Consideration of Diluents Selection and Input Amounts of the Hunter Process for Tantalum Production

Jae‑Jin Sim,Sang‑Hoon Choi,Yong‑Kwan Lee,Sung Gue Heo,Taek‑Soo Kim,Seok‑Jun Seo,Kyoung‑Tae Park 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

Tantalum (Ta) is a heavy refractory metal with an atomic weight of 180.95 g/mol, a density of 16.6 g/cm3, and a high meltingpoint of 3017 °C. With its refractory characteristics, it shows excellent chemical and physical stability as well as corrosionand heat resistance at elevated temperatures. The demand for Ta metal and related compounds is increasing with the expansionof the electronics and chemical industries. The Hunter process was proven to be effective in producing Ta powder in1953. Hunter proposed a method in which potassium heptafluorotantalate (K2TaF7) was reduced by sodium (Na). Thus far,this process has been the primary commercial method to produce Ta powder. In this study, quantitative differences wereanalyzed for diluent selection. Additionally, consideration was given to changes in the caloric value depending on the inputamount of diluents. Finally, the optimum material input and the properties of the prepared Ta were analyzed. Stoichiometricratios of K2TaF7(1 mol), NaCl (6.2–6.7 mol), Na (5–7 mol) were weighed, to perform a metallothermic reduction reaction. After the reaction, the tantalum powder was recovered and the flush process was carried out. After that, it was dried in avacuum atmosphere. Physical properties such as oxygen concentration, PSA, ICP-OES, and XRD of powder were conductedto evaluate the characteristics of Ta powder that was finally manufactured.

Changes in αB-crystallin, tubulin, and MHC isoforms by hindlimb unloading show different expression patterns in various hindlimb muscles

( Hyun Seok Jee ),( Taka Shi Skurai ),( Jae Young Lim ),( Hideo Hatta ) 한국운동영양학회 2014 Physical Activity and Nutrition (Phys Act Nutr) Vol.18 No.2

Hyun Seok Jee, Takashi Sakurai, Jae-Young Lim and Hideo Hatta. Changes in αB-crystallin, tubulin, and MHC isoforms by hindlimbunloading show different expression patterns in various hindlimb muscles. JENB., Vol. 18, No. 2, pp.161-168, 2014 [Purpose]αB-crystallin is a small heat shock protein that acts as a molecular chaperone under various stress conditions. Microtubules, whichconsist of tubulin, are related to maintain the intracellular organelles and cellular morphology. These two proteins have been shownto be related to the properties of different types of myofibers based on their contractile properties. The response of these proteinsduring muscular atrophy, which induces a myofibril component change, is not clearly understood. [Methods] We performed 15days of hindlimb unloading on rats to investigate the transitions of these proteins by analyzing their absolute quantities. Proteincontents were analyzed in the soleus, plantaris, and gastrocnemius muscles of the unloading and control groups (N = 6). [Results]All three muscles were significantly atrophied by hindlimb unloading (P < 0.01): soleus (47.5%), plantaris (16.3%), and gastrocnemius(21.3%) compared to each control group. αB-crystallin was significantly reduced in all three examined unloaded hindlimb musclescompared to controls (P < 0.01) during the transition of the myosin heavy chain to fast twitch muscles. α-Tubulin responded onlyin the unloaded soleus muscle. Muscle atrophy induced the reduction of αB-crystallin and α-tubulin expressions in plantar flexormuscles with a shift to the fast muscle fiber compared to the control. [Conclusion] The novel finding of this study is that bothproteins, αB-crystallin and α-tubulin, were downregulated in slow muscles (P < 0.01); However, α-tubulin was not significantly reduced compared to the control in fast muscles (P < 0.01). [Keyword] Microtubule, αB-crystallin, tubulin, myosin heavy chainisoform, skeletal muscle

일본의 역사 사전․개설(론)서에 보이는 古代 한—일 관계

이재석(Lee, Jae?Seok) 한일관계사학회 2006 한일관계사연구 Vol.25 No.-

서울의 Penicillinase Producing Neisseria Gonorrhoeae 발생빈도(1996)

김재홍,황동규,전재홍,김윤석,김중환,김용준,이창균,임동진,김현수,조창근,김경문,박상훈,전우형,김희성,이호정,차명수,김갑형,김형석,김석우,황지환,박병순,권오상,이민수,송기훈,성소영,이인섭,부태성 대한화학요법학회 1999 대한화학요법학회지 Vol.17 No.2

Background : In recent years, gonorrhea has been panedemic and remains one of the most commom STDs in the world, especially in developing countries. Objective & Methods: For the detection of a more effective therapeutic regimen and assessing the prevalence of PPNG, we have been trying to study the patients who have visited the VD Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results: In 1996, 139 strains of N. gonorrhoeae were isolated, among which 53(39.0%) were PPNG. Conclusion: Our results suggests that after a peak of 74.3% in 1993, the prevalence of PPNG in Seoul is gradually declining.

서울의 Penicillinase Producing Neisseria gonorrhoeae 발생빈도(1998)

김재홍,김준호,반재용,이정우,황성주,정준규,정성태,강진문,조흔정,홍창의,정혜신,이한승,김이선,이봉길,이종호,선영우,한기덕,윤성필,이성훈,안종성,박석범,문승현,조항래,김형섭,류지호,황재영,박준홍,손상욱 한양대학교 의과대학 2001 한양의대 학술지 Vol.21 No.1

In recent years, gonorrhea has been pandemic and remains one of the most common STDs in the world, especially in developing countries. For the detection of a more effective therapeutic regimen and assessing the prevalence of Penicillinase Producing Neisseria gonorrhoeae(PPNG), we have been trying to study the patients who have visited the Venereal Disease Clinic of Choong-Ku Public Health Center in Seoul since 1980 by menas of the chromogenic cephalosporin method. In 1998, 93 strians of N. genorrhoeae were isolated, among which 60(64.5%) were PPNG. The prevalence of PPNG in Seoul, which had been decreased to 39% in 1996 after a peak of 74.3% in 1993, is increased to 64.5% in 1998.

외상후 발작의 위험인자에 대한 조사

이재학,배학근,윤석만,도재원,이경석,윤일규,최순관,변박장 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.1

Risk Factors for Posttraumatic Seizure The authors evaluate the risk factors for posttraumatic seizures. this prospective study was performed in a series of 470 head injured patient from January 1996 to Decomber 1998. The patients who were dead within 1 week of injury or children from 3 years old and under were excluded. There were 358 male and 112 female with a mean age of 35.2±22.8 years (range, 4-88 years). The results were as follows : 1). Of the 470 patients, pasttraumatic seizure occurred in 48 patients(10.2%): early seizure in 28(6%) and late seizure in 20 patients(4.2%). 2). The clinical risk factors for posttraumatic seizure were poor consciousness at admission, presence of brainstem herniation signs, poor GCS score, and posttraumatic amnesia more than 24 hours after trauma(p<0.001). 3). The radiological risk factors for posttraumatic seizure were subdural hematoma(p<0.001), intracerebral hematoma (p<0.02), mutiple intracranial CT lesions(p<0.001), or delayed lesions on follow-up CT scans(p<0.001). the incidence of seizure increased according to the severity of diffuse brain lesion(p<0.001), and the seizure rate in mass lesion was higher than that in diffuse lesion(p<0.001). 5). Hypoxia and coagulopathy had a statistically significant influence on posttraumatic seizure(p<0.05). Hypoxia had a infuence on occurrence of late seizure(p<0.05). 6). The incidence of posttraumatic seizure signiticantly increased in surgical group compared with coservative group(p<0.001) and significantly increased in patient who underwent decompressive craniectomy compared with those who underwent craniotomy(p<0.001) 7). Preventive administration of antiepileptic drugs decreased the incidence of early seizure, but did not affect on the reduction of late seizure. 8). Multivariate logistic regression analysis showed the subdural hematoma, GCS score, delayed lesion, and intracerebral hematoma in order of importance for seizure risk. in conclusion, the risk factors affecting on the occurrence of seizure were clinical status at admission, CT lesions, and severity of diffuse brain inJury. Considering that hypoxia affected on the late seizure, it is necessary to detect and treat it immediately after trauma. In addition, the patients who underwent decompressive craniectomy should be carefully followed to evaluate the risk of late seizure. Even though preventive administration of antiepileptic drugs had a tendency to decrease the incidence of early seizure, it is unclear whether administration of antiepileptic drugs can reduce the incidence of posttraumatic seizures. Prospective study will be needed in the selected patients.

MgCl₂溶液內에서 STS 304 HP Stainless Steel 熔接部의 破壞擧動에 對한 硏究

金永奭,丁太權,朴昌彦,洪錫柱,梁仁榮,金基玉,朴煥奎,李茂錫,曺圭宰,鄭在康 조선대학교 생산기술연구소 1983 生産技術硏究 Vol.1983 No.-

This paper is based on an experiment analysing the stress corrosion cracking behaviour of welding specimens compared to that of non-welding specimens of STS 304 HP stainless steel in corrosion solution. As a corrosion condition, stainless steel has been known to be the most fragile in a solution of 42% MgCl₂heated to the boiling point, therefore the experiment was carried out in this condition. The experiment was carried out with argon gas TIG welding specimens and non-welding ones made of stainless steel plates, thickness 2mm, by tensile force. At this time, the tensile force was taken to be the value of the yield strength of the tensile test specimens divided by the safety factor of 3.0 to 3.5, 4.0, 4.5, and 5.0. In this paper, the relations between Time of Initial Crack, Time of Failure, Time of Final Fracture and Crack Propagation Length were investigated and then plotted. Furthermore, the relations between Stress Intensity Factor K proposed by Irwin and the Time of Initial Crack, the Time of Failure, the Time of Final Fracture were calculated and plotted. At the last, all the relations plotted were expressed to normal equations by computer, and the equations were used to analyse the data obtained in the experiment. The conclusions obtained in this study are as follows: 1. Welding materials, compared with non-welding ones, as the Time of Initial Crack, the Time of Failure, and the Time of Final Fracture were generally very fast, appeared to be a phenomenon of unstable brittleness fracture. 2. Non-welding materials, compared with welding ones, as the safety factor was larger or the working stress was smaller, appeared to be a phenomenon that the longer had had greater durability. Therefor, welding materials must be considered enough to be used in heate affected and stress corrosion atmosphere. 3. The normal equations of the Time of Initial Crack and the variation rate to the same Stress Intensity Factor K are as follows: (A) Non-welding T =259702.4-5451.2 K+28.386 K² T = -5451.2+28.386 K (B) Welding T= -332.693+28.043 K-0.211 K² T' =28.043-0.211 K here, T; Time of Initial Crack, T'; Variation Rate of Time of Initial Crack to Stress Intensity Factor K, K ; Stress Intensity Factor.

동일한 환자에서 조혈모세포이식 전후의 호중구감소 기간 중 감염양상에 대한 비교연구 : 중심정맥관 관련 패혈증을 중심으로 Based on Central Venous Catheter Related Septicemia

류재호,노규태,이영석,이영호,권혁찬,김재석,김효진,이영민,박혜원,박근희 대한조혈모세포이식학회 2002 대한조혈모세포이식학회지 Vol.7 No.1

연구배경: 동일한 환자를 대상으로 조혈모세포이식 전 일반 병실에서의 관해유도 항암제치료 및 강화요법으로 인한 호중구감소 기간의 감염양상과 고용량 항암제치료 후 무균실에서의 조혈모세포이식 시 호중구감소 기간의 감염양상을 중심정맥관 관련 패혈증을 중심으로 비교 연구함으로써 효율적인 감염관리지침을 마련하고자 하였다. 대상 및 방법: 1999년 1월부터 2001년 7월까지 2년 7개월간 동아대학교병원 일반병실에서 악성혈액질환으로 항암제 치료를 받다가 조혈모세포이식을 시행받았던 22명을 대상으로 중심정맥관 관련 패혈증의 형태를 비교분석하였다. 결과: 대상 환자들의 일반병실과 무균실에서의 입원기간은 각각 32±13일, 33±19일, 호중구 감소기간은 15±12일, 17±18일, 호중구 감소기간의 발열 횟수는 14회, 14회로서 입원병실의 종류에 따른 차이는 없었다. 환자들의 중심정맥관 사용일수는 일반병실에서 29일(7~545일), 무균실에서 100.5일(25~606일)이었으며, 총 사용일수는 각각 1,515일, 3,250일로서 무균실에서의 중심정맥관 사용일수가 의미 있게 길었다(P=0.001). 중심정맥관 사용 일수에 대한 감염률은 각각 5.28/1,000일, 3.08/1,000일로서 일반병실에서 그 빈도가 높았으나 통계적 유의성은 보이지 않았다(P=0.141). 결론: 중심정맥관 삽입 후 일반병실에서 항암제 치료를 받던 환자가 조혈모세포이식을 위하여 무균실에 입원하는 경우, 중심정맥관을 교체하는 것이 감염관리를 위하여 바람직할 것으로 생각된다. Background: We compared the incidence of central venous catheter (CVC) related septicemia during neutropenic period in the same patient, which developed following chemotherapy for remission induction and consolidation, or hematopoietic stem cell transplantation (HSCT). Methods: We retrospectively reviewed the medical records and laboratory data of 22 patients with hematologic malignancies who received anticancer chemotherapy followed by HSCT at Dong-A University Hospital between January, 1999 and July, 2001. We investigated the duration of hospitalization, duration of neutropenic period, duration of catheterization, microbiologically documented organisms and incidence of CVC related septicemia. Results: The data in general ward (before HSCT) and laminar air flow room (after HSCT) were as follows: duration of hospitalization was 32±13 days and 33±19 days, duration of neutropenic period was 15±12 days and 17±18 days, median duration of catheterization was 29 days (7~545 days) and 100.5 days (25~606 days) (P=0.001), and incidence of CVC related septicemia was 5.28/1000 days and 3.08/1000 days, respectively. In the CVC related septicemia, the most common etiologic organism was coagulase negative staphylococcus. Conclusion: We suggest that the exchange of CVC before admission to laminar air flow room could decrease the incidence of CVC related septicemia in HSCT recipients.

간세포암의 고주파 열치료 후 천자침 경로를 통한 전이 1례

조영완,박석주,진한영,김준영,이재익,강명주,박정하,윤정희,박성재,지삼룡,이연재,이상혁,설상영 인제대학교 2006 仁濟醫學 Vol.27 No.-

Radiofrequency ablation(RFA), as a form of minimally invasive therapy for hepatocellular carcinoma, has become an important treatment modality. Because of limitation of surgery, RFA has become standard therapy for hepatocellular carcinoma in some situations. But there are some complications of RFA such as bleeding, infection, hematoma, adjacent organ thermal damage including intestinal perforation, needle track seeding, and so on. There are few reports in the literature that systematically evaluate the incidence of needle tract seeding and its associated risk factors. And only 2 cases of needle tract seeding of hepatocellular carcinoma after RFA were reported in Korea. We report a case of needle tract seeding of hepatocellular carcinoma after RFA.

조경용 철쭉재배품종의 형태적 특성 및 분류기준

최재진,박석곤,Choi, Jae-Jin,Park, Seok-Gon 한국조경학회 2014 韓國造景學會誌 Vol.42 No.2

본 연구는 조경용으로 주로 이용되는 철쭉재배품종(이하 철쭉류)의 형태적 특성을 조사해 분류기준을 마련하고자 실시되었다. 공시재료로서 철쭉류 생산농가에서 대량 재배되는 주요 철쭉류를 수집하였다. 그 후에 국립종자원의 철쭉 신품종심사를 위한 특성조사요령에 준하여 철쭉류의 질적 양적 형질특성을 조사하여, 철쭉류의 재배품종 분류 및 분류기준을 마련하였다. 현재, 조경용 철쭉류는 재배품종명이 정립되어 있지 않았으므로 생산농가 등에서 사용하는 명칭대로 데이터를 정리하였다. 그 결과, 전남 순천지역에 조경용으로 주로 재배되는 철쭉류는 베니, 대왕, 쓰리, 자산홍, 한철, 산철쭉, 겹산철쭉, 백철쭉, 아까도, 석암 등 10개였다. 이 중에 베니, 대왕, 쓰리 품종은 생산농가에서 영산홍으로 통칭해 불리며, 잎과 꽃의 형태가 유사해 구분이 쉽지 않았다. 특히 베니의 화색은 '밝은 빨강'이었고, 대왕은 '선명한 자주', 쓰리는 '밝은 자주'로 조사되었다. 또한 자산홍과 한철은 그 형태가 비슷하였으나, 한철은 자산홍에 비해 꽃의 반점 발현정도와 잎 앞면의 광택이 강한 편이다. 산철쭉은 다른 철쭉류에 비해 4월 초에 꽃이 일찍 피었다. 겹산철쭉은 산철쭉의 기본종으로 모든 형질이 산철쭉과 유사하였으나, 꽃이 겹꽃으로 피었다. 백철쭉은 꽃이 흰색으로 피어 쉽게 구분되었지만, 잎이 아까도 품종과 비슷하여 두 재배품종의 구분이 쉽지 않았다. 아까도 품종은 다른 철쭉류에 비해 5월 초에 개화시기가 늦었고, 꽃의 직경이 백철쭉, 산철쭉과 함께 넓은 편이었다. 마지막으로 석암 품종은 잎 크기가 다른 재배품종에 비해 비교적 작아 쉽게 구분되었으며, 아까도 품종과 함께 늦게 개화하였다. This study was conducted to examine the morphological characteristics of those Azalea Cultivars(hereinafter, Azalea Cultivars) that are mainly used for landscaping in Korea in order to prepare classification criteria. As testing materials, major Azalea Cultivars cultivated in large quantities by its producing companies were collected. Thereafter, the qualitative and quantitative characteristics of the traits of Azalea Cultivars were investigated in the way of characteristic investigation for new cultivars of azalea used by the Korea Seed and Variety Service in order to classify them and prepare the classification criteria. Since cultivar names have not been established for Azalea Cultivars for landscaping thus far, the data were compiled using the names used by cultivating companies. According to the results, Azalea Cultivars cultivated in Suncheon, Jeonnam mainly for landscaping were 10 in number; Beni, Daewang, Three, Zasanhong, Hancheol, Sancheoljuk, Gyeobsancheoljuk, Baekcheoljuk, Akado, and Seok-am. Among them, the cultivars Beni, Daewang, and Three could not be easily distinguished from each other because they are commonly called Yeongsanhong by cultivating companies and the shapes of their leaves and flowers are similar to each other. In particular, the flower color of Beni was 'bright red', that of Daewang was 'vivid purple', and that of Three was 'bright purple'. In addition, Zasanhong and Hancheol were similar to each other in shape the degree of expression of spots on the flowers and the gloss on the front side of the leaves of Hancheol were higher and stronger compared to that of Zasanhong. Sancheoljuk flowered in early April, earlier compared to other Azalea Cultivars. Gyeobsancheoljuk is an elementary species of Sancheoljuk and it had double flowers although all other traits were similar to those of Sancheoljuk. Although Baekcheoljuk was easily distinguished because it had white flowers, its leaves were similar to those of Akado the reason why these two cultivars could not be easily distinguished from each other. The cultivar Akado flowered early May later compared to other Azalea Cultivars and its flowers were relatively large in diameter as with Baekcheoljuk and Sancheoljuk. Finally, the cultivar Seok-am was easily distinguished because it had smaller leaves compared to other cultivars and it flowered late as with the cultivar Akado.