Informatics Publishing Limited

D. Prakash ¹, P. Ravikumar ²

Affiliations
1 Arasu Engineering College, Kumbakonam, IN
2 St. Joseph College of Engineering and Technology, Thanjavur, IN

Abstract

Thermal comfort has become a problem to the occupants of many residential building without air-conditioning system in hot climates. Natural ventilation is the only positive option for those residential buildings to improve their thermal comfort. Hence, present work is focused in analyzing the indoor characteristics of air and thermal comfort prevailed inside the room with windows at their adjacent walls along with the additional vents. Additional openings include a roof vent and a vent in the windward side wall. In this study, Computational Fluid Dynamic technique is employed to study the indoor airflow behavior and the CFD simulation was validated with the network model. 3-Dimensional model was created and k-ε turbulence model was used. Indoor airflow behavior was studied under various locations of the roof vent and best location was identified. Also another additional vent in the windward side wall was provided and analyzed under various shapes like cylindrical and nozzle shape. Air velocity, temperature, low temperature zone, low velocity zone and Predicted mean vote contours are predicted for all the simulated cases. These results are very much useful to study the effectiveness of the additional vent. Finally, the best location for the roof vent and the best shape for additional vent at windward side wall were identified.

Keywords

Ventilation, Thermal Comfort, Residential Building, CFD, PMV

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P. Sivamurugan ¹, P. Ravikumar ²

Affiliations
1 Department of Mechanical Engineering, Anna University, Chennai 620 025, IN
2 Department of Mechanical Engineering, Mahendra Engineering College, Mahendhirapuri, Tiruchengode 637 503, IN

Abstract

The study of heat balance in a pressure vessel is an important research area for energy conservation. In the present study, experiments are conducted to measure the heat input, heat energy utilized and heat loss for different volumes of water filled in a pressure vessel. Experiments are conducted on a pressure vessel of volume 0.008 m³ (8 I) filled with 1, 2, 3 and 3.7 kg of water at 12.5%, 25%, 37.5% and 46% of its capacity respectively. Two approaches are adopted to determine the optimum condition of the pressure vessel. In the first approach, the pressure vessel is insulated and in the other approach it is non-insulated. For both cases, vessels of similar capacity, make and design are used. Outer surface of the vessel is insulated with asbestos rope, clay and cow-dung bindings. There is not much difference in heat input and heat utilization for insulated and non-insulated vessels when the water level is only about 12.5% volume. In other cases, the insulated vessel consumes more heat input than the non-insulated vessel. When the non-insulated pressure vessel is filled with 46% of its volume by water, it utilizes a maximum of 30% of total heat supplied. From the experimental results, polynomial equations are developed for the heat input (Q_i), heat utilized (Q_u) and heat loss (Q₁) in terms of mass of the water taken in the vessel under non-insulated and insulated conditions. The equations obtained are validated for different water levels in the same vessels with new sets of experiments.

Keywords

Energy Conservation, Heat Balance, Insulated and Non-insulated Conditions, Pressure Vessel.

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S. Sathish Kumar ¹, G. Melchias ¹, P. Ravikumar ², R. Chandrasekar ³, P. Kumaravel ⁴

Affiliations
1 Department of Botany, St. Joseph’s College (Autonomous), Tiruchirappalli, Tamil Nadu, IN
2 Govt. Arts College (Autonomous), Coimbatore, Tamil Nadu, IN
3 Institute of Forest Genetics and Tree Breeding, Coimbatore, Tamil Nadu, IN
4 Department of Biotechnology, Vysya College, Salem, Tamil Nadu, IN

Abstract

Development of reliable green synthesis of silver nanoparticles by various plants and microorganisms has been reported in many research aspects. However, the probable of plants as natural materials for the synthesis of nanoparticles and their compatibility to biological systems is yet to be fully explored. In this study, we report a simple green method for the synthesis of silver nanoparticles using Euphorbia hirta (E. hirta) leaves extract as a reducing and stabilizing agent. After exposing the silver ions to E. hirta leaves extract, rapid reduction of silver ions is observed leading to the formation of silver nanoparticles in solution. The synthesized nanoparticles were characterized by using UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), Field emission Scanning Electron Microscopy (FESEM) and Particle size analysis. The synthesized silver nanoparticles show maximum zone of inhibition against Bacillus subtilis, Vibrio cholera and Salmonella typhi.

Keywords

Silver Nanoparticles, E. hirta, Antimicrobial Activity.

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P. Ravikumar ¹

Affiliations
1 Department of Botany, Government Arts College, Coimbatore (T.N.), IN

Abstract

The chemical composition and insecticidal properties of T. erecta and T. patula (Family: Asteraceae) were carried out in the methanol, hexane and acetonitrile extracts of flower, foliage and ischolar_main. The major compounds are β – caryophyllene, piperitenone, tetracontane, C₃₃ botryococcane and decane. In which different concentration of volatile oil exhibit more insecticidal properties. In the present investigation the hexane extract of flowers of Tagetes erecta showed better anti insecticidal property against aphids and Spodoptera frugiperda.

Keywords

T. erecta and T. patula, Volatile, Insecticidal, Alphids, Spodoptera frugiperda.

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N. Jeyashanthi ¹, P. Ravikumar ¹, N. N. Baalakumar ¹

Affiliations
1 Department of Biomedical Engineering, Velalar College of Engineering and Technology, Erode – 638012, IN

Abstract

The flower of Cassia auriculata commonly used for treatment, especially in Ayurvedic medicine in India was tested for mutagenicity by the Ames test using Salmonella typhimurium TA 98, TA 100 and TA 102 strains. The genotoxicity assessment of flower powder of Cassia auriculata was performed in aqueous extract 1:10. The flower powder of Cassia auriculata did not induce any frame shift mutation in the strain TA 98, which indicates its antimutagenic effect and did not cause any base pair substitution at the dose level tested 100μg/plate. The colony counts in all the three strains were found close to the spontaneous revertants frequency showing that flower powder of Cassia auriculata is antimutagenic at the dose level tested (100μg/plate).

Keywords

Aqueous Extract, Cassia auriculata, Mutagenicity, Salmonella typhimurium.

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N. Jeyashanthi ¹, P. Ravikumar ¹, N. N. Baalakumar ¹

Affiliations
1 Department of Biomedical Engineering, Velalar College of Engineering and Technology, Erode – 638012, IN

Abstract

This study examines the relationship between erythrocyte membrane bound Acetyl cholinesterase (AChE) activity, glycated hemoglobin (HbA1c) level and lipid peroxidation (formation of malondialdehyde). The aim was to elucidate the effect of HbA1c and lipid peroxidation on the activity of acetyl cholinesterase (AChE). Control subjects were non diabetic volunteers and the test group was diabetic patients with fasting glucose level of more than 150mg%. HbA1c, total hemoglobin, plasma glucose, lipid peroxidation and activity of AChE were determined. Observations indicate that elevated levels of lipid peroxidation in erythrocyte membrane of glycated hemoglobin of diabetic patients. HbA1c significantly increases lipid peroxidation and decreases the activity of AChE. Our data indicates that erythrocyte membrane bound enzyme AChE is significantly related to lipid peroxidation. Glycation of the hemoglobin increases the lipid peroxidation and alters the membrane bound enzyme function.

Keywords

Glycosylation, Malondialdehyde MDA, AChE, HbA1c.

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