24 research outputs found

    Impact of climate change on yield of different crops grown in Cachar district of Assam, India

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    Impact of climate change on crop yield threatens food security which is detrimental to agricultural sector. Cachar district of Assam is a climate susceptible district due to its unique geographical location and hydrological regime in north-eastern India. So, the present study was carried out to assess impact of climate change on crop yield for sustainability of agriculture. Climatic data viz., rainfall, maximum-minimum temperature and sunshine hours were collected from an observatory of Tea Research Association, Silcoorie, Cachar district for 2007-2012. Statistical and correlation analysis was employed to evaluate potential climate change impact on productivity of twenty three major crops of the study site. The correlation coefficient (r, Pearsonā€™s Product Moment) between any climatic parameter and crop yield implied that climate has strong linear correlation with yield of crops resulting in twenty-two strong correlations. Among the climatic parameters rainfall was found to have most significant impact on yield. Noteworthy reduction was observed in yield of Autumn Paddy and Winter Paddy by 8.75 and 20.44 during the year 2008-2009 due to 3.98 and 36.22% decrease of rainfall with r values 0.95 and -0.76, respectively. Also, a quantum leap of 145.32% increase of rainfall during Rabi season of 2007-2008 decreased the yield of Potato and Rabi vegetables by 22.96 and 16.89%, respectively. The study revealed that climate change has significant impact on crop yield which could be alleviated by adopting rainwater harvesting technology at the top and foot hills of the hilly areas

    Indications, outcomes and complications of therapeutic endoscopic retrograde cholangiopancreatography procedures in a tertiary care centre in North East India

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    Background: Therapeutic endoscopic retrograde cholangiopancreatography (ERCP) is one of the most complex endoscopic procedures in the management of several pancreatobiliary diseases. There is no comprehensive data available till date about ERCP procedures from North East India. The aim of this study was to review the indications, outcomes and complications of endoscopic retrograde cholangiopancreatography (ERCP) procedures in a tertiary care centre of North East India.Methods: We retrospectively analysed the clinical records of all patients undergoing ERCP between July 2011 and November 2019. ERCP was performed under sedation (Midazolam + Pentazocine). Patientā€™s demographic characters, ERCP indications, outcome and post-ERCP complications were reviewed. Potential important patient and procedure related risk factors for overall post-ERCP complications were investigated.Results: A total 1038 patients were included in the study. Cannulation of the desired duct was successful in 89.2% of ERCPs. Among them male patients were 392 and females were 646. Mean age was 45 years and the age range were 7 to 92 years. Commonest indication was choledocholithiasis followed by malignancy. Overall Success rate was 82.66% with 84.64% in CBD stone and 75.65% in stenting of malignancy. Post ERCP complications developed in 96 patients (9.2%) and pancreatitis was the most common post-ERCP complication. Sedation related complications occurred only in few cases.Conclusions: Despite its associated morbidity and risk of mortality, ERCP is an important method for managing the pancreatic-biliary diseases. Indications, outcomes, and complications of therapeutic ERCPs in our centre are comparable to those reported from other centres

    Right-handed neutrino pair production via second-generation leptoquarks

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    No direct experimental constraints exist on Leptoquark (LQ) couplings with quarks and right-handed neutrinos (RHNs). If a LQ dominantly couples to RHNs, it can leave unique signatures at the LHC. The RHNs can be produced copiously from LQ decays as long as they are lighter than the LQs. LQ-induced RHN production has never been searched for in experiments. This channel can act as a simultaneous probe for RHNs and LQs that dominantly couple to RHNs. In this paper, we consider all possible charge-2/3 and 1/3 scalar and vector LQs that dominantly couple to second-generation quarks and RHN. We study the pair and single productions of TeV-scale LQs and their subsequent decay to sub-TeV RHNs, realised in the inverse seesaw framework. We also consider RHN pair production through a t-channel LQ exchange. The single LQ production and t-channel contributions can be significant for large LQ-RHN-quark couplings. We systematically combine events from these processes leading to a pair of RHNs plus jets to study the prospects of LQ-assisted RHN pair production. We analyse the monolepton and opposite-sign dilepton final states and estimate the discovery reach at the high-luminosity LHC

    Self-cleaning BiOBr/Ag photocatalytic membrane for membrane regeneration under visible light in membrane distillation

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    In this study, an innovative electrospun photocatalyst self-cleaning BiOBr/Ag membrane is introduced for the MD treatment of dyeing wastewater coupled with post-MD UV and visible light exposure for fouled membrane regeneration. The E-BiOBr/Ag membrane was fabricated by successfully coating an electrospun membrane with BiOBr/Ag catalyst particles using electrospray technology, with the goal to achieve higher hydrophobicity and the reproducible property. Along with the E-BiOBr/Ag membrane, two commercial polyvinylidene difluoride (PVDF) and polytetrafluoroethylene (PTFE) membranes were tested for comparison. The fouling processes on all three membranes were monitored in real-time using optical coherence tomography (OCT). The coating of BiOBr/Ag particles on the E-BiOBr/Ag membrane\u27s surface accelerated dye foulant degradation through the electron-holesā€™ strong oxidization capacity when exposed to UV. Meanwhile, after Ag nanoparticles were coated on the BiOBr photocatalyst by UV deposition method, not only improved the efficiency of electron separation and transfer but also lessened the electron recombination phenomenon effectively. Correspondingly, compared to the two commercial membranes, the BiOBr/Ag photocatalyst membrane achieved significant improvements in the recovery efficiencies of the water contact angle (95.6%) and water flux (92.2%) under UV illumination, pointing to its potential for fouled membrane regeneration. In addition, the deposition of Ag on BiOBr as cocatalyst enhanced the visible light harvesting. Finally, the BiOBr/Ag photocatalyst membrane maintained good flux recovery and dye rejection (99.9%) over a 5-cycle MD test coupled with visible light exposure, suggesting the application of the novel self-cleaning photocatalyst membrane as a potential alternative for upscaling MD technology to the industrial level

    Rational Design of PDA/P-PVDF@PP Janus Membrane with Asymmetric Wettability for Switchable Emulsion Separation

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    Water pollution caused by oil spills or sewage discharges has become a serious ecological environmental issue. Despite the membrane separation technique having a promising application in wastewater purification, the membrane fabrication method and separation robustness have remained unsatisfactory until now. Herein, we developed a novel strategy, spacer-assisted sequential phase conversion, to create a patterned polyvinylidene fluoride@polypropylene (P-PVDF@PP) substrate membrane with a multiscale roughened surface. Based on that surface structure, the underwater oil resistance behavior of the P-PVDF@PP membrane was improved. Moreover, owing to the abundant active sites on the P-PVDF@PP surface, the polydopamine/P-PVDF@PP (PDA/P-PVDF@PP) Janus membrane could be readily fabricated via wet chemical modification, which exhibited excellent switchable oilā€“water separation performance. Regarding surfactant-stabilized oil-water emulsion, the as-prepared PDA/P-PVDF@PP Janus membrane also had robust separation efficiency (as high as 99% in the n-hexane/water, chloroform/water, and toluene/water emulsion separation cases) and desirable reusability. Finally, the underlying mechanism of emulsion separation in the PDA/P-PVDF@PP Janus membrane was specified. The as-designed PDA/P-PVDF@PP Janus membrane with high-efficiency oilā€“water separation shows potential application in oily wastewater treatment, and the developed fabrication method has implications for the fabrication of advanced separation membranes

    A Conductive Hydrophobic Polyaniline Sandwiched Polyvinylidene Fluoride Membrane for Early Detection of Surfactant-Induced Wetting in Membrane Distillation Using Impedance

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    Wetting of hydrophobic membranes is considered to be one of the major limitations that must be overcome to further the development of membrane distillation technology. Low surface tension liquids can induce wetting, which can significantly affect permeate conductivity after the complete wetting of the membrane pores. In this study, a thin conductive hydrophobic polyaniline (PANI) layer was sandwiched between two nonconductive polyvinylidene fluoride (PVDF) layers by the phase inversion method. The surface of this PANI-PVDF membrane was then electrosprayed with polytetrafluoroethylene to impart superhydrophobicity (water contact angle, āˆ¼160Ā°). Finally, the wetting of membranes was monitored and detected during direct contact membrane distillation of a low surface tension saline feed containing sodium dodecyl sulfate by electrochemical impedance spectroscopy. Compared with measuring conductivity of the permeate side, we found that measuring the cross-membrane impedance at a constant frequency (100 kHz) demonstrated more precise detection and a superior ability in distinguishing different stages of wetting and their intrusion. Further, our experiments demonstrated the possible strategies to elude membrane wetting by flushing distilled water periodically
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