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.     

Otitis media with effusion: a disability or not?

Otitis media with effusion (OME) is a disease most commonly affecting the paediatric population. However, it is a condition that is also seen in adults and does lead to significant morbidity. We studied the effect of surgical treatment of OME in an adult population and found that the subjective relief of symptoms exceeded the objective audiometric gain. In children where subjective symptoms are perhaps more difficult to assess the clinician needs to beware of underestimating the effect of a hearing loss.     

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.     

Spray pyrolysis and heat treatment of CuInSe2 for photovoltaic applications

Thin films (about 1 μm) of CuInSe₂ were prepared by spray pyrolysis. The component ratios in the spray solutions and the glass substrate temperature were varied in order to produce films of the desired stoichiometry and the importance of this starting ratio is demonstrated. The optimum spray conditions were suggested by thermodynamical calculations using a free energy minimization computer program applied to the Cu-In-Se system. Optical absorption studies of the films verified the existence of the proper compound.Heat treatments of the films were performed in order to produce conductivities and crystal structures for photovoltaic applications and are discussed in detail. In particular for CuInSe₂ which gives the sphalerite structure under most spray conditions, a short heat treatment of a film with a starting Cu:In:Se ratio of 1.1:1:4 for 10 min at temperatures of 600, 500 and 400°C is described, which produces the chalcopyrite structure.     

Laser cutting of 7050 Al alloy reinforced with Al2O3 and B4C composites

In the present study, laser cutting of 7050 aluminum alloy sheets reinforced with Al₂O₃ and B₄C particles are carried out. The cut geometry is examined using scanning electron microscope and the optical microscope. The lump parameter analysis technique is used to formulate and determine the kerf width size. The predictions for kerf width are compared with experimental data. The percentage kerf width size variation along the cut edges is determined and the influence of the laser power level and duty cycle of the laser pulses on the percentage kerf width size variation is examined. It is found that 7050 aluminum alloy reinforced with 20% Al₂O₃ composite results in relatively large kerf width size as compared to its counter parts that corresponding to 7050 aluminum alloy reinforced with 20% B₄C composite. The kerf width size predicted agreed with the experimental data for both composites.     

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.     

An extended Hückel theory based atomistic model for graphene nanoelectronics

An atomistic model based on the spin-restricted extended Hückel theory (EHT) is presented for simulating electronic structure and I–V characteristics of graphene devices. The model is applied to zigzag and armchair graphene nano-ribbons (GNR) with and without hydrogen passivation, as well as for bilayer graphene. Further calculations are presented for electric fields in the nano-ribbon width direction and in the bilayer direction to show electronic structure modification. Finally, the EHT Hamiltonian and NEGF (Nonequilibrium Green’s function) formalism are used for a paramagnetic zigzag GNR to show 2e ²/h quantum conductance.     

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.