Contribution of components in Ce–Ti–Cr–Ox catalysts for selective propane-combustion in the presence of CO

Gas-phase combustion of hydrocarbons and CO in exhaust gases are normally performed competitively by supported noble metals. With the help of high-throughput technologies complex mixed oxides, such as the amorphous porous Ce₂₀Ti₅₀Cr₃₀O_x have been discovered, which selectively convert propane in the presence of excess of carbon monoxide. These findings are of fundamental importance for heterogeneous catalysis and may have implications on the future development of novel exhaust gas catalysts. In this study the effect of the various elements of the mixed oxide catalysts on activity and selectivity has been investigated and interpreted. The results of attempts to further improve the catalysts by additional doping are presented.     

Evolution of Structural and Mechanical Properties of TiN Films on SS 304LN

We investigate the effect of orientation and residual stress on mechanical properties of reactive magnetron‐sputtered TiN thin films on SS 304 LN with a function of substrate temperature. All these films are polycrystalline with a preferred orientation (200). Residual stress of these films were calculated by sin²Ψ technique and found to be in the range of ?2.6 to ?4.5 GPa. The hardness and modulus of these films ranged between 24–29 GPa and 326–388 GPa, respectively. Temperature‐dependent orientation change is clearly observed and this in turn influenced the residual stress. Hardness and modulus of these films exhibited dependence on the orientation and residual stress.     

Super-Resolution of Face Images Using Kernel PCA-Based Prior

We present a learning-based method to super-resolve face images using a kernel principal component analysis-based prior model. A prior probability is formulated based on the energy lying outside the span of principal components identified in a higher-dimensional feature space. This is used to regularize the reconstruction of the high-resolution image. We demonstrate with experiments that including higher-order correlations results in significant improvements     

Template-Based Gait Authentication Through Bayesian Thresholding

While gait recognition is the mapping of a gait sequence to an identity known to the system, gait authentication refers to the problem of identifying whether a given gait sequence belongs to the claimed identity. A typical gait authentication system starts with a feature representation such as a gait template, then proceeds to extract its features, and a transformation is ultimately applied to obtain a discriminant feature set. Almost every authentication approach in literature favours the use of Euclidean distance as a threshold to mark the boundary between a legitimate subject and an impostor. This article proposes a method that uses the posterior probability of a Bayes' classifier in place of the Euclidean distance. The proposed framework is applied to template-based gait feature representations and is evaluated using the standard CASIA-B gait database. Our study experimentally demonstrates that the Bayesian posterior probability performs significantly better than the de facto Euclidean distance approach and the cosine distance which is established in research to be the current state of the art.      

High pressure hydrogen adsorption apparatus: Design and error analysis

In the present work, design and operation of a high pressure gas adsorption apparatus at room temperature and at pressures up to 100 bar are discussed. A theoretical and experimental error analysis is done to determine accuracy and robustness of the measurements. For this study, activated carbon was selected as the adsorbent and hydrogen as the adsorbate gas. A sensitivity analysis was done by taking into account the effects of temperature, pressure, volume and weight of the sample. The analysis shows that the volumes of the sample and reference cells as determined by helium-free space measurements have significant effect on the accuracy of the adsorption uptake measurement. For instance, a 0.1% error in the measurement of either volume led to approximately a 3% error in hydrogen uptake measurement at 298 K and 100 bar.     

Developing an energy-efficient electrolytic cell for magnesium

About 80% of all magnesium is produced by an electrolytic process. The electrolytic route is an energy-intensive process, and many of the developed countries have realized the need to produce magnesium in a more cost-effective manner. Toward this goal, a less energy-intensive, more compact electrolytic cell has been developed at the Central Electrochemical Research Institute, India. A 2,200 A cell was operated for more than six weeks to study the feasibility of the technology. Higher current and energy efficiencies were realized, and specific energy consumption was reduced to around 11.5 kWh/kg of metal. For more information, contact N. Rajagopalan, Central Electrochemical Research Institute, Karaikudi 630 006, India; telephone 91-22368; fax 91-04565-37779; e-mail epm@cscercri.ren.nic.in.     

Juxta‐terminal Helix Unwinding as a Stabilizing Factor to Modulate the Dynamics of Transmembrane Helices

Transmembrane helices of integral membrane proteins often are flanked by interfacial aromatic residues that can serve as anchors to aid the stabilization of a tilted transmembrane orientation. Yet, physical factors that govern the orientation or dynamic averaging of individual transmembrane helices are not well understood and have not been adequately explained. Using solid‐state ²H NMR spectroscopy to examine lipid bilayer‐incorporated model peptides of the GWALP23 (acetyl‐GGALW(LA)₆LWLAGA‐amide) family, we observed substantial unwinding at the terminals of several tilted helices spanning the membranes of DLPC, DMPC, or DOPC lipid bilayers. The fraying of helix ends might be vital for defining the dynamics and orientations of transmembrane helices in lipid bilayer membranes.     

Widespread presence of naturally occurring perchlorate in high plains of Texas and New Mexico

Perchlorate (CLO4-) occurrence in groundwater has previously been linked to industrial releases and the historic use of Chilean nitrate fertilizers. However, recently a number of occurrences have been identified for which there is no obvious anthropogenic source. Groundwater from an area of 155,000 km2 in 56 counties in northwest Texas and eastern New Mexico is impacted bythe presence of ClO4-. Concentrations were generally low (<4 ppb), although some areas are impacted by concentrations up to 200 ppb. ClO4- distribution is not related to well type (public water system, domestic, agricultural, or water-table monitoring) or aquifer (Ogallala, Edward Trinity High Plains, Edwards Trinity Plateau, Seymour, or Cenozoic). Results from vertically nested wells strongly indicate a surface source. The source of ClO4- appears to most likely be atmospheric deposition. Evidence supporting this hypothesis primarily relates to the presence of ClO4- in tritium-free older water, the lack of relation between land use and concentration distribution, the inability of potential anthropogenic sources to account for the estimated mass of ClO4-, and the positive relationship between conserved anions (e.g., IO3-, Cl-, SO4(-2)) and ClO4-. The ClO4- distribution appears to be mainly related to evaporative concentration and unsaturated transport. This process has led to higher ClO4- and other ion concentrations in groundwater where the water table is relatively shallow, and in areas with lower saturated thickness. Irrigation may have accelerated this process in some areas by increasing the transport of accumulated salts and by increasing the number of evaporative cycles. Results from this study highlight the potential for ClO4- to impact groundwater in arid and semi-arid areas through long-term atmospheric deposition.