Abstract: With the self-designed welding powder formula,this experiment employed the SHS reaction to weld the base metal,which was steel Q235 here,then respectively used Olympus large-scale horizontal digital microscope to analyze the structure morphology of the welding seam's different regions,JEOL SEM to point-analyze and line-analyze elements' distribution near the the weld interface and HV-1000 CCD automatic measurement microscopic vickers hardness tester to measure the microhardness of the pure copper's welding seam.The experiment's result shows the hardness of different part of the welded joint varies largely,and that the join of alloy elements can increase the microhardness of the welding metal,and that the welding metal and base metal interdiffuse,grow and mix remarkably near the fusion line,realizing wonderful metallurgical bonding.
Abstract: Effect of attrition milling and subsequent ultrasonification of CNT on dispersion in ethanol was investigated. An attempt was also made to disperse the CNT in Mg alloy matrix by solid state friction stirring process for fabrication of metal matrix composite. Attrition milling was performed at a rotation speed of 700rpm for various times up to 6 hour. After 2 hours of milling, amorphous trace was observed in X-ray diffraction pattern. Attrition milling and subsequent ultrasonification enhanced dispersion of CNT in ethanol. Mg alloy matrix composite dispersed with the CNT was successfully fabricated by friction stirring process. The CNT-dispersed composite was analyzed by optical microscopy and Vickers hardness.
Abstract: Nano-size hydroxyapatite is the main inorganic component of bone. There is a critical particle size that each property starts to change. Each property can be modified under controlled conditions. Multifunctional materials for applications, one must consider several properties change. Bone properties, are those which dictate the properties of hydroxyapatite, properties to be followed the synthetic materials to be used successfully as implants. Of these mention those related to surface materials, solubility and biocompatibility and their mechanical strength. Depending on the location and functionality of the implant have met some of these properties. The purpose of this study is to develop a synthetic hydroxyapatite at nano scale, using sol-gel and pyrosol method, for its use in medicine
Abstract: As petroleum fuels are getting higher in price day after day. I is important to search for an alternative fuel as crude oil will not last forever specially in this high economical and industrial progress. In a parallel way engineers and scientists are searching for additives for the current known fuel until they find the best alternative fuel which has to fulfill the pollution and technical requirements. One of the solution is to implement the idea of downsizing engine fuelled with alternative biodiesel - in this case manufactured by the transestrification by using microwave heating. The process needs automation to keep control for manufacturing efficiency and quality of fuel properties. Authors show the automation layout and present equipment of test stand. There is short summary of combustion engine emission tests, too.
Abstract: Mg-doped ZnO was synthesized using a co-precipitation technique. X-ray diffraction (XRD) measurements and absorption spectra show that Mg ions are doped into the lattice positions of ZnO. In the room temperature photoluminescence (PL) spectra, two emission bands, ultraviolet (UV) and visible, were observed. Either of two emissions shows a blue-shift. The visible emission band is composed of the green emission and the blue emission. The amount of blue-shift in green emission is 0.03 eV, about half of the amount of blue-shift in blue emission. Mg substitution raises and lowers conduction- and valence-band edges, respectively.
Abstract: Based on a tight binding model, we investigate impurity effect upon the stability of neutral and negatively or positively charged 1D conjugated polymer chains. Impurities are introduced by an attractive or a repulsive potential located at the lattice sites. The offsets of system energy due to light doping are calculated within adiabatic approximation. We show that doping position has significant impact upon system stability. A general picture of impurity distribution along the stretch direction of the polymer chain is obtained for both attractive and repulsive impurity potentials in neutral as well as in charged conjugated polymers. A polymer chain can generally be divided into edge, center and transition regions in terms of impurity distribution. It is found the static impurity distribution within a polymer is dominated by the strength and the sign of the impurity potential as well as whether the polymer chain is neutral or charged. Impurity distribution within the edge and the transition region is characterized by cluster and that within the center region by separation.
Abstract: hydroxyapatite/Chitosan bioceramics were fabricated by combining in-situ chemical synthesis and freeze drying method, using (NH4)2HPO4, Ca(NO3)2·4H2O, and chitosan(CS) as raw materials. The effect of freezing temperatures, solid loading and freeze-drying time on microstructures of hydroxyapatite/Chitosan bioceramics was studied. The microstructures of the fabricated porous bioceramics were investigated by means of Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The results showed that the hydroxyapatite/Chitosan bioceramics have interconnected porous structures from several microns to 200um, more suitable to bone tissue implantation. In addition, the porous structures are affected by freezing temperature.
Abstract: The relation model established by artificial neural network that includes 4 corrosive material parameters that are Cl-, H2S, NH3 and pH value and corrosion testing parameter that is Fe2+ of the fractionator overhead recycle system, studied the corrosion sensitivity of the corrosion parameters, has got the sensitive areas, put forward the suitable range of the corrosive material parameters of corrosion control in the production process.
Abstract: To evaluate the blood and tissue compatibility of the dental implant samples, the whole blood clotting time, prothrombin time and partial prothrombin time, hemolytic rate and local implantation tests of the dental implant samples were determined, which will provide the basis for the clinical safety of such medical products. The WBCT, PT and PTT results showed that there were no significant difference (p> 0.05)between the testing groups and the negative control group, hemolysis rate of the dental implant samples was 1.38%, less than 5%, which in line with medical equipment blood compatibility test, all of these results indicated that the dental implant had a good blood and tissue compatibility.
Abstract: The azotobacter bacteria and the phosphate-solubilizing bacteria are separated and filtered from the rhizosphere soil of the fir plantation and the enzyme activity of azotobacter bacteria, the solubilizing power of phosphate-solubilizing bacteria and the characteristics of PGPR bacteria to produce IAA are measured in this paper. The results show that: there are 5 of the 16 azotobacter bacteria whose enzyme activity is greater than 150 nmol•mL-1•h-1, respectively NGJ-4, NGX-5, NGX-4, NGX-8 and NGJ-8. Py16, Py10 and Py3 own the strongest capacity to dissolve organic phosphorus, respectively 71.31 mg / L, 59.07 mg of / L and 65.14 mg / L; Pw10，Pw6 and Pw20 own the strongest capacity to dissolve inorganic phosphorus, respectively 232.0 mg/L，185.9 mg/L，172.6 mg/L. Py18，Py16 and Py3 own the strongest capacity to produce IAA and dissolve the organic phosphorus bacteria, respectively 38.80mg / L, and 37.29mg / L, and 35.79mg / L; Pw6, Pw8 and Pw21 own the strongest capacity to produce IAA and dissolve the inorganic phosphorus bacteria, respectively 45.340 mg/L, 39.340 mg/L, 27.480 mg/ L. Based on these results, the strains of NGJ-4, NGX-5 and NGJ-8 are selected to prepare the microbial compound bacterial fertilizer using Py16, Py3 and Pw6. Then the azotobacter bacteria, organic phosphate-solubilizing bacteria and inorganic phosphate-solubilizing bacteria is respectively diluted to the solution with the ratio of 15%, and then mix them with the volume proportion of 1.5:1:1 to obtain the mixed bacteria liquid; the proportion of solid carrier ash is 20%, the proportion of fermentation medium is 50%, and the proportion of the mixed bacteria liquid is 30%.