Calculation of ionization potential of amorphous organic thin-films using solvation model and DFT

Density functional theory and polarizable continuum model are used to calculate ionization potential of thin-films of 12 organic molecules. Computed values are compared with experimental values obtained from ultraviolet photoemission spectroscopy. The excellent correlation shows that it is possible to determine the ionization potential of organic molecules in solid-state within ±0.15 eV of the experimental value. This method is useful for chemists in designing molecules for organic electronics.     

Effect of Chemistry on Nonisothermal Tempering and Softening of Dual-Phase Steels

In sequel to our recent report,[1] we demonstrate in this article the effect of chemistry on nonisothermal tempering and softening behavior of dual-phase steels. The martensite morphology and tempered structure were analyzed using electron microscopy. Electron energy loss spectrometry and energy-dispersive X-ray spectroscopy were used for a compositional analysis. It was observed that characteristic of the tempered structure in dual-phase (DP) steels was a function of prior martensite structure and chemistry, which in turn influence the extent of softening.     

Polymer Light Emitting Diodes: Materials,Technology and Device

Polymer Light Emitting Diodes (PLEDs), the most promising name in the field of display technology has received tremendous attention from various research groups. The research on light emitting polymers are an interdisciplinary zone which has challenging investigates on materials science and engineering, physics of device architecture and technology. This review addresses the wide range of tailored polymers, evolution of LED device structure for high performance, single and multicolor polymer based LEDs. Though, polymers are possessing better efficiency and easy fabrication processes, it has very low stability and short life. This study also reviews, device degradation during device fabrication and operation.     

Electric Pulse Discharge Activated Carbon Supercapacitors for Transportation Application

ScienceTomorrow is developing a high-speed, low-cost process for synthesizing high-porosity electrodes for electrochemical double-layer capacitors. Four types of coal (lignite, subbituminous, bituminous, and anthracite) were used as precursor materials for spark discharge activation with multiscale porous structure. The final porosity and pore distribution depended, among other factors, on precursor type. The high gas content in low-grade carbon resulted in mechanical disintegration, whereas high capacitance was attained in higher-grade coal. The properties, including capacitance, mechanical robustness, and internal conductivity, were excellent when the cost is taken into consideration.     

Aluminium extraction and leaching characteristics of Talcher Thermal Power Station fly ash with sulphuric acid

Although fly ash disposal is of environmental concern the quality of residues can be improved with respect to high value applications. Fly ash is considered as a potential source of aluminium and other strategic metals. Leaching and metal extraction behaviour of fly ash collected from Talcher Thermal Power Station have been thoroughly studied using sulphuric acid as extractant. The chemical and mineralogical composition of post-leached samples have been determined. Aluminium extraction by direct leaching at low acid concentration and ambient temperature is not suitable for high recovery. The extraction efficiency of aluminium increases significantly at a higher solid:liquid ratio. It is evident that the leachability of metals from fly ash depends on the nature of leaching medium, solid:liquid ratio, temperature and leaching time.     

Dislocation processes in the deformation of nanocrystalline aluminium by molecular-dynamics simulation

The mechanical behaviour of nanocrystalline materials (that is, polycrystals with a grain size of less than 100 nm) remains controversial. Although it is commonly accepted that the intrinsic deformation behaviour of these materials arises from the interplay between dislocation and grain-boundary processes, little is known about the specific deformation mechanisms. Here we use large-scale molecular-dynamics simulations to elucidate this intricate interplay during room-temperature plastic deformation of model nanocrystalline Al microstructures. We demonstrate that, in contrast to coarse-grained Al, mechanical twinning may play an important role in the deformation behaviour of nanocrystalline Al. Our results illustrate that this type of simulation has now advanced to a level where it provides a powerful new tool for elucidating and quantifying--in a degree of detail not possible experimentally--the atomic-level mechanisms controlling the complex dislocation and grain-boundary processes in heavily deformed materials with a submicrometre grain size.     

The interaction between lid diameter,height and shape on wrist torque exertion in younger and older adults

The following study investigated wrist torque strength measurements of a group of younger and older adults. The aim of the study was to examine the impact of shape, diameter and height of lid on wrist torque opening strength. Forty participants took part in the study in four groups, younger males and females and older males and females. Data were collected for 12 test pieces. Anthropometric data were also obtained for stature, weight, hand breadth, hand length, chuck grip force, grip force, lateral grip force and pinch grip force. The analysis of the wrist torque strength measurements found that participants could exert greater force with square test pieces compared to circular test pieces of the same diameter. Examination of the circular test pieces found that as diameter and height increased, so did torque exertion data for the test pieces between 20 mm and 50 mm diameter. The surface area of the test pieces was found to be highly correlated with the level of torque exertion, thus a linear model was developed to describe this relationship. The model could be used to predict maximal torque closure levels for use in the packaging industry. The anthropometric data revealed that as height, weight, hand length and hand breadth increased, there was a correlation with the levels of torque exerted. Future research needs to further examine the relationship between surface area and torque exerted and the design of spherical lids to increase the contact area between the hand and the lid.     

Zero-Error Source–Channel Coding With Side Information

This correspondence presents a novel application of the theta function defined by Lovasz. The problem of coding for transmission of a source through a channel without error when the receiver has side information about the source is analyzed. Using properties of the Lovasz theta function, it is shown that separate source and channel coding is asymptotically suboptimal in general. By contrast, in the case of vanishingly small probability of error, separate source and channel coding is known to be asymptotically optimal. For the zero-error case, it is further shown that the joint coding gain can in fact be unbounded. Since separate coding simplifies code design and use, conditions on sources and channels for the optimality of separate coding are also derived     

A selective location update strategy for PCS users

A new location update strategy for personal communication services (PCS) networks and its implementation using a genetic algorithm are proposed. Most of the practical cellular mobile systems partition a geographical region into location areas (LAs) and users are made to update on entering a new LA. The main drawback of this scheme is that it does not consider the individual user mobility and call arrival patterns. Combining these factors with the LAbased approach, we propose an optimal update strategy which determines whether or not a user should update in each LA, and minimizes the average location management cost derived from a userspecific mobility model and call generation pattern. The location management cost optimization problem is also elegantly solved using a genetic algorithm. Detailed simulation experiments are conducted to capture the effects of mobility and callarrival patterns on the location update strategy. The conclusion from this work is that skipping location updates in certain LAs leads to the minimization of the overall location management cost for a user with a specific mobility pattern and even with moderately high call arrival rate.     

Characterization of laser and laser/thermal annealed semiconducting iron silicide thin films

-FeSi₂ is an important semiconducting silicide which is being studied extensively. In this paper, we report our results of the effect of laser and laser-thermal annealing on the properties of -FeSi₂. 5N purity Fe was deposited on Si substrate and was subsequently irradiated by CW and pulsed laser separately followed by thermal annealing to reduce the laser induced damage. The samples were then characterized by sheet resistance, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), optical reflectance and absorption studies. Lastly, -FeSi₂/n-Si heterojunctions were fabricated and the effect of laser treatment on the junction ideality factor was investigated. All these characterizations indicated the formation of good quality -FeSi₂, particularly after pulsed laser followed by thermal treatment.