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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.

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.

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.

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.

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.

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.

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.

Relative humidity (RH) at the body-seat interface is considered an important factor in both sitting comfort and generation of health concerns such as skin lesions. Technical difficulties appear to have limited research aimed at the detailed and simultaneous exploration of RH and temperature changes at the body-seat interface; using RH sensors without the capability to record temperature where RH is recorded. To explore the causes of a spike in RH consistently produced on first contact between body and seat surface, we report data from the first use of dual temperature and RH (HTU21D) sensors in this interface. Following evaluation of sensor performance, the effect of local thermal changes on RH was investigated. The expected strong negative correlation between temperature and RH (R2 = −0.94) supported the importance of considering both parameters when studying impact of sitting on skin health. The influence of sensor movement speed (higher velocity approach: 0.32 cm/s ± 0.01 cm/s; lower velocity approach: 0.17 cm/s ± 0.01 cm/s) into a static RH region associated with a higher local temperature were compared with data gathered by altering the rate of a person sitting. In all cases, the faster sitting down (or equivalent) generated larger RH outcomes: e.g., in human sitting 53.7% ± 3.3% RH (left mid-thigh), 56.4% ± 5.1% RH (right mid-thigh) and 53.2% ± 2.7% RH (Coccyx). Differences in size of RH change were seen across the measurement locations used to study the body-seat interface. The initial sitting contact induces a transient RH response (duration ≤ 40 s) that does not accurately reflect the microenvironment at the body-seat interface. It is likely that any movement during sitting would result in similar artefact formation. As a result, caution should be taken when investigating RH performance at any enclosed interface when the surfaces may have different temperatures and movement may occur.

This study examines numericaIly the fate of cooled ocean water discharged into the coastal oceano The ocean water wiIl eventuaIly be used to warm up petroleum liquid gas during transference ftom ship tanks to land tanks, being cooled during the processo The reftigerated water wiIl then be released verticaIly through a single port located at 2 meters below the surface in 15 m of water. The proposed operations wiIl take place at the São Sebastião Channellocated between the continent and the São Sebastião Island, at about 23º48'S, 045º22'W. Estimated mean temperature differences between the eflluent and the recipient sea water wiIl be at most 3ºC. The problem is treated by analogy to an upside-down (buoyant) thermal discharge using established initial mixing models developed by the US Environmental Protection Agency. During summer, when ambient stratification is high, the eflluent plume is evanescent: it reaches the bottom with a temperature greater than the ambient, bounces back towards the surface and reaches equilibrium 10m below the surface. During winter, on the other hand, the plume is bottom confined: it reaches the bottom with a temperature slightly lower than the ambient, remaining at that level. Model results also show that for any ambient ocean conditions the mixing time scale is of order of minutes and the final plume concentration obtained by mixing is smaIler than 10%.Este estudo examina numericamente a descarga de água reftigerada em águas oceânicas costeiras. A água do mar será utilizada para aquecimento do gás liqüefeito de petróleo durante sua transferência dos tanques do navio para o continente, sendo resftiada durante esse processo. A água reftigerada será liberada, através de um único duto localizado a 2 metros abaixo da superficie, em um local cuja profundidade é de 15 metros. Essa operação será realizada no Canal de São Sebastião, localizado entre o continente e a ilha de São Sebastião, em cerca de 23º48'S, 045º22'W. A diferença média da temperatura entre o efIuente e a água oceânica receptora será de no máximo 3ºC. O problema é tratado aqui de forma análoga ao problema de descarga termal (empuxo), utilizando modelos de mistura iniciais desenvolvidos pela Agência de Proteção Ambiental dos EUA. Durante o verão, quando a estratificação é grande, a pluma é evanescente: ela alcança o fundo oceânico com temperatura maior do que a do ambiente, voltando em direção a superficie e alcançando o equilíbrio a 10 metros de profundidade. Durante o inverno, por outro lado, a pluma fica confinada ao fundo oceânico, alcançando o fundo com temperatura ligeiramente menor que o ambiente, permanecendo nesse nível. Resultados do modelo também mostram que para qualquer condição oceânica local a escala temporal de mistura é da ordem de minutos e a concentração final da pluma obtida pela mistura é menor do que 10%.

A review of the effects of wildfires on Mediterranean soils was carried out with special emphasis on the biogeochemical processes involved in soil C sequestration. Modifications to the composition and properties of soil humic substances and related resilient C-forms in soil resulting from fires were also discussed. The systematic effects of fires on soil organic matter (SOM) mainly involve changes to its solubility and colloidal properties, selective thermal degradation, structural condensation and the cyclization of soil C and N-forms. These effects represent an increase in the biogeochemical stability and chemical diversity of the SOM after the thermal generation of structures that are not found in soils unless they are affected by fire. Non-systematic effects also depend on local environmental constraints and on the great differences in fire intensities and propagation patterns. The effects of fire were also discussed, taking advantage of the results of laboratory simulation experiments. This approach is indispensable for differentiating fire intrinsic effects on soil from those produced by fire-induced inputs of charred necromass and the subsequent effects of soil erosion. In some cases, the characteristic properties acquired by post-fire soils can be explained in terms of molecular-level features of humic substances and, in particular, those concerning resistance to biodegradation, cation exchange capacity, N-availability, soil water repellence and aggregate stability. En este trabajo se lleva a cabo una revisión sobre los efectos de los incendios forestales en los suelos mediterráneos, con especial énfasis sobre sus efectos en los procesos biogeoquímicos de acumulación o secuestro de C en el suelo. Asimismo, se revisan los efectos de los incendios sobre la composición y propiedades de las sustancias húmicas y otras formas resilientes de C en el suelo. Las principales efectos sistemáticos del fuego sobre la materia orgánica incluyen cambios en su solubilidad y propiedades coloidales, así como degradación térmica selectiva, condensaciones estructurales y ciclación de formas de C y N en el suelo. Estos efectos, en conjunto, se consideran responsables del aumento en la diversidad química de la materia orgánica debido a la generación térmica de nuevos compuestos inexistentes en los correspondientes suelos no afectados por el fuego. Además de ello, deben considerarse los efectos no sistemáticos del fuego, que dependen de las condiciones ambientales locales y la amplia diversidad de los tipos de incendios. También se discuten los resultados de estudios sobre efectos del fuego en experimentos de simulación en laboratorio, que constituyen una aproximación experimental indispensable para diferenciar los efectos intrínsecos de los incendios en el suelo de aquellos producidos por aportes de necromasa carbonizada. Finalmente, se revisan los efectos del fuego en la estructura molecular de las sustancias húmicas, que pueden ser asociadas con cambios en las propiedades de los suelos, en particular respecto a la resistencia a la biodegradación, capacidad de intercambio catiónico, disponibilidad de N, repelencia al agua y estabilidad de los agregados del suelo.Neste estudo faz-se uma revisão dos efeitos dos incêndios florestais nos solos mediterrânicos dando particular enfase aos efeitos nos processos biogeoquímicos de acumulação e sequestro de C no solo. Por outro lado, revem-se os aspectos relacionados com os efeitos dos incêndios sobre a composição e propriedades das substâncias húmicas e outras formas resilientes de C no solo. Os principais efeitos sistemáticos do fogo sobre a matéria orgânica incluem alterações da sua solubilidade e propriedades coloidais, bem como degradação térmica selectiva e condensação e ciclagem das formas de C e N no solo. Estes efeitos representam um aumento da estabilidade biogeoquímica e da diversidade química da matéria orgânica do solo devido à formação térmica de novas estruturas e compostos inexistentes nos solos não afectados pelos fogos. Para além disso, consideram-se os efeitos não-sistemáticos dos fogos, que dependem das condições ambientais locais bem como da grande diferença de intensidade dos fogos e padrões da sua propagação. Apresentam-se também resultados sobre o efeito dos fogos em ensaios de simulação laboratorial, que constituem uma abordagem experimental indispensável para distinguir os efeitos intrísecos dos incêndios dos produzidos devido a inputs no solo de necromassa carbonizada. Finalmente, faz-se uma revisão dos efeitos do fogo na estrutura molecular das substâncias húmicas associados a alterações nas propriedades do solo, particularmente no que se refere à resistência à biodegradação, capacidade de troca catiónica, disponibilidade de N, caracteristícas hidrofóbicas e estabilidade dos agregados do solo.