Investigation deuteron-induced reactions on cobalt

The excitation functions of deuteron-induced reactions were measured on metallic cobalt. Beyond the ^56,57,58,60Co cobalt isotopes, we also identified ⁵⁷Ni, ⁵⁴Mn, ⁵⁶Mn and ⁵⁹Fe in the deuteron experiments. For the above radionuclides, the excitation functions in the measured energy range were determined and compared with the data found in the literature and with the results of model calculations (ALICE-IPPE, EMPIRE-D, EAF, and TALYS (TENDL)). The excitation functions agree with previous measurements; furthermore, we calculated the yield and thin layer activation (TLA) curves that are necessary for practical and industrial applications.     

Advancement in materials for energy-saving lighting devices

This review provides a comprehensive account of energy efficient lighting devices, their working principles and the advancement of these materials as an underpinning to the development of technology. Particular attention has been given to solid state lighting devices and their applications since they have attracted the most interest and are the most promising. Solid state lighting devices including white light emitting diodes (LEDs), organic LEDs (OLEDs), quantum-dot LEDs (QLEDs) and carbon-dot LEDs (CLEDs) are promising energy efficient lighting sources for displays and general lighting. However there is no universal solution that will give better performance and efficiency for all types of applications. LEDs are replacing traditional lamps for both general lighting and display applications, whereas OLEDs are finding their own special applications in various areas. QLEDs and CLEDs have advantages such as high quantum yields, narrow emission spectra, tunable emission spectra and good stability over OLEDs, so applications for these devices are being extended to new types of lighting sources. There is a great deal of research on these materials and their processing technologies and the commercial viability of these technologies appears strong.     

To the understanding of the formation of the III–V based droplet epitxial nanorings

The paper deals with the kinetics of the droplet epitaxial GaAs quantum ring formation grown on AlGaAs (0 0 1) surface. The observation is, that the aspect ratio of these nano structures is depends not only on the technological parameters but on the size of the initial droplet. Under appropriate growth conditions, the depressions, in the middle of the rings are deeper than the surface level of the substrate. A large number of tests show, that the depressions in the middle of the small rings are often deeper than that of the larger ones. The number is larger, than just statistical fluctuation. An explanation for this phenomenon and its kinetics are given in the paper, based on the size dependence of the material properties, like for instance solubility. The plausible explanation assumes is that the probability of the crystal seed formation in the larger droplets is higher.     

Personally customizable content authoring service for Internet Protocol television subscribers

In this paper, we propose a personally customizable content authoring service (C2Channel) using an Internet Protocol television (IPTV) platform, in which a user terminal such as a PC or set‐top box sends various kinds of multimedia files from a camera or camcorder to a remotely located authoring server (C2Channel server). The C2Channel server creates personalized content in real time by combining special effects with the multimedia files transmitted from the user terminal and then retransmits them to a predefined relevant service group as a personal IPTV channel through an IPTV network provider. This content authoring service supplies an automatic multimedia editing/composition service and offers unicast, multicast, and groupcast services for a large number of interested groups via an IPTV‐based real‐time media delivery platform (Open Live IPTV Engine [OLIVE]), in which a service management server is used for user identification through the IPTV personal channel. Because this platform uses a remote server resource when authoring personally customizable content, resources remaining at the user's terminal can be variously utilized. Copyright © 2012 John Wiley & Sons, Ltd.     

CFD analysis of the HYPER spallation target

KAERI (Korea Atomic Energy Research Institute) is developing an accelerator driven system (ADS) named HYPER (HYbrid Power Extraction Reactor) for a transmutation of long-lived nuclear wastes. One of the challenging tasks for the HYPER system is to design a large spallation target with a beam power of 15–25 MW. The paper focuses on a thermal–hydraulic analysis of the active part of the HYPER target. Computational fluid dynamics (CFD) analysis was performed by using a commercial code CFX 5.7.1. Several advanced turbulence models with different grid structures were applied. The CFX results reveal a significant impact of the turbulence model on the window temperature. Particularly, the k–ε model predicts the lowest window temperature among the five investigated turbulence models.     

Input impedance matching of acoustic transducers operating at off-resonant frequencies

The input impedance matching technique of acoustic transducers at off-resonant frequencies is reported. It uses an inherent impedance property of transducers and thus does not need an external electric matching circuit or extra acoustic matching section. The input electrical equivalent circuit includes a radiation component and a dielectric capacitor. The radiation component consists of a radiation resistance and a radiation reactance. The total reactance is the sum of the radiation reactance and the dielectric capacitive reactance. This reactance becomes zero at two frequencies where the impedance is real. The transducer size can be properly chosen so that the impedance at one of the zero-crossing frequencies is close to 50 Ω, the output impedance of signal generators. At this off-resonant operating frequency, the reflection coefficient of the transducer is minimized without using any matching circuit. Other than the size, the impedance can also be fine tuned by adjusting the thickness of material that bonds the transducer plate to the substrates. The acoustic impedance of the substrate and that of the bonding material can also be used as design elements in the transducer structure to achieve better transducer matching. Lead titanate piezoelectric plates were bonded on Lucite, liquid crystal polymer (LCP), and bismuth (Bi) substrates to produce various transducer structures. Their input impedance was simulated using a transducer model and compared with measured values to illustrate the matching principle.     

Contingent Use of Negotiators’ Tactics in Construction Dispute Negotiation

In the course of negotiation, negotiators’ tactics should be responsive to the situational factors. This is commonly described as the contingent use of negotiators’ tactics. This study examines this concept in construction dispute negotiation and has three stages of work. Stage 1 develops taxonomies of the three construction dispute negotiation dimensions: dispute sources, negotiators’ tactics, and negotiation outcomes by exploratory factor analysis. A structural equation modeling is also used to confirm the taxonomies. Stage 2 examines the contingent use of negotiators’ tactics on outcomes respective to the dispute sources through the use of moderated multiple regression (MMR). Stage 3 discusses the findings. The dispute source, “Delay” is found to be a universal moderator in the MMR analysis of the tactic-outcome relationships. That means when the dispute source is delay, a wide range of negotiators’ tactics can be used, respective to outcome intended. It is also found that the most versatile tactics are those that seek progress. This group of tactics is effective in almost every group of dispute source and, in general, positive results can be expected. However, aggressive and assertive tactics should be used restrictively, as they will only be useful against a compromising negotiation counterpart.     

Electrochemical synthesis of ba- and Sr-based titanate thin films using Ti electrode prepared by RF sputtering

Barium and strontium titanate films were electrochemically synthesized onto Ti thin film prepared by RF sputtering. Applied current waveform was modulated to investigate the film growth mechanism. Superimposed cathodic pulses accelerated the formation of titanate thin films, and both the electrode surface pH and (Ba²⁺, Sr²⁺) ion size had a strong influence on film formation. Titanate film formation mechanism was investigated with a scanning electron microscope, an X-ray diffractometer and an electrochemical quartz crystal microbalance (EQCM).Insitu mass change of Ti electrode during electrolysis indicated that electrochemical method sets a limit to film growth.     

A design sensitivity analysis of bicycle stability and experimental validation

Journal of Mechanical Science and Technology - In this study, the sensitivities of weave and capsize speeds with respect to design parameters were calculated on the basis of the linear forms of...