Thermal ablation of FEL irradiation using gypsum as an indicator

Tanaka, Sakae; Sato, Yukie; Numata, Yoshihiro; Suwa, Taketoshi; Hayakawa, Tohru; Suzuki, Kunihiro; Kuwada, Takao; Hayakawa, Katsumi; Hayakawa, Yasushi; Tanaka, Toshinari; Sato, Iwao

doi:10.1007/s10103-006-0414-x

Cited by 10 publications

(9 citation statements)

References 31 publications

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“…Moreover, the obtained peak temperatures are close to that of CaSO 4 • 2H 2 O (~400 K) reported in previous papers (Beceiro et al, 2012;Lou et al, 2011;Sakae et al, 2007). However, there is a significant difference between the observed curves and the previously reported ones, where, in addition to the large endothermic peak around 400 K in the DSC curve, there is a small peak around 420 K (Beceiro et al, 2012;Sakae et al, 2007). On the other hand, the observed (a) and (b) curves for the single crystal and powder samples clearly exhibit a single sharp peak, and no shoulder or second peak is observed.…”

Section: Dsc and Tg-dta Measurementssupporting

confidence: 88%

“…The onset temperatures of the small and large peaks respectively were determined to be 392.6 and 375.9 K. The onset temperature of the powder sample (375.9 K, (b) curve) is very close to the boiling point of water (373 K). Moreover, the obtained peak temperatures are close to that of CaSO 4 • 2H 2 O (~400 K) reported in previous papers (Beceiro et al, 2012;Lou et al, 2011;Sakae et al, 2007). However, there is a significant difference between the observed curves and the previously reported ones, where, in addition to the large endothermic peak around 400 K in the DSC curve, there is a small peak around 420 K (Beceiro et al, 2012;Sakae et al, 2007).…”

Section: Dsc and Tg-dta Measurementssupporting

confidence: 87%

“…4. Large and small endothermic peaks in DSC and DTA curves were previously reported to be observed around 400 and 420 K, respectively, at atmosphere pressure (Beceiro et al, 2012;Lou et al, 2011;Sakae et al, 2007;Zhang et al, 1996). These peaks correspond to the two dehydration reactions described in the Introduction.…”

Section: Dsc and Tg-dta Measurementsmentioning

confidence: 76%

“…Gypsum is used as a generic name for several types of products with a chemical composition of calcium sulfate (Beceiro et al, 2012;Lou et al, 2011;Masuda & Celiz, 2009;Pinheiro & Camarini, 2015;Prasad et al, 2005;Saha et al, 2012;Sakae et al, 2007;Zhang et al, 1996). These compounds are classified into three types by the number of hydrogen present in the crystal; calcium sulfate dihydrate (CaSO 4 • 2H 2 O), calcium sulfate hemihydrate (CaSO 4 • 0.5H 2 O, αor β-hemihydrate forms), and calcium sulfate (CaSO 4 , αor γ-anhydrite forms).…”

Section: Introductionmentioning

confidence: 99%

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Synthesis, Crystal Structure, and Thermal Properties of CaSO4·2H2O Single Crystals

Fukami¹,

Tahara²,

Nakasone³

et al. 2015

IJC

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Single crystals were grown at room temperature from the precursors CaCO 3 and NH 2 SO 3 H by a gel method using agar-agar gel as the medium of growth. Differential scanning calorimetry, thermogravimetric-differential thermal analysis, and X-ray diffraction measurements were performed on the single crystals. The crystal structure of the grown crystals was confirmed to be very similar to that of calcium sulfate dihydrate (CaSO 4 • 2H 2 O, gypsum). The temperature at which dehydration and evaporation of intercalated water molecules in the single crystal occurred was found to be 375.9 K, which was very close to that in CaSO 4 • 2H 2 O. From all these results, we identified the grown single crystals as CaSO 4 • 2H 2 O. The weight loss owing to the thermal decomposition of anhydrous CaSO 4 formed by the dehydration of the single gypsum crystals was found to occur at ~1530 K. This weight loss was probably caused by the evolution of SO 3 gas by sublimation, and the chalky white substance left in the open vessel after decomposition was calcium oxide (CaO).

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Section: Dsc and Tg-dta Measurementssupporting

confidence: 88%

Section: Dsc and Tg-dta Measurementssupporting

confidence: 87%

Section: Dsc and Tg-dta Measurementsmentioning

confidence: 76%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Synthesis, Crystal Structure, and Thermal Properties of CaSO4·2H2O Single Crystals

Fukami¹,

Tahara²,

Nakasone³

et al. 2015

IJC

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“…The IR FEL can also be transported by a mirror actuator to several laboratories in a neighboring building. Since the IR FEL beamline was completed in 2003, it has been used for developing novel materials, studying dental treatments, and obtaining many unique results [17,18].…”

Section: Ir Fel At Lebramentioning

confidence: 99%

Complex light source composed from subterahertz-wave coherent synchrotron radiation and an infrared free-electron laser at the Laboratory for Electron Beam Research and Application

et al. 2014

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We have successfully transported subterahertz-wave (sub-THz-wave) coherent synchrotron radiation (CSR) from an accelerator room to an experimental room by using an existing IR free-electron laser (FEL) beamline at the Laboratory for Electron Beam Research and Application at Nihon University. The power of the transported CSR was 50 nJ per macropulse, and it was available at frequencies of 0.1-0.3 THz. From two-dimensional imaging performed with the sub-THz-wave CSR, metallic structures concealed by plastic in a smart card were nondestructively detected at a spatial resolution of 1.4 mm. We also verified the existence of hydrated water in a crystal by using chemometric two-band spectroscopy with the sub-THz-wave CSR and IR FEL. Pioneering applications, such as more reliable material identification, can be anticipated from this complex light source composed from the sub-THz-wave CSR and IR FEL beams.

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Evaluation of irradiation effects of near-infrared free-electron-laser of silver alloy for dental application

et al. 2017

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In the application of lasers in dentistry, there is a delicate balance between the benefits gained from laser treatment and the heat-related damage arising from laser irradiation. Hence, it is necessary to understand the different processes associated with the irradiation of lasers on dental materials. To obtain insight for the development of a safe and general-purpose laser for dentistry, the present study examines the physical effects associated with the irradiation of a near-infrared free-electron laser (FEL) on the surface of a commonly used silver dental alloy. The irradiation experiments using a 2900-nm FEL confirmed the formation of a pit in the dental alloy. The pit was formed with one macro-pulse of FEL irradiation, therefore, suggesting the possibility of efficient material processing with an FEL. Additionally, there was only a slight increase in the silver alloy temperature (less than 0.9 °C) despite the long duration of FEL irradiation, thus inferring that fixed prostheses in the oral cavity can be processed by FEL without thermal damage to the surrounding tissue. These results indicate that dental hard tissues and dental materials in the oral cavity can be safely and efficiently processed by the irradiation of a laser, which has the high repetition rate of a femtosecond laser pulse with a wavelength around 2900 nm.

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Thermal ablation of FEL irradiation using gypsum as an indicator

Cited by 10 publications

References 31 publications

Synthesis, Crystal Structure, and Thermal Properties of CaSO4·2H2O Single Crystals

Synthesis, Crystal Structure, and Thermal Properties of CaSO4·2H2O Single Crystals

Complex light source composed from subterahertz-wave coherent synchrotron radiation and an infrared free-electron laser at the Laboratory for Electron Beam Research and Application

Evaluation of irradiation effects of near-infrared free-electron-laser of silver alloy for dental application

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