JOURNAL OF SCIENCE (KHARAZMI UNIVERSITY)
Year:2011 | Volume:9 | Issue:2|Papers Count:8

Fe Doped CdS nanopaqrticles have been synthesized by a wet chemical method and TG used as a capping agent. The particle size of the nanoparticles calculated from XRD and optical methods has been found in the range 3-5 nm. The x-ray diffraction measurements showed that the nanoparticles have the structure of hexagonal phase. The broadening of XRD patterns indicate that the prepared CdS: Fe samples are nanostructures. The UV absorption results indicated that the doping increased optical band gap of nanoparticles which means the particle size decreased due to Fe doping. Also, effects of doping and capping agent concentration on the luminescence spectra of CdS: Fe nanoparticles investigated.

In this research, ac measurements of copper phthalocyanine thin film using aluminium electrodes are investigated in the frequency range 102 to 105 Hz and within the temperature range frequency and the capacitance and dissipation factor (loss tangent) decrease with increasing relative importance of the hopping model and band theory in describing the film conduction with regard to the operating conditions. It was observed that the band theory is dominant at high frequencies and high temperatures, whereas hopping model is dominant at low frequencies. The energy gap of CuPc was determined using dc measurements.

This article is a report of calculation and measurements of a p+-n InSb photo-diode leakage current fabricated by mesa on the basis of the calculation and measurement of different leakage currents in InSb photo-diode along with its variation it shows that at relatively low reverse biases (up to about 300 mV) G-R and shunt current are dominant. But at high reverse biases the tunneling current dominates. In this article we investigate the relation between device parameters and rate of leakage currents and investigated this relation by fabricating high quality p+-n diode.

The most popular phenomenological approaches for investigating the decay channels of B meson is the hypothesis of factorization, which applies to certain two body semileptonic decays. This research utilizes the factorization method according to the colour transparency hypothesis. We use the factorization method for obtaining the b quark decay amplitudes for calculating the B mesons decays amplitudes. We use the factorization method for leptonic and semileptonic decays.

Rudbar Lorestan dam is constructed on Abrudbar River, 100 km south of Aligudarz city. There is a segment of Main Recent Fault (MRF) called Saravand-Baznavid Fault (SBF) at 1.6 km south of dam site. Using Automatic Extraction Method, based on STA Algorithm, lineaments were extracted from sattelite images and Shaded Relif Model. For detailed structural analysis, the study area was divided into three zones based on geological map. In Eslamabad Fault zone, Eslamabad fault is the main structural element, that is likely of P-type fractures. The main structure in the SBF zone is Saravand-Baznavid active Fault, which caused the drainage to be displaced as much as 500-1000m in the northern height of study area. In the Dam axis zone, the main structure is F1 fault. This fault is about 150 meters in length with right lateral strike slip component. Thermoluminescence dating, sence of movement, dominant slikenside, and the orientation of groove marks on the fault plane indicate this fault to be active. Large dicplacements along with strike-slip faults in the study area, such as F1 fault, have been considered using shear zone and enechelon models. However, the main faults in the study area is SBF, that is relate in an enechelon pattern to seismic Dourud fault and has the right potential to movement in the future.

Intrusions between Arak and Borujerd in northern Sanandaj Sirjan zone are present different field and lithology. Three different groups: (a) the Astaneh intrusion, (b) the Borujerd complex, and (c), Tavandasht-Gosheh intrusions can be identified. First attempt to date these intrusions began with K-Ar method and obtained ages were about 60Ma based on studies on Alvand in Hamadan. Further Rb-Sr dating, published older ages and revealed two phases 60Ma and -120Ma for Borujerd complex and 100Ma for Astaneh intrusion. Following dating based on zircon, established the age of 170Ma for all unites. In order to cover gaps in data, we have undertaken MS U-Pb zircon geochronological studies for selected granitoids. Results confirm the presence of granitoids with 170Ma in Astaneh and Borujerd complex. But, for first time, the young age of 34.8Ma initiated for Tavandasht intrusions. It could be concluded that emplacements of plutons in this part of Sanandaj Sirjan began in Mid Jurassic (Bathonian stage) and last phase was on Late Eocene (Priabonian stage). However, based on the presence of field and geochemical differences between intrusions, more study needs to find the interval phases. Emplacement of these intrusions are related to calk alkaline subduction of Arabian plate with Central Iran plate, and obtained data, could assist on timing of  offered tectonomagmatic models.

Zolachay river has an area about 960 square kilometer located in south-west of Salmas city. The evaluation of shape and drainage density of catchment area shows a dense catchment with high flood discharge and erosion potential. The texture variations and particle size growth are investigated at 84 locations in river catchment area. The particle size increases exponentially toward the river downstream. The results indicate that particle size growth is due to tributary entry and lithology changes. In overall view the river sediment particle size distribution shows bad sorting with positive skewness. It is used the trend of particle size mean and median for selecting the proper SDR method. Also the river suspension sediment loads estimated approximately 105 ton per day using the Yang method.