Abstract: Heat transfer enhancment technique have a greater importance to deal with thermal management problem associated with varies engineering applications. Active techniques and passive techniques are used for heat transfer enhancement. Among this passive techniques of heat transfer enhancement are more compactable to improve heat transfer performance than active methods due to various reasons.  In this work the effect of surface modification on heat transfer performance is studied using ANSYS fluent software. A straight fin heat sink is selected and its heat transfer performance is analysed.  Surface of the existing flat plate fin is modified with hemispherical grooves called dimples on both sides of the plate. Hemispherical grooves of depth half as thickness of plate is chosen. The effect of dimples on heat transfer performance is analysed. Flat plate is replaced with a tapered plate of same base width and dimples are imposed on the surface. All modifications are analysed using ANSYS fluent for various flow conditions, under various flow conditions heat transfer coefficient, Nusselt number and temperature drop of all models are analysed. Results shows that heat transfer coefficient and Nusselt number of dimpled straight fin is higher than that of straight fin and tapered fin with dimples. Heat transfer performance of all the model increases with increase in flow velocity of air Also temperature drop on fin is maximum in straight fin with dimples.This shows heat transfer performance of straight fin with dimples is higher than that of straight fin and tapered fin with dimples.

Abstract: Design and reliable operation of Microelectromechanical systems (MEMS) depends on the material parameters that influence the failure and fracture properties of brittle and metallic thin films. Failure in brittle materials is quantified by the onset of castarophic fracture, while in metal, the onset of inelastic deformation is considered as failure as it increases the material compliance. This dissertation research developed new experimental method to address three aspects on failure response of these two categories of materials: (a) the role of microstructure and intrinsic stress gradient in the opening mode fracture of material which includes sharp pre-cracks in amorphous in poly crystalline brittle thin films, (b) the critical conditions for mixed mode I/II pre-cracks and their comparison with linear elastic fracture mechanism (LEFM) criteria for crack initiation in homogeneous materials, and (c) the strain rate sensitivity of textured monocrystalline Au and Pt films with grain sizes of 38 nm and 25 respectively. One of the technical objectives of this research was to develop- experimental and tools that could become standards in MEMS and thin film experimental mechanism. In this regards, a new method was introduced to conduct mode I and mixed mode I/II fracture studies with micro scale thin film specimens containing sharp edge pre-cracks. The mode I experiments permitted the direct application of LEFM. On the other hand, the newly introduced mixed mode I/II experiments in thin film were conducted by establishing a new protocol that employs non-standard oblique edge pre-cracks and a numerical analysis based in the stress intensity factors.
Keywords: Mems- micro electro mechanical devices, castrophic fractures,failure responses, linear elastic fracture mechanism (LEFM), farctures analyses of thin flims.
Title: FRACTURES AND FAILURE ANALYSIS IN MEMS
Author: PRAVEEN RAJ. S, RAHUL. R
International Journal of Novel Research in Engineering and Science
ISSN 2394-7349
Novelty Journals

Abstract: Urban lifestyles have contributed to consumers need for convenient and nutritious food products. This research was aimed at determining the optimum harvest time, storage temperature and the best variety of pineapple fruits (Anana Cosmosus) that could be used in juice and wine production. The maturity indices used were the acidity level and sugar concentration. Observations showed that as the fruit matures with time, the acidity level decreases while the sugar concentration increases. The empirical model developed at (P≤0.0001) showed that Optimum Harvest Time is 15weeks; Storage Temperature is 9.8℃and Carbazoni or smooth Cayenne as the best variety. The results would provide relevant information /data which the pineapple grower and processor need to make intelligent harvest decisions.

Abstract: With the increasing demand in agricultural produce, it has become important to increase productivity by using various fertilizers. Bio fertilizer was produced in this research by composting mixtures of sawdust, sewage sludge and succulent tissue of green leaves respectively using Effective Microorganisms (EM) as the accelerator. Pilot scale study was performed with containers made of polyethylene as the composter sequel to selection of right proportion of mixtures with the best Carbon to Nitrogen ratio (C/N). In this study, the mixtures of organic waste were composted at different weight ratios (1:1:2, 1:2:1, 2:2:2 and 2:1:1). Turning over was done once every week for aeration. Temperature was monitored at different depths daily. Other parameters such as N, C, organic matter, pH and heavy metals were determined at the end of the composting. The results of the study showed that dosage ratios of 1:1:2 and 1:2:1 gave the right proportion of carbon to nitrogen ratio. Organic matter and organic carbon decreased due to increase in temperature owing to the multiplication and activities of different communities of microorganisms. Highest temperature obtained was 59.82oC after 20 days. Also the temperature of some of the compost decreased slightly from day 25 due to maturity. The heavy metal content of all the composts decreased in accordance with World Health Organization (WHO) Acceptable Standards Established by United State Environmental Protection Agency 2004 [1] (2800mg/l for Zn, 300mg/l for Pb, 1500mg/l for Cu, 1200mg/l for Cr and 39mg/l for Cd).F-test analysis showed that the independent variables; dosage ratio, Time and type of materials are significant at 99% confidence level (p<0.01).

Abstract: Today, synthetic zeolites are used commercially more often than natural zeolites due to the purity of crystalline products and the uniformity of particle sizes. In view of the increasing rate of environmental pollution resulting from lead containing industrial effluents, The work reports the utilization of synthetic zeolite as an adsorbent for the removal of lead (II) ions from stimulated wastewater, and the significance of this study is to remediate industrial effluent so that the harmful effect of lead to man, aquatic life microorganisms and the environment will be reduced. The effect of sorption time, temperature,heavy metal concentration and pH, on the adsorption process were investigated using batch method. Langmuir, Freundlich, and Temkin isotherms were used to describe the adsorption isotherms and their constants evaluated. The equilibrium data was found to fit the Langmuir and Freundlich models. Kinetic models such as First-order, pseudo first-order, second-order and Elovich models were used to fit the experimental data. The result indicated that pseudo second-order model best describes the kinetics of the adsorption process.

Abstract: The objective of paper is to review possible opportunities of recycling of paint waste residues generated from automobile and engineering industry. Water based and solvent based paints are extensively used in automobile and storage solution industry to safeguard metal parts and for their aesthetical betterment. This painting process generates large quantum of paint wastes that are hazardous by nature and their conventional disposal mechanism involves negative environmental impacts.

Abstract: The kinetic study of the synthesis of an auto-oxidative drying modified palm stearin based alkyd resin was based on the polyesterification reaction process. The polyesterification process of the alkyd synthesis was studied using regression analysis of viscosity as a function of time applying integral method. The pendant chain of the Palm Kernel Stearin (PKS) was modified by blending it with measured ratio of rubber seed oil (RSO), followed by dehydration of the oil blend with the aim of increasing the degree of unsaturation in the oil chain. The modified dehydrated palm kernel stearin oil blend with ratio of 80:20, 75:25,70:30 and 65:35 by wt./wt.% of PKS to RSO respectively labelled as Oil A, Oil B, Oil C and Oil D were used to synthesized Alkyd A, Alkyd B, Alkyd C and Alkyd D respectively using a two stage alcoholysis-poly-esterification method. The film properties of synthesized  alkyds were determined as well as the drying schedule with the aim of getting optimum ratio of PKS to RSO which will yield auto- oxidative drying alkyds as regards to the total PKS content of the oil blend. Alkyd C gave the best result from the characterization and investigation study. The result of kinetic studies of the poly-esterification reaction of the synthesized alkyds shows that Alkyd A and B follows first order kinetics with rate constant of 0.0119/mins and 0.0136/mins whereas as Alkyd C and D follow second order kinetics with 0.0026 (Pa S)-1/min and 0.0026 (Pa S)-1/min , none follows third order kinetic.

Abstract: To design a controller is critical importance for an ability to perform a quadruped robot. In this paper, we present a method for embedded controller using   ARM Cortex M3 for controlling the quadruped robot. The controller mainly consist ARM Cortex m3 board for motion control. Based on sensors information the Arduino at mega 2560 controls motor speed, this paper is designing for agricultural purpose, military application, and forestry. A The wheel robots are not capable for some fields for that purpose we are designing a quadruped robot which as limbs for controlling and balancing the robots in different areas like rough terrain, mud soil, Rocky area. This designed robot is for agricultural field for spraying pesticides or we can use these types of robots in military applications for carrying the load and in forestry department.

Abstract: In this study, benzyl bis (thiosemicarbazole) monomer, polymer and poly benzyl bis (thiosemicarbazone) (PBTC) /CeO2 nanocomposites were synthesized through in situ polymerization and their thermal properties in presence of metal oxide, were investigated. Prepared samples were characterized by Fourier Transform Infrared spectroscopy (FTIR), X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC) and thermal gravimetric analysis (TGA). Structure and morphology of prepared nanocomposites were evaluated by Scanning Electron Microscopy (SEM) and XRD techniques. Particle sizes of CeO2 were calculated to be 10 nm from Debye-Scherrer equation. FT-IR verified polymerization of momomers. With more attention to TGA and DTA analyses, effect of nanosized particles on thermal properties of polymers can be easily observed.  

Abstract: The paper presents a review of power quality improvement of DC drives. Because of power quality should be improved for electrical devices, hence the multipulse converter are connected with DC drives and run at no load condition. FFT analysis are performed and Total Harmonic Distortion (THD) results, which are obtained by different parameter. The use of solid-state converters in various applications, as DC drives, variable frequency drives (VFD), heating and lighting industries, shipping (transportation) industry.

Abstract: Modern XLPE cable consist of a solid cable core, a metallic sheath and a non-metallic outer covering. The cable core consists of the conductor, wrapped with Semi-conducting tapes, The inner Semi-conductive layer, The solid main insulation and the outer semi-conducting layer. These three insulation layers are extruded in one process. Without Semi-conducting layer E and H fields are not uniformly concentrated in insulation material. During the process of cable joint the cable core peeled off. In the above process the Semi-conductive layer plays vital role. It is discovered that voids and contamination combined with ionic contamination in the Semi conducting shields led to voltage stress concentrations within the cable. These elevated voltage stresses combined with moisture ingress into cable structure created what are known today as cable trees. These dendritic growth of microscopic cavities degraded the insulation over time ultimately causing the cable to fail.

Abstract: In the past, wear at the disc and pads interface of disc brakes has rarely been accounted for in a 3-dimensional finite element (FE) model for studying brake squeal. Thus, its effect on disc brake squeal was only possible to investigate through experimental methods. In this present paper, wear over time at the pads interface is simulated using a modified wear rate formula. Confirmation of the proposed wear formula is made against experimental results. The surface topographies of two brand new pairs of brake pads are measured. The contact tests using pressure-indicating films are carried out in order to capture static pressure distributions. The same brake pads are tested under several braking applications. For each braking application, the static contact pressure distribution is measured. The results are used to compare with the simulated results predicted by the FE model. To do so, the detailed 3-dimensional finite element model of a real disc brake is developed and validated through appropriate analyses.