Fracture toughness and failure assessment for particulate reinforced composites considering viscoelasticity

Fracture mechanics models which are appropriate to describe failure behavior of highly filled elastomers were discussed, and then the strip‐yield and the inherent flaw models were applied to them. In order to generate failure assessment diagrams, the two models were moderately modified, and the experiments of fracture mechanics were conducted using center cracked tension (CCT) specimens made of a highly filled elastomer applying the ASTM E399 standard. The failure assessment diagram of the modified inherent flaw model was normalized to compare with that of the modified strip‐yield model. From the comparison between two failure assessment diagrams, it was found that the failure assessment diagram of the modified inherent flaw model more conservatively assesses the failure than that of the modified strip‐yield model.     

Physiological components of kiwifruits with in vitro antioxidant and acetylcholinesterase inhibitory activities

Five domestic kiwifruit varieties, Bidan (BD), Chiak (CA), Haegeum (HG), Haehyang (HH), and Mansoo (MS), in Korea and two imported varieties, Hayward (HW) and Hort16A (HT), from New Zealand were evaluated main active component groups in the fruit extracts involved in antioxidant and anti-dementia activities. HW, HT, and HH exhibited higher soluble solid content. BD, HG, and HH contained high total phenolics (TP), whereas two imported kiwifruits and green kiwifruits (MS and CA) had low TP content. BD showed the highest antioxidant and antidementia activities among kiwifruits studied. Vitamin C (Vc) in kiwifruit extracts had the highest correlation with antioxidant activities. TP in kiwifruits had the highest correlation with acetylcholinesterase inhibitory activity. Butyrylcholinesterase activity was not significantly correlated with TP or Vc content, but the butyrylcholinesterase activity was significantly correlated with total flavonoids. The results above suggest that domestic varieties have a potential source of Vc and phenolic bioactivities.     

A new method for detecting data matrix under similarity transform for machine vision applications

Data matrices are widely used in the automotive, aerospace and computer manufacturing industries. In industry, they are used to identify objects used in process control. In this paper, we focus on detecting data matrices where a camera is configured to see it in a perpendicular direction that is typical in machine vision applications. In this case, the image projection can be modeled as a similarity transform. Data matrices are attached or marked by laser on the surface of objects, and have L-shaped solid lines which act as references for decoding. Under a similarity transform, distances from the center of a data matrix to each side of the L-shape are equal. This symmetric property is used to detect a data matrix, and experimental results show the feasibility of the proposed algorithm.     

Seismic performance evaluation of Korean column-tree steel moment connections

International Journal of Steel Structures - The purpose of this study was to evaluate the seismic performance of existing Korean column-tree connection type in steel moment frames. The column-tree...     

Reduced Reference Quality Metric for Synthesized Virtual Views in 3DTV

Multi‐view video plus depth (MVD) has been widely used owing to its effectiveness in three‐dimensional data representation. Using MVD, color videos with only a limited number of real viewpoints are compressed and transmitted along with captured or estimated depth videos. Because the synthesized views are generated from decoded real views, their original reference views do not exist at either the transmitter or receiver. Therefore, it is challenging to define an efficient metric to evaluate the quality of synthesized images. We propose a novel metric—the reduced‐reference quality metric. First, the effects of depth distortion on the quality of synthesized images are analyzed. We then employ the high correlation between the local depth distortions and local color characteristics of the decoded depth and color images, respectively, to achieve an efficient depth quality metric for each real view. Finally, the objective quality metric of the synthesized views is obtained by combining all the depth quality metrics obtained from the decoded real views. The experimental results show that the proposed quality metric correlates very well with full reference image and video quality metrics.     

Characterization and Effect of Covalently Grafted Benzoic Acid on the Low Temperature Flexibility and Water Vapor Permeability of a Polyurethane Copolymer

Polyurethane was grafted with benzoic acid (BA series) or a phenyl group (C series) to compare the impact of the grafted groups on water contact angle, tensile strength, shape memory, and low temperature flexibility. Benzoic acid is different from a phenyl group because it has both a rigid phenyl ring and a carboxyl group. The tensile strengths of the BA and C series substantially increased compared to that of the unmodified polyurethane. The BA series with the grafted benzoic acid exhibited excellent low temperature flexibility compared to the C series with the grafted phenyl group.     

Design of Multi‐time Programmable Memory for PMICs

In this paper, a multi‐time programmable (MTP) cell based on a 0.18 μm bipolar‐CMOS‐DMOS backbone process that can be written into by using dual pumping voltages — VPP (boosted voltage) and VNN (negative voltage) — is used to design MTP memories without high voltage devices. The used MTP cell consists of a control gate (CG) capacitor, a TG_SENSE transistor, and a select transistor. To reduce the MTP cell size, the tunnel gate (TG) oxide and sense transistor are merged into a single TG_SENSE transistor; only two p‐wells are used — one for the TG_SENSE and sense transistors and the other for the CG capacitor; moreover, only one deep n‐well is used for the 256‐bit MTP cell array. In addition, a three‐stage voltage level translator, a VNN charge pump, and a VNN precharge circuit are newly proposed to secure the reliability of 5 V devices. Also, a dual memory structure, which is separated into a designer memory area of and a user memory area of , is newly proposed in this paper.     

LiMn2O4/CNTs and LiNi0.5Mn1.5O4/CNTs Nanocomposites as High-Performance Cathode Materials for Lithium-Ion Batteries

The demand of higher energy density and higher power capacity of lithium(Li)-ion secondary batteries has led to the search for electrode materials whose capacities and performance are better than those available today. Carbon nanotubes(CNTs), with their unique properties such as 1D tubular structure, high electrical and thermal conductivities, and extremely large surface area, have been used as materials to prepare cathodes for Li-ion batteries. The structure and morphology of CNTs were analyzed by X-ray diffraction(XRD), scanning electron microscopy(SEM), and transmission electron microscopy(TEM). The functional groups on the purified CNT surface such as –COOH, –OH were characterized by Fourier Transform infrared spectroscopy. The electrode materials were fabricated from LiMn2O4(LMO), doped spinel LiNi0.5Mn1.5O4, and purified CNTs via solid-state reaction. The structure and morphology of the electrode were characterized using XRD, SEM, and TEM. Finally, the efficiency of the electrode materials using CNTs was evaluated by cyclic voltammetry and electrochemical impedance spectroscopy.