Search results for "Thermal damage"
showing 6 items of 6 documents
Piezosurgery in endoscopic dacryocystorhinostomy
2009
Piezosurgery is a recently developed system for cutting bone with microvibrations. The equipment consists of two hand pieces, two inserts, and two peristaltic pumps connected to the control unit. The device is endowed with an irrigation system of high-flow saline solution that breaks up into very small particles, with a “bloodless” effect on the surgical site and a low indirect thermal damage to the bone surfaces and adjacent structures. 4,5 The touch screen of the main unit permits selection of the specific insert, and modulation of the irrigation and the power according to the bone density. The device uses low-frequency ultrasonic waves (24.7-29.5 kHz), the applied power can be modulated …
Evaluation of carotenoids and furosine content in air dried carrots and parsnips pre-treated with pulsed electric field (PEF)
2019
Carrot and parsnip slices were subjected to hot drying at 50, 60 and 70 °C with or without pulsed electric field (PEF) pre-treatment at 0.9 kV/cm and 1000 and 10,000 pulses. The effect of drying on processed samples was assessed by analysis of carotenoids, the furosine value, total phenols and the Whiteness Index (WI). PEF pre-treatment is effective in reducing drying times, but the degree of cellular breakdown makes the compounds more susceptible to chemical and enzymatic reactions. In our condition PEF pre-treatment increased the carotenoid degradation and promoted the Maillard reaction above all at the highest temperature of 70 °C. The assessment of carotenoid stability, together with th…
Farbenwandel der Zahnhartgewebe als Zeichen thermischer Sch�digung
1985
Die menschlichen Hartgewebe lassen nach thermischer Schadigung gewisse Ruckschlusse auf Brandparameter zu. Neben morphologischer Destruktion ist an den Zahnhartgeweben ein Farbenwandel zu beobachten. Diese Form der Zustandsanderung von Schmelz, Dentin und Zement ist an 330 menschlichen extrahierten Zahnen unter definierten Zeit-und Temperaturintervallen studiert worden. Die Farbphanomene als Ergebnisse der Gluh- und Aufheizversuche sind mit Hilfe der DIN- und RAL-Farbregister ausgewertet worden. Am leichtesten last sich die Zementfarbe bestimmen, da markierende Belage oder Konkremente fehlen. Auserdem bleibt die Wurzelform relativ lange erhalten, wahrend die Zahnkronen zerfallen konnen. Die…
Histologic evaluation of thermal damage produced on soft tissues by CO2, Er,Cr:YSGG and diode lasers
2010
Objective: The aim of this in vitro experimental study was to perform histological evaluation of the thermal effect produced on soft tissue irradiated with CO2 , Er,Cr:YSGG or diode lasers. Study design: Porcine oral mucosa samples were irradiated with Er,Cr:YSGG laser at 1 W with and without water / air spray, at 2 W with and without water / air spray, and at 4 W with water / air spray, with CO2 laser at 1 W, 2 W, 10 W, 20 W continuous mode and 20 W pulsed mode and diode laser at 2W, 5W, and 10W pulsed mode. The thermal effect was evaluated measuring the width of damaged tissue adjacent to the incision, stained positively for hyalinized tissue with Hematoxylin-Eosin and Masson Trichrome st…
Reduction of thermal damage in ultrathin gate oxides after intrinsic dielectric breakdown
2001
We have compared the thermal damage in ultrathin gate SiO2 layers of 5.6 and 3 nm thickness after intrinsic dielectric breakdown due to constant voltage Fowler-Nordheim stress. The power dissipated through the metal-oxide-semiconductor capacitor during the breakdown transient, measured with high time resolution, strongly decreases with oxide thickness. This is reflected in a noticeable reduction of the thermal damage found in the structure after breakdown. The effect can be explained as the consequence of the lower amount of defects present in the oxide at the breakdown instant and of the occurrence of a softer breakdown in the initial spot. The present data allow us to estimate the power t…
Comparison of diode laser – Oral tissue interaction to different wavelengths. In vitro study of porcine periodontal pockets and oral mucosa
2020
[Background] The aim of this in vitro study was to evaluate the effect of diode lasers at different wavelengths and power settings in handmade incisions in periodontal pockets and in oral mucosa of porcine tissue considering thermal damage, necrosis and the affected area of the soft tissue.