716 research outputs found
Model 0A wind turbine generator FMEA
The results of Failure Modes and Effects Analysis (FMEA) conducted for the Wind Turbine Generators are presented. The FMEA was performed for the functional modes of each system, subsystem, or component. The single-point failures were eliminated for most of the systems. The blade system was the only exception. The qualitative probability of a blade separating was estimated at level D-remote. Many changes were made to the hardware as a result of this analysis. The most significant change was the addition of the safety system. Operational experience and need to improve machine availability have resulted in subsequent changes to the various systems which are also reflected in this FMEA
Traveling-wave tube reliability estimates, life tests, and space flight experience
Infant mortality, useful life, and wearout phase of twt life are considered. The performance of existing developmental tubes, flight experience, and sequential hardware testing are evaluated. The reliability history of twt's in space applications is documented by considering: (1) the generic parts of the tube in light of the manner in which their design and operation affect the ultimate reliability of the device, (2) the flight experience of medium power tubes, and (3) the available life test data for existing space-qualified twt's in addition to those of high power devices
System reliability analysis through corona testing
A corona vacuum test facility for nondestructive testing of power system components was built in the Reliability and Quality Engineering Test Laboratories at the NASA Lewis Research Center. The facility was developed to simulate operating temperature and vacuum while monitoring corona discharges with residual gases. The facility is being used to test various high-voltage power system components
Integrative analysis of SF-1 transcription factor dosage impact on genome-wide binding and gene expression regulation
Steroidogenic Factor-1 (SF-1) is a nuclear receptor that has a pivotal role in the development of adrenal glands and gonads and in the control of steroid hormone production, being also implicated in the pathogenesis of adrenocortical tumors. We have analyzed the mechanisms how SF-1 controls gene expression in adrenocortical cells and showed that it regulates different categories of genes according to its dosage. Significant correlations exist between the localization of SF-1-binding sites in chromatin under different dosage conditions and dosage-dependent regulation of gene expression. Our study revealed unexpected functional interactions between SF-1 and Neuron-Restrictive Silencer Factor/RE1-Silencing Transcription Factor (NRSF/REST), which was first characterized as a repressor of neuronal gene expression in non-neuronal tissues, in the regulation of gene expression in steroidogenic cells. When overexpressed, SF-1 reshapes the repertoire of NRSF/REST—regulated genes, relieving repression of key steroidogenic genes. These data show that NRSF/REST has a novel function in regulating gene expression in steroidogenic cells and suggest that it may have a broad role in regulating tissue-specific gene expression programs
NR0B1 (nuclear receptor subfamily 0, group B, member 1)
Review on NR0B1, with data on DNA/RNA, on the protein encoded and where the gene is implicated
An Application of Discrete Inequality to Second Order Nonlinear Oscillation
AbstractBy using some simple discrete inequalities oscillation criteria are provided for the second order difference equations Δ2yn+an+1ƒ(yn+1)=0 n∈N where the operator Δ is defined by Δyn=yn+1−yn, {an} is a real sequence. The function ƒ is such that uƒ(u)>0 for u≠0 and ƒ(u)−ƒ(v)=g(u, v)(u−v) for u, v≠0 for some nonnegative function g
Simultaneous Continuation of Infinitely Many Sinks Near a Quadratic Homoclinic Tangency
We prove that the diffeomorphisms on surfaces, exhibiting infinitely
many sinksnear the generic unfolding of a quadratic homoclinic tangency of a
dissipative saddle, can be perturbed along an infinite dimensional manifold of
diffeomorphisms such that infinitely many sinks persist simultaneously.
On the other hand, if they are perturbed along one-parameter families that
unfold generically the quadratic tangencies, then at most a finite number of
those sinks have continuation
Mechanisms of institutional continuity in neoliberal "success stories" : developmental regimes in Chile and Estonia
© 2015 by The American Society for Biochemistry and Molecular Biology, Inc. Several mycoplasmas, such as the emergent human pathogen Mycoplasma genitalium, developed a complex polar structure, known as the terminal organelle (TO), responsible for a new type of cellular motility, which is involved in a variety of cell functions: cell division, adherence to host cells, and virulence. The TO cytoskeleton is organized as a multisubunit dynamic motor, including three main ultrastructures: the terminal button, the electrodense core, and the wheel complex. Here, we describe the interaction between MG200 and MG491, two of the main components of the TO wheel complex that connects the TO with the cell body and the cell membrane. The interaction between MG200 and MG491 has a KD in the 80 nM range, as determined by surface plasmon resonance. The interface between the two partners was confined to the >enriched in aromatic and glycine residues> (EAGR) box of MG200, previously described as a protein-protein interaction domain, and to a 25-residue-long peptide from the C-terminal region of MG491 by surface plasmon resonance and NMR spectroscopy studies. An atomic description of the MG200 EAGR box binding surface was also provided by solution NMR. An M. genitalium mutant lacking the MG491 segment corresponding to the peptide reveals specific alterations in cell motility and cell morphology indicating that the MG200-MG491 interaction plays a key role in the stability and functioning of the TO.This work was supported by Ministerio de Ciencia e Innovacion Grants BFU2012-36827 (to I. F.) and BFU2010-22209-C02-01 (to E. Q.), a grant from the Centre de Referencia de R+D de Biotecnologia (Generalitat de Catalunya, Spain) (to E. Q.), and by FEDER funds through the Operational Competitiveness Programme-COMPETE and by Portuguese national funds through FCT-Fundação para a Ciência e a Tecnologia under Project FCOMP-01-0124-FEDER-027581 (EXPL/BBB-BQB/0546/2012) (to B. C.). The NMR characterization was conducted through the FP7 Access to Research Infrastructures (Bio-NMR Contract 261863) and by Instruct, which is part of the European Strategy Forum on Research Infrastructures (ESFRI) and supported by national member subscriptionsPeer Reviewe
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