scholarly journals Nd:YAG laser disintegration of methyl methacrylate: analysis of gaseous products

1986 ◽  
Author(s):  
Daniel S. J. Choy ◽  
Michael Kaplan ◽  
Robert B. Case ◽  
Robert Zickel ◽  
Ivan P. Kaminow
Keyword(s):  
Methyl Methacrylate ◽  
Nd:Yag Laser ◽  
Gaseous Products

Bipolar radiofrequency induced thermotherapy and 1064 nm Nd:Yag laser in endovenous occlusion of insufficient veins: short term follow up results

VASA ◽  
2011 ◽  
Vol 40 (3) ◽  
pp. 235-240 ◽  
Author(s):  
Krnic ◽  
Sucic
Keyword(s):  
Side Effects ◽  
Success Rate ◽  
Nd:Yag Laser ◽  
Main Stem ◽  
Short Term ◽  
Main Trunk ◽  
Bipolar Radiofrequency ◽  
Saphenous Veins ◽  
Skin Redness ◽  
Complete Failure

Background: The aim of this study is to report our results in main stem vein closure using the bipolar radiofrequency induced thermotherapy (RFITT) system and the 1064nm Nd:Yag laser. Patients and methods: 44 incompetent main stem veins (37 great saphenous veins, one lesser saphenous vein, and 6 anterior accessory saphenous veins) in 29 patients were treated using RFITT. 53 incompetent main stem veins (45 great saphenous veins, 4 lesser saphenous veins, and 4 anterior accessory saphenous veins) in 43 patients were treated endovenously with 1064 nm Nd:Yag laser. All patients underwent postoperative duplex scanning within a month after procedure, as well as a short interview regarding postoperative discomfort. Results: In main stem veins treated with RFITT, the success rate within the first month was 86,4 % (38 out of 44 veins). Complete failure rate was 13,6 % (6 out of 44 veins). In 53 main stem veins treated by 1064 nm Nd:Yag laser, the success rate was 100 %, consisting of 98,1 % complete success (52/53 veins), and 1,9 % partial success (1/53 veins). None of the patients treated with RFITT experienced postoperative adverse effects, whereas 13/43 (30,2 %) patients treated with laser had to use oral analgesics after the treatment, and 21/43 (48,8 %) patients reported transient skin changes, such as bruising or skin redness. Conclusions: RFITT system was fairly efficient in the short term for closure of main trunk veins, whereas longer term results are still scarce. Postoperative side effects of RFITT were minimal. 1064nm Nd:Yag laser, according to short term results, proved to be very effective for main stem vein closure. Postoperative side effects related to 1064 nm Nd:Yag endovenous laser treatment proved to be minor, transient, and acceptable.

Das Management von Glaskörpertrübungen

2020 ◽  
Vol 10 (03) ◽  
pp. 243-254
Author(s):  
Albrecht Lommatzsch
Keyword(s):  
Nd:Yag Laser ◽  
Randomisierte Studien

ZusammenfassungDas Management von symptomatischen Glaskörpertrübungen stellt sich in der täglichen Praxis oft als kompliziert dar. Die Nd:YAG-Laser-Vitreolyse rückt als weitere therapeutische Option immer mehr in den Fokus. Vergleichende randomisierte Studien zur Vitrektomie, Nd:YAG-Laser-Vitreolyse und einer abwartenden Vorgehensweise zum Spontanverlauf gibt es leider nicht. Dieser Beitrag versucht, zu dieser Problematik einen Überblick zu geben.

Erfolgreiche Entfernung des OTSC®-Systems durch Destruktion mittels Nd:YAG-Laser

2010 ◽  
Vol 48 (08) ◽  
Author(s):  
M Fähndrich ◽  
M Sandmann ◽  
M Heike
Keyword(s):  
Nd:Yag Laser

Diagnostik und minimal invasive Therapie von Epiglottiserkrankungen beim Pferd

2003 ◽  
Vol 31 (05) ◽  
pp. 273-279
Author(s):  
E. Deegen ◽  
B. Ohnesorge
Keyword(s):  
Nd:Yag Laser ◽  
Minimal Invasive ◽  
Minimal Invasiv

ZusammenfassungIn der Zeit von 1993 bis 2001 wurden in der Klinik für Pferde der Tierärztlichen Hochschule Hannover 21 Pferde mit einem Epiglottisentrapment vorgestellt, davon 29% (6/21) Vollblutpferde. Drei der 21 Tiere wiesen zusätzlich eine Subepiglottiszyste auf. Im Rahmen der klinischen und endoskopischen Diagnostik wurden Entrapmentfalten in unterschiedlicher Größe, in einem Fall auch ein habituelles Entrapment festgestellt. Die verlagerte Schleimhautfalte, die in 24% (5/21) der Fälle ulzerativ verändert war, führte bei 52% (11/21) der Pferde zu einem Atemgeräusch bei Belastung, 38% (8/21) der Pferde zeigten Husten und 14% (3/21) die Symptome einer Dysphagie. Weitere Befunde waren Epiglottishypoplasie bzw. -deformation (5/21) und Dorsalverlagerung des Gaumensegels (6/21), sodass insgesamt 38% (8/21) der Pferde zusätzlich erhebliche morphologische oder funktionelle Abweichungen im Laryngopharynx aufwiesen. Die Behandlung des Entrapments erfolgte minimal invasiv transendoskopisch unter Anwendung unterschiedlicher Methoden. So wurde die Schleimhautfalte in Narkose oder beim sedierten Pferd transnasal entweder mittels eines hakenförmig gebogenen Hochfrequenzpapillotoms oder laserchirurgisch mit dem Nd:YAG-Laser und einer Barefiber median gespalten. Verbliebene Schleimhaut wurde falls erforderlich mit einer Hochfrequenz-Polypektomieschlinge reseziert. Letzteres Verfahren kam auch zur Resektion von subepiglottaler Schleimhaut im Fall des habituellen Entrapments zur Anwendung. Bei 80% (8/10) der Patienten ohne komplizierende Epiglottisveränderung oder Gaumensegelverlagerung gelang eine zufrieden stellende Therapie, wobei ein Rezidiv nachbehandelt wurde. Als besonders geeignet erwies sich die Operation mit dem gebogenen Hochfrequenzpapillotom am sedierten Pferd. Bei allen Patienten mit Entrapment und gleichzeitiger Subepiglottiszyste verlief die Behandlung erfolgreich (3/3). Im Gegensatz dazu zeigten nur 25% (2/8) der Pferde mit anderen komplizierenden Erkrankungen postoperativ keine Beeinträchtigungen.

Study of the Kinetics of Thermal Destruction of Crossed Polyethylene

2019 ◽  
Vol 5 (12) ◽  
pp. 37-46
Author(s):  
K. Chalov ◽  
Yu. Lugovoy ◽  
Yu. Kosivtsov ◽  
E. Sulman
Keyword(s):  
Total Yield ◽  
Calorific Value ◽  
High Heat ◽  
Process Temperature ◽  
Optimum Process ◽  
Quantitative Composition ◽  
Pyrolysis Gas ◽  
Gaseous Products ◽  
Liquid Products ◽  
Kinetics Of

This paper presents a study of the process of thermal degradation of crosslinked polyethylene. The kinetics of polymer decomposition was studied by thermogravimetry. Crosslinked polyethylene showed high heat resistance to temperatures of 400 °C. The temperature range of 430–500 °C was determined for the loss of the bulk of the sample. According to thermogravimetric data, the decomposition process proceeds in a single stage and includes a large number of fracture, cyclization, dehydrogenation, and other reactions. The process of pyrolysis of a crosslinked polymer in a stationary-bed metal reactor was investigated. The influence of the process temperature on the yield of solid, liquid, and gaseous pyrolysis products was investigated. The optimum process temperature was 500 °C. At this temperature, the yield of liquid and gaseous products was 85.0 and 12.5% (mass.), Respectively. Samples of crosslinked polyester decomposed almost completely. The amount of carbon–containing residue was 3.5% by weight of the feedstock. With increasing temperature, the yield of liquid products decreased slightly and the yield of gaseous products increased, but their total yield did not increase. For gaseous products, a qualitative and quantitative composition was determined. The main components of the pyrolysis gas were hydrocarbons C1–C4. The calorific value of pyrolysis gas obtained at a temperature of 500 °C was 17 MJ/m3. Thus, the pyrolysis process can be used to process crosslinked polyethylene wastes to produce liquid hydrocarbons and combustible gases.

MANUFACTURING GASEOUS PRODUCTS BY PYROLYSIS MICROALGAE BIOMASS

2019 ◽  
pp. 23-34
Author(s):  
N. I. Chernova ◽  
S. V. Kiseleva ◽  
O. M. Larina ◽  
G. A. Sytchev
Keyword(s):  
Raw Materials ◽  
Renewable Energy Sources ◽  
High Energy ◽  
Initial Mass ◽  
Solid Residue ◽  
Algae Biomass ◽  
Gaseous Products ◽  
Microalgae Biomass ◽  
Pyrolysis Liquid ◽  
Pyrolysis Gases

Algae biomass is considered as an alternative raw material for the production of biofuels. The search for new types of raw materials, including high-energy types of microalgae, remains relevant, since the share of motor fuels in the structure of the global fuel and energy balance remains consistently high (about 35%), and the price of oil is characterized by high volatility. The authors have considered the advantages of microalgae as sources of raw materials for fuel production. Biochemical and thermochemical conversion are proposed as technologies for their processing. This paper presents the results of the study of the pyrolysis of the biomass of clonal culture of blue-green microalgae / cyanobacteriumArthrospira platensis rsemsu 1/02-Pfrom the collection of the Research Laboratory of Renewable Energy Sources of the Lomonosov Moscow State University. An experiment to study the process of pyrolysis of microalgae biomass was carried out at the experimental facility of the Institute of High Temperatures RAS in pure nitrogen grade 6.0 to create an oxygen-free environment with a linear heating rate of 10 ºС / min from room temperature to 1000 ºС. The whole process of pyrolysis proceeded in the field of endothermy. The specific amounts of solid residue, pyrolysis liquid and gaseous products were experimentally determined. As a result of the pyrolysis of microalgae biomass weighing 15 g, the following products were obtained: 1) coal has the mass of the solid residue is 2.68 g, or 17.7% of the initial mass of the microalgae (while 9.3% of the initial mass of the microalgae remained in the reactor); 2) pyrolysis liquid – weight 3.3 g, or 21.9% of the initial weight; 3) non-condensable pyrolysis gases – weight 1.15 l. The specific volumetric gas yield (the amount of gas released from 1 kg of the starting material) was 0.076 Nm3/ kg. The analysis of the composition and specific volume yield of non-condensable pyrolysis gases formed in the process of pyrolysis, depending on temperature. It is shown that with increasing temperature, the proportion of highcalorie components of the gas mixture (hydrogen, methane and carbon monoxide) increases. The calorific value of the mixture of these gases has been estimated.

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