3D Investigation of Damage During Strain-Controlled Thermomechanical Fatigue of Cast Al–Si Alloys

The strain-controlled thermomechanical fatigue behavior is investigated for three cast near-eutectic Al–Si alloys with different Ni, Cu, and Mg contents. Synchrotron tomography and neutron diffraction experiments are used to correlate 3D microstructural features with damage initiation and evolution. The results show that the alloy with lower Cu, Ni, and Mg concentrations has up to 45% higher thermomechanical fatigue resistance for cooling/heating rates of 5 and 15 K s⁻¹. In addition, this alloy also exhibits damage formation at later stages during thermomechanical fatigue and slower damage accumulation compared to other alloys. This difference in behavior is a consequence of its higher ductility, which is a result of the lower volume fraction and global interconnectivity of the 3D hybrid networks formed by Si and intermetallics and the absence of large primary Si clusters which act as preferred crack initiation sites during the early stages of thermomechanical fatigue.     

Calculating SPRT Interpolation Error

Interpolation error is a major source of uncertainty in the calibration of standard platinum resistance thermometer (SPRT) in the subranges of the International Temperature Scale of 1990 (ITS-90). This interpolation error arises because the interpolation equations prescribed by the ITS-90 cannot perfectly accommodate all the SPRTs natural variations in the resistance–temperature behavior, and generates different forms of non-uniqueness. This paper investigates the type 3 non-uniqueness for fourteen SPRTs of five different manufacturers calibrated over the water–zinc subrange and demonstrates the use of the method of divided differences for calculating the interpolation error. The calculated maximum standard deviation of 0.25 mK (near \(100\,^{\circ }\hbox {C}\)) is similar to that observed in previous studies.     

Organization of partner preference and sexual behavior and its nocturnal rhythmicity in male rats.

Male rats were neonatally treated with 1,4,6-androstatriene-3,17-dione (ATD), which blocks aromatization of testosterone (T) to estradiol (E?), from Days 0, 2, or 5 through 14. Adult partner preference behavior (PPB; choice between estrous female rat [F] and active male rat [M]) was studied in the early part of the dark phase of the light-dark cycle. ATD Day 0 Ms showed a preference for the stimulus M or showed no preference for either of the stimulus Ss. Controls preferred the estrous F. ATD Days 2 and 5 Ms showed PPB intermediate between ATD Day 0 Ms and controls. Thus the neonatally sensitive period for organization of adult PPB extends beyond Day 5. Furthermore, PPB showed a nocturnal rhythmicity in ATD Ms but not in controls. In the late part of the dark phase, all Ms showed a preference for the stimulus F. ATD Days 2 and 5 Ms and control Ms were no longer different in PPB, but ATD Day 0 Ms still showed significantly lower preference scores for F than all other Ms. Thus the E? metabolite of T suppresses organization of an adult nocturnal rhythm in PPB. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biophotonic sensors with integrated Si3N4-organic hybrid (SiNOH) lasers for point-of-care diagnostics

Early and efficient disease diagnosis with low-cost point-of-care devices is gaining importance for personalized medicine and public health protection. Within t...     

Design and Production of Thin and Small Micro Strips

This article describes a recently started research project about the rolling of small and very thin strip, or in other words the production of micro strip using flat rolling processes. Main subject of the article is the finite element simulation of the production process and its validation. First the practical relevance of micro strip and its production process are presented. Furthermore the scaling effects which miniaturisation brings with it are introduced. Determination and consideration of the size effects are essentials in order to make optimisation possible. It is proposed to determine the size effects in the flow curve with a miniaturised multi‐layer plane strain compression test. The simulation will be done on a continuum base which includes the determined size effects out of the multi‐layer plane strain compression test. Finally a comparison of the FEM‐simulation results (rolling force, cross sectional geometry) with real processes validates the modified finite element simulation.     

Differences in mortality and coronary heart disease between Lithuania and The Netherlands: results from the WHO Kaunas-Rotterdam Intervention Study (KRIS)

There is no single task that nurses do more often than make decisions, yet many clinicians feel inadequately prepared to address and resolve ethical issues. The Intravenous Nurses Society Code of Ethics provides practice guidelines for intravenous nursing specialists who need to make these often difficult decisions. The availability of an ethical decision-making model can assist the IV nurse in providing ethical quality care, regardless of the clinical setting in which care is delivered.     

FDTD-Modelling of Dispersive Nonlinear Ring Resonators: Accuracy Studies and Experiments

The accuracy of nonlinear finite-difference time-domain (FDTD) methods is investigated by modeling nonlinear optical interaction in a ring resonator. We have developed a parallelized 3-D FDTD algorithm which incorporates material dispersion, chi⁽³⁾-nonlinearities and stair-casing error correction. The results of this implementation are compared with experiments, and intrinsic errors of the FDTD algorithm are separated from geometrical uncertainties arising from the fabrication tolerances of the device. A series of progressively less complex FDTD models is investigated, omitting material dispersion, abandoning the stair-casing error correction, and approximating the structure by a 2-D effective index model. We compare the results of the different algorithms and give guidelines as to which degree of complexity is needed in order to obtain reliable simulation results in the linear and the nonlinear regime. In both cases, incorporating stair-casing error correction and material dispersion into a 2-D effective index model turns out to be computationally much cheaper and more effective than performing a fully three-dimensional simulation without these features