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Wyszukujesz frazę "Das, S." wg kryterium: Autor


Tytuł:
On \(RS_k\) integrals
Autorzy:
Das, A. S.
Lahiri, В. K.
Powiązania:
https://bibliotekanauki.pl/articles/745404.pdf
Data publikacji:
1980
Wydawca:
Polskie Towarzystwo Matematyczne
Opis:
The article contains no abstract
Źródło:
Commentationes Mathematicae; 1980, 22, 1
0373-8299
Pojawia się w:
Commentationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculation of Lattice Relaxation in Some Substitutional Alloys Using a Green Function
Autorzy:
Das, S. K.
Datta Roy (Paul), S.
Powiązania:
https://bibliotekanauki.pl/articles/1995663.pdf
Data publikacji:
1999-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.72.Bb
61.82.Bg
Opis:
In this paper we calculate nearest neighbour relaxation in some dilute substitutional alloys using a lattice static Green function and the Morse potential function. Distant neighbour relaxation is calculated by invoking a continuum approximation. The potential parameters for the unlike interactions are calculated using simple interpolation formulae. Using the above relaxation, we calculate volume changes in the above alloys. It is observed that the simple model predicts values which are in reasonably good agreement with the experimental values in all cases. The calculated values are also compared with those obtained from the Vegard law. For Au-Ag alloy, our model reproduces both the correct sign and the magnitude of the volume change, whereas the Vegard law cannot even give the sign of the volume change. This shows the inherent strength of the present model.
Źródło:
Acta Physica Polonica A; 1999, 95, 3; 359-366
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Green Function Estimation of Correction to Vegards Law for isovalent Substitutional Defects in Alkali Halide Crystals
Autorzy:
Datta Roy (Paul), S.
Das, S. K.
Powiązania:
https://bibliotekanauki.pl/articles/2013286.pdf
Data publikacji:
2000-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.72.Bb
61.82.Bg
Opis:
A Green function method is developed for estimation of lattice parameter r(χ) of an AX-BX solid solution over entire composition range (χ=0 to 1). The r(χ) obtained in the present method is different from the value r$\text{}_{V}$(χ) suggested by Vegard's law. We estimated the deviation from Vegard's law, r(χ)-r$\text{}_{V}$(χ), over entire composition range for isovalent substitutional defect in alkali halide crystals. When compared to X-ray diffraction measurements, we find that the deviation is in correct direction, variation of r(χ) with χ is consistent with experiment and the overall agreement is fairly good considering the accuracy of the experiment.
Źródło:
Acta Physica Polonica A; 2000, 97, 4; 671-679
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal/reduction of organic pollutants from aqueous environment
Usunięcie/redukcja zanieczyszczeń organicznych ze środowiska wodnego
Autorzy:
Sarkar, M.
Das, M.
Manna, S.
Acharya, P.
Powiązania:
https://bibliotekanauki.pl/articles/1826240.pdf
Data publikacji:
2003
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
zanieczyszczenia organiczne wody
adsorpcja siarczanu
jakość wody
Opis:
The problem of considerable contamination of the aqueous environment with organic pollutants still requires the development of quick and simple methods for the removal, separation and determination of these compounds. The main classes of organic compounds that most of the industries use and discharge into the effluents are phenol, surfactant and dye. All these compounds are troublesome contaminants which pose not only to toxicity and health hazards but also hamper the environmental treatment processes. In chemical industry phenol is considered as an important starting materials for numerous intermediates and finished products. It is used for the production of a wide range of consumer goods and process materials ranging from adhesives, resins, emulsifiers and detergents, plasticizers, herbicides, dyes and flavors. The worldwide production of phenol is estimated to be 5 million tons per year. Phenol and its analogues are known to be toxic to microbes. The sign of acute illness induced by phenols in experimental animals as well as in humans is known. Continuous ingestion of phenol for a prolonged period of time causes mouth sore, diarrhoea, excretion of dark urine and impaired vision at concentration levels 10÷240 ppm. Lethal blood concentration for phenol is around 1.3 g/L. phenols are toxic to several biochemical functions and to fish life. It acts as a substrate inhibitor in the bio-transformation. World Health Organization (WHO) prescribed a concentration 1 ppb as the guideline concentration in drinking water [1]. Disposal of dyeing industry waste water pose one of the major problem, because such effluents contain a number of contaminants including acid or base, dissolve solids, surfactants and color. Out of these, color is the first contaminant to be recognized because it is visible to human eye. The dye causes the harmful action to various aquatic lives. As it is resistant to light it protects the sunlight from penetrating through it and reduces the aesthetic quality of water. Possible methods of color removal include chemical oxidation, froth flotation, coagulation, adsorption, etc. The anionic surfactants generally are removed by the chemical precipitation, foam separation, ultrafiltration and adsorption. Possible means of removal of phenols from waste water include ion exchange, reverse osmosis, chemical oxidation, precipitation, distillation, gas stripping, solvent extraction, adsorption or bio remediation. Removal of SDS, 4-nitrophenol and malachite green by activated carbon is an efficient and acceptable process. But the cost of operation is very high. Therefore, the present study is undertaken using fly ash as the adsorbent. Compared to activated carbon the efficiency of removal is less in case of 4-nitrophenol and SDS. But fly ash, being a waste material, is very cheap; only the carrying cost from the site of thermal plant to the laboratory is needed. Thus the use of fly ash in removing organic pollutants appears to be a cost viable. The simplicity of the technique makes the process quite acceptable.
Obecność organicznych zanieczyszczeń w strumieniu ścieków znacznie degraduje jakość wody. Zarówno własność estetyczne jaki i organizmy wodne stają wobec niebezpieczeństwa związanego z taką degradacją. Usunięcie zanieczyszczeń organicznych szczególnie za pomącą prostych i tanich metod jest wyzwaniem dla naukowców zajmujących się środowiskiem. Obecnie komunikaty naukowe mówią o możliwości zastosowania popiołów lotnych, odpadów stałych powstających w elektrociepłowniach, w usuwaniu albo redukcji ładunków niektórych organicznych zanieczyszczeń. W referacie przedstawiono wyniki badań nad adsorpcją siarczanu dodecylu sodu SDS (anionowy środek powierzchniowo czynny), zieleni malachitowej MG oraz 4-nitrofenolu na popiołach lotnych. Usunięcie SDS, 4-nitrofenolu i zieleni malachitowej na węglu aktywnym jest skutecznym i zadowalającym procesem. Ale koszt tej operacji jest bardzo wysoki. Dlatego, przedsięwzięto obecne badania używając popiołów lotnych jako substancji adsorbująca. W porównaniu do węgla aktywnego efektywność usunięcia na popiołach lotnych jest mniejsza w przypadku 4-nitrofenolu i SDS. Ale popioły lotne, będąc odpadem, są bardzo tanie. W ten sposób użycie popiołów lotnych w usuwaniu organicznych zanieczyszczeń okazuje się być wykonalne pod względem kosztów. Proces jest wykonalny kinetycznie i termodynamicznie, prosty w wykonaniu i tani.
Źródło:
Rocznik Ochrona Środowiska; 2003, Tom 5; 79-86
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Ergonomic Study on Posture-Related Discomfort Among Preadolescent Agricultural Workers of West Bengal, India
Autorzy:
Gangopadhyay, S.
Das, B.
Das, T.
Ghoshal, G.
Powiązania:
https://bibliotekanauki.pl/articles/90547.pdf
Data publikacji:
2005
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
preadolescence
agricultural worker
posture
discomfort
rolnictwo
ergonomia
młodociani
pozycja przy pracy
warunki pracy
choroby narządów ruchu
czynniki ryzyka
Opis:
In India, particularly in West Bengal, preadolescents are primarily associated with agricultural work in rural areas. Owing to poor socio-economic conditions, they are compelled to carry out a considerable number of manual, rigorous tasks in agricultural fields. The main aim of this study was to investigate postures adopted by preadolescent agricultural workers during individual agricultural activities and to analyze the causes of discomfort related to those postures. Fifty male and 50 female preadolescent agricultural workers were randomly selected and a detailed posture analysis was performed with the Ovako Working Posture Analysis System (OWAS). It was observed that those workers worked continuously in awkward postures during certain agricultural activities. Consequently they suffered from discomfort in different parts of their body. Even though they were very young, they were likely to suffer from serious musculoskeletal disorders in the future.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2005, 11, 3; 315-322
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preliminary results on direct photon-photon HBT measurements in square root sNN = 62.4 GeV and 200 GeV Au+Au collisions at RHIC
Autorzy:
Das, D.
Lin, G.
Chattopadhyay, S.
Chikanian, A.
Finch, E.
Nayak, T.
Panitkin, S.
Sandweiss, J.
Suaide, A.
Zhang, H.
Powiązania:
https://bibliotekanauki.pl/articles/148364.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
RHIC
HBT
interferometry
TPC
BEMC
photon
Opis:
We present the preliminary results on direct photon interferometry measurements in Au+Au collisions at square root sNN = 62.4 GeV and 200 GeV using the STAR (solenoidal tracker at RHIC) detector. Photons are reconstructed via e+/e- conversions in STAR Time Projection Chamber (TPC) and energy deposited by photons in STAR Barrel Electromagnetic Calorimeter (BEMC). The two-photon correlations are measured using (1) both photons measured with BEMC; (2) one photon from conversions and the other measured with BEMC. Both the methodologies and the possible constraints in the correlation function measurements are discussed.
Źródło:
Nukleonika; 2006, 51,suppl.3; 55-58
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of mixed traffic for mobile cellular network
Autorzy:
Islam, I.
Das, J. K.
Hossain, S.
Powiązania:
https://bibliotekanauki.pl/articles/307662.pdf
Data publikacji:
2007
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
quality of service
Markovian chain
time and call congestion
probability states and voice data integrated network
Opis:
The most convenient way of presenting one- or two-dimensional offered traffic in a network by Markovian chain to evaluate quality of service (QoS). Pictorial presentation of chain becomes very complicated for three dimensional traffic case, required for voice data integrated service/mixed traffic of mobile cellular network; hence application of cut or node equations become a cumbersome job. This paper proposes a model of three-dimensional traffic in a network for both unlimited and limited user case. Here direct analytical method is introduced instead of Markovian chain to achieve traffic parameters.
Źródło:
Journal of Telecommunications and Information Technology; 2007, 1; 83-89
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of voice data integrated traffic in 3G mobile cellular network
Autorzy:
Islam, I.
Das, J. K.
Hossain, S.
Powiązania:
https://bibliotekanauki.pl/articles/308765.pdf
Data publikacji:
2007
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
3G mobile
voice data integrated service
micro cell
macro cell
satellite cell
Markovian chain and thinning scheme
Opis:
The most important feature of 3G mobile cellular network is introduction of voice data integrated service under multilayered cell environment to support overflow traffic of lower layered cells by upper ones. This paper deals with traffic model of three layered cells, i.e., micro cell, macro cell and satellite cell. Here a new call admission control is introduced for three layered cell of 3G mobile cellular network. State transition chain is designed for theoretical analysis of above mentioned traffic. Blocking probability of data call, new voice call and handover failure of voice call, probability of utilization of micro cell channel, macro cell channel and satellite cell channel are analyzed against different traffic parameters and yield logical results.
Źródło:
Journal of Telecommunications and Information Technology; 2007, 2; 103-108
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of Optimum Value of Y-Capacitor for Reducing Emi in Switch Mode Power Supplies
Autorzy:
Jha, M. M.
Naik, K. B.
Das, S. P.
Powiązania:
https://bibliotekanauki.pl/articles/262807.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
EMI
CM noise
touch current
Y-capacitor
Opis:
Putting a Y-capacitor between the primary ground and secondary ground is a common practice in industry to reduce EMI; but, this capacitor increases touch current. A method is discussed to measure the touch current at circuit design level. An optimum value of Y-capacitor is predicted without exceeding touch current limit. Experimental results of touch current measurements and EMI measurements are analyzed.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2009, 15, 2; 47-50
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Ergonomics Study on Posture-Related Discomfort and Occupational-Related Disorders Among Stonecutters of West Bengal, India
Autorzy:
Gangopadhyay, S.
Das, B.
Das, T.
Ghoshal, G.
Ghosh, T.
Powiązania:
https://bibliotekanauki.pl/articles/90199.pdf
Data publikacji:
2010
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
stonecutters
OWAS
posture-related discomfort
posture
Opis:
Stonecutting and setting are important tasks in a construction site. A field study was conducted to assess occupational-related disorders and to conduct ergonomics assessment among stonecutters. The study focused on (a) the duration of work per day, (b) the working environment and working activities and (c) the feeling of discomfort in different parts of the body. A detailed posture analysis was performed with the Ovako working posture analysis system (OWAS). It was observed that stonecutters worked continuously in awkward postures during stonecutting and setting. Consequently, they suffered from discomfort in different parts of their body, specifically in the lower back, knees and shoulders, which mainly prevented them from continuing their work. This study also revealed that stonecutters had to work in congested work areas with a poor level of illumination. The noise level and dust particles emitted during stonecutting activities could affect stonecutters.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2010, 16, 1; 69-79
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of Orientational Order Parameters of Two Tri-Component Mixtures from Optical Birefringence and X-Ray Diffraction Measurements
Autorzy:
Basak, S.
Dasgupta, P.
Das, B.
Das, M.
Dabrowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/1492775.pdf
Data publikacji:
2011-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.05.cp
61.30.-v
42.70.Df
Opis:
Two tri-component mixtures as base mixtures for vertically aligned mode LCD's were prepared. The eutectic compositions were theoretically estimated and experimentally verified from differential scanning calorimetry studies. A room temperature nematic mixture with fairly broad operating range emerged from each of the tri-component mixtures. The optical birefringence of these mixtures at the eutectic composition was measured as a function of temperature. X-ray diffraction measurements were done on these mixtures to obtain the orientational order parameters as a function of temperature. The order parameter values were also determined from birefringence measurements and the results were compared with mean field theory. Structural parameters like intermolecular distance and apparent molecular length have also been determined.
Źródło:
Acta Physica Polonica A; 2011, 120, 6; 1037-1042
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinetics and mechanism of electron transfer to pyridinium chlorochromate (VI) from sulfur containing amino acid, L-cysteine in aqueous and micellar media
Autorzy:
Senapati, S.
Das, S.
Mohanty, P.
Patnaik, A.K.
Powiązania:
https://bibliotekanauki.pl/articles/779166.pdf
Data publikacji:
2011
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
kinetyka
przeniesienie elektronu
chlorochromian pirydyny
cysteina
kinetics mechanism
electron transfer
pyridinium chlorochromate
cysteine
micellar media
Opis:
The electron transfer reaction of L-cysteine (RSH) with pyridinium chlorochromate (PCC) has been studied spectrophotometrically over the range 2.0 ≤ 10^3 [RSH] ≤ 6.0; 0.01 ≤ [H+] ≤ 0.2; 298 ≤ T ≤ 318 K and I = 0.3 mol dm-3 (NaClO4). The electron transfer reaction has also been carried out in the presence of anionic, cationic and neutral micelle. The reaction in acid medium is strongly catalyzed by changing [SDS]T (sodium dodecyl sulfate) up to 3 × 10-2 mol dm-3, beyond this concentration of SDS, the rate is retarded. The cationic and neutral micelle has a small effect on the rate. ΔH≠ (kJ mol-1) and ΔS≠ (JK-1 mol-1) values for the k1 and k2 paths are 30.20 ± 0.25, -159.65 ± 0.83 and 29.60 ± 0.62, -127.09 ± 2.17, respectively. The negative activation entropy is indicative of the ordered transition state for the electron transfer reaction. Formation of 2-amino-3-(2-amino-2-carboxy-ethyl) disulfanyl-propanoic acid as product is strongly supported by IR spectra.
Źródło:
Polish Journal of Chemical Technology; 2011, 13, 2; 6-10
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Ergonomics Study on the Prevalence of Musculoskeletal Disorders Among Indian Bus Conductors
Autorzy:
Gangopadhyay, S.
Dev, S.
Das, T.
Ghoshal, G.
Ara, T.
Powiązania:
https://bibliotekanauki.pl/articles/90847.pdf
Data publikacji:
2012
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
bus conductor
musculoskeletal disorders
work study
India
Opis:
This study was undertaken among 100 randomly selected bus conductors from 2 routes. A questionnaire study based on the modified Nordic musculoskeletal questionnaire, assessment of physical and physiological parameters, analysis of working postures and a detailed work study were performed. The analysis revealed that conductors had a work schedule of 16–18 h each day; the duration of work could vary from 15 to 20 days at a stretch. Discomfort leading to musculoskeletal disorders mainly affecting the leg (93.3%), knee (83.3%), shoulder (80%) and back areas (56.7%) had the highest 12-month prevalence rates and increased day by day.The conductors also suffered from extreme physiological stress due to prolonged working hours in hazardous standing posture conditions, excessive work pressure and minimum rest between trips. Consequently, all those factors affected their health and work performance.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2012, 18, 4; 521-530
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of Ergonomic and Occupational Health-Related Problems Among Female Prawn Seed Collectors of Sunderbans, West Bengal, India
Autorzy:
Das, B.
Ghosh, T.
Gangopadhyay, S.
Powiązania:
https://bibliotekanauki.pl/articles/91151.pdf
Data publikacji:
2012
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
musculoskeletal disorders
physiological stress
prawn seed collectors
hand grip strength
rapid entire body assessment (REBA)
Opis:
Sixty female prawn seed collectors and 60 female control subjects from Sajenakhali and Sandeshkhali blocks of Sunderbans, West Bengal, India, were randomly selected to evaluate and compare musculoskeletal disorders and physiological stress. The control group was engaged in domestic work involving minimum handintensive activities. The modified Nordic musculoskeletal questionnaire and rapid entire body assessmentwere used. Most subjects suffered from discomfort in different body parts, especially in the lower back (98%), knees (88%), shoulders (75%), ankles (70%) and feet (67%). This study reveals that female prawn seed collectors suffer from significant physiological load and extreme physiological stress due to prolonged working hours in a standing posture and excessive work pressure. Consequently, all these factors affect female prawn seed collectors’ health and work performance.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2012, 18, 4; 531-540
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł

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