Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

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

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 28
Tytuł:
Flame Retardant and Antimicrobial Jute Textile Using Sodium Metasilicate Nonahydrate
Autorzy:
Basak, S.
Samanta, K. K.
Chattopadhyay, S. K.
Das, S.
Narkar, R.
Dsouza, C.
Shaikh, A. H.
Powiązania:
https://bibliotekanauki.pl/articles/779514.pdf
Data publikacji:
2014
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
flame retardant
sodium metasilicate nonahydrate
jute
LOI
antimicrobial
Opis:
Flame retardant and antimicrobial functionalities were imparted in jute textile using sodium metasilicate nonahydrate (SMSN), commonly known as “water glass”. Sodium metasilicate nonahydrate (SMSN) was applied in jute fabric in different concentration by padding method followed by drying. Flame retardancy of the fabric was evaluated by Limiting Oxygen Index (LOI) and burning behaviour under vertical flammability tester including the char length. Burning rate was found to decrease by almost 10 times after an application of 2% SMSN compared to the control sample. Thermogravimetry (TG) and differential scanning calorimetry (DSC) analysis of both the control and treated jute fabrics were utilized to understand the mechanism of developed flame retardance in jute fabric. It was observed that the SMSN treated samples showed excellent antimicrobial property against both gram positive and gram negative bacteria. Antimicrobial properties of both the control and treated jute fabrics were also measured quantitatively.
Źródło:
Polish Journal of Chemical Technology; 2014, 16, 2; 106-113
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical, experimental and fuzzy logic applications for investigation of crack location and crack depth estimation in a free-free aluminum beam
Autorzy:
Behera, S. K.
Parhi, D. R.
Das, H. C.
Powiązania:
https://bibliotekanauki.pl/articles/127769.pdf
Data publikacji:
2018
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
crack
natural frequency
mode shapes
numerical
fuzzy
pęknięcie
częstotliwość drgań własnych
kształty modów
Opis:
A beam structure under natural vibration in presence of crack undergoes a sharp change in its dynamic characteristics. In the present study the changes in two important modal vibration parameters like mode shapes and natural frequencies have been extensively studied for crack diagnosis in presence and absence of crack. Numerical and experimental investigations have been carried out using an aluminium Free-Free beam structure with and without crack. The crack presence is indicative of a decrease in local flexibility at crack location and a variation in mode shapes and natural frequencies are noticed. These variations in modal parameters have been used as the tools for crack diagnosis. In the present paper, efforts are made to analyse the presence of a crack using the application of fuzzy logic methodology. Here relative natural frequencies preferably first three are derived from experimental and theoretical investigations are utilised as input data to the fuzzy controller with Gaussian membership functions to obtain crack position and crack depth as output data. The resulted output data from fuzzy logic and the result from corresponding experimental and numerical analysis have been compared.The deviation of result of fuzzy logic from numerical and experimental results have been found to be within a limit of 3%.
Źródło:
Vibrations in Physical Systems; 2018, 29; 1-20
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The structure of Jhum (Traditional Shifting Cultivation System): prospect or threat to climate
Autorzy:
Bhagawati, K.
Bhagawati, G.
Das, R.
Bhagawati, R.
Ngachan, S.V.
Powiązania:
https://bibliotekanauki.pl/articles/10972.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Opis:
The knowledge behind the culture and beliefs of indigenous community needs to be harnessed and should be used to complement the modern technologies and policies for better and sustainable use of biological resources and increase resilience of the sector associated. The main objective of the current research was to study Jhum (Traditional Shifting Cultivation System) and the cycles and culture associated with it. The study was done in northeast Himalayan region of India and phenomenological approach was used. The research reveals that Jhum is the component of traditional agro-ecosystem encompassing diverse set of knowledge and practices of indigenous and local communities embodying traditional life-styles relevant for the conservation and sustainable use of natural resources for their livelihood. The cycle associated with the system reflects the synergy of practices with the natural phenomenon and indicators. Contrary to common modern belief, Jhum is carbon sink, maintain soil health, preserve biological diversity and sustain local climate. Forest clearing during Jhum is not deforestation but forest modification allowing forest regrowth during sufficiently long fallow. Fundamentally, Jhum as a system is an integrated approach to establish agro-ecosystem in the difficult terrains of tropical hill regions that involve forest, soil, biodiversity and livestock management through their culture, tradition and rituals that coevolved with associated ecosystem. Instead of being threat to climate or environment, the system can provide deeper insight into the many different aspects of sustainable and climate resilient development; and the interrelated role of local peoples and their cultures.
Źródło:
International Letters of Natural Sciences; 2015, 46
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study on the occurrence of Asian open bill stork, Anastomus oscitans in particular tree species at Nature Park, Kolkata, India
Autorzy:
Das, A.
Sarkar, S.
Banerjee, K.
Nandy, A.
Talapatra, S.N.
Swarnakar, S.
Powiązania:
https://bibliotekanauki.pl/articles/11152.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Opis:
The trees support many bird and animal species while the survival of urban-dwelling species e.g. bird species dominate over others. This particular Nature park in Kolkata is the habitat of birds and fish species suggesting a better environment for food chain maintenance. The Asian open bill stork, Anastomus oscitans among other bird species is a common and provides ecosystem health indicator. The present study aims to understand the occurrence and population nos. of Asian open bill stork on particular tree species surrounding wetlands at Nature Park, Kolkata, India. Our results clearly indicate that a total population of this bird species having 671 nos. on the particular trees but not in all other available trees in the study area. In conclusion, present research emphasizes a novel occurrence and higher population of the A. oscitans being observed on the basis of the presence of particular tree species, though no attempt has been made on physico-chemical properties of present water and microclimate within the park. Therefore, further research planning should be oriented considering the physico-chemical impacts as well as local microenvironment along with human interaction as visitors in such a way so that these barriers cannot affect nesting and breeding of those species as eco-indicator. Also further relevant research is needed to emphasize on the conservation of these specific tree species to increase population of Asian open bill stork, A. oscitans in Nature park.
Źródło:
International Letters of Natural Sciences; 2014, 22
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
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:
Effect of organic inputs on strength and stability of soil aggregates under rice-wheat rotation
Autorzy:
Das, B.
Chakraborty, D.
Singh, V.K.
Aggarwal, P.
Singh, R.
Dwivedi, B.S.
Powiązania:
https://bibliotekanauki.pl/articles/25472.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
tensile strength
stability
soil aggregate
rice
wheat
cereal crop rotation
Opis:
The study aims to elucidate the impact of organic inputs on strength and structural stability of aggregates in a sandy loam soil. Tensile strength, friability and water stability of aggregates, and the carbon contents in bulk soil and in large macro (>2 mm), small macro (0.25-2 mm), micro (0.053-0.25 mm) and silt+clay size (<0.053) aggregates were evaluated in soils from a long-term experiment with rice-wheat rotation at Modipuram, India, with different sources and amounts of organic C inputs as partial substitution of N fertilizer. Addition of organic substrates significantly improved soil organic C contents, but the type and source of inputs had different impacts. Tensile strength of aggregates decreased and friability increased through organic inputs, with a maximum effect under green gram residue (rice)-farmyard manure (wheat) substitution. Higher macroaggregates in the crop residue- and farmyard manure-treated soils resulted in a higher aggregate mean weight diameter, which also had higher soil organic C contents. The bulk soil organic C had a strong relation with the mean weight diameter of aggregates, but the soil organic C content in all aggregate fractions was not necessarily effective for aggregate stability. The soil organic C content in large macroaggregates (2-8 mm) had a significant positive effect on aggregate stability, although a reverse effect was observed for aggregates <0.25 mm. Partial substitution of nitrogen by organic substrates improved aggregate properties and the soil organic C content in bulk soil and aggregate fractions, although the relative effect varied with the source and amount of the organic inputs.
Źródło:
International Agrophysics; 2014, 28, 2
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomonitoring tool: morphological anomalies in Zygnema sp. of Ganga River Bank
Autorzy:
Das, K.
Gupta, K.
Swarnakar, S.
Talapatra, S.N.
Powiązania:
https://bibliotekanauki.pl/articles/11639.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Opis:
The present study aims to detect morphological abnormalities in Zygnema sp. because this test species have high adaptive capacity in unfavourable environmental stress. This alga is inhabited at the suburban bank of river Ganga, West Bengal, India. The study was done at experimental sites, downstream at Khardah near sewage water mixing area was compared with upstream control site Kalyani as no sewage water discharge. External and internal abnormal morphology such as undulating or wavy and extra outgrowth on cell wall, sometimes bending inwardly and outwardly as external deformities while internal anomalies such as pigment loss, nucleus was in circular, rectangular, oval and amoeboid shapes, also vacuolated and trilobed, broom like chloroplasts and central part of the thallas dried in between two segments. It was observed that this test species was surviving and well adapted with above mentioned deformities. The present preliminary study with Zygnema sp. can be utilized for in situ and ex situ indicator species for riverine biomonitoring. Further research may be relevant to know both tolerant and sensitive algae species inhabited at the river Ganga bank alongwith biochemical and genetic parameters. The present work is suggesting that other inhabiting algae and this adaptive test species can be used for bioremediation of pollutants.
Źródło:
International Letters of Natural Sciences; 2015, 47
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Slip effects on squeezing flow of nanofluid between two parallel disks
Autorzy:
Das, K.
Jana, S.
Acharya, N.
Powiązania:
https://bibliotekanauki.pl/articles/264490.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
pole magnetyczne
tarcie
poślizg
nanofluid
slip effect
squeezing flow
magnetic field
Opis:
In this study, the influence of temperature and wall slip conditions on the unsteady flow of a viscous, incompressible and electrically conducting nanofluid squeezed between two parallel disks in the presence of an applied magnetic field is investigated numerically. Using the similarity transformation, the governing coupled partial differential equations are transformed into similarity non-linear ordinary differential equations which are solved numerically using the Nachtsheim and Swigert shooting iteration technique together with the sixth order Runge-Kutta integration scheme. The effects of various emerging parameters on the flow characteristics are determined and discussed in detail. To check the reliability of the method, the numerical results for the skin friction coefficient and Nusselt number in the absence of slip conditions are compared with the results reported by the predecessors and an excellent agreement is observed between the two sets of results.
Źródło:
International Journal of Applied Mechanics and Engineering; 2016, 21, 1; 5-20
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of antimutagenic avenue and wild plant diversity on roadside near Nature Park, Kolkata, India
Autorzy:
Das, S.
Benerjee, K.
Nandy, A.
Nath Talapatra, S.
Powiązania:
https://bibliotekanauki.pl/articles/11170.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Opis:
The study of diversity of plants in an urban area is a suitable measure of the terrestrial ecosystem. The study of avenue and wild plants diversity is an important research work, which provides knowledge about naturally occurring chemicals in plants, to protect against mutation, cancer and other diseases. These are commonly called as phytochemicals and the natural chemical ingredients are potent to use in antimutagenicity. The present study aims to understand the occurrence and population nos. of different avenue and wild plants planted or natural on roadside near Nature Park, Kolkata, India. The results clearly indicate that a total population of these plant species are having 282 nos. in the study area. Various literatures clearly revealed that these plants and/or their parts have potent antimutagenic properties by the presence of several phytochemicals. In conclusion, present preliminary research emphasizes an occurrence of antimutagenic avenue and wild plants on roadsides, containing natural chemical ingredients. Previous research works confirmed that toxins or mutagens or carcinogens may cause mutation that leads to cancer. The present study is a preliminary assessment of antimutagenic avenue and wild plant species diversity that have not yet been studied in that particular geographical area. The present study also suggested that avenue and wild plants are suitable for antimutagenic potential along with aesthetical view of human as well as ecosystem support. Therefore, biodiversity study, phytochemicals estimation and conservation of these particular plant species and/or different antimutagenic species in other local area viz. roadsides, parks, forests etc. might be relevant because the plant species can be used for herbal medicine in human healthcare as well as to prevent mutation and cancer.
Źródło:
International Letters of Natural Sciences; 2015, 02
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Breeding and agronomic approaches for the biofortification of zinc in wheat (Triticum aestivum L.) to combat zinc deficiency in millions of a population: a Bangladesh perspective
Biofortyfikacja pszenicy (Triticum aestivum L.) cynkiem w celu ograniczenia niedoboru cynku w populacji: perspektywa Bangladeszu
Autorzy:
Das, S.
Chaki, A.K.
Hossain, A.
Powiązania:
https://bibliotekanauki.pl/articles/27742.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Botaniczne
Opis:
The World Health Organization (WHO) has estimated that around 2 billion people across the globe are suffering from “hidden hunger”, where 815 million are under malnutrition. The major essential elements for humans are Fe, Zn, I, Se, Ca, F, and also vitamins. Among them, Zn is considered in the fifth place leading to causes of several deficiency diseases. At least one-third of the population in the world is facing Zn deficiency including around 450,000 children under the age of five. Vitamin A, Fe, and Zn deficiencies can be overcome through the biofortification of staple foodstuffs. This review emphasizes various breeding and agronomic approaches for the biofortification of Zn in wheat grains, which is an encouraging and cost-effective method to enhance the Zn contents of cereal grains. Recently, the Bangladesh Wheat and Maize Research Institute (BWMRI), with technical support from CIMMYT, Mexico, released a promising new Zn-biofortified wheat cultivar, ‘BARI Gom 33’, a result from a conventional breeding program. It has 32 and 50–55 mg kg−1 Zn without and with soil application of ZnSO4, respectively. This cultivar could be a savior for a million people in South Asia, including Bangladesh.
WHO (Światowa Organizacja Zdrowia) oceniła, że około 2 miliardy ludzi na całym świecie cierpi z powodu „ukrytego głodu”, podczas gdy 815 milionów cierpi z powodu niedożywienia. Głównymi pierwiastkami niezbędnymi w diecie dla człowieka są Fe, Zn, J, Se, Ca, F oraz witaminy. Cynk zajmuje 5 miejsce pod względem deficytu w pożywieniu, a jego niedobory prowadzą do wielu groźnych chorób. Co najmniej jedna trzecia populacji na świecie wykazuje objawy niedoboru Zn, w tym około 450000 dzieci poniżej piątego roku życia. Niedobory witaminy A, Fe i Zn można niwelować poprzez biofortyfikację podstawowych artykułów spożywczych. Niniejsza praca przeglądowa podkreśla różne podejścia hodowlane i agronomiczne do biofortyfikacji Zn w ziarniakach pszenicy, co może stanowić zachęcające i opłacalne narzędzie służące zwiększaniu zawartości Zn. Niedawno Bangladeski Instytut Badań Pszenicy i Kukurydzy (BWMRI), przy wsparciu technicznym Międzynarodowego Centrum Ulepszania Kukurydzy i Pszenicy (CIM-MYT) w Meksyku, przekazał nową, wzbogaconą w Zn odmianę biofortyfikowanej pszenicy ‘BARI Gom 33’ uzyskaną w ramach konwencjonalnego programu hodowlanego. Zawartość Zn w ziarniakach wynosi odpowiednio 32,09 i 50–55 μg L−1 Zn bez nawożenia i po doglebowym nawożeniu ZnSO4. Ta odmiana może uratować przed niedożywieniem milion ludzi w Azji Południowej, w tym w Bangladeszu.
Źródło:
Acta Agrobotanica; 2019, 72, 2
0065-0951
2300-357X
Pojawia się w:
Acta Agrobotanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
First report of twig blight of ban tulsi (Croton bonplandianus Bail.) caused by Choanephora cucurbitarum (Berk.and Ravenel) Thaxt. in India
Autorzy:
Das, S.
Dutta, S.
Ray, S.K.
Powiązania:
https://bibliotekanauki.pl/articles/65731.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
twig blight
ban tulsi
Croton bonplandianus
Euphorbiaceae
herb
perennial plant
folk medicine
Choanephora cucurbitarum
plant pathogen
sporangium
India
Opis:
In August 2015, twig blight disease of ban tulsi (Croton bonplandianus Bail.) caused by Choanephora cucurbitarum (Berk. & Ravenel) Thaxt. was observed for the first time, in the Gangetic alluvial region of West Bengal, India. A severe disease incidence (40–50%) showed twig blight symptoms starting with shoot apical meristem (SAM), leaf, and blossom blight symptoms. Typical symptoms were characterized by over-projecting black pin head like emerging sporangiola which formed mycelial cushion on the infected surface. The present report describes the identification of the causal pathogen as C. cucurbitarum based on its morphology and the internal transcribed spacer of its ribosomal DNA (rDNA – ITS) sequences with 100% identity of NCBI-GenBank published Choanephora database. Optimum temperatures, 28–30°C, coupled with high relative humidity (80–90%) during the monsoon season enhances the disease’s progress. To the best of our knowledge this is the first report of twig blight of C. bonplandianus, caused by C. cucurbitarum, in India as well as globally.
Źródło:
Journal of Plant Protection Research; 2017, 57, 4
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameters estimation and life cycle economic analysis of a PV powered tri-cycle in India
Autorzy:
Das, S.
Sadhu, P. K.
Majhi, A.
Ghatak, U.
Bandyopadhya, T.
Powiązania:
https://bibliotekanauki.pl/articles/141519.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
PV
tri-cycle
LCEA
fuel-based
Opis:
This paper is devoted towards life cycle economic analysis (LCEA) of a solar photovoltaic (PV) powered tri-cycle. The paper is meant to propose a more systematic approach in determining the optimum use of scarce resources in order to determine the most cost-effective option of the solar tri-cycle. This analysis is based on the life cycle cost of this solar vehicle, involving its comparison with the customary fuel-based tri-cycle which exhibits the relatively less expenditure of the solar alternative. The economic analysis takes into account the fact that over 20 years, the overall price of solar component, replacement and electricity charges, is much lower as compared to that of a fuel-based tri-cycle in India taking into consideration the fuel cost, maintenance and annual inflation over the same period.
Źródło:
Archives of Electrical Engineering; 2018, 67, 3; 655--665
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
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:
Development of Electrically Conductive Nanocrystalline Thin Film for Optoelectronic Applications
Autorzy:
Das, S K.
Islam, J. M. M.
Hasan, M.
Kabir, H.
Gafur, Md. A.
Hoque, E.
Khan, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/412543.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Conductive thin film
Composite
TiO2
Solar cell
Optoelectronics
Sodium alginate
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 10, 1; 90-101
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Temperature and Frequency Dependence Electrical Properties of $Zn_{1-x}Ca_{x}O$ Nanoceramic
Autorzy:
Das, T.
Das, B.
Parashar, K.
Parashar, S.
Powiązania:
https://bibliotekanauki.pl/articles/1398349.pdf
Data publikacji:
2016-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.05.cP
68.37.xy
84.37.+q
72.80.Lc
77.22.Ch
Opis:
This work reports the temperature and frequency dependence electrical properties of Ca doped ZnO ($Zn_{1-x}Ca_{x}O$, x=0.01) nanoceramic synthesized by solid state reaction method. The X-ray spectra show that the synthesized powder has hexagonal wurtzite structure with space group P6₃mc. The average crystallite size decreases with Ca doping. The increase in oxygen positional parameter (u) indicates lattice distortion in the crystal structure. Doping with Ca caused a slight shift in the (101) plane peak towards lower diffraction angle. The formation of pores in field emission scanning electron microscopy micrograph may be due to the defect created by Ca substitution. The electrical property was investigated by impedance spectroscopy in the temperature range 300-500°C. The synthesized sample shows temperature dependence relaxation phenomena and negative temperature coefficient of resistance effects. Electrical conductivity ($σ_{ac}$) increases with increase in temperature as well as with frequency due to the drift mobility of electrons and hole by hopping conduction. Dielectric constant was found to decrease with increase in frequency and temperature. This decreases drastically in the magnitude of approximately < 10 times than the corresponding undoped one.
Źródło:
Acta Physica Polonica A; 2016, 130, 6; 1358-1362
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 28

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies