Inelastic Final-State Interactions and Two-body Hadronic B decays into Single-Isospin channels

The role of inelastic final-state interactions in CP asymmetries and branching ratios is investigated in certain chosen single isospin two-body hadronic B decays. Treating final-state interactions through Pomeron and Regge exchanges, we demonstrate that inelastic final state interactions could lead to sizeable effects on the CP asymmetry.Comment: 23 pages, Latex, 1 eps-figur

Low loss waveguide-based Butler matrix with iris coupling control method for millimeterwave applications

This paper proposes a low loss 4×4 Butler matrix based on rectangular waveguide cavity resonators technology for millimeterwave beamforming network using iris coupling method. This method has the advantage of controlling the electrical fields and the coupling factor inside a complex medium such as waveguide cavity resonators. The coupling factor of 6 dB for 4×4 Butler matrix is achieved by tuning the iris coupling k-value between the waveguide cavity resonators. Thus, avoiding a higher phase difference losses and component losses at upper millimeterwave bands. To validate the proposed method, CST software simulations are performed under several iris coupling k-values to achieve a 6 dB coupling factor. Then, the proposed 4×4 Butler matrix is 3D metal printed using selective laser melting (SLM) technique. The measured reflection and isolation coefficients are observed below −10 dB, with coupling coefficients ranging between −6 and −7 dB. The phase differences of −42.02°, 42.02°, −130.95°, and 133.3° are achieved at the outputs. It confirmed that using this proposed method has the superiority over the conventional microstrip and waveguide coupling methods by a 1 dB coupling factor loss and a 3° phase difference error

Pembangkit Listrik Tenaga Angin Dengan Inovasi Turbin Heliks Vertikal Untuk Kemandirian Energi Sekolah Daerah Pesisir

Indonesian coastal have wind great potential because it has the second longest coastline in the world. In contrast to conventional wind turbines can only absorb a maximum of about 30 % of wind energy, wind tur-bine theoretically and practically helices can absorb almost 40-50 % and convert it into mechanical energy due to the helical blade design that uses the principle of lift force and torque on the blades distribution, so it is very advantageous to be applied to the coastal regions of Indonesia. By combining the generator dual axi-al and helical turbine power can be generated with a range of about 500 Watts . One of the schools in the area Cumpat Kenjeran Surabaya chosen as a partner because of the location of the school adjacent to the coast followed by the electrical energy needs for learning tools such as computers , tools and other lab work. To manufacture helical blade assisted by PT Mitra Mandiri Perkasa which help in the problem of providing tools

c-axis electrodynamics of ybco

New measurements of surface impedance in ybco show that the c-axis penetration depth and conductivity below Tc exhibit behaviour different from that observed in the planes. The c-axis penetration depth never has the linear temperature dependence seen in the ab-plane. Instead of the conductivity peak seen in the planes, the c-axis microwave conductivity falls to low values in the superconducting state, then rises slightly below 20K. These results show that c-axis transport remains incoherent below Tc, even though this is one of the least anisotropic cuprate superconductors.Comment: 4-page

Active and passive aperture coupled microstrip antenna design

Microstrip antennas has a few feeding technique applicable to them. One of them is the non-contacting feeds, which is the aperture-coupled feed techniques. The main mechanism of power transfer between its feed line and patch is the coupling mechanism through the aperture. This work is an effort to design, simulate, fabricate and measurement of passive and active rectangular patch with aperture coupled feed techniques. Simulation is being done using the Method of Moments (MoM). This is simulated in Microwave Office software. This design intends to focus on studying the differences in simulated and measured parameters of the antenna on its return loss, bandwidth and radiation pattern

Semiclassical and Quantum Field Theoretic Bounds for Traversable Lorentzian Stringy Wormholes

A lower bound on the size of a Lorentzian wormhole can be obtained by semiclassically introducing the Planck cut-off on the magnitude of tidal forces (Horowitz-Ross constraint). Also, an upper bound is provided by the quantum field theoretic constraint in the form of the Ford-Roman Quantum Inequality for massless minimally coupled scalar fields. To date, however, exact static solutions belonging to this scalar field theory have not been worked out to verify these bounds. To fill this gap, we examine the wormhole features of two examples from the Einstein frame description of the vacuum low energy string theory in four dimensions which is the same as the minimally coupled scalar field theory. Analyses in this paper support the conclusion of Ford and Roman that wormholes in this theory can have sizes that are indeed only a few order of magnitudes larger than the Planck scale. It is shown that the two types of bounds are also compatible. In the process, we point out a "wormhole" analog of naked black holes.Comment: 15 page

Observation of the Transverse Optical Plasmon in SmLa0.8Sr0.2CuO4-d

We present microwave and infrared measurements on SmLa0.8Sr0.2CuO4-d, which are direct evidence for the existence of a transverse optical plasma mode, observed as a peak in the c-axis optical conductivity. This mode appears as a consequence of the existence of two different intrinsic Josephson couplings between the CuO2 layers, one with a Sm2O2 block layer, and the other one with a (La,Sr)O block layer. From the frequencies and the intensities of the collective modes we determine the value of the compressibility of the two dimensional electron fluid in the copper oxygen planes.Comment: REVTeX, 4 pages, 5 eps-figures, PRL, in pres

Microwave Conductivity due to Impurity Scattering in a d-wave Superconductor

The self-consistent t-matrix approximation for impurity scattering in unconventional superconductors is used to interpret recent measurements of the temperature and frequency dependence of the microwave conductivity of YBCO crystals below 20K. In this theory, the conductivity is expressed in terms of a fequency dependent single particle self-energy, determined by the impurity scattering phase shift which is small for weak (Born) scattering and approaches $\pi / 2$ for unitary scattering. Inverting this process, microwave conductivity data are used to extract an effective single-particle self-energy and obtain insight into the nature of the operative scattering processes. It is found that the effective self-energy is well approximated by a constant plus a linear term in frequency with a small positive slope for thermal quasiparticle energies below 20K. Possible physical origins of this form of self-energy are discussed.Comment: 5 pages, 4 figure

Robust efficiency and output elasticity of broiler production in Peninsular Malaysia

This study investigates issues on efficiency and elasticity of broiler production in Peninsular Malaysia. Data from 296 broiler farms were subjected to SFA, DEA and bootstrap methods for technical efficiency; Translog and Tobit regression analyses to estimate elasticity of production and determinants of efficiency respectively in broiler production. We found that farmers produce mean efficiency of 94, 95 and 97% with robust for small, medium and large scale farms respectively. Apart from inefficiency, we also found evidence that minimal bias/noise exists in broiler production. Relative to output elasticity, we observed an inelastic relationship in feeds but an elastic relationship in DOC, medications and utilities. Most of the socio-economic attributes (experience, age, education, business status and number of farms) show highly significant statistical relationship with efficiency and with appropriate signs. To ensure production at higher marginal returns and lower marginal costs, farms operating under increasing returns to scale should scale-up production while those producing at decreasing returns to scale need to scale-down production. The study also advocates to farmers to embrace adequate training/better education, contract farming and ownership of fewer number of farms in order to enhance efficiency, productivity and sustainability of the broiler industry

Microwave Spectroscopy of Thermally Excited Quasiparticles in YBa_2Cu_3O_{6.99}

We present here the microwave surface impedance of a high purity crystal of $YBa_2Cu_3O_{6.99}$ measured at 5 frequencies between 1 and 75 GHz. This data set reveals the main features of the conductivity spectrum of the thermally excited quasiparticles in the superconducting state. Below 20 K there is a regime of extremely long quasiparticle lifetimes, due to both the collapse of inelastic scattering below $T_c$ and the very weak impurity scattering in the high purity $BaZrO_3$-grown crystal used in this study. Above 20 K, the scattering increases dramatically, initially at least as fast as $T^4$.Comment: 13 pages with 10 figures. submitted to Phys Rev