The role of CuO in promoting photocatalytic hydrogen production over TiO2

Low cost semiconductor photocatalysts that can efficiently harvest solar energy to generate H₂ from water or biofuels will be critical to future hydrogen economies. In this study, low cost CuO/TiO₂ photocatalysts (CuO loadings 0–15 wt.%) were prepared, characterized and evaluated for H₂ production from ethanol–water mixtures (80 vol.% ethanol, 20 vol.% H₂O) under UV excitation. TEM, XRF, EDAX, EPR, Raman, TGA, XPS and Cu L-edge NEXAFS data showed that at CuO loadings <5 wt.%, Cu(II) was highly dispersed over the TiO₂ support, possibly as a sub-monolayer CuO species. At higher loadings, CuO crystallites of diameter 1–2 nm were identified. The photocatalytic activity of CuO/TiO₂ photocatalysts was highly dependent on the CuO loading, with 1.25 wt.% CuO being optimal (H₂ production rate = 20.3 mmol g⁻¹ h⁻¹). Results suggest that sub-monolayer coverages of Cu(II) or CuO on TiO₂ are highly beneficial for H₂ generation from ethanol–water mixtures and support the development of a sustainable H₂ economy.     

Vehicle matching in smart camera networks using image projection profiles at multiple instances

Tracking vehicles using a network of cameras with non-overlapping views is a challenging problem of great importance in traffic surveillance. One of the main challenges is accurate vehicle matching across the cameras. Even if the cameras have similar views on vehicles, vehicle matching remains a difficult task due to changes of their appearance between observations, and inaccurate detections and occlusions, which often occur in real scenarios. To be executed on smart cameras the matching has also to be efficient in terms of needed data and computations. To address these challenges we present a low complexity method for vehicle matching robust against appearance changes and inaccuracies in vehicle detection. We efficiently represent vehicle appearances using signature vectors composed of Radon transform like projections of the vehicle images and compare them in a coarse-to-fine fashion using a simple combination of 1-D correlations. To deal with appearance changes we include multiple observations in each vehicle appearance model. These observations are automatically collected along the vehicle trajectory. The proposed signature vectors can be calculated in low-complexity smart cameras, by a simple scan-line algorithm of the camera software itself, and transmitted to the other smart cameras or to the central server. Extensive experiments based on real traffic surveillance videos recorded in a tunnel validate our approach.     

Automated gear fault detection of micron level wear in bevel gears using variational mode decomposition

Journal of Mechanical Science and Technology - Gearboxes have an important role in power transmission systems. For such systems, vibration-based fault diagnosis techniques are frequently used to...     

Design of Time–Frequency Optimal Three-Band Wavelet Filter Banks with Unit Sobolev Regularity Using Frequency Domain Sampling

In this paper, we design three-band time–frequency-localized orthogonal wavelet filter banks having single vanishing moment. We propose new expressions to compute mean and variances in time and frequency from the samples of the Fourier transform of the asymmetric band-pass compactly supported wavelet functions. We determine discrete-time filter of length eight that generates the time–frequency optimal time-limited scaling and wavelet functions using cascade algorithm. Time–frequency product (TFP) of a function is defined as the product of its time variance and frequency variance. The TFP of the designed functions is close to 0.25 with unit Sobolev regularity. Three-band filter banks are designed by minimizing a weighted combination of TFPs of wavelets and scaling functions. Interestingly, empirical results show that time–frequency optimal, filter banks of length nine, designed with the proposed methodology, have unit Sobolev regularity, which is maximum achievable with single vanishing moment. Design examples for length six and length nine filter banks are given to demonstrate the effectiveness of the proposed design methodology.     

A self-optimizing mobile network: Auto-tuning the network with firefly-synchronized agents

The reduction of cost and complexity is a key driver in the evolution of mobile networks. This reduction not only applies to the pre-operational state (e.g. the deployment phase of a new network), but to the operational state as well. During the operational state, self-optimization processes can be performed to reduce the operating expenses (OPEX) of telecommunications operators. In this paper, we propose an agent-based mechanism for auto-tuning mobile networks with the aim of achieving energy savings in access networks. Firefly-based synchronization is used for the coordination of mutually dependent software agents located at the operator’s base stations. Once synchronized, agents can act together to obtain a global goal – i.e. the reduction of the telecommunications operator’s costs without reducing the quality of the provided services for mobile users. These agents build a self-organized overlay network where neither centralized nor decentralized control is needed and, therefore, is more robust.     

Automatic sleep stages classification based on iterative filtering of electroencephalogram signals

Neural Computing and Applications - Computer-aided sleep monitoring system can effectively reduce the burden of experts in analyzing the large volume of electroencephalogram (EEG) recordings...     

Formation of wurtzite InP nanowires explained by liquid-ordering

We report an in situ surface X-ray diffraction study of liquid AuIn metal alloys in contact with zinc-blende InP (111)(B) substrates at elevated temperatures. We observe strong layering of the liquid metal alloy in the first three atomic layers in contact with the substrate. The first atomic layer of the alloy has a higher indium concentration than in bulk. In addition, in this first layer we find evidence for in-plane ordering at hollow sites, which could sterically hinder nucleation of zinc-blende InP. This can explain the typical formation of the wurtzite crystal structure in InP nanowires grown from AuIn metal particles.     

The individually optimized bolus dose of nadroparin is safe and effective in diabetic and nondiabetic patients with bleeding risk on hemodialysis

The risk of bleeding is a well‐known complication in patients on hemodialysis (HD). The aim of this prospective study was to determine the lowest single bolus dose of low–molecular‐weight heparin nadroparin for safe and effective HD in patients with a bleeding risk. Forty HD patients were divided into 4 subgroups with 10 participants (diabetics with and without a bleeding risk, nondiabetics with and without a bleeding risk). The actual starting bolus dose was decreased by 25% after the initial 4 weeks, further decreased by 25% of the starting dose after 4 weeks, and changed due to extracorporeal circuit clotting in the last 4 weeks. The parameters of coagulation were measured at the beginning, after 2 and 4 h of HD sessions. A significant reduction of nadroparin (first vs. last HD session) was observed in: diabetics with a bleeding risk (49.66 ± 12.33 vs. 28.78 ± 9.60 IU/kg/HD; P<0.001), diabetics without a bleeding risk (50.70 ± 15.23 vs. 33.95 ± 16.97 IU/kg/HD; P<0.001), and nondiabetics with a bleeding risk (61.25 ± 18.68 vs. 32.96 ± 10.06 IU/kg/HD; P<0.001). Altogether, the reduction of the nadroparin dose in these groups was 42.05%; 33.04%, and 46.19%, respectively. Although anti‐Xa at hour 4 at the end of the study was <0.4 IU/mL in our diabetic and nondiabetic patients without a risk of bleeding, serious clottings in the extracorporeal circuit and vascular access thromboses were not found. This study demonstrated for the first time that individually optimized doses of nadroparin are sufficient for safe and effective HD in patients with a bleeding risk.     

Early adversity alters attention and locomotion in adult Sprague-Dawley rats.

This study investigated the effects of prenatal stress and its interaction with artificial rearing (AR) on adult rat behavior. Pregnant dams underwent restraint stress from Gestational Day 10 to 21. After parturition, pups were raised by their mothers or in the AR paradigm, with or without stroking stimulation. In adulthood, rats were tested on prepulse inhibition (PPI), locomotor activity, elevated plus-maze, and spatial working memory. There were main effects and interactions of both prenatal stress and AR on activity. Additional stimulation reduced activity in nonstressed AR rats but increased activity in prenatally stressed AR rats. AR altered PPI and plus-maze behavior whereas additional stimulation partially reversed these effects. This study demonstrates that prenatal experiences can modulate the effects of postnatal treatments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)