Characterization of evaporated tellurium oxide films

The evaporation of tellurium dioxide was carried out by resistive heating and electron-beam evaporation, and the resulting films were subsequently characterized using X-ray diffraction, infrared absorption spectroscopy and electron diffraction techniques. The infrared results of these films showed a marked deviation from the initial stoichiometry, indicating decomposition of the compound. From X-ray and electron diffraction data, it was found that the films had Te₂O₅ stoichiometry. Electron-beam evaporated films showed single crystal growth on a sodium chloride substrate, while those films obtained by resistive heating were wholly amorphous. Furthermore, when fabricated into capacitors, these films showed high capacitance and high dielectric strength (4.6×10⁶V cm^–1) suitable for passive devices.     

A.C. electrical breakdown in thin magnesium oxide films

A systematic study of a.c. breakdown in magnesium oxide films of thickness 40–200 Å fabricated into capacitors is reported. It is found that the breakdown strength is a power function of the thickness d, varying as d^?0.23, as predicted by the theory of Forlani and Minnaja based on the ionization avalanche mechanism.     

Studies on Triple Base Gun Propellant Based on Two Energetic Azido Esters

Triple base propellant is the workhorse propellant because it possesses several advantages like reduced flash, flame temperature, and erosion of the barrel as compared to double and single base propellant. Hence, efforts are going on worldwide to increase its performance by increasing its energy using energetic plasticizers and binders. In the present article, nonenergetic plasticizer dibutyl phthalate (DBP) is replaced by two energetic azido ester plasticizers, tris(azido acetoxy methyl) propane (TAAMP) and bis(azido acetoxy) bis(azido methyl) propane (BABAMP), in triple base composition and their different properties are studied.

Experimental closed vessel (CV) results (loading density 0.2 g/cm³) clearly indicate that the triple base composition with 2% DBP has force constant 1018 J/g, which is increased to 1026 and 1030 J/g on replacement of DBP by 1 and 2% TAAMP, respectively. Mechanical properties of propellant compositions containing 1 and 2% TAAMP (compression strength 279 and 291 kg_f/cm², percentage compression 11.2 and 10.5, respectively) are also better than those of composition containing DBP (compression strength 275 kg_f/cm² and 10.3% compression). Similarly, 1 and 2% replacement of DBP by BABAMP shows further rise in energy (1032 J/g, 1038 J/g respectively) than that of compositions containing 1 and 2% TAAMP. These two compositions also exhibit better mechanical properties (compression strength 311.2 and 312.3 kg_f/cm², % compression 11.0 and 10.5, respectively) than compositions containing 1 and 2% TAAMP. The differential thermal analysis (DTA) results brought out the fact that the compositions containing energetic plasticizers revealed maximum decomposition temperature in the range of 172–174°C which is close to DBP plasticized triple base gun propellants (174°C). The energetic plasticized propellant compositions of both (TAAMP and BABAMP) showed sensitivity data in the range of (H₅₀ 19 to 22 cm, F of I 25 to 29 and friction insensitivity 19.2 kg) acceptable limit for gun propellant.     

Improvement of Management Parameters in Public Construction Agency

Organizational effectiveness in construction administration covers a vast systemic area of organizational development, role pressure, satisfaction, decision making, cultural and societal influences, confidence and self-esteem, and technical and operational factors. These correspond to Maslow's systemic theory of health. As part of ongoing efforts at the State Department of Engineering Construction (SDEC) to develop its organizational resources, an independent pilot study was undertaken to estimate weak and strong areas of performance, and to assist in the design of intervention programs for further improvement. Comparisons were made between SDEC and private construction-management consulting firms. Analysis of variance (ANOVA) reveals that the organizational effectiveness at SDEC is significantly better than that at the private firms. The low score and high score areas of SDEC were identified, and intervention measures related to weaknesses and strengths also are ongoing. Further studies continue to monitor future performance.     

Unabsorbed Overhead and the Eichleay Formula

One of the less understood elements in construction damage claims is the home office expense that is incurred when a project is delayed. In compensable delay cases, there is no doubt that home office overhead is a legitimate expense of the contractor. However, the methodology for the calculation of the expense incurred has been widely debated as well as the circumstances under which the methodology should be applied. The Eichleay formula was born in 1960, and has come a long way over the past 40 years in its use and application. Court and board decisions have shaped the prerequisite criteria for its application and made it what it is today. This paper provides the background concept of compensable damage due to project delay, the effects of delay on home office overhead, the Eichleay formula evolution, precedence for prerequisite criteria for the formulas’ application, and other formulas and methods that have evolved and been used. A “Direct Method” is proposed by the authors, which is straightforward and simple to apply. In the final analysis, obtaining a 100% accurate estimate of home office expenses is practically onerous. Therefore, representative formulas and techniques are used to arrive at a reasonable value for the unabsorbed overhead.     

Assessment of Organizational Change for Public Construction Organizations

This paper explores change management for restructuring a public construction organization. The paper presents a model for organizational change and studies 20 change-management parameters for three engineering management levels—area engineers, project managers, and project engineers. The researchers studied the perception of engineers and the change process from initiation through completion, starting with forces that destabilize, spreading to awareness and management of anxiety, then acceptance and management of tasks, and finishing with integration and restart. These were examined quantitatively and qualitatively. The study concluded that engineers realize that changes are necessary but they perceive change management negatively. Though most engineers are aware of and committed to change, they perceive the communication of changes to be poor. Recommendations were made to adopt a participative style, improve the commitment of upper leadership, and apply incentives to implement changes. The organizational change model provides a simplified approach for any organization going through the process of change and reengineering.     

Fabrication of damage free micropatterns in silicon

A simple technique is reported for engraving damage free micropatterns in silicon. A pattern is written in PMMA by electron-beam lithography. Local oxidation and chemical etching are used to transfer the pattern into silicon.