Electrochemical sensor applications of Pt supported porous gold electrode prepared using cellulose-filter

A facile and rapid method for the synthesis of porous gold (PAu) electrodes on cellulose-filters is proposed. Morphology and active surface area of the electrode greatly influence the electrochemical properties of sensor. Compared to smooth electrode and glassy carbon, PAu and Pt/PAu electrode showed high roughness due to porous structure, which is helpful in electrochemical sensing of target molecules. The electrochemical sensing performance of Pt/PAu electrode was evaluated to detect hydrogen peroxide, glucose, and perchloric acid. The amperometric results with various concentrations of target molecules showed potential applications of Pt/PAu electrode in sensitive and effective chemical sensors.     

Leader-follower type distance-based formation control of a group of autonomous agents

International Journal of Control, Automation and Systems - We study distance-based formation control of a group of mobile agents consisting of several leaders and the remaining followers. The...     

Effect of bath composition on properties of electroless deposited Co–P/Ni foam catalyst for hydrolysis of sodium borohydride solution

The effect of bath composition on the properties of electroless deposited Co–P/Ni foam catalyst for hydrolysis of sodium borohydride solution was investigated by varying the bath composition. The NaH₂PO₂/CoCl₂ and NH₂CH₂COOH/CoCl₂ concentration ratio had a strong effect on the catalyst properties. The effect of NH₂CH₂COOH/CoCl₂ was larger than that of NaH₂PO₂/CoCl₂ for the concentration ratio range with practical deposition rates. The optimum concentration ratio of the coating bath was CoCl₂:NH₂CH₂COOH:NaH₂PO₂ = 1:4:10. As the concentration of each component increased at the optimum concentration ratio, the coating bath decomposed on its own. As the amount of solute dissolved in the coating bath increased, the coating bath became unstable. The optimum composition of the stable coating bath to realize Co–P/Ni foam catalyst with good catalytic activity was 0.1 m (molality, mol/kg) CoCl₂, 0.4 m NH₂CH₂COOH, and 1.0 m NaH₂PO₂. The weight percent of the deposited catalyst and hydrogen generation rate per deposited catalyst of 1 g at optimum composition were 8.39 wt% and 0.93 L/min·g (deposited catalyst), respectively. The bath composition was found to have a great effect on the Co–P/Ni foam catalyst properties and coating bath stability.     

A vacuum-sealed miniature X-ray tube based on carbon nanotube field emitters

ABSTRACT: A vacuum-sealed miniature X-ray tube based on a carbon nanotube field-emission electron source has been demonstrated. The diameter of the X-ray tube is 10 mm; the total length of the tube is 50 mm, and no external vacuum pump is required for the operation. The maximum tube voltage reaches up to 70 kV, and the X-ray tube generates intense X-rays with the air kerma strength of 108 Gy * cm2 min1. In addition, X-rays produced from the miniature X-ray tube have a comparatively uniform spatial dose distribution.     

Development of an embedded solar tracker for the enhancement of solar energy utilization

An embedded two‐axis solar tracking system using Laboratory Virtual Instrumentation Engineering Workbench to write the operation and control algorithms was developed for enhancing solar energy utilization. The system consists of a real‐time processor, two motion‐control modules, two step drives, two step motors, feedback devices, and other accessories needed for functional stability. The real‐time processor allows the solar tracker to be used as a stand‐alone, real‐time system that can operate automatically without any external control. The system combines two different solar tracking methods: the optical method and the astronomical method. Cadmium Sulfide (CdS) sensors are employed to continuously generate feedback signals to the controller, ensuring high‐precision solar tracking even under adverse conditions. The CdS sensor is a resistor whose electric resistance decreases with increasing incident light intensity. A database of solar altitude, azimuth, and sunrise and sunset times is provided by this solar tracking system. Other solar trackers operating in an astronomical method may access and use this database over the Internet. Solar position and sunrise and sunset times in the database were compared with those of the Astronomical Applications Department of the U.S. Naval Observatory. The differences were found to be negligible. Copyright © 2011 John Wiley & Sons, Ltd.     

Predicting the use of online information services based on a modified UTAUT model

There is a growing consensus that the conventional technology acceptance model should be modified and expanded to provide a better understanding of the behaviour related to Internet services. Recognising this need, this study re-evaluates the utility of Venkatesh et al.’s [2003. User acceptance of information technology: toward a unified view. MIS Quarterly, 27 (3), 425–478] Unified Theory of Acceptance and Use of Technology (UTAUT) model. First, this study proposes a new modified model of technology acceptance by adding the concepts of trust and flow experience to the original UTAUT model. Second, the study investigates how the model's explanatory power changes for different types of Internet services. For this, this study considers two services – ‘e-learning’ and ‘online gaming’ – for their utilitarian and hedonic characteristics, respectively. The results of this study suggest that the proposed model can better explain behavioural intentions towards Internet services than the original model. The two variables – flow experience and trust – contributed to the overall significance of the model. Furthermore, the type of Internet service moderated the effects of the independent variables on behavioural intentions and use behaviour.     

Enterotoxigenic Profiling of Emetic Toxin‐ and Enterotoxin‐Producing Bacillus cereus,Isolated from Food,Environmental, and Clinical Samples by Multiplex PCR

Bacillus cereus comprises the largest group of endospore‐forming bacteria and can cause emetic and diarrheal food poisoning. A total of 496 B. cereus strains isolated from various sources (food, environmental, clinical) were assessed by a multiplex PCR for the presence of enterotoxin genes. The detection rate of nheA, entFM, hblC, and cytK enterotoxin genes among all B. cereus strains was 92.33%, 77.21%, 59.47%, and 47.58%, respectively. Enterotoxigenic profiles were determined in emetic toxin‐ (8 patterns) and enterotoxin‐producing strains (12 patterns). The results provide important information on toxin prevalence and toxigenic profiles of B. cereus from various sources. Our findings revealed that B. cereus must be considered a serious health hazard and Bacillus thuringiensis should be considered of a greater potential concern to food safety among all B. cereus group members. Also, there is need for intensive and continuous monitoring of products embracing both emetic toxin and enterotoxin genes.     

Estimation of illuminant chromaticity based on highlight detection for face images with varying illumination

Illuminant chromaticity estimation is required in the fields of the tracking and recognition of human faces, compensation and detection of skin color, image reproduction, and color constancy. This article proposes a simple and effective method to estimate the illuminant chromaticity using highlights from the face region. We first select the candidate points through the detection of highlights around the leftmost pixel of the rg chromaticity space from the facial images under various illuminant conditions and then estimate the illuminant chromaticity by averaging the chromaticities of the candidate points. To enhance the illuminant chromaticity estimation accuracy, we propose a more elaborate estimation method, which effectively readjusts the candidate points of the highlight regions according to the conditions derived from two ethnic and three illuminant groups. The experiment results show that our proposed method reliably estimates the illuminant chromaticity under various color temperatures and illuminant directions. © 2012 Wiley Periodicals, Inc. Col Res Appl, 39, 188–199, 2014     

Thermoeconomic analysis of ground‐source heat pump systems

A thermoeconomic analysis of a ground‐source heat pump (GSHP) system with a vertical or horizontal ground heat exchanger, a type of heat delivery system, was performed using the modified productive structure analysis method. In this analysis, the unit cost of geothermal heat delivered to a room using GSHP system was estimated. The unit cost of heat delivered was calculated to be $0.063/kWh for input of electricity with a unit cost of $0.140/kWh for a GSHP with a coefficient of performance (COP) of 3.27. Exergy destruction and monetary losses due to the irreversibility that occurs at each component of the system were also estimated. The unit cost of heat was found to be inversely proportional to the COP of the heat pump and proportional to the electricity input. The greatest monetary loss occurs in the geothermal heat exchanger in which considerable mass of brine flows in long pipes and in the fan‐coil unit which features a complex configuration of pipes in the air passages, respectively. Copyright © 2013 John Wiley & Sons, Ltd.     

Extraction of landslide-related factors from ASTER imagery and its application to landslide susceptibility mapping

The aim of this study is to extract landslide-related factors from remote-sensing data, such as Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite imagery, and to examine their applicability to landslide susceptibility near Boun, Korea, using a geographic information system (GIS). Landslide was mapped from interpretation of aerial photographs and field surveying. Factors that influence landslide occurrence were extracted from ASTER imagery. The slope, aspect and curvature were calculated from the digital elevation model (DEM) with 25.77 m root mean square error (RMSE), which was derived from ASTER imagery. Lineaments, land-cover and normalized difference vegetation index (NDVI) layers were also estimated from ASTER imagery. Landslide-susceptible areas were analysed and mapped using the occurrence factors by a frequency ratio and logistic regression model. Validation results were 84.78% in frequency ratio and 84.20% in logistic regression prediction accuracy for the susceptibility map with respect to ground-truth data.