Numerical solutions on fracture of piezoelectric materials by hybrid element

The cracked piezoelectric problem is observed numerically. To simulate the characteristic singularity at the crack tip, a plane piezoelectric hybrid element is derived. The new model involves displacement u, stress σo, electric displacement D and electric potential p as independent variables. The electromechanical coupling behavior of the cracked piezoelectric ceramics PZT-4 and PZT-5 is investigated. Under impermeable crack condition, the 1/√r-singularity at the crack-tip zone is exactly represented for σ and D. The efficiency of implementing the permeable crack condition is also inspected. To examine current energy release rate formulas, the path-independent integral is computed, and then a fitting formula for the energy release rate is obtained. In this paper, all the numerical results are compared with the previously reported theoretical solutions. © 2001 Elsevier Science Ltd. All rights reserved.postprin

Effects of Ixeris Chinensis (Thunb.) Nakai boiling water extract on hepatitis B viral activity and hepatocellular carcinoma

Background: Hepatitis B virus (HBV) infection and hepatocellular carcinoma are major diseases that affect the Taiwanese population. Therefore, the development of an alternative herbal medicine that can effectively treat these diseases is a research target. In this study, we tested Ixeris Chinensis (Thunb.) Nakai boiling water extract (ICTN BWE) in vitro and analysed its effects on the HBV and liver cancer.Materials and Methods: We used a human liver cancer cell line (Hep3B, a cell line that continuously secretes HBV particles into a medium) as an experimental model for the screening of various ICTN BWE concentrations and their effects on the HBV in vitro.Results: Our results showed that 75 μg/mL ICTN BWE downregulated the relative expression of the hepatitis B virus surface antigens (HBsAg) to 77.1%. Using the human liver cancer cell lines HuH-7 and HepG2, and 3-(4,5- dimethylthiazol-zyl)-2,5-diphenyl tetrazolium bromide (MTT) and tumour clonogenic assays, we then showed that ICTN BWE inhibits hepatocellular carcinoma growth.Conclusion: Fluorescent microscopy of DAPI(4',6-Diamidino-2-phenylindole)-stained nuclei and DNA fragmentation assays confirmed the inhibitory effects of ICTN BWE on liver tumour cell growth through induction of apoptosis.Keywords: herbal medicine, Ixeris Chinensis (Thunb.) Nakai, antihepatocellular carcinoma, apoptosis, antihepatitis B viru

The comparison of immunomodulatory effects of peripheral mononuclear cells against proliferation in U937 in junior elderly habitual morning swimming in Taiwan cohort

The present investigation was carried out to evaluate the effect of greater immunomodulatory effects of human peripheral blood mononuclear cells against proliferation in human leukemia cells. To achieve this, cells U937 in junior elderly (with cool environmental physical activities) subjects with habitual morning swimming and sedentary lifestyle were recruited in relatively cool season in Taiwan; the isolated human peripheral blood mononuclear cells were stimulated by phytohemagglutinin to obtain the conditioned medium which contains various cytokines. However, the differential effects of the conditioned medium on growth inhibition in U937 leukemia cells were observed. The cytokines, including interferon-gamma, tumor necrosis factors-alpha and interleukine-2 secreted into conditioned medium were higher in the morning-swimming subjects than in the sedentary-lifestyle ones. Similarly, serum white blood cell, creatine phosphokinase, immunoglobulin G and immunoglobulin A in the morning-swimming and sedentary-lifestyle groups indicated that no further inflammatory status existed in the morning-swimming group. In summary, greater immunomodulatory effects of human peripheral blood mononuclear cells against proliferation in human leukemia cells U937 in junior elderly subjects came from the effects of regular moderate exercise in cool temperature rather than of inflammatory effects.Keywords: Immunomodulatory, junior elderly, morning swimming, leukemia, U937, human peripheral blood mononuclear cell

Experimental study and modeling of the influence of screw dislocations on the performance of Au/n-GaN Schottky diodes

The influence of screw dislocations on the performance of Au/n-GaN Schottky diodes was investigated. The current-voltage (I-V) characteristics of the diodes fabricated on different GaN templates grown by metallorganic chemical vapor deposition on sapphire substrates were studied. It was shown that these dislocations result in the lowering of the barrier height in the localized regions.published_or_final_versio

Impaired vowel discrimination in Mandarin-speaking congenital amusics

2015-2016 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Fabrication and characteristics of a GaInP/GaAs heterojunction bipolar transistor using a selective buried sub-collector

A C-doped GaInP/GaAs heterojunction bipolar transistor (HBT) with a selective buried sub-collector has been fabricated by two growth steps. The active HBT region was made on the selective buried sub-collector layer with minimum overlap of the extrinsic base and the sub-collector region resulting in substantial reduction of the base-collector capacitance. The experiment shows that the base-collector capacitance is reduced to about half of that of a conventional HBT while the base resistance remains unchanged resulting in a 40-50% increase in the maximum oscillation frequency. Both DC and RF characteristics are investigated and compared with a conventional HBT. A current gain of 40 cutoff frequency of 50 GHz and maximum oscillation frequency of 140 GHz were obtained for the GaInP/GaAs HBT. It is demonstrated that the selective buried sub-collector provides an effective means for enhancing RF performance of an HBT. © 1997 IEEE.published_or_final_versio

Verifying the Integrity of Hyperlinked Information Using Linked Data and Smart Contracts

We present an approach to verify off-chained information using Linked Data, Smart Contracts, and RDF graph hashes stored on a Distributed Ledger. We use the notion of a Linked Pedigree, i.e. a decentralised dataset for storing hyperlinked information, as modelling foundation. We evaluate our approach by comparing different ways to build the Smart Contract. We develop a cost model and show, based on our implementation, that for managing multiple Linked Pedigree instances, a single larger Smart Contract is superior to multiple smaller Smart Contracts for supply chains shorter than 50 participants

Protective Effects of L-Arginine Supplementation Against Exhaustive Exercise-Induced Oxidative Stress in Young Rat Tissues

[[abstract]]Recently, we showed I-arginine (L-Arg) supplementation could attenuate acute exercise-induced oxidative and inflammatory stress in aging rats. In this study, we investigate whether L-Arg supplementation protects cellular oxidative stress. inflammation, or the mitochondrial DNA 4834-bp large deletion (mtDNA(4834) deletion) in 14-week-old young rats tissues during exhaustive exercise. Rats were randomly divided into four groups: sedentary control (SC). SC with L-Arg treatment (SC+Arg); exhaustive exercise (E); and exhaustive exercise with L-Arg treatment (E+Arg). Rats in the SC+Arg and E+Arg groups received supplemental 2% L-Arg diet. Rats in groups E, and E+Arg performed in exhaustive running test on a treadmill. The results showed a significant increase in xanthine oxidase (XO) and myeloperoxidase (MPO) activities and lipid peroxide (malondialdehyde, MDA) levels of muscular, hepatic, and renal tissues in exercised rats as compared with sedentary rats. The increased XO. MPO. and MDA levels of these tissues significantly decreased in exercised rats supplemented with L-Arg. However. exhaustive exercise had no effect oil mtDNA4834 deletion,; of muscular and hepatic tissues. The activities of creatine kinase (CK)), aspartate aminotransferase (AST). alanine aminotransferase (ALT). blood urea nitrogen (BUN), creatinine (CRE), lac(ale. uric acid, non-esterified fatty acid (NEFA)., and D-3-hydroxybutyrate in the plasma significantly increased in the exercised rats compared with the sedentary rats, while, the CK, lactate and uric acid levels in the plasma significantly decreased in L-Arg-supplemented exercised rats. These findings suggest that L-Arg supplementation reduces the oxidative damage to and inflammatory response in skeletal muscles. the liver, and kidneys caused by exhaustive exercise in young rats

Physicochemical, pasting and thermal properties of tuber starches as modified by guar gum and locust bean gum

[[abstract]]This study was carried out in order to compare the functional characteristics of isolated starch from five tuber crops, yam, taro, sweet potato, yam bean and potato, as well as effect of guar gum (GG) and locust bean gum (LBG) on pasting and thermal properties of tuber starches. The results showed that total amylose content of five tested starches ranged from 17.85% to 30.36%. The results of pasting behaviour showed that potato starches exhibited the highest peak viscosity and yam starch presented a stable curve with little breakdown viscosity. Addition of GG and LBG resulted in a significant increase in peak, final viscosity, breakdown and setback viscosity for all tuber starches (P < 0.05), but a slight decrease in pasting temperature. The gelatinisation enthalpy (Delta H) for starches with GG and LBG was slightly lower than those of the starches alone in yam and sweet potato, but not in taro and yam bean