On the improvement of detection characteristics of trans-stilbene crystals by improving crystal perfection

Organic molecular scintillating crystals are noted for their good timing and particle discrimination process. Trans-stilbene is one such candidate noted for its good particle detection characteristics for the past five decades. Progressive strengthening of detection characteristics of trans-stilbene has been attempted by improving crystal perfection. A series of timing resolution studies have been carried out for the Bridgman grown trans-stilbene crystals under different experimental conditions. The results were compared with the previously reported values. Pulse shape discrimination process has been carried out for ²⁴¹Am and ²⁵²Cf sources and good discrimination has been obtained for gamma-alpha and gamma-neutron sources from the grown organic phosphor crystal. Electronic Publication     

Mobile application-based computer-aided diagnosis of skin tumours from dermal images

Skin tumour is defined as the enormous growth of cells in the skin. The aim is to design standalone application for diagnosis of skin tumours. The dermal images of three different types obtained from the authorized PH2 database are used to analyse the defined image processing algorithm. In this algorithm, pre-processing was performed to remove hair cells. Contour-based level set is used to segment lesion from which clinical and morphological features are extracted for classification. Significant features are obtained with the feature selection technique, Random subset. Classification is performed with three classifiers. The efficiency of the classifier obtained with different trials of classification is analysed with the ANOVA test. With these results, the Multiclass Support vector machine was configured as a suitable classifier to categorize dermal images. Therefore, an application is developed for the analysis of images acquired through mobile with the help of a magnification set-up. Thus, extracted features, segmented and original images are transferred to a database for storage.     

Stereovision based force estimation with stiffness mapping in surgical tool insertion using recurrent neural network

The Journal of Supercomputing - This paper proposes a novel method for estimating the reaction force, the Stereovision Based Force Estimation Method (SBFEM), with deep learning techniques to...     

Experimental and simulation studies on the effect of suction opening orientation on solar vertical chimney

The zero energy building considered is a single storey building in Tiruchirappalli city retrofitted with various green features. This study investigated the effect of a suction opening orientation on a vertical solar chimney (VSC), integrated into a one-storey building. It was designed, manufactured and tested through selection of different suction openings for the entry of air, including right, left, front, back, both right and left and both front and back sides. Genetic algorithm (GA) calculates maximum air flow rate for a building with VSC for better suction opening, in Tiruchirappalli's dry, environmental conditions. GA is a useful technique for finding an improved suction opening specifically in the presence of a host of independent parameters which are large. The obtained results are related to fluid flow temperature distribution along the chimney, mass flow rate and air change per hour. The findings between the GA and the experimental results show sound agreement.     

Preparation and thermomechanical properties of stir cast Al-2Mg-11TiO<Subscript>2</Subscript> (rutile) composite

Al-2Mg-11TiO₂ composite was successfully prepared by the conventional vortex method. The macrostructural observation revealed columnar structure with rutile particles being distributed throughout the matrix in the form of agglomerates. Microstructural observation showed the presence of micro voids in the particle-enriched zone. Electrical resistivity measurement showed a phase transformation at 360°C, which was consistent during DSC studies due to the precipitation of TiAl₃ phase. As-cast composite was both hot rolled and cold rolled successfully to 50 and 40% reduction, respectively. The mechanical properties of the thermomechanically-worked composite were studied. From fractographic analysis, it was clear that the crack had nucleated at the particle/matrix interface and propagated through the matrix by microvoid coalescence. Ultimate tensile strength of cold worked composite was found to be better than the hot worked material.     

Experimental verification of the generalized Schelkunoff'shorn-gain formulas for sectoral horns

An approximate formula has been recently proposed for the on-axis gain of rectangular waveguide antennas, that include open-ended rectangular waveguides and sectoral and pyramidal horns (see Selvan, K.T., IEEE Trans. Antennas Propagat., vol.47, p.1001-4, 1999). This formula is an approximate generalization of S.A. Schelkunoff's horn-gain formulas (see "Electromagnetic Waves", Van Nostrand, p.360-4, 1943). Gain measurements are reported for the gains of E plane and H plane sectoral horns and are used in an examination of the accuracy of Selvan's formulas. To the best of the authors' knowledge, these are the first ever measurement efforts on the gain of H-plane sectoral horns     

The influence of thickness and deposition temperature on the conduction activation energy of CdSe0.2Te0.8 thin films

The electrical conductivity and stability in resistance of CdSe_0.2Te_0.8 thin films in different ambients and deposited at different substrate temperatures were investigated. A reduction in conduction activation energy with increase in film thickness and deposition temperature is accounted for by the fact that in CdSe _x Te_1–x inhomogeneous semiconductor thin films, the potential relief inhomogeneity may be reduced with increase in film thickness and substrate temperature, which results in the decrease of conduction activation energy of the films.     

Compression and Deformation of Cylindrical Rubber Blocks

In the present study, compression and deformation behavior of vulcanized cylindrical rubber blocks has been examined using imaging techniques. Quantitative measurements of bulge radius and the associated lateral profile of the uniaxially loaded rubber blocks have been carried out experimentally using a newly developed imaging tool. The maximum bulge radius obtained using this method has shown good agreement with the established models. A significant increase in contact area has been observed in the images under large compressive strains. Also, at an intermediate strain level, a unique low intensity band occurred in the image between the outer ring and the center of compressed blocks. The nonlinear characteristics are obvious from the experiments conducted on the bonded cylinders using the developed imaging tool. It is evident from images that the deformed lateral profiles at larger compressive strain does not have parabolic shape and appeared to be more flat. Moreover the reliability of the testing tool has been evaluated and a data measurement technique has been proposed to characterize the behavior of rubber blocks under large compressive strains.     

High-pressure, high-temperature oxidation of toluene

The high-pressure single pulse shock tube (HPST) at the University of Illinois at Chicago has been used to study the oxidation of toluene at reflected shock pressures from 22 to 550 bar and temperatures from 1210 to 1480 K. Experiments were performed for dilute stoichiometric, Φ=1, and rich, Φ=5, reagent mixtures. Stable species were analyzed using gas chromatography and gas chromatography/mass spectrometry. The resulting data set is the first that provides species concentrations over such extremes of pressure, temperature, and stoichiometry, and it serves as an excellent base for the validation and refinement of future detailed chemical kinetic models. Two literature models for the oxidation of toluene that have been validated against atmospheric pressure turbulent flow reactor and jet stirred reactor data were used to simulate the experimental data. Several modifications were made to one model to more accurately simulate the high-pressure/high-temperature experimental data. The modified model reproduces the Φ=1 experimental data well and forms the first step in the development of a more comprehensive model for toluene combustion validated over wide ranges of temperature and pressure.