This paper describes a proper low cost way to fabricate defects free porous carbon preforms with interconnect pore structure for making reaction formed SiC (RFSC). Taking charcoal , poplar powder, camphene and polymer dispersant together, making slurries by milling under 55 °C for several hours, controlling the content of charcoal and poplar powder, after casting, sublimating and carbonizing, the porous carbon performs with a series density (0.66 g/cm3-0.78 g/cm3) and porosity (62.9 vol.%-68.6 vol.%) were prepared; through the Si infiltrating process under a vacuum condition (~5.0 Pa) at 1500°C for about 0.5 hour, the RFSCs with fine mechanic performance were fabricated, one RFSC sample has the density, Weibull modulus, and the max three points flexural strength is 2.91 g/cm3, 9.5 and 505.0 MPa respectively.

In this paper, effect of moisture absorption on high temperature thermal insulation performance of fiber insulation material is studied. Fiber material is stored in 40°C through a long period of time, then spontaneous moisture absorption of fiber material is measured. According this test result, 20% and 40% moisture absorption content gradient are determined. Pore distribution and high temperature thermal insulation property of samples of 20% and 40% moisture absorption and the dry samples are all tested in this study. The internal pore size distribution of fiber insulation material after moisture absorbing has a certain coarsening. Fiber material after moisture absorbing will make its pore size become large. And oxygen acetylene test results showed that: the larger moisture absorption, the more slowly the initial temperature rises. Fiber material after moisture absorbing will make its low temperature thermal insulation performance reduce, but it has little impact of its high temperature thermal insulation performance.

Fiber reinforced and aluminum phosphate-based composite was studied in this experiment. The composite was prepared through the process of lamination- hot press- sintering, binding material and fillers. The proper mixture ratio of Al2O3:AlPO4:H2O was 10:2.88:2.88.The slurry with this ratio was proper to prepare the composite. It indicated that the mechanical property of composite was excellent which was prepared by the slurry with this ratio. In order to improve the Mechanical property of silica glass fiber / aluminum phosphate composite, Al2O3 powders were graded in the slurry. Mechanical properties of composites were improved evidently.

continuous carbon fiber reinforced silicon carbide (Cf/SiC) ceramic matrix composites were prepared by precursor infiltration pyrolysis and chemical vapor infiltration (PIP-CVI process), in which the honeycomb sandwich structure preforms were fabricated by the three dimensional braid method. In this paper, the microstructure and the bending strength were observed and analyzed by SEM and three point bending method. The results of the study show that: The Cf/SiC ceramic matrix composites, which were lightweight and high strength, were prepared by that technique. The composite samples have a fiber volume fraction of 20%, a density of 0.38 g/cm3 and a flexural strength of 3.81 MPa. The honeycomb sandwich fiber reinforced ceramic matrix composite with a light weight, corrosion resistance and excellent physical and mechanical properties is a kind of structure and functional ceramic materials, which can realize the structure and the requirement of heat integration.

High thermal conductivity and dense SiC coating were fabricated by chemical vapor deposition (CVD) on surface of different graphite at temperature of 1100°C. The results indicated that the thickness of the coating influences the quality of coating. There was no crack in coating when thickness of the coating is less than 0.3mm. The structure of graphite affected the reaction badly. When the graphite is coarse and porous the reaction is chemical vapor infiltration (CVI) and the interface of coating and substrate isnt obvious. When the graphite is dense and smooth, the coating is covered in surface of graphite, the interface is found between the coating and substrate. Optical microscope and SEM were used to observe the surface and cross-section morphology and microstructure of coatings. It shown coating and substrate had a good combination and the deposited grains mainly showed equiaxed form with the crystallite size of 30 nm at 1100°C.

Silicon carbide ceramic has many attributes including high strength and stiffness, low thermal expansion coefficient, high thermal conductivity, low density and good resistant for radiation of space particles. These attributes make SiC ceramic becoming the third generation space mirror material. This paper describes the fabrication of lightweight SiC mirror blanks. By reducing the shrinkage of green body and controlling the drying conditions, lightweight SiC mirror blank with a diameter of 612mm has been prepared by using gelcasting process. The forming green body is infiltrated with liquid silicon at the temperature of 1600°C, then a CVD SiC layer is coated on the surface of SiC mirror blank. After grinding and polishing, the mirror shows good optical properties.

Objectives To identify barriers that deter parents/caretakers of infants and children enrolled in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) from taking full advantage of the services provided by the program.Subjects/Setting A total of 3,167 parents/caretakers at 51 New York State WIC local agency sites completed a barriers survey.Design Sixty-eight potential barriers to WIC were identified through a literature review, five focus groups with parents/caretakers of WIC participants, and an expert review panel. The barriers survey was administered per, son-to-person to parents/caretakers of infants and children on WIC.Statistical Analysis Classification tree analysis was used to identify characteristics that best predict WIC check usage behavior.Results A small set of barriers (n = 11) were identified by more than 20% of respondents. Waiting too long was the most frequently cited barrier (48%). Difficulties in bringing the infant/child to recertify and rescheduling appointments were key variables associated with failure to use (ie, pick up or cash) WIC checks. Further analyses indicated that (a) for each additional reported barrier, there was a 2% increase in failure to use WIC checks (P<.0001); (b) waiting for services was related to an increase in the number of people who failed to use checks; and (c) the longer the reported wait, the greater the number of reported barriers (P<.0001).Conclusions Conducting this barriers research enabled the New York State WIC to improve services provided to participants and their families. A decrease in waiting times should generally reduce exposure to noisy, crowded facilities and lead to fewer reports of nothing for kids to do.