Effects of heat and electron irradiation on the melting behavior of Al-Si alloy particles and motion of the Al nanosphere within

In situ heating and electron-beam irradiation in the transmission electron microscope were performed to study melting of Al-11.6 at.% Si alloy submicron particles supported on an amorphous-C thin film. It was found that electron irradiation could be used to melt the particles, even when the hot-stage specimen holder was kept at a much lower temperature than the bulk melting point (i.e. the eutectic temperature) of the particles. The critical current densities required to achieve partial melting increased linearly with the incident electron-beam energy for a given temperature. Comparison between this behavior and analytical calculations indicates that melting under electron-beam irradiation is caused by a temperature rise due to electron thermal spikes in the particles and poor thermal conduction away from the particles. The motion of the crystalline Al nanosphere inside the partially molten particles was also investigated, using the electron beam to both stimulate and observe the motion of the nanosphere. The irregular motion observed was quantified as antipersistent fractional Brownian motion. Analysis of possible phenomena contributing to the motion demonstrates that the incident electrons provide the fractional force that moves the Al nanosphere, and that gravity and the oxide shell on the partially molten particle cause the antipersistent behavior. Another interesting phenomenon observed in this study was that the crystalline Al nanosphere inside the partially molten Al-Si alloy particle followed a focused electron beam as it was moved about on the partially molten particle. This observation suggests that it may be possible to manipulate metallic nanospheres inside opaque liquids using an electron beam.     

Solvent extraction coupled on-line to a reversed micellar mediated chemiluminescence detection system for trace-level determination of atropine

A fast and sensitive method for the determination of atropine, an alkaloid closely related to cocaine, is proposed. The principles of on-line ion-pair formation of alkaloid-metal complexes and liquid-liquid extraction are applied to the chemiluminescence determination of atropine. On mixing with a reversed micellar medium of cetyltrimethylammonium chloride in dichloromethane-cyclohexane (1:1 v/v)-water (0.3 M Na2CO3) containing luminol, the ion-pair complex of tetrachloroaurate(III) with atropinium produced an analytical chemiluminescence signal when it entered the reversed micellar water pool. Using the reverse-flow injection and chemical conditions optimized for atropine in aqueous samples, a detection limit of 1 ng/mL was achieved and a linear calibration graph was obtained with a wide dynamic range from 10 ng/mL to 100 micrograms/mL. The proposed method is simple and provides a good precision with a relative standard deviation (n = 6) of ca. 3% at the atropine concentration of 100 ng/mL. After a preliminary study involving the potential interference from species of organic, inorganic, and metallic nature, the method was applied to the determination of atropine in artificial urine samples and of atropine and scopolamine in pharmaceutical formulations.     

HDR and MDR intracavitary treatment for carcinoma of the uterine cervix. A prospective randomized study

The multiple goals theory of conflict management (Ohbuchi & Tedeschi, in press) postulated that participants in a conflict pursue to achieve resource goals (economic and personal resources) and social goals (relationship, identity, justice, and power-hostility). The hypotheses based on this theory were examined by the episode method, in which 207 university students were asked to rate their recent experiences of interpersonal conflicts in terms of participants' attributes, goals, and tactics. More than 80% of the subjects answered that they were motivated to achieve multiple goals in their attempts to resolve the conflicts. Social goals were found to be more strongly activated, and economic resource goals were least strongly activated. Regression analyses revealed that the effects of participants' attributes on tactical preference were mediated by goals.     

Clinical evaluation of the centrifugal pump in open heart surgery: a comparative study of different pumps

Pulmonary embolism after cardiac surgery is attributed to embolization from thrombus within the deep venous system. We report two cases of pulmonary embolism after coronary artery bypass surgery in which transesophageal echocardiography detected in situ right atrial thrombus. The right atrium should be screened for thrombus in patients who have pulmonary embolism after cardiac surgery.     

R-curve measurement of silicon nitride ceramics using single-edge notched beam specimens

R-curve behaviour of three kinds of silicon nitride-based ceramics has been studied using the single-edge notched beam (SENB) technique. If the notch is deep enough, the specimen shows stable fracture during the bending test, even when the sample is a brittle material. The conditions required to obtain stable fracture in the bending test are clarified by the analysis. The crack length of the specimen was also calculated from the changing load during the fracture test. In this study, coarse-grained silicon nitride shows a large increase of theR-curve. On the other hand, silicon nitride with silicon carbide whiskers shows noR-curve increase. The rise of theR-curve should be related to the microstructure of the ceramics, and especially to the grain size of the specimen, because silicon carbide whiskers are not large compared to the silicon nitride grains, and silicon carbide can reduce the grain growth of silicon nitride during sintering.     

t-Model mechanism of high-T c cuprates

A doublon formalism ofd-p model Hubbard Hamiltonian is studied only with transfer integrals, and without the superexchange term. This gives excellent doping-dependent features ofT _c in high-T _c cuprates.     

Development of a high efficiency refrigeration compressor

In order to improve the energy efficiency ratio of small reciprocating hermetic compressors the following factors are investigated: clearance volume, bore and stroke, rod length ratio, geometric dimensions of a piston and valves and superheat of suction gas.A prototype machine is developed based on this investigation. The reliability of this new type of compressor is confirmed and its energy efficiency ratio reaches 3.02 J W⁻¹ s⁻¹, which is 25% higher than the average value of our current machines.     

Support system for finite element analysis

This paper describes work aimed at developing an intelligent support system for finite element modeling and a methodology for managing input data model. Analyzing various statement structures of input data, three structural interface models — the hierarchical browser, the spread sheet and the model generator — are proposed for advanced representation and editing. Two knowledge models composed of macro visual data representation (user oriented model) and micro regularized data representation (processor oriented model) are revealed in conformity with the approach of object-orientation. Moreover, an extended relational schema composed of a composite object (assembly of functional elements) and several abstracted scalar indexes has been implemented for case retrieval.