Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: force constant

Sortuj według:

Ogranicz wyniki do:

Influence of zinc substitution on structural, elastic, magnetic and optical properties of cobalt chromium ferrites

Zeeshan Talat, Anjum Safia, Waseem Salma, Majid Farzana, Ali Muhammad Danish, Aslam Ammara

Materials Science Poland

2021

Vol. 39, No. 1

139--151

The polycrystalline Co1−xZnxCr0.5Fe1.5O4 series with (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) has been synthesized by conventional ceramic rout method. The structural and elastic properties have been investigated by X-ray diffractometer and Fourier transform spectroscopy. Both XRD and FTIR confirm the formation of single phase cubic spinel ferrites. The cationic distribution for all samples has been proposed. The lattice parameter, X-ray density, hoping length, bond length, and packing factors–in accompaniment with variations in the zinc concentration–have been studied. The IR band position has been explained by the cations involved in the structure. The elastic moduli such as Young's modulus, bulk modulus, rigidity modulus and Poison's ratio have bee calculated using force constants. Scanning electron microscope (SEM) observation conveys information about the agglomeration of particles. The hysteresis curve obtained from vibrating sample magneto meter (VSM) conveys information about the soft nature of prepared compositions. The saturation magnetization decreases with addition of zinc ions and coercivity is almost zero. An increase in band gap energy has been observed with addition of zinc by Ultraviolet Visible Spectroscopy (UV-VIS), which is due to small crystallite size.

Studies on the Ballistic Parameters of a Deterred Triple Base Propellant Used in Large Caliber Ammunition

Dahiwale Sunil M., Bhongale Chetan J., Roy Shubhankar, Navle Pradeep B., Asthana Shrinandan N.

Central European Journal of Energetic Materials

2019

Vol. 16, no. 3

449--467

In this work, the energetic plasticizer N-n-butyl-N-(2-nitroxyethyl)nitramine (Bu-NENA) was used as a deterrent coating for a triple base propellant (TBP) that finds application in large caliber guns. Closed vessel (CV) evaluation was performed to study the ballistic performance of the deterred propellant. A TBP containing nitrocellulose (NC), nitroglycerine (NG) and nitroguanidine (NQ) was coated with an energetic plasticizer using a solution of Bu-NENA. The Bu-NENA coated propellant exhibited inhibition to burning resulting in a reduction in the values of the ballistic parameters viz. (dP/dt)max, burning rate coefficient (β) and relative vivacity (RV), while the pressure index (α) and rise time were increased. The trends obtained during this work display the potential of Bu-NENA as deterrent.

Influence of organic dopants (L-alanine and L-arginine) on structural, spectroscopic and thermal properties of ammonium dihydrogen phosphate crystal

Parikh K. D., Joshi J. H., Joshi M. J.

Materials Science Poland

2017

Vol. 35, No. 3

632--638

Ammonium dihydrogen phosphate is a popular nonlinear optical crystal used for second harmonic generation efficiency improvement in pump lasers. Due to molecular chirality and zwitterionic structure, amino acids are used to enhance various properties of ADP crystal. The single crystals of ammonium dihydrogen phosphate (ADP) added with different concentrations (0.3 wt.%, 0.4 wt.% and 0.5 wt.%) of amino acids (L-alanine and L-arginine) impurities were grown using slow evaporation solution growth (SESG) technique at room temperature. To study the structural properties, powder XRD study was carried out which revealed that all the grown crystals have tetragonal structural symmetry. The presence of various functional groups was confirmed using FT-IR spectroscopy. The thermal spectra (TGA/DTA/DSC) were recorded for all grown samples to determine their decomposition. Also kinetic and thermodynamic parameters were determined from the thermal study.