A plasmonic enhanced photodetector based on silicon nanocrystals obtained through laser ablation

We present a proof-of-concept photodetector which is sensitive in the visible spectrum. Silicon nanocrystals (Si-NCs) obtained by laser ablation are used as the active absorption region. Si-NC films are formed from a polymeric dispersion. The films are sandwiched between thin insulating films to reduce the electrical leakage current. Furthermore, Ag nanoparticles are integrated with the photodetector to enhance the visible response using plasmonic effects. The measured photocurrent is resonantly enhanced, which is explained in terms of enhanced local fields caused by localized plasmons. The UV-vis spectrum of Ag nanoparticles is also measured to verify the resonance. © 2012 IOP Publishing Ltd

2-Methyl-5-[(3-methyl-4-nitro­benz­yl)sulfan­yl]-1,3,4-thia­diazole

The mol­ecule of the title thia­diazole derivative, C11H11N3O2S2, has a butterfly-like structure and the whole mol­ecule is disordered with a site-occupancy ratio of 0.629 (4):0.371 (4). The mol­ecule is disordered in such a way that the 3-methyl-4-nitro­phenyl units of the major and minor components are approximately related by 180° rotation around the C—N bond axis. The dihedral angle between the 1,3,4-thia­diazole and benzene rings is 70.8 (4)° in the major component and 74.9 (6)° in the minor component. In the crystal, mol­ecules are arranged into screw chains along the c axis. These chains are stacked along the b axis. Weak inter­molecular C—H⋯O and C—H⋯π inter­actions and a short C⋯O contact [3.005 (7) Å] are present

The Mere Exposure Effect in the Domain of Haptics

Background: Zajonc showed that the attitude towards stimuli that one had been previously exposed to is more positive than towards novel stimuli. This mere exposure effect (MEE) has been tested extensively using various visual stimuli. Research on the MEE is sparse, however, for other sensory modalities. Methodology/Principal Findings: We used objects of two material categories (stone and wood) and two complexity levels (simple and complex) to test the influence of exposure frequency (F0 = novel stimuli, F2 = stimuli exposed twice, F10 = stimuli exposed ten times) under two sensory modalities (haptics only and haptics & vision). Effects of exposure frequency were found for high complex stimuli with significantly increasing liking from F0 to F2 and F10, but only for the stone category. Analysis of ‘‘Need for Touch’ ’ data showed the MEE in participants with high need for touch, which suggests different sensitivity or saturation levels of MEE. Conclusions/Significance: This different sensitivity or saturation levels might also reflect the effects of expertise on the haptic evaluation of objects. It seems that haptic and cross-modal MEEs are influenced by factors similar to those in the visual domain indicating a common cognitive basis

First- and second-order contributions to depth perception in anti-correlated random dot stereograms.

The binocular energy model of neural responses predicts that depth from binocular disparity might be perceived in the reversed direction when the contrast of dots presented to one eye is reversed. While reversed-depth has been found using anti-correlated random-dot stereograms (ACRDS) the findings are inconsistent across studies. The mixed findings may be accounted for by the presence of a gap between the target and surround, or as a result of overlap of dots around the vertical edges of the stimuli. To test this, we assessed whether (1) the gap size (0, 19.2 or 38.4 arc min) (2) the correlation of dots or (3) the border orientation (circular target, or horizontal or vertical edge) affected the perception of depth. Reversed-depth from ACRDS (circular no-gap condition) was seen by a minority of participants, but this effect reduced as the gap size increased. Depth was mostly perceived in the correct direction for ACRDS edge stimuli, with the effect increasing with the gap size. The inconsistency across conditions can be accounted for by the relative reliability of first- and second-order depth detection mechanisms, and the coarse spatial resolution of the latter

Imaging of subsurface lineaments in the southwestern part of the Thrace Basin from gravity data

Linear anomalies, as an indicator of the structural features of some geological bodies, are very important for the interpretation of gravity and magnetic data. In this study, an image processing technique known as the Hough transform (HT) algorithm is described for determining invisible boundaries and extensions in gravity anomaly maps. The Hough function implements the Hough transform used to extract straight lines or circles within two-dimensional potential field images. It is defined as image and Hough space. In the Hough domain, this function transforms each nonzero point in the parameter domain to a sinusoid. In the image space, each point in the Hough space is transformed to a straight line or circle. Lineaments are depicted from these straight lines which are transformed in the image domain. An application of the Hough transform to the Bouguer anomaly map of the southwestern part of the Thrace Basin, NW Turkey, shows the effectiveness of the proposed approach. Based on geological data and gravity data, the structural features in the southwestern part of the Thrace Basin are investigated by applying the proposed approach and the Blakely and Simpson method. Lineaments identified by these approaches are generally in good accordance with previously-mapped surface faults

Improvement in performance properties of asphalt using a novel boron-containing additive

In current times, many additives are used to improve the performance characteristics of asphalt. In this study, a new additive that contains boron, given the short name of cyclic borate ester (CBE), was chemically synthesised in laboratory conditions. It was added to the asphalt binder as 1%, 2%, 4% and 6% ratios of asphalt by weight, and modified asphalt samples were produced. The effects of CBE on the conventional properties of asphalt binder (penetration, softening point, ductility, flash point, Fraass breaking point) were examined using a dynamic shear rheometer, rotational viscosity, a rolling thin film oven, a pressure aging vessel and bending beam rheometer test methods. Results showed that the use of CBE additive increased the hardness, softening point, viscosity, flash-point value and rutting resistance of asphalt binder and decreased temperature sensitivity. CBE also enhanced elastic responses (increased complex shear modulus and decreased phase angle), aging resistance and low-temperature cracking resistance and did not change the cohesion property. © 201

PIV measurements on the passive control of flow past a circular cylinder

The passive control of water flow downstream of a circular cylinder with 50 mm diameter is experimentally investigated in this study using particle image velocimetry (PIV) technique. The experiments were carried out for three different Reynolds number (based on cylinder diameter) values of 3350, 6850 and 10,200. The flow structure was substantially vortical with large-scale downstream of the bare cylinder due to strong interactions of the shear layers separating from the cylinder surface. For the passive controlling of flow, a drop-shaped mesh surrounding the cylinder was used to suppress the formation of Karman vortex street in the wake region of the cylinder. Time averaged flow structures such as velocity distribution, vorticity, streamline topology, Reynolds shear stress and turbulent kinetic energy were referred for interpreting the experimental results. The spectral analysis of the measured velocity data was also performed to have information about the vortex shedding frequency of the unsteady flow in the cylinder wake. It was confirmed that flow was successfully controlled by paying attention to the absence of large-scale vortical flow structure (although small-scale vortices, which were not strong compared to the former one, were still present in the shear layers) as well as elongation in vorticity layers, attenuation in both Reynolds shear stress and turbulent kinetic energy distributions related to the fluctuating velocity components measured in the wake region. © 2015 Elsevier Inc