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Effect of rangeland rehabilitation on the herbaceous species composition and diversity in Suswa catchment,narok County,kenya

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Ecological Processes 2017年第1期6卷 427-435页

作者： n.J.Ombega S.M.Mureithi O.k.koech A.n.karuma C.k.k.Gachene Department of Land Resource Management and Agricultural Technology(LARMAT) University of NairobiP.O Box 29053Nairobi 00625Kenya Sustainable Land Management(SLM)Agro-Pastoral Project kenya NairobiKenya

Introduction:Land degradation is a serious environmental problem of our *** kenya,it is estimated that 30%of the total land mass is severely *** catchment within narok County is a good example with gullies of over 25 m deep and 30 m *** response to the increasing land degradation in the area,the Sustainable Land Management(SLM)project rehabilitated the catchment through establishment of soil and water conservation structures such as cutoff drains,semicircular bunds,and water retention *** the various rehabilitation approaches carried out,little research has been done to ascertain their effect on successful vegetation *** coupled with the fact that many restoration approaches have failed in East Africa and kenya in particular gave drive to the *** objective of this study was to determine the effects of rangeland rehabilitation on herbaceous species composition and diversity in a severely degraded ***:To assess the diversity of aboveground herbaceous layer in the rehabilitated and degraded areas along a slope(upper,middle,and lower),line transect and quadrat count methods were *** each slope position,three 100-m-long transects were placed across the hill parallel to one another 30 m apart using a *** species hit,the closest species to the hit,and hits on bare ground were *** the same transects,1-m2 quadrats were placed 25 m apart and aboveground biomass determined by the use of the destructive *** the determination of species richness,diversity,relative abundance,percentage cover,and species composition,the Shannon-Wiener diversity index was *** collected on vegetation attributes was subjected to analysis of variance(AnOVA)using Genstat and Tukey’s HSD post hoc used in means separation where F values were ***:The results showed that percent cover(74.67%),aboveground biomass(1459 kg/ha),relative abundance,richness,composition,and diversity of perennial grass

关键词： Rehabilitation Land degradation Slope,Herbaceous layer Biodiversity

Dispersion effect of nano-structure pyrolytic carbon on mechanical,electrical,and microstructural characteristics of cement mortar composite

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International Journal of Smart and nano Materials 2024年第3期15卷 534-578页

作者： n.k.karthikeyan S.Elavenil School of Civil Engineering Vellore Institute of TechnologyChennaiIndia

In material science,converting waste into nanomaterials by green technologies highlights the interest in producing sus-tainable carbon nanomaterial(SCn).This study first-ever uti-lized tyre-char as a nano-Structure Pyrolytic Carbon(nSPC)to develop electrically conductive *** other car-bon nanomaterials,the efficiency of nSPC particle as an SCn in developing electrically conductive composites was investi-gated in terms of dispersion,mechanical,water absorption,electrical resistivity,and *** results of sedi-mentation and zeta potential(-19 mV)showed the excellent dispersion of nSPC particle in water with the combined effect of superplasticizer and *** compressive(40.37%)and flexural strength(10.76%)than that of plain cement mortar composite(CMC)is achieved with 2 wt.%and 1.5 wt.%of nSPC particle,*** water absorption rate and volume of permeable voids were reduced,exhibiting less *** percolation zone of AC and DC resis-tivity of nSPC composite ranges between 1 and 2 wt.%,and the established percolation threshold is at 2 wt.%.XRD analysis showed C-S-H formation consistently increased with curing age,and HR-SEM with EDAX analysis exhibits the dense micro-structure and well-distributed nSPC particle at the *** experimental outcomes significantly enhanced the relia-bility and provided a framework for tailoring nSPC particle as SCn for developing electrically conductive composite.

关键词： Sustainable nanomaterial dispersion mechanical properties electrical resistivity microstructure analysis

Influence of Accompanying Anions on Potassium Retention and Leaching in Potato Growing Alluvial Soils

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Pedosphere 2013年第4期23卷 464-471页

作者： V.SHARMA k.n.SHARMA Department of Soils Punjab Agricultural University

A column study was carried out to assess the influence of accompanying anions on potassium （k） leaching at potato growing sites with different soil textures （sandy loam and clay loam） in northwestern India. Potassium was applied in the top 15 cm layer of soil column at 30 and 60 mg k kg-1 through different sources having different accompanying anions （CI-, SO^-, nO3 and H2PO4-）. Maximum k was retained in the top 0-15 cm layer with a sharp decrease in k content occurring in 15 30 cm layer of the soil column. The trend was similar for both levels of applied k as well as frequency of leaching and soil type. The decrease of k content in soil column after four leaching events was maximum in case of khanaura sandy loam, while only minor decrease was observed in Hundowal clay loam when k was applied at 60 mg k kg-1, indicating higher potential of clay rich soil to adsorb k. In general, the k leaching in presence of the accompanying anions followed the order of SO4^2-≤ H2PO42- 〈 nO3 = Cl-. Highest 1 mol·L^-1 CH3COOnH4-extractable k was retained when k was applied along with SO4^2- and H2PO4 anions, and the least was retained when accompanying anion was Cl-. The influence of anions was more pronounced in the light textured soil and at high amounts of k application. Higher levels of k application resulted in higher losses of k, especially in sandy loam soil as observed from the leachate concentration. Among the different k sources, the maximum amount of k leaching was noticed in the soil column amended with kC1. After four leachings, the maximum amount of k leached out was 6.40 mg L-1 in Hundowal clay loam and 9.29 mg L-1 in khanaura sandy loam at 60 mg k kg-1 of soil application through kC1. These concentrations were lower than the recommended guideline of the World Health Organisation （12.00 mg L-1）.

关键词： column study leaching events potassium application potassium sources soil texture

EXISTEnCE AnD UnIQUEnESS RESULTS FOR BOUnDARY VALUE PROBLEMS OF HIGHER ORDER FRACTIOnAL InTEGRO-DIFFEREnTIAL EQUATIOnS InVOLVInG GROnWALL'S InEQUALITY In BAnACH SPACES

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Acta Mathematica Scientia 2013年第3期33卷 758-772页

作者： Dimplekumar n. CHALISHAJAR k. kARTHIkEYAn Department of Mathematics and Computer Science Virginia Military Institute (VMI) 417 Mallory HallLexington VA 24450 USA Department of Mathematics KSR College of TechnologyTiruchengode-637 215 Tamilnadu India

We study boundary value problems for fractional integro-differential equations involving Caputo derivative of order α∈ （n-1, n） in Banach spaces. Existence and uniqueness results of solutions are established by virtue of the Holder＇s inequality, a suitable singular Cronwall＇s inequality and fixed point theorem via a priori estimate method. At last, examples are given to illustrate the results.

关键词： Boundary value problems fractional order integro-differential equations bound-ary value problems existence and uniqueness singular gronwall inequality fixed point theorem

Z-SCAn TECHnIQUE FOR MEASUREMEnT OF TOTAL CHOLESTEROL AnD TRIGLYCERIDES In BLOOD

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Journal of Innovative Optical Health Sciences 2009年第3期2卷 295-301页

作者： A.n.DHInAA P.k.PALAnISAMY Department of Physics Anna University Chennai 600025India

The measurement of cholesterol and triglycerides in blood by Z-scan technique is *** nonlinear refractive index of cholesterol and triglycerides was found to vary linearly with *** by calculating the nonlinear refractive index it is possible to measure their concentration in the *** measured values are found in equivalence with conventional colorimetric method.

关键词： Z-scan technique nonlinear refractive index cholesterol triglycerides

Efficient Energy Optimized Faithful Adder with Parallel Carry Generation

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Computers, Materials & Continua 2022年第2期70卷 2543-2561页

作者： k.n.Vijeyakumar S.Maragatharaj Dr.Mahalingam College of Engineering and Technology PollachiTamilnaduIndia Dhirajlal Gandhi College of Technology SalemTamilnaduIndia

Abstract:Approximate computing has received significant attention in the design of portable CMOS hardware for error-tolerant *** work proposes an approximate adder that to optimize area delay and achieve energy efficiency using Parallel Carry(PC)generation ***‘n’bits in input,the proposed algorithm use approximate addition for least n/2 significant bits and exact addition for most n/2 significant bits.A simple OR logic with no carry propagation is used to implement the approximate *** the exact part,addition is performed using 4-bit adder blocks that implement PC at block level to reduce node capacitance in the critical *** reveal that the maximum error of the proposed adder confines not more than 2n/*** an enhancement of the proposed algorithm,we use the Error Recovery(ER)module to reduce the average *** results of Proposed-PC(P-PC)and Proposed-PCER(P-PCER)adders with n-16 in 180nm Application Specific Integrated Circuit(ASIC)PDk technology revealed 44.2%&41.7%PDP reductions and 43.4%&40.7%ADP reductions,respectively compared to the latest best approximate design *** functional and driving effectiveness of proposed adders are examined through digital image processing applications.

关键词： Application-specific integrated circuit approximate computing power dissipation energy dissipation image processing

Re nanoclusters anchored on nanosheet supports: Formation of Re-O-matrix bonding and evaluation as all-pH-range hydrogen evolution reaction (HER) electrocatalysts

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Journal of Energy Chemistry 2022年第6期31卷 185-193,I0006页

作者： Shiyu Xu Hao Li Jeongbok lee n.Clament Sagaya Selvam Baotao kang Jin Yong lee Pil J.Yoo School of Chemical Engineering Sungkyunkwan UniversitySuwon 16419Republic of Korea Department of Chemistry Sungkyunkwan UniversitySuwon 16419Republic of Korea

Although the water splitting-based generation of hydrogen as an energy carrier can help to mitigate the global problems of energy shortage and climate change,the practical implementation of this strategy is hindered by the absence of inexpensive high-performance electrocatalysts for the hydrogen evolution reaction (HER).Re-based HER electrocatalysts exhibit predictable high performance within the entire pH range but suffer from arduous formation (i.e.,vulnerability to oxidation) and uncontrollable aggregation,which strongly discourages the maximisation of active site exposure required for activity *** overcome these limitations,we herein hydrothermally synthesise Re nanoclusters uniformly distributed on nanosheet supports,such as reduced graphene oxide nanosheets (Re nCs@rGO),revealing that this hybrid features abundant exposed active sites and high oxidation *** obtained electrocatalysts were elaborately characterized by microscopic and spectroscopic ***,density functional theory calculations confirm the optimised synthesis of Re nCs@rGO and indicate the crucial role of Re–O–C junction formation in securing *** effective suppression of Re nanocluster detachment/dissolution under HER conditions endows Re nCs@rGO with high electron conductivity and electrochemical stability,resulting in a durability superior to that of commercial Pt/C and an activity similar to that of this *** a result,Re nCs@rGO exhibited remarkably small HER overpotentials of 110,130,and 93 m V to deliver a current density of 10 mA cm^(-2) in 0.5 M H_(2)SO_(4),1 M PBS,and 1 M kOH,***,Re nCs@rGO is a promising alternative to conventional Pt-group-metal catalysts and should find applications in next-generation high-performance water splitting systems.

关键词： Hydrogen evolution reaction(HER) Hydrothermal synthesis Re nanoclusters nanosheet supports Electrocatalysts

Series solutions of stagnation slip flow and heat transfer by the homotopy analysis method

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Science China(Physics,Mechanics & Astronomy) 2009年第6期52卷 893-899页

作者： R.n.MOHAPATRA k.VAJRAVELU Department of Mathematics University of Central Florida

An analytical approximation for the similarity solutions of the two-and three-dimensional stagnation slip flow and heat transfer is obtained by using the homotopy analysis method. This method is a series expansion method, but it is different from the perturbation technique, because it is independent of small physical parameters at all. Instead, it is based on a continuous mapping in topology so that it is applicable for not only weakly but also strongly nonlinear flow phenomena. Convergent [m,m] homotopy Padé approximants are obtained and compared with the numerical results and the asymptotic approximations. It is found that the homotopy Padé approximants agree well with the numerical results. The effects of the slip length and the thermal slip constant β on the heat transfer characteristics are investigated and discussed.

关键词： stagnation slip flow navier boundary condition nano-fluidics heat transfer homotopy analysis method

Effect of dysprosium substitution on structural and dielectric properties of BiFeO_3-PbTiO_3 multiferroic composites

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Journal of Rare Earths 2015年第6期33卷 639-646页

作者： n.k.Mohanty A.k.Behera S.k.Satpathy Banarji Behera P.nayak Materials Research Laboratory School of Physics Sambalpur University

0.5BiDyxFe1-xO3-0.5PbTiOa（0.5BDxF1-x-0.5PT）（x=0.00, 0.05, 0.10, 0.15, 0.20） multiferroic composites were pre- pared by conventional solid state reaction method. Structural characterization was performed by X-ray diffraction and the mate- rials showed tetragonal structure at room temperature. Surface morphology of the composites was studied by a scanning electron microscope （SEM）. Frequency and temperature dependence of dielectric constant （er） and dielectric loss （tan~） of 0.5BDxF1_x- 0.5PT were measured in a wide range of frequency （100 Hz to 1 MHz） and temperature （25 to 400 ~C）. The analysis of the study showed that the er and tang decreased with increasing frequency in the given range for all the samples which could be explained through the occurrence of dipole relaxation process. The effect of substitution of rare earth element dysprosium （Dy） showed increase in er in all the samples prepared for different concentrations from 0.00 to 0.20. An explanation for high value of er for Dy modified 0.5BiFeO3-0.5PbTiO3 （0.5BF-0.5PT） compared to Gd modified 0.5BF-0.5PT was provided. The variation of AC conductivity with inverse temperature found to obey the Arrhenius equation and the composites showed negative temperature coefficient of resistance （nTCR） behavior. The activation energy was found to be in the range from 0.25 to 0.40 eV for all the studied samples.

关键词： X-ray diffraction dielectric constant tangent loss activation energy rare earths