Phase behavior in liquid crystallization for diblock copolymers consisting of rubbery amorphous and side-chain liquid crystalline components

Phase behavior in liquid crystallization was studied for a series of liquid crystalline (LC) diblock copolymers consisting of rubbery amorphous and side-chain liquid crystalline components, poly(n-butyl acrylate) (PBA) and poly[11-(4′-cyanophenyl-4″-phenoxy)undecyl acrylate] (PLC), respectively, using a time-resolved small-angle X-ray scattering (SAXS) techniques, DSC and polarized optical microscopy (POM). The block copolymers used had three kinds of copolymer compositions, 44, 20 and 15 wt% of PLC compositions (BLC44, BLC20 and BLC15, respectively). BLC44 showed a smectic liquid crystalline structure. In the process of liquid crystallization for BLC44, the SAXS peak due to the microphase separation structure existing before liquid crystallization was changed continuously to be at a smaller angular side, and at almost the same time, a new peak appeared at a further smaller angular side and developed. The former peak disappeared with the development of liquid crystallization. The behavior of these SAXS peaks suggests that the microphase separation structure was changed discretely at the transition from isotropic to smectic and that two phases coexist in the early stage of the liquid crystallization. The coexistence of two peaks in the early stage of the liquid crystallization corresponded to the POM observation. In the isotropization process, coexistence of two phases was not observed. For BLC20 exhibiting a cylindrical structure in both isotropic and liquid crystalline states, the liquid crystalline structure was not smectic but probably nematic, and the spacing was changed continuously in liquid crystallization. No liquid crystallization was observed in SAXS, POM and DSC for BLC15. The orientation of smectic layers within lamellar domains was investigated using 2D-SAXS images. The smectic layer was aligned perpendicularly to the lamellar interface.     

A 322 MHz random-cycle embedded DRAM with high-accuracy sensing and tuning

A 16 Mb embedded DRAM macro in a fully CMOS logic compatible 90 nm process with a low noise core architecture and a high-accuracy post-fabrication tuning scheme has been developed. Based on the proposed techniques, 61% improvement of the sensing accuracy is realized. Even with the smallest 5 fF/cell capacitance, a 322 MHz random-cycle access while 32 ms data retention time which contributes to save the data retention power down to 60 /spl mu/W are achieved.     

Highly reliable testing of ULSI memories with on-chip voltage-downconverters

Two testing techniques for ultra-large-scale integrated (ULSI) memories containing on-chip voltage downconverters (VDCs) are described. The first in an on-chip VDC tuning technique that adjusts internal V_CC to compensate for the monitored characteristics of the process parameters during repair analysis testing. The second is an operating-voltage margin test, performed at various internal V_CC levels during the water sort test (WT) and the final shipping test (FT)     

Another language for describing motions of mechatronics systems: a nonlinear position-dependent circuit theory

Dynamics and control of nonlinear mechanical systems and advanced mechatronic systems can be investigated more vividly and efficiently by using corresponding nonlinear position-dependent circuits that describe Lagrange's equations of motions and interactions with objects or/and task environments. Such expressions of Lagrange's equations via nonlinear circuits are indebted to lumped-parameter discretization of mechanical systems as a set of rigid bodies through equations of motion due to Newton's second law. This observation is quite analogous to validity of electric circuits that can be derived as lumped parameter versions of Maxwell's equations of electromagnetic waves. Couplings of nonlinear mechanical circuits with electrical circuits through actuator dynamics are also discussed. In such electromechanical circuits the passivity should be a generalization of impedance concept in order to cope with general nonlinear position-dependent circuits and play a crucial role in their related motion control problems. In particular, it is shown that the passivity as an input-output property gives rise to a necessary and sufficient characterization of H/sub /spl infin//-tuning for disturbance attenuation of robotic systems, which can give another system theoretic interpretation of the energy conservation law.     

Coherence-Based 3-D and Spectral Imaging and Laser-Scanning Microscopy

The basics of three-dimensional (3-D) and spectral imaging techniques that are based on the detection of coherence functions and other related techniques are reviewed. The principle of the 3-D source retrieval is based on understanding the propagation law of optical random field through the free space. The 3-D and spectral information are retrieved from the cross-spectral density function of optical random field or numerical calculation of the inverse propagation of the cross-spectral density. We will first introduce the coherence-based spectral tomography techniques with low-coherence light sources. These techniques limit their scheme of coherence detection only along the optical axis and some of them achieve simultaneously the high resolution and high speed of detection taking advantage of an imaging lens. We then provided explanations of the principle of 3-D source retrieval that is based on the propagation law of optical random field through the free space along with the introduction of the numerical holography and computed tomography techniques. We will lastly show 3-D spectral imaging schemes with the concurrent laser-scanning cross-sectioning techniques: one is the confocal laser scanning microscopy and the other is the two-photon laser-scanning fluorescence microscopy.     

Structure and Nonlinear Optical Properties of Lanthanide Borate Glasses

The third–order nonlinear optical susceptibility, χ⁽³⁾, of lanthanide (lanthanum, praseodymium, neodymium, and samarium) borate glasses has been measured by the third harmonic generation method. The structure of the present glass system has been studied by infrared and Raman spectroscopic methods. The network structures of the present Ln₂O₃–B₂O₃ glasses have been confirmed to be basically similar to each other. Praseodymium, neodymium, and samarium borate glasses exhibit χ⁽³⁾ values that are larger than lanthanum borate glasses, because of the optical resonance effect, in accordance with the f – f transition. Especially, the χ⁽³⁾ value for 30Pr₂O₃·70B₂O₃ glass is 1.8 × 10⁻¹² esu, which is a factor of ∼60 larger than that of SiO₂ glass. This striking enhancement of χ⁽³⁾ is mainly attributed to the large transition moment to the first excitation state.     

Formation of Zirconia Solid Solutions Containing Alumina Prepared by New Preparation Method

In the system ZrO₂–Al₂O₃, a new method for preparing ZrO₂ solid solutions from ZrCl₄ and AlCl₃ using hydrazine monohydrate is investigated. c -ZrO₂ solid solutions containing up to ∼40 mol% Al₂O₃ crystallize at low temperatures from amorphous materials. The formation mechanism is discussed from IR spectral data. The values of the lattice parameter α increase linearly from 0.5072 to 0.5105 nm with increasing Al₂O₃ content. At higher temperatures, transformation of the solid solutions proceeds as follows: c ( SS ) → t ( ss ) → t ( ss ) +α-Al₂O₃→ m +α-Al₂O₃. m -ZrO₂–α-Al₂O₃ composite ceramics are fabricated by hot isostatic pressing for 2 h at 1250°C and 196 MPa. Microstructures and mechanical properties are examined, in connection with increasing Al₂O₃ content.     

Noninvasive blood glucose assay using a newly developed near-infrared system

This paper reports in vivo near-infrared (NIR) noninvasive blood glucose assay using dermis tissue spectra. We assume that the glucose content in dermis tissue traces the variations in blood glucose. For dermis spectra measurements, epidermis, especially stratum corneum, acts as an interference in skin tissue. Thus, we have developed a method for the selective measurement of dermis tissue spectra, enabling us to obtain better quality spectra for an accurate blood glucose assay. The selective measurement of the dermis spectra realized by using a newly developed fiber-optic probe that consists of source and detector optical fibers separated by 0.65 mm on a skin surface. The light path in the skin tissue for this geometry has been simulated by a Monte Carlo method. The simulation results show that detected light mainly interrogates dermis tissue. As the absorbance signal of glucose in human tissue is extremely small, the quality of the measured spectra is critical for the reliable assay. The present method for blood glucose assay has been applied to one Type 1 diabetic. The correlation coefficient between the blood glucose content predicted by NIR spectra and those measured by finger-prick was 0.928 and the standard error of prediction was 32.2 mg/dL. These results demonstrate the potential of our methodology for noninvasive NIR blood glucose assay.     

Equivalence relations between learnability,output-dissipativity and strict positive realness

This paper was originally motivated by aiming at explicating why a simple iterative learning control scheme for complicated robot dynamics with strong non-linearities works well in acquiring any given desired motion over a finite or infinite time duration or any periodic motion. To gain a physical insight into the problem, a class of linear dynamical systems with specified input and output of the same dimension is treated by defining two properties: output-dissipativity and learnability. It is then shown that the former implies the latter and furthermore, for a class of linear systems with single input and single output, they are equivalent to each other and each of them is also equivalent to strict positive realness of input-output transfer function. For a class of MIMO (multiple inputs and multiple outputs) systems, it is possible to prove that each of these properties is equivalent to strict positive realness of the input-output transfer function matrix if it is strictly proper or otherwise its direct term from input to output satisfies an extra condtion.