Machining of Tungsten Heavy Alloy under Cryogenic Environment

AbstractThe machining of tungsten heavy alloy is very difficult as it has high strength and hardness, which requires special cutting tools and cutting process. Though carbide tools are extensively used in conventional cutting, these lead take high machining time and tool failures which cause to decrease in productivity. To overcome the above, special techniques are being practiced in machining of tungsten alloys, one such technique is machining under cryogenic environment. In this paper, liquid nitrogen is used as coolant in machining of tungsten heavy alloys, because it is cost effective, safe, non flammable and environmental friendly gas, in addition to that it cannot contaminate the work piece and no separate mechanism required for disposal. An experimental investigation has been carried out on machining of tungsten heavy alloys by the solid carbide cutting tools under cryogenic and conventional coolants. The material removal rate, surface integrity and cutting forces were studied for both the coolants. The chip morphology also measured for evaluation of shear stress and shear strain. The cryogenic coolant has enhanced the machinability of tungsten heavy alloys. It is observed that the material removal rate was three times higher in cryogenic cooling method when compared with conventional coolant method and the surface finish of the machined surfaces are extremely good and the magnitude of cutting forces are lesser in cryogenic coolant

Research Notes : United States : Screening for cytoplasmic/maternal effects in resistance to soybean cyst nematode

With the discovery of soybean cyst nematode (SCN) in the U.S. in 1954, the research for resistance was initiated. Ross and Brim (1957) identified several soybean plant introductions resistant to the North Carolina SCN populations. Epps and Hartwig (1972) reported PI lines resistant to race 4

Research Notes : United States : An improved greenhouse method of evaluation for inheritance of resistance to race 4 of soybean cyst nematode

Studies to determine mode of inheritance of resistance to soybean cyst nematode (SCN), Heterodera glycines, could be influenced by the methods of evaluation in use. Any improvement in growing conditions of the host and pathogen, superior inoculation techniques, inducement of desirable infection in the host with minimum genetic variability in the SCN population could result in optimum expression of full complement of genes conferring resistance to SCN races. Our objective was to determine the mode of inheritance of resistance in Soybean Plant Introduction PI 88.788 for SCN race 4 reaction, using the improved techniques of evaluation

Observed Inter annual Variability of Upwelling Characteristics during 2016 2017 A Study using Princeton Ocean Model

Oceanographic observations carried out during 2016 and 2017 onboard INS Sagardhwani in the Southeastern Arabian sea are used to study the inter-annual variability of the upwelling. In 2016, the strong upwelling signatures are noticed in the observations (SST < 27°C and strong up-slopping of isotherms) as well as in the satellite derived sea level anomaly data. Whereas in 2017 the low sea level in June (-2 cm) are weakened during the mid of July (+3 cm) along the southern track (8 °N and 9 °N). This decrease in the strength in 2017 can be attributed to two major reasons. One is the presence of an anti-cyclonic eddy along the coast (8.5 °N, 76.5 °E) weakens the upwelling processes and second is the weak northerly component of the wind compared to 2016. In addition, Lakshadweep low is less prominent and situated towards the southern side (around 7°N) of its usual region of occurrence in 2017. The inter-annual variability of upwelling during July 2016 and 2017 is investigated using the 3D ocean model Princeton Ocean Model. Experiments with model in different combinations of forcing reveals that the alongshore wind component is the major parameter influencing the upwelling characteristics during these periods

Effect of Azimuthal Asymmetry Caused by Upwelling on 3D Ocean Acoustic Propagation

3-D underwater parabolic equation model based on implicit finite difference method has been implemented for South Eastern Arabian Sea (SEAS). The bathymetric and geo-acoustic features have been integrated in the model for a 50 km circular region in SEAS. The model can simulate the effects of azimuthal variation in oceanographic features and compute azimuthally coupled pressure due to an omni-directional source. The azimuthal variation in oceanographic conditions can be observed during an upwelling event. In the first case study, the effect of upwelling event on three-dimensional acoustic propagation has been studied by using sound speed profile data derived from INS Sagardhwani observations. The difference in Transmission loss mosaic for upslope and downslope propagation is due to bathymetry as well as upwelling. In the second case study, the effect of upwelling only, is studied by running a model corresponding to range independent sound speed profile field and range dependent bathymetry. It was observed that during this upwelling event, the transmission loss is higher at longer ranges during upslope propagation than downslope propagation. This is due to the increase in the thickness of sonic layer duct as acoustic wave propagates from shallow to deep water. The effect of azimuthal variation

A study of adverse drug reaction profile of tuberculosis patients attending DOTS center at Dr. Bhim Rao Ambedkar memorial hospital, Raipur, Chhattisgarh, India

Background: Tuberculosis is second leading cause of death in the world. The causative organism is Mycobacterium tuberculosis. The objective was to study the adverse reactions of the patients attending the DOTS center and to assess their causality and severity of reported ADRs.Methods: Present study was a prospective observational study carried at the DOTS center of Dr. Bhim Rao Ambedkar Memorial Hospital, Raipur, Chhattisgarh, India between August 2011 to July 2012 (One year). The patients were monitored for adverse drug reactions. The assessment of ADRs were based upon the WHO assessment scale, Naranjo scale, European A.B.O scale.Results: Total number of patients attending DOTS center was 816. The number of males (428) exceeded that of females (388). Majority of patients in this study belonged to 21-30 years (26.96%) next 31-40 years (25.24%) and 41-50 years (16.5%) of age group. Prevalence of ADRs were more in males (57%) than in females 32 (43%). Majority of ADRs reported were moderate 33 (35.22%) followed by 29 (46,77%) were mild, no severe ADRs reported. According to severity of ADRs seen were gastritis 28 (45%) followed by 10 (16% ) rashes , 10 (16,12%) of arthralgia, 3 (4.83%) of hepatitis, 6 (9.7%) of peripheral neuropathy, 2 (3%) onsets of ADRs after starting anti-tubercular drug were 12 (19.35%) in 0-1 week followed by 19 (30%) ADRs showed onset in 1-2 week and 2-3 week, 8 (13%) in 3-4 week 3 (5%) in 4-5 week and 1 (2%) in 5-6 week.Conclusions: The casual link between the ADRs and the suspected anti-tubercular drug by Naranjo scale definitely relationship was established between the anti-tubercular drug and ADRs in 7 (11.25%) patient while 22 (35.45%) probable and 33 (53.22%) ADRs were categorized as possible

Rationality verses irrationality in fixed dose combinations: at a tertiary teaching hospital of rural Chhattisgarh, India

Background: Rational drug prescribing can be defined as appropriate drugs prescribed in the right dose, at correct time intervals and for a sufficient duration. Irrational drug use is a common problem in many countries of the world.Methods: A prospective observational study was conducted, total 300 patients attending various outpatient departments of tertiary health care rural hospital in Rajnandgaon district were interviewed and their prescriptions were analysed.Results: Total 350 drugs were prescribed 60 (17.14%) were prescribed by generic name and the rest 290 (82.86%) were prescribed by brand name. Only 18 (5.14%) drugs were not prescribed from hospital formulary. 264 (75.43%) drugs were dispensed from hospital pharmacy. On the basis of rationality score 53% prescriptions were rational, 30% semi rational and 17% irrational.Conclusions: In a rural hospital, where hospital formulary is based on WHO Essential medicine list, hundred percent utilization of hospital pharmacy service doctors and patients would ensure rational prescribing benefits of the patients coming from rural and uneducated background

Assessment of knowledge of pharmacotherapeutics amongst medical undergraduates of a tertiary care teaching hospital of Chhattisgarh, India: a questionnaire based study

Background: Knowledge of pharmacology forms the basis of rational pharmacotherapy practice. Teaching the medical students about systematic application of pharmacology in patients’ care forms an essential component. It facilitates the medical students to develop a methodical approach in solving patients’ clinical problems.Methods: A questionnaire-based study was conducted, at Government Medical College Rajnandgaon involving second year MBBS students. Total 100 students participated in the study.Results: Hundred percent of the students responded that pharmacology was presently taught to them, seventy nine percent of them agreed with the fact that pharmacology was preferred to pass the MBBS, eighty eight percent of them responded that in pharmacokinetics was the least preferred topic, ninety seven of them were not aware of the essential drug list. Their suggestions regarding the change in teaching methodology was recorded.Conclusions: This study concludes that efforts are needed to develop a curriculum that encompasses important aspects of clinical pharmacology and therapeutics along with incorporation of the useful suggestions by the undergraduate students

Detection of pulmonary Mycoplasma pneumoniae infections in HIV-infected subjects using culture and serology

SummaryObjectiveThe true prevalence of Mycoplasma pneumoniae infections involving the respiratory tracts of HIV-infected individuals is still unclear. This study examined the prevalence of M. pneumoniae in 100 HIV-infected individuals at an AIDS care center in Chennai, India, using conventional laboratory techniques and interpretation criteria.MethodsDiagnosis was based on culture, cold agglutination test, and commercial enzyme-linked immunosorbent assay (ELISA) for the qualitative determination of IgM antibodies against M. pneumoniae. The efficacies of the different diagnostic procedures used in the study were analyzed.ResultsThe prevalence of M. pneumoniae was 31% by culture and 21% by IgM ELISA. Cough (p=0.03, OR 3.8, 95% CI 1–17.8), myalgia (p=0.04, OR 2.5, 95% CI 1–6.6), rales (p=0.04, OR 2.4, 95% CI 1–6.6), and cervical adenopathy (p=0.03, OR 2.7, 95% CI 1–7.1) were the symptoms that significantly corroborated culture positivity. Patients positive for M. pneumoniae by culture or IgM antibody had significantly greater CD4+ T-cell depletion and anemia than those without any evidence of infection.ConclusionsThis study provides the means to diagnose M. pneumoniae infection and information on the prevalence of the pathogen in HIV-infected individuals in resource constrained settings. Although modern molecular techniques may provide more insight into the prevalence of M. pneumoniae in HIV-infected individuals, conventional methods can still be used in diagnosis

Transition of Care in Paediatric Surgery: Current practices and perspectives of paediatric surgeons in Malaysia

Objectives: Transition of care (TOC) from paediatric to adult care is still at an early stage in Malaysia. This study aimed to explore current practices and perspectives regarding TOC among paediatric surgeons in Malaysia. Methods: This study was carried out between June and December 2017. All 48 paediatric surgeons currently working in Malaysia were invited to participate in a questionnaire-based survey to assess demographic characteristics and practices and perspectives regarding TOC. Results: A total of 38 paediatric surgeons participated in the survey (response rate: 79.2%). Overall, 97.4% did not have an organised TOC model in their institution, with most (65.8%) caring for paediatric patients with complex surgical conditions until adulthood. Although the majority (86.8%) felt that care should be transitioned to adult surgeons with appropriate credentials, most surgeons (84.2%) nevertheless preferred to be involved in the management of adolescent patients after transition. However, there was no consensus regarding the most suitable age to begin the transition. Years of experience as a paediatric surgeon and place of practice did not affect overall TOC practice scores (P >0.050 each). The presence of adult comorbidities was considered the most common reason to initiate TOC (81.6%), while the lack of TOC guidelines was perceived to be the greatest barrier (84.2%). Conclusion: This study provides a better understanding of TOC from the point of view of paediatric surgeons in Malaysia. However, further studies involving other stakeholders (i.e. patients and adult surgeons) are needed to help formulate a suitable and successful TOC model in this setting.Keywords: Transition to Adult Care; Pediatrics; Adolescents; Surgery; Attitudes; Professional Practice; Malaysia