Affordance-based robot object retrieval

Autonomous Robots - Natural language object retrieval is a highly useful yet challenging task for robots in human-centric environments. Previous work has primarily focused on commands specifying...     

Influence of Pendant Group on Mobility of Organic Thin Film Transistor in Correlation with Reorganization Energy of Molecules

Charge transport properties of common donor copolymers in organic photovoltaics, poly({4,8‐bis[(2‐ethylhexyl)oxy]benzo[1,2‐b:4,5‐b′]dithiophene‐2,6‐diyl}{3‐fluoro‐2‐[(2‐ethylhexyl)carbonyl]thieno[3,4‐b]thiophenediyl}) (PTB7) and poly([2,6′‐4,8‐di(5‐ethylhexylthienyl)benzo[1,2‐b;3,3‐b]dithiophene]{3‐fluoro‐2[(2‐ethylhexyl) carbonyl]thieno[3,4‐b]thiophenediyl}) (PTB7‐Th), with molecular structures differing only in the pendant group, are studied. This is the first report of field‐effect transistor mobility (µ_FET) of PTB7‐Th (0.14 cm² V^?1 s^?1) and the highest µ_FET for PTB7 (0.01 cm² V^?1 s^?1). µ_FET of PTB7‐Th is found to be almost one order of magnitude higher than PTB7. To understand the influence of molecular structure on charge transport, hole reorganization energy (λ_h) is calculated from first‐principles. λ_h of PTB7‐Th (≈150 meV) is found to be lower than PTB7 (≈346 meV). Further, the ratio of hopping rate versus square of charge transfer integral calculated from Marcus theory using λ_h for these systems is found to indicate a higher rate of hole transfer across dimers or homojunction interface for PTB7‐Th. These results are supplemented by experimentally determined λ using bulk‐heterojunction organic solar cells, where λ_PTB7‐Th≈200 meV and λ_PTB7≈310 meV follow a similar trend. The effective hole‐mobility estimation from BHJ devices correlates well with these λ values. This study provides understanding of charge transport properties via reorganization energy, as a function of pendant group without altering the backbone of the chains.     

In situ metal tip sharpening of scanning probe microscopes

This article demonstrated a new approach for fabrication and sharpening of metal tips of scanning probe microscopes. Experimentally, a metal tip was heated and melted by a focused laser light. The tip was then sharpened by a strong electric field and consolidated as the laser was turned off. With a low‐vacuum and a high‐voltage source, a 25‐µm indium‐coated platinum wire was sharpened to a tip with diameters below 50 nm. The minimal tip radius by this method is estimated to be below 1 nm. With this technique, in situ tip sharpening for SPM would be possible. SCANNING 34: 76–79, 2012. © 2011 Wiley Periodicals, Inc.     

Exploiting GPUs with the Super Instruction Architecture

The Super Instruction Architecture (SIA) is a parallel programming environment designed for problems in computational chemistry involving complicated expressions defined in terms of tensors. Tensors are represented by multidimensional arrays which are typically very large. The SIA consists of a domain specific programming language, Super Instruction Assembly Language (SIAL), and its runtime system, Super Instruction Processor. An important feature of SIAL is that algorithms are expressed in terms of blocks (or tiles) of multidimensional arrays rather than individual floating point numbers. In this paper, we describe how the SIA was enhanced to exploit GPUs, obtaining speedups ranging from two to nearly four for computational chemistry calculations, thus saving hours of elapsed time on large-scale computations. The results provide evidence that the “programming-with-blocks” approach embodied in the SIA will remain successful in modern, heterogeneous computing environments.     

A Single Dose of Psilocybin Increases Synaptic Density and Decreases 5-HT2A Receptor Density in the Pig Brain

A single dose of psilocybin, a psychedelic and serotonin 2A receptor (5-HT_2AR) agonist, may be associated with antidepressant effects. The mechanism behind its antidepressive action is unknown but could be linked to increased synaptogenesis and down-regulation of cerebral 5-HT_2AR. Here, we investigate if a single psychedelic dose of psilocybin changes synaptic vesicle protein 2A (SV2A) and 5-HT_2AR density in the pig brain. Twenty-four awake pigs received either 0.08 mg/kg psilocybin or saline intravenously. Twelve pigs (n = 6/intervention) were euthanized one day post-injection, while the remaining twelve pigs were euthanized seven days post-injection (n = 6/intervention). We performed autoradiography on hippocampus and prefrontal cortex (PFC) sections with [³H]UCB-J (SV2A), [³H]MDL100907 (5-HT_2AR antagonist) and [³H]Cimbi-36 (5-HT_2AR agonist). One day post psilocybin injection, we observed 4.42% higher hippocampal SV2A density and lowered hippocampal and PFC 5-HT_2AR density (−15.21% to −50.19%). These differences were statistically significant in the hippocampus for all radioligands and in the PFC for [³H]Cimbi-36 only. Seven days post-intervention, there was still significantly higher SV2A density in the hippocampus (+9.24%) and the PFC (+6.10%), whereas there were no longer any differences in 5-HT_2AR density. Our findings suggest that psilocybin causes increased persistent synaptogenesis and an acute decrease in 5-HT_2AR density, which may play a role in psilocybin’s antidepressive effects.     

Application of Taguchi approach in describing the mechanical properties and thermal decomposition behavior of poly(vinyl chloride)/clay nanocomposites: Highlighting the Role of organic modifier

Mechanical and thermal properties of poly(vinyl chloride) (PVC)/nanoclay (NC) composites prepared via melt‐blending in a single‐screw extruder were investigated. The effects of NC type, NC content, and K‐value of PVC were evaluated by using L9 orthogonal array of the Taguchi approach. The most influential variables and significance of interactive effects were examined for the highest values of Young's modulus and hardness. Scanning electron micrographs and X‐ray diffraction patterns revealed the formation of exfoliated/intercalated structures. Although the K‐value has a minor individual effect on mechanical characteristics, the interaction of the K‐value with NC type and NC content is significant. The composites were also characterized and tested by using analysis by thermal gravimetry, differential thermogravimetry, and differential scanning calorimetry methods. The results of the thermal studies indicated that decomposition of the organic modifier of NCs has a catalytic effect on the dehydrochlorination of PVC. This finding justifies the rather low mechanical properties of PVC/organoclay nanocomposites. Fourier‐transform infrared spectra of the samples were indicative of accelerated degradation reactions, which provided support for above observations. J. VINYL ADDIT. TECHNOL., 22:182–190, 2016. © 2014 Society of Plastics Engineers     

基于ZigBee/IEEE 802.15.4的低成本辅助驾驶系统

本文提出一个完整的基于ZigBee的驾驶辅助系统解决方案,该方案充分利用了具有低成本、低功耗和安全无线网络功能等特性的ZigBee协议。     

Waveguiding Microactuators Based on a Photothermally Responsive Nanocomposite Hydrogel

The incorporation of gold nanoparticles within thermally responsive poly(N‐isopropyl acrylamide) hydrogels provides a simple means to define photothermally addressable materials. Relying on such composite gels, it is established here that micropatterned bilayer photoactuators demonstrate rapid and highly reversible bending and unbending behavior in response to illumination with visible light. In addition to actuation by free space light, as in most previous research on such responsive nanocomposite hydrogels, light from a 532 nm laser is also waveguided through a plastic optical fiber directly into the photoactuator, providing remotely controllable actuators that do not require line‐of‐sight access.     

Energy, greenhouse gas, and cost reductions for municipal recycling systems

Curbside recycling programs can be more cost-effective than landfilling and lead to environmental benefits from the recovery of materials. Significant reductions in energy and emissions are derived from the decrease of energy-intensive production with virgin materials. In many cities, competing priorities can lead to limited consideration given to system optimal collection and processing strategies that can drive down costs and increase revenue while simultaneously reducing system energy consumption and greenhouse gas (GHG) emissions. We evaluate three alterations to a hypothetical California city's recycling network to discern the conditions under which the changes.constitute system improvements to cost, energy, and emissions. The system initially operates with a collection zoning scheme that does not mitigate the impact of seasonal variations in consumer tonnage. In addition, two collection organizations operate redundantly, collecting recyclables from different customer types on the same street network. Finally, the system is dual stream, meaning recyclables are separated at the curbside. In some scenarios, this practice can limit the consumer participation rate leading to lower collection quantities. First, we evaluate a "business as usual" (BAU) scenario and find that the system operates at a $1.7 M/yr loss but still avoids a net 18.7 GJ and 1700 kg of greenhouse gas equivalent (GGE) per ton of material recycled. Second, we apply an alternative zoning scheme for collection that creates a uniform daily pickup demand throughout the year reducing costs by $0.2 M/yr, energy by 30 MJ/ton, and GHG emissions by 2 kg GGE/ton. Next, the two collection organizations are consolidated into a single entity further reducing vehicle fleet size and weekly vehicle miles traveled resulting in savings from BAU of $0.3 M/yr, 100 MJ/ton, and 8 kg GGE/ton. Lastly, we evaluate a switch to a single-stream system (where recyclables are commingled). We showthat single-stream recycling can increase the total amount of material collected to a degree that lowers overall net cost ($0.2 M/yr) and leads to further reductions in energy use (210 MJ/ton) and emissions(16 kg GGEton). However,there can be circumstances in which maintaining a consolidated dual stream system is preferred over single stream. A sensitivity analysis is also performed and a discussion is presented addressing the applicability of this city network to others.