Dietary α-Tocopheryl Acetate Enhances Beef Quality in Holstein and Beef Breed Steers

The effect of long-term feeding (252 days) of three supplemental levels of α-tocopheryl acetate (actual 0, 360 and 1290 IU/head/day) on meat quality was evaluated in Holstein and beef breed steers. Tissue vitamin E concentrations were increased by each increment of supplementation. The color display life of fresh beef under simulated retail conditions was extended 2 to 5 days by vitamin E and lipid oxidation was markedly reduced. Microbial population was not affected by level of supplementation. No deterioration in sensory quality occurred for steaks from supplemented steers that were displayed until the time steaks from unsupplemented steers discolored.     

A QFT-type design methodology for a parallel plant structure and its application in idle speed control

Developed in this paper is a frequency domain design methodology for disturbance rejection in a MISO plant which has a special parallel structure. Shown in this paper is that it is not necessary to close all the parallel loops in order to achieve the hard time domain constraints. The proposed methodology is applied to the idle speed control of a fuel-injected engine.     

DIRECT REDUCTION OF MIXED MAGNETITE AND COAL PELLETS USING INDUCTION HEATING

A low-temperature process for iron-making, using mixed pellets of magnetite and domestic coal with an organic binder was investigated. Reduction tests performed in an induction furnace resulted in a product direct reduced iron (DRI) containing 75–80% metallic iron. The coal energy consumption of 23.71?GJ/ton DRI compares favorably with current DRI processes, although the total energy consumption of 33.65?GJ/ton is relatively high for iron-making. The use of low-grade coal as a reductant may improve the economics of the process as high-grade coking coal supplies dwindle worldwide.     

Analysis of robot positioning error

Positioning errors of robots used for material handling and assembly can be sufficiently large to cause problems. These errors are due to imperfect repeatability of the robots, and their effects can be ameliorated or exacerbated by tolerances on the workpieces and on the jigs and fixtures. In this paper, a model for characterizing the positioning errors of robots is developed. A statistical analysis of positioning error data is performed to make inferences about the stochastic nature of the robotic system. The basic issue is whether the positioning errors of the robot are state dependent or state invariant.     

Optimal specialization of a maintenance workforce

This article develops an analytical method for determining an optimal specialization strategy for a maintenance workforce. The method assumes that maintenance tasks are generated by a system of statistically identical machines that experience random malfunctions and require periodic service. The impact of alternative workforce structures on system performance is evaluated with a queueing network model. Markov decision analysis is employed to determine an optimal assignment of maintenance personnel to pending tasks as the network status varies over time. A linear programming algorithm is derived to enable simultaneous optimization of specific assignment decisions and the overall workforce structure. A manufacturing example demonstrates the applicability of the method to many industrial contexts. The method is also applied to the problem of maximizing military aircraft sortie generation subject to a constraint on maintenance personnel expenditure.     

Visual and Spectrophotometric Evaluations of Beef Color Stability

Slices of longissimus and gluteus medius muscles from 96 beef steers were displayed under simulated retail display conditions. Meat color display life was calculated by methods termed (1) change between days and (2) days to threshold. The days to threshold approach yielded estimates of color display life which were more consistent among slaughter groups of steers and within muscles. Longissimus had a longer color display life than gluteus medius. Reflectance measurements of beef color provided similar relative estimates of color display life as visual assessment. The accumulation of metmyoglobin at the onset of discoloration was associated with variances which were more homogeneous than those for percentage discoloration determined by visual assessment.     

GATED COMMUNITIES AND SPATIAL INEQUALITY

ABSTRACT: In this article we analyze gated communities as a nexus of social and spatial relations within the context of urban inequality. We apply Tickamyer's (2000) sociological framework for incorporating space into the study of inequality, which allows us to substantiate the arguments that the process of gating increases urban inequality. The contributions of this article are three: (1) We generate a new systematic theoretical approach toward the study of gated communities, which we consider as middle range theory; (2) We argue that gated communities reproduce the existing levels of social stratification and that they also define a new, permanent differentiation order in the spatial organization of cities in the United States (in this respect we also arrive at six hypotheses, which can be tested in future research); (3) We introduce the term “gating machine,” where the combination of the interests and actions of local governments, real estate developers, the media, and consumers suggest that prevailing structural conditions assure the future proliferation of gated communities.     

Improvement of Color and Lipid Stability in Beef Longissimus with Dietary Vitamin E and Vitamin C Dip Treatment

The effects of dietary vitamin E supplementation and vitamin C dip treatment on color and lipid stability in longissimus muscle from Holstein and crossbred beef steers were studied during 16 days of display at 4°C. Dietary vitamin E supplementation retarded metmyoglobin formation of the meat and highly suppressed lipid oxidation compared to the control. Holstein longissimus showed higher metmyoglobin formation than crossbred beef longissimus. Dip treatment with a vitamin C solution was effective in maintaining stability of beef color and lipid.     

Corrosion of Phosphorus Oxynitride Glasses in Water and Humid Air

Phosphorus oxynitride (PON) glasses, prepared by remelting phosphate glasses in anhydrous ammonia vapor, are more resistant to dissolution in water and corrosion in humid environments than the parent phosphate glasses. The chemical durability of PON glasses is directly related to their nitrogen content. Solution analyses, pH stat titrations, and hydrogen depth profiles suggest that nitrogen improves the durability of phosphate glasses by cross-linking the polymeric phosphate chains in the network structure.