증발결정화에 의한 다형체 생성 및 물리화학적 특징

장효준,김광주 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1

현재 안정한 형태인 결정형 β로 시판되고 있는 신경퇴행성 질환 치료제의 가장 큰문제점이 있다. 그것은 바로 결정형 β인 치료제 물질이 결정형 α에 비해서 인체 내의 용해도가 떨어진다는 점이다. 하지만 결정형 α는 불안정하여 결정형 β로 변하려고 하는 성질을 지니고 있어, 증발결정화라는 새로운 방법으로 결정형 α를 생성하였다. 그리고 생성된 결정형을 XRD, Raman Spectrum, DSC, TGA, FT-IR, SEM, 현미경을 통해 물리화학적 특징을 분석하였다. 결과적으로 높은 증발속도에서는 α-form이 생성되는 경향을 보이며, 반대로 낮은 증발속도에서는 주로 β-form이 생성되었다. 또한 60℃에서 용액은 높은 용해도로 인해 매우 끈적해지며 표면 또한 쉽게 건조되어 높은 증발 속도에도 불구하고 결정이 형성되지 않았다.

Measurement the separation efficiency of TNT red water by ice crystallization

장효준,김광주 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.1

TNT is purified through sulfite washing to remove undesired non-symmetrical isomers. This washing process generates a huge volume of wastewater effluents with complex constituents and strong dark red color. The presence of various organic constituents gives a high COD load. In the experiment, TNT waste water is made to concentration 1000ppm, amount of 1L. A second time experiments are proceeded, each of amount is 500ml. The first experiment is washing water quantity 30% (150ml) and the second is 60% (300ml). At first, the original waste water concentration 1000ppm is changed to below 10ppm. Escaping to the waste ice slurry, washing water concentration is respectively 170.76ppm, 149.58ppm. Therefore, using the wash column is efficient to reducing the TNT red water concentration.

Controlling the many crystallization conditions of paracetamol by cooling crystallization

장효준,김광주 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.0

Paracetamol (acetaminophen) is an analgesic drug that is used worldwide in the manufacture of many millions of tablets and other dosage forms every year. The crystal structures for two known crystal modifications of paracetamol (monoclinic and orthorhombic) have already been published. Monoclinic paracetamol is the thermodynamically stable modification at room temperature with respect to the orthorhombic modification. Monoclinic paracetamol (form I), which is the commercially used form, is not suitable for direct compression into tablets. In this study, by adjusting the degree of supersaturation, crystallization mode (cooling) and operating crystallization conditions (cooling rate, agitation speed, initial concentration): needed polymorphs of paracetamol were selectively crystallized. While 60°C paracetamol’s saturation solution is cooled to 10°C, double jacket is mesured by inline Raman spectroscopy. Increasing the cooling rate, and decreasing the agitation speed, metastable formⅡis easily obtained. When the initial concentration is high or low, irregular movements showed (form I and form II all get).

Examining the Nexus between Economic Ties at the Kaesong Industrial Complex and Security on the Korean Peninsulaa: Theoretical frameworks and evaluations

장효준 국방대학교 국가안전보장문제연구소 2022 The Korean Journal of Security Affairs Vol.27 No.2

This article examines the nexus between economic ties and security on the Korean Peninsula by discussing three causal mechanisms. First, economic ties increase opportunity costs to constrain the two Koreas’ conflict behavior. Second, inter-Korean economic ties allow either or both to send a costly signal about their resolves during a crisis. Third, economic ties transform domestic interests and preferences in favor of cooperation. Through these analytical lenses, the past KIC operation did not clearly show its pacifying effect due to its low opportunity costs, weak signaling, and stalled transformation of interests and preferences in both countries. Those who support the liberal peace process with hope for the KIC resumption need to articulate these mechanisms from the longer-term perspective while acknowledging a marginal impact of pacifying security effect in the short term. Without measures to improve its efficiency of operation and seek domestic support, the KIC, if reopened, would remain liberals’ unfulfilled promise.

2P-80 EDOT의 in-situ 중합 반응에 있어서의 산화제에 의한 영향

장효준,조정호,정대원 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

본 연구에서는, 3,4-ethylenedioxythiophene (EDOT)의 in-situ 중합 반응을 다양한 조건하에서 검토하고 그의 반응 메카니즘에 관하여 고찰하였다. EDOT의 산화중합 반응에 필요한 산화제, 도핑제 및 중합 조건 등에 변화를 주어 제조한 필름의 전도도 및 투과도를 측정하여 기존의 연구와 비교/검토 하였으며, 수계 산화제도 함께 검토하였다.

Prognostic Implications of Postoperative Infectious Complications in Non-Small Cell Lung Cancer

장효준,송재원,조석기,김관민,전상훈 대한흉부외과학회 2018 Journal of Chest Surgery (J Chest Surg) Vol.51 No.1

Background: Few studies have evaluated the long-term impact of postoperative infectious complications in patients with non-small cell lung cancer (NSCLC). We aimed to determine the impact of infectious complications on long-term outcomes after surgical resection for NSCLC. Methods: We performed a retrospective study of 1,380 eligible patients who underwent pulmonary resection for NSCLC from 2003 to 2012. Complications were divided into infectious complications and non-infectious complications. Kaplan-Meier survival analysis was used to compare unadjusted 5-year cancer-specific survival (CSS) rates and recurrence-free survival (RFS) rates. Cox regression was used to determine the impact of infectious complications on 5-year CSS and RFS. Results: The rate of total complications and infectious complications was 24.3% and 4.3%, respectively. In the node-negative subgroup, the 5-year CSS and RFS rates were 75.9% and 57.1% in patients who had infectious complications, compared to 87.9% and 78.4% in patients who had no complications. Infectious complications were a negative prognostic factor for 5-year RFS (hazard ratio, 1.92; 95% confidence interval, 1.00–3.69; p=0.049). In the node-positive subgroup, the 5-year CSS rate and RFS were 44.6% and 48.4% in patients who had infectious complications, compared to 70.5% and 48.4% for patients who had no complications. Conclusion: Postoperative infectious complications had a negative impact on CSS and RFS in node-negative NSCLC. Our findings may help improve risk assessment for tumor recurrence after pulmonary resection for node-negative NSCLC.

졸-겔 공정으로 제조한 나노 실리카의 표면개질 및 가스차단성 필름으로의 응용

장효준,장미정,남광현,정대원 한국공업화학회 2019 공업화학 Vol.30 No.1

실리카 표면의 개질을 위하여 다양한 조건 하에서 tetraethyl orthosilicate (TEOS)로부터 졸-겔 공법으로 제조한 실리카졸에 실란 커플링제인 octyltrimethoxysilane (OTMS) 또는 hexadecyltrimethoxysilane (HDTMS)을 반응시켰다. 얻어진 반응물들의 SEM-EDS, 열분석 및 원소분석을 통하여 실리카의 표면이 유기물로 개질된 것을 확인할 수 있었다. 유기용매에서의 분산성 및 에폭시 수지와 복합화한 필름의 표면 조도 등을 평가한 결과, 에탄올을 용매로 사용하여 50 ℃에서 TEOS를 24 h 가수분해하고, OTMS를 2 h 반응시킨 물질이 최적으로 나타났다. 이와 같은 표면 개질 실리카를 포함하는 복합체 필름의 산소 투과도를 측정한 결과, 개질 실리카를 포함하지 않는 필름에 비하여 산소 투과도가 12% 저하된 것을 확인할 수 있었다.

Examining the Nexus between Human Rights and Security on the Korean Peninsula: Holistic and Integrative Approaches

장효준 통일연구원 2023 International journal of korean unification studie Vol.32 No.1

This article examines the nexus between human rights and security on the Korean Peninsula. The past policies toward North Korean human rights by South Korean governments were inconsistent and ineffectiveby being selective and subordinated to security policies. In this article, I suggest holistic and integrative approaches toward North Korean human rights. The holistic approach includes both political and civil rights and economic, social, and cultural rights as indivisible and interdependent. The integrative approach connects North Korean human rights to peace and security on the Korean Peninsula through denuclearization, economic engagement, and humanitarian aid. They would enable the South Korean government to devise more consistent and effective human rights policies by securing domestic and international support, increasing its coordination with a variety of actors, and sending a credible signal to the authoritarian regime in the North.

고분자 전해질 복합막 제조 및 전기적 탈염특

장효준,손원근,강병관,황윤이 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

전 세계적으로 물 산업이 ‘블루골드(Blue gold)’산업으로 떠오르는 가운데 내실 있는 물 산업육성을 위해 실질적인 노력이 필요함. 기후변화의 가속화에 따라 지구 상의 물 부족이 심각한 가운데 물 산업은 날이 갈수록 그 중요성이 확대되고 있음. 특히 물 산업에서 탈염기술은 “고도화 수 처리”기술로서 21세기의 유망산업으로 부상하고 있으며, 수 처리를 위한 화학소재 및 활용제품, 가공, 공정기술 등 국내ㆍ외수 처리 시장에서 경쟁력을 강화하기 위해 정부나 민간산업에서 다양하게 투자가 이루어지고 있음. 따라서 본 연구에서는 전기적으로 탈염이 가능한 이온교환 복합막 소재를 제조하기 위해 고분자 전해질 분말과 용액을 사용하여 슬러리를 제조하고 특성을 최적화하기 위해서 조성비를 조절하였으며 전기탈염특성을 평가하였음.

Membrane구조를 갖는 섬유 집합체형 흡음재의 흡음 인자 결정에 관한 연구

장효준,전두환 한국섬유공학회 2004 한국섬유공학회지 Vol.41 No.4

Basic mechanism of sound absorption in various sound absorbing materials is generally explained by the conversion of sound energy into heat energy. The important element governing the conversion from sound into heat depends on the material characteristics. Three types, such as porous, resonance and panel types, generally classify the geometrical structure of sound absorbers. These three types of sound absorbing materials demonstrate different sound absorption characteristics. In this study, for the absorption of the specific sound frequency, various parameters are investigated experimentally using the impedance tube method. The models used in the experiment are porous and panel type absorbers. The porous type absorber generally has the ability of sound absorption at the high frequency range and the panel type absorber has the capability of sound absorption of the specific sound frequency. The sound absorption characteristics of the panel type absorber are described in phenomenon related to the sound absorption characteristics of porous type products. Detail experiments are carried out to clarify the parameters governing the acoustic performance with different fabrics.