Catalytic properties and electronic structure of copper ions in Cu-ZSM-5

The effect of ion exchange conditions, such as Si/Al ratio, precursor copper salt, pH and concentration of the solution, on the catalytic activity in SCR of NO by propane and on the electronic state of copper ions in Cu-ZSM-5 has been studied. The NO conversion in NO SCR by C₃H₈ has been found to reach a maximum value at Cu/Al ratio about 0.37–0.4 and remain constant at higher Cu/Al.

ESR and UV–vis DR spectroscopy have been used to elucidate stabilization conditions of copper ions in Cu-ZSM-5 zeolites as isolated Cu²⁺ ions, chain copper oxide structures and square-plain oxide clusters. The ability of copper ions for reduction and reoxidation in the chain structures may be responsible for the catalytic activity of Cu-ZSM-5. These transformations of copper ions are accompanied by the observation of intervalence transitions Cu²⁺–Cu⁺ and CTLM of the chain structures in the UV–vis spectra.     

Current and future water issues in the Oldman River Basin of Alberta, Canada.

Long-term trends in alpine and prairie snow pack accumulation and melt are affecting streamflow within the Oldman River Basin in southern Alberta, Canada. Unchecked rural and urban development also has contributed to changes in water quality, including enhanced microbial populations and increased waterborne pathogen occurrence. In this study we look at changing environment within the Oldman River Basin and its impact on water quality and quantity. The cumulative effects include a decline in net water supplies, and declining quality resulting in increased risk of disease. Our data indicates that decreases in the rate of flow of water can result in sedimentation of bacterial contaminants within the water column. Water for ecosystems, urban consumption, recreation and distribution through irrigation is often drawn from waterholding facilities such as dams and weirs, and concern must be expressed over the potential for contaminate build-up and disproportionate potential of these structures to pose a risk to human and animal health. With disruption of natural flow rates for water resulting from environmental change such as global warming and/or human intervention, increased attention needs to be paid to use of best management practices to protect source water supplies.     

A Recursive Frequency Estimator Using Linear Prediction and a Kalman-Filter-Based Iterative Algorithm

This paper proposes a new Kalman-filter-based recursive frequency estimator for discrete-time multicomponent sinusoidal signals whose frequencies may be time-varying. The frequency estimator is based on the linear prediction approach and it employs the Kalman filter to track the linear prediction coefficients (LPCs) recursively. Frequencies of the sinusoids can then be computed using the estimated LPCs. Due to the coloredness of the linear prediction error, an iterative algorithm is employed to estimate the covariance matrix of the prediction error and the LPCs alternately in the Kalman filter in order to improve the tracking performance. Simulation results show that the proposed Kalman-filter-based iterative frequency estimator can achieve better tracking results than the conventional recursive least-squares-based estimators.     

Corrosion Behavior of 316LN and 316 Stainless Steels During Long-term Exposure to Aerated 0.5 M NaCl Using Electrochemical Noise Technique

In the present work 316LN as well as 316 stainless steel (SS) coupons each of dimensions (0.025 × 0.018 × 0.006 m³) in well-polished condition were used as two nominal electrodes which were immersed in the aerated solution of 0.5 M NaCl. Correlated current and potential electrochemical noise (EN) signals were collected at 1 Hz sampling frequency for 1 h daily over a period of 30 days. The detrended EN data were used to calculate the noise resistance (R _N) as well as the spectral noise resistance at zero frequency (R _SN^o) values and other statistical parameters. To study the nature of pits and distribution of their diameters as well as depths, extensive observations of the pitted and the blank specimens were carried out using Confocal Laser Scanning Microscopy (CLSM). The current and the potential records of the two alloys showed distinct differences in their corrosion behavior. It was observed that within less than 4 h of immersion, 316SS showed signals indicative of unstable pitting and onset of stable pitting was noticed after 48 h of exposure. However, until about 24 h, 316LN showed just the random signals and unstable pitting was observed after 28 h. The signals clearly indicated continuous growth of the stable pits in 316SS as against the repassivation of the unstable pits in 316LN after 7 days exposure. It was observed that R _N values showed a continuous decrease in the case of 316SS, but were quite stable in the case of 316LN over the exposure period. Concurrent to these observations it was observed that 316SS specimen was extensively pitted. The frequency distributions of pit diameters as well pit depths were observed to be highest at 10-20 μm and 5-10 μm, respectively. However, pits with as large as 70-80 μm diameter and as deep as 20-25 μm too were observed. No pits were observed in case of 316LN even after 30 days of exposure, an observation that corroborates well with the stable R _N values. Thus, in the present investigation, the long-term tests using EN technique coupled with CLSM studies conclusively prove that many unstable pits initiated in 316SS turn into stable ones resulting in insidious localized corrosion attack whereas the unstable pits initiated in 316LN get passivated in the simulated coastal environment.     

Optical switching properties of RCo2-type alloy thin films by electrochemical hydrogenation

The switchable optical properties of Pd-protected RCo₂-type Ho_0.6Mm_0.4Co₂ alloy thin films have been investigated in a KOH electrolyte. The reversible optical switching has been carried out simultaneously by measuring transmitted light through the thin film during electrochemical charging–discharging of hydrogen. The dependence of switching speed and cyclic durability of the film on the charging and discharging current density as well as concentration of KOH electrolyte has been studied. In addition, cyclic voltammetric measurements have been performed to examine the hydride formation and decomposition reactions.     

Origin and practical significance of the sticky dough factor in 1BL/1RS wheats

When translocated into wheat, the short arm of the 1R chromosome of rye carries with it linked resistance genes to powdery mildew, stripe rust, leaf rust and stem rust. The translocation is also reported to increase yield potential of hard wheats. However, many doughs made from some 1BL/1RS hard wheats are unacceptable for breadmaking purposes because of excessive stickiness and mixing intolerance. 1BL/1RS wheats may be sticky because of: the inheritance of secalin proteins from rye and absence of key glutenin subunits; higher amounts and/or differences in the composition of cell wall polysaccharides, β‐glucans and pentosans; and/or the presence of a ferulic acid ester moiety residing with the water‐soluble fraction of 1BL/1RS flours. None of these hypotheses has been proven or disproven, to date, as a cause of excessive stickiness. Investigators have found that 1BL/1RS doughs are not uniformly sticky and are in some instances less sticky than non‐1BL/1RS doughs. Significant genotype–environment interactions have been reported for dough stickiness and flour quality characteristics of 1BL/1RS wheats. Investigators have generally failed to find significant differences in the breadmaking performance of 1BL/1RS and non‐1BL/1RS hard wheats despite a report that 1BL/1RS doughs break down and soften during high‐speed mixing. The 1BL/1RS translocation has been shown to reduce cookie spread of soft wheat flours but has no deleterious effects on cake volume or texture. © 2002 Society of Chemical Industry     

Filled Fibrous Sorbents Modified with Transition Metal Ferro- and Ferricyanides for Recovery of Americium and Rare-Earth Metals

Filled fibrous sorbents modified with transition metal ferro- and ferricyanides capable to recover americium(III) and rare-earth metals(III) from nitric acid solutions were prepared. The most complete and rapid recovery is attained on complex-forming and cation-exchange sorbents (as filled fibrous materials) saturated with nickel ions. The sorbents are characterized by good kinetic properties and can be used for recovery of the above metals.     

Introduction to the special section on racial and ethnic identity in counseling psychology: Conceptual and methodological challenges and proposed solutions.

Racial and ethnic identity development have been important topics in counseling psychology research for the last four decades. At present, however, there appears to be some confusion and debate regarding the quality of theory and measurement in the topical area. The present article serves as an introduction to this Journal of Counseling Psychology special section on "Racial and Ethnic Identity in Counseling Psychology: Conceptual and Methodological Challenges and Proposed Solutions." A rationale is provided for the special section, the place of racial and ethnic identity scholarship is located within the history of multicultural counseling research, and the invited special section contributions by K. O. Cokley (2007), J. E. Helms (2007), J. E. Trimble (2007), S. M. Quintana (2007), J. S. Phinney and A. D. Ong (2007), and J. G. Ponterotto and J. Park-Taylor (2007) are introduced. (PsycINFO Database Record (c) 2010 APA, all rights reserved)