151,950 research outputs found
Structure Constants and Conformal Bootstrap in Liouville Field Theory
An analytic expression is proposed for the three-point function of the
exponential fields in the Liouville field theory on a sphere. In the classical
limit it coincides with what the classical Liouville theory predicts. Using
this function as the structure constant of the operator algebra we construct
the four-point function of the exponential fields and verify numerically that
it satisfies the conformal bootstrap equations, i.e., that the operator algebra
thus defined is associative. We consider also the Liouville reflection
amplitude which follows explicitly from the structure constants.Comment: 31 pages, 2 Postscript figures. Important note about existing (but
unfortunately previously unknown to us) paper which has significant overlap
with this work is adde
The Adjectival construct in Arabic
We propose an analysis of the adjectival construct in Arabic in LFG, building on previous work in LFG on a Welsh construction which shows several similarities to the Arabic (Mittendorf and Sadler, 2008) and work on the MSA and cognate Hebrew constructions by Hazout (2000); Kremers (2005); Siloni (2002); Heller (2002); Kim (2002). The construction involves an adjective occurring with an immediately following definite nominal, which denotes a property, part or quality of the noun that the adjectivemodifies (in attributive use) or is predicated of (in predicative constructions). The major characteristics of this construction are that the post-adjectival nominal serves to delimit the respect in which the adjective denotes a property of the external nominal, and the adjectival head and the GEN complement are subject to a very strict adjacency requirement. We present a syntactic analysis, showing that the construction is formed in the syntax rather than the morphology, and sketch out a proposal as to how the semantics of the construction might be captured
Measurement of the eta mass at KLOE
An integrated luminosity of 410 pb^(-1), corresponding to ~ 17 million of eta
events, has been analyzed to measure the eta mass using the decay eta to gamma
gamma. The measurement is insensitive to the calorimeter energy calibration and
the systematic error on the measurement is dominated by the uniformity of the
detector response. As a cross check of the method the pi0 mass from the decay
phi to pi0 gamma, pi0 to gamma gamma has been measured and it is in agreement
with the most accurate previous determinations. The result obtained is m(eta) =
547.873 +/- 0.007 (stat.) +/- 0.031 (syst.) MeV, that is today best measurement
of the eta mass.Comment: 7 pages, 8 figures, Contributed paper to Lepton Photon 200
Detection of water leakage in buried pipes using infrared technology; a comparative study of using high and low resolution infrared cameras for evaluating distant remote detection
Water is one of the most precious commodities around the world. However, significant amount of water is lost daily in many countries through broken and leaking pipes. This paper investigates the use of low and high resolution infrared systems to detect water leakage in relatively dry countries. The overall aim is to develop a non-contact and high speed system that could be used to detect leakage in pipes remotely via the effect of the change in humidity on the temperature of the ground due to evaporation. A small scale experimental test rig has been constructed to simulate water leakage in The Great Man- Made River Project in Libya, taking into consideration the dryness level of the desert sand and the scaled dimensions of the system. The results show that the infrared technology is an effective technology in detecting water leakage in pipes. The low resolution system has been found as valuable as the high resolution system in detecting water leakage. The results indicate the possibility of distant remote detection of leakage in water systems using infrared technologies which could be mobilised using drones, helium balloons, aeroplanes or other similar technologies
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Randomised, controlled trial of effectiveness of ampicillin in mild acute respiratory infections in Indonesian children.
The recommended treatment for mild acute respiratory infections (ARI) in children is supportive care only, but many physicians, especially in developing countries, continue to prescribe antibiotic treatment because they believe it prevents progression to more severe ARI. To find out whether ampicillin treatment conferred any benefit over supportive care alone, a randomised, controlled trial was carried out among 889 children (under 5 years) with mild ARI in Indonesia. 447 were randomly allocated ampicillin (25-30 mg/kg body weight three times daily for 5 days) plus supportive care (continued breastfeeding, clearing of the nose, and paracetamol to control fever); 442 were allocated supportive care only. The treatment groups were almost identical after randomisation in terms of age, sex, level of parental education, history of measles immunisation, and fever. After 1 week the percentages cured were nearly identical (204 [46%] ampicillin; 209 [47%] control), as were the percentages of cases progressing to moderate ARI (56 [13%] vs 53 [12%]). The effect of treatment was not modified by age, sex, measles immunisation status, or the educational level of the parents. At the 2-week follow-up, the percentages cured were 62% (277) in the ampicillin group and 58% (256) in the control group; 14% of both groups had progressed to moderate ARI; and 24% (107) and 28% (123), respectively, still had mild ARI. None of the differences in outcome between the ampicillin and control groups was statistically significant. Thus, ampicillin plus supportive care offers no benefit over supportive care alone for treatment of mild ARI in young Indonesian children
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