Droplet splashing by a slingshot mechanism

When a drop impacts onto a liquid pool, it ejects a thin horizontal sheet of liquid, which emerges from the neck region connecting the two liquid masses. The leading section of this ejecta bends down to meet the pool liquid. When the sheet touches the pool, at an "elbow," it ruptures and sends off microdroplets by a slingshot mechanism, driven by surface tension. High-speed imaging of the splashing droplets suggests the liquid sheet is of submicron thickness, as thin as 300 nm. Experiments in partial vacuum show that air resistance plays the primary role in bending the sheet. We identify a parameter regime where this slingshot occurs and also present a simple model for the sheet evolution, capable of reproducing the overall shape.     

Photogeneration of polyfunctional amines and novel thermal curing reactions of epoxy resin and polyurethane oligomer using these amines

Photochemical reactions of various blocked polyfunctional amines such as bis(4-formylaminophenyl)methane (FAPM), bis(4-acetylaminophenyl)methane (AAPM), bis(4-benzoylaminophenyl)methane (BAPM), 2,4-diformylaminotoluene (DFAT), m-xylene diformamide, and bis[[(2-nitrobenzyl)oxy]carbonyl]hexane-1.6-diamine were carried out to give the corresponding free amines in THF solution, in epoxy resin, or in polyurethane oligomer with terminal isocyanate groups. Photolysis of FAPM and DFAT to produce the corresponding polyfunctional amines such as 4,4'-methylenedianiline and 2,4-diaminotoluene proceeded with 80 and 75% conversions, respectively, in THF solution under UV irradiation at 5 h. AAPM and BAPM also produced the corresponding photo-Fries rearrangement products with 32 and 38% conversions, respectively, under the same irradiation conditions. The photolysis of those compounds also occurred with similar conversions in the epoxy resin and in the polyurethane oligomer under UV irradiation; and the thermal curing reactions of the epoxy resin and the polyurethane oligomer with photogenerated polyfunctional amines proceeded smoothly after heating at 140°C for 2 hrs. © 1993 John Wiley & Sons, Inc.     

An interior point algorithm for large scale portfolio optimization

The minimum-norm point problem which arises in portfolio selections is discussed and an interior point algorithm to solve the problem is proposed in this paper. Three kinds of problems, the mean-variance, the index matching and the multiple factor models are viewed as variants of the minimum-norm point problem. Results of the computational experiments are attached to show the proposed algorithm as a very powerful tool for large scale portfolio optimization.Revised version of On the minimum-norm point problem in portfolio selections.     

New fluorine-substituted analogue of eticlopride with high affinity toward dopamine D2 receptors.

Aiming at the development of positron-emitting ligands with specific and high affinity toward dopamine D2 receptors in the central nervous system, we synthesized a new fluorinated eticlopride derivative. A fluorine atom was introduced at the C-4 position of the pyrrolidine ring of eticlopride, a dopamine D2 antagonist of the benzamide series. The in vitro binding affinity of this ligand toward the D2 receptor was found to be as potent as eticlopride, suggesting that the corresponding 18F-labelled compound may be useful as an in vivo radioligand for positron emission tomography.     

Evaluation of the 3D-PIV standard images (PIV-STD project)

Particle Imaging Velocimetry (PIV) offers many advantages for studies of fluid flows. Lots of PIV techniques have been developed and applied to various flow fields. However, there are no standard tools for evaluation of the PIV system effectiveness and accuracy. To popularize the PIV for practical use, the PIV system should have some standard.     

Differential Pulse Voltammetric Determination of Free Chlorine for Water Disinfection Process

The electrochemical detection of free chlorine based on the reduction at a gold electrode has been studied. The differential pulse voltammetric curves exhibited well‐defined cathodic peaks. Investigations with this system suggested that the active species in the cathodic reaction is HClO. Excellent reproducibility was demonstrated at pH 5. The peak height could be used for accurate and rapid determination of free chlorine in a sample water. A linear relationship (r²=0.99) was found for the concentration range of 1–5 mg Cl dm^?3 and the detection limit was estimated to be 0.04 mg Cl dm^?3.     

Resonant inelastic x-ray scattering of CeB6 at the Ce L(1)- and L(3)-edges

We report a resonant inelastic x-ray scattering (RIXS) study of crystalline CeB(6). Ce L(α1,2) RIXS was measured with excitation energies resonant with the Ce L(3)-edge. A lifetime-broadening suppressed x-ray absorption near-edge structure (LBS-XANES), which successfully reproduced the L(α1,2) RIXS spectra over wide ranges of excitation and emission energies, was simulated using the SIM-RIXS program. A pre-edge structure in the LBS-XANES can be resolved, and many-body effects were suggested in the L(α1,2) RIXS around the Ce L(3)-edge energy. No convincing signs of Ce (II) or Ce (IV) states were observed in the LBS-XANES. Ce L(γ4) RIXS was measured at 302 K and 28 K with excitation energies across the Ce L(1)-edge. The interactions of p-valence electrons between Ce and B(6) were found to be considerably small, regardless of temperature. Thus, the electronic state of CeB(6) was concluded to be suitably described as a nominally Ce(4f(1))(3+)(e(-))(B(6))(2-) system with some hybridization among all valence orbitals of Ce and B.     

Scintigraphic evaluation of brain death with 99mTc-d,l-hexamethyl-propyleneamine oxime (HMPAO)

Lately, the criteria of brain death is being discussed. Cerebral scintigram, especially scintigraphic evaluation of brain death by dynamic study, has been previously reported. Cerebral imaging using radiolabeled amines such as 123I-IMP N-isopropyl-p-iodoamphetamin (IMP) or 99mTc d,l-hexamethyl-propyleneamine oxime (HMPAO) offers a significant information of brain death by the finding of "non visualized brain". However, the dynamic scintigram acquired during the bolus injection of 99mTc-HMPAO provides an additional information of brain death by classical "hot nose sign". 99mTc-HMPAO is able to be administered relatively in a large amount of dose. This cerebral perfusion tracer is lipophilic and remains in the central nervous system, which characterize its role as an reliable indicator of cerebral blood flow. As a result, this compound became suitable for the non-invasive study of brain circulation when the diagnosis of brain death is uncertain. We report a case of brain death in which diagnosis was made by the classical "hot nose sign" in dynamic scintigraphy performed when 99Tc-HMPAO was injected as well as the SPECT which showed a lack of cerebral visualization at the equilibrium state. As far as we are informed, this additional procedure used in the diagnosis of brain death has not reported before. The importance of performing a dynamic scintigram at the administration of 99mTc-HMPAO is also discussed in this report.     

Determination of atropine in biological specimens by high-performance liquid chromatography

A sensitive and selective method for the determination of atropine in biological specimens has been developed. Samples alkalinized with sodium hydroxide were extracted with dichloromethane, and the organic phase was evaporated in a water-bath at 50 degrees C for ca. 10 min. The residue was dissolved in the mobile phase and injected into a reversed-phase column (TSK gel ODS-120A). The retention time for atropine could be varied by changing either the acetonitrile-water ratio in the mobile phase or the pH of the mobile phase. Acetonitrile-water (2:8, v/v) containing 6 mM phosphoric acid was used as mobile phase. Samples of 200 microliters or less were injected into the chromatography and measured at 215 nm. The recoveries of atropine added to drug-free specimens were satisfactory with coefficients of variation of 4% or less. Ninety-two compounds tested did not interfere with the assay of atropine. The method has been applied for monitoring atropine concentrations in cases of organophosphate and drug poisoning.     

A study on particle identification in PTV particle mask correlation method

An algorithm for particle identification in PTV, which is classified in the category?particle mask correlation method, is presented and tested. A typical brightness pattern of a particle image is referred to as a particle mask. The particle mask is centered on a pixel in the image plane and the cross correlation between the particle mask and a region of the image plane centered on the given pixel is calculated. The particle mask is scanned over the entire image plane and the cross correlation coefficient is calculated at each pixel location. Small subareas with high correlation coefficients indicate central areas of particle images.