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Effects of mechanical vibration on the physical,metallurgical and mechanical properties of cast A308(LM21)aluminum alloy

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International Journal of Minerals,Metallurgy and Materials 2022年第6期29卷 1206-1215页

作者： Siddharth Yadav S.p.tewari J.K.Singh S.c.Ram Department of Mechanical Engineering Indian Institute of Technology(BHU)Varanasi 221005India Department of Metallurgical Engineering Indian Institute of Technology(BHU)Varanasi 221005India

This study investigated the microstructure,physical,and mechanical properties of die-cast A308 alloy subjected to mechanical vibration during *** frequencies(0,20,30,40,and 50 Hz)at constant amplitude(31μm)were employed using a power amplifier as the power input device.X-ray diffraction,optical microscopy,and scanning electron microscopy were used to examine the morphological changes in the cast samples under stationary and vibratory *** features of the castings were evaluated using Image J *** average values of metallurgical features,including primaryα-Al grain size,dendrite arm spacing,average area of eutectic silicon,aspect ratio,and percentage porosity,reduced by 34%,59%,56%,22%,and 62%,respectively,at 30 Hz frequency compared with stationary *** tests of the cast samples showed that the yield strength(YS),ultimate tensile strength(UTS),percentage elongation(%EL),and microhardness(HV)increased by 8%,13%,17%,and 16%,respectively,at 30 Hz frequency compared with stationary *** fractured surface of the tensile specimens exhibited mixed-mode fracture behavior because of brittle facets,cleavage facets,ductile tearing,and dimple *** presence of small dimples showed that plastic deformation occurred before fracture.

关键词： mechanical vibration microstructures microhardness tensile strength fractography

Significance of pathological positive superior mesenteric/portal venous invasion in pancreatic cancer

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Hepatobiliary & pancreatic Diseases International 2016年第6期15卷 572-578页

作者： Mallika tewari Hepato pancreatico Biliary and Gastrointestinal Division Department of Surgical OncologyInstitute of Medical SciencesBanaras Hindu University

BAcKGROUND： pancreaticoduodenectomy with superior mesenteric/portal venous resection for pancreatic ductal ad- enocarcinoma （pDAc） is frequently performed with no added morbidity or mortality in case of tumor abutment to the superior mesenteric or portal vein so as to obtain a margin negative resection. True histopathological portal vein invasion is found only in a small subset of such patients. The aim of this review aimed to discuss the significance of histopathological venous invasion in *** SOURcES： For this review available data was searched from pubMed and analyzed. No randomized trials have been published on this topic. RESULTS： Existing data on prognostic factors in histopathological venous invasion by pDAc are limited and recent studies indicate worse survival in this subgroup of patients. In addition, venous invasion in pDAc has been associated with large tumors, involved lymph nodes, perineural invasion and R1 resection. The survival of patients with portal venous re- section but without histologic venous invasion is reportedly better than those with histopathological venous invasion; though conflicting studies do exist on the subject. Some studies also relate the depth of venous invasion to prognosis after surgical resection of pDAc. cONcLUSIONS： Frank/＇histopathological＇ invasion of superior mesenteric/portal venous and R1 resection indicate a very poor survival. Such patients may be given the opportunity of benefit of neoadjuvant treatment.

关键词： pancreatic ductal adenocarcinoma superior mesenteric/portal venous invasion histologic venous invasion prognosis survival

Status and prospects for symmetric organic redox flow batteries

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Journal of Energy chemistry 2025年第1期100卷 125-143页

作者： Md Al Raihan c.Adam Dyker Department of chemistry University of New Brunswick

As environmental concerns from fossil fuel consumption intensify, large-scale energy storage becomes imperative for the integration of renewable sources like wind, hydro, and solar with the electrical *** flow batteries, particularly those employing organic molecules, are positioned as a key technology for this purpose. This review explores the growing field of symmetric organic redox flow batteries(ORFBs) within this context. Unlike traditional asymmetric designs based on unique active materials for each electrode, symmetric ORFBs involve a single bipolar species for both electrodes. This review highlights the benefits of a symmetric design, and categorizes five distinct classes of organic bipolar molecules used in both aqueous and non-aqueous solvents. By providing a comprehensive overview of their cell cycling and performance characteristics, the strengths and weaknesses of the diverse categories of bipolar molecules are highlighted for both solvent systems, as are opportunities for future development. This should guide new research directions and advance the development of practical symmetric ORFBs.

关键词： Redox flow battery Symmetric battery Organic battery Aqueous electrolyte Non-aqueous electrolyte

carbon sequestration in chir-pine(pinus roxburghii Sarg.) forests under various disturbance levels in Kumaun central Himalaya

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Journal of Forestry Research 2014年第2期25卷 401-405页

作者： Harshit pant Ashish tewari Department of Forestry & Environmental Sciences D.S.B. CampusKumaun University

We studied variations in tree biomass and carbon sequestration rates of chir pine （pinus roxburghii. Sarg.） forest in three categories of forest disturbance, protected, moderately disturbed, and highly disturbed. In the first year, total biomass was ***-1 in highly disturbed site, 94.46 ***-1 in moderately disturbed forest, and 112.0 ***-1 in protected forest. The soil organic carbon in the top 20 cm of soil ranged from 0.63 to 1.2%. The total rate of carbon sequestration was 0.60 （t/ha）.a-lon the highly disturbed site, 1.03 （t/ha）a-1 on the moderately disturbed site, and 4.3 （t/ha）.a-1 on the protectedsite. Keywords： carbon sequestration, soil organic carbon （SOc）, disturbed forest, vegetation analysis, allometric equations

关键词： carbon sequestration soil organic carbon (SOc) disturbed forest vegetation analysis allometric equations

Image processing algorithms for in-field cotton boll detection in natural lighting conditions

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Artificial Intelligence in Agriculture 2021年第1期5卷 142-156页

作者： Naseeb Singh V.K.tewari p.K.Biswas c.M.pareek L.K.Dhruwa Department of Agricultural and Food Engineering IIT KharagpurKharagpur 721302India Department of Electronics and Electrical communication Engineering IIT KharagpurKharagpur 721302India

In developing countries,the cotton harvesting operation is currently being performed *** to the monotonous nature of this task and the involvement of a considerable amount of labor,this operation becomes very tedious and *** harvesting robots can be a good alternative for the selective picking of cotton bolls from the *** this study,an attempt has been made to develop the image processing algorithms for in-field cotton boll detection in natural lighting conditions for the cotton harvesting *** image processing algorithms namely color difference,band ratio,Ycbcr method,and chromatic aberration were proposed for the real-time segmentation of cotton bolls under natural outdoor light *** performance of developed image processing algorithms was evaluated and the experimental results revealed that the chromatic aberration method outperforms as compared to other developed *** chromatic aberration method showed the highest identification rate of 91.05%with false positive and false negative rates of 6.99%and 4.88%respectively,among all the proposed *** highest sensitivity and specificitywere found to be 81.31%and 97.53%,respectively,using the chromatic aberration ***,the chromatic aberration approach demonstrated a very promising performance for in-field cotton bolls detection under natural lighting conditions which confirms its applicability for the robotic cotton harvesters.

关键词： cotton recognition Image segmentation color models color thresholding

Lightweight convolutional neural network models for semanticsegmentation of in-field cotton bolls

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Artificial Intelligence in Agriculture 2023年第2期8卷 1-19页

作者： Naseeb Singh V.K.tewari p.K.Biswas L.K.Dhruw Department of Agricultural and Food Engineering IIT KharagpurKharagpur 721302India Department of Electronics and Electrical communication Engineering IIT KharagpurKharagpur 721302India

Robotic harvesting of cotton bolls will incorporate the benefits of manual picking as well as mechanical harvesting. For robotic harvesting, in-field cotton segmentation with minimal errors is desirable which is a challengingtask. In the present study, three lightweight fully convolutional neural network models were developed for thesemantic segmentation of in-field cotton bolls. Model 1 does not include any residual or skip connections,while model 2 consists of residual connections to tackle the vanishing gradient problem and skip connectionsfor feature concatenation. Model 3 along with residual and skip connections, consists of filters of multiplesizes. The effects of filter size and the dropout rate were studied. All proposed models segment the cotton bollssuccessfully with the cotton-IoU (intersection-over-union) value of above 88.0%. The highest cotton-IoU of91.03% was achieved by model 2. The proposed models achieved F1-score and pixel accuracy values greaterthan 95.0% and 98.0%, respectively. The developed models were compared with existing state-of-the-art networks namely VGG19, ResNet18, EfficientNet-B1, and InceptionV3. Despite having a limited number of trainableparameters, the proposed models achieved mean-IoU (mean intersection-over-union) of 93.84%, 94.15%, and94.65% against the mean-IoU values of 95.39%, 96.54%, 96.40%, and 96.37% obtained using state-of-the-art networks. The segmentation time for the developed models was reduced up to 52.0% compared to state-of-theart networks. The developed lightweight models segmented the in-field cotton bolls comparatively faster andwith greater accuracy. Hence, developed models can be deployed to cotton harvesting robots for real-time recognition of in-field cotton bolls for harvesting.

关键词： cotton Semantic segmentation convolutional neural network Robotic harvesting Image segmentation Deep learning

Optimizing the seed-cell filling performance of an inclined plate seed metering device using integrated ANN-pSO approach

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Artificial Intelligence in Agriculture 2021年第1期5卷 1-12页

作者： c.M.pareek V.K.tewari Rajendra Machavaram Brajesh Nare Agricultural and Food Engineering Department Indian Institute of Technology KharagpurWest Bengal 721302India Indian council of Agricultural Research-central potato Research Station JalandharPunjab 144026India

Uniformseed distribution within the row is the prime objective of precision planters for better crop growth and *** plate planters are generally used for sowing bold seeds likemaize,groundnut,chickpea,and their operating parameters like the forward speed of operation,the seedmetering plate inclination,and the seed level in the hopper affect the cell fill and subsequently the uniformseed ***,to achieve precise seed distribution,these parameters need to be *** the present study,out of the different optimization techniques,a new intelligent optimization technique based on the integrated ANN-pSO approach has been used to achieve the set goal.A 3–5-1 artificial neural network(ANN)model was developed for predicting the cell fill of inclined plate seedmetering device,and the particle swarmoptimization(pSO)algorithmwas applied to obtain the optimum values of the operating parameters corresponding to 100%cell *** most appropriate optimal values of the forward speed of operation,the seed metering plate inclination,and the seed level in the hopper for achieving 100%cell fill were found to be 3 km/h,50-degree,and 75%of total height,*** proposed integrated ANN-pSO approach was capable of predicting the optimal values of operating parameters with amaximumdeviation of 2%compared to the experimental results,thus confirmed the reliability of the proposed optimization technique.

关键词： precision planter Inclined plate seed metering device cell fill percentage ANN pSO

Acquired sensorineural hearing loss,oxidative stress,and microRNAs

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Neural Regeneration Research 2025年第9期20卷 2513-2519页

作者： Desmond A.Nunez Ru c.Guo Division of Otolaryngology–Head&Neck Surgery Department of SurgeryFaculty of MedicineThe University of British ColumbiaVancouverBCCanada Division of Otolaryngology–Head&Neck Surgery Gordon&Leslie Diamond Health Care CentreVancouver General HospitalVancouverBCCanada Faculty of Medicine–The University of British columbia VancouverBCCanada

Hearing loss is the third leading cause of human ***-related hearing loss,one type of acquired sensorineural hearing loss,is largely responsible for this escalating global health ***-induced,ototoxic,and idiopathic sudden sensorineural are other less common types of acquired hearing *** etiology of these conditions is complex and multi-fa ctorial involving an interplay of genetic and environmental *** stress has recently been proposed as a likely linking cause in most types of acquired sensorineural hearing *** non-coding RNA sequences known as microRNAs(miRNAs)have increasingly been shown to play a role in cellular hypoxia and oxidative stress responses including promoting an apoptotic *** hair cell death is a central histopathological finding in sensorineural hearing *** these cells do not regenerate in humans,it underlies the irreversibility of human age-related hearing *** EMBASE,Ovid MEDLINE,Web of Science core collection,and *** databases over the period August 1,2018 to July 31,2023 were searched with"hearing loss,""hypoxamiRs,""hypoxia,""microRNAs,""ischemia,"and"oxidative stress"text words for English language primary study publications or registered clinical *** red clinical trials known to the senior author we re also assessed.A total of 222studies were thus *** excluding duplicates,editorials,retra ctions,secondary research studies,and non-English language articles,39 primary studies and clinical trials underwent full-text *** resulted in 11 animal,in vitro,and/or human subject journal articles and 8 registered clinical trial database entries which form the basis of this narrative *** miR-34a and miR-29b levels increase with age in *** miRNAs were demonstrated in human neuroblastoma and murine cochlear cell lines to target Sirtuin 1/peroxisome proliferato r-activated receptor gamma coactivator-1-alpha(SIRT1/p Gc-1α),SIRT

关键词： hearing loss hypoxia microRNAs oxidative stress sensorineural

Role of beneficial microbial gene pool in mitigating salt/nutrient stress of plants in saline soils through underground phytostimulating signalling molecules

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pedosphere 2023年第1期33卷 153-171页

作者： Shalini TIWARI Barkha SHARMA Neha BISHT Lakshmi tewari Department of Microbiology College of Basic Science&HumanitiesG.B.Pant University of Agriculture&TechnologyPantnagarUttarakhand 263145India

Soil salinity diminishes soil health and reduces crop yield,which is becoming a major global *** stress is one of the primary stresses,leading to several other secondary stresses that restrict plant growth and soil *** major secondary stresses induced in plants under saline-alkaline conditions include osmotic stress,nutrient limitation,and ionic stress,all of which negatively impact overall plant *** stressed conditions,certain beneficial soil microflora are known to have evolved phytostimulating mechanisms,such as the synthesis of osmoprotectants,siderophores,1-aminocyclopropane-1-carboxylic acid(Acc)deaminase activity,phosphate solubilization,and hormone production,which enhance plant growth and development while mitigating nutrient *** soil-borne bacterial species such as Bacillus,pseudomonas,and Klebsiella and fungal strains such as Trichoderma,Aspergillus,penicillium,Alternaria,and Fusarium also aid in reducing salinity ***-solubilizing microorganisms also assist in nutrient acquisition via both enzymatic and non-enzymatic *** the case of enzymatic processes,they produce different enzymes such as alkaline phosphatases and phytases,whereas non-enzymatic processes produce organic acids such as gluconic,citric,malic,and oxalic *** native halotolerant/halophilic soil microbial gene pool with multifunctional traits and stress-induced gene expression can be developed as suitable bio-inoculants to enhance stress tolerance and optimize plant growth in saline soils.

关键词： abiotic stress crop improvement gene expression halotolerant microbial diversity phosphate solubilization plant growth promoting traits soil health