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    Tytuł:
    Sample allocation decisions for program evaluation: a case of multiplicative effect on units due to the developmental initiatives carried out in a phased manner
    Autorzy:
    Pandey, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/38469.pdf
    Data publikacji:
    2010
    Wydawca:
    Instytut Badawczy Leśnictwa
    Tematy:
    developmental initiative
    stratified sampling
    temporal impact
    sample allocation
    weight
    Źródło:
    Folia Forestalia Polonica. Series A . Forestry; 2010, 52, 2
    0071-6677
    Pojawia się w:
    Folia Forestalia Polonica. Series A . Forestry
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Forestry’s contribution to livestock feed in Uttarakhand, India: a quantitative assessment of volume and economic value
    Autorzy:
    Pandey, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/38772.pdf
    Data publikacji:
    2011
    Wydawca:
    Instytut Badawczy Leśnictwa
    Tematy:
    forestry
    livestock feed
    Uttarakhand
    India
    quantitative assessment
    economic value
    Opis:
    Livestock sector forms an important livelihood activity for farmers, through supporting agriculture and supplementing income in India. The lack of availability of sufficient feed is one of the major limiting factors for better productivity of livestock. The feed are of two types as roughages (high in crude fibrous material) available at public forest, farm lands, etc. and concentrates (high in nutrients and mixture of oil, coarse grain, and cereals). The general degradation of forest reduces the fodder availability, severely. Therefore, improving forest condition may provide pathways for sustainability of both, livestock and forest. This may be addressed through sustainable forest management, which requires scientific inputs and may be shifting of some demand of locals to other resources. This requires huge amount from government. Presently, livestock sector is part of the Agriculture and Allied Activities sector in the accounting system of India, and therefore, all related shares and expenditure is part of the component. This results into under allocation for the actual shares of forestry contribution to livestock, in the Forestry and Logging sector. This occurs primarily, due to the lack of scientific information on the share and value of fodder from forest. This study has been undertaken to estimate the share and economic value of forests derived livestock feed. Primary data has been collected as per pretested questionnaire from 316 randomly selected households engaged in livestock rearing from 66 villages distributed across the Uttarakhand, India. Information pertaining to the fodder to livestock from all sources and socio-economic attributes were collected from each household to understand the feed consumption behavior of livestock. The feed sources were classified in forests, other than forests and market. The shares and economic value of livestock feed derived from different sources has been estimated for all livestock. The prices of various feeds were either collected directly from market or estimated through non market valuation techniques based on two scenarios (contingent valuation and ratio of dry and green matter basis of 0.40). The average proportion of feed quantity consumed by livestock was 58% from forests, 39% from other than forests and 3% from markets for hilly region. It was 97% from other than forests and 3% from markets for plain region. For hilly region, the proportion of economic value varies from 40– 41% for forest; 40– 41% for agriculture and 18– 20% from market. The total value of forest fodder was Rs 4811 millions in scenario 1 and Rs 5209 millions in scenario 2 for the Uttarakhand. The study concludes and recommends that these proportions may be utilized to allocate the appropriate share of livestock feed into Forestry and Logging sector, which may results into the realistic share of the sector.
    Źródło:
    Folia Forestalia Polonica. Series A . Forestry; 2011, 53, 2
    0071-6677
    Pojawia się w:
    Folia Forestalia Polonica. Series A . Forestry
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Modelling and optimization of temperature in orthopaedic drilling : An in vitro study
    Autorzy:
    Pandey, R. K.
    Panda, S. S.
    Powiązania:
    https://bibliotekanauki.pl/articles/307028.pdf
    Data publikacji:
    2014
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    analysis of variance
    ANOVA
    orthopaedic surgery
    response surface methodology
    Taguchi method
    thermal osteonecrosis
    analiza wariancji
    chirurgia ortopedyczna
    metoda Taguchi
    Opis:
    This present investigation uses the Taguchi and response surface methodology (RSM) for modelling and optimization of the temperature produced during bone drilling. The drilling of bone is a common procedure in orthopaedic surgery to produce hole for screw insertion to fixate the fracture devices and implants. A major problem which is encountered during such a procedure is the increase in temperature of the bone due to the plastic deformation of chips and the friction between the bone and the drill. The increase in temperature can result in thermal osteonecrosis which may delay healing or reduce the stability and strength of the fixation. The drilling experiments are conducted on poly-methyl-meth-acrylate (PMMA) (as a substitute for bone) using Taguchi’s L27 experimental design technique. The cutting parameters used are drill diameter, feed rate and cutting speed. The optimum cutting parameters for minimum temperature are determined by using S/N ratios and the effect of individual cutting parameters on temperature produced is evaluated using analysis of variance (ANOVA). A second-order model is established between the drilling parameters and temperature using RSM. The experimental results show that the drill diameter is the most significant drilling parameter affecting the temperature during drilling followed by cutting speed and feed, respectively. The values predicted and the values obtained from experiment are fairly close, which indicates that the developed RSM model can be effectively used to predict the temperature in orthopaedic drilling.
    Źródło:
    Acta of Bioengineering and Biomechanics; 2014, 16, 1; 107-116
    1509-409X
    2450-6303
    Pojawia się w:
    Acta of Bioengineering and Biomechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Surface Coating of Cyclotetramethylenetetranitramine (HMX) Crystals with the Insensitive High Explosive 1,3,5-Triamino-2,4,6-trinitrobenzene (TATB)
    Autorzy:
    Nandi, A. K.
    Ghosh, M.
    Sutar, V. B.
    Pandey, R. K.
    Powiązania:
    https://bibliotekanauki.pl/articles/358361.pdf
    Data publikacji:
    2012
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    surface coating
    cyclotetramethylenetetranitramine
    1,3,5-triamino-2,4,6-trinitrobenzene
    1,3,5-trichloro-2,4,6-trinitrobenzene
    scanning electron microscope
    Opis:
    A method to crystallize the thermally stable, insensitive high explosive, 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) onto the surface of another high explosive cyclotetramethylenetetranitramine (HMX) crystal is described. Amination of 1,3,5-trichloro-2,4,6-trinitrobenzene (TCTNB) in toluene produces TATB which is precipitated by a reactive crystallization process. When the reaction is carried out in the presence of HMX, TATB crystals are found to be deposited onto the HMX crystal surface. This phenomenon was utilized to obtain in situ surface coating of HMX crystals with TATB. Both the conventional amination and the sonochemical amination methods, using dry ammonia (NH3) gas and ammonium hydroxide (NH 4 OH) respectively as the aminating agents, were studied. The coated materials were characterized by Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), Simultaneous Thermal Analysis (STA) and sensitivity tests. The results were compared with those of the virgin materials. Sonochemical amination provided a uniform coating of the HMX crystals. Coated HMX has shown substantial friction insensitivity gain as compared to uncoated HMX. However there is a drop in impact insensitivity in the coated materials.
    Źródło:
    Central European Journal of Energetic Materials; 2012, 9, 2; 119-130
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Assay of the Insensitive High Explosive FOX-7 by Non-Aqueous Titration
    Autorzy:
    Nandi, A. K.
    Paramasivan, P.
    Singh, S. K.
    Mandal, A. K.
    Pandey, R. K.
    Powiązania:
    https://bibliotekanauki.pl/articles/358156.pdf
    Data publikacji:
    2012
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    1,1-diamino-2,2-dinitroethene
    FOX-7
    non-aqueous titration
    N,N-dimethylformamide
    Opis:
    A non-aqueous titration method was developed to assay the insensitive high explosive 1,1-diamino-2, 2-dinitroethene (FOX-7). The weak acidic nature of FOX-7 (pKa 10.6) was exploited in the assay method. The sample was dissolved in the protophilic solvent N, N-dimethylformamide and titrated against sodium methoxide solution in benzene/methanol using azo violet as indicator. FOX-7 samples obtained from regular batch operations were assayed by this method and the results were compared with that of a recrystallized sample. The method is simple, rapid and has good accuracy and precision.
    Źródło:
    Central European Journal of Energetic Materials; 2012, 9, 4; 343-352
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Preparation and characterization of ultrafine RDX
    Autorzy:
    Pant, A.
    Nandi, A. K.
    Newale, S. P.
    Gajbhiye, V. P.
    Prasanth, H.
    Pandey, R. K.
    Powiązania:
    https://bibliotekanauki.pl/articles/358126.pdf
    Data publikacji:
    2013
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    ultrafine RDX
    drowning-out crystallization
    BET surface area
    SEM
    mechanical and electrostatic spark sensitivity
    Opis:
    This paper describes the synthesis of ultrafine Hexogen (UF-RDX) of size <5μm by drowning-out crystallization. RDX was precipitated from acetone or dimethylformamide (DMF) solution by reducing the solvent power using either a miscible, non-aqueous antisolvent, n-hexane, or an aqueous antisolvent, water containing polyethylene glycol (PEG). Process parameters such as solvent/ antisolvent ratio, agitation, ultrasonication etc. were studied. UF-RDX was characterized for Brunauer-Emmett-Teller (BET) surface area, X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC) and sensitivity tests. In the case of the non-aqueous antisolvent, the precipitated RDX crystals were rod shaped of diameter <1 μm. For the aqueous antisolvent, oval shaped crystals (<5 μm) were precipitated. UF-RDX was found to be more sensitive to impact and less friction sensitive compared to production grade RDX (60-80 μm).
    Źródło:
    Central European Journal of Energetic Materials; 2013, 10, 3; 393-407
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Formation of Boric Acid by Surface Oxidation of Amorphous Boron Powder: Characterization and Quantitative Estimation
    Autorzy:
    Nandi, A. K.
    Ghosh, M.
    Newale, S. P.
    Jadhav, A. J.
    Prasanth, H.
    Pandey, R. K.
    Powiązania:
    https://bibliotekanauki.pl/articles/358160.pdf
    Data publikacji:
    2012
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    amorphous boron powder
    B2O3
    boric acid
    FTIR
    SEM
    EDX
    Opis:
    Amorphous Boron Powder (ABP) is used as a fuel in air breathing propulsion systems due to its high gravimetric and volumetric heat value. ABP is sensitive to air and undergoes slow oxidation during storage and handling, leading to the formation of a boric acid layer on the particle surface. This paper describes an analytical method for the estimation of boric acid in ABP. In-house samples obtained from the pilot plant of this laboratory, as well as commercial samples, were assayed for their boric acid content. The study is substantiated by characterization of the ABP samples by SEM with EDX and FTIR. The ageing characteristics of in-house boron powder was also studied.
    Źródło:
    Central European Journal of Energetic Materials; 2012, 9, 4; 387-398
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Assay of the Insensitive High Explosive 3-Nitro-1,2,4-triazol-5-one (NTO) by Acid-Base Titration
    Autorzy:
    Nandi, A. K.
    Singh, S. K.
    Kunjir, G. M.
    Singh, J.
    Mandal, A. K.
    Pandey, R. K.
    Powiązania:
    https://bibliotekanauki.pl/articles/358351.pdf
    Data publikacji:
    2013
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    NTO
    purity
    acid-base titration
    HPLC
    quality control
    Opis:
    The insensitive high explosive 3-nitro-1,2,4-triazol-5-one (NTO) is a weak acid (pKa 3.76) due to the labile N–H bond. The weakly acidic character of this compound is exploited for its assay by aqueous acid-base titration. The NTO sample was dissolved in water and the resultant solution was titrated against 0.07 N NaOH solution using phenolphthalein as indicator. Regular batch samples were assayed by this method and the results were compared with those obtained by the HPLC method. The aqueous acid-base titration method was found to be suitable for the quality control of the product.
    Źródło:
    Central European Journal of Energetic Materials; 2013, 10, 1; 113-122
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dynamical analysis of stiffened plates under patch loading
    Autorzy:
    Srivastava, A. K. L.
    Pandey, S. R.
    Kumar, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/265921.pdf
    Data publikacji:
    2013
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    metoda elementów skończonych
    obciążenie krawędziowe
    częstotliwość drgań
    usztywniacz
    FEM
    partial edge loadings
    buckling load
    vibration frequency
    stiffener
    Opis:
    The vibration characteristics of stiffened plates with cutouts subjected to in-plane partial edge loadings at one end at the plate boundaries are studied using the finite element method. Buckling loads and vibration frequencies are determined for different cutout ratios and extent of partial edge loading at one end. In the structural modelling, the plate and the stiffeners are treated as separate elements where the compatibility between these two types of elements is maintained. The main elegance of the formulation lies in the treatment of the stiffeners. The stiffeners can be placed anywhere within the plate element, and need not be placed on the nodal lines. The vibration characteristics are discussed and the results are compared with those available in the literature. Numerical results are presented for a range of cutout to plate size from 0 to 0.8.
    Źródło:
    International Journal of Applied Mechanics and Engineering; 2013, 18, 2; 537-553
    1734-4492
    2353-9003
    Pojawia się w:
    International Journal of Applied Mechanics and Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Process Optimization for the Gas-Liquid Heterogeneous Reactive Crystallization Process Involved in the Preparation of the Insensitive High Explosive TATB
    Autorzy:
    Nandi, A. K.
    Kshirsagar, A. S.
    Thanigaivelan, U.
    Bhattacharyya, S. C.
    Mandal, A. K.
    Pandey, R. K.
    Bhattacharya, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/358228.pdf
    Data publikacji:
    2014
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    TATB
    TCTNB
    amination
    reaction crystallization
    chloride impurity
    particle size
    Opis:
    The thermally stable, insensitive, high explosive 1,3,5-triamino-2,4,6- trinitrobenzene (TATB) is manufactured by amination of 1,3,5-trichloro-2,4,6- trinitrobenzene (TCTNB) in toluene with NH3 gas. It is an isothermal, single-feed, semi-batch, gas-liquid heterogeneous, reaction crystallization process. The amination process is discussed by applying the chemical engineering methodology of mass transfer and reactive crystallization processes based on Two-Film Mass- Transfer (TFMT) theory. Kinetic expressions have been developed to define the chemical reactions as well as the physical phenomena (mass transfer) associated with this process. A single expression has been derived to explain the dependence of the ammonia consumption rate on various process parameters. Subsequently, the influence of various process parameters on the product quality (particle size and chloride impurity content) has been studied on the laboratory scale. Finally, the process has been established in the pilot plant, with optimized process conditions, to realize TATB of desired particle size and chloride content. The effects of feeding excess ammonia, and the presence of mercaptans/hydrogen sulphide impurities in poor quality toluene on the formation of certain undesirable by-products in TATB, are also discussed.
    Źródło:
    Central European Journal of Energetic Materials; 2014, 11, 1; 31-57
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Preparation of Nano Aluminium Powder (NAP) using a Thermal Plasma: Process Development and Characterization
    Autorzy:
    Pant, A.
    Seth, T.
    Raut, V. B.
    Gajbhiye, V. P.
    Newale, S. P.
    Nandi, A. K.
    Prasanth, H.
    Pandey, R. K.
    Powiązania:
    https://bibliotekanauki.pl/articles/358835.pdf
    Data publikacji:
    2016
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    nano aluminium
    thermal plasma
    DC arc plasma
    RF induction plasma
    aluminium content
    BET surface area
    HR-TEM
    Opis:
    A bottom up approach for the preparation of Nano Aluminium Powder (NAP) using a Transferred Arc Thermal Plasma Reactor (TAPR) is described. The aluminium block is subjected to evaporation by the application of a thermal plasma. The aluminium vapour produced is rapidly quenched to room temperature resulting in crystallization of the aluminium vapour in nano-particulate form. Various process parameters, such as the plasma torch power, reactor pressure and plasma gas composition were optimized. This paper also describes the characterization of NAP by analytical methods, for the estimation of the Active Aluminium Content (AAC), Total Aluminium Content (TAC), XRD, bulk density, BET surface area, HR-TEM etc. The results are compared with those for samples prepared in other thermal plasma reactors, such as the DC Arc Plasma Reactor (DCAPR) and the RF Induction Thermal Plasma Reactor (RFITPR), and for commercially available NAP samples (ALEX, prepared by the EEW technique).
    Źródło:
    Central European Journal of Energetic Materials; 2016, 13, 1; 53-71
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Optimization of Ammonium Sulfamate Nitration for the Preparation of Ammonium Dinitramide
    Autorzy:
    Mandal, A. K.
    Kunjir, G. M.
    Singh, J.
    Adhav, S. S.
    Singh, S. K.
    Pandey, R. K.
    Bhattacharya, B.
    Lakshmi Kantam, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/358022.pdf
    Data publikacji:
    2014
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Opis:
    The reaction kinetics for the preparation of ammonium dinitramide (ADN) is described. ADN is the ammonium salt of the dinitramide anion, and belongs to the group of inorganic oxidizers, mainly useful for energetic rocket propellant formulations, particularly for underwater applications. It is also a potential candidate to replace ammonium perchlorate (AP), in order to develop chlorine-free, green propellants. At HEMRL, ADN is prepared by the nitration of ammonium sulfamate (AS) using mixed acid, followed by hydrolysis, neutralization with ammonia (g) and rectification using solvent. The nitration of ammonium sulfamate (AS) is carried out at a subzero temperature of -40 ±1 °C. The yield of ADN is reliant on the formation of dinitramidic acid, an intermediate product formed during the hydrolysis step, and its stability is predominantly dependent upon the level of acidity and temperature of the reaction medium. Prior to these kinetics studies, process optimization of the nitration of ammonium sulfamate (AS) was performed and gave the final mole ratio of AS:HNO3:H2SO4. Since the nitration of AS is sensitive to temperature, the rate of reaction was studied at fixed temperatures with variation of time, keeping all of the other parameters, such as vessel volume, agitator speed, feed rate etc., constant. During these studies, predetermined quantities of ammonium sulfamate (AS) and mixed acid were allowed to react at a fixed temperature (-40 ±1 °C) for different reaction periods to generate the concentration profile of AS. Using this concentration profile, the reaction order and reaction rate constant were evaluated. In order to find the effect of temperature on the reaction rate and yield, experiments were conducted at other temperatures such as -30 and -50 °C. In the present studies, it was found that the optimum temperature of nitration is -40 ±1 °C and that the rate of reaction follows a pseudo second order process with rate constant 0.01113 (min-1)•(mol/L)-1. The reaction time evaluated for 55 to 60% conversion is about 70-80 minutes at -40 ±1 °C, based on this kinetics. The activation energy of AS nitration was found to be -4.6 kcal/mol, using the reaction kinetic data based on the temperature dependent rate equation derived from Arrhenius’s law.
    Źródło:
    Central European Journal of Energetic Materials; 2014, 11, 1; 83-97
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Zero-Field Splitting Parameters of $Cr^{3+}$ in Lithium Potassium Sulphate at Orthorhombic Symmetry Site
    Autorzy:
    Pandey, S.
    Kripal, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/1400393.pdf
    Data publikacji:
    2013-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    76.30.-v
    76.30.Fc
    Opis:
    The superposition model is used to investigate the crystal field parameters, $B_{kq}$ of $Cr^{3+}$ in lithium potassium sulphate. The zero field splitting parameters D and E are then determined using microscopic spin Hamiltonian theory and compared with the experimental values obtained by electron paramagnetic resonance. Both zero field splitting parameters D and E evaluated theoretically are in good agreement with the experimental values. The results suggest that the $Cr^{3+}$ ion occupies substitutional K^{+} site in lithium potassium sulphate.
    Źródło:
    Acta Physica Polonica A; 2013, 123, 1; 101-105
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A Theoretical Analysis of Zero Field Splitting of $Mn^{2+}$ in Ammonium Oxalate Monohydrate
    Autorzy:
    Kripal, R.
    Pandey, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1535738.pdf
    Data publikacji:
    2010-10
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    71.70.Ch
    76.30.Fc
    Opis:
    The superposition model has been used to investigate the substitution of $Mn^{2+}$ in ammonium oxalate monohydrate. The zero field splitting parameters D and E calculated by the superposition model are compared with the experimental values $D_{exp}$ and $E_{exp}$, respectively, for $Mn^{2+}$ obtained by electron paramagnetic resonance. Both the zero field splitting parameters D and E calculated theoretically are in good agreement with the experimental values $D_{exp}$ and $E_{exp}$. The result indicates that the $Mn^{2+}$ ion substitutes for the $NH_4^{+}$ ion in ammonium oxalate monohydrate.
    Źródło:
    Acta Physica Polonica A; 2010, 118, 4; 629-632
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Size Dependent Acoustical Properties of bcc Metal
    Autorzy:
    Yadav, R. R.
    Pandey, D. K.
    Powiązania:
    https://bibliotekanauki.pl/articles/2043375.pdf
    Data publikacji:
    2005-06
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    62.20.Dc
    62.65.+k
    63.20.Kr
    Opis:
    The ultrasonic attenuation is evaluated at 300 K along [100], [110], and [111] directions for the characterization of bcc metal Ta. The size of the metal is considered in nanorange. Ultrasonic velocity, Grüneisen parameter and acoustic coupling constant that depend on second and third order elastic constants are calculated for determination of ultrasonic attenuation coefficient. Second and third order elastic constants of the bcc metal Ta at nanoscale at 300 K are also calculated starting with only two basic parameters. For the information about defects at nanoscale, the dislocation drag coefficients are calculated for the metal at different size along [100] orientation. The ultrasonic attenuation increases with the size of material as the size variation of the thermal conductivity and the thermal relaxation time. There is significant increase in the attenuation up to 150 nm.
    Źródło:
    Acta Physica Polonica A; 2005, 107, 6; 933-946
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Sound Attenuation at High Temperatures in Pt
    Autorzy:
    Singh, R. K.
    Pandey, K. K.
    Powiązania:
    https://bibliotekanauki.pl/articles/2044642.pdf
    Data publikacji:
    2006-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    62.20.Dc
    62.65.+k
    Opis:
    Ultrasonic attenuation due to phonon-phonon interaction and thermoelastic loss was evaluated in VIII group transition metal Pt in a wide temperature range (100 K to 1500 K) for longitudinal and shear waves along〈100〉, 〈110〉 and〈111〉 directions and for shear waves polarised along different directions. Electrostatic and Born-Mayer potentials were used to obtain second and third order elastic constants, taking nearest-neighbour distance and hardness parameter as input data. Second and third order elastic constants data obtained at different temperatures were used to obtain Gruneisen parameters and non-linearity or anisotropy parameters which in turn were used to evaluate (α/f$\text{}^{2}$)$\text{}_{l}$ and (α/f$\text{}^{2}$)$\text{}_{s}$ in Akhiezer regime. The results were discussed and it was found that at lower temperatures (α/f$\text{}^{2}$) increases rapidly with temperature and then rate of increase becomes very small. Contribution to the total attenuation due to thermoelastic loss is negligible so that due to phonon-phonon interaction establishing that major part of energy from sound wave is removed due to interaction with thermal phonons (lattice vibrations).
    Źródło:
    Acta Physica Polonica A; 2006, 109, 2; 219-228
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Electro-Optical Behavior of Dye Doped Nematic Liquid Crystal
    Autorzy:
    Yadav, S.
    Pandey, K.
    Misra, A.
    Manohar, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/1505061.pdf
    Data publikacji:
    2011-06
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    64.70.M-
    42.79.Kr
    Opis:
    We report electro-optical behavior of a dye doped nematic liquid crystal. The dye doped cells have shown some improvement in some parameters important for the display devices such as threshold voltage $(V_{th})$, splay elastic constant, rotational viscosity and response time. The suppression of screening effect improves the threshold voltage for the doped sample.
    Źródło:
    Acta Physica Polonica A; 2011, 119, 6; 824-828
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Quantum Mechanical Studies of Bond and Molecular Polarizabilities of Gas-Phase Metal Halides
    Autorzy:
    Pandey, A. N.
    Bigotto, A.
    Gulati, R. K.
    Powiązania:
    https://bibliotekanauki.pl/articles/1891514.pdf
    Data publikacji:
    1991-10
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    31.10.+z
    31.90.+s
    Opis:
    The bond and molecular polarizabilities are studied for the gas-phase metal halides using delta-function potential model of chemical binding on the basis of quantum mechanical approach. The applicability of the model is demonstrated. The contribution of the polarity corrections for the metal halides is thoroughly investigated and it has been found that it plays a significant role for fluorides. Our polarizability calculations resolve the discrepancy about the conformation of the barium dichloride and mercury dichloride and favour the nonlinear structure. Due to lack of experimental results for most of halides of transition metals, the decision whether to incorporate polarity corrections or not remains uncertain at this stage: we must await measurements of more experimental values before we reach any final conclusion. The ionic bond orders have been used for the first time to investigate polarizabilities of monomers and dimers of alkali halides. The results for dimers reveal that polarity contribution is essential for the lithium halides dimers and not for other dimers. The computed results will be asset for the interpretation of experimental measurements.
    Źródło:
    Acta Physica Polonica A; 1991, 80, 4; 503-520
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of Grit Blasting and Thermal Spraying on Microstructure Evolution of P91 Weldment
    Autorzy:
    Thakare, J. G.
    Pandey, C.
    Mulik, R. S.
    Mahapatra, M. M.
    Narang, H. K.
    Powiązania:
    https://bibliotekanauki.pl/articles/947576.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    P91
    HAZ
    IC-HAZ
    deformation zone
    Opis:
    In the present work, studies have been carried out on the variations in the microstructure and hardness of P91 base-metal and welded joint. This variations result from the grit blasting and thermal cycle experienced during the thermal spraying process. The microstructural effects have been analyzed in terms of the depth of the deformation zone. Scanning Electron Microscopy and Xray diffraction were used as characterization techniques. The grit blasting carried out prior to thermal spraying has resulted in the highest change in sub-surface hardness of the heat affected zone (HAZ). However, flame treatment further reduced the subsurface hardness of the heat affected zone. The depth of deformation zone was highest for inter-critical heat affected zone (IC-HAZ). The overall coating process resulted in an increase in subsurface hardness of various regions of HAZ and fusion zone (FZ). The base metal showed a 7% increase in subsurface hardness due to the overall coating process. The IC-HAZ showed maximum variation with 36% increase in subsurface hardness. The coarse grained heat affected zone (CG-HAZ) and FZ did not show any change in subsurface hardness. As a whole, the hardness and microstructure of the welded joint was observed to be more sensitive to the thermal spray coating process as compared to the base metal.
    Źródło:
    Archives of Metallurgy and Materials; 2018, 63, 4; 1725-1734
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Leaching of Al-Based Polygrain Quasicrystalline and Related Crystalline Surfaces
    Autorzy:
    Yadav, T.
    Mishra, S.
    Pandey, S.
    Singh, D.
    Lowe, M.
    Tamura, R.
    Mukhopadhyay, N.
    Srivastava, O.
    McGrath, R.
    Sharma, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/1373698.pdf
    Data publikacji:
    2014-08
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    61.44.Br
    81.16.Hc
    61.66.Dk
    68.37.Hk
    Opis:
    In the present investigation, we have studied leaching on polygrain Al-based quasicrystalline $(i-Al_{63}Cu_{25}Fe_{12})$ as well as crystalline (B2 phase; $Al_{55}Cu_{30}Fe_{15})$ alloy surfaces using a 10 mole NaOH solution. The surface was leached at varying times from 30 min to 8 h and subsequently characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray analysis. Leaching of the samples for 30 min generated a homogeneous layer. However further leaching for 1-8 h yielded nano-size particles on the surface. Spherical microstructure has been observed on the Al-Cu-Fe crystalline surface whereas on the quasicrystalline surface a petal-like microstructure appeared. The implications of the evolution of different microstructures in the context of structure, stability and activity are discussed. The results are compared with the microstructure of leached polygrained samples containing a mixture of different surface orientations.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 2; 629-632
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Bioremediation of melanoidin contamination in distillery effluent using Aspergillus brasiliensis
    Autorzy:
    Singh, T.A.
    Singh, T.
    Singh, R.
    Pandey, P.K.
    Gaur, R.
    Jamal, F.
    Patel, S.K.
    Bansal, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/2097092.pdf
    Data publikacji:
    2020
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    spent wash
    effluent
    melanoidin
    bioremediation
    decolorization
    Opis:
    The current investigation is the first report of utilization of Aspergillus brasiliensis for the decolorization of melanoidin in distillery effluent. The effluent generated from alcohol distilleries is one of the most complex wastewater with a high biological oxygen demand (BOD) and other organic, inorganic, and toxic constituents. The effluent contains melanoidin, a dark brown compound, which is difficult to remediate by using conventional technologies. The disposal of spent wash in the natural environment is hazardous and can deteriorate land and water resources. The decolorization of spent wash through physical and chemical methods remains unsuitable, and the only alternative to decolorize spent wash is biological treatment. In the current study, three fungal strains were isolated from the distillery waste and screened for their ability to decolorize melanoidin.The isolate RS2 exhibited maximum decolorization of 83% and was identified as Aspergillus brasiliensis. Its optimum growth temperature was 37EC, and the maximum efficiency was recorded after 120 h of incubation. Nutritional sources were investigated for the fungi showing the maximum decolorization of melanoidin, and starch and peptone were found to be the best carbon and nitrogen sources, respectively. At 1.5% starch concentration and 1.5% peptone concentration, the decolorization level attained was 87.45% and 88.74%, respectively. A. brasiliensis exhibited a high potential to decolorize melanoidin. The decolorization percentage was high, which makes this fungus a potential candidate for use at the industrial scale for the bioremediation of spent wash.
    Źródło:
    BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2020, 101, 3; 205-213
    0860-7796
    Pojawia się w:
    BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Integrated biostratigraphy of the Jurassic strata of the Wagad Uplift, Kachchh, western India
    Autorzy:
    Rai, J.
    Garg, S.
    Gupta, M.
    Singh, A.
    Pandey, D. K.
    Fürsich, F. T.
    Alberti, M.
    Garg, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/2077328.pdf
    Data publikacji:
    2015
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Jurassic
    calcareous nannofossils
    dinoflagellate cysts
    ammonites
    Oxfordian
    Kimmeridgian
    Wagad Uplift
    Kachchh
    jura
    wapienie
    bruzdnice
    amonity
    Oksford
    Kimeryd
    Opis:
    An integrated study based on calcareous nannofossils, organic-walled dinoflagellate cysts, and ammonites from the Washtawa and Kanthkot formations of the Wagad Uplift have allowed a detailed documentation of the stratigraphic position of these formations within the Oxfordian and Kimmeridgian sediments of the Kachchh Basin, western India. The nannofossil assemblages from the lower part of the Nara Shale Member exposed in the Nara and Washtawa domes, the Kanthkot Ammonite Beds along the Trambau River section, and the Patasar Shale Member exposed along the Trambau River section and the Patasar Tank section in the eastern part of the Wagad Uplift belong to the NJ 14 Cyclagelosphaera margerelli Zone of the Early Oxfordian, the NJ 15a Lotharingius sigillatus Zone of the Middle Oxfordian, and the NJ 15b Cretarhabdus conicus of Early Kimmeridgian age, respectively. Zonation schemes, based on calcareous nannofossils, dinoflagellate cysts, and ammonites were calibrated highlighting their biostratigraphic potential. These studies may represent a reference biochronology for Oxfordian–Kimmeridgian age strata applicable to the Tethyan realm of which India was a part during Late Jurassic times.
    Źródło:
    Volumina Jurassica; 2015, 13, 2; 55--80
    1896-7876
    1731-3708
    Pojawia się w:
    Volumina Jurassica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
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