Experimental force modeling for deformation machining stretching mode for aluminum alloys

Deformation machining is a hybrid process that combines two manufacturing processes—thin structure machining and single-point incremental forming. This process enables the creation of complex structures and geometries, which would be rather difficult or sometimes impossible to manufacture. A comprehensive experimental study of forces induced in deformation machining stretching mode has been performed in the present work. A table-type force dynamometer has been used to record the deforming forces in three Cartesian directions. The influence of five process parameters—floor thickness, tool diameter, wall angle, incremental step size, and floor size on the deforming forces—is investigated. Individual as well as combined empirical models of the parameters with regard to the forces have been formed. The results of this study indicate that the average resultant force primarily depends on the floor thickness to be deformed and the incremental depth in the tool path. This could be due to the variation in local stiffness of the sheet with change in floor thickness. The effect of tool diameter, deforming wall angle, and floor size is not significant.     

Effects of Gamma Irradiation on Proteins and Fatty Acids of Soybean

Two hundred grams of soybean seeds (moisture contents of 7.4, 15.3, 22.5, and 30.5%) were irradiated at dose levels of 0, 1, 5, 10, 20, 40, 60, 80 and 100 KGy using Cobalt-60 source. Radiation dose of 100 KGy caused a decrease in the percentage of nitrogen solubility from 80.3 to 67.2, 80.3 to 57.8, and 68.1 to 48.8 when deionized H₂O, 0.6M NaCl, and 0.2M Cacl₂ were used as solvents, respectively. Inhibition of 71% of lipoxygenase activities, 25.4% trypsin inhibitor activities, and 16.7% chymotrypsin inhibitor activities were found when the soybean seeds were irradiated at 100 KGy.     

CORRELATION OF TIME-TEMPERATURE INDICATOR RESPONSE WITH MICROBIAL GROWTH IN PASTEURIZED MILK

Commercially obtained pasteurized whole milk was stored at three constant temperatures (0°C, 5°C, and 10°C), and one variable temperature condition (cyclic exposure of 0°C for 14 days and 10°C for 2 days). Daily analyses were conducted to enumerate the growth of total bacteria, coliforms, psychrotrophs, and spore forming organisms in samples from each storage treatment. Microbial growth was correlated with the response of the I-POINT and LifeLine full-history time-temperature indicators. Response of the I-POINT model 2140 was strongly related to germination of the psychrotrophic bacteria, and significant correlations (r > 0.95) were found between total count enumeration and the LifeLine model 57 indicator.     

Grain Extract-Milk Beverage: Processing and Physicochemical Characteristics

Extracts from germinated barley, wheat, triticale, and corn showed compatibility when blended with milk in proportions of 30%, 40%, and 50%, respectively. The pH of grain extract-milk blends initially adjusted to 7.2 decreased to pH 6.2-6.4 when processed in bottles at 121°C for 15 min. The wheat and barley extract beverages scored highest preference followed by triticale and corn beverages. The beverage has excellent malty taste and smooth mouth feel.     

Studies on the skin uptake and efflux kinetics of N-phenyl-p-phenylenediamine: an aromatic amine intermediate

N-phenyl-p-phenylenediamine (N-PPDA), an industrial intermediate and hair dye ingredient, has been implicated in a variety of toxic symptoms including cutaneous manifestations. However, the role of physiological factors that may determine and modify its absorption and transport within and through the skin is not fully understood. The present study reveals that N-PPDA binds readily to skin showing saturation kinetics with K m and V_max of 2.54 × 10⁻⁴ M and 4.76 μmol g⁻¹ skin, respectively. The uptake was dependent upon the area of skin, concentration of the amine, exposure time, temperature and pH of the vehicle. Heat treatment facilitated the binding but temperatures abouv 50° caused significant lowering of the uptake, indicating the possible involvement of collagen matrix. Skin lipids also contributed in the binding of N-PPDA. Bioinhibitors such as KCN, sodium arsenate, NaF, N-ethylmaleimide, cycloheximide, iodoacetic acid and 2,4-dinitrophenol had no effect on the uptake potential, suggesting it to be a non-energy dependent process. Most of the skin-bound N-PPDA was effluxed through serum proteins reaching the target organs via systemic circulation.     

Surface Characteristics of Sodium (β-Alumina Electrolytes

Surfaces of sodium β/β"-alumina ceramics were characterized via techniques such as scanning electron microscopy, secondary ion mass spectroscopy, and electron spectroscopy for chemical analysis to determine the nature of the resistive surface film that leads to the phenomenon of asymmetric polarization in a sodium-sulfur cell. The results indicated that the resistive surface film is soda rich, has submicrometer thickness, and is removable by a surface treatment. A mechanism consistent with these observations is proposed for the formation of the resistive surface film on sodium β/β"-alumina during the sintering process.     

NATURAL AND APPLIED WAX COATINGS ON ORANGES

Scanning electron microscopy was used to examine the wax coating on oranges. The natural wax platelets are irregular in shape and size, have a rough surface and increase in numbers as the orange matures. Most natural platelets can be removed by dipping the orange in a chloroform-methanol solution and rubbing the surface. Store-bought oranges have natural wax platelets 1–2 microns thick covered with a 2–5 micron layer of commercial wax. Wax applied over platelets may be ineffective if the platelets break off in handling and expose the orange's surface. Removal of natural wax platelets prior to commercial waxing allows uniform wax application and consequently better storage life. Drying with air at 2.5 m/s produced uneven wax thickness while 14 m/s air produced a complete, uniform wax layer.     

Nutritional Quality of Vegetable Pigeonpeas [Cajanus cajan (L.) Mill sp.]: Mineral and Trace Elements

Mineral and trace elements of green and mature seed of pigeonpea genotypes were determined. Among the genotypes tested a considerable variation was observed in phosphorus, potassium and calcium of both green and mature seeds whereas the variation was small for magnesium. When consumed, green seeds are a richer source of iron, copper and zinc on a dry matter basis than the mature seed whereas there was a reverse trend for manganese. The calcium content of mature seed was significantly higher than green seed and this was attributed to the seed coat content of the mature seed.     

Characterization of silicides in high-temperature titanium alloys

Different types of silicides precipitate in high-temperature titanium alloys depending upon the composition and heat treatment of the alloys. However, there are inconsistencies and lacunae with respect to the chemical and crystallographic characteristics of the silicides and these are pointed out here. Hexagonal silicides s1 (a=0.7804 nm; c=0.5447 nm) and s2 (a=0.701 nm; c=0.368 nm) coexist in the ternary alloy Ti–5Zr–Si; however, only the s2 silicide exists when the addition of stabilizing element is made. In addition, there is no common agreement about the space group of s2 silicide while the space group of s1 silicide was found to be P63/mcm (hP16). The (TiZr)6Si3 stoichiometry of s2 silicide is based on the experimental findings; however, the (TiZr)5Si3 stoichiometry of s1 silicide is simply deduced. Also the orientation relationships of silicides with and phases of the matrix are discussed.