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
Abstract
Nano-crystalline ZSM-5 zeolite was synthesized by hydrothermal method using chelating agent and two gel compositions:Compositionɪ:Al2O3:86SiO2:5.5TPA:12.7Na2O:3.4Trien:3320H2O.Compositionɪɪ:Al2O3:68SiO2:5.4TPA:10Na2O:2.6Trien:2626H2O.Study of hydrothermal reaction factors on characteristics of nano- sized zsm-5 has been carried on ,among them are crystallization temperature, crystallization time and concentration of template ( TPAOH ) solution. Synthesis was accomplished in PTFE lined autoclave ( reactor ) . The product were characterized by X-ray diffraction ( XRD ),Atomic force microsc
... Show MoreBiosensor is defined as a device that transforms the interactions between bioreceptors and analytes into a logical signal proportional to the reactants' concentration. Biosensors have different applications that aim primarily to detect diseases, medicines, food safety, the proportion of toxins in water, and other applications that ensure the safety and health of the organism. The main challenge of biosensors is represented in the difficulty of obtaining sensors with accuracy, specific sensitivity, and repeatability for each use of the patient so that they give reliable results. The rapid diversification in biosensors is due to the accuracy of the techniques and materials used in the manufacturing process and the interrelationshi
... Show MoreMany clinical isolates of proteus spp. (30 isolates of P
mirabilis and 30 isolates of P. vulgaris) from patients with urinary
tract infections (UTIs) were examined for their ability to produce
proteolytic enzymes and their ability to form swarming growth. Most
(90%) of P. mirabilis and 60% of P. vulgaris isolates secreta
proteolytic enzymes. A strong correlation was found between the
ability of a strain to secreted proteases and it's ability to form
swarming growth. Non- swarming isolates invariably appeared to be
non- proteolytic. However, some isolates (12 isolates of P. vagaries)
were non- proteolytic even when they formed swarming growth
Mortar of ordinary Portland cement was blended with cockles shell
powder at different weight ratios to investigate the effect of powder
admixture on their strength and thermal conductivity. Results showed
that addition of cockles shell powder at 50% of mortar weight
improves hardness and compressive strength notably and reduces the
thermal conductivity of the end product. Results suggest the
possibility to incorporate cockles shell powders as constituents in
cement mortars for construction and plastering applications.
Lipoxygenase was extracted from the cup of Pleurotus ostreatus ( Jaq : Fr ) oyster mushroom for the first time in Iraq, and purified homogeneously through precipitation with 40% saturation of (NH4)2SO4 as a partial purification then loaded on DEAE-Cellulose (Diethyl amino ethyl Cellulose) ion-exchange chromatography column and then the highly active elution parts have been passed through gel filtration column with Sephacryl S-300 as a final purification with 804 (U/mg protein) specific activity, 11.32 fold of purification and 36.54% yield . The molecular weight of the enzyme was estimated to 74 KDa by gel filtration Sephacryl S-300 column and the isoelectric point for enzyme was 5.3. The optimal pH for lipoxygenase activity and stability
... Show MoreThe junction between polythiophene, a conducting polymer formed by electrochemical polymerization, and n-type silicon was studied the temperature and doping dependencies were observed in the junction characteristics. The increase of junction temperature leads to increase the saturation current, the barrier height, and decrease of the ideality factor for junction. While the reduction in doping concentration causes a decrease in the forward current. The results were explained according to the conventional Schottky diode theories.
Background: Accurate detection of thyroid autoantibodies by enzyme linked immunosorbant assay technique namely thyroglobulin antibody, thyroid peroxides antibody is crucial in the differentiation of autoimmune thyroid disorders from other form of thyroid diseases.
Objective: Evaluation of the detection of thyroglobulin antibody and thyroid peroxides antibody in different thyroid diseases using enzyme linked immunosorbant assay technique.
Methods: - Seventy-five patients admitted to Surgical Units of Baghdad Medical City Hospital for the period between "October 2010 to June 2011" they were waiting to do thyroidectomy. They were chosen nonselectively for serological evaluation of above autoantibodies , and correlation of the results
A dynamical system describes the consequence of the current state of an event or particle in future. The models expressed by functions in the dynamical systems are more often deterministic, but these functions might also be stochastic in some cases. The prediction of the system's behavior in future is studied with the analytical solution of the implicit relations (Differential, Difference equations) and simulations. A discrete-time first order system of equations with quadratic nonlinearity is considered for study in this work. Classical approach of stability analysis using Jury's condition is employed to analyze the system's stability. The chaotic nature of the dynamical system is illustrated by the bifurcation theory. The enhancement o
... Show MoreThe anatomical study showed the epidermis leaves of Ricinus communis L.glabrous and withparacytic pattern, also the midrib of leavescomposedfrom a pyramidal shapearea with a circular tip like ascamel humpfrom the upper side consisting of supported collenchyma tissue, and the cross section of leaf petiole formed as an ovate shape as for the cross section of stem was a circular, also observed many druces crystaland aleuron grains that are spread in the cortex area. Pollen grain appeared under a scanning electron microscope that tricolporate, either the surface pattern was reticulate and the shape of pollen grain prolate spheroidal to subprolate