Simulation of Cylindrical Resonator with Spiral Neck and Straight Neck to Attenuate the Low Frequency Noise of Muffler

This paper is concentrated for improving the transmission loss and reduces the low frequency noise level by development of Helmholtz Resonator within a limited space. The modified Helmholtz resonator, i.e. cylindrical resonator with spiral neck is used to occupy the small space. Introduction of spiral neck instead of straight neck with cylindrical cavity reduces the space of resonator. For first cut-off frequency (resonance frequency) the volume of resonator is fixed, so with the help of spiral neck its length increases, volume increases and its curvature effect is also helpful in the reduction of noise. The finite element analysis tool Comsol multiphysics is used to validate the result. The results shows interesting factor that resonator not only attenuate a particular low frequency noise as well it increases transmission loss with spiral neck. Helmholtz resonator with a spiral neck can achieve high sound reduction within a small space at low frequency

A Partition Based Novel Approach in AFIS for Forensics & Security

AbstractMany automatic fingerprint identification approaches have been suggested. Amongst those various methods, the minutiae-based fingerprint demonstration and recognition is widely used. Minutiae based representation has some disadvantages in comparison to other fingerprint approached in terms of sample size. This paper describes a novel concept of partition based approach for fingerprint identification which aims to improve error rates as well as processing time in matching fingerprints. We aim to split the identity image into well separated partitions in order to simplify the identification task. Our system will use the gray-scale information of the fingerprints. The system will select the primary fingerprint, perform feature extraction & feature matching to identify the image in the database by comparing the featured values of both the fingerprints. Our implementation mainly incorporates image pre-processing, image partitioning, image binarization, feature extraction and feature matching. It finally generates a score which tells whether two fingerprints match or not

Role of regular yoga practice in improvement of various pulmonary parameters in first year medical students

Background: tress at any stage of life virtually produces several respiratory limitations and reduces tolerance to physical efforts, sometimes leading to pulmonary diseases in individuals. Various yoga and Pranayama like Kapalbhati and Nadi-sodhan involves powerful strokes of exhalation, which trains the subject to make full use of diaphragm and abdominal muscles.Methods: This study is performed on 1st yr. medical students whose stress level is in higher side due to academic burden. 55 medical students were selected as participants through counseling and were divided into Yoga group (n= 27) and control group (n=28). Pulmonary functions of subjects were tested using Pony FX advanced desktop spirometer manufactured by Cosmed. Yoga is performed 1 hr/day for 6 days /week for 12 weeks by yoga group.Results: Pulmonary functions tested in Yoga and control group were FVC, FEV1, PEF and FVC/FEV1. There were significant improvements in pulmonary functions in yoga group. In Yoga group (FVC- 5.8% increases, FEV1- 5.2% increase, PEF- 34% increase and FVC/FEV1- 3.15% increase). In control group also, all parameters increased but P value was not significant.Conclusions: This study concludes that practicing Yoga has shown a significant improvement on pulmonary functions in 1st year medical students

Effect of traffic air pollution on spirometeric parameters in Eastern Uttar Pradesh population, India

Background: In the present era of the 21st century there are lots of discussion on environmental population and its impact on life and various clinical studies done to find out the effect of air pollution on respiratory physiology, particularly pulmonary functions. Pulmonary function tests give valuable information about lung physiology in health and disease. In the present study to assess the pulmonary function test between the population groups exposed to traffic related air pollution. Methods: A cross sectional retrospective cohort study was conducted in B R D Medical College. It was done on 73 males, out of which 35 were traffic policeman (15 smokers, 20 non- smokers) and remaining 38 belonged to non- exposed control group (15 smokers, 23 non-smokers). Pulmonary function tests (PFTs) were performed with computerized spirometer. The respiratory parameter was recorded and analyzed. To check statistical of data student t-test was performed.Results: Comparison of ratio FEV₁/FVC among two populations, revealed lower values for Traffic policeman group. This difference was significant among the non-smoker (P=0.0061), while not significant among the smoker (P=0.3419).Conclusions: The respiratory parameters were changed due to traffic related air pollution. So traffic related air pollution can be a risk factor in the development of respiratory obstruction

Design and Analysis of Composite Rotor Blades for Active/Passive Vibration Reduction.

The problem of vibration has limited the use of helicopters in both civil and military applications. In this research, further analysis has been performed for the various on-blade approaches available for vibration reduction using a unique optimization framework. For passive optimization, an aeroelastic environment with several well-established analysis codes from different sources was developed that can be used to analyze and design composite rotor blades for minimum vibration or maximum performance. This design environment enables conceptual/early preliminary multidisciplinary rotor blade design with realistic structural properties for modern composite rotor blades. For the design of a rotor blade with active twist, a new design strategy was introduced where the amplitude of dynamic twist is maximized. The optimization framework included the aeroelastic design environment described earlier along with surrogate based optimization technique. The surrogate based optimization is performed in combination with Efficient Global Optimization algorithm. Results showed that the amplitude of dynamic twist is a true indicator of control authority of active twist rotor for vibration reduction. Furthermore, the optimization framework was extended to include discrete design variables in the optimization and the solution for mixed-variable design problem was obtained using three different techniques. After modifying the aeroelastic analysis to account for the presence of active flaps, a Mach-scaled composite rotor blade was designed using the same mixed design variable optimization framework to enhance the vibration reduction capabilities of the active flap. In this case also, the amplitude of dynamic twist was used as the objective function and the analysis was carried out at three different spanwise flap locations. This thesis also includes work related to the design and fabrication of a composite rotor blade with dual flaps which can be tested in a Mach-scaled spin test stand. Finally, the use of camber actuation with quadratic and cubic camber deformation shapes for vibration reduction and performance enhancement in dynamic stall region was studied. The aeroelastic analysis was augmented with a modified version of the ONERA dynamic stall model that accounts for morphing airfoil section.PHDAerospace EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/98006/1/deveshk_1.pd

New Optimization Strategy for Design of Active Twist Rotor

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140683/1/1.j053195.pd

Role of yoga and meditation on serum DHEAS level in first year medical students

Background: Dehydroepiandrosterone sulfate (DHEAS), secreted by adrenal cortex, acts in the human body as a neurosteroid, cardio-protective, anti-diabetic, anti-obesity and immune-enhancing agent. It is also reported as a youth hormone. But due to various stimulators of stress, and also as an antagonist of cortisol, DHEAS level decreases. Yoga and meditation regulates the level of hormones and neurotransmitters that affect physiological function.Methods: This study was performed on 1st yr. medical students whose DHEAS level was low due to acute stress. 55 medical students were selected as participants through counseling and were divided into Yoga group (n= 27) and control group (n=28). Their morning serum DHEAS level was assessed and yoga group were instructed to practice Yoga (1hr/day for 12 weeks) under supervision of Yoga instructor. No such instruction was given to control group.Results: As a marker of youth and immunity, increase in DHEAS level decreases susceptibility to infections, reduces aging process as well as improves other functions. Yoga and meditation is documented to increase DHEAS level in regular practitioners. Statistical analysis has shown an increase in morning S. DHEAS level in yoga practitioners. Pre-study and post study values were 3.5±2.48 and 3.61±1.73 respectively in yoga group (overall 3.1% increase, P Value = 0.025, significant at 0.05) whereas 3.36±1.98 and 2.58±1.49 respectively in control group (23.2% decrease, P Value =0.84, not significant).Conclusions: This study concludes that practicing Yoga has significantly raised S. DHEAS level in medical students and improved their immunological status as well as enhances mood and behavior