Electrooptical Characterization of MWIR InAsSb Detectors

InAs_1?x Sb _x material with an alloy composition of the absorber layer adjusted to achieve 200-K cutoff wavelengths in the 5-μm range has been grown. Compound-barrier (CB) detectors were fabricated and tested for optical response, and J _dark–V _d measurements were taken as a function of temperature. Based on absorption coefficient information in the literature and spectral response measurements of the midwave infrared (MWIR) nCBn detectors, an absorption coefficient formula α(Ε, x, T) is proposed. Since the presently suggested absorption coefficient is based on limited data, additional measurements of material and detectors with different x values and as a function of temperature should refine the absorption coefficient, providing more accurate parametrization. Material electronic structures were computed using a k·p formalism. From the band structure, dark-current density (J _dark) as a function of bias (V _d) and temperature (T) was calculated and matched to J _dark–V _d curves at fixed T and J _dark–T curves at constant V _d. There is a good match between simulation and data over a wide range of bias, but discrepancies that are not presently understood exist near zero bias.     

The performance of superhydrophobic and superoleophilic carbon nanotube meshes in water–oil filtration

Vertically-aligned multi-walled carbon nanotubes (CNTs) were grown on stainless steel (SS) mesh by thermal chemical vapor deposition with a diffusion barrier of Al₂O₃ film. These three-dimensional porous structures (SS-CNT meshes) were found to be superhydrophobic and superoleophilic. Water advancing contact angles of 145–150° were determined for these SS-CNT meshes in air and oil (gasoline, isooctane). Oil, on the other hand, completely wet the SS-CNT meshes. This combined superhydrophobic and superoleophilic property repelled water while allowed the permeation of oil. Filtration tests demonstrated efficiencies better than 80% of these SS-CNT meshes as the filtration membranes of the water-in-oil emulsions. We have conducted quantitative analysis on the diameters of the oil droplets in both the feed emulsion and the filtrate. Then, we have evaluated the issue of water blockage and possible way to improve the filtration efficiency. Finally, the filtration and blockage mechanisms are proposed.     

Context-aware mobile image annotation for media search and sharing

In recent years, rapid advances in media technology including acquisition, processing and distribution have led to proliferation of many mobile applications. Amongst them, one of the emerging applications is mobile-based image annotation that uses camera phones to capture images with system-suggested tags before uploading them to the media sharing portals. This procedure can offer information to mobile users and also facilitate the retrieval and sharing of the image for Web users. However, context information that can be acquired from mobile devices is underutilized in many existing mobile image annotation systems. In this paper, we propose a new mobile image annotation system that utilizes content analysis, context analysis and their integration to annotate images acquired from mobile devices. Specifically, three types of context, location, user interaction and Web, are considered in the tagging processes. An image dataset of Nanyang Technological University (NTU) campus has been constructed, and a prototype mobile image tag suggestion system has been developed. The experimental results show that the proposed system performs well in both effectiveness and efficiency on NTU dataset, and shows good potential in domain-specific mobile image annotation for image sharing.     

Time-dependent Neutronic Analysis for High Level Waste Transmutation in a Fusion-driven Transmuter

This study presents time-dependent transmutations of high-level waste (HLW) including minor actinides (MAs) and long-lived fission products (LLFPs) in the fusion-driven transmuter (FDT) that is optimized in terms of the neutronic performance per fusion neutron in our previous study. Its blanket has two different transmutation zones (MA transmutation zone, TZ_MA, and LLFP transmutation zone, TZ_FP), located separately from each other. High burn-up pressured water reactor (PWR)-mixed oxide (MOX) spent fuel is used as HLW. The time-dependent transmutation analyses have been performed for an operation period (OP) of up to 10 years by 75% plant factor (η) under a first-wall neutron load (P) of 5 MW/m². The effective half-lives of the MA and LLFP nuclides can be shortened significantly in the considered FDT while substantial electricity is produced in situ along the OP.     

The influence of dead load on fracture energy measurements using the RILEM method

A procedure for testing concrete beams in three-point bending to determine the fracture energy G_F has been proposed by RILEM Technical Committee 50—Fracture Mechanics of Concrete. In the evaluation of the test data the proposal presents a formula for G_F in which beam and carried fixture weights are included. Herein it is demonstrated that the effects of these dead-weight forces are presented correctly only (and approximately) for a testing arrangement in which load and beam deformation are both downward. A formula for the case of upward load and deformation is proposed.     

Constructing the Voronoi diagram of a set of line segments in parallel

In this paper we give a parallel algorithm for constructing the Voronoi diagram of a polygonal scene, i.e., a set of line segments in the plane such that no two segments intersect except possibly at their endpoints. Our algorithm runs inO(log² n) time usingO(n) processors in the CREW PRAM model.The research of M. T. Goodrich was supported by NSF under Grants CCR-8810568 and CCR-9003299 and by NSF/DARPA under Grant CCR-8908092. C. K. Yap's research was supported in part by NSF Grants DCR-8401898 and CCR-9002819.     

Continuous background monitoring of plant performance utilizing asingle-chip microcomputer and PRTN sequences

The authors demonstrate a method suitable for a single-chip microcomputer or VLSI implementation that provides continuous real-time background monitoring of linear electromechanical systems. In this implementation method, pseudorandom noise is generated and digitized with a single-chip microcomputer and utilized to observe shifts in plant performance by monitoring the impulse response. A Butterworth filter was chosen to simulate the electromechanical system for ease and convenience of transfer function modification during testing. The feasibility of monitoring and detecting shifts in plant performance using pseudorandom noise in the background mode in real time while the plant continues to carry out routine control was demonstrated experimentally. Guidelines are provided for selecting the pseudorandom noise amplitude and the analog/digital quantization level. Pseudorandom trinary noise was demonstrated to be superior to pseudorandom binary noise     

Performance of ULV formulations (Pesguard 102/Vectobac 12AS) against three mosquito species

To study the effects of percutaneous ethanol injection therapy on livers, we investigated necrotic changes after ethanol injection and fibrotic changes during the repair process in cirrhotic livers in comparison with normal livers. Male rats were treated with oral doses of 3'-methyl-4-dimethylaminoazobenzene and thioacetamide to produce liver cirrhosis. Both control animals and cirrhotic animals were injected with 0.2 ml of absolute ethanol into livers. Histological samples were cut serially, and the maximum areas of necrosis and fibrosis were measured until 28 days after the injection. Although the maximum area of necrosis was not different between cirrhotic livers and control livers, the average fibrotic ratio [(maximum fibrotic area/maximum necrotic area + maximum fibrotic area) x 100] was 64% in control livers (n = 9) and 40% in cirrhotic livers (n = 9; p < 0.05). The fibrotic repair process after ethanol injection seems to be impaired in cirrhotic livers as compared with normal livers.     

An evaluation of two hypotheses concerning the dynamics of cognitive impulsivity: Anxiety-over-errors or anxiety-over-competence?

To test the appropriateness of the anxiety-over-errors and the anxiety-over-competence hypotheses in explaining reflective and impulsive behavior, 85 8–11 yr olds were classified as reflective or impulsive on the basis of their performance on 1 form of the Matching Familiar Figures Test (MFFT). Half of each cognitive style group was randomly assigned to a failure or control group. Ss in the failure group were given failure feedback concerning their performance on the 1st 10 items of an alternate form of the MFFT and were then tested on the 2nd 10 items. Control Ss were given a short rest period between the 2 10-item test administrations. All Ss rated their expectancy of success and completed the Test Anxiety Scale for Children. Teacher ratings of the children's reflection–impulsivity, confidence, and concern over errors were also obtained. Results support the anxiety-over-errors hypothesis: The impulsives in the failure group showed a significant decrease in errors from pre- to posttest, whereas controls did not differ in this respect. The reflectives in the failure group did not differ from those in the control group in their pre–post error rates. MFFT performance measures were significantly correlated with teacher ratings of concern over errors but not with confidence ratings. It is concluded that impulsive behavior may stem from a lack of motivation to perform well. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)