Numerical modeling of 3-D flow on porous broad crested weirs

Gabion weirs with optional design as a broad crested weirs are suitable structures to reduce flash flood with a minimal negative impact on the water environment. In the present study, the 3-D flow was simulated around gabion weirs with respect to free-surface water. The Reynolds-averaged Navier–Stokes equations are solved to predict water surface over the gabion weir. The VOF method with the geometric reconstruction scheme was applied to treat the complex free-surface flow. Simulations were performed using three variants of the k–ε and the RSM models to find the water level and velocity distribution profile and results are compared with several experimental data available in the literature. The structured mesh was used for all domains with high dense mesh near the solid region. A comparison between experimental data and simulations indicates that the k–ε model can be used to predict the complex flow and water level with high accuracy.     

A comparison of electromigration failure of metal lines with fracture mechanics

Atoms constructing an interconnecting metal linein a semiconductor device are transported by electron flowin high density.This phenomenon is called electromigration,which may cause the line failure.In order to characterize theelectromigration failure,a comparison study is carried outwith some typical phenomena treated by fracture mechanicsfor thin and large structures.An example of thin structures,which have been treated by fracture mechanics,is silica optical fibers for communication systems.The damage growth ina metal line by electromigration is characterized in comparison with the crack growth in a silica optical fiber subjectedto static fatigue.Also a brief comparison is made betweenthe electromigration failure and some fracture phenomena inlarge structures.     

Performance comparison between plastic-based fiber bundle and multimode fused coupler as probes in displacement sensors

Fiber optic displacement sensors with bundled and fused coupler fiber probes are being investigated. The effects of axial displacements on the detected output voltages are also investigated for fiber bundle probe sensor. The resolutions obtained are 0.9 and 4.0 μm, for the front and back slopes, respectively. A comparison is made with a commercial plastic based multimode fused coupler which gives a better range of 2.0 mm. This is longer than that achieved by the fiber bundle probe which is only 0.4 mm and has a lower resolution of 34 μm for the case of 50:50 coupling ratio.     

Foldable Detergents for Membrane Protein Study: Importance of Detergent Core Flexibility in Protein Stabilization

Membrane proteins are of biological and pharmaceutical significance. However, their structural study is extremely challenging mainly due to the fact that only a small number of chemical tools are suitable for stabilizing membrane proteins in solution. Detergents are widely used in membrane protein study, but conventional detergents are generally poor at stabilizing challenging membrane proteins such as G protein-coupled receptors and protein complexes. In the current study, we prepared tandem triazine-based maltosides (TZMs) with two amphiphilic triazine units connected by different diamine linkers, hydrazine (TZM−Hs) and 1,2-ethylenediamine (TZM−Es). These TZMs were consistently superior to a gold standard detergent (DDM) in terms of stabilizing a few membrane proteins. In addition, the TZM−Es containing a long linker showed more general protein stabilization efficacy with multiple membrane proteins than the TZM−Hs containing a short linker. This result indicates that introduction of the flexible1,2-ethylenediamine linker between two rigid triazine rings enables the TZM−Es to fold into favourable conformations in order to promote membrane protein stability. The novel concept of detergent foldability introduced in the current study has potential in rational detergent design and membrane protein applications.     

Picosecond Soliton Pulse Generation with a Zinc Phthalocyanine Thin-Film Saturable Absorber Via Mode Locking in an Erbium-Doped Fiber Laser Cavity

Journal of Russian Laser Research - In this paper, we employ a Zinc Phthalocyanine (ZnPc) organic material to construct a saturable absorber (SA) that is used in a laser cavity to generate...     

A novel method for predicting decomposition onset temperature of high-energy metal–organic frameworks

Journal of Thermal Analysis and Calorimetry - The decomposition onset temperature, Tdecom, is an important parameter for investigating the thermal stability of chemicals. A novel method is...