• Proceedings of the PSK Conference
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• 2002.10a
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• pp.252-252
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• 2002

Radiation synovectomy is an useful alternative treatment to rheumatoid arthritis and Re$\^$188/ is suggested as an ideal radiopharmaceutical agents because beta ray (2.1 MeV) emitted from Re$\^$188/ is appropriate for synovial cell ablation and gamma ray (155 KeV) is ideal for dosimetry. Its' ideal particle size (2-5 mm) was achieved by conjugation with tin-colloid, In this study, we investigated the toxicity, stability and biodistribution to evaluate the suitability of DA-7911 as a synovectomy agent. (omitted)

• Advances in materials Research
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• v.1 no.3
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• pp.205-219
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• 2012

Co-Re alloy development is prompted by the search for new materials for future gas turbines which can be used at temperatures considerably higher than the present day single crystal Ni-based superalloys. The Co-Re based alloys are designed to have very high melting range. Although Co-alloys are used in gas turbine applications today, the Co-Re system was never exploited for structural applications and basic knowledge on the system is lacking. The alloy development strategy therefore is based on studying alloying additions on simple model alloy compositions of ternary and quaternary base. Various strengthening possibilities have been explored and precipitation hardening through fine dispersion of MC type carbides was found to be a promising route. In the early stages of the development we are mainly dealing with polycrystalline alloys and therefore the grain boundary embrittlement needed to be addressed and boron addition was considered for improving the ductility. In this paper recent results on the effect of boron on the strength and ductility and the stability of the fine structure of the strengthening TaC precipitates are presented. In the beginning the alloy development strategy is briefly discussed.

• Korean Journal of Materials Research
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• v.16 no.5
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• pp.312-317
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• 2006

Binary skutterudite $CoSb_3$ compounds were prepared by the encapsulated induction melting (EIM) process, and their thermoelectric, microstructural and mechanical properties were examined. Single-phase ${\delta}-CoSb_3$ was successfully produced by the EIM and subsequent heat treatment at 773 K-873 K for 24 hours in vacuum. Seebeck coefficient increased with increasing heat treatment temperature up to 673 K, showing the positive signs in the range of measuring temperature. However, the samples heat-treated at 773 K-873 K showed negative Seebeck coefficient from room temperature to 400 K, while it showed positive signs above 400 K. Electrical resistivity decreased with increasing temperature, showing typical semiconducting conductivity. Thermal conductivity decreased drastically with increasing heat-treatment temperature. This is closely related with the phase transition to ${\delta}-CoSb_3$.

• Archives of Pharmacal Research
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• v.26 no.2
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• pp.168-172
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• 2003

Radiation synovectomy is one of the most useful methods for treating patients with refractory synovitis because of its convenience, long-term effects, repeatability and the avoidance of surgery. In this study, we investigated the toxicity, stability and biodistribution of a rhenium-188 ($^{188}$Re)-tin colloid to evaluate its suitability as a synovectomy agent. Twenty four hours after injecting the $^{188}$Re-tin colloids (74 KBq/0.1 mL) into the tail vein of ICR mice, most of the $^{188}$Retin colloidal particles was found in the lungs. In addition, there were no particle size changes at either room temperature or at $37^{\circ}C$ after injecting the $^{188}$Re-tin colloids in human plasma and synovial fluid. In vitro stability tests showed that the $^{188}$Re-tin colloid remained in a colloidal form without a critical size variation over a 2-day period. We investigated the leakage of $^{188}$Retin colloids from the intraarticular injection site with gamma counting in New Zealand white rabbits. The $^{188}$Re-tin colloids (55.5 MBq/0.15 mL) were injected at the cavum articular and the mean retention percentage of the $^{188}$Re-tin colloid was 98.7% for 1 day at the injection site, which suggests that there was neither change in the particle size nor leakage at the injection sites. In the biodistribution study with the SD rats, the liver showed the highest radioactivity (0.0427% ID/organ) except for the injected knees (99.49%). In the SD rats, mild toxicities including the skin or a synovium inflammation were observed as a result of a radioactivity of 15 mCi/kg at the intraarticular injection site. However, there was no systemic toxicity. In the Ovalbumin (OVA)-induced arthritic rabbits, the $^{188}$Re-tin colloid improved the macroscopic, the histological score and reduced the knee joint diameter when compared to the arthritic control. In conclusion, a $^{188}$Re-tin-colloid is considered as a strong candidate for radiation synovectomy with a superior efficacy and safety.

• Journal of the Korean institute of surface engineering
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• v.41 no.3
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• pp.88-93
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• 2008

Ir-Re thin films with Ti interlayer were deposited onto the tungsten carbide substrate by ion beam assisted DC magnetron sputtering. The Ir-Re films were prepared with targets of having two atomic percent of 7:3 and 5:5. The microstructure and surface analysis of the specimen were conducted by using SEM, XRD and AFM. Mechanical properties such as hardness and adhesion strength of Ir-Re thin film also were examined. The interlayer of pure titanium was formed with 100 nm thickness. The film growth of Ir-30at.%Re was faster than that of Ir-50at.%Re in the same deposition conditions. Ir-Re thin films consisted of dense and columnar structure irrespective of the different target compositions. The values of hardness and adhesion strength of Ir-30at.%Re thin film coated on WC substrate were higher than those of Ir-50at.%Re thin film.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.83-84
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• 2007

Sn-filled and Ni-doped $CoSb_3$ skutterudites were prepared by encapsulated induction melting, and their filling and doping effects on thermoelectric properties were investigated. Single phase ${\delta}-CoSb_3$ was successfully obtained by encapsulated induction melting and subsequent heat treatment at 823K for 5 days. Nickel atoms acted as electron donors by substituting cobalt atoms. Thermoelectric properties were remarkably improved by Sn filling and Ni doping.

• Elastomers and Composites
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• v.55 no.4
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• pp.347-353
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• 2020

Stearic acid (SA), polyethylene glycol (PEG), and malic acid (MA) have been used to modify the surface of waste gypsum to develop corresponding poly (butylene adipate-co-terephthalate) (PBAT) composites. According to the mechanical properties, MA-treated gypsum (MA-gypsum) showed the best performance, whereas SA-gypsum showed the worst performance. In contrast to SA and PEG (having -COOH and -OH as polar functional groups, respectively), the presence of both -OH and -COOH in MA is responsible for the superior surface treatment of gypsum and its better dispersion in the polymer matrix (as revealed by FE-SEM analyses). The presence of long aliphatic chain in SA is supposed to inhibit the dispersion of SA-gypsum. Further, the performance of MA-gypsum/PBAT was enhanced by adding polylactic acid (PLA). The maximum optimized contents of MA-gypsum and PLA are 20 and 7.5 wt% for developing a high-performance PBAT composite.

• KIEAE Journal
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• v.10 no.4
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• pp.101-109
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• 2010

As global warming progresses, nations around the world are trying to reduce emission of $CO_2$ that accounts for the greatest portion of greenhouse gases. To reduce $CO_2$ emission, it is first necessary to estimate $CO_2$ emission of each industry. Government authorities estimate basic unit of $CO_2$ emission from re-bar that is one of the key materials of construction industry with LCA technique (Life Cycle Assessment). However, basic unit of $CO_2$ emission varies from organization to organization. The Ministry of Land, Transport and Maritime Affairs (2004) publishes it 3.48($TCO_2/ton$) and 0.30($TCO_2/ton$) with input-output analysis while the Korea Environmental Industry & Technology Institute (2008) defines it as 0.34($TCO_2/ton$) with process analysis, which indicates ambiguity in application of basic unit of $CO_2$emission. Based on the analysis of conventional methods used for estimating the $CO_2$ emission, therefore, this research suggests existing problems on the methods and focuses on proposing an strategy to effectively estimate the basic unit of $CO_2$ emission according to the energy consumption limited to the re-bar production in steel mill in order to overcome the problems. The result of this research is expected to be helpful in calculating and reducing $CO_2$ emission.

• Bulletin of the Korean Chemical Society
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• v.15 no.2
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• pp.150-153
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• 1994

By treating mer, trans-Re(${\equiv}NC_6H_5)(PPh_3)_2Cl_3$, Ⅰ, with 5 atm of CO at room temperature for 52 h, fac-Re(${\equiv}NC_6H_5)(CO)(PPh_3)Cl_3$, Ⅱ, was obtained as dark green precipitates in 81% yield. The crystal structure of Ⅱ was determined through X-ray diffraction. Ⅱ crystallizes in the monoclinic system, space group $P2_1/n$ with cell parameters a=9.740 (2) ${\AA}$, b=16.210 (5) ${\AA}$, c=16.192 (6) ${\AA}$, ${\beta}$=97.50 $(2)^{\circ}$, and Z=4. Least-squares refinement of the structure led to a R$(R_w)$ factor of 0.030 (0.036) for 2878 unique reflections of I>3${\sigma}(I)$ and for 241 variables. In comparison to the starting material Ⅰ, the bond distance of Re-N became longer from 1.726 (6) to 1.736 (5) ${\AA}$ and the bond angle of Re-N-C(Ph) became smaller from 172.6 (6) to 167.0 $(2)^{\circ}$, indicating that the Re-N bond in Ⅱ is weakened and has a less triple-bond character than that in Ⅰ.

• Korean Journal of Materials Research
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• v.16 no.7
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• pp.435-438
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• 2006

The hot pressing was employed to prepare Fe-doped $CoSb_3$ skutterudites and their thermoelectric properties were investigated. Single phase ${\delta}-CoSb_3$ was successfully obtained by the hot pressing under 60MPa at 773 K for 2 hrs. Iron atoms acted as electron acceptors by substituting cobalt atoms. Thermoelectric properties were remarkably improved by the appropriate doping. $Co_{0.7}Fe_{0.3}Sb_3$ was found as an optimum composition for the best thermoelectric property in this work.