Barriers to Increased Engineering Graduate Enrollments: Counterforces and Their Implementation

This paper highlights the role of the faculty member in recruiting students currently enrolled in B.S. programs in engineering and the sciences into full-time pursuit of a graduate-level engineering degree. The faculty member is demonstrated to be in a unique position to influence such students, providing strong counterforces to a confluence of attitudes and pressures experienced during the B.S. experience which effectively create a barrier to full-time engineering graduate study. We analyze this barrier via the method of force field analysis, and demonstrate that effective recruitment into full-time graduate study must be based on a four-fold strategy of education, expectations, improved B.S. experience and better control of the B.S. environment. Approaches to implement these strategies are discussed.     

Solution of the problem of oscillations of laminated plates in geometrically nonlinear statement

The article deals with the problem of oscillations of laminated plates with large deflection. It analyzes the fields of application of the refined theory of shear for its solution.Translated from Problemy Prochnosti, No. 8, pp. 47–52, August, 1993.     

Combined use of laparoscopic cholecystectomy and endoscopic retrograde cholangiography (ERC) and papillotomy (ERCP) in management of cholecysto-choledocholithiasis

In a review of 328 cases the combination of laparoscopic cholecystectomy with specific use of endoscopic retrograde cholangiography (pre- and postoperatively) proved to be a riskless, secure and time-saving procedure. In our opinion this is a minimal invasive method of treatment for patients with cholecysto-/choledocholithiasis.     

3-D time domain BEM analysis with animated graphics

The intense computational requirements of a time domain solution of 3-D elastodynamic problems based on the boundary element method (BEM) have limited its implementation to main frame computers. In this work a simplified 3-D direct time domain BEM is described along with a 3-D interactive animated graphics code custom made to accompany the above BEM analysis. The simplifications introduced make its use efficient and accurate even in a microcomputer environment. Representative numerical results from the dynamic interaction of a rigid square machine foundation with an elastic half space are presented.     

Thermal and thermoelastic properties of fast extrusion furnace (FEF) carbon black loaded SBR vulcanizates

The effect of FEF carbon black as filler on the thermal capacity c, diffusivity a, and thermal conductivity λ, of styrene butadiene rubber (SBR) composites in the temperature range 300–420 K was studied. The filler strongly increases the thermal diffusivity, whilst strongly decreasing the thermal capacity and the thermal conductivity (except at high FEF content ≥80 phr). The influence of the filler on the thermoelastic behaviour of the same composites was also investigated. It was found that the thermoelastic temperature change (ΔT) increased with carbon black concentration as well as the entropy change per unit extension.     

An experimental investigation of thick-sample effects in the measurement of directional-hemispherical transmittance of advanced glazing materials

Samples that are thick with respect to the measuring apparatus can pose problems in the measurement of directional-hemispherical transmittance. Due to the lateral displacement of light that these samples induce, traditional small-beam techniques are often no longer applicable. Broad-area irradiation offers a solution to these problems, but, in practice, imperfections in the extent and the uniformity of the irradiation can create errors. This paper reports measurement of the “detector-integrated inscattering function”, which describes the lateral displacement of light, for a number of thick samples over a range of incidence angles. This function is used to determine the minimum area that must be irradiated for an accurate broad-area irradiation transmittance measurement. The errors caused by transverse non-uniformities in the irradiance distributions produced by a state-of-the-art broad-area irradiation spectrophotometer are also reported. Errors caused by transverse irradiation non-uniformities are estimated, and transmittance measurements made with small-area and broad-area irradiation are compared. It is shown that in most cases small-area irradiation transmittance measurements underestimate the transmittance of thick samples due to outscattering, and that broad-area irradiation measurements using state-of-the-art irradiation optics can contain large errors of up to 20%, due to irradiance non-uniformities, particularly at large angles of incidence.     

FLOW OF SAND-WATER MIXTURES AT VELOCITIES BELOW THE DEPOSITION CONDITION

An experimental study of sand-water flow in a horizontal pipeline has been conducted for the regime in which a stationary deposit was present. The particle diameter ranged between 0.2 mm and 0.01 mm and the particles were not flocculated. Axial pressure gradients and delivered concentrations were measured as functions of mean velocity and in-situ concentration.

A three layer model was found to be useful to predict the pipeline behavior at all but the lowest velocities. The Meyer-Peter sediment transport equation was satisfactory for very low velocities with the larger particles.     

Preparation of structurally-colored aromatic polyamides and their physicochemical properties

Conclusions One-, two-, and three-stage methods of preparing structurally-dyed aromatic polyamides with chromophoric fragments in the chain have been investigated.It has been shown that the molecular weight of the polymers obtained and the proportion of chromophores bound into their chain is determined by the reactivity of the starting diaminoanthraquinones.It has been found that the introduction of anthraquinone units into the poly-m-phenylene isophthalamide chain has little effect on the structure or basic physicochemical properties of the polyamide, but gives the polymer a uniform and regular coloration.Structural dyeing of poly-m-phenylene isophthalamide with fragments of 1,5-DAAQ or 4,8-DADHAQ increases the resistance of the polyamide fibres to UV irradiation.The authors express their thanks to Yu. Ya. Shavarin and N. M. Bol'bit for performance of the fibre irradiation, and also to B. A. Tsaplin for thermomechanical testing of the fibres.L. Ya. Karpov NIFKhI, Moscow. VNIISV, Tver'. Translated from Khimicheskie Volokna, No. 2, pp. 24–27, March–April, 1992.