48,866 research outputs found
An Application for Research: the Large Hadron Collider
The Large Hadron Collider (LHC) machine at CERN was designed and built
primarily to find or exclude the existence of the Higgs boson, for which a
large amount of data is needed by the LHC experiments. This requires operation
at high luminosity, which in turn requires running with thousands of
high-intensity proton bunches in the machine. After quantifying the data
required by the experiments and elucidating the LHC parameters needed to
achieve this, this paper explains how the LHC beams are fabricated from the
pulse(s) coming from the CERN Duoplasmatron source.Comment: 10 pages, contribution to the CAS-CERN Accelerator School: Ion
Sources, Senec, Slovakia, 29 May - 8 June 2012, edited by R. Bailey,
CERN-2013-00
Measuring the Lifetime of Trapped Sleptons Using the General Purpose LHC Detectors
In supergravity where the gravitino is the lightest supersymmetric particle
(LSP), the next-to-lightest supersymmetric particle (NLSP) decays to the
gravitino with a naturally long lifetime (10^4 - 10^8). However, cosmological
constraints favour charged sleptons with lifetimes below a year as the natural
NLSP candidate. For this scenario we report a method to accurately determine
the slepton lifetime and SUSY cross-section from observation of the decays of
sleptons trapped in the material comprising the main detector (ATLAS, CMS). A
measurement of the lifetime to 5% is possible after 3 years at nominal
luminosity and running conditions. This method is sensitive to the
cosmologically preferred stau lifetime of ~37 days and does not require the use
of ancillary trapping volumes
Electromagnetic wave energy converter
Electromagnetic wave energy is converted into electric power with an array of mutually insulated electromagnetic wave absorber elements each responsive to an electric field component of the wave as it impinges thereon. Each element includes a portion tapered in the direction of wave propagation to provide a relatively wideband response spectrum. Each element includes an output for deriving a voltage replica of the electric field variations intercepted by it. Adjacent elements are positioned relative to each other so that an electric field subsists between adjacent elements in response to the impinging wave. The electric field results in a voltage difference between adjacent elements that is fed to a rectifier to derive dc output power
Sentential Word Order and the Syntax of Question Particles
Polar question particles in languages with VO word order pose a problem for the otherwise
robust Final-Over-Final Constraint, which rules out a head-final phrase immediately
dominating a head-initial phrase (Holmberg 2000). This paper offers a description of these
particles and the constraint, and offers data supporting the hypothesis that these final particles
are different from their initial counterparts in a fundamental way
Implementation of Response to Intervention for English Language Learners
Response to Intervention is utilized to provide parents, teachers, and specialists with the data needed to implement and measure the effectiveness of evidence-based instructional and behavioral strategies matched to student needs. English Language Learners are in particular need of research-based instruction paired with progress monitoring as they seek to meet state standards in a new language. Parents, students, and school personnel all benefit from seeing Christ-like consideration for foreigners modeled through Response to Intervention
Null Subjects in Northeast English
This paper presents data and analysis relating to null subjects in spoken colloquial English.
While English is not a âpro-drop? language (i.e. subjects must usually be overt), a corpus of
speech collected on Tyneside and Wearside in 2007 shows that null subjects are permitted in
finite clauses in certain contexts. This paper analyses these examples and follow-up
questionnaires, and compares the data with the other types of null subject described in the
literature (pro-drop, topic-drop, early null subjects, aphasics? null subjects and âdiary-drop?),
ultimately concluding that the colloquial English phenomenon is most closely related to diary-
drop
Status and projections of the NAS program
NASA's Numerical Aerodynamic Simulation (NAS) Program has completed development of the initial operating configuration of the NAS Processing System Network (NPSN). This is the first milestone in the continuing and pathfinding effort to provide state-of-the-art supercomputing for aeronautics research and development. The NPSN, available to a nation-wide community of remote users, provides a uniform UNIX environment over a network of host computers ranging from the Cray-2 supercomputer to advanced scientific workstations. This system, coupled with a vendor-independent base of common user interface and network software, presents a new paradigm for supercomputing environments. Background leading to the NAS program, its programmatic goals and strategies, technical goals and objectives, and the development activities leading to the current NPSN configuration are presented. Program status, near-term plans, and plans for the next major milestone, the extended operating configuration, are also discussed
Interaction of hydrogen chloride with alumina
The influence of outgas conditions and temperature on the adsorptive properties of two aluminas Alon-c and Al6sG were studied using adsorption isotherm measurements. Alon-C and Al6SG were characterized using X-ray powder diffraction, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and BET nitrogen surface areas. Some of these techniques were applied to two other aluminas but no isotherm data was obtained. Isotherm data and techniques applied to each alumina are summarized in tabular form
An in-flight investigation of pilot-induced oscillation suppression filters during the fighter approach and landing task
An investigation of pilot-induced oscillation suppression (PIOS) filters was performed using the USAF/Flight Dynamics Laboratory variable stability NT-33 aircraft, modified and operated by Calspan. This program examined the effects of PIOS filtering on the longitudinal flying qualities of fighter aircraft during the visual approach and landing task. Forty evaluations were flown to test the effects of different PIOS filters. Although detailed analyses were not undertaken, the results indicate that PIOS filtering can improve the flying qualities of an otherwise unacceptable aircraft configuration (Level 3 flying qualities). However, the ability of the filters to suppress pilot-induced oscillations appears to be dependent upon the aircraft configuration characteristics. Further, the data show that the filters can adversely affect landing flying qualities if improperly designed. The data provide an excellent foundation from which detail analyses can be performed
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