• Environmental Analysis Health and Toxicology
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• 제14권4호
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• pp.145-153
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• 1999

Effects of various concentrations of copper in solid fibrous form and methylglyoxal (MG) on phosphorus uptake and growth change of green algae Scenedesmus obliquus were studied. There was significant differences among cultures treated with various concentrations of copper and MG in growth of algae with parameters of cell numbers, photosynthetic rate and cellular morphology, and phosphorus uptake by cell. When the copper in media is treated with 25 mg or 50 mg per 100 ml of Bristol solution, the mean cell number of algae was 15.642${\times}$10$\^$6/ cells$.$ml$\^$-1/ and 12.986${\times}$10$\^$6/ cells$.$ml$\^$-1/, respectively, while those of algae in culture without copper was 18.486${\times}$10$\^$6/ cells$.$ml$\^$-1/. The mean cell area of 2450 ${\mu}$m$^2$, 1894 ${\mu}$m$^2$and 1697 ${\mu}$m$^2$in basic media, basic media with 25 mg of copper and basic media with 50 mg of copper was showed the inhibitory effect of copper on algal growth. The algal growth was stimulated by MG when the culture was treated with 25 mg of copper or without copper, while it was inhibited when the culture was treated with 50 mg of copper. It was considered that there was significant interaction between copper and MG on algal growth. The phosphorus concentration in algal medium treated with 25 mg or 50 mg of copper was 29.435 ppm and 26.224 ppm, respectively, while those of algae in culture without copper was 52.8 ppm, which shows that the application of copper in algal medium can prevent the availability of phosphorus to algal cell.

• 한국약용작물학회지
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• 제4권2호
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• pp.132-138
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• 1996

패모의 기내 주년 생산 체계를 확립하기 위한 연구의 일환으로 cytokinin이 첨가된 배치에서 배양 방법의 차이가 자구 형성과 비대에 미치는 영향, 배지의 삼투 포텐셜 조절을 위한 mannitol 첨가나 활성 탄소 및 생장 억제제 처리가 기관 형성과 인편 비대에 미치는 영향에 대해서 실험한 결과는 다음과 같다. 1. 0mg/L kinetin과 0. 3mg/L NAA가 혼용 처리된 MS 고체 배지에서 액체 배지나 액체 현탁배지에서보다 효과적인 자구 생장과 증식율을 나타냈으며, 액체 배지나 액체 현탁처리 배지에서는 비슷한 결과를 나타냈다. 활성 탄소의 농도는 $0.01%{\sim}0.1%$ 처리구에서 형성된 자구의 비대가 양호하였고, 0. 5% 이상 농도에서는 오히려 생장이 억제되었다. $1{\sim}2%$ mannitol이 첨가된 배지에서 인편으로부터의 자구 형성수 및 구비대가 양호하였으며, 그 이상의 농도에서는 생장에 저해적으로 작용하였다. 생장 억제제인 B-9과 Chloromequat 처리구에서는 $10{\sim}100mg/L$ 처리구에서 자구 발생 및 비대가 양호하였으나, 발생 인편의 생육 상태가 억제되었으며, ABA 처리구에서는 배양 중 인편이 모두 고사하였다.

• 한국재료학회지
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• 제29권11호
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• pp.684-689
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• 2019

Single crystals, which have complexed composition, are fabricated by solid state grain growth. However, it is hard to achieve stable properties in a single crystal due to trapped pores. Aerosol deposition (AD) is suitable for fabrication of single crystals with stable properties because this process can make a high density coating layer. Because of their unique features (nano sized grains, stress inner site), it is hard to fabricate single crystals, and so studies of grain growth behavior of AD film are essential. In this study, a $BaTiO_3$ coating layer with ${\sim}9{\mu}m$ thickness is fabricated using an aerosol deposition method on (100) and (110) cut $SrTiO_3$ single crystal substrates, which are adopted as seeds for grain growth. Each specimen is heat-treated at various conditions (900, 1,100, and $1,300^{\circ}C$ for 5 h). $BaTiO_3$ layer shows different growth behavior and X-ray diffraction depending on cutting direction of $SrTiO_3$ seed. Rectangular pillars at $SrTiO_3$ (100) and laminating thin plates at $SrTiO_3$ (110), respectively, are observed.

• 한국환경과학회지
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• 제33권1호
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• pp.17-25
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• 2024

This study aimed to determine the most suitable coir substrate mixing ratio for optimizing the growth and yield of the "lpduelkkae 1" cultivar. We comprehensively analyzed the physicochemical properties, growth, and yields of four different substrate combinations: perlite (coir with mixing ratios of 70:30 (PC30), 50:50 (PC50), and 30:70 (PC70)) and 100% coir (C100). The results revealed substantial differences in substrate properties. C100 exhibited the highest total porosity and the lowest solid phase, indicating excellent air permeability. The pH levels and electrical conductivity (EC) values ranged from 5.4-6.8 and 1.2-3.1 dS·m^-1, respectively. Leaf growth parameters, including length, width, and dry weight, showed positive correlations with high coir ratios, except for PC30. PC70 and C100 outperformed other substrates in stem growth, exhibiting superior stem diameter and fresh and dry weights. The quantity of marketable leaves was the highest in the C100 substrate. Furthermore, C100 comprised integrated levels of essential nutrients, such as Ca and Mg, owing to its high coir content. In conclusion, a coir ratio of approximately 70% (v/v) should be maintained in the substrate for creating an optimal cultivation environment. Furthermore, the selection of humidity-resistant varieties as well as precise nutrient and moisture management for different seasons and growth stages are crucial for a successful perilla leaf hydroponic cultivation.

• Current Applied Physics
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• 제18권11호
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• pp.1426-1430
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• 2018

High magnetic field effects on the microstructure and magnetic properties of $BaFe_{12}O_{19}$ hexaferrites synthesized hydrothermal method have been investigated. The obtained results indicate that the lattice constant decreases gradually as the magnetic field strength increases, which may be attributed to the lattice distortion resulted from the high magnetic field. Polycrystalline $BaFe_{12}O_{19}$ samples prepared under magnetic field strength at zero and 5 T are single phase. It is found that application of external magnetic field during synthesis can induce orientated growth of the hexaferrite crystals along the easy magnetic axis. The magnetic properties can be effectively regulated by an application of high magnetic fields. It is observed that the $BaFe_{12}O_{19}$ prepared under a 5 T magnetic field exhibits a higher room-temperature saturation magnetization (66.3 emu/g) than that of the sample (43.6 emu/g) obtained without magnetic field. The results can be explained as the enhanced crystalline, improvement of $Fe^{3+}$ ions occupancy and the oriented growth induced by the external magnetic field. The growing orientation of particles gives rise to increased coercivity due to the enhancement in shape anisotropy. It is expected that an application of magnetic field during the formation of magnetic nanoparticles could be a promising technique to modify magnetic properties with excellent performance.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권2호
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• pp.140-144
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• 2003

Ameloblastoma is cytologically a benign tumor, but is clinically characterized by infiltrative growth and high recurrency. The criteria for surgical treatment of ameloblastoma has not yet established and it is generally accepted that ameloblastoma be treated differently based on clinical types. The purpose of this paper is to consider effectiveness of enucleation in large-sized intraosseous ameloblastoma that has treated more frequently by radical treatment. 39 cases of the intraosseous ameloblastomas were treated by enucleation in the department of oral and maxillofacial surgery of Yonsei University, dental college from February 1990 to January 2001. 25 cases were selected because they were large in size that could produce facial disfigurement or pathologic fracture of jaws. They were radiographically characterized by the cortical bone that was expanded or eroded locally and histopathologically by 19 solid ameloblastomas and 6 intramural type of unicystic ameloblastomas. Among the 25 cases, 4 cases - 3 solid ameloblastomas and 1 intramural type of ameloblastoma - recurred. Recurrence rate was 16%. The compact bone which is not invaded by ameloblastoma was used as surgical margin of enucleation with accompanying chemical cauterization for killing the residual tumor cells. This may have been the reason for the low recurrence rate. So, it is considered that enucleation and long-term follow-up enable the large-sized intraosseous ameloblastomas that were characterized by almost destroyed cancellous bone and expanded or discontinued cortical bone to treat minimizing facial disfigurement and masticatory dysfunction and sociopsychological impact produced by radical treatment. I recommend that the large-sized intraosseous ameloblastomas without involvement to the surrounding soft tissues be first treated by enucleation.

• Archives of Pharmacal Research
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• 제20권5호
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• pp.410-413
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• 1997

In the course of screening synthetic compounds to inhibit tumor cell growth, pyrrolo[1,2-.alpha.] benzimidazole (PBI), an intermediate of azamitosene, was found to inhibit a proliferation of gastric cancer cell lines. Despite a potential cytotoxic activity against solid tumor cells as opposed to that against rapidly-doubled leukemic cells, there has been no report on the inhibition of gastric cancer cell line by PBI and its' derivatives. The present experiment was designed to determine if PBI derivatives can effectively inhibit the cellular proliferation of gastric cancer cells by using in vitro as well as in vivo chemosensitivity system (MTT assay, clonogenic assay and human tumor xenografted assay). Of the tested PBI derivatives, PBI (18) and PBI (20), displayed the effective growth inhibition of cultured gastric cancer cells or even in the xenografted nude mouse model.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3397-3406
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• 2012

Three types of spherulitic morphologies have been investigated in dual substrate mode of Belousov-Zhabotinsky (BZ) type reaction system. Prior to growth of spherulites, three distinct patterning behaviors have been observed sequentially during the reaction process. Initial and the early-phase of reaction showed the emergence of concentric ring-like wave patterns. A colloidal-state of reaction consists of numerous fine solid particles, which forms primarily some nucleation centers of dendritic characters. The nucleation centers were found to grow in sizes and shapes with the progress of reaction. It leads to growth of dendritic-like spherulitic crystal patterns. The resultant spherulites showed transitions in their morphologies, including sea-weeds and rhythmic spherulitic crystal patterns, by the effects substituted organic substrate and in the higher concentration of bromate-initiator respectively. The branching mechanism and crystal ordering of spherulitic textures were studied with help of optical microscope (OPM) and scanning electron microscope (SEM). Characteristics of crystal phases were also evaluated using X-ray diffraction (XRD) and differential thermal analysis (DTA). Results indicated that the compositions of reactants and crystal orderings were interrelated with morphological transitions of spherulites as illustrated and described.

• 한국결정성장학회지
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• 제24권4호
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• pp.164-168
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• 2014

나트륨 유황 전지는 $350^{\circ}C$ 이상의 고온에서 작동하는 대용량 전지로 에너지 저장 시스템에 주로 사용된다. 전지는 음극 액체 나트륨과 양극 액체 유황 그리고 고체 전해질 베타 알루미나(${\beta}^{{\prime}{\prime}}$-alumina)로 구성되어 있다. 이 전지는 초기충방전 사이클에서 상당한 전압변화를 보이기 때문에 전지의 안정화를 위해 컨디셔닝 과정이 필요하다. 실험 결과 전지 전압 변화의 주요한 원인 중의 하나가 액체 나트륨과 고체 전해질과의 접촉 면적이 변하기 때문인 것을 알았다.

• 한국결정성장학회지
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• 제17권3호
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• pp.91-94
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• 2007

Vapor liquid solid 기구에 의한 열화학기상증착법을 이용하여 Si (001) 기판 위에 $SnO_2$ 나노와이어를 성장시켰다. Au 박막 (3 nm)을 성장을 위한 촉매로 사용하여 Si(001) 기판 이에 순수 SnO powder (purity, 99.9%)를 반응 원료로 대기압 하 $950{\sim}100^{\circ}C$ 온도 범위, $750{\sim}800\;sccm$ 아르곤 분위기에서 $SnO_2$ 나노와이어를 성장시켰다. X-ray diffraction 분석을 통해 성장한 $SnO_2$ 나노와이어가 tetragonal rutile 구조임을 확인하였고, transmission electron microscopy 분석을 통해 단일 나노와이어의 결정 특성을 분석하였다. 또한, 상온 photoluminescence 분석을 통해 나노와이어 샘플로부터 600 nm 부근에서 나타나는 defect level 천이에 의한 넓은 emission band를 확인함으로써 성장한 나노와이어 $SnO_2$임을 확인하였다.