D. Singh

Studies on Aluminum Armour Plates Impacted by Deformable and Non-Deformable Projectiles

Aluminium alloy armour (7017) plates have been impacted by deformable and non-deformable high velocity steel projectiles. The projectiles were fired on the targets at 10 meters distance at 0 0 angle of attack with velocities around 840 m/s. The resulting microstructure, damage pattern and hardness along the path of the penetration in both the cases have been studied and compared. Introduction Aluminium alloy 7017 is one of the commonly used armour materials. It is therefore of interest to study and report how it deforms and changes its structure and hardness during penetration by typical projectiles which may be soft and deformable or hard and non-deformable. A recent work by Kennedy and Murr [1] covers some of these aspects. In that work, tungsten heavy alloy projectiles were used against Aluminium 7039 target plates. The microstructural changes and the hardness variations away from the crater edge and shear band formation along the direction of penetration are studied. Backman et al. [2,3] observed adiabatic shear bands and deformed grains in aluminium 2024 target plates impacted by steel spheres and blunt steel projectiles. Rupert et al. [4] has carried out similar studies on Ti and RHA, and studied the microstructure and hardness variations along the edge of the crater. Material failure at high strain rates as encountered in high velocity impact situations is a complex process. Under dynamic loading failure can occur by a variety of mechanisms depending on the material constitution and state of stress, temperature, rate of loading and a number of other variables [5]. The failure of the material can be brittle or ductile in nature. The material deforms as the projectile penetrates through the plate causing various types of defects like void-formation, nucleation and growth of shear bands, cracking all of which ultimately result in material failure [6]. The study of failure covers a wide range of material responses of both projectile and the target. The depth of penetration of the target material depends mainly upon the resistance offered by the target material, which in turn depends upon the flow factor, yield stress and the extent of flow field. The Waller-Anderson penetration model [7] for the penetration by cylindrical rods gives an expression for the resistance to the penetration offered by the target material when impacted with projectiles with a hemispherical nose. The resistance to penetration is directly proportional to the flow stress of the target material. It also depends on a flow factor, which varies with the shape of the projectile. The flow factor for a projectile with a hemispherical nose is higher than the flow factor for a projectile with a conical nose. The present study covers some aspects of deformation, shear band formation and cracking along the path of penetration by deformable and non-deformable projectiles.

Effect of Different Potting Media in Different Potted Croton (Codieum variegatum) Varieties under Shade Net Condition in Allahabad, India

Croton (Codieum variegatum) belongs to the family Euphorbiaceae, also called as Garden Croton or Variegated Croton. It is very popular indoor plant due to its colorful ornamental foliage with thick, leathery, glabrous and waxy texture in various shapes and commonly used as hedges, potted patio specimen or in shrubberies. Foliage plants are often used as indoor plants because of their attractive foliage and their ability to survive and grow under limited indoor light (Chen and Henny, 2008).Indoor plants also fulfill psychological needs of people by providing green color and comfort and enhance the indoor environment to make it more aesthetically pleasing (Bringslimark et al., 2007). Shape of leaves vary from ovate to linear, entire or lobed, flat or twisted and variegated with green, white, purple, orange, yellow, red or pink. Variegation is the occurrence of pattern, results of differences in the amount or composition of chlorophyll although other pigments i.e. anthocyanin and carotenoids and the variegation appearance can be altered by environmental factors, particularly light intensity (Tilney-Bassett, 1988).House plants provide people with aesthetic appreciation and other beneficial effects. Plants can effectively improve the indoor air quality by reducing volatile organic compounds, such as formaldehyde, benzene, toluene, ethylene, and xylene (Thomsen et al., International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 6 Number 8 (2017) pp. 3760-3764 Journal homepage: http://www.ijcmas.com

Effect of Inorganic and Organic Fertilizers on Yield and Economics of Broccoli (Brassica olerasia var. italica)

Broccoli (Brassica olerasia var. italica) is one of the important cool season vegetable of Brassicacae family (Swarup, 2012). It is a high value exotic vegetable and cultivated for its tender flowering head and the secondary heads i. e. spears. It was a rare cole crop in India but now it is gaining popularity in metropolitan cities, reputed hotels and restaurants (Maurya, 2008). Generally it can be classified into three distinct group viz., white purple and green, out of which green type is highly nutritious (Yoldas et al., 2008). Broccoli is rich source of vitamins, minerals and essential amino acids, also contains the compound glucoraphanin which have anticancerous properties (Swarup, 2012). It is either consumed raw as salad or cooked to prepare curries, soup and pickles. In the world market broccoli sold about 60 percent as frozen and remaining 40 percent as fresh. Now days, broccoli emerges as an important crop under protected cultivation during off season around metropolitans and tourist places (Swarup, 2012).

High Spin Spectroscopy and Shape Evolution in 105 Cd

High spin states in 105Cd were studied using 16O beam on 92Mo reaction at an incident beam energy of 75 MeV. The level scheme of 105Cd has been observed up to an excitation energy of 10.8 MeV with the addition of 30 new gamma transitions to the previous work. Spin and parity for most of the reported levels are assigned from the DCO ratios and linear polarization measurements. The microscopic origin of the investigated band structures is discussed in the context of triaxial projected shell model. The energies of observed positive and negative parity bands agree with the predictions of the TPSM by considering triaxial deformation for the observed excited band structures. The shape evolution with increasing angular momentum is explained in the framework of Cranked Shell Model and the Total Routhian Surface calculations.

Reaction mechanisms in the system {sup 20}Ne+{sup 165}Ho: Measurement and analysis of forward recoil range distributions

Keeping in view the study of complete and incomplete fusion of heavy ions with a target, the forward recoil range distributions of several evaporation residues produced at 164 MeV {sup 20}Ne-ion beam energy have been measured for the system {sup 20}Ne+{sup 165}Ho. The recoil catcher activation technique followed by off-line gamma spectroscopy has been employed. Measured forward recoil range distributions of these evaporation residues show evidence of several incomplete fusion channels in addition to complete fusion. The entire and partial linear momentum transfers inferred from these recoil range distributions were used to identify the evaporation residues formed by complete and incomplete fusion mechanisms. The results indicate the occurrence of incomplete fusion involving the breakup of {sup 20}Ne into {sup 4}He+{sup 16}O and/or {sup 8}Be+{sup 12}C followed by fusion of one of the fragments with target nucleus {sup 165}Ho. Complete and incomplete fusion reaction channels have been identified in the production of various evaporation residues and an attempt has been made to separate out relative contributions of complete and incomplete fusion components from the analysis of the measured recoil range distribution data. The total contribution of complete and incomplete fusion channels has also been estimated.