Possible use of self-calibration to reduce systematic uncertainties in determining distance-redshift relation via gravitational radiation from merging binaries

By observing mergers of compact objects, future gravity wave experiments would measure the luminosity distance to a large number of sources to a high precision but not their redshifts. Given the directional sensitivity of an experiment, a fraction of such sources (gold plated -- GP) can be identified optically as single objects in the direction of the source. We show that if an approximate distance-redshift relation is known then it is possible to statistically resolve those sources that have multiple galaxies in the beam. We study the feasibility of using gold plated sources to iteratively resolve the unresolved sources, obtain the self-calibrated best possible distance-redshift relation and provide an analytical expression for the accuracy achievable. We derive lower limit on the total number of sources that is needed to achieve this accuracy through self-calibration. We show that this limit depends exponentially on the beam width and give estimates for various experimental parameters representative of future gravitational wave experiments DECIGO and BBO.Comment: 6 pages, 2 figures, accepted for publication in PR

Diurnal and seasonal variations of <i>hm</i>F2 deduced from digitalionosonde over New Delhi and its comparison with IRI 2001

International audienceUsing digital ionosonde observations at a low mid-latitude station, New Delhi (28.6°N, 77.2°E, dip 42.4°N), we have derived hourly monthly values of hmF2 (the real height corresponding to the peak electron density in the F2-region), employing both the Dudeney (1983) and Bilitza (1990) empirical formulations for the period from January 2001 to August 2002. The diurnal and seasonal variations of hmF2 are analyzed. Further, to assess the predictability of the latest available model, International Reference Ionosphere, (IRI-2001), we have obtained the median values of hmF2 derived from M(3000)F2 for each hour during different seasons and compare these with the model. Our results show that both the Dudeney (1983) and Bilitza (1990) formulations reveal more or less a similar diurnal trend of hmF2, with higher values around midnight and lower during sunrise, in all the seasons. It is also noted that the hmF2 shows a larger variability around midnight than by daytime, in all the seasons. Further, the study shows that median values of observed hmF2, using both formulations, are somewhat larger than those predicted by the IRI, in all seasons and at all local times. During summer, the IRI values agree comparatively well with the observations, especially during daytime. Major discrepancies occur when the IRI underestimates observed hmF2 for local times from about 14:00 LT to 18:00 LT and 04:00 LT to 05:00 LT during winter and equinox, where the percentage deviation of the observed hmF2 values with respect to the IRI model varies from 15 to 25%. The difference between the model and observations, outside this time period, remains less than 20% during all the seasons. Key words. Ionosphere (modelling and forecasting; equatorial ionosphere

Identification of Gut Microflora from Green Mussel (Perna viridis)

The main source of Bacterial contamination of Estuary waters are domestic waste water and sewage discharge. In this present investigation, Green Mussels were collected from three different stations of Chennai Coast - Ennore, Royapuram and Muttukadu. The mussels were degutted and bacteria were isolated using selective and non-selective agar medium and further confirmed by biochemical tests. The organisms were ident illed to generic or group level according to Bergey's manual of systematic Bacteriology. Different group of fecal coli forms and Vibrio spp. have been isolated. Escherichia coli, Vibrio alginolyticus, V. parahaemolyticus and V. harveyi were the dominant species. Vibrio parahaemolyticus, a facultative pathogen widely complicated in outbreaks of gastroenteritis related to the consumption of improperly processed seafood was present in the gut of Green Mussels

Seasonal Variations and Identification of Pathogenic Pollution Indicators from Royapuram Backwaters

Sewage and industrial effluents from Ennore, Chennai harbour and surrounding area have a greater impact on the Royapuram back water affecting the aquatic animals and in tum the human population. These waste carry enormous number of microbial pathogens and other heavy metals resulting in greater economic loss. The current study is aimed at analysing the total viable count of bacteria and pathogenic bacterial species in the water and sediment samples taken from different places of Royapuram fishing area, from where many kind of fishes and molluscans are taken for human consumption .The samples werc collected in pre monsoon, monsoon and post monsoon seasons. Water analysis was done by multiple tube tests to assess the MPN values. The bacteria were isolated using Zobell's agar medium, selective and non selective medias and identified using biochemical test. The organisms were identified to genus, level according to Bergey's manual. Results of field Investigations showed a definite association between the levels pollution and microbial population. Results showed a higher distribution of pathogenic and non pathogenic bacteria in the sediment than in the water sample both in monsoon and post monsoon seasons. Analysis showed the prevalence of human pathogens and fecal indicator organisms like Escherichia coli, Salmonella sp.,Vibrio sp., Shigella sp. in water and in the sediment samples

Development and life cycle analysis of double slope active solar still with flat plate collector

Potable water is an essential ingredient of socio-economic development and economic growth. Often water sources are brackish (i.e. contain dissolved salts) and/or contain harmful bacteria and therefore cannot be used for drinking. In addition, there are many coastal locations where seawater is abundant but potable water is not available. This study is focused on a development of solar still with flat plat collector for water desalination considered for small scale applications at remote locations where only saline water is available. In this paper the cost of distilled water per kg has been calculated by using the concept of life cycle cost analysis. The pay back periods for different conditions of the distribution of distilled water, namely at the cost it is produced and at the selling price on market rate have been evaluated. The cost of water per kg is minimum Rs. 0.59, when the interest rate and the lifetime of solar still are taken as 4% and 50 years respectively. The lowest payback time 1.23 years is obtained when the selling price of water Rs. 10 per kg

Improvement in word recognition following treatment failure for sudden sensorineural hearing loss

AbstractObjectivesPatients with sudden sensorineural hearing loss (SSNHL) may have word recognition scores (WRS) that correlate with pure tone average (PTA). We hypothesize that there is a subset of patients with SSNHL who have improved WRS despite stable PTA.MethodsRetrospective case review at a tertiary otolaryngology practice.ResultsWe identified 13 of 113 patients with SSNHL whose WRS increased despite overall stable pure tone averages. There was an observed average improvement in WRS by 23.8 points in this patient cohort at follow-up, with mean initial PTA in the affected ear at 48.7 dB.ConclusionsWe identify a novel cohort of SSNHL patients that have failed treatment as measured by PTA, but who have increased WRS over time. These data have implications for patient counseling and lend insight into the pathophysiology of SSNHL

Density Evolution in the New Modified Chaplygin Gas Model

In this paper, we have considered new modified Chaplygin gas (NMCG) model which interpolates between radiation at early stage and $\Lambda$CDM at late stage. This model is regarded as a unification of dark energy and dark matter (with general form of matter). We have derived the density parameters from the equation of motion for the interaction between dark energy and dark matter. Also we have studied the evolution of the various components of density parameters.Comment: 6 Latex pages, 4 figures, RevTex styl

Attitude determination of a high altitude balloon system. Part 1: Development of the mathematical model

A mathematical model for predicting the three dimensional motion of the balloon system is developed, which includes the effects of bounce, pendulation and spin of each subsystem. Boundary layer effects are also examined, along with the aerodynamic forces acting on the balloon. Various simplified forms of the system mathematical model were developed, based on an order of magnitude analysis