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Tytuł:
Development of dual hesitant fuzzy prioritized operators based on Einstein operations with their application to multi-criteria group decision making
Autorzy:
Biswas, A.
Sarkar, A.
Powiązania:
https://bibliotekanauki.pl/articles/229705.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
multi-criteria group decision-making
aggregation operator
dual hesitant fuzzy numbers
Einstein operations
prioritized weighted averaging operator
prioritized weighted geometric operator
Opis:
The purpose of this article is to develop a multicriteria group decision making (MCGDM) method in dual hesitant fuzzy (DHF) environment by evaluating the weights of the decision makers from the decision matrices using two newly defined prioritized aggregation operators based on score function to remove the inconsistencies in choosing the best alternative. Prioritized weighted averaging operator and prioritized weighted geometric operator based on Einstein operations are described first for aggregating DHF information. Some of their desirable properties are also investigated in details. A method for finding the rank of alternatives in MCGDM problems with DHF information based on priority levels of decision makers is developed. An illustrative example concerning MCGDM problem is considered to establish the application potentiality of the proposed approach. The method is efficient enough to solve different real life MCGDM problems having DHF information.
Źródło:
Archives of Control Sciences; 2018, 28, 4; 527-549
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytic Approximation to Localised ab initio Pseudopotential and Some Applications
Autorzy:
Sarkar, A.
Sen, D.
Powiązania:
https://bibliotekanauki.pl/articles/1964217.pdf
Data publikacji:
1997-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
63.10.+a
71.10.-w
Opis:
The localised version of the density functional based norm-conserving pseudopotential has already been applied to various metallic solids and aggregate state properties with some success. Applications to the study of liquid phonons and to the surface dynamics are specially discussed in the present paper. An analytic fit to the pseudopotential is obtained and further application to molecular dynamics is indicated.
Źródło:
Acta Physica Polonica A; 1997, 91, 6; 1081-1089
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Outcome of nanofluid flow containing arbitrary shape nanoparticles induced by a permeable stretching sheet
Autorzy:
Sarkar, A.
Kundu, P. K.
Powiązania:
https://bibliotekanauki.pl/articles/264501.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
przenoszenie ciepła
nanociecze
promieniowanie cieplne
nanofluid
heat transfer
boundary layer flow
thermal radiation
permeable stretching sheet
Opis:
In this work we have discussed the impact of thermal radiation on heat transfer to nanofluid flow over an unsteady permeable stretching sheet using various types of arbitrary shape nanoparticles of Copper (Cu), Silver (Ag), Alumina [...], and Titania Oxide [...] in the base fluid. Suitable transformations have been employed to build ODEs from the partial differential equations. Numerical results are therefore obtained particularly for cylindrical shape and spherical shape nanoparticles. Our analysis substantiates that the velocity and temperature profiles increases with enhanced thermal radiation parameter. Further, Nusselt number is more advanced for the nanofluid that contains cylindrical shape nanoparticles as compared to spherical shape nanoparticles.
Źródło:
International Journal of Applied Mechanics and Engineering; 2020, 25, 2; 142-156
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effective Pair Interaction from Ab Initio Pseudopotentials - Importance and Applications
Autorzy:
Haldar, S.
Sarkar, A.
Sen, D.
Powiązania:
https://bibliotekanauki.pl/articles/1858123.pdf
Data publikacji:
2000-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
63.10.+a
65.90.+i
Opis:
Computation of reliable effective interionic pair interaction for simple metals has been discussed on the basis of localised ab initio pseudopotential within linear screening approximation. The influence of different commonly used screening functions on the shape of pair potential is examined and the temperature dependence of the interaction is also investigated. Various features of the potential are studied and compared with empirical and available first principle results. Importance of the present study and some related problems are also analysed.
Źródło:
Acta Physica Polonica A; 2000, 97, 4; 651-662
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Static Local Field Factor and Ground State Properties of Interacting Electron Gas
Autorzy:
Sarkar, A.
Haldar, S.
Roy, D.
Sen, D.
Powiązania:
https://bibliotekanauki.pl/articles/2038378.pdf
Data publikacji:
2004-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.10.-w
71.45.Gm
Opis:
In the most general case, the calculation of the static local field factor G(q) for the unpolarised electron gas requires the knowledge of exchange-correlation energy functionals for both the parallel and antiparallel relative spin orientations of the electron gas system. Accurate density interpolation formulae using the quantum Monte Carlo data of Ceperley-Alder for the correlation energy of electron gas in both the "para" and "ferro" states, respectively, in the given density range are used for the calculation of G( q). Fulfilment of relevant consistency criteria is ensured and the local field factor so obtained renders significant improvement of ab initio pseudopotential calculation of effective interaction of Al. The Levin like interpolant of the correlation energy Ceperley-Alder data has been further used to study the ground state properties of the electron gas. It is also noted that a better understanding of the interacting electron gas properties requires a more accurate spin interpolation formula for the correlation energy than the existing ones.
Źródło:
Acta Physica Polonica A; 2004, 106, 4; 497-514
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Laterite as a filter media for reducing some priority inorganic contaminants in water
Lateryt jako medium filtracyjne do usuwania niektórych priorytetowych nieorganicznych zanieczyszczeń z wody
Autorzy:
Sarkar, A. R.
Goswami, J.
Banerjee, A.
Sarkar, M.
Powiązania:
https://bibliotekanauki.pl/articles/1826188.pdf
Data publikacji:
2004
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
zanieczyszczenie wody
metale ciężkie
fluor
filtry do oczyszczania wody
lateryt
Opis:
Occurrence of elevated concentration of different inorganic pollutants in surface and/or ground water has created immense social problems. Among the various toxicants, heavy metal ions and fluoride are the priority contaminants, considering their magnitude, time of residence and human health hazards. While the heavy metals enter the water bodies primarily through industrial discharge (1), fluoride may come both from industries as well as via geological sources (2). All these toxicants are of serious concerns to the environmentalists due to their non-biodegradable character (3). Occurrence of excessive fluoride in ground water, causes serious and irreversible health damage, known as fluorosis. At present twenty nine countries including India are facing the problem due to excess fluoride in ground water (4). A conservative estimate of fluoride victims around the globe, at present is 67 million while 64 million people are at risk (5). All the chemicals were of analytical-reagent grade. Stock solutions (1000 ppm) of Cu(II), Ni(II), Zn(II), Fe(II) were prepared by dissolving the respective metal salts in doubly distilled water. Fluoride solution (stock) of 100 ppm was prepared by dissolving potassium fluoride in doubly distilled water, kept in plastic container. Laterite obtained from Bankura, (West Bengal, India) was washed with doubly distilled water, air-dried and sieved at different size fractions. Activated carbon is considered as a universal and most efficient adsorbent for treatment of water contaminated by a wide range of pollutants (16). But its higher cost limits its use. Therefore, more research is directed towards the search of alternative adsorbents. In India laterite is readily available in plenty, as a large area is covered by laterite. Therefore laterite filter media can be used as an alternative, for some metal ions and fluoride removal. Moreover the capacity of laterite filter media in suitable experimental conditions is more or less comparable to activated carbon, at least for some solutes. Further the laterite media can be extended for development of a simple household filter.
Pojawienie się podwyższonych stężeń różnych nieorganicznych zanieczyszczeń w wodach powierzchniowych i/lub gruntowych spowodowało pojawienie się ogromnych problemów społecznych. Spośród wielu różnych substancji toksycznych, metale jony metali ciężkich oraz fluor są zanieczyszczeniami priorytetowymi, biorąc pod uwagę ich rozpowszechnienie, czas pozostawania w środowisku oraz zagrożenie jakie niosą dla życia i zdrowia ludzkiego. Podczas gdy metal ciężkie trafiają do środowiska głównie poprzez zrzut ścieków przemysłowych, to fluor może pochodzić zarówno ze źródeł przemysłowych jak również ze źródeł geologicznych. Wszystkie te związki stanowią bardzo poważny problem z powodu ich trudno biodegradowalnego charakteru. W badaniach, których wyniki przedstawiono w niniejszym referacie, zastosowano lateryt do efektywnego usuwania metali ciężkich: miedzi, niklu, cynku i żelaza oraz fluoru z wody. Lateryt jest zwietrzałą skałą dostępną w dużych ilościach w wielu częściach Indii. Jest to więc materiał łatwo dostępny i tani. Co więcej proces adsorpcji jest prosty w prowadzeniu i może być stosowany nawet przez ludzi mieszkających na wsi. Główne składniki laterytu to: krzemionka, tlenek glinu, oraz tlenek żelazowy. Pozostałe składniki to różne tlenki metali: sodu, potasu, wapnia, magnezu manganu i tytanu. Proces sorpcji wybranych metali na laterycie badano zarówno w warunkach statycznych jak i dynamicznych. Metoda statyczna służyła do określenia pojemności sorpcyjnej oraz kinetykę procesu adsorpcji. Metodę dynamiczną zastosowano do określenia wpływu prędkości przepływu i objętości próbki na wyniki adsorpcji w kolumnie. Badania wykazały, że usuwanie poszczególnych metali zachodziło według następującego szeregu powinowactwa: Fe(II) > Cu(II) > Ni(II) > Zn(II). Efektywność usuwania fluoru w czasie adsorpcji w kolumnie przekraczała 96%. Na podstawie danych równowagi obliczono czas połowicznego wyczerpania złoża, czyli czas potrzebny na wyczerpanie połowy całkowitej pojemności sorpcyjnej laterytu. Z badań wynika, że wartość ta waha się od 20 do 45 minut dla jonów poszczególnych metali (tabela 2), oraz wynosi 40 minut podczas adsorpcji fluoru. Niższe wartości t1 wskazują, że kinetyka interakcji pomiędzy laterytem a usuwanym składnikiem jest wystarczająco szybka. Wyniki badań pokazują, że pojemność sorpcyjna laterytu jako medium filtracyjnego, w odpowiednich doświadczalnych warunkach jest mniej więcej porównywalna z pojemnością węgla aktywnego, przynajmniej dla niektórych usuwanych substancji. W związku z tym celowe są dalsze badania nad zastępowaniem węgla aktywnego laterytem w prostych domowych filtrach oczyszczających wodę.
Źródło:
Rocznik Ochrona Środowiska; 2004, Tom 6; 9-18
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On discontinuties in thermoelastic plane waves without energy dissipation due to a thermo-mechanical shock
Autorzy:
Sarkar, N.
Lahiri, A.
Powiązania:
https://bibliotekanauki.pl/articles/265406.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
termosprężystość
natężenie Greena-Naghdiego
generalized thermoelasticity
Green-Naghdi model
thermoelastic half-space
pulse function
eigenvalue approach
Opis:
The present paper deals with the thermoelastic plane waves due to a thermo-mechanical shock in the form of pulse at the boundary of a homogeneous, isotropic thermoelastic half-space. The field equations of the Green- Naugdhi theory without energy dissipation for an thermoelastic solid in the generalized thermoelasticity theory are written in the form of a vector-matrix differential equation using Laplace transform techniques and then solved by an eigenvalue approach. Exact expressions for the considered field variables are obtained and presented graphically for copper-like material. The characteristic features of the present theory are analyzed by comparing these solutions with their counterparts in other generalized thcrmoelasticity theories.
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 2; 503-519
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cause, effect and remedial options for fluoride in drinking water
Przyczyna, skutek i opcje zaradcze dla fluoru w wodzie pitnej
Autorzy:
Sarkar, M.
Banerjee, A.
Powiązania:
https://bibliotekanauki.pl/articles/1826208.pdf
Data publikacji:
2003
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
woda pitna
fluor
jakość wody
oczyszczalnia wody
Opis:
Increasing population in developing countries and high industrialization of the advanced countries are creating environmental problems of enormous dimensions. Fluoride contamination of drinking water is one of such problems worldwide. At present, twenty nine countries, are reported to be affected with fluorosis, the fluoride related disease. The problem in India, too is known for quite a long time. Recently the fluoride concentration in the ground water of Rampurhat and Nalhati block of Birbhum district, West Bengal, is found much above the safe limit. In the present communication the fluoride level in the drinking water of different parts of India with special emphasis on West Bengal is highlighted. The cause of elevated fluoride level in the ground water, its effect on the health status of the people in the affected area is presented. Moreover, the remedial options for reduction of fluoride from drinking water are discussed. Considering the limitations and difficulties of the above processes we develop a simple, low cost and technofeasible method in our laboratory for removal of fluoride in drinking water. The locally available natural material Laterite (or red soil) is used as an adsorbent. The fluoride partitioning between Laterite-solution phases is determined by clay type and dominant cations of Laterite, total amount of fluoride in the solution and the pH and temperature of operation. The quick attainment (1 hr) of equilibrium makes the process technofeasible. The adsorption isotherm follows a favourable L-type nature. Either Langmuir or Freundlich adsorption isotherm can be applied changing particular range of fluoride concentration. The process is energetically favourable as indicated by negative free energy change of process. The process is aided by higher temperature and higher dose of Laterite. The kinetic consideration indicates that both surface adsorption and pore diffusion are operative and the process is favorable kinetically. The local abundance of Laterite as well as its easy regeneration makes the process quite cheap and acceptable by rural people.
Celem obecnych badań przedstawionych w tym artykule jest przegląd miejsc występowania fluoru w różnych częściach Indii. Pomiary jakości wody wskazują, że niektóre części dzielnicy Birbhum w West Bengal są również dotknięte wysokim stężeniem fluoru w wodzie do picia. Mieszkańcy wsi, którzy są biedni i ze stosunkowo niską świadomością zdrowia, bardzo cierpią na fluorozę zębową, szkieletową i nie szkieletową. Powaga problemu we wsi Nashipur w Birbhum jest taka, że zamieniła się ona teraz w wioskę "niepełnosprawnych". Ludzie spożywają wodę do picia o wysokiej zawartości fluoru (19 mg/l), gdy górna granica określana przez WHO wynosi 1,5 mg/l. Wysokie zawartość fluoru spowodowana jest budową geologiczną terenu. Możliwość pojawienia się fluoru w wodzie gruntowej w pobliskich dzielnicach jak Bankura i Purulia, mających podobną geologiczną budowę, nie może zostać odrzucona. Aby złagodzić cierpienia miejscowych ludzi i dostarczyć bezpieczną wodę do picia zaproponowano prostą, tanią i wykonalną technicznie metodę oczyszczania wody. Lokalnie dostępny, naturalny minerał laterit (albo czerwona ziemia) został zastosowany jako substancja adsorbująca. Miejscowa obfitość lateritu, jak również jego łatwa regeneracja czyni proces całkiem tanim i do przyjęcia przez mieszkańców wsi.
Źródło:
Rocznik Ochrona Środowiska; 2003, Tom 5; 123-129
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interactions due to moving heat sources in generalized thermoelastic half-space using L-S model
Autorzy:
Sarkar, N.
Lahiri, A.
Powiązania:
https://bibliotekanauki.pl/articles/265642.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
termosprężystość
źródło ciepła
procedura Laplace'a
generalized thermoelasticity
L-S model
elastic half-space
moving heat sources
eigenvalue approach
Opis:
A one-dimensional problem for a homogeneous, isotropic and thermoelastic half-space subjected to a moving plane of heat source on the boundary of the space, which is traction free, is considered in the context of Lord- Shulaman model (L-S model) of thermoelasticity. The Laplace transform and eigenvalue approach techniques are used to solve the resulting non-dimensional coupled equations. Numerical results for the temperature, thermal stress, and displacement distributions are represented graphically and discussed.
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 3; 815-831
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ethological study of flower visiting insects in two parks, Kolkata, India
Autorzy:
Sarkar, S.
Nandy, A.
Talapatra, S.N.
Powiązania:
https://bibliotekanauki.pl/articles/11497.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
ethology
flower
visiting insect
insect
park
urban park
Calcutta city
India
Opis:
Flower visiting insects attract by the flowers colour, shape, size and fragrance as pollinator. This is a mutual relationship between flowers and insects. The present study aims to know behavioural response or ethology of flower visiting insect in relation to particular flower and/or probable atmospheric changes in two managed parks, Kolkata, India. The study areas were selected as per heavily-populated neighborhoods, nearby office buildings, nearby roads and continuous vehicular movements, human interactions as visitors. The study was carried out at 2 sampling stations viz (i) Elliot park and (ii) Agri-Horticulture Society. The flower species were selected viz. Helianthus annuus (sunflower), Petunia sp. (petunia) and Buganvilia spectabilis (Buganvilia) planting above mentioned areas because these species are more common among other species. In each flower, behavioural response or ethology of visiting insects were studied by visual observation and total 10 flowers of each species were observed randomly. The present results clearly indicate that various insects were majorly showed foraging and feeding behaviour and only mating behaviour was found in two species. This study is a preliminary assessment of flower visiting insects’ ethology but further researches are needed in relation to pollination efficiencies of flower visiting insects in the particular flower and air pollution load nearby area by using instruments. It was concluded that insect visitors are showing foraging and feeding behavior but only two species were showed mating behaviour, which may be due to the vehicular air pollution because two parks are located nearby roads and continuous vehicular movements were observed.
Źródło:
International Letters of Natural Sciences; 2014, 12, 1
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Failure analysis of laminated composite plate under hygro-thermo mechanical load and optimisation
Autorzy:
Choudhury, A.
Mondal, S. C.
Sarkar, S.
Powiązania:
https://bibliotekanauki.pl/articles/264515.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
współczynnik wytrzymałości
kompozyt hybrydowy
obciążenia
first ply failure load
last ply failure load
strength ratio
fiber orientation angle
hybrid composite
Opis:
Failure analysis of laminated composite plates for different mechanical, thermo mechanical and hygro-thermo mechanical loads for different ply thicknesses, stacking sequences, fiber orientation angles and composite material systems is presented in the paper. A comparative study of different failure theories is also presented in the paper. The effect of fiber orientation angles on the first ply failure load is also studied. A hybrid composite laminate is developed based on the first ply failure load which minimizes weight and cost. The last ply failure load based on fully discounted method is calculated for different stacking sequences. An optimum composite material system and laminate layup is studied for a targeted strength ratio which minimizes weight.
Źródło:
International Journal of Applied Mechanics and Engineering; 2019, 24, 3; 509-526
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of heat transfer on thermal stresses in an annular hyperbolic fin: an approximate analytical solution
Autorzy:
Mallick, A.
Ranjan, R.
Sarkar, P. K.
Powiązania:
https://bibliotekanauki.pl/articles/279437.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
thermal stresses
Adomian decomposition method (ADM)
variable thermal conductivity
Opis:
An approximate analytical solution is presented for thermal stresses in an annular convectiveconductive fin of a hyperbolic profile with temperature dependent thermal conductivity. The classical thermo-elasticity theory coupled with the ADM based polynomial form of temperature field is employed for an approximate analytical solution of thermal stresses. The influence of thermal parameters, i.e. variable thermal conductivity, the thermo-geometric parameter and the non-dimensional coefficient of thermal expansion on temperature and sttress fields are investigated. The results for the stress field obtained from the ADM based solution are compared with those available in literature and found to be in close agreement.
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 2; 437-448
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Temperature on the Refractive Indices of Liquid Crystals and Validation of a Modified Four-Parameter Model
Autorzy:
Thingujam, K.
Sarkar, S.
Choudhury, B.
Bhattacharjee, A.
Powiązania:
https://bibliotekanauki.pl/articles/1418322.pdf
Data publikacji:
2012-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.15.+e
78.20.Fm
64.70.M-
Opis:
The variation of refractive indices with temperature of three pure nematogenic compounds 5OCB, CPHB and 6CHBT were studied experimentally using thin prism technique. The refractive indices $n_{o}$ and $n_{e}$ were measured using 633 nm lines from a He-Ne laser. A modified four-parameter model was taken which is based on the Vuks equation describing the effect of temperature on the refractive indices of liquid crystals. In this paper we report the variation of refractive indices of these three liquid crystals with temperature, using the thin prism method. The variation in birefringence was determined experimentally. The variation in refractive indices and birefringence were also fitted theoretically using the modified Vuks equation. On comparison, the theoretically fitted values show close agreement with the experimental values.
Źródło:
Acta Physica Polonica A; 2012, 122, 4; 754-757
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigations on Chemical, Thermal Decomposition Behavior, Kinetics, Reaction Mechanism and Thermodynamic Properties of Aged TATB
Autorzy:
Singh, A.
Kaur, G.
Sarkar, C.
Mukherjee, N.
Powiązania:
https://bibliotekanauki.pl/articles/357970.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
1,3,5-triamino-2,4,6-trinitrobenzene
thermal decomposition
kinetics
thermodynamics
Opis:
1,3,5-triamino-2,4,6-trinitrobenzene (TATB) is a kind of insensitive high explosive that can be used as an energetic material in nuclear weapon and space applications. In this work, we have studied the effect of aging on the properties of TATB from a 20 year old lot that had been in direct contact with casing and natural environment conditions. The kinetics was studied using the temperature at the maximum reaction rate (peak) and isoconversional methods from TGA and DTA data obtained at five heating rates under a nitrogen atmosphere. The properties investigated for thermal stability indicate that there is no change in the properties during prolonged exposure in natural environment conditions. The activation energy calculated by the Kissinger method was 179.9 kJ·mol−1 by DTG and the 176.9 kJ·mol−1 by DTA. The experimental results of kinetic analysis obtained by isoconversional methods are in good agreement and very close to each other. In the analysis of reaction mechanisms, the reaction models could be probably best described by a surface contraction mechanism using the Coats-Redfern and Criado methods. The thermodynamic parameters such as Gibbs free energy, enthalpy and entropy of activation were also investigated. The self-accelerating decomposition temperature (TSADT) and critical temperature for thermal explosion (Tb) were also calculated.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 2; 258-282
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of bird diversity as bioindicators in two parks, Kolkata, India
Autorzy:
Chowdhury, R.
Sarkar, S.
Nandy, A.
Talapatra, S.N.
Powiązania:
https://bibliotekanauki.pl/articles/11495.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
assessment
bird diversity
bioindicator
vehicular traffic
vehicular pollution
urban park
biomonitoring
landscape change
park
Calcutta city
India
Opis:
The trees of parks and gardens support many species, the survival of urban-dwelling species mainly bird species. Birds amongst other species provide a wide range of environmental and social functions to cities and urban dwellers. The present study aims to know bird diversity in two parks as bioindicator of automobile air pollution exposure, landscape changes and/or human interactions. The study areas were selected as per heavily-populated neighborhoods, nearby office buildings, nearby roads and continuous vehicular movements, human interactions as visitors, where high levels of human disturbance are common. The study was carried out at 2 sampling stations viz (i) Elliot park and (ii) Agri-horticulture Society. The bird species diversity was studied by qualitative and quantitative assessment. Indices were Species richness, Index of Dominance, Relative abundance, Shannon-Wiener Diversity Index and Evenness Index for birds for all selected sites were calculated using the statistical formulae. The present results as bioindicators bird species clearly indicate that the bird species are very few in numbers in both the parks. When comparison made between both the parks, it was observed less number of bird varieties (16 types) in Elliot park than varieties (9 types) more less in number in Agri-horticulture society. This study is a preliminary assessment of bird diversity but further researches are needed in relation to biochemical and genetic damage study as well as air pollution load by using instruments. In the present study it was concluded that the less numbers of birds and their different diversity indices were found a decreasing trends, though there no attempt has been made on physico-chemical properties of present air pollutants. The less number of varieties of bird species are as tolerant bioindicators, which may be due to the vehicular pollution and/or human interference and/or landscape changes due to nearby neighborhood blocks, office and residential buildings, continuous movement of vehicles etc.
Źródło:
International Letters of Natural Sciences; 2014, 11, 2
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł

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