• The Journal of the Petrological Society of Korea
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• v.20 no.1
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• pp.1-21
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• 2011

Eoil basalt in the Eoil basin and Yeonil basalt and its related volcanic rocks in Guryongpo and Daebo area were researched and analyzed to purse the tectonic settings and magma characteristics of those Tertiary volcanic rocks in the south-east Korean peninsula. It is highly suggested that zoning, resorption and sieve texture in plagioclase and reaction rim in pyroxene indicate unstable tectonic environments and complex volcanism in the study area. Volcanic rocks from Janggi basin are identified as basalt and basaltic andesite in TAS diagram and sub-alkaline series in terms of magma differentiation. $Na_2O$ and $K_2O$ show positive trend however FeO, CaO, MgO and $P_2O_5$ indicate negative trend in Harker variation diagram with $SiO_2$. Basaltic rocks from Eoil area are identified as calc-alkaline series in AFM diagram and show medium K series calc-alkaline in $K_2O-SiO_2$ diagram. Compatible trace elements of Co, Ni, V, Zn, and Sc in Yeonil basalt show negative trend with crystallization but incompatible trace element of Ba, Rb show positive trend with $SiO_2$ 0.81~1.00 of $Eu/Eu^*$ value suggests minor effect of plagioclase fractionation in Yeonil basaltic rocks. Plagioclase composition of Eoil basalt ranges from $An_{63.46-98.38}\;Ab_{1.62-32.96}\;Or_{0-3.58}$ (anorthite-labradorite) in core to $An_{40.89-82.44}\;Ab_{17.10-46.43}\;Or_{0-12.68}$ (bytownite-labradorite) in rim. $^{87}Sr/^{86}Sr$ and 143Nd;t44Nd ranges 0.704090~0.704717 and 0.512705~0.512822 respectively. Negative linear trends in 87Sr/86Sr and $^{143}Nd/^{144}Nd$ correlation diagram indicate that magma produced Yeonil basalt and basaltic andesite has been originated as partial melting product of mantle wedge by subducting Pacific plate affected by oceanic crust with less effect of continental crust indicating calc-alkaline magma characteristics.

• Membrane and Water Treatment
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• v.4 no.4
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• pp.265-275
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• 2013

China is one of the countries with the highest reserves of coal bed methane (CBM) in the world. Likewise, the CBM industry is significantly growing in China. However, activities related to CBM development have led to more environmental problems, which include serious environmental damage and pollution caused by CBM-produced water. In this paper, the detailed characteristics of CBM-produced water in the southern Qinshui Basin were investigated and analyzed and compared with local surface water and coal mine drainage. Most of CBM-produced water samples are contaminated by higher concentration of total dissolved solids (TDS), K (Potassium), Na (Sodium) and $NH_4$. The alkalinity of the water from coalmines and CBM production was higher than that of the local surface water. The concentrations of some trace elements such as P (Phosphorus), Ti (Titanium), V (Vanadium), Cr (Chromium), Ni (Nickel), Zn (Zinc), Ge (Germanium), As (Arsenic), Rb (Rubidium), and Pd (Palladium) in water from the coalmines and CBM production are higher than the acceptable standard limits. The ${\delta}D$ and ${\delta}^{18}O$ values of the CBM-produced water are lower than those of the surface water. Similarly, the ${\delta}D$ values of the CBM-produced water decreased with increasing drainage time.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.59-61
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• 2005

In this paper, in order to develop the low temperature sintering ceramics for multilayer piezoelectric transformer, $Pb[(Mn_{1/3},Nb_{2/3})_{0.07}(Zn_{1/3}Nb_{2/3})_a(Zr_{0.48}Ti_{0.52})_{1-0.07-a}O_3]$ ceramics were manufactured with the variations of PZN from 2 to 14mol% and their dielectric and piezoelectric properties were investigated. Sintering temperature was varied from 910 to $1000^{\circ}C$. At 8mol% PZN substituted specimen sintered at $970^{\circ}C$, electromechanical coupling factor(kp), mechanical quality factor(Qm), dielectric constant and peizoelectric constant($d_{33}$) showed the optimal values of 0.536, 1803, 1551 and 328[pC/N), respectively, for multilayer piezoelectric transformer application.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.2
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• pp.83-100
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• 2022

The Zhenzigou Pb-Zn deposit, which is one of the largest Pb-Zn deposit in the northeast of China, is located at the Qingchengzi mineral field in Jiao Liao Ji belt. The geology of this deposit consists of Archean granulite, Paleoproterozoinc migmatitic granite, Paleo-Mesoproterozoic sodic granite, Paleoproterozoic Liaohe group, Mesozoic diorite and Mesozoic monzoritic granite. The Zhenzigou deposit which is a strata bound SEDEX or SEDEX type deposit occurs as layer ore and vein ore in Langzishan formation and Dashiqiao formation of the Paleoproterozoic Liaohe group. White mica from this deposit are occured only in layer ore and are classified four type (Type I : weak alteration (clastic dolomitic marble), Type II : strong alteration (dolomitic clastic rock), Type III : layer ore (dolomitic clastic rock), Type IV : layer ore (clastic dolomitic marble)). Type I white mica in weak alteration zone is associated with dolomite that is formed by dolomitization of hydrothermal metasomatism. Type II white mica in strong alteration zone is associated with dolomite, ankerite, quartz and alteration of K-feldspar by hydrothermal metasomatism. Type III white mica in layer ore is associated with dolomite, ankerite, calcite, quartz and alteration of K-feldspar by hydrothermal metasomatism. And type IV white mica in layer ore is associated with dolomite, quartz and alteration of K-feldspar by hydrothermal metasomatism. The structural formulars of white micas are determined to be (K_0.92-0.80Na_0.01-0.00Ca_0.02-0.01Ba_0.00Sr_0.01-0.00)_0.95-0.83(Al_1.72-1.57Mg_0.33-0.20Fe_0.01-0.00Mn_0.00Ti_0.02-0.00Cr_0.01-0.00V_0.00Sb_0.02-0.00Ni_0.00Co_0.02-0.00)_1.99-1.90(Si_3.40-3.29Al_0.71-0.60)_4.00O₁₀(OH_2.00-1.83F_0.17-0.00)_2.00, (K_1.03-0.84Na_0.03-0.00Ca_0.08-0.00Ba_0.00Sr_0.01-0.00)_1.08-0.85(Al_1.85-1.65Mg_0.20-0.06Fe_0.10-0.03Mn_0.00Ti_0.05-0.00Cr_0.03-0.00V_0.01-0.00Sb_0.02-0.00Ni_0.00Co_0.03-0.00)_1.99-1.93(Si_3.28-2.99Al_1.01-0.72)_4.00O₁₀(OH_1.96-1.90F_0.10-0.04)_2.00, (K_1.06-0.90Na_0.01-0.00Ca_0.01-0.00Ba_0.00Sr_0.02-0.01)_1.10-0.93(Al_1.93-1.64Mg_0.19-0.00Fe_0.12-0.01Mn_0.00Ti_0.01-0.00Cr_0.01-0.00V_0.00Sb_0.00Ni_0.00Co_0.05-0.01)_2.01-1.94(Si_3.32-2.96Al_1.04-0.68)_4.00O₁₀(OH_2.00-1.91F_0.09-0.00)_2.00 and (K_0.91-0.83Na_0.02-0.01Ca_0.02-0.00Ba_0.01-0.00Sr_0.00)_0.93-0.83(Al_1.84-1.67Mg_0.15-0.08Fe_0.07-0.02Mn_0.00Ti_0.04-0.00Cr_0.06-0.00V_0.02-0.00Sb_0.02-0.01Ni_0.00Co_0.00)_2.00-1.92(Si_3.27-3.16Al_0.84-0.73)_4.00O₁₀(OH_1.97-1.88F_0.12-0.03)_2.00, respectively. It indicated that white mica of from the Zhenzigou deposit has less K, Na and Ca, and more Si than theoretical dioctahedral mica. Compositional variations in white mica from the Zhenzigou deposit are caused by phengitic or Tschermark substitution [(Al³⁺)^VI+(Al³⁺)^IV <-> (Fe²⁺ or Mg²⁺)^VI+(Si⁴⁺)^IV] substitution. It means that the Fe in white mica exists as Fe²⁺ and Fe³⁺, but mainly as Fe²⁺. Therefore, white mica from layer ore of the Zhenzigou deposit was formed in the process of remelting and re-precipitation of pre-existed minerals by hydrothermal metasomatism origined metamorphism (greenschist facies) associated with Paleoproterozoic intrusion. And compositional variations in white mica from the Zhenzigou deposit are caused by phengitic or Tschermark substitution [(Al³⁺)^VI+(Al³⁺)^IV <-> (Fe²⁺ or Mg²⁺)^VI+(Si⁴⁺)^IV] substitution during hydrothermal metasomatism depending on wallrock type, alteration degree and ore/gangue mineral occurrence frequency.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.6
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• pp.701-717
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• 2003

The objective of this study was to extensively estimate the air quality trends of the study area by surveying con-centration trends in months or seasons, after analyzing the mass concentration of PM-10 samples and the inorganic lements, ion, and total carbon in PM-10. Also, the study introduced to apply the PMF (Positive Matrix Factoriza-tion) model that is useful when absence of the source profile. Thus the model was thought to be suitable in Korea that often has few information about pollution sources. After obtaining results from the PMF modeling, the existing sources at the study area were qualitatively identified The PM-10 particles collected on quartz fiber filters by a PM-10 high-vol air sampler for 3 years (Mar. 1999∼Dec.2001) in Kyung Hee University. The 25 chemical species (Al, Mn, Ti, V, Cr, Fe, Ni, Cu, Zn, As, Se, Cd, Ba, Ce, Pb, Si, N $a^{#}$, N $H_4$$^{+}$, $K^{+}$, $Mg^{2+}$, $Ca^{2+}$, C $l^{[-10]}$ , N $O_3$$^{[-10]}$ , S $O_4$$^{2-}$, TC) were analyzed by ICP-AES, IC, and EA after executing proper pre - treatments of each sample filter. The PMF model was intensively applied to estimate the quantitative contribution of air pollution sources based on the chemical information (128 samples and 25 chemical species). Through a case study of the PMF modeling for the PM-10 aerosols. the total of 11 factors were determined. The multiple linear regression analysis between the observed PM-10 mass concentration and the estimated G matrix had been performed following the FPEAK test. Finally the regression analysis provided source profiles (scaled F matrix). So, 11 sources were qualitatively identified, such as secondary aerosol related source, soil related source, waste incineration source, field burning source, fossil fuel combustion source, industry related source, motor vehicle source, oil/coal combustion source, non-ferrous metal source, and aged sea- salt source, respectively.ively.y.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2923-2928
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• 2010

This study examined the synthesis of the crystal structure of bis(2,2'-bipyridine)nitrato zinc (II) nitrate, $[Zn(bipy)_2(NO_3)]^+NO_3^-$ using a microwave treatment at 300 W and 60 Hz for the application to dye-sensitized solar cells. The simulated complex structure of the complex was optimized with the density functional theory calculations for the UV-vis spectrum of the ground state using Gaussian 03 at the B3LYP/LANL2DZ level. The structure of the acquired complex was expected a penta-coordination with four nitrogen atoms of bipyridine and the oxygen bond of the $NO_3^-$ ion. The reflectance UV-vis absorption spectra exhibited two absorptions (L-L transfers) that were assigned to the transfers from the ligand ($\sigma$, $\pi$) of $NO_3$ to the ligand ($\sigma^*$, $\pi^*$) of pyridine at around 200 - 350 nm, and from the non-bonding orbital (n) of O in $NO_3$ to the p-orbital of pyridine at around 450 - 550 nm, respectively. The photoelectric efficiency was approximately 0.397% in the dye-sensitized solar cells with the nanometer-sized $TiO_2$ at an open-circuit voltage (Voc) of 0.39 V, a short-circuit current density (Jsc) of $1.79\;mA/cm^2$, and an incident light intensity of $100\;mW/cm^2$.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.27.1-27.1
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• 2011

We obtained the spectra of 93 Planet host stars and 73 normal field stars in F, G, K type using BOES at BOAO. We measured the equivalent width of Fe and 25 elements lines using the automatic EW measurement program, TAME(Tools for Automatic Measurement of Equivalent-widths) and estimated the elemental abundances by synth and abfind driver of MOOG code. Since the absence of planets in the normal field stars cannot be "completely" proved, this work focused on the chemical abundances and planet properties of planet host stars, which have the massive planets close to the parent star relatively. We carried out an investigation for the difference of abundances between stars with "Hot Jupiter" and normal field stars with no known planets. We examined the chemical composition of 25 elements, such as C, N, O, S, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd, and Eu by EW measurements, and the S abundances were estimated using synthetic spectrum. We have found that [Mg/Fe] and [Al/Fe] for planet host stars have lower limit comparing with those of comparison stars, and [Ca/Fe] of host star with Neptunian planets is relatively lower than the other host stars with massive planets. We have performed the Kolmogorov-Smirnov test, and examined the ratio of planet host stars to all stars for each bin of [X/H]. As a result, we noted that the O, Si, and Ca abfor undances are strongly related with the presence of planets.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.5
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• pp.418-425
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• 2019

A piezoelectric ceramic fiber composite (PCFC) was successfully fabricated using $0.69Pb(Zr_{0.47}Ti_{0.53})O_3-0.31[Pb(Zn_{0.4}Ni_{0.6})_{1/3}Nb_{2/3}]O_3$ (PZT-PZNN) for use in small-scale wind energy harvesters. The PCFC was formed using an epoxy matrix material and an array of Ag/Pd-coated PZT-PZNN piezo-ceramic fibers sandwiched by Cu interdigitated electrode patterned polyethylene terephthalate film. The energy harvesting performance was evaluated in a custom-made wind tunnel while varying the wind speed and resistive load with two types of flutter wind energy harvesters. One had a five-PCFC array vertically clamped with a supporting acrylic rod while the other used the same structure but with a five-PCFC cantilever array. Stainless steel (thickness: $50{\mu}m$) was attached onto one side of the PCFC to form the PZT-PZNN cantilever. The output power, in general, increased with an increase in the wind speed from 2 m/s to 10 m/s for both energy harvesters. The highest output power of $15.1{\mu}W$ at $14k{\Omega}$ was obtained at a wind speed of 10 m/s for the flutter wind energy harvester with the PZT-PZNN cantilever array. The results presented here reveal the strong potential for wind energy harvester applications to supply sustainable power to various IoT micro-devices.

• Membrane Journal
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• v.32 no.3
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• pp.181-190
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• 2022

Membrane separation provides various advantages including cost effectiveness and high efficiency over traditional wastewater treatment methods such as flocculation and adsorption. However, the effectiveness of membrane separation greatly declines due to membrane fouling, where pollutants are accumulated on the membrane surface. Among different groups of membranes, ceramic membranes can provide good antifouling properties due to its hydrophilicity and chemical stability. In addition, composite membranes such as graphene oxide modified membranes can help prevent membrane fouling. Recently, hybrid photocatalytic membranes have been proposed as a solution to prevent membrane fouling and provide synergetic effects. Membrane separation can solve the disadvantages of photocatalytic oxidation such as low reutilization rate, while photocatalytic oxidation can help reduce membrane fouling.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.4
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• pp.547-555
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• 2014

Objective: This study was conducted to investigate the association between subjective distress symptoms and argon welding among workers in Gyeongnam Province shipyard. Method: 31 argon and 29 non-argon welding workers were selected as study subjects in order to measure concentrations of personal dust, welding fumes and other hazardous materials such as ZnO, Pb, Cr, FeO, MnO, Cu, Ni, $TiO_2$, MgO, NO, $NO_2$, $O_3$, $O_2$, $CO_2$, CO and Ar. An interviewer-administered questionnaire survey was also performed on the same subjects. The items queried were as follows: age, height, weight, working duration, welding time, welding rod amounts used, drinking, smoking, and rate of subjective distress symptoms including headache and other symptoms such as fever, vomiting and nausea, metal fume fever, dizziness, tingling sensations, difficulty in breathing, memory loss, sleep disorders, emotional disturbance, hearing loss, hand tremors, visual impairment, neural abnormality, allergic reaction, runny nose and stuffiness, rhinitis, and suffocation. Statistical analysis was performed using SPSS software, version 18. Data are expressed as the mean ${\pm}SD$. An ${\chi}^2$-test and a normality test using a Shapiro wilk test were performed for the above variables. Logistic regression analysis was also conducted to identify the factors that affect the total score for subjective distress symptoms. Result: An association was shown between welding type (argon or non-argon welding) and the total score for subjective distress symptoms. Among the rate of complaining of subjective distress symptoms, vomiting and nausea, difficulty breathing, and allergic reactions were all significantly higher in the argon welding group. Only the concentration of dust and welding fumes was shown to be distributed normally after natural log transformation. According to logistic regression analysis, the correlations of working duration and welding type (argon or non-argon) between the total score of subjective distress symptoms were found to be statistically significant (p=0.041, p=0.049, respectively). Conclusion: Our results suggest that argon welding could cause subjective distress symptoms in shipyard workers.