Abstract: Efficient luminescence is reported for the first time in Eu2+ activated double Chlorides A2BCl4 (A=Alkali metal, B=Alkaline earth element). A simple wet-chemical preparation is described. Emission intensities are comparable to that of the commercial phosphor. Excitation covers near UV region. These phosphors may be useful for applications like solid state lighting, scintillation detectors and X-ray storage using photo-stimulable phosphors.
Abstract: Elastic and inelastic scattering of α-particles by 9Be nuclei at different incident energies have been analyzed. Optical model parameters (OMPs) of α-particles elastic scattering by 9Be at different energies have been obtained. Coupled Reaction Channel (CRC) of elastic scattering, inelastic scattering and transfer reaction has been calculated using Fresco Code. The effect of involving CRC calculations on the analysis of differential cross section has been studied. The transfer reaction of (5He) in the reaction 9Be(α,9Be)α has been studied. The spectroscopic factor of 9Be≡α+5He has been extracted.
Abstract: In this paper we describe the design and implementation of a parallel algorithm for data assimilation with ensemble Kalman filter (EnKF) for oil reservoir history matching problem. The use of large number of observations from time-lapse seismic leads to a large turnaround time for the analysis step, in addition to the time consuming simulations of the realizations. For efficient parallelization it is important to consider parallel computation at the analysis step. Our experiments show that parallelization of the analysis step in addition to the forecast step has good scalability, exploiting the same set of resources with some additional efforts.
Abstract: The main aim of this study is to describe and introduce a method of numerical analysis in obtaining approximate solutions for the SIR-SI differential equations (susceptible-infectiverecovered for human populations; susceptible-infective for vector populations) that represent a model for dengue disease transmission. Firstly, we describe the ordinary differential equations for the SIR-SI disease transmission models. Then, we introduce the numerical analysis of solutions of this continuous time, discrete space SIR-SI model by simplifying the continuous time scale to a densely populated, discrete time scale. This is followed by the application of this numerical analysis of solutions of the SIR-SI differential equations to the estimation of relative risk using continuous time, discrete space dengue data of Kuala Lumpur, Malaysia. Finally, we present the results of the analysis, comparing and displaying the results in graphs, table and maps. Results of the numerical analysis of solutions that we implemented offers a useful and potentially superior model for estimating relative risks based on continuous time, discrete space data for vector borne infectious diseases specifically for dengue disease.
Abstract: The Stokes equation connected with the fluid flow
over the axisymmetric bodies in a cylindrical area is considered. The
equation is studied in a moving coordinate system with the
appropriate boundary conditions. Effective formulas for the velocity
components are obtained. The graphs of the velocity components and
velocity profile are plotted.
Abstract: A SnO2/CdS/CdTe heterojunction was fabricated by
thermal evaporation technique. The fabricated cells were annealed at
573K for periods of 60, 120 and 180 minutes. The structural
properties of the solar cells have been studied by using X-ray
diffraction. Capacitance- voltage measurements were studied for the
as-prepared and annealed cells at a frequency of 102 Hz. The
capacitance- voltage measurements indicated that these cells are
abrupt. The capacitance decreases with increasing annealing time.
The zero bias depletion region width and the carrier concentration
increased with increasing annealing time. The carrier transport
mechanism for the CdS/CdTe heterojunction in dark is tunneling
recombination. The ideality factor is 1.56 and the reverse bias
saturation current is 9.6×10-10A. The energy band lineup for the n-
CdS/p-CdTe heterojunction was investigated using current - voltage
and capacitance - voltage characteristics.
Abstract: The bonding configuration and the heat of adsorption
of a furfural molecule on the Pd(111) surface were determined by ab
initio density-functional-theory calculations. The dynamics of pure
liquid water, the liquid-solid interface formed by liquid water and the
Pd(111) surface, as well as furfural at the water-Pd interface, were
investigated by ab initio molecular dynamics simulations at finite
temperatures. Calculations and simulations suggest that the bonding
configurations at the water-Pd interface promote decarbonylation of
furfural.
Abstract: According to Hermite there exists only a finite
number of number fields having a given degree, and a given value of
the discriminant, nevertheless this number is not known generally.
The determination of a maximum number of number fields of degree
10 having a given discriminant that contain a subfield of degree 5
having a fixed class number, narrow class number and Galois group
is the purpose of this work. The constructed lists of the first
coincidences of 52 (resp. 50, 40, 48, 22, 6) nonisomorphic number
fields with same discriminant of degree 10 of signature (6,2) (resp.
(4,3), (8,1), (2,4), (0,5), (10,0)) containing a quintic field. For each
field in the lists, we indicate its discriminant, the discriminant of its
subfield, a relative polynomial generating the field over its quintic
field and its relative discriminant, the corresponding polynomial over
Q and its Galois closure are presented with concluding remarks.
Abstract: In this paper two mathematical models for definition of gas accidental escape localization in the gas pipelines are suggested. The first model was created for leak localization in the horizontal branched pipeline and second one for leak detection in inclined section of the main gas pipeline. The algorithm of leak localization in the branched pipeline did not demand on knowledge of corresponding initial hydraulic parameters at entrance and ending points of each sections of pipeline. For detection of the damaged section and then leak localization in this section special functions and equations have been constructed. Some results of calculations for compound pipelines having two, four and five sections are presented. Also a method and formula for the leak localization in the simple inclined section of the main gas pipeline are suggested. Some results of numerical calculations defining localization of gas escape for the inclined pipeline are presented.
Abstract: In this work we adopt a combination of Laplace
transform and the decomposition method to find numerical solutions
of a system of multi-pantograph equations. The procedure leads to a
rapid convergence of the series to the exact solution after computing a
few terms. The effectiveness of the method is demonstrated in some
examples by obtaining the exact solution and in others by computing
the absolute error which decreases as the number of terms of the series
increases.
Abstract: In this work, we apply the Modified Laplace
decomposition algorithm in finding a numerical solution of Blasius’
boundary layer equation for the flat plate in a uniform stream. The
series solution is found by first applying the Laplace transform to the
differential equation and then decomposing the nonlinear term by the
use of Adomian polynomials. The resulting series, which is exactly the
same as that obtained by Weyl 1942a, was expressed as a rational
function by the use of diagonal padé approximant.
Abstract: Transient shape variation of a rotating liquid dropletis
simulated numerically. The three dimensional Navier-Stokes
equations were solved by using the level set method. The shape
variation from the sphere to the rotating ellipsoid, and to the two-robed
shapeare simulated, and the elongation of the two-robed droplet is
discussed. The two-robed shape after the initial transient is found to be
stable and the elongation is almost the same for the cases with different
initial rotation rate. The relationship between the elongation and the
rotation rate is obtained by averaging the transient shape variation. It is
shown that the elongation of two-robed shape is in good agreement
with the existing experimental data. It is found that the transient
numerical simulation is necessary for analyzing the largely elongated
two-robed shape of rotating droplet.
Abstract: Cryptography, Image watermarking and E-banking are
filled with apparent oxymora and paradoxes. Random sequences are
used as keys to encrypt information to be used as watermark during
embedding the watermark and also to extract the watermark during
detection. Also, the keys are very much utilized for 24x7x365
banking operations. Therefore a deterministic random sequence is
very much useful for online applications. In order to obtain the same
random sequence, we need to supply the same seed to the generator.
Many researchers have used Deterministic Random Number
Generators (DRNGs) for cryptographic applications and Pseudo
Noise Random sequences (PNs) for watermarking. Even though,
there are some weaknesses in PN due to attacks, the research
community used it mostly in digital watermarking. On the other hand,
DRNGs have not been widely used in online watermarking due to its
computational complexity and non-robustness. Therefore, we have
invented a new design of generating DRNG using Pi-series to make it
useful for online Cryptographic, Digital watermarking and Banking
applications.
Abstract: Developing a stable early warning system (EWS)
model that is capable to give an accurate prediction is a challenging
task. This paper introduces k-nearest neighbour (k-NN) method
which never been applied in predicting currency crisis before with the
aim of increasing the prediction accuracy. The proposed k-NN
performance depends on the choice of a distance that is used where in
our analysis; we take the Euclidean distance and the Manhattan as a
consideration. For the comparison, we employ three other methods
which are logistic regression analysis (logit), back-propagation neural
network (NN) and sequential minimal optimization (SMO). The
analysis using datasets from 8 countries and 13 macro-economic
indicators for each country shows that the proposed k-NN method
with k = 4 and Manhattan distance performs better than the other
methods.
Abstract: This research contribution is drafted to present the
orbit design, orbit propagator and geomagnetic field estimator for the
nanosatellites specifically for the upcoming CUBESAT, ICUBE-1 of
the Institute of Space Technology (IST), Islamabad, Pakistan. The
ICUBE mission is designed for the low earth orbit at the approximate
height of 700KM. The presented research endeavor designs the
Keplarian elements for ICUBE-1 orbit while incorporating the
mission requirements and propagates the orbit using J2 perturbations,
The attitude determination system of the ICUBE-1 consists of
attitude determination sensors like magnetometer and sun sensor. The
Geomagnetic field estimator is developed according to the model of
International Geomagnetic Reference Field (IGRF) for comparing the
magnetic field measurements by the magnetometer for attitude
determination. The output of the propagator namely the Keplarians
position and velocity vectors and the magnetic field vectors are
compared and verified with the same scenario generated in the
Satellite Tool Kit (STK).
Abstract: Temperature dependence of force of gravitation is one
of the fundamental problems of physics. This problem has got special
value in connection with that the general theory of relativity,
supposing the weakest positive influence of a body temperature on its
weight, actually rejects an opportunity of measurement of negative
influence of temperature on gravity in laboratory conditions. Really,
the recognition of negative temperature dependence of gravitation,
for example, means basic impossibility of achievement of a
singularity («a black hole») at a gravitational collapse. Laboratory
experiments with exact weighing the heated up metal samples,
indicating negative influence temperatures of bodies on their physical
weight are described. Influence of mistakes of measurements is
analyzed. Calculations of distribution of temperature in volume of the
bar, agreed with experimental data of time dependence of weight of
samples are executed. The physical substantiation of negative
temperature dependence of weight of the bodies, based on correlation
of acceleration at thermal movement of micro-particles of a body and
its absolute temperature, are given.
Abstract: A Data Warehouses is a repository of information
integrated from source data. Information stored in data warehouse is
the form of materialized in order to provide the better performance
for answering the queries. Deciding which appropriated views to be
materialized is one of important problem. In order to achieve this
requirement, the constructing search space close to optimal is a
necessary task. It will provide effective result for selecting view to be
materialized. In this paper we have proposed an approach to reoptimize
Multiple View Processing Plan (MVPP) by using global
common subexpressions. The merged queries which have query
processing cost not close to optimal would be rewritten. The
experiment shows that our approach can help to improve the total
query processing cost of MVPP and sum of query processing cost
and materialized view maintenance cost is reduced as well after views
are selected to be materialized.
Abstract: Sputter deposition processes, especially for sputtering
from metal targets, are well investigated. For practical reasons, i.e.
for industrial processes, energetic considerations for sputter
deposition are useful in order to optimize the sputtering process. In
particular, for substrates at floating conditions it is required to obtain
energetic conditions during film growth that enables sufficient dense
metal films of good quality. The influence of ion energies, energy
density and momentum transfer is thus examined both for sputtering
at the target as well as during film growth. Different regimes
dominated by ion energy, energy density and momentum transfer
were identified by using different plasma sources and by varying
power input, pressure and bias voltage.
Abstract: In present work the problem of the ITER fusion
plasma neutron source parameter reconstruction using only the
Vertical Neutron Camera data was solved. The possibility of neutron
source parameter reconstruction was estimated by the numerical
simulations and the analysis of adequateness of mathematic model
was performed. The neutron source was specified in a parametric
form. The numerical analysis of solution stability with respect to data
distortion was done. The influence of the data errors on the
reconstructed parameters is shown:
• is reconstructed with errors less than 4% at all examined values
of δ (until 60%);
• is determined with errors less than 10% when δ do not overcome
5%;
• is reconstructed with relative error more than 10 %;
• integral intensity of the neutron source is determined with error
10% while δ error is less than 15%;
where -error of signal measurements, (R0,Z0), the plasma center
position,- /parameter of neutron source profile.
Abstract: Recent progress in calculation of the one-loop selfenergy
of the electron bound in the Coulomb field is summarized.
The relativistic multipole expansion is introduced. This expansion
is based on a single assumption: except for the part of the time
component of the electron four-momentum corresponding to the
electron rest mass, the exchange of four-momentum between the
virtual electron and photon can be treated perturbatively. For non Sstates
and normalized difference n3En −E1 of the S-states this
itself yields very accurate results after taking the method to the third
order. For the ground state the perturbation treatment of the electron
virtual states with very high three-momentum is to be avoided. For
these states one can always rearrange the pertinent expression in such
a way that free-particle approximation is allowed. Combination of
the relativistic multipole expansion and free-particle approximation
yields very accurate result after taking the method to the ninth order.
These results are in very good agreement with the previous results
obtained by the partial wave expansion and definitely exclude the
possibility that the uncertainity in determination of the proton radius
comes from the uncertainity in the calculation of the one-loop selfenergy.