559 research outputs found
THE EFFECTS OF TEMPERATURE DEPENDENT VISCOSITY AND VISCOUS DISSIPATION ON MHD CONVECTION FLOW FROM AN ISOTHERMAL HORIZONTAL CIRCULAR CYLINDER IN THE PRESENCE OF STRESS WORK AND HEAT GENERATION
Temperature dependent viscosity and Viscous Dissipation effects are considered on hydromagnetic natural convection flow from horizontal circular cylinder immersed in an electrically conducting fluid with viscosity proportional to a linear function of temperature in the presence of stress work and heat generation. The partial differential governing equations are transformed to dimensionless forms. The numerical computations are carried out for several values of physical parameters involved in the transformed equations. The resulting nonlinear system of partial differential equations is solved numerically by Keller box method which is an implicit finite difference technique with Newton's linearization method. The features of the flow and heat transfer characteristics for different values of the governing parameters are analyzed and discussed. To support the accuracy of the numerical results, a comparison is made with known results from the open literature for some particular cases of the present study and the results are found to be in good agreement
Telleparallel Lagrange Geometry and a Unified Field Theory: Linearization of the Field Equations
The present paper is a natural continuation of our previous paper:
"Teleparallel Lagrange geometry and a unified field theory, Class. Quantum
Grav., 27 (2010), 045005 (29pp)" \cite{WNA}. In this paper, we apply a
linearization scheme on the field equations obtained in \cite{WNA}. Three
important results under the linearization assumption are accomplished. First,
the vertical fundamental geometric objects of the EAP-space loose their
dependence on the positional argument . Secondly, our linearized theory in
the Cartan-type case coincides with the GFT in the first order of
approximation. Finally, an approximate solution of the vertical field equations
is obtained.Comment: 18 pages, LaTeX fil
On Finslerized Absolute Parallelism spaces
The aim of the present paper is to construct and investigate a Finsler
structure within the framework of a Generalized Absolute Parallelism space
(GAP-space). The Finsler structure is obtained from the vector fields forming
the parallelization of the GAP-space. The resulting space, which we refer to as
a Finslerized Parallelizable space, combines within its geometric structure the
simplicity of GAP-geometry and the richness of Finsler geometry, hence is
potentially more suitable for applications and especially for describing
physical phenomena. A study of the geometry of the two structures and their
interrelation is carried out. Five connections are introduced and their torsion
and curvature tensors derived. Some special Finslerized Parallelizable spaces
are singled out. One of the main reasons to introduce this new space is that
both Absolute Parallelism and Finsler geometries have proved effective in the
formulation of physical theories, so it is worthy to try to build a more
general geometric structure that would share the benefits of both geometries.Comment: Some references added and others removed, PACS2010, Typos corrected,
Amendemrnts and revisions performe
Hardware Implementation of the Multirate Decimation Filter for Noise Thermometer based on FPGA
Extended Absolute Parallelism Geometry
In this paper, we study Absolute Parallelism (AP-) geometry on the tangent
bundle of a manifold . Accordingly, all geometric objects defined in
this geometry are not only functions of the positional argument , but also
depend on the directional argument . Moreover, many new geometric objects,
which have no counterpart in the classical AP-geometry, emerge in this
different framework. We refer to such a geometry as an Extended Absolute
Parallelism (EAP-) geometry. The building blocks of the EAP-geometry are a
nonlinear connection assumed given a priori and linearly independent
vector fields (of special form) defined globally on defining the
parallelization. Four different -connections are used to explore the
properties of this geometry. Simple and compact formulae for the curvature
tensors and the W-tensors of the four defined -connections are obtained,
expressed in terms of the torsion and the contortion tensors of the EAP-space.
Further conditions are imposed on the canonical -connection assuming that it
is of Cartan type (resp. Berwald type). Important consequences of these
assumptions are investigated. Finally, a special form of the canonical
-connection is studied under which the classical AP-geometry is recovered
naturally from the EAP-geometry. Physical aspects of some of the geometric
objects investigated are pointed out and possible physical implications of the
EAP-space are discussed, including an outline of a generalized field theory on
the tangent bundle of Comment: 27 pages, LaTeX-file, The last version of this paper was replaced by
mistake (by arXiv: 0905.0209[gr-qc]
Synthesis, computational study and biological evaluation of 9-acridinyl and 1-coumarinyl-1,2,3-triazole-4-yl derivatives as topoisomerase II inhibitors
Topoisomerase (IIB) inhibitors have been involved in the therapies of tumour progression and have become a major focus for the development of anticancer agents. New three-component hybridised ligands, 1,4-disubstituted-1,2,3-triazoles (8–17), were synthesised via a 1,3-dipolar cycloaddition reaction of 9-azidoacridine/3-azidocoumarin with N/O-propargyl small molecules under click reaction conditions. Cancer cell growth inhibition of the synthesised triazoles was tested against human cell-lines in the NCI-60-cell-panel, and the most active compounds tested against topoisomerase (IIB)-enzymes. The acridinyl ligands (8–10) revealed 60–97% cell growth inhibition in six cancer cell-panels. Cell-cycle analysis of MCF7 and DU-145 cells treated with the active acridinyl ligands exhibited cell-cycle arrest at G2/M phase and proapoptotic activity. In addition, compound 8 displayed greater inhibitory activity against topoisomerase (IIB) (IC50 0.52 µM) compared with doxorubicin (IC50 0.83 µM). Molecular dynamics simulation studies showed the acridine–triazole–pyrimidine hybrid pharmacophore was optimal with respect to protein–ligand interaction and fit within the binding site, with optimal orientation to allow for intercalation with the DNA bases (DG13, DC14, and DT9)
Reduction of Radar Cross Section by Adopting Symmetrical Coding Metamaterial Design for Terahertz Frequency Applications
This work focused on the novel and compact 1-bit symmetrical coding-based metamaterial for radar cross section reduction in terahertz frequencies. A couple of coding particles were constructed to impersonate the elements '0' and '1', which have phase differences of 180. All the analytical simulations were performed by adopting Computer Simulation Technology Microwave Studio 2019 software. Moreover, the transmission coefficient of the element '1' was examined as well by adopting similar software and validated by a high-frequency structure simulator. Meanwhile, the frequency range from 0 to 3 THz was set in this work. The phase response properties of each element were examined before constructing various coding metamaterial designs in smaller and bigger lattices. The proposed unit cells exhibit phase responses at 0.84 THz and 1.54 THz, respectively. Meanwhile, the analysis of various coding sequences was carried out and they manifest interesting monostatic and bistatic radar cross section (RCS) reduction performances. The Coding Sequence 2 manifests the best bistatic RCS reduction values in smaller lattices, which reduced from −69.8 dBm2 to −65.5 dBm2 at 1.54 THz. On the other hand, the monostatic RCS values for all lattices have an inclined line until they reach a frequency of 1.0 THz from more than −60 dBm2. However, from the 1.0 THz to 3.0 THz frequency range the RCS values have moderate discrepancies among the horizontal line for each lattice. Furthermore, two parametric studies were performed to examine the RCS reduction behaviour, for instance, multi-layer structures and as well tilt positioning of the proposed coding metamaterial. Overall it indicates that the integration of coding-based metamaterial successfully reduced the RCS values
Teleparallel Lagrange Geometry and a Unified Field Theory
In this paper, we construct a field theory unifying gravity and
electromagnetism in the context of Extended Absolute Parallelism (EAP-)
geometry. This geometry combines, within its structure, the geometric richness
of the tangent bundle and the mathematical simplicity of Absolute Parallelism
(AP-) geometry. The constructed field theory is a generalization of the
Generalized Field Theory (GFT) formulated by Mikhail and Wanas. The theory
obtained is purely geometric. The horizontal (resp. vertical) field equations
are derived by applying the Euler-Lagrange equations to an appropriate
horizontal (resp. vertical) scalar Lagrangian. The symmetric part of the
resulting horizontal (resp. vertical) field equations gives rise to a
generalized form of Einstein's field equations in which the horizontal (resp.
vertical) energy-momentum tensor is purely geometric. The skew-symmetric part
of the resulting horizontal (resp. vertical) field equations gives rise to a
generalized form of Maxwell equations in which the electromagnetic field is
purely geometric. Some interesting special cases, which reveal the role of the
nonlinear connection in the obtained field equations, are examined. Finally,
the condition under which our constructed field equations reduce to the GFT is
explicitly established.Comment: Latex file, 33 page
New Method to Implement and Analysis of Medical System in Real Time
The use of information technology and technological medical devices has contributed significantly to the transformation of healthcare. Despite that, many problems have arisen in diagnosing or predicting diseases, either as a result of human errors or lack of accuracy of measurements. Therefore, this paper aims to provide an integrated health monitoring system to measure vital parameters and diagnose or predict disease. Through this work, the percentage of various gases in the blood through breathing is determined, vital parameters are measured and their effect on feelings is analyzed. A supervised learning model is configured to predict and diagnose based on biometric measurements. All results were compared with the results of the Omron device as a reference device. The results proved that the proposed design overcame many problems as it contributed to expanding the database of vital parameters and providing analysis on the effect of emotions on vital indicators. The accuracy of the measurements also reached 98.8% and the accuracy of diagnosing COVID-19 was 64%. The work also presents a user interface model for clinicians as well as for smartphones using the Internet of things
Prediction of Gut Wall Integrity Loss in Viral Gastroenteritis by Non-Invasive Marker
BACKGROUND: Intestinal fatty acid binding proteins (I-FABPs) are mainly expressed in the intestinal villi, which are the initial site of destruction in viral gastroenteritis.AIM: This study was designed to assess serum I-FABPs as a predictor of gut wall integrity loss in viral gastroenteritis.PATIENTS AND METHODS: This case-control cross-sectional study was conducted on 93 cases of acute viral gastroenteritis. Twenty-eight healthy children matching in age were recruited as control group. Serum I-FABPs were measured using ELISA technique. Viral detection and typing were done by PCR for adenovirus, and by Reverse transcriptase PCR for rotavirus, astrovirus and norovirus.RESULTS: Serum I-FABPs level was significantly higher in the cases compared to the controls and was also higher in the 46 rotavirus gastroenteritis cases compared to other viral gastroenteritis cases. Serum I- FABPs level was significantly higher in severely dehydrated cases as compared to mildly dehydrated ones (P=0.037).CONCLUSION: Serum I-FABPs could be used as an early and sensitive predictor marker of gut wall integrity loss in children with viral gastroenteritis and its level can indicate case severity
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