Corrosion Behaviour of Type 316L Stainless Steel in Hot Caustic Aqueous Environments

Metals and Materials International - The corrosion behaviour of type 316L stainless steel in aqueous 30–50 wt%. NaOH at temperatures up to 90 °C has been elucidated....     

Interpersonal and Print Nutrition Communication for a Spanish-Dominant Latino Population: Secretos de la Buena Vida.

Participants (N = 357) were randomly assigned to 1 of 3 conditions: lay health advisor (promotora) plus tailored print materials, tailored print materials only (tailored), or off-the-shelf print materials (control). The primary outcomes were calories from fat and daily grams of fiber. Secondary outcomes included total energy intake, total and saturated fat intake, and total carbohydrates. Adjusted for baseline values, calories from fat were 29%, 30%, and 30% for the promotora, tailored, and control conditions, respectively, and grams of fiber consumed were 16 g, 17 g, and 16 g. Significant Condition X Time interactions were not observed between baseline and 12-weeks postintervention. The LHA condition achieved significantly lower levels of energy intake, total fat and saturated fat, and total carbohydrates. The relative superiority of the promotora condition may derive from the personal touch achieved in the face-to-face interactions or from the women's use of print materials under the promotora's guidance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

748 K (475 °C) Embrittlement of Duplex Stainless Steel: Effect on Microstructure and Fracture Behavior

22Cr-5Ni duplex stainless steel (DSS) was aged at 748 K (475 °C) and the microstructure development correlated to changes in mechanical properties and fracture behavior. Tensile testing of aged microstructures confirmed the occurrence of 748 K (475 °C) embrittlement, which was accompanied by an increase of strength and hardness and loss of toughness. Aging caused spinodal decomposition of the ferrite phase, consisting of Cr-enriched α″ and Fe-rich α′ and the formation of a large number of R-phase precipitates, with sizes between 50 and 400 nm. Fracture surface analyses revealed a gradual change of the fracture mode from ductile to brittle delamination fracture, associated with slip incompatibility between ferrite and austenite. Ferrite became highly brittle after 255 hours of aging, mainly due to the presence of precipitates, while austenite was ductile and accommodated most plastic strain. The fracture mechanism as a function of 748 K (475 °C) embrittlement is discussed in light of microstructure development.     

Precise variable-Q filter design [DSP Tips & Tricks]

We have shown how to analyze and design simple variable-Q bandpass filters. The simplest variable-Q filter suffers from two shortcomings. Its center frequency is not exactly the planned-for center frequency, and the amplitude at the center frequency is not exactly the planned-for amplitude of unity. We presented a slightly more complicated filter in (6) that meets all the variable-Q filter's desired specifications quite precisely.     

Sigma-Delta Converters: Theory and Simulations

One of the most important pieces of instrumentation used to make measurements is the analog-digital converters. It consists of a sample and hold circuit, a one-bit ADC, a one-bit digital-to-analog converter (DAC), a summing circuit, and an analog differencing unit. The actual conversion to a multi-bit digital value is performed by some form of microprocessor that implements a digital low-pass filter. Using digital signal processing techniques it is simple to calculate the average value and output it as a binary word. It is possible to simulate a reasonably complicated system using Excel. Furthermore, Excel can help with the analysis of the system-up to a point. Using a very common and reasonably simple tool, you can learn about and experience the SigmaDelta converter.     

Fast method for physical optics propagation of high-numerical-aperture beams

A method is presented that expands the scheme of physical optics propagation beyond the Fresnel approximation to include beams that are nonparaxial. The formalism retains most of the calculation advantages of the Fresnel approach; i.e., it is based on a single Fourier transform step. The kernel of the new transformation is no longer separable in Cartesian coordinates; thus the formalism can account for astigmatic coupling effects originating purely from diffraction. The validity limits of the proposed algorithm are explored. Analytical expressions, numerical simulation results, and experimental data are compared.     

Weakly-Acyclic (Internet) Routing Games

Weakly-acyclic games—a superclass of potential games—capture distributed environments where simple, globally-asynchronous interactions between strategic agents are guaranteed to converge to an equilibrium. We explore the class of routing games introduced in Fabrikant and Papadimitriou (The Complexity of Game Dynamics: BGP Oscillations, Sink Equilibria, and Beyond, pp. 844–853, 2008) and in Levin et al. (Interdomain Routing and Games, pp. 57–66, 2008), which models important aspects of routing on the Internet. We show that, in interesting contexts, such routing games are weakly acyclic and, moreover, that pure Nash equilibria in such games can be found in a computationally efficient manner.     

Performance Optimization of Cold Rolled Type 316L Stainless Steel by Sand Blasting and Surface Linishing Treatment

Sand blasting followed by a surface linishing treatment was applied to optimize the near-surface microstructure of cold rolled type 316L stainless steel. The introduction of cold rolling led to the formation of α-martensite. Specimens with large thickness reductions (40, 53%) were more susceptible to localized corrosion. The application of sand blasting produced a near-surface deformation layer containing compressive residual stresses with significantly increased surface roughness, resulting in reduced corrosion resistance. The most resistant microstructure was obtained with the application of a final linishing treatment after sand blasting. This treatment produced microstructures with compressive near-surface residual stresses, reduced surface roughness, and increased resistance to localized corrosion.