Experimental procedures and standard specimens for characterizing and evaluating TiO2-SiO2 ultra-low expansion glasses with periodic striae using the line-focus-beam (LFB) ultrasonic material characterization system are discussed. Two types of specimens were prepared, with specimen surfaces parallel and perpendicular to the striae plane using two different grades of glass ingots. The inhomogeneities of each of the specimens were evaluated at 225 MHz. It was clarified that parallel specimens are useful for accurately measuring velocity variations of leaky surface acoustic waves (LSAWs) excited on a water-loaded specimen surface associated with the striae. Perpendicular specimens are useful for obtaining periodicities in the striae for LSAW propagation perpendicular to the striae plane on a surface and for precisely measuring averaged velocities for LSAW propagation parallel to the striae plane. The standard velocity of Rayleigh-type LSAWs traveling parallel to the striae plane for the perpendicular specimens was numerically calculated using the measured velocities of longitudinal and shear waves and density. Consequently, a reliable standard specimen with an LSAW velocity of 3308.18 +/- 0.35 m/s at 23 degrees C and its temperature coefficient of 0.39 (m/s)/degrees C was obtained for a TiO2-SiO2 glass with a TiO2 concentration of 7.09 wt%. A basis for the striae analysis using this ultrasonic method was established.
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http://dx.doi.org/10.1109/tuffc.2006.1678191 | DOI Listing |
J Mech Behav Biomed Mater
December 2024
LMS, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Palaiseau, France; Inria, Palaiseau, France. Electronic address:
Cornea is an essential element of our eye. The refractive power of the cornea is closely related to its shape, which depends on the balance between its mechanical properties and the intraocular pressure. However, in keratoconus, the shape of the cornea is altered, and the mechanical properties (i.
View Article and Find Full Text PDFBiomed Res Int
January 2023
Department of Hematology and Critical Care Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.
Background: Mild traumatic brain injury (mTBI) is a widespread and serious public health problem which also causes physical and psychological suffering to patients and their families and imposes a significant economic burden on society. But it is usually very difficult to detect and provide warning of mTBI in early stage. Therefore, a novel method is urgent for the increasing demands on the accurate and rapid prediction and feature selection of mTBI.
View Article and Find Full Text PDFCurr Eye Res
August 2022
Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India.
Purpose: To highlight the magnitude of ocular higher order aberrations (HOA) and lower order aberrations (LOA), including component contributions from corneal and internal planes in Primary Congenital Glaucoma (PCG) patients.
Methods: Consecutive treated PCG patients co-operative for ocular examination and aberrometry, were enrolled over two years for this cross-sectional, comparative, single-center, unmasked study. Best-corrected visual acuity, refraction, IOP, wavefront aberrometry and topography (iTrace) were performed and results were compared with unaffected fellow eyes of unilateral glaucoma patients as well as age and sex-matched controls with no ocular anomalies other than treatable refractive error.
Aesthet Surg J
January 2022
Department of Medicine/Dermatology, University of Washington, Seattle, WA, USA.
Background: Over the past several years, hyperdilute calcium hydroxylapatite (CaHA) has emerged as an effective modality for improving skin quality and managing laxity in the face, arms, hands, neck, décolletage, upper arms, abdomen, buttocks, and upper legs, as well as for treating cellulite and striae. Whereas undiluted CaHA is used to provide volume, hyperdilute CaHA is distributed across a much larger surface area in a more superficial plane to stimulate neocollagenesis and elastin formation over time. The absence of lymphocytic infiltrates and predominance of type 1 collagen in the tissue response to CaHA make hyperdilute CaHA a valuable tool for nonsurgical skin tightening.
View Article and Find Full Text PDFActa Dermatovenerol Croat
March 2019
Sevkiye Copur, MD, Department of Dermatology & Venereology, Istanbul University, Istanbul Medical Faculty , Millet Street (Caddesi), 34093 Capa , Istanbul, Turkey;
Lichen sclerosus (LS), also known as lichen sclerosus et atrophicus, is a chronic inflammatory mucocutaneous disease affecting the genital and/or extragenital areas. Although LS usually occurs alone, its coexistence in morphea patients has been reported in 5.7% and 38.
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