Search results for "etching"
showing 10 items of 186 documents
Effects of Stretching on Upper-Body Muscular Performance
2008
The purpose of this investigation was to examine the influence of upper-body static stretching and dynamic stretching on upper-body muscular performance. Eleven healthy men, who were National Collegiate Athletic Association Division I track and field athletes (age, 19.6 +/- 1.7 years; body mass, 93.7 +/- 13.8 kg; height, 183.6 +/- 4.6 cm; bench press 1 repetition maximum [1RM], 106.2 +/- 23.0 kg), participated in this study. Over 4 sessions, subjects participated in 4 different stretching protocols (i.e., no stretching, static stretching, dynamic stretching, and combined static and dynamic stretching) in a balanced randomized order followed by 4 tests: 30% of 1 RM bench throw, isometric ben…
Hybrid layers of etch-and-rinse versus self-etching adhesive systems.
2010
Objective: To evaluate the effectiveness in the formation of resin tags, adhesive lateral branches and hybrid layers of five adhesive systems, when bonding to dentine. Material and Methods: Flat dentin surfaces from 25 molars were bonded with several adhesive systems according to the manufacturers? instructions. Composite build-ups were constructed incrementally with Tetric Ceram. The Specimens were sectioned parallel to the long axis. One section was treated with phosphoric acid and sodium hypochlorite in order to reveal the hybrid layer formation. The other section was stored in 30% hydrochloric acid to detect resin tags and adhesive lateral branch formation. Results: The two etch-and-rin…
Micro-Raman spectroscopic characterization of a CR-39 detector.
2013
Characterization by micro-Raman spectroscopy of polymeric materials used as nuclear track detectors reveals physico-chemical and morphological information on the material's molecular structure. In this work, the nuclear track detector poly(allyl diglycol carbonate), or Columbia Resin .39 (CR-39), was characterized according to the fluence of alpha particles produced by a 226Ra source and chemical etching time. Therefore, damage of the CR-39 chemical structure due to the alpha-particle interaction with the detector was analyzed at the molecular level. It was observed that the ionization and molecular excitation of the CR-39 after the irradiation process entail cleavage of chemical bonds and…
Optical properties of the low-molecular amorphous azochromophores and their application in holography
2015
The films based on the low-molecular amorphous azochromophore 2-(3-(4-((4- (Ethyl(2-(trityloxy)ethyl)amino)phenyl)diazenyl)styryl)-5,5-dimethylcyclohex-2-enylidene) malononitrile (IWK-2M) were prepared. The optical properties of the material, such as transmittance and reflection spectra of the film, sensitivity to polarization holographic recording by two wavelengths (405 and 532 nm) were studied. The direct relief formation during the polarization holographic recording was explored, relief depth dependence on exposure and record beam intensity was investigated. The holographic matrix on this material base was produced without chemical etching process; the replication of holographic image w…
Temporal Structure of Human Gaze Dynamics Is Invariant During Free Viewing.
2015
We investigate the dynamic structure of human gaze and present an experimental study of the frequency components of the change in gaze position over time during free viewing of computer-generated fractal images. We show that changes in gaze position are scale-invariant in time with statistical properties that are characteristic of a random walk process. We quantify and track changes in the temporal structure using a well-defined scaling parameter called the Hurst exponent, H. We find H is robust regardless of the spatial complexity generated by the fractal images. In addition, we find the Hurst exponent is invariant across all participants, including those with distinct changes to higher or…
Artificial dielectric optical structures: A challenge for nanofabrication
1998
Diffractive optical components can be made using multiple level kinoforms or single level artificial dielectric structures. The latter require the fabrication of pillars of equal depth but differing width and spacing. As a demonstration device, the diffractive optic equivalent of a wedge has been made in GaAs for use at 1.15 μm. The need for all pillars to have the same height was met by using a selective etch and a very thin etch-stop layer on AlGaAs. The experimental diffraction efficiency was 87.8%, among the best ever obtained and close to the theoretical maximum of 97.6%. © 1998 American Vacuum Society.
Effects of an adapted physical activity program on psychophysical health in elderly women.
2016
Giuseppe Battaglia,1,2 Marianna Bellafiore,1,2 Marianna Alesi,1,2 Antonio Paoli,3 Antonino Bianco,1,2 Antonio Palma1,2 1Department of Psychological, Pedagogical and Educational Sciences, 2Sport and Exercise Sciences Research Unit, University of Palermo, Palermo, 3Department of Biomedical Sciences, University of Padova, Padua, Italy Background: Several studies have shown the positive effects of adapted physical activity (APA) on physical and mental health (MH) during the lifetime. The aim of this study was to assess the effectiveness of a specific APA intervention program in the improvement of the health-related quality of life (QOL) and functional condition of spine in elderly women. Method…
Creating Digital Musical Instruments With and for Children: Including Vocal Sketching as a Method for Engaging in Codesign
2020
International audience; A class of master of science students and a group of preschool children codesigned new digital musical instruments based on workshop interviews involving vocal sketching, a method for imitating and portraying sounds. The aim of the study was to explore how the students and children would approach vocal sketching as one of several design methods. The children described musical instruments to the students using vocal sketching and other modalities (verbal, drawing, gestures). The resulting instruments built by the students were showcased at the Swedish Museum of Performing Arts in Stockholm. Although all the children tried vocal sketching during preparatory tasks, few …
A Case of Cooperative Sound Design
2016
In this design case study, protocol and linkographic analysis are applied to a task of cooperative vocal sketching, proposed in the scope of educational research activities. The understanding of the cognitive behaviors involved in sound creation is aimed at setting the ground for the development of rigorous, designerly evaluation practices tailored to sound design, all the way to the final interactive product. Relevant qualitative and quantitative information about the creative process informs the assessment and possibly improvement of sound design methods.
Effects of a dynamic stretching warm-up on functional movement patterns in female hip-hop dancers
2022
Background: A large percentage of dancers suffer an injury to their musculoskeletal system at least once in their careers, as well as from pain caused by overloading or overtraining this system. A high frequency of injuries has been observed in hip-hop dancers. Before each workout, there should be a solid warm-up and stretching period. The lack of these two important elements increases the risk of injury. Aim of the study: This study aimed to examine the effects of dynamic stretching warm-ups on fundamental movement patterns in female hip-hop dancers. Material and methods: This study included 14 hip-hop female dancers, aged 15–17. Dancers participated in 6 weeks of dynamic stretching warm-u…