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Pollution of water resources due to industrialization in arid zone of Rajasthan, India

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Journal of Environmental Sciences 2001年第2期13卷 218-223页

作者： m A Khan Central Arid Zone Research Institute Jodhpur-342003 India.

In arid zone of Rajasthan, India, nearly 21,900 hm2 area along Bandi River has been affected by industrial effluent discharge into the river bed. Analysis of groundwater samples collected from these sites revealed that area at the vicinity of the river is most affected. The effluent water in the river is the main source of contamination of ground water. Concentration of sodium and chloride has been higher with proportional increase in TDS and EC value in the area within zone A (river water), zone B (0-100 m), zone C (101-250 m), zone D (251-500 m) and zone E (501-1000 m). There is decreasing trend in ion concentration from zone A to zone E and F, reflecting reduced effect of effluents. The pollution of water resources has resulted in the degradation of other natural resources such as land, soil and vegetation. Nearly 4463 hm2 (20.38%) area has been very severely affected. EC value at places exceeds 20 dS/m. Soil and land have become hard, compact and saline. Cropping intensity has declined. In the area (3633 hm2) affected severely, the EC value of water varies from 10-20 dS/m. Irrigation with such water has created problem of salinity, sodicity in soils. Herbal biomass declined considerably. Double cropping has almost stopped. Almost 8494 hm2 area is affected moderately. EC of ground water varies from 5 to 10 dS/m. Fragile surface crust, declining trend of phosphorous and potassium in the soil, poor density of natural vegetation are significant manifestations. Apart from this, 5305 hm2 area is slightly affected.

关键词： India Pollution of water resources due to industrialization in arid zone of Rajasthan

Trust-based co-operative routing for secure communication in mobile ad hoc networks

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Digital Communications and Networks 2024年第4期10卷 1079-1087页

作者： Ankita A.mahamune m.m.Chandane Dept.of Comp.Engg.&Information Tech. Veermata Jijabai Technological InstituteMumbaiMaharashtra StateIndia

The working of a mobile Ad hoc NETwork(mANET)relies on the supportive cooperation among the network *** due to its intrinsic features,a misbehaving node can easily lead to a routing *** paper presents two trust-based routing schemes,namely Trust-based Self-Detection Routing(TSDR)and Trust-based Cooperative Routing(TCOR)designed with an Ad hoc On-demand Distance Vector(AODV)*** proposed work covers a wide range of security challenges,including malicious node identification and prevention,accurate trust quantification,secure trust data sharing,and trusted route *** brings a prominent solution for mitigating misbehaving nodes and establishing efficient communication in *** is empirically validated based on a performance comparison with the current Evolutionary Self-Cooperative Trust(ESCT)scheme,Generalized Trust model(GTm),and the conventional AODV *** extensive simulations are conducted against three different varying network *** results affirm the improved values of eight popular performance metrics overcoming the existing routing *** the two proposed works,TCOR is more suitable for highly scalable networks;TSDR suits,however,the mANET application better with its small *** work thus makes a significant contribution to the research community,in contrast to many previous works focusing solely on specific security aspects,and results in a trade-off in the expected values of evaluation parameters and asserts their efficiency.

关键词： mobile Ad hoc NETwork Secure communication AODV Co-operative routing Trust metric

magnetic properties of Sn-substituted Ni-Zn ferrites synthesized from nano-sized powders of NiO, ZnO, Fe2O3, and SnO2

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Chinese Physics B 2017年第7期26卷 377-382页

作者： m A Ali m m Uddin m N I Khan F U Z Chowdhury S m Hoque S I Liba Department of Physics Chittagong University of Engineering and Technology (CUET) materials Science Division Atomic Energy Center

A series of Ni0.6-x/2Zn0.4-x/2SnxFe2O4(x = 0.0, 0.05, 0.1, 0.15, 0.2, and 0.3)(NZSFO) ferrite composities have been synthesized from nano powders using a standard solid state reaction technique. The spinel cubic structure of the investigated samples has been confirmed by x-ray diffraction(XRD). The magnetic properties such as saturation magnetization(ms),remanent magnetization(mr), coercive field(Hc), and Bohr magneton(μ) are calculated from the hysteresis loops. The value of msis found to decrease with increasing Sn content in the samples. This change is successfully explained by the variation of A-B interaction strength due to Sn substitution in different sites. The compositional stability and quality of the prepared ferrite composites have also been endorsed by the fairly constant initial permeability(μ’) over a wide range of frequency. The decreasing trend of μ’ with increasing Sn content has been observed. Curie temperature TChas been found to increase with the increase in Sn content. A wide spread frequency utility zone indicates that the NZSFO can be considered as a good candidate for use in broadband pulse transformers and wide band read-write heads for video recording. The composition of x = 0.05 shows unusual results and the possible reason is also mentioned with the established formalism.

关键词： magnetic properties saturation magnetization permeability Curie temperature

Evolution of plasma parameters in an Ar-N2/He inductive plasma source with magnetic pole enhancement

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Plasma Science and Technology 2017年第2期19卷 34-42页

作者： maria YOUNUS N U REHmAN m SHAFIQ m NAEEm m ZAKA-UL-ISLAm m ZAKAULLAH Department of Physics Plasma Physics LaboratoryQuaid-i-Azam University45320 IslamabadPakistan Plasma Physics Laboratory Department of PhysicsCOMSATS Institute of Information Technology44000 IslamabadPakistan Department of Physics Faculty of ScienceJazan University114 JazanSaudi Arabia

magnetic pole enhanced inductively coupled plasmas （maPE-ICPs） are a promising source for plasma-based etching and have a wide range of material processing applications. In the present study Langmuir probe and optical emission spectroscopy were used to monitor the evolution of plasma parameters in a maPE-ICP Ar-Na/He mixture plasma. Electron density （ne） and temperature （Te）, excitation temperature （Texc）, plasma potential （Vp）, skin depth （6） and the evolution of the electron energy probability function （EEPF） are reported as a function of radiofrequency （RF） power, pressure and argon concentration in the mixture. It is observed that ne increases while Te decreases with increase in RF power and argon concentration in the mixture. The emission intensity of the argon line at 750.4 nm is also used to monitor the variation of the ‘high-energy tail＇ of the EEPF with RF power and gas pressure. The EEPF has a ‘bi-maxwellian＇ distribution at low RF powers and higher pressure in a pure N2 discharge. However, it evolves into a ‘maxwellian＇ distribution at RF powers greater than 70 W for pure N2, and at 50 W for higher argon concentrations in the mixture. The effect of argon concentration on the temperatures of two electron groups in the ‘bi-maxwellian＇ EEPF is examined. The temperature of the low-energy electron group TL shows a decreasing trend with argon addition until the ‘thermalization＇ of the two temperatures occurs, while the temperature of high-energy electrons Ta decreases continuously.

关键词： maPE-ICP Langmuir probe OES EEPF

Engineering of efficient visible light photocatalysts:Ti_(1-x+y)Cu_(x)La_(y)O_(2)(x=0.03;y=0,0.005,0.01) compositions

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Journal of Rare Earths 2024年第3期42卷 497-505,I0003页

作者： S.m.Yakout A.m.Youssef Inorganic Chemistry Department National Research Centre(NRC)El Buhouth StDokkiCairo12622Egypt

In dye-photocatalysis, widening the wavelengths absorption range of catalysts as well as aborting the recombination of the photoexcited charge carriers(electrons-holes pairs) are of paramount *** the current study, we report the photocatalytic characteristics of four compositions composed of TiO_(2),Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders for two harmful dyes(Congo red and methylene blue). The X-ray diffraction technique verified the configuration of mixed anatase and rutile phases in pure TiO_(2)and Ti_(0.97)Cu_(0.03)O_(2)powders while Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders possess anatase phase only. The changes of the band gap structure and dimensions of the unit cell volume of TiO_(2)confirm the substitution of Ti^(4+)sites by Cu^(2+)and La^(3+)ions. Remarkable widening of wavelengths absorption with formation of long absorption tails were found in TiO_(2)(3.13 e V) through insertion of La^(3+)plus Cu^(2+)ions. Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)samples exhibit a visible light band gap of 2.3 and 2.7 e V, respectively. Based on SEm images, incorporation of Cu^(2+)and La^(3+)ions influences the surface morphology of TiO_(2). The resulting Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders present enhanced photocatalytic activity towards Congo red dye degradation compared to pure one under natural solar spectrum. The best Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst exhibits superior photocatalytic activity of 96% for 10 ppm CR dye in 20 min as well as above average photocatalytic efficiency of 63% for 30 ppm CR dye in 120 min. As well, it showed acceptable photodegradation activity of 52% for 30 ppm mB solution in 140 min of sunlight irradiation. The heightened photodegradation efficiency of Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst can be clarified in terms of higher ch

关键词： Semiconductor TiO_(2) Rare earths Congo red methylene blue Solar spectrum Photodegradation

Atmospheric pressure gliding arc discharge plasma treatments for improving germination, growth and yield of wheat

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Plasma Science and Technology 2018年第11期20卷 90-100页

作者： N C ROY m m HASAN A H KABIR m A REZA m R TALUKDER A N CHOWDHURY Plasma Science and Technology Laboratory Department of Applied Physics and Electronic EngineeringUniversity of Rajshahi Rajshahi 6205 Bangladesh Department of Agronomy and Agricultural Extension University of Rajshahi Rajshahi 6205 Bangladesh Depatment of Botany University of Rajshahi Rajshahi 6205Bangladesh Department of Genetic Engineering and Biotechnology University of Rajshahi Rajshahi 6205Bangladesh Bangladesh Council of Scientific and Industrial Research Laboratory Rajshahi Rajshahi 6206Bangladesh

Wheat （Triticum aestivum） seeds were treated with atmospheric pressure gliding arc discharge plasmas to investigate the effects on water absorption, seed germination rate, seedling growth and yield in wheat. The surface architectures and functionalities of the seeds were found to modify due to plasma treatments. 6 rain treatment was provided 95%-100% germination rate. For the treatment duration of 3 and 9 rain the growth activity, dry matter accumulation, leaves chlorophyll contents, longest spikes, number of spikes/spikelet and total soluble protein content in shoots were improved. The grain yield of wheat was increased ,--20% by 6 min treatment with H2O/O2 plasma with respect to control.

关键词： atmospheric pressure gliding arc discharge plasmas wheat germination growth improvement total soluble protein

Solidification, microstructure, and mechanical properties of the as-cast ZRE1 magnesium alloy with different praseodymium contents

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International Journal of minerals,metallurgy and materials 2017年第11期24卷 1306-1320页

作者： Z.m.Sheggaf R.Ahmad m.B.A.Asmael A.m.m.Elaswad Department of manufacturing and Industrial Engineering Faculty of Mechanical and Manufacturing Engineering Universiti Tun Hussein Onn Malaysia Parit Raja86400 BatuPahat Johor Malaysia Department of mechanical Engineering Eastern Mediterranean University North Cyprus Gazimagsa TRNC Mersin 10 Turkey

The influence of praseodymium(Pr) content on the solidification characteristics, microstructure, and mechanical properties of ZRE1 magnesium(mg) cast alloy was investigated. The obtained solidification parameters showed that Pr strongly affected the solidification time, leading to refinement of the microstructure of the alloys. When the freezing time was reduced to approximately 52 s, the grain size decreased by 12%. mg_(12)Zn(Ce,Pr) was formed as a new phase upon the addition of Pr and was detected via X-ray diffraction analysis. The addition of Pr led to a substantial improvement in mechanical properties, which was attributed to the formation of intermetallic compounds; the ultimate tensile strength and yield strength increased by approximately 10% and 13%, respectively. Pr addition also refined the microstructure, and the hardness was recovered. The results herein demonstrate that the mechanical properties of mg alloys are strongly influenced by their microstructure characteristics, including the grain size, volume fraction, and distribution of intermetallic phases.

关键词： metal solidification microstructure mechanical properties magnesium alloys intermetallics

Differential transformation method for studying flow and heat transfer due to stretching sheet embedded in porous medium with variable thickness, variable thermal conductivity,and thermal radiation

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Applied mathematics and mechanics(English Edition) 2014年第11期35卷 1387-1400页

作者： m.m.KHADER A.m.mEGAHED Department of mathematics and Statistics College of Science Al-Imam Mohammad Ibn Saud Islamic University (IMSIU) Department of mathematics Faculty of Science Benha University

This article presents a numerical solution for the flow of a Newtonian fluid over an impermeable stretching sheet embedded in a porous medium with the power law surface velocity and variable thickness in the presence of thermal radiation. The flow is caused by non-linear stretching of a sheet. Thermal conductivity of the fluid is assumed to vary linearly with temperature. The governing partial differential equations （PDEs） are transformed into a system of coupled non-linear ordinary differential equations （ODEs） with appropriate boundary conditions for various physical parameters. The remaining system of ODEs is solved numerically using a differential transformation method （DTm）. The effects of the porous parameter, the wall thickness parameter, the radiation parameter, the thermal conductivity parameter, and the Prandtl number on the flow and temperature profiles are presented. moreover, the local skin-friction and the Nusselt numbers are presented. Comparison of the obtained numerical results is made with previously published results in some special cases, with good agreement. The results obtained in this paper confirm the idea that DTm is a powerful mathematical tool and can be applied to a large class of linear and non-linear problems in different fields of science and engineering.

关键词： Newtonian fluid stretching sheet differential transformation method(DTm) thermal radiation variable thermal conductivity variable thickness

Grain refinement of bronze alloy by equal-channel angular pressing(ECAP) and its effect on corrosion behaviour

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Defence Technology（防务技术） 2016年第4期12卷 316-323页

作者： m.m.SADAWY m.GHANEm mining and Pet. Dept. Faculty of Engineering Al-Azhar University mechanical Dept. Faculty of Industrial Education Suez University

The corrosion behaviour of bronze alloy prepared by equal channel angular pressing(ECAP) was investigated in 3.5 wt. % Na Cl *** corrosion tests and different electrochemical techniques were carried out. The results showed that ECAPed bronze samples exhibited higher corrosion resistance compared with the as-cast alloy and the passive current density decreased with increasing number of passes. moreover,the morphology of alloys indicated that the corrosion damage on the surface of ECAPed bronze was smooth and uniform while the as-cast alloy suffered from selective corrosion.

关键词： Bronze ECAP Corrosion resistance Passive film Pitting