Wyniki wyszukiwania - Biblioteka Nauki

1

Toxic fatty acid resistant mutant of Trichophyton rubrum

100%

Das S. K. , Banerjee A. B.

Acta Microbiologica Polonica

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1977

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tom 26

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nr 4

2

Kłopotliwa prawda o utracie wagi

100%

Roberts S. B. , Das S. K.

Świat Nauki

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2017

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nr 08

3

Evaluation of liquefaction potential of soil based on standard penetration test using multi-gene genetic programming model

100%

Muduli P. K. , Das S. K.

Acta Geophysica

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2014

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tom Vol. 62, no. 3

529--543

EN

This paper discusses the evaluation of liquefaction potential of soil based on standard penetration test (SPT) dataset using evolutionary artificial intelligence technique, multi-gene genetic programming (MGGP). The liquefaction classification accuracy (94.19%) of the developed liquefaction index (LI) model is found to be better than that of available artificial neural network (ANN) model (88.37%) and at par with the available support vector machine (SVM) model (94.19%) on the basis of the testing data. Further, an empirical equation is presented using MGGP to approximate the unknown limit state function representing the cyclic resistance ratio (CRR) of soil based on developed LI model. Using an independent database of 227 cases, the overall rates of successful prediction of occurrence of liquefaction and non-liquefaction are found to be 87, 86, and 84% by the developed MGGP based model, available ANN and the statistical models, respectively, on the basis of calculated factor of safety (Fs) against the liquefaction occurrence. Key words: liquefaction index, standard penetration test, limits state function, artificial intelligence, multi-gene genetic programming, factor of safety

4

An overview of current research trends on graphene and it’s applications

80%

Krishna R. S. , Mishra J. , Das S. K. , Mustakim S. M.

World Scientific News

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2019

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tom 132

5

Free radical scavenging and antioxidant potential of mangrove plants: a review

80%

Thatoi H. N. , Patra J. K. , Das S. K.

Acta Physiologiae Plantarum

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2014

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tom 36

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nr 03

EN

Free radicals derived from reactive oxygen species and reactive nitrogen species are generated in our body by normal cellular metabolism which is enhanced under stress conditions. The most vulnerable biological targets of free radicals are cell structures including proteins, lipids and nucleic acids. Since antioxidants synthesized in the body are not sufficient under oxidative stress, their exogenous supply is important to prevent the body from free radical-induced injury. Recent researches have shown that antioxidants of plant origin with free radical scavenging property could have great importance as therapeutic agents in management of oxidative stress. Mangrove plants growing in inhospitable environment of the intertidal regions of land and sea in tropics and sub-tropics are equipped with very efficient free radical scavenging system to withstand the variety of stress conditions. These mangrove plants possess variety of phytochemical and are rich in phenolic compounds such as flavonoids, isoflavones, flavones, anthocyanins, coumarins, lignans, catechins, isocatechins, etc., which served as source of antioxidants. Isolation and identification of these antioxidant compounds offer great potential for their pharmaceutical exploitations. However, no comprehensive literature is available on antioxidants’ studies in mangrove plants in particular. Hence, the present review discusses the antioxidant potential of mangrove plants with its specific role under salt stress as well as the progress made so far in evaluation of antioxidant activities of different mangrove species.

6

Heuristic Procedure for the Assembly Line Balancing Problem With Postural Load Smoothness

80%

Jaturanonda C. , Nanthavanij S. , Das S. K.

International Journal of Occupational Safety and Ergonomics

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2013

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tom Vol. 19, No. 4

531--541

EN

This paper presents a heuristic procedure for assigning assembly tasks to workstations where both productivity and ergonomics issues are considered concurrently. The procedure uses Kilbridge and Wester’s algorithm to obtain an initial task–workstation assignment solution which minimizes the balance delay of an assembly line. A task reassignment algorithm was applied to improve the initial solution by exchanging assembly tasks, which smooth postural load among workers, between workstations. A composite index of variation was used to measure the effectiveness of the task–workstation assignment solution. On the basis of clothes assembling, it was found that the task–workstation assignment solution with a minimum composite index of variation can be obtained with relatively equal weights in balance delay and postural load.

7

Composition of lipids from the glands of the external ear canal of the adult chicken

80%

Dutta S. , Das S. K. , Bhattacharyya S. P.

Folia Biologica

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1997

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tom 45

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nr 3-4

8

Symbiotic effectiveness of a siderophore overproducing mutant of Mesorhizobium ciceri

80%

Raychaudhuri N. , Das S. K. , Chakrabartty P. K.

Polish Journal of Microbiology

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2005

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tom 54

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nr 1

EN

Mutants of Mesorhizobium ciceri BICC 651 were generated by N-methyl-N'-nitro-Af-nitrosoguanidine mutagenesis. Siderophore overproducing mutants were identified on Chrome azurol S agar plates. One of them determined as N15 was examined for symbiotic efficiency and compared to its wild type parent i.e. BICC 651 strain under sterile conditions using Leonard jars in growth chamber and also in pots containing nonsterile alluvial field soil. It was observed that the strain N15 produced about 30% higher number of nodules per plant, fixed 25% more nitrogen per gram of nodule and caused more than 30% increased dry weight of plant shoots.

9

In situ-formed, low-cost, Al-Si nanocomposite materials

61%

Guba P. , Gesing A. J. , Sokolowski J. , Conle A. , Sobiesiak A. , Das S. K.

Journal of Achievements in Materials and Manufacturing Engineering

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2017

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tom Vol. 84, nr 1

5--22

EN

Aluminum-Silicon (Al-Si) alloys are the “bread-and-butter” of the aluminum foundry industry being cast at an annual rate of over 2 million tonnes/year in North America for use mainly in transportation. Coarse microstructure of these alloys limits their specific mechanical properties and consequently their potential for vehicle lightweighting. Purpose: We report on a new family of cast Al-Si alloys producing in-situ formed nanocomposites of up to 25 vol.% ultrafine equiaxed silicon particles in Al alloy matrix which can be ductile, or reinforced by nano-scale spinodal constituents. Design/methodology/approach: The hypereutectic Al-Si-X alloy (A390) was melted, solidified and cooled on the novel High Pressure Die Casting Universal Metallurgical Simulator and Analyser Technology Platform (HPDC UMSA) at specific process parameters. The HPDC cast samples consecutively were solution treated and artificially aged to spheroidize the Si and to dissolve the intermetallics in Al(SS) and to re-precipitate them in the solid state as nano-sized spinodal structures. The heat treatment was performed using the High Temperature UMSA Technology Platform. Findings: The nano scale structure of these new materials gives them significantly improved strength, hardness, and wear resistance while retaining adequate toughness and ductility for applications in the transportation applications. Research limitations/implications: Desired composite nanostructures have been produced and characterized in-situ in small laboratory test samples. Practical implications: These new materials can be produced by conventional casting technologies such as continuous strip casting, or high-pressure die-casting from conventional low-cost Al-Si melts. Originality/value: These materials can be produced with a significantly higher volume fraction of ultrafine Si dispersoids than has been done to date in in-situ formed materials, while retaining and improving the density-specific mechanical properties.

10

Thermal Properties of Carbon Nanotube (CNT) Reinforced Polyvinyl Alcohol (PVA) Composites

61%

Hasan M. , Das S. K. , Islam J. M. M. , Gafur M. A. , Hoque E. , Khan M. A.

International Letters of Chemistry, Physics and Astronomy

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2013

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tom Vol. 12

59--66

EN

Homogeneous Polyvinyl alcohol (PVA)/Carbon nanotube (CNT) composite has been prepared by solution casting method using gum acacia as a surfactant. CNT content in the composite was varied from 5-10 % by weight. The thermal properties of PVA/CNT composites were investigated by Thermo Gravimetric/Differential Thermal Analyzer (TG/DTA) and Thermo Mechanical Analyzer (TMA). TG/DTA results showed that higher thermal stability in higher percentage of CNT in the composites. The 10 % CNT containing PVA composite exhibit highest onset of melting, glass transition point and offset of melting temperature and the recoded values are 330.4K, 379K and 421.3K respectively. All of the result indicates that the developed PVA/CNT composite might be promising for use in solar cell application.

11

Development of Electrically Conductive Nanocrystalline Thin Film for Optoelectronic Applications

61%

Das S. K. , Islam J. M. M. , Hasan M. , Kabir H. , Gafur M. A. , Hoque E. , Khan M. A.

International Letters of Chemistry, Physics and Astronomy

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2013

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tom Vol. 10, iss. 1

90-101

EN

Sodium alginate (TiO2) sand composites were prepared by solution casting. Purified sand was added in the composite films to increase electrical conductivity. Electrical properties such as conductivity, capacitance, dielectric constant, and loss tangent of the composites were investigated. The current voltage characteristics for all the composites showed ohmic behavior. All the electrical properties have been found to improve with the incorporation of sand (SiO2) but 6 % sand containing composite exhibits the best electrical properties. The mechanical properties tensile strength (TS), elongation at break (Eb) and Young modulus for 6 % sand containing composite film are found to be 4.445 MPa, 9.76 %, and 72.8 MPa respectively. The experimental results reveal that the blended films exhibit higher stability and improved mechanical properties of both tensile strength and elongation at break in dry state. Water absorption properties of the composites are found to decrease with the increase of sand content. Lowest water uptake properties and highest stability were demonstrated by 6 % sand containing sample. Electrically conductive composite films have useful applications for solar cells and optoelectronics. Thus, this study is very much expected to aid in the design and selection of proper composite for the potential application of solar cell and optoelectronics.