Fabrication of Surface Micromachined AlN Piezoelectric Microstructures and its Potential Apllication to RF Resonators

We report on a novel microfabrication method to fabricate aluminum nitride (AlN) piezoelectric microstructures down to 2 microns size by a surface micromachining process. Highly c-axis oriented AlN thin films are deposited between thin Cr electrodes on polysilicon structural layers by rf reactive sputtering. The top Cr layer is used both as a mask to etch the AlN thin films and as an electrode to actuate the AlN piezoelectric layer. The AlN layer is patterned anisotropically by wet etching using a TMAH (25%) solution. This multilayer stack uses silicon-di-oxide as a sacrificial layer to make free-standing structures. One-port scattering paramenter measurement using a network analyzer show a resonant frequency of 1.781 GHz on a clamped-clamped beam suspended structure. The effective electromechanical coupling factor is calculated as 2.4 % and the measured bandwidth is 13.5 MHz for one such a doubly clamped beam (990x30) μm2

Clinical Properties in Sangam Literature

The people of the Sangam period lived a high life in harmony with nature. Sangam literature and other literature conveyed to the world that they excelled in various fields like geology, astronomy, medicine, etc. Living in harmony with nature in all stages of their lives, the Tamils used the types of plants like trees, plants, and vines and their parts to make their lives better. The same has been shown in literature as parables, metaphors, and symbols. The ancient Tamils lived dividing medicine as health medicine and psychiatry. It can be known through the literature that medicine for physical health has been classified as natural medicine, music medicine, and surgical medicine, and they have been maintaining health on the basis of food as medicine, and they have removed stress through methods such as relaxation, soothing, and hysteresis as medicine for mental health. Also, classifying the diseases as pain, illness, and suffering, they prescribed medicines for them. Our forefathers used to call doctors "pathologists" and medical women "doctor and midwife." Also, this article is a study that shows the people of the Sangam period knew the medicinal properties of plants and used them as food and medicine with the high principle of 'food is medicine and medicine is food'

Optimum Design of Shell and Tube Heat Exchanger Using Artificial Immune System Approach

This paper presents the economic optimization of shell and tube heat exchangers design approach through an artificial immune system algorithm for minimizing the cost. Since complex geometric parameters, with thermodynamic and fluid dynamic factors, consume more time and offer a minimum possibility for an optimum result in the case of conventional design, the design process becomes difficult. The proposed algorithm provides the designer with an optimum solution in less amount of time by analyzing three different case studies.  Three design variables such as shell internal diameter, tube outer diameter and baffle spacing from the different design parameters are taken into account for this optimization. The results are weighed against those obtained by various researchers

STATISTICAL MODEL BASED OPTIMAL PREDICTION ON DRILLING PARAMETERS

The drilling is an imperative machining practice in the mechanical field for fitting or cutting the materials devoid of any disturbance. Various elements are basically employed within the automobile applications on account of the light weight, exceptional firmness and the moderate cheapness. The effectiveness of the drilled opening for the material shields is expanded by minimizing the eccentricity factor. The eccentricity is a degree of the nature of a drilled hole, and the process is based on input parameters. The significant intention of the suggested procedure is to built a mathematical modeling   with the support  of the optimization techniques. The mathematical modeling is done by minimizing the time consumed in the case of extension of the real time experiment. It is utilized to predict the diameter of the drill whole entry and exit, material removal rate and the eccentricity factor for the drilling process. Different optimization algorithms are utilized to find the optimal weights α and β of the mathematical modeling. All the optimum results demonstrate that the attained error values between the output of the experimental values and the predicted values are near equal to zero in the designed model. From the results, the minimum error 97.2% is determined by the mathematical modeling attained in the Artificial Fish Swarm Optimization (AFSO) process

Videogame Playing and Aggression Behaviour: A Correlation Study among School Students

The purpose this study is to explore school students' videogame playing and its correlation to aggressive behaviour. Four hundred and six (406) videogame playing students from different socio-economic background in Chennai city of India and its suburban areas participated in the study. Data on aggressive behaviour from the students were collected in the Buss and Perry Aggression Questionnaire format. The General Aggression Model was used to predict the students' aggression. The study reveals that gender was significant in hostility, physical and verbal aggression. Further, analyses indicated that parents' education has a significant bearing on students' aggression behaviour