Hafnium carbide structural foams synthesized from polymer precursors

Hafnium carbide （HfC） was applied in space and aerospace due to its ultra high melting temperature, high specific strength and moderate oxidation resistance. A novel synthesizing method was used to produce low density and high strength HfC structural foams through the thermolysis and pyrolysis of Hf containing polymer precursors （mixing of hafiaium trifluoroacetylacetonate and epoxy） under vacuum atmosphere. The X-ray diffraction analysis shows that the produced foam is primarily composed of HfC containing 9%-10% HfO2. Several polymer powder compaction methods were used to improve the mechanical properties of HfC foam. Compression strengths of 200 MPa are achieved for HfC foams with density of 1.9 g/cm^3 （total porosity about 85%）. The proposed methodology of synthesizing HfC foam has the advantages of simple, inexpensive and less production time than alternate methods.     

Chemical Composition and Nutritional Quality of Faba Bean (Vicia faba L. Minor) Based Tofu

Chemical composition and antinutritional factors in soy and faba beans and tofus produced thereof were evaluated. Both bean curds had higher protein contents (55.7 and 82.0% dry basis for soy and faba bean curds, respectively) than the corresponding raw beans. Tofu made from faba bean (FBT) contained only 1.5% total lipids (dry basis) compared to 34.4% in soybean tofu (SBT). Antinutritional and flatulence factors were much lower in FBT. Favism factors were not examined. In vitro studies showed that SBT and FBT are comparable in terms of digestibility and amino acid availability.     

Effect of Processing and Storage Conditions on the Fate of Vitamins B1, B2, and C and on the Shelf-Life of Goat's Milk

Goat's milk was heat-processed under different time-temperature conditions of pasteurization and sterilization. Losses of thiamin, riboflavin, and total vitamin C in HTST, Flash, and UHT were less than that by LTLT and Autoclave. Also residual oxygen in the milk affected the loss of total vitamin C during storage. A longer shelf-life of pasteurized milk was obtained with HTST, HTST overpasteurization, and Flash process; however, there was no significant difference between UHT and Autoclave sterilized products. From the above results, HTST pasteurization was considered the best process to preserve milk quality.     

Measurement of Stress-Optical Coefficient and Rate of Stress Release in Commercial Soda-Lime Glasses

A method is described for measuring the stress-birefringence properties of soda-lime glasses in the range 23° to 650°C. Data on three glasses show that the stress-optical coefficient increases slowly with temperature, reaching a definite maximum in the range 570° to 590°C. The same apparatus was used to measure the rate of stress release in two of these glasses. Data obtained under thermal equilibrium conditions can be represented by equations that suggest that two or more concurrent mechanisms are involved in stress release in these glasses within the viscosity range log 12 to log 14.5 (a rapid one of 0.4 to 10 minutes in duration and a slow one of 2 to 60 minutes).