Newtonian liquid jet impaction on a high-speed moving surface

In the railroad industry a friction modifying agent may be applied to the rail or wheel in the form of a liquid jet. In this mode of application the interaction between the high-speed liquid jet and a fast moving surface is important. Seven different Newtonian liquids with widely varying shear viscosities were tested to isolate the effect of viscosity from other fluid properties. Tests were also done on five surfaces of different roughness heights to investigate the effects of surface roughness. High-speed video imaging was employed to scrutinize the interaction between the impacting jet and the moving surface. For all surfaces, decreasing the Reynolds number reduced the incidence of splash and consequently enhanced the transfer efficiency. At the elevated Weber numbers of the testing, the Weber number had a much smaller impact on splash than the Reynolds number. The ratio of the surface velocity to the jet velocity has only a small effect on the splash, whereas increasing the roughness-height-to-jet-diameter ratio substantially decreased the splash threshold.     

Classification of Dysphonic Voice: Acoustic and Auditory-Perceptual Measures

The purpose of this study was (1) to determine the relationship between acoustic measures and auditory-perceptual dimensions of overall voice severity and pleasantness and (2) to evaluate the ability of acoustic and auditory-perceptual measures to discriminate normal from dysphonic voices. Thirty adult dysphonic speakers and six, age-matched normal control speakers were asked to provide oral reading samples of the Rainbow Passage. Acoustic analysis of the speech samples was used to identify abnormal phonatory events associated with dysphonia. The acoustic program calculated long-term average spectral measures, glottal noise measures, and those measures based on linear prediction (LP) modeling. Twelve adult listeners judged overall voice severity and pleasantness from the connected speech samples using direct magnitude estimation (DME) procedures. The acoustic measures accounted for 48% of overall voice severity and 40% of voice pleasantness for dysphonic speakers. The classification performance of the acoustic measures and auditory-perceptual measures was quantified using logistic regression analysis. When acoustic measures or auditory-perceptual measures were considered in isolation, classification was generally accurate and similar across measures. Classification accuracy improved to 100% when acoustic and auditory-perceptual measures were combined. These data provide further support for use of both auditory-perceptual evaluation and acoustic analyses for classifying and evaluating dysphonia.     

Scaling of Voice Pleasantness and Acceptability in Tracheoesophageal Speakers

The purpose of this study was (1) to determine the psychophysical character of auditory-perceptual ratings of voice pleasantness (VP) and voice acceptability (VA) for tracheoesophageal (TE) speakers using direct magnitude estimation (DME) and equal-appearing interval (EAI) scaling procedures and (2) to determine the relationship between listeners' ratings of VP and VA. Ten adult listeners judged overall VP and VA from connected speech samples produced by 20 adult male TE speakers. Although results yielded a prothetic continuum for VP and a metathetic continuum for VA, the amount of variance accounted for by a curvilinear model of VP was minimally more than that accounted for by a linear model. Results also revealed a significant relationship between VP and VA (r = 0.939). Findings from this study do not suggest any greater validity associated with VP and VA ratings obtained by the DME than the EAI method. As a result of the significant relationship between these ratings and to the ease of applying EAI scales, it is recommended that VA be used as a current clinical outcome measure. These data illustrate the need to identify attributes that best describe TE speech that are measured appropriately and are clinically useful.     

The Effect of Perceptual Training on Inexperienced Listeners'' Judgments of Dysphonic Voice

OBJECTIVES/HYPOTHESIS: The purpose of this study was (1) to determine whether changes in intra- and interrater reliability occur for inexperienced listeners' judgments of overall severity, roughness, and breathiness in dysphonic and normal speakers after 2 hours of listener training; and (2) to determine the acoustic bases of inexperienced listeners' judgments before and after training. STUDY DESIGN: Prospective, single group, pre- and postdesign. METHODS: Thirty adult dysphonic and six normal speaker samples were selected from a database. Samples included 21 test stimuli and 15 training stimuli of both sustained vowels and connected speech. Sixteen inexperienced listeners judged all samples for overall severity, roughness, and breathiness using visual analog scales. Each listener provided pretraining ratings at baseline. Listeners were then trained using 15 anchor voice samples and 15 training stimuli. During training, listeners were provided with definitions of rating dimensions, accuracy feedback, and anchor samples. Listeners then judged test stimuli in a posttraining session. Speaker samples also were analyzed acoustically. RESULTS: Intrarater reliability was least variable for judgments of overall severity, but improved further with training. Listener judgments of roughness and breathiness in vowels were least reliable at baseline, but they significantly improved between listeners after training. Finally, measures of cepstral peak prominence significantly predicted all voice quality judgments except roughness in vowels, which was predicted by shimmer. The acoustic bases of group perceptual judgments did not seem to change with training. CONCLUSIONS: These findings have implications for developing training programs in perceptual evaluation and mapping relationships between acoustic and perceptual characteristics of voice disorders.     

The Psychosocial Consequences of BOTOX Injections for Spasmodic Dysphonia: A Qualitative Study of Patients'' Experiences

OBJECTIVES/HYPOTHESIS: The purpose of this study is to examine the psychosocial consequences of BOTOX (Allergan, Inc. Irvine, CA) treatment for spasmodic dysphonia (SD). This article also explores how patients judge the success of treatment and make decisions about future treatment based on psychosocial issues relevant to them. STUDY DESIGN: This study follows the phenomenological tradition of qualitative inquiry in which the objective is to explore the lived experiences of a group of persons who share a common phenomenon, in this case receiving BOTOX injections for SD. METHODS: Six adults with SD who had been receiving BOTOX injections on a long-term basis participated in face-to-face interviews. The interviews were recorded, transcribed, and analyzed according to phenomenological guidelines to identify consistent themes as well as differences among participants' experiences. RESULTS: The results are summarized in three primary themes that suggest (1) participants' experiences vary over time based on changes in factors such as lifestyle and personal priorities; (2) BOTOX has multidimensional psychosocial implications in physical, personal, and social domains; and (3) participants individualize their treatment regimens, taking into consideration the burden of treatment, scheduling priorities, and other strategies to maximize the benefits of BOTOX. CONCLUSIONS: Based on this study, suggestions are provided for future research into a psychosocial outcome measurement, including longitudinal evaluations that accommodate changing patient priorities over time; multidimensional evaluations that incorporate physical, personal, and social issues; evaluations that include a measure of the burden of treatment; and evaluations that support a shared decision-making model with the voice clinicians.     

Fluorimetric assay of ergotamine

Studies on the fluorescence properties of ergotamine in water at various pH values, and in several organic solvents are described. An assay procedure for ergotamine, based on its intense fluorescence in ethanol, is presented. Extraction of ergotamine into benzene from basic aqueous solution is followed by transfer of the extract to ethanol for fluorescence determination. The plot of fluorescence intensity vs. concentration is linear up to 5 μg ml^?1, and the assay has a limit of detection of 0.002 μg ml^?1. Reproducibility data at the 2.5-μg ml^?1 level are given.     

Osmotically driven crystal morphogenesis: a general approach to the fabrication of micrometer-scale tubular architectures based on polyoxometalates

The process of osmotically driven crystal morphogenesis of polyoxometalate (POM)-based crystals is investigated, whereby the transformation results in the growth of micrometer-scale tubes 10-100 μm in diameter and many thousands of micrometers long. This process initiates when the crystals are immersed in aqueous solutions containing large cations and is governed by the solubility of the parent POM crystal. Evidence is presented that indicates the process is general to all types of POMs, with solubility of the parent crystal being the deciding parameter. A modular approach is adopted since different POM precursor crystals can form tubular architectures with a range of large cationic species, producing an ion-exchanged material that combines the large added cations and the large POM-based anions. It is also shown that the process of morphogenesis is electrostatically driven by the aggregation of anionic metal oxides with the dissolved cations. This leads to the formation of a semi-permeable membrane around the crystal. The osmotically driven ingress of water leads to an increase in pressure, and ultimately rupture of the membrane occurs, allowing a saturated solution of the POM to escape and leading to the formation of a "self-growing" microtube in the presence of the cation. It is demonstrated that the growth process is sustained by the osmotic pressure within the membrane surrounding the parent crystal, as tube growth ceases whenever this pressure is relieved. Not only is the potential of the modular approach revealed by the fact that the microtubes retain the properties of their component parts, but it is also possible to control the direction of growth and tube diameter. In addition, the solubility limits of tube growth are explored and translated into a predictive methodology for the fabrication of tubular architectures with predefined physical properties, opening the way for real applications.