• Title/Summary/Keyword: Thermolysis

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Preparation of Biodegradable Porous Calcium Metaphosphate Matrix (생분해성 다공질 Calcium Metaphosphate Matrix의 제조)

  • 이중환;김석영
    • Journal of Biomedical Engineering Research
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    • v.19 no.5
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    • pp.449-454
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    • 1998
  • It is well known that new tissue or blood vessel is grown into a porous calcium phosphate ceramics used as a bone graft substitute due to their excellent biocompatibility. In this study, the most chemically stable porous $\beta$-crystalline form in various forms of calcium metaphosphate, Ca(PO$_3$)$_2$is prepared by the controlled thermolysis of monocalcium phosphate, Ca(H$_2$PO$_4$)$_2$.The diameter of cylindrical pores formed during cooling was controlled by a holding time at the melting point of a monocalcium phosphate and by the change of a crystallization temperature, to obtain the most appropriate size (about 200$\mu$m) of pores for the application of bone substitutes and matricuts. It was observed that the increasing holding time at the melting point of monocalcium phosphate results in the decreases of cylindrical pore sizes.

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Musculocutaneous and Median Neuropathy after MiraDry® Procedure for Axillary Hyperhidrosis (다한증 치료 기구인 MiraDry®에 의한 근피 및 정중신경 손상 증례)

  • Kim, Youngmin;Yoon, Mi-Jeong;Park, Sunha;Kim, Min Wook
    • Clinical Pain
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    • v.20 no.2
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    • pp.135-140
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    • 2021
  • MiraDry®, a microwave thermolysis device, is comparably new non-surgical agent in the field of eradication of sweat glands for treating axillary hyperhidrosis and osmidrosis. So far, altered sensation, swelling, and compensatory sweating are widely known as adverse effects of MiraDry®. Of the few reported MiraDry®-induced neuropathy cases, median and ulnar neuropathies are common. Although, one case has described radial nerve and posterior cord damage with maximized stimulation intensity, musculocutaneous nerve damage induced by MiraDry® has not been reported. Here, we report a case of a 30-year-old woman experiencing left hand weakness after receiving MiraDry® at a local dermatology clinic. Left brachial plexopathy, mainly involving the median nerve and the musculocutaneous nerve with partial axonotmesis, was confirmed by electrodiagnostic studies. Ultrasound evaluation showed corresponding results. This is the first case report of the musculocutaneous neuropathy by MiraDry®.

Synthesis of Tungsten Doped Vanadium Dioxide and Its Thermochromic Property Studies (텅스텐이 도핑된 바나듐 산화물의 합성 및 열전이 특성 연구)

  • Hwang, Kyung-Jun;Jo, Cho Won;Yoo, Jung Whan
    • Applied Chemistry for Engineering
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    • v.24 no.1
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    • pp.44-48
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    • 2013
  • In this work, we have prepared tungsten doped vanadium oxide ($W-VO_2$) particles with a low phase transition temperature. $W-VO_2$ particles were synthesized via thermolysis method using vanadyl (IV) sulfate and ammonium bicarbonate as precursors. The structure and thermochromic property of synthesized $W-VO_2$ particles were investigated by FE-SEM, EDS, XRD, XPS, and DSC analysis. The prepared $W-VO_2$ showed a nearly platy morphology, which indicates that the tungsten was successfully doped in the crystal lattices of $VO_2$. $W-VO_2$ nanoparticles with the size of 60 nm exhibited a monoclinic crystal structure and its chemical composition and surface state were also likely to be close to that of $VO_2$. In addition, the phase transition temperature of $W-VO_2$ was $38.5^{\circ}C$, which was approximately $29.2^{\circ}C$ lower than that of pure $VO_2$ ($67.7^{\circ}C$), indicating that the prepared sample had a good reversible thermochromic stability.

In-situ Fourier Transform Infrared Spectroscopic Study during Thermolysis of Trimethylaluminum and its Adduct (Trimethylaluminum (TMA), $NH_3$ 및 TMA :$NH_3$Adduct의 열분해 반응에 대한 in-situ FTIR 분광학적 연구)

  • Hyang Sook Kim;Seong Han Kim;Jin Soo Hwang;Joong Gill Choi;Paul Joe Chong
    • Journal of the Korean Chemical Society
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    • v.37 no.12
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    • pp.995-1002
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    • 1993
  • The thermal decomposition of trimethylaluminum (TMA) with ammonia has been investigated by in-situ Fourier transform infrared spectroscopy. The spectroscopic reaction cell, which permits heating interna lly up to 1100$^{\circ}C$, consists of stainless-steel hexagonal-port chamber containing two NaCl windows installed in parallel. In this work, the stoichiometric reaction between TMA and $NH_3$ is found to be completed immediately after mixing. FTIR spectra observed in the range of temperature 25∼1100$^{\circ}C$ show that TMA and TMA : $NH_3$ adduct decompose into methane as a predominant product around 500$^{\circ}C$. The assignments of the IR bands due to the gaseous TMA, $NH_3$ and TMA : $NH_3$ adduct are attempted on the basis of the published data. Furthermore, the decomposition of TMA can be described as a first-order reaction. Kinetic data about the decompositon of TMA and TMA : $NH_3$adduct will also be discussed.

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