3-DOF planar parallel-wire driven robot with an active balancer and its model-based adaptive control

This paper has proposed a parallel-wire driven robot (PWDR) with an active balancer, which is notably useful for such applications as ceiling maintenance and object conveyance near a ceiling in a factory. Because this robot is an under-actuated system, the uncertainty of the inertial parameters of the load strongly affects the resultant motion and reduces the control accuracy because of the dynamics interference. However, to date, the dynamics of this robot has not been thoroughly elucidated. Thus, this study analyzes the dynamics of a PWDR that controls three degree-of-freedom using two wires and an active balancer. Moreover, based on the dynamic analysis, a model-based adaptive controller for the parameter uncertainty of a load is proposed, and its effectiveness is demonstrated through simulation.     

Thoracic aneurysm repair using circulatory arrest or retrograde cerebral perfusion]

The meaning and process of reflection and reflective practice appear to be currently accepted and institutionalized within the nursing profession. This paper, through use of a literature review, attempts to question the value that is consequently placed on this strategy and argues that on closer examination, reflection has no clear or universal definition, an uncertain framework for implementation, and is of unproven benefit to the professional practice of nurses. Given this evidence, the author concludes that reflection is a fundamentally flawed strategy that must be of limited benefit to the nursing profession.     

Radiation-induced reactions of ring-substituted polystyrenes analyzed by radiolysis of low molecular-weight model compounds

Radiation-induced reactions of polystyrene derivatives have been studied by the radiolysis of ring-substituted isopropylbenzene derivatives, i. e., 4-amino. 4-hydroxy, 4-methoxy, 4-methyl, 4-chloromethyl, 4-chloro, and 4-acetyl derivatives. Low-temperature ESR analyses measured at 77 K indicate that. In general, the a-position is the most sensitive site to radiation and that thus a-radicals are produced through a-hydrogen removal. However, among these derivatives, the amino, acetyl, chloromethyl, and. chloro derivatives undergo different reactions from the other derivatives. A phCO? CH₃ cleavage from the- acetyl derivative and N? H cleavage from the amino derivative occur, and chlorine removal takes place from the chloro-methyl and chloro derivatives. Final products detected by gas chromatography-mass spectrometry indicate not only that radiation-induced free radical recombination occurs. but also that if chlorine is produced by radiation, hydrogen abstraction by radiation-induced chlorine takes place prior to the free radical recombination. The susceptibility of each derivative to hydrogen abstraction by radiation-induced active chlorine increases, as the electron-donation of ring-substituents is increased. Based on the clarified reaction mechanism, the design of polystyrene derivatives as resist materials is discussed and two new types of resist systems are described. One is a new chloromethylstyrene based blend resist, which is formulated from poly(4-meth-oxystyrene) and poly(4-chloromethylstyrene). The other is a new non-swelling alkaline developable negative resist, which is formulated from poly(4-hydroxystyrene) and a chlorine-releasing compound.     

Efficiency enhancement in a Cherenkov laser loaded with a Kerr-likemedium

Efficiency enhancement in energy conversion for a Cherenkov free elctron laser loaded with a Kerr-like medium is discussed with the aid of particle simulation. For the analysis of the problem, a two-dimensional model for the Cherenkov free electron laser is considered which is composed of a planar relativistic electron beam and a parallel plate waveguide one plate of which is loaded with a nonlinear dielectric sheet exhibiting a Kerr-like effect. To follow the growth of an electromagnetic wave and the decrease in the kinetic energy of the electron beam in the specified model of the Cherenkov free electron laser, a particular segment of the electron beam with the longitudinal length of one guide wavelength is picked out. In that segment, as it travels down the waveguide, the interaction between the electromagnetic wave and a group of electrons is analyzed with the use of the finite-difference time-domain (FDTD) method. The result of numerical simulation shows that the efficiency of energy transfer from the electron beam to the electromagnetic wave is greatly enhanced by the proper choice of the nonlinear parameter for a Kerr-like medium. The enhanced efficiency is due to the improved velocity matching between the electron beam and the electromagnetic wave, and to the self-focusing effect of a Kerr-like medium     

Lack of selectin-dependent adhesion in prostate cancer cells expressing sialyl Le(x)

In the muscle lesions of inclusion body myositis (IBM), two populations of T cells can morphologically be distinguished, T cells that invade muscle fibers and T cells that remain in interstitial areas. Using combined immunohistochemistry and RT-PCR, we analysed the TCR expressed by these distinct T cell populations. In three of eight IBM muscle specimens, the autoinvasive T cells were stained with one of the available mAbs: anti-Vbeta5.3 in patient 1, anti-Vbeta5.2 in patient 2, and anti-Vbeta3 in patient 3. The corresponding TCR Vbeta mRNAs were amplified by RT-PCR and the PCR products were cloned and sequenced. In all three specimens, the TCRs expressed by the autoinvasive T cells were clonally restricted. Furthermore, in patient 1 two different mAbs labelled two distinct populations of T cells: an autoaggressive population of CD8 + Vbeta5.3 + cells that invaded muscle fibers and a noninvasive interstitial population of CD8 - Vbeta5.1 + cells. TCR sequence analysis revealed that the noninvasive Vbeta5.1 + T cells were clonally diverse, whereas the autoinvasive Vbeta5.3 + T cells were clonally restricted.     

Improvement of fatigue properties of fillet lap joints by local TIG arc heating

Summary

The temper embrittlement affecting the HAZ of 2 1/4Cr-1Mo steel subjected to SR treatment and subsequent reheating is investigated with synthetic HAZ specimens and compared with the embrittlement observed in specimens tempered in the same temperature range without SR treatment (direct tempering). The synthetic HAZ specimens are de-embrittled on application of suitable SR treatment (975 K × 5 hours). Subsequent reheating at 775 to 925 K, however, produces four different types of embrittlement in the specimens. These are the second, third, fourth, and fifth types of embrittlement already identified in the direct-tempered specimens. The first type of embrittlement which occurs during direct tempering in the shortest time range does not appear after SR treatment. The second type (the short-term type), which occurs over a wide time-temperature range during direct tempering, only appears in a narrow range after SR treatment. The third and fourth types (the long-term types) occur just as intensively as during direct tempering. The fifth type (the high-temperature type) also appears after SR treatment. This suggests that embrittlement in the short-term range is to some extent suppressed by SR treatment, but the types of embrittlement arising in the long-term range and high-temperature range occur after SR treatment as well. The ‘step cooling process’ can be applied for short-term detection of temper embrittlement in this steel. However, there is considered to be little or no embrittlement promotion effect due to step cooling per se.