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Journal of Rock Mechanics and Geotechnical Engineering 2021年第5期13卷 1101-1112页

作者： Nitin Tiwari neelima satyam Department of Civil Engineering Indian Institute of Technology IndoreIndoreIndia

This study explores the coupling effect of pond ash(PA)and polypropylene(PP)fiber to control the strength and durability of expansive *** PA is used to chemically treat the expansive soil and PP fiber is adopted as reinforcement against tensile *** sustainable use of PA and PP fiber are demonstrated by performing mechanical(*** compressive strength,split tensile strength and ultrasonic pulse velocity),chemical(pH value,electrical conductivity and calcite content),and microstructural analyses before and after 2nd,4th,6th,8th and 10th freezing-thawing(F-T)*** curing methods with 7 d,14 d and 28 d curing periods are considered to reinforce the 5%,10%,15%and 20%PA-stabilized expansive soil with 0.25%,0.5%and 1%PP *** order to develop predictive models for mechanical and durability parameters,the experimental data are processed utilizing artificial neural network(ANN),in association with the leave-one-out cross-validation(LOOCV)as a resampling method and three different activation *** mechanical and durability properties of the PA-stabilized expansive soil subgrades are increased with PP fiber *** results of ANN modeling predict the mechanical properties perfectly,and the correlation coefficient(R)approaches up to 0.96.

关键词： Expansive soil subgrades Waste utilization Freezing-thawing(F-T) Microstructural assessment Pond ash(PA) Polypropylene(PP)fiber

Probabilistic rainfall thresholds in Chibo, India: estimation and validation using monitoring system

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Journal of Mountain Science 2019年第4期16卷 870-883页

作者： Abhirup DIKSHIT neelima satyam Discipline of Civil Engineering Indian Institute of Technology Indore Simrol

The Himalayan region has been severely affected by landslides especially during the monsoons. In particular, Kalimpong region in Darjeeling Himalayas has recorded several landslides and has caused significant loss of life, property and agricultural land. The study region, Chibo has experienced several landslides in the past which were mainly debris and earth slide. Globally, several types of rainfall thresholds have been used to determine rainfall-induced landslide incidents. In this paper, probabilistic thresholds have been defined as it would provide a better understanding compared to deterministic thresholds which provide binary results, i.e., either landslide or no landslide for a particular rainfall event. Not much research has been carried out towards validation of rainfall thresholds using an effective and robust monitoring system. The thresholds are then validated using a reliable system utilizing Microelectromechanical Systems(MEMS) tilt sensor and volumetric water content sensor installed in the region. The system measures the tilt of the instrument which is installed at shallow depths and is ideal for an early warning system for shallow landslides. The change in observed tilt angles due to rainfall would give an understanding of the applicability of the probabilistic model. The probabilities determined using Bayes' theorem have been calculated using the rainfall parameters and landslide data in 2010-2016. The rainfall values were collected from an automatic rain gauge setup near the Chibo region. The probabilities were validated using the MEMS based monitoring system setup in Chibo for the monsoon season of 2017. This is the first attempt to determine probabilities and validate it with a robust and effective monitoring system in Darjeeling Himalayas. This study would help in developing an early warning system for regions where the installation of monitoring systems may not be feasible.

关键词： Early warning Probabilistic thresholds Kalimpong Monitoring

Optimization of growth medium for microbially induced calcium carbonate precipitation(MICP) treatment of desert sand

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Journal of Arid Land 2023年第7期15卷 797-811页

作者： Monika DAGLIYA neelima satyam Ankit GARG Department of Civil Engineering Indian Institute of TechnologyIndore 453552India Guangdong Engineering Center for Structure Safety and Health Monitoring Shantou UniversityShantou 515063China

Wind-induced sand erosion is a natural process, and can have several negative impacts on human health, environment, and economy. To mitigate the wind-induced sand erosion, an environmental friendly technique that helps to bind soil particles is desirable. The microbially induced calcium carbonate precipitation(MICP) treatment has lately become renowned and a viable alternative to enhance the binding of sand particles(especially against wind erosion). The efficiency of Sporosarcina pasteurii bacteria in inducing calcite formation can be influenced by various factors, including the type of growth media used for bacterial culture. Most of the studies have mainly validated the efficiency of S. pasteurii bacteria usually under single growth media for the MICP treatment. However, the efficiency of S. pasteurii under different growth media on calcite formation is rarely explored. The current study explores the effect of *** bacteria on calcite formation under the presence of three different growth media, namely,molasses(MS), tryptic soy broth(TB), and nutrient broth(NB). The three growth media have been applied in the laboratory with and without bacterial solution(control samples). Altered cementation media concentrations(0.5 and 1.0 M) with different pore volumes(PVs), namely, 0.25, 0.50, and 1.00 PV were used in sand-filled tubes for 7 and 14 treatment cycles(1 cycle=24 h). The pH and EC were measured for 12-h period in every 2 h interval, to monitor values at the time of treatment at room temperature. The calcite precipitation was confirmed using SEM(scanning electron microscope), PXRD(powder X-ray diffraction), and calcimeter tests. It was observed that MS generates lower calcite precipitation as compared with NB and TB. However, MS has the advantage of being more economical and abundant(waste product from sugar mills and refineries) as compared with other growth media(NB and TB). It was observed that the minimum and the maximum calcite precipitation using MS i

关键词： growth media molasses tryptic soy broth nutrient broth S.pasteurii calcium carbonate

Rock-like behavior of biocemented sand treated under non-sterile environment and various treatment conditions

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第3期13卷 705-716页

作者： Meghna Sharma neelima satyam Krishna RReddy Discipline of Civil Engineering Indian Institute of Technology IndoreIndore453552India Department of Civil Materialsand Environmental EngineeringUniversity of Illinois at ChicagoChicagoILUSA

Microbially induced calcite precipitation(MICP)is a recently developed technique for microbiological ground improvement that has been applied for mitigating various geotechnical ***,the major challenges,such as calcite precipitation uniformity,presence of different bacteria,cementation solution optimization for cost reduction,and implementation under non-sterile and uncontrolled field environment are still not fully explored and require detailed investigation before field *** study aims to address these challenges of MICP to improve the geotechnical properties of sandy *** series of experiments were conducted using poorly graded Narmada River(India)sand,which were subjected to various biotreatment schemes and tested for unconfined compressive strength(UCS),split tensile strength(STS),ultrasonic pulse velocity(UPV),hydraulic conductivity(after 6 d,12 d,and 18 d of treatment),and calcite *** microstructure of sand was examined through a scanning electron microscope(SEM).Initially,the sand was individually augmented with two non-pathogenic bacterial strains,***(S.)pasteurii and Bacillus(B.)*** stopped-flow injection method was adopted to provide cementation solutions at three different durations(treatment cycle)of 12 h,24 h,and 48 h and three different pore volumes(PVs)of 1,0.75,and *** pore volume here refers to the porosity which is expressed as a ratio,i.e.a porosity of 50%was used as *** results showed rock-like behaviors of biocemented sand with the UCS,STS,and UPV enhancement up to 2333 kPa,437 kPa,and 2670 m/s,*** hydraulic conductivity reduction of 96.6%was achieved by 12%of calcite formation after 18 d of treatment using Sporosarcina pasteurii,12-h treatment cycle,and one pore volume of cementation media in each ***,a 24-h treatment cycle and 0.5-pore volume cementation solution were found to be the optimal treatment which was effective and economical to achiev

关键词： Bacteria Microbially induced calcite precipitation (MICP) Soil stabilization Microstructure Calcite content

Experimental study on mitigating wind erosion of calcareous desert sand using spray method for microbially induced calcium carbonate precipitation

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第5期14卷 1556-1567页

作者： Monika Dagliya neelima satyam Meghna Sharma Ankit Garg Department of Civil Engineering Indian Institute of Technology IndoreIndoreIndia Department of Civil and Environmental Engineering Shantou UniversityShantouChina L.N.Gumilyov Eurasian National University Nur-SultanKazakhstan

Wind erosion is one of the significant natural calamities worldwide, which degrades around one-third of global land. The eroded and suspended soil particles in the environment may cause health hazards, *** and respiratory diseases, due to the presence of harmful contaminants, bacteria, and *** present study evaluates the feasibility of microbially induced calcium carbonate precipitation(MICP)technique to mitigate wind-induced erosion of calcareous desert sand(Thar desert of Rajasthan province in India). The temperature during biotreatment was kept at 36℃ to stimulate the average temperature of the Thar desert. The spray method was used for bioaugmentation of Sporosarcina(S.) pasteurii and further treatment using chemical solutions. The chemical solution of 0.25 pore volume was sprayed continuously up to 5 d, 10 d, 15 d, and 20 d, using two different concentration ratios of urea and calcium chloride dihydrate viz 2:1 and 1:1. The biotreated samples were subjected to erosion testing(in the wind tunnel) at different wind speeds of 10 m/s, 20 m/s, and 30 m/s. The unconfined compressive strength of the biocemented crust was measured using a pocket penetrometer. The variation in calcite precipitation and microstructure(including the presence of crystalline minerals) of untreated as well as biotreated sand samples were determined through calcimeter, scanning electron microscope(SEM), and energydispersive X-ray spectroscope(EDX). The results demonstrated that the erosion of untreated sand increases with an increase in wind speeds. When compared to untreated sand, a lower erosion was observed in all biocemented sand samples, irrespective of treatment condition and wind speed. It was observed that the sample treated with 1:1 cementation solution for up to 5 d, was found to effectively resist erosion at a wind speed of 10 m/s. Moreover, a significant erosion resistance was ascertained in15 d and 20 d treated samples at higher wind speeds. The calcite content

关键词： Control wind erosion Microbially induced calcium carbonate precipitation(MICP) Surface strength Wind tunnel Calcite precipitation

Debris flow simulation 2D(DFS 2D):Numerical modelling of debris flows and calibration of friction parameters

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第6期14卷 1747-1760页

作者： Minu Treesa Abraham neelima satyam Biswajeet Pradhan Hongling Tian Department of Civil Engineering Indian Institute of Technology IndoreIndoreIndia Centre for Advanced Modelling and Geospatial Information Systems(CAMGIS) School of Civil and Environmental EngineeringFaculty of Engineering and Information TechnologyUniversity of Technology SydneySydneyAustralia Center of Excellence for Climate Change Research King Abdulaziz UniversityJeddahSaudi Arabia Earth Observation Centre Institute of Climate ChangeUniversity Kebangsaan MalaysiaBangiMalaysia Key Laboratory of Mountain Hazards and Surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengduChina

Debris flows are rapid mass movements with a mixture of rock,soil and ***-intensity rainfall events have triggered multiple debris flows around the globe,making it an important concern from the disaster management *** study presents a numerical model called debris flow simulation 2D(DFS 2D)and applicability of the proposed model is investigated through the values of the model parameters used for the reproduction of an occurred debris flow at Yindongzi gully in China on 13 August *** model can be used to simulate debris flows using three different rheologies and has a userfriendly interface for providing the *** DFS 2D,flow parameters can be estimated with respect to space and *** values of the flow resistance parameters of model,dry-Coulomb and turbulent friction,were calibrated through the back analysis and the values obtained are 0.1 and 1000 m/s^(2),*** new methods of calibration are proposed in this study,considering the crosssectional area of flow and topographical changes induced by the debris *** proposed methods of calibration provide an effective solution to the cumulative errors induced by coarse-resolution digital elevation models(DEMs)in numerical modelling of debris *** statistical indices such as Willmott's index of agreement,mean-absolute-error,and normalized-root-mean-square-error of the calibrated model are 0.5,1.02 and 1.44,*** comparison between simulated and observed values of topographic changes indicates that DFS 2D provides satisfactory results and can be used for dynamic modelling of debris flows.

关键词： Debris flows Numerical model Rheology Debris flow simulation 2D(DFS 2D)

Ensemble machine learning models based on Reduced Error Pruning Tree for prediction of rainfall-induced landslides

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International Journal of Digital Earth 2021年第5期14卷 575-596页

作者： Binh Thai Pham Abolfazl Jaafari Trung Nguyen-Thoi Tran Van Phong Huu Duy Nguyen neelima satyam Md Masroor Sufia Rehman Haroon Sajjad Mehebub Sahana Hiep Van Le Indra Prakash Division of Computational Mathematics and Engineering Institute for Computational ScienceTon Duc Thang UniversityHo Chi Minh CityViet Nam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh CityViet Nam Research Institute of Forests and Rangelands Agricultural ResearchEducationand Extension Organization(AREEO)TehranIran Institute of Geological Sciences Vietnam Academy of Sciences and TechnologyHanoiViet Nam Faculty of Geography V.N.U.University of ScienceVietnam National UniversityHanoiViet Nam Discipline of Civil Engineering Indian Institute of Technology IndoreMadhya PradheshIndia Department of Geography Jamia Millia IslamiaNew DelhiIndia School of Environment Education and DevelopmentUniversity of ManchesterManchesterUK Institute of Research and Development Duy Tan UniversityDa NangViet Nam DDG(R)Geological Survey of India GujaratIndia

In this paper,we developed highly accurate ensemble machine learning models integrating Reduced Error Pruning Tree(REPT)as a base classifier with the Bagging(B),Decorate(D),and Random Subspace(RSS)ensemble learning techniques for spatial prediction of rainfallinduced landslides in the Uttarkashi district,located in the Himalayan range,*** do so,a total of 103 historical landslide events were linked to twelve conditioning factors for generating training and validation *** Mean Square Error(RMSE)and Area Under the receiver operating characteristic Curve(AUC)were used to evaluate the training and validation performances of the *** results showed that the single REPT model and its derived ensembles provided a satisfactory accuracy for the prediction of *** D-REPT model with RMSE=0.351 and AUC=0.907 was identified as the most accurate model,followed by RSS-REPT(RMSE=0.353 and AUC=0.898),B-REPT(RMSE=0.396 and AUC=0.876),and the single REPT model(RMSE=0.398 and AUC=0.836),*** prominent ensemble models proposed and verified in this study provide engineers and modelers with insights for development of more advanced predictive models for different landslide-susceptible areas around the world.

关键词： Machine learning ensemble modeling Bagging Decorate Random Subspace

Myrmechis bakhimensis ***,*** & ***,a new species of Orchidaceae from Sikkim Himalaya

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植物分类学报 2007年第3期45卷 321-323页

作者： Debabrata MAITY neelima PRADHAN Gaurgopal MAITI Botanical Survey of India Sikkim Himalayan CircleGangtok-737 103SikkimIndia Department of Botany University of KalyaniKalyani-741 235NadiaWest BengalIndia

Myrmechis bakhimensis D. Maity,N. Pradhan & G. G. Maiti (Orchidaceae),a new species from Sikkim Himalaya,is described and illustrated. The new species most closely resembles M. japonica (Reichb.) Rolfe and M. chinensis Rolfe with similar shape and size of lamina and the “T”-shaped epichile,but differs by the perfectly glabrous and eciliate floral bract,5-nerved dorsal sepal,and emarginate,mucronate epichile.

关键词：新种喜玛拉雅锡金兰科植物 Myrmechis bakhimensis D. Maity N. Pradhan & G. G. Maiti

A paradigm shift:emerging roles of microglia,a non-neuronal cell,in learning and memory

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Neural Regeneration Research 2021年第10期16卷 1992-1993页

作者： neelima Gupta S.Thameem Dheen Department of Anatomy Yong Loo Lin School of MedicineNational University of SingaporeSingapore

Microglial cells are non-neuronal cells which serve as the first line of defence against various injuries and insults in the central nervous system(CNS).They act as sentinels that constantly patrol the surrounding parenchyma through their ramified processes in the *** response to any pathological insult,microglia become activated,undergo proliferation,migrate to the site of injury or infection,and release chemokines and cytokines followed by the phagocytosis of dead cells and debris.

关键词： injuries debris migrate

Immunomodulatory and anticancer activity of Bombax ceiba Linn leaf extract

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Asian Pacific Journal of Tropical Biomedicine 2020年第9期10卷 426-432页

作者： neelima Sharma Sneha Kispotta Papiya Mitra Mazumder Department of Pharmaceutical Sciences&Technology Birla Institute of TechnologyMesraRanchiIndia

Objective:To evaluate the immunomodulatory and anticancer activity of the methanolic extract of Bombax ceiba leaves in vitro and in ***:The antioxidant property of methanolic extract of Bombax ceiba leaves was determined by measuring hydrogen peroxide scavenging and DPPH scavenging *** effect on cellular immunity in vivo was determined by measuring neutrophil adhesion,carbon clearance,sheep red blood cell induced DTH response and cyclophosphamide-induced *** vitro anticancer activity was evaluated on human leukaemia cell line(HL-60)by MTT assay,caspase-3 activity,and cell cycle ***:The methanolic extract of Bombax ceiba leaves showed antioxidant activity and significantly increased neutrophil adhesion,carbon clearance from blood,DTH response and cyclophosphamideinduced *** MTT assay showed a significant increase in the death of HL-60 cell line.A rise in caspase-3 activity and sub-G1 population in the presence of methanolic extract of Bombax ceiba leaves was ***:The methanolic extract of leaves of Bombax ceiba L possesses anticancer activity,immunomodulatory activity,and antioxidant properties,proving its therapeutic usefulness in the treatment of immuno-compromised diseases and cancers.

关键词： Anticancer Antioxidative Bombax ceiba Immunomodulatory