A Finite Element Approach to Bending, Contact and Fatigue Stress Distribution in Helical Gear Systems

AbstractIn the face of extensive research into the theoretical basis and performance characteristics of helical gear design, a complete mathematical description of the relationship between the design parameters and the performance matrices is still to be clearly understood because of the great complexity in their interrelationship. The objective of this work is to conduct a comparative study on helical gear design and its performance based on various performance metrics through finite element as well as analytical approaches. The theoretical analysis for a single helical gear system based on American Gear Manufacturing Association (AGMA) standards has been assessed in Matlab. The effect of major performance metrics of different helical gear tooth systems such as single, herringbone and crossed helical gear are studied through finite element approach (FEA) in ANSYS and compared with theoretical analysis of helical gear pair. Structural, contact and fatigue analysis are also performed in order to investigate the performance metrics of different helical gear systems. The benefit of such a comparison is quickly estimating the stress distribution for a new design variant without carrying out complex theoretical analysis as well as the FEA analysis gives less scope for manual errors while calculating complex formulas related to theoretical analysis of gears. It will significantly reduce processing time as well as enhanced flexibility in the design performance

Assessment of the degree of awareness among post-graduate medical physicians and Pharmacists about look-alike, sound-alike drug and potential medication errors

Background: With thousands of drugs currently in the market, the potential for medication errors due to confusing drug names amongst practising physicians, pharmacists and patients is significant. The existence of confusing drug names is one of the most common causes of medication error. There are many look-alikes, sound-alike (LASA) combinations that could potentially result in medication errors. There is insufficient data about medication errors due to LASA. Hence, we conducted the present study to determine the degree of awareness regarding LASA drugs among post graduate medical physicians and Pharmacists.Methods: This study was a cross-sectional, questionnaire-based survey, conducted among 137 year post graduate medical residents of a tertiary care teaching hospital and 121 local pharmacists in an urban metropolitan Indian city.Results: There were 34% resident doctors and 17% pharmacists were aware of concept of LASA drugs. Only 46% resident doctors and 22% pharmacists had knowledge about the full form of LASA. Among resident doctors, 39% came across prescription errors due to LASA drugs. Only 69% of the pharmacists agreed that they consulted their doctors when they faced problems due to prescription errors due to similar looking and similar sounding drugs.Conclusions: Look-Alike, Sound-Alike (LASA) drugs are common source of medication errors. Our study suggests that there is lack of awareness about LASA drugs amongst resident doctors and pharmacists, which may contribute to occurrence of medication errors. Therefore, combined efforts by prescribers, pharmacists, organizations, manufacturers and patients is required to overcome medication errors due to LASA drugs

Understanding the degree of awareness among medical professionals regarding the ethics of pharmaceutical marketing activities in context of revised medical council of India code of ethics

Background: Pharmaceutical marketing activities are regarded as ethically challenging by most medical professionals. This study was planned to understand the extent of the interaction of pharmaceutical companies with healthcare providers & to determine the level of awareness about the ‘Medical Council of India (MCI) Code of Ethics’.Methods: A questionnaire based survey was conducted among 100 consultants and residents. The questionnaire mainly dealt with ethical issues about accepting free gifts, medicines and other sponsorships from pharmaceutical representatives, interactions and expectations from representatives of pharmaceutical companies by doctors and ascertaining among them the level of awareness about the MCI’s code of ethics.Results: 59.4% residents and 58.8% consultants do not consider small gifts (stationery/books/drug samples) as ethically problematic. 88% residents and 85% consultants felt that offers should be limited. 72% of consultants were aware of the revised MCI code of ethics as compared to 28% of residents.Conclusions: Most physicians do maintain a code of ethics with regards to accepting gifts and they felt that inexpensive gifts do not influence clinical judgment. Consultants were of the view that amended MCI code of ethics would not affect their clinical practice significantly

Performance up gradation of static VAR compensator with thyristor binary switched capacitor and reactor using model reference adaptive controller

There are various static var compensator configurations are available and listed in the literature. Their performances are evaluated based on their voltage support, dynamic response, losses, cost, and additional filter requirement, if any. In this paper, efforts are made to improve the dynamic performance parameter such as rise time, settling time, and peak overshoots. A new topology with an adaptive controller is presented, in which capacitor and reactor banks are divided in their binary values and connected in the shunt. Capacitor and reactor banks are operated by thyristorised switches. Both these banks are operated in closed-loop form as a cascade control. Amongst these, capacitor bank operates as coarse control, and reactor bank acts as fine control. For the performance enhancement, a model reference adaptive controller is used. The system identification toolbox is used to evaluate the mathematical model of the plant with Matlab. The model\u27s performance was analyzed deeply by the adaptive controller with different reference models such as critical, under, and overdamped. The performance parameters such as rise time, settling time, and peak overshoot in the form of reactive power swings, are evaluated and plotted for different adaptive gains using MIT rules

Enhanced production of amidase from Rhodococcus erythropolis MTCC 1526 by medium optimisation using a statistical experimental design

In the present work, statistical experimental methodology was used to enhance the production of amidase from Rhodococcus erythropolis MTCC 1526. R. erythropolis MTCC 1526 was selected through screening of seven strains of Rhodococcus species. The Placket-Burman screening experiments suggested that sorbitol as carbon source, yeast extract and meat peptone as nitrogen sources, and acetamide as amidase inducer are the most influential media components. The concentrations of these four media components were optimised using a face-centred design of response surface methodology (RSM). The optimum medium composition for amidase production was found to contain sorbitol (5 g/L), yeast extract (4 g/L), meat peptone (2.5 g/L), and acetamide (12.25 mM). Amidase activities before and after optimisation were 157.85 units/g dry cells and 1,086.57 units/g dry cells, respectively. Thus, use of RSM increased production of amidase from R. erythropolis MTCC 1526 by 6.88-fold

Mifepristone: an alternate to dinoprostone in induction of labour

Background: To assess and compare the efficacy, safety and fetomaternal outcome of mifepristone versus dinoprostone in priming the cervix and in inducing labour in pregnant women at term.Methods: This is a prospective comparative study done in Chettinad health and research institute, over a period of one year from October 2015 to October 2016. 50 pregnant women (Group 1) in 3rd trimester with unfavorable cervix were given 200mcg of mifepristone orally. If labour did not start or if the Bishop score remained poor at the end of 24hrs, induction was continued with 0.5mg of dinoprostone gel at a maximum of 3 gels at 6th hourly interval. Another 50 pregnant women (Group2) in 3rd trimester underwent induction according to the routine dinoprostone gel regimen of maximum 3 gels at intervals of 6hrs.Results: Improvement in Bishop score was significant with mifepristone by the end of 24hrs.But, in comparison, there was statistically significant improvement in Bishop score in favour of dinoprostone (Mean 4.7) than mifepristone (Mean 4.0). Also, the induction delivery interval was significantly less (Mean 11.5 hrs) with dinoprostone than mifepristone (Mean 20.3 hrs). Number of cases undergoing LSCS for failed induction was less in mifepristone group (4%). The rate of vaginal delivery, Caesarean sections, instrumental delivery and overall fetal outcome was comparable in both groups.Conclusions: Mifepristone is a safe, effective and suitable alternate agent for cervical ripening and initiation of labour when given 24 h before onset of labour.

Imaging Active Infection in vivo Using D-Amino Acid Derived PET Radiotracers.

Occult bacterial infections represent a worldwide health problem. Differentiating active bacterial infection from sterile inflammation can be difficult using current imaging tools. Present clinically viable methodologies either detect morphologic changes (CT/ MR), recruitment of immune cells (111In-WBC SPECT), or enhanced glycolytic flux seen in inflammatory cells (18F-FDG PET). However, these strategies are often inadequate to detect bacterial infection and are not specific for living bacteria. Recent approaches have taken advantage of key metabolic differences between prokaryotic and eukaryotic organisms, allowing easier distinction between bacteria and their host. In this report, we exploited one key difference, bacterial cell wall biosynthesis, to detect living bacteria using a positron-labeled D-amino acid. After screening several 14C D-amino acids for their incorporation into E. coli in culture, we identified D-methionine as a probe with outstanding radiopharmaceutical potential. Based on an analogous procedure to that used for L-[methyl-11C]methionine ([11C] L-Met), we developed an enhanced asymmetric synthesis of D-[methyl-11C]methionine ([11C] D-Met), and showed that it can rapidly and selectively differentiate both E. coli and S. aureus infections from sterile inflammation in vivo. We believe that the ease of [11C] D-Met radiosynthesis, coupled with its rapid and specific in vivo bacterial accumulation, make it an attractive radiotracer for infection imaging in clinical practice

Policy of foreign direct investment liberalisation in India: implications for retail sector

This study has analysed the impact of liberalisation of Indian economy and FDI policy on the retail sector since its implementation in the 1990s. It also further analyses sub-categories by investigating its impact on the unorganised retail sector and the flow of FDI in single-brand retail and multi-brand retail sectors. A comprehensive and critical review of the existing evidence on the subject was carried out, and descriptive statistical analysis of data from 1991 to 2013 was performed which leads to conclude that the policy of FDI liberalisation has proved to provide diversification and sustainable development to the Indian economy and specifically retail sector which is considered to be one of the significant pillars of economy. Furthermore, for continuous growth of the economy, it seems vital to encourage more investment in other sectors by liberalising the restrictive policies

Healthcare Worker Occupation and Immune Response to Pneumocystis jirovecii

Humans may be a reservoir for this pathogen and transmit it from person to person