Comparison of I-V, CV, and chemical datafor quality control studies of SiOxNy films on Si

Capacitance-voltage (CV) and current-voltage (I- V) measurements for SiO_xN_y films are compared with chemical data in order to provide some diagnostic capabilities in relating aberrant electrical characteristics with contaminants incorporated in the insulator film structure. In-process monitoring of film quality (utilizing electrical characteristics and chemical data) is especially critical in very large-scale integration (VLSI) processing control where the films are utilized both as an integral part of specific semiconductor device processing steps or as part of the semiconductor device structure     

On crack extension sensitivity

The relationship between the critical stress intensity factor and the energy release rate is re-examined. It is shown that additional terms of the Williams' series can be used to provide insight into the sensitivity of crack extension after crack initiation.

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Résumé On réévalue la relation qui lie le facteur d'intensité critique de contraintes et la vitesse de relaxation de l'énergie et on montre que l'on peut utiliser les termes additionnels de la série de Williams pour avoir un aperçu de la sensibilité à l'extension d'une fissure après son amorçage.

     

Size-exclusion phases and repulsive protein--polymer interaction/recognition

Size-dependent exclusion of macromolecules from gel matrices has long been discussed in terms of pore models. An alternate approach is to calculate the partition coefficient of the distributed species between the matrix material and the mobile phase assuming that the gel can be treated as a polymer solution of appropriate concentration and molecular weight. This approach is particularly appealing in attempting to predict the behaviour of 'tentacle' phases in which the matrix contains anchored linear neutral polymers. The mean field theory of polymer solution is used to predict K, the partition coefficient of a polymer molecule distributing between the gel and mobile phases. The reduction in entropy suffered by the macromolecule in the gel phase is sufficient to produce an exponential dependence of K on the molecular weight of the partitioning species. The enthalpy of interaction between the gel polymer and the distributed species provides a parameter which describes the specificity or recognition in the interaction. The predicted linear dependence of in K on protein molecular weight is satisfactorily borne out by a data set on eight standard proteins chromatographed on four separate gel types.     

Psychiatric diagnosis and the surgical outcome of pancreas transplantation in patients with type I diabetes mellitus

To examine the role of psychiatric diagnosis in the surgical outcome of pancreas transplantation, we studied candidates with type I diabetes mellitus. Eighty of 140 candidates underwent transplantation. Survival analysis found the extent of human leukocyte antigen-DR (HLA-DR) matching, two diagnoses, and patients' perceived support from first-degree relatives to be related to duration of full-graft function. Lifetime diagnoses of tobacco use disorder (P = 0.029) and alcohol abuse/dependence (P = 0.006) were associated with less favorable outcomes; perceived support was associated with positive outcomes (P = 0.048). Subsequent analysis suggested that the four variables independently and directly affect outcome.     

Spare receptors and intrinsic activity: studies with D1 dopamine receptor agonists

Anti-nitric oxide synthase antibody was used to study the distribution, cytoarchitecture, and synaptic relations of nitric oxide synthase-like immunoreactive neurons in the whole rostral-caudal length of the dorsal raphe nucleus of the rat and compared them with serotonergic neurons. Results showed that the distribution of the nitric oxide synthase in the dorsal raphe nucleus was similar to that of the serotonergic neurons at the rostral part of the dorsal raphe nucleus, including the mediodorsal and the medioventral cell groups, and changed at the middle and caudal parts of the dorsal raphe nucleus. The cytoarchitecture of the nitric oxide synthase-like immunoreactive neurons in the medioventral cell group of the dorsal raphe nucleus was similar to that of the serotonergic neurons. Similar to the serotonergic neurons there, nitric oxide synthase-like immunoreactive neurons also received synapses from axon terminals that contained round, or flattened vesicles, or both kinds. Different to the serotonergic neurons, the few nitric oxide synthase-like immunoreactive axon terminals that were in this area formed synapses.     

Dynamic Modeling of Large-Scale Magnetorheological Damper Systems for Civil Engineering Applications

Magnetorheological (MR) dampers are one of the most promising new devices for structural vibration mitigation. Because of their mechanical simplicity, high dynamic range, low power requirements, large force capacity, and robustness, these devices have been shown to mesh well with earthquake and wind engineering application demands and constraints. Quasistatic models of MR dampers have been investigated by researchers. Although useful for damper design, these models are not sufficient to describe the MR damper behavior under dynamic loading. This paper presents a new dynamic model of the overall MR damper system which is comprised of two parts: (1) a dynamic model of the power supply and (2) a dynamic model of the MR damper. Because previous studies have demonstrated that a current-driven power supply can substantially reduce the MR damper response time, this study employs a current driver to power the MR damper. The operating principles of the current driver, and an appropriate dynamic model are provided. Subsequently, MR damper force response analysis is performed, and a phenomenological model based on the Bouc–Wen model is proposed to estimate the MR damper behavior under dynamic loading. This model accommodates the MR fluid stiction phenomenon, as well as fluid inertial and shear thinning effects. Compared with other types of models based on the Bouc–Wen model, the proposed model has been shown to be more effective, especially in describing the force rolloff in the low velocity region, force overshoots when velocity changes in sign, and two clockwise hysteresis loops at the velocity extremes.     

Comparison of the structure and expression of odd-skipped and two related genes that encode a new family of zinc finger proteins in Drosophila

The odd-skipped (odd) gene, which was identified on the basis of a pair-rule segmentation phenotype in mutant embryos, is initially expressed in the Drosophila embryo in seven pair-rule stripes, but later exhibits a segment polarity-like pattern for which no phenotypic correlate is apparent. We have molecularly characterized two embryonically expressed odd-cognate genes, sob and bowel (bowl), that encode proteins with highly conserved C2H2 zinc fingers. While the Sob and Bowl proteins each contain five tandem fingers, the Odd protein lacks a fifth (C-terminal) finger and is also less conserved among the four common fingers. Reminiscent of many segmentation gene paralogues, the closely linked odd and sob genes are expressed during embryogenesis in similar striped patterns; in contrast, the less-tightly linked bowl gene is expressed in a distinctly different pattern at the termini of the early embryo. Although our results indicate that odd and sob are more likely than bowl to share overlapping developmental roles, some functional divergence between the Odd and Sob proteins is suggested by the absence of homology outside the zinc fingers, and also by amino acid substitutions in the Odd zinc fingers at positions that appear to be constrained in Sob and Bowl