• Title/Summary/Keyword: Al-Mg-Si

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Change in Chemical Composition of Acer mono Saps Collected in Different Region and Time Depending on Storing Period (저장기간에 따른 채취 지역 및 시기별 고로쇠 수액의 성분분석)

  • Kim, Ho-Yong;Kim, Seon-Hong;Gwak, Ki-Seob;Park, Mi-Jin;Choi, Won-Sil;Kang, Ha-Young;Choi, In-Gyu
    • Journal of the Korean Wood Science and Technology
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    • v.38 no.1
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    • pp.75-84
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    • 2010
  • This study was performed to investigate change in chemical composition of Acer mono saps collected in Hamyang, Inje, Namyangju and Yeongwol depending on storing period. pH of A. mono sap was in the range of 4.43~5.68, and it was decreased rapidly with the increase of storing period. A. mono sap collected in Yeongwol in Feb. 22 contained 2.06% sucrose. Degradation of sucrose was occurred when storing period was extended, and it caused production of organic acid like pyruvic acid, lactic acid, acetic acid and ethanol. Detected minerals in A. mono sap were K, Ca, Na, Mg, P, Si, Al, Mn, Fe, Cu and Zn, however, K and Ca content reached 93%. A. mono sap collected in Inje in Mar. 03 contained 131.72 mg/${\ell}$, which was especially high K content among the A. mono sap. 1.55~3.50 mg/${\ell}$ of Ascorbic acid was found in the A. mono sap. Sap collected in early date was less degraded.

Geochemical Study on Pegmatites in Central Region of Taebaek Mineralized Area (태백산(太白山) 광화대(鑛化帶) 중부지역(中部地域) 페그마타이트에 대한 지화학적(地化學的) 연구(硏究))

  • Choi, Sung-Hoon;Chi, Jeong-Mahn
    • Economic and Environmental Geology
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    • v.23 no.1
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    • pp.35-57
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    • 1990
  • This study has been carried out on the Pegmatites, Naedeogri Granites, Nonggeori Granites and Metasedimentary rocks in the middle area of Taebaeksan region to investigate the geochemical properties and possibility of productivity. Pegmatites are characterized by metamorphosed anatectic pegmatite and differentiated magmatic pegmatite, and are mixed type of rare-element pegmatite and mica-bearing pegmatite by the classification of Ginsburg(1979). The petrological type of the igneous rocks is thought to be calcalkali, subalkaline and peralumious. According to chemical variations against D. I., differentiation trends from Naedeogri and Nonggeori Granites through non-mineralized pegmatites to mineralized pegmatites are supposed. From the relationship between oxided and $SiO_2$, pegmatites and Nonggeori Granite have shown similar tendencies and bulk composition of pegmatites and similar to metasedimentary rocks near the intrusives. By judging the correlations of trace elements, it is elucidated that pegmatites adjacent to Naedeogri and Nonggeori Granites have been originated in magma differentiation from these granites and the others have been differentiated by remelting or partial melting from metasedimentary rocks. $Sp_5$, $Sp_8$, and $Sp_9$ pegmatites are considered as productive rocks, and $Sp_4$, $Sp_6$, $Sp_7$, $Sp_{10}$, $Sp_{11}$, and $Sp_{12}$ pegmatites and granites are supposed to have a weak productivity, in terms of element ratios related with Sn mineralizations. Tourmalines in productive pegmatites are formed under the circumstance of Li-poor granitoids and associated with pegmatites, and the others are seemed to be originated in metapelites and metapsammites which are not coexisting with an Al-saturating phase. Three types of chemical zoning are noticed in tourmalines: (1) apparently homogeneous compositional patterns, (2) a continuous core-to-rim zoning and, (3) a discontinuous core-to-rim zoning. From results of EPMA of tourmalines, Al, Mg and Ca increase closer to rim, while Fe decreases.

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Characteristics of Basalt Materials Derived from Recycling Steel Industry Slags (철강산업 슬래그를 이용하여 제조한 바잘트 소재의 특성)

  • Jung, Woo-Gwang;Back, Gu-Seul;Yoon, Mi-Jung;Lee, Jee-Wook
    • Korean Journal of Materials Research
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    • v.27 no.5
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    • pp.281-288
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    • 2017
  • In this study, Fe-Ni slag, converter slag and dephosphorization slag generated from the steel industry, and fly ash or bottom ash from a power plant, were mixed at an appropriate mixing ratio and melted in a melting furnace in a mass-production process for glass ceramics. Then, glass-ceramic products, having a basalt composition with $SiO_2$, $Al_2O_3$, CaO, MgO, and $Fe_2O_3$ components, were fabricated through casting and heat treatment process. Comparison was made of the samples before and after the modification of the process conditions. Glass-ceramic samples before and after the process modification were similar in chemical composition, but $Al_2O_3$ and $Na_2O$ contents were slightly higher in the samples before the modification. Before and after the process modification, it was confirmed that the sample had a melting temperature below $1250^{\circ}C$, and that pyroxene and diopside are the primary phases of the product. The crystallization temperature in the sample after modification was found to be higher than that in the sample before modification. The activation energy for crystallization was evaluated and found to be 467 kJ/mol for the sample before the process modification, and 337 kJ/mol for the sample after the process modification. The degree of crystallinity was evaluated and found to be 82 % before the process change and 87 % after the process change. Mechanical properties such as compressive strength and bending strength were evaluated and found to be excellent for the sample after process modification. In conclusion, the samples after the process modification were evaluated and found to have superior characteristics compared to those before the modification.

Element Mobility during the Weathering of Granitic Gneiss in the Yoogoo Area, Korea. (유구지역 화강암질 편마암의 풍화작용에 따른 원소의 거동)

  • 이석훈;김수진
    • Journal of the Mineralogical Society of Korea
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    • v.14 no.1
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    • pp.39-51
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    • 2001
  • 공주군 유구면 일대의 화강암질 편마암의 풍화작용에 따른 원소의 거동과 pH와 이차광물과의 관계를 XRF, ICP-AES, ICP-MS를 이용한 원소분석결과를 통하여 검토하였다. 이 지역의 암석은 pH6 내외의 산성환경, 침철석, 아나타제와 같은 다양한 이차광물을 생성하면서 심각한 화학조성의 변화를 초래했다. 주원소의 화학조성을 이용한 풍화지수는 토양층에서 79~88로 모암 중의 사장석이 용해되고 흑운모가 변질되어 캐올리광물의 생성이 활발한 방향으로 풍화작용이 진행되었다. 지표층으로 가면서 Al에 대한 주 원소의 거동은 Si, Ca, Na, K, P가 감소하고 Fe, Ti, Mn이 증가하는 경향을 보이며 pH가 낮은 풍화단면에서 주 원소의 변화량이 더 크다. 이 풍화대에서 Mg은 거의 일정하다. Li, As 모든 전이원소는 pH가 감소함에 따라 증가하며 특히 이들 원소는 Fe의 함량과 비례해서 증가해 침철석과 공침하였거나 표면에 흡착되어 있는 것으로 보인다. Ga은 Fe와 비례하기는 하지만 변화량은 전 풍화단면에서 일정하다. Zr, Mo, Sn, Cd은 pH에 변화에 상관없이 일정한 반면에 Rb, Sr, Ba, Y, Pb, Th, U 등은 감소하는 경향을 보인다. 특히 Rb 과 Sr은 Ca에 비례해서 감소한다. 희토류원소는 전 풍화단면에서 감소하는 경향을 보이는데 $Al_2$$O_3$에 대한 상대적인 변화량을 보면 경희토류원소는 사프롤라이트(saprolite)하부와 상부에서 부화되어 있고 중부 사프롤라이트와 토양층에서 감소하는 반면에 중희토류원소는 사프롤라이트 하부와 상부에서 감소하고 중부사프롤라이트 및 토양층에서 부화되는 경향을 보인다. 전반적으로 희토류원소의 원자번호가 클수록 손실율이 커진다. 이 풍화단면에서 원소의 거동은 각 풍화층의 pH와 생성된 이차광물의 조성에 지배를 받았다.

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Distribution Characteristics of Gold in the Volcanic Rocks, Korea (국내에 분포하는 화산암류중 금의 분포특징에 관한 연구)

  • Yoon, Chung-Han;Oh, Keun-Chang
    • Economic and Environmental Geology
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    • v.29 no.3
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    • pp.257-267
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    • 1996
  • One hundred of thirty volcanic rocks col1ected from the Jeju island, Jeongog, Guryongpo and other areas were analyzed for major elements and trace elements with Au by inductively coupled argon plasma and graphite furnace atomic absorptiom spectrometry. The Au content is the highest values (0.2~43.4 ppb, average; 10.34 ppb) from the Jeju island volcanic rocks and the lowest (0.5~11.0 ppb, average; 1.23 ppb) from the Guryongpo volcanic area. The content of Au tends to be higher in the Quarternary volcanic rocks than Tertiary or Cretaceous volcanic rocks. The Au content of the calc alkali volcanic rocks tends to increase from mafic to felsic volcanic rocks, but that of the alkalic volcanic rocks tends to increase from felsic to mafic volcanic rocks. The Au content of the volcanic rocks collected from the Jeju island shows the highest values in the feldspar olivine basalts. Elements or oxides which have positive or negative correlations with Au are Ag, Mo, Rb, V, Y, $K_2O$, MgO and $SiO_2$, but other elements analyzed are not shown correlations with Au. It has a tendency to show that samples from the Jeju with 5 ppb gold and more are plotted in the non-Dupal area and those with less than 5 ppb gold in the Dupal area, while those from the Jeongog with 5 ppb gold and more are plotted in the Dupal area and those with less than 5 ppb gold in the non-Dupal area, in the Ba/Nb-La/Nb, Zr/Nb-Ba/Nb diagrams. It shows that samples from the Jeju and Guryongpo with high gold content are plotted in the within-plate, while those with low gold content are plotted in the arc-related area, and those from the Jeongog are scattered in the $TiO_2-Al_2O_3$, $Zr/A1_2O_3-TiO_2/Al_2O_3$ diagrams.

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A study on bulk deposition flux of dustfall and insoluble components by the wind intensity in Busan, Korea (바람의 강도에 따른 강하먼지와 불용성 성분의 조성특성)

  • 황용식;김유근;박종길;문덕환
    • Journal of Environmental Science International
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    • v.11 no.7
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    • pp.651-662
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    • 2002
  • Weather elements were observed by the AWS (Automatic Weather System) and dustfall particles were collected by the modified American dust jar (wide inlet bottle type) at 4 sampling sites in Busan area from March. 1999 to February, 2000. Thirteen chemical species (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Si, and Zn) were analyzed by AAS and ICP. The purposes of this study were to estimate qualitatively various bulk deposition flux of dustfall and insoluble components by applying regional and seasonal wind intensity. Frequency of wind speed were found in order of low(1-3m/s), very low(<1m/s), medium(3-8m/s) and high(>8m/s), and annual mean had higher range at low(1-3m/s) for 56.3%. Strong negative linear correlation were observed between dustfall and wind direction (northeastern and eastern), but strong positive linear correlation were observed between dustfall and wind direction (western and northwestern) at industrial, commercial and coastal zone(p<0.05). While a negative correlation were observed between wind speed frequency of very low(<1 m/s) and dustfall, and positive correlation were observed between wind speed frequency of low(1-3m/s) and dustfall in coastal zone(p<0.05). The correlation coefficient was observed 0.556 between wind speed frequency of low(1-3m/s) and Ni by commercial zone(p<0.05). The correlation coeffcient show well-defined insoluble trace metals (Al, Ca, Cr, Cu, Fe, Pb, and Zn) and wind speed frequency of low(1-3m/s) at coastal zone, which was found significant difference(p<0.01).

Qualitative Analysis and Plasma Characteristics of Soil from a Desert Area using LIBS Technique

  • Farooq, W. Aslam;Tawfik, Walid;Al-Mutairi, Fahad N.;Alahmed, Zeyad A.
    • Journal of the Optical Society of Korea
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    • v.17 no.6
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    • pp.548-558
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    • 2013
  • In this work, laser induced breakdown spectroscopy (LIBS) is used to investigate soil samples collected from different desert areas of Riyadh city in Saudi Arabia. Both qualitative analysis and plasma parameters are studied via the observed LIBS spectra. These experiments have been done using a Spectrolaser-7000 system with 50 mJ fundamental wavelength of Nd:YAG laser and detection delay time of 1 microsecond. Many spectral lines are highly resolved for many elements like Al, Fe, Mg, Si, Mn, Na, Ca and K. The electron temperatures Te and electron densities Ne, for the constituent of generated LIBS plasma, are determined for all the collected samples. It is found that both Te and Ne vary from one desert area to other. This variation is due to the change of the elemental concentration in different desert areas that affects the sample's matrices. Time dependent measurements have also been performed on the soil samples. While the signal-to-base ratio (SBR) reached its optimal value at 1 microsecond, the plasma parameters Ne and Te reach values of $4{\times}10^{17}cm^{-3}$ and 9235 K, respectively, at 2.5 microsecond. The later indicate that the plasma cooling processes are slow in comparison to the previously observed results for metallic samples. The observed results show also that in the future it is possible to enhance the exploitation of LIBS in the remote on-line environmental monitoring application, by following up only the values of Ne and Te for one element of the soil desert sample using an optical fiber probe.

Investigations on borate glasses within SBC-Bx system for gamma-ray shielding applications

  • Rammah, Y.S.;Tekin, H.O.;Sriwunkum, C.;Olarinoye, I.;Alalawi, Amani;Al-Buriahi, M.S.;Nutaro, T.;Tonguc, Baris T.
    • Nuclear Engineering and Technology
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    • v.53 no.1
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    • pp.282-293
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    • 2021
  • This paper examines gamma-ray shielding properties of SBC-Bx glass system with the chemical composition of 40SiO2-10B2O3-xBaO-(45-x)CaO- yZnO- zMgO (where x = 0, 10, 20, 30, and 35 mol% and y = z = 6 mol%). Mass attenuation coefficient (µ/ρ) which is an essential parameter to study gamma-ray shielding properties was obtained in the photon energy range of 0.015-15 MeV using PHITS Monte Carlo code for the proposed glasses. The obtained results were compared with those calculated by WinXCOM program. Both the values of PHITS code and WinXCOM program were observed in very good agreement. The (µ/ρ values were then used to derive mean free path (MFP), electron density (Neff), effective atomic number (Zeff), and half value layer (HVL) for all the glasses involved. Additionally, G-P method was employed to estimate exposure buildup factor (EBF) for each glass in the energy range of 0.015-15 MeV up to penetration depths of 40 mfp. The results reveal that gamma-ray shielding effectiveness of the SBC-Bx glasses evolves with increasing BaO content in the glass sample. Such that SBC-B35 glass has superior shielding capacity against gamma-rays among the studied glasses. Gamma-ray shielding properties of SBC-B35 glass were compared with different conventional shielding materials, commercial glasses, and newly developed HMO glasse. Therefore, the investigated glasses have potential uses in gamma shielding applications.

Influence of Surface Roughness of Tools on the Friction Stir Welding Process

  • Hartmann, Michael;Bohm, Stefan;Schuddekopf, Sven
    • Journal of Welding and Joining
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    • v.32 no.6
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    • pp.22-28
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    • 2014
  • Most publications on friction stir welding describe phenomena or results with given process parameters like feed rate, rotation speed, angle and depth of penetration. But without a complete documentation of tool design, the results under the same process parameters are completely different. For this purpose, the Institute of Cutting and Joining Manufacturing Processes (tff), University of Kassel investigated the influence of tool roughness on the friction stir welding process. Therefore a defined surface finish was produced by turning and die sinking. As basis of comparison the constant parameters were rotation speed, feed rate, tilt angle and a heel plunge depth. Sound butt-welds were produced in aluminium alloy 6082 (AlMgSi1) with 1.5 mm sheet thickness with a turned reference tool with a surface of $Ra=0.575{\mu}m$ in position controlled mode. The surfaces are manufactured from a very fine to a very rough structure, classified by the VDI-classes with differences in the arithmetical mean roughness. It can be demonstrated with the help of temperature measures, that less heat is generated at the surfaces of the shoulder and the pin by the higher roughness due to lower active friction contact surface. This can also be seen in the resulting wormhole defects.

A Study on the Surface Crystallization of Glass (표면결정화유리에 관한 연구)

  • 박용완;강은태
    • Journal of the Korean Ceramic Society
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    • v.14 no.4
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    • pp.230-235
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    • 1977
  • In this paper the conditions of surface crystallization of glass were studied. The basic glass which is apt to crystallize, with $SiO_2$ 72.50, $Al_2O_3$ 5, 00, $Na_2O$ 8.00 $K_2O$ 3.50, CaO 5.00, MgO 3.00, $B_2O_3$ 3.00 Wt% is chosen. The strain point and softening point of this glass is 4$25^{\circ}C$ and 778$^{\circ}C$ each, and between the two temperatures we could get grystal on its surface by immersion in salt baths during some controlled hours. The kind of crystal on the surface of glass was confirmed by X-ray diffraction analysis and the change of the thickness of crystalline layers depending on temperature and time, was surveyed by using optical microscope. The results are as follows; 1. The chloride group is more suitable than sulfate group for the treating salt. 2. In the condition with 50 LiCl.50NaCl at 62$0^{\circ}C$ for 2 hrs and with 50 LiCL.20-30 NaCl.30-20 $CaCl_2$ at 72$0^{\circ}C$ for 15-20 min. we could get the best crystalline layers. 3. The crystal was silica-O and petalite with a little tridymite and nepheline. 4. The thickness of crystalline layers increased with increasement of temperature and time.

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