An intelligent railway surveillance framework based on recognition of object and railway track using deep learning

Multimedia Tools and Applications - In high speed railways, the intelligent railway safety system is necessary to avoid the accidents due to collision between trains and obstacles on the railway...     

8 MeV electron irradiation effects in silicon photo-detectors

Results of investigations on the electrical properties of n⁺-p-p⁺ silicon (Si) photo-detectors irradiated with 8 MeV electrons are presented. The photo-detectors were irradiated with electrons of doses up to 100 kGy. Current-voltage (I-V) and capacitance-voltage (C-V) characteristics under dark conditions were measured as a function of dose. A significant change in the diffusion component of the saturation current is observed after irradiation, while the generation-recombination component of the saturation current remains almost unchanged. The series resistance is found to increase with increasing dose while the shunt resistance and carrier concentration decrease with dose. Optoelectronic properties, namely short circuit current I_sc, open circuit voltage V_oc under air mass zero illumination and spectral response, were measured at various doses. From the spectral responses of the devices, the minority carrier diffusion length was estimated.     

Electrospray mass spectrometric characterization of bimetallic group 8 — Gold clusters

Bimetallic clusters containing gold in conjunction with Group 8 metals have been intensively studied as it is proposed that these compounds may find uses as catalysts or materials (or as precursors to catalysts/materials). These types of compounds are very difficult to characterize by the mass spectrometric techniques traditionally used to analyse transition metal clusters. In this paper we report a derivatization method employing electrospray ionization mass spectrometry that is reliable and informative for these types of compounds.     

Early Experiences in Cross‐Disciplinary Education in Biomedical Technology Innovation at Stanford University*

This paper describes two new educational programs at Stanford that address some of the unique issues in teaching medical technology innovation and design. The first is a team‐based medical device design and prototyping course that is based on clinical immersion and “hands‐on” device prototyping. Medical device innovation at Stanford is further encouraged by means of a series of university‐wide competitions, called Invention Challenges, to invent solutions to defined clinical problems with the potential for real‐world impact.     

Correlations Among Signatures for Detection of Different Types of Fires

One way of overcoming the problem of false alarms encountered in a single parameter detection system due to non-fire stimulii is the simultaneous use of multiple signatures. Researchers have found significant benefits of multi-sensor detection in reducing false triggering. Appreciable interest has been expressed in using carbon monoxide (CO) or carbon dioxide (CO₂) gas sensors in combination with smoke sensors. The present study has been carried out to determine the correlation and inter-dependence between two different fire signatures like CO–OD (optical density), CO–CO₂, CO₂–OD. The signatures have been investigated using experimental measurements of a fire inside a closed compartment measuring 7 x 7 x 4.2 m. A range of fuels are used, and both smouldering and flaming combustion are examined. Attempts have been made to examine whether correlation coefficients between two signatures can form a basis of detection and be exploited as one of the components in multi- criteria fire detection algorithm. The CO/CO₂ ratio as a criterion for detector operation has also been examined and discussed in the light of existing literature and codal provisions.     

Socially Assistive Robots in Elderly Care: A Mixed-Method Systematic Literature Review

The world’s population is aging, and developed countries are engaged in developing a new aged-care paradigm to reduce spiraling healthcare costs. Assistive technologies like Socially Assistive Robots (SAR) are being considered as enablers to support the process of care giving or keep elderly at home longer. This article reports a mixed-method systematic review of SAR in elderly care and recognizes its impact on elderly well-being, integrating evidence from qualitative and quantitative studies. It follows the principles explained in Cochrane Handbook for Systematic Reviews of Interventions and classifies interventions, measures, and outcomes of field trials of SAR in elderly care. Eighty-six studies in 37 study groups have been included. The findings imply positive effects of SAR on elderly well-being. Ten significant recommendations are made to help avoid the current limitations of existing research and to improve future research and its applicability. This review revealed that SAR can potentially enhance elderly well-being and decrease the workload on caregivers. There is a need for rigorous research methodology, person-centered care, caregiver expectation model, multimodal interaction, multimodal data collection, and modeling of culturally diverse groups to facilitate acceptability of SAR.     

Microstructure and mechanical properties of friction stir welded oxide dispersion strengthened alloy

Effect of friction stir welding (FSW) on microstructure and mechanical properties of oxide dispersion strengthened alloy MA956 was investigated. Fine grained microstructure was developed in the processed region with slight particle coarsening. Tensile behavior of the processed material was compared with that of the as-received material at room temperature. Results indicated that significant grain refinement during FSW compensated for the reduced particle strengthening contribution and enhanced tensile strength by 145 MPa without loss in ductility. Further analysis indicated a good agreement between experimentally measured yield strength and the strength calculated by Pythagorean superimposition of strengthening contribution in FSWed material.     

Steady-state methanation kinetics over a Ni/Al2O3 catalyst

Extensive kinetic data for the methanation reaction over a Ni/Al₂O₃ catalyst were obtained in a specially designed gradientless reactor operating at steady state. The reactor pressure was 101.3 kPa, and three temperatures were used, namely, 503, 513 and 523 K. The following three-parameter phenomenological model based on a proposed Langmuir-Hinshelwood mechanism adequately describes the data: r = L² K₃ K₄^0.5 k₅ P^0.5H₂ Pco/ [1 + K₃ (k₅ / k₆)Pco + K₄^0.5 P^0.5H₂ ]² With dissociative adsorption of hydrogen and hydrogen-assisted dissociation of adsorbed carbon monoxide, the postulated mari is the CH surface group, and the rds is the hydrogenation of the surface CH group.     

A Possible Explanation of Critical Temperature and Isotope Effect Coefficient of High T c Cuprate Superconductors

The expressions for superconducting transition temperature (T _c) and isotope effect coefficient (α) have been derived from a generalized integral gap equation for a strongly coupled superconductor, when electrons–phonons and electrons–biexcitons are simultaneously present in high-T _c cuprate superconductors.