S. K. Shukla

Isolation and identification of a fowl adenovirus from wild black kites (Milvus migrans).

A fowl adenovirus was isolated from wild Black Kites (Milvus migrans) that died around Kashipur, Uttarakhand, India. This virus isolate produced cytopathic effects in chicken embryo liver (CEL) cells and reacted with fowl adenovirus 4 (FadV-4) antiserum in agar gel immunodiffusion and immunofluorescence tests. The virus isolate was neutralized by FadV-4 antiserum with a neutralization titer of 800. Electron microscopy of infected CEL cells showed the presence of hexagonal virion particles measuring in size about 80–100 nm. An amplicon of 1,223 base pairs was detected using polymerase chain reaction with primers designed to target the hexon gene of FadV-4.

Active Sintered Controlled Porosity Dispenser (CPD) Cathode

CPD cathode, made out of tungsten wire, using active sintering resulted in uniform and two-fold emission as compared to B-type cathode. Studies on wire diameter using MATLAB code suggests that 20 μm diameter provides optimum barium coverage. Detailed experimental results will be presented.

Comparative Efficacy of Melia azedarach Extracts with Amprolium against Experimentally Induced Coccidiosis in Broilers

ISSN: 2319-7706 Volume 7 Number 04 (2018) Journal homepage: http://www.ijcmas.com The present study was planned to investigate the alternative and economical way for treating caecal coccidiosis in Broilers. An experiment was conducted to evaluate the anticoccidial efficacy of aqueous and methanolic extract of Melia azedarach (Bakain) leaves in experimentally induced Eimeria tenella infection in Broilers. Acute toxicity test of herbal extract was conducted in 21 days old broiler. The birds were observed 24 hours for sign of toxicity. At three weeks of age the chicks were randomly divided in to eight groups each group having 15 birds. Group I were healthy control, Group II, III and V were uninfected medicated control group received Amprolium @ 250 mg/l, water, aqueous extract of Melia azedarach leaves @1000mg/kg body weight, methanolic extract of Melia azedarach leaves @ 1000mg/kg body weight, on day 21 to 28 day of age, once daily respectively, Group IV, Group VI, VII and VIII were infected with 40,000 infected oocysts of Eimeria tenella at 21 days of age. Birds of group IV, VI and VII were treated with Amprolium @ 250 mg/l water, aqueous extract of Melia azedarach leaves @1000mg/kg body weight, and methanolic extract of Melia azedarach leaves @1000mg/kg body on day 0 to7 day of post infection respectively. Group VIII kept as infected control and not receive any medicine. No sign of toxicity seen during the acute toxicity test even at highest dose. The birds treated with methanolic extract of Melia azedarach leaves resulted in progressively decrease in severity of clinical sign, faecal score, percent survival, percent weight gain, performance index, average oocyst production, per cent reduction in oocyst production, average oocyst index, average lesion score and percent protection against lesion and restorations of haematological and bio chemicals parameters. The result of this study indicated that methanolic extract of Melia azedarach leaves @1000mg/kg body weight for 7 day having has better anticoccidial activity without affecting the growth of broiler. K e y w o r d s

Study and Development of Active Sintered Controlled Porosity Dispenser Cathode

The sintered wire cathode offers a significant improvement in density and uniformity of emission. In the present technique of active sintering, an activator is introduced, which relaxes the sintering temperature of tungsten (W)-wire bunch significantly. The technique also offers well-opened columnar pores with a uniform distribution all across the cross section. The pellets are made out of the sintered bunch of W-wires, each of diameter 50 μm. The pellets are impregnated using triple carbonates and are integrated with potted heaters. The cathode assemblies are tested in an analytical system containing an anode and an Auger electron spectroscopy facility. The pulse emission measurements revealed that the emission density of these cathodes is higher than twice that of a conventional B-type cathode. This high emission is attributed to a relatively high Ba/W and O/W ratios on the surface as compared with those of a B-type cathode. The Miram curves, generated out of pulse emission data, exhibit sharp temperature-limited fully space charge-limited transition, indicating lower patchiness of emission as compared with that of a B-type. The theoretical studies are carried out to estimate the optimum wire gauge that can produce good coverage and recovery to the ion bombardment.

Yttrium-doped nano-scandate cathode for THz VED

Vacuum electron devices (VEDs) in THz regime require very high cathode current density. A cathode is made out of nano-powder, containing Yttria-scandia-tungsten and Ba-Ca-aluminates. Emission >70 A/cm2 achieved when tested in analytical chamber containing anode, AES and THEM. These results will be presented.

Characterization of multi-beam cathode using thermionic emission microscope

Thermionic emission microscope (THEM) is an analytical research tool to study the emission uniformity of a thermionic cathode. In this paper, the design of electrostatic lens for a multi-beam cathode (MBC) has been given using 2-D TRAK and Omni-TRAK codes. The design of single beam lens system, available with us, containing a small cathode has been modified to study large size MBC using scaling laws. The present MBC contains 19 protruding buttons contributing to 19 beamlets whose image is projected onto the screen for study. The influence of various parameters such as protrusion, diameter of button, and their interspacing has been studied. The studies prove that THEM could be used as an effective tool for the characterization of MBC.