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高产纤维红麻的选种

中国麻作 1981年第1期3卷 47-49页

作者： k.chakravarty 广林

红麻(Hibiscus Cannabinus)和玫瑰红麻(Hibiscus Sabdariffa)的生长习性有明显差别。现有玫瑰红麻所有类型的特点是生长速度慢(表1),在最适期(三月中旬到五月中旬)播种需要180—237天的营养生长期,不论何时播种,十一月上旬之前都不能成... 详细信息

红麻(Hibiscus Cannabinus)和玫瑰红麻(Hibiscus Sabdariffa)的生长习性有明显差别。现有玫瑰红麻所有类型的特点是生长速度慢(表1),在最适期(三月中旬到五月中旬)播种需要180—237天的营养生长期,不论何时播种,十一月上旬之前都不能成熟(表2)。反之,红麻的品种生长很快(表1),成熟期上有明显差异(表3)。纤维产量最高的红麻品种的最大营养生长期需135天左右(本地品种)

关键词：红麻玫瑰红营养生长期选种高产播种本地品种纤维成熟差别

Swarm Optimization and Machine Learning for Android Malware Detection

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Computers, Materials & Continua 2022年第12期73卷 6327-6345页

作者： k.Santosh Jhansi P.Ravi kiran Varma Sujata chakravarty Centurion University of Technology and Management ParalakhemundiOdishaIndia Maharaj Vijayaram Gajapathi Raj College of Engineering VizianagaramIndia Centurion University of Technology and Management BhubaneswarOdishaIndia

Malware Security Intelligence constitutes the analysis of applications and their associated metadata for possible security *** Programming Interfaces(API)calls contain valuable information that can help with malware *** malware analysis with reduced feature space helps for the efficient identification of *** goal of this research is to find the most informative features of API calls to improve the android malware detection *** swarm optimization methods,viz.,Ant Lion Optimization(ALO),Cuckoo Search Optimization(CSO),and Firefly Optimization(FO)are applied to API calls using auto-encoders for identification of most influential *** nature-inspired wrapperbased algorithms are evaluated using well-known Machine Learning(ML)classifiers such as Linear Regression(LR),Decision Tree(DT),Random Forest(RF),k-Nearest Neighbor(kNN)&SupportVector Machine(SVM).A hybrid Artificial Neuronal Classifier(ANC)is proposed for improving the classification of android *** experimental results yielded an accuracy of 98.87%with just seven features out of hundred API call features,i.e.,a massive 93%of data optimization.

关键词： Android malware API calls auto-encoders ant lion optimization cuckoo search optimization firefly optimization artificial neural networks artificial neuronal classifier

Numerical analysis of rainfall effects in external overburden dump

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International Journal of Mining Science and Technology 2016年第5期26卷 825-831页

作者： Radhakanta koner Debashish chakravarty Department of Mining Engineering Indian Institute of Technology

The effect of slope angle for external overburden dump in response to average and heavy rainfall has been analyzed using a two dimensional finite difference method of transient water flow through unsaturated–saturated soil. The external dump stability is evaluated for five geomaterial types on the basis of globally accepted safety factor analysis technique, based on shear strength reduction approach using finite difference method. The results obtained from the finite difference method of analysis indicate that the external dump with more than 30° slope angle is greatly influenced by the rainfall under the studied conditions for geomaterial 3, 4 and 5, whereas dumps with geomaterial 1 and 2 remain safe. The analysis shows that major slope failure is out of preview for the studied rainfall conditions.

关键词： External overburden dumps Shear strength reduction Finite difference approach Rainfall Stability

Effect of nitrofurazone on the reproductive organs in adult male mice

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Asian Journal of Andrology 2001年第1期3卷 39-44页

作者： Shio kumar Singh Sumana chakravarty Department of Zoology Banaras Hindu University Varanasi IndiaDepartment of Zoology Banaras Hindu University Varanasi India

Aim: To study the effect of 5-nitro-2-fumldehyde semicarbazone (nitrofurazone), a derivative of nitrofuran, onmale reproductive organs of Parkes (P) swain mice. Methods: Mice were given nitrofurazone orally at a dose of 64mg/kg body weight per day, for 10 and 20 days, and were killed 24 h and/or 56 days after the last treatment. Histo-logical appearance of testis, motility and number of spermatozoa in cauda epididymidis, and biochemical indices in epi-didymis and seminal vesicle were evaluated. Results: Histologically, testis showed marked regressive changes inthe seminiferous tubules in mice treated with nitrofurazone. Ten days after treatment, there was much depletion of germcells in the seminiferous tubules, and the germinal epithelium was lined mainly with Sertoli cells, spermatogonia, sper-matocytes, and a few round spermatids; intraepithelial vacuoles and multinucleated giant cells were also observed intubules. By 20 days, regressive changes in the seminiferous tubules were further pronounced, and pachytene spermato-cytes were the most advanced germ cells noticed in the tubules. In severe cases, the tubules were lined with a thin layerof Sertoli cells and spermatogonia. The treatment also caused marked reductions in the motility and number of sperma-tozoa in the cauda epididymidis, in weight and the level of fructose in the seminal vesicle, and in sialic acid level in theepididymis. Fifty six days after drag withdrawal, the alterations induced in the reproductive organs returned to controllevels. Conclusion: Our results suggest that nitrofurazone treatment in P mice induces marked alterations in themale reproductive organs, and that the alterations are reversible following cessation of treatment.(Asian J Androl 2001 Mar; 3: 39-44)

关键词： nitrofurazone testis epididymis seminal vesicles sperm fructose sialic acids

Design of crown pillar thickness using finite element method and multivariate regression analysis

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International Journal of Mining Science and Technology 2017年第6期27卷 955-964页

作者： kumar Hemant Deb Debasis chakravarty D. Department of Mining Engineering Indian Institute of Technology (Indian School of Mines) Dhanbad 826004 India Department of Mining Engineering Indian Institute of Technology Kharagpur 721302 India

Minerals are now being extracted from deep mines due to drying up of resource in shallow ground. The need for suitable supports and ground control mechanisms for safe mining necessitates proper pillar design with filling technology. In addition, high horizontal stress may cause collapse of hanging wall and footwall rocks, hence designing of suitable crown pillars is absolutely necessary for imposing overall safety of the stopes. This paper provides a methodology for the evaluation of the required thickness of crown pillars for safe operation at depth ranging from 600 m to 1000 m. Analyses are conducted with the results of 108 non-linear numerical models considering Drucker-Prager material model in plane strain condition. Material properties of ore body rock and thickness of crown pillars are varied and safety factors of pillars estimated. Then, a generalized statistical relationship between the safety factors of crown pillars with the various input parameters is developed. The developed multivariate regression model is utilized for generating design/stability charts of pillars for different geo-mining *** design charts can be used for the design of crown pillar thickness with the depth of the working,taking into account the changes of the rock mass conditions in underground metal mine.

关键词： Cut and fill mining Crown pillar FEM Regression model Design chart

Histologic changes in the mouse testis after bilateral vasectomy

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Asian Journal of Andrology 2000年第2期2卷 115-120页

作者： Shio kumar Singh Suman chakravarty Department of Zoology Banaras Hindu University Varanasi 221 005 IndiaDepartment of Zoology Banaras Hindu University Varanasi 221 005 India

Aim: To study the effect of vaseetomy on histological appearance of the testis. Methods: Parkes strain mice wereused as the animal model; they were bilaterally vasectomized (Vx) or sham-operated (So) and killed at intervals of 4,6, 9, and 12 months after the operation. Testes were excised from 5 Vx and 5 So mice at each interval and processed for histological examination. Results: Testes of So mice showed normal histological features. By contrast, marked al-terations were observed in the seminiferou tubules in testes of Vx mice, except in those killed 4 months after the opera-tion. The seminiferous epithelium in the tubules was only 2-3 layers thick and showed much depletion of germ cells;in severe cases, the epithelium consisted of only a thin layer of Sertoli cells, spermatogonia and a few *** of germ cells, occurrence of multinucleated giant cells and vacuolated appearance of the epithelium were ofcommon features in the tubules. Furthermore, lumen of the rete testis in Vx mice was greatly dilated and showed accu-mulation of sermatozoa with immature germ cells; in mice vasectomized for 6-12 months, several macrophages in-gesting spermatozoa were ofte observed in the lumen of the rete testis. Spermatic granuloma was also somettimes no-ticed in corpus or in cauda regions of the epididymis in mice vasectomized for 6-12 months. Conclusion: We sug-gest that consequences of vasectomy should be thoroughly understood in order to make this method rather more popularas a reversible method of male contraception.

关键词： vasectomy testis mouse contraception

Distribution of mineral species in different coal seams of Talcher coalfield and its transformation behavior at varying temperatures

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International Journal of Coal Science & Technology 2016年第2期3卷 97-103页

作者： Amit Banerjee P. R. Mishra Ashok Mohanty k. chakravarty R. Das Biswas R. Sahu S. chakravarty Analytical Chemistry Division CSIR - NationalMetallurgical Laboratory Jamshedpur Jharkhand 831007India Department of Metallurgical and Materials Engineering National Institute of Technology JamshedpurJharkhand 831014 India R&D Tata Steel Ltd Jamshedpur Jharkhand 831007 India

Mineral phase characterization and thorough understanding of its transformation behavior during combustion are imperative to know the potential utilization of coal in the thermal industries. The primary objective of this work is to analyze the quality of Indian Coals and obtain their mineral species-specific information at different depths. The samples were obtained from Talcher Coalfield, Odisha, India. Coal from four seam sections in the Talcher coalfield, India are mainly high ash coal （〉50 %） and volatile matter deceases along with the seam depth. XRD results show that the major mineral phases present in the coal are quartz and kaolinite. Siderite, illite, and anatase were found in minor quantities. It has been observed that the clay minerals （kaolinite, silimanite, illite） decompose at higher temperature and traces of dolomite, mullite, hematite etc. are formed during the process of combustion. Among the four seams （M2, M12, M24 and M43） studied, ash of M43 has high A1203%, TIO2% and k20% content and low SIO2%, CaO% and MgO% content. High acid- to-base ratios contributed to high ash fusion temperatures （IDT 〉 1500 ℃） and low slagging potential of the coals studied. Relatively low fouling index （〈0.3） was estimated for all the coal seams studied. Furthermore, thermodynamic modeling software, FactSage, have been used to envision the mineral phase transformations that take place between 800 and 1500℃ during coal combustion.

关键词： Proximate analysis - Ultimate analysis FactSage XRD AFT Talcher coalfield

Discrete element approach for mine dump stability analysis

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Mining Science and Technology 2010年第6期20卷 809-813页

作者： RADHAkANTA koner DEBASHISH chakravarty Department of Mining Engineering Indian Institute of Technology

Mine overburden dumps have posed significant safety issues in the operations of various unit operations of open pit min-ing especially the external dumps. The external dumps are composed of a mixture of fragmented rocks and loose soil. Their charac-teristic is comparable to heavily discontinuous solid mass. The conventional approach of limit equilibrium methods provide safety factors for the slope but nothing about the stress-strain characteristics of the large dump mass. The designs of dump location and their respective geometry are integrated for the know-how of the stability characteristics of these dumps. The discrete element method uses a circular disk to represent the granular solid mass and their interactions are described by the Newton’s third law of motion. The displacement is described by the sliding of the circular disk. This work is focused on the modeling efficiency of the discrete element methods to represent the behaviour of mine dump masses with the specified joint plane for the limit equilibrium method. The advantage of the work lies on the ease of information retrieval at any point at the dump mass concerning the stress and strain histories, displacement, failures etc. which when integrated produces a better understanding of the stability of the dump masses.

关键词： dump slope safety factor discrete element method micromechanical properties discontinuity plane

Development of a mass model in estimating weight-wise particle size distribution using digital image processing

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International Journal of Mining Science and Technology 2017年第3期27卷 435-443页

作者： Maiti Abhik.chakravarty Debashish Biswas kousik Halder Arpan Department of Mining Engineering Indian Institute of Technology Kharag-pur 721302 India

Particle size distribution of coarse aggregates through mechanical sieving gives results in terms of cumu- lative mass percent. But digital image processing generated size distribution of particles, while being fast and accurate, is often expressed in terms of area function or number of particles. In this paper, a mass model is developed which converts the image obtained size distribution to mass-wise distribution, mak- ing it readily comparable to mechanical sieving data. The concept of weight/particle ratio is introduced for mass reconstruction from 2D images of particle aggregates. Using this mass model, the effects of several particle shape parameters （such as major axis, minor axis, and equivalent diameter） on sieve-size of the particles is studied. It is shown that the sieve-size of a particle strongly depend upon the shape param- eters, 91% of its variation being explained by major axis, minor axis, bounding box length and equivalent diameter. Furthermore, minor axis gives an overall accurate estimate of particle sieve-size, error in mean size （D-50） being just 0.4%. However, sieve-size of smaller particles （〈20 ram） strongly depends upon the length of the smaller arm of the bounding box enclosing them and sieve-sizes of larger particles （〉20 mm） are highly correlated to their equivalent diameters. Multiple linear regression analysis has been used to generate overall mass-wise particle size distribution, considering the influences of all these shape parameters on particle sieve-size. Multiple linear regression generated overall mass-wise particle size distribution shows a strong correlation with sieve generated data. The adjusted R-square value of the regression analysis is found to be 99 percent （w.r,t cumulative frequency）. The method proposed in this paper provides a time-efficient way of producing accurate （up to 99%） mass-wise PSD using digital image processing and it can be used effectively to renlace the mechanical sieving.

关键词： Particle size distribution Image analysis Particle shape parameters Weight/particle ratio Sieve analysis