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81.
Turid Rustad Ivar Storrø Rasa Slizyte 《International Journal of Food Science & Technology》2011,46(10):2001-2014
Fish industry by‐products can account for up to 75% of the catch depending on postharvest or industrial preparation processes. Different terms such as ‘fish waste’, ‘by‐product’ and ‘rest raw materials’ have been used. The review gives an overview of value‐added processes that provide an alternative to low‐profit uses such as silage, fish meal and mince. The preparation of different by‐product fractions such as fish blood, marine lipids, omega‐3 fatty acids, fish protein fractions and bioactive components with nutraceutical potential, i.e. antioxidants and bioactive peptides, is considered. There are several future opportunities for the preparation of high‐value by‐products such as enzymes, minerals and other bioactive substances including hydroxyapatite, phosphorus, taurine and creatine. Both regulatory status and future market potential need to be considered. In addition, there is a need for technologies that maintain good quality by‐products and ‘simple’ processes to produce bulk products for further refining. 相似文献
82.
Fjell Anders M.; Westlye Lars T.; Espeseth Thomas; Reinvang Ivar; Dale Anders M.; Holland Dominic; Walhovd Kristine B. 《Canadian Metallurgical Quarterly》2010,24(2):258
Burgmans, van Boxtel, Vuurman, et al. (2009) published an interesting study titled “The Prevalence of Cortical Gray Matter Atrophy May Be Overestimated in the Healthy Aging Brain” on how subclinical cognitive disorders may affect correlations between age and cortical volume. Correlations between cortical gray matter volume and age were found in 30 elderly with cognitive decline after 6 years, but not in 28 elderly without cognitive decline. This study is important, and demonstrates that preclinical cognitive disorders may affect cortical brain volumes before being detectable by neuropsychological tests. However, we are not convinced by the conclusions: “… gray matter atrophy… is to a lesser extent associated with the healthy aging process, but more likely with brain processes underlying significant cognitive decline” (p. 547) and “… cortical gray matter atrophy in the aging brain may be overestimated in a large number of studies on healthy aging” (p. 547). We analyzed the cross-sectional MR data (n = 1,037) as well as longitudinal data from a sample of very well-screened elderly followed by cognitive testing for 2 years. In the cross-sectional data, the correlations between age and brain volumes were generally not much reduced when the upper age limit was lowered. This would not be expected if age-related incipient cognitive disorders caused the correlations given that the incidence of cognitive decline increased with age. Longitudinally, 1-year atrophy was identified in all tested regions. It is likely that cortical brain atrophy is manifested in cognitively normal elderly without subclinical cognitive disorders. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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85.
The electronic charge carrier concentration in La1?x Sr x FeO3?δ was shown to depend on the partial pressure of O2 (pO 2). Chemical diffusion coefficient and surface exchange coefficient, k chem, were determined by conductivity relaxation in O2/N2 and CO/CO2 mixtures. k chem was proportional to pO 2 1.06 in O2/N2, while in CO/CO2 k chem was controlled by a reaction mechanism involving both CO and CO2. 相似文献
86.
Joseph Van Sant David Diercks Theo Fett Ivar E. Reimanis 《Journal of the American Ceramic Society》2019,102(11):6552-6563
Degradation of glass under zero applied load in the presence of humidity at ambient temperature is of great interest to the container and fiber glass industries. The phenomenon is well documented for fused silica used in optical fibers, but has not been studied in detail for multi-component glasses. In this work notches of varying length (500-1500 nm) were placed with a focused ion beam into two types of multi-component glass fibers, E-glass (48 μm diameter) and soda-lime-silicate (35 μm diameter). Notched specimens were exposed to dry and humid conditions for up to 32 days. Transmission electron microscopy revealed the presence of extensive reaction products within the root of the notch, even after only 1 day of aging in the nominally dry environment for the soda-lime-silicate glass. Surprisingly, the extensive reactions have no measurable effect on the fiber strength. The uniaxial tensile strength of the notched glass fibers, measured with the fracture surface mirror radius method, does not follow a classic fracture mechanics prediction, implying that the notches are not classic Griffith flaws. Fracture mechanics is applied to show that sharpness at the notch base may be important, especially when subcritical crack growth is present during the strength measurement. 相似文献
87.
Andrew N. Winter ‡ Brian A. Corff Ivar E. Reimanis § Barry H. Rabin 《Journal of the American Ceramic Society》2000,83(9):2147-2154
Composites of nickel and Al2 O3 with compositionally graded microstructures were fabricated from powders through an empirically determined thermal-behavior-matching process that was designed to minimize processing-induced stresses. Compositions ranged from pure Al2 O3 to pure nickel. Specimen geometries included round disks 25 mm in diameter and 5–25 mm thick, as well as rectangular bars 25 mm × 25 mm in cross section and 75 mm long. Several different gradients were produced, including samples with single interlayers. Compacts were formed by cold uniaxial pressing in a die, followed by consolidation through sintering at 1 atm or hot isostatic pressing. Several different particle sizes of nickel and Al2 O3 comprised the composite interlayers. The compaction behavior, sintering start temperature, sintering rate, and total linear shrinkage of each composition were evaluated. Careful data analysis, coupled with sintering theory, led to a layer configuration with matched green density and sintering behavior. Thermomechanically matched layers allowed large, crack-free, graded composites to be produced. 相似文献
88.
The need for materials for demanding optical applications has engendered a resurgent interest in transparent ceramics. Transparent polycrystalline magnesium aluminate spinel is one especially promising and rapidly maturing technology that can fill this niche. Although it has been studied for over 50 yr, it is only recently that highly transparent components with acceptable mechanical properties have been reliably fabricated at reasonable cost. Development has been hindered by the inherent difficulty in sintering spinel to the near‐theoretical density required for transparency, a high sensitivity to powder and processing parameters, variable stoichiometry, and a lack of understanding of the synthesis–processing–property relationships. The driver of recent success is an emerging understanding of complex, multiscale, multivariable interactions that occur during green‐body formation and sintering. In particular, certain key variables play a decisive role in determining compact properties and their evolution must be controlled from synthesis to the finished product. This article features the interactions between these key variables during processing and gives an exposé of the state of the art in transparent polycrystalline spinel fabrication. 相似文献
89.
Keith Rozenburg J. R. Berger Paul A. Martin Ivar Reimanis 《International Journal of Fracture》2007,143(3):207-217
The analysis of moiré data obtained in bimaterials with near-interface cracks is examined. To extract stress intensity factors,
a collocation-type method is developed where Westergaard crack-tip expansions are used for displacements in the cracked portion
of the bimaterial, expansions from the method of fundamental solutions are used for displacements in the uncracked portion
of the bimaterial, and continuity conditions at the interface are used to couple the two expansions. Proof-of-principle numerical
experiments performed on synthetic data from a boundary element analysis of a cracked bimaterial successfully demonstrated
the analysis method. Mixed-mode stress intensity factors were then determined from actual moiré data obtained in a copper–tungsten
specimen. 相似文献
90.
众多的软件开发过程到底是为我们解决的问题多,还是造成的问题更多?它们是否真的能够为改进团队的工作方式提供深刻的见解和所需的指导?文中对当代软件开发过程所面临的问题做了深刻的分析,并指出为什么我们现在拥有如此多的过程。 相似文献