procedure allows efficient numerical simulations to be performed at an urban scale. Specifically, this work proposes a novel methodology to optimize the data treatment of highly transient real exploitation regimes by integrating energy transfer in the environment to reduce more than 90% registered raw datasets. The proposed methodology is then applied to and validated on five different real optimization scenarios in which upscaling transformation of the injection temperature series of 15-min sampling frequency has been considered. The error derived from each approach was evaluated and compared for validation purposes. The results obtained from the upscaling procedures have proven the usefulness and transferability of the proposed method for achieving daily time functions to efficiently reproduce the exploitation regimes of these systems with an acceptable error in a sustainable resource management framework. [ABSTRACT FROM AUTHOR]