Search results for "SPACE"
showing 10 items of 21658 documents
Age-related accumulation of congophilic fibrillar inclusions in endocrine cells
1991
Intracellular fibrillar congophilic inclusions are well known as neurofibrillary tangles in neurons and as Biondi bodies in choroid plexus epithelial cells. Recently similar amyloid-like inclusions in adrenal cortical cells were described (Eriksson and Westermark 1990). This study on 150 adrenal glands confirms these observations. In our material the age-related accumulation of congophilic inclusions starts earlier (in the sixth decade) and reaches a higher incidence (42.7%). We found similar intracellular inclusions in other endocrine organs, for example in the anterior lobe of the pituitary, in the cells of parathyroid glands and in Sertoli cells. The age-related incidence of these fibril…
Biochemical evidence that the atypical antipsychotic drugs clozapine and risperidone block 5-HT(2C) receptors in vivo.
2002
Clozapine and risperidone are two atypical antipsychotic drugs which bind, among other receptors, to 5-HT(2C) receptor subtypes. They inhibit the basal inositol phosphate production in mammalian cells expressing rat or human 5-HT(2C) receptors. This biochemical effect is indicative of inverse agonist activity at these receptors. There is evidence that 5-HT(2C) receptors are involved in the control of the activity of central dopaminergic system. Therefore, the effects of clozapine (5 mg/kg ip), risperidone (0.08 mg/kg ip) and of the typical antipsychotic haloperidol (0.1 mg/kg ip) were studied on the extracellular concentration of dopamine (DA) in the nucleus accumbens of chloral hydrate-ane…
Products of snowflaked Euclidean lines are not minimal for looking down
2017
We show that products of snowflaked Euclidean lines are not minimal for looking down. This question was raised in Fractured fractals and broken dreams, Problem 11.17, by David and Semmes. The proof uses arguments developed by Le Donne, Li and Rajala to prove that the Heisenberg group is not minimal for looking down. By a method of shortcuts, we define a new distance $d$ such that the product of snowflaked Euclidean lines looks down on $(\mathbb R^N,d)$, but not vice versa.
Risk Assessment of Fuel Quantity Indicator Replacement in ATR72 Aircraft
2015
Aircraft maintenance activities are rife with opportunities for error. The concurrent in-flight failure of all of the engines of a non-scheduled airline flight and the following list of human lives highlight one of these opportunities. As commonly recognized among flight operators, each flight safety agency follows the criteria of the International Civil Aviation Organization Annex 16 in which all the evidences of the technical investigation pave the way for avoiding future flight accidents or incidents. On the other hand, when the Italian penal procedure code was applied for the Tuninter aircraft ATR 72 (identification code TS-LBB) crash at issue on 6 August 2005 near Palermo (Italy), the…
An Extended Kalman Filter-Based Technique for On-Line Identification of Unmanned Aerial System Parameters
2015
ABSTRACT: The present article deals with the identification, at the same time, of aircraft stability and control parameters taking into account dynamic damping derivatives. Such derivatives, due to the rate of change of the angle of attack, are usually neglected. So the damping characteristics of aircraft dynamics are attributed only on pitch rate derivatives. To cope with the dynamic effects of these derivatives, authors developed devoted procedures to estimate them. In the present paper, a complete model of aerodynamic coefficients has been tuned-up to identify simultaneously the whole set of derivatives. Besides, in spite of the employed reduced order model and/or decoupled dynamics, a s…
Computational Analysis of the Active Control of Incompressible Airfoil Flutter Vibration Using a Piezoelectric V-Stack Actuator
2021
The flutter phenomenon is a potentially destructive aeroelastic vibration studied for the design of aircraft structures as it limits the flight envelope of the aircraft. The aim of this work is to propose a heuristic design of a piezoelectric actuator-based controller for flutter vibration suppression in order to extend the allowable speed range of the structure. Based on the numerical model of a three degrees of freedom (3DOF) airfoil and taking into account the FEM model of a V-stack piezoelectric actuator, a filtered PID controller is tuned using the population decline swarm optimizer PDSO algorithm, and gain scheduling (GS) of the controller parameters is used to make the control adapti…
Shock control bump design optimization on natural laminar aerofoil
2011
The chapter investigates Shock Control Bumps (SCB) on a Natural Laminar Flow (NLF) aerofoil; RAE 5243 for Active Flow Control (AFC). A SCB approach is used to decelerate supersonic flow on the suction/pressure sides of transonic aerofoil that leads delaying shock occurrence or weakening of shock strength. Such an AFC technique reduces significantly the total drag at transonic speeds. This chapter considers the SCB shape design optimisation at two boundary layer transition positions (0 and 45%) using an Euler software coupled with viscous boundary layer effects and robust Evolutionary Algorithms (EAs). The optimisation method is based on a canonical Evolution Strategy (ES) algorithm and inco…
Explicit Kutta Condition for Unsteady Two-Dimensional High-Order Potential Boundary Element Method
1997
An explicit unsteady pressure Kutta condition is discribed that was directly and efficiently implemented in a time domain high-order potential panel method so as to ensure the pressure equality on the upper and lower surfaces at the trailing edge of the airfoil at each time step.
Aroma release in the oral cavity after wine intake is influenced by wine matrix composition
2018
The aim of this study has been to investigate if wine matrix composition might influence the interaction between odorants and oral mucosa in the oral cavity during a “wine intake-like” situation. Aroma released after exposing the oral cavity of three individuals to different wines (n = 12) previously spiked with six target aromas was followed by an -in vivo intra-oral SPME approach. Results showed a significant effect of wine matrix composition on the intra-oral aroma release of certain odorants. Among the wine matrix parameters, phenolic compounds showed the largest impact. This effect was dependent on their chemical structure. Some phenolic acids (e.g. hippuric, caffeic) were associated t…
Search for neutral MSSM Higgs bosons at LEP
2006
The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the Minimal Supersymmetric Standard Model (MSSM). The data of the four collaborations are statistically combined and examined for their consistency with the background hypothesis and with a possible Higgs boson signal. The combined LEP data show no significant excess of events which would indicate the production of Higgs bosons. The search results are used to set upper bounds on the cross-sections of various Higgs-like event topologies. The results are interpreted within the MSSM in a number of "benchmark" models, including CP-conserving and CP-violating scenarios. Thes…