Journal articles: 'Direct heat meter'

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Magonski, Zbigniew. "Combustion Heat Meter." Journal of Microelectronics and Electronic Packaging 14, no. 3 (July 1, 2017): 100–107. http://dx.doi.org/10.4071/imaps.0531.

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Abstract In Memoriam—In memory of Dr. Zbigniew Magonski, a talented electronic engineer and inventor, was born in Glubczyce, Poland in 1950 and passed away in Cracow, Poland in 2017. He received M.Sc. degree in Solid State Technology from the Technical University of Wrocław, Poland in 1973, and PhD degree from the AGH University of Science and Technology, Cracow, Poland in 2000. For 15 years, he was with the R&D Center for Hybrid Microelectronics, Cracow Poland. At that time, his interest was focused on hybrid A/D, D/A converters also on DC HV power converters. Later, for 28 years, he was with the Department of Electronics, AGH University of Science and Technology, Cracow, Poland. His research interests covered ceramic microfluidic systems, hydrocarbon combustors, and high-temperature solid oxide fuel cells. In 1994–1995, he was with Summit Technology, Massachusetts, involved in a project relating to HV supplying of excimer lasers. He was a member of IMAPS US Chapter, the author of 13 patents and almost 50 technical papers connected with electronic technology. He was a caring husband and father and a good friend of many of us. We will miss you, Zbyszek. This article presents a proposal of a thermal instrument intended for the evaluation of heat energy of fluid fuels. Two thermal devices the flow meter and the combustor are the basic components of the instrument. The meter maintains a constant temperature in the vicinity of the combustion zone. The amount of heat energy in the fuel is calculated as the ratio of the electric power change expressed in Watts to the change of fuel supply delivered to the combustor within a time period of 1 s. The method enables a direct evaluation of fuel energy expressed in Joules per unit of mass or volume. For some applications, the meter may be a good alternative for a bulky bomb calorimeter.

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Magonski, Zbigniew. "Meter for the measurement heat of combustion." International Symposium on Microelectronics 2011, no. 1 (January 1, 2011): 000938–46. http://dx.doi.org/10.4071/isom-2011-tha2-paper4.

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This paper presents a proposal of a thermal instrument intended for the evaluation of heat energy of fluid fuels. Two thermal devices the flowmeter and the combustor are the basic components of the instrument. The meter maintains a constant temperature in the vicinity of the combustion zone. The amount of heat energy in the fuel is calculated as the ratio of the electric power change expressed in Watts to the change of fuel supply delivered to the combustor within a time period of 1sek. The method enables a direct evaluation of fuel energy expressed in Jules per unit of mass or volume. For some applications, the meter may be a good alternative for a bulky bomb calorimeter.

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Feng Wei, Ji, Li Qun Sun, Kai Zhang, XiaoYang Hu, and Shan Zhou. "Heat exchange model in absorption chamber of water-direct-absorption-typed laser energy meter." Optics & Laser Technology 67 (April 2015): 65–71. http://dx.doi.org/10.1016/j.optlastec.2014.09.015.

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Pereselkov, A., and O. Kruglyakova. "EXPERIMENTAL STUDY OF ELEMENTARY ACTS OF HYDRODYNAMICS AND HEAT TRANSFER DURING THE INTERACTION BETWEEN WATER DROPS AND FILM AND CASTING ROLLER SURFACE." Integrated Technologies and Energy Saving, no. 4 (December 12, 2022): 3–12. http://dx.doi.org/10.20998/2078-5364.2022.4.01.

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Experimental studies of the boundary conditions of heat transfer for the thermally stressed state of casting rollers while are spraying with flat-jet nozzles in a thermal preconditioning unit have been carried out. It is shown that the hydrodynamic conditions on the sprinkling surface are formed as a result of both the influx of "primary" dispersed water from the flat jet nozzle, and the "secondary" liquid coming from neighboring areas in the form of reflected drops and films. The heat transfer effecting individual factors that form the hydrodynamic conditions on the sprinkling surface was studied separately. The heat transfer intensity was studied depending on the spraying density, the injection-pressure drop and the temperature of the cooled surface when the "primary" drop flow runs in the heat exchange surface. The local sprinkling density of droplets on the surface under the flat-jet nozzle spray were measured using a sampling tube moved by a coordinator. At the same time, the ingress of “secondary” liquid into it was excluded. The specific heat flux and heat transfer coefficient were determined using a heat meter made of a nichrome tape heated by direct current. In this case, the isothermality of the surface of the measuring section was ensured. Thermocouples measured the temperature of the lower surface of the tape, and then the stationary temperature of the upper surface of the heat meter sprinkled with drops is calculated. As a result of the multivariate analysis of the experimental data, the correlation dependence of the heat transfer coefficient in dependance on the local spraying conditions of the heat meter surface was obtained. Also, studies of the heat transfer during water film flow over the heat meter surface were carried out. A similar situation takes place when water spreads between the adjacent nozzles sprinkling zones of the roller surface. The correlation dependence between the heat transfer coefficient, the water film speed and the cooled surface temperature was obtained. Studies of heat transfer during combined influence of moving water film and a flat-jet nozzle drop flow on the heat exchange surface showed that the heat transfer rate is approximately 80–90 % of the arithmetic sum of the coefficients obtained by separate cooling the heat meter with drops and a water film.

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Tirado-Conde, Joel, Peter Engesgaard, Sachin Karan, Sascha Müller, and Carlos Duque. "Evaluation of Temperature Profiling and Seepage Meter Methods for Quantifying Submarine Groundwater Discharge to Coastal Lagoons: Impacts of Saltwater Intrusion and the Associated Thermal Regime." Water 11, no. 8 (August 9, 2019): 1648. http://dx.doi.org/10.3390/w11081648.

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Surface water-groundwater interactions were studied in a coastal lagoon performing 180 seepage meter measurements and using heat as a tracer in 30 locations along a lagoon inlet. The direct seepage meter measurements were compared with the results from analytical solutions for the 1D heat transport equation in three different scenarios: (1) Homogeneous bulk thermal conductivity (Ke); (2) horizontal heterogeneity in Ke; and (3) horizontal and vertical heterogeneity in Ke. The proportion of fresh groundwater and saline recirculated lagoon water collected from the seepage experiment was used to infer the location of the saline wedge and its effect on both the seepage meter results and the thermal regime in the lagoon bed, conditioning the use of the thermal methods. The different scenarios provided the basis for a better understanding of the underlying processes in a coastal groundwater-discharging area, a key factor to apply the best-suited method to characterize such processes. The thermal methods were more reliable in areas with high fresh groundwater discharge than in areas with high recirculation of saline lagoon water. The seepage meter experiments highlighted the importance of geochemical water sampling to estimate the origin of the exchanged water through the lagoon bed.

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Uusikivi, Jari, Jens Ehn, and Mats A. Granskog. "Direct measurements of turbulent momentum, heat and salt fluxes under landfast ice in the Baltic Sea." Annals of Glaciology 44 (2006): 42–46. http://dx.doi.org/10.3189/172756406781811150.

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AbstractMeasurements of under-ice turbulence were performed using an acoustic three-dimensional current meter with an attached fast-repetition temperature–conductivity sensor at two coastal areas in the Baltic Sea during two winters. Observations covered both the ice-growth and spring-melt periods. The objective of these measurements was to obtain knowledge of under-ice turbulence and oceanic heat and salt fluxes to and from the ice in the coastal fast-ice region using eddy correlation techniques. The maximum observed daily average heat flux was 1 Wm–2, and the maximum for 10 min periods was an order of magnitude larger. Under-ice turbulence was much smaller than that recorded in the oceans and in coastal regions with tide. These results provide better knowledge of under-ice turbulence and heat-flux variations and are useful for the future development of a Baltic Sea ice salinity model.

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Usoltseva, Liliya O., Dmitry S. Volkov, Evgeny A. Karpushkin, Mikhail V. Korobov, and Mikhail A. Proskurnin. "Thermal Conductivity of Detonation Nanodiamond Hydrogels and Hydrosols by Direct Heat Flux Measurements." Gels 7, no. 4 (December 3, 2021): 248. http://dx.doi.org/10.3390/gels7040248.

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The methodology and results of thermal conductivity measurements by the heat-flow technique for the detonation nanodiamond suspension gels, sols, and powders of several brands in the range of nanoparticle concentrations of 2–100% w/w are discussed. The conditions of assessing the thermal conductivity of the fluids and gels (a FOX 50 heat-flow meter) with the reproducibility (relative standard deviation) of 1% are proposed. The maximum increase of 13% was recorded for the nanodiamond gels (140 mg mL−1 or 4% v/v) of the RDDM brand, at 0.687 ± 0.005 W m−1 K−1. The thermal conductivity of the nanodiamond powders is estimated as 0.26 ± 0.03 and 0.35 ± 0.04 W m−1 K−1 for the RUDDM and RDDM brands, respectively. The thermal conductivity for the aqueous pastes containing 26% v/v RUDDM is 0.85 ± 0.04 W m−1 K−1. The dignities, shortcomings, and limitations of this approach are discussed and compared with the determining of the thermal conductivity with photothermal-lens spectrometry.

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Mintorogo, Danny Santoso. "THE AQUATIC-POLYCARBONATE SKYLIGHT FOR SURABAYA INDONESIA." DIMENSI (Journal of Architecture and Built Environment) 35, no. 1 (July 9, 2007): 100–106. http://dx.doi.org/10.9744/dimensi.35.1.100-106.

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This paper will indicate of how appropriate use of aquatic skylight module installed on buildings in the tropical zone compared to the ones in the subtropical climate. In order for energy saving strategies, the aquatic-polycarbonate skylight system is used in the tropical climate. In the tropical hot humid climate, Indonesia has received huge amount of global direct and diffuse radiations on horizontal roofs throughout the year, approximately 525 watts per square meter of solar radiation will impact on flat roofs or skylights on a clear sunny day in Surabaya city. Ironically, most of the commercial and institution buildings are equipped with Western skylight styles in Surabaya without any modifications. The aquatic-polycarbonate skylight is the system that will control daylight, scatter direct solar heat radiation, cool the indoor polycarbonate surface temperature, and collect solar hot water at the same time. The concept of using the water as shading device has three goals: first of all, the flushing water in the polycarbonate holes tries to scatter horizontal or tiled skylight direct sun-ray radiation, and minimize the direct sun heat temperature on the polycarbonate with flushing water continuously. Secondly, the sparkle flushing water in series of square holes of polycarbonate will bounce and disperse the direct sunlight into the space below enhancing daylight patterns. Finally, while bouncing, sparkling and scattering direct sunlight, those series of flushing water holes would also collect the solar heat radiation as solar hot water. Each system could works nicely to absorb, to scatter, to minimize, and to obtain the solar heat radiation for solar hot water in buildings. This strategy aims to provide a clean environment living zones with applying passive heating and cooling systems.

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Kassai, Miklos. "Energy Performance Investigation of a Direct Expansion Ventilation Cooling System with a Heat Wheel." Energies 12, no. 22 (November 8, 2019): 4267. http://dx.doi.org/10.3390/en12224267.

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Climate change is continuously bringing hotter summers and because of this fact, the use of air-conditioning systems is also extending in European countries. To reduce the energy demand and consumption of these systems, it is particularly significant to identify further technical solutions for direct cooling. In this research work, a field study is carried out on the cooling energy performance of an existing, operating ventilation system placed on the flat roof of a shopping center, located in the city of Eger in Hungary. The running system supplies cooled air to the back office and storage area of a shop and includes an air-to-air rotary heat wheel, a mixing box element, and a direct expansion cooling coil connected to a variable refrigerant volume outdoor unit. The objective of the study was to investigate the thermal behavior of each component separately, in order to make clear scientific conclusions from the point of view of energy consumption. Moreover, the carbon dioxide cross-contamination in the heat wheel was also analyzed, which is the major drawback of this type heat recovery unit. To achieve this, an electricity energy meter was installed in the outdoor unit and temperature, humidity, air velocity, and carbon dioxide sensors were placed in the inlet and outlet section of each element that has an effect on the cooling process. To provide continuous data recording and remote monitoring of air handling parameters and energy consumption of the system, a network monitor interface was developed by building management system-based software. The energy impact of the heat wheel resulted in a 624 kWh energy saving and 25.1% energy saving rate for the electric energy consumption of the outdoor unit during the whole cooling period, compared to the system without heat wheel operation. The scale of CO2 cross-contamination in the heat wheel was evaluated as an average value of 16.4%, considering the whole cooling season.

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Kong, Zhenyi, Yonghui Li, Shuichi Hokoi, and Shi Hu. "The rising damp in two traditional clay-brick masonry walls and influence on heat transfer performance." MATEC Web of Conferences 282 (2019): 02097. http://dx.doi.org/10.1051/matecconf/201928202097.

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This paper studies the law of capillary water rise in the brick solid wall and the brick cavity wall under the influence of high-humidity wall foundation. It is found that the rising height of the capillary water sharp front is proportional to the time to the 0.5 power, but the coefficient is related to the wall structure, and the speed in cavity wall is higher than that in the solid wall. The heat flow meter method was used to compare the influence of the capillary water to the heat transfer when it rises to different heights. It is found that the presence of capillary water has a direct impact on the heat transfer coefficient of the wall. The presence of capillary water may increase the heating load by 11.1% and the cooling load by 15% of a common historical building in hot summer and cold winter area of China.

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Fair, Chris, Ricardo Flores, Eamonn Montague, Bilal Hakim, Soumitra Nande, Venera Zhumagulova, Analicia Caylor, and Paul Draper. "Using the wellbore as a d/p meter to calculate gas rate." APPEA Journal 55, no. 1 (2015): 385. http://dx.doi.org/10.1071/aj14032.

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The common use of high-resolution tree gauges and downhole permanent pressure/temperature gauges has made it possible to use the measured pressure drop in the wellbore to directly and accurately calculate the gas rate. This is accomplished by first combining an equation of state with a dynamic heat transfer model to create a phase-thermal model (PTM). The PTM is then integrated with a direct solution to the mechanical energy balance (MEB) for flow in pipes. The results obtained using this technique can be as accurate as, or in some cases more accurate than, conventional rate measurements. Since the wellbore may also be used for fluid density validation, the effective gas gravity (an input for many conventional flow rate calculations) may also be determined during shut-ins and used as an input to improve the accuracy of meter provers. The purpose of this paper is to explain the physics behind the gas rate calculation and to present case study results from the implementation of this method in both real-time and historic data processing. The paper will also discuss the limitations of this method and the range of potential applications.

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Jung, Wongeon, and Hyocher Kim. "Evaluation of Heat Stress Levels Inside Greenhouses during Summer in Korea." International Journal of Environmental Research and Public Health 19, no. 19 (September 30, 2022): 12497. http://dx.doi.org/10.3390/ijerph191912497.

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Farmers working inside greenhouses during summer are at risk of heat-related illness. In this study, we compared the dry-bulb temperatures (DTs) and the wet-bulb globe temperature (WBGT) index inside and outside greenhouses. We then determined the criteria for appropriate working and resting times inside greenhouses. The measurements were performed during the hottest period in 2020 and 2021 for two greenhouses, representative of those commonly found in rural areas. A direct-reading WBGT index meter was used for these measurements, and Automated Synoptic Observing System (ASOS) data were used to obtain regional DT data. DTs inside the greenhouses were significantly higher than the ASOS DTs (p < 0.001). In addition, the August WBGT index inside was significantly higher than that outside the greenhouses (p < 0.001). We found that the temperature during the period between 08:00 and 19:00 exceeded the international threshold of 28 °C for heat-acclimatized workers performing moderate-intensity work, above which heat stress becomes a concern. Our results revealed that the thermal index inside can be significantly higher than that found outside greenhouses. Therefore, when work is required inside greenhouses during the summer, stricter standards and safety measures should be considered.

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Smith, Benjamin C., Brett C. Ramirez, and Steven J. Hoff. "Development of Thermal Performance Metrics for Direct Gas-Fired Circulating Heaters." Agriculture 11, no. 7 (June 24, 2021): 588. http://dx.doi.org/10.3390/agriculture11070588.

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Many climate-controlled agricultural buildings use direct gas-fired circulating heaters (DGFCH) for supplement heat. There is no standardized test to calculate thermal efficiency for these heaters. This study aimed to develop a measurement system and analytical analysis for thermal efficiency, quantify the measurement uncertainty, and assess economics of DGFCH efficiency. The measurement system developed was similar to the ASHRAE 103 standard test stand with adaptations to connect the apparatus to the DGFCH. Two different propane measurement systems were used: input ratings < 30 kW used a mass flow system and input ratings > 30 kW used a volumetric gas meter. Three DGFCHs (21.9, 29.3, 73.3 kW) were tested to evaluate the system. Thermal efficiencies ranged from 92.4% to 100.9%. The resulting uncertainty (coverage factor of 2; ~95% Confidence Interval) ranged from 13.1% to 30.7% for input ratings of 56.3 to 11.4 kW. Key sources of uncertainty were propane and mass flow of air measurement. The economic impact of 1% difference in thermal efficiency ranged from USD $61.3 to $72.0 per heating season. Refinement of the testing system and procedures are needed to reduce the uncertainty. The application of this system will aid building designers in selection of DGFCHs for various applications.

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Jaisi, Sushil, Asha Thapa, and Mukti Ram Poudel. "STUDY OF CORRELATION COEFFICIENT AND PATH ANALYSIS AMONG YIELD PARAMETERS OF WHEAT: A REVIEW." INWASCON Technology Magazine 3 (February 4, 2021): 01–04. http://dx.doi.org/10.26480/itechmag.03.2021.01.04.

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Wheat is third most important food crop in Nepal after rice and maize. The productivity of wheat in Nepal is lower than world productivity. The causes behind it are drought and heat stresses, genotype, climate change, global warming lack of inputs and irrigation. Yield of wheat is quantitative trait which is adversely affected by environmental factors. Therefore, only genotypic selection is not effective and selection should be based on performance of yield components and morpho-physiological characters. Correlation coefficient analysis provides the direction and degree of relationship between yield attributing characters. Path coefficient analysis helps to analysis direct and indirect effect of one variable to another. It helps in partitioning direct and indirect causes of correlation. Among agronomic trait, days to booting, days to heading and days to maturity show negative correlation to grain yield but chlorophyll content, plant height, spike/m2, number of spikelet/spike, number of grain/spike, spike length, spike weight is directly correlate to grain yield .Spike weight, spike length, thousand kernel weight, and number of spike per meter square, number of grains per spike and days to anthesis has direct positive effect on grain yield and plant height, chlorophyll content and days to heading have negative direct effect on grain yield.

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Gabdrakhmanov, Azat, Lenar Shafigullin, Tansylu Gabdrakhmanova, and Azat Galiakbarov. "Study of the properties of metal powder received by plasma." MATEC Web of Conferences 298 (2019): 00050. http://dx.doi.org/10.1051/matecconf/201929800050.

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In this work, a new method for producing metal and ceramic powders by plasma spraying of rod blanks is proposed. A distinctive feature of this method is the use of a direct-acting plasmatron, where a bar-stock acts as one of the electrodes, and the cooling of the molten particles occurs place with a water screen. The water screen is not only in the lower part of the installation, but also it flows evenly from the walls, which gives a more efficient cooling of all molten particles, forming a regular spherical shape, and plasma flow. Water constantly circulates in a closed circuit, the heat is removed in a heat exchanger. Studies of powders were performed on scanning electron microscope “VEGA 3 LMH” produced by the company TESCAN, the Czech Republic, with the help of x-ray energy dispersive microanalysis AZtecEnergy Advanced busatti detector X-max 20 Standart, production company Oхford Instruments. The microhardness of the particles was measured according to GOST R ISO 6507-1-2007 on a MicroMet 5104 microhardness meter, with a load of 100 gs.

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Erkan, K. "Crustal heat flow measurements in western Anatolia from borehole equilibrium temperatures." Solid Earth Discussions 6, no. 1 (January 30, 2014): 403–26. http://dx.doi.org/10.5194/sed-6-403-2014.

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Abstract. Results of a crustal heat flow analysis in western Anatolia based on borehole equilibrium temperatures and rock thermal conductivity data are reported. The dataset comprises 113 borehole sites that were collected in Southern Marmara and Aegean regions of Turkey in 1995–1999. The measurements are from abandoned water wells with depths of 100–150 m. Data were first classed in terms of quality, and the low quality data, including data showing effects of hydrologic disturbances on temperatures, were eliminated. For the remaining 34 sites, one meter resolution temperature-depth curves were carefully analyzed for determination of the background geothermal gradients, and any effects of terrain topography and intra-borehole fluid flow were corrected when necessary. Thermal conductivities were determined either by direct measurements on representative surface outcrop or estimated from the borehole lithologic records. The calculated heat flow values are 85–90 mW m−2 in the northern and central parts of the Menderes horst-graben system. Within the system, the highest heat flow values (> 100 mW m−2) are observed in the northeastern part of Gediz Graben, near Kula active volcanic center. The calculated heat flow values are also in agreement with the results of studies on the maximum depth of seismicity in the region. In the Menderes horst-graben system, surface heat flow is expected to show significant variations as a result of active sedimentation and thermal refraction in grabens, and active erosion on horst detachment zones. High heat flow values (90–100 mW m−2) are also observed in the peninsular (western) part of Çanakkale province. The heat flow anomaly here may be an extension of the high heat flow zone previously observed in the northern Aegean Sea. Moderate heat flow values (60–70 mW m−2) are observed in eastern part of Çanakkale and central part of Balıkesir provinces.

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Gao, Ru-Shan, Karen H. Rosenlof, Bernd Kärcher, Simone Tilmes, Owen B. Toon, Christopher Maloney, and Pengfei Yu. "Toward practical stratospheric aerosol albedo modification: Solar-powered lofting." Science Advances 7, no. 20 (May 2021): eabe3416. http://dx.doi.org/10.1126/sciadv.abe3416.

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Many climate intervention (CI) methods have been proposed to offset greenhouse gas–induced global warming, but the practicalities regarding implementation have not received sufficient attention. Stratospheric aerosol injection (SAI) involves introducing large amounts of CI material well within the stratosphere to enhance the aerosol loading, thereby increasing reflection of solar radiation. We explore a delivery method termed solar-powered lofting (SPL) that uses solar energy to loft CI material injected at lower altitudes accessible by conventional aircraft. Particles that absorb solar radiation are dispersed with the CI material and heat the surrounding air. The heated air rises, carrying the CI material to the stratosphere. Global model simulations show that black carbon aerosol (10 microgram per cubic meter) is sufficient to quickly loft CI material well into the stratosphere. SPL could make SAI viable at present, is also more energy efficient, and disperses CI material faster than direct stratospheric injection.

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Atmaja, Bian Ganda, Yuliani Setyaningsih, and Ida Wahyuni. "Relationship of Noise Intensity, Heat Stress, and Physical Workload to Workers' Health Complaints at Semarang Timber Factory." Disease Prevention and Public Health Journal 16, no. 2 (September 25, 2022): 138–46. http://dx.doi.org/10.12928/dpphj.v16i2.5758.

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Background: As a country with a developed industry, the majority of entrepreneurs in Indonesia use modern industrial tools to help make their work easier. However, using modern technology causes side effects, such as noise from machines that cause hearing complaints. In addition, the hot work environment causes discomfort during work, and the excessive physical workload makes workers experience health complaints. Methods: This quantitative research uses a cross-sectional study approach with a purposive sampling technique. The sample consisted of 60 workers from a total of 126 in a wood factory in Semarang. The research instrument is a health complaint questionnaire sheet and a noise (a sound level meter), a physical workload (an oximeter), and a heat pressure (the QUESTemp). Data was analyzed by univariate and bivariate using the chi-square test. Results: The highest noise intensity is 98.02 dB, the highest heat pressure is 33.4°C, and the majority of the physical workload felt by workers is in the medium category. The chi-square test shows a relationship between noise intensity, heat stress, and health complaints of workers in a Semarang wood factory (p<0.05). Meanwhile, physical workload has no relationship with the health complaints of workers at the Semarang wood factory (p>0.05). Conclusion: Semarang wood factory has noise intensity and heat stress exceeding the threshold value, and most workers experience moderate physical workloads. The company should direct control of workers through the use of personal protective equipment and adequate drinking water, as well as controlling physical workloads on workers with workplace stretching exercises.

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Wang, W. G., Y. Hasegawa, Yong Bum Choi, Nobuyuki Fuyama, Kazuhiro Matsugi, Osamu Yanagisawa, and Gen Sasaki. "Effect of Al₁₈B₄O₃₃ Whisker Surface Treatment on Aging Behavior of Al₁₈B₄O₃₃ Whisker/ ZK60 Magnesium Alloy Composites." Key Engineering Materials 326-328 (December 2006): 1673–76. http://dx.doi.org/10.4028/www.scientific.net/kem.326-328.1673.

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MgAl2O4 layer with several decade nano-meter in thickness was coated uniformly on Al18B4O33 whisker by vapor-deposition of pure magnesium in vacuum and then heat-treated in atmosphere in order to prevent to the direct reaction between Al18B4O33 whisker and molten ZK60 (Mg-(4.8-6.2)%Zn-(0.45-0.8)%Zr) alloy in preparing the composites. By the coating, the composite have no interfacial reaction in whisker and matrix. As the consumption of Zn at the interface was not observed during preparation of the composites, the composites have good aging behavior, but showed the shortening of the time to reach the peak hardness. As the cooling speed of the composite after solution treatment is slow because of low thermal conductivity of the composites, some precipitation (MgZn2) was observed in the composites. Furthermore, the precipitation grew around the interface between whisker and matrix preferentially because of thermal stress around the interface. It seems these phenomena affect to the shortening of the time to reach the peak hardness.

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Mancini, Francesco, and Benedetto Nastasi. "Energy Retrofitting Effects on the Energy Flexibility of Dwellings." Energies 12, no. 14 (July 19, 2019): 2788. http://dx.doi.org/10.3390/en12142788.

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Electrification of the built environment is foreseen as a main driver for energy transition for more effective, electric renewable capacity firming. Direct and on-time use of electricity is the best way to integrate them, but the current energy demand of residential building stock is often mainly fuel-based. Switching from fuel to electric-driven heating systems could play a key role. Yet, it implies modifications in the building stock due to the change in the temperature of the supplied heat by new heat pumps compared to existing boilers and in power demand to the electricity meter. Conventional energy retrofitting scenarios are usually evaluated in terms of cost-effective energy saving, while the effects on the electrification and flexibility are neglected. In this paper, the improvement of the building envelope and the installations of electric-driven space heating and domestic hot water production systems is analyzed for 419 dwellings. The dwellings database was built by means of a survey among the students attending the Faculty of Architecture at Sapienza University of Rome. A set of key performance indicators were selected for energy and environmental performance. The changes in the energy flexibility led to the viable participation of all the dwellings to a demand response programme.

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Gorinov, Yu A., and P. N. Anisimov. "Icreasing the efficiency of district heating supply systems by local heat distribution station modernation." Power engineering: research, equipment, technology 24, no. 3 (June 14, 2022): 101–11. http://dx.doi.org/10.30724/1998-9903-2022-24-3-101-111.

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The PURPOSE of the study is to improve the efficiency of district heating systems. To achieve this purpose, the following tasks must be completed. To consider the problems of functioning of an open heat supply system functioning. Perform an analysis of technical solutions for the modernization of local heat distribution and metering station are presented. To develop a technological scheme of local heat distribution station with a hot-water supply system. To determine the main technical, economic and investment indicators of the developed technical solution.MATERIALS AND METHODS. Measurements were made using the local heat metering station. When solving the set tasks, a methodology for assessing efficiency was applied with the calculation of capital and operating costs, including the calculation of the payback period.RESULTS. A new scheme for regulating of hot water supply system recirculation with open connection of consumers to a centralized source is proposed. The results of the implementation of the developed technical solution of local heat distribution and metering station for apartment buildings in Yoshkar-Ola city are presented. An experimental study of the effect of a joint additional installation of a pump and a control valve on the hot water supply system recirculation line before the mixing unit for hot water recirculation with return pipe and before the direct-acting temperature controller was the first to do. As a result, the consumption of district water was reduced by 36 - 39%, the temperature in the return pipeline was reduced by 13.5%; the enthalpy of the hot water was reduced from 0.168 to 0.145 Gcal/m3, the required circulation in all risers of the hot water supply system was ensured.CONCLUSION. The use of the developed technical solution for the modernization of local heat distribution and metering station increases the efficiency of district heating supply systems. Calculations made on the basis of the readings of automatic custody heat transfer meter showed that the payback period for the technical solution is 40 days. The proposed solution is recommended for use in local heat distribution station of open heat supply system in order to reduce water rate, lower the temperature in the return pipeline and reduce heat losses, improve circulation in all riser pipes of the hot water system.

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Setyowati, Dina Lusiana, Zahroh Shaluhiyah, and Baju Widjasena. "Penyebab Kelelahan Kerja pada Pekerja Mebel." Kesmas: National Public Health Journal 8, no. 8 (May 1, 2014): 386. http://dx.doi.org/10.21109/kesmas.v8i8.409.

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Di industri modern, kelelahan kerja adalah fenomena kompleks yang disebabkan berbagai faktor. Penelitian ini bertujuan untuk mengetahui berbagai faktor yang memengaruhi kelelahan pada pekerja mebel. Penelitian dilaksanakan pada Februari – Maret 2013 di suatu perusahaan mebel di Kabupaten Jepara. Penelitian ini adalah dengan desain potong lintang melibatkan 70 orang responden. Kelelahan kerja diukur menggunakan reaction timer, stres kerja diukur menggunakan General Health Questionnaire-12. Monoton kerja, kerja lembur, motivasi, konflik kerja diukur dengan wawancara. Status gizi diukur dengan indeks massa tubuh (IMT). Rata-rata intensitas kebisingan atau Level Equivalent diukur dengan sound level meter, penerangan lokal diukur dengan lux meter, iklim kerja dengan questemp, dan beban kerja diukur dengan denyut nadi. Data diuji dengan kai kuadrat dan multivariat dianalisis dengan visual partial least square. Kelelahan kerja dipengaruhi oleh umur (nilai p = 0,018), monoton kerja (nilai p = 0,053), dan konflik kerja (nilai p = 0,019). Menurut analisis multivariat, kelelahan kerja dipengaruhi langsung oleh konflik kerja, stres kerja, lingkungan fisik, dan kapasitas kerja. Secara tidak langsung, kelelahan kerja dipengaruhi motivasi melalui stres kerja dan melalui beban kerja dan stres kerja, beban kerja melalui stres kerja dan melalui kapasitas kerja. Faktor yang memengaruhi kelelahan kerja adalah konflik kerja, lingkungan fisik tempat kerja, kapasitas kerja, dan stres kerja.In modern industries, fatigue is complex phenomenon caused by various factors. This study aimed to find out the factors related to fatigue case of furniture workers. This study was conducted in February - March 2013 at a furniture company in Jepara. Desaign of this study was cross-sectional method with 70 respondents. Fatigue was measured using reaction timer, General Health Questionnaire-12 was used to measure psychological distress. Monotony, overtime work, motivation and conflict was measured using questionnaire. BMI was used to measure nutrition status. Adaily noise Level equivalent was estimated using sound level meter; illumination was estimated using lux meter; heat stress was estimated using questemp and workload was estimated using heart rate. Data was analyzed using chisquare and multivariate was analyzed using visual partial least square program. Results of the research indicated that there was a relationship between age (p value = 0.018), monotonous (p value = 0.053), conflict at work (p value = 0.019) and fatigue. Multivariate analysis, which were conflict at work, stress of work, physical work environment and work capacity had a direct effect to the fatigue. Motivation had an indirect effect through stress at work and it had an indirect effect through the workload and stress at work. Physical workload had an indirect effect through stress at work to the fatigue and had an indirect effect through work capacity to the fatigue. The dominant factor related to fatigue is conflict at work, physical work environmental, work capacity and stress at work.

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Clarke, Robin E., Andrea Pianella, Bahman Shabani, and Gary Rosengarten. "Steady-state thermal measurement of moist granular earthen materials." Journal of Building Physics 41, no. 2 (May 23, 2016): 101–19. http://dx.doi.org/10.1177/1744259116637864.

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A technique based on the heat flow meter method is proposed for measuring the thermal conductivity of moist earthen and granular loose-fill materials. Although transient methods have become popular, this steady-state approach offers an uncertainty that can be reliably estimated and a test method that is widely accepted for building certification purposes. Variations to the standard method are proposed, including the use of a rigid holding frame with stiff base and silicone sponge buffer sheets, in conjunction with difference measurement to factor out the contributions from base, buffers and contact resistance. Using this approach, results are presented for green-roof substrates based on scoria, terracotta and furnace-ash at different moisture contents. Thermal conductivity ranged from 0.13 to 0.80 W/m K and fitted well to linear regression plots against moisture content. Further comparative measurements of a single specimen showed that direct measurement was less consistent than difference measurement and thus indicated that thermal resistance was higher by 0.023 m2 K/W, attributable to the presence of contact resistance.

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Goodman, William A. "3D Printed and Additively Manufactured RoboSiC™ for Space, Cryogenic, Laser and Nuclear Environments." International Symposium on Microelectronics 2018, no. 1 (October 1, 2018): 000099–103. http://dx.doi.org/10.4071/2380-4505-2018.1.000099.

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Abstract Goodman Technologies has been directly responsive to, and focused on, 3D printing and additive manufacturing techniques, and what it takes to manufacture in zero-gravity. During a NASA Phase I SBIR project, using a small multi-printhead machine, we showed that it was possible to formulate and 3D print silicon carbide into shapes appropriate for lightweight mirrors and structures at the production rate of 1.2 square-meter/day. Gradient lattice coupons with feature sizes on the order of 0.8mm were printed and were easily machined to very fine tolerances, ten-thousandths of an inch by Coastline Optics in Camarillo, CA. To further elaborate on the list of achievements, in Phase I, Team GT demonstrated three different ceramization techniques for 3D printing low areal cost, ultra-lightweight Silicon Carbide (SiC) mirrors and structures, radiation shielding, and electronics, several of which could be employed in microgravity The Goodman Technologies briefing presented at 2017 Mirror Technology Days “3D Printed Silicon Carbide Scalable to Meter-Class Segments for Far-Infrared Surveyor: NASA Contract NNX17CM29P along with sample coupons resulted in extreme interest from both Government and the Contractor communities. Our materials, which we call RoboSiC™, is suited for many other applications including heat sinks and radiation shielding for space electronics, and we have already started to make the first parts for these applications. The successful Phase I project suggests that we will meet or exceed all NASA requirements for the primary mirror of a Far-IR Surveyor such as the Origins Space Telescope (OST) and have a high probability solution for the LUVOIR Surveyor in time for the 2020 Decadal Survey. Results indicate that printing on the ground will achieve an areal density of 7.75 kg/square-meter (~39% of a James Webb Space Telescope (JWST) beryllium segment), a cost to print of $60K/segment, and an optical surface that has nanometer-scale tolerances. Printing in the microgravity environment of space we have the potential to achieve an areal density of 1.0–2.0 kg/square meter (<10% of a JWST beryllium segment), with a cost to print of ~$10K/segment. The areal density is 2–15 times better than the NASA goal of 15 kg/square meter, and the costs are substantially better than the NASA goal of $100K/square meter. The encapsulated gradient lattice construction provides a uniform CTE throughout the part for dimensional stability, incredible specific stiffness, and the added benefit of cryo-damping. For the extreme wavefront control required by the Large UV/Optical/IR Surveyor (LUVOIR) the regularly spaced lattice construction should also provide deterministic mapping of any optical distortions directly to the regular actuator spacing of a deformable mirror (DM). Some of our processes will also allow for direct embedding of electronics for active structures and segments. Encapsulation of the lattice structures will allow for actively cooling with helium for unprecedented low emissivity and thermal control. Several decades of experience and testing with SiC have shown that our materials will survive, nay thrive in, the most extreme Space, Cryogenic, Laser and Nuclear Environments.

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Chernick, Victor. "Test for the Concentration of Electrolytes in Cystic Fibrosis of the Pancreas Utilizing Pilocarpine by Iontophoresis, by Lewis E. Gibson and Robert E. Cooke,Pediatrics; 1959;24:545–549." Pediatrics 102, Supplement_1 (July 1, 1998): 230–31. http://dx.doi.org/10.1542/peds.102.s1.230.

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Aim. To develop a method for stimulating sweating that is rapid, painless, and avoids the risk of heat stress. Background. Since the discovery that there is a high concentration of sodium and chloride in the sweat of patients with cystic fibrosis of the pancreas in 1953, the sweat test has been performed by placing the patient's body in a plastic bag with or without hot water bottles to stimulate sweating. This method is unsatisfactory because of complications such as hyperpyrexia and heat stroke. Direct injection of a cholinergic agent intradermally is painful and therefore not practical. Methods. A rheostat with a milliampere meter was constructed at a cost of ∼$7 that allowed the iontophoresis of pilocarpine into the skin using negative and positive (2-cm diameter) electrocardiography electrodes. The positive electrode was placed on the flexor surface of the arm over a filter paper soaked in 0.2 mL of 0.2% pilocarpine nitrate. Current (0.2 mA) was applied for 5 minutes and then sweat was collected onto a preweighed filter paper for 30 minutes. Sweat chloride was determined by a polarographic method. Sweat tests were performed on 25 patients with cystic fibrosis (CF), 17 asymptomatic relatives and 27 control patients. Patients with CF had sweat chloride concentration >80 mEq/L; relatives, 32.5 mEq/L (highest 57 mEq/L); and control subjects, 21.1 mEq/L (highest 60 mEq/L). Conclusions. The iontophoresis of pilocarpine into the skin is a rapid, painless, safe, and reliable method for stimulating sweating and facilitating the determination of sweat chloride concentration.

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Begeman, Carolyn Branecky, Xylar Asay-Davis, and Luke Van Roekel. "Ice-shelf ocean boundary layer dynamics from large-eddy simulations." Cryosphere 16, no. 1 (January 24, 2022): 277–95. http://dx.doi.org/10.5194/tc-16-277-2022.

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Abstract. Small-scale turbulent flow below ice shelves is regionally isolated and difficult to measure and simulate. Yet these small-scale processes, which regulate heat and salt transfer between the ocean and ice shelves, can affect sea-level rise by altering the ability of Antarctic ice shelves to “buttress” ice flux to the ocean. In this study, we improve our understanding of turbulence below ice shelves by means of large-eddy simulations at sub-meter resolution, capturing boundary layer mixing at scales intermediate between laboratory experiments or direct numerical simulations and regional or global ocean circulation models. Our simulations feature the development of an ice-shelf ocean boundary layer through dynamic ice melting in a regime with low thermal driving, low ice-shelf basal slope, and strong shear driven by the geostrophic flow. We present a preliminary assessment of existing ice-shelf basal melt parameterizations adopted in single component or coupled ice-sheet and ocean models on the basis of a small parameter study. While the parameterized linear relationship between ice-shelf melt rate and far-field ocean temperature appears to be robust, we point out a little-considered relationship between ice-shelf basal slope and melting worthy of further study.

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Santos, Paulo, Diogo Mateus, Daniel Ferrandez, and Amparo Verdu. "Numerical Simulation and Experimental Validation of Thermal Break Strips’ Improvement in Facade LSF Walls." Energies 15, no. 21 (November 2, 2022): 8169. http://dx.doi.org/10.3390/en15218169.

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Thermal bridges may have a significant prejudicial impact on the thermal behavior and energy efficiency of buildings. Given the high thermal conductivity of steel, in Lightweight Steel Framed (LSF) buildings, this detrimental effect could be even greater. The use of thermal break (TB) strips is one of the most broadly implemented thermal bridge mitigation technics. In a previous study, the performance of TB strips in partition LSF walls was evaluated. However, a search of the literature found no similar experimental campaigns for facade LSF walls, which are even more relevant for a building’s overall energy efficiency since they are in direct contact with the external environmental conditions. In this article the thermal performance of ten facade LSF wall configurations were measured, using the heat flow meter (HFM) method. These measurements were compared to numerical simulation predictions, exhibiting excellent similarity and, consequently, high reliability. One reference wall, three TB strip locations in the steel stud flanges and three TB strip materials were assessed. The outer and inner TB strips showed quite similar thermal performances, but with slightly higher thermal resistance for outer TB strips (around +1%). Furthermore, the TB strips were clearly less efficient in facade LSF walls when compared to their thermal performance improvement in load-bearing partition LSF walls.

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Johns, W. E., L. M. Beal, M. O. Baringer, J. R. Molina, S. A. Cunningham, T. Kanzow, and D. Rayner. "Variability of Shallow and Deep Western Boundary Currents off the Bahamas during 2004–05: Results from the 26°N RAPID–MOC Array." Journal of Physical Oceanography 38, no. 3 (March 1, 2008): 605–23. http://dx.doi.org/10.1175/2007jpo3791.1.

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Abstract Data from an array of six moorings deployed east of Abaco, Bahamas, along 26.5°N during March 2004–May 2005 are analyzed. These moorings formed the western boundary array of a transbasin observing system designed to continuously monitor the meridional overturning circulation and meridional heat flux in the subtropical North Atlantic, under the framework of the joint U.K.–U.S. Rapid Climate Change (RAPID)–Meridional Overturning Circulation (MOC) Program. Important features of the western boundary circulation include the southward-flowing deep western boundary current (DWBC) below 1000 m and the northward-flowing “Antilles” Current in the upper 1000 m. Transports in the western boundary layer are estimated from direct current meter observations and from dynamic height moorings that measure the spatially integrated geostrophic flow between moorings. The results of these methods are combined to estimate the time-varying transports in the upper and deep ocean over the width of the western boundary layer to a distance of 500 km offshore of the Bahamas escarpment. The net southward transport of the DWBC across this region, inclusive of northward deep recirculation, is −26.5 Sv (Sv ≡ 106 m3 s−1), which is divided nearly equally between upper (−13.9 Sv) and lower (−12.6 Sv) North Atlantic Deep Water (NADW). In the top 1000 m, 6.0 Sv flows northward in a thermocline-intensified jet near the western boundary. These transports are found to agree well with historical current meter data in the region collected between 1986 and 1997. Variability in both shallow and deep components of the circulation is large, with transports above 1000 m varying between −15 and +25 Sv and deep transports varying between −60 and +3 Sv. Much of this transport variability, associated with barotropic fluctuations, occurs on relatively short time scales of several days to a few weeks. Upon removal of the barotropic fluctuations, slower baroclinic transport variations are revealed, including a temporary stoppage of the lower NADW transport in the DWBC during November 2004.

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Ruslan, Muhammad, M. Saleh Al-Amin, and Emidiana Emidiana. "Perancangan Sistem Fire Alarm Kebakaran Pada Gedung Laboratorium XXX." Jurnal Tekno 18, no. 2 (November 11, 2021): 51–61. http://dx.doi.org/10.33557/jtekno.v18i2.1412.

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Abstract Fire is a phenomenon that occurs when a material reaches a critical temperature and reacts chemically with oxygen (for example) producing heat, flame, light, smoke, water vapor, carbon monoxide, carbon dioxide, or other products and effects. Fires can occur anywhere, be it in office buildings, residences or public facilities. As for other than in public areas, fires often occur, both in rooms and laboratories, the triggers are almost the same due to negligence and not being careful in using flammable tools. For this reason, the need for a fire detector with a detector system using an alarm so that once a fire occurs, all those in the building can find out through the detector with an alarm sound as a fire marker. In order to reduce casualties, the need for a sprinkler system to extinguish the fire, and can assist the officers or authorities in the building as soon as possible. From the above problems, this research will determine how many detectors and sprinklers are needed, as well as how much water volume, pump power, and ground water tank are needed. This type of research is quantitative research by direct observation of the object under study, then researchers measure the room one by one using a building meter. From the calculation results by taking a sample on the 1st floor, the number of detectors needed is 10 smoke detectors and 3 heat detectors, the number of sprinklers is 47, the volume of water needed is 846 m3, the pump power and ground water tank needed are hydraulic power. pump (HHP) 3,28621 kW, pump shaft power (BHP) 4.38 kW, pump electric power (P) 6 kW, diesel pump (PpD) 4 HP, jocky pump (PJk) 0.6 kW, capacity GWT ( QGWT) 44 m3.

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Du, Jing Long, Xiang Huang, and Da Wei Tang. "Research on the Heat Transfer Characteristics of Receiver in Designed Solar Direct Steam Generation System." Applied Mechanics and Materials 472 (January 2014): 286–90. http://dx.doi.org/10.4028/www.scientific.net/amm.472.286.

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The direct steam generation (DSG) with parabolic collector is an attractive option regarding the economic improvement of parabolic technology for solar thermal electricity generation system. On the basis of theory analysis of flow and heat transfer mechanism in the DSG system, this paper presents the numerical simulation results of one 650 meters loop under different direct normal irradiation values, performance parameters such as water temperature, heat transfer coefficient and dryness of the fluid in the absorber pipe are obtained in the simulation results. This paper shows that fluids parameters are susceptible to the solar direct normal values , high heat transfer efficiency and sensitive control system are the key to ensure DSG systems stable operation.

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Marques, Débora Salomon. "Technology Focus: Production and Facilities (December 2022)." Journal of Petroleum Technology 74, no. 12 (December 1, 2022): 56–57. http://dx.doi.org/10.2118/1222-0056-jpt.

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The COVID-19 pandemic has caused unprecedented circumstances affecting production and facilities. Restrictions in mobility between sites and reduction in manpower challenged the business continuity of several operations. This accelerated the development and implementation of various technological solutions. We can see many examples in the works submitted this year: drone surveillance, inspection robots, digital twins, and automated systems. The digitalization tendency brought by the fourth industrial revolution continues to be the dominant topic of the works submitted. Approximately 28% were on simulation and modeling, of which one-third used machine learning. A total of 9% addressed intelligent management systems, 5% robotics and drones, 3% 3D printing, and 1.5% digital twins and augmented reality. The main topics addressed were inspection and maintenance (20%), flow assurance (7%), corrosion (6%), drilling (6%), nonmetallic materials (3%), and debottlenecking (2%). A few papers were on clean energy subjects, such as hydrogen energy and wind turbines (2%). I would like to highlight the following works as promising technological developments for production and facilities: innovative measurement techniques, such as the development of a new adjustable cone meter that adapts automatically to flow conditions of wet and dry gas (paper SPE 207505); improvements to drilling safety, such as the design of a new casing connector that significantly reduces rig time and health, safety, and environmental exposure risks (paper OTC 31075); new developments in piping inspection, such as the combination of direct-response spectroscopy with microwave for inspection of hard-to-inspect piping with coatings and overwraps (paper IPTC 21799); and a very interesting study of triangular vs. circular cross-sectional pipes, which shows that triangular pipes and elbows have significant less erosion, better heat transfer properties, and reduced slug frequencies for multiphase flow (paper SPE 208101). In the matter of optimizing production, debottlenecking continues to be a challenge. Whether it is for increase of production needs or for handling greater water cuts from aging wells, new technological solutions are arising to make production facilities increasingly efficient. Paper IPTC 22365 discusses dual-frequency AC/DC desalting technology. It shows a reduction in costs and energy requirements while achieving superior basic sediment and water removal. One of the topics becoming more relevant is the reduction of CO2 emissions. At least 5% of the abstracts I reviewed addressed lowering CO2 emissions as their main topic. Energy harvesting is an economically interesting way to reduce emissions because the energy consumption of the facility is reduced. The study shown in paper OTC 31724 describes energy harvesting from hydraulic pressure drops as an example of the circular economy applied to oil-production facilities. In this study, the energy and costs savings were evaluated at different pressure-drop points of a gas/oil separation plant. Paper SPE 207096 uses pinch analysis to perform a detailed heat-exchange-network retrofitting study of a crude distillation unit, predicting 8% of energy savings. I sincerely hope that we can see more developments in this area in coming years. Recommended additional reading at OnePetro: www.onepetro.org. IPTC 21799 Effectiveness of Dynamic-Response Spectroscopy and Microwave-Inspection Technology for Substrate Pipe and Composite Wraps by Rehan Ahmed, Petronas, et al. OTC 31075 Premium Antirotation Casing Connector With Metal-to-Metal Seal Optimized for High-Fatigue Performance To Meet Market Needs by Reducing Operational Expenditure and Risk Exposure by Scott Patrick Ellisor, Dril-Quip, et al. SPE 207096 A Practical Approach to Energy Optimization Using Pinch Analysis: A Case Study of an Oil Refinery by Paschal Uzoma Ndunagu, Honeywell, et al. OTC 31724 Circular Economy Initiatives at Upstream Surface Facilities by Ahmed Khalid Bu Ali, Aramco, et al.

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Moray, Neville, John Lee, Kim J. Vicente, Barclay G. Jones, and Jens Rasmussen. "A Direct Perception Interface for Nuclear Power Plants." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 38, no. 9 (October 1994): 481–85. http://dx.doi.org/10.1177/154193129403800905.

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Following the suggestions of Beltracchi (1987) a direct perception interface for the thermal hydraulic systems of a pressurized water nuclear power reactor (PWR) was developed. It presents operators with an animated graphic of the Rankine heat cycle describing the functional relations of steam generation in a PWR. The ability of students of thermal and nuclear systems to recall system states, and detect and diagnose nine transients was compared to that of experienced nuclear power plant operators. The results were compared to a display representing traditional analog meters. The direct perception interface supported better diagnostic performance, but did not improve memory for quantitative information. Problems in evaluating such displays are discussed, in particular concerning choice of scenarios, and investigation of failure modes of advanced displays.

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Huang, Junji, Jorge-Valentino Bretzke, and Lian Duan. "Assessment of Turbulence Models in a Hypersonic Cold-Wall Turbulent Boundary Layer." Fluids 4, no. 1 (February 26, 2019): 37. http://dx.doi.org/10.3390/fluids4010037.

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In this study, the ability of standard one- or two-equation turbulence models to predict mean and turbulence profiles, the Reynolds stress, and the turbulent heat flux in hypersonic cold-wall boundary-layer applications is investigated. The turbulence models under investigation include the one-equation model of Spalart–Allmaras, the baseline k - ω model by Menter, as well as the shear-stress transport k - ω model by Menter. Reynolds-Averaged Navier-Stokes (RANS) simulations with the different turbulence models are conducted for a flat-plate, zero-pressure-gradient turbulent boundary layer with a nominal free-stream Mach number of 8 and wall-to-recovery temperature ratio of 0.48 , and the RANS results are compared with those of direct numerical simulations (DNS) under similar conditions. The study shows that the selected eddy-viscosity turbulence models, in combination with a constant Prandtl number model for turbulent heat flux, give good predictions of the skin friction, wall heat flux, and boundary-layer mean profiles. The Boussinesq assumption leads to essentially correct predictions of the Reynolds shear stress, but gives wrong predictions of the Reynolds normal stresses. The constant Prandtl number model gives an adequate prediction of the normal turbulent heat flux, while it fails to predict transverse turbulent heat fluxes. The discrepancy in model predictions among the three eddy-viscosity models under investigation is small.

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Musiy, L. Y., O. Y. Tsisaryk, and I. M. Slyvka. "Development of technology of herodietic smoothies." Scientific Messenger of LNU of Veterinary Medicine and Biotechnologies 23, no. 95 (April 9, 2021): 38–45. http://dx.doi.org/10.32718/nvlvet-f9507.

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The purpose of the work was to develop recipes and technology of smoothies with high nutritional value by enrichment with fruit and vegetable filler. Experimental studies of organoleptic, physicochemical and microbiological parameters of the strip were conducted in the laboratory of the Department of Milk and Dairy Products Technology. In the first stage, a new product was developed using different ratios of milk and fruit-vegetable base (banana and pumpkin puree in different proportions) and chia seeds. For research, 4 formulations of the strip were developed: control – milk base 75 %, fruit puree – 10 %, pumpkin puree – 10 %, chia seeds – 5 %; sample № 1 – milk base 60 %, fruit puree – 15 %, pumpkin puree – 15 %, chia seeds – 10 %; sample № 2 – milk base 50 %, fruit puree – 20 %, pumpkin puree – 20 %, chia seeds – 10 %; sample № 3 – milk base 40 %, fruit puree – 20 %, pumpkin puree – 20 %, chia seeds – 20 %. Yogurt was used as a milk base. Yogurt was made by tank method. Bacterial preparation of direct application of FD DVS ABY-3 was added to the mixture cooled to a temperature of (37 ± 1) ºС. The increase in titrated and active acidity was monitored during fermentation. The titratable acidity was determined according to GOST 3624-92 “Milk and dairy products. Titrometric methods for determining acidity. Measurements of active acidity were performed using an electronic pH meter “Muttler Toledo MP220”. The vegetable base was prepared as follows: the pumpkin after washing and cleaning was rubbed on a fine grater, then crushed with a blender to obtain a more homogenized mass. Heat treatment of the crushed mass was performed in a water bath at a temperature of +74 ºC for 25 min. The banana was washed, peeled and crushed with a blender to obtain a homogeneous mass. Heat treatment of the crushed mass was performed in a water bath at a temperature of +74 ºC for 25 min. Chia seeds were cleaned of damaged specimens, dust, dirt and other impurities, washed with water for 10 minutes. at a temperature of 20 °C. Chia seeds were mixed with yogurt in a ratio of 1 : 10 at a temperature of 37 °C. Left to swell for 30 min. Then the estimated amount was made to the bulk. Organoleptic and physicochemical parameters according to DSTU 4343:2004 “Yogurts. General technical conditions”. The microbiological parameters of the product were studied according to DSTU IDF 117B:2003 “Yogurt. Determination of the number of characteristic microorganisms. The method of counting colonies at a temperature of 37 °C”. The introduction of chia seeds affected the energy value of the product. The highest energy value is calculated for the sample using 20 % of chia seeds – 110 kcal. The lowest energy value for control is 70.6 kcal, in which the share of milk base prevails. The introduction of chia seeds in the product reduces the number of lactic acid bacteria in the test samples of the smoothies, which in particular correlates with the titrated acidity of the product. When examining the presence of pathogenic microflora in the samples of the strip, it was found that all samples met the requirements for microbiological safety. The number of viable cells of Escherichia coli and bifidobacteria gives the product probiotic properties. According to the results of organoleptic parameters, the best shelf life for the strip is 14 days. All samples of the strip after 14 days had a sour taste and smell and a slight serum. The lowest value of titratable acidity for 14 days of storage was in the sample when using more chia seeds – 20 %. At 21 days of storage in all samples of the strip, the titrated acidity was higher than the allowable value. To expand the range of dairy products with high nutritional value and heroic properties, it is recommended to use in the technology of the strip 50 % milk base (yogurt), 20 % banana puree, 20 % pumpkin puree and 10 % chia seeds.

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McCabe, Ailie, W. Ewen Smith, Grant Thomson, David Batchelder, Richard Lacey, Geoffrey Ashcroft, and Brian F. Foulger. "Remote Detection Using Surface-Enhanced Resonance Raman Scattering." Applied Spectroscopy 56, no. 7 (July 2002): 820–26. http://dx.doi.org/10.1366/000370202760171473.

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Surface-enhanced resonance Raman scattering (SERRS) provides intense Raman signals that are shown here to be stable in a target and to be detectable at least 10 meters from the spectrometer. The results indicate that SERRS labeling of objects and their detection at a distance with a low-power laser is feasible. Rhodamine and a dye specifically designed to give good surface adhesion, [4(5′-azobenzotriazyl)-3,5-dimethoxyphenylamine] (ABT DMOPA), were adsorbed onto silver particles and the particles dispersed in poly(vinyl acetate) (PVA) and varnish. SERRS from rhodamine was not detected from colloid dispersed either in PVA or varnish, presumably due to displacement of the dye from the silver surface. ABT DMOPA gave good SERRS. Maps of the SERRS intensity of films indicated variability of 10–20% if ultrasound was applied to improve dispersion during mixing. Scattering performance was evaluated using a system with the sample held up to one meter from the probe head. The intensity of the scattering from samples kept in the dark showed little change over a period of up to one year. However, when the samples were left in direct sunlight, the scattering intensity dropped significantly over the same period but could still be determined after eight months. An optical system was designed and constructed to detect scattering at longer distances. It consisted of a probe head based on a telephoto or CCTV lens that was fiber-optically coupled to the spectrometer. Effective detection of SERRS was obtained 10 m from the spectrometer using 3.6 mW of power and a 20 s accumulation time.

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Hilmi, Amirul, Andi Maria Ulfa, and Muh Iman Darmawan. "Kajian Sifat Fisika-Kimia Air Bahang dan Indeks Pencemaran di Perairan PLTU Sumbawa Barat." Kappa Journal 5, no. 1 (June 30, 2021): 57–67. http://dx.doi.org/10.29408/kpj.v5i1.3110.

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This research examines the physical and chemical properties of the potential contamination of condenser cooling water (heat water) at the 2x7 MW West Sumbawa Steam Power Plant. Method’s this research is direct observation in the field. The determination of the sample point was done by purposive sampling. The results showed that the hot water had met the predetermined quality standards, namely a pH of 8.21, a temperature of 38.50C and a content of free chlorine (Cl2) of 0.03 mg / L. There was an increase in sea water temperature in a radius of 17 meters east and west by 80C from 280C to 360C. Direct discharge of hot water has the potential to pollute the marine prawn environment around the 2x7 MW West Sumbawa PLTU. From the results of the study, it was found that the temperature of the hot water had met the specified quality standard, which was 40oC, but direct disposal caused the sea water temperature to rise, exceeding the set sea water temperature quality standard of 320C and the temperature increase should not be more than 20C from the temperature. at first. The status of sea water quality due to the entry of hot water is determined using a pollution index. From the calculation results obtained PIj of 1.125 at the sample point Outfall 2, meaning that the sea water conditions at a radius of 17 meters are lightly polluted. As a form of control and prevention of pollution due to the entry of high temperature hot water, continuous monitoring is necessary and it is necessary to create a mixing pool between sea water and hot water before the heat is discharged into the sea.

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Gulida, E., and I. Movchan. "MAIN WAYS OF REDUCING THE FIRE DAMAGE RISKS ON PROTECTING OBJECTS." Fire Safety, no. 33 (December 31, 2018): 41–47. http://dx.doi.org/10.32447/20786662.33.2018.05.

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Formulation of the problem. For the cities of Ukraine, the problem of preventing the occurrence of fires and minimizing their consequences is of particular importance. Reducing the number of fires and losses from them requires an improved system approach that will ensure the interaction of all interested bodies and organizations to solve the problem. Proceeding from the above we can state that there is a problem for the cities of Ukraine that the main directions of reducing the risks of fires on the objects of the city are developed. The goal of the work. To develop a methodology for reducing the risks of fire on the relevant objects of protection and minimizing their consequences in the event of a fire (damage to the objects from the fire and expenses of fire and rescue units for its elimination). Setting tasks and their solutions. According to statistical indicators of the state of fires in Ukraine, for example, in 2017, the main causes of the fires are: 1) arson; 2) malfunction of production equipment; 3) violation of the rules of fire safety in the installation and operation of electrical installations; 4) violation of the rules of fire safety in the installation and operation of heat-generating units and installations; 5) careless handling of the fire; 6) the wisdom of children with fire; 7) other reasons. The largest number of fires occurred in the residential sector, accounting for 73.8%. The main cause of these fires (up to 71.2%) is the careless handling of fire. Therefore, the main tasks to be solved and related to reducing the risks of fire on the relevant security objects will be as follows: Determine the effect of the fire risk value associated with the risk of fire, on the duration of free burning during the fire. Determine the direct damage from the fire for the object, depending on the duration of free burning. Determine the expenses of the fire and rescue units that are associated with the elimination of the fire. Determine the effect of the fire risk value on the total fire damage. Develop a methodology for reducing the risks of fire on objects of protection. Determination of the risk of a fire is performed on the basis of the statistics of the fire of the State DPSU of Ukraine in the Lviv region (information form F-701 as of December 31, 2017). The total number of fires on the objects of the Lviv region Nn = 3137, and No = 474521 - the total number of objects for the Unified State Register of Deputies of Ukraine, located on the area of the region (data of the Main Directorate of Statistics in the Lviv region). Then εо = 0,00661. After processing the obtained results by the method of mathematical statistics, dependence was obtained for determining the duration of free burning depending on the fire risk. To determine the direct damage from the fire for the object of protection, depending on the duration of free burning, we will use the dependence, where Co is the average cost per square meter of the area of the fire protection object, UAH / m2; SP - area of the object destroyed by a fire, m2. Determine the expenses of the Bf of the fire and rescue units, where Cn - the average cost of one minute of the operation of the PRP during the firefighting process during the time τz.p.p, UAH / min. The main directions were devised to develop the main measures to reduce the "risks of fire" at the protection objects. Conclusions and specific suggestions: Influence of the fire risk, which is connected with the risk of fire, on the duration of free burning during a fire is established, which makes it possible to carry out the analysis and predict the impact of the risk of a fire on the total fire damage and reduce the value of this risk. The work shows that the duration of the free development of a fire has a linear dependence on the fire risk within its classification. 3. It is shown that the area of the fire in the process of its localization increases and it is necessary to take into account when it is determined during the time of free development of the fire.

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Zilli Lo Presti Heinz, Solange, Katia De Angelis, Glauber Heinz, Ariane Viana, Fernanda Marciano Consolim-Colombo, Agatha Calegari Bonfadine, Ruthe Rodrigues Nemesio, et al. "Effect of Transcranial Direct Current Stimulation associated with aerobic exercise on the autonomic modulation of hemiparetic individuals due to stroke: a study protocol for a double-blind randomized controlled trial." F1000Research 10 (March 8, 2021): 191. http://dx.doi.org/10.12688/f1000research.36394.1.

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Background: Individuals after a stroke have an imbalance in the autonomic nervous system, which increases the risk of death or recurrent episodes of stroke. Transcranial Direct Current Stimulation (tDCS) combined with aerobic exercise has shown an effect on the modulation of this system. Objective: The Heart Rate Variability (HRV) and the distance traveled on the exercise bike will be assessed to verify the additional impact of tDCS combined with aerobic exercise on individuals with chronic stroke sequelae. Methods: The 34 adult individuals with diagnoses of chronic stroke will be randomized into two aerobic exercise intervention groups: G1 (with active tDCS) and G2 (with sham tDCS), three times a week, for 12 weeks. Procedures: tDCS will be implemented during the aerobic exercise with the anodal electrode positioned over the lateral dorsal prefrontal left cortex, and the cathodal electrode over the contralateral supraorbital region, with 2mA, for 20 minutes. Assessments will be carried out pre, immediately after the intervention, and on the 12th, 24th, 36th interventions, and 30 days later. The HRV data that are pulse interval (PI), square root of the mean of the squares of the differences between adjacent normal RR intervals (rMSSD), absolute high frequency (HF), absolute low frequency (LF), high and low frequency ratio (LF / HF) will be collected using a cardio frequency meter. The analysis of the distance traveled on the exercise bike before and after interventions will be analyzed in meters. Discussion: The autonomic control via brain networks after a stroke can be altered and can promote an increase in sympathetic tone, and a higher risk of sudden death or relapse of stroke. It is crucial to demonstrate the effectiveness of available treatments to improve the autonomic function. Trial registration: The study is registered as a BRAZILIAN CLINICAL TEST RECORD (ReBEC): U1111-1222-4588 on the 2018/10/16

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Zilli Lo Presti Heinz, Solange, Katia De Angelis, Glauber Heinz, Ariane Viana, Fernanda Marciano Consolim-Colombo, Agatha Calegari Bonfadine, Ruthe Rodrigues Nemesio, et al. "Effect of Transcranial Direct Current Stimulation associated with aerobic exercise on the autonomic modulation of hemiparetic individuals due to stroke: a study protocol for a double-blind randomized controlled trial." F1000Research 10 (October 11, 2021): 191. http://dx.doi.org/10.12688/f1000research.36394.2.

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Background: Individuals after a stroke have an imbalance in the autonomic nervous system, which increases the risk of death or recurrent episodes of stroke. Transcranial Direct Current Stimulation (tDCS) combined with aerobic exercise has shown an effect on the modulation of this system. Objective: The Heart Rate Variability (HRV) and the distance traveled on the exercise bike will be assessed to verify the additional impact of tDCS combined with aerobic exercise on individuals with chronic stroke sequelae. Methods: The 34 adult individuals with diagnoses of chronic stroke will be randomized into two aerobic exercise intervention groups: G1 (with active tDCS) and G2 (with sham tDCS), three times a week, for 12 weeks. Procedures: tDCS will be implemented during the aerobic exercise with the anodal electrode positioned over the lateral dorsal prefrontal left cortex, and the cathodal electrode over the contralateral supraorbital region, with 2mA, for 20 minutes. Assessments will be carried out pre, immediately after the intervention, and on the 12th, 24th, 36th interventions, and 30 days later. The HRV data that are pulse interval (PI), square root of the mean of the squares of the differences between adjacent normal RR intervals (rMSSD), absolute high frequency (HF), absolute low frequency (LF), high and low frequency ratio (LF / HF) will be collected using a cardio frequency meter. The analysis of the distance traveled on the exercise bike before and after interventions will be analyzed in meters. Discussion: The autonomic control via brain networks after a stroke can be altered and can promote an increase in sympathetic tone, and a higher risk of sudden death or relapse of stroke. It is crucial to demonstrate the effectiveness of available treatments to improve the autonomic function. Trial registration: The study is registered as a BRAZILIAN CLINICAL TEST RECORD (ReBEC): U1111-1222-4588 on the 2018/10/16

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Zhang, Xiao Hui, and Wei Chen. "Numerical Predicts of Flow and Heat Transfer in Joule-Heated Rectangular Pool." Applied Mechanics and Materials 217-219 (November 2012): 2492–96. http://dx.doi.org/10.4028/www.scientific.net/amm.217-219.2492.

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Based on the Joule heating nuclear waste treatment technology, a series of numerical simulations have been studied to predict transient flow and heat transfer.The physical model is a rectangular cavity filled with fluid, the direct current contributes heat for heating the process medium by a pair of plate electrodes. For Pr=1 fluid, the thermally driven stable convection and the electromagnetically driven stable flow can be observed respectively or both gravitationally and electromagnetically driven stable convection exhibit. The threshold Hartmann number for the flow transition from an asymmetric 2 cells steady flow to a steady non- asymmetric state 1 roll flow is 159.687, where the Nusselt number exhibits a minimum value. And the second transition from non- asymmetric state 1 roll flow to a steady asymmetric 2 rolls flow is fixed at 178.88 with Ra=1.0×105. The results can provide some guidelines for conceptual thermal control for Joule heated ceramic melter technology.

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Abu-Hamdeh, Nidal H., and Khaled A. Alnefaie. "A Small Concentrating Solar Power Tower System." Applied Mechanics and Materials 575 (June 2014): 640–43. http://dx.doi.org/10.4028/www.scientific.net/amm.575.640.

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A small scale prototype of functional R&D solar tower system (about 10 kW) to gather solar energy and store it in a molten salt tank will be designed, developed and built. The prototype tower system will be built at King Abdulaziz University in Jeddah, Saudi Arabia where direct irradiation is very high. Collectors of large mirrors (called heliostats) will be used to track the incident sunrays. The heliostats focus the energy flow towards solar receivers, where energy is transferred to a working thermal fluid. The proposed system consists of several heliostats directing incident solar rays to a tower of height about 20 meters. A solar receiver will be installed at the top of the tower to collect solar energy reflected from the heliostats. The heat transfer fluid (HTF) re-circulated in the receiver transfers the collected heat in the receiver to a storage tank. The storage tank contains molten salts.

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Salehizadeh, Aliakbar, Morteza Khodagholi, and Amir Gandomkar. "Temperature Conditions for Determination of Beekeeping Regions in the Light of Climate Change. Case study: Fars Province." Environmental and Climate Technologies 24, no. 1 (January 1, 2020): 88–104. http://dx.doi.org/10.2478/rtuect-2020-0006.

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AbstractThe importance of the honey bee lays in its huge role in pollination and, as a result, maintaining the flora of the environment and also increasing agricultural production. Temperature is the most important element of the atmosphere affecting beekeeping. Results of stationary conclusions are generalized to the area of Fars province by using geographical information system (GIS) according to direct relationship between elevation changes and temperature variations. A beekeeping capability map was then drawn for the Fars province by months of the year. The results showed that heat conditions in four months of the year, from December to March, are not suitable in most of the northern and eastern parts of the province. The southern regions with an altitude of less than 1100 meters above sea level are considered as a suitable place for deployment, wintering and beginning of bee colony activities. The most optimal months of the year for honey bee activities are May and October. For fixed beekeeping, the central strip of the province with an average height of 1500 meters above sea level is the most suitable places.

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Kastinen, Daniel, Johan Kero, Alexander Kozlovsky, and Mark Lester. "Resolving the ambiguous direction of arrival of weak meteor radar trail echoes." Atmospheric Measurement Techniques 14, no. 5 (May 19, 2021): 3583–96. http://dx.doi.org/10.5194/amt-14-3583-2021.

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Abstract. Meteor phenomena cause ionized plasmas that can be roughly divided into two distinctly different regimes: a dense and transient plasma region co-moving with the ablating meteoroid and a trail of diffusing plasma left in the atmosphere and moving with the neutral wind. Interferometric radar systems are used to observe the meteor trails and determine their positions and drift velocities. Depending on the spatial configuration of the receiving antennas and their individual gain patterns, the voltage response can be the same for several different plane wave directions of arrival (DOAs), thereby making it impossible to determine the correct direction. A low signal-to-noise ratio (SNR) can create the same effect probabilistically even if the system contains no theoretical ambiguities. Such is the case for the standard meteor trail echo data products of the Sodankylä Geophysical Observatory SKiYMET all-sky interferometric meteor radar. Meteor trails drift slowly enough in the atmosphere and allow for temporal integration, while meteor head echo targets move too fast. Temporal integration is a common method to increase the SNR of radar signals. For meteor head echoes, we instead propose to use direct Monte Carlo (DMC) simulations to validate DOA measurements. We have implemented two separate temporal integration methods and applied them to 2222 events measured by the Sodankylä meteor radar to simultaneously test the usefulness of such DMC simulations on cases where temporal integration is possible, validate the temporal integration methods, and resolve the ambiguous SKiYMET data products. The two methods are the temporal integration of the signal spatial correlations and matched-filter integration of the individual radar channel signals. The results are compared to Bayesian inference using the DMC simulations and the standard SkiYMET data products. In the examined data set, ∼ 13 % of the events were indicated as ambiguous. Out of these, ∼ 13 % contained anomalous signals. In ∼ 95 % of all ambiguous cases with a nominal signal, the three methods found one and the same output DOA, which was also listed as one of the ambiguous possibilities in the SkiYMET analysis. In all unambiguous cases, the results from all methods concurred.

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Asada, Ryuta, Hiroyasu Abe, Hidetoshi Hamada, Yusuke Fujimoto, Hyonmin Choe, Daisuke Takahashi, Shusuke Ueda, et al. "Femoral head collapse rate among Japanese patients with pre-collapse osteonecrosis of the femoral head." Journal of International Medical Research 49, no. 6 (June 2021): 030006052110233. http://dx.doi.org/10.1177/03000605211023336.

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Objective In this study, we aimed to elucidate the relationship between the duration from diagnosis to femoral head collapse and the collapse rate among patients with pre-collapse osteonecrosis of the femoral head (ONFH). Methods In this retrospective, observational, multicenter study, we analyzed 268 patients diagnosed with ONFH and classified them using the Japanese Investigation Committee classification. The primary endpoint was duration from the time of diagnosis to femoral head collapse for each type of ONFH. Results The 12-, 24-, and 36-month collapse rates among participants were 0%, 0%, and 0% for type A, respectively; 0%, 2.0%, and 10.8% for type B, respectively; 25.5%, 40.8%, and 48.5% for type C-1, respectively; and 57.4%, 70.3%, and 76.7% for type C-2 ONFH, respectively. A comparison of unilateral and bilateral ONFH, using Kaplan–Meier survival curves demonstrated similar collapse rates. Conclusions The lowest collapse rate was observed for ONFH type A, followed by types B, C-1, and C-2. Additionally, a direct association was observed between the collapse rate and location of the osteonecrotic lesion on the weight-bearing surface.

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Al-Kharsan, Ibrahim, Ali Marhoon, and Jawad Mahmood. "Fair and Balance Demand Response application in Distribution Networks." 3D SCEEER Conference sceeer, no. 3d (July 1, 2020): 139–51. http://dx.doi.org/10.37917/ijeee.sceeer.3rd.20.

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The unprogrammed penetration for the loads in the distribution networks make it work in an unbalancing situation that leads to unstable operation for those networks. the instability coming from the imbalance can cause many serious problems like the inefficient use of the feeders and the heat increased in the distribution transformers. The demands response can be regarded as a modern solution for the problem by offering a program to decreasing the consumption behavior for the program's participators in exchange for financial incentives in specific studied duration according to a direct order from the utility. The paper uses a new suggested algorithm to satisfy the direct load control demand response strategy that can be used in solving the unbalancing problem in distribution networks. The algorithm procedure has been simulated in MATLAB 2018 to real data collected from the smart meters that have been installed recently in Baghdad. The simulation results of applying the proposed algorithm on different cases of unbalancing showed that it is efficient in curing the unbalancing issue based on using the demand response strategy.

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Rybach, Ladislaus. "Geothermal Heat Pump Production Sustainability—The Basis of the Swiss GHP Success Story." Energies 15, no. 21 (October 24, 2022): 7870. http://dx.doi.org/10.3390/en15217870.

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Geothermal heat pump systems (GHP) are the spearhead of geothermal achievement and development, and one of the fastest growing applications of renewable energy technologies worldwide. When Swiss GHP activities started in the late 1970s, market introduction and penetration needed science-based proof of reliable, stable, long-term GHP operation. A special, extended project, realized in a field-laboratory setting, provided this proof. Detailed measurements, as well as numerical model simulations, proved the sustainable operation of the installed GHP system. The measurement setup, the recording of the various time series, and their interpretation are presented. Furthermore, basic perceptions were elaborated concerning geothermal resources behavior in production and regeneration. The Swiss GHP was developed from nothing. Early GHP installation costs halved within 20 years; GHP growth was nearly exponential from 1980 to 2020 (8.5% annually). Drilled borehole heat exchanger (BHE) meters are today around 300,000 m per year; heat delivery of GHPs in Switzerland amounted to 3280 GWh 2020—over 85% of Swiss geothermal direct uses (among others like thermal spas, district heating). Large installations with hundreds of BHEs are now common, and are also used for heating and cooling. The international ranking of Swiss GHP realizations is excellent in terms of annual energy use (TJ/yr/area), and is number one worldwide. Switzerland is a global GHP leader, and the Swiss success story is well documented.

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Lamas, Francisco B., and Vítor A. F. Costa. "The Role of the Compressor Isentropic Efficiency in Non-Intrusive Refrigerant Side Characterization of Transcritical CO2 Heat Pump Water Heaters." Clean Technologies 4, no. 3 (August 17, 2022): 815–23. http://dx.doi.org/10.3390/cleantechnol4030050.

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Characterizing the refrigerant side of heat pump water heaters (HPWHs) can be intrusive and expensive. On the other hand, direct external measurement techniques can be unfeasible, particularly in commercial HPWHs for residential applications. Non-intrusive in situ characterization methods have already been successfully implemented in subcritical heat pumps. They provide the refrigerant mass flowrate and the equipment energy performance, by using contact temperature sensors and electric power meters. Subcritical suction and discharge-specific enthalpies necessary to apply the method can be obtained from the measured temperatures and their corresponding saturation pressures. Nevertheless, this approach does not apply to the transcritical CO2 HPWHs. In the supercritical region, temperature and pressure are independent variables, and an iterative process regarding the compressor isentropic efficiency has to be considered. However, when isentropic efficiency data are not available, an additional procedure is required, using a validated gas cooler model to verify the physical reliability of the numerical solutions. This work aims at presenting base thermodynamic analysis of a novel methodology for non-intrusive refrigerant side characterization of transcritical CO2 HPWHs, exploring the influence of the compressor isentropic efficiency condition.

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Lammert, A., and F. Ament. "CO<sub>2</sub>-flux measurements above the Baltic Sea at two heights: flux gradients in the surface layer?" Earth System Science Data 7, no. 2 (November 16, 2015): 311–17. http://dx.doi.org/10.5194/essd-7-311-2015.

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Abstract. The estimation of CO2 exchange between the ocean and the atmosphere is essential to understand the global carbon cycle. The eddy-covariance technique offers a very direct approach to observe these fluxes. The turbulent CO2 flux is measured, as well as the sensible and latent heat flux and the momentum flux, a few meters above the ocean in the atmosphere. Assuming a constant-flux layer in the near-surface part of the atmospheric boundary layer, this flux equals the exchange flux between ocean and atmosphere. The purpose of this paper is the comparison of long-term flux measurements at two different heights above the Baltic Sea to investigate this assumption. The results are based on a 1.5-year record of quality-controlled eddy-covariance measurements. Concerning the flux of momentum and of sensible and latent heat, the constant-flux layer theory can be confirmed because flux differences between the two heights are insignificantly small more than 95 % of the time. In contrast, significant differences, which are larger than the measurement error, occur in the CO2 flux about 35 % of the time. Data used for this paper are published at http://doi.pangaea.de/10.1594/PANGAEA.808714.

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Lammert, A., and F. Ament. "CO<sub>2</sub>-flux measurements above the Baltic Sea at two heights: flux gradients in the surface layer." Earth System Science Data Discussions 8, no. 2 (July 13, 2015): 587–601. http://dx.doi.org/10.5194/essdd-8-587-2015.

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Abstract. The estimation of CO2 exchange between the ocean and the atmosphere is essential to understand the global carbon cycle. The eddy-covariance technique offers a very direct approach to observe these fluxes. The turbulent CO2 flux is measured as well as the sensible and latent heat flux and the momentum flux, a few meters above the ocean in the atmosphere. Assuming a constant-flux layer in the near surface part of the atmospheric boundary, this flux equals the exchange flux between ocean and atmosphere. The goal of this paper is the comparison of long-term flux measurements at two different heights above the Baltic Sea due to this assumption. The results are based on an one-and-a-half year record of quality controlled eddy covariance measurements. Concerning the flux of momentum and of sensible and latent heat, the constant-flux layer theory can be validated because flux gradients between the two heights are more than 95 % of the time insignificantly small. In contrast, significant gradients, which are larger than the measurement error, occur for the CO2 flux in nearly 35 % of the time. Data, used for this paper are published at http://doi.pangaea.de/10.1594/PANGAEA.808714.

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King, Hunter, Samuel Ocko, and L. Mahadevan. "Termite mounds harness diurnal temperature oscillations for ventilation." Proceedings of the National Academy of Sciences 112, no. 37 (August 27, 2015): 11589–93. http://dx.doi.org/10.1073/pnas.1423242112.

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Many species of millimetric fungus-harvesting termites collectively build uninhabited, massive mound structures enclosing a network of broad tunnels that protrude from the ground meters above their subterranean nests. It is widely accepted that the purpose of these mounds is to give the colony a controlled microclimate in which to raise fungus and brood by managing heat, humidity, and respiratory gas exchange. Although different hypotheses such as steady and fluctuating external wind and internal metabolic heating have been proposed for ventilating the mound, the absence of direct in situ measurement of internal air flows has precluded a definitive mechanism for this critical physiological function. By measuring diurnal variations in flow through the surface conduits of the mounds of the species Odontotermes obesus, we show that a simple combination of geometry, heterogeneous thermal mass, and porosity allows the mounds to use diurnal ambient temperature oscillations for ventilation. In particular, the thin outer flutelike conduits heat up rapidly during the day relative to the deeper chimneys, pushing air up the flutes and down the chimney in a closed convection cell, with the converse situation at night. These cyclic flows in the mound flush out CO2 from the nest and ventilate the colony, in an unusual example of deriving useful work from thermal oscillations.

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Journal articles on the topic 'Direct heat meter'

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