2,917 research outputs found
Probing the deviation from maximal mixing of atmospheric neutrinos
Pioneering atmospheric muon neutrino experiments have demonstrated the
near-maximal magnitude of the flavor mixing angle . But the
precise value of the deviation from
maximality (if nonzero) needs to be known, being of great interest --
especially to builders of neutrino mass and mixing models. We quantitatively
investigate in a three generation framework the feasibility of determining
in a statistically significant manner from studies of the atmospheric
survival probability including both vacuum oscillations
and matter effects. We show how this determination will be sharpened by
considering the up-down ratios of observed - and -induced
events and the differences of these ratios in specified energy and zenith angle
bins. We consider 1 Megaton year of exposure to a magnetized iron calorimeter
such as the proposed INO detector ICAL, taking into account both energy and
zenith angle resolution functions. The sensitivity of such an exposure and the
dependence of the determination of on the concerned oscillation parameters
are discussed in detail. The vital use of matter effects in fixing the octant
of is highlighted.Comment: Version to appear in PR
Non-classical photon pair generation in atomic vapours
A scheme for the generation of non-classical pairs of photons in atomic
vapours is proposed. The scheme exploits the fact that the cross correlation of
the emission of photons from the extreme transitions of a four-level cascade
system shows anti-bunching which has not been reported earlier and which is
unlike the case of the three level cascade emission which shows bunching. The
Cauchy-Schwarz inequality which is the ratio of cross-correlation to the auto
correlation function in this case is estimated to be for
controllable time delay, and is one to four orders of magnitude larger compared
to previous experiments. The choice of Doppler free geometry in addition to the
fact that at three photon resonance the excitation/deexcitation processes occur
in a very narrow frequency band, ensures cleaner signals.Comment: 18 pages, 7 figure
A STUDY ON MECHANICAL PROPERTIES OF CEMENT CONCRETE BY PARTIAL REPLACEMENT OF FINE AGGREGATES WITH BOTTOM ASH
Bottom Ash is a new waste material and abundantly available. It is a solid residue which falls into furnace bottom in modern large thermal power plants and constitutes about 20% of total ash content of the coal fed in the boilers. Direct use of this material with a large quantity, will provide a solution to dispose of this material, and the possibility as alternative materials in construction. The main objective of this research is to study the behavior of concrete mix which comprises of partial replacement of fine aggregates with bottom ash against plain concrete. The study was carried out using coal bottom ash as a partial replacement with fine aggregates in the concrete mix by 20%, 30%, 40%, and 50% by weight. The various strength properties studied consist of compressive strength, flexural strength and splitting tensile strength. The results shows that the compressive strength, split tensile strength and flexural strength decreased as the percentage of replacement of bottom ash increased as compared to plain concrete. It was observed that up to 20% replacement the results of compressive test, flexural test and split tensile test are approximately same as that of the controlled concrete
Trial of ORG 10172 in acute stroke treatment classification and associated risk factors of ischemic stroke: a prospective study from a tertiary care center in South India
Background: Stroke is the leading cause of acquired disability worldwide. Better understanding of risk factors helps to reduce the community burden of stroke. Aim of the study was to determine pattern of ischemic stroke subtype and associated risk factors.Methods: Of 220 patients with first ever stroke, 168 patients of ischemic stroke were enrolled prospectively from January 2016 to May 2016 at ESIC Superspeciality hospital, Hyderabad. Patients were categorized in accordance with the Trial of Org 10172 in Acute Stroke treatment (TOAST) criteria.Results: Of 168 patients, 110 (65.4%) were males; male to female ratio was 1.8:1. The mean age was 53.912.3 years. Small vessel occlusion (SVO) occurred in younger age group as compared to other stroke subtypes. Frequency of large-artery atherosclerosis (LAA) (46.4%) was highest (Extracranial: 41.1%, intracranial: 36.9%), followed by SVO (32.4%), cardio embolism (15.4%), undetermined (4.7%) and other determined causes (1.1%). Risk factors included dyslipidemia (79%), hypertension (67.8%), smoking (58.3%), alcohol use (54.7%), diabetes (40.4%) and physical inactivity (27.3%). Common association observed was smoking (P - 0.004) and alcohol (P - 0.003) with LAA and SVO, and dilated cardiomyopathy with cardio embolism.Conclusions: LAA was observed frequently than SVO. Frequency of SVO was lower than Asian but higher than western, while cardio embolism was lower than Western and similar to Asian stroke studies. Dyslipidemia was the predominant risk factor than hypertension reported from Asian and Western stroke registry. This unique pattern can be attributed to differences in demographic and risk factor profiles. The study confirms the need for vigorous primary and secondary prevention measures targeting modifiable risk factors of stroke
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