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Influence of gaseous and particulate species on neutralization processes of polar aerosol and snow——A case study from Ny-?lesund

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Journal of Environmental Sciences 2019年第2期31卷 12-25页

作者： roseline c.thakur Meloth Thamban ESSO-National centre for Antarctic and Ocean Research Institute of Atmospheric and Earth System Research University of Helsinki

The inter-conversion of nitrogen and sulfur species between the gas and particulate phases and their interaction with alkaline species influences the acidity of the aerosols and surface snow. To better understand these processes, a short field campaign was undertaken in Ny-?lesund,Svalbard, during 13th April 2012 to 24th April 2012. Air measurements were carried out through a particulate sampler equipped with denuders and filter packs for simultaneous collection of trace gases(HNO_3, NO_2, SO_2 and reactive nitrogen compounds) and aerosols, with daily collection of snow samples. Ionic composition of the samples was analyzed using ion chromatography technique. The results suggested that nitrate-rich aerosols are formed when PAN(peroxy acetyl nitrate) disassociates to form NO_2 and HNO_3 which further hydrolyzes to form pNO_3^-(particulate nitrate). This resulted in a high contribution of pNO_3^-(62%) to the total nitrogen budget over the study area. The acidity of the aerosols and snow evaluated through cation/anion ratio(c/A)indicated alkaline conditions with c/A > 2. The bicarbonates/carbonates of Mg^(2+) played an important role in neutralization processes of surface snow while the role of NH_3 was dominant in aerosol neutralization processes. Such neutralization processes can increase the aerosol hygroscopicity causing warming. chloride depletion in the snow was significant as compared to the aerosols, indicating two important processes, scavenging of coarse sea salt by the snow and gaseous adsorption of SO_2 on the snow surface. However, a more systematic and long term study is required for a better understanding of the neutralization processes and chemical interconversions.

关键词： Particulate Aerosol Scavenging Neutralization Arctic

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An overview of deep eutectic solvents:Alternative for organic electrolytes,aqueous systems&ionic liquids for electrochemical energy storage

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Journal of Energy chemistry 2023年第7期82卷 592-626,I0013页

作者： Akshay Sharma Renuka Sharma Ramesh c.thakur Lakhveer Singh Department of chemistry Himachal Pradesh UniversitySummer HillShimla171005Himachal PradeshIndia Department of chemistry Sardar Patel UniversityMandi175001Himachal PradeshIndia

As the demand for sustainable energy sources continues to rise,the need for efficient and reliable energy storage systems becomes *** order to effectively store and distribute renewable energy,new and innovative solutions must be *** review examines the deep eutectic solvents(DESs)as a green,safe,and affordable solution for the electrochemical energy storage and conversion field,offering tremendous opportunities and a promising *** are a class of environment-friendly solvents known for their low toxicity and unique properties,such as their good conductivity,high thermal stability,and *** review explores the fundamentals,preparations,and various interactions that often predominate in the formation of DESs,the properties of DESs,and how DESs are better than traditional solvents involving cost-ineffective and unsafe organic electrolytes and ionic liquids as well as inefficient aqueous systems due to low energy density for electrochemical energy storage ***,a particular focus is placed on the various electrochemical applications of DESs,including their role in the electrolytes in batteries/supercapacitors,electropolishing and electrodeposition of metals,synthesis of electrode materials,recycling of electrodes,and their potential for use in cO_(2)*** review concludes by exploring the challenges,research gaps,and future potential of DESs in electrochemical applications,providing a comprehensive overview,and highlighting key considerations for their design and use.

关键词： Deep eutectic solvent Green solventHole theory Energy storage devices Aqueous electrolyte

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An experimental and numerical study of packing, compression, and caking behaviour of detergent powders

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Particuology 2014年第1期12卷 2-12页

作者： Subhash c.thakur Hossein Ahmadian Jin Sun Jin Y.Ooi School of Engineering University of Edinburgh Newcastle Innovation centre Procter and Gamble Technical Centre Ltd

This paper presents an experimental and numerical study of the packing, compression, and caking behaviour of spray dried detergent （SDD） powders with a two-fold aim： an experimental process of observation and evaluation of the packing, compression and caking behaviour of SDD powders, and a numerical approach based on discrete element modelling （DEM）. The mechanical properties, including the stress-strain response and the corresponding porosity change as a function of consolidation stress in a confined cylinder, the stress-strain response during unconfined shearing and the cake strength as a func- tion of consolidation stress, were evaluated and compared for different SDD powders using an extended uniaxial tester （Edinburgh Powder Tester - EPT）. The experiments using EPT showed excellent repro- ducibility in the measurement of packing, compression and caking behaviour and were therefore very useful for describing the handling characteristics of these powdered products including screening new products and different formulations. It was found that the sample with higher moisture had lower bulk porosity but higher compressibility and cake strength. The porosity, compressibility and cake strength were found to vary across different size fractions of the same sample. The larger sieve-cut samples had higher initial bulk porosity, compressibility and cake strength. It is revealed that moisture plays a sig- nificant role in packing, compression, and shearing behaviour of the powder. Three-dimensional DEM modelling using a recently developed elasto-plastic adhesive-frictional contact model showed that the contact model is able to capture the detergent behaviour reasonably well and can be used to model complex processes involving these powders.

关键词： Discrete element methodPowder flowcohesive materialUniaxial testPlasticitycontact model

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Examining global warming factors using self-organizing map and Granger causality network: a case from South Korea

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Ecological Processes 2023年第1期12卷 142-152页

作者： thakur Dhakal Tae-Su Kim Do-Hun Lee Gab-Sue Jang Department of Life Science Yeungnam University National Institute of Ecology

Background Understanding and patterning the possible causal variables of global warming is attributed to the development of effective prevention and mitigation strategies for climate change. Therefore, we aimed to pattern and visualize the possible causal variables of global warming and measure the causality between *** We patterned and visualized the time series（103 years, from 1918 to 2020） of global surface temperature（GTemp） data with the gross domestic product（GDP） per capita, human population（Pop）, and carbon dioxide（cO2）emissions of South Korea using a self-organizing map（SOM） and examined the causable local feature of global warming using the Granger causality（Gc） test. The time-series data were trained and mapped in 4 × 4 SOM grids, and causality networks between variables were examined using multivariate Granger test *** SOM patterned 103 years of data, and a dominant cluster contained continuous time-series data from 2007to 2020. Similarly, the cO2emissions of South Korea were obtained as a predictable unidirectional causal variable for GTemp from Gc analysis. Based on data from the past 34 years, significant causality（p-value = 0.01） was observed with the integrated effect of Pop, GDP, and cO2on *** This study patterned the time-series data using SOM and examined the causal relationship between variables using the Gc test. The study framework could be used as a reference by future scholars, ecologists, and the United Nations Sustainable Development Goals.

关键词： climate change Ecology Self-organizing map Sustainable development goal Greenhouse gas

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Effects of heterofunctional alkali-metal formate doping on perovskite solar cell performance

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Journal of Materiomics 2022年第6期8卷 1165-1171页

作者： Sakshi thakur Sung-Nam Kwon Dilpreet Singh Mann Seok-In Na Department of Flexible and Printable Electronics and LANL-JBNU Engineering Institute-Korea Jeonbuk National University567Baekje-daeroDeokjin-guJeonju-si54896Republic of Korea

Various internal and external defects present in the perovskite film are one of the main factors that causelow efficiency and stability, and in order to realize high-performance perovskite solar cells, it is necessaryto develop a method to effectively suppress them. In this study, a heterofunctional dopants strategy wasattempted to integrate the effect of alkali metal cations (Rbþ and Kþ) and formate anion (HcOO) throughdoping engineering with alkali-metal formates, i.e., rubidium formate (RbHcOO) and potassium formate(KHcOO). Inclusive physical and photoelectric analysis revealed that doping with a small amount ofalkali-metal formate leads to crystal growth and reduction of grain boundaries, and further passivates orinhibits bulk and surface defects. As a result, the photogenerated charge recombination was reduced andthe charge carrier transport was improved, leading to improved PSc performance. RbHcOO-dopedinverted planar PScs achieved a PcE of up to 20.41% with long-term stability. Our findings provide away for producing high-quality perovskite films with low defect densities that are essential for realizinghigh-performance PScs.

关键词： Perovskite solar cells Heterofunctional dopant Alkali-metal formate Rubidium formate Potassium formate Reduction of the charge trap density

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Palaeoenvironmental reconstruction for the Permian(lower Gondwana)succession of the Godavari Valley coalfield in southern India based on a combined palynofacies,carbon isotope,and biomarker study

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Journal of Palaeogeography 2022年第1期11卷 123-144页

作者： Neha Aggarwal Runcie Paul Mathews Arif Husain Ansari Biswajeet thakur Shailesh Agrawal Birbal Sahni Institute of Palaeosciences 53 University RoadLucknow 226007India

The study presents integrated palynofacies,organic carbon isotope,and biomarker data to reconstruct palaeoenviromental setting for the Permian sediments(borehole MGK-6)of the Kachinapalli block of the Godavari Valley coalfield,southern *** palynofacies data reveal three distinct palynofacies(A-c)as *** A is dominated by abundant arborescent vegetation(glossopterids and conifers)along with structured organic matter,suggesting freshwater forest swamps in proximal *** B is dominated by abundant degraded organic matter and amorphous organic matter,suggesting lakeshore/flooded palaeomires in slightly dismal *** has a high water level in the hinterland,which enables bacterial degradation of organic matter and establishes low-oxygenation conditions within the water *** conditions would have provided grounds for the accumulation of either degraded or amorphous organic *** c is dominated by the abundance of charcoal/opaque phytoclasts,indicating prolonged transportation or postdepositional alteration,suggesting a highly-oxidizing condition in distal *** bulk organic δ^(13)c range(-25.1‰ to-20.9‰)in the borehole MGK-6 is in close agreement with the global Permian *** study also shows a weak but statistically significant correlation with the major forms of palynofacies A and *** interlinked behaviour of bulk organic δ^(13)c and palynofacies suggests that the changes in palaeobiogeography/palaeodepositional settings were most likely driven by the change in mean annual *** biomarker study shows the presence of n-alkane from c_(15) to c_(31) with unimodal and bimodal distribution patterns,revealing the source materials as vascular plants and microbially-altered organic *** combined palynofacies,organic carbon isotope,and biomarker data provide vital clue to salient findings for the development of environmental conditions of Godavari Valley coalfield during lower Gond

关键词： Artinskian Guadalupian Depositional environment carbon isotope Biomarker Godavari valley coalfield

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Fat,oil,and grease as new feedstock towards bioelectrogenesis in microbial fuel cells:Microbial diversity,metabolic pathways,and key enzymes

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Journal of Energy chemistry 2023年第10期85卷 418-429,I0011页

作者： Monika Sharma Mohammed Jalalah Saeed AAlsareii Farid AHarraz Abdulrhman AAlmadiy Nandini thakur El-Sayed Salama Xiangkai Li MOE Key Laboratory of Cell Activities and Stress AdaptationsSchool of Life SciencesLanzhou UniversityLanzhou 730000GansuChina Promising centre for Sensors and Electronic Devices(PcSED) Advanced Materials and Nano-Research CentreNajran UniversityP.O.Box:1988Najran 11001Saudi Arabia Department of Electrical Engineering College of EngineeringNajran UniversityNajran 11001Saudi Arabia Department of Surgery College of MedicineNajran UniversityNajran 11001Saudi Arabia Department of chemistry Faculty of Science and Arts at SharurahNajran UniversitySharurah 68342Saudi Arabia Department of Biology Faculty of Arts and SciencesNajran University1988 NajranSaudi Arabia Department of Occupational and Environmental Health School of Public HealthLanzhou UniversityLanzhou 730000GansuChina

Microbial fuel cells(MFcs)are a well-known technology used for bioelectricity production from the decomposition of organic waste via electroactive ***,oil,and grease(FOG)as a new substrate in the anode and microalgae in the cathode were added to accelerate the *** effect of FOG concentrations(0.1%,0.5%,1%,and 1.5%)on the anode chamber was *** FOG degradation,volatile fatty acid(VFAs)production,and soluble chemical oxygen demand along with voltage output kinetics were ***,the microbial community analysis and active functional enzymes were also *** maximum power and current density were observed at 0.5%FOG which accounts for 96 mW m^(-2)(8-folds enhancement)and 560 mA m^(-2)(3.7-folds enhancement),*** daily voltage output enhanced upto 2.3-folds with 77.08%coulombic efficiency under 0.5%FOG,which was the highest among all the *** 0.5%FOG was degraded>85%,followed by a 1%FOG-loaded *** chief enzymes inβ-oxidation and electrogenesis were acetyl-coA c-acetyltransferase,riboflavin synthase,and riboflavin *** identified enzymes symbolize the presence of clostridium sp.(>15%)and Pseudomonas(>10%)which served as electrochemical active bacteria(EAB).The major metabolic pathways involved in electrogenesis and FOG degradation were fatty acid biosynthesis and glycerophospholipid *** of lipidic-waste(such as FOG)in MFcs could be a potential approach for simultaneous biowaste utilization and bioenergy generation.

关键词： Lipidic-waste Microalgae Electrogenesis Microbial community Functional enzymes

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Variation of turbidity during subsurface abstraction of river water: A case study

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International Journal of Sediment Research 2010年第4期25卷 355-365页

作者： A.K.thakur c.S.P.OJHA Department of Science and Technology Patna India Department of civil Engineering IIT Roorkee Uttarakhand 247667 India

Rivers are known to carry sediment loads. Many rivers in Asia including Kosi, Brahmaputra, Bagmati rivers in India and Yellow and Yarlung Tsangpo rivers in china are well known for their carriage of excessive sediment loads. In India, many water abstraction units are located along river banks. Their success depends on how the sediment load is trapped as the sediment laden water flows towards the pumping wells located few hundred meters away from river bank. In this work, based on the analysis of a data of one year on suspended load variations in a canal, located at Haridwar, India, trap efficiency variations are studied during the passage of source water to the abstraction well. considering the subsurface basin, located within the source water and the abstraction well, as a hypothetical settling basin, variation of trap efficiency is related with the influent concentration. It is observed that the trap efficiency depends on the influent concentration. Appropriate functional forms for the variation of trap efficiency with the influent concentrations are also identified.

关键词： Turbidity River bank filtration Suspended sediment Bank filtrate clogging Influent concentration and effluent concentration Trap efficiency

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A 2000 Year Multi-Proxy Evidence of Natural/Anthropogenic Influence on climate from the Southwest coast of India

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Journal of Earth Science 2020年第5期31卷 1029-1044页

作者： M.c.Manoj Jyoti Srivastava Prem Raj Uddandam Biswajeet thakur Birbal Sahni Institute of Paleosciences 53 University RoadL ucknowUttar Pradesh 226007India Banaras Hindu University VaranasiUttar PradeshIndia

The last millennium climate reconstructions are complex and limit our understanding of the mechanisms behind environmental and climate variability. We present multi-proxy centennial-scale records from the cherai, southwest India. The last 2000 cal yr AD record suggests a complex environmental condition that prevailed at the depositional site augmenting the role of natural as well as anthropogenic agents. Increased elemental variations and indices values indicate stronger weathering, presumably wetter conditions and intense precipitation. Provenance studies suggest diverse sources and the main composition fall close to the charnockite and Gneissic composition. Multi-proxy data suggests that a shift towards wetter climatic conditions, which occurred from 910 to 1230 cal yr AD. The core also records a shift towards the drier conditions that started around 1230 cal yr AD with a loss in vegetation diversity. The pollution load index values suggest that the overall study area falls in moderate contamination levels, which are also substantiated with the diatom data indicating human influence in the natural habitat during the deposition time. The present study reveals that the enhanced cd and As concentration is due to strong anthropogenic influence. We compared the multi-proxy record with other continental and marine palaeoclimatic records to explore global and/or regional trends in climate variability during the last 2000 years.

关键词： estuaries monsoon provenance vegetation clmate contamination

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Effect of rhizobial inoculations on nitrogen metabolism of Albizia lebbek seedlings

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Journal of Forestry Research 2013年第4期24卷 671-676页

作者： A.Kaur S.P.chaukiyal A.thakur T.c.Pokhriyal Botany Division(FRI)

Rhizobia were isolated from Albizia lebbek （L） Benth. seed- lings collected from six different places, tested against the nodulation test and inoculated into 45 day old Albizia lebbek seedlings in sterile soil mixture under glass house conditions. After a period of two and three months, the plant samples were taken to study the influence of inoculation treatments on nitrogen fixation, assimilation, biomass production and nitrogen content in different plant parts. The seedlings inoculated with isolates III（1） and III（2） of Lalpani had the maximum nodular biomass,

关键词： Rhizobium biomass nitrogenase nitrate reductase (NR) nitrogen

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