Protective steel doors are widely used in buildings due to their high resistance against the impact loads. However, its heavy weight has been always considered as a major drawback for these doors. In this paper, a new optimized stiffened impact-protective steel door incorporating sandwich panel with aluminum foam core (OSSA) is examined. This door consists of two face sheets, main and secondary stiffeners, and aluminum foam as the inner core. In order to optimize the door, at first the rigidity and weight functions of the stiffened steel door were extracted. Then an optimal door weighing 42% less than the primary door was obtained. Due to the high energy absorption capacity of the combined foam core and stiffened steel door structure, the use of aluminum foam core in the optimized steel door was proposed. By doing numerical analysis, and depending on the thickness of the face sheet of OSSA, 20 to 32% reduction in the maximum displacement was observed. The results also showed that, with 67% increase in the peak overpressure, OSSA has kept almost the same maximum displacement as that of the steel door without an aluminum foam. In other words, by using aluminum foam core in the optimized stiffened door, the door will resist 67% more impact load.

Introduction: Dendritic cells are very important in basic studies and vaccine research, but isolation and culture of these cells face challenges due to their small number in tissues. Since there is no standard method, we addressed some of the factors affecting the efficiency of dendritic cell isolation and culture from BALB/c mouse bone marrow. Materials & Methods: Bone marrow cells isolated from femur and tibia, were seeded in plates and treated with GM-CSF. On day 3, half of the media was transferred to a new plate with fresh media plus GM-CSF. On day 5, cells were induced with CpG oligonucleotide. Cell survival as well as maturation markers of CD11C, MHC-II and CD86 were investigated by flow cytometry on day 5 (immature cells) and day 7 (mature cells). Findings: It was found that the presence of endotoxin in the culture of immature cells, significantly reduces the recovery of dendritic cells (p value <0. 05). Less than one million cells seeded in non-treated 6-well plates and transfer of cells to a new plate on day 3 increased the efficiency of immature cell retrieval by preventing early maturation and premature death. Further treatment of immature cells with CpG on day 7 was used to induce the Th1 pathway. Significant difference (p value <0. 05) with control group showed that CpG induces maturation after treatment with GM-CSF (without IL-4). Discussion & Conclusions: Optimization of dendritic cell culture in terms of different culture conditions highly impacts the efficiency of immature cell formation and maturation.

The recovery process of selenium from Iranian Sar-Cheshmeh copper anode slimes employing hydrometallurgical methods has been investigated. The copper anode slimes are made up of those components of the anodes, which are not soluble in the electrolyte. They contain varying quantities of precious metals like gold, silver, selenium and tellurium. They are being extracted as a by product in the copper production process. In this paper, some parameters affecting the leaching conditions of anode slimes in nitric acid are studied. Taguchi experimental design method is used to find out the effect of acid concentration, temperature and time. The statistical results of the experiments show that the above parameters are important in the leaching of -10 microns fraction. The optimum conditions determined are: T = 90 degrees C, acidity = 4 M and the leaching time = 60 min. Under these conditions, 99 % of the selenium is leached out.

b-glucosidase, is one of the cellulase enzymes system, hydrolyses cellobiose or cellooligoschrides to glucose.In this research for production of b-glucosidase enzyme, b-glucosidase activity was measured in the optimum conditions in 30 isolates of Trichoderma sp. In order to obtain the optimum conditions: an isolate of Trichoderma (T.reesei PTCC 5142) was grown in Mandels media containing CMC, Avicel and filter paper as carbon source at pH 4,5, 6 and 7. Lactose and cellubiose were added to media as inducer agents. Media were incubated at 25, 29 and 32 oC for 14 days. Samples were collected in 24h intervals, and enzyme activity was measured. Results showed that the optimum conditions for hyperproduction of b-glucosidase were pH=5, CMC as carbon source, lactose as inducer on seventh day at 29 oC. After screening the -glucosidase activity of all 30 isolates in the optimized conditions, it was shown that T.reesei PTCC 5142 had the highest level of -glucosidase specific activity (0.45 U/mg). For characterization and study of b-Glucosidase gene, CTAB method used for genomic DNA extraction.The expected PCR product with 566 bp was amplified with two specific primers (CP11 & CP12). The amplified fragment was confirmed by restriction pattern.

Dimethyl amino ethane azide (DMAZ) is a good replacement of hydrazine derivatives in aerospace industries. It is produced from the reaction between dimethyl amino ethyl chloride and aqueous sodium azide. DMAZ is formed in organic phase with a purity of at least 90%. High pure DMAZ is necessary for aerospace utilization. Thermal sensitivity of DMAZ leads the purification procedure to be performed at low temperatures. So, the Distillation at sub-atmospheric pressures is a good choice for this purpose. In this paper, effect of various parameters such as temperature and pressure on the distillation time and loss of material and final purity of DMAZ was studied in regular packed column, known as vigorous column, and optimized conditions were found.

Here, we have synthesized vertically aligned carbon nanotubes (VA-CNTs), using chemical vapor deposition (CVD) method. Cobalt and ethanol are used as the catalyst and the carbon source, respectively. The effects of ethanol flow rate, thickness of Co catalyst film, and growth time on the properties of the carbon nanotube growth are investigated. The results show that the flow rate of ethanol and the Co layer thickness play important roles on the length and the degree of alignment of the carbon nanotubes. High density VA-CNTs with forest-like structure are grown at a very low ethanol flow rate of 0. 8 sccm, which is the optimized flow rate in our experiments. Therefore, the cost of synthesizing VA-CNTs is decreased by a low consumption of ethanol and utilizing the cheap CVD synthesis method. High density of small-sized catalyst particles is formed in the Co-catalyst thickness of 1 and 2nm, resulting in the growth of vertically aligned nanotubes. However, increasing the thickness of Co layer to 10 and 16 nm, leads to the growth of nanotubes parallel to the substrate with the spaghetti-like structure. The experiments reveal that enhancing the growth time from 5 to 120 min can mostly affect the uniformity and length of VA-CNTs.

Recently, small (<2 nm) and monodispersed Pt clusters has gained much attention due to their high catalytic activity in the aerobic oxidations. However, the chemical synthesis of small Pt clusters is not trivial; high temperature is often required to completely reduce the Pt4+/2+ ions to Pt0, which accelerates the growth of the Pt clusters. Here, we discussed a very simple microfluidic reduction of Pt4+ to Pt0 by NaBH4 in the presence of PVP that produces<2 nm Pt clusters in any variable reduction conditions. The microfluidic reduction conditions were optimized for the synthesis of possible smallest Pt clusters in terms of five reaction parameters: (1) temperature, (2) concentration of H2PtCl6, (3) molar ratio of NaBH4 to Pt4+. ions, (4) molar ratio of PVP-monomer to Pt4+ ions, and (5) molecular weight/chain length of PVP. We found that possible smallest particles with average diameter 1.3± 0.3 nm were produced when aqueous solutions of H2PtCl6 (4 mM) and NaBH4 (40 mM) containing PVP (160 mM) were injected into the micromixer placed in an icebath at a flow rate of 200 mL/h. The produced particles were characterized by UV–visible absorption spectrophotometry, powder X-ray diffractometry and transmission electron microscopy.

Nanostructured RuO2 powders were synthesized via a hydrothermal method at 180 °C for 12 h using 1 and 2 M NaOH aqueous solutions. The structure of the obtained nanomaterials was investigated by powder X-ray diffraction (PXRD) technique. The morphology the obtained materials were studied by field emission scanning electron microscope (FESEM). The technique showed that with changing the reaction rout, the homogeneity of the size and morphology of the synthesized nanomaterials were changed. It was found that the morphology of the obtained materials were spherical particles using 2 M NaOH aqueous solution. Catalytic performance of the synthesized nanomaterials was investigated in Biginelli reactions for the one-pot synthesis of 3, 4-dihydropyrimidin-2 (1H) -ones (DHPMs) using Benzaldehyde derivatives, urea and ethylacetoacetate as raw materials. Experimental design method was used to obtain optimized reaction conditions. It was found that the optimized conditions were 0.028 g of catalyst, 110oC reaction temperature and 66 min reaction time.

Developing of new infection imaging agents is a mandate in the detection of resistant species in the clinic due to the mortality of various new strains of bacteria including mycobacterium tuberculosis. In this study, various conditions were optimized for the rapid and efficient labeling of rifampicin antibiotic labeled with Tc-99m for ultimate use in infection imaging. Radiochemical purities were checked by RTLC using methyl ethyl ketone, and normal saline on Whatman No.1 paper. The time, temperature, ligand concentration, stannous ion amount, pH were optimized in the radiolabeling process and the best conditions were room temperature, pH 7, 20 micrograms of stannous chloride for 1 mg of rifampicin solid and 20 mCi of freshly milked technetium-99m pertechnetate. The complex demonstrated satisfactory stability in the presence of human serum and final formulations for 6 hours.