Advanced Materials Research Vols. 239-242

Abstract: Normal corn starch was used as raw material in this research and was treated by autoclaving method to produce corn resistant starch (CRS). This research was focused on techniques of preparing CRS through autoclaving method and effects of autoclaving method parameters on yields of CRS from corn starch. The optimum conditions were investigated with carrying out an L₉(3⁴) orthogonal experiment. The yield of CRS was 8.05 % under combination of optimum parameters obtained from L₉(3⁴) orthogonal experiment. The optimum parameters were concentration of NCS solution 25 %, pH6.5, autoclaving temperature 125 °C, autoclaving time 35 min.

Abstract: In this study, the basic material for sound absorption was porous nonwoven made of polyester nonwoven and low-melting polyester fiber. Nonwoven was then attached with foam polyurethane as composite plank for sound absorption and sound isolation. We used two microphone impedance tube for sound absorption test and INSTRON 5566 mechanical testing machine for tensile test. The optimum sound absorption coefficients as 0.67 ± 0.008 was obtained when density of foam polyurethane was 1.0 Kg/㎥ with thickness of 20 mm; Polyester (PET) nonwoven were laminated with 9 layers in a total thickness of 10 mm; and its low-melting polyester fiber was 30 wt%. The composite plank obtained the maximum fracture stress when it contained low-melting-point (low-Tm) PET fiber at 30~40 wt%. The results of this study could be applied in the partitions inside ships, vehicles or buildings.

Abstract: This study investigated the biaxially drawn behavior of polypropylene (PP) containing different crystalline structure in between of either α-monoclinic or β-hexagonal crystal form or a combination of both. The precursor sheet with α-crystalline PP was prepared from neat resin using the sheet extrusion process. The high content of β-crystalline phase (K-value of about 84%) was developed in the polypropylene sheet using a proprietary type and concentration of β-crystal nucleator. Biaxial film stretching was carried out using a laboratory stretching machine at the temperature of 145°C. Stretching speed and stretch ratio were kept relatively constant at 400 %/sec and 5.5 x 5.5, respectively. β-PP sample demonstrated a distinct biaxially drawn behavior as compared to that of the neat-PP sample, in particular, biaxial yield stress of neat PP (α-PP) was 3.55 MPa, where a much lower biaxial yield stress value was apparent for β-PP (~1.69 MPa). Interestingly, the total calculated area under stretching curves of the β-nucleated PP sample was about 34.8 % lower than that of the neat PP sample. These findings indicate the less energy required for stretching process of β-nucleated PP. Moreover, the drawn β-PP films also showed comparable mechanical properties to the α-PP sample as well as a good optical property, evidenced by low haze values of <1% which was close to that for the normal BOPP films.

Abstract: Strip casting of Al-25%Si was tried using the vertical type high speed twin roll caster. Some devices were adopted to enable the strip casting of Al-25%Si. Control of the roll gap, semisolid casting and non-use of the lubricant were useful devices to cast Al-25%Si strip. Roll-casting-ability of the Al-25%Si was discussed. The strip could be cast at 20m/min and 40m/min. As-cast strip was hot rolled down to 1mm by one pass. Bulging was tried at 550°C and it was able.

Abstract: The causes that lead to the shrunken cause of dome roof oil tank were analyzed and some practical measures were offered for the prevention of this kind of shrunken, which is valuable about ensuring security of oil tank and protection of external pressure caused destruction in oil tank. With the rapid development of China's oil economy, increased dramatically the demand for large-scale storage and transportation equipment. In the refining and chemical production equipment, the vertical cylindrical steel dome tank is a widely used storage device, it is low cost, easy to operate. Mainly used for storing crude oil, diesel and some chemical products. Tank design pressure is lower, the tank wall, tank top, tank bottom are thinner, and it is easy depression because of large negative pressure inside the tank in the course. Therefore, the correct understanding of the reasons of depression and mastering tank preventive measures, security maintenance for the storage of equipment is very important. In this paper, a refinery in Harbin City, take the dome tank as an example of crude oil and analysis cause of their depression.

Abstract: Here we reported SnO₂ can be synthesized by irradiation of SnCl₄ solution with Hg lamp in N₂ atmosphere. The preparation mechanism was proposed. The as-prepared sample showed higher photocatalytic activity than TiO₂ (Degussa P25) and the commercial SnO₂ for hydrogen production from ethanol aqueous solution.

Abstract: In order to improve the barrier property of the biaxially oriented polypropylene (BOPP) film, the PVA/SiO₂ organic-inorganic hybrid coating on BOPP film was prepared by the sol–gel method. And the structure and properties of the hybrid composite films were characterized. The results showed that, the oxygen barrier property of the composite films was enhanced with the increase of PVA content, while the water vapor barrier property of the composite films was dropped. As the mass ratio of PVA increased to 80%, the oxygen barrier property of the composite films was 308 times that of the pure BOPP film, however, water vapor barrier character was half of the BOPP film.

Abstract: Electroslag metallurgy production practice showed that the initial composition and final slag composition of ANF-6 were very different. The multiple electroslag with different ratio of CaF₂ (58%-70%), Al₂O₃(18%-30%), CaO(0%-12%), SiO₂(0%-9.3%) and MgO(0-2.7%) were used to simulate the changes of ANF-6 slag composition in production. Then the melting point, density, viscosity, surface tension and electrical conductivity of different slags were measured respectively. The results demonstrated that, with the content of CaF₂ and Al₂O₃ decreasing, and the content of CaO, SiO₂ and MgO increasing, the melting point first increased and then decreased(increased from 1339°C to 1350°C, and then dropped to 1297°C), the density gradually decreased(from 2.96g/cm3 to 2.28 g/cm3), viscosity first decreased and then increased(reduced from 0.097Pa.s to 0.015Pa.s,then gradually rose to 0.083Pa.s), the surface tension increased gradually(from 0.3N/m to 0.39N/m), the conductivity first increased and then decreased(reduced sharply from 3.33S/cm to 3.17S/cm,then increased slowly to 3.30S/cm, decreased gradually to 2.83S/cm). The changes of physical properties of slag would cause changes in operating parameters. In order to get good electroslag ingots, the electrical parameters, process parameters should be adjusted according to the properties changes timely in electroslag refining process.

Abstract: Sm₂(WO₄)₃ crystals have been synthesized through liquid-phase reaction. The structure, morphology and optical properties of the products have been investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer, SEM, and spectrofluorometer, respectively. The compound crystallized in the monoclinic hexagonal system, space group C2/c. Heat treat promoted the crystallization and regulated the micro-structure of Sm₂(WO₄)₃. In the Sm₂(WO₄)₃ host, the WO₄^2- group could transfer the energy of near-UV light to Sm³⁺ ions, emitting blue, green and red light at 429 nm (⁶P_5/2→⁶H_5/2), 453 nm (⁴G_9/2→⁶H_5/2), 495, 507 nm (⁴G_7/2→⁶H_5/2), 563 nm (⁴G_5/2→⁶H_5/2), 601 nm ( ^4G_5/2→⁶H_7/2) and 649 nm ( ^4G_5/2→⁶H_9/2), respectively. The ratio of blue, green and red light was appropriate to achieve white light. The Sm₂(WO₄)₃ powders have potential to act as UV absorber for solar cell and may be helpful to the development of white light LED.

Abstract: Five testing matrixes were prepared to test with sound absorption, tensile strength, and thermal conductivity respectively. The low-melting-point (low-Tm) polyester (PET) fibers were blended with weight ratios (10 wt%, 20 wt%, 30 wt%, 40 wt% and 50 wt %) with PET staples, forming the PET nonwoven fabrics. The thermoplastic polyurethane (TPU) was thermal bounded with the nonwoven fabrics with different lamination number to examine the sound absorption rate, creating the PET/ TPU composites. Afterward, four sets of samples – PET nonwoven fabrics and PET/ TPU composites with TPU films laminated on the front, in the middle, and on the rear of the composites, were compared. PET/ TPU composite with TPU film laminated in the middle exhibited the optimum sound absorption; moreover, 30 wt% was proved to be the optimum parameter of the low-Tm PET fibers for the PET/ TPU composites.