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P. Sakthivel ¹, N. Nedunchezhian ², P. Ponnusamy ¹

Affiliations
1 Dept. of Mechanical Engg., Surya Engineering College, Erode, Tamilnadu, IN
2 Dept. of Automobile Engg., Institute of Road & Transport Technology, Chithod, Tamilnadu, IN

Abstract

This study discusses the effect of copper, nickel and chromium coating on the spark ignition engine performance, emission and combustion characteristics. The maximum brake thermal efficiency for copper coated engine is about 5% higher than standard engine at full load and about 4% higher than the standard engine at 2800 rpm. Nitrogen oxides emission for catalytic coated engine is 7% to 20% higher than standard engine at full load. It was observed that carbon monoxide and carbon dioxide emissions of standard engine were higher than catalytic coated engines at all loads. Copper coated engine has the lowest hydro carbon emission. Catalytic coated engines have 6% to 12% higher cyclinder pressure when compared to the standard engine. The crank angle of heat release values and combustion parameters indicate that a faster heat release occured for catalyst coated engines. Similarly combustion duration of standard engine is higher than that of catalytic coated engines. Catalytic coatings increase the pre-flame reactions which lead to better and faster combustion.

Keywords

Spark Ignition Engine, Catalytic Coatings, Emission Control, Brake Thermal Efficiency, Heat Release Rate.

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M. Ananda Chitra ¹, K. Jayalakshmi ², P. Ponnusamy ¹, R. Manickam ¹, B. S. M. Ronald ¹

Affiliations
1 Department of Veterinary Microbiology, Veterinary College and Research Institute, Tamil Nadu Veterinary and Animal Sciences University, Orathanadu-614625, Thanjavur, Tamil Nadu, IN
2 Department of Veterinary Medicine, Veterinary College and Research Institute, Tamil Nadu Veterinary and Animal Sciences University, Orathanadu-614625, Thanjavur, Tamil Nadu, IN

Abstract

Aim: The study was conducted to isolate and identify Dermatophilus congolensis (DC) using conventional and molecular diagnostic techniques in scab materials collected from skin infections of sheep and goats in the Delta region of Tamil Nadu.
Materials and Methods: A total of 20 scab samples collected from 18 goats and 2 sheep from Nagapattinam, Thanjavur, and Tiruvarur districts of Tamil Nadu. Smears were made from softened scab materials and stained by either Gram’s or Giemsa staining. Isolation was attempted on blood agar plates, and colonies were stained by Gram’s staining for morphological identification. Identification was also done by biochemical tests and confirmed by 16S rRNA polymerase chain reaction (PCR), followed by sequencing and phylogenetic analysis of the amplified product.
Results: The peculiar laddering arrangement of coccoid forms in stained smears prepared from scab materials revealed the presence of DC. Isolated colonies from scab materials of sheep and goats on bovine blood agar plate were small, hemolytic, rough, adherent, and bright orange-yellow in color, but some colonies were white to cream color. Gram-staining of cultured organisms revealed Gram-positive branching filaments with various disintegration stages of organisms. 16S rRNA PCR yielded 500 bp amplicon specific for DC. Sequence analysis of a sheep DC isolate showed 99-100% sequence homology with other DC isolates available in NCBI database, and phylogenetic tree showed a close cluster with DC isolates of Congo, Nigeria, and Angola of Africa. Genes for virulence factors such as serine protease and alkaline ceramidase could not be detected by PCR in any of the DC strains isolated of this study.
Conclusion: The presence of dermatophilosis in Tamil Nadu was established from this study.

Keywords

16S rRNA Sequence Analysis, Dermatophilus congolensis, Sheep and Goats, Tamil Nadu.

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