Results 281 to 290 of about 17,860 (317)

Impulsive hydrofracture of polymethyl methacrylate

Journal of Applied Mechanics and Technical Physics, 1987
The intensification of geotechnological processes by means of impulse hydrofracture in many areas of the mining industry requires engineering estimates of the parameters of the cracks formed (length, opening, number, orientation), especially if the technology employed requires deliberate fracturing of a solid mass with cracks with definite sizes and ...
A. A. Vovk, Yu. I. Voitenko, A. V. Mikhalyuk   +2 more
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Fracture Markings in Polymethyl Methacrylate

Nature, 1958
THE surface markings on the fracture surfaces of glass and plastics show that the fracture is discontinuous and that patterns are formed through secondary initiations ahead of the main fracture front which unite to form the completed fracture surface1–3.
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Anelastic creep of polymethyl methacrylate

Journal of the Mechanics and Physics of Solids, 1958
Abstract The deformation of polymethyl methacrylate over the temperature range 263° K to at least 410° K is entirely anelastic. That is, removal of the stress causes the material to return completely to its original length, provided sufficient time is allowed to permit complete recovery to take place. In the temperature range 263° K to 320° K it is
O.D. Sherby, John E. Dorn
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Polymethyl Methacrylate for the Body

2020
Polymethyl methacrylate (PMMA) is a permanent filler used to correct furrows and deep depressions of the body and also for volume replacement. Among all permanent fillers available in the market, PMMA is the most regularly used. PMMA is demonstrated to be safe, effective, and long lasting with few adverse reactions when indicated correctly.
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Strength of irradiated polymethyl methacrylate

Soviet Materials Science, 1971
The effect of the form of radiation (reactor andγ-radiation, X-rays and ultraviolet light) and absorbed energy on the strength of polymethyl methacrylate was studied. It was shown that the strength of this polymer depends in the first place on the size of radiation-induced defects and not on their distribution across the specimen thickness.
Z. A. Bazilevich, S. I. Mikitishin, A. N. Tynnyi   +2 more
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Upcycling polymethyl methacrylate to methacrylic acid

Reaction Chemistry & Engineering
Upcycling PMMA to methacrylic acid rather than methyl methacrylate is a viable economic alternative to treat end-of-life plastic.
Yanfa Zhuang, Nooshin Saadatkhah, Tien-Dat Nguyen, Jacopo De Tommaso, Clive Yi Jie Ng, Chunyu Wang, Abdellah Ajji, Gregory S. Patience   +7 more
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The sequence length in polymethyl methacrylate

European Polymer Journal, 1977
Abstract The sequence length and tacticity of methyl methacrylate polymers prepared at 303–363°K in the presence of trichlorobromomethane as a transfer agent were measured from NMR spectra. The lengths did not change appreciably but there was an increase in syndiotacticity with increasing concentration of transfer agent.
Sathi Roy, James N. Hay
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The viscoelastic behavior of polymethyl methacrylate

Journal of Colloid Science, 1952
Abstract Complete stress relaxation data for polymethyl methacrylate are presented covering behavior of this linear amorphous polymer from the rubbery state to the glassy state. The effect of water on stress relaxation rates in the glassy state and in the transition region is shown. Fast cooling is shown to increase subsequent stress relaxation rates
J.R McLoughlin, A. V. Tobolsky
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The dynamic mechanical behavior of polymethyl methacrylate*)

Rheologica Acta, 1974
In order to investigate the short time response of solid polymers, a high resolution laser interferometer has been employed to observe the detailed structure of stress waves produced by the impact of polymeric plates. From the observed stress waves the loading and unloading stress-strain paths followed by the material can be determined. For the polymer,
K. W. Schuler, J. W. Nunziato
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Cranioplasty using polymethyl methacrylate prostheses

Journal of Clinical Neuroscience, 2009
In this retrospective study we attempted to assess the clinical performance of prefabricated polymethyl methacrylate (PMMA) prostheses and to determine whether they outperform intra-operatively moulded PMMA prostheses in reducing operating time, blood loss and surgical complications in elective delayed cranioplasty operations, after decompressive ...
Shih-Tseng Lee, Chen Po-Jen, Sai-Cheung Lee, Chieh-Tsai Wu   +3 more
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