Modified reverse tapering method to prevent frequency shift of the radiation in the planar undulator

This paper presents a modified reverse tapering method to generate a polarized soft x ray in x-ray free-electron lasers (XFELs) with a higher photon power and a shorter undulator length than the simple linear reverse tapering method. In the proposed method, a few untapered planar undulators are added before the simple linear reverse tapering section of the undulator line. This simple modification prevents the frequency shift of the radiation that occurs when the simple linear reverse tapering method is applied to planar undulators. In the proposed method, the total length of planar undulators decreased in spite of the additional untapered undulators. When the modified reverse tapering method is used with four untapered planar undulators, the total length of the planar undulators is 64.6 m. On the other hand, the required length of the planar undulators is 94.6 m when the simple linear reverse tapering method is used. The proposed method gives us a way to generate a soft x-ray pulse (1.24 keV) with a high degree of polarization (>0.99) and radiation power (>30 GW) at the new undulator line with a 10-GeV electron beam in the Pohang Accelerator Laboratory X-ray Free-Electron Laser. This method can be applied in the existing XFELs in the world without any change in the undulator lines. ? 2017 authors. Published by the American Physical Society.111Ysciescopu

Transient response analysis of a submerged floating tunnel under seismic and wave excitations

In this study, a numerical procedure is described for the transient response analysis of a submerged\ud floating tunnel with reference of a designed tunnel in Japan. Tension legs seizing the tunnel are simply modeled by a\ud spring elements and the tunnel itself is assumed by two rigid bodies between which a flexible joint is used. A recorded\ud seismic excitation is used while the wave load is calculated under a specific design condition. Hydro-damping and\ud added mass are considered for numerically modeling the underwater condition. A numerical procedure is validated with\ud compared to the previous results of the designed tunnel. Some modifications are proposed through the validating\ud process in terms of modeling and analysis procedure. Eventually, the modified numerical procedure will be used in\ud analyzing the transient response of a newly designed tunnel

Learning Curve for Robot-Assisted Laparoscopic Radical Prostatectomy for Pathologic T2 Disease

Purpose: To investigate the learning curve for robot-assisted laparoscopic radical prostatectomy (RALP) for pathologic T2 disease, we examined differences in perioperative outcomes according to time period. Materials and Methods: Between July 2005 and June 2008, a total of 307 consecutive patients underwent RALP for prostate cancer and 205 patients had pathologic T2 disease. Patients were grouped into 6-month time periods. We collected and examined the patient's perioperative data including age, body mass index (BMI), prostate-specific antigen (PSA), operation time, estimated blood loss, and positive surgical margin. Results: There were no significant differences among the groups in age (p=0.705), BMI (p=0.246), PSA (p=0.425), or prostate volume (p=0.380). Operation time (p<0.001) and estimated blood loss (p<0.001) decreased significantly with time. The positive surgical margin rate also showed a decreasing trend, but this was not significant (p=0.680). Conclusions: Operation time and estimated blood loss had a steep learning curve during the early 24 cases and then stabilized. A positive surgical margin rate, however, did not have a significant learning curve, although the positive surgical margin decreased continuously. ?? the Korean Urological Association, 2010

BCS theory for s+g-wave superconductivity borocarbides Y(Lu)Ni2_2B2_2C

The s+g mixed gap function \Delta_k=\Delta {[(1-x)-x\sin^4\theta\cos4\phi]} (x: weight of g-wave component) has been studied within BCS theory. By suitable consideration of the pairing interaction, we have confirmed that the coexistence of s- and g-wave, as well as the state with equal s and g amplitudes (i.e., x=1/2) may be stable. This provides the semi-phenomenological theory for the s+g-wave superconductivity with point nodes which has been observed experimentally in borocarbides YNi_2B_2C and possibly in LuNi_2B_2C.Comment: 5 pages, 3 figure

Neutron beam test of CsI crystal for dark matter search

We have studied the response of Tl-doped and Na-doped CsI crystals to nuclear recoils and $\gamma$'s below 10 keV. The response of CsI crystals to nuclear recoil was studied with mono-energetic neutrons produced by the $^3$H(p,n)$^3$He reaction. This was compared to the response to Compton electrons scattered by 662 keV $\gamma$-ray. Pulse shape discrimination between the response to these $\gamma$'s and nuclear recoils was studied, and quality factors were estimated. The quenching factors for nuclear recoils were derived for both CsI(Na) and CsI(Tl) crystals.Comment: 21pages, 14figures, submitted to NIM

Cooperative Jahn-Teller transition and resonant x-ray scattering in thin film LaMnO3{\rm LaMnO_3}

Epitaxial thin films of stoichiometric ${\rm LaMnO_3}$ were grown on ${\rm SrTiO_3(110)}$ substrates using the pulsed laser deposition technique. From the high resolution x-ray diffraction measurements, the lattice parameters were determined as a function of temperature and the cooperative Jahn-Teller transition was found to occur at $T_{JT}$=573.0 K. Also measured was resonant x-ray scattering intensity of the orthorhombic (100) peak of ${\rm LaMnO_3}$ near the Mn K edge from low temperatures to above $T_{JT}$. We demonstrate that the integrated intensity of the (100) peak is proportional to the 3/2 power of the orthorhombic strain at all temperatures, and thus provide an experimental evidence that the resonant scattering near the Mn K edge in ${\rm LaMnO_3}$ is largely due to the Jahn-Teller effect.Comment: 13 pages, 4 figure

Statistical nature of non-Gaussianity from cubic order primordial perturbations: CMB map simulations and genus statistic

We simulate CMB maps including non-Gaussianity arising from cubic order perturbations of the primordial gravitational potential, characterized by the non-linearity parameter $g_{NL}$. The maps are used to study the characteristic nature of the resulting non-Gaussian temperature fluctuations. We measure the genus and investigate how it deviates from Gaussian shape as a function of $g_{NL}$ and smoothing scale. We find that the deviation of the non-Gaussian genus curve from the Gaussian one has an antisymmetric, sine function like shape, implying more hot and more cold spots for $g_{NL}>0$ and less of both for $g_{NL}<0$. The deviation increases linearly with $g_{NL}$ and also exhibits mild increase as the smoothing scale increases. We further study other statistics derived from the genus, namely, the number of hot spots, the number of cold spots, combined number of hot and cold spots and the slope of the genus curve at mean temperature fluctuation. We find that these observables carry signatures of $g_{NL}$ that are clearly distinct from the quadratic order perturbations, encoded in the parameter $f_{NL}$. Hence they can be very useful tools for distinguishing not only between non-Gaussian temperature fluctuations and Gaussian ones but also between $g_{NL}$ and $f_{NL}$ type non-Gaussianities.Comment: 18+1 page

Square to stripe transition and superlattice patterns in vertically oscillated granular layers

We investigated the physical mechanism for the pattern transition from square lattice to stripes, which appears in vertically oscillating granular layers. We present a continuum model to show that the transition depends on the competition between inertial force and local saturation of transport. By introducing multiple free-flight times, this model further enables us to analyze the formation of superlattices as well as hexagonal lattice

Asian emissions in 2006 for the NASA INTEX-B mission

A new inventory of air pollutant emissions in Asia in the year 2006 is developed to support the Intercontinental Chemical Transport Experiment-Phase B (INTEX-B) funded by the National Aeronautics and Space Administration (NASA). Emissions are estimated for all major anthropogenic sources, excluding biomass burning. We estimate total Asian anthropogenic emissions in the year 2006 as follows: 47.1 Tg SO2, 36.7 Tg NOx, 298.2 Tg CO, 54.6 Tg NMVOC, 29.2 Tg PM10, 22.2 Tg PM2.5, 2.97 Tg BC, and 6.57 Tg OC. We emphasize emissions from China because they dominate the Asia pollutant outflow to the Pacific and the increase of emissions from China since 2000 is of great concern. We have implemented a series of improved methodologies to gain a better understanding of emissions from China, including a detailed technology-based approach, a dynamic methodology representing rapid technology renewal, critical examination of energy statistics, and a new scheme of NMVOC speciation for model-ready emissions. We estimate China's anthropogenic emissions in the year 2006 to be as follows: 31.0 Tg SO2, 20.8 Tg NOx, 166.9 Tg CO, 23.2 Tg NMVOC, 18.2 Tg PM10, 13.3 Tg PM2.5, 1.8 Tg BC, and 3.2 Tg OC. We have also estimated 2001 emissions for China using the same methodology and found that all species show an increasing trend during 2001-2006: 36% increase for SO2, 55% for NOx, 18% for CO, 29% for VOC, 13% for PM10, and 14% for PM2.5, BC, and OC. Emissions are gridded at a resolution of 30 minW30 min and can be accessed at our web site (mic.greenresource.cn/intex-b2006)