Monatomic oxygen adsorption on halogen-substituted monovacant graphene

Doping of graphene-based materials with heteroatoms relies on the disruption of existing charge densities found on pristine graphene. Even though it is known that this phenomenon helps catalyze oxygen reduction reaction (ORR), there are only a few theoretical studies regarding the use of halogen as dopants despite their high electronegativity differences with carbon. Using density functional theory calculations, this work explores the low-concentration halogenation of monovacant graphene as well as the adsorption of oxygen atom onto resulting halogen-based substrates (X = F, Cl, Br, I). In general, formation of doped graphene and the subsequent adsorption of monatomic oxygen is more favored in non-coplanar systems than in their coplanar counterparts. In addition, F-based systems exhibited the most favorable energetics for monoatomic adsorption and electronic properties among the four substrates. Electronegativity also plays a key role on the destruction and formation of molecular structures during the adsorption of monatomic oxygen. Further work with adsorption of O₂ on these substrates is warranted to elucidate their potential to catalyze ORR.     

Rheological predictions of sensory attributes of lotions

Complex behavior of 33 commercial lotions was investigated in order to identify correlations between laboratory instrumental measurements and sensory attributes of these products. Sensory attributes were evaluated by trained panelists. Six attributes were identified as potentially related to rheology, which belong to three main sensory categories: appearance, pickup, and rub out. Potential rheological predictors were extracted from the data of rotational rheometry. Yield stress and instantaneous viscosity maximum (IVM) were determined in stress ramp. Alternative definitions of yield stress based on step‐shear and oscillatory strain sweeps were also considered along with linear viscoelastic moduli, G′ and G″. Statistical analysis has shown all these definitions of yield stress and IVM are in fact closely correlated and that IVM is the best overall predictor of most attributes although G′/G″ ratio also is significant for rub out attributes. However, integrity of shape, the main appearance attribute, is even better predicted by an imitative slump‐like test in which image analysis is used to quantify sample spreading on a flat surface.     

Effects of nanoparticle feed location during nanocomposite compounding

Polymer nanocomposites can provide improved mechanical, barrier, flame retardancy, and other properties at low filler loading, but these properties depend on the dispersion of the nanoparticles. In this work, the impact of feeding configuration on dispersion, mechanical properties, and airborne particle concentration was examined in a model nanocomposite system. Dynamic mechanical analysis and differential scanning calorimetry were performed to determine glass transition temperature of the nanocomposite. Transmission electron microscopy was used to assess dispersion of the nanoparticles in the polymer matrix whereas mechanical properties were measured using ISO standards. A fast mobility particle analyzer was used to measure airborne particle levels at from the hopper and the feed ports. These levels were correlated to the particle size and material loss. An indirect relationship was established among material loss, measured dispersion levels, and mechanical properties. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

Controlling Fiber Repulsion in Multijet Electrospinning for Higher Throughput

A novel electrospinning set‐up has been developed to successfully electrospin multiple jets with controlled fiber repulsion using a plastic filter. This set‐up shows reduced fiber repulsion as compared to a multineedle set‐up, along with increased throughput. The effect of processing parameters on the fiber repulsion in a multineedle set‐up was also studied. It was found that fiber repulsion could be reduced by controlling emitter voltage and emitter/collector distance. Other important parameters studied included fiber distribution and throughput. It was found that the plastic filter set‐up produced fibers with lower mean diameters and better uniformity. This novel plastic filter design for electrospinning provides increased electrospinning rates with better fiber uniformity.

     

Influence of nanoparticle diameter on conjugated enzyme activity

Lactase conjugated to nanomaterials represents an area of significant potential to the food processing as a means to produce novel value-added products, reduce waste, and enable diagnostics. While it is recognized that, in general, matter exhibits unique properties when manipulated at the nanoscale, little is known about how reducing the size of the carrier to the nanoscale effects attached lactase. The purpose of this work is to investigate the influence of particle size on activity retention of lactase (Aspergillus oryzae) covalently conjugated to magnetic nanoparticles of varying sizes. Lactase was attached to carboxylic acid functionalized magnetic nanoparticles 18 nm, 50 nm, and 200 nm in diameter using carbodiimide chemistry. After attachment, activity retention was 73%, 39%, and 14% compared to the free enzyme for the 18 nm, 50 nm, and 200 nm conjugates, respectively. The apparent K_m was not significantly different as a function of particle size while the apparent k_cat decreased with increasing particle size. Reducing the particle size of magnetic nanoparticles can increase the activity retention of conjugated lactase. This work provides improved understanding of enzyme-nanoparticles systems and allows for enhanced design of lactase-conjugated materials.     

融化在自然中

设计使室内外界线模糊，加强了人与自然环境的融合度，让人尽量融入于大自然中，褪去一切烦扰心情，一起回归到大自然的怀抱,才能真正将压力释放出来。故此，空间的布局利用亭园、回廊与花园，以亭园为中心，再集合室内，室外的多功能水疗设施，便成了一座桥梁，将日与夜、动与静的感觉，渗进水疗中心的每个角落。[编者按]     

The Influences of Deception and Computer-Mediation on Dyadic Negotiations

This article reports on an experiment investigating the differences between computer-mediated and face-to-face negotiations and between negotiators being deceptive about hidden agendas and negotiators without hidden agendas. Our results supported the hypotheses that individuals negotiating via instant messaging are more likely to use forcing negotiating, experience more tension, and have lower deception detection accuracy than individuals negotiating face-to-face. Unexpectedly, it was found that individuals negotiating via instant messaging were more satisfied with the negotiation process than were face-to-face negotiators. Finally, results supported the hypothesis that those being deceptive about hidden agendas experienced higher tension than those without hidden agendas. These findings have several implications for organizations: higher levels of tension from computer-mediated negotiations and from deception can affect the long-term effectiveness of employees, undetected deception in computer-mediated negotiations can have a negative impact on negotiations, and computer-mediation can lead to the use of a forcing negotiation style, which may improve the effectiveness of negotiators with individualistic goals.     

Why aren’t organizations adopting virtual worlds?

The purpose of this study was to understand why organizational adoption of virtual worlds much has been much slower than expected, by empirically identifying factors that influence organizational intent to adopt virtual worlds. To do so, we developed a model of factors that influence organizational adoption of virtual worlds, based on the Technology–Organization–Environment framework. The model was tested using survey data from organizations, as well as secondary data. Interestingly, mimetic pressures and normative pressures exhibit the strongest effects on organizational intent to adopt virtual worlds. Contrary to expectations, none of the technical factors were to be found significant. These findings provide insights into why the organizational adoption rate of virtual worlds is much slower than expected. First, organizations are intended to adopt virtual worlds if other organizations are adopting virtual worlds. However, organizations are not adopting virtual worlds. Second, because respective competitors that have adopted virtual worlds are not benefiting or succeeding, organizations are not induced to adopt. Last, technological factors, such as relative advantage and compatibility, do not currently have a significant impact on an organization’s intent to adopt virtual worlds.     

StencilMaps and EphemeralMaps: spatially stable interfaces that highlight command subsets

Identifying a target command can be difficult and time-consuming when the user is unfamiliar with a software system. One technique for assisting command identification is to provide a subset interface that contains only a limited set of the system's capabilities. We examine the design of subset interfaces, showing that subsets can be presented separately to the full user interface (UI) (e.g. in a palette) or in place, with in-place methods using either static or dynamic methods to identify the subset. We introduce the StencilMap and EphemeralMap as in-place subset UIs that, respectively, use static and dynamic highlighting. Both StencilMaps and EphemeralMaps make all of an application's commands concurrently available for selection within a grid. To highlight subset items StencilMaps use a static dark semi-transparent ‘stencil’ overlay to de-emphasise all but the subset items; EphemeralMaps, in contrast, use a short delay, with subset items shown immediately, and other items gradually faded in. A first experiment compares user performance with the in-place presentation of StencilMaps against that of the separate presentation of a subset palette. Results confirm the predicted spatial memory benefits for StencilMaps. A second experiment analyses the performance impact of three approaches to highlighting: none, static highlighting in StencilMaps, and dynamic highlighting in EphemeralMaps. Results show an interesting trade-off – while highlighting can offer benefits in assisting rapid target identification (particularly when the user is unfamiliar with the interface layout), there can also be longer-term performance benefits when highlighting is absent because the increased difficulty of visual search promotes the use and formation of spatial memory.