The structure of the edge radial electric field E r inferred from the poloidal rotation velocity is compared with that of the particle and thermal transport barrier for //-mode plasmas in JFT-2M. Both E r and its gradient dE r /dr in the thermal transport barrier are found to become more negative at the L-H transition. On the other hand, dE r /dr is more positive outside of the separatrix. The shear of the radial electric field and poloidal rotation velocity in the H mode is localized within the order of an ion poloidal gyroradius near the separatrix, in the region of ion collisionality v*, ~ 20-40.PACS numbers: 52.55. Fa, 52.55.Pi, 52.70.Kz Since the //-mode plasma was discovered in ASDEX, it has been observed in many tokamaks. 2 " 0 Several theoretical models on the transition from L-mode to Hmode plasmas have been presented. 6 " 11 Recently, a radial electric field (E r ) near the plasma periphery has been found both experimentally and theoretically to play an important role in the L-H transition. 12 " 19 A more negative radial electric field was observed a few ms before the L-H transition in DIII-D (Ref. 12), and a decrease in particle transport was observed with negative E r , by driving a radial current, in the Continuous Current Tokamak. 13 Theoretical models associated with the radial electric field have been proposed to explain the L-H transition. 14 " 17 However, the predicted change of the gradient of the radial electric field (dE r /dr) is different between the models. In Shaing and Crume's model, 16 the poloidal flow velocity changes at the L-H transition and the corresponding radial electric field E r becomes more negative and dE r /dr becomes more positive, hence suppressing the fluctuations. On the other hand, Itoh and Itorfs model 17 predicts positive values of dE r /dr in the L mode and negative values of dE r /dr in the H mode, and that this negative dE r /dr reduces the banana width of the ions and the electron anomalous flux by the improved microstability. Thus it is crucial to measure the gradient or profile of the radial electric field for Land //-mode plasmas in tokamaks.In this paper we present the radial electric-field profile and temperature gradient profile a few cm inside the separatrix where the transport barrier is produced in Hmode plasmas in JFT-2M. 5 The radial electric-field profiles are inferred from poloidal and toroidal rotation velocity profiles and ion pressure profiles using the ionmomentum-balance equation, eZ { n, orwhere Z,, /?,, and n, are the ion charge, pressure, and density, B^ and B e are the toroidal and poloidal magnetic fields, and i> and v e are the toroidal and poloidal rotation velocities. The toroidal rotation velocity, ion temperature, and fully stripped carbon density profiles are measured using a multichannel charge-exchangespectroscopy technique 18,19 at Cvi 5292 A with toroidal arrays (two sets of 34 channels) with a spatial resolution of 1 cm. The poloidal rotation velocity and edge ion temperature profiles are measured using the intrinsic radiat...

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The present article describes a method that preserves circulation during the preparation of the pectoralis major myocutaneous flap used in head and neck reconstruction. The major disadvantage of this flap is its poor circulation and consequent partial necrosis. To solve this problem, we analyzed the circulation and hemodynamics of the pectoralis major myocutaneous flap (the perforator of the anterior intercostal branch located about 1 to 2 cm medial to the areola in the fourth intercostal space is important), evaluated the safe donor sites in the chest wall for a skin island (the perforator is included on the skin island's central axis), improved the surgical procedure for elevating flaps (for preventing perforator injuries), and devised a means to transfer flaps, thereby increasing the range of the flaps (the transfer route is under the clavicle). Using this technique, head and neck reconstruction was performed on 62 patients. The diagnosis included oral cancer (21), oropharyngeal carcinoma (10), parotid carcinoma (10), hypopharyngeal carcinoma (9), and other head and neck malignant tumors (12). Of these, partial or marginal necrosis of the flap caused by circulatory problems was detected in three patients (5 percent). Using our method, the problems associated with inadequate circulation in the pectoralis major myocutaneous flap were greatly alleviated, thus reconfirming the usefulness of this flap in head and neck reconstruction.