36,254 research outputs found

    Gauge-Higgs Unification and Radiative Electroweak Symmetry Breaking in Warped Extra Dimensions

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    We compute the Coleman Weinberg effective potential for the Higgs field in RS Gauge-Higgs unification scenarios based on a bulk SO(5) x U(1)_X gauge symmetry, with gauge and fermion fields propagating in the bulk and a custodial symmetry protecting the generation of large corrections to the T parameter and the coupling of the Z to the bottom quark. We demonstrate that electroweak symmetry breaking may be realized, with proper generation of the top and bottom quark masses for the same region of bulk mass parameters that lead to good agreement with precision electroweak data in the presence of a light Higgs. We compute the Higgs mass and demonstrate that for the range of parameters for which the Higgs boson has Standard Model-like properties, the Higgs mass is naturally in a range that varies between values close to the LEP experimental limit and about 160 GeV. This mass range may be probed at the Tevatron and at the LHC. We analyze the KK spectrum and briefly discuss the phenomenology of the light resonances arising in our model.Comment: 31 pages, 9 figures. Corrected typo in boundary condition for gauge bosons and top mass equation. To appear in PR

    Antibacterial apple cider vinegar eradicates methicillin resistant Staphylococcus aureus and resistant Escherichia coli

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    Methicillin-resistant Staphylococcus aureus (MRSA) and resistant Escherichia coli (rE.coli) infections can spread rapidly. Further they are associated with high morbidity and mortality from treatment failure. Therapy involves multiple rounds of ineffective antibiotics alongside unwanted side effects, alternative treatments are crucial. Apple cider vinegar (ACV) is a natural, vegan product that has been shown to have powerful antimicrobial activity hence we investigated whether ACV could ameliorate these resistant bacteria. The minimum dilution of ACV required for growth inhibition was comparable for both bacteria (1/25 dilution of ACV liquid and ACV tablets at 200 µg/ml were effective against rE. coli and MRSA). Monocyte co-culture with microbes alongside ACV resulted in an increase in monocyte phagocytosis by 21.2% and 33.5% compared to non-ACV treated but MRSA or rE. coli stimulated monocytes, respectively. Label free quantitative proteomic studies of microbial protein extracts demonstrated that ACV penetrated microbial cell membranes and organelles, altering the expression of key proteins. This resulted in significant reductions in total protein expression, moreover we could only detect ribosomal proteins; 50 s 30 s, enolase, phosphenol pyruvate and the ATP synthase subunit in rE. coli. Elongation factor iNOS and phosphoglycerate kinase OS were the only proteins present in MRSA samples following ACV treatment

    An assembly-oriented novel low-carbon masonry building method with unfired 3D printed earthen blocks

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    Conventional earthen building methods such as cob and adobe are relevant for developing countries but labour-intensive, expensive and slow for developed countries. Automation in construction has been increasingly favourable in developed countries, especially buildings constructed with 3D printed cementitious materials. 3D printed earthen materials demonstrate a better environmental performance compared to 3D printed cementitious materials due to the energy intensive manufacturing of cement. Moreover, conventional earthen methods, such as cob, create earthen buildings with solid sections while 3D printing allows a hollow section and various infill designs using less material. Despite the benefits, the research on the mechanical strength of 3D-printed earthen structures is still limited. The lack of data on the mechanical performance of 3D printed earthen structures, is one of the obstacles preventing the mainstream construction industry from approaching this novel building method. Our research investigates an assembly-oriented novel low-carbon masonry building method with unfired 3D-printed earthen blocks and explores its adaptability to the mainstream construction industry with a critical comparison based on mechanical properties

    Scaling and Formulary cross sections for ion-atom impact ionization

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    The values of ion-atom ionization cross sections are frequently needed for many applications that utilize the propagation of fast ions through matter. When experimental data and theoretical calculations are not available, approximate formulas are frequently used. This paper briefly summarizes the most important theoretical results and approaches to cross section calculations in order to place the discussion in historical perspective and offer a concise introduction to the topic. Based on experimental data and theoretical predictions, a new fit for ionization cross sections is proposed. The range of validity and accuracy of several frequently used approximations (classical trajectory, the Born approximation, and so forth) are discussed using, as examples, the ionization cross sections of hydrogen and helium atoms by various fully stripped ions.Comment: 46 pages, 8 figure

    Transient terahertz spectroscopy of excitons and unbound carriers in quasi two-dimensional electron-hole gases

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    We report a comprehensive experimental study and detailed model analysis of the terahertz dielectric response and density kinetics of excitons and unbound electron-hole pairs in GaAs quantum wells. A compact expression is given, in absolute units, for the complex-valued terahertz dielectric function of intra-excitonic transitions between the 1s and higher-energy exciton and continuum levels. It closely describes the terahertz spectra of resonantly generated excitons. Exciton ionization and formation are further explored, where the terahertz response exhibits both intra-excitonic and Drude features. Utilizing a two-component dielectric function, we derive the underlying exciton and unbound pair densities. In the ionized state, excellent agreement is found with the Saha thermodynamic equilibrium, which provides experimental verification of the two-component analysis and density scaling. During exciton formation, in turn, the pair kinetics is quantitatively described by a Saha equilibrium that follows the carrier cooling dynamics. The terahertz-derived kinetics is, moreover, consistent with time-resolved luminescence measured for comparison. Our study establishes a basis for tracking pair densities via transient terahertz spectroscopy of photoexcited quasi-two-dimensional electron-hole gases.Comment: 14 pages, 8 figures, final versio

    Design of Subsurface Geodrain for Automated Industrial Unit – Case Study

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    This paper describes the pre-construction modeling for design and post-construction evaluation of subsurface drainage systems for an industrial plant. Rajshree Polyfil Ltd has a polyester filament manufacturing plant spread over 50 hectare area in Bharuch district of Gujarat State, India. The plant is fully automatic and robotics operated. The cable duct for control system was laid below formation level. The seepage water was observed in the cable trench and nearby vicinity. This seriously affects the functioning of computer controlled production system. Preliminary investigation revealed that the ground water level was around 1.0m depth below formation level, which was more than 15m depth during the construction of unit. Detailed subsurface investigations and field permeability tests are carried out. Subsurface drainage system was designed and its performance was estimated prior to construction of drain with the help of computer modeling using software MODFLOW. The model area was divided in three to five layers having different permeability values obtained from field test. After construction of subsurface geodrain, discharge was measured and water level was also measured at few piezometers installed near the drain. It is found that the performance of the drain is well in accordance with the design
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