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The initial stages of gas-source growth of Si(001) using disilane have been investigated using a combination of elevated-temperature STM and atomistic modelling. The reaction pathway from the initial adsorption of disilane fragments up to the nucleation of short strings of epitaxial dimers is discussed. By the use of our STM to study disilane at the temperatures of interest, and atomistic modelling to calculate structural stability and significant activation barriers, we are able to propose a complete description of the mechanisms which underlie gas-source growth.

Background: The $^{22}\mathrm{Ne}(\ensuremath{\alpha},n)^{25}\mathrm{Mg}$ reaction is the dominant neutron source for the slow neutron capture process ($s$ process) in massive stars, and contributes, together with $^{13}\mathrm{C}(\ensuremath{\alpha},n)^{16}\mathrm{O}$, to the production of neutrons for the $s$ process in asymptotic giant branch (AGB) stars. However, the reaction is endothermic and competes directly with $^{22}\mathrm{Ne}(\ensuremath{\alpha},\ensuremath{\gamma})^{26}\mathrm{Mg}$ radiative capture. The uncertainties for both reactions are large owing to the uncertainty in the level structure of $^{26}\mathrm{Mg}$ near the $\ensuremath{\alpha}$ and neutron separation energies. These uncertainties affect the $s$-process nucleosynthesis calculations in theoretical stellar models.Purpose: Indirect studies in the past have been successful in determining the energies and the $\ensuremath{\gamma}$-ray and neutron widths of the $^{26}\mathrm{Mg}$ states in the energy region of interest. But, the high Coulomb barrier hinders a direct measurement of the resonance strengths, which are determined by the $\ensuremath{\alpha}$ widths for these states. The goal of the present experiments is to identify the critical resonance states and to precisely measure the $\ensuremath{\alpha}$ widths by $\ensuremath{\alpha}$-transfer techniques.Methods: The $\ensuremath{\alpha}$-inelastic scattering and $\ensuremath{\alpha}$-transfer measurements were performed on a solid $^{26}\mathrm{Mg}$ target and a $^{22}\mathrm{Ne}$ gas target, respectively, using the Grand Raiden Spectrometer at the Research Center for Nuclear Physics in Osaka, Japan. The $(\ensuremath{\alpha},{\ensuremath{\alpha}}^{\ensuremath{'}})$ measurements were performed at $0.{45}^{\ensuremath{\circ}}, 4.{1}^{\ensuremath{\circ}}, 8.{6}^{\ensuremath{\circ}}$, and $11.{1}^{\ensuremath{\circ}}$ and the $(^{6}\mathrm{Li},d)$ measurements at ${0}^{\ensuremath{\circ}}$ and ${10}^{\ensuremath{\circ}}$. The scattered $\ensuremath{\alpha}$ particles and deuterons were detected by the focal plane detection system consisting of multiwire drift chambers and plastic scintillators. The focal plane energy calibration allowed the study of $^{26}\mathrm{Mg}$ levels from ${E}_{x}$ = 7.69--12.06 MeV in the $(\ensuremath{\alpha},{\ensuremath{\alpha}}^{\ensuremath{'}})$ measurement and ${E}_{x}$ = 7.36--11.32 MeV in the $(^{6}\mathrm{Li},d)$ measurement.Results: Six levels (${E}_{x}$ = 10717, 10822, 10951, 11085, 11167, and 11317 keV) were observed above the $\ensuremath{\alpha}$ threshold in the region of interest (10.61--11.32 MeV). The $\ensuremath{\alpha}$ widths were calculated for these states from the experimental data. The results were used to determine the $\ensuremath{\alpha}$-capture induced reaction rates.Conclusion: The energy range above the $\ensuremath{\alpha}$ threshold in $^{26}\mathrm{Mg}$ was investigated using a high resolution spectrometer. A number of states were observed for the first time in $\ensuremath{\alpha}$-scattering and $\ensuremath{\alpha}$-transfer reactions. The excitation energies and spin-parities were determined. Good agreement is observed for previously known levels in $^{26}\mathrm{Mg}$. From the observed resonance levels the ${E}_{x}$ = 10717 keV state has a negligible contribution to the $\ensuremath{\alpha}$-induced reaction rates. The rates are dominated in both reaction channels by the resonance contributions of the states at ${E}_{x}$ = 10951, 11167, and 11317 keV. The ${E}_{x}$ = 11167 keV state has the most appreciable impact on the $(\ensuremath{\alpha},\ensuremath{\gamma})$ rate and therefore plays an important role in the prediction of the neutron production in $s$-process environments.

A candidate resonant tetraneutron state is found in the missing-mass spectrum obtained in the double-charge-exchange reaction ^{4}He(^{8}He,^{8}Be) at 186 MeV/u. The energy of the state is 0.83±0.65(stat)±1.25(syst) MeV above the threshold of four-neutron decay with a significance level of 4.9σ. Utilizing the large positive Q value of the (^{8}He,^{8}Be) reaction, an almost recoilless condition of the four-neutron system was achieved so as to obtain a weakly interacting four-neutron system efficiently.

We have measured the energy spectrum of pionic 121Sn atoms by missing-mass spectroscopy of the 122Sn(d, 3He) reaction near the π − emission threshold. The measurement serves as a pilot experiment for high precision systematic spectroscopy of deeply bound pionic atoms in a new pionic Atom Factory project (piAF) at the RI beam factory (RIBF) of RIKEN. The status of the analysis is reported.

With the aim of clarifying roles of the 3NFs in nuclei experimental programs with the polarized deuteron beam at intermediate energies are in progress at RIKEN RI Beam Factory. As the first step, we have measured a complete set of deuteron analyzing powers in deuteron–proton elastic scattering at 250 and 294 MeV/nucleon. The obtained data are compared with the Faddeev calculations based on the modern nucleon–nucleon forces together with the Tucson–Melbourne’99, and UrbanaIX three nucleon forces.

In a practical motor, the compressive stress of more than 100 MPa is sometimes impressed by a shrink fitting etc, as a result, the magnetic properties of iron core deteriorate. Therefore, it is necessary to measure magnetic properties under the compressive stress. However, the measurement under the compressive stress of more than 100 MPa is difficult if a single sheet tester is used, because of the buckling of a single sheet specimen. Then, we measured the magnetic properties under the compressive stress up to 150 MPa without buckling by using a laminated specimen. It is shown that the permeability rapidly decreases even by small stress in both cases of rolling and transverse directions. The iron loss is increased by the stress, but it almost does not increase when the stress is larger than about 50 MPa. Furthermore, the permeability and iron losses of the rolling direction and transverse direction become the same values, and the anisotropy disappears when the stress is larger than about 50 MPa.

We performed the stress analysis of a SPM motor core with the shrink fitting, and calculated the iron loss by FEM using the B-H curve and iron loss measured under a compressive stress. We examined the effect of shrink fitting on iron loss of an actual motor and the validity of the estimation of the iron loss by FEM analysis using the measured properties affected by the stress. It is shown that the magnetic properties under the compressive stress should be considered for the precise estimation of the iron loss in a motor with the shrink fitting.

Este estudo procurou investigar a utilização de polímeros para condicionamento de lodo de ETE para desidratação em filtro prensa de placa e verificar as eventuais vantagens em relação ao condicionamento com cal e cloreto férrico. Para isso foram realizadas pesquisa bibliográfica, consulta a fornecedores de polímeros e de equipamentos e trabalhos experimentais em laboratório e em escala piloto com lodo gerado nos digestores anaeróbios da ETE Barueri da SABESP que mostrava interesse em fazer o condicionamento do lodo com polímeros. Atualmente, na ETE Barueri o condicionamento de lodo é feito com cal e cloreto férrico, com dosagens em torno de 25% e 10% respectivamente e a desidratação em filtro prensa de placas, com tempo de ciclo de 4 horas, produz tortas com 40% de teor de sólidos e densidade de 1,20 kg/L. Nos experimentos foram utilizados polímeros catiônicos de alto peso molecular. O equipamento piloto utilizado foi um filtro prensa de placa do tipo membrana diafragma com dez placas de 800 x 800 mm. Nos ensaios do filtro prensa piloto, com a utilização de polímero em pó para o condicionamento de lodo, indicou-se uma redução nos custos de produtos químicos consumidos em relação ao condicionamento com cal e cloreto férrico. O condicionamento com polímero em pó e cloreto férrico, com dosagens respectivamente de 4,83 kg/ton e 6,3%, resultou numa torta com teor de sólidos de 31% e densidade de 1,13 kg/L. Já o condicionamento feito somente com polímero em pó, com dosagem de 5,38 kg/ton, resultou numa torta com teor de sólidos de 30% e densidade de 1,08 kg/L, porém apresentou problemas na soltura das tortas. A utilização de polímeros permitiu trabalhar em taxas iniciais de filtração mais altas, resultando num tempo de filtração em torno de 120 minutos, implicando em tempos de ciclo mais curtos. This study investigated the utilization of polymers for the conditioning of the sludge generated at Wastewater Treatment Plants (WTP) for dewatering at filter presses, verifying the eventual advantages in comparison with the conditioning with lime and ferric chloride. Specific bibliography was researched, polymer and equipment suppliers were consulted and experimental studies were carried out at the laboratory and in a pilot scale. The sludge was generated at the anaerobic digesters of Barueri WTP operated by SABESP which has shown interest in this method. Currently, at Barueri WTP the sludge conditioning is performed with lime and ferric chloride at dosages around 25% and 10%, respectively. The dewatering is processed by filter presses during a cycle period of 4 hours, producing cakes with 40% of solids and a density of 1,20 kg/L. The experimental studies were carried out with high molecular weight cationic polymers. The pilot equipment consisted of a filter press with a diaphragm membrane with 10 plates measuring 800 x 800 mm each. During the tests at the pilot filter press, when dry polymers for sludge conditioning were utilized, it was verified that the cost of chemical products consumed was reduced in comparison with the conditioning with lime and ferric chloride. The sludge conditioning with dry polymers and ferric chloride at respective dosages of 4,83 kg/ton and 6,3% resulted in cakes with 31% of solids and density of 1,38 kg/L. On the other hand, the sludge conditioned only with dry polymers at a dosage of 5,38 kg/ton resulted in cakes with 30% of solids and density of 1,08 kg/L, but the cake release from the plates was difficult. The utilization of polymers allowed higher initial filtration rates resulting in a 120 minute filtration period with a consequent reduction of the cycle time.

Jet production rates are measured in p+p and d+Au collisions at sqrt[s_{NN}]=200 GeV recorded in 2008 with the PHENIX detector at the Relativistic Heavy Ion Collider. Jets are reconstructed using the R=0.3 anti-k_{t} algorithm from energy deposits in the electromagnetic calorimeter and charged tracks in multiwire proportional chambers, and the jet transverse momentum (p_{T}) spectra are corrected for the detector response. Spectra are reported for jets with 12p_{T}50 GeV/c, within a pseudorapidity acceptance of |η|0.3. The nuclear-modification factor (R_{dAu}) values for 0%-100% d+Au events are found to be consistent with unity, constraining the role of initial state effects on jet production. However, the centrality-selected R_{dAu} values and central-to-peripheral ratios (R_{CP}) show large, p_{T}-dependent deviations from unity, challenging the conventional models that relate hard-process rates and soft-particle production in collisions involving nuclei.

A candidate resonant tetraneutron state is found in the missing-mass spectrum obtained in the double-charge-exchange reaction ^{4}He(^{8}He,^{8}Be) at 186 MeV/u. The energy of the state is 0.83±0.65(stat)±1.25(syst) MeV above the threshold of four-neutron decay with a significance level of 4.9σ. Utilizing the large positive Q value of the (^{8}He,^{8}Be) reaction, an almost recoilless condition of the four-neutron system was achieved so as to obtain a weakly interacting four-neutron system efficiently.

With the aim of clarifying roles of the 3NFs in nuclei experimental programs with the polarized deuteron beam at intermediate energies are in progress at RIKEN RI Beam Factory. As the first step, we have measured a complete set of deuteron analyzing powers in deuteron–proton elastic scattering at 250 and 294 MeV/nucleon. The obtained data are compared with the Faddeev calculations based on the modern nucleon–nucleon forces together with the Tucson–Melbourne’99, and UrbanaIX three nucleon forces.

© 2015 AIP Publishing LLC. The links between the microscopic dynamics and macroscopic threshold physics of the L → H transition are elucidated. Emphasis is placed on understanding the physics of power threshold scalings, and especially on understanding the minimum in the power threshold as a function of density Pthr (n). By extending a numerical 1D model to evolve both electron and ion temperatures, including collisional coupling, we find that the decrease in Pthr (n) along the low-density branch is due to the combination of an increase in collisional electron-to-ion energy transfer and an increase in the heating fraction coupled to the ions. Both processes strengthen the edge diamagnetic electric field needed to lock in the mean electric field shear for the L → H transition. The increase in Pthr (n) along the high-density branch is due to the increase with ion collisionality of damping of turbulence-driven shear flows. Turbulence driven shear flows are needed to trigger the transition by extracting energy from the turbulence. Thus, we identify the critical transition physics components of the separatrix ion heat flux and the zonal flow excitation. The model reveals a power threshold minimum in density scans as a crossover between the threshold decrease supported by an increase in heat fraction received by ions (directly or indirectly, from electrons) and a threshold increase, supported by the rise in shear flow damping. The electron/ion heating mix emerges as important to the transition, in that it, together with electron-ion coupling, regulates the edge diamagnetic electric field shear. The importance of possible collisionless electron-ion heat transfer processes is explained.

We propose to measure the γ-ray emission probability from excited states above 5 MeV including giant resonance of 16O and 12C as a function of excitation energy in 1-MeV step. Here, we measure both the excitation energy (Ex=5-30MeV) at the forward scattering angles (0°-3°) of the 16O, 12C (p, p’) reaction using Grand-Raiden Spectrometer and the energy of γ-rays (Eγ) using an array of NaI(Tl) counters. The purpose of the experiment is to provide the basic and important information not only for the γ-ray production from primary neutral-current neutrino-oxygen (-carbon) interactions but also for that from the secondary hadronic (neutron-oxygen and -carbon) interactions.

A commercial serodiagnostic kit for diagnosing pulmonary disease due to Mycobacterium avium complex (MAC-PD) was developed and launched in Japan in 2011.To evaluate the performance of this kit in routine clinical settings.In this retrospective single-centre study, data on serum levels of anti-glycopeptidolipid (GPL) core IgA antibody (U/ml) measured using the kit were analysed in patients diagnosed with MAC-PD according to American Thoracic Society criteria, in those with pulmonary tuberculosis (PTB) or pulmonary M. kansasii disease and in healthy volunteers.The anti-GPL-core IgA antibody levels of serum were significantly higher (P0.0001) in patients with MAC-PD (n = 485) than in those with PTB (n = 133) or pulmonary M. kansasii disease (n = 23) or in healthy subjects (n = 265). When the cut-off level was set at 0.7 U/ml, the sensitivity and specificity were respectively 78.6% and 96.9%. Higher antibody levels were observed in patients with greater extent of disease on chest computed tomography (P0.0001).The serodiagnostic kit revealed good sensitivity and specificity. The antibody levels may reflect disease activity. Additional work is needed to determine whether the diagnostic assay could be used in conjunction with current diagnostic criteria to improve the diagnosis of MAC-PD.

1D indium islands have been formed by epitaxial growth on a self-assembled template. The templates are formed from Bi nanolines, which are 1.5 nm wide, and can be over 500 nm in length. The islands conform to the template width and are over 100 nm long. The first layer of the island forms a novel chain structure of In and Bi atoms, which accounts for the epitaxial growth of the nanocrystals on the template. The second layer shows a hexagonal structure 19 A or 2.5 dimer rows wide. Epitaxial growth saturates after two layers of In have been deposited. With further deposition, a transition to the growth of 3D In droplets is observed.

We report two patients exhibiting complete polymetatarsia between the fourth and fifth metatarsals of the right foot, without supernumerary digit. To our knowledge, only a few cases of polymetatarsia without supernumerary digit have been reported, and all of those cases have involved incomplete duplication. Although there were no externally visible deformities in the present cases, plain radiographs revealed an extra bone between the fourth and fifth metatarsals. Case 1 presented with pain between the fourth and fifth metatarsals, and this pain ceased after resection of the extra metatarsal. Although case 2 was asymptomatic, the extra metatarsal of the left foot was resected during surgery for postaxial polydactyly of the right foot. Although differential diagnosis with os intermetatarseum was problematic, we concluded that the extra bones in the present cases were duplicated metatarsals, rather than accessory bones, based on three clinical findings: configuration of the extra metatarsal (articular cartilage and growth plate), in case 1; location of extra metatarsal (the most common site of polydactyly of the foot), in both cases; and polydactyly of the opposite foot, in case 2.

We thank Drs Echavarria-Pinto and Escaned1 for their interest in our article.2 To analyze coronary blood flow pattern, thermodilution curves need to be obtained by brisk injection of 3 mL of room temperature saline by hand into the coronary artery through the guiding catheter at steady-state hyperemia.3 As pointed by Drs Echavarria-Pinto and Escaned,1 however, the shape of thermodilution …

Charged-pion-interferometry measurements were made with respect to the second- and third-order event plane for Au+Au collisions at sqrt[s_{NN}]=200 GeV. A strong azimuthal-angle dependence of the extracted Gaussian-source radii was observed with respect to both the second- and third-order event planes. The results for the second-order dependence indicate that the initial eccentricity is reduced during the medium evolution, which is consistent with previous results. In contrast, the results for the third-order dependence indicate that the initial triangular shape is significantly reduced and potentially reversed by the end of the medium evolution, and that the third-order oscillations are largely dominated by the dynamical effects from triangular flow.

25th International Nuclear Physics Conference, Florence, Italy, 2 Jun 2013 - 7 Jun 2013; The European physical journal / Web of Conferences Web of Conferences : proceedings proceedings 66, 09014 (2014). doi:10.1051/epjconf/20146609014, Published by EDP Sciences, Les Ulis

A complete high-precision set of deuteron analyzing powers for elastic deuteron-proton (dp) scattering at 250 and 294 MeV/nucleon has been measured. These data and previously existing data sets for the cross section at similar energies are compared to the results of three-nucleon Faddeev calculations based on modern nucleon-nucleon (NN) potentials alone or combined with two models of three-nucleon forces: the Tucson-Melbourne 99 and Urbana IX. Large discrepancies between pure NN theory and data, which are not resolved by the current three-nucleon forces, were found at c.m. backward angles θc.m.≳120∘ for all the deuteron analyzing powers and the cross section. Because only small relativistic effects were found for the deuteron analyzing powers and the cross section, the inclusion of short-range components of the three-nucleon force is probably required to get a better description of the data.

© 2014 IAEA, Vienna. The turbulence and flows at the plasma edge during the L-I-H, L-I-L and single-step L-H transitions have been measured directly using two reciprocating Langmuir probe systems at the outer midplane with several newly designed probe arrays in the EAST superconducting tokamak. The E× B velocity, turbulence level and turbulent Reynolds stress at ∼1cm inside the separatrix ramp-up in the last ∼20ms preceding the single-step L-H transition, but remain nearly constant near the separatrix, indicating an increase in the radial gradients at the plasma edge. The kinetic energy transfer rate from the edge turbulence to the E×B flows is significantly enhanced only in the last ∼10ms and peaks just prior to the L-H transition. The E×B velocity measured inside the separatrix, which is typically in the electron diamagnetic drift direction in the L-mode, decays towards the ion diamagnetic drift direction in response to fluctuation suppression at the onset of the single-step L-H, L-I-L as well as L-I-H transitions. One important distinction between the L-I-H and the L-I-L transitions has been observed, with respect to the evolution of the edge pressure gradient and mean E×B flow during the I-phase. Both of them ramp up gradually during the L-I-H transition, but change little during the L-I-L transition, which may indicate that a gradual buildup of the edge pedestal and mean E×B flow during the I-phase leads to the final transition into the H-mode. In addition, the transition data in EAST strongly suggest that the divertor pumping capability is an important ingredient in determining the transition behaviour and power threshold.

Our experimental goal is to study the non-resonant triple alpha reaction rate at low temperture (T < 108 K). The 13C(p,d) reaction at 66 MeV has been used to probe the alpha-unbound continuum state in 12C just below the 2nd 0+ state at 7.65 MeV. The transition strength to the continuum state is predicted to be sensitive to the non-resonant triple alpha reaction rate. The experiment has been performed at iThemba LABS. We report the present status of the experiment.

2nd FAIR NExt generation ScientistS, Berlin, Germany, 16 Sep 2013 - 21 Sep 2013; Journal of physics / Conference Series Conference Series 503, 012037 (2014). doi:10.1088/1742-6596/503/1/012037, The spectroscopy of deeply bound pionic atoms provides a way to understand the restoration of chiral symmetry breaking at finite density. We have been performing a series of experiments of missing-mass spectroscopy of the (d,3He) reaction at RIBF to investigate pionic atoms of several Sn isotopes. As a first step, we conducted a pilot experiment to measure deeply bound pionic states of 121Sn and successfully observed the deeply bound pionic states. In addition to the experiment at RIBF, we are planning the spectroscopy of deeply bound pionic atoms in inverse kinematics and conducted a feasible study by simulations. We showed that by using a deuterium gaseous active target TPC and silicon detectors, the Q-value resolution is about 500 keV (FWHM) and the yield of the pionic 1s state is 20 counts/day, indicating the experiment is feasible., Published by IOP Publ., Bristol

Transitions between low (L-mode) and intermediate (I-phase) confinement regimes triggered by sawteeth are investigated using multiple Langmuir probe arrays in the edge plasmas of the HL-2A tokamak. The I-phase is characterized by limit-cycle oscillations (LCOs). Repeated L-I-L transitions induced by sawtooth heat pulses are also observed. Statistical analyses show that the delay time of the L-I transition relative to sawtooth crashes is less than ∼1 ms. The intensity of turbulence bursts in the I-phase is stronger than those observed in L-mode plasmas. Measurements are consistent with zonal flow reducing turbulence intensity in the frequency band ∼20-100 kHz, while the LCO turbulence of frequency higher than 100 kHz has more power than that in the L-mode. The analyses of time-resolved power transfers between turbulence and zonal flows suggest that power transfers exist between turbulence and zonal flows. The direction of the power transfers is from turbulence into geodesic acoustic modes in ohmic plasmas. © 2013 IAEA, Vienna.

Tensile tests were performed in Al–Bi alloys in order to show experimental evidences of elongation enhancement by a liquid phase and to understand its underlying causes. Peak elongation of 150–200% was obtained above the melting temperature (539 K) of Bi dispersoids, indicating that the liquid phase can enhance tensile elongation. It was found that homogeneous dispersion of liquid needs to be maintained during deformation. Otherwise, the liquid phase would agglomerate along perpendicular grain boundaries to the tensile axis, causing grain-boundary fracture. When elongation enhancement by the liquid phase was observed, the dislocation density was low and the cavity volume fraction increased slowly, resulting in the delay of cavitation failure. The role of the liquid phase on elongation enhancement was considered to be accommodation of stress concentration and delay in cavitation.

Structures of the ‘nanowire’ and 2× n phase of the submonolayer system of Bi/Si(001) have been studied by X-ray photoelectron diffraction (XPD). The general features of Bi 4d XPD patterns show that Bi atoms exist only at the topmost layer for the two phases. Single-scattering cluster simulations were performed for several structural models, including those for the ‘nanowire’ [Miki et al., Phys. Rev. B 59 (1999) 14 868] and for the 2× n phase [Hanada et al., Surf. Sci. 242 (1991) 137], to find they are very feasible.

When retinoic acid-primed F9 cells are allowed to aggregate, they form embryoid bodies with an outer layer of (α)-fetoprotein-producing visceral endoderm cells and an internal cavity. I show that maturation of the visceral endoderm is dependent on the size of F9 aggregates. Size fractionation of aggregates of retinoic acid-primed F9 cells on Percoll density gradients revealed that only aggregates with diameters larger than 180 microm developed into embryoid bodies with an endoderm layer secreting (α)-fetoprotein. Size dependent alpha-fetoprotein-secretion was also observed when retinoic acid-primed F9 cells were cultured on porous microcarrier beads larger than 185 microm. Retinoic acid-primed F9 cells on flat microporous membranes did not differentiate and secrete alpha-fetoprotein unless exposed to a limited volume of medium at their basolateral surface. This suggested that maturation of the visceral endoderm is signaled by the volume of liquid phase below the epithelium. I postulate that the epithelial layer of an F9 aggregate encloses liquid and forms a barrier to diffusion of some critical factor(s). The concentration of such a factor may reach a threshold due to enlargement of the liquid phase during growth of the F9 aggregate and thereby signal maturation of the outer layer of cells into visceral endoderm.

Atomically perfect bismuth lines form on Si(001) by a selective desorption process around the temperature at which most of the bismuth desorbs from bismuth epitaxial layers. The lines are perpendicular to the silicon dimer rows; they are 1 nm wide and can be hundreds of nm long in a flat Si(001) surface. They are utterly free of kinks or other defects. In our proposed model three silicon dimers in the surface are replaced with two Bi dimers, with a rebonded missing dimer defect between them. It is suggested that the lines are straight because of kinetic reasons rather than thermodynamic ones -- they form straight and are unable subsequently to kink.

As a measurement of the level of anxiety in psychiatric outpatients with anxiety, we determined the saliva level of free 3-methoxy-4-hydroxyphenyleglycol (MHPG) using gas chromatography- mass spectrometry and scored the levels of anxiety with the Hamilton Anxiety Scale (HAS) in patients, before and after drug treatment with alprazolam for 1 week. The saliva level of free-MHPG at first visit to hospital was significantly higher than that of control individuals and disease control individuals and was reduced by alprazolam treatment for 1 week. There was no correlation between MHPG level and the HAS score at the first hospital visit. The MHPG levels after treatment correlated with the HAS scores. The reduction of the anxiety level as scored by the HAS correlated with the reduction of MHPG level. These results indicate that the free saliva MHPG level may be a useful indicator for assessing not only the level of anxiety, but also the response to drug treatment for anxiety in these patients.

Inclusions of liquid phase are generally considered to cause liquid-metal embrittlement. On the other hand, there have been some reports implying the enhancement of tensile elongation by liquid inclusions. In this paper, the possibility of elongation enhancement by liquid and its underlying mechanism were investigated in a model binary system of Al-Bi and a composite of (Al-Mg)- Si3N4. Clear evidence of elongation enhancement was observed in the Al-Bi alloy. Liquid inclusions of Bi were found to assist stress accommodation processes and to delay cavitation failure. In the (Al-Mg)-Si3N4 composite, a close correlation was found between the incipient melting temperature and an optimum temperature for high-strain-rate superplasticity. The liquid phase was observed along grain boundaries and interfaces of the composite, suggesting a similar stress accommodation process to that of the Al-Bi alloy. The interface microstructure was also studied by high-resolution transmission electron microscopy to under...

An understanding of the diffusion of hydrogen on Si(001) is important in the gas-source growth of silicon and silicon-germanium alloys. We have imaged the saturated monohydride surface between 600 and 700 K using an elevated-temperature scanning tunneling microscope (STM), and have observed the concerted diffusion of pairs of hydrogen atoms along the dimer rows. The barrier for this process has been estimated from the STM data to be $1.95\ifmmode\pm\else\textpm\fi{}0.2\mathrm{eV}.$ Using our experimental images, we have narrowed down the mechanism to two possible routes, which we have modeled with tight binding. Only one of these routes has a barrier (1.98 eV) which is consistent with the experiment, leading to a conclusive identification of the diffusion mechanism.

Tensile properties of an Al-3.4mass% Bi alloy up to 700 K were studied to understand the effects of the liquid Bi phase. Strain-rate sensitivity near the melting point of Bi was found to take values in a range of 0.17–0.31. Elongation showed a maximum value slightly above the melting temperature, indicating that the liquid phase could enhance tensile elongation in the Al-Bi alloy. Above the melting temperature, the dislocation density was found to decrease and the increment of the cavity volume fraction with strain slowed down in comparison to the results below the melting temperature. The increase of the tensile elongation was attributed to an efficient stress accommodation mechanism provided by the liquid phase.

A novel structure has been observed by scanning tunneling microscopy (STM) on the Si(001) surface after exposure to disilane between 400 and 600 K. The feature is a bright square, with dark lines running across it forming a cross. The proposed structure, a ring of four silicon atoms bonded together and connected by one back-bond per atom to the underlying silicon dimers, has been modelled using tight-binding and density functional theory (DFT) calculations. This ring has been found to be energetically stable with respect to isolated ad-dimers. As it is the first feature to form from disilane fragments with increasing temperature, and its local bonding configuration is very similar to the rebonded B-type step edge which is known to be the favoured adsorption site for epitaxial growth, it may play a crucial role as the nucleus of the new epitaxial layer during gas-source growth of silicon.

Metalorganic molecular beam etching of GaSb using trisdimethylaminoantimony (TDMASb) and triisopropylantimony (TIPSb) is studied. When non-precracked TDMASb or TIPSb alone is supplied, reflection high-energy electron diffraction (RHEED) intensity oscillation is observed, indicating the monolayer-by-monolayer etching. Etching rate of GaSb by TDMASb is highest compared with those of GaAs, InP and GaP, corresponding to the weakest bond strength of GaSb. When the substrate temperature is decreased, the surface reconstruction is changed from (1 × 3) pattern to (1 × 5) due to the increase in the surface coverage of Sb. Activation energy for etching rate is simultaneously increased from 1.7 to 2.1 eV for TDMASb and from 1.1 to 1.8 eV for TIPSb, indicating that the etching process is affected by the surface coverage of Sb. Quadrupole mass spectroscopy measurement shows that isopropyl radicals are stable in high vacuum condition. It is considered that isopropyl-groups released from TIPSb molecules react with surface atoms and etch them. TIPSb is completely decomposed at around 380°C, while TDMASb at around 300°C, indicating that TDMASb easily releases much Sb atoms than TIPSb does. This leads to the larger activation energy for etching by TDMASb.

We report on model studies of stimulated L → H transitions [K. Miki et al., Phys. Rev. Lett. 110, 195002 (2013)]. These studies use a reduced mesoscale model. Model studies reveal that L → H transition can be triggered by particle injection into a subcritical state (i.e., P

We present results for three charmonia states (ψ', χc, and J/ψ) in d+Au collisions at |y|0.35 and sqrt[s(NN)]=200 GeV. We find that the modification of the ψ' yield relative to that of the J/ψ scales approximately with charged particle multiplicity at midrapidity across p+A, d+Au, and A+A results from the Super Proton Synchrotron and the Relativistic Heavy Ion Collider. In large-impact-parameter collisions we observe a similar suppression for the ψ' and J/ψ, while in small-impact-parameter collisions the more weakly bound ψ' is more strongly suppressed. Owing to the short time spent traversing the Au nucleus, the larger ψ' suppression in central events is not explained by an increase of the nuclear absorption owing to meson formation time effects.

International audience; Since ITER will operate close to threshold and with limited control, the H → L back transition is a topic important for machine operations as well as physics. Using a reduced mesoscale model [Miki et al., Phys. Plasmas 19, 092306 (2012)], we investigate ELM-free H → L back transition dynamics in order to isolate transport physics effects. Model studies indicate that turbulence spreading is the key process which triggers the back transition. The transition involves a feedback loop linking turbulence and profiles. The I-phase appears during the back transition following a slow power ramp down, while fast ramp-downs reveal a single burst of zonal flow during the back transition. The I-phase nucleates at the pedestal shoulder, as this is the site of the residual turbulence in H-mode. Hysteresis in the profile gradient scale length is characterized by the Nusselt number, where Nu = χi,turb/χi,neo. Relative hysteresis of temperature gradient vs density gradient is sensitive to the pedestal Prandtl number, where Prped = Dped/χi,neo. We expect the H-mode to be somewhat more resilient in density than in temperature.

International audience; We report on model studies of stimulated L→H transitions. These studies use a novel reduced mesoscale model. Studies reveal that L→H transitions can be triggered by particle injection into a subcritical state (i.e., P

Determination of intestinal permeability by measuring nonmetabolized sugars has been used to assess the integrity of intestinal mucosa. We have developed and validated a modified HPLC method for determining the concentration of L-rhamnose, mannitol, and lactulose in urine, using an amine-modified silica column and refractive index detection. Probe sugars are simultaneously resolved within 18 min. The calibration curve for each sugar is linear to 20 mmol/L. The minimum detectable concentration of lactulose is 0.05 mmol/L. Recovery of probe sugars is between 99.3% and 105.1%. Overall precision (CV) of estimation of probe sugars ranges from 4.2% to 6.5%. In 14 urine samples from healthy children who ingested the test solution containing 1 g of L-rhamnose, 1 g of mannitol, and 5 g of lactulose, the 5-h urinary excretion ratios of lactulose/rhamnose and lactulose/mannitol were 0.047 +/- 0.018 and 0.021 +/- 0.010 (mean +/- SD), respectively. This method presents a rapid, convenient, and practical technique for determining intestinal permeability in clinical pediatric practice.