The induced photodegradation of methyl cellulose (MC) films in air was investigated in the absence and presence of aromatic carbonyl compounds(photosenssitizers): 1,4-naphthaquinone (NQ) and benzophenone (BPH) by accelerated weathering tester. The addition of (0.01 wt %) of low molecular weight aromatic carbonyl compounds to cellulose derivatives films(25µm in thickness) enhanced the photodegradation of the polymer films.The photodegradation rate was measured by the increase in carbonyl absorbance. Decreases in solution viscosity and reduction of molecular weight were also observed in the irradiated samples. Changes in the number-average chain scission, the degree of deterioration and in the quantum yield of chain scission values are also observed, and it was concluded that branching or cross-linking has occurred for cellulose derivative with NQ and BPH. Findings from all analytical techniques indicated that the 1,4-naphthaquinone (NQ) photosensitizer enhance the photodegradation of methyl cellulose more than benzophenone (BPH). The effect of the photosensitizer concentration, (ranging from 0.01 to 0.1 %), on the rate of photodegradation was also monitored for MC films. The rates are increased with increasing the photosensitizer concentration. The effect of film thickness is also studied at fixed sensitizer concentration (0.05%), and results show that the rate of cellulose derivative photodegradation decreases with increasing film thickness. The rate constants of the photodegradation of the photosensitizers deduced in cellulose derivatives films, [at concentration of (0.1%)by weight and thickness (25µm)]. Biodegradation of irradiated cellulose derivatives films was conclusively established with bacteria type Pseudomonas aeuroginosa Rb-19 isolated from crude oil. The amount of bacteria growth on MC after 30 days was lower, while there was no growth observed in MC with BPH
AbstractBACKGROUND: Some cases of vitiligo require melanocyte transplantation, but these surgical techniques have varying degrees of success. OBJECTIVES: To perform melanocytes transplantion in patients with vitiligo using a new needling micrografting technique. PATIENTS and METHODS: This interventional case study took place at the Department of Dermatology and Venereology at Baghdad Teaching Hospital from December 2010 to September 2011. Twelve patients with vitiligo were included. A split-thickness skin graft was taken from the normal area and cut into micropieces ranging from 0.1 mm to 0.3 mm in diameter. The recipient area was anesthetized, and the micrografts were then implanted into the dermis using the needling technique. The number
... Show MoreIn this paper, a new third kind Chebyshev wavelets operational matrix of derivative is presented, then the operational matrix of derivative is applied for solving optimal control problems using, third kind Chebyshev wavelets expansions. The proposed method consists of reducing the linear system of optimal control problem into a system of algebraic equations, by expanding the state variables, as a series in terms of third kind Chebyshev wavelets with unknown coefficients. Example to illustrate the effectiveness of the method has been presented.
The use of Near-Surface Mounted (NSM) Carbon-Fiber-Reinforced Polymer (CFRP) strips is an efficient technology for increasing flexural and shear strength or for repairing damaged Reinforced Concrete (RC) members. This strengthening method is a promising technology. However, the thin layer of concrete covering the NSM-CFRP strips is not adequate to resist heat effect when directly exposed to a fire or at a high temperature. There is clear evidence that the strength and stiffness of CFRPs severely deteriorate at high temperatures. Therefore, in terms of fire resistance, the NSM technique has a significant defect. Thus, it is very important to develop a set of efficient fire protection systems to overcome these disadvantages. This pape
... Show MoreDuodenal and gastric ulcers remain the two most common perforations of the gastrointestinal tract and might be reduced by the early detection of predictive factors, which has limitedly researched. This study conducted to examine the predictive factors for developing of gastroduodenal ulcer among patients attending Gastrointestinal Teaching Hospitals in Baghdad, Iraq.
A cross-sectional survey with a total of 100 patients with gastric and duodenal ulcers was recruited using a nonprobability (purposive) sampling techniqu
Finding the shortest route in wireless mesh networks is an important aspect. Many techniques are used to solve this problem like dynamic programming, evolutionary algorithms, weighted-sum techniques, and others. In this paper, we use dynamic programming techniques to find the shortest path in wireless mesh networks due to their generality, reduction of complexity and facilitation of numerical computation, simplicity in incorporating constraints, and their onformity to the stochastic nature of some problems. The routing problem is a multi-objective optimization problem with some constraints such as path capacity and end-to-end delay. Single-constraint routing problems and solutions using Dijkstra, Bellman-Ford, and Floyd-Warshall algorith
... Show MoreZinc, Copper, Selenium, Magnesium, Manganese, Chromium, Iron, Nickel, Cobalt, Vanadium and Germanium were determined by atomic absorption spectrophotometer (AAS) in blood serum of patients with rheumatoid arthritis, (30) patients (14male and 16female) with age range (37-60) years compared with normal tensive control. The analysis of results showed that the mean value of concentration (Magnesium, Manganese and Nickel) were significantly higher in patients with rheumatoid arthritis compared to that of healthy, while the mean levels of serum (Zinc, Copper, Selenium, Chromium, Iron, Cobalt and Germanium) were significantly lower than controls. There were no significant changes in overall mean concentration of serum Vanadium in patients
... Show MoreThe disposal of textile effluents to the surface water bodies represents the critical issue especially these effluents can have negative impacts on such bodies due to the presence of dyes in their composition. Biological remediation methods like constructed wetlands are more cost-effective and environmental friendly technique in comparison with traditional methods. The ability of vertical subsurface flow constructed wetlands units for treating of simulated wastewater polluted with Congo red dye has been studied in this work. The units were packed with waterworks sludge bed that either be unplanted or planted with Phragmites australis and Typha domingensis. The efficacy of present units was evaluated by monitoring of DO, Temperature, COD
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