P. V. Raja Shekar

Dislocations, microhardness and optical studies on glycine potassium nitrate crystal

Single crystals of glycine potassium nitrate (GPN), a semiorganic nonlinear optical crystal, of dimensions 15×12×4 mm3 were grown in a period of 10 days. The defect content present in the crystals was estimated by chemical etching technique. The results indicate that the average dislocation density is about 4.1×103/cm2. The UV-Vis. studies indicate that the crystal has a wide transmission range. The Kurtz powder test indicates that the second harmonic generation efficiency of GPN is 2.5 times that of KDP. The load-hardness curves for GPN were studied over the load range 10-100 g. The anisotropy in hardness was studied using Knoop indentation technique.

Measuring the Impact of Design Fixation on Indian Engineering Students

A major concern in engineering education pertains to design fixation, which hinders the conception of novel ideas. The term design fixation refers to the designer’s reluctance (or inability, in some cases) to consider multiple strategies to formulate and solve a design need. The design fixation phenomenon severely limits creativity and results in pedestrian design solutions. The primary objective of this paper is to correlate the effect of the Indian engineering education with the extent of design fixation in the engineering students of different disciplines. This work provides a deeper understanding of the design fixation phenomenon by establishing a conceptual framework for the design process based on the theories of knowledge representation in cognitive science. It can provide crucial insights that will help students to overcome the adverse effects of fixation.

Analysis of Divergent Thinking in Indian Engineering Students

Divergent thinking (DT) is one of the design skills which helps in generation of alternative design solutions for any given design task and is very much essential for addressing a design problem. Hence, an attempt has been made to evaluate the DT skills of Indian engineering students. The level of design fixation is also determined. The methodology of the work carried out to estimate and analyze DT skills and the results obtained are discussed in detail. The results throw light on the design skills of Indian engineering students, which perhaps help in the development of effective teaching methods.

Evaluation of mechanical properties of some glycine complexes

The variation of Vickers hardness with load for (101) glycine zinc chloride (GZC), (001) glycine lithium sulphate (GLS), (001) triglycine sulphate (TGS) and (010) glycine phosphite (GPI) crystals was studied. From the cracks initiated along the corners of the indentation impression, crack lengths were measured and the fracture toughness value and brittle index number were determined. The hardness related parameters viz. yield strength and Young’s modulus were also estimated. The anisotropic nature of the crystals was studied using Knoop indentation technique.

Growth and characterization of a nonlinear optical crystal: Bisglycine hydrogen chloride

Single crystals of bisglycine hydrogen chloride (BGHC), a semiorganic nonlinear optical crystal, of dimensions 13×6×4 mm3 were grown in a period of 10 days. The grown crystals were confirmed by powder XRD, FTIR and DSC studies. For the first time, the defect content present in the crystals was estimated by chemical etching studies. The results indicate that the average dislocation density is about 3.1×103/cm2. The load-hardness curves for BGHC were studied over the load range 10-100 g. The UV-Vis. studies indicate that the crystal has a wide transmission range. The Kurtz powder test indicates that the second harmonic generation efficiency of BGHC is almost two times that of KDP.