Effect of supercritical carbon dioxide as an exfoliation aid on bio-based polyethylene terephthalate glycol-modified/clay nanocomposites

Jang, Kwangho,Lee, Jae Wook,Hong, In-Kwon,Lee, Sangmook 한국유변학회 2013 Korea-Australia rheology journal Vol.25 No.3

Bio-based PETG (bio-based glycol modified polyethylene terephthalate, Ecozen T95) / clay (organo-modified montmorillonite, OMMT, C10A) nanocomposites were prepared by co-rotating twin screw extruder attached with supercritical carbon dioxide ($scCO_2$) injection system. The effects of nano-clay and $scCO_2$ on the properties of PETG/clay nanocomposites were investigated by measuring thermal, rheological, tensile, impact, and barrier properties. The thermal and mechanical properties decreased with increasing nano-clay content, but they recovered or even exceeded the properties of neat PETG as $scCO_2$ was added. It was verified due to a good dispersion of the nano-clay in PETG matrix for PETG/clay nanocomposites by XRD, SEM, and TEM. It was thought that $scCO_2$ could be an effective exfoliation agent for many nanocomposites systems as well as for bio-based PET/clay nanocomposites.

Global Green Building Leader, SK E&C

Jang, Jaehee(장재희),Nam, Kwangho(남광호),Park, Hyungeun(박현근) 대한건축학회 2012 建築 Vol.56 No.5

Investigation of benzimidazole anthelmintics as oral anticancer agents

Jang Jiyoon,Lee Kwangho,Koh Byumseok 대한화학회 2022 Bulletin of the Korean Chemical Society Vol.43 No.5

Recently, there has been social controversy regarding whether benzimidazole anthelmintic drugs can be used as anticancer drugs. On this note, we wish to address the use of current benzimidazole anthelmintic drugs for the treatment of cancer patients. We explored the anticancer efficacy of benzimidazole anthelmintic drugs in vitro and their mechanism of action. We also conducted pharmacokinetic studies of two benzimidazole anthelmintics and assessed the predictive systemic efficacy. Finally, we present the anticancer efficacy of benzimidazole anthelmintics’ putative metabolites from hydrolysis. Our data suggest that benzimidazole anthelmintic drugs are not expected to show systemic anticancer efficacy in vivo due to poor pharmacokinetic parameters. Therefore, patients should not consider oxibendazole or fenbendazole as cancer treatment option.

글로벌 그린빌딩 리더, SK건설

장재희(Jang, Jaehee),남광호(Nam, Kwangho),박현근(Park, Hyungeun) 대한건축학회 2012 建築 Vol.56 No.5

다문화 가정을 위한 사회서비스 전달과정 분석 : 위탁과 바우처 방식의 비교

정광호(Kwangho Jung),최슬기(Seul-ki Choi),장윤희(Yun-hee Jang) 한국공공관리학회 2009 한국공공관리학보 Vol.23 No.4

최근 한국사회는 외국인노동자와 결혼이주민 여성의 증가로 여러 유형의 다문화가정 지원정책을 시행하고 있다. 본 연구는 위탁(contracting-out)과 전자 바우처 (electronic voucher)라는 상이한 정책도구를 사용하는 다문화가정지원서비스를 비교분석하고 있다. 본 연구에서는 위탁방식의 서울시 마포구 건강가정지원센터와 전자바우처 방식의 대전시 송강종합사회복지관을 비교분석하고 있다. 본 연구는 두 기관의 관리자에 대한 심층면담과 현황자료를 근거하여 양자의 유사점과 차이점을 분석하였다. 본 연구의 분석에 따르면 위탁방식은 운영ㆍ관리의 안정성에서 좋은 것으로 나타났고, 전자바우처 방식은 투명성과 효율성에서 우월한 것으로 나타났다. 하지만 전자바우처 방식의 경우 복잡한 신청절차로 인해 전자급부방식(electronic benefit transfer)의 초기 단계에 나타나는 번거로움이 있었다. 또한 해당 지역에는 다문화가정지원서비스 기관이 하나 밖에 없어 바우처의 선택권을 활용하는데 한계가 있었다. 그렇지만 전자바우처는 여전히 투명성과 효율성이라는 장점을 가지고 있었다. Recently, South Korea has experienced a rapid increase in muticultural families. Korean government has provided various types of supporting services like 'Korean learning program' that helps multicultural wives adjusting in Korean society. These services have been provided in two policy tools, contracting out and electronic voucher. This study attempts to examine differences and similarities in terms of service delivery, providers' satisfaction, beneficiaries' satisfaction, and service contents regarding different policy tools between contracting out and voucher. We had interviewed with two service providers such as Songkang with electronic voucher tool and Mapo family center with contracting out tool. At present, contracting out appears to provide a better performance than voucher in terms of service accessibility, beneficiaries' satisfaction, and equality. In contrast, voucher appears to have advantages of efficiency and transparency.

차량용 고 분해능 디지털 MEMS 가속도센서 시스템 IC 개발

유광호(Kwangho Yoo),고형호(Hyoungho Ko),이아라(Ahra Lee),임재상(Jaesang Lim),이상윤(Sang-Yoon Lee),정덕균(Deog-Kyoon Jeong),박민하(Minha Park),장현수(Hyunsu Jang),이정표(Jeongpyo Lee),조동일(Dong-il Dan Cho) 한국자동차공학회 2006 한국자동차공학회 Symposium Vol.- No.-

This paper presents design, fabrication and measurement of a high resolution digital microelectromechanical systems (MEMS) accelerometer system IC. This system IC consists of a MEMS sensing element and a high resolution digital readout circuit. The MEMS sensing element is fabricated using the sacrificial/bulk micromachining (SBM) process. In order to protect the sensing element from environmental changes, wafer level hermetic packaging(WLHP) process is performed. The developed readout circuit offers 32-bit resolution using an 1-bit, 4th-order ΣΔ modulator and a digital decimator/demodulator. The proposed system IC provides a 128-㎐, 32-bit digital output with ±5g dynamic range, 0.52% nonlinearity, and 1.6*10? count/g scale factor.

A multi-level analysis of the relationship between urban built environment and severe injury traffic crashes

Kitae Jang,Kwangho Kim,Hwan Yong Kim,강상혁 대한토목학회 2018 KSCE Journal of Civil Engineering Vol.22 No.4

This study investigates the relationship between urban built environment and traffic crash occurrences in San Diego County byemploying a multi-level Poisson regression model. This model is intended to address the so-called ‘Modifiable Areal Unit Problem’by properly capturing the spatial correlations that might exist among crash occurrences within or across zones specified for dataaggregation. A preliminary inspection based on a geographic information system reveals that the crash occurrences of TrafficAnalysis Zones (TAZs) tend to show similar spatial pattern if they belong to the same city. This observation motivated us toincorporate hierarchical random components into a Poisson regression model to complement its systematic components (i.e. explanatory variables) related to socio-demographic characteristics, travel characteristics, or urban built environment. This approachturns out to improve the model’s explanatory power in assessing the relationship between urban built environment and traffic crashoccurrences while controlling other variables. A key finding from this study is that crash occurrences of individual TAZs tend todecrease with the expansion of their urban portion.

전동식 파워스티어링 용 전자기유도 방식 토크센서 개발에 관한 연구

유광호(Kwangho Yoo),서정욱(Jungwook Seo),반재원(Jaewon Ban),김완일(Wanil Kim),Manfred Bartscht,장현섭(Hyunsup Jang),권도욱(Dowook Kwon),한상휘(Sangwhi Han) 한국자동차공학회 2011 한국자동차공학회 부문종합 학술대회 Vol.2011 No.5

In this paper, we will present an inductive torque sensor development which could be preferably used in EPS systems. This torques sensor has capability of both input and output side rotary positions sensing with resolution of 0.005deg/0.01deg respectively. Differential angle between two rotating shaft linked by a torsion-bar can be calculated simply using two angle signals by the ECU. Digital output protocol “SENT” interface applied to strengthen noise performance in an automotive environment and diagnosis capability. For redundancy, the torque sensor consists of two sensors which can independently measure both input shaft and output shaft angles. The two sensors are electrically isolated from each other with their own power supply, ASIC, excitation and receiver coils. That means altogether four angles are measured whereby two angles are transmitted via each SENT signal line. This redundancy allows the ECU to crosscheck the signals to be able to detect faults inside the sensor or the wiring harness. Due to its both side angle measurement principle, the most critical performance parameter is a ripple which means output variation with 0-torque input during 360deg rotation. And the ripple parameter can be understood as superposition of offset error, low frequency ripple(LFR), high frequency ripple(HFR) and random noise. Averaged ripple measured from the developed sensors are to be 0.002deg offset, 0.032deg LFR, 0.010deg HFR, which are sufficiently acceptable for stable control of EPS system and good feeling for drivers.

Suspicious foreign body reaction on the forehad: chrysiasis without gold intake

( Yeji Jang ),( Junyeong Park ),( Eunbyul Cho ),( Eunjoo Park ),( Kwangho Kim ),( Kwangjoong Kim ) 대한피부과학회 2018 대한피부과학회 학술발표대회집 Vol.70 No.1

A 37-year-old female presented with pigmentation on the forehead, after treating with CLARITY laser toning (Dual platform of Alexandrite 755nm and Nd:YAG 1064nm) in the private clinic 2 months ago. Physical examination revealed two dark blue colored indurated nodule on the forehead. Clinically, hemosiderosis and laser-induced foreign body reaction were suspected. Histopathological examination revealed crystallized granules in the dermis. Special stain with Fontana-Manson and iron staining were negative. Orange-red birefringence was detected through polarizing microscope. Based on the excisional biopsy results, even though the gold intake history was absent, a diagnosis of laser-induced chrysiasis was made. Q-switched laser treated patient with any time of gold treatment history presents immediate, permanent blue-gray discoloration of skin, and in this case called laser-induced chrysiasis. Histopathologically, aggregates of gold in the papillary and reticular dermis are detected in the light microscopy. Orange-red birefringence in polarizing microscope and aurosomes in electron microscopy are also helpful signs for diagnosis. Q-switched lasers are suspected to alter the physiochemical propertices of dermal gold, from crystalline to elemental gold. We report this case as it is an uncommon condition with the intent to consider the possibility of laser-induced chrysiasis in the patient showing discoloration after laser treatment.

Nevus lipomatosus cutaneous superficialis: an unusual presentation on the scalp

( Yeji Jang ),( Yosup Shin ),( Eunbyul Cho ),( Eunjoo Park ),( Kwangho Kim ),( Kwangjoong Kim ) 대한피부과학회 2018 대한피부과학회 학술발표대회집 Vol.70 No.1

A 76-year-old female presented with a gradually enlarging skin lesion on the scalp with severe itching over 50 years. Physical examination revealed localized skin colored skin-fold patches on the scalp. Histopathological examination revealed an orthokeratosis and scattered lobules of fat cells entrapped between bundles of dermal collagen fibers on the dermis. Based on the histopathological features, a diagnosis of a solitary form of Nevus lipomatosus cutaneous superficialis(NLCS) was made. NLCS is a rare benign hamartoma of adipose tissue in the dermis. It is clinically divided into two types, the classical Hoffman-Zurhelle or the multiple form and the pedunculated solitary form. Histopathologically, it is characterized by the presence of ectopic mature fat in the dermis mostly around the perivascular area and varies from 10% to 50% of the lesion. Excessive, loose, or irregular organization of the connective tissue has been noted in many cases. In most cases, staining with alcian blue shows substantially increased deposition of mucopolysaccharides in the reticular dermis and fatty tissue, which was not evident in this case. We report this case as it is an uncommon condition with the intent to highlight its clinical and histopathological features, and differential diagnosis.