Slow pressure modes in thin accretion discs

Thin accretion discs around massive compact objects can support slow pressure modes of oscillations in the linear regime that have azimuthal wavenumber $m=1$. We consider finite, flat discs composed of barotropic fluid for various surface density profiles and demonstrate--through WKB analysis and numerical solution of the eigenvalue problem--that these modes are stable and have spatial scales comparable to the size of the disc. We show that the eigenvalue equation can be mapped to a Schr\"odinger-like equation. Analysis of this equation shows that all eigenmodes have discrete spectra. We find that all the models we have considered support negative frequency eigenmodes; however, the positive eigenfrequency modes are only present in power law discs, albeit for physically uninteresting values of the power law index $\beta$ and barotropic index $\gamma$.Comment: 9 pages, 7 figures, 1 table, accepted in MNRAS for pulicatio

Effects of polarisation on study of anomalous VVH interactions at a Linear Collider

We investigate the use of beam polarisation as well as final state $\tau$ polarisation effects in probing the interaction of the Higgs boson with a pair of heavy vector bosons in the process $e^+ e^- \to f \bar f H$, where $f$ is any light fermion. The sensitivity of the International Linear Collider (ILC) operating at $\sqrt s=500$ GeV, to such $VVH$($V = W/Z$) couplings is examined in a model independent way. The effects of ISR and beamstrahlung are discussed.Comment: To appear in the proceedings of 2007 International Linear Collider Workshop (LCWS07 and ILC07), Hamburg, Germany, 30 May - 3 Jun 2007. 4 pages, LaTeX, 1 eps figure. requires ilcws07.cls. included in submissio

Two-Proton Radioactivity with 2p halo in light mass nuclei A==18−-34

Two-proton radioactivity with 2p halo is reported theoretically in light mass nuclei A $=$ 18-34. We predict $^{19}$Mg, $^{22}$Si, $^{26}$S, $^{30}$Ar and $^{34}$Ca as promising candidates of ground state 2p-radioactivity with S$_{2p}$ $$ 0. Observation of extended tail of spatial charge density distribution, larger charge radius and study of proton single particle states, Fermi energy and the wave functions indicate 2p halo like structure which supports direct 2p emission. The Coulomb and centrifugal barriers in experimentally identified 2p unbound $^{22}$Si show a quasi-bound state that ensures enough life time for such experimental probes. Our predictions are in good accord with experimental and other theoretical data available so far.Comment: 5 Pages, 5 figure

On Chaplygin’s Method For First Order Neutral Differential Equation

In this paper we discuss the existence of a solution of a first order neutral differential equation with piecewise constant argument. We extend the method of Chaplygin’s sequence to obtain two sided bounds for the solution. These bounds are in the form of sequences of functions which are solutions of associated linear neutral differential equations with piecewise constant argument. This construction of monotonic sequences of upper and lower functions approximate, with increasing accuracy, the desired solution of the neutral differential equation with piecewise constant argument. Further we show that these sequences converge uniformly and monotonically to the unique solution of the equation.The error estimate obtained is better than the corresponding one for ordinary differential equations

Microbial Study of Water Samples Collected from Different Districts of Himachal Pradesh

Water Microbiology deals with the study of the living organisms of microscopic size present in water that causes infectious diseases of man. The primary test performed on water taken from 10 different sites act as an indicator of different types of water pollution, especially fecal pollution of water due to the presence of coliforms bacteria because they are invariably present in feces of human beings. The safety of drinking water is an ongoing concern within the global village. Traditionally, the safety of potable water supplies has been controlled by disinfection, usually by chlorination and coliform population estimates. However, it has been reported that coliform-free potable water may not necessarily be free of pathogens. Some diseases causing microorganisms enter the water from different sources and causes different types of diseases such as Polio, Typhoid, Hepatitis, Shigellosis, Salmonellosis can spread through this contaminated water which is a matter of concern

A Rare Case of an Intratonsillar Abscess

The case describes the anatomy and pathophysiology of the palatine tonsils and the development of intratonsillar abscess. The abscess can be caused by a suppurative focus that arises in acute tonsillitis when outward drainage is prevented, leading to pus accumulation in the tonsillar tissue. Dehydration or a history of peritonsillar abscess can also lead to intratonsillar abscess. The condition can be mistaken for tonsillolith or malignancy, such as lymphoma. A computed tomography (CT) scan is recommended for diagnosis, showing a low-density and ring enhancement. Aspiration using a large bore needle is the preferred mode of treatment, but if repeated aspirations fail, tonsillectomy may be necessary. Intratonsillar abscess is rare and so far only 29 cases have been reported.1 The differential diagnoses include lymphoma, which usually presents as unilateral enlargement of the tonsil, tonsillolith due to its appearance and peritonsillar abscess again due to the unilateral enlargement of the tonsil. This case is different as compared to other reported cases we did not do a CT scan as recommended by most of the studies (cost being a concern). Also, in this case, we resorted to surgery as the main modality unlike other cases wherein the surgeons opted to do an aspiration of the pus mainly keeping the intraoperative complications in mind

Body Stalk Syndrome: A Curiosity

Limb body wall complex (LBWC) /Body stalk syndrome anomaly refers to a rare complicated polymalformative fetal malformation syndrome of uncertain etiology firstly described by Van Allen et al in 1987. There are very few cases reported in literature and thus we report a rare case of LBWC. Twenty seven years female presented to labour room with 32 weeks of gestation with no prenatal care and delivered a low birth weight still born fetus weighing 1100gms. On fetal autopsy large abdominal wall defect was noted with difficulty in identifying abdomino-pelvic organs and ambiguous genitalia. Placenta weighed 250gms with attached short umbilical cord measuring 7cms, arising from periphery. A cyst noted attached to placental membrane measuring 9x5cms which on dissection retrieved partially maldeveloped organs. Post mortem radiological findings included Absence of right femur with short tibia and right fibula, Complex vestibral malformation, Craniosynostosis and Overcrowding of ribs

Effect of microencapsulated plant extracts on mosquito repellency

Mosquitoes are the most important single group of insects in terms of public health importance. Mosqui-toes not only cause nuisance by their bites but also transmit deadly diseases. The activity of mosquitoes is affected by climate, light and temperature. In tropical areas like India, the population of mosquitoes is found huge day by day. Repeated use of synthetic insecticides for mosquito control has disrupted environment as well as human health. To overcome this problem, plant derived compounds may be the better alternate over synthetic insecticides. To enhance the health and hygiene qualities by means of use of medicinal plants through effective application technique on textiles, marigold (petals) and nirgundi (leaves) methanol extract was used as mosquito repellent finish on 100 % woven cotton. For applying mosquito repellent finish on fabric, complex coacervation technique of microencapsulation was used through pad-dry-cure method. Finished cotton samples were tested against Anopheles stephensi by using laboratory cage method for their efficacy and durability to washing and sun-drying as per standard test methods. Marigold (petals)and nirgundi (leaves) extract finished fabric samples showed 96 and 94 % repellency respectively after 60 minutes of observation. It remained 56 % and 54 % (after 15 washes) and 54 and 52 % (after expo-sure in sun for 3 hours) by the application of marigold and nirgundi extracts respectively. Hence, microencapsulation technique on selected cotton textile proved effective to repel mosquitoes up to acceptable level according to WHO (1996)