• Journal of Radiopharmaceuticals and Molecular Probes
• /
• v.1 no.1
• /
• pp.31-37
• /
• 2015

Chelating agents 1,4,7-triazacyclononanetriacetic acid (NOTA), 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and 30-amino-3,14,25-trihydroxy-3,9,14,20,25-penta-azatriacontane-2,10,13,21,24-pentaone (desferrioxamine, DFO) were labeled with $^{68}Ga$ and tested in vitro properties to check the feasibility of using DFO as a bifunctional chelating agent or renal imaging agent. The chelating agents of concentration $2{\mu}M$ were labeled with $^{68}Ga$ in 0.1 M HCl at pH 1.7-10.3 at room temperature and $80^{\circ}C$ and the optimal pH for labeling each chelating agent was found. And then, the chelating agents were labeled with $^{68}Ga$ in various concentration of chelating agents at optimal pH. The labeled chelating agents were subject to stability test in human serum and to binding studies to human red blood cell (RBC) and plasma protein. The optimal pH's of NOTA, DOTA and DFO for $^{68}Ga$-labeling were 4.4, 3.6 and 5.6, respectively. DFO ($10{\mu}M$) showed high labeling efficiency (>97%) at pH 5.6. All the labeled chelating agents showed high stability in human serum. $^{68}Ga$-DFO showed low RBC binding but significant amount was bound to plasma protein. The results demonstrated that $^{68}Ga$-DFO can be used as a bifunctional chelating agent but not as a renal imaging agent.

• Journal of Adhesion and Interface
• /
• v.10 no.4
• /
• pp.182-190
• /
• 2009

In this work, effect of antistrip additives to reduce moisture damage of asphalt mixture were studied. Asphalt antistripping agents were prepared by condensation of formaldehyde with tetraethylene pentamine (TEPA), triethylenetetramine (TETA) and bis(hexamethylene)-triamine (BHMT), respectively. And also the metal type antistripping agent was prepatred by neutralization of stearic acid or palmitic acid with metal hydroxide. Mechanical characteristics of the asphalt mixture added antistripping agent were evaluated with Marshall stability, submerging residuals and coating rate. It was found that antistripping agent prepared in this study reduced moisture damages of asphalt mixtures. In particular, asphalt mixtures added BHMT and C/S (Calcium stearate hydroxide) antistripping agent showed highest submerging and coating rate. Because BHMT and C/S type antistripping agent was to improve bonding between asphalt and aggregate owing to increase of amine concentration and role of metal surfactant.

• Proceedings of the Korean Fiber Society Conference
• /
• 1999.10a
• /
• pp.509-512
• /
• 1999

• Journal of Institute of Control, Robotics and Systems
• /
• v.18 no.7
• /
• pp.617-621
• /
• 2012

This paper studies asymptotic consensus problem for linear multi-agent systems. We propose a distributed state feedback control algorithm for solving the problem under fixed and undirected network communication. In contrast with the conventional algorithms that use global information (e.g., graph connectivity), the proposed algorithm only uses local information from neighbors. The principle for achieving asymptotic consensus is that, for each agent, a distributed update law gradually increases the coupling gain of LQR-type feedback and thus, the overall stability of the multi-agent system is recovered by the gain margin of LQR.

• Journal of radiological science and technology
• /
• v.43 no.4
• /
• pp.273-280
• /
• 2020

In this study, the P contrast agent of Iopamidol, which is a nonionic iodide contrast agent most commonly used as a vascular contrast agent in medical institutions, and the O contrast agent of Ioversol, were studied. The physicochemical changes according to the temperature change were compared and analyzed using the Bruker Avance 500MHz Nuclear Magnetic Resonance Spectrometer owned by the Korea Basic Science Institute (KBSI). There was no physical or chemical change in the O contrast medium of Ioversol formulation in temperature change. However, in the P contrast agent of Iopamidol, a doublet peak began to appear in the 1.1 ppm region of the sample at 60℃, and the doublet peak was clearly observed in the sample at 80℃. As a result of this study, 1H-NMR analysis revealed that the P contrast agent of the Iopamidol formulation was dissociated from chemical bonds as it rose to a high temperature of 60℃ or higher, resulting in the formation of foreign substances. It was evaluated that the O contrast agent of Ioversol formulation had physico-chemical stability than the P contrast agent of Iopamidol formulation. As shown in this study, it is necessary to analyze the physical and chemical changes of contrast agents according to various environmental factors.

• Fashion & Textile Research Journal
• /
• v.24 no.6
• /
• pp.775-781
• /
• 2022

As part of research to develop a permanent wave-reducing agent for hair, in the current study, 0.1%-1.0% of Polyquaternium-10 was added to a permanent reagent containing Nicotinoyl Dipeptide-23 to prepare the agent, which was tested on damaged hair. The pH change was relatively stable even after a date, but due to the hair's natural composition, 0.1%-0.6% of the Polyquaternium-10 concentration according to pH was suitable. The temperature safety experiment demonstrated it to be stable at a high temperature and at room temperature, but when a Polyquaternium-10 concentration of 0.9% or higher was added at 0℃, coagulation occurred. In terms of the force efficiency of permanent wave formation, wave efficiency lowered as the concentration increased: the longer the wave lasts, the lower the Polyquaternium-10 concentration. The permanent moisture content was found to be higher as the concentration of Polyquaternium-10 increased. Therefore, when Polyquaternium-10 is applied to the permanent wave-reducing agent, considering stability, permanent formation, durability, and moisture rate, the most suitable concentration was found to be that of Polyquaternium-10 in the cysteine-reducing agent. A novel finding from this study is that as the concentration of Polyquaternium-10 increases, the consistency of the permanent wave-reducing agent changes, shifting from a liquid to a viscous liquid formulation.

• Journal of the Korean Society of Safety
• /
• v.30 no.4
• /
• pp.79-85
• /
• 2015

Onboard fire extinguishing system is important to protect cargo and human lives and every oil tanker has foam type fire extinguishing system. Because of environmental problem, agent which contains materials such as Perfluorinated compounds are regulated and the development of the environmental friendly agent is required. The protein foam has less environmental pollution problem and has an excellent fire extinguish performance to oil fire. In the research, bivalency metal salts were added as stabilizer to increase fire resistance and stability of the foam. Ferrous sulfate, Iron chloride and Nickel chloride were used and to adjust to vessel, sea water was applied. As a stabilizer increased, the expansion ratio was raised. However 25% drainage time was decreased over 2.0 wt.% which is knowable that the foam brokes easily. The amount of generated foam was measured to check fluidity of foam and it appeared that when $FeSO_4$ 1.2 wt.% was added, the amount of generated foam reached large and also the 25% drainage time was high. To evaluate the fire extinguishing performance for oil fire, the small scale oil fire test was executed. When $FeSO_4$ 1.2 wt.% was added, fire extinguishing time was in its shortest which informs fluidity of foam and stability are important factors on fire extinguishing efficiency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1997.11a
• /
• pp.275-278
• /
• 1997

We investigated effectness of sort and volume of conductive agent to charge/discharge capacity of LiMn$_2$O$_4$. LiMn$_2$O$_4$is prepared by reacting stoichiometric mixture of LiOH . $H_2O$ and MnO$_2$(mole ratio 1 : 2) and heating at 80$0^{\circ}C$ for 24h, 36h, 48h, 60h and 72h. All LiMn$_2$O$_4$cathode active materials show spinel structure. Cathode active materials calcined at 80$0^{\circ}C$ for 36h, charge/discharge characteristics and cycle stability have remarkable advantages. Used that super-s-black and 20wt% as conductive agent in LiMn$_2$O$_4$, it is excellent than property of cathode used Acetylene black or mixture of Super-s-black and acetylene black at charge/discharge capacity and cycle stability. Also, specific efficiency of cathode is excellent as over 98% and that of first cycle is excellent as 92%.

• Textile Coloration and Finishing
• /
• v.31 no.2
• /
• pp.118-126
• /
• 2019

This study aims to investigate the effect of polytriazolesulfone(PTS) addition on fracture toughness of diglycidyl ether of bisphenol A(DGEBA) and 4,4'-diaminodiphenylsulfone(DDS). Various amounts of PTS were added to DGEBA/4,4'-DDS in diazide and dialkyne monomer forms and polymerized during the epoxy curing process. Fracture toughness(K1C), tensile properties and thermal stability of the PTS added epoxy resin were evaluated and compared with those of PES, the conventional high Tg toughening agent, added epoxy resin. Fracture toughness of the PTS added epoxy resin was dramatically improved up to 133%, as the amount of PTS added increased, whereas that of the PES added epoxy resin was improved by only 67%. The tensile strength of PTS added DGEBA/4,4'-DDS was similar to the epoxy resin without PTS and tensile modulus was improved by 20%. And thermal stability of the PTS added epoxy resin was improved up to 14%. Therefore, PTS addition to DGEBA/4,4'-DDS, as a toughening agent, is very effective way to improve its fracture toughness without any lowering in other properties.

• Journal of Pharmaceutical Investigation
• /
• v.37 no.4
• /
• pp.243-247
• /
• 2007

Retinoids have many important and diverse functions and particularly, have been widely used as anti-aging agent and for the treatment of acne and psoriasis in cosmetics. However, retinoids have low stability against the air, light, water, oxygen and heat, thus, to stabilize the retinoids in formulations is very critical procedure. In this study, cubic liquid crystalline phase of monoolein was applied to stabilize the retinylpalmitate (RP) and to enhance the transdermal permeation. Cubic liquid crystalline phase significantly enhanced the stability of RP. After 15 days, the content of RP in the cubic formulation was 94.7% while the content of RP in ethanol solution was below 0.5% at room temperature. Although BHT containing crystalline phase showed the slightly increased stability of RP, there were no significant differences in RP stability between with or without antioxidants (ascorbic acid, ${\alpha}$-tocopherol, BHT, BHA) at $40^{\circ}C$. The skin retention of RP in crystalline formulations was approximately $5.3{\sim}6.4$ times greater than that of o/w cream formulation. Incorporation of RP into cubic liquid crystalline phase of monoolein effectively stabilized the RP and worked as excellent topical vehicle for RP. Liquid crystalline phase is considered to be suitable formulation for RP for topical delivery system as a stabilizer and permeation enhancing agent.