QScience Connect - الأعداد السابقة

Polyvinyl alcohol (PVA)/Na-rich Montmorillonite (MMT) nanocomposites were prepared using solution method to create polymer-clay nanocomposite (PCN) material. The PCN material was studied using X-ray diffraction (XRD), demonstrating polymer-clay intercalation that has a high d-spacing (lower diffraction angles) in the PCN XRD pattern, compared to the pure MMT clay XRD pattern, which has a low d-spacing (high diffraction angles). Read More

We realize noncommutative phase spaces as coadjoint orbits of extensions of the Aristotle group in a two-dimensional space. Through these constructions the momenta of the phase spaces do not commute due to the presence of a naturally introduced magnetic field. These cases correspond to the minimal coupling of the momentum with a magnetic potential.

The anisotropy factor as a function of fiber arrangement, fiber fineness and sample thickness has been derived from the theories of soundwave transformation due to phase changing. The sound absorption coefficient of the anisotropic fibrous material is then theoretically calculated. The fibrous materials were prepared so that the fibers are arranged parallel (perpendicularly laid fiber web called STRUTO technology) in the direction of Read More

Harnessing waste energy from the manmade air fields of buildings presents a new area of renewable energy to explore. Due to the unpredictability of the natural wind, this study is to evaluate the practicality for harnessing waste energy from the air conditioner exhaust units which are a more constant and predictable source available in the buildings. A prototype of the micro wind turbine has been designed to minimize the negative effect of Read More

The distribution and localization of serotonin immunoreactive cells in the superior colliculus of the porcupine (Hystrix cristata) was studied using the peroxidase-antiperoxidase method and an antiserum against serotonin. The study was performed on four superior colliculus' of porcupine. Serotonin immunoreactivity showed a dense body of positively labelled cells throughout the superior colliculus. These serotonin immunoreactive cells h Read More

Background: Attempts to produce greener bromination of 2-acetyl 9H-fluorene with KBr+KBrO3 reagent using fly-ash:H2O catalyst in aqueous media gave 9H-fluorenacylbromides. Generally, the halo-keto compounds possess insect antifeedant activities. Therefore, the insect antifeedant activities of these acyl bromides have been studied using 4th instar larvae Achoea janataL against castor semilooper. Methods: Solvent free bromination Read More

Background: The aim of this study was to synthesise some substituted styryl 3,4-dimethoxy phenyl ketones using solvent-free SiO2–H2SO4 catalyzed aldol condensation between 3,4-dimethoxy acetophenone and substituted benzaldehydes under microwave irradiation. Then to characterize them by their analytical, physical and spectroscopic data, and also to study their the spectral correlation and antimicrobial activities. Methods: Solvent Read More

The aim of this work was to study the effect of friction time on the microstructure and mechanical properties of alumina 0, 25, 50 wt% yttria stabilized zirconia (YSZ) composite and 6061 aluminium alloy joints formed by friction welding. The alumina-YSZ composites were prepared through slip casting in plaster of Paris molds (POP) and subsequently sintered at 1600°C, while the aluminium rods were machined down using a lathe machine to th Read More

Background: Depression and obesity are common disorders. Obesity is also predictive of several chronic diseases like hypertension and diabetes. The aim of this study was to evaluate and compare depression frequency of obese patients with hypertension or diabetes. Methods: Weight, height and body mass index (BMI) were measured. The definition of obesity was a body mass index (weight (kg)/height (m)2) ≥ 30 kg/m2. Obese patients with Read More

With the significant rise in hospital infection management in dental hospitals as well as in hospitals, and in order to identify the distribution of pathogenic bacteria on hands and nasal cavity of workers in a dental hospital, bacteria from the hands and nasal cavities of six dentists and 44 dental hygienists from four dental hospitals were investigated. The results showed Staphylococcus aureus, Staphylococcus capitis, Staphylococcus epidermidis Read More

Intrahepatic cholangiocarcinomas are rare, aggressive tumours. We discuss an afflicted patient who had relatively larger thrombi disseminated into the right atrium. A 63-year-old female patient with intrahepatic cholangiocarcinoma referred with complaints of swellings on her face, upper half of her body, and both arms. On contrast-enhanced thoracic CT scans and transthoracic echocardiograms of the patient an intraluminal thrombus m Read More

Medicinal plants play an important role in human livelihoods. However, the harvest of different organs may be destructive. Sarcocephalus latifolius is a species whose roots are harvested for medicinal purposes. This study was carried out to assess the root characteristics, biomass yield and morphological variations within different habitats of southern Benin. Forty-eight S. latifolius individual plants were randomly selected in three l Read More

In this paper, a simulation optimization-based decision support tool has been developed to study the capacity enhancement scenarios in a tire manufacturing company located in Iran. This company is experiencing challenges in synchronizing production output with customer demand causing an unbalanced work-in-process (WIP) inventory distribution throughout the tire manufacturing process. However, a new opportunity to increase Read More

This article is an introduction to a new approach to first principles electronic structure calculation. The starting point is the Hartree-Fock-Roothaan equation, in which molecular integrals are approximated by polynomials by way of Taylor expansion with respect to atomic coordinates and other variables. It leads to a set of polynomial equations whose solutions are eigenstate, which is designated as algebraic molecular orbital equatio Read More

Background: The frequent co-abuse of alcohol and tobacco may suggest that they share some common neurological mechanisms. For example, nicotine acts on Nicotinic acetylcholine receptors (nAChRs) in the brain to release dopamine to sustain addiction. Might nAChRs be entwined with alcohol? Objectives: This review summarizes recent studies on the relationship between alcohol and nAChRs, including the role of nAChRs in Read More

Background: Unwanted hair is one of the most common medical problems affecting women of reproductive age inducing a lot of psychological stress and threatening their femininity and self-esteem. Old methods of removing unwanted hair include shaving, waxing, chemical depilation, and electrolysis, all of which have temporary results. However laser-assisted hair removal is the most efficient method of long-term hair removal currently av Read More

Background: Hepatic fibrosis results from an imbalance between fibrogenesis and fibrolysis in the liver. The process of Ito cell activation, which is thought to be the central pathogenic mechanism in liver fibrogenesis/cirrhosis, may involve distinct interactions with Kupffer cells (KCs) mediated by various cytokines and growth factors. The aim of this study was to determine whether targeting KC function using GdCl3, which specifically ac Read More

Background: This study aims to synthesise a series of 1-thiocarbomyl pyrazolines, including 3-(3,4-dibromophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamides, using solvent-free fly-ash:PTS catalyzed cyclization between chalcones and thiosemicarbazide, under microwave irradiation. Then to characterize them using analytical, physical and spectroscopic data. Methods: Solvent-free microwave assisted cyclizatio Read More

This paper shows the combination of an efficient transformation and Exp-function method, to construct generalized solitary wave solutions of the nonlinear Burger's equations of fractional-order. Computational work and subsequent numerical results re-confirm the efficiency of the proposed algorithm. It is observed that the suggested scheme is highly reliable and may be extended to other nonlinear differential equations of fractional order.

We report the discovery of the blister beetle, Meloe coelatus Reiche, 1957, in Qatar. According to the Catalogue of Palaearctic Coleoptera there is no record for the genus Meloe in Qatar, although the genus is well represented in other areas of the Arabian Peninsula. M. coelatus is a rare species, that is present along a wide area of Northern Africa and Western Asia. Our findings bridge the current geographic gap in the known distribution of th Read More