• Fibers and Polymers
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• 제5권1호
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• pp.1-5
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• 2004

The ability of inherently conducting polymer (ICP) coated textiles to recover gold metal from aqueous solutions containing $[AuCl_4]^-$ was investigated. Nylon-lycra, nylon, acrylic, polyester and cotton were coated with a layer of polypyrrole (PPy) doped with 1,5-naphthalenedisulfonic acid (NDSA), 2-anthraquinonesulfonic acid (AQSA) or p-toluenesulfonic acid (pTS). Textiles coated with polyaniline (PAn) doped with chloride were also used. The highest gold capacity was displayed by PPy/NDSA/nylon-lycra, which exhibited a capacity of 115 mgAu/g coated textile, or 9700 mgAu/g polymer. Varying the underlying textile substrate or the ICP coating had a major effect on the gold capacity of the composites. Several ICP coated textiles recovered more than 90 % of the gold initially present in solutions containing 10 ppm $[AuCl_4]^-$ and 0.1 M HCl in less than 1 min. Both PPy/NDSA/nylon-lycra and PAn/Cl/nylon-lycra recovered approximately 60 % of the gold and none of the iron present in a solution containing 1 ppm $[AuCl_4]^-$, 1000 ppm $Fe^{3+}$ and 0.1 M HCl. The spontaneous and sustained recovery of gold metal from aqueous solutions containing $[AuCl_4]^-$ using ICP coated textiles has good prospects as a potential future technology.

• 암석학회지
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• 제22권1호
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• pp.63-70
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• 2013

우리는 선광팬, 일회용 체, 수돗물을 이용해 효과적이고 간편하게 저어콘을 분리하는 방법을 보고한다. 먼저 $230{\mu}m$ 이하로 분말화 한 시료를 약 $10^{\circ}$ 정도 기울인 선광팬에 넣고 물을 흘려보낸다. 밀도가 낮은 입자들과 더불어 선광팬으로부터 넘쳐흐른 물을 망간격이 ${\sim}70{\mu}m$인 체로 걸러낸다. 물의 공급량이 초당 0.1 리터이고 수도꼭지의 높이가 수면으로부터 20-25 cm일 때 가장 효율적으로 저어콘이 분리되었다. 수돗물을 공급한지 20-30분 정도 지나면 다음 작업인 자력 분리(필요시 중액 분리) 또는 저어콘 수선별을 진행할 수 있을 만큼 중광물들이 팬에 모인다. 이 방법은 중액을 사용하는 고전적 방법에 비해 안전하며, 저어콘 뿐만 아니라 모나자이트와 같은 다른 중광물의 분리에도 사용될 수 있다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.307.2-307.2
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• 2016

In this study, we synthesized Au nanoparticles (AuNPs) in polyacrylonitrile (PAN) thin films using a simple annealing process in the solid phase. The synthetic conditions were systematically controlled and optimized by varying the concentration of the Au salt solution and the annealing temperature. X-ray photoelectron spectroscopy (XPS) confirmed their chemical state, and transmission electron microscopy (TEM) verified the successful synthesis, size, and density of AuNPs. Au nanoparticles were generated from the thermal decomposition of the Au salt and stabilized during the cyclization of the PAN matrix. For actual device applications, previous synthetic techniques have required the synthesis of AuNPs in a liquid phase and an additional process to form the thin film layer, such as spin-coating, dip-coating, Langmuir-Blodgett, or high vacuum deposition. In contrast, our one-step synthesis could produce gold nanoparticles from the Au salt contained in a solid matrix with an easy heat treatment. The PAN:AuNPs composite was used as the charge trap layer of an organic nano-floating gate memory (ONFGM). The memory devices exhibited a high on/off ratio (over $10^6$), large hysteresis windows (76.7 V), and a stable endurance performance (>3000 cycles), indicating that our stabilized PAN:AuNPs composite film is a potential charge trap medium for next generation organic nano-floating gate memory transistors.

• 공업화학
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• 제18권5호
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• pp.467-474
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• 2007

팔라듐과 금 나노입자 등이 첨착된 높은 비표면적을 갖는 Polyacrylonitrile (PAN)계 활성탄소섬유(ACF: Activated Carbon Fiber)를 제조하였다. 여러 첨착 ACF에 대하여 BET, FE-SEM, TEM, XPS 등으로 비표면적과 기공부피, 미세구조, 시간에 따른 산소관능기의 표면변화를 관찰하였으며 $SO_2$에 대한 흡착성능을 연구하였다. 그 결과 첨착과정으로 인하여 총 기공부피 대비 미세기공 부피는 95.5%에서 30.5~43.7%로 대부분 감소하였으며, 산소관능기의 표면변화는 대기중에서 시간이 경과함에 따라 나노입자보다 금속염의 산소관능기 변화가 컸음을 알 수 있었다. 또한 Au 나노입자와 금속염을 첨착한 ACF의 $SO_2$ 파과시간은 무첨착 ACF에 비하여 크게 변하지 않았으나, 100 ppm의 Pd 나노입자를 첨착한 ACF는 $SO_2$ 파과시간이 880 s로 흡착성능이 우수하였다. 이러한 결과로 볼 때 $SO_2$ 흡착성능은 시간에 따른 산소관능기의 표면 변화와 연관성이 있다고 볼 수 있으며, PAN계 활성탄소섬유에 적정한 농도의 Pd 나노입자 첨착은 촉매작용으로 인하여 $SO_2$ 흡착 성능을 증가시키는 것으로 판단된다

• Journal of Microbiology and Biotechnology
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• 제26권11호
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• pp.1871-1880
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• 2016

Bio-oxidation is an effective technology for treatment of refractory gold concentrates. However, the unsatisfactory oxidation rate and long residence time, which cause a lower cyanide leaching rate and gold recovery, are key factors that restrict the application of traditional bio-oxidation technology. In this study, the oxidation rate of refractory gold concentrates and the adaption of microorganisms were analyzed to evaluate a newly developed two-step pretreatment process, which includes a high temperature chemical oxidation step and a subsequent bio-oxidation step. The oxidation rate and recovery rate of gold were improved significantly after the two-step process. The results showed that the highest oxidation rate of sulfide sulfur could reach to 99.01 % with an extreme thermophile microbial community when the pulp density was 5%. Accordingly, the recovery rate of gold was elevated to 92.51%. Meanwhile, the results revealed that moderate thermophiles performed better than acidophilic mesophiles and extreme thermophiles, whose oxidation rates declined drastically when the pulp density was increased to 10% and 15%. The oxidation rates of sulfide sulfur with moderate thermophiles were 93.94% and 65.73% when the pulp density was increased to 10% and 15%, respectively. All these results indicated that the two-step pretreatment increased the oxidation rate of refractory gold concentrates and is a potential technology to pretreat the refractory sample. Meanwhile, owing to the sensitivity of the microbial community under different pulp density levels, the optimization of microbial community in bio-oxidation is necessary in industry.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.581-589
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• 2003

The variable flotation response ores from different deposits results basically from mineralogical association and their differences. Development of new techniques for analyzing the metallurgical performance of flotation and other concentration processes is demanded even in the treatment of rather simple ores such as porphyry ores. Diagnostic metallurgical analysis can be used to quantify the most possible recovery processes. Several porphyry copper/gold ores around the world were used to examine the responses in flotation, gravity separation and cyanidation in order to define the linkage between the recovery processes for both copper and old values. Laboratory batch flotation, gravity separation and cyanidation tests were carried out on these samples. All results were used to correlate the relative recovery of copper and gold, and to predict the highest possible metal recovery in the system. The metallurgical predictions were made according to the flotation conditions used and gravity separation. The results of various concentration processes on each porphyry ore samples are presented and discussed. All seven samples have shown significantly different gold/copper metallurgy. The grade/recovery relationships of gold and copper in the laboratory batch tests for the best results and the plants are given in the Figures below. The results of laboratory tests show that the copper recoveries converged to about $90\%$, but the gold recoveries were spread over $55-80\%$, except the K S ore. Series of standard cyanidation tests on the flotation concentrate samples and gravity separation using Knelson Separator on heads ores were carried out to cross-link the metallurgy and mineralogy of gold in the porphyry ores.

• 한국미생물·생명공학회지
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• 제46권2호
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• pp.162-170
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• 2018

Non-typhoidal Salmonella is one of the main pathogens causing food-borne illness in humans, with up to 20% of cases resulting from consumption of pork products. Over the gastroenteritis signs, multidrug resistant Salmonella has arisen. In this study, pan-susceptible phenotypic strains of Salmonella enterica serotype Weltevreden recovered from pig production chain in Chiang Mai, Thailand during 2012-2014 were chosen for analysis. The aim of this study was to use whole genome sequencing (WGS) data with an emphasis on antimicrobial resistance gene investigation to assess their pathogenic potential and genetic diversity determination based on whole genome Multilocus Sequence Typing (wgMLST) to expand epidemiological knowledge and to provide additional guidance for disease control. Analyis using ResFinder 3.0 for WGS database tracing found that one of pan-susceptible phenotypic strain carried five classes of resistance genes: aminoglycoside, beta-lactam, phenicol, sulfonamide, and tetracycline associated genes. Twenty four and 36 loci differences were detected by core genome Multilocus Sequence Typing (cgMLST) and pan genome Multilocus Sequence Typing (pgMLST), respectively, in two matching strains (44/13 vs A543057 and A543056 vs 204/13) initially assigned by conventional MLST and Pulsed-field Gel Electrophoresis (PFGE). One hundread percent discriminant ability can be achieved using the wgMLST technique. WGS is currently the ultimate molecular technique for various in-depth studies. As the findings stated above, a new of "gold standard typing method era" for routine works in genome study is being set.

• Journal of Microbiology and Biotechnology
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• 제19권9호
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• pp.904-910
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• 2009

The development of effective cellular imaging requires a specific labeling method for targeting, tracking, and monitoring cellular/molecular events in the living organism. For this purpose, we studied the cellular uptake of isocyanide-functionalized silver and gold nanoparticles by surface-enhanced Raman scattering (SERS). Inside a single mammalian cell, we could monitor the intracellular behavior of such nanoparticles by measuring the SERS spectra. The NC stretching band appeared clearly at ${\sim}2,100cm^{-1}$ in the well-isolated spectral region from many organic constituents between 300 and 1,700 or 2,800 and $3,600cm^{-1}$. The SERS marker band at ${\sim}2,100cm^{-1}$ could be used to judge the location of the isocyanide-functionalized nanoparticles inside the cell without much spectral interference from other cellular constituents. Our results demonstrate that isocyanide-modified silver or gold nanoparticle-based SERS may have high potential for monitoring and imaging the biological processes at the single cell level.

• 방사성폐기물학회지
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• 제19권1호
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• pp.9-27
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• 2021

As an example of research activities in decontamination for decommissioning, new data are presented on the options for corrosion layer dissolution during the decommissioning decontamination, or persulfate regeneration for decontamination solutions re-use. For the management of spent decontamination solutions, new method based on solvent extraction of radionuclides into ionic liquid followed by electrodeposition of the radionuclides has been developed. Fields of applications of composite inorganic-organic absorbers or solid extractants with polyacrylonitrile (PAN) binding matrix for the treatment of liquid radioactive waste are reviewed; a method for americium separation from the boric acid containing NPP evaporator concentrates based on the TODGA-PAN material is discussed in more detail. Performance of a model of radionuclide transport, developed and implemented within the GoldSim programming environment, for the safety studies of the LLW/ILW repository is demonstrated on the specific case of the Richard repository (Czech Republic). Continuation and even broadening of these activities are expected in connection with the approaching end of the lifespan of the first blocks of the Czech NPPs.

• 미생물학회지
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• 제27권3호
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• pp.225-230
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• 1989

1983년 우리나라에서 처음으로 전염성췌장괴저 바이러스가 분리되기 시작한 이래 여러가지 종류의 내수며 양식 물고고기로부터 이 바이러스가 검출되어 왔다. 세계적으로 안정되고 있는 세가지 표준혈청형 즉 VR-299, Sp 그리고 Ab형 에 대한 중화항체 실험으로, 우리나라에서 발견되는 전염성췌장괴저 바이러스는 주로 VR-299형임이 확인되어 왔으나 대청댐에서 양식된 송어로부터 발견된 한 주의 바이러스는 독특한 혈청형을 보이고 있어 그 특성을 조사하였다. 이 바이러스로부터 단백질과 핵산을 분리하여 세가지 표준 혈청형 바이러스의 그것과 비교하여 본 결과, 크기에 있어 분명한 차이가 보였고 중화항체를 이용한 감염저지 실험으로 Sp 형과 비교적 가까운 연관관계를 가지는 거승로 밝혀졌으나, 세가지 표준 혈청과는 뚜렷이 구분되는 새로운 혈청형으로 판정되었다.