We have investigated the magnetic ground state of the antiferromagnetic Kondo-lattice compounds CeMAl4Si2(M = Rh, Ir) using neutron powder diffraction. Although both of these compounds show two ...magnetic transitions TN1 and TN2 in the bulk properties measurements, evidence for magnetic long-range order was only found below the lower transition TN2. Analysis of the diffraction profiles reveals a commensurate antiferromagnetic structure with a propagation vector k = (0, 0, 1/2). The magnetic moment in the ordered state of CeRhAl4Si2 and CeIrAl4Si2 were determined to be 1.14(2) and 1.41(3) μB Ce−1, respectively, and are parallel to the crystallographic c-axis in agreement with magnetic susceptibility measurements.
The synthesis, crystal structure and physical properties studied by means of x-ray diffraction, magnetic, thermal and transport measurements of CeMAl4Si2 (M = Rh, Ir, Pt) are reported, along with the ...electronic structure calculations for LaMAl4Si2 (M = Rh, Ir, Pt). These materials adopt a tetragonal crystal structure (space group P4/mmm) comprised of BaAl4 blocks, separated by MAl2 units, stacked along the c-axis. Both CeRhAl4Si2 and CeIrAl4Si2 order antiferromagnetically below TN1 = 14 and 16 K, respectively, and undergo a second antiferromagnetic transitition at lower temperature (TN2 = 9 and 14 K, respectively). CePtAl4Si2 orders ferromagnetically below TC = 3 K with an ordered moment of μsat = 0.8 μB for a magnetic field applied perpendicular to the c-axis. Electronic structure calculations reveal quasi-2D character of the Fermi surface.
This paper presents optimization and uncertainty analysis of operation policies for Hirakud reservoir system in Orissa state, India. The Hirakud reservoir project serves multiple purposes such as ...flood control, irrigation and power generation in that order of priority. A 10-daily reservoir operation model is formulated to maximize annual hydropower production subjected to satisfying flood control restrictions, irrigation requirements, and various other physical and technical constraints. The reservoir operational model is solved by using elitist-mutated particle swarm optimization (EMPSO) method, and the uncertainty in release decisions and end-storages are analyzed. On comparing the annual hydropower production obtained by EMPSO method with historical annual hydropower, it is found that there is a greater chance of improving the system performance by optimally operating the reservoir system. The analysis also reveals that the inflow into reservoir is highly uncertain variable, which significantly influences the operational decisions for reservoir system. Hence, in order to account uncertainty in inflow, the reservoir operation model is solved for different exceedance probabilities of inflows. The uncertainty in inflows is represented through probability distributions such as normal, lognormal, exponential and generalized extreme value distributions; and the best fit model is selected to obtain inflows for different exceedance probabilities. Then the reservoir operation model is solved using EMPSO method to arrive at suitable operational policies corresponding to various inflow scenarios. The results show that the amount of annual hydropower generated decreases as the value of inflow exceedance probability increases. The obtained operational polices provides confidence in release decisions, therefore these could be useful for reservoir operation.
Livestock insurance, an important risk management tool, is becoming popular in Nepal after Crop and Livestock Insurance Directives, 2013, came into action. To widen the adaptability of the insurance ...throughout the country, key determinants of insurance adoption need proper investigation. We designed this study to identify the factors that influence farmer's decisions in adopting livestock insurance. Primary data were collected from 415 respondents including 245 livestock insured and 170 non-insured farmers. Probit regression model using STATA15 was employed to analyze factors influencing livestock insurance adoption. The regression result revealed that the probability of insurance adoption significantly increases with farmers having membership in groups or cooperatives, raising awareness, and rearing improved animal. Intensifying public awareness campaigns through a combined effort of all the stakeholders including local government authorities, broadcasting media, insurance companies, and farmer's groups or cooperatives is necessary for insurance uptake in the farming community. Provision of insurance through farmers' group or cooperatives making them a formal insurer agent is required for wider adoption of livestock insurance in Nepal.
Preparation of adsorption gel for metal ions from orange wastes by simple chemical modification was investigated. Two types of adsorption gels, Ca
2+-form and H
+-form gels, were prepared by ...saponifying orange juice residues with calcium hydroxide and its subsequent acid treatment, respectively. Both gels were adequately stable against dissolution in aquatic environment. The Ca
2+-form gel was effective for the complete and selective removal of Pb(II), Cu(II) and Fe(III) compared with other divalent metal ions. The selectivity order for metal ion uptake by the gel is Pb(II)
>
Fe(III)
>
Cu(II)
>
Cd(II)
≈
Zn(II)
>
Mn(II). Among these metal ions, the maximum loading capacities for divalent metal ions such as Pb(II), Cd(II) and Zn(II) were evaluated as 1.1 mol/kg-dry gel while that for Fe(III) was 1.55 mol/kg-dry gel. The H
+-form gel showed a different adsorption profile for Fe(III) compared to the Ca
2+-form gel. The experimental results clearly suggest that both gels are quite effective for removing heavy metal ions in acidic pH ranges.
AbstractDam operators often do not know whether an auxiliary spillway will fail until it is loaded, which can be infrequent. Such failures have the potential to result in overall dam failure, leading ...to loss of life and substantial property damage. The purpose of this paper is to develop a screening technique to identify potentially risky auxiliary spillways. The paper uses the National Inventory of Dams (NID) data and analyzes a sample of 400 earthen dams with auxiliary spillways. The main innovation of the paper is to employ code to create multiple input files and analyze them in the Windows Dam Analysis Modules (WinDAM) C software. This technique is more efficient than the current functionality of WinDAM C, which evaluates one dam at a time. The proposed method serves as a quick screening and decision-making tool for multiple embankments for extreme flooding events by identifying potentially risky auxiliary spillways that may require in-depth analysis. The results of this screening found 75% of spillways are likely to sustain heavy damage. Additionally, heavy damage was related to narrower spillway widths.
As a consequence of degeneracies arising from crystal symmetries, it is possible for electron states at band-edges ('valleys') to have additional spin-like quantum numbers. An important question is ...whether coherent manipulation can be performed on such valley pseudospins, analogous to that implemented using true spin, in the quest for quantum technologies. Here, we show that valley coherence can be generated and detected. Because excitons in a single valley emit circularly polarized photons, linear polarization can only be generated through recombination of an exciton in a coherent superposition of the two valley states. Using monolayer semiconductor WSe2 devices, we first establish the circularly polarized optical selection rules for addressing individual valley excitons and trions. We then demonstrate coherence between valley excitons through the observation of linearly polarized luminescence, whose orientation coincides with that of the linearly polarized excitation, for any given polarization angle. In contrast, the corresponding photoluminescence from trions is not observed to be linearly polarized, consistent with the expectation that the emitted photon polarization is entangled with valley pseudospin. The ability to address coherence, in addition to valley polarization, is a step forward towards achieving quantum manipulation of the valley index necessary for coherent valleytronics.
Orange waste, an available biomass, was immobilized with zirconium(IV) to investigate its feasibility for phosphate removal from an aquatic environment. Kinetics, effects of pH and foreign anions, ...and the adsorption isotherm for phosphate have been examined. The adsorption capacity has been compared to that of two commercially available adsorbents such as zirconium ferrite and MUROMAC XMC 3614. The prepared gel was an effective adsorption gel for phosphate removal with a reasonably high sorption capacity of 57
mg-P/g, which was four times higher than that of zirconium ferrite. The highest removal of phosphate was observed at low pH, whereas higher pH suppressed phosphate removal, but even up to pH 9 more than 85% phosphate removal was observed. Adsorbed phosphate was eluted by NaOH solution. Fixed bed column-mode experiments confirmed the complete adsorption of phosphate in continuous-mode operation. Throughout the operating conditions, zirconium was not leaked.
Background Wheat is the third important cereal after rice and maize in Nepal. Its yield suffers from several factors such as lack of reliable irrigation, inclement weather, incidence of disease and ...lack of improved technology. New virulence race Ug99 (Uganda-99) has threatened all available commercial wheat varieties around the world and Asia. Some of the popular varieties of wheat in Nepal are also getting susceptible to different diseases. Vijay is one of the recently released first Ug99-resistant improved wheat varieties for Terai region in Nepal. Nepal has put special emphasis on the seed production and diffusion of this variety to promote rapidly in the farmers’ fields to mitigate the potential epidemics of newly emerging pathotype of stem rust (Ug99). This variety is being promoted by several organizations and seed companies’ before and after its release. Therefore, this study was undertaken to know the seed supply of Vijay and identify the factors that are contributing for its commercialization. Methods Sunsari, Morang, Rupandehi, Banke and Kailali districts were selected purposely representing Eastern, Western, Mid-western and Far-Western Terai regions of Nepal, respectively. Seed companies, agro-vets (input dealers) and cooperatives involved in Vijay seed multiplication and distribution in the respective districts were selected for the purpose of the study. From the list of agro-vets in respective study sites, a total of 87 wheat seed selling agro-vets were selected randomly as a sample. The sample survey covered 44% of the target population in both categories (dealers and non-dealers of national seed company). Out of total samples, 40% were national seed company dealer agro-vets, while 60% were non-dealers. Multivariate regression analysis was used to find out different factors responsible for commercialization of Vijay seed. Results Results indicate that about 67% of the agro-vets were involved in Vijay seed trading and their average time of involvement was 2.65 years. Majority of the agro-vets perceived this variety performed better than other existing popular varieties such as Gautam, Bhrikuti, Aditya and Nepal 297. However, there was still gap in timely supply of the seed. Based on the estimated Certified-1 seed production in 2015/16, Vijay must cover 56.88% (11,943 ha) of total wheat area in Terai, but share of Vijay seed was about 22% of the total wheat seed sold by agro-vets in 2015/16. Nevertheless, it seems that this variety is getting popular in the study area compared to other improved wheat varieties in short time period. The factors influencing commercialization of Vijay were: agro-vets having dealership of national seed company, perception on comparative better performance of Vijay with Nepal 297, total quantity of wheat seed sold by agro-vets and total business transaction of the agro-vets. Moreover, other factors such as pre-release multiplication of Vijay variety by private seed companies and participation on seed related training have found positive contribution on its commercialization. Conclusion It seems that the current production of Vijay’s breeder seed is more than enough to cultivate in total wheat area in Terai of Nepal if proper seed cycle is maintained. But this is not in reality. NARC should decentralized foundation seed to private actors such as private seed companies, national seed companies and community-based organizations to maximize the resource use efficiency in the seed cycle through introducing effective monitoring and technical backstopping mechanism from public sector. Therefore, the close coordination and commitment of the public and private seed companies, community seed groups, cooperatives and public extension agencies to multiply seeds in subsequent cycles is required. Moreover, awareness program about superiority of Vijay with other improved wheat varieties should be emphasized for the rapid commercialization of the Vijay seed which would be an instrumental to mitigate the potential epidemics of newly emerging pathotype of stem rust (Ug99) in the future.
PDF
