Showing papers by "Jordan University of Science and Technology published in 1990"
TL;DR: An inclusion complex between famotidine and β-cyclodextrin was prepared by mixing the two components in a millimolar ratio in distilled water and heating under reflux for l h followed by stirring at room temperature for 5 days as mentioned in this paper.
87 citations
TL;DR: In this article, analytical solutions for fully developed natural convection in open-ended vertical concentric annuli are presented and four fundamental boundary conditions have been investigated and corresponding fundamental solutions are obtained.
55 citations
TL;DR: In this article, an experimental investigation into the nature of the noise generated when a stylus travels over a frictional surface has been carried out using several engineering materials, and the relation between the sound pressure level (SPL) and surface roughness under various contact loads was established.
Abstract: An experimental investigation into the nature of the noise generated when a stylus travels over a frictional surface has been carried out using several engineering materials. The relation between the sound pressure level (SPL) and surface roughness under various contact loads was established. An acoustic device was designed and constructed to be used as a reliable tool for measuring roughness. For each tested material, it has been found that the filtered noise signal within a certain spectrum bandwidth contains a specified frequency at which the amplitude is maximum. This frequency was named the dominating frequency and was found to be a material constant independent of surface roughness and contact load. It was also found that the dominating frequency for a given material is proportional to the sonic speed in that material.
42 citations
01 Jan 1990
TL;DR: 12 extracts were active in brine shrimp cytotoxicity bioassay with LC50 in the range of 74-748 μg/rnl, and the most active extract was Peganum harmala which was mutagenic against both TA98 and TA100, while Ceratonia siliqua showed the lowest activity against both tested strains.
Abstract: Ethanolic extracts of forty Jordanian medicinal plants were examined for cytotoxicity, mutagenicity and antimicrobial activity. Among the 40 tested plants, 12 extracts were active in brine shrimp cytotoxicity bioassay with LC50 in the range of 74-748 μg/rnl. These positive extracts were further tested for their antitumor activity on human cell cultures. Nerium oleander and Calotropis procera showed an activity in the antitumor human cell line test with ED50 varied in the range of 0.008 to 2.13 μg/ml. depending upon the cell line. Regarding the mutagenic effect, ten extracts were active on Salmonella typhimurium strains TA98 and TA100. The most active extract was Peganum harmala which was mutagenic against both TA98 and TA100, while Ceratonia siliqua showed the lowest activity against both tested strains. Four extracts showed antibacterial activity on both Escherichia coli and Bacillus subtilis and two showed antifungal activity agains Candida albicans.
34 citations
TL;DR: In this paper, the effect of the nature and size of the raw phosphate particles as well as acetic acid concentration, liquid/solid ratio (vol/wt basis) and reaction time have been studied.
31 citations
TL;DR: The mechanism of the hypocholesterolemic action of ginseng involves the suppression of cholesterol biosynthesis, which results in a lowering of the serum total cholesterol level and of serum low density lipoprotein cholesterol level.
Abstract: The effect of the ginseng root powder on avian hepatic cholesterol biosynthesis and serum lipoprotein cholesterol levels were examined Lohman strain broiler females were fed for 4 weeks a corn-based diet (control) or an experimental diet in which 025% Korean ginseng was incorporated (treatment) B-hydroxy-B-methylglutaryl-CoA) HMG-CoA reductase activity was significantly lower (P < 001) in the treatment group (47% of control activity) Ginseng treatment affected a lowering of the serum total cholesterol level (83% of control, (P < 005) and of serum low density lipoprotein cholesterol level (77% of control, P < 005) The mechanism of the hypocholesterolemic action of ginseng involves the suppression of cholesterol biosynthesis
31 citations
TL;DR: In this article, a new technique for determining surface roughness is introduced based on measuring the generated noise due to dry friction of a metallic blade which travels over the surface under consideration.
Abstract: A new technique for determining surface roughness is introduced. It is based upon measuring the generated noise due to dry friction of a metallic blade which travels over the surface under consideration. If the frictional force is made small enough to excite the blade, and not the entire system, then the noise will be proportional to surface roughness, and independent of the measured specimen size and material. A prototype acoustic device was designed and constructed and then used to substantiate the technique. Several specimens were machined by different machining processes to obtain a wide range of roughnesses. The specimen surface roughness was measured by a widely used commercial instrument (Talysurf 10), and the prototype transducer. A straight line correlation (on a logarithmic graph) between sound pressure levels (SPL), obtained from the transducer, and roughnesses, obtained from the Talysurf instrument, was found over the range from 0.025 to 100 μm. The coefficient of correlation between the measured values of SPL and roughness was as high/as 98 percent. Therefore, the technique could be adopted for measuring roughness and the prototype may thus be considered as a new roughness measuring device. The prototype device has the advantages of being sensitive, accurate and compact. It also has the capability of measuring the roughness of almost any type of surface regardless of its shape, material and complexity. Hence it is considered adequate for most engineering applications.
25 citations
TL;DR: A method based on combining electrical and mechanical scanning using a concentric-ring applicator and computer simulations demonstrate the possibility of the combined technique to produce useful heating patterns which cannot be produced by either technique separately.
Abstract: While two-dimensional phased arrays can be electronically focused and steered in three dimensions without physically moving the applicator, they generally require a relatively large number of small transducer elements and, consequently, complex drive electronics. A configuration that does not require a large number of elements is that of a concentric-ring array. The field conjugation method can be used to produce a focal spot (or multiple spots) along the array axis. The resulting focal regions are very small and need to be steered transversely to heat tumours of typical size. However, steering the focused beam away from the array axis results in annular heating patterns which are often associated with undesired secondary foci (hot spots). In this paper, a method based on combining electrical and mechanical scanning using a concentric-ring applicator is presented. Advantages of the new method over the mechanically scanned fixed-focus transducers, currently in use, are pointed out. Computer simulations are...
25 citations
TL;DR: It is shown that the survival of B. melitensis in the different dairy products was inversely proportional to the pH of the product.
Abstract: In this study we report the effect of the pH of various dairy products on the survival and growth of Brucella melitensis. The growth patterns of B. melitensis in broth media at different pHs (rangi...
23 citations
01 Jun 1990
TL;DR: Nineteen patients with bilateral ectopia lentis and no other ocular abnormalities in two Arab families demonstrate an autosomal recessive inheritance in contrast to the majority of reported family pedigrees with this condition which show dominant inheritance.
Abstract: Nineteen patients with bilateral ectopia lentis and no other ocular abnormalities in two Arab families are described. The two family pedigrees demonstrate an autosomal recessive inheritance in contrast to the majority of reported family pedigrees with this condition which show dominant inheritance. The early onset of the condition, its natural course and its consequences on visual function are described.
21 citations
TL;DR: It is shown that it is possible to manipulate the duration of these developmental stages and develop genotypes with high yield potential and early maturity, a highly desirable in drought-prone environments.
Abstract: A germplasm collection comprising 132 landrace genotypes of durum wheat (Triticum turgidum) ssp. turgidum L. conv. durum (Desf.) MK., from 10 districts in Jordan was evaluated for days to booting (DB), days to heading (DH), days to anthesis (DA), days to maturity (DM), filling period (FP) and grain yield (GY). In spite of the relatively strong genetic (Gr) and phenotypic (Pr) correlation coefficients between the developmental traits, the variation among genotypes was significant. GY was only positively and significantly correlated with DA and FP, while it was negatively correlated with DH. Genotypes with different combinations of early, medium and late developmental traits have been identified. Different combinations of DH and FP may or may not lead to differences in DM and GY. However, genotypes with long FP and medium-late DH gave the highest grain yield. Multiple linear regression of the duration of maturity (M) stage on the duration of booting (B), heading (H) and anthesis (A) stages (M = −260.87 + 2.09 B + 1.23 H + 0.9 A, R 2 = 0.92) indicates that it is possible to manipulate the duration of these developmental stages and develop genotypes with high yield potential and early maturity, a highly desirable in drought-prone environments.
TL;DR: The ash of the retort residue of the oil shale from central Jordan has been further tested to evaluate its pozzolanic activity as mentioned in this paper, showing that up to 20% of cement could be replaced by ash used as an admixture.
TL;DR: A procedure for the determination of methotrexate in human plasma is reported, which is selective, reproducible, and covers a wide range of metotrexate concentrations in patient's plasma.
Abstract: A procedure for the determination of methotrexate in human plasma is reported. The analysis involved extraction of methotrexate as an ion pair in ethyl acetate. Reconstituted residue was analyzed using reverse phase C-18 column and a mobile phase consisting of acetate buffer (87%), methanol (6.5%), and acetonitrile (6.5%). The methotrexate recovery range was 95-97%. Theophylline was used as internal standard with a recovery of 96%. The intraday coefficient of variation for the assay ranged from 1.8-3.0%, while interday variation coefficient range was 3.5-3.7%. The method is selective, reproducible, and covers a wide range of methotrexate concentrations in patient's plasma.
TL;DR: It is demonstrated that by combining the multiple focusing feature with a new field phasing concept, typical undesired hot spots can be eliminated.
Abstract: Computer simulations to demonstrate the possibility of heating small tumors by appropriately driving the electronic control circuitry of an n*n square-element ultrasonic phased array are conducted. The synthesis method consists of simultaneously focusing the ultrasonic beam at different points uniformly distributed along the tumor periphery and, hence, involves no scanning. It is demonstrated that by combining the multiple focusing feature with a new field phasing concept, typical undesired hot spots can be eliminated. The tissue thermal response to this heating modality is investigated by iteratively solving the three-dimensional steady-state bioheat equation. Temperature distributions associated with different directly synthesized power deposition patterns are simulated and discussed. >
TL;DR: In this article, a multiphase turbulence closure employing one transport equation, namely, the turbulence kinetic energy equation, is presented. But the proposed form of this equation is different from the earlier formulations in some aspects.
Abstract: We present a multiphase turbulence closure employing one transport equation, namely, the turbulence kinetic energy equation. The proposed form of this equation is different from the earlier formulations in some aspects. The power spectrum of the carrier fluid is divided into two regions, which interact in different ways and at different rates with the suspended particles as a function of the particle-eddy size ratio and density ratio
TL;DR: In this paper, the effects of particle size, extraction time, extraction temperature, mixing rate, solvent-to-oil-shale ratio, and type of solvent were investigated.
Abstract: Oil-shale deposits at El-lajjun, a rich oil-shale area south of Jordan, were extracted with organic solvents. The amount of extracted oil depends on the operating conditions and parameters which affect the process. The effects of particle size, extraction time, extraction temperature, mixing rate, solvent-to-oil-shale ratio, and type of solvent were investigated.
TL;DR: Small particles of highdensity lipoproteins (HDL) were isolated from fresh, fasting human plasma and from the ultracentrifugally isolated high density lipoprotein fraction by means of ultrafiltration through membranes of molecular weight cutoff of 70,000, found to contain cholesterol, phospholipids, and apolipoproteins A-I and A-II.
TL;DR: In this article, a model analysis approach is used to study the forced response of an actual flexible bladed-disk-shaft system, in which both in-plane and out-of-plane flexible deformations of the disk assembly are considered, in addition to its rigid-body translations and rotations, resulting from the bending of the supporting flexible shaft in two orthogonal planes.
TL;DR: There is a deficit in the beta-adrenoceptor-mediated renin release distal to cAMP formation in immature fetuses, which may be related to low renal content of renin at this stage of development.
Abstract: We studied the content and secretion of renin by renal cortical slices obtained from ovine fetuses at 0.62-0.77 gestation (n = 5 immature) and at 0.84-1.00 gestation (n = 5 mature). Renin content of fresh slices and renin secretion after the incubation of slices in Robinson's medium with or without isoproterenol or dibutyryl (DB) adenosine 3',5'-cyclic monophosphate (cAMP) (10(-4)-10(-8) M) were measured. Renin content of immature fetal kidneys (ng.ml homogenate-1.h-1.mg-1) and basal renin secretion rate [ng (ANG I/h).mg tissue-1.h incubation-1] were 24.3 +/- 3.0 and 1.4 +/- 0.4, respectively. Both of these values were significantly lower (P less than 0.02) than the corresponding results obtained with mature fetal kidneys (67.0 +/- 4.5 and 3.4 +/- 0.5). Renin content and basal secretion rates were strongly correlated (r = 0.78, P less than 0.01). The addition of isoproterenol or DBcAMP induced a significant increase in renin secretion only when incubated with slices from mature fetuses. We conclude that there is a deficit in the beta-adrenoceptor-mediated renin release distal to cAMP formation in immature fetuses, which may be related to low renal content of renin at this stage of development.
TL;DR: In this paper, the problem of transmission networks expansion has been solved by considering the cost of losses as well as the investment in the objective function using an exact quadratic programming technique.
Abstract: In this paper, the problem of transmission networks expansion has been solved by considering the cost of losses as well as the cost of investment in the objective function. The problem is solved using an exact quadratic programming technique. This new formulation has been applied to a 6- bus system. The final configurations, which are characterized by minimum cost of losses show that as the cost of the Kwh increases, the total system cost decreases.
TL;DR: A variable-step method is developed for the calculation of the two- and three-dimensional stability of compressible and incompressible two-dimensional boundary layers that is more efficient and requires less computer storage than both of these methods.
TL;DR: In this paper, a finite-difference scheme for solving the boundary layer equations governing laminar mixed convection heat transfer from a rotating sphere that is maintained at uniform surface heat flux and subjected to a uniform stream in the direction of its axis of rotation is presented.
Abstract: This paper presents a finite-difference scheme for solving the boundary layer equations governing laminar mixed (forced and free) convection heat transfer from a rotating sphere that is maintained at uniform surface heat flux and subjected to a uniform stream in the direction of its axis of rotation. Numerical results are presented to show the effect of a superimposed aiding or opposing free convection on the meridional and azimuthal velocities, wall shear stress components, separation angle, local Nusselt number, and wall temperature. As compared with power series studies available in the literature, the present scheme is capable of obtaining solutions for considerably larger values of the parameter Ta/Re2.
TL;DR: In this paper, a new technique to compensate for the offset voltage and to improve the S/N ratio of high-gain MOSFET pre-amplifiers is proposed.
Abstract: We explain a new technique to be used with high-gain MOSFET pre-amplifiers, to compensate for the offset voltage and to improve the S/N ratio. This technique is based on the carrier-heating phenomenon associated with short-channel MOSFETs. Study and analysis of this technique indicates that the geometry (channel length L and width Z) has to be optimized for the best offset compensation and noise reduction. It also shows that it is compatible with the MOSFET scaling-down trends. The paper presents a study and characterization of the offset voltage and drift of the MOSFET IC operational amplifiers, It comprises an investigation and modelling of the noise sources of short-channel MOSFETs. This study helps to evaluate and predict the a.c. response and the noise performance of the high-gain MOSFET pre-amplifiers in video-frequency regions.
TL;DR: In this paper, correlation equations for the Gibbs free energy of ammonia, water and ammonia-water solutions are used to develop equations suitable for use with computers to study the performance of intermittent solar refrigerators working on the constant-temperature-absorption cycle.
TL;DR: A new microcomputer-based stereogram generator was designed and implemented to generate various visual stimuli that are used for testing the binocular vision system and this system has applied to the measurement of eye movement and computer vision.
Abstract: A new microcomputer-based stereogram generator was designed and implemented to generate various visual stimuli that are used for testing the binocular vision system. The system is capable of generating static and dynamic stereoscopic stereograms that can be varied in size, shape, speed and disparity. It can also be used to generate a luminous stimulus on a dark background which, except for the depth parameters, can be varied in a similar way to the stereoscopic stimulus. A 16/32-bit microprocessor has been employed for the overall control of the stereogram parameters, which provides flexibility, versatility, compactness and speed at reduced cost. We have applied this system to the measurement of eye movement and computer vision.
TL;DR: The methods described in this paper are based on the uricase catalyzed oxidation of uric acid to allantoine and hydrogen peroxide and can be rapidly and readily performed on patient serum samples without deproteinization.
Abstract: The methods described in this paper are based on the uricase catalyzed oxidation of uric acid to allantoine and hydrogen peroxide. By making use of the catalytic activity of peroxidase the generated H2O2 is measured either spectrophotometrically with 3-methyl-benzothiazoline-2-one hydrazone (MBTH) and 3-dimethylaminobenzoic acid (DMAB) (M1) or fluorimetrically with tyramine (M2) or L-tyrosine (M3). The methods are simple, sensitive and selective. The procedures developed can be rapidly and readily performed on patient serum samples without deproteinization using 100 microliters and 5 microliters for colorimetric and fluorimetric assay, respectively.
Patent•
28 Nov 1990TL;DR: The acetabular cup has, on the outer face, protuberances for supporting an open-work structure matching the profile of the face by being fixed on the latter by means of members capable of bearing in the cotyloid cavity, forming a space for the said structure in such a way as to embed it in the thickness of the cement as discussed by the authors.
Abstract: The acetabular cup has, on the outer face, protuberances (1e) for supporting an open-work structure matching the profile of the said face by being fixed on the latter by means of members (4) capable of bearing in the cotyloid cavity, forming a space for the said structure (3) in such a way as to embed it in the thickness of the cement.
TL;DR: In this paper, Riemann's solution of the Cauchy problem for the linear wave equation is used to find a closed-form solution for the problem of transient nonsinusoidal waves is lossy media.
Abstract: B. Riemann's (1953) solution of the Cauchy problem for the linear wave equation is used to find a closed-form solution for the problem of transient nonsinusoidal waves is lossy media. A method for finding the required Riemann-Green function is discussed. The evolution of a wavefront propagating in a semi-infinite lossy medium is studied, and a series solution for the corresponding electric field is obtained. >
TL;DR: In this paper, the authors present the results for an experimental investigation of the flow pattern around a rotating cylinder placed in a crossflow air stream, and the velocity profiles upstream and downstream of the cylinder, skin friction coefficient, stagnation, and separation points are obtained for different rotation speed ratios (α = Ω R / V ∞ ) varying from 0.0 to 1.25.
TL;DR: A new salt of ibuprofen was prepared by reaction with t-butylamine; its formation was confirmed by IR and 1H-NMR spectroscopy and the salt was characterized by thermoanalytical, X-ray powder diffraction and solubility studies.