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Active learning in materials science with emphasis on adaptive sampling using uncertainties for targeted design

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npj Computational Materials 2019年第1期5卷 966-982页

作者： Turab Lookman Prasanna V.Balachandran Dezhen Xue Ruihao Yuan Theoretical Division Los Alamos National LaboratoryLos AlamosNM 87545USA Department of Materials Science and Engineering University of VirginiaCharlottesvilleVA 22902USA State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong University710049 Xi’anChina

One of the main challenges in materials discovery is efficiently exploring the vast search space for targeted properties as approaches that rely on trial-and-error are impractical.We review how methods from the information sciences enable us to accelerate the search and discovery of new materials.In particular,active learning allows us to effectively navigate the search space iteratively to identify promising candidates for guiding experiments and computations.The approach relies on the use of uncertainties and making predictions from a surrogate model together with a utility function that prioritizes the decision making process on unexplored data.We discuss several utility functions and demonstrate their use in materials science applications,impacting both experimental and computational research.We summarize by indicating generalizations to multiple properties and multifidelity data,and identify challenges,future directions and opportunities in the emerging field of materials informatics.

关键词： materials. Active directions

Influence of volume percentage of NanoTiB2 particles on tribological&mechanical behaviour of 6061-T6 Al alloy nano-surface composite layer prepared via friction stir process

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Defence Technology（防务技术） 2017年第1期13卷 16-21页

作者： v.Kishan Aruri Devaraju K.prasanna Lakshmi Department of Mechanical Engineering MRCETHyderabadT.S.India Department of Mechanical Engineering SR Engineering CollegeWarangalT.S.India Department of Mechanical Engineering College of EngineeringJNTU ManthiniT.S.India

The aim of present study is to analyze the influence of volume percentage(vol.%) of nano-sized particles(TiB_2: average size is 35 nm) on microstructure, mechanical and tribological behavior of 6061-T6 Al alloy surface nano composite prepared via Friction stir process(FSP). The microstructure of the fabricated surface nanocomposites is examined using optical microscopy(OM) and scanning electron microscope(SEM) for distribution of TiB_2 nano reinforcement particles, thickness of nano composite layer formed on the Aluminum alloy substrate and fracture features. The depth of surface nano composite layer is measured as 3683.82 m m along the cross section of stir zone of nano composite perpendicular to FSP. It was observed that increase in volume percentage of TiB_2 particles, the microhardness is increased up to132 Hv and it is greater than as-received Al alloy's microhardness(104 Hv). It is also observed that at 4volume percentage higher tensile properties exhibited as compared with the 2 and 8 vol. %. It is found that high wear resistance exhibited at 4 volume percentage as-compared with the 2 and 8 vol. %. The observed wear and mechanical properties are interrelated with microstructure, fractography and worn morphology.

关键词： Friction stir process Al alloy Surface nano composites Tensile Tribology

Automatic feeding mechanism of a vegetable transplanter

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International Journal of Agricultural and Biological Engineering 2012年第2期5卷 20-27页

作者： prasanna Kumar G.v H.Raheman Department of Agricultural Engineering Triguna Sen School of TechnologyAssam UniversitySilchar 788011AssamIndia Department of Agricultural and Food Engineering Indian Institute of TechnologyKharagpur 721302West BengalIndia

An automatic feeding mechanism consisting of a timing shaft,an actuating device and a clutch for feeding paper pot seedlings from a horizontal slat type chain conveyor to a horizontal pusher type chain conveyor of a vegetable transplanter,was developed.The slat type chain conveyor carried the pot seedlings in upright orientation in the form of a rectangular array with each linear array of pot seedlings on a slat.The pusher type chain conveyor received a linear array of pot seedlings and delivered them to the seedling drop tube.Feeding of each linear array of pot seedlings to the pusher type conveyor at appropriate times was done using an automatic feeding mechanism.The laboratory evaluation indicated that the feeding rate of 33 to 50 pot seedlings per minute can be achieved with single set of conveyors.The feeding mechanism also worked effectively under actual field conditions with 98%to 99%of all the pot seedlings,which were properly separated and fed for planting when the forward speed of the vegetable transplanter was 0.9 km/h.The feeding mechanism has the general application of singulating rectangular array of items on the slat type chain conveyor in any industry and machine in motion on a level surface.

关键词： automatic feeding mechanism chain conveyor feed index singulation vegetable transplanter

Evaluation of hydrogeochemical characteristics and the impact of weathering in seepage water collected within the sedimentary formation

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Acta Geochimica 2017年第1期36卷 44-51页

作者： M.v.prasanna R.Nagarajan S.Chidambaram A.Anand Kumar C.Thivya Department of Applied Geology Faculty of Engineering and ScienceCurtin University Sarawak Department of Earth Sciences Annamalai University Department of Geology University of Madras

A study was conducted by collecting eight seepage water samples that drain through the sedimentary rocks,mainly sandstone and shale,to evaluate the hydrogeochemical characteristics.The collected samples were analyzed for physico-chemical parameters using standard procedures.Three water types were identified in the Piper plot and the hydrogeochemical evolution starts from a CaCl facies(type 1) via mixed Ca-Mg-Cl and Ca-Na-HCO_3 facies(type 2) to Na-Cl facies(type 3).Increasing trend of electrical conductivity(EC) values were observed from type 1 water to type 3 water.Lower ionic concentrations with an average EC value of 35.7(is/cm in Ca-Cl facies indicate the recharge water by monsoonal rainfall,and ion exchange/weathering process is reflected in the mixing zone.Higher ionic concentration with an average EC value of 399(is/cm is noted in Na-Cl facies,which indicates the ion exchange during water-rock interaction.Higher log PCO_2 values are also found in this facies,revealing the longer residence time of seepage water in the rock matrix,which release more ions into the water.The relative mobility of elements during weathering suggest that the order of mobility in both sandstone and shale is Na > Ca > Mg > K.It was observed that the hydrogeochemistry of seepage water is mainly controlled by the bedrock geology.

关键词： Hydrogeochemistry 渗出物水水岩石相互作用捱过元素的活动性

Prediction of Link Failure in MANET-IoT Using Fuzzy Linear Regression

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Intelligent Automation & Soft Computing 2023年第5期36卷 1627-1637页

作者： R.Mahalakshmi v.prasanna Srinivasan S.Aghalya D.Muthukumaran Department of Electrical and Electronics Engineering Dhanalakshmi Srinivasan College of Engineering and TechnologyMamallapuramTamil NaduIndia Department of Information Technology R.M.D.Engineering CollegeKavaraipettaiChennaiTamil NaduIndia Department of Electronics and Communication Engineering St.Joseph’s College of EngineeringChennaiTamil NaduIndia Department of Electronics and Communication Engineering Sri Chandrasekharendra Saraswathi Viswa Mahavidyalaya UniversityKancheepuramTamil NaduIndia

A Mobile Ad-hoc NETwork(MANET)contains numerous mobile nodes,and it forms a structure-less network associated with wireless links.But,the node movement is the key feature of MANETs;hence,the quick action of the nodes guides a link failure.This link failure creates more data packet drops that can cause a long time delay.As a result,measuring accurate link failure time is the key factor in the MANET.This paper presents a Fuzzy Linear Regression Method to measure Link Failure(FLRLF)and provide an optimal route in the MANET-Internet of Things(IoT).This work aims to predict link failure and improve routing efﬁciency in MANET.The Fuzzy Linear Regression Method(FLRM)measures the long lifespan link based on the link failure.The mobile node group is built by the Received Signal Strength(RSS).The Hill Climbing(HC)method selects the Group Leader(GL)based on node mobility,node degree and node energy.Additionally,it uses a Data Gathering node forward the infor-mation from GL to the sink node through multiple GL.The GL is identiﬁed by linking lifespan and energy using the Particle Swarm Optimization(PSO)algo-rithm.The simulation results demonstrate that the FLRLF approach increases the GL lifespan and minimizes the link failure time in the MANET.

关键词： Mobile ad-hoc network fuzzy linear regression method link failure detection particle swarm optimization hill climbing

A hydrochemical approach to estimate mountain front recharge in an aquifer system in Tamilnadu, India

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Acta Geochimica 2018年第3期37卷 465-488页

作者： Banaja Rani Panda S.Chidambaram N.Ganesh v.S.Adithya M.v.prasanna K.Pradeep U.vasudevan Department of Earth Sciences Annamalai University Department of Applied Geology Faculty of Engineering and Science Curtin University Malaysia

Mountain-front recharge(MFR) is a process of recharging an aquifer by infiltration of surface flow from streams and adjacent basins in a mountain block and along a mountain front(MF). This is the first attempt in India to estimate MFR along the foothills of Courtallam using hydrogeochemistry and geostatistical tools. The estimation of MFR has been carried out by collecting groundwater samples along the foothills of Courtallam. Collected water samples were analyzed for major cations and anions using standard procedures. Hydrogeochemical facies show the existence of four water types in this region. Calcium-rich water derived from gneissic rock terrain indicates significant recharge from higher elevation. Log p CO_2 and ionic strength of the samples were also calculated to identify the geochemical process. Majority of the collected samples have sodium-rich water and weak ionic strength, which indicate foothill recharge and low residence time. Silicate and carbonate weathering have an equal interplay along the foothills with a relatively large fraction of Mg from the MF. The spatial diagrams of three factors show that the southern part of the study area is dominated by both weathering and anthropogenic processes, whereas the northern part is dominated by both leaching and weathering processes. Thus, the dominant weathering process represented by the second factor indicates the large recharge process along the foothills.

关键词： Mountain-front recharge Geostatistical toolsHydrogeochemical facies Ionic ratio Anthropogenicprocesses

Cryptic species composition and genetic diversity within Bemisia tabaci complex in soybean in India revealed by mtCOI DNA sequence

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Journal of Integrative Agriculture 2015年第9期14卷 1786-1795页

作者： prasanna H C Kanakala S Archana K Jyothsna P varma R K Malathi v G Division of vegetable Improvement Indian Institute of Vegetable Research Advanced Centre for Plant virology Division of Plant PathologyIndian Agricultural Research Institute Department of Plant Pathology Jawaharlal Nehru Krishi Vishwavidyalaya

Bemisia tabaci is a cryptic species complex, causing signiifcant loss on many agricultural y important crops worldwide. Knowledge on species composition and diversity within B. tabaci complex is critical for evolving sustainable pest management strategies. Here we investigate the whitelfy species complex in soybean in major soybean growing states of India. The mitochondrial cytochrome oxidase gene subunit-1 (mtCOI) based phylogenetic relationships established using Bayesian methods indicated the existence of three cryptic species namely Asia I, Asia II 1, and Asia II 7. Al the haplotypes detected in the study could be assigned to these three cryptic species fol owing the species demarcation criteria of 3.5%divergence threshold. Of these, Asia II 1 was found to be predominant with wide spread distribution across the surveyed regions from cool temperate zones to hot and humid tropical plains. On the contrary, cryptic species Asia II 7 showed localized distribu-tion. The Asia II 1 exhibited the highest haplotype diversity and Asia I showed high level of nucleotide diversity. There was a signiifcantly high genetic differentiation among these three cryptic species. The MEAM 1, a dreadful invasive species was not detected in the specimens tested in the current study. The diversity and distribution of three cryptic species is discussed in the light of current knowledge on distribution of whitelfy species in India and yel ow mosaic disease observed during sampling survey.

关键词： whitefly,mitochondrial cytochrome oxidase gene subunit-1,AsiaⅠ,AsiaⅡ 1,AsiaⅡ 7,begomovirus and yellow mosaic disease

Cytotoxic (A549) and antimicrobial effects of Methylobacterium sp.isolate (ERI-135) from Nilgiris forest soil,India

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Asian Pacific Journal of Tropical Biomedicine 2012年第9期2卷 712-716页

作者： balachandran C Duraipandiyan v Ignacimuthu S Division of Microbiology Entomology Research InstituteLoyola College Department of Botany and Microbiology Addiriyah Chair for Environmental StudiesCollege of ScienceKing Saud University

Objective:To assess the antimicrobial and cytotoxic effects of Methylobacterium sp.isolated from soil sample of Doddabetta forest,Nilgiris,Western Ghats of Tamil Nadu.Methods:Isolation of Methylobacterium was performed from soils by serial dilution plate technique.The strain was grown in modified nutrient gulucose agar(MNGA)medium to study the morphology and biochemical characteristics.Methylobacterium sp.was screened for its antimicrobial activity against pathogenic bacteria and fungi.The strain was subjected to 16S rRNA analysis and was identified as Methylohacterium sp.The nucleotide sequence of the 16S rRNA gene of the isolate exhibited close similarity with other Methylobacterium sp.and has been submitted to Genbank.The antibacterial substances were extracted using chloroform and ethyl acetate from MNGA medium in which ERI-135 had grown for 5 d at 30℃.Cytotoxic effect was also studied.GC-MS analysis was carried out.The antimicrobial activity was assessed using broth micro dilution technique.Results:Ethyl acetate extract showed activity against bacteria such as Bacillus subtilis,Klebsiella pneumoniae(K.pneumoniae),Pseudomonas aeruginosa,Salmonella typkimurium,Shigella flexneri,Enterobacter aerogenes,Staphylococcus aureu and Staphylococcus epidermidis(S.epidermidis)and fungi such as,Candida albicans and Trichophyton rubrum.The lowest minimum inhibitory concentrations were:250μg/mL against 5.epidermidis and 250μg/mL against K.pneumonia.The isolate had the ability to produce enzymes such as protease.The exyract showed cytotoxic effect in human adenocarcinoma cancer cell line(A549).GC-MS analysis showed the presence of isovaleric acid(3.64%),2-Methylbulanoic acid(5.03%),isobutyramide(5.05%),N,Noimethylformamide-di-t-butylacetal(9.79%),benzeneacetamide(15.56%),octyl butyl phthalate(3.59%)and diisooctyl phthalate(5.79)in the extract.Conclusions:Methylobaeterium sp.(ERI-135)showed promising antibacterial and cytotoxic activity.This is the first report in the antimicrobial and cytotoxic effect of Methylobaeterium sp.

关键词： Methylobacterium sp l6S rRNA Antimicrobial Cytotoxicity GC-MS Soil sample Western Ghats

Determination of the major geochemical processes of groundwater along the Cretaceous-Tertiary boundary of Trichinopoly,Tamilnadu,India

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Acta Geochimica 2020年第5期39卷 760-781页

作者： N.Devaraj S.Chidambaram U.vasudevan K.Pradeep M.Nepolian M.v.prasanna v.S.Adithya R.Thilagavathi C.Thivya Banajarani Panda Department of Earth Sciences Annamalai UniversityChidambaramTamilnadu 608002India Water Research Centre Kuwait Institute for Scientific ResearchKuwait CityKuwait Department of Applied Geology Faculty of Engineering and ScienceCurtin University Malaysia.CDT 25098009 MiriSarawakMalaysia

The hydrogeochemical variations in groundwater are mainly influenced by lithology,residence time of water in the aquifer matrix,and anthropogenic activities.This study was focused on the geochemical variations of groundwater in different lithological units(Archaean,Cretaceous,Tertiary,and Quaternary)by understanding the major factors governing the geochemical variations in each lithology.The 71 groundwater samples were collected from these rock types,namely,Archaean(14),Cretaceous(37),Tertiary(11),Quaternary(9).The collected samples were measured for major ions and they were used for preparation of standard geochemical plots and ionic ratios.Factor analysis and factor score were used to identify the major factors controlling the hydrochemistry and their spatial distribution in the study area.In addition,geochemical model,WATEQ 4 F was used to determine the saturation condition of carbonate and sulphate minerals in the groundwater.Na–Cl and mixed Ca–Na–HCO3 were the dominant hydrochemical facies irrespective of lithological units.The overall interpretation of geochemical data revealed that leaching of secondary salts,weathering and ion exchange reaction along the groundwater flow path through various lithological units,and anthropogenic influence from domestic sewages and agricultural activities constitute the major geochemical processes in the study area.Hence,this study brings out the multiple hydrogeochemical process in the complex geological terrain along the Cretaceous-Tertiary boundary.

关键词： Groundwater Geochemical process Major ions Correlation Factor analysis