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The main ring (MR) of the Japan Proton Accelerator Research Complex (J-PARC) is a high-intensity proton synchrotron that supplies proton beams for the long-baseline neutrino experiment, called the Tokai to Kamioka (T2K). To satisfy the experimental condition for the T2K, the increase in the present beam power of 450 kW to 750 kW and beyond is mandatory. The scheme of the high-repetition-rate operation is adopted for the MR upgrade. The repetition cycle is planned to be shortened from 2.48 s at present to 1.28 s in this scheme. This upgrade involves the increase in the power variation of the electrical system. To suppress the power variation, an energy storage that consists of capacitor banks (CBs) was developed and installed in the power supply of the main magnets, since the main magnets are the primary source of power variation. The CB was designed with a sufficient consideration to avoid serious failures. The number of fuses were installed in the CB to avoid energy concentration on a short-circuited capacitor. The scheme for the safe dissipation of the concentrated energy was also employed. A fuse arcing test was carried out to clearly show the fuse reliability since the CB safety is strongly dependent upon the fuses.

The parallel operation of plural undulator beam lines is an important means of improving the efficiency and usability of x-ray free-electron laser facilities. After the installation of a second undulator beam line (BL2) at SPring-8 Angstrom compact free-electron laser (SACLA), pulse-by-pulse switching between two beam lines was tested using kicker and dc twin-septum magnets. To maintain a compact size, all undulator beam lines at SACLA are designed to be placed within the same undulator hall located downstream of the accelerator. In order to ensure broad tunability of the laser wavelength, the electron bunches are accelerated to different beam energies optimized for the wavelengths of each beam line. In the demonstration, the 30 Hz electron beam was alternately deflected to two beam lines and simultaneous lasing was achieved with 15 Hz at each beam line. Since the electron beam was deflected twice by 3° in a dogleg to BL2, the coherent synchrotron radiation (CSR) effects became non-negligible. Currently in a wavelength range of 4–10 keV, a laser pulse energy of 100–150 μJ can be obtained with a reduced peak current of around 1 kA by alleviating the CSR effects. This paper reports the results and operational issues related to the multi-beam-line operation of SACLA.

One of the most important matters in keeping membrane structures in healthy condition is to maintain the proper tension distribution over the membrane. However, it is not easy to know the real stress level in the membrane quantitatively after completion of the structures. The authors proposed a new method that can measure membrane stresses in two different directions separately using sound waves –instead of measuring the membrane stresses directly. In this paper, various problems in the downsizing of measurement equipment and reduction of measurement time for practical application are examined, and clarified both theoretically and experimentally. In addition, not only the experimental tests using the membrane material of PTFE coated glass fabric as well as ETFE film with various combinations of the membrane stress, but also the actual measurement for existing suspension structure covered with ETFE film is carried out for practical use. The results verify the developed equipment can be used to continue measurement as a tool for scientifically and quantitatively determining the membrane stress which exists in the membrane material of the actual membrane structures.

A concise total synthesis of the 11-membered cyclic (+)-aspercyclide C is reported. Key to success was the fine-tuning of the reaction media to realize an oxidative, macrocyclic diaryl C–O bond for...

In a design criterion of a nonrigid airship, such as FAA-P-8110-2, Airship Design Criteria, it is specified to measure the tear strength of the envelope material. However, the tear strength itself has no definite relationship with the actual tear propagation characteristics of an airship envelope material. Therefore, there are several investigations to establish the relationship. To study it, tests are conducted to measure the tear propagation stress to find the appropriate formula. To simulate the actual stress field, two kinds of tests are carried out: a biaxial tensile test and a pressurized cylinder test. Both tests simulate the biaxial stress field on an airship envelope. The material tested is the high-strength and lightweight envelope material, Z2929T-AB. This is one of the envelope materials with Zylon as its base fabric and is developed especially for the technology demonstrator of a stratospheric platform. This material has a density as low as 157 g/m 2 ; nevertheless, the tensile strength is as high as 997 N/cm. The measurement is made to find the stress that initiates the tear propagation. The data are fitted to Thiele's formula and the correlation is excellent. By using Thiele's empirical equation, the minimum slit size of the tear propagation under the limit stress is estimated. For the technology demonstrator of the stratospheric platform, which is planned to have an overall length of 150 m and the maximum diameter of 38 m, the slit size of less than 40 mm does not allow tear propagation under the limit load. The consideration of the stress field near the slit introduces a different approach for the empirical formula, and this leads to the equation which correlates very well the tear propagation stress with the tensile strength of the envelope material. These two results are described, as well as the test details.

In this paper, we describe the structure analysis by the finite element method of the gas-inflatable membrane structure with initial shape before pressure loading, on the assumption of the structure analysis of the gas-inflatable membrane reflector. The initial shape is assumed to be a paraboloid of revolution or similar shape. In the finite element formulation, to consider the influence of the initial shape, the strain based on the extensional strain is introduced. The experiment is also conducted to compare with the numerical calculation result. The agreement of the experiment result and the numerical result shows that our finite element formulation is appropriate.

A highly efficient total synthesis of the 11-membered cyclic aspercyclides A (1) and B (2) has been achieved by chemo- and regioselective intramolecular oxidative C-O bond formation from differently substituted diphenols.

The present paper proposes and discusses a new formulation of continuum constitutive equations for fabric membranes for architecture. The formulation is based on a fabric lattice model where the structure of the fabric membranes is replaced into an equivalent structure composed of truss bars representing yarns and coated materials. The equations consider the material nonlinearities of yarns and coatings and include crimp interchange between warps and wefts. Since the equations are formulated in an incremental form in terms of in-plane strains, the formulations can be directly applied to FEM analysis of the fabric membranes. The validity of the proposed constitutive equations is discussed by comparing the simulated results with those obtained by testing the materials under uni-axial, bi-axial and shear loadings.

Degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was examined together with nitrogen conversion by using an activated sludge acclimated to artificial sewage containing 2,4-D and urea-N, which were the sole carbon and nitrogen sources, respevtively. Ammonification of urea and nitrification of ammonia proceeded concurrently with 2,4-D degradation by the acclimated activated sludge.

In a design criterion of a nonrigid airship, such as FAA-P-8110-2, Airship Design Criteria, it is specified to measure the tear strength of the envelope material. However, the tear strength itself has no definite relationship with the actual tear propagation characteristics of an airship envelope material. Therefore, there are several investigations to establish the relationship. To study it, tests are conducted to measure the tear propagation stress to find the appropriate formula. To simulate the actual stress field, two kinds of tests are carried out: a biaxial tensile test and a pressurized cylinder test. Both tests simulate the biaxial stress field on an airship envelope. The material tested is the high-strength and lightweight envelope material, Z2929T-AB. This is one of the envelope materials with Zylon as its base fabric and is developed especially for the technology demonstrator of a stratospheric platform. This material has a density as low as 157 g/m 2 ; nevertheless, the tensile strength is as high as 997 N/cm. The measurement is made to find the stress that initiates the tear propagation. The data are fitted to Thiele's formula and the correlation is excellent. By using Thiele's empirical equation, the minimum slit size of the tear propagation under the limit stress is estimated. For the technology demonstrator of the stratospheric platform, which is planned to have an overall length of 150 m and the maximum diameter of 38 m, the slit size of less than 40 mm does not allow tear propagation under the limit load. The consideration of the stress field near the slit introduces a different approach for the empirical formula, and this leads to the equation which correlates very well the tear propagation stress with the tensile strength of the envelope material. These two results are described, as well as the test details.

ETFE membrane film structures are often realized in construction. Because ETFE film is a kind of polymer materials, it shows both elasto-plastic and visco-elastic characteristics. Using FEM and experimental results of ETFE film, the authors developed the constitutive equation. First to investigate the elasto-plastic characteristics of ETFE, a biaxial tensile test was carried out. The elasto-plastic characteristics are formulated adopting the von Mises criterion under biaxial stresses. FEM analysis of the test of rectangular ETFE cushion under pressure showed the validity in presenting ETFE behaviour based on the proposed constitutive equation. Then to investigate the viscoelastic properties, an incremental formula of the constitutive equation was extended and introduced to FEM analysis. The test showed that uniaxial creep properties can be presented using the proposed constitutive equation. Furthermore, to present biaxial creep properties, the incremental form of the constitutive equation was extended and the confirmation was given for its validity In this paper, also to investigate temperature dependency of the elasto-plastic characteristic, the following points are focused on: 1. Under multiple temperature conditions, uniaxial and biaxial tensile tests as well as creep testes are carried out. 2. To include these properties, an incremental form of the constitutive equation is presented. 3. Confirmation of the validity of the proposed constitutive equation is given.