MANAGEMENT SUPPORT SYSTEM AT PROMUS Using IT to Ensure Customer Satisfaction

Information-based organizations are structured to function with as small and efficient a staff as possible. To this end, executives at The Promus Companies are using IT to spread decision-making authority and responsibility for customer satisfaction and customer service throughout the organization.     

The use of topology optimization in disposing carbon fiber reinforcement for concrete structures

A topology optimization procedure is presented as a tool for determining the distribution of external strengthening of concrete slabs, using Carbon Fiber Reinforced Polymer (CFRP). Although the procedure is applied to slabs in this work, the technique can be used in any concrete structure to be reinforced. Numerical simulations are performed using the Finite Element Method, in combination with the automated topology optimization procedure, to indicate the optimal region for placement of the reinforcement. The influence of some aspects of the slab’s structural behavior on the optimization results is presented: concrete cracking, boundary conditions and reinforcement rate. A brief discussion is given of the similarity between the topology optimization results obtained by the maximum stiffness and ultimate strength criteria. Gains are found in the stiffness and strength of reinforced parts. A comparison with conventional reinforcement techniques demonstrates that topology optimization can be a useful tool for defining the region of reinforcement, allowing for material cost savings.     

Influence of Nb2O5 on the varistor behavior of TiO2–Cr2O3 system

This work investigated the influence of Nb₂O₅ dopant on the varistor behavior of the ternary system (99.95 ? x)%TiO₂, 0.05 %Cr₂O₃, x%Nb₂O₅, where x = 0.10; 0.15; 0.20; 0.25 % in mol. The processing was carried out using the conventional oxide mixture method. The initial oxides were homogenized in alcoholic media in a ball mill, for 3 h, dried in oven and isostatically pressed at 210 MPa and sintered at 1,400 °C for 2 h in air atmosphere and cooled at 5 °C/min cooling rate, resulting in pellets with high densification. Electrical measurements in continuous current at different temperatures revealed that for the lowest Nb₂O₅ concentration the breakdown electric field, E_B = 4.41 V/cm and non-linear coefficient, α = 4.6 were obtained, and for the highest Nb₂O₅ concentration the breakdown electric field, E_B = 9.71 V/cm and non-linear coefficient, α = 15.3 were obtained. These low values in the breakdown electric field enable these varistor systems to be used in protection systems for low-voltage energy grids. Changes in the potential barrier present in the grain–grain boundaries could also be observed, in which the height increased and the width decreased with the increase in the dopant concentration. However, for x = 0.25 % in mol Nb₂O₅, a significant reduction in the potential barrier height and the voltage per barrier was obtained. Furthermore, the tendency to increase the volume of the unitary cell with the increase of dopant concentration, which was interrupted in the system with 0.25 % Nb₂O₅, was another evidence that suggested the occurrence of Nb₂O₅ segregation in the grain boundaries, or even that the reduction in the average grain size could possibly dilute Nb₂O₅ concentration in the grain boundaries. The average grain size was calculated through SEM micrographs and ranged from 7 to 16 μm, with larger sizes occurring for lower dopant concentrations and presenting higher porosity and lower uniformity in the grains shape.     

Influence of graded interfaces on the exciton energy of type-I and type-II Si/Si<Subscript>1-<Emphasis Type="Italic">x</Emphasis></Subscript> Ge<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> quantum wires

The exciton properties of Si/Si _1-x Ge _x cylindrical quantum wires (QWRs) are calculated using the variational method and taking into account the existence of an interface layer between the materials. We consider two possibilities for the conduction band lineup, type-I and type-II. Our numerical results show that an interfacial fluctuation of 15Å in a Si _0.85 Ge _0.15 (Si_0.70Ge_0.30) type-I (type-II) wire of 50Å wire radius leads to an exciton energy blue shift of the order of 10 (10) meV.     

Strain Effects and Spalling in Alpha-Bombarded ThO2

Samples of bulk polycrystalline ThO₂ were bombarded with 5-MeV α-particles to doses between 9.4×10¹⁶ and 6.0×10¹⁷ ions/cm². The sample which received the highest dose spalled during bombardment; those receiving lower doses either did not spall or did so only after postirradiation annealing. The spalling was investigated by X-ray analysis and replica and transmission electron microscopy. It is concluded that spalling resulted from severe lattice strains at the interface between damaged and undamaged material and that sintering pores played a part in the fracture process. The role of lattice defects in initiating fracture is discussed.     

Endotracheal naloxone reversal of morphine-induced respiratory depression in rabbits

In an emergency, intravenous access may be difficult to obtain rapidly. Alternate routes of administration for drugs are, therefore, desirable. Our study was performed to determine if naloxone could be efficacious in reversing morphine-induced respiratory depression in rabbits when administered using the endotracheal route. Our results indicate that naloxone administered in this fashion is effective in reversing morphine-induced respiratory depression in the rabbit. Mean minute ventilation was depressed to greater than half of resting baseline levels using morphine sulfate. Endotracheally administered naloxone reversed this respiratory depression and resulted in a greater than five-fold increase in mean minute ventilation above baseline levels. We concluded that endotracheal naloxone is efficacious in reversing morphine-induced respiratory depression in the rabbit. The endotracheal route may be an effective alternative for naloxone administration in man when rapid intravenous access is not obtainable.     

Disaccommodation of Mn-Zn Ferrite After Temperature Cycling

It was shown that cycling Mn-Zn ferrite through or near the temperature of the zero crossing of the anisotropy constant K ₁ makes significant changes in the domain patterns and thus changes in disaccommodation rates. For the ferrite studied, with a secondary peak in permeability at—65°C, cycling to −80° or rapid cooling to −40° from room temperature affected the permeability and disaccommodation in a manner very similar to that of an ac demagnetization. Likely mechanisms which may explain these effects are discussed.     

Mechanism of Creep in MgO Brick

Creep of selected brands of periclase refractories was studied using rate process theory to provide information on activation energy and on the dominant method of deformation. A brand studied over the range 2200° to 2600°F at 25 psi gave an activation energy of 62 kcal/mole. All brands were studied at selected stresses and 2500°F to determine the flow mechanism. Plastic flow was indicated for all brands tested.