Development and implementation of a finite element program for static electromagnetic field problems

Bibliography: leaves 102-106.A program is presented for the solution of static electromagnetic fields in bounded and unbounded 2- dimensional domains. The program comprises of a mesh generator which descretises the domain into triangular finite elements or if applicable into special elements, called infinite elements which model the bounded and unbounded domains respectively. The potential function is solved for, using a special solution technique which enhances the speed of the program. The program outputs data in the form of potential or flux component distributions along lines of interest

The influence of the jet opening angle on the appearance of relativistic jets

We reinvestigate the problem of the appearance of relativistic jets when geometrical opening is taken into account. We propose a new criterion to define apparent velocities and Doppler factors, which we think being determined by the brightest zone of the jet. We numerically compute the apparent velocity and the Doppler factor of a non homokinetic jet using different velocity profiles. We argue that if the motion is relativistic, the high superluminal velocities beta_{app} ~ gamma, expected in the case of an homokinetic jet, are only possible for geometrical collimation smaller than the relativistic beaming angle 1/gamma. This is relatively independent of the jet velocity profile. For jet collimation angles larger than 1/gamma, the apparent image of the jet will always be dominated by parts of the jet traveling directly towards the observer at lorentz factors < gamma resulting in maximal apparent velocities smaller than gamma}. Furthermore, getting rid of the homokinetic hypothesis yields a complex relation between the observing angle and the Doppler factor, resulting in important consequences for the numerical computation of AGN population and unification scheme model.Comment: Accepted in MNRAS, 12 pages and 9 Figure

Further evidence for intra-night optical variability of radio-quiet quasars

Although well established for BL Lac objects and radio-loud quasars, the occurrence of intra-night optical variability (INOV) in radio-quiet quasars is still debated, primarily since only a handful of INOV events with good statistical significance, albeit small amplitude, have been reported so far. This has motivated us to continue intra-night optical monitoring of bona-fide radio-quiet quasars (RQQs). Here we present the results for a sample of 11 RQQs monitored by us on 19 nights. On 5 of these nights a given RQQ was monitored simultaneously from two well separated observatories. In all, two clear cases and two probable case of INOV were detected. From these data, we estimate an INOV duty cycle of $\sim$8% for RQQs which would increase to 19% if the `probable variable' cases are also included. Such comparatively small INOV duty cycles for RQQs, together with the small INOV amplitudes ($\sim$1%), are in accord with the previously deduced characteristics of this phenomenon.Comment: 15 Pages, 4 Tables, 24 Figures; Accepted in BAS

Jet stability, dynamics and energy transport

Relativistic jets carry energy and particles from compact to very large scales compared with their initial radius. This is possible due to their remarkable collimation despite their intrinsic unstable nature. In this contribution, I review the state-of-the-art of our knowledge on instabilities growing in those jets and several stabilising mechanisms that may give an answer to the question of the stability of jets. In particular, during the last years we have learned that the limit imposed by the speed of light sets a maximum amplitude to the instabilities, contrary to the case of classical jets. On top of this stabilising mechanism, the fast growth of unstable modes with small wavelengths prevents the total disruption and entrainment of jets. I also review several non-linear processes that can have an effect on the collimation of extragalactic and microquasar jets. Within those, I remark possible causes for the decollimation and decelleration of FRI jets, as opposed to the collimated FRII's. Finally, I give a summary of the main reasons why jets can propagate through such long distances.Comment: For the proceedings of High Energy Phenomena in Relativistic Outflows III (HEPRO III, IJMPD, accepted). 12 page

A STUDY ON KNOWLEDGE, ATTITUDES, AND PRACTICES FOR THE PREVENTION OF DIABETIC FOOT IN RURAL TERTIARY CARE TEACHING HOSPITAL

Objective: To assess the knowledge, attitude, and practice of diabetic patients regarding care of their own feet.Methods: This is a cross-sectional study conducted in the inpatient department of surgery at Adichunchanagiri hospital and research centre, B. G. Nagara, Karnataka, India from 1st Nov. 2016 to 31st Dec. 2016. The relation between gender and knowledge, attitude and practices of people with diabetes patients were compared by using the Chi-square test at 95% confidence interval at p&lt;0.05.Results: Out of 51 patients, 72.54% were male and 27.46% female and 45.1% of the patients were in the age range 61-80 y. The mean SD of the age was 60.49±14.02. The mean SD of body weight of the patient was 66.17±8.54. The majority of the patients 45.1% were farmers and 41.7% were illiterate. Most of them did not know the practice of correct foot hygiene (39.22%) and what abnormalities observe in their feet (66.67%). We found that 90.2% patients were engaged in foot self-care practice and more than half of them (54.1%) always inspected their footwear before using it. Interestingly, more women were involved in foot care (100%) as compared to men (86.46%) but statistically not significant (p=0.147).Conclusion: We found that patients were not having sufficient knowledge about the correct hygiene of the foot, what abnormalities to observe in their feet and about ideal footwear. Even though females were showing interest towards self-care examination and foot care practice, it is essential that all the diabetic patients must be educated about the knowledge, attitude and foot self-care practice to prevent diabetic foot related complications

Outbreak report of investigation and control of an outbreak of Panton-Valentine Leukocidin-positive methicillin-sensitive Staphylococcus aureus (PVL-MSSA) infection in neonates and mothers

Background In January 2011, there was an outbreak of Panton-Valentine Leukocidin-positive methicillin-sensitive Staphylococcus aureus (PVL-MSSA) infection in a neonatal unit (NNU). We describe the investigation and control of an outbreak of PVL-MSSA infection in neonates. Setting: Neonatal unit in West London. Methods We performed descriptive and analytical (case-control study) epidemiological investigations. Microbiological investigations including screening of MSSA isolates by PCR for the presence of the luk-PV, mecA and mecC genes and comparison of isolate with Pulsed field gel electrophoresis (PFGE). Control measures were also introduced. Results Sixteen babies were infected/colonised with the outbreak strain. Of these, one baby developed blood stream infection, 12 developed skin pustules and four babies were colonised. Four mothers developed breast abscesses. Eighty-seven babies in the unit were screened and 16 were found to have same PVL-MSSA strain (spa type t005, belonging to MLST clonal complex 22). Multivariate analysis showed gestational age was significantly lower in cases compared to controls (mean gestational age: 31.7 weeks v 35.6 weeks; P = 0.006). Length of stay was significantly greater for cases, with a median of 25 days, compared to only 6 days for controls (P = 0.01). Most (88%) cases were born through caesarean section, compared to less than half of controls. (P = 0.002). No healthcare worker carriers and environmental source was identified. The outbreak was controlled by stopping new admissions to unit and reinforcing infection control precautions. The outbreak lasted for seven weeks. No further cases were reported in the following year. Conclusions Infection control teams have to be vigilant for rising prevalence of particular S. aureus clones in their local community as they may cause outbreaks in vulnerable populations in healthcare settings such as NNUs