This paper demonstrates the spatial response uniformity (SRU) of two types of heterojunctions (CdS, PbS /Si) laser detectors. The spatial response nonuniformity of these heterojunctions is not significant and it is negligible in comparison with p+- n silicon photodiode. Experimental results show that the uniformity of CdS /Si is better than that of PbS /Si heterojunction
In the current research, we investigated the absorption spectrum for R590 and C480 dyes in ethanol solvent for different dye solution concentrations of 10-4, 10-5 and 10-6M. These dyes have been prepared and studied before and after gamma irradiation (first, second ionization) using cesium-137 source with absorbed doses of 18.36 Gy (time exposure of 10 days) and 73.44 Gy (with time exposure of 40 days). We noticed that the absorption intensity was decreased with decreasing concentration, before gamma irradiation while the absorption spectrum peak shifted towards the short wavelength (blue shift). It was also found that the intensity of absorption spectrum increased and shifted the absorption spectrum peak towards the long wavelength (red
... Show MoreThe A.C conductivity of three samples of lanthanide oxide : zinc oxide (La2O3)1-x(ZnO)x pellets with different zinc oxide content which were sintered 1273 K temperatures were studied using LRC meters in the frequency range of 50–106 Hz at temperature of 30 °C. The a.c conductivity, was analyzed depending of the universal power law proposed by Jonsher,. The slope of the relation between logarithm of a.c conductivity and angular frequency represent the s value were in the range (0.44-0.77) which found to increase by increasing of zinc oxide content which coincided with the small po
A linear and nonlinear theoretical and experimental aeroelastic investigation of a wing-flap-tab typical section model undergoing two-dimensional incompressible airflow is described. The linear flutter velocity (LFV) and frequency are predicted using linear analysis. Then a freeplay structural nonlinearity is considered in the tab. The structural equations of motion have been coupled with Theodorsen aerodynamic theory to produce the theoretical aeroelastic model which is analyzed by a state space method to predict the LFV and flutter frequency. Linear piecewise function has been used to introduce the tab spring stiffness in the freeplay state. The ground vibration test is used to measure the model structural dynamic characteristics. Then th
... Show MoreHemorrhoids are one of the most common surgical conditions. The hemorrhoid may cause symptoms that are: bleeding, pain, prolapse, itching, spoilage of feces, and psychologic discomfort. There are many methods for treatment of hemorrhoid like, medical therapy, rubber band ligation, electerocoagulation, stapled hemorrhoidpexy, photocoagulation, sclerothereapy, doppler guided artery ligation, Cryosurgery, and surgery. All methods for treatment of hemorrhoids have advantages, disadvantages, and limitations. Conventional haemorrhoidectomy was the traditional operation for the treatment of hemorrhoids. But recently other modalities of treatment had been used as an alternative operations including CO2 laser haemorrhoidectomy. This work aims to
... Show MoreIn-situ gelation is a process of gel formation at the site of application, in which a drug product formulation that exists as a liquid has been transformed into a gel upon contact with body fluids. As a drug delivery agent, the in-situ gel has an advantage of providing sustained release of the drug agent. In-situ gelling liquid suppositories using poloxamer 188 (26-30% W/W) as a suppository base with 10% W/W naproxen were prepared, the gelation temperature of these preparations were measured and they were all above the physiological temperature. Additives such as polyvinylpyrrolidin "PVP" ,hydroxylpropylmethylcellulose "HPMC", sodium alginate and sodium chloride were used in concentration ranging from (0.25-1
... Show MoreSilymarin (SM) is a plant extract obtained from Silybum marianum( milk thistle) . It is class II type drug according to Biopharmaceutics Classification System with low bioavailability due to its low solubility.
Micro/nanonization during crystallization, surface modification and crystal structure modification may improve the dissolution rate of poorly water-soluble drugs.
The aim of this study was to increase the water solubility and dissolution rate of SM by in-situ micronization using solvent change either by stirring or ultrasonic method. Stabilizers like Gelatin, PVP-K30, HPMC15, Pulullan were used to stabilize the prepared ultrafine crystals. Effect of type and concentration of hydrophilic polymer, solv
... Show MoreThe purpose of this study was to develop poloxamer-based in-situ gel of chloramphenicol aiming to increase bioavailability and prolong corneal contact time, controlling drug release, and enhancing ocular bioavailability. The in-situ gel was prepared using different concentrations of poloxamer 407 combined with hydroxypropyl methyl cellulose (HPMC) or carbapol 940 to achieve gelation temperature about physiological temperature and improve rheological behavior and gelling properties of poloxamer gel. The prepared formulations were evaluated for their appearance, pH, and sol-gel transition temperature. The formulations F2, F3, and F5 have a gelation temperature within the accepted range 35-370C an
... Show More