Laboratory techniques for evaluating solid oxide fuel cells

The construction of a small solid oxide fuel cell laboratory is described in terms of required materials, measuring techniques and equipment design. Details of various electrode deposition techniques and ways of making contacts to the electrodes are also outlined.     

Evaluating color and texture features for forgery localization from illuminant maps

Multimedia Tools and Applications - Images are widely accepted as a record of events even when images are prone to easy manipulations. It is difficult to identify image alterations by the human...     

Oxidative dimerisation of methane on a supported Pd-Ag catalyst using a diffusion controlled ceramic wall reactor

Supported palladium-silver oxides were used as catalysts for the partial oxidation of methane by molecular oxygen in a tubular reactor with ceramic wall separation. The ceramic wall controls the O₂ supply in the catalyst bed. The results indicate that the reactor configuration can play an important role in methane oxidation. C₂H₆, C₂H₄, CO₂ and H₂O were obtained at temperatures less than 300 °C. At this temperature any contribution from homogeneous gas phase reaction can be ruled out.     

Room temperature photo-activation of methane on TiO2 supported molybdena

Methane is activated at room temperature and atmospheric pressure on TiO₂, supported molybdena catalyst excited by band gap illumination. With pure TiO₂, complete oxidation to CO₂ is observed in the presence of oxygen. The deposition of 4% molybdena has a pronounced effect on methane activation, partial oxidation to CO becoming a competing pathway. CO is the major oxidation product if TiO₂ loaded with both MoO₃ and H₄SiW₁₂O₄₀ is used as a catalyst. MoO₃ used alone or in conjunction -with A1₂O₃ or SiO₂ as carriers exhibits poor activity in the photoactivation of methane.     

Self-organized night video enhancement for surveillance systems

Night video enhancement techniques are widely used for identifying suspicious activities captured by night visual surveillance systems. However, artificial light sources present in the surroundings deteriorate the visual quality of the video captured during night. This non-uniform illumination reduces the object identification and tracking capability of a real-time visual security system. Thus, a uniform enhancement technique is insufficient for handling such uneven illumination. In this paper, we propose a novel night video enhancement scheme based on a hierarchical self-organizing network. This proposed scheme automatically groups and enhances the neighboring pixels of dark and light regions in each frame. In this scheme, two-level self- organizing neural networks were hierarchically arranged to group similar pixels present in the night video frame. We applied the no-reference-based performance evaluation metrics for measuring the objective quality of the video. The experimental results showed that our proposed approach considerably enhances the visual perception of the video captured at night under varied illumination conditions.     

Experimental analysis of a two‐axis tracking system for solar parabolic dish collector

In this paper, an attempt has been made to develop a two‐axis tracking system for solar parabolic dish concentrator and experimentally evaluated the performance of the tracking system. In this proposed design, the sensor design uses the illumination produced by the convex lens on the apex of a pyramid to align the dish in‐line with the sun. The change in incident angle of the solar rays on the lens surface shifts the area of illumination from the apex of the pyramid towards its faces. Photodiodes placed on the faces of the pyramid are used as the sensitive elements to detect the movement of the sun. The sensor output is fed to a microcontroller‐based system to drive the stepper motor on the basis of the programmed algorithm such that it receives normal incidence of sunlight on the sensor. To evaluate the performance of the proposed system, a conventional available 1‐W photovoltaic (PV) panel is placed at the focal point to measure the short circuit current and open circuit voltage. With respect to the conventional solar PV panel, it is observed that the positioning accuracy of the proposed tracking system enhances the short circuit current of 0.11 A by 86%. Thus, the proposed tracking system can be used in a stand‐alone parabolic dish with concentrating PV module as the focal point for further studies.     

Nighttime visual refinement techniques for surveillance video: a review

Video surveillance systems substitute manual efforts in various safety critic domains such as border area, assisted living, banking, service stations, and transportation. The multimedia-based surveillance system has a significant role in security and forensic systems because people tend to be easily convinced after observing voice, image, and video. Hence, these videos are strong evidence in the forensic investigation. However, most of the criminal activities such as ATM robbery and assassination are occur at nighttime because of the crime supporting dark environment. Many of the night surveillance systems in military, as well as commercial applications, are equipped with infrared and thermal based night vision systems. Its poor capability of texture and color interpretations are the major issues to ensure secure nighttime video monitoring. Specifically, visual refinements of nighttime surroundings and foreground objects provide a valuable assistance in the nighttime security system. In this scenario, it is highly recommended a review of the state-of-the-art nighttime visual refinement approaches. We conducted an extensive literature review and classified the nighttime visual refinement approaches into nighttime restoration and enhancement. This comparative literary analysis identified the research gap fields to explore future research directions in nighttime visual enhancement techniques. Finally, we discussed various open issues and future directions in the context enhancement based nighttime enhancement research.

     

Transfer factor of the radionuclides in food crops from high-background radiation area of south west India

It is necessary to obtain the transfer factor (TF) of long-lived radionuclides because soil type and vegetation can affect TF. We studied the food crops commonly consumed by the general public of Kanyakumari district of south India. The main focus was on rice, fruits, vegetables and tapioca because the consumption of these is high. The soil to rice TF for the radionuclides, (226)Ra, (232)Th, (238)U and (40) K are 8.8×10(-2), 14.2×10(-2), 5.8×10(-2) and 6.3×10(-2), respectively. The TF of tapioca for (226)Ra, (232)Th, (238)U and (40) K are 6.2×10(-2) , 11×10(-2), 1.9×10(-2) and 8.9×10(-2), respectively. For fruits and vegetables, the TFs are low. In the majority of the crops the non-edible parts accumulate more radionuclides than the edible parts.     

Influence of grease formulation parameters on the tribological property of rice bran oil based lubricating grease

The negative environmental impacts and depletion of resources caused due to the excess usage of petroleum based products made researchers to think about an alternative biodegradable product. In the present study, rice bran oil (RBO) was used as a base oil for formulating 16 different grease samples. The thickener used was generated in situ by mixing 12-hydroxy stearic acid (12 HSA) to calcium hydroxide at a different ratio from 1.25 to 2. The formulation parameters such as weight % of thickener, saponification time, and maximum temperature spanned the ranges 5–11 wt.%, 1–2.5 h, and 150–180°C, respectively. The tribological properties such as wear scar diameter (WSD) and friction of 16 different grease samples formulated by varying these parameters were evaluated using a standard four-ball tester as per ASTM standards. The grease samples were characterized by evaluating the penetration value using a standard cone penetrometer. The influence of these formulation parameters on the experimentally evaluated properties was also examined in this work. The results indicated that the variation of these parameters during grease formulation has a significant influence on the evaluated properties.     

Nanocrystalline dye‐sensitized solar cells having maximum performance

This paper presents an overview of the research carried out by a European consortium with the aim to develop and test new and improved ways to realise dye‐sensitized solar cells (DSC) with enhanced efficiencies and stabilities. Several new areas have been explored in the field of new concepts and materials, fabrication protocols for TiO₂ and scatterlayers, metal oxide blocking layers, strategies for co‐sensitization and low temperature processes of platinum deposition. Fundamental understanding of the working principles has been gained by means of electrical and optical modelling and advanced characterization techniques. Cost analyses have been made to demonstrate the potential of DSC as a low cost thin film PV technology. The combined efforts have led to maximum non‐certified power conversion efficiencies under full sunlight of 11% for areas <0ċ2 cm² and 10ċ1% for a cell with an active area of 1ċ3 cm². Lifetime studies revealed negligible device degradation after 1000 hrs of accelerated tests under thermal stress at 80°C in the dark and visible light soaking at 60°C. An outlook summarizing future directions in the research and large‐scale production of DSC is presented. Copyright © 2006 John Wiley & Sons, Ltd.