Greenside Design Center College of Design

Balance disorders and dizziness are common in people with multiple sclerosis (MS), suggesting dysfunction of the vestibular system. Evaluating how people with MS perform on objective clinical vestibular tools will help broaden understanding of vestibular function in MS. This cross-sectional study's goal was to complete a robust battery of vestibular-ocular reflex (VOR), dynamic visual acuity (DVA), subjective visual vertical (SVV), and cervical and ocular vestibular-evoked myogenic potential (c/oVEMP) tests in people with and without MS. Forty people with relapsing-remitting MS (Expanded Disability Status Scale [EDSS] ≤6.5) and 20 controls completed the vestibular testing battery. Results were compared between groups and correlations with EDSS scores were calculated. People with MS were less able to visually cancel their VOR and showed a larger variance in response on SVV. EDSS significantly correlated with VOR cancellation, SVV variance, and DVA lines lost; linear regression showed that VOR cancellation and SVV variance significantly predicted EDSS. Vestibular functions requiring central integration of vestibular information, but not reflexive vestibular functions like VEMP, were impaired in people with MS and correlated with EDSS, suggesting that clinical evaluation of functions requiring central integration best evaluates MS-related vestibular dysfunction. Measures assessing central vestibular integration and not vestibular reflexes may be more sensitive to detecting vestibular deficits in people with mild to moderate MS.Video Abstract available for more insight from the authors (see Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A344).

A lack of knowledge and objective data on the effects of welding process variables in the application and performance of weld deposited hardfacings has led to many past failures and a subsequent mistrust of the technology. This paper sets out, first, to review both the influence of welding process variables in hardfacing and the important characteristics and properties which determine the effective performance of a hardfacing deposit. Second, the results are presented of a full factorial experiment, which was performed in an effort to evaluate and interpret the effects of arc current, voltage, and polarity, as well as of travel speed, torch stand-off distance, and preheat, on the nature and properties of a commercial flux cored arc welded hardfacing deposit. In this programme, the effects of the welding parameters were evaluated with the aid of a number of computer analyses, with arc current, voltage, and polarity being shown to have the greatest effect: a high arc current (360 A) gives the most satisfactory deposit in terms of weld metal dilution, hardness, and porosity, as well as of both deposition rate and efficiency, provided that electrode negative arc polarity is used, together with a low (24 V) arc voltage. In attempting to achieve more cost effective use of hardfacings in abrasive wear resistant applications, both the potential of this approach and the value of the results obtained are clearly demonstrated.