Surface structural and solar absorptance features of nitrate-based copper-cobalt oxides composite coatings: Experimental studies and molecular dynamic simulation

The copper and cobalt oxides composites coatings on aluminum substrates have been successfully synthesized via sol-gel method using nitrate-based sol precursors. The composites were characterized by X-ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Field Emission Scanning Electron Microscopy (FESEM), Atomic Force Microscopy (AFM), and UV–Vis–NIR spectrophotometry. The sol-gel reactions were discussed and Molecular Dynamics (MD) simulation was integrated into the study to predict molecules assembly properties. The XRD analyses revealed that the CuO and the Co₃O₄ composites were formed after the annealing process with the average difference of the calculated lattice parameters compared to ICDDs was 1.17%. The surface electronic structure was mainly consisted of tetrahedral Cu(I), octahedral Cu(II), tetrahedral Co(II), octahedral Co(III) as well as surface, sub-surface and lattice oxygen O^?. The XRD, XPS and MD simulation results showed that there was minimal (or possibly non-existing) indication of copper-cobalt mixed phase oxides formations. FESEM and AFM surveys revealed that the coating had a porous surface composed of interlinked nanoparticles in the range of ~?10 to ~?40?nm. UV–Vis–NIR reflectance spectra showed that the sol precursors concentration and the dip-drying cycle significantly influenced the absorptance value with optimum absorptance (α) of 88.7% exhibited by coating synthesized using sol concentration of 0.1?M and 10 dip-drying cycles. High absorptance value and simplicity in the synthesis process render the coatings to be very promising candidates for solar selective absorber (SSA) applications.     

Progress toward roll-to-roll processing of inorganic monolithic electrochromic devices on polymeric substrates

As electrochromic device (ECD) emerges into the market, the necessity of cost reduction via high-throughput manufacturing is unavoidable. Inorganic monolithic ECD has compatibility in its manufacturing steps, allows continuous processing and hence low-cost ECD. A roll-to-roll (R2R) production is the industrial standard for high-throughput processing and was chosen to synthesize ECD on polymeric substrates. Preliminary success by implementing methods compatible to the aforementioned R2R processing has been achieved; however, continuous test-runs on an R2R machine are still limited.     

A high-capacity broadband packet switch architecture based on a multilink approach

Broadband packet networks based on asynchronous transfer mode (ATM) are expected to provide a wide range of services, including motion video, voice, data and image. When these networks become prevalent, some applications such as motion video and high-speed LAN interconnections will place a very large bit rate requirement on the channels. Currently, the physical layer supported by the synchronous optical network (SONET) allows the transmission of up to 2.4 Gbit/s with the OC-48 optical interface. However, it is not feasible for the electronic packet switch to route packets at this rate on a single link. In this paper we present a design of a broadband packet switch that uses multiple links in parallel to realize a high-speed channel. This implementation permits the switch to operate at the lower link rate, which can be at 150 Mbit/s, while having the ability to support a virtual circuit at a higher rate (up to 2.4 Gbit/s). The main contribution of the design is that packet sequence on a channel is still maintained even though packets are allowed to use any of the links belonging to the same channel. Besides allowing the switch to function at a slower rate than the transmission channel rate, the implementation of the multilinks benefits from statistical multiplexing gain. Analytical results show the performance advantages of multilink design with respect to delay, throughput and packet loss probability.     

Privacy Preserving Geo-Linkage in the Big Urban Data Era

Big data technologies and a range of Government open data initiatives provide the basis for discovering new insights into cities; how they are planned, how they managed and the day-to-day challenges they face in health, transport and changing population profiles. The Australian Urban Research Infrastructure Network (AURIN – www.aurin.org.au) project is one example of such a big data initiative that is currently running across Australia. AURIN provides a single gateway providing online (live) programmatic access to over 2000 data sets from over 70 major and typically definitive data-driven organizations across federal and State government, across industry and across academia. However whilst open (public) data is useful to bring data-driven intelligence to cities, more often than not, it is the data that is not-publicly accessible that is essential to understand city challenges and needs. Such sensitive (unit-level) data has unique requirements on access and usage to meet the privacy and confidentiality demands of the associated organizations. In this paper we highlight a novel geo-privacy supporting solution implemented as part of the AURIN project that provides seamless and secure access to individual (unit-level) data from the Department of Health in Victoria. We illustrate this solution across a range of typical city challenges in localized contexts around Melbourne. We show how unit level data can be combined with other data in a privacy-protecting manner. Unlike other secure data access and usage solutions that have been developed/deployed, the AURIN solution allows any researcher to access and use the data in a manner that meets all of the associated privacy and confidentiality concerns, without obliging them to obtain ethical approval or any other hurdles that are normally put in place on access to and use of sensitive data. This provides a paradigm shift in secure access to sensitive data with geospatial content.     

Unary finite automata vs. arithmetic progressions

We point out a subtle error in the proof of Chrobak's theorem that every unary NFA can be represented as a union of arithmetic progressions that is at most quadratically large. We propose a correction for this and show how Martinez's polynomial time algorithm, which realizes Chrobak's theorem, can be made correct accordingly. We also show that Martinez's algorithm cannot be improved to have logarithmic space, unless L = NL.     

Image reconstruction from in-line Fresnel holograms by using coherent background elimination

Image reconstruction from in-line Fresnel holograms by eliminating a coherent background is studied by computer simulation. The coherent background is calculated by averaging an intensity of a recorded hologram. The quality of the reconstructed image is measured by using a ratio of peak signal to noise. In comparison with the conventional reconstruction method, the results show that the background elimination can improve significantly the quality of the reconstructed images. The text was submitted by the authors in English.     

Need for Affiliation,Need for Popularity,Self-Esteem,and the Moderating Effect of Big Five Personality Traits Affecting Individuals’ Self-Disclosure on Facebook

The purpose of this study is to explore the moderating effect of Big Five personality traits on the relationship between the predictors (need for affiliation, need for popularity, and self-esteem) and self-disclosure on Facebook. The sample of this study is 354 Facebook users from 5 different cultures in East Asia. A partial least square structural equation modeling data analysis technique was performed to analyze the moderator research framework. This study demonstrates that particular Big Five personality traits moderate each relationship. Specifically, Conscientiousness and Emotional Stability negatively moderate the relationship between need for affiliation and self-disclosure. Agreeableness negatively moderates the relationship between self-esteem and self-disclosure. Openness to New Experience negatively moderates the relationship between need for popularity and self-disclosure. The study suggests the importance of the interaction of personality variables to better understand self-disclosure phenomenon on Facebook. The findings and implications of this study are discussed in the article.     

Femtocells [Guest Editorial]

Femtocells are destined to transform the way mobile operators build their cellular networks and grow their coverage and capacity. Femtocells are small base stations operating in the licensed cellular bands. They are so small and inexpensive, and transmit at such low power, that they are meant to be placed in individual homes and backhauled onto the operator?s network via conventional digital subscriber line (DSL) or cable broadband access (or, when available, fiber).     

Femtocells [Guest Editorial]

Momentum is building rapidly around femtocells, as several operators worldwide have commercially launched 3G femtocells. This will further accelerate during the course of 2010, with many more operators expected to deploy. As explained in the first part of this series, which appeared in the September 2009 issue of IEEE Communications Magazine, femtocells are small, inexpensive base stations operating in the licensed cellular bands; they are meant to be placed in individual homes or businesses, and backhauled onto the operator's network via wireline broadband access.     

Synthesis, characterization and photopolymerization of vinyl ether and acrylate functionalized hybrid oligo-caprolactone

Linear vinyl ether-(oligo-caprolactone)-acrylate (VPCLA), combining fast free radical and complete cationic photopolymerizable groups, was synthesized, functionalized, and photopolymerized to produce polycaprolactone (PCL) network. Fourier Transform Infrared (FTIR) spectra confirmed that the C = C peaks from both vinyl ether and acrylate end groups were consumed after photopolymerization. Kinetics parameters obtained from differential scanning photo-calorimetry (DPC) analysis showed that photopolymerization of VPCLA at early stage was accelerated as the time needed to reach peak maximum was shortened, and the induction time was significantly shortened compared to monofunctional vinyl ether-(oligo-caprolactone) (VPCL). The activation energy (E_a) was calculated to be 14 kJ/mol, assuming second-order autocatalytic model was followed. Rate of polymerization of the hybrid oligomers was doubled in dual photoinitiators system, which contained both cationic and radical photoinitiators. Furthermore, the conversion was greatly improved at the presence of divinyl ether/hydroxybutyl vinyl ether in 1:1 ratio.