Search results for "Intensity"
showing 10 items of 1091 documents
Optic fibre as a transducer of tendomuscular forces
1996
Direct in vivo tendon force measurements open up new possibilities for understanding of muscle-tendon loads during natural locomotion. The present report presents a new optic fibre method for such applications. The method is based on light intensity modulation by mechanical modification of the geometric properties of the optic fibre. A special optic fibre with a plastic covering buffer and with a total diameter of either 265 microns or 500 microns was carefully prepared at both ends for receiving and transmitting light. The fibre was inserted through the rabbit common calcaneal tendon with a 20 gauge needle. By removing the needle the optic fibre remained in situ. Static loading demonstrate…
<title>Pressure sensitivity of the side-glowing optical fibers</title>
2001
Remarkable impact of external mechanical pressure to the transmitted radiation intensity has been observed for glowing fibers with various silica core diameters and side- scattering efficiencies. A physical model on deformation- simulated light scattering has been developed and discussed. The results of experimental studies confirmed the basic model assumptions.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
High-speed and high-resolution interrogation of FBG sensors using wavelength-to-time mapping and Gaussian filters
2019
In this work we report a novel intensity-based technique for simultaneous high-speed and high-resolution interrogation of fiber Bragg grating (FBG) sensors. The method uses a couple of intensity Gaussian filters and the dispersion-induced wavelength-to-time mapping effect. The Bragg wavelength is retrieved by means of the amplitude comparison between the two filtered grating spectrums, which are mapped into a time-domain waveform. In this way, measurement distortions arising from residual power due to the grating sidelobes are completely avoided, and the wavelength measurement range is considerably extended with respect to the previously proposed schemes. We present the mathematical backgro…
Mixed Probabilistic-Guaranteed Optimal Design
2009
This chapter deals with the mixed probabilistic-guaranteed approach to optimal design of quasi-brittle membrane shells. Special attention is devoted to different problem formulations and analytical methods for their solution. Optimal thickness distributions are presented for various axisymmetric membrane shells. The presentation follows research results of [BRS03b].
Treatment of snoring disorder with a non-ablactive Er:YAG laser dual mode protocol. An interventional study
2020
Background Snoring disorder is a common problem among world population. Treatment modalities may involve surgical and non-surgical procedures. As main objective we proposed to evaluate the efficacy of non-ablative Er:YAG laser in the treatment of snoring disorder. Material and Methods We performed an interventional study in 30 patients with snoring disorders. Three sessions were performed with Er:YAG laser 2940nm in long pulse mode (2J/cm2) and smooth mode (10-8J/cm2) in oropharynx region. We analyzed the efficacy of this protocol using questionnaires for snoring intensity, snoring related characteristics of quality of life (including the Epworth sleepness scale and OHIP-14), the satisfacti…
Color of orange juice treated by High Intensity Pulsed Electric Fields during refrigerated storage and comparison with pasteurized juice
2008
Abstract High Intensity Pulsed Electric Field (HIPEF) is one of the nonthermal minimal processing technologies interesting for scientists and food industry as a new, alternative (preservation) process for liquid food. We have evaluated the effect on color, browning and hydroxymethylfurfural (HMF) of a pasteurized orange juice and the same orange juice treated by HIPEF, during 7 weeks stored in refrigeration at 2 °C and 10 °C. Pasteurized orange juice presents greater yellow tendency ( b ∗ ) and less red tendency ( a ∗ ) than the untreated orange juice, while HIPEF orange juice presents a coloration more similar to the untreated orange juice. Color variations (Δ E ) during storage are greate…
Carotenoid Profile Modification during Refrigerated Storage in Untreated and Pasteurized Orange Juice and Orange Juice Treated with High-Intensity Pu…
2006
A comparative study was made of the evolution and modification of various carotenoids and vitamin A in untreated orange juice, pasteurized orange juice (90 degrees C, 20 s), and orange juice processed with high-intensity pulsed electric fields (HIPEF) (30 kV/cm, 100 micros), during 7 weeks of storage at 2 and 10 degrees C. The concentration of total carotenoids in the untreated juice decreased by 12.6% when the juice was pasteurized, whereas the decrease was only 6.7% when the juice was treated with HIPEF. Vitamin A was greatest in the untreated orange juice, followed by orange juice treated with HIPEF (decrease of 7.52%) and, last, pasteurized orange juice (decrease of 15.62%). The decreas…
Changes of colour and carotenoids contents during high intensity pulsed electric field treatment in orange juices
2005
Abstract Liquid chromatography (LC) was the method chosen to evaluate the effects of high intensity pulsed electric fields (HIPEF), with different electric field intensities (25, 30, 35 and 40 kV/cm) and different treatment times (30–340 μs), on orange juice cis / trans carotenoid contents. In parallel, a conventional heat treatment (90 °C, 20 s) was applied to the orange juice in order to compare the effect on the carotenoid contents. HIPEF processing of orange juice is an alternative to the thermal treatment of pasteurization, provided that it is kept refrigerated, because, when the most extreme conditions of this kind of treatment are applied, the decrease in the concentration of caroten…
Diferenças na ativação muscular entre a realização de flexões com apoio fixo e com um sistema de suspensão unilateral em forma de V em diferentes alt…
2014
This study was designed to analyze upper extremity and core muscle activation performing push-ups under different stability conditions and body positions. Trained university male students (n= 29) performed 3 push-ups each under stable conditions and using suspension device (AirFit Trainer ProTM) with their hands at 2 different heights (i.e., 10 and 65 cm). Push-up speed was controlled using a metronome and the testing order was randomized. The average amplitudes of the electromyographic root mean square of the Triceps Brachii, Upper Trapezius, Anterior Deltoid, Clavicular Pectoralis, Rectus Abdominis, Rectus Femoris, Lumbar Erector Spinae and Gluteus Maximus were recorded and normalized to …
Assessment of the stresses produced on the bone implant/tissue interface to the different insertion angulations of the implant - a three-dimensional …
2020
Background The present study aimed to assess the stresses produced on the surface of the bone tissue around dental implants with three different insertion angulations subjected to axial and oblique loading. Material and methods The study was created according to the recommendations of the Checklist for Reporting In-vitro Studies (CRIS). The Straumann™ bone level RC (4.1 x 10 mm) implant, Cone Morse connection (CM), RC Straumann Variobase™ with abutment (3.5 mm) was placed in the region of element 16, with the platform positioned at the height of the bone crest. Three assessment models were produced: model M1 or control - implant perpendicular to the bone crest; model M2 - implant angulated …