Showing papers by "Jordan University of Science and Technology published in 1997"
TL;DR: A robust variable step-size LMS-type algorithm providing fast convergence at early stages of adaptation while ensuring small final misadjustment is presented, providing performance equivalent to that of the regular LMS algorithm.
Abstract: A number of time-varying step-size algorithms have been proposed to enhance the performance of the conventional LMS algorithm. Experimentation with these algorithms indicates that their performance is highly sensitive to the noise disturbance. This paper presents a robust variable step-size LMS-type algorithm providing fast convergence at early stages of adaptation while ensuring small final misadjustment. The performance of the algorithm is not affected by existing uncorrelated noise disturbances. An approximate analysis of convergence and steady-state performance for zero-mean stationary Gaussian inputs and for nonstationary optimal weight vector is provided. Simulation results comparing the proposed algorithm to current variable step-size algorithms clearly indicate its superior performance for cases of stationary environments. For nonstationary environments, our algorithm performs as well as other variable step-size algorithms in providing performance equivalent to that of the regular LMS algorithm.
702 citations
TL;DR: CR006 benefitted from AM infection more than the CR057 under dry soil conditions, despite the fact that CR057 roots were highly infected, and it appears that CR006 is more dependent on AM symbiosis than CR057.
Abstract: The effects of an arbuscular mycorrhizal (AM) fungus and drought stress on the growth, phosphorus, and micronutrient uptake of two wheat genotypes exhibiting differences in drought resistance were investigated. Plants were grown on a low P (4 mg kg–1 soil) silty clay (Typic Xerochrept) soil-sand mix. Mycorrhizal infection was higher under well-watered than under dry soil conditions and the drought-resistant genotype CR057 had a higher mycorrhizal colonization than the drought-sensitive genotype CR006. Total and root dry matter yields and total root length were higher in mycorrhizal than in nonmycorrhizal plants of both genotypes. CR057 had higher total dry matter but not root dry matter than CR006 plants. The enhancement in total dry matter due to AM inoculation was 42 and 39% under well-watered and 35 and 45% under water-stressed for CR057 and and CR006, respectively. For both genotypes, the contents of P, Zn, Cu, Mn, and Fe were higher in mycorrhizal than in nonmycorrhizal plants and higher under well-watered than under dry soil conditions. The enhancement of P, Zn, Cu, Mn, and Fe uptake due to AM inoculation was more pronounced in CR006 than in CR057, particularly under water-stressed conditions. Thus CR006 benefitted from AM infection more than the CR057 under dry soil conditions, despite the fact that CR057 roots were highly infected. It appears that CR006 is more dependent on AM symbiosis than CR057.
178 citations
TL;DR: In this article, simple ball-and roller-burnishing tools were used for the experimental work of the present study, these tools being quite similar in their design principles, and the performance of the tools, together with the effects of the burnishing force and the number of burnishing tool passes on the surface roughness and surface hardness of commercially available aluminum and brass, were studied.
158 citations
TL;DR: The advantage of localising and separating ECG signals from high as well as intermediate frequencies is demonstrated and the classification algorithm is developed to classify ECG records on the basis of the computation of three parameters defined in the time-frequency plane of the wavelet transform.
Abstract: Time-frequency wavelet theory is used for the detection of life threatening electrocardiography (ECG) arrhythmias. This is achieved through the use of the raised cosine wavelet transform (RCWT). The RCWT is found to be useful in differentiating between ventricular fibrillation, ventricular tachycardia and atrial fibrillation. Ventricular fibrillation is characterised by continuous bands in the range of 2–10 Hz; ventricular tachycardia is characterised by two distinct bands: the first band in the range of 2–5 Hz and the second in the range of 6–8 Hz; and atrial fibrillation is determined by a low frequency band in the range of 0–5 Hz. A classification algorithm is developed to classify ECG records on the basis of the computation of three parameters defined in the time-frequency plane of the wavelet transform. Furthermore, the advantage of localising and separating ECG signals from high as well as intermediate frequencies is demonstrated. The above capabilities of the wavelet technique are supported by results obtained from ECG signals obtained from normal and abnormal subjects.
142 citations
TL;DR: An analytical treatment of the mean-square error (MSE) performance for the leaky LMS adaptive algorithm for Gaussian input data and exact expressions that completely characterize the second moment of the coefficient vector and algorithm steady-state excess MSE are developed.
Abstract: Despite the widespread usage of the leaky LMS algorithm, there has been no detailed study of its performance. This paper presents an analytical treatment of the mean-square error (MSE) performance for the leaky LMS adaptive algorithm for Gaussian input data. The common independence assumption regarding W(n) and X(n) is also used. Exact expressions that completely characterize the second moment of the coefficient vector and algorithm steady-state excess MSE are developed. Rigorous conditions for MSE convergence are also established. Analytical results are compared with simulation and are shown to agree well.
122 citations
TL;DR: The ingestion of trivalent and hexavalent chromium compounds by adult male and female mice would cause adverse effects on fertility and reproduction.
113 citations
TL;DR: Results of this study indicate that iron therapy is effective in the treatment of BHS and that iron-deficient children seem to be more likely to benefit from such therapy.
112 citations
TL;DR: A system of disaggregate models that accounts for the effect of intersection, driver, and traffic characteristics on gap acceptance for left-turn maneuvers at urban T-intersections controlled by stop signs on the minor roads shows that the distribution of critical gaps is influenced by driver socioeconomic characteristics, expected waiting time, time of day, and trip purpose.
Abstract: This paper develops a system of disaggregate models that accounts for the effect of intersection, driver, and traffic characteristics on gap acceptance for left-turn maneuvers at urban T-intersections controlled by stop signs on the minor roads. The waiting time for each driver is first modeled using the hazard function. The binary probit model is then used to find the drivers' probabilities of accepting or rejecting a gap. These probabilities are used to calculate the critical gaps of individual drivers. The expected waiting time is included in the model as an explanatory variable. A multiple regression model is used for predicting the intersection mean critical gap. To estimate the parameters of the models, disaggregate data were collected by observing and interviewing drivers at 15 urban T-intersections in the Greater Amman area. The results show that the distribution of critical gaps is influenced by driver socioeconomic characteristics, expected waiting time, time of day, and trip purpose. The mean c...
109 citations
TL;DR: A significant proportion of mesially impacted mandibular M3 had changed their angulation and became fully erupted by the time the individual reached 24 years of age, indicating Positional changes and eruption of impacted M3 are unpredictable phenomena.
Abstract: Objective. To measure changes in angular position and eruption status of mesially impacted mandibular third molars (M3) during 4-year follow-up period. Study design. Standardized panoramic radiographs were taken at the start of the study (the average age of the subjects was 19.7 years) and 4 years later. Angulation and degree of impaction of M3 were determined by their sagittal relationships to the adjacent second molars. The impacted M3 were either partially erupted or unerupted. Results. Initial examination showed that among a total of 59 mesioangular M3, 49 (83%) had inclination between 5 and 30 degrees. The proportion of M3 that became upright (zero tilt) was 76% ( 13 17 ) with initial angulations of 5 to 10 degrees, 61% ( 11 18 ) with initial angulations of 15 to 20 degrees, and 14% ( 2 14 ) with initial angulations of 25 to 30 degrees. None of the M3 originally presented at 35 degrees or more became upright, but an average decrease of 12 degrees in angulation was registered. In total, 26 M3 of 59 (44%) became upright during the follow-up period. Initial examination of levels of eruption showed that among 59 M3, 13 (22%) were partially erupted and the rest were unerupted. Of the 46 M3 initially unerupted, 17 (37%) became fully erupted and 7(15%) erupted partially during the 4-year follow-up. Of the total sample, 25 (42%) had erupted to full occlusion during the observation period. Conclusion. A significant proportion of mesially impacted mandibular M3 had changed their angulation and became fully erupted by the time the individual reached 24 years of age. Positional changes and eruption of impacted M3 are unpredictable phenomena.
103 citations
TL;DR: In this article, the effect of water film cooling of the glass cover on the efficiency of a single-basin still has been investigated numerically and the results showed that the presence of the cooling film neutralizes the effects of wind speed on still efficiency.
89 citations
TL;DR: The clinical, haematological and pathological findings indicate that the animals suffered from haemolytic anaemia which responded to imidocarb therapy.
TL;DR: In this article, the effects of plant phosphorus (P) level on detrimental effects of sodium chloride (NaCl) on barley dry matter (DM) were investigated in a controlled setting.
Abstract: Increasing plant phosphorus (P) supply can increase or decrease salt tolerance of many plants. Barley (Hordeum vulgare L., cv. ACSAD 176) was grown in nutrient solution under controlled conditions to determine effects of P level on detrimental effects of sodium chloride (NaCl). Increasing level of P improved tolerance of barley to NaCl. At 3, 30, and 60 μM P, the NaCl concentrations to reduce shoot dry matter (DM) by 50% were 158, 193, and 260 mM, respectively. Increased NaCl levels reduced shoot P concentrations. Plants grown with NaCl had higher Internal P requirements. When NaCl in solution was 10, 150, and 300 mM, the corresponding concentrations of P in shoots required to obtain 50% DM were 1.6, 4.2, and 4.7 mg‐g‐1 dry weight, respectively. Increasing solution P level from 3 to 60 μM P decreased sodium (Na) and increased potassium (K) concentrations in shoots. Accumulation of mineral ions for osmotic adjustment and restriction of Na accumulation in shoots was involved in P enhancement of sal...
TL;DR: This is the first study to demonstrate the presence of LH/hCG receptors and neurotrophic effects of hCG in fetal rat brain neurons, implying that locally produced gonadotropins may possibly play a role in the growth and development of the fetal brain.
Abstract: Adult and neonatal rat brains contain functional LH/hCG receptors. These findings have led us to hypothesize that the fetal rat brain may also contain these receptors. To test this hypothesis, we isolated neurons from 19-day-old fetal rat brains and cultured them in chemically defined serum-free medium. The reverse transcription polymerase chain reaction amplified an expected 256-base pair size LH/hCG receptor fragment that could hybridize with a full-length LH/hCG receptor cDNA in Southern blotting. Northern blotting demonstrated that neurons contained a major 2.6 kilobase (kb) and a minor 4.3 kb transcript. Immunocytochemistry demonstrated that the neurons contained LH/hCG receptor immunostaining. Western immunoblotting showed that neurons contained an 80-kDa receptor protein that increased to a maximal level on Day 3 of culture and then gradually decreased until the 9th day of culture. Culturing neurons for 3 days in the presence of highly purified hCG resulted in a dose-dependent increase in the outgrowth of neurite processes and total cellular protein and a decrease in DNA fragmentation as compared to values in the corresponding controls. At the maximally effective hCG concentration, the number of neurite-bearing cells was increased by 53% and the total cellular protein by 60%, and DNA fragmentation decreased by 31%. In summary, this is the first study to demonstrate the presence of LH/hCG receptors and neurotrophic effects of hCG in fetal rat brain neurons. These findings imply that locally produced gonadotropins may possibly play a role in the growth and development of the fetal brain.
TL;DR: In this paper, a perturbation technique is used to simplify the generalized governing equations of the parabolic two-step model, where diffusion terms in both electron and lattice energy equations are simplified.
Abstract: A perturbation technique is used to simplify the generalized governing equations of the parabolic two-step model The generalized form of the two-step model contains diffusion terms in both electron and lattice energy equations and assumes that incident laser radiation is absorbed by both electron gas and solid lattice to account for the thermal behavior of semiconducting and impure materials The simplified perturbation technique is used to eliminate the coupling between the electron and the lattice energy equations when the temperature difference between the electron and the lattice is a small perturbed quantity, which is true in materials exhibiting high coupling factors A mathematical criterion is derived to determine the conditions under which electron and lattice are in thermal equilibrium It is found that five dimensionless parameters control the state of thermal equilibrium between the lattice and the electron
TL;DR: Piroxicam, a nonpolar drug exhibited the highest permeability of the compounds studied, indicating consistent permeability estimation within subjects, and can be used to establish a consistent data base of human permeabilities for estimation of human drug absorption and for establishing the biopharmaceutic permeability class of drugs.
Abstract: Purpose. To determine the human jejunal permeabilities of compounds utilizing different transport mechanisms using a regional perfusion approach and to establish a standard procedure for determining drug permeability class to be used for the establishment of drug product bioequivalence standards.
TL;DR: In this article, the effects of different burnishing parameters (force, speed and feed) on surface roughness and hardness of cast Al-Cu alloys were studied with a simply designed ball burnishing tool.
Abstract: Burnishing is considered as a surface finishing process. In this process the metallic surface of the workpiece undergoes plastic deformation by the pressing action of a hard and highly polished rotating burnishing ball or roller. In the present work an attempt was made to study the effects of different burnishing parameters (force, speed and feed) on surface roughness and hardness of cast AlCu alloys. The experiments were conducted with a simply designed ball burnishing tool. The results obtained show that an improvement in surface characteristics can be achieved by the application of this process on cast AlCu workpieces.
TL;DR: In this article, a simulation program was written to describe the performance of solar desalination with a humidification-dehumidification process, which is an efficient method of utilizing solar energy for obtaining fresh water from saline water.
TL;DR: It is suggested the addition of the word "spondyloepiphyseal" to the name adopted by the International Working Group on Constitutional Diseases of Bone, to become "progressive pseudorheumatoid spondylosleepyseal dysplasia", and speculate on candidate genes for this disorder.
Abstract: Progressive pseudorheumatoid dysplasia is an inherited skeletal dysplasia with radiographic changes notably in the spine, similar to spondyloepiphyseal dysplasia tarda. There is also articular cartilage involvement which gives it some clinical resemblance to rheumatoid arthritis. We report here on six subjects from one inbred family from Jordan. Based on previously published reports and this one, we review the clinical and radiological features and discuss the genetics and differential diagnosis of the disorder. We suggest the addition of the word "spondyloepiphyseal" to the name adopted by the International Working Group on Constitutional Diseases of Bone, to become "progressive pseudorheumatoid spondyloepiphyseal dysplasia". We also speculate on candidate genes for this disorder.
Journal Article•
TL;DR: It appears that meswak is probably not particularly active against caries through its fluoride content, but it does act as a brush for removing dental plaque and polishing the teeth.
Abstract: The use of a wood stick (meswak or chewing stick) for brushing the teeth continues to be an important tool for oral hygiene care in many Afro-Asian communities. It is inexpensive, customary and used for religious reasons as well. Despite the wide use of meswak, information on its chemical and pharmaceutical contents are scant, particularly in regard to an anticaries effect. In the present study, sticks from Salvadora persica, the most common source for meswak, were analyzed for their soluble and total content of fluoride, calcium, phosphorus and silica. Results showed that the fluoride released from meswak soaked in water was negligible (< 0.07 microgram/ml). Approximately 39% of the total fluoride in the sticks was in a form that could be leached out. The leached calcium and phosphorus averaged 582 micrograms/ml and 34 g/ml, respectively, representing 19.6% and 26.4% of their total content in the sticks. There was a substantial amount of silica in the ashes of meswak. It appears that meswak is probably not particularly active against caries through its fluoride content, but it does act as a brush for removing dental plaque and polishing the teeth.
TL;DR: In this article, the Brinkman-Forchheimer-extended Darcy model is used to model the flow inside the porous domain and the effects of different parameters regarding the geometry, the solid matrix, and the fluid on the hydrodynamic and thermal behavior are investigated.
Abstract: Numerical solutions are presented for the problem of transient, developing, forced-convection flow in concentric annuli partially filled with porous substrates. The porous substrate is attached either to the inner cylinder (case I), or to the outer cylinder (case O). In both cases, the boundary in contact with the porous substrate is exposed to a sudden change in its temperature while the other boundary is kept adiabatic. Including the macroscopic inertial term, the Brinkman-Forchheimer-extended Darcy model is used to model the flow inside the porous domain. The effects of different parameters regarding the geometry, the solid matrix, and the fluid on the hydrodynamic and thermal behavior are investigated. It is shown that porous substrates may improve Nusselt number by 1200 percent keeping other flow and geometrical parameters fixed. Also, it is found that there is an optimum thickness for the porous substrate beyond which there is no significant improvement in Nusselt number. In the present work, the dimensionless hydrodynamic entrance length Z en varies within the range 2-45 and it has significant effect on the fully developed Nusselt number at steady-state conditions
TL;DR: Famotidine, crystallized from different solvents and solvent mixtures, was found to exist in three crystal forms, A, B, and C, depending on the solvent system used as mentioned in this paper.
TL;DR: The results suggest that the plastics in the rumen may play an important role in the pathogenesis of rumenitis and the most common types of foreign bodies in Jordan are plastics and a clean up of the environment would substantially reduce the prevalence of foreign body-pica syndrome in sheep.
TL;DR: In this article, the authors used TRNSYS, a transient simulation program, to optimize the design parameters for a thermosyphon solar water heater for two regions in Jordan represented by two cities, namely Amman and Aqaba.
TL;DR: The long-term ingestion of chromium chloride and potassium dichromate would have adverse effects on sexual behavior and territorial aggression in adult male rat.
Abstract: The effects of long-term ingestion of chromium chloride (trivalent compound) and potassium dichromate (hexavalent compound) was investigated on sexual behavior, aggressive behavior and fertility in male rats. Adult male rats were exposed to chromium chloride and potassium dichromate in drinking water at a concentration of 1000 ppm for 12 weeks. The exposure of male rats to chromium chloride and potassium dichromate reduced the number of mounts. The exposure of male rats to potassium dichromate increased the time to ejaculation. On the other hand, the exposure of male rats to chromium chloride and potassium dichromate increased the post ejaculatory interval. The number of animals ejaculating were reduced in chromium chloride and potassium dichromate exposed male rats. The exposure of male rats to chromium chloride and potassium dichromate decreased lateralizations, boxing bouts and fights with stud male. The exposure of male rats to chromium chloride and potassium dichromate had no effect on fertility. Testes, seminal vesicle and preputial gland weights were significantly reduced in chromium chloride- and potassium dichromate-exposed males. In conclusion, the long-term ingestion of chromium chloride and potassium dichromate would have adverse effects on sexual behavior and territorial aggression in adult male rat.
TL;DR: This review clearly indicates that the later method is taking over due to its ability to handle cruise problems which are too noisy and difficult to model.
TL;DR: Great grand multiparous woman are at increased risk of having pre‐eclampsia, intrauterine fetal death and macrosomia.
TL;DR: Findings from a 3-dimensional model of wound repopulation support the concept of a gradual transition from the fetal to adult phenotype in wound healing.
Abstract: To overcome the difficulties of studying wounding and wound repopulation in monolayer systems, a 3-dimensional model of wound repopulation has been developed which allows the in vitro investigation of fibroblast migration in response to experimental wounding. This model was utilized to determine whether fibroblasts derived from sites which demonstrate preferential healing (child and oral mucosal fibroblasts) possessed an increased ability to repopulate experimental wounds when compared to adult dermal fibroblasts. Fibroblasts were established from specimens derived from healthy donors undergoing minor elective surgery. Standard wounds were created in fibroblast populated collagen lattices (FPCLs) which were then overlaid upon an extracellular wound matrix. Fibroblast repopulation of the wounds was studied over 12 days using light- and scanning electron microscopy and quantified using computerized image analysis. Wound repopulation by fibroblasts derived from child donors (n = 3) was significantly (P < 0.0...
TL;DR: In this paper, cooling and heating load calculations for air-conditioned and heated buildings have been calculated for three different cities in Jordan, representing three climatic regions; namely, Irbid, Amman and Aqaba To analyze the insulation effect of buildings, for each region four combinations of wall and ceiling insulation were considered: no insulation; only wall insulated; only ceiling insulated; and both ceiling and wall insulated.
TL;DR: In this article, the Freundlich adsorption isotherm was found to best describe the data indicating that the extent of ketotifen adaption is a continuous function of the initial drug concentration.
TL;DR: In this paper, the in vitro propagation of wild pear (Pyrus syrica) was studied and the root height decreased to 1.8-1.6 cm and 1.3 cm with benzyl adenine.