Numerical study of the energy efficiency of the building envelope containing multi-alveolar structures under Tunisian weather conditions

The study of the thermal inertia of buildings is a subject of major interest. The thermal insulation and the nature of the wall sensitively modify the inertia of the building and are the solutions to improve the energy efficiency of the envelope. The roof is well exposed to solar radiation in summer and contributes to significant losses in winter due to convective exchanges. To lead to a thermal comfort, a thermal insulation is necessary. In this context, we carry out a numerical study of the thermal behavior of a building with two zones in variable meteorological conditions for a Tunisian climate (region of Sousse) based on the thermoelectric analogy and using the nodal method as a numerical method. The object of this work is to study the effect of the thermal inertia of the roof equipped with a multi-alveolar structure on the thermal behavior of the air inside the room and on its energy consumption. Taking into account the energy input of occupant, a complete model was established to increase the accuracy of the calculations. The results show that the multi-alveolar structure placed on the outside of the roof reduces energy consumption during the winter period when the alveolar structure is placed in the conductive direction and during the summer period when the alveolar structure is placed in the insulate direction.

Visibility over Indian airports during winter season

Visibility plays a key role at the time of landing and take off operations at airports. The daily visibility data from 1969 onwards for 25 stations in the country (at 2100, 0000, 0300 and 0600 UTC) are examined for the winter period. Side by side the dry bulb temperatures and the relative humidity recorded at the same time are also examined. Linear trend regressions have been fitted on the data sets for each of the cities. The significance is tested at 99% level of confidence. In recent years, degradation of air quality in the cities has often been suggested as the cause for the increase in the number of poor visibility days <2000 meters) particularly in the morning hours. Continuous persistence of this phenomenon for a number of days has also been reported. The results show that there are decreasing trends in visibility at most of the stations. At 0300 UTC the visibility is generally low and increased afterwards due to mixing and turbulence in the boundary layer.

Ramdas layer and thermal wave during winter period

Earlier works on Ramdas Layer were about its certainty, its existence, energy balance on the layer and a matching mathematical model. We, first identified it in Thiruvananthapuram, Kerala, for eight days during a fortnight study on soil heat flux. A lifted minimum in temperature could have implications in agriculture and horticulture and so with a view to finding out a range of height through which Ramdas layer occurs, Ramdas-max, Ramdas-min are identified. On 24 January 1994, Ramdas layer occurred at a maximum height of 0.8m from the surface and the day is labeled as Ramdas-max. On 1 February 1994, it occurred at a lower height of 0.4m from the surface and the day is labeled as Ramdas-min. The thermal wave at the ground and at 0.05m depth, the range of thermal wave, its relationship with Ramdas layer, the temperature profile, the rate of change of heat in that layer with that at the surface and the subsoil heat flux at the sub-soil surface stratum(surface-0.05m) during R~mdas-max and Ramdas-min are duly compared and discussed.

Organic carbon in atmospheric precipitation in the urbanized territory of the South of Western Siberia, Russia

This paper presents the results of studying the contents of total (TOC) and dissolved (DOC) organic carbon in atmospheric precipitation and their deposition fluxes on the territory of the city of Barnaul. Samples of atmospheric precipitation (rain and snow) were collected from May 2016 to December 2020 in the city center, additionally at the end of winter 2018–2019 samples of snow cover were taken in the territory of the city and its environs. The studies showed a significant content of organic carbon (OC) in atmospheric precipitation: the weighted average concentrations for the study period were 7.2 ± 0.6 and 4.2 ± 0.4 mg/L for TOC and DOC, respectively. The annual flux of OC deposition with atmospheric precipitation on the territory of Barnaul over the past three years has varied within 2.4–3.9 t/km2 for TOC and 1.4–2.1 t/km2 for DOC. To visualize the spatial distribution of organic matter over the territory of Barnaul, simple kriging was used, implemented in the Geostatistical Analyst module (ArcGIS® Desktop). The flow of organic carbon input into the snow cover during the winter period was used as data for the geostatistical model. According to the model, the deposition of OC from the atmosphere occurs unevenly throughout the urban area and depends on the location and intensity of pollution sources.

Factors Influencing Changes of the Initial Stable Water Isotopes Composition in the Seasonal Snowpack of the South of Western Siberia, Russia

Stable water isotopes in snowpack and snowfalls are widely used for understanding hydrological processes occurring in the seasonally snow-covered territories. The present study examines the main factors influencing changes of the initial stable water isotopes composition in the seasonal snow cover of the south of Western Siberia. Studies of the isotopic composition of snow precipitation and snow cover, as well as experiments with them, were carried out during two cold seasons of 2019–2021, and laser spectroscopy PICARRO L2130-i (WS-CRDS) was used for the determination of water isotope composition (δ18O and δD). The main changes in the isotopic composition of the snow cover layers in the studied region are associated with the existence of a vertical temperature gradient between the layers and with the penetration of soil moisture into the bottom layers in the absence of soil freezing. During the winter period, the sublimation from the top layer of snow is observed only at the moments of a sharp increase in the daily air temperature. At the end of winter, the contrast between day and night air temperatures determines the direction of the shift in the isotopic composition of the top layer of snow relative to the initial snow precipitation.

Impact of Urbanization on Urban Heat Island Intensity in Major Districts of Bangladesh Using Remote Sensing and Geo-Spatial Tools

Urbanization is closely associated with land use land cover (LULC) changes that correspond to land surface temperature (LST) variation and urban heat island (UHI) intensity. Major districts of Bangladesh have a large population base and commonly lack the resources to manage fast urbanization effects, so any rise in urban temperature influences the population both directly and indirectly. However, little is known about the impact of rapid urbanization on UHI intensity variations during the winter dry period in the major districts of Bangladesh. To this end, we aim to quantify spatiotemporal associations of UHI intensity during the winter period between 2000 and 2019 using remote-sensing and geo-spatial tools. Landsat-8 and Landsat-5 imageries of these major districts during the dry winter period from 2000 to 2020 were used for this purpose, with overall precision varying from 81% to 93%. The results of LULC classification and LST estimation showed the existence of multiple UHIs in all major districts, which showed upward trends, except for the Rajshahi and Rangpur districts. A substantial increase in urban expansion was observed in Barisal > 32%, Mymensingh > 18%, Dhaka > 17%, Chattogram > 14%, and Rangpur > 13%, while a significant decrease in built-up areas was noticed in Sylhet < −1.45% and Rajshahi < −3.72%. We found that large districts have greater UHIs than small districts. High UHI intensities were observed in Mymensingh > 10 °C, Chattogram > 9 °C, and Barisal > 8 °C compared to other districts due to dense population and unplanned urbanization. We identified higher LST (hotspots) zones in all districts to be increased with the urban expansion and bare land. The suburbanized strategy should prioritize the restraint of the high intensity of UHIs. A heterogeneous increase in UHI intensity over all seven districts was found, which might have potential implications for regional climate change. Our study findings will enable policymakers to reduce UHI and the climate change effect in the concerned districts.

Hematological condition of breeding bulls after a long winter period of operation in the conditions of the Udmurt Republic

Purpose: to study hematological parameters of blood in bulls-producers of dairy breeds on the day of semen collection in the Udmurt Republic after a long winter period of operation, depending on the breeds, age and place of selection.Materials and methods. The work was performed at the Federal Research Center for Animal Husbandry named after Academy Member L. K. Ernst on the basis of AO "Udmurtplem" of the Udmurt Republic in the period from 2020 to 2021 on dairy bulls (n=20) aged 15-69 months, including a purebred Holstein breed of domestic selection (n=6), a Holstein black-and-white breed of European selection (the Netherlands, n=6), a black-and-white breed with blood transfusion on Holsteins on at the level of 94-98% (n=8). The content of white blood cells, red blood cells, hemoglobin and hematocrit, depending on age and breed, was studied on the ABC VET hematological analyzer on the day of taking the seed.Results. It was found that on average, in 20 bulls aged 15-69 months, the level of white blood cells was at the level of reference values of 8.8±0.25 x 109/l, red blood cells 10.3 x 1012/l, which is 50% more than the reference values. The concentration of hemoglobin is 128.0±2.92 g/l, hematocrit is on average 54.3%, with a norm of 24-46%. Breeding bulls at a reliable level, differing in age, showed that some animals had high indicators for red blood cells of 10.3±0.26 x 102, for hematocrit of 54.3% against 24-46% of reference values. Also, according to hematological indicators, there was a tendency to increase the concentration of hemoglobin and hematocrit in European-bred bulls.Conclusion. The study of the variability in hematological parameters depending on the selection showed that there is no significant difference in leukocytes and all indicators are at the level of reference values, and in erythrocytes more than 50% than the highest indicators. The highest hemoglobin values were at the level of 141-156 g/l instead of 128 g/l according to the highest reference values. Hematocrit also showed high max values in all groups in comparison with the reference values of 59-66% versus 46% in the norm. It is necessary when analyzing hematological blood parameters in addition to the average statistical indicators (M+m) also, monitor the variability (min-max) in order to obtain more objective information.

The specific features of the thermal radiation of lake Kenon during freeze-up in the infrared band

This work is the study of the infrared images of Lake Kenon located in the city of Chita. The images were obtained from a satellite Lansat-8. The images revealed the thermal anomalies of the said internal water body. The anomalies consisted in the fact that areas of open water having negative temperature are formed in the lake in the winter period. The phenomenon may be caused both by surface supercooling of the lake water and by formation of water aerosol at the temperature below 0°C. The emergence of areas with supercooled water may be, paradoxical as it may sound, due to the impact of the thermal power plant located near the lake. Its functioning prevents formation of the ice cover, especially at the locations of warm water discharge. Analysis of the satellite images in the IR-band obtained over the recent five years has shown the area of the higher water temperature on the lake surface not to exceed 10% of the total area of the lake. The time before the freeze-up in the absence of wind, October – November, is the best time for revealing the maximum temperature difference.

ASSESSMENT OF THE IMPACT OF ANTHROPOGENIC AND TECHNOGENIC FACTORS ON THE CONTAMINATION OF THE SOIL COVER OF THE CITY

The aim of the study is to assess the ecological state of the territory of an industrial city based on moni-toring the soil cover. In the winter period, the study of the soil cover of the urbanized territory for the con-tent of sulfates, nitrates, chlorides was carried out, and the pH values were determined. Analysis of the spatial distributions of the studied substances in the soil cover in the area of influence of a large industrial center show the variation of the content of pollutants due to the impact of anthropogenic sources; there is an excess of the background concentration for all tested ingredients. In the course of the research, it has determined that it is advisable to use data on soil pollution in the study area as a means of control-ling the impact of anthropogenic sources on the environment.

On the applicability of ARPS models in modelingand forecasting the dynamics of new cases of COVID-19 infection

The aim of the work is to study the applicability of the methodology for constructing ARIMA models in the problem of modeling and predicting the dynamics of new cases of coronavirus infection in the autumn-winter period of 2020 in the KhMAO-Yugra.