4,786 research outputs found
Fermionic Glauber Operators and Quark Reggeization
We derive, in the framework of soft-collinear effective field theory (SCET),
a Lagrangian describing the -channel exchange of Glauber quarks in the Regge
limit. The Glauber quarks are not dynamical, but are incorporated through
non-local fermionic potential operators. These operators are power suppressed
in relative to those describing Glauber gluon exchange, but give the
first non-vanishing contributions in the Regge limit to processes such as
and . They therefore represent an
interesting subset of power corrections to study. The structure of the
operators, which describe certain soft and collinear emissions to all orders
through Wilson lines, is derived from the symmetries of the effective theory
combined with constraints from power and mass dimension counting, as well as
through explicit matching calculations. Lightcone singularities in the
fermionic potentials are regulated using a rapidity regulator, whose
corresponding renormalization group evolution gives rise to the Reggeization of
the quark at the amplitude level and the BFKL equation at the cross section
level. We verify this at one-loop, deriving the Regge trajectory of the quark
in the color channel, as well as the leading logarithmic BFKL equation.
Results in the and color channels are obtained by the
simultaneous exchange of a Glauber quark and a Glauber gluon. SCET with quark
and gluon Glauber operators therefore provides a framework to systematically
study the structure of QCD amplitudes in the Regge limit, and derive
constraints on higher order amplitudes.Comment: 31 pages, many figure
Efficient Analysis for the Design Refinement of Large Multilayered Printed Reflectarrays
In this paper, we present an efficient numerical technique for the analysis of a reflectarray and its design refinement by the characterization of the “actual” influence of each radiating element when embedded in the antenna structure. The method makes use of the MLayAIM, a fast full-wave formulation suitable for the analysis of electrically large multilayered printed arrays which have one or more planar metallizations and vertical conductors. The low numerical complexity of the analysis method allows the development of a recursive procedure that, starting from the equivalent currents relevant to each cell of the reflectarray when this is immersed in the actual antenna layout, calculates the real phase-shift introduced by each radiating element and corrects its dimensions to better fit the antenna requirements
P-wave pi pi amplitude from dispersion relations
We solve the dispersion relation for the P-wave pi pi amplitude.We discuss
the role of the left hand cut vs Castillejo-Dalitz-Dyson (CDD), pole
contribution and compare the solution with a generic quark model description.
We review the the generic properties of analytical partial wave scattering and
production amplitudes and discuses their applicability and fits of experimental
data.Comment: 10 pages, 7 figures, typos corrected, reference adde
Kinetics and Penetration into Inflammatory Tissue Cage Fluid of Cefepime Administered to Rabbits
The kinetics and penetration of cefepime into inflammatory tissue cage fluid were determined in rabbits. Ten adult healthy rabbits were used. Concentrations of cefepime were measured in serum and induced inflammatory exudate by biological methods. The kinetic analysis was performed by mean of a non-compartmental model. Pharmacokinetic results in serum (S) and inflammatory tissue cage fluid (ITCF) (means ± standard error) were: half life of elimination [t1\2 (S) ]= 1.6 ± 0.2 and (ITCF) 3.7 ± 0.3 h; area under the curve [AUC (S)]= 225.3 ± 21.4 and (ITCF) 208.0 ± 13.6 (μg/ml/h]; maximum concentration [Cmax (ITCF)]= 37.7 ± 3.6 μg/ml and time to reach Cmax [tmax (ITCF)]= 1.8 ± 0.4 h and the penetration into inflammatory tissue cage fluid [P (ITCF)] = 92.3 ± 8.7 %. In conclusion, the cefepime administered to rabbits penetrate rapidly and nearly completely into inflammatory tissue cage fluid.
Pemodelan Persentase Kriminalitas dan Faktor-Faktor yang Mempengaruhi di Jawa Timur dengan Pendekatan Geographically Weighted Regression (GWR)
Kejahatan atau kriminalitas merupakan perbuatan seseorang yang dapat diancam hukuman berdasarkan KUHP atau undang-undang serta peraturan lainnya di Indonesia. Pada tahun 2010 Polda Jawa Timur menduduki peringkat keempat jumlah kriminalitas tertinggi di Indonesia setelah Polda Metro Jaya, Polda Sumatera Utara dan Polda Jawa Barat. Perbedaan karakteristik geografis menyebabkan perbedaan atau keterikatan faktor ekonomi, sosial, budaya yang juga berpengaruh pada tindakan kriminalitas di setiap daerah. Karena itu penelitian ini akan memodelkan persentase kriminalitas dan faktor-faktor yang mempengaruhinya di Provinsi Jawa Timur dengan pendekatan Geographically Weighted Regression (GWR). Dari hasil penelitian ini didapatkan bahwa adanya pengaruh spasial dalam pemodelan persentase kriminalitas di Jawa Timur. Pemilihan pembobot dilakukan dengan cara memilih pembobot yang memiliki nilai AIC terkecil yaitu fix gaussian. Wilayah yang berdekatan cenderung memiliki kesamaan faktor-faktor yang mempengaruhi persentase kriminalitas di Jawa Timur. Variabel kepadatan penduduk dan persentase penduduk migran berpengaruh signifikan pada sebagian besar kabupaten/kota di Jawa Timur. Model GWR menghasilkan R2 sebesar 86,95 persen lebih besar dari model OLS yaitu 54,1 persen.
Computer-aided simulation and testing of spatial linkages with joint mechanical errors
Tolerance allocation influences production costs in a big way. For this reason it is very important to have an accurate study about the effects of manufacturing errors on the functioning and performances of linkages. In this paper, the authors present a computer-aided methodology based on a 3D geometrical approach using the dual-algebra fundamentals. The purpose is to give ail useful tool which can be integrated into CAD software in order to evaluate the performances of spatial mechanisms with mechanical errors. The proposed methodology has been validated by means of experimental tests on a Cardan joint mechanism with clearances, misalignments and dimensional errors. Copyright (c) 2005 John Wiley & Sons, Ltd
Pemodelan Dan Simulasi Katalitik Konverter Packed Bed Untuk Mengoksidasi Jelaga Pada Gas Buang Kendaraan Bermesin Diesel
Modelling and Simulation of Packed Bed Catalytic Converter for Oxidation of Soot in Diesel Powered VehiclesFlue Gas. Diesel vehicle is used in Indonesia in very big number. This vehicle exhausts pollutants especially diesel sootthat can be reduces by using a catalytic converter to convert the soot to CO2. To obtain the optimal dimension ofcatalytic converter it is needed a model that can represent the profile of soot weight, temperature and pressure along thecatalytic converter. In this study, a model is developed for packed bed catalytic converter in an adiabatic conditionbased on a kinetic study that has been reported previously. Calculation of developed equations in this model usesPolymath 5.X solver with Range Kutta Method. The simulation result shows that temperature profile along catalyticconverter increases with the decrease of soot weight, while pressure profile decreases. The increase of soot weight inentering gas increases the needed converter length. On the other hand, the increase of catalyst diameter does not affectto soot weight along converter and temperature profile, but results a less pressure drop. For 2.500 c diesel engine,packed bed catalytic converter with ellipse's cross sectional of 14,5X7,5 cm diagonal and 0,8 cm catalyst particlediameter, needs 4,1 cm length
Estimating annual groundwater recharge coefficient for karst aquifers of the southern Apennines (Italy)
Abstract. To assess the mean annual groundwater recharge of the karst aquifers in the southern Apennines (Italy), the estimation of the mean annual groundwater recharge coefficient (AGRC) was conducted by means of an integrated approach based on hydrogeological, hydrological, geomorphological, land use and soil cover analyses. Starting from the hydrological budget equation, the coefficient was conceived as the ratio between the net groundwater outflow and the precipitation minus actual evapotranspiration (P − ETR) for a karst aquifer. A large part of the southern Apennines, which is covered by a meteorological network containing 40 principal karst aquifers, was studied. Using precipitation and air temperature time series gathered through monitoring stations operating in the period 1926–2012, the mean annual P − ETR was estimated, and its distribution was modelled at a regional scale by considering the orographic barrier and rain shadow effects of the Apennine chain, as well as the altitudinal control. Four sample karst aquifers with available long spring discharge time series were identified for estimating the AGRC. The resulting values were correlated with other parameters that control groundwater recharge, such as the extension of outcropping karst rocks, morphological settings, land use and covering soil type. A multiple linear regression between the AGRC, lithology and the summit plateau and endorheic areas was found. This empirical model was used to assess the AGRC and mean annual groundwater recharge in other regional karst aquifers. The coefficient was calculated as ranging between 50 and 79%, thus being comparable with other similar estimations carried out for karst aquifers of European and Mediterranean countries. The mean annual groundwater recharge for karst aquifers of the southern Apennines was assessed by these characterizations and validated by a comparison with available groundwater outflow measurements. These results represent a deeper understanding of an aspect of groundwater hydrology in karst aquifers which is fundamental for the formulation of appropriate management models of groundwater resources at a regional scale, also taking into account mitigation strategies for climate change impacts. Finally, the proposed hydrological characterizations are also supposed to be useful for the assessment of mean annual runoff over carbonate mountains, which is another important topic concerning water management in the southern Apennines
Two-loop QCD corrections to the MSSM Higgs masses beyond the effective-potential approximation
We compute the two-loop QCD corrections to the neutral Higgs-boson masses in
the MSSM, including the effect of non-vanishing external momenta in the
self-energies. We obtain corrections of O(alpha_t*alpha_s) and
O(alpha*alpha_s), i.e., all two-loop corrections that involve the strong gauge
coupling when the only non-vanishing Yukawa coupling is the top one. We adopt
either the DRbar renormalization scheme or a mixed OS-DRbar scheme where the
top/stop parameters are renormalized on-shell. We compare our results with
those of earlier calculations, pointing out an inconsistency in a recent result
obtained in the mixed OS-DRbar scheme. The numerical impact of the new
corrections on the prediction for the lightest-scalar mass is moderate, but
already comparable to the accuracy of the Higgs-mass measurement at the LHC.Comment: 22 pages, 5 pdf figures; v2: version to appear in EPJ
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