Mixed-Metal MOF-74 Templated Catalysts for Efficient Carbon Dioxide Capture and Methanation

The vast chemical and structural tunability of metal–organic frameworks (MOFs) are beginning to be harnessed as functional supports for catalytic nanoparticles spanning a range of applications. However, a lack of straightforward methods for producing nanoparticle-encapsulated MOFs as efficient heterogeneous catalysts limits their usage. Herein, a mixed-metal MOF, NiMg-MOF-74, is utilized as a template to disperse small Ni nanoclusters throughout the parent MOF. By exploiting the difference in Ni O and Mg O coordination bond strength, Ni²⁺ is selectively reduced to form highly dispersed Ni nanoclusters constrained by the parent MOF pore diameter, while Mg²⁺ remains coordinated in the framework. By varying the ratio of Ni to Mg in the parent MOF, accessible surface area and crystallinity can be tuned upon thermal treatment, influencing CO₂ adsorption capacity and hydrogenation selectivity. The resulting Ni nanoclusters prove to be an active catalyst for CO₂ methanation and are examined using extended X-ray absorption fine structure and X-ray photoelectron spectroscopy. By preserving a segment of the Mg²⁺-containing MOF framework, the composite system retains a portion of its CO₂ adsorption capacity while continuing to deliver catalytic activity. The approach is thus critical for designing materials that can bridge the gap between carbon capture and CO₂ utilization.     

Investigation of the effects of recycled engine oil bottoms on asphalt field performance following an oxidation modeling approach

This work investigates the effects of recycled engine oil bottoms (REOBs) on asphalt field performance by comparing asphalts with and without REOBs in terms of the asphalt properties required for pavement oxidation modeling. Specifically, oxidation reaction kinetics parameters, dynamic shear rheometer (DSR) function (DSRFn) hardening susceptibility (HS), and low sheer viscosity (LSV) HS are determined and compared for base binder, 5 wt.% REOBs, and 15 wt.% REOBs blends. At the higher percentage, addition of REOBs appears to increase the initial oxidation rate at field temperatures and significantly increases LSV HS, but does not significantly increase the DSRFn HS. A field modeling example elucidates the effects.     

Access to Pediatric Neurologists - Will Telemedicine Close the Gap?

Many times both physicians and patients take for granted that they are qualified to treat certain ages and certain conditions. Neurological conditions are diagnosed and treated by neurologists, pediatric neurologists, and neurosurgeons. What is the difference and why does it matter? It is a balancing act of risk and benefit and the physician’s obligation to know her/his limitations. Telemedicine may play a key role in enabling a greater access to pediatric neurologists. If telemedicine becomes more available, then access even in more remote areas without child neurologists may be possible. As this article discusses, there may be certain limitations to using telemedicine, which is distinguishable from telehealth, in relation to pediatric neurology. This article examines the type of neurological physician that is the most appropriate; the availability of and access to pediatric neurologists; and the applicability of telemedicine to the diagnosis and treatment of pediatric neurological conditions.     

Traffic‐aware downlink power allocation in multiuser OFDM system

Multiuser orthogonal frequency division multiplexing (OFDM) is a promising technology to achieve high uplink/downlink (DL) capacities in the next generation broadband wireless networks such as WiMAX (Worldwide Interoperability for Microwave Access). In this paper, we investigate the DL adaptive power allocation (APA) in multiuser OFDM system from the perspective of cross‐layer design. Specifically, we formulate APA as an optimization problem with the traffic profile of each user asit a priori knowledge. To solve the optimization problem, we develop a fairness‐constrained optimal prioritized effective throughput (PET) strategy and the corresponding iterative algorithms, aiming at balancing the prioritized effective throughput and the linear or logarithmic user satisfaction‐based fairness. Simulation results show that our proposed APA optimization approach can achieve satisfying performance. Copyright © 2011 John Wiley & Sons, Ltd.     

Unequal motor durations under simple-, go/no-go, and choice-RT tasks: Extension of Miller and Low (2001).

The logic of the Subtraction Method is used implicitly or explicitly in a variety of work, ranging from traditional response-time research to functional neuroimaging. One assumption of all forms of the Subtraction Method is that components may be inserted (or deleted) without causing changes in the remaining components. We tested this assumption as it applies to the duration of late motor processing using the lag between the onset of lateralized readiness potential (LRP) and the production of the required response as the measure of late motor processing. In contrast to a similar, previous study that used this approach (Miller & Low, 2001), we found differences in the LRP lags across the types of task that are used in the Subtraction Method. The LRP lag for simple-RT was shorter than the lags for either go/no-go or choice-RT. This finding constitutes evidence against an assumption required by the Subtraction Method, at least as applied to component durations, but can be explained in terms of a supplementary (non-subtractive) inhibitory component that is only employed in the go/no-go task. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Minimization of actinide waste by multi-recycling of thoriated fuels in the EPR reactor

The multi-recycling of innovative uranium/thorium oxide fuels for use in the European Pressurized water Reactor (EPR) has been investigated. If increasing quantities of ²³⁸U, the fertile isotope in standard UO₂ fuel, are replaced by ²³²Th, then a greater yield of new fissile material (²³³U) is produced during the cycle than would otherwise be the case. This leads to economies of natural uranium of around 45% if the uranium in the spent fuel is multi-recycled. In addition we show that minor actinide and plutonium waste inventories are reduced and hence waste radio-toxicities and decay heats are up to a factor of 20 lower after 10³ years. Two innovative fuel types named S90 and S20, ThO₂ mixed with 90% and 20% enriched UO₂ respectively, are compared as an alternative to standard uranium oxide (UOX) and uranium/plutonium mixed oxide (MOX) fuels at the longest EPR fuel discharge burn-ups of 65 GWd/t. Fissile and waste inventories are examined, waste radio-toxicities and decay heats are extracted and safety feedback coefficients are calculated. Finally, we discuss the economics of such strategies.     

Prospective associations between friendship adjustment and social strategies: Friendship as a context for building social skills.

The proposal that friendships provide a context for the development of social skills is widely accepted. Yet little research exists to support this claim. In the present study, children and adolescents (N = 912) were presented with vignettes in which a friend encountered a social stressor and they could help the friend and vignettes in which they encountered a stressor and could seek help from the friend. Social strategies in response to these vignettes were assessed in the fall and spring of the school year. Different indicators of friendship adjustment had unique effects on youths' strategies in response to helping tasks. Whereas having more friends predicted decreases in avoidant or hostile strategies, having high-quality friendships predicted emotionally engaged strategies that involved talking about the problem. Moreover, whereas having more friends predicted increases in relatively disengaged strategies, like distraction and acting like the problem never happened, having high-quality friendships predicted decreases in these strategies. The present study also tested whether youths' strategies in the fall predicted changes in friendship adjustment by the spring. Only strategies which may be seen as major friendship transgressions (i.e., avoiding or blaming the friend when the friend encounters a problem) predicted changes in friendship over time. Collectively, these results provide important new information on the interplay between social competencies and friendship experiences and suggest that friendships may provide a critical venue for the development of important relationship skills. (PsycINFO Database Record (c) 2011 APA, all rights reserved)