Phase-insensitive all-optical transistors based on second-ordernonlinearities

We demonstrate and compare two phase-insensitive all-optical transistors (AOT's) based on frequency-degenerate quadratic three-wave interactions. In particular, we demonstrate gain using KTP in a type II geometry. Both AOT's exploit the phase insensitivity inherent to three-wave parametric processes when only two fields are input, providing amplification of a small signal at the operating frequency via the interaction with a second-harmonic wave. The first scheme is based on successive up- and down-conversion (i.e., cascading) while the second relies on parametric down-conversion. We obtain gains of 5 and 160 in the two configurations, respectively, with a significant background and output coherent to the pump in the first case, no background and coherence between output and signal in the second     

A priori ordering protocols to support consensus-building in multiple stakeholder contexts

In a complex social, political, economic, technological, and/or environmental context, corporate, military, government, and other organizations are often faced with collective decision-making situations. The rationale for group decision exercises is that the judgment of many will usually prove superior to the judgment of one. However, it has been shown that collective decision exercises are often highly dependent on matters of perspective, values and opinion, all of which - being essentially subjective in nature - are beyond the reach of existing formal decision technology. Furthermore, it can be expected that many collective decision exercises - particularly those of strategic import - will not lend themselves to the quantitative analysis instruments that have long dominated the management and decision science repertoire. This does not, however, mean that they must remain entirely and forever outside the bounds of scientific rationality. The ordering protocols which are currently available do not have enough technical mechanics to be relied upon to bring us to any satisfying resolution of a priori disputation. Hence, we propose an a priori ordering reference model that might support consensus-building in a multiple stakeholders context. In order to detect whether the subjective arguments are products of proper reasons or merely instances of raw rhetoric and to suggest how any logical or syntactical flaws might best be repaired, we propose logical ordering facilities and protocols for integrating procedural and instrumental provisions for a group-decision process with two lines of technical innovation: the superimpositional ordering function and the logical ordering support facilities.     

A computational approach to characterize formation of a passivation layer in lithium metal anodes

Li metal anode is the “Holy Grail” material of advanced Lithium-ion-batteries (LIBs). However, it is plagued by uncontrollable dendrite growth resulting in poor cycling efficiency and short-circuiting of batteries. This has spurred a plethora of research to understand the underlying mechanism of dendrite formation. While experimental studies suggest that there are complex physical and chemical interactions between heterogeneous solid-electrolyte interphase (SEI) and dendrite growth, most of the studies do not reveal the mechanisms triggering these interactions. To deal with this knowledge gap, we propose a multiscale modeling framework which couples kinetic Monte Carlo and Molecular Dynamics simulations. Specifically, the model has been developed to account for (a) heterogeneous SEI, (b) dendrite-SEI interactions, and (c) effect of electrolyte on Li electrodeposition and potential dendrite formation. This allows the proposed computational model to be extended to various electrolytes and SEI species and generate results consistent with previous experimental studies.     

Silver Nanoflower Decorated Graphene Oxide Sponges for Highly Sensitive Variable Stiffness Stress Sensors

Soft conductive materials should enable large deformation while keeping high electrical conductivity and elasticity. The graphene oxide (GO)‐based sponge is a potential candidate to endow large deformation. However, it typically exhibits low conductivity and elasticity. Here, the highly conductive and elastic sponge composed of GO, flower‐shaped silver nanoparticles (AgNFs), and polyimide (GO‐AgNF‐PI sponge) are demonstrated. The average pore size and porosity are 114 µm and 94.7%, respectively. Ag NFs have thin petals (8–20 nm) protruding out of the surface of a spherical bud (300–350 nm) significantly enhancing the specific surface area (2.83 m² g^?1). The electrical conductivity (0.306 S m^?1 at 0% strain) of the GO‐AgNF‐PI sponge is increased by more than an order of magnitude with the addition of Ag NFs. A nearly perfect elasticity is obtained over a wide compressive strain range (0–90%). The strain‐dependent, nonlinear variation of Young's modulus of the sponge provides a unique opportunity as a variable stiffness stress sensor that operates over a wide stress range (0–10 kPa) with a high maximum sensitivity (0.572 kPa^?1). It allows grasping of a soft rose and a hard bottle, with the minimal object deformation, when attached on the finger of a robot gripper.     

Pan Evaporation Modeling Using Neural Computing Approach for Different Climatic Zones

The purpose of this study was to develop and apply the neural networks models to estimate daily pan evaporation (PE) for different climatic zones such as temperate and arid climatic zones, Republic of Korea and Iran. Three kinds of the neural networks models, namely multilayer perceptron-neural networks model (MLP-NNM), generalized regression neural networks model (GRNNM), and support vector machine-neural networks model (SVM-NNM), were used to estimate daily PE. The available climatic variables, consisted of mean air temperature (T_mean), mean wind speed (U_mean), sunshine duration (SD), mean relative humidity (RH_mean), and extraterrestrial radiation (R_a) were used to estimate daily PE using the various input combinations of climate variables. The measurements for the period of January 1985?CDecember 1990 (Republic of Korea) and January 2002?CDecember 2008 (Iran) were used for training and testing the employed neural networks models. The results obtained by SVM-NNM indicated that it performs better than MLP-NNM and GRNNM for estimating daily PE. A comparison was also made among the employed models, which demonstrated the superiority of MLP-NNM, GRNNM, and SVM-NNM over Linacre model and multiple linear regression model (MLRM).     

Evaluation of the complex hygrothermal behaviors of epoxy–amine systems

In this study, the complex hygrothermal behavior of two epoxy systems used for strengthening applications was studied. In these systems, property loss by plasticization simultaneously occurred with property gain during additional curing. A comparison of the changes in the glass-transition temperature (T_g) and crosslink density with water immersion at different temperatures clearly showed that the two effects of additional curing by a postcuring reaction and plasticization by water absorption were in competition with each other during the exposure. The changes in the conversion with different exposure conditions suggested that water accelerated the postcuring reaction, even at low temperatures; this resulted in a significant difference in the postcuring reaction between unexposed and exposed epoxies. The construction of the plot of T_g versus conversion for the unexposed system and the placement of the T_g for exposed systems onto this master plot provided a method for evaluating the plasticization effect while excluding the influence of additional curing. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Enablers and barriers of the multi-user virtual environment for exploratory creativity in architectural design collaboration

Pioneering psychology and co-design research has highlighted the potential that multi-user virtual environment (MUVE) may help architects’ exploratory creativity that is a recursive search to discover an optimal match of novel and appropriate solutions. However, it has been not reported hitherto in what ways MUVE helps or obstructs architects’ exploratory creativity in individual and collaborative modes of collaboration. To investigate this issue, we compared MUVE and sketching media in face-to-face and remote collaboration modes, involving 22 pairs of architecture major students. Based on interview and video-observation, we discovered that (1) in MUVE, anthropomorphic avatars, which other media do not have, enabled individual and collaborative explorations to discover unexpected affordances of new solutions, with evaluation on physical properties and layouts of solutions. In addition, (2) co-presence with collaborator’s avatars enabled inspiration on new ways of problem-solving and puzzle-making through shared design processes and events, with co-evaluation on social aspects of design solutions. (3) Co-presence in a shared environment also allowed mutual co-exploration that promotes emerging creative solutions, with co-modification on design errors. As barriers of MUVE, (4) avatar’s immersion caused inconvenient perception to explore large-scaled environments and track collaborators’ different experiences, but the barriers were not reported in remote collaboration.     

Cardiomyopathy associated with clozapine.

Clozapine is an atypical antipsychotic agent that is more effective than the standard neuroleptics currently used for treating refractory schizophrenia. In addition, clozapine is a drug with few extrapyramidal side effects. However, clozapine is also associated with potentially serious adverse effects, such as cardiac complications as well as agranulocytosis. Clozapine-related cardiomyopathy has not been previously reported in East Asia. This report describes a 31-year-old Korean male patient with schizophrenia who developed dilated cardiomyopathy on treatment with clozapine. The removal of clozapine caused subsequent physical improvement. However, the readministration of clozapine for managing relapse of psychosis caused a recurrence of dilated cardiomyopathy in this patient. Therefore, this is the 1st report showing that the 2nd trial of clozapine caused recurrence of cardiomyopathy associated with clozapine. Thus, this report adds important support for a causal relation between clozapine and cardiac complications. In conclusion, this report attempts to raise awareness of clozapine-related cardiomyopathy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)