Heavy-ion fusion cross-section data for systems with compound atomic mass between 18 and 80

Fusion cross-section data are presented as a function of center-of-mass energy for different reactions involving light and medium-light heavy-ion systems with compound atomic mass number between 18 and 80. The systems range from ⁶Li + ¹²C to ⁴⁰Ca + ⁴⁰Ca. The data are given for the region starting from slightly below the Coulomb barrier energy to about six to seven times its value, if they are available. This compilation is primarily to facilitate theoretical interpretation of experimental results. It also serves to give researchers an overview of the range and status of the data. Literature published up to June 1983 has been surveyed.     

New approach to avoid erroneous interpretation of results derived from generalized two-dimensional correlation analysis for applications in catalysis

Surface characterization and catalysis can significantly benefit from the application of generalized two-dimensional (2D) correlation analysis. This two-dimensional approach allows a better resolution of overlapping peaks, can reveal new features not readily observable in the raw spectra, gives clear evidence for spectral intensities that change as an effect of a perturbation applied to the system, and allows the establishment of time sequences for the changes occurring in different spectral features of interest for determining reaction intermediates and/or mechanisms. The interpretation of the synchronous and asynchronous plots was observed to lead to erroneous time sequences when spectral features change in a non-monotonic way, such as a biphasic or oscillatory behavior, under the influence of a perturbation. We propose a new approach to the 2D correlation analysis to avoid misinterpretation of the results calculated in the asynchronous plot. Progressive correlation analysis (ProCorA) calculates the synchronous plot from the first two spectra of the data matrix and one spectrum is added at every step of the analysis. The sequence of changes can be set up from the progressive evolution of peaks in both the synchronous and asynchronous plots.     

SAPO-34 supported Pt–Sn-based novel catalyst for propane dehydrogenation to propylene

The Pt–Sn-based catalyst was intensified using SAPO-34 as support for direct propane dehydrogenation to propylene. The catalyst was prepared by sequential impregnation method and characterized by XRF, BET, XRD, NH₃-IR, NH₃-TPD, H₂-TPR, HR-TEM and O₂-pulse coke analysis. NH₃-TPD, IR spectra and XRD results suggested that the doping of metals on SAPO-34 did not affect its acidic strength and structural topology of support, respectively. Propylene selectivity of 94% and total olefins selectivity greater than 97% was achieved using Pt–Sn/SAPO-34. The results were compared with Pt–Sn/ZSM-5 under identical conditions. The possible reasons for improvement were the larger surface area, shape selectivity and particular by suitable acidity of SAPO-34.     

Robotic System for Closed-Bore MRI-Guided Prostatic Interventions

This paper reports on the development of a new closed-bore magnetic resonance imaging (MRI) compatible robotic system for image-guided prostatic interventions: ablation, brachytherapy, and biopsy. The first stage of development addresses only laser-based ablation. The robot actuators are ultrasonic motors. The first physical robot prototype was manufactured and tested in the MRI with an ablation tool. The tests covered magnetic resonance (MR) compatibility, tool visualization, and robot control accuracy. Robot tip position error is less than 2 mm at points closer than 0.5 m to the isocenter. A method to control ultrasonic motors for MRI-compatibility is reported.     

Current scenario and potential of biodiesel production from waste cooking oil in Pakistan: An overview

Biodiesel utilization has been rapidly growing worldwide as the prime alternative to petrodiesel due to a global rise in diesel fuel demand along with hazardous emissions during its thermochemical conversion. Although, several debatable issues including feedstock availability and price, fuel and food competition, changes in land use and greenhouse gas emission have been raised by using edible as well as inedible feedstocks for the production of biodiesel. However, non-crop feedstocks could be a promising alternative. In this article, waste cooking oils have been recommended as a suitable option for biodiesel production bearing in mind the current national situation. The important factors such as the quantity of waste cooking oil produced, crude oil and vegetable oil import expenses, high-speed diesel imports, waste management issues and environmental hazards are considered. Moreover, process simulation and operating cost evaluation of an acid catalyzed biodiesel production unit are also conducted. The simulation results show that the production cost of waste cooking oil-based biodiesel is about 0.66USD·L^-1. We believe that the present overview would open new pathways and ideas for the development of biofuels from waste to energy approach in Pakistan.     

Experimental and numerical characterization of mechanical properties of carbon/jute fabric reinforced epoxy hybrid composites

Journal of Mechanical Science and Technology - Natural fiber composites have great potential for reducing the product cost, lowering weight and enhancing renewability. Functionality and performance...     

On the selection of software defect estimation techniques

Estimating the number of defects in a software product is an important and challenging problem. A multitude of estimation techniques have been proposed for defect prediction. However, not all techniques are applicable in all cases. The selection of the proper approach to use depends on multiple factors: the features of the approach; the availability of resources; and the goals for using the estimated defect data. In this paper a survey of existing estimation techniques and a decision support approach for selecting the most suitable defect estimation technique for a project, with specific goals, is proposed. The results of the ranking are a clear indication that no estimation technique provides a single, comprehensive solution; the selection must be done according to a given scenario. Copyright © 2009 John Wiley & Sons, Ltd.     

Investigation on material mixing during FSW of AA7475 to AISI304

AA7xxx and AISI304 stainless steel (SS) are employed in promising applications. Al alloy-to-SS dissimilar joining is difficult and challenging. Major challenge in the joining of these alloys is the difficulty in mixing of these materials which possess exotic and widely distant properties. AA7475-T761 is a high strength aluminum alloy which is used in key aircraft components. Maiden AA7475-T761 and AISI304 dissimilar joints were fabricated using friction stir welding. Welding was performed with tool having pin diameter of 4 mm and offset of 1.25 mm on Aluminum side. Tool rotational speed, traverse speed and shoulder diameter were varied in the range of 450–560 rpm, 50–63 mm/min, and 12–14 mm, respectively. Mechanical tests showed that joint formed with 14 mm diameter, 560 rpm and 50 mm/min gave the best joint efficiency of 71% of Al-alloy at 7.31% elongation. The materials mixing issues during processing were analyzed with SEM mircrostructure and fractography. Metallography also revealed that offset is critical to the success of joint as it controlled effective mixing of SS and Al in 15 and 85 vol.%, respectively. SS fragments from thermo-mechanically affected zone of SS were found to be partially sheared forming layer of thickness equal to tool traverse/revolution ratio.     

Influence of Chemical Reaction on Mass Transport in Yield Stress Exhibiting Flow Regime

Theoretical Foundations of Chemical Engineering - In this study, the simulations for first-order chemical reactions (constructive and destructive) in the flow of the Casson fluid with...