Synthesis and superconductivity of new BiS2 based superconductor PrO0.5F0.5BiS2

We report synthesis and superconductivity at 3.7K in PrO0.5F0.5BiS2. The newly discovered material belongs to the layered sulfide based REO0.5F0.5BiS2 compounds having ZrCuSiAs type structure. The bulk polycrystalline compound is synthesized by vacuum encapsulation technique at 7800C in single step. Detailed structural analysis has shown that the as synthesized PrO0.5F0.5BiS2 is crystallized in tetragonal P4/nmm space group with lattice parameters a = 4.015(5) {\AA}, c = 13.362(4) {\AA}. Bulk superconductivity is observed in PrO0.5F0.5BiS2 below 4K from magnetic and transport measurements. Electrical transport measurements showed superconducting transition temperature (Tc) onset at 3.7K and Tc ({\rho}=0) at 3.1K. Hump at Tc related to superconducting transition is not observed in heat capacity measurement and rather a Schottky-type anomaly is observed at below ~6K. The compound is slightly semiconducting in normal state. Isothermal magnetization (MH) exhibited typical type II behavior with lower critical field (Hc1) of around 8Oe.Comment: Short note 10 pages text+figs. First report on PrO.5F.5BiS2 Su

Superconductivity at 5K in NdO0.5F0.5BiS2

We report appearance of superconductivity at 5K in NdO0.5F0.5BiS2 and supplement the discovery [1] of the same in layered sulfide based ZrCuSiAs type compounds. The bulk polycrystalline compound is synthesized by conventional solid state route via vacuum encapsulation technique. Detailed structural analysis showed that the studied compound is crystallized in tetragonal P4/nmm space group with lattice parameters a = 3.9911(3) {\AA}, c = 13.3830(2) {\AA}. Bulk superconductivity is established in NdO0.5F0.5BiS2 at 5K by both transport and magnetic measurements. Electrical transport measurements showed superconducting Tc onset at 5.2K and Tc ({\rho}=0) at 4.7K. Under applied magnetic field both Tc onset and Tc ({\rho} =0) decrease to lower temperatures and an upper critical field [Hc2(0)] of above 23kOe is estimated. Both AC and DC magnetic susceptibility measurements showed bulk superconductivity below 5K. Isothermal magnetization (MH) exhibited typical type II behavior with lower critical field (Hc1) of around 15Oe. Isothermal magnetization (MH) exhibited typical type-II behavior with lower critical field (Hc1) of around 15Oe. Specific heat [Cp(T)] is investigated in the temperature range of 1.9-50K in zero external magnetic field. A Schottky-type anomaly is observed at low temperature below 7K. This low temperature Schottky can be attributed to the change in the entropy of the system.Comment: 10 pages text + Figs (New Version):comments/suggestion welcome ([email protected]

Prospect of Protected Agricultural Structure and its Constraints for Utilizing in Nepal

Protected agricultural structures have been adopted by commercial farmers throughout the world including Nepal to cope with climate change and its adverse effects on agriculture. Technology based production system is important for sustainable agricultural development. It could be the tool for low-income countries like Nepal where agriculture is the priority of income generation for the rural people. A field study was conducted in 2021 and 2022 to understand the prospects of protected agriculture structures adaptation by farmers and agricultural entrepreneur in Nepal. The study was traversed with both physical observation and the user’s interviews. The opportunities and the constraints have been critically analysed based on these field study along with the review of different policy documents and success stories published. This study found that the protected cultivation practice has been rapidly increased with increasing number of protected structures like plastic house or tunnel framed with bamboo or GI pipe, Agri-net house, naturally ventilated poly house and semi or hi-tech green house. In contrary, the import of horticulture products has also been increased more than 200% in last 10 years. This study finds the gap mismatching between technology enhancement, production and import of horticulture crops

Magnetization and Magneto-resistance in Y(Ba1-xSrx)2Cu3O7-{\delta} (x = 0.00 - 0.50) superconductor

Here we present the magnetic properties and upper critical field (BC2) of polycrystalline Y(Ba1-xSrx)2Cu3O7-{\delta} superconductors, which are being determined through detailed ac/dc susceptibility and resistivity under magnetic field (RTH) study. All the samples are synthesized through solid state reaction route. Reduction in Meissner fraction (the ratio of field cooled to zero field cooled magnetization) is observed with increasing Sr content, suggesting occurrence of flux pining in the doped samples. The ac susceptibility and resistivity measurements reveal improved grain couplings in Sr substituted samples. Consequently the inter-grain critical current density (Jc), upturn curvature near the Tc in temperature dependence of upper critical field [BC2(T)], and BC2 are enhanced. Both Jc and BC2 increase in lower Sr substitution (up to x = 0.10) samples followed by decrease in higher doping due to degradation in effective pining and grain coupling.Comment: 17 pages text + Figs, [email protected]

Appearance of superconductivity in new BiS2 based layered LaO0.5F0.5BiS2

We report here synthesis, structural, DC magnetization, and transport studies of new BiS2 based layered LaO0.5F0.5BiS2 superconductor [1]. The sample was synthesized by conventional solid state route via vacuum encapsulation technique at 800oC for 12h. LaO0.5F0.5BiS2 crystallizes in tetragonal P4/nmm space group with lattice parameters a = 4.0703(5){\AA}, c = 13.3902(4){\AA}. Bulk superconductivity is confirmed with superconducting transition temperature (Tc) of 2.7K by DC magnetization measurements. The Isothermal magnetization (MH) measurements showed closed loops with clear signatures of flux pinning and irreversible behavior. The resistivity measurements confirmed an onset Tc of 2.7K. The magneto-transport {\rho}(T,H) measurements showed a resistive broadening and decrease in Tc ({\rho}=0) to lower temperatures with increasing magnetic field. The magnetic phase diagram involving upper critical and irreversibility fields as a function of temperature has been ascertained. Our DC magnetization and electrical transport measurements confirm the appearance of bulk superconductivity in LaO0.5F0.5BiS2 superconductor.Comment: 11 pages figures + Text: First observation/approval of LaO/FBiS2 superconductivity: comments/suggestions: [email protected]

Information needs assessment in digital environment

The information needs represent gaps in the current knowledge of the user. The professional can assess the information needs of clientele at two levels: first, by analyzing the characteristics of the community served; and second, by analyzing the needs of specific individuals when and where they seek information. Assessment of information need typically occurs through a communication process called interview of information user. The process of assessment of information need through interview can be divided in eight stages. These are determining the purpose, researching the topic, selecting interviewees, structuring the interview, conducting the interview, preparing the report, presenting the report and feedback & further refinement. These have been changed in digital era due to introduction of Internet, e-mail, online groups and blogs. Identifying information needs is a complex process as some of the respondents may think that it is a wastage of time as it is a somewhat time taking process and may attempt to test whether the information provider will provide the information or not. This paper takes up the change brought up due to introduction of digital means in all the eight steps mentioned in assessment of information need through interview

Design of Automated Rainout Shelter to Conduct Experiment on Drought Tolerant Maize Genotype

Uneven and low precipitation areas of Nepal are continuously suffering from drought and received low productivity because of unavailability of suitable drought tolerant maize genotype. An attempt has been made first time in Nepal by constructing an automated rainout shelter with soil moisture based automated drip irrigation system at National Maize Research Program in 2018-2019 to conduct an experiment on drought tolerant maize genotype. The rainout shelters automatically covers the cropping area as soon as the rain sensor received a single drop of precipitation and also if the light intensity decreased to value set in the control panel. Likewise, the soil water level in different treatments were maintained on the basis of the treatment controlled with automatic drip irrigation system set to irrigate at threshold value set in the microcontroller. The complete system had found very useful in determining accurate amount of water required to cultivate drought tolerant maize genotype. We have tested drought tolerant variety RampurSo3Fo8 under 10 level of irrigation and it was determined that 495.2 mm of water is maximum level of water to produce highest yield of 3.32 t/ha whereas 445.6 mm to 247.6 mm of water could can be manage to produce competitive yield without any reduction. An experiment under such kind of infrastructure provide useful information on irrigation management practices required for drought variety in the natural environment. The research output also guides farmers and agriculturist in making Nepalese agricultural more sustainable, mechanized and productive

Design and Development of Soil Moisture Based Automatic Irrigation System in Nepal

A prototype soil moisture based an automated irrigation system were developed at National Maize Research Program in 2018 to study the water requirement of drought tolerant crop genotype. The irrigation system has been controlled by Arduino UNO as a micro controller. The instant soil moisture data were collected either in Excel format or graphical format using internet of things through the programming of Global System for Mobile Communication: Subscriber Identity Module (GSM:SIM card) of Nepal Telecom. The developed automated irrigation system has found maintained the predetermined threshold soil moisture. This automated irrigation system has been developed to make applicable for drip irrigation system which has operated at low water pressure maintained by 1.5² professional-grade solenoid valve. The introduction of this automated irrigation system has developed the base for Nepalese agricultural scientist in designing and promoting irrigation technology to make Nepalese agricultural more sustainable, mechanized and productive

Room temperature magnetic entropy change and magnetoresistance in La_{0.70}(Ca_{0.30-x}Sr_x)MnO_3:Ag 10% (x = 0.0-0.10)

The magnetic and magnetocaloric properties of polycrystalline La0.70(Ca0.30-xSrx)MnO3:Ag 10% manganite have been investigated. All the compositions are crystallized in single phase orthorhombic Pbnm space group. Both, the Insulator-Metal transition temperature (TIM) and Curie temperature (Tc) are observed at 298 K for x = 0.10 composition. Though both TIM and Tc are nearly unchanged with Ag addition, the MR is slightly improved. The MR at 300 K is found to be as large as 31% with magnetic field change of 1Tesla, whereas it reaches up to 49% at magnetic field of 3Tesla for La0.70Ca0.20Sr0.10MnO3:Ag0.10 sample. The maximum entropy change (\DeltaSMmax) is 7.6 J.Kg-1.K-1 upon the magnetic field change of 5Tesla, near its Tc (300.5 K). The La0.70Ca0.20Sr0.10MnO3:Ag0.10 sample having good MR (31%1Tesla, 49%3Tesla) and reasonable change in magnetic entropy (7.6 J.Kg-1.K-1, 5 Tesla) at 300 K can be a potential magnetic refrigerant material at ambient temperatures.Comment: 11 pages text + Figs comments/suggestions ([email protected]