Line width control in electron-beam lithography

A method for predicting line widths in electron beam lithography is described. Computer predictions of line dimension as a function of dose, and profile as a function of proximity to another line are compared with experimental results on 0.35?m thick PMMA at a beam energy of 15 keV.     

Isolation of fatty acids from an egyptian petroleum

A mixture of straight-chain fatty acids (from C₇ to C₁₉) was isolated from an Egyptian petroleum via extractive crystallisation with urea. Although the total acidic content in Egyptian petroleum is low, the fatty acids constitute at least 32% of the total acids. n-Pentadecanoic and n-nonadecanoic acids were isolated for the first time from petroleum acids by a sequence involving fractional distillation of the methyl esters, extractive crystallisation with urea and recrystallisation of amide derivatives.     

Power system voltage regulation based on voltage feedback using a dynamic capacitor

Over twenty-four hours of operation of a power system there is a wide variation in the demand, resulting in voltage fluctuation. This fluctuation may be large enough to lead to inefficient and unreliable operation of industrial plants. The fluctuation can be overcome by proper choice of controls (capacitors) located at suitable points on the power networks. To maintain the voltages within tight admissible limits, it is necessary to obtain a complete dynamic model of the generation-transmission system.In this paper, the dynamic model of a power system consisting of a synchronous generator, a transmission line containing four buses, and control capacitors placed at the buses is considered. Two types of control (capacitor) are used to regulate the voltages, (i) a synchronous capacitor and (ii) a static capacitor.A mathematical model of the controls is also presented. In this study, three separate cases of loads at the buses are simulated in the dynamic system. In all the cases the proposed controls are used to regulate the system voltages. The results indicate that, with the variation of loads, the desired voltage regulation can be achieved by proper choice of capacitor controls as functions of time.     

Uncertainty propagation in probabilistic risk assessment: A comparative study

Three uncertainty propagation techniques, namely method of moments, discrete probability distribution (DPD), and Monte Carlo simulation, generally used in probabilistic risk assessment, are compared and conclusions drawn in terms of the accuracy of the results. For small uncertainty in the basic event unavailabilities, the three methods give similar results. For large uncertainty, the method of moments is in error, and the appropriate method is to propagate uncertainty in the discrete form either by DPD method without sampling or by Monte Carlo.     

Modeling the rate of corrosion of carbon steel using activated diethanolamine solutions for CO2 absorption

A mechanistic model is developed to investigate the influence of an activator on the corrosion rate of carbon steel in the absorption processes of carbon dioxide (CO₂). Piperazine (PZ) is used as the activator in diethanolamine (DEA) aqueous solutions. The developed model for corrosion takes into consideration the effect of fluid flow, transfer of charge and diffusion of oxidizing agents and operating parameters like temperature, activator concentration, CO₂ loading and pH. The study consists of two major models: Vapor-liquid Equilibrium (VLE) model and electrochemical corrosion model. The electrolyte-NRTL equilibrium model was used for determination of concentration of chemical species in the bulk solution. The results of speciation were subsequently used for producing polarization curves and predicting the rate of corrosion occurring at the surface of metal. An increase in concentration of activator, increases the rate of corrosion of carbon steel in mixtures of activated DEA.     

Performance Evaluation for Transform Coding Using a Nonseparable Covariance Model

Intraframe transform coding of pictures for the case of a nonseparable covariance model is considered. Performances of the Walsh-Hadamard, discrete cosine and Karhunen-Loeve transforms are compared based on the compaction of signal energy in the transform components, and, the degree of decorrelation of the data. The results demonstrate that the performances of the discrete cosine and Karhunen-Loéve transforms compare closely, as is the case with a separable covariance model. The corresponding performance of the Walsh-Hadamard transform is inferior.     

Personality characteristics and socioeconomic variables.

Conducted a study of 125 male and 128 female heads of household in Ontario, Canada in order to determine the relationship between scores on 11 personality scales (from the Personality Research Form, MPI, and CPI) and socioeconomic status and age. Results reveal a number of significant correlations of male Ss with age, household income, occupational status, and educational level. The Dominance scale showed the highest correlation with male Ss' income and educational level. Male non-high school graduates' scores on Harmavoidance and Change scales varied markedly with age level. Although the above findings with regard to age and education applied to both male and female Ss, correlations with male Ss were considerably higher than those with female Ss. (17 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)