جستجوی مقالات مرتبط با کلیدواژه « taguchi experimental design » در نشریات گروه « فنی و مهندسی »

In this research, in order to coating pentaerythritol tetranitrate (PETN) particles, estane compound and nano-pigment of red Lithol rubine B 57:1 (NLR) were used. After structural studies of nanocomposite by infrared (FT-IR) and field emission scanning electron microscopy (FESEM), Taguchi statistical design method was used to investigation and optimization of optical reflectance of nano-composite at 532 nm. The effect of four factors of estane concentration, NLR concentration, stirring speed and ultrasonic bath temperature in three levels on optical reflection was investigated and analysis of variance (ANOVA) showed that NLR concentration with the participation of 79.36 percent had highest effect. Optimal conditions to achieve a minimum light reflectance were obtained of estane 5 wt%, NLR 7 wt%, stirring speed 400 rpm and ultrasonic bath temperature of 50°C. The lowest light reflectance by analyzing the data variance for optimum conditions was estimated 4.97 ± 1.67. The mean experimental result for optical reflectance of the synthesized nano-composite under optimum conditions was 5.90 percent. Follows, thermal behavior and vacuum stability of the optimal sample was investigated that the results show that the melting point temperature and decomposition of nano-composite are not different compared to the pure PETN Indicating the compatibility of NLR and estane with PETN.

Due to the increasing use of concrete and the use of additives in it , research in this direction is very important . Resistance is one of the effective values in the design and control of concrete quality that numerous factors and parameters affect it . Perhaps increasing in concrete mixing time is one of the parameters that are considered less attention and in this research ; the effect of mixing time on compressive strength of Nano - silica concrete with pozzolan rice husk was studied and were compared with concrete without Nano - silica and pozzolan rice husk .Therefore the effect of sulfate to reduce the resistance of this type of concrete was studied and compared . So , a number of pieces of concrete cube with sides of 15 cm contains %1 Nano - silica and 20% pozzolan husk Rice with a time of mixing varies between 10 to 40 minutes , that every 5 minutes , 3 samples of concrete were taken and made in the days 3 , 7 and 28 under the stress test and ultimately the results of mixing different compressive strength by the time was drawn and reported . Rice husk also tested and its components determined and compared with the standard . Nano - silica concrete and concrete pozzolan rice husk and without Nano – silica and pozzolan was also photographed to compare the density of particles , and at the end testing plan was written by Taguchi testing of concrete . The results show that for the most compressive strength of concrete pozzolan Nano comes with rice husk , the right time (optimal) 25 minutes with a Taguchi test results differ by about 9 percent lower than the margin of error is permitted , that at this time the concrete maximum compressive strength shows the maximum compressive strength at 28 days after the concrete 415 kg/cm2 and then does not show significant strength concrete . Pozzolan concrete without silica and rice husk increasing mixing time increases the compressive strength of concrete 375 kg/cm2 in 28 days from the time the concrete mixing process increase the resistance of shows . Ash consumption in the non - crystalline silica , which is 88% of the project , has shown its high pozzolanic activity . Physical and chemical (XRF) examination showed that rice husk ash used in this project within the requirements of ASTM C-618 for pozzolan is located . XRD results show that the consumer is fully amorphous silica from rice husk ash . As the electro - microscopic pictures (sem) is observed in samples without Nano - silica and pozzolan rice husk , the concrete has uneven texture and large crystals are clearly visible which are connected with needle - shaped crystals and large pores are clear in concrete . However , the concrete samples with Nano - silica and rice husk pozzolan , concrete has a more amorphous structure which are homogeneous and integrated together . And the porosity of the concrete is significantly reduced , which increases the resistance of concrete.

Reduction in the oil reserves’ levels, the variation of fossil fuel prices and GHG have led to grow the value of attention to biodiesel. Reserves of fossil fuels are running out and should have proper alternative for them. Environmental benign and renewable properties of biodiesel make it consider suitable candidate to replace fossil fuels. In this study, continuous production of biodiesel and optimization of important and influential parameters have been investigated. The method was concluded of trans-esterification of soya oil with methanol as feed in presence of homogeneous catalyst of NaOH. A plug flow reactor containing a static mixer with high efficiency, low cost and controllable operating conditions was used. The reactor was designed as it used the combination of advantages other reactors to achieve %94.72 conversion at 1.61minute. Four factors including; (1) the methanol/oil molar ratio, (2) flow rate of feed, (3) the reaction temperature and (4) the catalyst percent in 3-level were optimized by Taguchi experimental design. The optimized conversion point which was obtained by ANOVA method at %98.53 was converted to 98.02% after merging the temperature factor.

In this research, zinc oxide (ZnO) nanoparticles were selected as reinforcing agent with the aim of improving antibacterial and mechanical properties of polyvinyl chloride (PVC). PVC-ZnO nanocomposite was prepared by dispersing ZnO nanoparticles into a PVC solution. Taguchi experimental design method was used to determine the optimal conditions for preparation of nanocomposite. The effects of five factors including ZnO weight percentage, kind of solvent, the addition method of ZnO, film drying temperature and stirring time were investigated on different levels. Optimal conditions were determined by using the signal/noise (S/N) method. It was distinguished that, kind of solvent, the addition method of ZnO and ZnO weight percentage are three significant factors in the confidence level of 95%. Staphylo coccus aureus and Escherichi coli, two different types of bacteria (one gram-positive bacteria and one gram-negative bacteria) were used in Mueller-Hinton broth for antimicrobial testing. This test confirmed the antibacterial property of the optimal nanocomposite in respect to pure polyvinyl chloride. A scanning electron microscope (SEM) coupled with an energy dispersive X-ray system (EDX) was used to characterize the composition and structure of the optimal nanocomposite film.