• 약학회지
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• 제31권2호
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• pp.45-51
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• 1987

Methyl orange(MO) and cetyltrimethylammonium bromide(CTA) were mixed and added to 10ml of the buffer solution and then the solution was shaken for 5 minutes. The maximum absorption wavelength of the reaction product was 419nm. Dichloromethane was the best extracting solvent among the several organic solvents and the most suitable pH range was 2~8. When the CTA-MO calibration curve was made in the best experimental condition, the Lambert-Beer's law was obeyed in the range of CTA concentration of $1.5\times$$10^{-5}$~1.0$\times$$10^{-4}M$ by UV spectrophotometer. This method was possible to determine quaternary ammonium salts in the pharmaceutical preparations.

• 약학회지
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• 제35권1호
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• pp.15-21
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• 1991

Quaternary amines which are widely used as medicines are nitrogen compounds. Metanil yellow(MY) and benzalkonium chloride(BKC) were mixed and added to 10ml of the buffer solution and then the solution was shaken for 5 minutes. The maximum absorption wavelength of the reaction product was 402 nm. Dichloromethane was the best extracting solvent among the several organic solvents and the most suitable pH range was 2~8. When the BKC-MY calibration curve was made in the best experimental condition, the Lambert-Beer's law was obeyed in the range of BKC concentration of 2$\times$$10^{-6}$~9$\times$$10^{-6}$M by UV spectrophotometer. This method was possible to determine quaternary ammonium salts in the pharmaceutical preparation.

• 약학회지
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• 제38권4호
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• pp.366-371
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• 1994

To improve the identification power of TLC/HPTLC the in situ reflectance spectra obtained directly from plates with commercial scanner are used. The spectrum normalization should be carried out prior to comparing and searching the spectra from library for the identification of compounds. Because the reflectance does not obey the Lambert-Beer's law, there arise some problems in normalization. These problems could be solved to some extent by normalizing the spectra with regression methods. The spectra are manipulated with the regression function of a curve obtained from the correlation plot. When the parabola was used as the manipulating function, the spectra were identified with the accuracy of 97% and this result was better than that of conventionally used the point and area normalization method.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 1993년도 한국우주과학회보 제2권2호
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• pp.11-11
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• 1993

The Korean sounding rockets(KSR) 1, 2 equigped with the UV optical detectors have been launched at An-heung, Chungchongnam-do, of June 4 and September 1, 1993,respectively. The UV detector is used to measure the attenuation of solar UV radiation for various frequency bards in the stratospgere. We obtained the profile of the ozone number density within the altitulde of 15 - 30 km by applying the Beer-Lambert law. It is found that the maHimum of the ozone distribution occurs near 2sht which is quite consistent with the mean value in the mid-latituderegions. We will also compare our results froiu KSR 1,2 with the other observational data from the Dobson speceo meter at Yonsei Univ. and the LIDAa which were performed simultaneously with the sounding rocket experiments.

• Smart Structures and Systems
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• 제8권5호
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• pp.471-486
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• 2011

Various types of strain sensors have been developed and widely used in the field for monitoring the mechanical deformation of structures. However, conventional strain sensors are not suited for measuring large strains associated with impact damage and local crack propagation. In addition, strain sensors are resistive-type transducers, which mean that the sensors require an external electrical or power source. In this study, a gold nanoparticle (GNP)-based polymer composite is proposed for large strain sensing. Fabrication of the composites relies on a novel and simple in situ GNP reduction technique that is performed directly within the elastomeric poly(dimethyl siloxane) (PDMS) matrix. First, the reducing and stabilizing capacities of PDMS constituents and mixtures are evaluated via visual observation, ultraviolet-visible (UV-Vis) spectroscopy, and transmission electron microscopy. The large strain sensing capacity of the GNP-PDMS thin film is then validated by correlating changes in thin film optical properties (e.g., maximum UV-Vis light absorption) with applied tensile strains. Also, the composite's strain sensing performance (e.g., sensitivity and sensing range) is also characterized with respect to gold chloride concentrations within the PDMS mixture.

• 한국분말재료학회지
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• 제24권6호
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• pp.483-488
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• 2017

Transition-metal oxide semiconductors have various band gaps. Therefore, many studies have been conducted in various application fields. Among these, methods for the adsorption of organic dyes and utilization of photocatalytic properties have been developed using various metal oxides. In this study, the adsorption and photocatalytic effects of $WO_3$ nanomaterials prepared by hydrothermal synthesis are investigated, with citric acid added in the hydrothermal process as a structure-directing agent. The nanostructures of $WO_3$ are studied using transmission electron microscopy and scanning electron microscopy images. The crystal structure is investigated using X-ray diffraction patterns, and the changes in the dye concentrations adsorbed on $WO_3$ nanorods are measured with a UV-visible absorption spectrophotometer based on Beer-Lambert's law. The methylene blue (MB) dye solution is subjected to acid or base conditions to monitor the change in the maximum adsorption amount in relation to the pH. The maximum adsorption capacity is observed at pH 3. In addition to the dye adsorption, UV irradiation is carried out to investigate the decomposition of the MB dye as a result of photocatalytic effects. Significant photocatalytic properties are observed and compared with the adsorption effects for dye removal.

• 대한화학회지
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• 제39권2호
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• pp.87-93
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• 1995

크롬도금 용액에 공존하고 있는 Cr(III)와 Cr(VI)의 양을 자외선/가시광선 분광기에 장착한 흐름계 장치를 이용하여 시료당 5분 이내에 두 가지 물질의 양을 동시에 분석하는 방법을 개발하였다. Cr(III)와 Cr(VI)는 각각 580 nm와 440 nm에서 0.05 g/L와 0.005 g/L 이상의 범위에서 Beer-Lambert 법칙에 따르는 특성 ${\lambda}_{max}$를 나타내며, 이 파장들에서의 흡광도는 pH<4의 조건에서는 pH변화에 거의 영향을 받지 않았다. 따라서 일반적으로 크롬의 농도가 수 g/L인 후처리 크롬 도금조의 용액을 흐름계의 장치에서 pH=1의 황산 용액으로 묽힌 후, 자외선/가시광선 분광기로 측정하면 Cr(III)와 Cr(VI)의 양 및 총 크롬의 양을 기존의 산화-환원 적정 방법(최소 40분/sample)보다 간편하고 신속정확하게 동시 정량할 수 있었다. 이 장치는 설치 및 사용이 간단하고, 설치 비용이 저렴하므로 많은 도금 산업 현장에서 용이하게 응용할 수 있다.

• 센서학회지
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• 제13권4호
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• pp.258-263
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• 2004

In this study, we carried out a basic study for the development of optical transcutaneous $pCO_{2}$ gas sensor and analyzer using non-invasive method. The basic principle of $pCO_{2}$ measurement is adapted Beer lambert's law and embodied the system using NDIR method. This measuring system was composed of a IR lamp, a optical filter, a optical reaction chamber, pyroelectric sensor and a signal process. We measured $EtCO_{2}'s$ concentration in basis step instead of $pCO_{2}$ gas that can collect by inflicting heat in outer skin. We minimize the size of optical reaction chamber which takes up the largest volume, to make the portable sensor. We made optical reaction chamber in Si wafer using MEMS technology and the optical reaction chamber was shortened to 2 mm and we carried out an experiment. When we injected the $EtCO_{2}$ to the inside of the optical reaction chamber, we could confirm change of 4.6 mV. The system response time was within 2 second that is fairly fast.

• 한국염색가공학회지
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• 제1권1호
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• pp.19-25
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• 1989

In past, dye diffusion and dyeing rate in fibers have been emphasized in dyeing phenomena. However, in the light of the properties of colloids in the surface of disperse phase and dispersion, there exist specific characters such as adsorption or electric double layer, which seems to play important roles in determining the physiochemical properties in the dyeing system. Electrostatic bonding, hydrogen bonding and Van der Waals adsorption are common in dyeing as well as covalent bonding. Particularly, electrostatic bonding is premised on the existance of ionic radicals in fibers. The present study was aimed to clarify the electrokinetic phenomena of dyeing through the role of electric double layer by ion in amphoteric fibers with different ionic effects under different pH. Spectrophotometric analysis method was used to compare dyeing condition of surface, which can be detected by electrokinetic phenomena and the inner of fibers after deceleration of dyed fibers. Nylon and wool, the typical amphoteric fibers were dyed with monoazo acid dyes such as C.I. Acid Orange 20, and C.I. Acid Orange 10. Various combinations were prepared by combining pH, temperature and dye concentration, in order to generate streaming electric potential which were measured by microvolt meter and specific conductivity meter. The results were transformed to zeta potential by Helmholtz-Smoluchowski formular and to surface electric charge density by Suzawa formular, surface dye amount, and effective surface area of fibers. The amount of dyes of inner fibers were also measured by the Lambert-Beer’s law. The main results obtained are as follows. 1. By measuring zeta pontential, it was possible to detect the dyeing mechanism, surface charge density, surface dye amount and effective surface area concerning dye adsorption of the amphoteric fibers. 2. Zeta pontential increases in negative at low pH and high dye concentration in the process of dyeing. This implied that there existed ionic bond formation in the dyeing mechanism between acid dyes and amphoteric fibers. 3. Dibasic acid dye had little changing rate in zeta potential due to the difference in solubility of dye and in number of dissociated ions per dye molecule to bond with amino radicals of amphoteric fibers. The dye adsorption of mono basic acid dye was higher than that of dibasic acid dye. 4. The effective surface areas concerning dyeing were $6.3E+05\;cm^2/g$ in nylon, $1.6E+07\;cm^2/g$ in wool fiber being higher order of wool then nylon.

• Journal of Forest and Environmental Science
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• 제3권1호
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• pp.1-9
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• 1983

본(本) 연구(硏究)는 설악산(雪嶽山)에 분포(分布)하는 마가목 천연림(天然林)의 생태환경(生態環境)과 생리기능(生理機能)을 측정분석(測定分析)한 것으로 그 결과(結果)는 다음과 같다. 1. 마가목의 주분포지(主分布地)는 900m~1,00m로 온난지수(溫暖指數) WI는 42$3.2{\times}10^3{\sim}9.2{\times}10^3$, CEC는 13.7~19.5mg/100g, N은 0.21~0.39%, $P_2O_5$는 22.6~38.7ppm, pH는 5.6~5.8로 배수양호(排水良好)하고 양분(養分)이 풍부한 토양(土壤)이다. 4. 마가목 군락지(群落地)의 상층목(上層木)으로는 분비나무, 주목나무, 자작나무, 물참나무, 고로쇠단풍, 까치박달, 달피나무 등이며 하층목(下層木)으로는 만병초, 참단풍, 측백, 개암, 철쭉, 진달래, 함박꽃 등이 혼생(混生)하고 있다. 5. 임분밀도(林分密度)는 1,160m가 1,556본/ha, 1,300m가 3,600본/ha이며 DBH를 단면적(斷面積)으로 한 피도(被度)(C)는 1,600m가 0.37, 1,300m가 0.31이며 수관투영면적(樹冠投影面積)에 대한 식피도(植被度)는 1,600m가 2.04, 1,300m가 1.61이였다. 6. 마가목 군락지(群落地)의 엽층(葉層)의 광분포(光分布)는 Beer-Lambert 법칙(法則)에 따라 감소(減少)하며 F(Z)를 엽면적지수(葉面積指數)(LAI) 대신 관수층(冠樹層)의 선단(先端)으로부터의 거리로 나타냈을 때 흡광계수(吸光係數) k는 0.17이었다. 7. 마가목 지엽(枝葉)(shoot)의 수분특성(水分特性)은 최대포수시(最大飽水時)의 침투압(浸透壓)이 -16.2bar, 팽압(膨壓)이 14.5bar, 초기원형질분리점(初期原形質分離點)의 삼투압(渗透壓)이 -19.4bar, 이때의 상대함수율(相對含水率) $v_p/v_o$와 $v_p/w_s$가 각각 83.1%와 87.1%였다. 8. 지엽(枝葉)의 생세포군(生細胞群)의 탄성계수(彈性係數) E는 69.6이며 총수분함량(總水分含量)에 대한 총(總) Symplasmic water 는 67.7%이며 Apoplastic water 는 32.3%였다.