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Promising light converting BaMoO_4:Er^(3+)-Tm^(3+)-Yb^(3+) phosphors for display and optical temperature sensing

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Journal of Rare Earths 2018年第12期36卷 1256-1263页

作者： abhishek kumar Soni Vineet kumar Rai Chemistry Division Bhabha Atomic Research Centre Laser and Spectroscopy Laboratory Department of Applied Physics Indian Institute of Technology (Indian School of Mines)

Er-Tm3+-Ybtri-doped BaMoOphosphors were synthesized by co-precipitation technique and characterized by X-ray diffraction analysis, absorption study and field emission scanning electron microscopy analysis. Upconversion as well as downconversion luminescence studies were performed by using near infrared(980 nm) and ultraviolet(380 nm) excitations. Energy level diagram, pump power dependence and colour coordinate study were utilized to describe the multicolor upconversion emission properties. Under single 980 nm diode laser excitation the dual mode sensing behaviour is realized via Stark sublevels and thermally coupled energy levels of the Tm3+ and Erions in the prepared tri-doped phosphors. A comparative fluorescence intensity ratio analysis for integrated emission intensities arising from the Stark sublevels {~1 G4(a)) and ~1 G4(b))} and thermally coupled energy levels {~2 Hand 4 S3/2} of the Tm3+ and Er3+ ions, respectively was carried out in the prepared tri-doped BaMoOphosphors. The maximum sensitivity for thermally coupled energy levels of the Er3+ and Stark sublevels of the Tm3+ ion was reported. The developed phosphors could be useful in the display devices and optical thermo metric applications.

关键词： Phosphor Optical temperature sensing Stark sublevels Thermally coupled energy levels Rare earths

Chemical hardness-driven interpretable machine learning approach for rapid search of photocatalysts

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npj Computational Materials 2021年第1期7卷 1850-1862页

作者： Ritesh kumar abhishek K.Singh Materials Research Centre Indian Institute of ScienceBangaloreKarnataka 560012India

Strategies combining high-throughput(HT)and machine learning(ML)to accelerate the discovery of promising new materials have garnered immense attention in recent *** knowledge of new guiding principles is usually scarce in such studies,essentially due to the‘black-box’nature of the ML ***,we devised an intuitive method of interpreting such opaque ML models through SHapley Additive exPlanations(SHAP)values and coupling them with the HT approach for finding efficient 2D watersplitting *** developed a new database of 30992D materials consisting of metals connected to six ligands in an octahedral geometry,termed as 2DO(octahedral 2D materials)*** ML models were constructed using a combination of composition and chemical hardness-based features to gain insights into the thermodynamic and overall *** importantly,it distinguished the target properties of the isocompositional 2DO materials differing in bond connectivities by combining the advantages of both elemental and structural *** interpretable ML regression,classification,and data analysis lead to a new hypothesis that the highly stable 2DO materials follow the HSAB *** most stable 2DO materials were further screened based on suitable band gaps within the visible region and band alignments with respect to standard redox potentials using the GW method,resulting in 21 potential ***,HfSe_(2)and ZrSe_(2)were found to have high solar-tohydrogen efficiencies reaching their theoretical *** proposed methodology will enable materials scientists and engineers to formulate predictive models,which will be accurate,physically interpretable,transferable,and computationally tractable.

关键词： intuitive formulate visible

Effects of Nonmonotonic Functional Responses on a Disease Transmission Model:Modeling and Simulation

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Communications in Mathematics and Statistics 2022年第2期10卷 195-214页

作者： abhishek kumar Nilam Department of Applied Mathematics Delhi Technological UniversityDelhi 110042India

In this article,a novel susceptible-infected-recovered epidemic model with nonmonotonic incidence and treatment rates is proposed and analyzed *** Monod-Haldane functional response is considered for nonmonotonic behavior of both incidence rate and treatment *** model analysis shows that the model has two equilibria which are named as disease-free equilibrium(DFE)and endemic equilibrium(EE).The stability analysis has been performed for the local and global behavior of the DFE and *** the help of the basic reproduction number(R_(0)),we investigate that DFE is locally asymptotically stable when R_(0)*** local stability of DFE at R_(0)=1 has been analyzed,and it is obtained that DFE exhibits a forward transcritical ***,we identify conditions for the existence of EE and show the local stability of EE under certain ***,the global stability behavior of DFE and EE has been ***,numerical simulations have been done in the support of our theoretical findings.

关键词： Monod-Haldane functional Basic reproduction number Local and global stability Bifurcation

Deep Neural Network and Pseudo Relevance Feedback Based Query Expansion

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Computers, Materials & Continua 2022年第5期71卷 3557-3570页

作者： abhishek kumar Shukla Sujoy Das Department of Mathematics Bio-Informatics and Computer ApplicationsMaulana Azad National Institute of Technology BhopalBhopalMadhya Pradesh462003India

The neural network has attracted researchers immensely in the last couple of years due to its wide applications in various areas such as Data mining,Natural language processing,Image processing,and Information retrieval *** embedding has been applied by many researchers for Information retrieval *** this paper word embedding-based skip-gram model has been developed for the query expansion *** terms are obtained from the top“k”initially retrieved documents using the Pseudo relevance feedback model and then they are trained using the skip-gram model to find the expansion terms for the user *** performance of the model based on mean average precision is *** proposed model compares with other existing *** improvement of 6.61%,6.93%,and 9.07%on MAP value is observed compare to the Original query,BM25 model,and query expansion with the Chi-Square model *** proposed model also retrieves 84,25,and 81 additional relevant documents compare to the original query,query expansion with Chi-Square model,and BM25 model respectively and thus improves the recall value *** per query analysis reveals that the proposed model performs well in 30,36,and 30 queries compare to the original query,query expansion with Chi-square model,and BM25 model respectively.

关键词： Information retrieval query expansion word embedding neural network deep neural network

Three-phase AC-DC Converter for Direct-drive PMSG-based Wind Energy Conversion System

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Journal of Modern Power Systems and Clean Energy 2023年第2期11卷 589-598页

作者： kumar abhishek Singh Ayushi Chaudhary Kalpana Chaudhary Department of Electrical Engineering Indian Institute TechnologyVaranasiIndia Department of Electrical Engineering Indian Institute TechnologyKanpurIndia

In this paper,a wind energy conversion system(WECS)is presented for the electrification of rural areas with wind energy availability.A three-phase AC-DC converter based on a bridgeless Cuk converter is used for power extraction from the permanent magnet synchronous generator(PMSG).The bridgeless topology enables the elimination of the front-end diode bridge rectifier(DBR).Moreover,the converter has fewer components,simple control,and high efficiency,making it suitable for a small-scale WECS.A squirrel cage induction motor(SCIM)is used to emulate a MOD-2 wind turbine to implement the PMSG-based WECS.A direct-drive eight-pole PMSG is used in this study;thus,a low-input-voltage system is *** converter is designed to operate in the discontinuous inductor current mode(DICM)for inherent power factor correction(PFC)and the maximum power point tracking(MPPT)is achieved through the tip-speed ratio(TSR)*** performance of the developed system is analyzed through simulation,and a 500 W hardware prototype is developed and tested in different wind speed conditions.

关键词： Permanent magnet synchronous generator(PMSG) three-phase AC-DC converter wind energy conversion system(WECS) wind turbine emulator

Inhibitory Interaction and Pharmacological Analyses of Berries Phenolics Against Listeria monocytogenes Virulent Protein Internalin B

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World Journal of Traditional Chinese Medicine 2023年第1期9卷 71-80页

作者： abhishek kumar Archana Vimal Awanish kumar School of Agriculture Indira Gandhi National Open UniversityNew DelhiIndia Department of Bioengineering Integral University LucknowUttar PradeshIndia Department of Biotechnology National Institute of TechnologyRaipurChhattisgarhIndia

Background: Traditional plants, their parts, and phytochemicals obtained from them are beneficial for human beings. They are used as potent antimicrobials, but very little research is conducted on the use of traditional medicine against food-borne infection. Different berry plants are rich in phenolic compounds and conventionally known to have many properties such as antioxidants, anti-carcinogenic, anti-inflammatory, anti-bacterial, and anti-diabetics. However, only limited polyphenols are known for their antilisterial effect. The present study aimed to explore the antimicrobial efficacy of phenolic compounds of berries for the treatment of food-borne infection caused by the bacteria Listeria monocytogenes. Materials and Methods: Molecular docking studies employing the Swiss DOCK server were performed to evaluate the antimicrobial activity of phenolic compounds obtained from different varieties of berries. Internalin B(Inl B), a virulence protein of L. monocytogenes was selected as a target. The absorption, distribution, metabolism, excretion, and toxicity profiling of each test ligand was done through the Swiss ADME tool. Results: Among all the test ligands, p-coumaric acid, epicatechins, chlorogenic acid, and quercetin showed better binding efficiency with the target protein Inl B. The binding energy obtained for quercetin, p-coumaric acid, chlorogenic acid, and epicatechins was-8.93,-8.23,-8.18,-7.58, kcal/mol, respectively. Quercetin and p-coumaric acid were forming 4 H-bonds, whereas chlorogenic acid and epicatechins were forming 3-H bonds inside the binding pocket. Conclusion: In a nutshell, analyses indicated that identified ligands have the potential to block the virulent protein Inl B of L. monocytogenes and help combat Listeria infection. These phenolic compounds could be a substitute for synthetic antimicrobials and can be used in food preservation and combat food-borne diseases. However, future in-depth in vitro and in vivo analysis is needed to get mor

关键词： Berry plant internalin B Listeria monocytogenes pharmacological analyses phenolics potent inhibitor traditional medicine

Ultrasound‑assisted osmotic dehydration,followed by convective drying of papaya:effect on physicochemical and functional quality parameters

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Systems Microbiology and Biomanufacturing 2023年第4期3卷 615-626页

作者： abhishek Chandra Sourabh kumar Sachin kumar Prabhat kumar Nema Department of Food Engineering National Institute of Food Technology Entrepreneurship and ManagementSonipat 131028India School of Health Sciences and Technology University of Petroleum and Energy StudiesDehradunUttarakhandIndia

Papaya is a rich source of nutrients,antioxidants,and vitamins;however,it is highly perishable and hence needs to be preserved using suitable unit *** is an economical method of papaya treatment,but results in the loss of essential nutrients and also degrades its pigments,color,and ***,this work aims to utilize ultrasound and osmotic dehydration as pretreatment strategies to preserve the rich composition of papaya during conventional hot air *** dried papaya slices were evaluated for moisture content,water activity,total phenolic content,β-carotene,color,antioxidant activity,microstructure,and *** showed that sample pretreatment with 33 kHz ultrasound frequency and dehydrated with 35°Brix osmotic solution resulted in lower moisture content(<12%w.b.)and water activity(<0.41),high phenolic content(88.5 mg GAE/mL),highβ-carotene content(184.54 mg/g)and antioxidant capacity(48.3%),and preserved color after *** texture(hardness)of the pretreated samples was also more desirable from an industrial standpoint,which was further validated using SEM micrographs that showed a more porous *** study concludes that pretreatment of papaya slices with ultrasound and osmotic dehydration is recommended before drying.

关键词： Carica papaya Microstructure Carotenoids Texture Drying Pretreatment

Human Verification over Activity Analysis via Deep Data Mining

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Computers, Materials & Continua 2023年第4期75卷 1391-1409页

作者： kumar abhishek Sheikh Badar ud din Tahir Senior Member IEEESeattle98103USA Department of Software Engineering Capital University of Science and Technology(CUST)Islamabad44000Pakistan

Human verification and activity analysis(HVAA)are primarily employed to observe,track,and monitor human motion patterns using redgreen-blue(RGB)images and *** human interaction using RGB images is one of the most complex machine learning tasks in recent *** models rely on various parameters,such as the detection rate,position,and direction of human body components in RGB *** paper presents robust human activity analysis for event recognition via the extraction of contextual intelligence-based *** use human interaction image sequences as input data,we first perform a few denoising ***,human-to-human analyses are employed to deliver more precise *** phase follows feature engineering techniques,including diverse feature ***,we used the graph mining method for feature optimization and AdaBoost for *** tested our proposed HVAA model on two benchmark *** testing of the proposed HVAA system exhibited a mean accuracy of 92.15%for the Sport Videos in theWild(SVW)*** second benchmark dataset,UT-interaction,had a mean accuracy of 92.83%.Therefore,these results demonstrated a better recognition rate and outperformed other novel techniques in body part tracking and event *** proposed HVAA system can be utilized in numerous real-world applications including,healthcare,surveillance,task monitoring,atomic actions,gesture and posture analysis.

关键词： AdaBoost classification deep features mining graph mining human detection human verification

Clinical Evidence on the Effects of Saffron(Crocus Sativus L.)in Anxiety and Depression

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World Journal of Traditional Chinese Medicine 2022年第2期8卷 181-187页

作者： Vanktesh kumar Navjot Kaur Pankaj wadhwa Department of Pharmaceutical Chemistry School of Pharmaceutical ScienceLovely Professional UniversityPhagwaraPunjabIndia

Crocus sativus L.,a member of the Iridaceae family,commonly known as saffron has very much popular as both medicine and *** saffron was used as one of the important constituents in opioid preparations for pain *** uses in the treatment of mild-to-moderate depression are well *** can affect the quality of life of individuals by causing headaches,difficulty in thinking,and loss of *** clinical trials have been conducted for evaluating the efficacy of saffron in depression *** fifty constituents of *** L are well *** of the major constituents include crocin,picrocrocin,and *** the present review,the main focus is on the antidepressant effects of saffron and its major constituents,in which it was found that saffron has substantial effects on depression and anxiety because of double-blind study the data can be trusted.

关键词： Anxiety Crocus sativus L depression double blind saffron safranin