• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1991년도 춘계학술대회 논문집
• /
• pp.356-362
• /
• 1991

자동차, 항공기, 선박등과 같은 산업제품과 전화기, TV브라운관과 같은 가전제품, 심미적 기능을 갖는 제품등과 같은 일상용품등은 많은 부분이 자유곡면(sculptured surface)으로 이루어져 있다. 이러한 해석적으로 정의 하기 어려운 제품 또는 그것을 생산하는데필요한 금형을 가공하는데 있어서 기존에는 석고 모형이나 목형을 이용한 모방 절삭을 하였다. 그러나 근래에는 자유곡면으로이루어진 제품을 설계하고 가공하는데 있어서 CAD/CAM system을 이용하고 있다. 제품의 곡면을 표현하거나 이들을 NC가공하기 위해서는 곡면을 나타내는 형상 정보가 필요 하고 이들 형상정보로 곡면모델링을 하여공구 경로를 구한다. 그러므로 이들 형상정보를 허용한도내에서 적절히 정하여 실제형상에 가까운 곡면을 형성하여야 한다. CAD/CAM 기술의 발달에 따라 다양한 형태의 곡면을 형성하는 기능을 가진 system이 많이 출현되었고 점토, 석고 또는 나무등으로 만든 physical model로 부터 얻어진 형상정보에 의해 surface fitting을 함으로서 자유곡면을 표현하는 방법이 많이 사용되고 있다. 어떠한 곡면을 표현할때는 곡면의 특성을 잘 표현하면서 전체적으로 smooth 한 것이 바람직하다. 그러므로 곡면의 형태를 설계자가 쉽게 이해할 수 있고 적은 수의 patch로도 복잡한 형상을 나타내야 하며 또한 국부적으로 수정이 용이하여야한다. 본 논문에서는 자유곡면을 나타낼 수 있는 수학적 표현 방법에 관하여 논하고, 해석적 곡면으로 부터 형상정보를 얻어 곡면 모델링을 한 후의 Ferguson곡면, UBS와 NUBS의 차이점을 분석하고, 이들 곡면과 해석적 곡면으로부터 얻은 실제곡면과의 오차를 측정하여 실제형상에 가까운 모델링 곡면을 찾고자 하였다.. 라. MCl(M:K$^{+}$, $Na^{+}$, NH$_{4}$$^{+}$ 및 H$^{+}$) 수용액 메디움에서의 Cd(II), Mg(II) 및 Zn(II)의 Dowex 1-X8, Cl$^{-}$ 수지에 대한 흡착은 역시 어떤 메디움에서도 Cd(II) 흡착이 제일 크며, 다음이 Zn(II) 이고 착이온을 형성않는 Mg(II)이 제일 작았다. 한편 메디움 종류별 D값의 크기순위는 H$^{+}$>K$^{+}$> $Na^{+}$>NH$_{4}$$^{+}$이였다. 메디움의 종류에 따라 D값의 차이가 나는 것은 금속이온의 착이온 형성과 금속이온의 용액내에서의 이온종의 상태와 관련이 있다고 생각된다. 마. MCl(M:K$^{+}$, $Na^{+}$, NH$_{4}$$^{+}$ 및 H$^{+}$)과 MNO$_{3}$ 용리액에 의한 Cd(II), Mg(II) 및 Zn(II)의 용리는 예상한 바와 같이 MCl에서 작은 Dv 값을 갖는데, 이것은 CdCl$_{4}$$^{2-}$ 착이온을 형성하거나 ZnCl$_{4}$$^{2-}$ , ZnCl$_{3}$$^{-}$같은 이온과 MgCl$^{+}$, MgCl$_{2}$같은 이온종을 형성하기 때문인것 같다. 한편 어떠한 용리액에서던지 N

• 대한한의학회지
• /
• 제27권4호
• /
• pp.162-173
• /
• 2006

The water-extracts of Scutellaria barbata Don (SBDE) were isolated from Chinese medicinal plant sources. The extracts showed strong growth-inhibitory activity and cancer chemopreventive activity on the growth and DNA incorporation of MG63 human osteosarcoma and K562 human leukemia cell lines. The growth of human cancer cells was inhibited in the presence of the extracts (20, 50 and 100 ${\mu}$g/ml), and the effects were concentration-dependent and incubation time-dependent up to 8 days. When 50 ${\mu}$g/ml of the extracts was added to the media of MG63 and K562, cell growth after 8 days or 6 days of incubation was retarded by 93.2 to 97.3% of the control group. Morphological changes of MG63 and K562 cell lines were observed. As the concentration of the extracts increased up to 50 ${\mu}$g/ml, degree of cell aggregation decreased. Moreover, the DNA incorporation of the cells which were labeled with [3H] thymidine was significantly reduced after 3 days of incubation at $37^{\circ}C$ with the extract. Therefore, it is suggested that the extract is highly effective on inhibition of cancer cell growth. The extract also inhibited gene expression of IGF-II in transcriptional level. Since IGF-II works as a mitogenic effector on MG63 and K562 cell lines, these results suggest that the growth inhibition is in part mediated through the inhibition of IGF-II gene expression.

• Archives of Pharmacal Research
• /
• 제8권2호
• /
• pp.59-65
• /
• 1985

Besides (-) pimara-8(14), 15-dien-19-oic acid [I] which had already been isolated as an active anti-inflammtory principle of Aralia continentalis, (-) kaur-16-en-19-oic acid [II] was separated as another active component of the plant, by tracing albumin stabilizing activity. $IC_{50}$ of [II] for the protein stabilizing activity was 0.026mg/3ml, when those of [I] and phenylbutazone were 0.032 and 0.32 mg/3ml, respectively. Being investigated employing carrageenin-induced edema test in rat hind paw, the anti-inflammatory activity of [II] administered s. c. was slightly lower than that of phenylbutazone, whereas the activity of [II] administered p. p. was three times greater than that of phenylbutazone. These results of [II] were contrary to those of [I] in the aspect of administration routes.

• 분석과학
• /
• 제36권1호
• /
• pp.1-11
• /
• 2023

A new, sensitive, and reliable flow injection methodology was investigated for the determination of lead ion (II) in vegetables' samples using a laboratory-prepared reagent 2-[(6-methoxy-2-benzothiazoly)azo]-4-methoxy phenol (6-MBTAMP). Infrared spectroscopy, UV-visible spectrophotometry, Energy dispersive X-ray spectroscopy (EDX), Elemental Analysis (CHN), nuclear magnetic resonance spectroscopy ¹HNMR, and ¹³CNMR techniques were used to characterize the reagent and lead (II) complex. The method is based on lead ion (II) reacting with the reagent (6-MBTAMP) in a neutral solution to produce a green-red complex with a maximum absorbance at 670 nm. The optimum conditions, such as flow rate, lead ion (II) volume, reagent volume, medium pH, reagent concentration, and reaction coil length were thoroughly examined. The limits of detection (LOD) and quantification (LOQ) were determined to be 0.621 mg·L^-1 and 2.069 mg·L^-1 , respectively, while Sandell's sensitivity was determined to be 0.345 ㎍·cm^-2.

• 한국식품영양과학회지
• /
• 제32권4호
• /
• pp.513-518
• /
• 2003

일반 시판 개량메주 이외에 Aspergillus속 균주로 생산된 곰팡이성 개량메주 및 Bacillus속 균주로 생산된 세균성 개량메주로 각각 담금한 사과고추장의 숙성중 품질 특성에 대해 조사하였다. 총유리당 함량은 사과고추장(II)가 발효 10주에 22.43%로 가장 높았으며, 사과고추장(III)은 유리당의 구성에서 glucose비율이 현저히 높았다. 총 유리 아미노산 함량은 사과고추장(I)에서 107.53~401.52 mg%, 사과고추장(II)에서 108.69~441.19 mg% 사과고추장(III)에서 106.82~423.28 mg%였으며, aspartic acid와 glutamic acid가 높은 비율이었다. 견고성과 부착성은 사과고추장(I)에서 높은 경향을 나타내었으나 거침성은 3종의 사과고추장간에 차이가 거의 없었다. 사과고추장의 맛이나 색상에 대해서는 유의적인 차이가 없었으나, 향 및 전반적인 기호도는 사과고추장(III)에서 가장 높은 점수를 얻었다.

• 셀메드
• /
• 제4권3호
• /
• pp.20.1-20.7
• /
• 2014

Ethanolic leaf extract of Bauhinia variegata has been tested for its possible antioxidant potentials against sodium arsenite induced toxicity in mice. Mice were randomized into two groups of five and fifty mice. Group I consisting of 5 mice without any treatment with food and water ad libitum which served as normal control. Group II mice were fed with sodium arsenite in drinking water at 100 ppm concentration for two monthsthen they were segregated into five groups which were treated differently. Group II a mice received only arsenic as sodium arsenite with drinking water, Group II b were fed chronically 1 : 20 alcohol to distilled water (vehicle), Group II c, d, e mice were orally fed 50 mg/kg, 150 mg/kg and 250 mg/kg of B. variegata leaf extract of once daily for 15 and 30 days respectively along with arsenic. Several toxicity marker enzymes such as gamma glutamyl transferase, lactate dehydrogenase, aspartate and alanine aminotransferase, acid and alkaline phosphatase, catalase and superoxide dismutase along with haematological variables such as glucose 6-phosphate dehydrogenase, creatinine, bilirubin, haemoglobin and sugar in different groups of treated and control mice were studied. Results obtained from the in vivo experiment revealed that administration of sodium arsenite caused a significant increase in some enzymes while decrease in some. A similar trend was also observed with haematological variables. In contrast B. variegata treatment at 150 mg/kg favourably modulated these alterations and maintained the antioxidant status than other two doses i.e. 50 mg/kg and 250 mg/kg thereby making it a good candidate to be used as supportive palliating measures in arsenic induced toxicity.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제6권6호
• /
• pp.402-409
• /
• 2001

Different bioligands carrying synthetic adsorbents have been reported in the literature for protein separation, We have developed a novel and new approach to obtain high protein ad-sorption capacity utilizing 2-methacrylamidohistidine(MAH) as a bioligand. MAH was synthe-sized by reacting methacrylocholride and histidine, Spherical beads with an average size of 150-200㎛ were obtained by the radical suspension polymerization of MAH and 2-hydrosyethyl-methacrylate(HEMA) conducted in an aqueous dispersion medium. p(HEMA-co-MAH) beads had a specific surface area of 17.6㎡/g . Synthesized MAH monomer was characterized by NMR. p(HEMA-co-MAH) beads were characterized by swelling test, FTIR and elemental analysis. Then Cu(II) ions were incorporated onto the beads and Cu(II) loading was found to be 0.96 mmol/g.These affinity beads with a swelling ration of 65% and containing, 1.6 mmol MAH/g were used in the adsorption/desorption of human serum albumin(HSA) from both aqueous solutions and hu-man serum. The adsorption of HSA onto p(HEM-co-MAH) was low(8.8 mg/g). Cu(II) chelation onto the beads significantly increased the HSA adsorption (56.3 mg/g). The maximum HSA ad-sorption ws observed at pH 8.0 Higher HSA adsorption was observed from human plasma(94.6 mgHSA/g) Adsorption of other serum proteins were obtained as 3.7 mg/g for fibrinogen and 8.5mg/g for γ-globulin. The total protein adsorption was determined as 107.1mg/g. Desorption of HSA was obtained using 0.1 M Tris/HCl buffer containing 0.5 M NaSCN, High desorption rations(up to 98% of the adsorbed HSA) were observed. It was possible to reuse Cu(II) chelated-p(HEMA-co-MAH) beads without significant decreases in the adsorption capacities.

• 보존과학회지
• /
• 제29권3호
• /
• pp.279-286
• /
• 2013

지금까지 분석된 삼국시대 12개 유적의 적갈색 유리구슬 141점에 대하여 화학 조성과 제작 기법을 비교하여 적갈색 유리구슬의 특성과 유형을 분류하였다. 적갈색 유리구슬의 화학 조성은 1점을 제외하고 모두 소다유리군으로 안정제와 소다 원료의 특성에 따라 3가지 유형으로 구분된다. CaO보다 $Al_2O_3$ 함량이 높은 고알루미나유리인 I형은 점유율이 78.6 %이고 유적 대부분에서 출토된 가장 일반적인 유형으로 확인된다. 이에 비하여 점유율 13.6 %인 II형은 안정제인 CaO와 $Al_2O_3$ 함량이 약 5 %이고 MgO와 $K_2O$ 성분이 1.5 % 내외로 식물재유리의 조성과 유사하다. III형은 $Al_2O_3$보다 CaO의 함량이 높고 MgO와 $K_2O$ 함량이 1.5 % 이하로 네트론유리의 조성과 일치하며 점유율은 7.9 %로 가장 낮게 확인된다. 이중에서 III형은 MgO와 $K_2O$의 함량 차이에 따라 2가지 유형으로 세분된다. 현미경을 이용한 제작 기법 조사에서 I, II형은 늘인 기법, III형은 주조 기법으로 각 유형에 따라 성형 방법에 차이가 확인된다. II, III형은 점유율이 낮음에도 비교적 여러 유적에서 출토되고 있으므로 각각 원료가 다른 적갈색 유리구슬로 볼 수 있다. 따라서 한반도에서 유통된 적갈색 유리구슬은 적어도 3가지 문화적 계통으로 그 특성이 구분됨을 알 수 있다.

• Membrane and Water Treatment
• /
• 제13권5호
• /
• pp.227-233
• /
• 2022

The objective of the study, to develop adsorbent based purifier for removal of radiological and nuclear contaminants from contaminated water. In this regard, 3-aminopropyl silica functionalized with ethylenediamine tetraacetic acid (APS-EDTA) adsorbent prepared and characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). Prepared APS-EDTA used for adsorptive studies of Cs(I), Co(II), Sr(II), Ni(II) and Cd(II) from contaminated water. The effect on adsorption of various parameters viz. contact time, initial concentration of metal ions and pH were also analyzed. The batch method has been employed using metal ions in solution from 1000-10000 ㎍/L, contact time 5-60 min., pH 4-10 and material quantities 50-200 mg at room temperature. The obtained adsorption data were used for drawing Freundlich and Langmuir isotherms model and both models were found suitable for explaining the metal ions adsorption on APS-EDTA. The adsorption data were followed pseudo second order reaction kinetics. The maximum adsorption capacity obtained 1.3037-1.4974 mg/g for above said metal ions. The results show that APS-EDTA have great potential to remove Cd(II), Co(II), Cs(I), Ni(II) and Sr(II) from aqueous solutions through chemisorption and physio-sorption.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
• /
• pp.129-132
• /
• 2004

A hybrid permeable reactive barriers(hybrid PRBs) composed of Fe(II) PRB, biological PRB and sorptive PRB was investigated to treat groundwater with multiple contaminations. We performed batch, column and pilot tests to determine removal rates and design parameters of each PRB media, and operated two hybrid PRB systems with pilot-scale barriers in series. The pilot test of the hybrid PRB system with the combination of Fe(II), biological media and black shale showed multiple contaminations could be removed in ground water. Nitrate could be treated below 20 mg/L and Cr(VI) was treated down to 0.05 mg/L. TCE was degraded below 0.001 mg/L in system. The hybrid PRB system with a proper combination of PRBs could remediate ground water with multiple contaminations.