Morphology and Properties of Polyamide/Multi-walled Carbon Nanotube Composites

하헌주,김성철,하기룡 한국고분자학회 2010 Macromolecular Research Vol.18 No.7

The effect of van der Waals force interactions between multi-walled carbon nanotubes and the polymer matrix was examined using three different types of polyamides: polyamide 6, polyamide 11 and polyamide 12. A comparison of the degree of dispersion of multi-walled carbon nanotubes in the polymer and the measured physical properties showed that the hydrophobicity of the polymer matrix is an important factor for determining the properties of the polyamide nanocomposite material. Polyamides with longer hydrophobic methylene groups in the repeating unit had a better dispersion of multi-walled carbon nanotubes and correspondingly lower surface resistivity.

영업담보제도의 법리와 도입방안

하헌주 한국기업법학회 2004 企業法硏究 Vol.0 No.16

Although it is advisable for a person entering into a loan or credit agreement with a company to secure the advancement of funds by means of a fixed charge, a company may have already created a fixed charge over the particular asset with which the subsequent creditor wishes to secure his loan. In such circumstances, priority issues may deem that it is not in the subsequent creditor’s interests to secure his loan by means of a second fixed charge. Indeed, the merits of taking a second fixed charge will depend upon the value of the asset in relation to the amount of credit which the first fixed charge purported to secure. Where circumstances are such so as to render the creation of a subsequent fixed charge or mortgage ineffectual, a creditor may secure his loan by means of the floating charge. After discussing the nature of the specific problems to the company’s property, I concluded that some provisions should be prescribed to protect company capital economic interests.

당뇨병성 신증의 발생과 진행에 관여하는산화성 스트레스의 역할

하헌주,김경환 대한신장학회 1997 추계학술대회 초록집 Vol.1997 No.-

UV Curing Kinetics and Properties of Polyurethane Acrylate/Multi-walled Carbon Nanotube Coatings

하헌주,김성철,하기룡 한국고분자학회 2010 Macromolecular Research Vol.18 No.7

Polyurethane (PU) acrylate/multi-walled carbon nanotube (MWNT) composite coatings were synthesized by simple UV irradiation at ambient temperature. In particular, aromatic PU acrylate and aliphatic PU acrylate were chosen to examine the effect of the π-π interaction between the MWNTs and the aromatic PU acrylate. The electrical properties showed that the incorporation of only a few hundred MWNT in wt% was sufficient for electrostatic dissipative applications. Other properties, such as the rheological properties and transparency were also examined.

Effect of Molecular Weight of Polymer Matrix on the Dispersion of MWNTs in HDPE/MWNT and PC/MWNT Composites

하헌주,김성철,하기룡 한국고분자학회 2010 Macromolecular Research Vol.18 No.5

In this study, the effect of the molecular weight of the polymer matrix on the dispersion of multi-walled carbon nanotubes (MWNTs) was investigated for high-density polyethylene (HDPE)/MWNT and polycarbonate (PC)/MWNT composite materials. The dispersion of MWNTs in the polymer matrix showed a strong correlation with the melt viscosity of the polymer matrix, i.e., with the molecular weight of the polymer material. Several experimental methods, such as 4-point probe, SEM and ARES, were used to examine the effect of the molecular weight of the polymer matrix on the dispersion of the MWNTs and various physical properties of the composites. The use of a high melt viscosity polymer as the matrix material restricted the mobility of the MWNTs, and also hindered the dispersion of MWNTs due to the high entanglement density of the polymer matrix.

문화유산관광 체험요소에 따른 사후 행동의도 연구

하헌주,이슬기 사단법인 한국비즈니스이벤트컨벤션학회 2023 이벤트 컨벤션 연구 Vol.19 No.3

Purpose – This study aims to investigate the effects of cultural heritage experience factors on behavior intentions, such as intent to re-visit and word-of-mouth after visiting. Design, data, and methodology – The survey was conducted from October 1st 2022 to February 28th 2023 and a total of 221 copies were used for this study. For statistical analysis, AMOS R 4.2.2., SEM (Structural Equation Modeling) statistical package programs were used. Result – As a result of SEM, Interesting experience, Euducational experience, Novelty experience are valuable to re-visit intention and word-of-mouth. Specially Novelty is the most influential factor that can make behavior intention positively in Cultural heritage tourism place. Escape ordinary life factor is not a meaningful factor during visiting Cultural heritage place. As a result of Mean-value(Likert 5 scale, max.5), shows Educational⟩Novelty⟩Escape ordinary life⟩Interest. Conclusions – Through the verified result of this study, it is intended to provide implications for cultural heritage place management strategies by expanding the understanding of needs of Novelty , to prepare parts of educational role and add interesting things in heritage place exhibition and facilities.

Blockade of Thromboxane Influences Does Not Affect Renal Blood Flow Deficit in Anesthetized Diabetic Rats

하헌주,얼웨인던함,Ha, Hun-Joo,Dunham, Earl W. The Korean Society of Pharmacology 1988 대한약리학잡지 Vol.24 No.2

본 연구는 스트렙토조토신 투여에의해 유도된 인슐린 의존적 당뇨 흰쥐에서 관찰되는 신혈류량의 감소가 내인성 혈관 수축계의 하나인 쓰롬복산의 영향이 증가된 때문인지를 규명하고자 하였다. 펜토바비탈을 이용하여 마취를 유도한 후 주어진 시간동안 아무런 약리학적 자극이 없는 상태에서 신동맥의 헐류량 (ml $min^{-1}$ $gKw^{-1})$, 혈압 (mm Hg) 및 그때의 신동맥 저항 (혈압/신동맥의 혈류량)을 관찰하였다. 그 각각에 대응하는 값은 당뇨쥐에서는 $5.9{\pm}0.3$(P<0.01, 대조군과 비교), $115{\pm}3$ 및 $20.3{\pm}1.0$(P<0.01, 대조군과 비교)이었고, 연령 대조군에서는 각각 $8.4{\pm}0.4$, $123{\pm}3$및 $15.1{\pm}0.8$이었다. 스트렙토조토신에 의한 고혈당 유도를 방지한다고 알려진 3-O-메칠 글루코즈로 진처리한 후에 스트렙토조토신을 투여한 흰쥐에서 관찰되는 혈압 및 신동맥의 혈류량은 연령 대조군의 값과 동일하였다. 신동맥이 확장될 수 있음이 확인된 상태에서, 쓰롬복산의 합성을 저해할 수 있는 용량의 OKY-1581(1 mg/kg, i.v.에 뒤이은 0.4mg/kg min 지속적 투여)는 대조군 (n=4)뿐 아니라 실험군(n=4) 흰쥐의 혈압, 신혈류량 및 신동맥의 저항을 변화시키지 많았다. 마찬가지로 쓰롬복산/프로스타글란딘 엔도펄옥사이드 효현제인 U46619에 의한 신동맥 수축을 저해할 수 있는 용량의 쓰롬복산 수용체에대한 길항제인 SQ29548(100 ng/m1 신혈류량)을 신동맥으로 투여했을 때에도, 관찰되는 신혈류역학에 아무런 변화가 없었다(n=8 각 군). OKY-1581 투여후에 사이클로옥시게나아제의 활성을 저해하는 약물인 인도메타신(2 mg/kg)을투여했을 때에도 관찰되는 신동맥의 저항은 대조군에서 뿐만 아니라 실험군인 당뇨쥐에서도 변화가 없었다. 따라서 본 연구 결과는 스트렙토조토신 투여후 관찰되는 신동맥의 저항 증가는 약물의 신장에대한 직접적인 독성이 아닌, 유도된 당뇨에 기인함을 제시하였고, 이러한 신동맥 저항 증가는 고조된 내인성 혈관 수축계의 하나인 쓰롬복산의 영향이 아님을 시사하고 있다. Studies were conducted to determine whether reduced renal blood flow (RBF) exhibited by rats with uncontrolled, streptozotocin (STZ)-induced diabetes is attributable to diabetes-associated, enhanced renal vasoconstrictor influence of endogenous thromboxane $(TX)A_2$. Rats which were injected with STZ after pretreatment with 3-O-methyl glucose (3OMG), an agent which prevents STZ-induced hyperglycemia, were also studied. Basal values of total RBF (RBF; ml $min^{-1}$ $gKw^{-1}$; electromagnetic flow probe), systemic arterial pressure (BP; mm Hg) and renal vascular resistance (RVR;BP $RBF^{-1})$in pentobarbital-anesthetized rats during a control period were $5.9{\pm}0.3$(P<0.1_{VS}. CR), $115{\pm}3$ and $20.3{\pm}1.0$(P<0.1_{VS}. CR) for STZR (n=15), and $8.4{\pm}0.4$, $123{\pm}3$ and $15.1{\pm}0.8$ for age-matched control rats (CR; n= 15), respectively. Basal values of RBF, BP and RVR in 3OMG pretreated STZR were identical to CR. In preparations shown capable of renal vasodilatation, OKY 1581 (1 mg/kg, i.v. followed by 0.4 mg/kg min infusion) abolished arachidonate-induced $(TX)A_2$ synthesis, but did not alter basal BP, RBF or RVR in either STZR or CR (n=4/group). Similarly, i.r.a. infusion of SQ29548 (100 ng/ml RBF) abolished renal vasoconstriction induced by a TX/prostaglandin endoperoxide mimic, U46619, but had no discern able affect on RVR in either STZR (n=8) or CR (n=8). The data indicates that $TXA_2$ does not participate in the elevated basal RVR of STZR which are associated with the diabetic state.

美國 統一商法典 第9編 擔保付去來上의 浮動擔保

하헌주 한국재산법학회 2003 재산법연구 Vol.20 No.1

Article 9 of the Uniform Commercial Code covers most aspects of the creation, perfection and enforcement of a security interest in almost any kind of tangible or intangible personal property and fixtures, given by a debtor to a secured party to secure the performance of an obligation of almost any kind. The property in which a security interest is to be created, the collateral. may include property owned when the security agreement is entered into or property to be acquire thereafter. The obligation secured will usually be one incurred to acquire the collateral or one incurred through the contemporaneous, past or future borrowing of money. Although a few of the rules vary with the nature of the debtor, generally one set of rules governs all security transactions. It is sometimes alleged that through the combined effect of a number of provisions, article 9 permits the debtor to create a floating lien, tying up all of this assets with one creditor and hampering his ability to get credit from anyone else. The lien floats from one bit of collateral to another, and may first secure one debtor and then another. The provisions of article 9 about which discussion of the floating lien centers include those which permit the debtor (i) to hypothecate any Dr all of his personal property, including after-acquired property, the lien on the property following over into products into which it is wrought or commingled, or proceeds resulting from its disposition; (ii) to give present security for future advances; (iii) to use with respect to any kind of collateral the notice filing heretofore restricted to inventory and accounts receivable; and (iv) to exercise such dominion or contra over the collateral as may be agreed upon between the parties.

Oxidative Stress and Chronic Allograft Nephrothy

하헌주,박재현,김유선,Hitoshi Endou 연세대학교의과대학 2004 Yonsei medical journal Vol.45 No.6

Oxidative stress defined as outbalanced generation of reactive oxygen species (ROS) than the existing antioxidative defense mechanisms plays an important role in tissue injury. Ischemia/reperfusion accompanied during organ transplantation is well- established oxidative stress-induced tissue injury. We hypothesized that oxidative stress may also play a role in the development and progression of chronic allograft nephropathy (CAN), since that ROS are major signaling molecules of growth factors and cytokines [platelet-derived growth factors, transforming growth factor-β1 (TGF-β1)] upregulated in the kidney of CAN, that ROS in turn upregulate TGF-β1, and that mycophenolic acid may inhibit features of CAN [proliferation and extracellular matrix (ECM) accumulation in vascular smooth muscle cells and glomerular mesangial cells] through inhibiting cellular ROS. Cellular ROS activate signal transduction cascade (protein kinase C, mitogen-activated protein kinases, and janus kinases) and transcription factors (nuclear factor-κB, activated protein-1, specificity protein 1, and signal transducers and activators of transcription) leading to regulation of genes and proteins involved in cellular proliferation, ECM remodeling, and apoptosis accompanied in CAN. This review is intended to provide an overview of oxidative stress in renal allograft nephropathy.

항산화제 투여가 stretozotocin 당뇨쥐의 단백뇨와 사구체의 TGF - B1 및 fibronectin mRna 표현에 미치는 영향

하헌주,유미라,김경환 대한신장학회 1998 춘계학술대회 초록집 Vol.1998 No.-