Comparative vibration study of EN 8 and EN 47 cracked cantilever beam

Since earlier days, most of the failures encountered by the structures or machines are mainly due to material fatigue. The dynamic behaviour of the beam may change when cracks begin to appear in it. Knowledge of these changes in the dynamic individualism is important in crack detection as well as in structure or in machine design. This paper deals with systematic study on the free vibration of Euler-Bernoulli beam containing open edge transverse cracks. In this study, two springs steel materials (EN 8 and EN 47) are considered. The effect of the top side cracks and bottom side cracks on the natural frequency of a cantilever beam is discussed. The natural frequency of a cracked case cantilever beam is investigated numerically using FE analysis software ANSYS. Experimental work is done by using DeweFRF to investigate the natural frequency of cracked beams for strong validation of the numerical results. The results of this study suggest that the average value of natural frequencies for all top side cracked beams are identical to the average value of natural frequency for all bottom side cracked beams. This is true for both EN 47 and EN 8. Hence, it is clear that the dynamic characteristic (natural frequency) is not changing, when same configuration of cracks is either on top or bottom side of the beam. The natural frequencies for EN 8 material are comparatively on higher side than EN 47 material for the same crack configurations. In most of the cracked cases, the damping effect of EN 47 is greater than EN 8. It is also found that as crack location increases at constant crack depth, then natural frequency increases. At the last location, as crack depth increases, natural frequencies almost remain same. It is observed that, the presence of top side crack and bottom side crack of the same configuration in the cantilever beam is not a function of natural frequency, when cantilever beam is of a square cross section

Impact of MCCD workshop on knowledge and awareness in post graduate residents at a tertiary care teaching hospital

Background: Medical Certificate of Cause of Death is a vital document, important scientific tool issued by the doctors. It is the physician\u27s primary responsibility to complete the medical certificate of cause of death correctly.  Incorrect filling up of the certificate will result in gross errors in legal scrutiny in medico-legal deaths. Method:  At the beginning the self-designed, pretested questionnaire open ended was distributed to participants, immediately after distribution pre-test was conducted. After the pre-test an interactive workshop was conducted on the MCCD. After the workshop post test was conducted. Result: There was an increase in the knowledge about who issues death certificates, long form of MCCD, who issues death certificate, maximum period within which you have to inform the registrar office about death in your clinic/hospital, detent dead body until your bills paid, what matter you are going to write on 1a. column and version present available in medical students from 0% to 61%, 30% to 100 %, 0% to 91 %, 0% to 91 %, 70 % to 96 %, 26 % to 87 % and 39 % to 100 % respectively. Conclusion: In the present study there is an improvement in knowledge and awareness in post graduates students after an interactive workshop on the MCCD

Impact of MCCD workshop on knowledge and awareness in post graduate residents at a tertiary care teaching hospital

Background: Medical Certificate of Cause of Death is a vital document, important scientific tool issued by the doctors. It is the physician's primary responsibility to complete the medical certificate of cause of death correctly.  Incorrect filling up of the certificate will result in gross errors in legal scrutiny in medico-legal deaths. Method:  At the beginning the self-designed, pretested questionnaire open ended was distributed to participants, immediately after distribution pre-test was conducted. After the pre-test an interactive workshop was conducted on the MCCD. After the workshop post test was conducted. Result: There was an increase in the knowledge about who issues death certificates, long form of MCCD, who issues death certificate, maximum period within which you have to inform the registrar office about death in your clinic/hospital, detent dead body until your bills paid, what matter you are going to write on 1a. column and version present available in medical students from 0% to 61%, 30% to 100 %, 0% to 91 %, 0% to 91 %, 70 % to 96 %, 26 % to 87 % and 39 % to 100 % respectively. Conclusion: In the present study there is an improvement in knowledge and awareness in post graduates students after an interactive workshop on the MCCD

Free vibration study of v-shape and rectangular shape double-sided cracks in a cantilever beam

The vibration response of a structural member changes due to the presence of crack because crack introduced local flexibility in it. Depending upon the vibration amplitude the crack may be of open or close type. Crack gives catastrophic failure to the structure hence it is very crucial to understand the dynamic of the structure. In the inverse problem, vibrating properties like natural frequency, resonance amplitude can be used as a basic criterion in crack detection or in design of structures. Previously, a mathematical model was developed by W. M. Ostachowicz and M. Krawczuk for the cantilever beam which has two open double-sided v-shape cracks. This model is used to find the natural frequency and characteristics roots in bending mode. The aim of this study is to prove whether the developed mathematical model can be used for rectangular shape cracks because in various applications existence of v shape and rectangular shape cracks are very general. For this reason, results of v-shape cracked cases are used as a reference model. Modal analysis is done by using ANSYS software to get the pure bending natural frequencies of the various cracked cases. Then the same mathematical model is used for rectangular shape cracked cases to calculate the characteristics roots. The value of characteristics roots obtained for a v-shape crack by W. M. Ostachowicz and M. Krawczuk and a rectangular shape crack cases studied are in good agreement. Hence it proves the flexibility of the model developed with v-shape cracks. In addition to this, the effect of two double-sided cracks on the characteristics roots is studied for all the cracked cases given in the reference model. It is found that as crack depth increases at any unique location then natural frequency decreases. At last location even though crack depth increases value of natural frequency almost remains constant

STUDY OF FREE UNDAMPED AND DAMPED VIBRATIONS OF A CRACKED CANTILEVER BEAM

This paper deals with the analytical study on the free un-damped and damped vibration of Euler–Bernoulli beam containing edge cracks. In this study, the effects of the different crack parameters such as crack depth, crack location and crack angle on the dynamic responses of the beam are discussed. Research studies presented the effect of transverse cracks on the natural frequency. Earlier studies have not considered the effect of oblique cracks on the cantilever beam. Presence of cracks in various parts of machine changes its vibration parameters to a considerable degree i.e. natural frequency and damping factor. In this paper, the transverse cracks and oblique cracks are considered on a cantilever beam at different locations and depths to study its effects on the various vibration parameters. The information of the dynamic response i.e. changes in the natural frequency, is much needed in the health monitoring of the beam to determine the location and depth of the crack in the beam. The response of a cracked cantilever beam for a damping factor has been studied by the combination of finite element analysis and theoretical method. Tests were conducted on the cantilever beam for both an intact and cracked cases by using FFT Analyzer. ANSYS software is used to validate the experimental results. The results of this study suggest that the natural frequency of the beam decreases significantly, when crack depth increases to 80% of the depth of the beam and it is least affected, when depth of the crack is either 20% or less than 20% of the depth the beam. Further it is also observed that the value of damping factor is least affected when crack remains present in the beam more towards the free end, when compared to damping factor of an intact beam

USING BIOABSORBENTS TO REDUCE RIVER WATER POLLUTION: A REVIEW

In present scenario, the river water has become wastewater due to disposal of city waste through which it flows. Most of the existing wastewater treatment plants are getting overload because of unexpected rapid urbanization and due to change in life style of common man. With such a pitch dark future of fresh water we have to think out of the box for new, better and efficient treatment method. In the recent years biosorption have emerged as an economical and environmental friendly method for the decontamination of polluted water in which impurities sequestering by different parts of the cell can occur via various processes: complexation, chelation, coordination, ion exchange, precipitation, and reduction. Biosorption is a process with some unique characteristics. It can effectively sequester dissolved metals from very dilute complex solutions with high efficiency

Phytosome as a Novel Drug Delivery System for Bioavailability Enhancement of Phytoconstituents and its Applications: A Review

Phytoconstituents are used extensively in modern science due to their varied therapeutic actions with few side effects. Regardless of their excellent pharmacodynamic activity, many Phytoconstituents have shown less bioavailability in vivo. Novel drug delivery systems have gained vital importance due to their increased bioavailability, and overall therapeutics. The water miscible Phytoconstituents have excellent bioactivity in vitro, however poor or no action in vivo. Phytosome technology can overcome this drawback during which the Phyto actives are allowed to react with phospholipid molecules. The Phytoconstituents with low lipoid solubility on complexation into herbal extract. Phospholipids show high affinity for polyphenolics, and type supramolecular adducts having a certain ratio. Hydrogen bond interactions between Phytoconstituents and phospholipids enable phospholipid complexes as an integral part. Complexation of phospholipids with active constituents of plants improves their bioavailability and is being extensively studied by researchers, and additional research during this regard is predicted within the future. This review highlights the unique property of phospholipids in drug delivery, phospholipid chemistry, stoichiometric ratios. We also discuss recent progress in research on the preparation, characterization, structural verification, advantages, recent patents, marketed formulation their application to enhance the bioavailability of active herbal Phytoconstituents. Keywords: Phytosome, Novel drug delivery, Phosphatidylcholine, Bioavailability, Patents, Applications