Continuous extraction and separation of Am(III) and Cm(III) using a highly practical diamide amine extractant

A highly practical diamide-type extractant, which is an alkyl diamide amine with 2-ethylhexyl alkyl chains (ADAAM(EH)), was investigated for the mutual separation of Am(III) and Cm(III). ADAAM(EH) is a multidentate ligand with one soft N-donor atom and two hard O-donor atoms as part of its central frame. This tridentate arrangement of donor atoms provides selective binding to Am(III) compared to that with Cm(III) in highly acidic media (1.5 M HNO₃), resulting in separation factors of up to 5.5. A continuous liquid–liquid extraction and stripping test was conducted using a multistage countercurrent mixer-settler extractor with ADAAM(EH) in n-dodecane. In this test, the separation of Am(III) and Cm(III) was achieved with very high yield.     

Developing a Lisp‐based preprocessor for TEX documents

TEX allows users to define a macro that abstracts a sequence of typesetting commands. However, defining macros is not easy for most users, because the mechanism of macro expansion in TEX is complicated. As a remedy for this situation, a new system that enables users to define macros for TEX documents as Lisp programs has been developed. The system acts as a preprocessor for TEX; given a document that contains Lisp programs as S‐expressions, the system expands each S‐expression on the basis of Lisp's evaluation rules, thus generating an ordinary TEX document. The system is very flexible and easy‐to‐use, thanks to the underlying language's general‐purpose data structure, i.e. the S‐expression, applicative order evaluation, and rich set of predefined functions. This paper also demonstrates that the proposed system is really effective for practical use by giving some concrete examples of Lisp macros, some of which are difficult to define in terms of TEX commands. The system is currently implemented on the Emacs Lisp, and a user‐friendly environment is thus available in the Emacs text editor. Copyright © 2002 John Wiley & Sons, Ltd.     

Permanent magnet synchronous motors using primarily reluctance torque

Permanent magnet synchronous motors (PMSMs) are widely used in many applications as high‐performance variable‐speed drives. In traction drives, such as those used for electric vehicles or for the compressor drives of air conditioners, a wide constant‐power speed range and high‐efficiency operation are desired. The aim of this paper is to develop a high‐performance PMSM that offers high‐efficiency performance in the high‐speed region, including light‐load conditions, as well as a wide constant‐power speed range. Simulations show that the proposed interior PMSM, which produces chiefly reluctance torque and in which the permanent magnet flux assists torque production, is capable of meeting the above performance requirements. A prototype PMSM is designed in accordance with this new design concept and several drive tests are carried out. The saliency ratio of the prototype IPMSM is about 5, and, as a result, reluctance torque is the principal torque component, representing more than 70% of total torque. The prototype IPMSM can attain a constant‐power speed range of up to 5:1 with high‐efficiency drive in the high‐speed, constant‐power region. The proposed IPMSM is suitable for variable‐speed drives requiring high‐speed, constant‐power operation. © 2000 Scripta Technica, Electr Eng Jpn, 134(3): 60–68, 2001     

Use of polymeric indicator for electrochemical DNA sensors: poly(4-vinylpyridine) derivative bearing [Os(5,6-dimethyl-1,10-phenanthroline)2Cl]2+

A poly(4-vinylpyridine) (PVP) derivative bearing redox-active osmium complexes, PVP-[Os(5,6-dmphen)(2)Cl](2+) (5,6-dmphen = 5,6-dimethyl-1,10-phenanthroline), was employed as a hybridization indicator for electrochemical DNA sensors. PVP-[Os(5,6-dmphen)(2)Cl](2+) exhibited approximately 1000 times higher sensitivity than the corresponding monomeric analogue, [Os(5,6-dmphen)(3)](2+), in DNA determination due to polymeric effects. The detection limit of the present sensor was approximately 0.5 amol. Another merit of the polymeric indicator is that the redox potential was found to be +360 mV (vs Ag/AgCl), which is significantly lower than that reported for the monomeric analogue (+672 mV). The polymeric indicator was applicable to the discrimination of single- and double-base-mismatched DNAs from fully matched target DNA. The polymeric indicator can be removed from the electrode surface by rinsing the electrode in a high-temperature buffer for 6 min, and thus, the polymeric indicator-based DNA sensor can be used repeatedly.     

Upper Critical Field of Organic Superconductor κ-(ET)2Cu(NCS)2 Determined by Specific Heat Measurements

Both specific heat and resistance measurements of organic superconductor -(ET)₂Cu(NCS)₂ under magnetic field were performed. Upper critical fields, obtained from the specific heat data, are significantly less than those from the magnetoresistance measurements. At temperatures below 2 K and magnetic fields below 1 T, we observed additional power dissipation due to the field sweep. This effect may be attributed to the existence of irreversibility line.     

InfoPoint: A Device that Provides a Uniform User Interface to Allow Appliances to Work Together over a Network

This paper proposes a new hand-held device called “InfoPoint” that allows appliances to work together over a network. We have applied the idea of “drag-and-drop” operation as provided in the GUIs of PC and workstation desktop environment. InfoPoint provides a unified interface that gives different types of appliances “drag-and-drop”-like behaviour for the transfer of data. Moreover, it can transfer data from/to non-appliances such as pieces of paper. As a result, InfoPoint allows appliances to work together, in the real-world environment, in terms of data transfer. A prototype of InfoPoint has been implemented and several experimental applications have been investigated. InfoPoint has shown its applicability in a variety of circumstances. We believe that the idea proposed in this paper will be a significant technology in the network of the future.     

Design of a small‐size interlocking system with high availability

An interlocking system consists of an interlocking logical unit and a power controlling unit. After this logical unit calculates the relationship among the train position, the rail shifting position, and the signal, it decides the aspect of the signal. The power controlling unit supplies electrical power to the switch motor and the signal light according to the decision of the logical unit. This paper proposes a small‐sized interlocking system which uses a triplex redundant off‐the‐shelf controller with fail‐safe checker as an interlocking logical unit. A majority voting circuit ensures the safety of parallel output from the interlocking logical unit. This circuit satisfies the condition of total self‐checking (of D.A. Anderson) and also the condition of high availability. In other words, no single fault ever leads to a hazardous state and this circuit ensures safety after single fault occurrence. © 1999 Scripta Technica, Electr Eng Jpn, 128(2): 63–73, 1999     

Functional electrolytes: Synergetic effect of electrolyte additives for lithium-ion battery

We have found that certain combinations of specific additives show a very interesting behavior in Li-ion batteries. During the course of investigating further improvements in the performance of the triple-bonded compounds, which we very recently reported, a novel and unique effect of an additive combination was observed. The combination of the triple-bonded compounds and the double-bonded compounds has proven to show a much improved battery performance, especially in cycleability and gas evolution than the case when they are singly used. Especially, the synergetic effect of propargyl methanesulfonate and vinylene carbonate is remarkable. To clarify the synergetic effect, the electrochemical properties of the additives and the electrode analyses were investigated. It is assumed that the higher battery performance of the combination effect resulted not only from the thin and dense SEI on the negative electrode but also from the positive electrode surface co-polymerized film produced by the synergetic decomposition of the additives. We suggest that the keys for producing the synergetic functions are (1) a structural difference in the unsaturated moiety, and (2) a greater difference in the reduction potential.