5,017 research outputs found
Reduced Fine-Tuning in Supersymmetry with R-parity violation
Both electroweak precision measurements and simple supersymmetric extensions
of the standard model prefer a mass of the Higgs boson less than the
experimental lower limit of 114 GeV. We show that supersymmetric models with R
parity violation and baryon number violation have a significant range of
parameter space in which the Higgs dominantly decays to six jets. These decays
are much more weakly constrained by current LEP analyses and would allow for a
Higgs mass near that of the . In general, lighter scalar quark and other
superpartner masses are allowed and the fine-tuning typically required to
generate the measured scale of electroweak symmetry breaking is ameliorated.
The Higgs would potentially be discovered at hadron colliders via the
appearance of new displaced vertices. The lightest neutralino could be
discovered by a scan of vertex-less events LEP I data.Comment: 5 pages, 2 figures. Significant detail added to the arguments
regarding LEP limits - made more quantitative. Better figures used, plotting
more physical quantities. Typos corrected and references updated. Conclusions
unchange
A Data Model to Manage Data for Water Resources Systems Modeling
Current practices to identify, organize, analyze, and serve data to water resources systems models are typically model and dataset-specific. Data are stored in different formats, described with different vocabularies, and require manual, model-specific, and time-intensive manipulations to find, organize, compare, and then serve to models. This paper presents the Water Management Data Model (WaMDaM) implemented in a relational database. WaMDaM uses contextual metadata, controlled vocabularies, and supporting software tools to organize and store water management data from multiple sources and models and allow users to more easily interact with its database. Five use cases use thirteen datasets and models focused in the Bear River Watershed, United States to show how a user can identify, compare, and choose from multiple types of data, networks, and scenario elements then serve data to models. The database design is flexible and scalable to accommodate new datasets, models, and associated components, attributes, scenarios, and metadata
Some Polysorbate Compounds as Corrosion Inhibitors for Carbon Steel in Hydrochloric Acid
Some commercial non-ionic surfactants polysorbate, namely, polysorbate 80, polysorbate 40 and polysorbate 20, were tested as inhibitors for corrosion of C-steel in 2.0M HCl solution using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy techniques. It was found that all the three used compounds act as inhibitors for acid corrosion of C-steel. The inhibition efficiencies obtained by the three techniques were almost the same, and increase with increasing the hydrocarbon chain length and the surfactant concentration. The polarization studies show that these compounds act as mixed inhibitors. The inhibition action of these surfactants can be explained by their ability to adsorb on the metal surface making a barrier to mass and charge transfer.ĂÂ It was found that the adsorption of these surfactants follows Langmuir adsorption isotherm. The negative values ofĂÂ adsorption free energy indicating that the adsorption process is spontaneous and increases, for different surfactants, in the same direction as inhibition efficiency
Hydro-institutional mapping in the Steelpoort River Basin, South Africa
River basins / Institutions / Organizations / Private sector / Public sector / Local government / Mapping / Water resource management / Water policy / Legislation / Rural women / Constraints / Groundwater / Surface water / Water quality / Water use / Water users / Dams / Reservoirs / Large-scale systems / Irrigation management / Industrialization / Case studies / Operations / Maintenance / Canals / Conflict / Farmer-agency interactions / Policy / Water supply / Rural development
Limits on the Electromagnetic and Weak Dipole Moments of the Tau-Lepton in E_6 Superstring Models
We obtain limits on the electromagnetic and weak dipole moments of the
tau-lepton in the framework of a Left-Right symmetric model (LRSM) and a class
of inspired models with an additional neutral vector boson .
Using as an input the data obtained by the L3 and OPAL Collaborations for the
reaction , we get a stringent limit on the LRSM
mixing angle , , which in
turn induces bounds on the tau weak dipole moments which are consistent with
the bounds obtained recently by the DELPHI and ALEPH Collaborations from the
reaction . We also get similar bounds for the weak
dipole moments of the tau lepton in the framework of superstring models.Comment: 18 pages, 5 figure
Fifteen years experience: Egyptian metabolic lab
Background: Inborn errors of metabolism (IEM) are single gene disorders responsible for abnormalities in the synthesis or catabolism of proteins, carbohydrates and fats by means of defective enzymes or transport proteins which results in a block of the metabolic pathway and accumulation of metabolites in different tissues. This study shows the most common diagnosed inherited inborn errors of metabolism among the Egyptian population. Prior to 1995, the diagnosis of inherited metabolic disorders in Egypt was very limited and diagnosed mainly on clinical suspicion. In 1995, The Biochemical Genetics Unit at The National Research Centre has been established as a part of The Human Genetics Department and later on in 2003 it was developed into The Biochemical Genetics Department by applying advanced techniques and equipments and providing early diagnosis for the metabolic disorders which led to better outcome in our patients. Material and methods: We have retrospectively reviewed a total of 12,148 cases suspected to have inborn errors of metabolism (IEM) with different age groups. They had been referred from several diagnostic centers and hospitals in Egypt to The Department of Biochemical Genetics at The National Research Centre. The diagnosis of these disorders was confirmed by qualitative determination of amino acid profile, quantitative determination of phenylalanine and galactose levels using dried blood spots (DBSs), quantitative determination of urinary glycosaminoglycans (GAGs), twodimensional electrophoretic separation of GAGs in urine and the assay for lysosomal enzymes activities in plasma and leukocytes. Results: Out of the total number of cases; 1041 (8.6%) patients were proved to have metabolic disorders. Those patients were classified as: 722 patients (69.4%) with lysosomal storage disorders, 302 patients (29%) with amino acid disorders and 17 patients (1.6%) with galactosemia. Conclusion: This study illustrates the experience of the reference metabolic lab in Egypt over 15 years. The lab began metabolic disorder screening by using simple diagnostic techniques like thin layer chromatography and colored tests in urine which by time updated and upgraded the methods to diagnose a wide range of disorders. This study shows the most common diagnosed inherited inborn errors of metabolism among the Egyptian population.Keywords: IEM; Consanguineous marriages; Aminoacidopathies; Lysosomal storage disorder
Synthesis and cytotoxicity evaluation of thiazole derivatives obtained from 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitrile
Reactivity of 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitrile towards thioglycolic acid resulted in thiazole derivative 1. The latter reacted with different chemical reagents to give thiazole, pyrano[2,3-d]thiazole and thiazolo[4,5-d]thiazole derivatives. Cytotoxicity effects of the newly synthesized products against six cancer cell lines, namely, human gastric cancer (NUGC), human colon cancer (DLD-1), human liver cancer (HA22T and HEPG-2), human breast cancer (MCF) and nasopharyngeal carcinoma (HONE-1) as well as against a normal fibroblast cell (WI-38) were evaluated. The study showed that the 4,5,6,7 tetrahydrobenzo[b]thiophene derivatives 6a, 7, 8a,b, 9b and 10b,c were the most active compounds. Their potencies were attributed to the presence of the electron withdrawing groups
Heavy Quark Spin Symmetry and Heavy Baryons: Electroweak Decays
Heavy quark spin symmetry is discussed in the context of single and doubly
heavy baryons. A special attention is paid to the constraints/simplifications
that this symmetry imposes on the non-relativistic constituent quark model wave
functions and on the b->c semileptonic decays of these hadrons.Comment: Presented at the 21st European Conference on Few-Body Problems in
Physics, Salamanca, Spain, 30 August - 3 September 201
Coyote multi-objective optimization algorithm for optimal location and sizing of renewable distributed generators
Research on the integration of renewable distributed generators (RDGs) in radial distribution systems (RDS) is increased to satisfy the growing load demand, reducing power losses, enhancing voltage profile, and voltage stability index (VSI) of distribution network. This paper presents the application of a new algorithm called âcoyote optimization algorithm (COA)â to obtain the optimal location and size of RDGs in RDS at different power factors. The objectives are minimization of power losses, enhancement of voltage stability index, and reduction total operation cost. A detailed performance analysis is implemented on IEEE 33 bus and IEEE 69 bus to demonstrate the effectiveness of the proposed algorithm. The results are found to be in a very good agreement
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