On the opto-voltaic measurements in CO and CO2 lasers

We observed and compared the opto-voltaic signals in CO and CO2 lasers. The signals are obtained capacitively from the water cooling jacket as a low voltage source not influencing the current circuit. We observed from measurement that the output power and the so-called optovoltaic input power have a distinct relationship depending on laser current and cavity parameters. It will be shown that opto-voltaic detection is a very sensitive method especially for CO lasers

High pressure X-ray preionized TEMA-CO2 laser

The construction of a high-pressure (up to 20 atm) transversely excited CO2 laser using transverse X-ray preionization is described. High pressure operation was found to be greatly improved in comparison to UV-preionized systems. Homogeneous discharges have been achieved in the pressure range 5–20 atm, yielding a specific laser output in the order of 35 J/l

Towards a cognitive neuroscience of prosody perception and its modulation by alexithymia

This dissertation examines what network in the human brain is involved in the perception of prosody and whether activity within this network is modulated by the personality trait alexithymia. The first four chapters of this dissertation reveal that a bihemispheric network consisting of Heschl__s gyrus, the middle superior temporal gyrus, the posterior superior temporal gyrus and the pars opercularis of the inferior frontal gyrus is involved in the perception of emotional prosody. Furthermore, relative right hemispheric specialization for emotional prosody perception can be demonstrated but no hemispheric specialization can be found for linguistic prosody perception. Moreover, hemispheric specialization for emotional prosody perception seems to be driven by hemispheric specialization for non-prosody-specific acoustic dimensions of the speech signal, and not for abstract emotional processing. Additionally, automaticity of processing can be demonstrated for emotional prosody, particularly for anger, but not for emotional music. Last, alexithymia can indeed be demonstrated to modulate activity within the emotional prosody perception network, particularly at relatively early components of the emotional prosody perception pathway. This dissertation is of interest to neurolinguists, (neuro-)phoneticians, psychologists, cognitive neuroscientists, comparative biologists and neurologists specialized in aphasiaUBL - phd migration 201

Characteristics and content of intrusive images in patients with eating disorders

Contains fulltext : 206049.pdf (publisher's version ) (Open Access)The aim of this study was to examine the characteristics and content of intrusive images in patients with different subtypes of eating disorders (EDs). Data were collected from 74 ED patients, 22 dieting and 29 non-dieting controls. Participants completed a set of self-report questionnaires. Intrusive images of ED patients were significantly more repetitive, detailed, vivid and distressing than intrusive images of dieting and/or non-dieting controls. Most of the intrusive images were the same for the ED subtypes, however patients with AN were more likely to report an observer vantage perspective than patients with BN, who were more likely to report a field vantage perspective. As expected, intrusive images' content was related to body-checking (weight and shape) or negative self (evaluated by themselves or others). Finally, there were significant associations between intrusive images' vividness and weight and shape concerns. These findings indicate that intrusive images may be a core element of EDs and targeting intrusive images in therapy may be helpful.12 p

Transverse Optical Mode Patterns for an RF Excited Ar-He-Xe Laser

Transverse optical modes for an RF excited Ar-He-Xe laser are studied both experimentally and theoretically. A diffraction model for a waveguide with a nonsaturable gain and refractive index gradients placed between two plane mirrors is formulated. The effects of gain and diffraction index gradients and of diffraction in free space are evaluated for typical experimental conditions. A direct comparison between theoretical mode patterns and experimentally measured ones at distances of 17 and 114 cm from the output mirror demonstrated a satisfactory agreement for various laser wavelengths and gas mixture composition

Formation and quenching mechanisms of the electron beam pumped (XeRb)+ ionic excimer in different buffer gases

The ionic excimer molecule XeRb+ is formed in an electron beam excited gas mixture of Xe, Rb, and a buffer gas. The formation and quenching mechanisms of ionic excimers are investigated by measuring the XeRb+fluorescence as a function of the gas composition and gas pressure. The formation of XeRb+ is achieved by a three‐body association reaction between Xe+, Rb, and a buffer gas atom. For the buffer gases He, Ne, or Ar the values of the important formationrate constants are determined from the observed fluorescence signal decay