Thermal Zone Research Articles

Immunity to Invasive Fungal Diseases.

Invasive fungal diseases are rare in individuals with intact immunity. This, together with the fact that there are only a few species that account for most mycotic diseases, implies a remarkable natural resistance to pathogenic fungi. Mammalian immunity to fungi rests on two pillars, powerful immune mechanisms and elevated temperatures that create a thermal restriction zone for most fungal species. Conditions associated with increased susceptibility generally reflect major disturbances of immune function involving both the cellular and humoral innate and adaptive arms, which implies considerable redundancy in host defense mechanisms against fungi. In general, tissue fungal invasion is controlled through either neutrophil or granulomatous inflammation, depending on the fungal species. Neutrophils are critical against Candida spp. and Aspergillus spp. while macrophages are essential for controlling mycoses due to Cryptococcus spp., Histoplasma spp., and other fungi. The increasing number of immunocompromised patients together with climate change could significantly increase the prevalence of fungal diseases.

Evaluation of simplified building energy models for urban-scale energy analysis of buildings

Simplification of building energy models is one of the most common approaches for efficiently estimating the energy performance of buildings over a whole city. In city-scale models, the abstraction of a building into an information model and the division of the model into representative thermal zones cannot be building-specific but must be generic and applicable to many buildings. Considering the limited research on the performance of such methods, in this study, a comprehensive evaluation of the most relevant assumptions on zoning configurations and levels of detail is conducted in three building energy simulation tools IDA ICE, TRNSYS, and EnergyPlus. The findings from the evaluation of zoning configuration on building level and its comparison with the measured energy performance of buildings suggest that a single-zone model of a residential building gives a very similar result to a multi-zone model with one core zone and perimeter zones for every floor of the building. For the single-zone model, IDA ICE overestimates and EnergyPlus underestimates the energy demand compared to the more complex models by approximately the same amount, but EnergyPlus is preferred due to the shorter simulation time. It is also proven that higher levels of detail in building models can increase the accuracy of the results by approximately 6% annually. When extending the scope of the study from building level to district level analysis where a somewhat lesser degree of accuracy can be allowed on the individual building, the simplified models give acceptable results.

Integrated Assessment of Weldability of Steel with Increased Strength

Modern production of agricultural equipment and facilities, hulls of ships, stationary oil drilling platforms, wind energy installations and other metal structures makes extensive use of sheet steel of increased strength. The main manufacturing process is welding, the quality of which depends on multiple factors, including the ability of steel to resist welding. It is known that the properties of the thermal influence zone are highly dependent on phase transformations, the nature of which is determined by the intensity and development of diffusion processes of carbon redistribution and alloying elements under the impact of the welding thermal cycle. Therefore, it is necessary to evaluate the weldability of the steel of a certain chemical composition, in order to choose the optimal method and the technological parameters of the welding mode for the manufacture of a specific metal structure. In order to reduce material costs, you can use analytical calculation methods that were developed at the E.O. Paton Electric Welding Institute. They are based on the analysis of the literature and the study of about 150 diagrams of the thermokinetic decomposition of austenite. Mathematical models make it possible to predict with a sufficient degree of accuracy the phase composition and mechanical properties of the high-temperature thermal influence zone depending on the chemical composition and cooling time of the metal, heated to a maximum temperature of 1350ºC, in the temperature range 850-500ºC. However, such tests are quite expensive and do not allow optimization of weld properties when the welding mode, mode, welding materials and other underlying technological factors change. In this connection, the objective was to assess the reliability of the proposed methodology in the study of weldability of shipbuilding steel of the increased strength of the category E36, for the weakest T(transverse) – the orientation of the sheet of 50 mm thickness. A high performance of the steel category is achieved by a limited increase in the aluminium content or other grain-crushing elements (Nb, V, Ti), which ensures that the size of the austenitic grain is not greater than the fifth point. The research showed that analytical methods for calculating the mechanical characteristics of high temperature HAZ sites by chemical composition, taking into account the cooling rate after welding, provide a level of confidence sufficient for practical application and can be recommended for the primary evaluation of the properties of welded compounds of high-thickness steel plates of category E36 (T-orientation). The impact work (KV-40) of the high-temperature sections of the high-temperature thermal influence zone is not subject to an analytical evaluation with the degree of accuracy required for production practice

Miniaturized and IoT Enabled Continuous-Flow-Based Microfluidic PCR Device for DNA Amplification.

Herein, a continuous-flow driven microfluidic device has been designed and fabricated using the CO2 laser ablation method for polymerase chain reaction (PCR). The device consists of a polymethyl methacrylate (PMMA) microfluidic channel with 30 serpentine thermal cycles, an arduino board, two custom-made cartridge heaters, and thermocouple sensors. The portable thermal management system, with aluminium blocks placed on a wooden substrate, working on the PID controller principle, is low-cost, battery-powered, automated, integrated, and IoT-enabled. The device with dimensions 80×72×36 mm3 (L × W × H) has a temperature accuracy of ±0.2 °C. The IoT module enables accessing and storage of real-time temperature values directly onto the smartphone through ThingSpeak analytics. It was developed to achieve desirable accurate temperature at two thermal zones, denaturation and annealing (95 °C and 60 °C) on the microfluidic thermal management platform. A PCR mixture of [Formula: see text] was infused into the serpentine-based microchannel using a syringe pump. Amplification of DNA template with 594-base pair (bp) fragment of the rat GAPDH gene was successfully performed on the miniaturized thermal management system. The total time required for a complete PCR reaction was 32 min at an optimum flow rate of [Formula: see text]/min. The amplified sample of the target DNA obtained from the PCR microchannel was then separated by agarose gel electrophoresis and was further analyzed using a gel-doc system. Finally, the obtained results were compared to the conventional PCR instrument showing excellent performance.

Full-Fledged Use of Semi-Basement Space by Building Seismic-Resistance, Energy-Efficiency, Microclimate and Preventing Influences of Thermal Bridges and Mold Growth

The known theory and experience of energy-saving architecture allow solving the article's task and ensuring sufficient insolation, passive solar heating, and occupants contact with nature through semi-basement windows. The goal is a full-fledged use of the semi-basement space achieved for seismically active regions with a moderate, cold, and hot climate by ensuring the normative seismic-resistance, energy-efficiency, and microclimate of the building and preventing influence of thermal bridges and mold growth. The set of recommendations also covers the provision of the required sanitary-hygienic conditions in the semi-basement rooms. The multidisciplinary problem is solved by integrating the methodologies of various fields of science. By means of numerical investigations, it established that the soil adjacent to the semi-basement foundation wall increases the thermal mass and building envelope heat-protection capacity. The isotherms and the intensity of heat fluxes made it possible to eliminate the effect of thermal bridges that interact with the soil and outside air. The expedient thickness and width of the additional layer of thermal insulation of thermal bridge zones in excess of the normative layer of the enclosure's thermal insulation were established. The graphical dependence of the wall's inner corner temperature from this width allows selecting the microclimate level. A multilateral contribution to building improvement is derived from a single-family home example: comfortable microclimate conditions have been created in the semi-basement for placing main rooms there; energy savings for heating this space is 16-20%; saving of monolithic frame and foundation concrete is 10-12% ensuring the higher than normative building seismic-resistance.

THE PROPERTIES OF THE SECONDARY COPPER ALLOY

The use of scrap metal and waste solves the problems of preservation of natural resources, reduces energy and economic costs. In mechanical engineering, aluminum bronzes are one of the most popular, they are used in products where such indicators as high strength and ductility, wear resistance and corrosion resistance are needed. (Research purpose) The research purpose is to make a surfacing electrode from scrap copper alloys, to investigate the properties and the coating processes when applying this material. (Materials and methods) The article presents the microstructure and microhardness of the secondary bronze coating and the material for surfacing by the method of electroerosive dispersion of bronze scrap. A compact semi-finished product was created from the resulting powder using spark plasma sintering technology, which was applied to steel samples by electric spark treatment. (Results and discussion) The study of the microhardness of the coatings showed that the coatings made of bronze BrAZh9-4 have a microhardness approximately 1.7-2 times greater than sintered bronze, while the characteristics of the thermal influence zone and its presence directly depend on the substrate material and the electrode material. When getting materials by this method, the elemental composition can be adjusted depending on the required tasks. (Conclusions) The studied material after spark plasma sintering consists of finely dispersed spherical grains, which affects the application parameters and coating characteristics. When applying a coating with the same electrode to different grades of steel, the coating changes with the same parameters of the material application.

Impact of land-use dynamics on land surface temperature in Mumbai city, India: A geospatial approach

To assess and monitor the environmental dynamics on a regional or global scale, Land Surface Temperature (LST) has been estimated for South Mumbai, using Landsat data for the years 2000, 2010, 2015, and 2020. The urban heat island (UHI) effect has also been assessed by analysing the LST pattern in the study area. The normalized difference vegetation index (NDVI) analysis shows that LST and UHI effects are less when vegetation cover is high. On the contrary, the normalized difference built-up index (NDBI) is directly proportional to LST which indicates the impact of human activities on LST as well as UHI. The relationship between LST of the study area and ambient air temperature has shown a strong correlation with an increasing trend of LST from 2000 to 2020. The study reveals that the average LST of Mumbai has been increased from 27.1 to 32.7 °C in the last twenty years. The ward-wise temperature profile analysis has been carried out to address the worst thermal discomfort zone and associated population. The study suggests increasing the green space for maintaining the average LST in Mumbai. This study provides a baseline for future studies like LST and human health, climate change, assessment of the ecological status, etc. of the urban environment.

Design and manufacture of automotive components in thermoplastic composite (Part II)

The thermoplastic RTM process (T-RTM) is currently one of the most demanded process for R&D in the automotive sector. This sector tries to lighten the weight of the vehicle with highly resistant non-metallic components and with efficient manufacturing in cycle-time and cost. In the framework of the BIHARKONP project, EDERTEK-TECNALIA proposes the migration of a suspension arm, currently manufactured by means of metal stamping, to high mechanical requirements composite materials, obtaining a weight reduction of 30%. For the manufacture of this component it was proposed to redesign the component in carbon fiber (CF) and polyamide 6 matrix (APA6). The redesign (Part I) consisted in a mechanical calculation of the loads that the component had to support. The geometry has been changed with the aim of fulfilling the part specification and the peculiarities of the T-RTM process. For the manufacture of the component, a CF/APA6 composite laminate was defined and characterized and a specific CF for thermoplastics was selected. Subsequently, a T-RTM mold was designed and manufactured with inserts for fiber compaction and eight thermal control zones. The geometry of the control arm involves the manufacture of CF preforms by means of a thermal forming process with thermoplastic veils. Caprocast technology has been used to manufacture the prototype by caprolactam injection and its polymerization inside the heated mold. The prototype was subjected to bearing test, bushing insertion-extraction test and bushing strength test. The component was validated.

Modification of gas-thermal coatings by laser radiation

The results of the researches which determine the dependence of gas-thermal coating porosity on the laser radiation parameters are given in the article. It determines such operational characteristics as thermocyclic and corrosion stability. In order to solve the problem, at the first stage the based on analytic dependences effect of a laser radiation to surface layers of gas-coating is described. The discontinuity of coating was taken into account, what was explained by presence of open and closes pores. It was shown that it’s necessary to produce the temperature range of “point of fusion — boiling point” on the surface of coating for the decrease of coating porosity as the action of laser radiation. The increase of the temperature above this range which is generated by the rise of the radiation rate results to evaporating of coating surface layers leading to its complete elimination in the thermal affect zone. At the second stage the experimental researches were realized. They consisted in the laser treatment of two types gas-thermal coating with a preliminary evaporation. The coatings which are based on the metal lic (PN-85-U-15) and non-metallic (Al2O3) components were analyzed. The quantitative assessment of porosity modification were realized by means of the based on Visual Studio 2008 program. This image processing program allows to compare the microstructure of the occupied by pores and coating material areas pixel-by-pixel. It has been established that the action of laser radiation leads to reduction of average porosity of gas-thermal coating. This reduction is: — the porosity in the initial position for coating of a PN 85-U-15-based alloy is 17 %; after the laser treatment it’s 5...8 %; — the porosity in the initial position for ceramic coating of Al2O3 is 24,5 %; after the laser treatment it’s 15...18 %.

The feasibility of jet fan-assisted ventilation for temperature control of heating belts on a downward-facing sphere in a scientific facility

To avoid the deformation of the large-scale scientific facility for neutrinos detection due to temperature changes, the heat generated during the top-down annealing of the inorganic glass panels needs to be released in time to maintain temperature control of 21±1°C in the built-up area. Due to the unique shape and the changing heating sources, a novel ventilation strategy that combines jet fans with general ventilation was proposed to satisfy the special environmental control requirement. A small-scale field experiment was conducted to obtain the CFD methods for simulation. Then, the feasibility of the jet fan-assisted ventilation system was discussed in terms of two thermal control zones based on the distance from the heat source. Besides, the effectiveness of the proposed ventilation design was compared with traditional general ventilation with air-conditioned air supplied from the hall ceiling and directly opposite the heating belt based on the temperature and velocity distribution. The results show that: the area outside the thermal control range under jet fan-induced ventilation was reduced by around 60%, and the maximum temperature fluctuated over time within 0.33°C. These results provide a preliminary insight into the use of jet fan-assisted ductless ventilation to achieve precision local temperature control in a large space.

CO2 fractional laser-assisted transdermal delivery of silk nanofiber carriers in a rabbit ear hypertrophic scar model.

Hypertrophic scars are skin fibrotic diseases, characterized by fibroblast hyperproliferation and excessive accumulation of extracellular matrix. However, topical drug application for hypertrophic scars are unsatisfactory. The purpose of this study was to explore the permeability of silk nanofiber hydrogels (SNFs) loaded with rhodamine 6G (R6G) and rhodamine 110 (R110) mediated by CO2 fractional laser irradiation into hypertrophic scar tissues. In this work, R6G and R110 were chosen as hydrophilic and hydrophobic model molecules. They were loaded inside SNFs. In vivo rabbit ear hypertrophic scars were treated with CO2 fractional laser irradiation and then R6G/R110-laden SNFs were applied to the scars to evaluate their synergetic effect on drug penetration efficiency. Their permeability was quantified by fluorescence intensity and measured by confocal laser scanning microscopy on days 1, 3, 5 and 7. More specifically, the thermal coagulation zone (CZ) and its surrounding area (peri-CZ) caused by the thermal coagulation of the laser were discussed separately. Our data indicated that the SNFs promoted the penetration of R6G but not that of R110 in the peri-CZ on day 1 when combined with laser irradiation. Interestingly, both R6G and R110 were abundant in the CZ and remained stable on days 1, 3 and 5. Moreover, rapid re-epithelialization hindered the long-term permeability of both drugs. Combining CO2 fractional laser irradiation with SNF drug delivery could improve the efficiency of hydrophilic drug delivery within 24h before total re-epithelialization.

Numerical Investigation of a Co2 Cooling System Connected to Spawn of Energyplus Thermal Zones

Numerical Investigation of a Co2 Cooling System Connected to Spawn of Energyplus Thermal Zones

Криогенные литопотоки горного массива Мунку-Сардык

The article deals with exogenous cryogenic relief-forming litopotoks: periglacial (supraglacial) zone, modern glacial zone; the thermal zone of paleoglacials of regressive stage, erosive or fluvial zone of proluvial, solifluction, high-altitude ice and permafrost-stone mountain streams.

Quantifying HVAC electrical flexibility from building thermal mass: a case study of the DOE reference building

As a means to adjust the temperature of the thermal zones in buildings, building thermal mass is regarded as one of the essential sources of energy flexibility. It is still challenging to quantify the energy flexibility of passive thermal mass, making it oppugning to use thermal mass for buildings’ demand response (DR). A method to accurately quantify the energy flexibility from heating, ventilation, and air conditioning systems (HVAC) is important for buildings to participate in DR projects. This paper proposes a novel data-driven model to quantify HVAC’s electrical demand under dynamic global temperature adjustment. The Markov chain is first used to implement an effective sampling method to produce a global temperature resetting schedule representing different temperature resetting. Next, EnergyPlus evaluates the HVAC electrical demand under the various temperature reset scenarios. In the end, the LightGBM algorithm is used to develop the data-driven model. Having validated the proposed model, the case study was conducted in a DOE reference office building for EnergyPlus. Results demonstrate that the Markov chain outperforms the probabilistic method when sampling temperature setpoint schedules. In the future, the proposed data-driven model can be used to evaluate the flexibility capacity of an energy management system in grid-integrated buildings.

Interaction Effects Between Aquifer Thermal Energy Storage Systems.

Aquifer thermal energy storage (ATES) is an energy efficient technique to provide heating and cooling to buildings by storage of warm and cold water in aquifers. In regions with large demand for ATES, ATES adoption has lead to congestion problems in aquifers. The recovery of thermal energy stored in aquifers can be increased by reducing the distance between wells of the same temperature while safeguarding individual system performance. Although this approach is implemented in practice, the understanding of how this affects both the recovery efficiency and the needed pumping energy is lacking. In this research, the effect of well placement on the performance of individual systems is quantified, and guidelines for planning and design are developed. Results show an increase in thermal recovery efficiency of individual systems when the thermal zones of wells of the same temperature are combined, which is explained by reduced surface area of the thermal zone over which losses occur. The highest increase of the thermal recovery efficiency is found for systems with a small storage volume and long well screens. The relative increase of the thermal recovery efficiency is 12% for average-sized systems with a storage volume of 250,000 m3 /year, and 25% for small systems (50,000 m3 /year). The optimal distance between wells of the same temperature is 0.5 times the thermal radius, following the trade-off between an increase of the thermal recovery efficiency and the increase in pumping energy. The distance between wells of opposite temperature must be larger than three times the thermal radius to avoid negative interaction.

The Potential of Harnessing Real-Time Occupancy Data for Improving Energy Performance of Activity-Based Workplaces

Currently, the available studies on the prediction of building energy performance and real occupancy data are typically characterized by aggregated and averaged occupancy patterns or large thermal zones of reference. Despite the increasing diffusion of smart energy management systems and the growing availability of longitudinal data regarding occupancy, these two domains rarely inform each other. This research aims at understanding the potential of employing real-time occupancy data to identify better cooling strategies for activity-based-working (ABW)-supportive offices and reduce the overall energy consumption. It presents a case study comparing the energy performance of the office when different resolutions of occupancy and thermal zoning are applied, ranging from the standard energy certification approach to real-time occupancy patterns. For the first time, one year of real-time occupancy data at the desk resolution, captured through computer logs and Bluetooth devices, is used to investigate this issue. Results show that the actual cooling demand is 9% lower than predicted, unveiling the energy-saving potential to be achieved from HVAC systems for non-assigned seating environments. This research demonstrates that harnessing real-time occupancy data for demand-supply cooling management at a fine-grid resolution is an efficient strategy to reduce cooling consumption and increase workers’ comfort. It also emphasizes the need for more data and monitoring campaigns for the definition of more accurate and robust energy management strategies.

Thermal Unit with Controlled Distribution of Flow Speeds of Processed Raw Materials in Zones of Electrified Modules

The article reviews the possibility of thermal treatment of vermiculite concentrates in thermal units of the modular-launch type after the defects of the units appeared during operation were fixed. It was observed that the temperatures of the electric heaters and the refractory surface of the firing modules distribute unevenly horizontally: the temperatures decreased significantly from center to periphery. This feature showed a technical solution — the division of the total flow of the expanded vermiculite into local and controlled flows between the thermal zones of the furnace modules taking into account their temperatures. The required time for particles movement in each thermal zone was determined, as well as average local speeds of their movement in the indicated zones were by comparing the thermal capacities of local vermiculate flows. The calculations of local flow rates were carried out and the total productivity of the modernized furnace was determined. The productivity of modernized furnace is 24% higher than the prototype furnace. It is shown that with an increase in productivity but equal to electricity consumption, the specific energy consumption of firing processes decreases by the same 24%. It makes the furnace more perfect and competitive.

Structural-&-Phase Condition and the Damageability of the Welded Joints of Steam Pipelines at Thermal Power Plants

The authors studied the interrelation between the type of structure and the damage rate of the welded joints of steam pipelines made of the heat-resistant pearlitic steels that were operated for a long time, i.e. more than 270 thousand hours in the conditions of creepage and low-cycle fatigue. The purpose of this research was to establish the interrelation between the structural-&-phase condition of the metal used for welded joints of the elements of steam systems and their damageability rate for the service life of welded joints exceeding 270 thousand hours. During the studies, the methods of optical and electron microscopy were used according to the requirements of the guideline documentation and also the methods that are used for the determination of mechanical properties. The level of their reliability has been substantiated and the residual life has been determined. To impart functional performances to welded joints we used well-known methods that were appropriately emended according to the structural changes of above joints. Such changes condition the conversion of the original structure of welded joints into the ferrite-carbide mixture. The availability of the conversion process of the initial structure on the thermal action zone sections (TAZ) of welded joints has essential distinctions due to a different disposition of metal to its own damageability. On the whole, the welded joints are damaged more intensively in comparison to the basic metal of steam pipelines. The analysis of the structural state of welded joints in the steam pipelines of thermal power plants as for the extension of their service life results in a considerable economic effect. Understanding the fact that the metal deterioration in welded joints adheres mainly to the fragile mechanism we managed to establish the level of their damageability that demands the renewal of damaged welded joints. We believe that the damageability level of welded joints that tots up to 0.25 or 0.35 of the volume of their TAZ section should be considered as critical for the service life exceeding 270 thousand hours. The damaged welded joints should be renewed throughout the time period of 15 to 20 thousand hours as soon as the specified damageability level is attained.

Temperature conditions during commercial transportation of cull sows to slaughter

Management of ambient temperature is central in sow production, but temperature in commercial trucks transporting sows has only received limited scientific focus. We aimed to describe temperature inside trucks depending on season and on shifts in state of the trucks (‘non-stationary’, ‘stopped’, ‘waiting’) transporting sows (up to 8 h) to slaughter. Temperature outside the trucks was described during the last part of the journeys, and compared with temperature inside the trucks. Data were collected during 12 months and included 39 commercial journeys. We measured temperature (°C) inside trucks every minute in one compartment holding sows at commercial density. Data for temperature outside the trucks were collected from an official weather station near the slaughterhouse. Mean journey duration was 233 ± 114 min (range 47–470 min). From GPS-data, 26 of the journeys involved at least one stop lasting 5 min or more. Stops had a mean duration of 14 ± 8 min (range 5–40 min). Mean temperature inside trucks during journeys was 13.8 ± 5.3 °C (3.3–26.0), and differed between seasons. During journeys, temperature inside trucks increased during stationary periods. When compared to the outside temperature during 10 min before arriving at the slaughterhouse, and in the first 10 min of waiting after arrival, the mean temperature difference between inside and outside the truck ranged from 3 to 7 °C.The results suggest that in a moderate climatic zone like Denmark, temperature in trucks transporting sows to slaughter was not maintained within the thermal comfort zone of sows, and increased during stationary periods. This may have adverse consequences in terms of animal welfare. Future studies of optimization of transport management, ventilation and logistics are needed to examine possibilities to maintain temperatures in the comfort zone.

Economic feasibility of ice storage systems for office building applications: A climate sensitivity analysis

The impact of different climatic conditions on the economic feasibility of ice energy-storage systems in a typical office building is investigated. The climate zones cover a range of thermal zones from warm to extremely hot according to the thermal climate zone definitions of ASHRAE Standard 169. Hourly cooling load of the building is simulated for a monthly typical day in five cities representing the aforementioned climate zones. Four different energy storage strategies including full, partial, two-chiller and on-peak window, are also considered for peak-shaving purpose. By analyzing the extra capital cost required for installing an ice energy-storage system instead of a conventional one, and the potential savings due to transferring the cooling load from on-peak to off-peak hours, the economic viability of employing ice storage systems is evaluated for twenty different cases (i.e. five climate zones and four storage strategies). The results show that the payback period is highly sensitive to the climatic conditions, storage strategy and electricity tariff. It is found that the payback period is virtually one order of magnitude lower in very hot zones compared to that in hot zones using the partial storage strategy with the mid-peak electricity tariff of 5.1 ¢/kWh. To generalize the results, sensitivity analyses are performed by varying electricity tariffs and capital investments. A wide range of electricity tariffs from 0.25 ¢/kWh (off-peak) to 40 ¢/kWh (on-peak) are considered for the economic analysis. Considering the partial storage strategy, although in very hot zones, the payback period is less than 7 years for all considered electricity tariffs, the corresponding figure for hot zones varies between 1 and 60 years.