Effects Of Solar Radiation Research Articles

Long-Term Performance of Monolithic Silica Aerogel with Different Hydrophobicities: Physical and Color Rendering Properties after an Accelerated Aging Process.

Due to its excellent properties, monolithic silica aerogel is a promising material for innovative glazing systems. Since glazing systems are exposed to deteriorating agents during building service life, it is essential to investigate the long-term performance of aerogel. In the present paper, several 12.7 mm-thick silica aerogel monoliths produced by a rapid supercritical extraction method were tested, including both hydrophilic and hydrophobic samples. After fabrication and characterization of hydrophobicity, porosity, optical and acoustic properties, and color rendering, the samples were artificially aged by combining temperature and solar radiation effects in an experimental device specifically developed at the University of Perugia. The length of the experimental campaign was determined using acceleration factors (AFs). Temperature AF was evaluated according to the Arrhenius law using thermogravimetric analysis to estimate the aerogel activation energy. A natural service life of 12 years was achieved in about 4 months, and the samples' properties were retested. Contact angle tests supported by FT-IR analysis showed loss of hydrophobicity after aging. Visible transmittance values in the 0.67-0.37 range were obtained for hydrophilic and hydrophobic samples, respectively. The aging process involved optical parameter reduction of only 0.02-0.05. There was also a slight loss in acoustic performance (noise reduction coefficient (NRC) = 0.21-0.25 before aging and NRC = 0.18-0.22 after aging). For hydrophobic panes, color shift values in the 10.2-59.1 and 8.4-60.7 ranges were obtained before and after aging, respectively. The presence of aerogel, regardless of hydrophobicity, results in a deterioration in light-green and azure tones. Hydrophobic samples had lower color rendering performance than hydrophilic aerogel, but this did not worsen after the aging process. This paper makes a significant contribution to the progressive deterioration assessment of aerogel monoliths for applications in sustainable buildings.

Characterization of triglycerides photooxidation under solar radiations: A stepwise Raman study.

Triglycerides (TGs) are one of the main components of the glycerolipid family. Their main task in cells is to store excess fatty acids. TG energy storage is mainly concentrated in adipocytes. TGs and free fatty acids constitute the majority (57.5%) of the skin surface lipids (SSLs). TGs are essential for the formation of the skin water barrier. This work is the second part of a global study that aims to evaluate the effect of solar radiations on SSLs using vibrational spectroscopy. In the first part of this work, a stepwise characterization of free fatty acids was performed, and different spectral descriptors were used to follow the different structural modifications during the photo-oxidation process, that is hydrogen abstraction, formation of hydroperoxides and peroxyl radicals as primary oxidation products and the formation of aldehydes, ketones, alcohol as secondary products. In this second part, the photo-oxidation of TGs was evaluated using Raman spectroscopy. A decrease in the CH2/CH3 stretching bands ratio that confirmed the hydrogen abstraction, an increase in the 1165/1740cm-1 ((δ(OH) and υ(C-O))/ν(C=O) (ester)) ratio indicated the formation of secondary oxidation products such as hydroperoxides. And finally, an increase in the 1725/1740cm-1 (υ(C=O) (ald.)/υ(C=O) (ester)) ratio and the trans ν(C=C)/cis ν(C=C) ratio highlighted the formation of aldehydes, alcohols, ketone, trans secondary products and others.

Health and safety risks behavior among local and international tourists at Borobudur Temple before COVID-19 pandemic

<span lang="EN-US">Tourists are vulnerable to certain diseases and health-related issues, including experiencing danger during their visit to a destination. This study aims to compare the health and safety behavior of local and foreign tourists during their visit to Borobudur Temple, Indonesia from September to November 2019. Additionally, it was carried out quantitatively with a cross-sectional approach. The sample consisted of 200 foreign and 200 local tourists visiting Borobudur Temple; they were selected using convenient sampling. The data were analyzed using the frequency distribution and the Chi-square test. The results showed that health risks related to food and beverage hygiene were the most experienced by foreign tourists (p-value 0.030), and solar radiation effects were experienced by both foreign and local tourists (p-value 0.006). Tourists' knowledge to prevent health and safety risks was categorized as moderately adequate, and foreign tourists have more understanding than their local counterparts. This study reported no difference in health and safety behaviors between foreign and local tourists. It was suggested that tourism managers should provide information to the visitors concerning health and safety risks prevention by delivering leaflets, booklets, and brochures to minimize danger, sunburn, and food as well as beverage-related diseases.</span>

Non-Unique Solutions of Magnetohydrodynamic Stagnation Flow of a Nanofluid towards a Shrinking Sheet Using the Solar Radiation Effect

This study aims to investigate the magnetohydrodynamic flow induced by a moving surface in a nanofluid and the occurrence of suction and solar radiation effects using the Buongiorno model. The numerical findings are obtained using MATLAB software. The effects of various governing parameters on the rates of heat and mass transfer along with the nanoparticles concentration and temperature profiles are elucidated graphically. Non-unique solutions are discovered for a specific variation of the shrinking strength. The temporal stability analysis shows that only one of them is stable as time passes. Furthermore, raising the Brownian motion parameter reduces both the local Sherwood number and the local Nusselt number for both solutions. It is also observed that increasing the thermophoresis parameter reduces the rate of heat transfer, whereas the opposite trend is observed for the rate of mass transfer.

Skin surface lipids photo‐oxidation: A vibrational spectroscopy study

AbstractSkin surface lipid (SSL) film is a mixture of sebum and epidermal lipids protecting the skin from the effects of the environment such as solar radiation. SSLs are a suitable target and scavenger for all reactive oxygen species (ROS) generated in the skin. In the SSLs, vitamin E has been identified as one of the main antioxidants that can capture ROS. This paper is the third part of a global study that evaluates the effect of solar radiation on the lipid classes that constitute SSLs. In the first two parts, the effect of solar radiation on fatty acids and triglycerides was studied using vibrational spectroscopy. In this part, the effect on the other lipid classes such as squalene (SQ), cholesterol (Chol), and wax ester (WE) (Palmitoleyl Palmitate) was studied and then the behavior of vitamin E under solar radiation was monitored. Finally, SSLs were irradiated and analyzed using vibrational spectroscopy and HT‐GC/MS to respectively follow the oxidation process and to identify the first target of solar radiation in SSLs. When irradiated alone, SQ oxidation process was detectable only after 2430 J/cm2 dose. Similar observations were obtained for vitamin E (after 1620 J/cm2). No changes were observed on the cholesterol and on the wax ester (Palmitoleyl Palmitate). In contrast, when extracted human SSLs film was irradiated, the more marked modifications were observed on SQ. This confirmed the antioxidant role of SQ by scavenging free radicals generated from the oxidation of polyunsaturated fatty acids (PUFA).

Mapping areas prone to piping using random forest with key explanatory variables

In previous studies, areas prone to soil piping were mapped on the catchment scale by integrating data-mining algorithms and geographical databases. However, this left the question of which input data layers are most influential on soil pipe distribution in semiarid regions, and how they can be exploited for accurate predictions of areas prone to piping. Here, a random forest (RF) procedure was applied to classify areas prone to piping using input data layers selected based on knowledge gained through previous theoretical modeling and empirical measurements. The input data layers were: potential incoming solar radiation; distance from the closest streambank; streambank slope gradient; topographic wetness index; flow accumulation; and vegetation cover as a proxy for the shading effect. An extensive dataset of field measurements (N = 774) was used to train and validate the RF classification procedure. Our results indicated that: (i) RF—based on carefully selected influential input data layers—can be used to map areas prone to soil piping at the catchment scale with high accuracy; (ii) the effect of potential solar radiation and—to a lesser extent—tree shading is noteworthy for soil cracking and subsequent piping development; and (iii) soil pipes were found at short distances (<30 m) from steep bank slopes due to the effect of tension cracks in the streambanks. These observations, over a wide region, further establish the effect of soil cracking, and drying and wetting processes, on soil pipe development in semiarid regions. Future studies applying piping susceptibility mapping at the catchment scale may benefit from using these input layers.

Asymmetric response of primary productivity to precipitation anomalies in Southwest China

Southwest China has been the largest terrestrial carbon sink in China over the past 30 years, but has recently experienced a succession of droughts caused by high precipitation variability, potentially threatening vegetation productivity in the region. Yet, the impact of precipitation anomalies on the vegetation primary productivity is poorly known. We used an asymmetry index (AI) to explore possible asymmetric productivity responses to precipitation anomalies in Southwest China from 2003 to 2018, using a precipitation dataset, combined with gross primary productivity (GPP), net primary productivity (NPP), and vegetation optical depth (VOD) products. Our results indicate that the vegetation primary productivity of Southwest China shows a negative asymmetry, suggesting that the increase of vegetation primary productivity during wet years exceeds the decrease during dry years. However, this negative asymmetry of vegetation primary productivity was shifted towards a positive asymmetry during the period of analysis, suggesting that the resistance of vegetation to drought, has increased with the rise in the occurrence of drought events. Among the different biomes, grassland vegetation primary productivity had the highest sensitivity to precipitation anomalies, indicating that grasslands are more flexible than other biomes and able to adjust primary productivity in response to precipitation anomalies. Furthermore, our results showed that the asymmetry of vegetation primary productivity was influenced by the effects of temperature, precipitation, solar radiation, and anthropogenic and topographic factors. These findings improve our understanding of the response of vegetation primary productivity to climate change over Southwest China.

A complex wireless sensors model (CWSM) for real time monitoring of dam temperature

The following work is based on real-time temperature monitoring during the construction and during the operation of a dam. For this purpose, we have proposed a sensing model named: the “complex wireless sensors model (CWSM)” for measuring the value of different factors like temperature, humidity and pressure on the dam. The installation of the proposed model has been discussed with its wireless networking. The model contains five types of sensors i.e. humidity, temperature, pressure, sun and irradiance sensors for measuring the variation of different factors. The computation modeling of CWSM has been discussed in the paper. 3-D Finite Element method is used for thermal analysis. As the result, it is concluded that the wireless network will be more suitable for measuring and analyzing the effects of temperature, humidity, water pressure and solar radiation on the dam.

Design of a radiation shield applied to surface air temperature monitoring

Due to the solar radiation effect, the current thermometric instruments may produce a radiation error of about 1°C. In this paper, a new radiation shield was designed. Initially, a Computational Fluid Dynamics (CFD) method was employed to create the radiation shield structure. Then, the CFD method was used to quantify the radiation errors of the radiation shield under various environmental conditions. Next, a Multi-layer Perceptron (MLP) network was employed to form a radiation error correction approach for this radiation shield. Finally, the air temperature observation experiments were performed to verify the accuracy of the new radiation shield. A 076B fan aspirated radiation shield was served as an air temperature reference during experiments. The mean absolute error, root mean square error, and correlation coefficient between the radiation error results provided by the correction approach and the measured radiation error results given by the experiments are 0.012°C, 0.015°C, and 0.796°C, respectively.

Optical and color rendering long-term performance of monolithic aerogel after laboratory accelerated aging: Development of a method and preliminary experimental results

Innovative transparent solutions such as monolithic aerogel in the building envelope have a considerable impact on both the indoor environmental quality and thermo-acoustic performance. However, the long-term effect of this new material is not yet known in the scientific literature. In this context, the present study investigates the influence of accelerated aging on the optical and color rendering properties of monolithic aerogel. In the aging process, the combined effect of temperature and solar radiation was considered. An acceleration factor for temperature equal to 13.6 was obtained following the Arrhenius Law, after evaluating the activation energy value by means of thermogravimetric analysis. The acceleration factor for radiation was evaluated as the ratio between artificial radiation of the chosen lamps used in the laboratory aging device and the natural radiation of the solar spectrum, by adding the direct and diffuse components related to the site. Accelerated aging equivalent to 2.6 years did not lead to significant changes in the optical transmission properties of the monolithic aerogel; however, the material tends to yellow and a bluish hue is obtained for the color patches seen through the aged material. Furthermore, an increase in the color shift is measured for all colors (from the 5.62–43.40 range to the 6.42–45.30 range), with the higher variations between before and after aging registered for a sample of bluish green color.

Effects of pH and light exposure on the survival of bacteria and their ability to biodegrade organic compounds in clouds: implications for microbial activity in acidic cloud water

Abstract. Recent studies have reported that interactions between live bacteria and organic matter can potentially affect the carbon budget in clouds, which has important atmospheric and climate implications. However, bacteria in clouds are subject to a variety of atmospheric stressors, which can adversely affect their survival and energetic metabolism and, consequently, their ability to biodegrade organic compounds. At present, the effects of cloud water pH and solar radiation on bacteria are not well understood. In this study, we investigated how cloud water pH (pH 3 to 6) and exposure to solar radiation impact the survival and energetic metabolism of two Enterobacter bacterial strains that were isolated from ambient air collected in Hong Kong and their ability to biodegrade organic acids. Experiments were conducted using simulated sunlight (wavelength from 320 to 700 nm) and microcosms comprised of artificial cloud water that mimicked the pH and chemical composition of cloud water in Hong Kong, South China. Our results showed that the energetic metabolism and survival of both strains depended on the pH. Low survival rates were observed for both strains at pH&lt;4, regardless of whether the strains were exposed to simulated sunlight. At pH 4 to 5, the energetic metabolism and survival of both strains were negatively impacted only when they were exposed to simulated sunlight. Organic compounds such as lipids and peptides were detected during exposure to simulated sunlight at pH 4 to 5. In contrast, there were minimal effects on the energetic metabolism and the survival of both strains when they were exposed to simulated sunlight at pH&gt;5. The biodegradation of organic acids was found to depend on the presence (or absence) of simulated sunlight and the pH of the artificial cloud water medium. Overall, this study provides new insights into how two common atmospheric stressors, cloud water pH and exposure to solar radiation, can influence the survival and energetic metabolism of bacteria, and consequently the roles that they play in cloud processes.

Entropy Generation and Thermal Radiation Analysis of EMHD Jeffrey Nanofluid Flow: Applications in Solar Energy.

This article examines the effects of entropy generation, heat transmission, and mass transfer on the flow of Jeffrey fluid under the influence of solar radiation in the presence of copper nanoparticles and gyrotactic microorganisms, with polyvinyl alcohol-water serving as the base fluid. The impact of source terms such as Joule heating, viscous dissipation, and the exponential heat source is analyzed via a nonlinear elongating surface of nonuniform thickness. The development of an efficient numerical model describing the flow and thermal characteristics of a parabolic trough solar collector (PTSC) installed on a solar plate is underway as the use of solar plates in various devices continues to increase. Governing PDEs are first converted into ODEs using a suitable similarity transformation. The resulting higher-order coupled ODEs are converted into a system of first-order ODEs and then solved using the RK 4th-order method with shooting technique. The remarkable impacts of pertinent parameters such as Deborah number, magnetic field parameter, electric field parameter, Grashof number, solutal Grashof number, Prandtl number, Eckert number, exponential heat source parameter, Lewis number, chemical reaction parameter, bioconvection Lewis number, and Peclet number associated with the flow properties are discussed graphically. The increase in the radiation parameter and volume fraction of the nanoparticles enhances the temperature profile. The Bejan number and entropy generation rate increase with the rise in diffusion parameter and bioconvection diffusion parameter. The novelty of the present work is analyzing the entropy generation and solar radiation effects in the presence of motile gyrotactic microorganisms and copper nanoparticles with polyvinyl alcohol-water as the base fluid under the influence of the source terms, such as viscous dissipation, Ohmic heating, exponential heat source, and chemical reaction of the electromagnetohydrodynamic (EMHD) Jeffrey fluid flow. The non-Newtonian nanofluids have proven their great potential for heat transfer processes, which have various applications in cooling microchips, solar energy systems, and thermal energy technologies.

Weather drives variation in COVID-19 transmission and detection

The debate over the influence of weather on COVID-19 epidemiological dynamics remains unsettled as multiple factors are conflated, including viral biology, transmission through social interaction, and the probability of disease detection. Here we distinguish the distinct dynamics of weather on detection and transmission with a multi-method approach combining econometric techniques with epidemiological models, including an extension of a susceptible-exposed-infectious-recovered model, to analyse data for over 4000 geographic units throughout the year 2020. We find distinct and significant effects of temperature, thermal comfort, solar radiation, and precipitation on the growth of infections. We also find that weather affects the rates of both disease transmission and detection. When we isolate transmission effects to understand the potential for seasonal shifts, the instantaneous effects of weather are small, with R0 about 0.007 higher in winter than in summer. However, the effects of weather compound over time, so that a region with a 5 ∘C drop over three months in winter is expected to have 190% more confirmed cases at the end of that 90 days period, relative to a scenario with constant temperature. We also find that the contribution of weather produces the largest effects in high-latitude countries. As the COVID-19 pandemic continues to evolve and risks becoming endemic, these seasonal dynamics may play a crucial role for health policy.

Resource-based growth models reveal opportunities to mitigate climate change effects on beech regeneration by silvicultural measures

Successful European beech (Fagus sylvatica L.) regeneration is both of great ecological and economical importance in European forest ecosystems and severely threatened by climate change impacts. To increase our knowledge of beech regeneration dynamics under climate change and the potential for controlling it through forest management, we studied interactive effects of solar radiation (PHAR), water and nutrient availability on the height growth of artificially (AR) and naturally regenerated (NR) beech seedlings. The study was conducted in the framework of experimental canopy gaps, under the influence of the 2018/19 drought and heatwaves. We measured PHAR by means of hemispherical photography, approximated water availability based on the inverse of modeled fine root density distributions of overstorey beech (BGRB) and oak (BGRO) and approximated nutrient availability based on soil fertility (SF), derived from forest site mapping. Results indicate that seedling resource availability and resulting growth responses increase with canopy gap size and vary among locations within the gap. Multiplicative non-linear mixed models suggest that AR and NR relative height growth (RI) was best explained by interactive effects of PHAR, BGRB, BGRO and SF, which reflect complementary resource use patterns of beech seedlings. At optimal resource availability, AR reached a potential RI of 174%, which is about 20% higher compared to NR. While the low light growth responses of AR and NR both reflect saturation at 5 to 15% PHAR, depending on individual size and the availability of the remaining resources, NR showed a higher RI than AR at intermediate and high PHAR levels in cases of limited BGR and SF. In contrast to AR, NR growth was affected to a lesser extent by SF and BGRB and not significantly affected by BGRO. These results suggest that overstorey oaks have a lower effect on water availability of beech seedlings than overstorey beeches. Additionally, NR showed higher tolerance to water and nutrient limitation than AR, probably due to better root system development. In conclusion, site-specific potential for mitigating the effects of climate change on beech regeneration through forest management lies in the adaptation of silvicultural systems, i.e., the creation of canopy gaps larger than 200 m2, thus significantly exceeding the average gap size of the natural disturbance regime, and the choice of the regeneration method.

Plants from Brazil with Potential Photoprotective Activity: A Review

Background: Skin cancer due the solar radiation is an important public health issue in Brazil. Sunscreen formulations protect the skin from the harmful effects of solar radiation. Plants products can have photoprotective compounds that can be incorporated into sunscreen formulations which attend a demand of society for the use of natural compounds in different cosmetics. This review aims to summarize studies that evaluated the photoprotective activity of plants in Brazil in the last ten years. Materials and Methods: A search was conducted in Medline, Scopus, and Embase databases, using the descriptors Brazilian natural products, photoprotection, natural sunscreen, plant extract, and photoprotective activity. Results: A total of 392 manuscripts were retrieved in the databases searched. After applying the criteria of inclusion and exclusion, thirty-six papers were selected, followed by a final screen resulting in twenty-nine. Plant extracts and oils were tested in these studies. The solar photoprotector factor was determined in vitro in most studies. Only three studies were performed in tests in vivo and there were no clinical studies with an adequate sample effort. Conclusion: Several plant extracts demonstrated promising solar photoprotective activity in vitro, such as Erythrina velutina, Dalbergia monetaria, and Garcinia brasiliensis, which recommend complementary studies for use in sunscreens formulations as most of the studies with Brazilian plants were focused on preliminary analyses in the last decade.

Effects of Solar Radiation on Leaf Development and Yield of Tuberous Roots in Multilayered Sweet Potato Cultivation

The purpose of this study was to develop a novel method to dramatically improve the production efficiency of sweet potatoes (Ipomoea batatas (L.) Lam.) by elucidating the effect of solar radiation stress on the growth of sweet potato in a multilayer cultivation system. Twenty-five pots planted with sweet potato vine seedlings were arranged in three layers and cultivated for 160 days while supplying liquid fertilizer to the root zone. While solar radiation in the middle and lower layers decreased to 69% and 45% of that in the upper layer, respectively, the yield of tuberous roots was 0.89 kg/pot in the upper layer, 0.79 kg/pot in the middle layer, and 0.66 kg/pot in the lower layer. As a result, the productivity of tuberous roots reached 10.5 kg/m2, 4.4 times that of conventional farming. On the other hand, the amounts of leaves and stems increased in the lower layer than in the upper layer, and the biomass energy yield (photosynthetic efficiency) was 2.8% in the upper layer, 3.7% in the middle layer, and 5.1% in the lower layer. Leaves in the lower layer with less solar radiation had a lower polyphenol content and increased the amounts of low-brightness leaves. In contrast, the upper leaves were found to contain more polyphenols and have brighter, smaller leaves. These results suggest that the yield can be further increased by optimizing solar radiation stress by using the multilayer cultivation method.

A bidirectional solar thermoelectric generator combining heat storage for daytime and nighttime power generation

A solar thermoelectric generator (STEG) is a promising technology for harvesting solar energy for standalone applications. However, the STEG cannot generate electricity during nighttime due to unavailability of solar energy. The efficiency of thermoelectric generator (TEG) is also low that limits its application areas. This low efficiency can be improved by partially utilizing the waste heat from its cold side using phase change materials (PCMs). Further, the STEG systems operating during day and nighttime are not proposed so far. Therefore, an experimental test rig of a bidirectional (operative in day and night both) STEG coupled with latent heat storage and cooling system (LHSCS) has been developed in this paper. The LHSCS acts as a sink by storing waste heat from the TEG cold side in a phase change material during the daytime and regulates its temperature effectively. During nighttime, LHSCS acts as a heat source for TEG power generation. This proposed bidirectional model aims to provide non-intermittent electricity generation for 24 h. An experimental setup was tested under laboratory conditions and adjusted using a numerical model previously developed in COMSOL Multiphysics software. Once both models are mutually adjusted and verified, the proven numerical model is used to simulate the prototype in the environmental conditions of the Atacama Desert in Chile. The transient effects of solar radiation, ambient temperature and wind speed of the selected location on the hot and cold side temperatures, voltage, power output and efficiency of STEG have been analyzed. A maximum temperature difference of 120 °C is obtained between the TEG hot and cold sides. The experimental results showed TEG efficiency of 5%. The system generated average annual electricity of 5735 Wh. The STEG generated around 0.6 % of the total electricity during the night in the Atacama Desert location. The levelized cost of energy and storage have also been calculated for the proposed system and compared with PV and STEG systems. The LCOE and LCOS of the proposed system are 8850 and 566 USD/MWh respectively. The proposed configuration may provide a reference study for design and development of an efficient and cost-effective STEG coupled LHSCS system.

Predicting the distributions of Pouteria adolfi‐friederici and Prunus africana tree species under current and future climate change scenarios in Ethiopia

AbstractDistributions of potential ranges of plant species are not yet fully known in Ethiopia where high climatic variability and vegetation types are found. This study was undertaken to predict distributions of suitable habitats of Pouteria adolfi‐friederici and Prunus africana under current and two future climate scenarios (RCP 4.5 and RCP 8.5 in 2050 and 2070) in Ethiopia. Eleven environmental variables with less correlation coefficients (r &lt; 0.7) were used to make the prediction. Shifting in extents of habitat suitability and effects of elevation, solar radiation and topographic position in relation to the current and future climatic scenarios were statistically analysed using independent t‐test and linear model. We found decreasing area of highly suitable habitat from 0.51% to 0.46%, 0.36% and 0.33%, 0.24% for Prunus africana and 1.13% to 1.02%, 0.77% and 0.76%, 0.60% for Pouteria adolfi‐friederici, under RCP 4.5 and RCP 8.5 by 2050 and 2070 respectively. Moist and dry afromontane forests are identified as the most suitable habitat for both species. Overall, our results suggest that climate change can promote dynamic suitable habitat niches under different future climate scenarios. Therefore, biodiversity conservation strategies should take into account habitat suitability dynamics issues and identify where to conserve species before implementing conservation practices.

Связь активности Солнца и лесных пожаров с позиций онкогенеза

The effect of solar radiation and forest fires smoke on cancer incidence has been studied and published in many research periodicals. Researchers found many indirect signs of the impact of the solar activity on the periodicity of landscape fires. The paper presents the research on the relationship between the solar activity and landscape fires, as well as the assessment of the role of natural events in carcinogenesis. The Pearson correlation analysis of the relationship between the dynamic series of the solar activity and the number of forest fires in the Khabarovsk Territory (1970-2019), in Russia and also separately in all its administrative territories (1992-2019) was analyzed in 11 iterations with a lag from 0 to 10 years. The reliable correlation was revealed in the Khabarovsk Territory (r=0.414; p=0.003) and in the whole Russia (r=0.472; p=0.011) with a lag of 7 years. The average bond strength in the regions of Russia in the 23rd cycle of the solar activity increased to a strong one (r=0.700±0.235), the average lag was 7.2±0.9 years. The role of cyclic changes in the solar radiation as the prerequisites for the landscape fires occurrence and the causes of fires was discussed. The discovery of an internal relation between the powerful environmental factors such as solar activity and forest fires is a significant supplement to the existing ideas about the nature of environmentally incused carcinogenesis.

Thermal radiation effect on Non-Newtonian Casson fluid through a porous material over a magnetic field with buoyancy

The magnetohydrodynamic (MHD) chemically reactive of Casson non-Newtonian nanofluid flow on a two-dimensional incompressible steady from stretched sheet in a porous quiescent medium with buoyancy effect is investigated numerically. Additional effects included in the originality of the model are the applied magnetic field and solar radiation effect. The Chebyshev collocation method (CCM) was used to solve the ordinary differential equations (ODEs) with MATHEMATICA 11.3 software. The present tables and graphs show the performance of fluid physical quantities, momentum flow, energy distribution, nanoparticle concentration, and velocity for various values of applicable dimensionless numbers. The numerical outcomes demonstrate the effect of different physical parameters of the fluid, and it was observed that the velocity profile increased as the thermal and mass Grashof number increased due to an increase in buoyant force caused by heat transferred from the vertical plate to the fluid but decreased as the Casson parameter increased due to a decrease in its yield stress, porosity, and magnetic parameter. Also Analyses reveal that the thermal profile reduce with an increase in variable thermal conductivity parameter. This study will be of considerable economic value to marine engineers, mechanical engineers, physicists, chemical engineers, and others since its application will help them improve their operations.