Investigations on the Three Commercial Species of Rosaceae

Physico-chemical properties of the seed oils of three species of Rosaceae family, namely Prunus armeniaca (apricot), Prunus cerasifera (prune), and Prunus persica (peach) have been determined. Fatty acid composition of the oils and amino acids composition of seed cake proteins have also been determined and their utility in every day life has been discussed.     

Synthesis and characterization of photopolymerizable hydrogels based on poly (ethylene glycol) for biomedical applications

Hydrogels are polymeric materials widely used in medicine due to their similarity with the biological components of the body. Hydrogels are biocompatible materials that have the potential to promote cell proliferation and tissue support because of their hydrophilic nature, porous structure, and elastic mechanical properties. In this work, we demonstrate the microwave-assisted synthesis of three molecular weight varieties of poly(ethylene glycol) dimethacrylate (PEGDMA) with different mechanical and thermal properties and the rapid photo of them using 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184) as UV photoinitiator. The effects of the poly(ethylene glycol) molecular weight and degree of acrylation on swelling, mechanical, and rheological properties of hydrogels were investigated. The biodegradability of the PEGDMA hydrogels, as well as the ability to grow and proliferate cells, was examined for its viability as a scaffold in tissue engineering. Altogether, the biomaterial hydrogel properties open the way for applications in the field of regenerative medicine for functional scaffolds and tissues.     

CuxNi1-xO nanostructures and their nanocomposites with reduced graphene oxide: Synthesis,characterization, and photocatalytic applications

NiO nanostructure was synthesized using a simple co-precipitation method and was embedded on reduced graphene oxide surface via ultrasonication. Structural investigations were made through X-ray diffraction (XRD) and functional groups were confirmed by Fourier transform infrared spectroscopy (FTIR). XRD analysis revealed the grain size reduction with doping. Fourier transform infrared spectroscopy confirmed the presence of metal-oxygen bond in pristine and doped NiO nanostructure as well as the presence of carbon containing groups. Scanning electron microscopy (SEM) indicated that the particle size decreased when NiO nanostructure was doped with copper. BET surface area was found to increase almost up to 43 m²/g for Cu doped NiO nanostructure/rGO composite. Current-voltage measurements were performed using two probe method. UV–Visible spectroscopic profiles showed the blue and red shift for Cu doped NiO nanostructure and Cu doped NiO Nanostructure/rGO composite respectively. Rate constant for Cu doped NiO nanostructure/rGO composite found to increase 4.4 times than pristine NiO nanostructure.     

Investigation of the impact of global warming on precipitation pattern of Saudi Arabia

This study has been carried out to forecast the impact of global warming on the precipitation pattern of Saudi Arabia by the end of year 2100. Simulation has been done using EdGCM model software (with available 8×10 resolution) developed at Columbia University on which there have been produced global precipitation maps for the seasonal and annual averages for the last 5 years (2096–2100). For each map, EdGCM grid values surrounding Saudi Arabia are used as input to one of the tools of Eagle point software called surface modelling (SM). SM is a new approach for downscaling global climate model results. SM software modelled out isohyets at 0.2 mm/day interval. The results indicate that the present pattern of precipitation (more in winter and less in summer) is going to change by almost equal occurrence of precipitation in all seasons for double_CO₂ (2CO₂) experiment. The 2CO₂ experiment indicates an increase of about 16.05% over the annual average precipitation across the country.     

Design and precision construction of novel magnetic-levitation-based multi-axis nanoscale positioning systems

This paper presents two novel six-axis magnetic-levitation (maglev) stages capable of nanoscale positioning. These stages have very simple and compact structures, which is advantageous to meet the demanding positioning requirements of next-generation nanomanipulation and nanomanufacturing. Six-axis motion generation is accomplished by the minimum number of actuators and sensors. The first-generation maglev stage, namely the Δ-stage, is capable of generating translation of 300 μm and demonstrates position resolution better than 2 nm root-mean-square (rms). The second-generation maglev stage, namely the Y-stage, is capable of positioning at a resolution better than 3 nm rms over a planar travel range of 5 mm × 5 mm. A novel actuation scheme was developed for the compact structure of this stage that enables six-axis force generation with just three permanent-magnet pieces. This paper focuses on the design and precision construction of the actuator units, the moving platens, and the stationary base plates. The performance of the two precision positioners is compared in terms of their positioning and load-carrying capabilities and ease of manufacture. Control system design for the two positioners is discussed and an experimental plant transfer function model is presented for the Y-stage. The superiority of the developed instruments is also demonstrated over other prevailing precision positioning systems in terms of the travel range, resolution, and dynamic range. The potential applications of the maglev positioners include semiconductor manufacturing, microfabrication and assembly, nanoscale profiling, and nanoindentation.     

Monte Carlo study of ion-induced secondary electron emission from SiO2

Here we describe a recently developed direct Monte Carlo program to study kinetic electron emission from SiO₂ target. The program includes excitation of the target electrons (by projectile ions, recoiling target atoms and fast primary electrons), subsequent transport and escape of these electrons from the target surface. The program can be used to calculate the electron yields, distribution of electron excitation points in the target and other physical parameters of the emitted electrons. In order to demonstrate the capabilities of this program, we report a study on the kinetic electron emission from SiO₂ induced by fast (1-10 keV) rare gas ions. The calculated kinetic electron yield for various ion energies and masses is in good agreement with the predictions of most frequently applied theoretical model. In addition, the effects of projectile energy, mass and impact angle on the depth distribution of electron excitation points and average escape depth of the outgoing electrons were investigated. It is important to mention that the existing experimental techniques are not capable to measure these parameters.     

Effect of cobalt-60 γ radiation on the physical and chemical properties of poly(ethylene terephthalate) polymer

The structural, optical, and morphological properties of Co⁶⁰ γ irradiation on poly(ethylene terephthalate) polymer samples were studied with X-ray diffraction (XRD), ultraviolet–visible spectroscopy, scanning electron microscopy (SEM), and Raman spectroscopy. The diffraction pattern of virgin sample showed that the polymer was semicrystalline in nature. However, because of irradiation, the crystallinity decreased up to a dose level of 110 kGy and increased up to 300 kGy. The crystallite size, strain, and dislocation were calculated from the XRD data, and the crystallite size decreased from 291.07 to 346.90 Å. The absorption edge shifted from 315 to 330 nm, and the band gap of the samples decreased from 3.79 to 3.66 eV. The SEM micrographs showed radial bulging along with inhomogeneous liner exfoliation, and also, a rocky shape pattern with different sizes was observed. A significant change was found in the Raman spectra of the γ-irradiated polymer at the highest dose. The results of the structural, optical, and morphological studies show recovery characteristics at the highest dose level of 300 kGy. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effect of the licensing process on hygiene in retail butchers' premises in the West Midlands,United Kingdom

As the result of a change in legislation, all retail butchers in England were required to be licensed by 1 November 2000. A fully implemented hazard analysis critical control point plan was a condition of the license. This longitudinal study assessed the effect of licensing on hygiene in a group of retail butchers in the West Midlands, England. A hygiene audit and environmental sampling were used to determine if the licensing process improved hygiene in the study group. At the end of the study, 30% of the original group were no longer trading as they had been, having either altered the product they were selling or ceased to trade. The remaining butchers showed a significant improvement in the hygiene of their premises, both in the audit scores and in the environmental sampling. The mean audit score for the group had improved from an initial score of 47.54 to 54.95 (P < 0.02). The contamination with Enterobacteriaceae on equipment used for cooked meat had also improved, decreasing from mean contamination levels of 1.38 log CFU/cm2 before licensing to mean contamination levels of -0.11 log CFU/cm2 after licensing (P < 0.00001).