atmospheric factors
Recently Published Documents


TOTAL DOCUMENTS

140
(FIVE YEARS 59)

H-INDEX

13
(FIVE YEARS 5)

2022 ◽  
pp. 252-266
Author(s):  
Elhoucine Essefi

This work aimed to study the cyclicity of the geochemical chemical parameters and the carbonate percentages along a 59 cm core from the sebkha of Mchiguig, Central Tunisia. In fact, from the bottom upwards, six climatic phases were recorded including the Warming Present (Great Acceleration), the Late Little Ice Age (Anthropocene), the Early Little Ice Age, the Medieval Climatic Anomaly, the Dark Age, and the Roman Warm Period. In fact, the spectral analysis of the studied parameters visualized many cycles. Those cycles are related to sun activity, oceanographic, and atmospheric factors. Solar activity generated 500 yr cycles; however, the oceanographic circulation generated other cycles of 1500 yr and 700-800 yr. The 1500 yr cycle may be the result of the solar activity and NAO-like circulation.


2021 ◽  
Vol 8 (4) ◽  
pp. 1575-1581
Author(s):  
Carla Talita Pertille ◽  
Marcos Felipe Nicoletti

This research aimed to evaluate the potential of orbital images from the Landsat-8/OLI and Sentinel-2 /MSI sensors in the distinction of species from a forest stand located in Campo Belo do Sul, State of Santa Catarina, Brazil. A total of 53 plots were allocated in the field, in which the central coordinate of the plot was collected using GPS receivers. In SIG environment, two images were used, one from each sensor, closely dated to the field campaign and with no clouds and other atmospheric factors. Then, the images were processed, and 17 vegetation indexes were calculated for each one. The indices were compared statistically by the t-Student test for independent samples. The indices that provided the best species differentiation were: CRI, GNDVI, NDI11, NDI12, NDVI, RDVI, SAVI, and SR. In addition, the species with greater prominence in the Landsat-8/OLI images was Eucalyptus spp. whereas Cunninghamia lanceolata (Lamb.) Hooker was easily distinguished in Sentinel-2 images. It was possible to differentiate the species from remote data derived from the Sentinel-2/MSI and Landsat-8/OLI sensors. However, further studies using other Remote Sensing data sources and other species are suggested.


Author(s):  
N. M. Morozova

During long-term storage, climatic and atmospheric factors affect the agricultural machine, which cause changes in the physical and chemical properties of structural materials, technical fluids, lubricants. Therefore, the development of technical and organizational measures related to improving the storage efficiency of combine harvesters is an urgent scientific task that the leading scientific institutes of the country are engaged in.


Author(s):  
V.P. Rudnev ◽  

The use of transparent thermoplastics as construction materials imposes special requirements on them, both in terms of strength characteristics and physical properties. The stability of these properties plays an important role in the use of transparent thermoplastics in complex technical systems, where these materials are used as a structural material for the outer contour of the product, which is exposed to aggressive climatic factors. In this work, the influence of atmospheric factors in the warm humid climate zone (the coastal atmosphere of humid subtropics) on the optical properties of transparent thermoplastics was investigated, which made it possible to obtain important information for assessing the performance of polymers of this class in natural climatic conditions.


2021 ◽  
Author(s):  
Dushyant Singh Chauhan ◽  
Gurjit kaur ◽  
Dinesh Kumar

Abstract The performance of FSO communication link is subject to numerous atmospheric factors in wireless communication like fog, rainfall, and haze which leads to deteriorate the performance of a system in term of BER and power at the receiver side. Due to numerous advantages of OCDMA over other access techniques, it allows various users to access a channel simultaneously without intervention with the other user. It has the ability to provide security, large number of users, privacy, reduce interference from multiple users and operate asynchronously. So, in this paper, Multi-Diagonal codes along with the fiber brags grating filters for Spectral amplitude coded OCDMA technique is developed for FSO system and performance analysis is performed in terms of BER and received power.


Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4186
Author(s):  
Gabriel López ◽  
Diego Ramírez ◽  
Joaquín Alonso-Montesinos ◽  
Juan Sarmiento ◽  
Jesús Polo ◽  
...  

Atmospheric factors, such as clouds, wind, dust, or aerosols, play an important role in the power generation of photovoltaic (PV) plants. Among these factors, soiling has been revealed as one of the most relevant causes diminishing the PV yield, mainly in arid zones or deserts. The effect of soiling on the PV performance can be analyzed by means of I–V curves measured simultaneously on two PV panels: one soiled and the other clean. To this end, two I–V tracers, or one I–V tracer along with a multiplexer, are needed. Unfortunately, these options are usually expensive, and only one I–V tracer is typically available at the site of interest. In this work, the design of a low-cost multiplexer is described. The multiplexer is controlled by a low-cost single-board microcontroller manufactured by ArduinoTM, and is capable of managing several pairs of PV panels almost simultaneously. The multiplexer can be installed outdoors, in contrast to many commercial I–V tracers or multiplexers. This advantage allows the soiling effect to be monitored on two PV panels, by means of I–V indoor tracers. I–V curves measured by the low-cost multiplexer are also presented, and preliminary results are analyzed.


2021 ◽  
Vol 30 (1) ◽  
pp. 75-85
Author(s):  
Konrad Podawca ◽  
Agata Grzymała

Nature friendly technologies in today’s world are the subject of scientific research and the interest of local authorities and the residents themselves. In the context of the city, one of the most important issues is the neutralization of air pollution generated by transport and heating of the premises with the use of solid fuels. The article analyses differences of the response of traditional and photocatalytic paving stones. We analysed water absorption, frost resistance, tensile strength at splitting and abrasion of paving stones. It has been proved that paving stones exposed to atmospheric factors and pollution during one heating season met the assumed quality criteria. In addition, the results obtained for the characteristics analysed were higher than the results of samples tested in laboratory conditions. The results also indicate a slight advantage of photocatalytic cubes in terms of their resistance to abrasion and tensile strength at splitting. Traditional and photocatalytic paving stones withstand well the operating conditions. It seems that products based on TioCem® cement are the future implementation of pedestrian and traffic routes.


2021 ◽  
Author(s):  
Yujie Li ◽  
Xiaoqing Gao ◽  
Zhenchao Li ◽  
Junxia Jiang ◽  
Peidu Li

2021 ◽  
Vol 67 (5) ◽  
pp. 383-393
Author(s):  
V.V. Salmin ◽  
A.V. Morgun ◽  
R.Ya. Olovyannikova ◽  
V.A. Kutyakov ◽  
E.V. Lychkovskaya ◽  
...  

The review focuses on molecular and biochemical mechanisms of nonspecific protection of respiratory epithelium. The authors provide a comprehensive analysis of up-to-date data on the activity of the lactoperoxidase system expressed on the surface of the respiratory epithelium which provides the generation of hypothiocyanate and hypoiodite in the presence of locally produced or inhaled hydrogen peroxide. Molecular mechanisms of production of active compounds with antiviral and antibacterial effects, expression profiles of enzymes, transporters and ion channels involved in the generation of hypothiocyanite and hypoiodate in the mucous membrane of the respiratory system in physiological and pathological conditions (inflammation) are discussed. In the context of antibacterial and antiviral defense special attention is paid to recent data confirming the effects of atmospheric air composition on the efficiency of hypothiocyanite and hypoiodate synthesis in the respiratory epithelium. The causes and outcomes of lactoperoxidase system impairment due to the action of atmospheric factors are discussed in the context of controlling the sensitivity of the epithelium to the action of bacterial agents and viruses. Restoration of the lactoperoxidase system activity can be achieved by application of pharmacological agents aimed to compensate for the lack of halides in tissues, and by the control of chemical composition of the inhaled air.


Sign in / Sign up

Export Citation Format

Share Document