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981.
Liya Yi Catriona M.M. Lakemond Leonard M.C. Sagis Verena Eisner-Schadler Arnold van Huis Martinus A.J.S. van Boekel 《Food chemistry》2013
Tenebrio molitor, Zophobas morio, Alphitobius diaperinus, Acheta domesticus and Blaptica dubia were evaluated for their potential as a future protein source. Crude protein content ranged from 19% to 22% (Dumas analysis). Essential amino acid levels in all insect species were comparable with soybean proteins, but lower than for casein. After aqueous extraction, next to a fat fraction, a supernatant, pellet, and residue were obtained, containing 17–23%, 33–39%, 31–47% of total protein, respectively. At 3% (w/v), supernatant fractions did not form stable foams and gels at pH 3, 5, 7, and 10, except for gelation for A. domesticus at pH 7. At 30% w/v, gels at pH 7 and pH 10 were formed, but not at pH 3 and pH 5. In conclusion, the insect species studied have potential to be used in foods due to: (1) absolute protein levels; (2) protein quality; (3) ability to form gels. 相似文献
982.
So far the literature on inventory control for perishable products has mainly focused on (near-) optimal replenishment policies for a stylized environment, assuming no lead-time, no lot-sizing, stationary demand, a first in first out withdrawal policy and/or product life time equal to two periods. This literature has given fundamental insight in the behavior and the complexity of inventory systems for perishable products. In practice, many grocery retailers have recently automated the inventory replenishment for non-perishable products. They recognize they may need a different replenishment logic for perishable products, which takes into account e.g. the age of the inventory in the system. Due to new information technologies like RFID, it now also becomes more economically feasible to register this type of information. This paper suggests a replenishment policy for perishable products which takes into account the age of inventories and which requires only very simple calculations. It will be shown that in an environment, which contains important features of the real-life retail environment, this new policy leads to substantial cost reductions compared with a base policy that does not take into account the age of inventories. 相似文献
983.
Fedderik van der Bos Bernard J. Geurts 《Computer Methods in Applied Mechanics and Engineering》2010,199(13-16):903-915
A computational error-assessment of large-eddy simulation (LES) in combination with a discontinuous Galerkin finite element method is presented for homogeneous, isotropic, decaying turbulence. The error-landscape database approach is used to quantify the total simulation error that arises from the use of the Smagorinsky eddy-viscosity model in combination with the Galerkin discretization. We adopt a modified HLLC flux, allowing an explicit control over the dissipative component of the numerical flux. The optimal dependence of the Smagorinsky parameter on the spatial resolution is determined for second and third order accurate Galerkin methods. In particular, the role of the numerical dissipation relative to the contribution from the Smagorinsky dissipation is investigated. We observed an ‘exchange of dissipation’ principle in the sense that an increased numerical dissipation implied a reduction in the optimal Smagorinsky parameter. The predictions based on Galerkin discretization with fully stabilized HLLC flux were found to be less accurate than when a central discretization with (mainly) Smagorinsky dissipation was used. This was observed for both the second and third order Galerkin discretization, suggesting to emphasize central discretization of the convective nonlinearity and stabilization that mimics eddy-viscosity as sub-filter dissipation. 相似文献
984.
M. C. Raphulu J. McPherson E. van der Lingen J. A. Anderson M. S. Scurrell 《Gold bulletin》2010,43(1):21-28
CO is a useful probe in the characterization of surface properties of both metal and metal oxide via adsorption. Adsorption
of CO was used to monitor the possible active site of an Au/TiO2 catalyst for the CO oxidation reaction. CO adsorption on the reduced catalyst results in the band at 2104 cm−1 indicative of Au0. During the reaction (in the presence of both CO and O2 present) the band is shifted to higher wave numbers indicating non-competitive adsorption on the surface of Au species. This
study also reveals the relationship between the presence of CO (in the absence of oxygen) and the build-up of surface species
such as bicarbonates, formates and carbonate species which decreases the activity of the catalyst. The presence of both the
reduced and the cationic species of Au seem to be requirement for the activity of the catalyst. 相似文献
985.
C. van Trigt 《Color research and application》2010,35(3):164-183
986.
An account is given of a study of the behaviour of three basic wool weft-knitted structures when subjected to ‘shear at constant length of sides’. It was found that all the weft-knitted structures studied had a relatively low over-all shear-resistance when compared with other textile structures, such as woven and non-woven fabrics. This low over-all resistance was found to be a combination of a relatively large frictional restraint and a very low resistance once frictional slippage had started. These and other effects are discussed in terms of the geometrical changes occurring within the knitted unit cell during shearing. 相似文献
987.
Rademaker Arthur R.; van Zuiden Mirjam; Vermetten Eric; Geuze Elbert 《Canadian Metallurgical Quarterly》2011,120(2):299
Psychological trauma and prolonged stress may cause mental disorders such as posttraumatic stress disorder (PTSD). Pretrauma personality is an important determinant of posttraumatic adjustment. Specifically, trait neuroticism has been identified as a risk factor for PTSD. Additionally, the combination of high negative affectivity or neuroticism with marked social inhibition or introversion, also called Type D personality (Denollet, 2000), may compose a risk factor for PTSD. There is no research available that examined pretrauma Type D personality in relation to PTSD. The present study examined the predictive validity of the Type D personality construct in a sample of Dutch soldiers. Data were collected prior to and 6 months after military deployment to Afghanistan. Separate multiple regression analyses were performed to examine the predictive validity of Type D personality. First, Type D personality was defined as the interaction between negative affect and social inhibition (Na × Si). In a second analysis, Type D was defined following cutoff criteria recommended by Denollet (2000). Results showed that negative affectivity was a significant predictor of PTSD symptoms. Social inhibition and the interaction Na × Si did not add to the amount of explained variance in postdeployment PTSD scores over the effects of childhood abuse, negative affectivity, and prior psychological symptoms. A second analysis showed that Type D personality (dichotomous) did not add to the amount of explained variance in postdeployment PTSD scores over the effects of childhood abuse, and prior psychological symptoms. Therefore, Type D personality appears to be of limited value to explain development of combat-related PTSD symptoms. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
988.
van der Velden Peter G.; Kleber Rolf J.; Grievink Linda; Yzermans Joris C. 《Canadian Metallurgical Quarterly》2010,2(2):135
The extent to which the frequency of facing aggression incidents is associated with mental health problems among police officers when organizational stressors, life-events, and previous mental health problems are taken into account is unclear. To elucidate this data from a longitudinal study of police officers was analyzed (N = 473). Mental health problems (MHPs) are here defined as severe anxiety, depression, hostility, burnout symptoms, and/or sleeping problems according the SCL-90–R and MBI. All MHPs were assessed at baseline and 27 months later. Logistic regression showed that serious threat was statistically significant associated with MHPs at follow-up among officers without MHPs at baseline, but not among those with MHPs at baseline. However, stepwise logistic regression showed that serious threat and/or physical aggression were not independently associated with MHPs at follow-up. Organizational stressors, that is, problems with colleagues were independent predictors in all analyses. Among the total study sample, previous MHPs were the strongest independent predictors. These findings suggest superiors should attend to the mental health, organizational stressors and life-events of their officers regularly and not only following critical incidents at work. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
989.
We consider a small traditional retailer that is managing its inventory under strict cash constraints, mainly because typically informal loans are offered to customers. These stores are widely present in emerging markets, and we refer to them as nanostores (also called ‘mom-and-pop stores’). As the suppliers require immediate payments for goods delivered, a nanostore can only replenish products to the level for which it has on-hand cash available. To improve delivery efficiency, a supplier might offer a nanostore credit for its replenishments. However, currently, suppliers are often reluctant to do so as these nanostores quickly go bankrupt or disappear, hence defaulting on all outstanding credits. The objective of this paper is to determine when it is beneficial to offer supplier credits. We propose a multi-period, stochastic inventory model, and numerically compare scenarios with and without supplier credits. Our study shows that even in the presence of this risk, suppliers often have good incentives to provide these credits, even if interest is not incurred. For this to hold, the operations of the retailer should be (a little) profitable in the first place, for which we provide analytical conditions. 相似文献
990.
Proportional symbol maps visualize numerical data associated with point locations by placing a scaled symbol—typically an
opaque disk or square—at the corresponding point on a map. The area of each symbol is proportional to the numerical value
associated with its location. Every visually meaningful proportional symbol map will contain at least some overlapping symbols.
These need to be drawn in such a way that the user can still judge their relative sizes accurately. 相似文献