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Wyszukujesz frazę "Ghosh, S," wg kryterium: Autor


Tytuł:
Trend of arsenic pollution and subsequent bioaccumulation in Oryza sativa and Corchorus capsularis in Bengal Delta
Autorzy:
Bhattacharya, S.
Guha, G.
Gupta, K.
Chattopadhyay, D.
Mukhopadhyay, A.
Ghosh, U.C.
Powiązania:
https://bibliotekanauki.pl/articles/10831.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
trend
arsenic pollution
bioaccumulation
rice
Oryza sativa
jute
Corchorus capsularis
Bengal Delta zob.Ganges Delta
Ganges River
Ganges Delta
Opis:
Oryza sativa Linn. (rice) and Corchorus capsularis Linn. (jute) are the two major crops of the Bengal basin. Both rice and jute are generally grown in submerged flooded conditions, where arsenic bioavailability is high in soil. The consumers of the edible parts from both plants therefore face an inevitable source of exposure to arsenic, with consequent accumulation and toxicity. The objective of the study was to observe the in-vivo temporal variation of arsenic bioaccumulation in the different parts of O. sativa and C. capsularis. Rice plant specimens (Aman rice, Ratna variety) of different age groups (1, 2 and 3 months old) were analyzed in HG-AAS for absorbed arsenic content in different parts. The accumulation of arsenic remained significantly high in the initial phase of growth, but decreased with time. Amount of arsenic bioaccumulation followed the decreasing order: root > basal stem > median stem > apical stem > leaves > grains in all the three age groups of the rice plant samples. C. capsularis followed a trend of arsenic bioaccumulation similar to O. sativa. O. sativa had more accumulation potential than C. capsularis, but C. capsularis showed much higher efficiency of arsenic translocation in the above ground parts. This is the first ever report of time-dependent decrease in arsenic bioaccumulation in O. sativa and C. capsularis. The contamination level can reach the grain part in significant amount and can cause health hazards in more severely arsenic affected areas. Intensive investigation on a complete food chain is urgently needed in the arsenic contaminated zones for further risk assessments.
Źródło:
International Letters of Natural Sciences; 2014, 16
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trend analysis of climate change in Chittagong Station in Bangladesh
Autorzy:
Roy, M.
Biswas, B.
Ghosh, S.
Powiązania:
https://bibliotekanauki.pl/articles/11430.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Opis:
The amount of rainfall received over an area is an important factor in assessing availability of water to meet various demands for agriculture, industry, irrigation, generation of hydroelectricity and other human activities. Over the study period of recent 30 years, trend values of monsoon average rainfall in Chittagong have increased. This paper has measured the correlation coefficients between rainfall and time for Chittagong, where correlation coefficient for Chittagong is positive. In order to check the strength of linear relationship between rainfall and time, P-value has been measured. Due to various factors of Chittagong region of Bangladesh, there is a growing need to study the rainfall, temperature and humidity pattern. This study was checked annual average rainfall of 30 years, temperature of 60 years and humidity of 28 years for this region. It is hoped that this research may be of help to the concerned organizations and experts working on increasing climate variation in Chittagong.
Źródło:
International Letters of Natural Sciences; 2015, 47
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Technique Based on Fuzzy Logic for Cotton Bale Lay-down Management
Nowa technika zarządzania składowaniem bel bawełny
Autorzy:
Das, S.
Ghosh, A.
Powiązania:
https://bibliotekanauki.pl/articles/232810.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
cotton bale
cluster analysis
fibre property
fuzzy logic
fuzzy c-means algorithm
składowanie bawełny
logika rozmyta
bela bawełny
Opis:
In this paper a new technique has been proposed for cotton bale management using fuzzy logic. The fuzzy c-means clustering algorithm has been applied for clustering cotton bales into 5 categories from 1200 randomly chosen bales of the J-34 variety. In order to cluster bales of different categories, eight fibre properties, viz., the strength, elongation, upper half mean length, length uniformity, short fibre content, micronaire, reflectance and yellowness of each bale have been considered. The fuzzy c-means clustering method is able to handle the haziness that may be present in the boundaries between adjacent classes of cotton bales as compared to the K-means clustering method. This method may be used as a convenient tool for the consistent picking of different bale mixes from any number of bales in a warehouse.
W artykule zaproponowano nową technikę zarządzania składowaniem bawełny opartą na logice rozmytej. Badaniu poddano 1200 losowo wybranych bel bawełny. W celu pogrupowania bel w 5 kategoriach zbadano właściwości, tj. wytrzymałość, wydłużenie, średnią długość, jednorodność długości, zawartość włókien krótkich, dojrzałość, współczynnik odbicia i zażółcenie każdej beli. Opracowana metoda może być stosowana jako wygodne narzędzie do sortowania różnych mieszanek z dowolnej liczby bel w magazynie.
Źródło:
Fibres & Textiles in Eastern Europe; 2017, 2 (122); 30-33
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies on Aluminized, High Burning Rate, Butacene® Based, Composite Propellants
Autorzy:
Ghosh, K.
Behera, S.
Kumar, A.
Padale, B. G.
Deshpande, D. G.
Gupta, M.
Powiązania:
https://bibliotekanauki.pl/articles/358702.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
Butacene®
ferrocene
pressure exponent
Opis:
This paper reports on a Butacene® based composite propellant with high burning rate. The effect of replacing HTPB with Butacene® on the physical, mechanical and ballistic properties, and sensitivity towards impact and friction, has been studied. The ballistic properties were evaluated as burning rates at various pressures (7-11 MPa), pressure exponents, ignition temperatures etc. As expected, a remarkable enhancement in burning rate at low pressures was observed with increasing percentage of Butacene®. Comparatively lower n-values were observed for compositions containing Butacene® than for HTPB based propellants. The sensitivity of Butacene® based compositions, in terms of impact and friction, was found to be increased with an increasing percentage of Butacene®.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 3; 323-333
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Strongly Correlated Electron Behaviour in $CeT_2Al_8$ (T~=~Fe,~Co)
Autorzy:
Ghosh, S.
Strydom, A.
Powiązania:
https://bibliotekanauki.pl/articles/1427072.pdf
Data publikacji:
2012-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.40.Cx
71.27.+a
75.30.Mb
75.20.Hr
Opis:
We report on studies of physical properties of the two compounds $CeFe_2Al_8$ and $CeCo_2Al_8$ in which we have found varying degrees of electronic correlational phenomena. No magnetic ordering was detected down to 0.4 K in either of the two compounds. At elevated temperatures an incoherent Kondo interaction between the Ce 4f-electron and the conduction electrons is prevalent in both compounds. $CeCo_2Al_8$ exhibits a stable 4f-electron magnetic moment, but in $CeFe_2Al_8$ an intermediate-valent state prevails near room temperature that eventually transforms into a Fermi-liquid ground state. The low-temperature specific heat of $CeCo_2Al_8$ shows typical strongly correlated electron behaviour and a - logT upturn in its electronic specific heat below about 10 K.
Źródło:
Acta Physica Polonica A; 2012, 121, 5-6; 1082-1084
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Speech and Music – Nonlinear Acoustical Decoding in Neurocognitive Scenario
Autorzy:
Bhaduri, S.
Ghosh, D.
Powiązania:
https://bibliotekanauki.pl/articles/177385.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
speech signal
multifractality
Visibility Graph
Fractal Darwinism
neurocognitive disorders
Opis:
Speech and music signals are multifractal phenomena. The time displacement profile of speech and music signal show strikingly different scaling behaviour. However, a full complexity analysis of their frequency and amplitude has not been made so far. We propose a novel complex network based approach (Visibility Graph) to study the scaling behaviour of frequency wise amplitude variation of speech and music signals over time and then extract their PSVG (Power of Scale freeness of Visibility Graph). From this analysis it emerges that the scaling behaviour of amplitude-profile of music varies a lot from frequency to frequency whereas it’s almost consistent for the speech signal. Our left auditory cortical areas are proposed to be neurocognitively specialised in speech perception and right ones in music. Hence we can conclude that human brain might have adapted to the distinctly different scaling behaviour of speech and music signals and developed different decoding mechanisms, as if following the so called Fractal Darwinism. Using this method, we can capture all non-stationary aspects of the acoustic properties of the source signal to the deepest level, which has huge neurocognitive significance. Further, we propose a novel non-invasive application to detect neurological illness (here autism spectrum disorder, ASD), using the quantitative parameters deduced from the variation of scaling behaviour for speech and music.
Źródło:
Archives of Acoustics; 2018, 43, 4; 593-602
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Socio-environmental surveys of Tinchuley and Takdah: two emerging ecotourism hamlets of North Bengal, India
Autorzy:
Bhattacharya, S.
Ghosh, U.C.
Powiązania:
https://bibliotekanauki.pl/articles/10934.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
socio-environmental survey
Tinchuley village
Takdah village
ecotourism hamlet
North Bengal
India
Opis:
Tinchuley (Latitude: 26.89748 N, Longitude: 88.23268 E) is a remote hamlet located close to Darjeeling which can be reached through a drive of 32 kilometers. Takdah Cantonment (Latitude: 26.89745 N, Longitude: 88.23265 E) is a settlement located in Darjeeling district, West Bengal, India. It is one of the upcoming tourist centers of the Darjeeling hills, around 4 km. from Tinchuley. The winding roads, tall pine and fir trees, intruding packs of cloud and warm and hospitable people makes it an ideal destination for people looking to escape from the hectic lifestyle of the city. The main objective of the present research work was to construct the social, environmental, cultural and economic framework of Tinchuley and Takdah Cantonment area and to highlight the proposals for sustainable management policies of those ecologically sensitive zones. The study was done in May, 2014 by visiting Tinchuley and Takdah and the information was gathered through field survey and direct contact with common people and authorized centers of the regions. Surveys on the agriculture, horticulture, livestock, water management, education, culture, health, waste management, transport and biodiversity were done in these areas. Tinchuley and Takdah have become the prominent tourist spots of West Bengal for pleasure trips, biological and geographical excursions and medical research works. In spite of getting so much attention in the recent time, the areas are not adequately developed. There is an urgent need for implementing sustainable management systems in the areas for the betterment of the socio-environmental structures. Some of the possible management strategies have been suggested for maintaining the social, environmental, economic and ecological balance of the regions.
Źródło:
International Letters of Natural Sciences; 2014, 18
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Socio-environmental survey of an ecologically important hamlet of Darjeeling district, West Bengal, India
Autorzy:
Bhattacharya, S.
Ghosh, G.
Banerjee, T.
Goswami, S.
Das, P.
Powiązania:
https://bibliotekanauki.pl/articles/11842.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
socio-environmental survey
ecologically important hamlet
management
biodiversity
environment
Darjeeling district
West Bengal
India
Opis:
Forest cover in hills is essential to maintain environmental, economic and ecological balances. North Bengal accounts for 3,086 sq km (26 %) of the 11,876 sq km area of classified forests in the state, and for nearly 5,000 sq km (40 %) of all land under tree cover. Upper Chatakpur is one of the emerging ecotourism spots of north Bengal, located at an altitude of 7887 feet in Darjeeling district. It is a 180 years old ethnic village with 19 houses and a population of about 89, and at an altitude of 7887 ft. It is about 8 km. from Sonada (26° 57' N, 88° 16' E), 22 km. from Darjeeling (26° 2' N, 88° 15' E) and 72 km. from Siliguri (26° 42' N, 88° 25' E). Upper Chatakpur Village situated within Senchal Wildlife Sanctuary, Darjeeling. The sanctuary with an area of 38.88 sq. km has an elevation of 1500-2600 m. The survey work was done in December, 2014 by visiting upper Chatakpur village and the primary data were gathered through field survey and direct contact with common people and authorized centers of the region. Surveys on the topography, demography, agriculture, livestock, water management, education, culture, health, waste management, transport, biodiversity, human animal conflict were done in this area. Medicinal plant diversity was studied in the village area and information was gathered from the local forest department centre. Information regarding the transport system was collected from the local transport office and syndicate. Census report was collected from the Sonada Panchayat Office. Health and education information was collected from the local primary school and the local sub health centre. Information on sustainable agricultural practices and waste management policies is collected through surveys in the village houses and agricultural fields. Biodiversity of Senchal Wildlife Sanctuary was documented by visiting the forest areas. Pictorial documentation was done in every phase of study. In spite of getting so much attention in the recent time, the village is not adequately developed. There is an urgent need for implementing sustainable management systems in the areas for the betterment of the socio-environmental structures. Some of the possible management strategies have been suggested for maintaining the social, environmental, economic and ecological balance of the region.
Źródło:
International Letters of Natural Sciences; 2015, 06
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Socio-Environmental survey of an ecologically important forest edge hamlet in Buxa Tiger Reserve, West Bengal, India
Autorzy:
Bhattacharya, S.
Maity, R.
Sarkar, G.
Ghosh, G.
Mukherjee, D.
Mukhopadhyay, C.
Powiązania:
https://bibliotekanauki.pl/articles/11301.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Opis:
Buxa Tiger Reserve (BTR) is located in Alipurduar Sub Division of West Bengal, India. It comprises of the entire forest area of the erstwhile Buxa Forest Division (Created in 1877 – 78) and some territory of the erstwhile neighboring Cooch Behar Forest Division. The Reserve lies between Latitudes 23o30′ N to 23o50′ N and Longitudes 89o25′ E to 89o55′ E. The total area of the reserve is 760.87 km2 of which 385.02 km2 has been constituted as the Buxa Sanctuary and National Park (Core zone of the BTR) and the balance 375.85 km2 areas is treated as a buffer zone. It has 37 forest villages and 4 fixed demand holdings, 46 revenue villages and 34 tea gardens in and around it. The survey work was done in May, 2015 by visiting a forest edge village, 28 Mile, in Buxa Tiger Reserve and the primary data were gathered through field survey and direct contact with common people and authorized centres of the region. Surveys on the demography, agriculture, livestock management, water management, education, culture, health, waste management, disaster management, transport, biodiversity, joint forest management activities, Non-timber forest product usage and human animal conflict were done in this area. In every phase of the survey work, photographic documentation was done. In spite of being positioned in a diverse and sensitive ecological zone, the village is not adequately managed. There is an urgent need for implementing sustainable management systems in the areas for the betterment of the socio-environmental structures. Some of the possible management strategies have been suggested for maintaining the social, environmental, economic and ecological balance of the region.
Źródło:
International Letters of Natural Sciences; 2016, 52
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Seeking the best practices of assessment in maritime simulator training
Autorzy:
Tusher, H. M.
Nazir, S.
Ghosh, S.
Rusli, R.
Powiązania:
https://bibliotekanauki.pl/articles/24201462.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
maritime education and training
human factor
maritime simulator training
assessments in simulated environments
Performance Assessment
assessment model
STCW
literature review
Opis:
Simulator-based training has become an integral part of Maritime education, and its effectiveness hinges on the use of appropriate assessment protocols. Despite the existence of several subjective and objective assessment techniques, instructors face difficulties in selecting and implementing the best practices that fit different learning contexts. The contextualized utility of the available assessment techniques further complicates the contexts. This study adopts a systematic literature review approach to comprehensively analyse available assessment techniques employed in maritime simulator training and to elicit their relationship with the desired learning outcomes. The study also presents a nuanced understanding of the advantages and limitations of the identified assessment techniques. Further, the state-of-the-art of assessment methods is discussed along with a few proposals for the future considering both research and practical implications. The findings of this study are expected to provide valuable guidance to maritime instructors in selecting and implementing appropriate assessment techniques that align with desired learning outcomes in simulator training.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2023, 17, 1; 105--114
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Respiratory Problems of Workers in the Zarda Industry in Kolkata, India
Autorzy:
Ghosh, T.
Barman, S.
Powiązania:
https://bibliotekanauki.pl/articles/90560.pdf
Data publikacji:
2007
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
zarda manufacturing workers
respiratory function
tobacco dust
Opis:
This study was undertaken to assess the pulmonary and respiratory problems of workers in a zarda factory. A total of 70 permanent zarda workers (50 manufacturing workers and 20 office ones) were studied in a factory in Baguihati, Kolkata, India. The study included (a) completion of a questionnaire (on pulmonary and respiratory problems), (b) measurement of physical parameters, (c) spirometry and (d) measurement of peak expiratory flow rate. At the same time, the worksite was analyzed with an OSHA-recommended ergonomics checklist. Many zarda manufacturing workers complained of respiratory symptoms. Continuous exposure to the tobacco processing environment reduced the workers lung volume and peak expiratory flow rates. Our study indicates that zarda manufacturing workers may have respiratory and pulmonary disorders related to exposure to tobacco dust in their work environment.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2007, 13, 1; 91-96
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Potentiality assessment of fish scale biodegradation using mangrove fungi isolated from Indian Sundarban
Autorzy:
Nandy, V.
Bakshi, M.
Ghosh, S.
Sharma, H.
Basu, B.R.
Chaudhuri, P.
Powiązania:
https://bibliotekanauki.pl/articles/11014.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
fish scale
biodegradation
mangrove
fungi
Aspergillus niger
Penicillium
Indian Sundarban
Opis:
The mangrove fungi, morphologically and physiologically adapted in a different habitat, were isolated from mangrove habitat of Jharkhali, Sundarban, India. The physico-chemical properties like temperature, pH, soil colour, moisture content, carbon and nitrogen content of soil determines the load of microbial population. The soil sample was serially diluted and plated on potato dextrose agar plate with ampicillin to obtain fungal isolates. Total of six isolates were characterized microscopically by lacto phenol cotton blue staining. Two of them were identified as Aspergillus niger and Penicillium sp. and are subjected to biodegradation of fish scale, the major waste of fish processing industries. Aspergillus niger was found to be the best for degradation of fish scale powder by producing zone of clearance. Moreover, media without fish scale didn’t show any zone of clearance indicates the mangrove fungi are capable of degrading the fish scale component.
Źródło:
International Letters of Natural Sciences; 2014, 09
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phonon-plasmon interactions in inhomogeneous semiconductor plasma embedded with nanoparticle cluster
Autorzy:
Ghosh, S.
Dubey, P.
Powiązania:
https://bibliotekanauki.pl/articles/1050820.pdf
Data publikacji:
2018-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.30.+q
72.50.+b
73.22.Lp
Opis:
Phonon-plasmon interaction in inhomogeneous piezosemiconductor embedded with a nanoparticle cluster is examined using hydrodynamic model of plasma and macroscopic model of piezoelectric media. Present work dealt with the extensive investigation of acoustic wave amplification characteristics. The effects of density gradient δ and non-dimensional parameter l related to nanoparticle cluster on acoustic gain have been studied with varying medium electron density n_{0e}, wave frequency ω and velocity ratio ϑ_{0}/ϑ_{s}. The results so obtained, infer that the varying inhomogeneity and presence of nanoparticle cluster within the semiconductor plasma medium play decisive role in depicting the gain characteristics of acoustic wave.
Źródło:
Acta Physica Polonica A; 2018, 133, 5; 1287-1293
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pattern Classification of Fabric Defects Using a Probabilistic Neural Network and Its Hardware Implementation using the Field Programmable Gate Array System
Klasyfikacja rodzaju defektów tkanin za pomocą probabilistycznej sztucznej sieci neuronowej oraz za pomocą systemu FPGA
Autorzy:
Hasnat, A.
Ghosh, A.
Khatun, A.
Halder, S.
Powiązania:
https://bibliotekanauki.pl/articles/234369.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
classification
fabric defect
field programmable gate array (FPGA)
radial basis function
probabilistic neural network
klasyfikacja wad tkanin
probabilistyczna sieć neuronowa
Opis:
This study proposes a fabric defect classification system using a Probabilistic Neural Network (PNN) and its hardware implementation using a Field Programmable Gate Arrays (FPGA) based system. The PNN classifier achieves an accuracy of 98 ± 2% for the test data set, whereas the FPGA based hardware system of the PNN classifier realises about 94±2% testing accuracy. The FPGA system operates as fast as 50.777 MHz, corresponding to a clock period of 19.694 ns.
W pracy zaprezentowano system klasyfikacji wad tkanin przy użyciu probabilistycznej sieci neuronowej (PNN) i przy zastosowaniu systemu Field Programmable Gate Array (FPGA). PNN pozwala na osiągnięcie dokładności 98 ± 2% dla zbioru danych testowych, podczas gdy system FPGA pozwala na osiągnięcie dokładności około 94 ± 2%. System FPGA pracuje przy częstotliwości 50,777 MHz, co odpowiada 19,694 ns.
Źródło:
Fibres & Textiles in Eastern Europe; 2017, 1 (121); 42-48
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parametric Amplification in Magnetized Nondegenerate Semiconducting Plasmas
Autorzy:
Jat, K. L.
Neogi, A.
Ghosh, S.
Powiązania:
https://bibliotekanauki.pl/articles/1887743.pdf
Data publikacji:
1991-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.65.Ky
72.20.Ht
73.50.Rb
78.20.Hp
Opis:
Using the straightforward coupled-mode theory, the parametric amplification is analytically investigated in magnetized piezoelectric as well as non-piezoelectric semiconductors. The origin of nonlinear interaction is taken to be in the second-order optical susceptibility χ$\text{}^{(2)}$ arising from the nonlinear induced current density. The threshold value of the pump electric field E$\text{}_{0th}$ is obtained for crystals. E$\text{}_{0th}$ is found to decrease with the rise in magnetic field and fall with the rise in scattering angle. Parametric gain constants are obtained for different situations of practical interest, i.e. (i) for piezoelectric coupling only g$\text{}_{p}$, (ii) for deformation potential coupling only g$\text{}_{d}$, (iii) for both the couplings g$\text{}_{b}$. Numerical investigations reveal that the magnetic field increases the gain. Maximum gains are obtained for backward scattered mode. g$\text{}_{d}$ is always found to be less than g$\text{}_{p}$ and g$\text{}_{b}$. It is also found that g$\text{}_{p}$ and g$\text{}_{b}$ both are identical up to k ≈ x 10$\text{}^{7}$m$\text{}^{-1}$ and for k ≥ 3 x 10$\text{}^{7}$m$\text{}^{-1}$, g$\text{}_{b}$ exceeds g$\text{}_{p}$.
Źródło:
Acta Physica Polonica A; 1991, 79, 6; 829-841
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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