The influence of certain fungi on the sporulation of Melanospora destruens shear and of some other ascomycetes

This article does not have an abstract

Latent wither-tip infection on citrus

1. Small pinkish-white fungal areas ofColletotrichmu gloeosporioides Penz. were observed on trunks and main branches of orange plants. In certain localities mosambi plants were also infected. 2. Water shoots and young twigs were always found free from the infection. 3. During summer months the mycelium of the fungus survives in the form of pink coloured stroma in small cracks in the bark of orange or mosambi trees and thus tides over the unfavourable atmosphere condition. 4. Mycelium on the host persists as inter- and intra-cellula parasite in one or two layers of the cortical tissue. 5. The disease could be induced artificially. 6. Measurements of the spores, setae and hyphae are given. 7. The isolated strain of C. gloeosporioides corresponds to strain A, No. 316 of Chaudhari and practically falls within the second group of Baker, Crowdy and MeKee. 8. Acervuli of the pathogen has been observed on dead wood also

Bacterial leaf-spot on arum

This article does not have an abstract

Combustion Behaviour of Advanced Solid Propellants.

The study reports the effect of incorporation of Al and ammonium perchlorate (AP) individually and in combination with each other on combustion pattern and specific impulse (Isp) of minimum signature propellants. Incorporation of Al obviates the combustion instability problems; however, it has marginal effect on burning rates. The composition containing AP and zirconium silicate combination gives superior performance; however, its Isp is considerably lower than the composition incorporating 9 per cent AP. A combination of 6 per cent Al gave 20 per cent enhancement in burning rate and 12 s increase in Isp as compared to purely nitramine-based composition, cal-val results also reveal increase in energy output on incorporating AP and Al. Hot stage microscopic and propellant combustion studies indicate occurrence of intense decomposition reaction in case of AP-based compositions

Thermal Behaviour of AP Based CMDB Propellants with Stabilizers

Stability test results and DTA studies indicate the superiority of molecular sieve (MS) over zirconium silicate (ZrSiO/sub 4/) as the stabilizer for a composite modified double base (CMDB) system. Shelf life as computed from autoignition test results was 30 years for MS-based composition which is almost double the life of ZrSiO/sub 4/, but approximately half the life of resorcinol-based composition which was used as a reference. Higher stabilizing effect of MS as compared to ZrSiO/sub 4/ has been explained on the basis of the presence of channels and cavities in its structure, which makes it an effective adsorbent for decomposition catalysing species. Poor stabilization capability of m-dinitrobenzene as compared to resorcinol suggests the catalytic involvement of acidic decomposition products of nitrate esters in autodecomposition process of CMDB propellants

Active Metal Brazing and Characterization of Brazed Joints in Titanium to Carbon-Carbon Composites

The Ti-metal/C-C composite joints were formed by reactive brazing with three commercial brazes, namely, Cu-ABA, TiCuNi, and TiCuSiI. The joint microstructures were examined using optical microscopy and scanning electron microscopy (SEM) coupled with energy dispersive spectrometry (EDS). The results of the microstructure analysis indicate solute redistribution across the joint and possible metallurgical bond formation via interdiffusion, which led to good wetting and spreading. A tube-on-plate tensile test was used to evaluate joint strength of Ti-tube/ C-C composite joints. The load-carrying ability was greatest for the Cu-ABA braze joint structures. This system appeared to have the best braze spreading which resulted in a larger braze/C-C composite bonded area compared to the other two braze materials. Also, joint loadcarrying ability was found to be higher for joint structures where the fiber tows in the outer ply of the C-C composite were aligned perpendicular to the tube axis when compared to the case where fiber tows were aligned parallel to the tube axis

Preliminary note on a new species of Eremascus

This article does not have an abstract

Tip-burn of Piper betle in the central provinces

This article does not have an abstract

Observation of direct and indirect magnetoelectricity in lead free ferroelectric (Na 0.5Bi 0.5TiO 3)-magnetostrictive (CoFe 2O 4) particulate composite

A particulate composite consisting of 65 mol. % Na 0.5Bi 0.5TiO 3 and 35 mol. % CoFe 2O 4 was synthesized, and it's structure, microstructure, ferroelectric, magnetostrictive, magnetic, and direct/indirect magnetoelectric properties were studied. The composite showed different magnetization behaviour under electrically poled and un-poled conditions. The percentage change in magnetization as a result of poling is approximately -15% at 500 Oe magnetic field. Magnetostriction measurements displayed a value of λ 11 = -57 × 10 -6 and piezomagnetic coefficient δλ 11/δH = 0.022 × 10 -6 kOe -1 at 2.2 kOe for the composite. The maximum magnetoelectric output varied from 1350 mV/cm to 2000 mV/cm with change in the electrical poling condition

Glycidyl Azide Polymer-based Enhanced Energy LOVA Gun Propellant

In this study, cyclotrimethylene trinitramine propellants with triacetin (TA)-plasticisedcellulose acetate (CA) and nitrocellulose (NC) combination as binders were evaluated for lowvulnerable ammunition (LOVA). Triacetin was replaced by energetic plasticiser; glycidyl azidepolymer (GAP) in increments to enhance the performance in terms of force constant . In additionto ballistics, parameters like vulnerability, mechanical and thermal properties of GAP-basedpropellants in comparison to those of TA-based propellants, were also determined. The studybrings out that the incorporation of 2-6 per cent GAP in place of TA resulted in the enhancementof force constant by 22-70 J/g and improved overall combustion characteristics. DSC revealedthat thermal decomposition of GAP-LOVA propellants evolved more energy than TA-LOVApropellants. GAP-based LOVA propellant similar to TA-plasticised LOVA propellant, was foundsuperior to NQ propellant in vulnerability tests as well as in hot fragment conductive ignition(HFCI) studies. As regards mechanical properties, incorporation of GAP resulted in improvedcompression strength