포수제(捕收劑) 종류(種類)에 따른 공작석(孔雀石)의 부유선별(浮遊選別) 특성(特性)

김형석,김완태,한인규,김상배,Kim, Hyung-Seok,Kim, Wan-Tae,Han, In-Kyu,Kim, Sang-Bae 한국자원리싸이클링학회 2010 資源 리싸이클링 Vol.19 No.4

공작석의 부선에 적합한 포수제를 규명하기 위하여 각종 포수제의 종류에 따른 공작석의 부유선별 특성을 연구하였다. 공작석의 제타전위를 측정한 결과, 공작석의 등전점은 약 pH 8.2로, 등전점 이상의 pH에서는 공작석의 표면이 음(-)으로 하전되고, 등전점 이하에서는 양(+)으로 하전됨을 확인하였다. 공작석은 음이온 포수제인 sodium oleate와 Aeropromoter 845에 의해서 pH 5~11의 범위에서 97%이상 부유되었다. 그러나 alkyl hydroxamate 및 양이온 포수제인 dodecyl trimethyl ammonium chloride와 dodecyl ethyl methyl ammonium chloride에 의해서는 pH 5 이상에서 첨가량에 관계없이 15%미만으로 부유되었다. 공작석을 $(NH_4)_2S$로 황화처리한 후 potassium amyl xanthate로 부선하였을 때, 공작석은 97%이상 부유되었다. 이때 황화처리하지 않았을 때 보다 potassium amyl xanthate의 첨가량이 1/3 정도 적어졌고, 부선시간도 단축되었다. 따라서 공작석의 부선에 적합한 포수제는 potassium amyl xanthate와 음이온 포수제인 sodium oleate 및 Aeropromoter 845이었다. In order to select the proper collector for the flotation of malachite, we had floated malachite by using various collectors. When measuring the zeta potential of malachite, we knew that the point of zero charge of malachite is found at pH 8.2 and malachite particles are negatively charged above this pH value; and positively, below this pH value. The floatability of malachite by the anionic collectors like sodium oleate and Aeropromoter 845, was about 97% in pH 5~11 range, whereas that of malachite by alkyl hydroxamate and the cationic collector like dodecyl trimethyl ammonium chloride and dodecyl ethyl methyl ammonium chloride, was below 15% above pH 5 regardless of dosage increase of collector and flotation time. The malachite sulphidised by $(NH_4)_2S$ was floated above 97% by potassium amyl xanthate. The dosage of potassium amyl xanthate decreased and the flotation period shortened to one third than when it was not sulphidised by $(NH_4)_2S$. Therefore, potassium amyl xanthate and the anionic collectors like sodium oleate and Aeropromoter 845 can be used as the collector of malachite.

Trinitrotoluene의 환원반응에서 가스크로마토그래피 모니터링을 이용한 2,6-diamino-4-nitrotoluene의 합성

김형석,유재철,김호기,김새롬,최근배,정원복,서원준,김진석,Kim, Hyoung-Sug,Yu, Jae Chul,Kim, Ho Gi,Kim, Sae Rom,Choi, Keun Bae,Jung, Won Bok,Seo, Won Jun,Kim, Jin-Seuk 한국군사과학기술학회 2014 한국군사과학기술학회지 Vol.17 No.2

In this research, we investigated synthetic method of 2,6-DANT that can be used as a chain extender of urethane/urea and epoxy materials in a demilitarization method via chemical transformations considering environmental, economical aspects and stability of process. We was able to identify through GC monitoring that 2,4-DANT and 2,6-DANT were produced when we inject 'hydrazine monohydrate 3.3 eq. by TNT 1 eq.' with a fine metering pump for 30 minutes and then, reflux for an additional 2 hours. We was able to isolate only 2,6-DANT(99.3% purity and 45.0% yield) from mixture of 2,4-DANT and 2,6-DANT through the separating and refining methods using 2,6-DANT solubility in methanol and crystallinity of 2,6-DANT.

옥탄가 변화에 따른 가솔린의 발화특성에 관한 연구

김형석,김원길,최유정,김정훈,최재욱,Kim, Hyeong Seok,Kim, Won Kil,Choi, Yu Jung,Kim, Jung-Hun,Choi, Jae-Wook 한국안전학회 2018 한국안전학회지 Vol.33 No.2

This study was conducted to assess the hazards of gasoline in relevance to the changes in octane numbers, and gasoline's spontaneous ignition temperature and instantaneous ignition temperature were measured. Spontaneous ignition temperature of regular gasoline was $301^{\circ}C$ for sample quantity of $100{\sim}125{\mu}{\ell}$. Spontaneous ignition temperature of middle gasoline was $380^{\circ}C$ for sample quantity of $125{\mu}{\ell}$ and that of premium gasoline was $400^{\circ}C$. As gasoline's octane numbers increased, their spontaneous ignition temperatures increased, and their instantaneous ignition temperature were almost identically $499^{\circ}C$ for sample quantity of $125{\mu}{\ell}$. In addition, activation energies of regular gasoline, middle gasoline, and premium gasoline were 10.48 Kcal/mol, 16.89 Kcal/mol, and 24.55 Kcal/mol respectively.

돼지의 과립막세포 종양

김형석,강상철,정지열,김현섭,김대용,김재훈,Kim, Hyeong-Seok,Kang, Sang-Chul,Jung, Ji-YouI,Kim, Hyun-Sup,Kim, Dae-Yong,Kim, Jae-Hoon 대한수의학회 2008 大韓獸醫學會誌 Vol.48 No.3

A two-year-old mixed breed sow was requested to the Veterinary Pathology Laboratory of Cheju National University with a clinical signs of severe abdominal pain and sudden death. Grossly, there was severe hemorrhage in abdominal cavity. Most of internal parenchymas and subcutaneous muscle showed severe pale discoloration. Both ovaries were enlarged with oval to round protruding multilobular masses and dark red in color. And they were firm and contained multiple small cysts in their cut surface. Histopathologically, numerous neoplastic granulosa cells had spherical-to-oval, hyperchromatic nuclei and scant eosinophilic cytoplasms were distributed with follicular pattern in ovarian masses. And the typical Call-Exner bodies, distinctive microcavityies, were observed in the center of small neoplastic follicles. Based on the gross and histopathologic findings, this case was diagnosed as granulosa cell tumor. In our best knowledge, this is believed to be the first report of granulosa cell tumor in a sow in Korea.

실시간 In-situ IR을 이용한 Glycidyl Azide Monomer(GAM)의 양이온중합 반응속도 연구

김형석,김관영,강신춘,노시태,김진석,유재철,최근배,Kim, Hyoung-Sug,Kim, Kwan-Yung,Kang, Shin-Choon,Noh, Si-Tae,Kim, Jin-Seuk,Yu, Jae-Chul,Choi, Keun-Bae 한국군사과학기술학회 2009 한국군사과학기술학회지 Vol.12 No.2

We synthesized glycidyl azide monomer(GAM) as a monomer for polymerization of glycidy azide polymer(GAP) which is a promising energetic prepolymer for a plastic-bonded explosive. Using quantitative real-tim in-situ infrared(in-situ IR) spectroscopy, kinetic study on the cationic ring opening polymerization of GAM was carried out. The reaction rate was obtained from monitoring the change of ether C-O stretching band($1050cm^{-1}$) in series IR spectra. The reaction was in accordance with the first-order reaction law for each of reaction temperature at 100/1 mole ratio of [GAM]/[$BF_3*etherate$]. In the ring opening polymerization of GAM, with ratio of [GAM]/[$BF_3*etherate$] to equal 100/1 at various temperature, the activation parameters obtained from the evaluation of kinetic data were ${\Delta}H^*$=14.34kcal/mol, ${\Delta}S^*=-12.31cal/mol{\cdot}K$ and $E_a$=14.89kcal/mol.

전층 각막이식 후 경면현미경, 초음파 각막두께측정계 및 Orbscan을 이용한 중심 각막두께 측정치의 비교

김형석,김준헌,김효명,송종석,Hyoung-Seok Kim,Jun Heon Kim,Hyo Myong Kim,Jong-Suk Song 대한안과학회 2007 대한안과학회지 Vol.48 No.2

Purpose: To compare the accuracy and reproducibility of central corneal thickness measured by non-contact specular microscopy, ultrasound pachymetry, and Orbscan in the post-penetrating keratoplasty eyes. Methods: Central corneal thickness was prospectively measured in eyes that had recieved penetrating keratoplasty at least 1 month before. One experienced technician measured all eyes using three methods; non-contact specular microscopy (Topcon SP-2000P; Topcon Corporation, Tokyo, Japan), Orbscan IIz (Orbtek; Bausch & Lomb, Rochester, USA), and ultrasound pachymetry (AL-2000; Tomey, Erlangen, Germany). Three consecutive measurements were performed using each method and the mean values and coefficient of variation were compared. Results: The mean values of central corneal thickness were 550.7±63.3 ?m with specular microscopy, 548.2±72.5 ?m with ultrasound pachymetry, and 472.5±151.7 ?m with Orbscan. There was no significant difference between the measurements obtained by specular microscopy and ultrasound pachymetry (p=0.53), and both methods showed high reproducibility. The corneal thickness measured by Orbscan was remarkably variable and in some patients, Orbscan was unable to measure corneal thickness. Conclusions: Non-contact specular microscopy appears to be an effective technique, potentially replacing ultrasound pachymetry for measuring central corneal thickness in the post-penetrating keratoplasty eyes.

컨버전스에 대응한 BT와 NTT의 포트폴리오 변화 전략

김형석,Kim, H.S. 한국전자통신연구원 2006 전자통신동향분석 Vol.21 No.2

현재 대부분의 국내외 종합통신사업자들은 외부적인 통신산업의 경쟁 격화 및 새로운산업 트렌드 변화로 인해 매출과 영업이익이 정체되는 위기상황에 처해 있으며, 이를 타개하기 위해 미래 통신산업의 mega trend에 대응하여 사업구조를 재편하고 신규 수익모델을 창출하는 등 사업포트폴리오를 변화시키고 있다. 국내외 수많은 종합통신사업자들 중에서 일부는 미래 통신산업 mega trend 변화에 적극적으로 대응하여 다양한 전략적 옵션들을 취함으로써 성공적으로 변모해가고 있는 반면, 다른 일부는 소극적으로 대처하거나 또는 아무런 인식이 없이 본업에만 안주하여 스스로 위기를 자초하고 있는 듯 하다. 이에 본 고에서는 새로운 패러다임 변화에 적극적으로 대처하고 있는BT와 NTT 그룹의 사업포트폴리오 변화 사례 분석을 통해 국내 종합통신사업자에게 미래 서비스 사업구조 개선 방향에 대한 시사점을 제공하고자 하였다.

그림으로 보는 농업통계

김형석,Kim, Hyeong-Seok 한국농업경영인중앙연합회 2007 한농연 Vol.58 No.-

슬관절내에 발생한 심부 양성 섬유성 조직구증 - 1례 보고 -

김형석,홍기도,하성식,이영화,이효진,Kim, Hyung-Seok,Hong, Ki-Do,Ha, Sung-Sik,Lee, Young-Hwa,Lee, Hyo-Jin 대한근골격종양학회 1999 대한골관절종양학회지 Vol.5 No.3

Benign fibrous histiocytoma is characteristically composed of fibroblastic and histiocytic cells. Most commonly, this tumor occurs in the dermis and superficial subcutis, but it is uncommon in the knee. We experienced a case of deep benign fibrohistiocytoma in a 38-year-old woman who complained of palpable tender mass on the medial aspect of the right knee. MR imaging findings included a well-delineated oval mass with low signal intensity on T1-weighted and high-signal intensity of T2-weighted images, as well as a marked peripheral contrast enhancement. Histopathologically, the lesion contained a mixture of fibroblastic and histiocytic cells that were often arranged in a cartwheel or storiform pattern and accompanied by varying numbers of inflammatory cells, foam cells, and siderophages. After surgical removal of the lesion, no recurrence was observed.

국내(國內) 석회석(石灰石)의 품위(品位) 향상(向上) 필요성(必要性)

김형석,Kim, Hyung-Seok 한국자원리싸이클링학회 2011 資源 리싸이클링 Vol.20 No.4

최근까지 국내에서는 노천에 부존된 고품위 석회석이 주로 채광되었기 때문에 고품위 석회석의 매장량은 감소되었다. 현재는 노천에 부존된 고품위 석회석이 고갈되어 석회석의 채굴적이 심부화되고 있다. 그러나 석회석 광체가 심부화될수록 석회석에 함유된 불순물 및 유색광물의 양이 많아져 석회석의 품위가 낮아진다. 따라서 본고에서는 국내 석회석의 광상 특성, 수당현황, 그리고 용도별 규격을 조사하고 국내외 석회석 정제기술의 현황을 분석하여 국내 석회석의 품위를 향상시키는 방안을 모색하였다. Until recently, domestic high grade limestone have mainly mined so high grade limestone deposits have reduced. Because of exhaustion of high grade limestone, mine of limestone have moved from ground to deep position, the grade of limestone become lower because the amount of impurities and colored mineral increased as mining position become deeper. This paper was described about grade improvement of limestone to make a high grade limestone and suitable quality of limestone products by analysis of ore genesis and characteristics, supply and demand situation, use patterns and application standards of domestic lime-stone.