Effect of Temperature on Reliability and Degradation of 0.63?m Laser Diode

The reliability of optical sources is strongly dependent on the degradation and device characteristics are critically dependent on temperature. The degradation behaviours and reliability test results for the laser diode device (Sony-DL3148-025) will be presented .These devices are usually highly reliable. The degradation behaviour was exhibited in several aging tests, and device lifetimes were then estimated. The temperature dependence of 0.63?m lasers was studied. An aging test with constant light power operation of 5mW was carried out at 10, 25, 50 and 70°C for 100hours. Lifetimes of the optical sources have greatly improved, and these optical sources can be applied to various types of transmission systems. Within this degradation range, the device life for system application is estimated to be more than 100 h at 70 ºC at a constant power of 5mW

Potential of aqueous extracts of Allium sativum, Mentha spicata, Myrtus communis and Thymus vulgaris as antimicrobials and curing of antibiotic resistant genes in Klebsiella pneumoniae / Adel Kamal Khider and Sazan Qadir Mawlud

Eighty six clinical isolates of Klebsiella pneumoniae were isolated from various pathogenic cases from Erbil hospitals. The isolates were varied in their resistance to antibiotics, and ranged between 13-18 antibiotics out of 22. Genetic transformation between purified plasmid from K. pneumoniae and E. coli JM83 demonstrated that all tested antibiotic resistant genes were plasmid DNA born except Doxycilin resistance gene was chromosomal born. The watery extracts of Allium sativum, Mentha spicata Myrtus communis and Thymus vulgaris were proved to be most powerful against K. pneumoniae K11 and K32 isolates. A comparative evaluation of plasmids elimination from K. pneumoniae isolates by sub-MIC of plant extracts showed that these extracts could cure plasmids effectively at their respective sub-MIC concentration. Plasmid cured was observed by sub-MIC of Allium sativum and Thymus vulgaris at 350 µg ml-1 cured 2, 4 and 3 plasmids, Mentha spicata and Myrtus communis extract at 250 µg ml-1cured 2, 3 and 2, 4 plasmids from K. pneumoniae K11 and K32 isolates. Curing of plasmid DNA from K. pneumoniae isolates confirmed by determining the loss of resistance markers in cured cultures

Effect of Zinc Oxide on Structural and Optical Properties Borotellurite Glass: Ternary Glass

A series of zinc borotellurite glass with the composition of (70-x)TeO2-30B2O3-xZnO (0= x ≥ 20) have been successfully synthesized by melt quenching techniques. Physical parameters such as density, molar volume and refractive index have been calculated, and maximum values of refractive index and density were obtained at 2.315 and 4.57, respectively. The amorphous nature of the glass sample was confirmed using the X-ray diffraction (XRD) technique; no sharp pick was observed in the XRD pattern, which confirms that the glass sample structure has amorphous nature. The absorption spectra were studied by using a UV-Vis-NIR spectrometer, and the values of direct band gap (Edir), indirect band gap (Eind) and Urbach energy (Eu) were obtained through the absorption edge studies. It was found that the values were between 3.54 and 3.69 eV and the values of lies between 3.33 and 3.51 eV. The Eu values lie between 0.17 to 0.21 eV. The bonding parameters of the glasses were analyzed by using Fourier Transform Infrared (FTIR) technique, and the formation of non-bridging oxygen (NBO) was observed, which indicates the presence of TeO4, BO3 and BO4 units

Structural Properties of Lead Oxide-Doped Zinc Tellurite Glasses

The melt quenching technique was used to create a ternary (90-x) TeO2 - xPbO -10ZnO glass system (x = 0, 10, 20, 25, 30, 35, and 40 mol%). The X-ray diffraction (XRD) technique is used for improving the amorphous nature of the glass samples. In addition, to examine the structural characteristics of the glass samples, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy are used. Raman spectroscopy was used to evaluate the impact of PbO on the glass structure. A strong frequency peak at 729.63-774.69 cm-1 was detected in the Raman spectra, indicating that the TeO4 and TeO3/TeO3+1 structural units make up the majority of the glass network. The TeO3/TeO3+1 structural unit contain non-bonding oxygen molecules that are stretched in the Pb-O, Zn-O, Te-O, and Te-O-Te bridging configurations, vibrations, and Raman spectra

Optimization of the Geometrical Parameters for the Output Mirror in a He-Ne Laser

The aim of this study is to produce a model via iterative description of the beam distribution to connect the output power of a He-Ne, continuous and low power laser in terms of its beam radius by operating it as regular pattern of repeated wave front with in the space between the mirrors. Because of the spherical shapes of laser resonators have complete Gaussian shapes. Hence the beam radius changes according to its position and along the principle axis of the cavity. We used a LASCAD simulation program as an analyzer for our data; the results didn’t change that much with those of original Gaussian beam model

Theoretical Study of Influence of Some Material Parameters on Solar Cell Efficiency

Silicon solar cells are prevailing types in the commercial market due to their stability, robustness and reliability. In this article, we explored the important controllable design parameters affecting the performance of the silicon p-n junction solar cells by using the computer program (Matlab scrip file).  Through the simulation process we also determined the sensitivities of each parameter.  Besides that, some hypothetical materials are also examined to explore the effect of   band gap, doping process and thickness of n-layer.  We have come out the optimum parameters to achieve the best performance of this type of cell. A simple one-diode model is used in order to predict how the performance Silicon solar cell changes its characteristics with doping process. It was found that the optimum doping concentration of the base from (1016- 1019) cm-3and optimal thickness of n-layer is about (10-100) µm for silicon solar cell

Influence of mannitol concentration on the physicochemical, mechanical and pharmaceutical properties of lyophilised mannitol

Mannitol is a pharmaceutical excipient that is receiving increased popularity in solid dosage forms. The aim of this study was to provide comparative evaluation on the effect of mannitol concentration on the physicochemical, mechanical, and pharmaceutical properties of lyophilised mannitol. The results showed that the physicochemical, mechanical and pharmaceutical properties of lyophilised mannitol powders are strong functions of mannitol concentration. By decreasing mannitol concentration, the true density, bulk density, cohesivity, flowability, netcharge-to-mass ratio, and relative degree of crystallinity of LM were decreased, whereas the breakability, size distribution, and size homogeneity of lyophilised mannitol particles were increased. The mechanical properties of lyophilised mannitol tablets improved with decreasing mannitol concentration. The use of lyophilised mannitol has profoundly improved the dissolution rate of indomethacin from tablets in comparison to commercial mannitol. This improvement exhibited an increasing trend with decreasing mannitol concentration. In conclusion, mannitols lyophilised from lower concentrations are more desirable in tableting than mannitols from higher concentrations due to their better mechanical and dissolution properties

The effects of long-term anticonvulsive treatment on serum lipid profile

Serum lipids were determined in 10 untreated patients with recently diagnosed epilepsy, 21 patients treated with carbamazepine (CBZ), 10 patients treated with valproate (VPA) and in 15 healthy children. In relation to the controls, patients receiving CBZ showed increased serum high-density lipoprotein cholesterol (HDLc), apolipoprotein A (Ape-A) and apolipoprotein B (Apo-B). Patients receiving VPA showed increased Apo-B levels. There were no significant differences in total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDLc) or very low-density lipoprotein cholesterol (VLDLc) between all groups. The changes in lipid metabolism may be associated with the induction of liver enzymes during anti-epileptic drug metabolism. The CBZ-induced change in serum lipid levels was considered to be a possible factor against atherosclerosis and coronary heart disease in epileptic patients