system changes
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2021 ◽  
Vol 9 ◽  
Author(s):  
Shakil Ahmad Romshoo ◽  
Aazim Yousuf ◽  
Sadaff Altaf ◽  
Muzamil Amin

Soil erosion is one of the serious environmental threats in the Himalayas, primarily exacerbated by the steep slopes, active tectonics, deforestation, and land system changes. The Revised Universal Soil Loss Equation was employed to quantify soil erosion from the Vishav watershed in the Kashmir Himalaya, India. Topography and land use/land cover (LULC) are important driving factors for soil erosion. Most often, a Digital Elevation Model (DEM) is used in erosion models without any evaluation and testing which sometimes leads to erroneous estimates of soil erosion. For the best topographic characterization of the watershed, four publicly available DEMs with almost identical resolution (∼30 m), were evaluated. The DEMs were compared with GPS measurements to determine the most reliable among the tested DEMs for soil erosion estimation. Statistical evaluation of the DEMs with GPS data indicated that the CARTO DEM is better with root mean square error (RMSE) of 18.2 m than the other three tested DEMs viz., Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Shuttle Radar Topography Mission (SRTM), and Advanced Land Observing Satellite (ALOS). Slope length and slope steepness factors were computed from the DEMs. Crop cover and management factors were generated from the satellite-derived LULC. Moreover, rainfall data of the nearest stations were used to compute rainfall erosivity and soil erodibility factor was derived from the soil texture data generated from 375 soil samples. The simulated erosion estimates from SRTM, ALOS, and CARTO DEMs showed similar spatial patterns contrary to the ASTER estimates which showed somewhat different patterns and magnitude. The mean erosion in the study area has almost doubled from 2.3 × 106 tons in 1981 to 4.6 × 106 tons in 2019 mainly driven by the anthropogenic LULC changes. The increased soil erosion is due to the degradation of forest cover, urbanization, steep slopes, and land system changes observed during the period. In absence of the observations, the simulated soil erosion was validated with the land degradation map of the watershed which showed a good correspondence. It is hoped that the results from this work would inform policymaking on soil and water conservation measures in the data-scarce mountainous Kashmir Himalaya.


2021 ◽  
Vol 5 (4) ◽  
pp. 60-63
Author(s):  
Oleh Lebediev ◽  
Valentyn Lebediev

A method of risk analysis in information systems is being developed. The ways of ensuring the efficiency of control systems in the conditions of information confrontation with the use of the game theory apparatus are investigated. The desire to ensure high efficiency of modern management information systems, minimize financial costs, provide energy and information protection of the management system, highlights the creation of a system of analysis and risk management in information systems. It is assumed that the control system can implement the following behavioral strategies in a conflict situation: the control system does not change the algorithm, but changes the class of algorithms used to achieve the maximum value of the average quality by choosing the probability Pij for a given set of countermeasures, the control system changes the algorithm operation, the class of operating algorithms used to maximize the average quality of fixed countermeasures, the control system changes the operating algorithm and the class of operating algorithms used depending on the countermeasure strategy in order to achieve maximum quality. Using the apparatus of game theory, an analysis was performed and a method for estimating the average value of the quality of the communication system with different strategies of the conflicting parties was developed. The technique of estimation of average value of an indicator of quality of functioning of a control system is developed and expressions for an estimation of average value of an indicator at various strategies of behavior are received. It is shown that the solution to the problem of improving the quality of the control system is possible through the use of a mixed strategy of system behavior and the choice of structure and parameters of the control system that increase the partial quality of its operation.


Author(s):  
Robert Santa

Abstract The presence of the lubricant POE 68 in the refrigeration system changes the thermophysical properties of the refrigerant, which significantly affects the heat transfer and the hydraulic processes. The purpose of this research is to investigate the thermodynamic properties of the R152a, R125, R134a and R123 refrigerant and POE 68 lubricant mixtures at different temperatures from 233,15 to 313,15 K. There have been investigated the values of the densities and kinematic viscosities of the mixtures at different concentrations (100%, 90%, 80%). Finally, it was found that, the density and kinematic viscosity of the R123/POE 68 mixture were most affected by the change of the concentration.


2021 ◽  
Vol 21 (21) ◽  
pp. 16479-16497
Author(s):  
Anthony Y. H. Wong ◽  
Jeffrey A. Geddes

Abstract. Our work explores the impact of two important dimensions of land system changes, land use and land cover change (LULCC) as well as direct agricultural reactive nitrogen (Nr) emissions from soils, on ozone (O3) and fine particulate matter (PM2.5) in terms of air quality over contemporary (1992 to 2014) timescales. We account for LULCC and agricultural Nr emissions changes with consistent remote sensing products and new global emission inventories respectively estimating their impacts on global surface O3 and PM2.5 concentrations as well as Nr deposition using the GEOS-Chem global chemical transport model. Over this time period, our model results show that agricultural Nr emission changes cause a reduction of annual mean PM2.5 levels over Europe and northern Asia (up to −2.1 µg m−3) while increasing PM2.5 levels in India, China and the eastern US (up to +3.5 µg m−3). Land cover changes induce small reductions in PM2.5 (up to −0.7 µg m−3) over Amazonia, China and India due to reduced biogenic volatile organic compound (BVOC) emissions and enhanced deposition of aerosol precursor gases (e.g., NO2, SO2). Agricultural Nr emission changes only lead to minor changes (up to ±0.6 ppbv) in annual mean surface O3 levels, mainly over China, India and Myanmar. Meanwhile, our model result suggests a stronger impact of LULCC on surface O3 over the time period across South America; the combination of changes in dry deposition and isoprene emissions results in −0.8 to +1.2 ppbv surface ozone changes. The enhancement of dry deposition reduces the surface ozone level (up to −1 ppbv) over southern China, the eastern US and central Africa. The enhancement of soil NO emission due to crop expansion also contributes to surface ozone changes (up to +0.6 ppbv) over sub-Saharan Africa. In certain regions, the combined effects of LULCC and agricultural Nr emission changes on O3 and PM2.5 air quality can be comparable (>20 %) to anthropogenic emission changes over the same time period. Finally, we calculate that the increase in global agricultural Nr emissions leads to a net increase in global land area (+3.67×106km2) that potentially faces exceedance of the critical Nr load (>5 kg N ha−1 yr−1). Our result demonstrates the impacts of contemporary LULCC and agricultural Nr emission changes on PM2.5 and O3 in terms of air quality, as well as the importance of land system changes for air quality over multidecadal timescales.


2021 ◽  
Vol 8 (3) ◽  
pp. 147-151
Author(s):  
N Karunakaran ◽  
T Bayavanda Chinnappa

Liberalization and deregulation process started in 1991 has made lot of changes in the banking system. From a totally regulated environment, banking institutions have moved into a market driven competitive system. Changes gained momentum in the last few years. Globalization would gain greater speed in coming years particularly on account of expected opening up of financial services under WTO. Four trends changed the banking industry world over, viz, consolidation of players through mergers and acquisitions, globalization of operations, development of new technology, and universalisation of banking.


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