A theoretical model of the wave particle interaction of plasma in space

A theoretical model, based on the kinetic theory for the perturbation of plasma in the magnetosphere, is proposed to study the observed disturbances which are caused by both natural and artificial sources that generate wave-like perturbations propagating around the globe. The proposed model covers the wave propagation through a media of transitional (from collisional to collisionless) fully ionized magnetoactive plasma. A systematic formulation of the problem is presented and the method of solution for the transitional model of magnetosphere is discussed. The possible emission of hydromagnetic waves in the magnetosphere during the quiet and disturbed time are also discussed

Multifluids description of dynamics of upper atmosphere

A multifluids model to investigate ionospheric dynamics was established on kinetic theory. Its resultant equations are used to examine the following dynamic problems in the gamma region of 80-2000 Km of the ionosphere: (1) propagation of acoustic modes in the 500-2,000 Km of the ionosphere (two fluid model); (2) the relation between the cross field plasma drift instabilities and type I and type II ionospheric irregularities; and (3) time dependent neutral wind structure and horizontal pressure gradient

Severe storm initiation and development from satellite infrared imagery and Rawinsonde data

The geographical distribution of potential temperatures, mixing ratio, and streamlines of flow patterns at 850, 700, and 500 mb heights are used to understand the prestorm convection and the horizontal convergence of moisture. From the analysis of 21 tornadoes the following conclusions are reached: (1) Strong horizontal convergence of moisture appeared at the 850, 700, and 500 mb levels in the area 12 hours before the storm formation; (2) An abundantly moist atmosphere below 3 km (700 mb) becomes convectively unstable during the time period between 12 and 24 hours before the initiation of the severe storms; (3) Strong winds veering with height with direction parallel to the movement of a dryline, surface fronts, etc; (4) During a 36-hour period, a tropopause height in the areas of interest is lowest at the time of tornadic cloud formation; (5) A train of gravity waves is detected before and during the cloud formation period. Rapid-scan infrared imagery provides near real-time information on the life cycle of the storm which can be summarized as follows: (1) Enhanced convection produced an overshooting cloud top penetrating above the tropopause, making the mass density of the overshooting cloud much greater than the mass density of the surrounding air; (2) The overshooting cloud top collapsed at the end of the mature stage of the cloud development; (3) The tornado touchdown followed the collapse of the overshooting cloud top

On processing development for fabrication of fiber reinforced composite, part 2

Fiber-reinforced composite laminates are used in many aerospace and automobile applications. The magnitudes and durations of the cure temperature and the cure pressure applied during the curing process have significant consequences for the performance of the finished product. The objective of this study is to exploit the potential of applying the optimization technique to the cure cycle design. Using the compression molding of a filled polyester sheet molding compound (SMC) as an example, a unified Computer Aided Design (CAD) methodology, consisting of three uncoupled modules, (i.e., optimization, analysis and sensitivity calculations), is developed to systematically generate optimal cure cycle designs. Various optimization formulations for the cure cycle design are investigated. The uniformities in the distributions of the temperature and the degree with those resulting from conventional isothermal processing conditions with pre-warmed platens. Recommendations with regards to further research in the computerization of the cure cycle design are also addressed

The Impact of Macroeconomic Variables on the Fluctuation of Jakarta Composite Index (Jci) in Indonesia Stock Exchange (Study at Indonesia Stock Exchange for the Period of 2003-2012)

The purpose of this paper is to analyze the impact of macroeconomic variables on the fluctuation of Jakarta Composite Index (JCI) in Indonesia Stock Exchange. This research consists of four macroeconomic variables as independent variables; inflation, BI rate, exchange rate of rupiah against U.S. dollar and real GDP. The using of JCI as dependent variable is because of it reflects the price change in different types of stocks in the Indonesia capital market as generally. Ordinary Least Square (OLS) is used as data analysis technique. Quarterly data are obtained for the period of ten years starting from January 2003 until December 2012. Augmented Dickey Fuller (ADF) and Phillips-Perron (PP) Unit Root test is employed to check the stationary of data. The results show that data has autocorrelation problem, therefore modifying original equation is taken to take account of the serial correlation by transforming all the variables by r differencing using first differences (regressing yt – yt-1 and xt – xt-1). The result reveals that macroeconomic variables simultaneously have significant impact on JCI. In addition, there are significantly negative impact of BI rate and exchange rate on JCI. The result also reveals that inflation and real GDP do not have any significant impact on JCI

Complete Set of Homogeneous Isotropic Analytic Solutions in Scalar-Tensor Cosmology with Radiation and Curvature

We study a model of a scalar field minimally coupled to gravity, with a specific potential energy for the scalar field, and include curvature and radiation as two additional parameters. Our goal is to obtain analytically the complete set of configurations of a homogeneous and isotropic universe as a function of time. This leads to a geodesically complete description of the universe, including the passage through the cosmological singularities, at the classical level. We give all the solutions analytically without any restrictions on the parameter space of the model or initial values of the fields. We find that for generic solutions the universe goes through a singular (zero-size) bounce by entering a period of antigravity at each big crunch and exiting from it at the following big bang. This happens cyclically again and again without violating the null energy condition. There is a special subset of geodesically complete non-generic solutions which perform zero-size bounces without ever entering the antigravity regime in all cycles. For these, initial values of the fields are synchronized and quantized but the parameters of the model are not restricted. There is also a subset of spatial curvature-induced solutions that have finite-size bounces in the gravity regime and never enter the antigravity phase. These exist only within a small continuous domain of parameter space without fine tuning initial conditions. To obtain these results, we identified 25 regions of a 6-parameter space in which the complete set of analytic solutions are explicitly obtained.Comment: 38 pages, 29 figure

Quantum many-body models with cold atoms coupled to photonic crystals

Using cold atoms to simulate strongly interacting quantum systems represents an exciting frontier of physics. However, as atoms are nominally neutral point particles, this limits the types of interactions that can be produced. We propose to use the powerful new platform of cold atoms trapped near nanophotonic systems to extend these limits, enabling a novel quantum material in which atomic spin degrees of freedom, motion, and photons strongly couple over long distances. In this system, an atom trapped near a photonic crystal seeds a localized, tunable cavity mode around the atomic position. We find that this effective cavity facilitates interactions with other atoms within the cavity length, in a way that can be made robust against realistic imperfections. Finally, we show that such phenomena should be accessible using one-dimensional photonic crystal waveguides in which coupling to atoms has already been experimentally demonstrated

Superradiance for atoms trapped along a photonic crystal waveguide

We report observations of superradiance for atoms trapped in the near field of a photonic crystal waveguide (PCW). By fabricating the PCW with a band edge near the D$_1$ transition of atomic cesium, strong interaction is achieved between trapped atoms and guided-mode photons. Following short-pulse excitation, we record the decay of guided-mode emission and find a superradiant emission rate scaling as $\bar{\Gamma}_{\rm SR}\propto\bar{N}\cdot\Gamma_{\rm 1D}$ for average atom number $0.19 \lesssim \bar{N} \lesssim 2.6$ atoms, where $\Gamma_{\rm 1D}/\Gamma_0 =1.1\pm0.1$ is the peak single-atom radiative decay rate into the PCW guided mode and $\Gamma_{0}$ is the Einstein-$A$ coefficient for free space. These advances provide new tools for investigations of photon-mediated atom-atom interactions in the many-body regime.Comment: 11 pages, 10 figure

Studies on the effect of MegaPixel sensor resolution on displayed image quality and relevant metrics

This paper investigates camera phone image quality, namely the effect of sensor megapixel (MP) resolution on the perceived quality of images displayed at full size on high-quality desktop displays. For the purpose, we use images from simulated cameras with different sensor MP resolutions. We employ methods recommended in the IEEE 1858 Camera Phone Image Quality (CPIQ) standard, as well as other established psychophysical paradigms, to obtain subjective image quality ratings for systems with varying MP resolution from large numbers of observers. These are subsequently used to validate image quality metrics (IQMs) relating to sharpness and resolution, including those from the CPIQ standard. Further, we define acceptable levels of quality - when changing MP resolution - for mobile phone images in Subjective Quality Scale (SQS) units. Finally, we map SQS levels to categories obtained from star-rating experiments (commonly used to rate consumer experience). Our findings draw a relationship between the MP resolution of the camera sensor and the LCD device. The chosen metrics predict quality accurately, but only the metrics proposed by CPIQ return results in calibrated JNDs in quality. We close by discussing the appropriateness of star-rating experiments for the purpose of measuring subjective image quality and metric validation

Rare kaon decays in SUSY with non-universal A terms

We study the rare kaon decays in the framework of general SUSY models. Unlike the results in the literature, we find the contributions from the gluino exchange to the branching ratio of $K^+\to \pi^+ \nu \bar{\nu}$ can reach the central value ($\sim 1.5 \times 10^{-10}$) of the new E787 data while the predicted value of standard model is less than $10^{-10}$. We also find that the same effects also enhance the decays of $K_{L}\to \pi^0 \nu \bar{\nu}$, $K_L\to\pi^0e^{+} e^{-}$ and $K_L\to\mu^+ \mu^-$.Comment: 9 pages, references added, revised version to appear in J. Phys.