3,310 research outputs found

    Discussant\u27s response to taxonomization of internal controls and errors for audit research

    Get PDF
    https://egrove.olemiss.edu/dl_proceedings/1126/thumbnail.jp

    Electronic Structure and Stability of Hydrogen Halides and of Complex Ions XO4

    Full text link
    (1) It is shown that in the hydrogen halide molecules (internuclear distance r0) the proton penetrates the electronic shell of the anion to a depth which for the simplified case of spherical symmetry can be characterized by the condition: The amount of negative charge beyond the sphere of radius r0 equals −1e. (2) From the dipole moments μ=xer0 of the hydrogen halide molecules it can be concluded: The wave mechanical distribution of the negative charge of the free halide ions is changed by the introduction of the proton in such a way that the center of gravity of an amount of charge equal to —(1−x)e is shifted from the halogen nucleus to the proton. The fraction (1—x) increases with the electronic polarizability of the anion, and would be equal to 1 for an ion of infinitely large polarizability, leading to a completely unpolar type of binding in this case. (3) It is shown that for the complex ions SiO44—, PO43—, SO4=, and ClO4−, the gradation of the X☒O distances and of the molar dispersion can be easily understood from the point of view used in 1924 for the case of the molar refraction: These ions represent the result of the polarization of O= by Si4+, P5+, S6+, and Cl7+, and the X☒O binding in them shows gradual changes toward the unpolar type. (4) It is pointed out that the relatively unstable HI and ClO4− approach the unpolar type of binding more closely than any other of the compounds considered here. The generalization of this connection between instability and the degree of deformation of electronic shells explains why compounds like FO4− and BrO4− are unknown.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70366/2/JCPSA6-10-7-410-1.pd

    On stability of switched differential algebraic systems – conditions and applications

    Get PDF
    We obtain an efficient parametrization that ensures stability of switched linear systems under arbitrary switching. Apart from stability analysis, our results are useful for addressing several important system theoretic problems, e.g. designing controllers that ensure robustness against arbitrary combinations of sensor or actuator failure. We illustrate our results by considering control of a distillation column

    Et og andet om tibetanske Bøger og deres Fremstilling

    Get PDF

    Geometric variational problems of statistical mechanics and of combinatorics

    Full text link
    We present the geometric solutions of the various extremal problems of statistical mechanics and combinatorics. Together with the Wulff construction, which predicts the shape of the crystals, we discuss the construction which exhibits the shape of a typical Young diagram and of a typical skyscraper.Comment: 10 page

    KCNK5 is Functionally Down-Regulated Upon Long-Term Hypotonicity in Ehrlich Ascites Tumor Cells

    Get PDF
    Background/Aims: Regulatory volume decrease (RVD) in response to acute cell swelling is well described and KCNK5 (also known as TASK-2 or K2P5.1) has been shown to be the volume sensitive K+ channel in Ehrlich cells. Very little is, on the other hand, known about the effects of long-term hypotonicity on expression and function of KCNK5, thus we have investigated the effect of long-term hypotonicity (24h - 48h) on KCNK5 in Ehrlich cells on the mRNA, protein and physiological levels. Methods: Physiological effects of long-term hypotonicity were measured using patch-clamp and Coulter counter techniques. Expression patterns of KCNK5 on mRNA and protein levels were established using real-time qPCR and western blotting respectively. Results: The maximum swelling-activated current through KCNK5 was significantly decreased upon 48h of hypotonicity and likewise the RVD response was significantly impaired after both 24 and 48h of hypotonic stimulation. No significant differences in the KCNK5 mRNA expression patterns between control and stimulated cells were observed, but a significant decrease in the KCNK5 protein level 48h after stimulation was found. Conclusion: The data suggest that the strong physiological impairment of KCNK5 in Ehrlich cells after long-term hypotonic stimulation is predominantly due to down-regulation of the KCNK5 protein synthesis

    Developmental pathways towards mood disorders in adult life: Is there a role for sleep disturbances?

    Get PDF
    Introduction: Mood disorders are among the most prevalent and serious mental disorders and rank high among to the leading global burdens of disease. The developmental psychopathology framework can offer a life course perspective on them thus providing a basis for early prevention and intervention. Sleep disturbances, are considered risk factors for mood disorders across childhood, adolescence and adulthood. Assuming that sleep disturbances may play a pivotal role in the pathogenesis of mood disorders from a life course point of view, we reviewed the data on developmental pathways towards mood disorders in adult life in relation to sleep disturbances. Method: From February 2017, a systematic search was conducted in PubMed, PsycINFO and Embase electronic databases for literature on developmental pathways to mood disorders in adult life in relation to sleep disturbances and to 1) pre-natal stress, 2) early brain developmental processes, and 3) temperaments, character and attachment style. Results: Eleven, 54 and 15 articles were respectively selected. Conclusions: Experimental and clinical studies revealed that exposure to prenatal/early life stress results in sleep disturbances such as poor sleep and altered circadian regulation phases and may predict or even precipitate mood disorders in adulthood. Chronic sleep disruption may interfere with neuronal plasticity, connectivity and the developing brain thus contributing to the development of mood disorders. In addition sleep and circadian dysregulations have been shown to be related to those temperaments, character and attachment styles which are considered precursors of mood disorders. Sleep and circadian behaviours may serve as early targets regarding mood disorders

    Brazing in SiH4-Doped Inert Gases: A New Approach to an Environment Friendly Production Process

    Get PDF
    Engineering under protective atmospheres or in vacuum allows the production of materials and components, where the absence of oxygen is an essential requirement for a successful processing. Ideally, joining or coating of (and with) metallic materials needs oxide free material surfaces, in order to achieve durable joints or coatings. Using the established technology of brazing in controlled atmosphere, fundamental physical mechanisms for deoxidation of metal surfaces are presented and the role of oxygen and water residue in the process atmosphere is analyzed. Furthermore, the doping of gases with monosilane for generating virtually oxygen-free process atmospheres is introduced and its advantages for an oxygen-free production are discussed. © 2019, The Author(s)

    A quadratic stability result for singular switched systems with application to anti-windup control

    Get PDF
    In this note we consider the problem of determining necessary and sufficient conditions for the existence of a common quadratic Lyapunov function for a pair of stable linear time-invariant systems whose system matrices are of the form A, A−ghT , and where one of the matrices is singular. We then apply this result in a study of a feedback system with a saturating actuator
    • …
    corecore