Search results for "Sound"
showing 10 items of 1845 documents
A comprehensive study on the atom flow in the cross-field discharge of a Hall thruster
2011
The flow properties of Xe atoms were investigated in the 1 kW class PPS100-ML Hall effect thruster by means of Doppler-shifted laser-induced fluorescence spectroscopy in the near infrared. Fluorescence spectra of the resonant level and the metastable level have been acquired inside and outside the thruster channel under several operating conditions. Analytical treatment and modelling of the measured lineshapes indicate the atom axial velocity increases inside the channel to a value well above the sound speed before decreasing quickly in the near-field plume. Numerical simulations performed with a fluid/kinetic hybrid approach allow us to explain the shape of the velocity profile. Atomic flo…
Entwicklung der Hornhautdicke während der UV-Vernetzungstherapie unter Anwendung verschiedener Kompositionen von Riboflavin-Augentropfen
2011
Background During the UVA-cross-linking treatment in keratoconus patients, the UVA rays are partially absorbed in the stroma of the riboflavin-loaded cornea. This effect protects the corneal endothelium from UVA irradiation damage. The intensity of UVA light reaching the endothelium is inversely correlated with corneal thickness. The common composition of riboflavin eye drops may lead to a marked reduction in corneal thickness increasing the risk of endothelial damage. Patients and methods In a retrospective analysis of 23 UVA-cross-linking procedures on 23 patients we collected data about the pre-, intra- and postoperative corneal thickness (measured with ultrasound). Among these patients …
A Note on Palaeolithic Soundscapes. Further Thoughts on the LMT (Landscape Mind Theory)
2010
Homo sapiens sapies' mind possesses a cognitive module specifically for landscape that spatially organizes perceptions, representations and individual and collective knowledge. This module also acts in the conceptual and symbolic organization of sounds.
Sonographische Verlaufskontrolle von experimentellen Muskelverletzungen
1995
Experimental muscle lesions were produced in 28 rabbits by stab incision, thus creating a lesion of known extent and site. The changes in the course of healing were followed up and documented at short intervals for a period of two months via sonography. The changes take place in regular course and can be explained by fine tissue changes, taking into consideration the fundamentals of theoretical ultrasound physics. Sonography renders both valuable assistance in diagnosing muscular lesions and in following up the healing process--the latter, however, with some reservations due to the clinical terminology defining the extent of muscular lesions.
New trends in photobiology
1993
Abstract At the beginning of our century few scientists paid attention to the phenomenon of inactivation of photosynthesis by high light intensities which was later called photoinhibition. In the period 1925–1950, the idea was established that photoinhibition is a reversible inactivation, determined by light intensity and exposure time, followed by irreversible damage of the photosynthetic apparatus. However, the absence of a uniform terminology demonstrates that photoinhibition was not completely perceived and understood. In 1956, B. Kok gave the first definition of photoinhibition as a photochemical inactivation of pigment complexes.
Hyperspectral venous image quality assessment for optimum illumination range selection based on skin tone characteristics
2014
Background Subcutaneous veins localization is usually performed manually by medical staff to find suitable vein to insert catheter for medication delivery or blood sample function. The rule of thumb is to find large and straight enough vein for the medication to flow inside of the selected blood vessel without any obstruction. The problem of peripheral difficult venous access arises when patient’s veins are not visible due to any reason like dark skin tone, presence of hair, high body fat or dehydrated condition, etc. Methods To enhance the visibility of veins, near infrared imaging systems is used to assist medical staff in veins localization process. Optimum illumination is crucial to obt…
Effects of high power ultrasound treatments on the phenolic, chromatic and aroma composition of young and aged red wine
2019
Abstract In this study, the effects of both ultrasonic bath and probe treatments on the phenolic, chromatic and aroma composition of young red wine Cabernet Sauvignon were studied and modeled by artificial neural networks (ANNs). Moreover, the effect of high power ultrasound (HPU) along with antioxidants addition (sulfur dioxide and glutathione) was investigated during 6 months of aging in bottles. Lower amplitude and temperature, shorter treatment duration and particularly lower frequency showed a more favorable and milder effect on the chemical composition of wine. In the case of the ultrasonic probe treatment, similar effect was achieved primarily by a larger probe diameter as well as lo…
Diagnóstico de Metástasis Ováricas de un linfoma B diseminado mediante ecografía 3D
2018
RESUMEN La participación del aparato genitourinario en el contexto de la enfermedad hematológica maligna es bien conocida. No obstante, la afectación ovárica por linfomas es inusual, ya sea de novo o como manifestación tardía de linfoma diseminado. El objetivo de esta comunicación es exponer la aportación diagnóstica de la ecografía tridimensional (3D) en la detección de metástasis ováricas, cuando todavía algunas de las pruebas de imagen estándar como la tomografía computarizada (TAC) son normales. En este caso presentamos una paciente con linfoma B difuso de células grandes mediastínico de crecimiento rápido y diseminación precoz a aparato gastrointestinal y genitourinario. ABSTRACT Genit…
For the use of sound. Film sound analysis for audio-description: some key issues
2012
This article aims to outline the issues involved in the production and reception of film sound with a view to identifying its challenges for audio-description (AD). It thereby hopes to provide insights into the way in which a careful analysis and integration of film sound and sound effects are required for the production of coherence in AD, if it is to function as part of a new filmic text. However, the article also points to the limits of analysis and interpretation, and to the need for reception research as well as collaboration with visually impaired users. A detailed analysis of a scene from Saving Private Ryan (Spielberg 1998), a film that won an Oscar for best sound effect editing, de…
Numerical and experimental study of liquid metal stirring by rotating permanent magnets
2018
In this work, we study liquid gallium stirring by rotating permanent magnets. We demonstrate possibility of easily creating different flow patterns by rotating permanent magnets, which can be industrially important for controlling heat and mass transfer processes in the system. Unlike the typical approach of simulating magnet rotation as a transient problem and time-averaging the Lorentz forces, we solve the magnet rotation as a harmonic (frequency domain) problem, which leads to forces equal to time-averaged ones and decreases the simulation time considerably. Numerical results are validated using qualitative flow structure results from the neutron radiography visualization of tracer parti…