scholarly journals Role of Solar Radiation in Thermo-technical Analysis of Roadbed of Railway Track

2021 ◽  
Vol 54 ◽  
pp. 503-512
Author(s):  
Alexander Isakov ◽  
Bibisulu Zhuraeva
2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Gerry K. Schwalfenberg

This paper looks at the environmental role of vitamin D and solar radiation as risk reduction factors in autoimmune disease. Five diseases are considered: multiple sclerosis, type 1 diabetes, rheumatoid arthritis, autoimmune disease of the thyroid, and inflammatory bowel disease. Clinical relevant studies and factors that may indicate evidence that autoimmune disease is a vitamin D-sensitive disease are presented. Studies that have resulted in prevention or amelioration of some autoimmune disease are discussed. An example of the utility of supplementing vitamin D in an unusual autoimmune disease, idiopathic thrombocytic purpura, is presented.


2019 ◽  
Vol 91 ◽  
pp. 05006
Author(s):  
Rami Qaoud ◽  
Alkama Djamal

The urban fabric of the desert cities is based on the principle of reducing the impact of urban canyons on direct solar radiation. Here comes this research, which is based on a comparative study of the periods of direct solarisation and values of the solar energy of urban canyons via two urban fabrics that have different building densities, where the ratio between L/W is different. In order to obtain the real values of the solar energy (thermal, lighting), the test field was examined every two hours, each three consecutive days. The measurement stations are positioned by the three types of the relationship between L/W, (L≥2w, L=w, L≤0.5w). According to the results, we noticed and recorded the difference in the periods of direct solarization between the types of urban engineering canyons, reaching 6 hours a day, the difference in thermal values of air, reaching 4 °C, and the difference in periods of direct natural lighting, reaching 6 hours. It should be noted that the role of the relationship between L/W is to protect the urban canyons by reducing the impact of direct solar radiation on urban canyons, providing longer hours of shading, and reducing solar energy levels (thermal, lighting) at the urban canyons. This research is classified under the research axis (the studies of external spaces in the urban environment according to the bioclimatic approach and geographic approach). But this research aims to focus on the tracking and studying the distribution of the solar radiation - thermal radiation and lighting radiation - in different types of street canyons by comparing the study of the direct solarization periods of each type and the quantity of solar energy collected during the solarization periods.


2015 ◽  
Vol 14 (11) ◽  
pp. 2007-2013 ◽  
Author(s):  
Nadia Diovisalvi ◽  
Armando M. Rennella ◽  
Horacio E. Zagarese

A schematic representation of the seasonal cycle of rotifer in L. Chascomús. In this figure the relative abundances of the three dominant rotifer species are expressed as fractions of the estimated clear-sky mean daily incident solar radiation.


2016 ◽  
Vol 181 ◽  
pp. 1-6 ◽  
Author(s):  
E. Ortega-Gómez ◽  
M.M. Ballesteros Martín ◽  
B. Esteban García ◽  
J.A. Sánchez Pérez ◽  
P. Fernández Ibáñez

2019 ◽  
Vol 14 (1) ◽  
pp. 126-136
Author(s):  
A. Ya. Tamakhina ◽  
A. A. Akhkubekova ◽  
A. B. Ittiev

Aim.The aim of the work described herein was to study the dynamics of allantoin accumulation in the underground phytomass ofEchium vulgareL.,Symphytum caucasicumM. Bieb. andS. asperumLepech. as well as to clarify the role of allantoin in plant adaptation to stress factors.Methods.We studied the roots of plants growing in the foothill (Nalchik, 490–512 m above sea level) and the mountain zones of the Kabardino-Balkarian Republic (Terskol village, 2530 m above sea level; Verkhnyaya Balkaria village, 2680 m above sea level). The roots were collected at the stages of rosetting, flowering, fruiting and at the end of the growing season. Aqueous-alcoholic extracts of shredded roots were analyzed by high-performance liquid chromatography.Results.The highest content of allantoin in the roots ofEchium vulgare,Symphytum caucasicum,S. asperumplants was noted at the end of the growing season, respectively 0.915; 0.342–0.658; 2,842–3,426%. Under conditions of low temperatures and increased solar radiation, the content of allantoin in the roots increases 1.2–1.9 times as compared with the plants of the foothill zone.Conclusion.Allantoin plays an important role in the process of adapting species of the family Boraginaceae to oxidative stress caused by hypothermia and increased solar radiation.


2021 ◽  
pp. 1-13
Author(s):  
Kehan Li

Climate change is of great importance in modern times and global warming is considered as a significant part of climate change. It is proved that human’s emissions such as greenhouse gases are one of the main sources of global warming (IPCC, 2018). Apart from greenhouse gases, there is another kind of matter being released in quantity via emissions from industries and transportations and playing an important role in global warming, which is aerosol. However, atmospheric aerosols have the net effect of cooling towards global warming. In this paper, climate change with respect to global warming is briefly introduced and the role of aerosols in the atmosphere is emphasized. Besides, properties of aerosols including dynamics and thermodynamics of aerosols as well as interactions with solar radiation are concluded. In the end, environmental policies and solutions are discussed. Keywords: Climate change, Global warming, Atmospheric aerosols, Particulate matter, Radiation, Environmental policy.


2016 ◽  
Vol 13 (16) ◽  
pp. 4637-4643 ◽  
Author(s):  
Juntian Xu ◽  
Lennart T. Bach ◽  
Kai G. Schulz ◽  
Wenyan Zhao ◽  
Kunshan Gao ◽  
...  

Abstract. Coccolithophores are a group of phytoplankton species which cover themselves with small scales (coccoliths) made of calcium carbonate (CaCO3). The reason why coccolithophores form these calcite platelets has been a matter of debate for decades but has remained elusive so far. One hypothesis is that they play a role in light or UV protection, especially in surface dwelling species like Emiliania huxleyi, which can tolerate exceptionally high levels of solar radiation. In this study, we tested this hypothesis by culturing a calcified and a naked strain under different light conditions with and without UV radiation. The coccoliths of E. huxleyi reduced the transmission of visible radiation (400–700 nm) by 7.5 %, that of UV-A (315–400 nm) by 14.1 % and that of UV-B (280–315 nm) by 18.4 %. Growth rates of the calcified strain (PML B92/11) were about 2 times higher than those of the naked strain (CCMP 2090) under indoor constant light levels in the absence of UV radiation. When exposed to outdoor conditions (fluctuating sunlight with UV radiation), growth rates of calcified cells were almost 3.5 times higher compared to naked cells. Furthermore, the relative electron transport rate was 114 % higher and non-photochemical quenching (NPQ) was 281 % higher in the calcified compared to the naked strain, implying higher energy transfer associated with higher NPQ in the presence of calcification. When exposed to natural solar radiation including UV radiation, the maximal quantum yield of photosystem II was only slightly reduced in the calcified strain but strongly reduced in the naked strain. Our results reveal an important role of coccoliths in mitigating light and UV stress in E. huxleyi.


1993 ◽  
Vol 58 (01) ◽  
pp. 23-44 ◽  
Author(s):  
Hector Neff

How archaeologists analyze pottery is determined by archaeological theory, sampling considerations, and available analytical techniques. The most damaging impediment to methodological advance is lack of a theory of how patterns of ceramic variation are generated. It is argued herein that Darwinian evolutionary theory (or selectionism) provides a body of concepts capable of explaining patterned variation and specifies measurements to make in testing specific explanatory statements. Most existing analytical procedures (e.g., the "Type-Variety" system) are regarded as aspects of sampling, the role of which is to help reduce some of the bewildering heterogeneity in ceramic collections before attempting to measure evolutionarily significant variation. Technical analysis, often considered the domain of nonarchaeological specialists, actually produces the measurements needed to test explanatory statements made about pottery observed in the archaeological record.


Hydrobiologia ◽  
2010 ◽  
Vol 654 (1) ◽  
pp. 253-265 ◽  
Author(s):  
Oldřich Jarolím ◽  
Jan Kubečka ◽  
Martin Čech ◽  
Mojmír Vašek ◽  
Jiří Peterka ◽  
...  

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