[en] Simple linear models including the linear driving force (LDF) model for approximating unsteady-state diffusion, adsorption in an adsorbent under cyclic operating environments have been proposed to reduce the computational load of the exact partial differential equations. The models are in the form of a first-order ordinary differential equation and consist of a term with the external concentration surrounding the adsorbent particle and another term with the average adsorbate concentration in the adsorbent. Although very simple to use, the approximation models are first-order approximations of the pore diffusion model, and hence their accuracy is not high enough to compute fine details of fast responses. By incorporating the time derivative of the external concentration into the approximation, an improved linear formula for cyclic adsorption is developed in this study. As the time derivative is usually computed simultaneously with the external concentration, the improved formula has little additional complexity over the previous approximations in its applications, and yet it is considerably more accurate than the previous first-order approximations for cyclic adsorption.

[en] During the last decade, radiation therapy employing microbeam has been spotlighted due to its highly enhanced therapeutic effectiveness. Even though the microbeam radiation therapy (MRT) has its limitations for common use, it still arouses the interest of the researchers who look for new protocols in therapeutic radiology. In this study, Monte Carlo simulations were performed to suggest the design criteria of microbeam collimator for better radiation treatment result

[en] Full-field magnetic soft X-ray transmission microscopy is a powerful tool to study with elemental sensitivity at a lateral resolution down to 15nm micromagnetic structures and microscopic magnetization reversal phenomena in ferromagnetic systems such as thin films, magnetic multilayers, micropatterned elements and arrays. Fast spin dynamics in such systems can be addressed with a temporal resolution below 100ps by a stroboscopic pump-and-probe scheme. The current status of the imaging soft X-ray microscopy beamline XM-1 at the Advanced Light Source is reported. and future perspectives with respect to improved spatial and temporal resolution are described

[en] Domain reversal dynamics in ferromagnetic thin films has been quantitatively investigated by means of a magneto-optical microscope magnetometer (MOMM), capable of grabbing domain reversal patterns in real time under an applied magnetic field and of measuring local magnetic properties with 400-nm spatial resolution. The domain reversal behavior sensitively changed between wall-motion and nucleation-dominant behavior with changing multilayer structure of the Co-Pd multilayers. Quantitative analysis revealed that the contrasting reversal behavior was mainly caused by a sensitive change in wall-motion speed and that the reversal ratio of wall-motion speed over nucleation rate was a governing parameter for the contrasting domain reversal dynamics. The activation volumes of the wall-motion and nucleation processes were generally unequal, and the inequality was closely related with the domain dynamics. Based on a Monte-Carlo simulation, both the macroscopic magnetic properties and the local magnetic variation were responsible for the contrasting domain reversal behavior

[en] The complications of pancreatitis, such as pseudocyst or abscesses, are well known to radiologists. Yet formation of a pseudoaneurysm of the short gastric artery is an uncommon complication of acute pancreatitis. It is also very rare for a psuedoaneurysm of the short gastric artery to cause splenic vein occlusion and the final result is gastric varices. We report here on a case that showed the dramatic effect of embolotherapy for a pseudoaneurysm of the short gastric artery that caused gastric variceal bleeding

[en] In CT image, the final image is formed only after the rather long, tortuous, and subtle process of reconstruction has reconstruction has taken place. The reconstruction algorithm makes use of all x-ray measurements in reconstruction between the patient's anatomy and machine. Therefore, CT image artifacts will be classified as to following. 1. Geometric artifacts are errors due to situations in which not all ray measurements occurred along lines with the proper orientation in space. Aliasing is an inherent problem due to an insufficient number of ray samples per beam with in the x-ray plane. In T/R and R/S scanner, it can be greatly diminished by increasing the sample rate, which may necessitate a slower scanning speed. It is only secondarily affected by the use of a smoothed reconstruction filter. Insufficient angular sampling can be reduced or eliminated by use of a smoothed reconstruction. Edge gradient streaks artifacts are an inherent problem due to the finite width of the scanning beam. This can be reduced by the use of a harder (higher energy) photon spectrum. Geometric misalignment artifacts are due to some kind of mechanical misalignment in the detectors or x-ray source. This can be corrected by either mechanical alignment or software correction. Partial volume effect can be mitigrated by overscanning or reduction of slice width. Motion artifacts can be greatly reduced by overscanning, short scan time, anesthesia and window setting control. 2. Algorithm distortions and artifacts are those artifacts in the image caused by the form of reconstruction algorithm used. Point spread effect can be reduced only by improving spatial resolution, and the intelligent manipulation of the window level and width viewer controls. 3. Attenuation measurement artifacts are caused by any malfunction of the radiation detectors that cause an inaccurate reading of the x-ray attenuation passing through the patient. Nonlinear attenuation errors can be partially overcome by use of a linearizing function in the software. 4. Photon spectrum effect artifacts are errors caused by alterations that occur in the x-ray energy spectrum as the beam passes through the patient. This effect is due to certain fundamental law of x-ray physics rather than any imperfection of equipment manufacture. Beam-hardening artifacts are caused by the inherent change induced in the x-ray energy spectrum. Harding in water is easily correctable in software. Hardening in bone can be eliminated with post reconstruction correction algorithms

[en] Nanocrystalline Fe-doped TiO₂ powders were synthesized by mechanical alloying (MA) with varying Fe contents from 0 up to 4.8 wt.% to shift the absorption threshold into the visible light region. The photocatalytic feasibility of the Fe-doped TiO₂ powder was evaluated by quantifying the visible light absorption capacity using ultraviolet and visible (UV-Vis) spectroscopy and photoluminescence spectroscopy. Effects of Fe additions on the crystal structures and the morphologies of the Fe-doped powders were also investigated as a function of the doping content using transmission electron microscopy-electron diffraction pattern (TEM-EDP), X-ray diffraction (XRD) and energy dispersive X-ray (EDAX) and X-ray photoelectron spectroscopy (XPS). The UV-Vis study showed that the UV absorption for the Fe-doped powder moved to a longer wavelength (red shift) and the photoefficiency was enhanced. Based on the analysis of the photoluminescence spectra, the red shift was believed to be induced by localizing the dopant level near the valence band of TiO₂. The UV-Vis absorption depended on the Fe concentration. TEM-EDP and XRD investigations showed that the Fe-doped powder had a rutile phase in which the added Fe atoms were dissolved. The rutile phase was composed of spherical particles and chestnut bur shaped particles, resulting in a larger surface area than the spherical P-25 powder

[en] Complications during the placement of a central venous catheter, via the right internal jugular vein puncture include local hematoma, hemothorax, pneumothorax, central vein thrombosis, and hemopericardium. Iatrogenic right internal jugular vein-right subclavian artery fistula with the formation of right subclavian artery pseudoaneurysms is an extremely rare complication in patients undergoing a central vein puncture. We report the case of a patient who developed a local hematoma at the vein puncture site and dyspnea due to a right internal jugular vein-subclavian artery fistula and a right subclavian artery pseudoaneurysm at the mediastinum after puncture of right internal jugular vein. The patient was successfully treated by embolization using microcoils

[en] The occurrence of an anastomosis between the coronary artery to the systemic artery is rare. However, the probability of hemodynamic changes sufficient to cause clinical symptoms is extremely low. Anastomosis of the coronary to bronchial artery can cause myocardial ischemia due to the decreased flow to the coronary arteries. The authors report a case of coronary to bronchial artery anastomosis presenting as coronary steal syndrome that was treated with transarterial microcoil embolization instead of surgical ligation

[en] In this study the cycloaddition of glycidyl methacrylate (GMA) and CO₂ using ionic liquid as catalyst was performed for the technology of CO₂ reduction. The structure of synthesized cyclic carbonate, [2-oxo-1,3-dioxolan-4-yl]methacrylate (DOMA) was analyzed and confirmed by FT-IR and ¹H-NMR. The change in conversion with respect to reaction time was investigated using ¹H-NMR. Interestingly, the ionic polymerization of vinyl groups and crosslinking reaction between cyclic carbonate rings of DOMA were observed following completion of cycloaddition