Search results for "IPR"

Dielectric investigations of pure and mixed fluorocarbons in their condensed phases

1991

We review recent work and present new results on the liquid and solid fluocarbons CMF3 with M = H, F, Cl, Br, CH3, and CF3. The pure compounds as well as several series of binary mixtures were investigated using dielectric measurements. The permittivities of the non-hydrogenatcd non-polar and polar liquids could be described using the Clausius-Mosotti and the Onsager equation, respectively. In CHF3 and C2H3F3 hydrogen bridging leads to deviations from this simple behavior. The trends in the miscibility of four series of fluorocarbon mixtures are in qualitative accord with regular solution theory. The geometrical shapes of the compounds dominate the degrees of order below their melting point…

La aporofobia como desafío antropológico. De la lógica de la cooperación a la lógica del reconocimiento

2019

el objetivo de este trabajo es poner en relación el núcleo crítico de la última obra de Adela Cortina, Aporofobia, que puede ser resu- mido como una protesta contra los límites del paradigma de la cooperación y la reciprocidad, con algunos elementos aparecidos en obras ante- riores de la autora 1 . Para ello expondré primero algunos límites y virtualidades del paradigma de la reciprocidad. Tras bosquejar el núcleo de la obra Aporofobia, deteniéndome en los lugares en que este problema se hace más patente, terminaré rastreando algunos lugares anteriores en los que la autora anticipaba ya, desde una óptica diferente, esta misma crítica. he aim of this paper is to connect the critical core of …

Influence of peroxisome proliferators on phosphoprotein levels in human and rat hepatic-derived cell lines.

1995

To elucidate the effect of peroxisome proliferators on the signal-transduction pathway, we have compared the effect of ciprofibrate, an hypolipaemic agent, on the overall phosphoprotein level between rat and human well differentiated hepatic derived cell lines. The phosphorylation status of several phosphoproteins in the rat Fao cell line was increased by the drug while no changes were observed in the human HepG2 cell line. In rat Fao cells, this increase, which is concentration and time dependent, can be as much as eightfold for 20-kDa and 22-kDa proteins. Wy-14,643, a non-fibrate molecule and a more potent peroxisome proliferator than ciprofibrate, increased the phosphorylation status of …

FUSED NITROGEN HETEROCYCLES AS PROMISING SMALL MOLECULES FOR THE TREATMENT OF CANCER

2020

The PANDA DIRC Detectors at FAIR

2017

The PANDA detector at the international accelerator Facility for Antiproton and Ion Research in Europe (FAIR) addresses fundamental questions of hadron physics. An excellent hadronic particle identification (PID) will be accomplished by two DIRC (Detection of Internally Reflected Cherenkov light) counters in the target spectrometer. The design for the barrel region covering polar angles between 22 deg. to 140 deg. is based on the successful BABAR DIRC with several key improvements, such as fast photon timing and a compact imaging region. The novel Endcap Disc DIRC will cover the smaller forward angles between 5 deg. (10 deg.) to 22 deg. in the vertical (horizontal) direction. Both DIRC coun…

Time imaging reconstruction for the PANDA Barrel DIRC

2020

The innovative Barrel DIRC (Detection of Internally Reflected Cherenkov light) counter will provide hadronic particle identification (PID) in the central region of the PANDA experiment at the new Facility for Antiproton and Ion Research (FAIR), Darmstadt, Germany. This detector is designed to separate charged pions and kaons with at least 3 standard deviations for momenta up to 3.5 GeV/c, covering the polar angle range of 22$^{\circ}$-140$^{\circ}$. An array of microchannel plate photomultiplier tubes is used to detect the location and arrival time of the Cherenkov photons with a position resolution of 2 mm and time precision of about 100 ps. The time imaging reconstruction has been develop…

Visualizing a protein quake with time-resolved X-ray scattering at a free-electron laser

2014

We describe a method to measure ultrafast protein structural changes using time-resolved wide-angle X-ray scattering at an X-ray free-electron laser. We demonstrated this approach using multiphoton excitation of the Blastochloris viridis photosynthetic reaction center, observing an ultrafast global conformational change that arises within picoseconds and precedes the propagation of heat through the protein. This provides direct structural evidence for a 'protein quake': the hypothesis that proteins rapidly dissipate energy through quake-like structural motions. peerReviewed

Necessary Transformation or Safe Permanence? A Philosophical Approach to the Desire for Change

2011

What is proposed is a meditation on the phrase ‘transformation of the educational system’, paying attention to the sense of the words, and showing what the desire for educational change can reveal. After explaining to what extent ‘educational system’ is a quasi-oxymoron, the meaning of ‘transformation’ has to be compared to those of revolution and utopia. The claim to be transforming the educational system is an attempt to adapt education to social and political situations and constraints. The case of the Langevin-Wallon project in France, which was never applied, helps when wondering what has to be adapted to what. What sort of reciprocity is there between school and society? The organisa…

Drift chamber calibration and particle identification in the P-349 experiment

2019

The goal of the P-349 experiment is to test whether 3.5 GeV/c antiprotons produced in high-energy proton-proton collisions are polarized in view of the preparation of a polarized antiproton beam. In this article, we present the details of the ongoing analysis focused on the drift chambers calibration and particle identification with DIRC.

Precision mass measurements of antiprotons in a Penning trap

1992

Utilizing electron cooling, the TRAP collaboration has lowered the energy at which antiprotons can be stored and studied by more than 10 orders of magnitude, starting with 6 MeV particles from LEAR. We have held cryogenic antiprotons a few degrees above absolute zero for two months and the storage lifetime so established, more than 3.4 months is the longest directly measured limit for antiprotons. Measuring their cyclotron frequencies in a precision cylindrical Penning trap, we have shown that the inertial masses of the antiprotons and protons are the same to a fractional accuracy of 4 parts in 108, a 1000-fold improvement over the previous comparisons. This is the most stringent test of CP…