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AbstractTungsten coating as a plasma-facing material on copper alloys is an important issue of a tokamak fusion device. Tungsten tile was created by means of plasma-spraying technology. The properties of the tungsten coating are as follows: low porosity of 4.7%, ˜92% of the theoretical tungsten bulk density, and high thermal conductivity of ˜79.7 W/m·K, which are interesting properties for the plasma-facing material. To alleviate the stress concentration, the tile was designed with rounded edges with a radius of 5 mm. The fatigue performance of the tungsten tile was tested at 5 MW/m2in an electron beam facility. No damage was observed after 38 cycles at 250 s per cycle. It is concluded that the rounded-edge design is helpful in reducing the maximum stress and in improving the resistant heat load property, which was proved by finite element analysis.

AbstractFive-layered W/Cu functionally graded materials with fine grain sizes of 0.2, 1, and 7 μm were fabricated by resistance sintering under ultrahigh pressure. Microstructure analysis found that they have a good graded composition distribution and mechanical properties. After about 2000 s edge plasma exposure in the HT-7 superconducting tokamak, the results indicated that the fine-grained tungsten can enhance mechanical strength, and it is favorable to hold back crack propagation and growth; however, the effects on impurity deposition and compound formation were not obvious.

ABSTRACTCommunity methicillin-resistant Staphylococcus aureus(CMRSA) strains are being isolated with increasing frequency around the world. In Western Australia CMRSA are endemic in geographically remote communities and have been found to belong to five different contour-clamped homogeneous electric field (CHEF) electrophoretic patterns. Representatives of each of these CHEF patterns have been compared to CMRSA representative of CHEF patterns from other Australian states and New Zealand. With one exception, all of the isolates were nonmultiresistant and were not resistant to many antimicrobial agents other than the ß-lactams. With one exception, which is not believed to be a CMRSA, all of the isolates harbored a ß-lactamase plasmid. Erythromycin resistance was associated with a 2-kb plasmid. One of the ß-lactamase plasmids was found to be able to acquire additional resistance determinants to become a multiple resistance plasmid. There were 10 multilocus sequence types belonging to eight distantly related clonal complexes of S. aureus. One new sequence type was found. Although most of the CMRSA harbored the type IVa SCCmec, a type IV structural variant was found and two new SCCmectypes were identified. Protein A gene (spa) typing revealed two new spatypes and, with two exceptions, corresponded to multilocus sequence typing. In contrast to other reports on CMRSA, most of the CMRSA strains studied here did not contain the Panton-Valentine leukocidin genes. The results also demonstrate that nonmultiresistant hospital strains such as UK EMRSA-15 may be able to circulate in the community and could be mistaken for CMRSA based on their resistance profiles.

The peripheral arterial vessel often appears as an elliptic shape under the constraints of the surrounding tissues. In this study, the gradient-based Hough transform was used to detect the central location of the ellipse and the lumen area of the arterial vessel non-invasively using power Doppler imaging. Sequential ultrasound images were used to construct arterial distension waveforms in both the major- and minor-axis directions for a few cardiac cycles. The common carotid arteries (CCAs) for nine healthy male volunteers (mean age 24 years), in the sitting position, were investigated in vivo. The CCAs (n=9) had a mean diameter of 5.83 mm, and the pulsatile diameter distension was 13.7±1.9%. The brachial artery and dorsalis pedis artery for five healthy male volunteers (mean age 26 years), in the supine position, had mean diameters of 4.03 mm and 2.83 mm and distensions of 16.7±4.6% and 15.5±5.4%, respectively. The movement of the arterial centre location during the cardiac cycle reflected the asymmetry of the reaction forces produced by the surrounding soft tissues. The present method can obtain the response of vessel distension to pulse pressure, as well as the constrained conditions of the arteries.

Theoretical analysis of the vibration of plates excited by piezoelectric actuators is presented in this paper. The geometric non-linear finite element model and the loading model of the piezoelectric actuators were developed for non-linear analysis. It is found that non-linear analysis is more accurate than linear analysis for large displacement vibration. A comparison of the results of the numerical model with experiment results shows that the numerical model and the computer program are correct. The vibration excited by piezoelectric actuators is also compared with the sound radiation generated by actuators.

Theoretical and experimental analyses are presented in this paper to investigate the sound attenuation at low frequency in a close-fitting enclosure, The enclosure is a rectangular cavity having four rigid walls and a rigid bottom, with a flexible top cover in the form of a clamped rectangular panel. Firstly, the effect of the vibration of the panel upon the characteristics of the sound field in the enclosure is studied in bath theory and experiment. Secondly, the effectiveness of using a smart actuator as a vibration control source to cancel the unwanted noise is studied experimentally. It is found that the sound pressure near the panel can be reduced by about 20 dB in the close-fitting enclosure by controlling the vibration of the panel.

Upon photolysis at 355 nm, dioxygen is released from a (mu-peroxo)(mu-hydroxo)bis[bis(bipyridyl)cobalt-(III)] complex in aqueous solutions and at physiological pH with a quantum yield of 0.04. The [Co(bpy)2(H2O)2]2+ (bpy = bipyridyl) photoproduct was generated on a nanosecond or faster time scale as determined by time-resolved optical absorption spectroscopy. A linear correspondence between the spectral changes and the oxygen production indicates that O2 is released on the same time scale. Oxyhemoglobin was formed from deoxyhemoglobin upon photodissociation of the (mu-peroxo) (mu-hydroxo)bis[bis(bipyridyl)cobalt(III)] complex, verifying that dioxygen is a primary photoproduct. This complex and other related compounds provide a method to study fast biological reactions involving O2, such as the reduction of dioxygen to water by cytochrome oxidase.

Intrauterine contraception has a number of important advantages over other forms of contraception and remains, therefore, an important method of birth control. However, side-effects and other drawbacks have reduced its overall acceptance. Also misconceptions and lack of updated scientific knowledge among the potential users and providers are major obstacles to the widespread use of intrauterine contraception.Ideally, an intrauterine device (IUD) should prevent pregnancy effectively, be well tolerated, not become displaced or expelled over time, cause a minimum of side-effects, be long-lasting, have a strictly local effect, and be easy to insert and remove.A group at the University of Ghent, Belgium, the International Study Group on Intrauterine Drug Delivery, has developed, since 1985, a totally new concept in order to improve current intrauterine contraceptive efficacy and enhance tolerance, by creating a harmonious relationship between the uterine cavity and the contraceptive'foreign body'. The new concept (GyneFix®) consists of a non-biodegradable suture thread made of surgical 00 monofilament polypropylene on which six copper tubes are threaded, providing a total surface area of 330 mm2. The upper and lower tubes are crimped onto the thread to keep the tubes in place. The upper extremity of the thread is provided with a knot which serves as an anchor. The knot is implanted in the myometrium of the uterine fundus with a specially designed insertion instrument, thereby permanently securing the device in the uterine cavity.Since the initial clinical investigations, over 10 000 woman years of experience and up to 10 years' follow-up in international multicenter, non-comparative and comparative clinical trials have been collected. The clinical material also included a large number of nulligravid and nulliparous women. Due to the design characteristics of the GyneFix® and its anchoring in the uterine fundus, an optimal tolerance and almost complete absence of expulsion were obtained. The constant release of copper ions in the upper part of the uterine cavity results in the high effectiveness of the anchored device. The effectiveness is higher than in the high-load conventional copper IUDs which have a risk of becoming displaced, partially or totally expelled in 10% or more (nulliparous women), resulting in a significant number of accidental pregnancies. The absence of a frame and, as a consequence, its flexibility, explain the low incidence of side-effects and the very low incidence of complications, such as pelvic inflammatory disease and ectopic pregnancies.This new concept could be a major step forward in the acceptance of intrauterine contraception worldwide and increase its popularity. This article reviews the experience with the new concept for interval, postabortal and postpartum contraception.

The mode of transmission of Helicobacter pylori is unknown. Since viable bacteria have been shown to be excreted in feces from infected individuals and houseflies habitually develop and feed on excrement, we hypothesized that flies ingest and harbor H. pylori and, in turn, contaminate the human environment. This study examined the possible vector potential of houseflies (Musca domestica) for H. pylori. Caged houseflies were exposed to freshly grown H. pylori on agar plates. After a 6-h feeding period, the plates were removed and were replaced with sterile petri dishes containing a droplet of sterile brucella broth. At regular intervals, small numbers of houseflies were removed for microbiological and histological analysis, and the petri dishes were replaced with fresh sterile plates with fresh drops of brucella broth. The flies' bodies, the flies' dissected alimentary tracts, and excreta on the petri dishes were cultured for H. pylori, whose identity was confirmed by the urease, catalase, and oxidase reactions and Gram staining. In contrast to control flies, viable H. pylori could be isolated from external surfaces for up to 12 h and from gut and excreta for as long as 30 h after the initial feeding period. After 30 h other gram-negative bacteria overgrew the cultures of samples from all locations tested, rendering the selective culture of H. pylori colonies impossible. Histological analysis revealed Helicobacter-like organisms in the gut lumen and attached to intestinal epithelial cells. We conclude that houseflies can harbor viable H. pylori on their bodies and in their intestinal tracts. They are also able to disseminate viable H. pylori in excreta, and they may therefore present a significant reservoir and be a vector in the transmission of H. pylori.

Electroencephalograph (EEG) is an electrical field that generated by our brain incessantly. The EEG signal released by the brain is different when a people is performing different activities in their daily life. And such EEG signals consist complicated information that can be interpreted. The aims of this study is to analyse the specific EEG channels of a user when they are performing a typing task with laptop. Meanwhile, this research also aimed to verify the performance of the different sub frequency band which is alpha and beta to recognize the specified tasks. The frequency sampling was set at 1024 Hz and the impedance was kept below 5k ohm of each channels. The Truscan EEG (Deymed, Diagnostic, Czech Republic) device consists of 19 channels and only selected channels which is F3 and F4 is filtered through butterworth bandpass filter (1Hz-80Hz) in the pre-processing stage. Power Spectra Density was calculated by using Welch and Burg Method to extract the features from filtered data. K-Nearest Neighbour (KNN) classifier and Linear Discriminant Analysis (LDA) were used in classification. It is found that the combination of channel F3 and F4 for Alpha frequency using Welch method gives the highest accuracy which is 98.45%.