Home About us Contact
|
Home About us Contact | ||
|
|
||
Possible Replacement (possible + replacement)
Selected AbstractsProcessing, mechanical properties, and interfacial bonding of a thermoplastic core-foam/composite-skin sandwich panel,ADVANCES IN POLYMER TECHNOLOGY, Issue 3 2010S. Pappadą Abstract In this work, a thermoplastic sandwich panel was designed, produced, and tested for use in insulating walls of containers for food transportation. A sandwich construction comprising a poly(ethylene terephthalate) core and polypropylene/glass fiber skins was evaluated as possible replacement of systems consisting of polyurethane foam in combination with unsaturated polyester glass-reinforced skins that are currently used for the manufacture of these structures. Factors were taken into account to satisfy the simultaneous need of thermal insulation and adequate mechanical properties that are required for the production of large flat panels 100-mm thick. The influences of different manufacturing processes and skin-core adhesion on the mechanical properties of this thermoplastic sandwich were investigated and are discussed in the text. © 2010 Wiley Periodicals, Inc. Adv Polym Techn 29:137,145, 2010; View this article online at wileyonlinelibrary. DOI 10.1002/adv.20186 [source] VISCOUS PROPERTIES OF TARO FLOUR EXTRUDED WITH WHEY PROTEINS TO SIMULATE WEANING FOODS,JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 3 2002C. I. ONWULATA Taro flour, derived from the corm of Colocasia Esculenta cv. Lehua, a root tuber grown in the tropical regions of the world, was extruded with whey protein concentrate (WPC), whey protein isolate (WPI) or lactalbumin (LAC), to derive blends containing 20% protein, simulating the protein content of some weaning foods. Taro flour is unique because of its extremely small particle size (1,5 micron) and high mucilage or gum content, making it a possible replacement for corn or wheat starch in weaning foods. Extrusion processing temperatures were from 100 to 130C and moisture of the feed blends was held constant at 18%. The extrudates were pulverized, made into powders, and rehydrated to make a paste. Viscosities of the feed blends before extrusion and the pastes made from the extrudates were determined using a Rapid Visco Analyzer (RVA) to determine peak, final, and breakdown viscosities. Water solubility and absorption indices were also determined. Extrudates made from taro containing whey products expanded more than taro alone; were easier to grind into powders; and rehydrated readily in water to form pastes. Before extrusion, the peak viscosities of the blends were 5000, 2600, 1600, 1600 cP for taro flour, taro with WPI, taro with WPC, or taro with LAC, respectively. After extrusion cooking, the viscosities for taro flour, taro with WPI, taro with WPC, or taro with LAC were 110, 65, 70 or 90 cP, respectively. Taro extrudates without protein absorbed the most water, and were more soluble than products containing whey proteins or LAC. The addition of whey proteins reduced peak viscosities, but WPI and taro pastes were characteristic of weaning foods. Both extrusion cooking and the [source] Genetic evaluation of a proposed introduction: the case of the greater prairie chicken and the extinct heath henMOLECULAR ECOLOGY, Issue 7 2004Eric P. Palkovacs Abstract Population introduction is an important tool for ecosystem restoration. However, before introductions should be conducted, it is important to evaluate the genetic, phenotypic and ecological suitability of possible replacement populations. Careful genetic analysis is particularly important if it is suspected that the extirpated population was unique or genetically divergent. On the island of Martha's Vineyard, Massachusetts, the introduction of greater prairie chickens (Tympanuchus cupido pinnatus) to replace the extinct heath hen (T. cupido cupido) is being considered as part of an ecosystem restoration project. Martha's Vineyard was home to the last remaining heath hen population until its extinction in 1932. We conducted this study to aid in determining the suitability of greater prairie chickens as a possible replacement for the heath hen. We examined mitochondrial control region sequences from extant populations of all prairie grouse species (Tympanuchus) and from museum skin heath hen specimens. Our data suggest that the Martha's Vineyard heath hen population represents a divergent mitochondrial lineage. This result is attributable either to a long period of geographical isolation from other prairie grouse populations or to a population bottleneck resulting from human disturbance. The mtDNA diagnosability of the heath hen contrasts with the network of mtDNA haplotypes of other prairie grouse (T. cupido attwateri, T. pallidicinctus and T. phasianellus), which do not form distinguishable mtDNA groupings. Our findings suggest that the Martha's Vineyard heath hen was more genetically isolated than are current populations of prairie grouse and place the emphasis for future research on examining prairie grouse adaptations to different habitat types to assess ecological exchangeability between heath hens and greater prairie chickens. [source] Physical, chemical and environmental properties of selected chemical alternatives for the pre-plant use of methyl bromide as soil fumigantPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 2 2006Luis O Ruzo Abstract Production and use of methyl bromide, a soil fumigant, are being restricted because of this chemical's deleterious effects on stratospheric ozone concentrations. Several products, some of which are currently used as soil fumigants, are being considered as possible replacements for methyl bromide, alone and in various combinations. Among these, 1,3-dichloropropene, methyl isothiocyanate generators such as metam-sodium, and chloropicrin are currently registered, while others such as methyl iodide and sodium azide are at different stages of the registration process. This review examines physicochemical properties, environmental fate, and metabolism of the various potential methyl bromide replacement products. Copyright © 2005 Society of Chemical Industry [source] | ||||||||||