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41.
Twenty-nine selected styles of subprimals or sections of veal were obtained from a commercial facility to assist in the development of a support program for retailers. They were fabricated into bone-in or boneless retail cuts and associated components by trained meat cutters. Each style selected (n = 6) was used to generate mean retail yields and labor requirements, which were calculated from wholesale and retail weights and processing times. Means and standard errors for veal ribs consisting of five different styles (n = 30) concluded that style #2, 7-rib 4 (10 cm) x 4 (10 cm), had the lowest percentage of total retail yield (P < .05) owing to the greatest percentage of bone. Furthermore, rib style #2 required the longest total processing time (P < .05). Rib styles #3, 7-rib chop-ready, and #5, 6-rib chop ready, yielded the greatest percentage of total retail yield and also had the shortest total processing time (P < .05). Within veal loins, style #2, 4 (10 cm) x 4 (10 cm) loin kidney fat in, had the greatest percentage fat (P < .05). Loin styles #2 and #3, 4 (10 cm) x 4 (10 cm) loin special trimmed, generated more lean and fat trimmings and bone, resulting in lower percentage of total retail yields than loin style #1, 0 (0 cm) x 1 (2.5 cm) loin special trimmed (P < .05). Results indicated that bone-in subprimals and sections required more processing time if fabricated into a boneless end point. In addition, as the number of different retail cuts increased, processing times also increased.  相似文献   
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43.
In the microscopic theory of Bose-condensed liquids, the condensate wave function leads to a coupling of the density fluctuations and the single-particle excitations. A simple parametrized model of this based on coupling weakly damped zero-sound modes with strongly damped free-particle-like excitations Q 2/2m* explains why the phonon-roton resonance inS(Q, ) for superfluid4He exists above and belowT but only plays the role of an elementary excitation belowT . It is pointed out that this model also predicts thatS(Q, ) should exhibit a weak, low-frequency peak centered atQ 2/2m*, with weight roughly proportional to the condensate fractionn 0. As a stimulus to further experimental searches for this branch, some model calculations are given forS(Q, ) forQ1 Å–1.  相似文献   
44.
Summary The throughput of a satellite channel communication is depending upon the link protocol. It is well known that the classical HDLC protocol is inadequate when applied to satellite links instead of short terrestrial links. Several modifications have been proposed to overcome this problem. The present paper gives an analysis and evaluation of a new class of protocols called Virtual Subchannel schemes which splits the satellite link into several components; these subchannels are assigned for transmission in cyclic order and are controlled independently of each other by the classical HDLC procedure.  相似文献   
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46.
A simple electronic circuit is proposed as an analog of the excitable membrane. It is based on the Hodgkin-Huxley model and their squid axon voltage clamp data. The simulated potassium and sodium conductances are reproduced satisfactorily and the electronic action potentials are very similar to the experimentally recorded ones. Since this analog contains only a few electronic elements, it is small and inexpensive to build. It could be very useful as a means of simulating a wide variety of membrane conductances and different types of action potentials. Also, the simplicity of the circuit makes it an ideal unit to build complex neuron networks.  相似文献   
47.
We have investigated the axial distribution of the liquid phase in a three-phase fluidized bed in which the particles were glass beads of two different diameters, 710-850 μm and 2 mm. Two methods were used to reduce the axial heterogeneity and homogenize the bed: the use of packing elements and the addition of a small quantity of a high molecular weight polymer. The use of packing elements was shown to be very efficient in controlling phases distribution in the bed. The packing consisted of 1 mm thick steel horizontal plates punched and stretched to obtain parallelogram-shaped openings. The addition of a high molecular weight polyisobutylene (BASF Oppanol B246, Mu, =6.15 Lo6) on the phase distribution was also studied. Low polymer concentrations up to 397 ppm (based on the liquid phase) were investigated. The addition of the polymer reduced bubble coalescence and allowed for a better distribution of the phases.  相似文献   
48.
A surfactant‐free method to produce responsive polymer microgels is introduced. As an example, poly(methacrylic acid) hydrogels with varying crosslinking density have been synthesized in bulk and then chopped using a high shear mechanical cutter to form microgel particles dispersed in water. The mechanical cutting technique enables the concentration and particle size distribution of the microgel suspensions to be easily controlled, therefore making the rheology of the suspensions tuneable. The particle size distribution of the dispersions, characterized using light scattering, was dependent on the speed and duration of mechanical cutting. The particle size distribution also depended on the degree of crosslinking of the hydrogel. The higher the crosslinking density, the lower the average mean diameter of the resulting microgel particles. The lower the crosslinking density of the hydrogel, the larger the difference between the maximum and minimum particle size. The time to complete swelling of the particles upon change in pH was measured to be up to 45 s, depending on the particle size. The rheology of the resulting suspensions as a function of pH was investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 104: 1912–1919, 2007  相似文献   
49.
Reaction‐induced vitrification takes place in the network‐forming epoxy–amine system diglycidyl ether of bisphenol A (DGEBA) + methylenedianiline (MDA) when the glass‐transition temperature (Tg) rises above the cure temperature (Tcure). This chemorheological transition results in diffusion‐controlled reaction and can be followed simultaneously with the reaction rate in modulated‐temperature DSC (MTDSC). To predict the effect of Tcure and the NH/epoxy molar mixing ratio (r) on the reaction rate in chemically controlled conditions, a mechanistic approach was used based on the nonreversing heat flow and heat capacity MTDSC signals, in which the reaction steps of primary (E1OH = 44 kJ mol?1) and secondary amine (E2OH = 48 kJ mol?1) with the epoxy–hydroxyl complex predominating. The diffusion factor DF as defined by the Rabinowitch approach expresses whether the chemical reaction rate or the diffusion rate determines the overall reaction rate. A model based on the free volume theory together with an Arrhenius temperature dependency was used to calculate the diffusion rate constant in DF as a function of conversion (x) and Tcure. The relation between x, r, and Tg, needed in this model, can be predicted with the Couchman equation. An experimental approximation for DF is the mobility factor DF* obtained from the heat capacity signal at a modulation frequency of 1/60 Hz, normalized for the effect of the reaction heat capacity in the liquid state and the change in Cp in the glassy region with x and Tcure. In this way, an optimized set of diffusion parameters was obtained that, together with the optimized kinetic parameters set, can predict the reaction rate for different cure schedules and for stoichiometric and off‐stoichiometric mixtures. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2814–2833, 2004  相似文献   
50.
Recent progress in road and lane detection: a survey   总被引:2,自引:0,他引:2  
The problem of road or lane perception is a crucial enabler for advanced driver assistance systems. As such, it has been an active field of research for the past two decades with considerable progress made in the past few years. The problem was confronted under various scenarios, with different task definitions, leading to usage of diverse sensing modalities and approaches. In this paper we survey the approaches and the algorithmic techniques devised for the various modalities over the last 5 years. We present a generic break down of the problem into its functional building blocks and elaborate the wide range of proposed methods within this scheme. For each functional block, we describe the possible implementations suggested and analyze their underlying assumptions. While impressive advancements were demonstrated at limited scenarios, inspection into the needs of next generation systems reveals significant gaps. We identify these gaps and suggest research directions that may bridge them.  相似文献   
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