• Title, Summary, Keyword: chemical composition

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Concentration Measurement of Alcohol Solution Using Immersion-Type On-Line Refractometer (침적식 온라인 굴절계를 이용한 알코올 농도의 측정)

  • 정옥진;김영한
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.6
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    • pp.473-477
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    • 2003
  • An immersion-type on-line refractometer useful for the in-situ measurement of chemical composition and temperature is developed, and its performance is examined by applying the refractometer to known alcohol solution having concentrations between 0 vol. % and 25 vol. %. Because refractive index and temperature are measured simultaneously, it is possible to compensate the effect of temperature for fast and direct measurement. The outcome of composition measurement for the different concentrations of alcohol solution indicates that the device is suitable for the chemical composition measurement by yielding stable and reproducible reading.

물리정수법에 의한 형광 X선분석과 만장굴석주의 연대측정

  • 택훈
    • Proceedings of the Speleological Society Conference
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    • pp.163-172
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    • 1993
  • Cheju island is situated at about 90km south of southern most tip of the Korean peninsula. Its shape is an ellips with size of 80$\times$40$km^2$, and it is characterized by a symmetrical form whose peak is Mt. Halla (1950m). Major chemical composition of the rock samples from Manjang gul cave is determined by XRF using the fundamental parameter method consisting of fully auto quantitative analysis, semi quantitative analysis (order estimation) and group quantitative analysis. Judging from chemical composition ($SiO_2 = 53.07Wt% Fe_2 O_3=11.34Wt%, MgO=6.48Wt%, Na_2 O=3.07Wt%, K_2 O=1.05Wt%$), this rocks may belong to non alkalic basalt. K-Ar ages of two rocks samples from the Manjang gul cave are also determined. The discrepancy of K-Ar ages is found. They are 0.03Ma and 0.42Ma, respectively. This paper describes some problems experienced in dating young volcanic rocks and then discusses chemical composition, X-ray fluorescence analysis and the age of the formation of a lava tunnel such as Manjang gul cave in cheju Island.

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물리정수법에 의한 형광 X선분석과 만장굴석주의 연대측정

  • 택훈
    • Proceedings of the Speleological Society Conference
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    • pp.108-109
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    • 1994
  • Cheju island is situated at about 90km south of southern most tip of the Korean peninsula. Its shape is an ellips with size of 80$\times$$40km^2$, and it is characterized by a symmetrical form whose peak is Mt. Halla (1950m). Major chemical composition of the rock samples from Manjang gul cave is determined by XRF using the fundamental parameter method consisting of fully auto quantitative analysis, semi quantitative analysis (order estimation) and group quantitative analysis. Judging from chemical composition ($SiO_2=53.07Wt% Fe_2O_3=11.34Wt%, MgO=6.48Wt%, Na_2O=3.07Wt%, K_2O=1.05Wt%$), this rocks may belong to non alkalic basalt. K-Ar ages of two rocks samples from the Manjang gul cave are also determined. The discrepancy of K-Ar ages is found. They are 0.03Ma and 0.42Ma, respectively. This paper describes some problems experienced in dating young volcanic rocks and then discusses chemical composition, X-ray fluorescence analysis and the age of the formation of a lava tunnel such as Manjang gul cave in cheju Island.

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On the Characteristics of Oxide Film on Gap (GaP 산화막 특성에 관하여)

  • Park, J.W.;Moon, D.C.;Kim, S.T.
    • Proceedings of the KIEE Conference
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    • pp.193-195
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    • 1988
  • The native oxide films were thermally and anodically formed on the n-GaP substrates grown by SSD method and measured this oxide thickness and the chemical composition and the electrical properties with formation condition. The chemical composition of themally oxidized GaP film was composed of mostly $GaPO_4$ at temperature below $800^{\circ}C$ and mostly $\beta-Ga_{2}O_{3}$ above $800^{\circ}C$. But The chemical composition of anodically oxidized GaPfilm was composed of the mixture of $Ga_{2}O_{3}$ and $P_{2}O_{5}$. The barrier height of Al/oxide/n-Gap which was formed at $700^{\circ}C$ by thermal oxidation method were 1.10eV, 1.03eV in Current-Voltage measurement. Interface charge density were $4{\times}10^{12}q(C/cm^2)$ and $3{\times}10^{12}q(C/cm^2)$ in Capacitance-Voltage measurement respectively.

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Chemical Composition and Pharmacological Activities of Vietnamese Ginseng, Panax viehamensis

  • Duc, Nguyen-Minh;Nham, Nguyen-Thoi
    • Proceedings of the Ginseng society Conference
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    • pp.127-137
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    • 1998
  • From the underground part of Panax vietnamensis Ha et Grushv., commonly known as Vietnamese ginseng, 50 triterpene glycosides including 24 new dammarane saponins named visa-ginsenosides-Rl-24 were isolated and identified. The structure of the new saponins was elucidated based on chemical and spectroscopic evidence. The saponin composition of Vietnamese ginseng is almost similar to that of ginseng (Panax ginseng C.A. Meyer) and other cultivated Panax spp. However, the content of ocotillos-type saponins, especially that of the major saponin, majonoside-R2 (5.29% yield), was surprisingly very high. The pharmacological activities of Vietnamese ginseng are essentially similar to those of ginseng. In addition, it has marked antibacterial activity against pathogenic Streptococcus app. and is effective in treatment of granular angina. The chemical composition and pharmacological activities have made Vietnamese ginseng an interesting member of Panax spp. from chemotaxonomical and pharmacological points of view,

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물리정수법에 의한 형과 X 선분석과 만장굴석주의 연대측정

  • ;Hong, Si-Hwan
    • Journal of the Speleological Society of Korea
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    • v.20 no.21
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    • pp.34-43
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    • 1989
  • Cheju island is situated at about 60km south of southern most tip of the Korean peninsula. Its shape is an ellips with size of 80*40$\textrm{km}^2$, and it is characterized by a symmetrical form whose peak is Mt. Halla(1950m). Major chemical composition of the rock samples from Manjang gul cave is determined by XRF using the fundamental parameter method consisting of fully auto quantitative analysis, semi quantitative analysis (order estimation) and group quantitative analysis. Judging from chemical composition (SiO$_2$ = 53.07Wt%, Fe$_2$O$_3$ = 11.34Wt%, MgO=6.48Wt%, Na$_2$O=3.07Wt%, $K_2$O=1.05Wt%), this rocks from the Manjang gul cave are also determined. The discrepancy of K-Ar ages is found. They are 0.03 Ma and 0.42Ma, respectively. This paper describes some problems experienced in dating young volcanic rocks and then discusses chemical composition, X-ray fluorescence analysis and the age of the formation of a lava tunnel such as Manjang gul cave in cheju Island.

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Chemical Composition of Panax Ginseng-Leaf Tea (고려인삼 엽록차의 화학성분 조성)

  • Joong Ho Kwon;Myu
    • Journal of Ginseng Research
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    • v.16 no.1
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    • pp.1-6
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    • 1992
  • Chemical composition was determined to evaluate the quality of Panel ginseng-leaf tea over green teas. Ginseng-leaf tea was shown to contain higher contents of soluble matter, ascorbic acid and lower contents of tannins, as compared to tea leaves. The profiles of ginsenoside and sugar of ginseng-leaf tea were noticeably different from those of ginseng roots and the sample maintained high levels of these components under the manufacturing process. Total unsaturated fatty acids and free amino acids were estimated to be decreased in ginseng-leaf tea as compared to those of ginseng leaves. The compositions of amino acids and minerals in ginseng-leaf tea were similar to those of tea leaves and glutamic acid, aspartic acid, leucine, calcium, potassium, sodium, and copper were found to be major components.

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Determination of Optimal Cutting Conditions Based on the Relationship between Tool Grade and Workpiece Material (피삭재와 공구재종의 상관관계에 근거한 적정 절삭조건의 결정)

  • 한동원;고성림;이건우
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.6
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    • pp.79-89
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    • 1998
  • In determining optimal cutting condition for face milling operation, tool wear is an important factor. For the purpose of establishing the relationship between various machining factors and tool wear, cutting tests have been performed. As a result, hardness and chemical composition of workpiece material, chemical composition and grain size of cutting tool and cutting speed have been selected as machining factors. In addition, relationship between feed rate and workpiece hardness has been observed. Prior to utilizing cutting conditions recommended by ‘Machining Data Handbook(MDH)’ as a knowledge base, an analysis for the validity of the MDH has been provided. Based on this analysis, tool life criteria applied by MDH has been modified. Finally, using MDH recommended data for neural network trainning, the results from the trained neural network for optimal cutting condition for some given workpiece and cutting tool can be used as reference cutting conditions.

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Effects of Chemical Composition and Temperature for the Production of Volatile Fatty Acids During Anaerobic Decomposition Process of Marine Sinking Particles

  • PARK Young-Tae;Nishimura Masahiko;Ohwada Kouichi
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.29 no.6
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    • pp.888-892
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    • 1996
  • Anaerobic decomposition experiments were performed to know the effect of chemical composition and temperature for the production of volatile fatty acids (VFAs) from marine sinking particles. Sinking particles were obtained with sediment traps set in Aburatsubo Inlet, Kanagawa Prefecture, Japan, in February, May and August. Sinking particles collected in May were composed of higher fraction of chl. a than the other two months. February and May samples were used to perform the decomposition experiments. VFAs production rates were higher in May sample than February. The production rates increased with increase of incubation temperature, and order of production rates of four VFAs were acetate>n-butyrate>propionate>iso-butyrate at $10^{\circ}C\;and\;20^{\circ}C$. At $28^{\circ}C$, the production rate of propionate was higher than n-butyrate. Based on these results, it is considered that production of VFAs from sinking particles during anaerobic decomposition depends on the chemical composition and temperature.

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A Fundamental Study on the Properties of Cement Collected at Different Process Line (시멘트 분쇄공정별 물성에 관한 기초적 연구)

  • Kim, Jong-Back;Cha, Wan-Ho;Kwon, O-Bong;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • pp.111-114
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    • 2006
  • This paper is to investigate the chemical composition and physical properties of cements collected at different crushing process line of ordinary portland cement to verify the possibility for producing special purpose cement based on the particle distribution technique. According to test results, six different cement samples with different blaine were gathered. loss on ignition and chemical composition of cements gathered were satisfied with KS L 5201. Cement collected at line 5 had the lowest blaine value while cement at line 4 had the highest blaine value. The coarser the cement particle is, the larger the fluidity of cement is. The compressive strength of cement was highly affected by the blaine value of cement. It is confirmed that the use of cement produced by the process of particle distribution control may be applied for special purpose cement without modification of chemical composition.

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