20,183 research outputs found
Z lineshape and forward-backward asymmetries
Preliminary but close to final results on the Z lineshape and
Forward-Backward asymmetries from the four LEP experiments are presented.
Combined values extracted from ALEPH. DELPHI, L3 and OPAL data recorded at
energies around the Z pole are discussed.Comment: 5 pages, 6 figures, sunbmitted to the Vancouver conference, ICHEP'9
PSP resins, new materials which can be hardened by thermal treatment for use in composite materials resistant to heat and fire
A class of easy-to-prepare heterocyclic-aromatic polymers which can be used for matrices in reinforced laminates is described. These polymers can be cured after B-staging with very little evolution of volatile materials, and they retain a low melt-viscosity which leads to low-void laminates. Resins are stable at temperatures below 150 C. Properties of composites with various reinforcements, in particular carbon-fiber unidirectional laminates, are described, and the fire behavior of PSP-glass laminates is reported
Cesium standard for satellite application
A Cesium frequency standard that was developed for satellite applications is discussed. It weighs 23 lbs. and uses 23.5 watts of power, achieves a stability of 1 x ten to the minus 13th power/100,000 seconds, and is radiation hardened. To achieve the weight and reliability requirements, both thick and thin film hybrid circuits were utilized. A crystal oscillator is used to improve short-term stability and performance on a moving platform
Comment on "Nucleon form factors and a nonpointlike diquark"
Authors of Phys. Rev. C 60, 062201 (1999) presented a calculation of the
electromagnetic form factors of the nucleon using a diquark ansatz in the
relativistic three-quark Faddeev equations. In this Comment it is pointed out
that the calculations of these form factors stem from a three-quark bound state
current that contains overcounted contributions. The corrected expression for
the three-quark bound state current is derived.Comment: 6 pages, 1 figure, revtex, eps
Recent results from NA48/2 on decays and interpretation in terms of scattering lengths
Preliminary results from a new measurement of the decay by the Na48/2 collaboration at the CERN SPS are reported. An unprecedented sample of more than 670000 decays in both charged modes have been collected in 2003. The form factors of the hadronic current (F, G, H) and phase shift () of the scattering have been measured using a model independent method and their variation with the ππ mass has been investigated. First evidence for a non zero term is reported. Thanks to a sizeable acceptance at large mass, a low background and a very good resolution, an improved accuracy can be reached when extracting the scattering length . Using more elaborated theory inputs and another NA48/2 result from decays, a consistent picture can be drawn for the scattering lengths and , in good agreement with Chiral Perturbation Theory predictions
Preserving Biological Diversity in the United States: The Case for Moving to an Ecosystems Approach to Protect the Nation\u27s Biological Wealth
Protecting the biodiversity of the planet from human impact is essential to maintaining the existing balance found throughout nature. This paper provides a general discussion of the reasons why biological diversity must be preserved. In addition to the need to ensure the survival of the planet, reasons for biodiversity protection are based on economic, spiritual, and moral concerns. The author describes the current level of biodiversity destruction, and examines the shortcomings of current laws focusing on the protection of endangered species and their habitats. In light of those shortcomings, the author then analyzes and contrasts four methods which could be used to protect biodiversity in the United States. These four models are 1) a living museums approach, 2) the Biological Diversity Conservation Act, introduced in the 102d Congress, 3) a rezoning of the public lands of the United States, and 4) an ecosystems protection act. The author concludes that the best way to preserve biological diversity in the United States would be to implement an ecosystems protection act, a legal model which is sound from both biological and political standpoints
My Backpack : a children\u27s book about separation
This thesis opens with a copy of My Backpack, a fictional book based on actual events to be read to children between the ages of three and four years prior to their entry to preschool and as a support during the separation process during the first weeks and months of school. The author then continues with an explanation of the genesis of the book, a developmental section incorporating theorists\u27 views on separation for children ages 3 and 4, children\u27s reactions and responses to the book, and a review of other valuable books on separation
Spending time with money: from shared values to social connectivity
This article has been made available through the Brunel Open Access Publishing Fund.There is a rapidly growing momentum driving the development of mobile payment systems for co-present interactions, using near-field communication on smartphones and contactless payment systems. The design (and marketing) imperative for this is to enable faster, simpler, effortless and secure transactions, yet our evidence shows that this focus on reducing transactional friction may ignore other important features around making payments. We draw from empirical data to consider user interactions around financial exchanges made on mobile phones. Our findings examine how the practices around making payments support people in making connections, to other people, to their communities, to the places they move through, to their environment, and to what they consume. While these social and community bonds shape the kinds of interactions that become possible, they also shape how users feel about, and act on, the values that they hold with their co-users. We draw implications for future payment systems that make use of community connections, build trust, leverage transactional latency, and generate opportunities for rich social interactions
Blood levels of PAF are elevated during induction of immune complex mediated enteropathy in the rat
Intravenous injection into rats of immune complexes (IC) prepared in 5 × antigen excess rapidly induces annular bands of vascular congestion and transmural haemorrhage producing a striped appearance of the small intestine. Indirect evidence suggested a major role for PAF in the induction of lesions. In the present study, we showed that blood and leukocyte levels of PAF were elevated in most rats injected 10 min earlier with sufficient IC to induce lesions of 3+ to 4+ intensity. There was no significant difference in the number of rats with elevated plasma levels of PAF. The possibility that changes in blood PAF levels might be mirrored at sites closer to the lesions was considered. The overall effect of PAF on the small intestine of the rats is to induce stasis of flow; the precise target of PAF in mediating this effect is unknown
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