جستجوی مقالات مرتبط با کلیدواژه « ضریب جذب » در نشریات گروه « مواد و متالورژی »

In this study، after preparation of Li2O-Al2O3-SiO2-TiO2 base glass containing Cr2O3 dopant using casting method، the effect of different amount of dopant on spectroscopic and optical properties of glass has been investigated. Due to the spectroscopic، optical and structural properties of glasses، UV-Vis and FTIR spectrophotometers have been utilized. Hence، optical parameters such as absorption coefficient، extinction coefficient، Fermi energy level، optical band gap and Urbach energy have been calculated. According to results of calculations، augment of dopant to 1. 5% leads to the reduction of molar volume، optical band gap، Fermi energy، Urbach energy and enhancement of density. The mentioned changes could be attributed to the role of Cr3+ as the network modifier.

The sample used in the photo/dark measurement was fabricated in the sandwich Al/Polyamide/TiOPc/Oxadiazole/ITO/Glass. Nanostructure Titanium Oxide Phthalocyanine with the average particle size about 25 nm (TiOPc) is used as Charge Generation Material (CGM). Photoreceptor absorption spectra shows that there are some peaks at wavelengths 282,402,578 and 762 nm and there is no absorption in the region of 402-578 nm. Photo/dark induced discharge curve shows 67% contrast is achieved at 345 ms.

Thermophysical properties, electrical contact resistance (ECR) and corrosion performance are considered as critical properties of coatings, which are utilized in the satellite manufacturing industry. Chromate conversion coatings (CCCs) for Al alloys are among these coatings.In this study, CCCs were applied on Alclad AA7075-T6 Al Alloy by means of a chromating solution having chemical composition very near to the commercial chromating solution of Alodine 1200S. Influence of coating time on the coatings thermophysical properties including coefficients of solar absorption or Absorptivity (αs) and thermal emission or Emissivity (εT) as well as their ECR values were investigated. The εT was measured directly by Emmisometer device, while αs was determined indirectly by Reflectometer equipment. In coating time from 30 up to 180 seconds αs and εT values were measured in the ranges of 0.7-0.94 and 0.06-0.22, respectively. The results were revealed that different εT and αs as well as desired ECR values according to the specifications of satellite industry are obtainable by control of coating parameters such as coating time. In addition, base on the results of surface coating morphology evaluating conducted by SEM and AFM, it was concluded that developed coatings were formed in nanocrystalized structures.