Improvement of linewidth enhancement factor in 1.55-μmmultiple-quantum-well laser diodes

The improvement of the linewidth enhancement factor in complex-coupled laser diode (CC-LD), or loss-coupled, was confirmed by measuring the spontaneous emission spectra below threshold from the sidewall of laser diodes. In addition, the serial resistance of the device was measured. The linewidth enhancement factor is improved by the presence of a light absorbing InGaAs grating for loss coupled distributed-feedback (DFB) laser diode (LD). We report the comparison of the linewidth enhancement factors of Fabry-Perot (FP) LD, conventional DFB-LD, and loss coupled DFB-LDs     

Distributed source modeling and direction-of-arrival estimationtechniques

In direction-of-arrival (DOA) estimation, the direction of a signal is usually assumed to be a point. If the direction of a signal is distributed due to some environmental phenomenon, however, DOA estimation methods based on the point source assumption may result in poor performance. We consider DOA estimation when the signal sources are distributed. Parametric and nonparametric models are proposed, and estimation methods are considered under these models. In addition, the asymptotic distribution of estimation errors is obtained to show the models' statistical properties     

Numerical analysis of a weak shock wave propagating in a medium using lattice boltzmann method (LBM)

This study introduced a lattice Boltzmann computational scheme capable of modeling thermo hydrodynamic flows with simpler equilibrium particle distribution function compared with other models. The equilibrium particle distribution function is the local Maxwelian equilibrium function in this model, with all the constants uniquely determined. The characteristics of the proposed model is verified by calculation of the sound speeds, and the shock tube problem. In the lattice Boltzmann method,a thermal fluid or compressible fluid model simulates the reflection of a weak shock wave colliding with a sharp wedge having various angles θ_w. Theoretical results using LBM are satisfactory compared with the experimental result or the TVD.     

Experimental study on forced convective boiling heat transfer of pure refrigerants and refrigerant mixtures in a horizontal tube

Convective boiling heat transfer coefficients of pure refrigerants (R22, R32, R134A, R290, and R600a) and refrigerant mixtures (R32/R134a, R290/R600a, and R32/R125) are measured experimentally and compared with Gungor and Winterton correlation. The test section is made of a seamless stainless steel tube with an inner diameter of 7.7 mm and is uniformly heated by applying electric current directly to the tube. The exit temperature of the test section was kept at 12°C ± 0.5°C for all refrigerants in this study. Heat fluxes are varied from 10 to 30 kW m⁻² and mass fluxes are set to the discrete values in the range of 424–742 kg m⁻² s⁻¹ for R22, R32, R134a, R32/R134a, and R32/R125; 265–583 kg m⁻² s⁻¹ for R290, R600a, and R290/R600a. Heat transfer coefficients depend strongly on heat flux at a low quality region and become independent as quality increases. The Gungor and Winterton correlation for pure substances and the Thome-Shakil modification of this correlation for refrigerant mixtures overpredicts the heat transfer coefficients measured in this study.     

fMRI analysis of excessive binocular disparity on the human brain

The aim of this study is to evaluate brain regions related with excessive binocular disparity that may be linked to stereoscopic visual fatigue. In stereoscopic displays, excessive binocular disparity may generate blurring or double vision in the stereovision and induce unnatural oscillations in accommodation and vergence. These phenomena may lead to visual fatigue and activation (or deactivation) of human brain related with sensory and eye movement functions. A functional magnetic resonance imaging (fMRI) method is used to investigate the effect of excessive binocular disparity on human brain. Subjective assessments of visual fatigue are also conducted with the same stimuli as the fMRI experiment. Based on the subjective assessment results, participants are classified into low‐ and high‐fatigue groups. From the fMRI experiments, the high‐fatigue group showed more activation at the intraparietal sulcus (IPS) than the low‐fatigue group, when viewing an excessive disparity stimulus. The results showed that the excessive binocular disparity stimulus may induce overload to the IPS region, which is related with stereo processing and saccadic eye movement. In addition, it could be possible to use fMRI as an objective measurement method for understanding the stereoscopic visual fatigue when stimuli with excessive binocular disparity are applied.     

Determination of drug levels in human serum by circular dichroism

Cryopreserved skin must be used immediately after thawing or discarded owing to rapid post-thaw deterioration in viability. This is inconvenient and wasteful. The purpose of this study was to evaluate whether release of protease enzymes from cryogenically damaged cells or the action of free radicals on skin cells, is the cause of this deterioration. Following thawing. skin was incubated for 24 h at 4 degrees C in a range of protease inhibitors and free radical inhibitors/scavengers. The rate of deterioration was significantly reduced by using complex treatments including addition of serum, egg white and raised pH. These treatments are known to inhibit various groups of protease enzymes but would clearly have additional effects on the cells. Of the remaining treatments most of the specific protease inhibitors improved viability although not significantly. Treatments designed to inhibit or scavenge free radicals had little or no effect.     

Freiheit im Cyberspace

1 ]. Doch liefert diese keine unumstrittenen Vorgaben. Vielmehr bieten verschiedene staatsphilosophische und verfassungstheoretische Haltungen unterschiedliche Orientierungen. Daher dürfen die allein staatsorientierten Ausführungen Fiedlers [ 2 ] an dieser Stelle nicht unwidersprochen bleiben, soll Informatikern keine einseitige Sicht der Rechtswissenschaft auf die Probleme von Recht, Staat und Demokratie im Cyberspace geboten werden.     

Testicular tumors: clinically relevant histological findings

Testicular germ cell neoplasms affect young men in the prime of life. Although the overwhelming majority are malignant, they are curable. In addition to the stage of the disease and the presence of serum markers, there are important pathological changes that have clinical significance. These include (1) the cell type, (2) the amount of the component, and (3) the presence or absence of vascular invasion. Pure embryonal carcinoma or embryonal carcinoma in excess of 80% in a mixed tumor and vascular/lymphatic invasion are high-risk factors as they are predictors of relapse. These factors should be recognized by the pathologist and should be taken into account by the oncologist when selecting the management of a patient with a germ cell tumor of the testis.