Search results for "InP"

Theory of modal attraction in bimodal birefringent optical fibers

2013

Nonlinear mode coupling among two beams of different wavelength that copropagate in a bimodal highly birefringent optical fiber may lead to the effect of modal attraction. Under such circumstances, the modal distribution of light at a pump wavelength is replicated at the signal wavelength, nearly irrespective of the input mode excitation conditions of the signal.

Nonlinear repolarization dynamics in optical fibers: transient polarization attraction

2011

International audience; In this work, we present a theoretical and experimental study of the response of a lossless polarizer to a signal beam with a time-varying state of polarization (SOP). By lossless polarizer, we mean a nonlinear conservative medium (e.g., an optical fiber) that is counterpumped by an intense and fully polarized pump beam. Such a medium transforms input uniform or random distributions of the SOP of an intense signal beam into output distributions that are tightly localized around a well-defined SOP. We introduce and characterize an important parameter of a lossless polarizer--its response time. Whenever the fluctuations of the SOP of the input signal beam are slower th…

A review of DEA models when the internal structure of the decision making units is considered

2005

Classical Data Envelopment Analysis (DEA) models consider each Decision Making Unit (DMU), whose relative efficiency they evaluate, as a "black box", i.e., its internal structure is disregarded. The paper presents a comprehensive framework of the most advanced theoretical findings in DEA when the internal structure of the. DMUs is taken into account, thus giving directions for novel applications of such methodology and introducing it as a powerful toot for complex processes performance evaluation.

Mapping palliative care provision in European prisons

2021

ObjectivesPrison populations around the world are ageing and numbers are rising, leading to greater demand for palliative care for prisoners approaching the end of life. This paper reports a survey that was undertaken by the European Association for Palliative Care Task Force on mapping palliative care provision for prisoners in Europe. The Task Force was established to begin to address the gap in research knowledge by exploring prison systems and care provision across different countries.MethodsThe survey, developed by the Task Force Steering Committee, consisted of 40 questions in six sections. It was completed through online searches; only data that were publicly available on the interne…

A subset of ventral tegmental area dopamine neurons responds to acute ethanol

2015

The mechanisms by which alcohol drinking promotes addiction in humans and self-administration in rodents remain obscure, but it is well known that alcohol can enhance dopamine (DA) neurotransmission from neurons of the ventral tegmental area (VTA) and increase DA levels within the nucleus accumbens and prefrontal cortex. We recorded from identified DA neuronal cell bodies within ventral midbrain slices prepared from a transgenic mouse line (TH-GFP) using long-term stable extracellular recordings in a variety of locations and carefully mapped the responses to applied ethanol (EtOH). We identified a subset of DA neurons in the medial VTA located within the rostral linear and interfascicular n…

2019

Background: Recently, the number of refugees in Germany has skyrocketed, leading to a marked increase in refugee children admitted to hospitals. This study describes the special characteristics encountered in pediatric surgical inpatient refugees compared to locally residing patients. Methods: Hospital records of minor refugees admitted to our department from 2005 up to and including 2015 were retrospectively reviewed. Demographic data, diagnoses, comorbidities, body mass indexes, hemoglobin values, and lengths of stay were extracted and statistically compared to local patients. Results: A total of 63 refugee children were analyzed and compared to 24,983 locally residing children. There was…

Evaluation of Organophosphorus Pesticide Residues in Citrus Fruits from the Valencian Community (Spain)

1997

Abstract Approximately 200 citrus samples from markets of the Valencian Community (Spain) were analyzed to establish their residue levels in 12 organophosphorus pesticide residues during the 1994-1995 campaign. The organophosphorus pesticides carbophenothion, chlorpyriphos, chlorfenvinphos, diazinon, ethion, fenitrothion, malathion, methidation, methylparathion, phosmet, quinalphos, and tetradifon were simultaneously extracted by matrix solidphase dispersion and determined by gas chromatography- mass spectrometry using selected ion monitoring mode. A total of 32.25% contained pesticide residues and 6.9% exceeded the European Union Maximum Residue Levels (MRLs). The pesticides found in the s…

NMR enantiodifferentiation of triphenylphosphonium salts by chiral hexacoordinated phosphate anions

2003

BINPHAT anion—rather than TRISPHAT—is an efficient NMR chiral shift reagent for triphenylphosphonium salts containing stereogenic centers on the aliphatic side-chain. BINPHAT—rather than TRISPHAT—anion is an efficient NMR (1H and 31P) chiral shift reagent for chiral triphenylphosphonium salts.

Characterization of PTW-31015 PinPoint ionization chambers in photon and proton beams

2018

The increased use of complex forms of radiotherapy using small-field photon and proton beams has invoked a growing interest in the use of micro-ionization chambers. In this study, 48 PTW-TM31015 PinPoint-type micro-ionization chambers that are used in the commissioning and patient specific QA of a proton pencil beam scanning (PBS) delivery system have been characterized in proton and high-energy photon beams. In both beam modalities, the entire set of PinPoint chambers was characterized by imaging them, by evaluating their stability using check source measurements, by experimentally determining the ion recombination, polarity effect and by cross calibrating them in terms of absorbed dose to…

Field Dependence of the Electron Spin Relaxation in Quantum Dots

2005

Interaction of the electron spin with local elastic twists due to transverse phonons has been studied. Universal dependence of the spin relaxation rate on the strength and direction of the magnetic field has been obtained in terms of the electron gyromagnetic tensor and macroscopic elastic constants of the solid. The theory contains no unknown parameters and it can be easily tested in experiment. At high magnetic field it provides parameter-free lower bound on the electron spin relaxation in quantum dots.