Thermal Integration of Sulfuric Acid and Continuous Catalyst Regeneration of Naphtha Reforming Plants

An optimal reactor design is proposed that simultaneously improves the naphtha reforming reactor performance and increases sulfur trioxide production. In this new configuration, the naphtha reforming process as an endothermic reaction is coupled with the oxidation reaction of sulfur dioxide, which is an exothermic reaction. The differential evolution optimization technique is applied to maximize the produced amounts and yields of aromatics and hydrogen. The results obtained with the optimized thermally coupled reactor are compared with those of the conventional and thermally coupled reactors, proving the superiority of the proposed configuration.     

Enhanced dielectric and piezoelectric response in PZT superlattice-like films by leveraging spontaneous Zr/Ti gradient formation

Spontaneous Zr/Ti gradient formation during crystallization in sol-gel-processed Pb(Zr_xTi_1−x)O₃ films is used to prepare superlattice-like (SL), highly (1 0 0)-oriented thin films on Pt/Ti/SiO₂/Si substrates. SLs with stacking periodicity ranging from 13 up to 60 nm are synthesized with compositional gradient normal to the film surface and composition centered at x ≈ 0.53. X-ray diffraction (XRD) shows high order satellite peaks and no secondary phases. XRD structural refinement, along with XPS depth profile chemical analysis, reveals that the crystal structure alternates between rhombohedral and in-plane polarized tetragonal phases, effectively corresponding to “artificially created” phase boundaries. SL films have ∼45% and ∼20% higher d_33,f piezoelectric coefficient and dielectric permittivity, respectively, with respect to compositional-gradient-free films of similar thickness, possibly due to enhanced reorientation of electrical dipoles and higher extrinsic contributions due to the motion of the “artificially created” phase boundaries in SL films. Dielectric nonlinear studies indicate a higher amount of extrinsic contributions to the dielectric response in SL and gradient-enhanced films than in conventional films of similar average composition. This processing method provides a simple chemical route to create thin ferroelectric films with enhanced dielectric and piezoelectric properties suitable for a range of miniaturized applications.     

Bio‐lubricant flow behaviour in mini‐channels

One of the most common causes of failures in total joint replacements is the generation of wear particles within the joint. This contributes to bone lost and aseptic loosening of the implant, eventually requiring its replacement. Many studies have been carried out to improve the wear characteristics of bearing surfaces in total joint replacement. From the lubrication point of view, the friction behaviour of surfaces and rheology of the joint lubricant (synovial fluid) have been extensively studied. However, little attention has been paid to the interaction between the lubricant and the bearing surfaces. The aim of this study is to develop a methodology for studying the behaviour of bio‐based lubricant in mini‐channels. For this purpose, micro‐particle image velocimetry was used in order to characterise the lubricant behaviour. Channels made of relevant materials such as ultra‐high molecular weight polyethylene, cobalt–chromium–molybdenum alloy and titanium–aluminium–vanadium alloy with 1 and 1.5 mm width, 45 mm length and 2 mm depth were experimentally investigated. Results suggested that the used polymeric solution interaction with solid surfaces is very sensitive to the polymer concentration in the lubricant. Moreover, it was observed that there exist differences between water (Newtonian reference fluid) and the polymeric solution behaviour even at very simple movements; although usually, the properties of this lubricant at high shear rates are estimated by water properties. Copyright © 2015 John Wiley & Sons, Ltd.     

Attentional bias to pictures of fear-relevant animals in a dot probe task.

Attentional bias to fear-relevant animals was assessed in 69 participants not preselected on self-reported anxiety with the use of a dot probe task showing pictures of snakes, spiders, mushrooms, and flowers. Probes that replaced the fear-relevant stimuli (snakes and spiders) were found faster than probes that replaced the non-fear-relevant stimuli, indicating an attentional bias in the entire sample. The bias was not correlated with self-reported state or trait anxiety or with general fearfulness. Participants reporting higher levels of spider fear showed an enhanced bias to spiders, but the bias remained significant in low scorers. The bias to snake pictures was not related to snake fear and was significant in high and low scorers. These results indicate preferential processing of fear-relevant stimuli in an unselected sample. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On performance evaluation of swarm-based live peer-to-peer streaming applications

During recent years, swarm-based peer-to-peer streaming (SPS) mechanisms have become increasingly popular for scalable delivery of live streams over the Internet. The performance of SPS mechanisms depends on the overall effect of several factors including the connectivity of the overlay, the details of packet scheduling scheme and environment settings (e.g., peer and source bandwidth). Prior studies often presented overall performance of their proposed techniques in terms of delivered quality to all peers at a particular setting without demonstrating their inherent performance bottlenecks. Therefore, it is difficult to determine whether and how the reported performance of an SPS mechanism might change as a function of available resources or the connectivity of the overlay. In this paper, we present a simple yet effective methodology for performance evaluation of SPS mechanisms. Our methodology leverages an organized view of an overlay coupled with a two-phase notion of content delivery in SPS mechanisms to derive a set of metrics that collectively capture the behavior of each phase of content delivery. Therefore, the collection of our metrics can be viewed as the “signature of content delivery” of a given SPS mechanism. We also present the signature of a well-performing SPS mechanism that can be used as a reference for assessment of other mechanisms. To demonstrate the ability of our proposed evaluation methodology in identifying performance bottlenecks of SPS mechanisms and their underlying causes, we conduct two case studies: (1) assessing the performance of a set of candidate packet scheduling schemes; and (2) examining the effect of overlay localization on the performance of SPS mechanisms. In addition to illustrating the use of our methodology through examples, our case studies shed an insightful light on the performance bottlenecks in our target scenarios.     

Infrared Absorption Coefficients of Silica Glasses

The absorption coefficient values of several silicate glasses in the IR radiation range were determined. Four methods were employed in this study: (1) direct transmission by CO₂ laser, (2) direct transmission through ultrathin sections using an IR spectrometer, (3) glass particle dispersions in KBr pressed pellets, and (4) IR reflection spectral analysis. Wide variations in values were observed for some of these techniques. The reasons for the variations were explored, and evidence is presented to support the conclusion that the reflection measurements and the low-power transmission technique yield accurate values. The pellet technique was found to possess too many experimental variables which could not be controlled and gave erroneous data. The damage produced by direct transmission of high-power radiation was severe and introduced effects which gave spurious results.     

Multifunctional 3D‐Printed Patches for Long‐Term Drug Release Therapies after Myocardial Infarction

A biomaterial system incorporating nanocellulose, poly(glycerol sebacate), and polypyrrole is introduced for the treatment of myocardial infarction. Direct ink writing of the multicomponent aqueous suspensions allows multifunctional lattice structures that not only feature elasticity and electrical conductivity but enable cell growth. They are proposed as cardiac patches given their biocompatibility with H9c2 cardiomyoblasts, which attach extensively at the microstructural level, and induce their proliferation for 28 days. Two model drugs (3i‐1000 and curcumin) are investigated for their integration in the patches, either by loading in the precursor suspension used for extrusion or by direct impregnation of the as‐obtained, dry lattice. In studies of drug release conducted for five months, a slow in vitro degradation of the cardiac patches is observed, which prevents drug burst release and indicates their suitability for long‐term therapy. The combination of biocompatibility, biodegradability, mechanical strength, flexibility, and electrical conductivity fulfills the requirement of the highly dynamic and functional electroresponsive cardiac tissue. Overall, the proposed cardiac patches are viable alternatives for the regeneration of myocardium after infarction through the effective integration of cardiac cells with the biomaterial.     

Incorporating contribution-awareness into mesh-based Peer-to-Peer streaming systems

While Peer-to-Peer streaming has become increasingly popular over the Internet during recent years, the proper allocation of available resources among peers in a resource constraint environment, remains a challenging problem. In a resource constraint environment, the allocated resources and thus delivered quality to individual peers should be proportional to their contribution to the system, i.e., resource allocation should be contribution aware. This in turn results in fairness among peers and encourages active contribution from participating peers which is essential for scalability of P2P systems. However, contribution-aware resource allocation is challenging due to the distributed and dynamic nature of resources in P2P systems. In this paper, we present a tax-based contribution-aware scheme for live mesh-based P2P streaming approaches. In our proposed scheme, individual peers use a tax function to determine their number of parent peers (i.e., their share of resources) based on the number of their child peers (i.e., peers’ contributed resources) and the aggregate available resources in the system. We examine the behavior of a commonly used tax function, and describe how the contribution aware scheme can leverage the tax function. Through extensive simulations we demonstrate the ability of our proposed scheme to properly allocate available resources among participating peers over a wide range of scenarios. We show that the amount of resources (i.e., bandwidth) is divided across peers proportional to their contribution and in our default simulation setting the median delivered quality to high bandwidth peers with high contribution is improved by 100%. We believe that our results shed an insightful light on the dynamics of resource utilization and allocation in the context of live mesh-based P2P streaming.     

Open for Entrepreneurship: How Open Innovation Can Foster New Venture Creation

This paper explores how an open approach to new venture creation – purposefully managing knowledge flows across the venture's organizational boundary – can be beneficial for start‐up entrepreneurs. Our inductive case study, of both failure and success, identifies the key attributes of this open approach and how they affect start‐ups' short‐term survival. We find that ecosystem collaboration, user involvement and an open environment directly influence new venture survival, and that their effects were moderated by the entrepreneurs' open mindset. These findings carry a number of implications for entrepreneurship and innovation research and practice, providing some attention points for researchers, entrepreneurs, investors and policy makers interested in developing successful new ventures.