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In recent years, multielement films have been required for high-performance cutting tools. In this paper, a Y-shaped filtered-arc-deposition (Y-FAD) system with two vacuum-arc sources was developed. First, an optimum magnetic coil arrangement was experimentally established to transport two plasma beams through the Y-shaped duct at the same time. Since the two plasma beams have the same electrical polarity, they naturally tend to repel each other. Therefore, in the second step, the two plasma beams were combined into one plasma beam through a mixer part by vibrating the plasma beams with a laterally oscillating magnetic field. Third, the electrical bias applied to the duct was optimized to obtain a higher transportation rate of plasma and deposition rate. After these design developments and tuning, titanium-aluminum (Ti-Al) film with a combined deposition pattern was finally obtained with Al and Ti cathodes. The controllability of the composition ratio by the arc current was verified.

An X-shaped filtered-arc-deposition (X-FAD) apparatus was developed in order to prepare hydrogen-free tetrahedral amorphous carbon (ta-C), which is a kind of diamond-like carbon (DLC), and metal film as a binding interlayer on the superhard alloy using a plasma beam irradiated from the same direction. First of all, the droplet-reduction performance was verified, and then, the appropriate duct-bias voltages and deposition rate were measured. Optima of duct biases for chromium (Cr) and DLC were found to be 25 and 15 V, respectively. From the result of X-ray diffraction analysis, it was found that Cr film that is prepared at a higher substrate-bias voltage was well crystallized and has less internal stress. The appropriate substrate bias for preparing ta-C was -100 to -200 V. DLC film was also prepared with substrate heating. It was found that ta-C could be prepared at a substrate temperature of less than 200degC, and the film was graphitized at higher temperature. By following these results, 2.5-mum-thick ta-C film was prepared on a superhard alloy with an interlayer by X-FAD.

SUMMARY The ability of seismic isolators to develop restoring forces, also referred as self-centring capacity, is commonly associated with the system ability to prevent excessively large unit deformations and possible isolator failure. This concept is emphasized in some of the current standards or guide specifications for the design of seismic isolated structures that usually impose minimum values of the isolator restoring force capacity. In this paper a numerical study is performed to investigate the influence of the parameters that characterize the model of a structure–isolator system on its self-centring capacity. The system is idealized as a rigid mass mounted on a single isolator in which a bilinear force–displacement relation, which approximates the nearly bilinear behaviour exhibited by most of the currently available devices, characterizes the isolator response. Results from this study provide insights on the merit of current guide specifications and on the overall isolation behaviour of the models. Copyright # 2006 John Wiley & Sons, Ltd.

It is imperative to preserve ancient Chinese timber architecture because the impacts of time and the environment have seriously reduced the resistance capability of these historical relics. However, little information can be found to provide basic knowledge for maintenance and reinforcement. Based on an experimental study of an ancient timber structure—the front tower over the North Gate of the Xi'an City Wall in China—a semirigid finite-element model (FEM) was developed to simulate the behavior of dou gong (corbel brackets) and tenon joints and a 3D FEM model was used to study the dynamic characteristics of the structure. The FEM program SAFATS was developed to conduct dynamic and earthquake response analysis for this kind of timber structure. By comparison with experimental results, the equivalent stiffness of the semirigid element was defined and the dynamic characteristics of the structure were obtained. Based on the analysis, it was found that the use of semirigid connections in timber structures, su...

As an important part of the civilization in China, ancient Chinese architecture has an indigenous and unique system of construction that has retained its principal characteristics from prehistoric times to the present and spread its influence to other countries such as Korea and Japan. With the exacerbating environmental encroachment and time impacts that have been reducing their structural resistance, it has become imperative to preserve this architectural heritage. To provide the basic characteristics of the timber structures as fundamental information for research and preservation, on-site measurements and model tests were conducted on the front tower over the North Gate of the Xi'an City Wall. In the full-scale on-site tests, the vibration modes of the tower were measured. The first four natural frequencies of the structure were found to be 1.10, 1.70, 2.73, and 3.10 Hz, respectively. Multipoint excitation tests on wooden and polymethyl methacrylate (Perspex) models validate that the first and second ...

A planar lattice network of beam elements is used to study the mechanisms of fracture in cement‐based materials. Beam properties are controlled by a nonlinear elastic fracture law which roughly accounts for three‐dimensionality of the material and fracture process. Special attention is given to modeling toughening mechanisms associated with aggregate‐matrix interface failure. The distributions of damage and fracture energy consumption are resolved at the material mesoscale and are shown to depend on strain gradient. An adaptive remeshing procedure is used to reduce computational cost and enable analyses of specimens of significantly differing scale, while keeping the lattice density constant. Larger process zones, higher specific fracture energies, and lower specific peak loads are obtained with increasing specimen size, in agreement with published test results. These computations provide information useful in developing refined macromodels for engineering analyses.

Tetrahedral amorphous-carbon (ta-C) without hydrogen is the hardest in diamond-like carbon (DLC), and expected of the application to coating on dry cutting tool for aluminum. The only method to prepare ta-C on an industrial scale is cathodic vacuum arc deposition. The authors have been developed T-shape filtered arc deposition (T-FAD) system with efficient droplet reduction. However, ta-C usually requires a binding interlayer between the workpiece and film, since the internal stress of the film is very high and adhesion to the substrate is not good. In the present study, in order to prepare DLC and metal film on the superhard alloy depositing from same direction, the authors developed on X-shape filtered arc deposition (X-FAD) apparatus. First of all, the authors verified the droplet reduction function, and then the appropriate duct bias voltages and deposition rate. DLC was also prepared with substrate heating. By considering and following these results, 1 a thick ta-C film was prepared on a superhard alloy with interlayer by X-FAD

Leftward shift of the infundibular septum (IS) in interrupted aortic arch (IAA) with ventricular septal defect (VSD) often develops significant left ventricular outflow obstruction (LVOTO). Seven-day-old boy with 2.6 kg body weight underwent the two-stage operation for this anomaly. The aortic arch was interrupted between the left common carotid and the left subclavian artery. At the first stage, a 5 mm GORE-TEX graft was used to connect the interrupted arch, and pulmonary artery banding was performed. In closure of VSD at the second stage, IS was penetrated by stitches for the VSD patch to left ventricular outflow tract. IS with leftward shift could be pulled toward right ventricular side with patch fixation and LVOTO was prevented by this method.

In pediatric open heart surgery, a right-angled metal cannula (Pacifico's venous cannula) for direct superior vena caval cannulation is frequently used. But it is often difficult to be inserted into superior vena cava due to "right-angled" shape especially in small babies. We developed a new holder which can make straight line from the metal tip to flexible plastic end of the cannula. It is easy and safe even in cases of small babies.

A modification of De Leval technique for closure of ventricular septal defect (VSD) in atrioventricular discordance (AVD) with double outlet right ventricle (DORV) was reported. A 2-year-and-8-month-old boy underwent total repair for this anomaly. The first two stitches for closure of VSD were placed on the lower margin of the defect in which conducting tissues were not situated. Next remained stitches for closure of the defect could be continued toward upper margin of VSD in the morphologically right ventricular side of VSD while pulling the just previous stitches with good exposure and ease. We concluded that this modification was useful for making safe De Leval technique for closure of VSD in AVD.

Fine YBCO powders were shock-compacted at around 5 GPa using a propellant gun. Shock-compacted pellets have large grains of 5–25 μm in length with large growth-steps caused mainly by heats generated in a shock-loading.