Search

Air temperature rise due to global warming can increase the demand for electricity, because of the more frequent and intensive use of air conditioners and fans. Based on this phenomenon, it is necessary to study the correlation between air temperatures and peak electric demands. This study aims to obtain a correlation between maximum air temperatures and peak demand and then estimate the peak demand of Padang city for the year 2030. The correlation between air temperatures to peak demand is identified by Pearson coefficient. The demand forecasts are calculated using a multivariable linear regression method. Correlation test results show a low correlation between maximum air temperature and peak demand but a strong correlation between population and peak demand. The results of the forecast for 2030 are 422 MW for case 0, where the independent variables are the population and daily maximum air temperature. The peak demand is 421.59 MW for case 1, where the independent variable is only the population. For case 2, where the independent variables are population and daily maximum air temperature according to Paris Agreement, the peak demand is 421.03 MW. The forecast result that excluded the air temperature resulted in 410 KW lower peak demand than the forecast that includes air temperature. The higher air temperatures result in higher peak demand. [ABSTRACT FROM AUTHOR]

Recently, the use of greenhouse is developing. Farming fruits and vegetables using a greenhouse can overcome the unpredictable climate. The plants that need specific air temperature and humidity could grow well inside a greenhouse. As a preliminary study, the effect of circulating water as a thin film at the outer surface of the greenhouse is observed. The water film is intended to cool the greenhouse. In this experiment, there are three models used. The first isthe greenhouse (called GH1) with cooling water flowing at the outer surface of greenhouse periodically. The second is a greenhouse (called GH2) without a cooling system and the third is in the open space or natural farming. A water sprayer is installed in each model to water the plants. It sprays periodically. In each greenhouse, three temperature and humidity loggers are installed to measure the air temperature and humidity. The loggers are installed in the middle of the greenhouses with some different heights from the plants. From the experimental results, the air temperature in the greenhouse GH1 decreased compared to the ambient temperature at position 3, while at GH 2 and open space farm N thetemperature increased at positions 1, 2, and 3. The average relative humidity was 72%, 68 %, and 47% at GH 1, GH 2, and open space farm (N). [ABSTRACT FROM AUTHOR]

Utilization of geothermal energy is still dominated by indirect use for electricity generation, beside geothermal energy can also be used for direct application. Direct use is mostly using a low enthalpy geothermal resources (<150°C), one of the applications of low enthalpy geothermal energy is for drying process. Drying is a post-harvest method that aims to improve the quality of agricultural products by removing some of the water to an agreed an d safe limit, while microorganisms unable to grow and multiply. Coffee is one of the important commodity which has an important role in economic sector in Indonesia. In this study, the Computational Fluid Dynamics (CFD) method is used to determine and predict the drying chamber's temperature and air flow distribution patterns. The simulation process is carried out by varying the thermosiphon heat temperature (50, 60, and 70 °C) and the air inlet velocity (0.2, 0.4, and 0.6 m/s). The simulation results show the uniformity of temperature in the drying chamber, with the highest drying air temperature is 57.72°C, where the air temperature is influenced by the thermal temperature of the thermosiphon and the large air flow velocity. Based on the simulation conditions, the highest amount of heat needed in the drying process is 118.79 kJ/kg at temperature condition of 50°C with velocity 0.6 m/s and the lowest is 117.41 kJ/kg. [ABSTRACT FROM AUTHOR]

Condensate is the result of condensation of vapor in the air by the evaporator of the air conditioning (A/C). The production rate of condensate depends on the capacity of the A/C. In addition, the production rate of the condensate is also influenced by the condition of outdoor air. The present study investigates the production rate of condensate produced by A/C in two cities in Indonesia, namely Bandung and Garut. These two cities represent areas with cool and temperate climates. As a result, these two cities have different outdoor air conditions. The investigation was carried out on the split-type A/Cs installed in bedrooms with compressor capacity of 0.5 HP (0.38 kW). Site data collection was carried out for 24 hours, where the amount of condensate, indoor and outdoor air temperatures and relative humidity were recorded for each hour. The results showed that in 24 hours, the A/C in Bandung and Garut produced 18.555 and 20.370 liters of condensate, respectively. A part from that, the condensate rates in Bandung and Garut are equivalent to 773,125 ml/h and 848,750 ml/h, respectively. The correlation between condensate production in Bandung and Garut to the difference outdoor and indoor air temperatures shows a directly proportional relationship. It means that the higher the indoor and outdoor air temperature difference, the higher the condensate generation. [ABSTRACT FROM AUTHOR]

This study investigated the effect of operating parameters on basic essential quality parameters of the dried salt, such as physical quality, water content, NaCl percentage, and whiteness in novel salt processing technology. This novel technology was designed, built, and installed at the salt mini plant, University of Trunojoyo Madura, and consists feed hopper, grinding chamber, hot air blower, and separator chamber. Novel salt processing technology was investigated under various operating parameters : temperatures (60°C, 65 °C, 70 °C, 75 °C, 80 °C), air velocities (17.7, 20, 22.5, 24.4, and 27.5 m/s), and feeding rate at 44.28 and 49.35 kg/h. In terms of physical quality, the produced salt has uniform particle size, powder shape, and white color. The water content tends to decrease with increasing temperature and air velocity. The NaCl percentage and whiteness initially increased to an optimum value and then decreased with increasing temperature. However, increasing air velocity increased both NaCl percentage and whiteness. Nevertheless, while this study result has shown this novel technology to be successful, further investigation and improvement were required. The current study highlights recent developments of valuable salt processing technology to promote sustainability in the salt industry. [ABSTRACT FROM AUTHOR]

In January 2017 an excessive number of deaths (with respect to the corresponding period in 2016) was reported for Poland. Number of deaths observed in Bielanski Hospital in Warsaw in January 2017 shows a consistent increase when compared to the country-wide data. Analysis indicates that the excess visible in hospital data was due to respiratory system related deaths. We were able to statistically quantify this excess and build a numerical predictive model linking the number of deaths to ambient air temperature and air pollution in Warsaw. We were also able to estimate the number of deaths attributed to air pollution. [ABSTRACT FROM AUTHOR]

This paper presents the results obtained by adsorption-calorimetric method of isotherms and basic (ΔH, ΔF and ΔS) thermodynamic characteristics of ammonia adsorption in Cs3,17ZSM-5 zeolite, also the adsorption isotherm described by the equations of the volume filling theory of micropores (TFSM). For measurements of isotherms and differential heat of adsorption, a system consisting of a universal high-vacuum adsorption unit and a coupled differential modified Tian-Calvet type microcalorimeter, DAK-1-1A, was used which directly quantifies and qualifies the nature and forces of adsorption interaction. The correlation between the adsorption-energy characteristics is found and the molecular mechanism of ammonia adsorption in Cs3,17ZSM-5 zeolite in the whole filling region is revealed. Ammonia adsorbed in the Cs3,17ZSM-5 zeolite is located in the first coordination sphere with the Cs+ cation, forming penta-ammonia complexes. It is determined that the average molar entropy of ammonia adsorption on the Cs3,17ZSM-5 zeolite, indicates that in the zeolite the mobility of ammonia molecules is below the liquid phase and close to the mobility of the solid phase, indicating a strong limitation of mobility of ammonia adsorbed on cations. [ABSTRACT FROM AUTHOR]

The aim of the current review is to conduct a detailed survey from the published papers and indicate the effect of some operating parameters on the performance of gas turbine cycle (outer ambient temperature), and compare between the simple cycle (the open Brighton cycle) and the improved cycle, the effect of the air filtration process entering the compressor, and modelling processes that are specific to the power generation system. Logical sequence has been followed in analyzing the reviewed studies to make the required and accurate comparison. It was found that the high temperature of the incoming air reduces the performance of gas turbine cycle. On the other hand, choosing good types of filtration and performing regular maintenance of the filters can improve the performance. [ABSTRACT FROM AUTHOR]

The amount of heat transferred within a building defines its level of comfort. The data's conformance to the SNI (Indonesian National Standard) thermal comfort zone can be utilized as a reference for the outside air temperature data's features. This study aims to provide an overview of the idiosyncrasies associated with data on outside air temperature in the Ternate region. Daily, weekly, and monthly intervals of 30 minutes are used to group the data. Additionally, the mean value, standard deviation, data volume, maximum value, and minimum air temperature value are tabulated. The graphic illustration comprises a polynomial equation line generated from the average value and the data correlation coefficient value of the resulting equation (R). The data illustrate the characteristics of air temperature in 2021, with April having the highest maximum and January having the lowest minimum. [ABSTRACT FROM AUTHOR]

The ground air heat exchanger (GAHE) system is an energy-efficient system for building cooling and heating. To ensure the economic feasibility of the GAHE system, it is assumed in this research that the excavated trench can be partly filled (around the GAHE pipe) with a BFM having excellent thermal qualities. The study compares and contrasts the thermal efficiency of the GAHE system using three different pipe configurations: straight, U-shaped, and helical. To examine the effect of backfilling materials (i.e., secondary soil around the GAHE pipes), a CFD model of the GAHE system with backfilling material has been constructed. After testing the GAHE system with four different backfilling materials, we learned that temperature changes in the air throughout the pipe's length should be considered when assessing the system's efficiency. However, in the case of a basic pipe, the measured outlet temperature is 28.28 ° Celsius, while in the case of a U-shaped pipe, the recorded outlet temperature is 30.74 °Celsius, and in the case of a helical pipe, the measured outlet temperature is 27.77 °Celsius. According to the findings of the investigation, the helical pipe exhibited the highest level of thermal performance. [ABSTRACT FROM AUTHOR]

The rapidly improving development of the city of Surabaya has implications for expanding built-up land, increasing air temperature, which affects the urban heat island (UHI) phenomenon. Remote sensing technology can be used to analyze land-use change on the UHI phenomenon in urban areas. This study aims to explain the UHI phenomenon in Surabaya in 2015-2020 using satellite image data. Landsat 8 images of Surabaya City were analyzed to obtain land-use maps, air temperature, and average urban thermal field variance index (UTFVI). The results showed that the city of Surabaya experienced a change of land use by 18% or 6017.48 ha. The air temperature distribution increased by 1.01-3.11 °C with a maximum temperature distribution pattern in the city centre and a minimum temperature distribution in the suburbs. The UHI phenomenon in Surabaya City shows a similar trend. The city centre has a UTFVI value with a threshold of >0.02, indicating the most robust UHI phenomenon. This UHI effect spreads to the suburbs of Surabaya City along with the development of urban land. [ABSTRACT FROM AUTHOR]

To get the OTTV value, you must first calculate the solar radiation value. Solar radiation occurs as a result of the sun's heat being exposed to the surface of the building and then goes inside so that the air temperature inside the building gets hotter. The solar factor is one of the elements of solar radiation which is important in determining the overall thermal transfer value for each outer area of a building. The availability of solar factor data in one place is very important to use for building design purposes. Calculating the solar factor is very difficult, moreover, SNI only contains data for the city of Jakarta. There are several ways to calculate the solar factor, with available SNI tables or by laboratory experiments or direct measurements of sunlight. So to make it easier for the designer, we propose to use the rule of thumb formula. The method used is based on local solar factor data, then a radian angle is made from 0 ° -360 °, which results in an ellipse shape in an equation. This paper concludes that the Rule of thumb formula is very helpful for architects in calculating the SF value and can also complete the table in SNI: 2011, which only contains the SF value for the city of Jakarta, meaning that it only applies in Jakarta, so similar research is needed to get the SF value for other cities in Indonesia. [ABSTRACT FROM AUTHOR]

Grasshopper (Oxya chinensis) is one of the insects suggested as a future animal food source and has been used as a food source in several regions of Indonesia, one of which is in Gunung Kidul Regency of Yogyakarta. One of the processing products is a fried grasshopper. Currently, the frying method has developed a lot, one of which is the frying method using air frying. This study proposed to determine the effect of air frying temperature and cooking times of grasshoppers on nutritional value and toxicity. The experimental design used a factorial, completely randomized design (FCRD) with variations in air frying time (10 mins, 15 mins, and 20 mins) and temperature of cooking (180°C and 200°C). Fried grasshopper was analyzed for toxicity, nutrition composition, color, and texture. Fried grasshopper was also analyzed for sensory characteristics with the hedonic method. The result showed that the interaction between temperature and cooking times significantly affected moisture, ash, fat, carbohydrates, and energy (p<0.05), while temperature significantly affected protein content. The color and fracture-ability of fried grasshoppers were significantly affected by temperature and cooking time. Product hardness increased with prolonged cooking times. The W3S1 treatment has the highest level of acceptance overall. The W3S1 sample has the lowest level of toxicity with a value of 192.45 µg/mL. Based on the nutritional composition, physical properties, and hedonic and toxicity tests, fried grasshoppers produced in the W3S1 treatment were the ideal air frying products. [ABSTRACT FROM AUTHOR]

Factors that affect the drying process are temperature, pressure, humidity, and airflow. Generally, the drying process depends on heat transfer. The twin tower desiccant dryer consists of a desiccant chamber, an air heater, a blower, and a tray chamber connected with the piping system and controlled by the Arduino microcontroller system. The desiccant dryer with the twin tower system simultaneously produces dry air in the first tower and regenerates the adsorbent in the second tower. The addition of a dry-air generator system is expected to speed up the process. This research aims to evaluate the performance of the dry air generator in a twin tower desiccant dryer, for high temperature sensitive materials. This research used the experimental method. The observable variables are desiccant mass, temperature, and humidity. The absorption of water vapor increases air temperature while decreasing relative humidity. For varying desiccant masses 5 kg, 10 kg, and 15 kg produced air temperatures of 41.7°C, 43.58 °C, and 44.76 °C, respectively, and relative humidity of 32.46%, 29.70%, and 27.00%. From the experiments, a desiccant mass of 10 kg achieved the best response value. The desiccant is able to capture 143.19 grams of water vapor per hour from a kilogram of airflow. In addition, the potential drying capacity of this system is 1392.14 gwater/hour. [ABSTRACT FROM AUTHOR]

Air temperature is one of the climates that needs to be observed for various purposes so that there is a need for forecasting to facilitate use. Air temperature data is in the form of fluctuations that are suitable for use with several forecasting methods, one of which is Grey Forecasting. In addition, to forecast air temperature can also use Fourier Analysis by finding the value of the period and the results of air temperature prediction. So in this study the forecasting used is Grey Forecasting model and Fourier Analysis. This study aims to compare the accuracy of the two methods to determine which is more accurate between the two in air temperature prediction. The Grey Forecasting model used is GM(3,1) using a differential equation 3-order (third) and 1 (one) variable. Meanwhile, Fourier Analysis uses Fast Fourier Transform to determine the period and approximation of the Fourier Series for air temperature forecasting. Based on the calculation using Fast Fourier Transform, the air temperature period at the Karakates Observation Post, Malang Regency from 2015 to 2021 of 10.5≈11 months with an approximation of Fourier Series is 1-order. Furthermore, by using MAPE to determine the error of GM(3,1), a MAPE value of 3.3161 ×105 was obtained in the seventh-eleven data of air temperature and of 1.3690 × 1022 for the entire air temperature data. Because the error of the GM(3,1) > 50% can be categorized as weak and inaccurate forecasting. Meanwhile, the error in the Fourier Analysis was 2.6331 in the seventh-11 (eleven) data and 4.9756 for all air temperature data. This means that the error of Fourier Analysis is less than 10% then it can be categorized as a forecast with a high degree of accuracy. Thus, the best accuracy of the two the method is The Fourier Analysis. [ABSTRACT FROM AUTHOR]

We present a study of the effects of different aerosol climatologies on the weather forecast of air temperature at 2 meters over Northern Eurasia using NWP mesoscale COSMO 5.6 model system. The application of different aerosol climatologies (Tanre, Tegen, MACv2) has revealed the differences in air temperature in the regions of southern Europe, Middle East, and Central Asia mainly due to changes in aerosol optical thickness. We show that the application of the modern Macv2 climatology in COSMO-Ru model simulations has led to the improvement of air temperature forecast at 2 meters with the decrease in the root-mean-square error by 0.1–0.2°C (to 0.5°C for some stations). In cloudless conditions, this error reduction can reach 1°C. However, above 850 hPa, the decrease does not exceed 0.1°C. [ABSTRACT FROM AUTHOR]

The rapid increase of the globally averaged near-surface air temperature, and the retreat of sea ice represent alarming signals of rapid changes of the Arctic climate system. Climate models systematically underestimate the observed sea ice decrease. Due to lacking crucial observational data (e.g., surface albedo), it is challenging to understand the processes and effects of the changes and to realistically implement them into projections of the Arctic climate system. Using the helicopter-borne probe HELiPOD during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) in summer 2020, simultaneous observations of surface reflection properties and meteorological parameters were collected. This contribution analyzes images of the surface obtained simultaneously by a fisheye camera and broadband solar radiation by upward and downward looking pyranometers. Based on the camera images, the observed surfaces were classified by an RGB approach into white ice/snow, bright melt ponds, dark melt ponds and open water. The classification is used to evaluate the current surface albedo scheme (SAS) of the High-Resolution High Area-North Atlantic/Arctic Ocean-Sea Ice Model (HIRHAM-NAOSIM). The results show an underestimation of the natural variability and an overestimation of the surface albedo, which can be mainly attributed to the insufficient parameterization of the surface type fractions. [ABSTRACT FROM AUTHOR]

The study assesses an impact of climate on the development of organic farming (wheat) in Siberian regions over the short and medium terms. To verify the results obtained, a comparative data analysis is carried out for six grain-producing regions in the Asian and European parts of Russia. A correlation analysis of eleven climatic factors influencing grain production efficiency has confirmed the premise about climate change. The variation range in the number of days when an air temperature exceeds 15°C is 43 and 48 for the Omsk and Rostov regions accordingly. The "0∼5°C temperature range" is the most risk-related of the considered indicators as it has a detrimental effect on crop plants during the growing season. Its maximum was reached in Rostov (348 days); no cold winter season was observed in Krasnodar during the study period; the extremes in the Asian part of Russia (Tyumen and Omsk) were 202 and 226 days; while the values for Voronezh and Belgorod were approximately the same, ranging 228∼302 days. The earliest date of permanent snow cover destruction was recorded on February, 20 (Belgorod and Voronezh), the latest – on April, 18 (Tyumen). Similarly, the earliest formation of permanent snow cover was recorded on October, 14 (Omsk), and the latest – on December, 13 (Voronezh). Overall, Siberian regions have the least favorable climatic situation: in view of the local climate pattern and the weather conditions for every spring, additional, short-term (3-5 years) and medium-term (5-10 years) investments are necessary to get new varieties of spring grains, replenish the seed fund of winter crops, renew sowing and harvesting equipment, and cover the cost of fuel and other consumables. [ABSTRACT FROM AUTHOR]

Vegetation is formed by the presence and interaction of several species of plants, one of them is association. This study aims to analyze the types and levels of association among five epiphytic fern species and their host in Srengseng City Forest, Jakarta. The method used was a survey method with a purposive sampling technique. The data collected were the number of individuals of 5 epiphytic ferns, the number of individuals, and the species of host trees. Measurements of light intensity, air temperature, and humidity were also carried out as supporting data. The association type was identified using 2 x 2 contingency tables by comparing observation value (a) toward expectation value E (a). The association levels were identified using Jaccard Index and Dice Index. The results showed that association types between epiphytic ferns and host trees were 71.79% positively and 28.21% negatively. Research indicates that association levels of epiphytes fern with the host were variously from low to high. The highest association occurred between Drynaria quercifolia with Zapoteca tetragona and Pyrrosia piloselloides with Zapoteca tetragona. Factors affecting the occurrence of associations are environmental conditions such as light intensity, air temperature, and humidity. [ABSTRACT FROM AUTHOR]

Climate change is significantly affecting the photosynthesis of mangrove plants. The effects of climatic factors, namely the elevated carbon dioxide (CO2) concentration, air temperature, and water regime on the photosynthetic of mangrove (Rhizophora apiculata), were investigated through physiological properties by using Response Surface Methodology (RSM) analysis for selecting tree species adaptive to climate change. The seedlings were grown in environment-controlled growth chambers with seven combinations of various CO2 concentrations and different temperatures. Each group has had four boxes at multiple water levels and salinity for almost three months. The DoE program was employed to find the effects and interactions between climatic factors. After 35 to 40 days of growth, the R. apiculata plant recorded optimum photosynthesis of CO2 at 525 ppm and the temperature at 32-34°C. Also, when the water level rises, R. apiculata's photosynthesis increases gradually, but it decreases gradually when the salt concentration rises. These results suggest that the low level of photosynthetic capacity may be attributed to the decreased CO2 fixative reaction system rather than the photochemical reaction system. [ABSTRACT FROM AUTHOR]

The purpose of the current work is to investigate the influence of a partial replacement of Cadmium (Cd) for yttrium (Y) on the electrical characteristics of yttrium-based alloys of the Y1-xcdxBa2Cu2.8Zn0.2O6+δ Superconducting compound, where x=0, 0.05, 0.1, 0.15,0.2 and 0.25. Using the solid-state reaction approach, the samples were produced (SSR). The samples were sintered in normal air at temperatures of 850 degrees Celsius for 24 hours at a rate of 10 degrees Celsius per minute. The Four-Probe Technique was used to obtain All samples exhibited superconducting behavior at temperatures below their critical temperatures. The samples showed superconducting behaviour, with the highest critical temperature (Tc (offset)) equal to 108.5 K and the highest energy gap value (Eg)=0.033034eV at the Cadmium concentration x=0.05. [ABSTRACT FROM AUTHOR]

The paper presents the test results of measurement into thermal comfort in the smart building "Energis" of Kielce University of Technology. The goal of the study was to assess the comfort level in the selected building and indicate problems related to the indoor environment. Three separate lecture rooms were analysed with regard to how students felt in the indoor conditions using questionnaires that they filled in. At the same time physical parameters of air such as temperature, humidity, carbon dioxide level and etc. were measured. The results are the basis for discussion on the human perception of indoor air in the considered smart building. It has been observed that even smart buildings do not offer a high level of comfort and the thermal conditions were not fine for all the people (quite many felt too warm or cold). The overall recommendation is that building managers should conduct such questionnaire tests at certain time intervals of at least a few months to obtain data that they can use to set indoor air parameters (temperature, humidity). [ABSTRACT FROM AUTHOR]

Cockpit temperature controlsystem requires maintaining the supply air temperature from the Air Cycle Machine (ACM) to havecomfortable condition inside the cockpit. The cockpit supply air temperature is influenced by many factors like bleed air flow & its rate of change, ambient condition and the attitude of the aircraft. In order to effectively design these sub systems, system simulation model has been created in AMESim. After validating the model for various static and dynamic cases in previous work, the model is then studied for sensitivity for various input and external factors. The results of the same are presented in this paper. From this analysis, the performance of ECS is studied and found that the system meets all the flight and environmental operating requirements. [ABSTRACT FROM AUTHOR]

Fluctuation in the hygrothermal environment is the main cause of deterioration of the surfaces of the statues and murals in grottoes, seriously undermining the value of grottoes. Large-scale, intensive tourist visits during the peak season is a key factor in the short-term dramatic fluctuations of the hygrothermal environment inside grottoes. This study aims to optimize the current visitor patterns and reduce the impact of tourist visits on hygrothermal environment in grottoes, taking the World Heritage Site of Maijishan Grottoes as an example. The hygrothermal environment under different visitor patterns were quantitatively evaluated by a heat and moisture coupled transfer model. The monitoring results shows that the indoor air temperature is relatively stable in the Grotto No. 135, only 10 days more than 4 °C occur in winter, and the relative humidity is high during summer, with a risk of mold growth. The simulation results show that the current sustained visiting pattern has a different effect on the temperature and humidity inside the grotto in winter than in summer. The current pattern of continuous visitation causes an 8% drop in relative humidity within the grotto during the visit, making daily fluctuations in relative humidity close to 10% in winter, and causes a 2 °C rise in temperature during the summer. The air temperature and relative humidity in the grotto could keep the same to the situation of no visitation when using the interval visitation model, it largely eliminates the impact of visitors. [ABSTRACT FROM AUTHOR]

The indoor environment can influence not only people's well-being but also their productivity. The paper presents a questionnaire study on a large number of volunteers, who assessed their productivity under various environmental conditions (air temperature, relative humidity, CO2 concentration). The physical parameters of indoor air were measured in each room with the microclimate meter (Testo 400). The data obtained during these measurements was compared with the subjective assessments of the respondents. The tests were performed in the educational intelligent building of Kielce University of Technology (Poland). Based on it, the conclusions were drawn on the influence of indoor environment on productivity. The results indicate that the students' productivity was weak in almost 30% of the responses, which is quite intriguing considering the high level of building sophistication. The highest self-reported productivity values were obtained for the air temperature range of 21 – 23 °C. A similar finding of the optimal level of thermal sensations in the range of about +/-0.4 has been found for highest productivity rating. Additionally, a relation between productivity and the subjective well-being rating was observed. The experimental material collected from a large group of volunteers can be used by building managers to set such indoor conditions that maximize productivity and working performance. Such tests are rare in intelligent buildings, which makes the data presented in the paper valuable and important. [ABSTRACT FROM AUTHOR]

When assessing the moisture damage risks of different external wall designs using hygrothermal simulation software, the user of said software can choose between different inputs for the determination of the indoor climate. This paper aims to compare results from field measurements in three Swedish buildings using different standards available in a widely used commercial hygrothermal simulation software, WUFI Pro. In this project, field measurements on external walls were conducted before the implementation of interior insulation. Measurements were conducted indoors, outdoors, and on the exterior and interior surfaces of the external walls. Comparing measurement and simulation results shows that on-site measurements give more accurate modelling of an existing external wall. However, the results also show that, when needed, any of the current standards can be used as replacements for actual measurements regarding indoor air temperature. The comparisons show that the most accurate results regarding the relative humidity are generated when ASHRAE Standard 160 is applied with an intermediate approach and a higher air change rate than in the nominal case. However, several parameters must be known for such an approach, such as the actual air change rate and the number of bedrooms. If such parameters are not known, the standard that gives the best fit between measured and simulated relative humidity is EN15026. [ABSTRACT FROM AUTHOR]

A better understanding of the urban heat island (UHI) effect has heightened interest in measuring, assessing, and modeling the outdoor thermal environment in urban areas around the world. Its modeling is currently becoming crucial for urban planning and design which facilitates the analysis of the phenomena. To get around this topic, this paper investigates the heat profile in a new urban area located in a vast semi-desert region characterized by a hot Mediterranean climate and how green spaces affect the outdoor thermal environment. In this work, we used two approaches: first, we created an urban weather generator workflow using the visual programming software Grasshopper to estimate a city's thermal conditions using many key geometric and material parameters of the urban landscape, such as buildings height, albedo, surface properties (roads, roofs, and walls), and heat traffics; after that the obtained weather file was used to map the heat using the universal thermal climate index (UTCI), which is strictly for outdoor spaces and takes into consideration the air temperature, mean radiant temperature, humidity, wind velocity, and solar radiation of the studied area. The outcoming results demonstrated that the value of the UTCI in the urban area without green space could reach 36°C in the hottest month of the year, whereas the modeling of the urban area with green spaces helped to reduce the value of the UTCI by 7°C to reach 29°C. [ABSTRACT FROM AUTHOR]

The current work includes studying the effect of partial substitution of antimony nanoparticles instead of bismuth on the electrical and structural properties of the superconducting compound Bi2-xSbxBa2Ca2Cu3O10+δ, where x = 0, 0.1, 0.2, 0.3, and the samples were prepared by the solid state reaction (SSR) method. The samples were sintered in normal air and at a temperature of 800°C for 48 hours at a heating rate of 10°C/min. X-ray diffraction tests were carried out on the four samples of different antimony concentrations. The results showed that all samples had a orthotropic structure, with differences in the lattice constants (a, b and c,)with a clear increase in the dimension c = 36.6899 A° for the second sample when x = 0.1, as well as an increase in the percentage of the high phase HTP%, which equals 68.16%, and the formation of And the structure (morphology) by the SEM device for the samples, the formation of a granular size with Nano-dimensions was observed, and the element analysis for each sample was examined through EDS examination, as the results showed the presence of the elements and their different proportions in each sample. [ABSTRACT FROM AUTHOR]

The article gives a brief analysis of the hydrological and climatic features of the Far Eastern seas from the viewpoint of their exposure on the concrete freezing mechanism in structures of port facilities. Monitoring of the concrete working conditions in the zone of variable water level determined an actual concrete freezing mechanism, which depends on the external conditions and the freezing temperature of the concrete. All port facilities of the Far Eastern seas have two patterns in the zone of variable water level, which differ in the concrete freezing mechanisms. The hydrological conditions of the Far Eastern seas, which emerge mainly under the influence of the Pacific Ocean, create a microclimate for the concrete in tidal areas. The monsoonal climate of the Far Eastern seas and the long coastline affect the air temperature in the seaport locations, which in turn has an impact on the mechanism of the concrete freezing under long-lasting icing conditions. [ABSTRACT FROM AUTHOR]

One of the most tough and crucial tasks in today's society is predicting the temperature of the Earth. Predicting the status of atmospheric characteristics such as temperature, humidity, and so on is the goal of temperature prediction. A historical dataset is used in this study to investigate weather forecasting. Traditional approaches are ineffective and inefficient due to the complexity and nonlinearity of the atmospheric pattern. Using Recurrent Neural Networks to solve these kinds of issues is a popular approach. Different neurons, hidden layers and transfer functions are used to forecast temperature for 365 days of the year in the proposed Attention based LSTM Model. Three models were tested for comparing the performance based on the mean square error (MSE) and the mean absolute error (MAE) criterion to pick a suitable model. The data model and procedure proposed in the article provided less MSE and MAE (i.e., more accurate findings) compared to prior studies, and the computing complexity was lowered as well (i.e. better performance). [ABSTRACT FROM AUTHOR]

At solar tower systems, open volumetric air receivers are attractive for electricity generation as well as for chemical and other industrial processes. In order to overcome inherent limitations within the previous lines of development, a fundamentally new receiver concept has been developed – the VoCoRec. It is characterized by a conical cavity with hexagonal cross-section, a two-stage air heating and modularity. Several simulations have been performed. For 800 °C hot air temperature, a total receiver efficiency of 88 % has been calculated, which is regarded very promising. A prototype receiver module with approx. 175 kW thermal output has been designed for the first tests in the solar simulator Synlight. The next step will be to manufacture the prototype. The tests in Synlight are scheduled to start in December 2021. [ABSTRACT FROM AUTHOR]

As proven by the continuous operation of the Solar Tower Juelich, central receiver power plants with open volumetric receivers are a valid alternative to other receiver types. Evolving new manufacturing techniques will allow to advance the technology further by improving its core component, the porous absorber structures. Using ceramic 3D screen printing, the new StepRec absorber design is fabricated out of siliconized silicon carbide and is presented along with the second new structure, the Emitec absorber made of very thin metal sheets. Based on experiments in the high-flux solar simulator Synlight, the thermal efficiency of both new designs is derived for reduced-size absorber probes. The new structures outperform the state-of-the-art HiTRec absorber with efficiencies above ninety percent at air temperatures of 650°C. Full-size absorber modules have been tested under real irradiation conditions at the research platform of the Solar Tower Juelich. The thermal efficiencies of the full modules will be quantified with further experiments in the Synlight facility in the near future. [ABSTRACT FROM AUTHOR]

Particle-based solar power tower is a promising technology that can surpass the temperature limit of today's commercial molten salt systems, which will improve the system's efficiency. King Saud University (KSU) in collaboration with Saudi Electricity Company (SEC) have built an experimental particle-based power tower system integrated with gas-microturbine at King Saud University. This test facility is, mainly, aimed to: (1) prove the concept of using solid particles as a solar thermal energy storage medium from which the gas-turbine receives its heat source; therefore, fossil fuel consumption decreases, and (2) prove the system's ability to raise the temperature of the solar-heated particles above 600 °C, surpassing the temperature limit of molten salt power tower systems, i.e., typically limited to around 600 °C. Previous on-sun tests using red sand have shown the system's ability to achieve both goals independently, in separate tests. The current paper presents further tests using red sand to reach both goals simultaneously and with better results, i.e., better solar contribution and higher temperature of solar-heated particles. Results show that the system is able to raise the particles temperature to a maximum temperature of 630 °C and to increase the compressed air temperature by around 17 °C before entering the combustor by utilizing the heat from solar-heated particles. It was also found that one of the issues that can decrease or prevent the solar contribution is the temperature drop on the hot particles as they flow from the particle heating receiver (PHR) outlet to the inlet of particle-to-working-fluid-heat exchanger (PWFHX). This can happen if the thermal energy storage (TES) bin, located upstream of the PWFHX, is nearly empty/partially filled, allowing outside air to be entrained with the particle flow into the bin; on the other hand, fully filled TES bin blocks the air to enter it, which will reduce the temperature drop significantly. [ABSTRACT FROM AUTHOR]

Global climate changes are observed in recent decades. Some aspects of the global climate stabilization problem at a current level by means geoengineering methods are investigated here. The study is based on a three-dimensional hydrodynamic global climate coupled model, including ocean model with real depths and continents configuration, sea ice evolution model and atmospheric general circulation model. Aerosol concentration from the 2010 up to 2100 year is calculated as a controlling parameter to stabilize mean year surface air temperature. It is analyzed possibility to get prescribed space and time global distribution of the stratosphere aerosol when exist limited number of artificial aerosol sources. Wind transport and deposition of aerosol are taken into account. [ABSTRACT FROM AUTHOR]

While studying the impact of climatic changes on the hydrological regime in the basin, the forecast or at least an estimate of runoff for some future decades (e.g. for water works operating time) seems to be the main problem. A significant runoff decrease was recorded in Slovak rivers after 1980. Nowadays, hydrologists are interested above all in looking for solutions to this problem. They ask what share of runoff decrease (or increase) is caused by growing air temperature, and what share follows from natural multiannual runoff oscillation. This paper deals with a statistical analysis of cyclicity and trends in discharge time series of the Danube River at Bratislava station and with a stochastic forecast of minimal, maximal and average annual discharge for the next years. In the paper two statistical methods of long-term runoff prediction are presented: classical time series analysis and Harmonic analysis (Fourier and wavelet transform). In the analysis 145-year data series (1876–2020) of maximal, minimal and average annual discharge of the Danube River at Bratislava were used. All, the stationarity, homogeneity, trend, and periodicity of annual discharge series were studied. To illustrate the results of the Danube discharge prediction Fourier harmonic model and the seasonal integrated mixed model ARIMA(P,D,Q) x(p,d,q)L models were used. From trend analysis it follows that minimal discharges are slightly increasing, but the average discharges do not show long-term trend. From analysis of the cyclicity and trends of the discharge time series the following conclusions can be outlined: 1. in the Danube River, the significant multiannual dry periods were: 1881–1887, 1898–1904; 1928–1934; 1946–1953; 1971–1973; 1989–1994, as well as the years 2014–2020. 2. Using spectral analysis, periods of 2.4-; 4.2-; 5-; 7-; 14-; 21 and 28-29-years were identified. It was mainly caused by a natural 28-30 years discharge oscillation cycle. 3. The Fourier harmonic model, as well as integrated mixed model ARIMA (P,D,Q) x(p,d,q)L predict a moderate increase of annual Danube discharge at Bratislava station for the next decade. [ABSTRACT FROM AUTHOR]

The requirements for thermal insulation of external partitions are very strict, in particular for low-energy, passive buildings or for the standard of buildings with almost zero energy consumption. The member states of the European Union have introduced the standard of nearly zero-energy buildings (nZEB). Buildings designed and constructed in accordance with this standard are characterized by very good insulation of the casing and very high tightness, limiting heat loss through leaks. This is a new standard for the design and implementation of buildings (nZEB). The article presents a methodology for determining heat losses through partitions of such buildings. An example of a real building that has been correctly measured shows a measuring system for examining the building envelope. The analyzes and conclusions carried out in the article also indicate the dependence of heat flow through partitions on internal and external climatic conditions. The innovative methodology and conclusions contained in the article can form the basis for the design of buildings with almost zero energy demand. [ABSTRACT FROM AUTHOR]

While studying the impact of climatic changes on the hydrological regime in the basin, the forecast or at least an estimate of runoff for some future decades (e.g. for water works operating time) seems to be the main problem. A significant runoff decrease was recorded in Slovak rivers after 1980. Nowadays, hydrologists are interested above all in looking for solutions to this problem. They ask what share of runoff decrease (or increase) is caused by growing air temperature, and what share follows from natural multiannual runoff oscillation. This paper deals with a statistical analysis of cyclicity and trends in discharge time series of the Danube River at Bratislava station and with a stochastic forecast of minimal, maximal and average annual discharge for the next years. In the paper two statistical methods of long-term runoff prediction are presented: classical time series analysis and Harmonic analysis (Fourier and wavelet transform). In the analysis 145-year data series (1876–2020) of maximal, minimal and average annual discharge of the Danube River at Bratislava were used. All, the stationarity, homogeneity, trend, and periodicity of annual discharge series were studied. To illustrate the results of the Danube discharge prediction Fourier harmonic model and the seasonal integrated mixed model ARIMA(P,D,Q) x(p,d,q)L models were used. From trend analysis it follows that minimal discharges are slightly increasing, but the average discharges do not show long-term trend. From analysis of the cyclicity and trends of the discharge time series the following conclusions can be outlined: 1. in the Danube River, the significant multiannual dry periods were: 1881–1887, 1898–1904; 1928–1934; 1946–1953; 1971–1973; 1989–1994, as well as the years 2014–2020. 2. Using spectral analysis, periods of 2.4-; 4.2-; 5-; 7-; 14-; 21 and 28-29-years were identified. It was mainly caused by a natural 28-30 years discharge oscillation cycle. 3. The Fourier harmonic model, as well as integrated mixed model ARIMA (P,D,Q) x(p,d,q)L predict a moderate increase of annual Danube discharge at Bratislava station for the next decade. [ABSTRACT FROM AUTHOR]

The requirements for thermal insulation of external partitions are very strict, in particular for low-energy, passive buildings or for the standard of buildings with almost zero energy consumption. The member states of the European Union have introduced the standard of nearly zero-energy buildings (nZEB). Buildings designed and constructed in accordance with this standard are characterized by very good insulation of the casing and very high tightness, limiting heat loss through leaks. This is a new standard for the design and implementation of buildings (nZEB). The article presents a methodology for determining heat losses through partitions of such buildings. An example of a real building that has been correctly measured shows a measuring system for examining the building envelope. The analyzes and conclusions carried out in the article also indicate the dependence of heat flow through partitions on internal and external climatic conditions. The innovative methodology and conclusions contained in the article can form the basis for the design of buildings with almost zero energy demand. [ABSTRACT FROM AUTHOR]

Electrical control of air outlet temperature relation with absorber plates angle in window solar air collector have been experimentally investigated. The present paper involves the construction of a control circuit employing Arduino UNO, NTC thermistor and Gear Motor that will automatically control the absorber plates angle of the window solar air collector according to the required air outlet temperature from the user. An Arduino software IDE is employed in programming the microcontroller that is based on the desired function. The original manual mechanical mechanism of the absorber plates angle was being disabled and substituted with the constructed control circuit. All investigations were carried out at air mass flow rates of 0.0151 and 0.0224 kg/s and three different solar irradiances of 330, 530, and 730 W/m2. Results indicated that the higher the required air outlet temperature would be, the more the plates will move towards the vertical position (angle 0°) and vice versa. [ABSTRACT FROM AUTHOR]

The article considers the conditions for the formation of elevated temperatures in the surface layer of urban space in relation to its environment. Such studies are relevant in connection with climate warming, an increase in urbanization processes, and an increase in the availability of satellite images in the thermal IR range. Using the example of the large industrial city of Ufa, located in the temperate climate zone, the paper considers in detail the natural and anthropogenic factors influencing the formation of the urban heat island and the distribution of temperature anomalies. The article describes methods for processing thermal data from the Landsat-8 satellite to identify temperature anomalies. Using the QGIS, ArcGISPro and MultiSpec programs, the authors created an information-cartographic database, with the help of which the patterns of distribution of thermal anomalies in different parts of the city were revealed. An analysis of thermal summer images was carried out, coupled with a map of the functional zones of the city of Ufa, which revealed significant differences in summer surface temperatures near water bodies and in green areas compared to temperatures in industrial areas and in areas with dense residential development. Differences can reach more than 10°C. [ABSTRACT FROM AUTHOR]

In the present study, conductance and viscosity values have been measured for aliphatic amino acids; glycine and L-alanine in aqueous solutions of 1-Butyl-3-propyl imidazolium bromide, ([BPim][Br]) (mIL=0.01, 0.03 and 0.05 mol kg−1) at different temperatures and atmospheric pressure. Using conductance as well as viscosity data, various thermodynamic parameters have been investigated which in turn assisted to infer the molecular interactions occurring in the (glycine/L-alanine + water + ([BPim][Br])). From conductance values, limiting molar conductivities have been determined using Onsager equation and further, Walden product have been computed. Joules-Dole equation have been analyzed using viscosity data. A and B-coefficients of Joules-Dole equation and temperature derivative of B-coefficient have also been calculated. Moreover, Eyring transition state theory utilized to compute different viscous flow's activation parameters. [ABSTRACT FROM AUTHOR]

The study involved extraction and purification of humic acids from Shola Forest of Munnar, Kerala. Size reduction of the purified humic acid extracts to nano forms enhances the surface physical properties such as cation exchange capacity and surface area. Higher rate of percentage of methylene blue (MB) on nano humic acid than the extracted form was described by the enhanced CEC, surface area and -COOH acidity during nano conversion. Adsorption isotherm modeling showed the best fit with Themkin isotherm and established the relationship between the adsorption heat energy and numbers of layers of molecule adsorbed. Thermodynamic studies revealed the spontaneity of the process with positive ΔG (195.317 KJ mol-1). [ABSTRACT FROM AUTHOR]