A prototyping language for real-time software

PSDL is a language for describing prototypes of real-time software systems. It is most useful for requirements analysis, feasibility studies, and the design of large embedded systems. PSDL has facilities for recording and enforcing timing constraints, and for modeling the control aspects of real-time systems using nonprocedural control constraints, operator abstractions, and data abstractions. The language has been designed for use with an associated prototyping methodology. PSDL prototypes are executable if supported by a software base containing reusable software components in an underlying programming language (e.g. Ada)     

Moving object detection in the encrypted domain

Multimedia Tools and Applications - The privacy-preserving moving object detection has drawn a lot of interest lately. Nevertheless, current approaches use Paillier’s scheme for encryption...     

Rolling Friction Enhanced Free‐Standing Triboelectric Nanogenerators and their Applications in Self‐Powered Electrochemical Recovery Systems

Heavy metals contained in wastewater are one of the most serious pollutions in natural resources. A self‐powered electrochemical recovery system for collecting Cu ions in wastewater by incorporating a rolling friction enhanced freestanding triboelectric nanogenerator (RF‐TENG) is developed here. The RF‐TENG utilizes integrated cylindrical surfaces using the conjunction of rolling electrification and freestanding electrostatic induction, which shows outstanding output performance and ultrarobust stability. By using the kinetic energy of flowing water, a collection efficiency of up to 80% for Cu²⁺ ions in wastewater has been achieved. Self‐powered electrochemical systems are one of the most promising applications of TENGs for independent and sustainable driving of electrochemical reactions without the need for any additional power supply. This research is a substantial advancement towards the practical applications of triboelectric nanogenerators and self‐powered electrochemical systems.     

Estimation of deuterium recovery from the separation of water isotopes in thermal-diffusion columns of a countercurrent-flow frazier scheme with optimal plate aspect ratio

The effect of plate aspect ratio on the performance of deuterium recovery from the separation of water–isotope mixture in thermal-diffusion columns of a countercurrent-flow Frazier scheme was investigated. The equations for the optimal plate aspect ratios and the corresponding maximum recovery and maximum production rate were derived. Considerable improvement in performance is obtained when thermal-diffusion columns are operated at the optimal plate aspect ratio. Further improvement can be achieved if the scheme is connected and operated in countercurrent flow, instead of concurrent flow.     

Adjustment behaviour of capital structure over the business cycles: evidence from the construction industry of Taiwan

Prior studies have found that firms may deviate from the target capital structure in the short run and adjust towards the target in the long run. However, little attention has been given to the adjustment behaviour of capital structure in the construction industry over the business cycles, in particular within the context of emerging markets. The partial adjustment model with the GMM (i.e. generalized method of moments) estimation is used to examine the adjustment behaviour of capital structure in the construction industry within the context of Taiwan during the period 1982 to 2007. The results suggest that, first, the average rate of adjustment is 26.3% of the adjustment gap between the target debt ratios and the previous debt ratios for firms in the construction industry of Taiwan. However, the average rate of adjustment towards the target debt ratios has slowed down after the Asian financial crisis of 1997. Secondly, firms with the financial constraint of over‐leverage relative to the target debt ratios have lower debt ratios than those firms with the financial constraint of under‐leverage. In addition, the difference in debt ratios between firms with the financial constraint of over‐leverage and under‐leverage has become narrower after the Asian financial crisis. Lastly, the findings suggest that macroeconomic conditions do not have a significant, negative effect on debt ratios.     

Structural color of polymeric physical gels

In this study, the coloration mechanism of isotactic poly(1-butene) (iPB) in o-xylene and o-xylene/ethyl alcohol mixture gels were carried out. iPB gel becomes yellow because of transmitted light or blue because of reflected light. Changing the temperature, solvent composition, or even the thickness of samples of this gel continuously changes its color to blue, violet, purple, red, and yellow. Structural characterization, electron microscopy, and transmittance measurements were carried out for iPB dissolved in o-xylene to form a three-dimensional sponge-like network with different mesh sizes under various conditions. Subsequently, the relative refractive index between the solvent and gel network produces incoherent Tyndall blue scattering. Finally, color change due to variations in solvent composition or temperature contributes to the interplay between the refractive index of network structure n_network and solvent n_s. For a Tyndall medium with n_s/n_network >1, normal reflection creates a blue gel; when n_s/n_network ≒1, strong transmittance of light passing through the medium leads to a yellowish gel. This is the first report on the concept of structural color for polymeric physical gel systems.     

Oxygen depletion properties of glucose-grafted polyethylene resins filled with sodium ascorbate/modified iron compounds

Oxygen scavenging plastic can react with oxygen that was trapped in the packaging materials or permeated into the packages, and then, extend the shelf life of food contained in packages. Sodium ascorbate (SA) and modified iron (MFe) compounds were chosen as the main components of oxygen scavengers to prepare the oxygen scavenging LDPE plastics. However, the widely used hydrophobic LDPE packaging material will slow down the oxygen depletion rate of these oxygen scavenger compounds. So glucose was used to modify the hydrophobic property of LDPE to improve the oxygen depletion properties of LDPE oxygen scavenging plastic. The oxygen depletion efficiency of L₉₅[SA_x(MFe)_y]₅ series samples improved initially as the weight ratios of SA/MFe increase, and reached the best as the weight ratios of SA/MFe approach 7/3. After modifying LDPE with glucoses, the oxygen depletion efficiency of each ML₉₅[SA_x(MFe)_y]₅ specimen improved even better than that of the corresponding L₉₅[SA_x(MFe)_y]₅ specimen with the same loading of oxygen scavenger compound, wherein the oxygen depletion efficiency of ML₉₅[SA_x(MFe)_y]₅ series specimens reached the best as the weight ratios of SA/MFe approach 1/9. In consistent with the oxygen depletion properties found in the previous section, the peroxide values of modeled food samples tested in the airtight flask with L₉₅[SA_x(MFe)_y]₅ and ML₉₅[SA_x(MFe)_y]₅ series samples reduce consistently as their oxygen depletion properties improve. In order to understand the interesting oxygen depletion properties of L₉₅[SA_x(MFe)_y]₅ and ML₉₅[SA_x(MFe)_y]₅ series samples, Fourier transform infrared spectroscopy, scanning electron microscope and energy dispersive X-rays analysis of these samples were performed.     

Improved shape evolution of copper interconnects prepared by jet-stream etching

In the preparation of copper interconnects in the conductor pattern of a printed circuit board (PCB), wet etching processes are commonly adopted for creating patterns of high-density interconnects. Currently available techniques of immersion and spray etching could lead to poorly shaped wires due to complex flow fields or the disturbing puddling effect. A modified technique of arrayed jet-stream etching was developed in this work, aiming at producing well-defined copper interconnects on a PCB in a significantly shorter time. The results were appealing in that copper interconnects of 35/140 μm (thickness/width) exhibiting etching factors of greater than 6 were obtained in 20 s, much better than the conventional ones with etching factors of 3 to 5 and etching times of at least 2 min. In addition, uniformly etched copper interconnects with less than 20 μm undercuts were observed on one etching line. One additional point to note is that no banking agents or inhibitors as commonly seen in conventional etching techniques were needed in this new processing method.     

Melting behavior of poly(trimethylene terephthalate)

In this study, the melting behavior of isothermally crystallized polytri‐ methylene terephthalate (PTT) was investigated. Multiple melting behaviors in DSC heating trace were found because two populations of lamellar stacks were formed during primary crystallization and the recrystallization at heating process, respectively. This fact could be also confirmed from the result of optical microscopy observation. The Hoffman–Weeks equation was applied to obtain equilibrium melting temperature (T). The T value of PTT is about 525 K, which is 10 K higher than that reported. Combining the enthalpy of fusion from the DSC result and the degree of crystallinity from WAXD result, the value of the equilibrium‐melting enthalpy ΔH was deduced to be approximately 28.8 kJ mol^?1. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2426–2433, 2002     

Effect of dispersion method and process variables on the properties of supercritical CO2 foamed polystyrene/graphite nanocomposite foam

In this study, polystyrene/nanographite nanocomposite foams were made by different compounding methods, such as direct compounding, pulverized sonication compounding, and in situ polymerization, to understand the effect of the process variables on the morphology of the nanocomposites and their foam. The foam was made by batch foaming using CO₂ as the blowing agent. Various foaming pressures and temperatures were studied. The results indicated that the cell size decreased and the cell morphology was improved with the advanced dispersion of the nanoparticles. Among the three methods, the in situ polymerization method provided the best dispersion and the resulting nanocomposite foam had the finest cell size and the highest cell density. In addition, adding nanoparticles as a nucleating agent can make foams of similar cell size and cell density at a much lower foaming pressure. This result can be explained by the classical nucleation theory. This discovery could open up a newroute to produce microcellular foams at a low foaming pressure. POLYM. ENG. SCI., 53:2061–2072, 2013. © 2013 Society of Plastics Engineers