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Aims We aim to investigate the effect of single dose of statin pretreatment prior to primary Percutaneous Coronary Intervention (PCI) on long-term clinical outcomes in patients with ST-elevation Myocardial Infarction (STEMI). Methods Using data from China Acute myocardial Infarction (CAMI) registry, we compared the outcome in STEMI patients with vs without atorvastation pretreatment prior to primary PCI. The primary endpoint was the composite outcome of all-cause mortality, non-fatal MI or stroke events during follow-up. Propensity-score (PS) matching was used to assemble a cohort of patients with similar baseline characteristics. All patients were followed till 24 months since baseline. Results Of all 3772 patients who met our inclusion criteria at 108 hospitals in China, 3288 patients (1644 patients in each arm) were included in our PS-matched cohort. In the PS-match cohort, overall 144 (8.65%) and 113 (6.79%) patients in the control group and pretreatment group had the primary endpoint respectively (p=0.048). The estimated HRs were 0.78 (95% CI: 0.606–0.997, p=0.046) in the unadjusted model and 0.76 (95% CI: 0.596–0.984, p=0.032) in the adjusted model (Figure). The HRs were broadly similar for the pretreatment dosage of 40 mg or 80 mg (0.78 vs 0.77, p=0.75). The HRs were even stronger in patients with single-vessel only than multi-vessel coronary artery disease (0.31 vs 0.75, p=0.014). Conclusion Among Chinese patients with STEMI, atorvastatin pretreatment before primary PCI may have better long-term composite outcome of all-cause mortality, non-fatal MI, or stroke events. Acknowledgement/Funding CAMS Innovation Fund for Medical Sciences (CIFMS) (2016-I2M-1-009)

An ultrathin and angularly stable metamaterial perfect absorber (MPA) is demonstrated for VHF-band using four connected split-square resonators structure and low-cost fabrication process. The total incoming energy of electromagnetic wave (at 250 MHz) is consumed inside the efficient thickness, which is 240 times smaller than the absorption wavelength of MPA. Our MPA works well for a very wide range of incident angle up to 45° of electromagnetic wave and exhibits the polarization-independent behavior. Furthermore, by scaling the initial design and integrating a ferroelectric material (strontium titanate), a thermo-tunable ultrathin MPA is realized in the THz region. At room temperature (300 K), the thickness of THz MPA reaches roundly 1/300 of the working wavelength. In addition, a fractional frequency shift of 49% at the absorption over 90% can be controlled in the varied temperature range from 150 to 400 K. Our results presents good candidates for potential devices operating from the radio to the THz range.

Shape optimization design is carried out in the paper aiming at the feature of openings on curved shells to enhance the structural stability and reduce the stress concentration. In order to make sure that the hole boundary curve are always located on the prescribed curved shell, the parametrical mapping method is employed to describe the hole boundary on the curved shells with shape design variables defined in the intrinsic reference domain. Then, different optimization models are established and the specific sensitivity is calculated for buckling optimization. Finally, it concludes from numerical examples that the structural stability and the intensity benefit together for a curved surface with a large curvature, and they are contradictory for a curved surface with a small curvature.

Definitions of angle radius and coordinates axis are presented to propose a new transient stability method that is simple and reliable for transient stability assessment. The concept of angle radius is further developed to introduce the novel concept of projection energy function (PEF), which in turn allow to the assessment of critical clearing time and generation limit of system in a new way. The advantage of the new method is that no concept of advanced generator group is required in the assessment contingency stability index. Case studies on the ten-generator New England test power system are reported to verify the validity of the PEF method.

There is a cyclical aperture at a certain part of the fiberglass reinforced plastic compound pipeline with a stainless steel pipe as a liner, which becomes the weakness of the conduit. The field of stress and strain of the aperture was investigated using the nonliner finite element code Marc. The results of the finite element analysis showed that there were concentrations of stress and strain in the layer of stainless steel at the part of the pipeline where the aperture existed. The method to solve these problems was also discussed.

Many complicated analytical methods have been proposed to predict the effects of the geometric nonlinearity of a single-story multi-bay steel frame and the material nonlinearity of its steel members. However, some structural engineers have difficulty in understanding the complicated methods and applying them in designing steel structures. Therefore, this study has been performed to provide a simplified analytical model that is only applicable in the preliminary design stage. Using the simplified analytical model, structural engineers can easily predict the storey drift, maximum allowable loads, and bracing stiffness of a single-storey multi-bay steel frame. The application feasibility of the simplified model is verified by performing a two-dimensional finite element analysis.

This study investigates the moment–rotation relationship of a double angle connection and proposes two simplified analytical models for predicting the initial stiffness and ultimate connection moment. These are considered to be the most influential parameters affecting the connection behavior. In addition, this study provides some basic data that can be used by structural designers to choose the most appropriate prediction equation for the moment–rotation relationship of a double angle connection and to design such a connection more precisely. Experimental tests and a three-dimensional nonlinear finite element analysis are performed.

A major research goal of the national spherical torus experiment is establishing long-pulse, high beta, high confinement operation and its physics basis. This research has been enabled by facility capabilities developed during 2001 and 2002, including neutral beam (up to 7?MW) and high harmonic fast wave (HHFW) heating (up to 6?MW), toroidal fields up to 6?kG, plasma currents up to 1.5?MA, flexible shape control, and wall preparation techniques. These capabilities have enabled the generation of plasmas with of up to 35%. Normalized beta values often exceed the no-wall limit, and studies suggest that passive wall mode stabilization enables this for H mode plasmas with broad pressure profiles. The viability of long, high bootstrap current fraction operations has been established for ELMing H mode plasmas with toroidal beta values in excess of 15% and sustained for several current relaxation times. Improvements in wall conditioning and fuelling are likely contributing to a reduction in H mode power thresholds. Electron thermal conduction is the dominant thermal loss channel in auxiliary heated plasmas examined thus far. HHFW effectively heats electrons, and its acceleration of fast beam ions has been observed. Evidence for HHFW current drive is obtained by comparision of the loop voltage evolution in plasmas with matched density and temperature profiles but varying phases of launched HHFW waves. Studies of emissions from electron Bernstein waves indicate a density scale length dependence of their transmission across the upper hybrid resonance near the plasma edge that is consistent with theoretical predictions. A peak heat flux to the divertor targets of 10?MW?m?2 has been measured in the H mode, with large asymmetries being observed in the power deposition between the inner and outer strike points. Non-inductive plasma startup studies have focused on coaxial helicity injection. With this technique, toroidal currents up to 400?kA have been driven, and studies to assess flux closure and coupling to other current drive techniques have begun.

The National Spherical Torus Experiment (NSTX) at Princeton University, Princeton, NJ, is designed to assess the potential of the low-aspect-ratio spherical torus concept for magnetic plasma confinement. The plasma has been heated by up to 7 MW of neutral beam injection (NBI) at an injection energy of 100 keV and up to 6 MW of high harmonic fast wave (HHFW) at 30 MHz. NSTX has achieved /spl beta//sub T/ of 32%. A variety of MHD phenomena have been observed to limit /spl beta/. NSTX has now begun addressing /spl tau//sub E/ scaling, /spl beta/ limits, and current drive issues. During the NBI heating experiments, a broad T/sub i/ profile with T/sub i/ up to 2 keV, T/sub i/>T/sub e/ and a large toroidal rotation were observed. Transport analysis suggests that the impurity ions have diffusivities approaching neoclassical. For L-Mode plasmas, /spl tau//sub E/ is up to two times the ITER97L L-Mode scaling and exceeds the ITER98pby2 H-Mode scaling in some cases. Transitions to H-Mode have been observed which result in an approximate doubling of /spl tau//sub E/ after the transition in some conditions. During HHFW heating, T/sub e/>T/sub i/ and T/sub e/ up to 3.5 keV were observed. Current drive has been studied using both coaxial helicity injection with up to 390 kA of toroidal current and HHFW. HHFW has produced H-modes with significant bootstrap current fraction at low I/sub p/, high q, and high /spl beta//sub p/.

Double angle connections, which are welded to the beam web and bolted to the column flange, are studied to establish the effect of bolt gage distance and angle thickness. An analysis is performed to establish the moment–rotation relationship for the double angle connections and the stress distribution of each specimen is observed. They are subjected to shear loads and the elastic–perfectly plastic constitutive law is assumed. The software package ABAQUS is used to analyze the nonlinear behavior of a double angle connection. To verify the finite element model analysis, experimental tests with the same geometric and material conditions as the analysis are also conducted.

The main aim of the National Spherical Torus Experiment (NSTX) is to establish the fusion physics principles of the spherical torus (ST) concept. The NSTX device began plasma operations in February 1999 and the plasma current Ip was successfully brought up to the design value of 1 MA on 14 December 1999. The planned plasma shaping parameters, elongation κ = 1.6-2.2 and triangularity δ = 0.2-0.4, were achieved in inner wall limited, and single null and double null diverted configurations. The coaxial helicity injection (CHI) and high harmonic fast wave (HHFW) experiments were also initiated. CHI current of 27 kA produced up to 260 kA toroidal current without using an ohmic solenoid. With the injection of 2.3 MW of HHFW power, using 12 antennas connected to six transmitters, electrons were heated from a central temperature of 400 eV to 900 eV at a central density of 3.5 × 1013 cm-3, increasing the plasma energy to 59 kJ and the toroidal β, βT, to 10%. The NBI system commenced operation in September 2000. The initial results with two ion sources (PNBI = 2.8 MW) show good heating, producing a total plasma stored energy of 90 kJ corresponding to βT ≈ 18% at a plasma current of 1.1 MA.

La 0.75 M 0.25 Cr 0.75 Fe 0.25 O 3 (M = Sr, Ba) compounds are synthesized by a wet chemical method, the crystal structure of the compounds belongs to the orthorhombic system. The Mossbauer spectra of 57 Fe reveal that all the iron ions in the compounds are trivalent and in high-spin state. There is a linear relationship between the quadrupole splitting of the 57 Fe nucleus and the electronegativity of the M ion in La 0.75 M 0.25 Cr 0.75 Fe 0.25 O 3 (M = Ca, Sr, Ba). Unlike in La 1-x Sr x FeO 3 , the substitution of the divalent alkaline earth ion for the trivalent lanthanum ion does not lead to an increasing valence state of the Fe 3+ ion in La 0.75 M 0.25 Cr 0.75 Fe 0.25 O 3 (M = Sr, Ba). Doping the alkaline earth ion will more likely lead to an increasing valence state of the Cr 3+ ion.

The Korea Superconducting Tokamak Advanced Research (KSTAR) project is the major effort of the national fusion programme of the Republic of Korea. Its aim is to develop a steady state capable advanced superconducting tokamak to establish a scientific and technological basis for an attractive fusion reactor. The major parameters of the tokamak are: major radius 1.8 m, minor radius 0.5 m, toroidal field 3.5 T and plasma current 2 MA, with a strongly shaped plasma cross-section and double null divertor. The initial pulse length provided by the poloidal magnet system is 20 s, but the pulse length can be increased to 300 s through non-inductive current drive. The plasma heating and current drive system consists of neutral beams, ion cyclotron waves, lower hybrid waves and electron cyclotron waves for flexible profile control in advanced tokamak operating modes. A comprehensive set of diagnostics is planned for plasma control, performance evaluation and physics understanding. The project has completed its conceptual design and moved to the engineering design and construction phase. The target date for the first plasma is 2002.

In order to support the high-power r.f. experiments in the Hanbit large magnetic mirror device and to study low-temperature plasma processing applications, an r.f. test facility (RFTF) was constructed. The RFTF has a total chamber length of 1.5 m, maximum chamber diameter of 0.6 m and maximum magnetic field of 1.2 tesla. In the RFTF, we have studied various plasma sources such as the ICP (inductively coupled plasma), ECR (electron cyclotron resonance), Helicon and ICRH (ion cyclotron resonance heating). From these experiments, we present new experimental results related to a uniform plasma density profile. The characteristics of r.f. (4 MHz) discharges are investigated by using a double half turn antenna with a combination of limiters in a variety of the magnetic field, neutral gas pressures, and applied powers. The results show that the plasma density is uniform over the diameter of 320 mm under a density regime of 10 10 cm −3 .

Based on the recently developed heating theory (see Yoon et al., Phys. Rev. E, vol.55, no.6, p.7536-48 (1997)), a theoretical formula of E- and H-discharge transition power in a transformer-coupled plasma (TCP) discharge has been developed. The present result agrees well with an experimental observation for argon discharge.

A new tree structure called the two-level computation tree model is proposed for real time dynamic simulation of large-scale power systems. The features of the computation tree method are that the root node of the tree corresponds to a disconnected linear network, which is easy to be dealt with, and the tree leaf-nodes represent the partitioned subsystems. In the process of trajectory simulation, the correction factors of Newton type iteration are computed through a tree traversal procedure. One advantage of the new method is that the computation tasks for all subsystems can be carried out simultaneously using any parallel computation facilities. Case studies on the 10-generator New England test power system and on a representation of Northeast China power system verify the accuracy and validate the potential application of the proposed method in the real time contingency simulation for realistic large-scale power system.

High-performance concrete (HPC) is a very complex material and hence very hard to predict its compressive strength. This paper deals with building a regression model for predicting concrete's compressive strength. First of all, eight process variables are identified as determinants of Concrete Compressive Strength (CCS). These variables are Cement, Blast Furnace Slag, Fly Ash, Water, Superplasticizer, Coarse Aggregate, Fine Aggregate, and Age. Further, correlation among these variables is computed and it is found that a few of them are highly correlated. Therefore, interactions among these variables are taken into account. After that, a regression model is developed by regressing CCS against all process variables and significant interactions. Finally, diagnostics are conducted to fine tune the model and a parsimonious model is obtained with 84.37% coefficient of determination. Appropriateness of the model is investigated by testing it against unseen data points.

Summary form only given. Experiments are underway to demonstrate an amplified radiation power of 200 kW operating at 28 GHz. A long pulse operation of up to 500 msec is required for plasma heating experiments of Hanbit. A five-cavity interaction circuit is designed by the use of small signal and large signal non-linear simulation codes. Simulations predict a saturated gain of 54 dB and an electronic efficiency of 35%. An input drive cavity designed by the use of HFSS consists of a WR-28 waveguide, a TE311 single-ridged coaxial cavity, and a circular TE011 central cavity. In this high gain amplifier, an input power of less than 1 W is enough to saturate the amplifier, which is the power level available from a high power solid state power amplifier. Three penultimate cavities are loaded by lossy ceramic rings. A water cooled beam collector is designed to spread the beam over a wide surface by carefully tapering an external magnetic field. An input window which is a typical pillbox configuration is designed. Simulations predicts a bandwidth of more than 7% with a center frequency of 28 GHz at -20 dB return loss. An half wavelength thick BeO window is designed for extracting the amplified radiation power of 200 kW with a pulse length of 500 msec. Thermal analyses on ceramic loaded cavities, RF vacuum windows, beam collector performed by ANSYS are currently underway to design the tube to be operated at a duty of 50%. Cold tests of the interaction circuits are presented.

The KSTAR (Korea Superconducting Tokamak Advanced Research) project is the major effort of the Korean National Fusion Program to design, construct, and operate a steady-state-capable superconducting tokamak. The project is led by Korea Basic Science Institute and shared by national laboratories, universities, and industry along with international collaboration. It is in the conceptual design phase and aims for the first plasma by mid 2002. The key design features of KSTAR are: major radius 1.8 m, minor radius 0.5 m, toroidal field 3.5 T, plasma current 2 MA, and flexible plasma shaping (elongation 2.0; triangularity 0.8; double-null poloidal divertor). Both the toroidal and the poloidal field magnets are superconducting coils. The device is configured to be initially capable of 20 s pulse operation and then to be upgraded for operation up to 300 s with non-inductive current drive. The auxiliary heating and current drive system consists of neutral beam, ICRF, lower hybrid, and ECRF. Deuterium operation is planned with a full radiation shielding.

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).