Determinants o f Disruptive Innovation That Influences F inancial S ervice Performance

Khalifa Khalfan Muftah Al Mansoori(Khalifa Khalfan Muftah Al Mansoori ),Mohammed Hariri Bakri(Mohammed Hariri Bakri ) People&Global Business Association 2023 Global Business and Finance Review Vol.28 No.2

Behavior of Steel-framed Buildings in a Fire

Khalifa S. Al-Jabri 한국강구조학회 2007 International Journal of Steel Structures Vol.7 No.3

The rules presented in the current codes of practice for the design of steel-framed buildings in fire conditions are based ontingconditions were obviously diferent from the real situation wherein the structure is subjected to natural fires. It has been knownfor many years, from observations of acidental fires, that structural members behave beter in fire when they constitute partof a structural arrangement than when they are tested in isolation. These observations have been confirmed by results fromform part of the structure can withstand much higher temperatures than those tested singly. This has raised doubts concerningthe conservative design aproaches provided by current fire enginering design codes. The atack on the twin towers of theWorld Trade Centre in New York on 11 September 201 has prompted close examination of the way in which buildings canfail in fires and has brought into the public eye the hazards that fires can pose to major building structures. This paper examinesmay allow for the construction of safer buildings in the future.

The harmonic analysis associated to the Heckman-Opdam's theory and its application to a root system of type $BC_d$

Khalifa Trimeche 강원경기수학회 2019 한국수학논문집 Vol.27 No.1

In the five first sections of this paper we define and study the hypergeometric transmutation operators $V^W_k$ and ${}^tV^W_k$ called also the trigonometric Dunkl intertwining operator and its dual corresponding to the Heckman-Opdam's theory on $\mathbb{R}^d$. By using these operators we define the hypergeometric translation operator $\mathcal{T}^W_x, x \in \mathbb{R}^d$, and its dual ${}^t\mathcal{T}^W_x, x \in \mathbb{R}^d$, we express them in terms of the hypergeometric Fourier transform $\mathcal{H}^W$, we give their properties and we deduce simple proofs of the Plancherel formula and the Plancherel theorem for the transform $\mathcal{H}^W$. We study also the hypergeometric convolution product on $W$-invariant $L^p_{\mathcal{A}_k}$-spaces, and we obtain some interesting results. In the sixth section we consider a some root system of type $BC_d$ (see [17]) of whom the corresponding hypergeometric translation operator is a positive integral operator. By using this positivity we improve the results of the previous sections and we prove others more general results.

Bezoin in Heterocyle Synthesis: Synthesis and Reactions of 2, 3-Diphenyl-4-cyanopyrrole-5-thione

Khalifa, Fathy A.,Zohdi, Hussein F.,Ibrahim, M.K.A.,Ismail, N.A. The Pharmaceutical Society of Korea 1990 Archives of Pharmacal Research Vol.13 No.4

2, 3-diphenyl-4-cyano-pyrrole-5-thione (4) was either by the reaction of benzoin (1) and cyanothioacetamide (3) followed by cyclization using AcOH/sodium acetate or by refluxing a mixture of benzoin (1) and cyanothioacethamide in pyridine to afford directly 4. Several new pyrrole and pyrazole derivatives were synthesised using 4 as synthon. The structure of the newly synthesised derivatives were based on celemental and spectral data studies. Methylation of the SH group in 4 afforded 5. Reaction of 4 with ethyl bromo acetate afforded (6). Treatment of (5) and (6) with hydrazine hydrate afforded the same pyrazole derivative (10) through the intermediate (9). Treatment of 6 with aniline and phenylhydrazine afforded the pyrrole derivatives 8a, b respectively. Treatment of 6 while dill HCI gave 2, 3-diphenyl-4-cyano-pyrrole-5-one (7). Treatment of 6 with $NH_3$/EtOH afforded the amidic derivatives (11) with treatment of 6 $NH_3$/ heat then acidification it gave the carboxylic derivatives (12).

Predicting the Behaviour of Semi-rigid Joints in Fire Using an Artificial Neural Network

Khalifa S. Al-Jabri,Saleh M. Al-Alawi 한국강구조학회 2007 International Journal of Steel Structures Vol.7 No.3

In this paper, we describe an artificial neural networking (ANN) model developed to predict the moment-rotation responseof semi-rigid beam-to-column joints at elevated temperature. Five types of beam-to-column joints, which represent typicaljoints used in construction, were modelled. Three flush end-plate bare-steel joints, one flexible end-plate bare-stel joint andtwo flexible end-plate composite joints were considered. The aplied moment and joint’s temperatures were used as inputeused for training and testing and validating the neural network models. The model’s predicted values were compared with actualtest results. The results indicate that the models can predict the momentrotationtemperature behaviour of semi-rigid beam-to-column joints with very high accuracy. The developed model can be modified easily to investigate other parameters thatinfluence the performance of joints in fire.

Earth Albedo perturbations on Low Earth Orbit Cubesats

Khalifa, N.S.,Sharaf-Eldin, T.E. The Korean Society for Aeronautical and Space Scie 2013 International Journal of Aeronautical and Space Sc Vol.14 No.2

This work investigates the orbital perturbations of the cubesats that lie on LEO due to Earth albedo. The motivation for this paper originated in the investigation of the orbital perturbations for closed- Earth pico-satellites due to the sunlight reflected by the Earth (the albedo). Having assumed that the Sun lies on the equator, the albedo irradiance is calculated using a numerical model in which irradiance depends on the geographical latitude, longitude and altitude of the satellite. However, in the present work the longitude dependency is disregarded. Albedo force and acceleration components are formulated using a detailed model in a geocentric equatorial system in which the Earth is an oblate spheroid. Lagrange planetary equations in its Gaussian form are used to analyze the orbital changes when $e{\neq}0$ and $i{\neq}0$. Based on the Earth's reflectivity data measured by NASA Total Ozone Mapping Spectrometer (TOMS project), the orbital perturbations are calculated for some cubesats. The outcome of the numerical test shows that the albedo force has a significant contribution on the orbital perturbations of the pico-satellite which can affect the satellite life time.

An Advanced ANN Model for Predicting the Rotational Behaviour of Semi-rigid Composite Joints in Fire Using the Back-Propagation Paradigm

Khalifa S. Al-Jabri,M. Al-Alawi2 한국강구조학회 2010 International Journal of Steel Structures Vol.10 No.4

This paper describes an artificial neural networking (ANN) model developed to predict the behaviour of semi-rigid composite joints at elevated temperature. Three different semi-rigid composite joints were selected, two flexible end-plates and one flush end-plate. Seventeen different parameters were selected as input parameters representing the geometrical and mechanical properties of the joints as well as the joint’s temperature and the applied loading, and used to model the rotational capacity of the joints with increasing temperatures. Data from experimental fire tests were used for training and testing the ANN model. Results from nine experimental fire tests were evaluated with a total of 280 experimental cases. The results showed that the R2 value for the training and testing sets were 0.998 and 0.97, respectively. This indicates that results from the ANN model compared well with the experimental results demonstrating the capability of the ANN simulation techniques in predicting the behaviour of semi-rigid composite joints in fire. The described model can be modified to study other important parameters that can have considerable effect on the behaviour of joints at elevated temperatures such as temperature gradient, axial restraints,etc.

Synthesis of New Imidazolyl Acetic Acid Derivatives with Anti- inflammatory and Analgesic Activities

Khalifa, Maha M.,Abdelbaky, Nayira A. 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.4

We synthesized 2-(4-(4-fluorobenzylidene)-2-(4-fluorophenyl) 5-oxo-4,5-dihydroimidazol-1-yl) acetic acid 3. Chlorination afforded the chloro derivative 4, which reacted with different amines and hydrazine to afford compounds 5-8. Pyrazole, pyrazolone, and thiazolidinone derivatives were also synthesized from Imidazol-1-ylacetic acid hydrazide 8 to give compounds 9-12. Compounds were then evaluated for their anti-inflammatory activity against carrageenaninduced rat paw edema and their analgesic activity using the writhing test in albino mice. Compounds 5, 9, 10, 12 exhibited maximum anti-inflammatory activity, and all the compounds inhibited writhing, with10 and 12 being two times more effective than the reference standard.

Microdetermination of Vitamin A (retinol) with N-Bromosuccinimide

Khalifa, Fathy A.,Turk, Zeinab M. The Pharmaceutical Society of Korea 1990 Archives of Pharmacal Research Vol.13 No.4

A novel method for the microdetermination of vitamin A in its pure state and pharmaceutical preparation using NBS is reported. The new method is easy, simple and accurate.

Ground Base Laser Torque Applied on LEO Satellites of Various Geometries

Khalifa, N.S. The Korean Society for Aeronautical and Space Scie 2012 International Journal of Aeronautical and Space Sc Vol.13 No.4

This paper is devoted to investigate the feasibility of using a medium power ground-based laser to produce a torque on LEO satellites of various shapes. The laser intensity delivered to a satellite is calculated using a simple model of laser propagation in which a standard atmospheric condition and linear atmospheric interaction mechanism is assumed. The laser force is formulated using a geocentric equatorial system in which the Earth is an oblate spheroid. The torque is formulated for a cylindrical satellite, spherical satellites and for satellites of complex shape. The torque algorithm is implemented for some sun synchronous low Earth orbit cubesats. Based on satellites perigee height, the results demonstrate that laser torque affecting on a cubesat has a maximum value in the order of $10^{-9}$ which is comparable with that of solar radiation. However, it has a minimum value in the order of $10^{-10}$ which is comparable with that of gravity gradient. Moreover, the results clarify the dependency of the laser torque on the orbital eccentricity. As the orbit becomes more circular it will experience less torque. So, we can conclude that the ground based laser torque has a significant contribution on the low Earth orbit cubesats. It can be adjusted to obtain the required control torque and it can be used as an active attitude control system for cubesats.