• Journal of the Korean Institute of Gas
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• v.26 no.3
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• pp.1-9
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• 2022

The causes of accidents occurring in chemical plants vary, but 96% of industrial accidents occurring worldwide are caused by workers' unsafe behavior. The International Labour Organization (ILO) has announced 20 elements of workers' anxiety-warning behaviors that occur on multiple occasions at industrial sites in order to warn them of the risk of accidents caused by workers' anxiety-driven behavior, and to prevent industrial accidents, workers' anxiety-driven behavior should be controlled under stress In this study, major types of unsafe behavior were analyzed on the basis of information on the accident investigation history of domestic workspaces in order to find out how workers can manage their unsafe behavior. Based on the results of the analysis of the major anxiety war behavior, the root cause of causing anxiety war behavior was analyzed using the Swiss Cheese Model, and each root cause management method was proposed.

• Journal of Korean Society of Forest Science
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• v.40 no.1
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• pp.63-69
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• 1978

A bark comprises about 10 to 20 percents of a typical log by volume, and is generally considered as an unwanted residue rather than a potential1y valuable resourses, As the world has been confronted with decreasing forest resources, natural resources pressure dictate that a bark should be a raw material instead of a waste. The utilization of the largely wasted bark of genus Pinus, Quercus, and Populus grown in Korea can be enhanced by learning their chemical properties. However, the chemical study of tree bark grown in korea have never been undertaken. In the present paper, the studies on the chemical properties of bark comprise carbohydrates, lignin, and extractives, composition of reducing sugars and five essential elements. The results may be summarized as follows: 1. Bark are much richer in quantity of lignin and extractives than the corresponding wood, and are chiefly consisted of lignin, extractives and carbohydrates orderly. It is the same with ash contents. Alcohol-benzene extractives of populus bark are the highest among three genus. 2. Although glucose constitutes the major sugar in both pine and hardwoods bark, in pinus, arabinose and xylose are the next but in hard woods, the next is xylose. 3. Essential elements, Ca and Kjeldahl-N are higher in the bark than in the wood. Ca content is the highest among others, and N,K followed it. Essential elements are higher in Quercus than in Populus and pinus.

• The Journal of the Petrological Society of Korea
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• v.22 no.2
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• pp.137-151
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• 2013

This study is focused on element behaviors and mineral compositions of the fault rock developed in Yongdang-ri, Yangbuk-myeon, Gyeongju City, Korea, using XRF, ICP, XRD, and EPMA/BSE in order to better understand the chemical variations in fault rocks during the fault activity, with emphasis on dependence of chemical mobility on mineralogy across the fault zone. As one of the main components of the fault rocks, $SiO_2$ shows the highest content which ranges from 61.6 to 71.0%, and $Al_2O_3$ is also high as having the 10.8~15.8% range. Alkali elements such as $Na_2O$ and $K_2O$ are in the range of 0.22~4.63% and 2.02~4.89%, respectively, and $Fe_2O_3$ is 3.80~12.5%, indicating that there are significant variations within the fault rock. Based on the chemical characteristics in the fault rocks, it is evident that the fault gouge zone is depleted in $Na_2O$, $Al_2O_3$, $K_2O$, $SiO_2$, CaO, Ba and Sr, whereas enriched in $Fe_2O_3$, MgO, MnO, Zr, Hf and Rb relative to the fault breccia zone. Such chemical behaviors are closely related to the difference in the mineral compositions between breccia and gouge zones because the breccia zone consists of the rock-forming minerals including quartz and feldspar, whereas the gouge zone consists of abundant clay minerals such as illite and chlorite. The alteration of the primary minerals leading to the formation of the clay minerals in the fault zone was affected by the hydrothermal fluids involved in fault activity. Taking into account the fact that major, trace and rare earth elements were leached out from the precursor minerals, it is assumed that the element mobility was high during the first stage of the fault activity because the fracture zone is interpreted to have acted as a path of hydrothermal fluids. Moving toward the later stage of fault activity, the center of the fracture zone was transformed into the gouge zone during which the permeability in the fault zone gradually decreased with the formation of clay minerals. Consequently, elements were effectively constrained in the gouge zone mostly filled with authigenic minerals including clay minerals, characterized by the low element mobility.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.996-1002
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• 1999

The oxalate precipitation of lanthanide and actinide by oxalic acid was investigated in the simulated radioactive liquid waste, which was composed of 17 elements of alkali, alkaline earth(Cs, Rb, Ba, Sr), transition metal(Zr, Fe, Mo, Ni, Pd, Rh), lanthanide(La, Y, Nd, Ce, Eu) and actinide(Np, Am) in nitric acid solution. The effect of concentrations of nitric acid and ascorbic acid on the precipitation yield of each element in the simulated solution was examined at 0.5 M oxalic acid concentration. The precipitation yields of the elements were usually decreased with nitric acid concentration, nevertheless, the precipitation yields of lanthanide and actinide were more than 99%. Palladium was precipitated due to the reduction of Pd(II) into Pd metal by the addition of ascorbic acid in the oxalate precipitation and then, the precipitation yields of Mo, Fe, Ni, Ba decreased by 10~20% with concentration of ascorbic acid. The reductive precipitation of Pd(II) into Pd metal by the addition of ascorbic acid into the simulated radwaste occurred at below 1 M nitric acid concentration and its yield showed maximum at the ascorbic acid concentration of 0.01~0.02 M. The hydrazine suppressed the reductive precipitation of Pd by the ascorbic acid.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.446-452
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• 2010

Five year term study from 2002 to 2006 was carried out to examine the effects of continuous long-term application of swine liquid manure on soil chemical properties including heavy metal contents and yield of tomato (Lycopersicon esculentum) and cucumber (Cucumis sativus L.) in a greenhouse. Treatments were conventional chemical fertilizers and three types of swine slurry; Slurry composting and biofiltration (SCB), Thermophilic aerobic oxidation (TAO), and Bio-mineral water (BMW). Total nitrogen level of the SCB, TAO, and BMW was 0.47%, 0.09%, and less than 0.01%, respectively. The heavy metal contents of the three liquid manures were much lower than the Korean regulation level. The soil phosphorus, potassium, and heavy metal contents after five year continuous application of swine slurry were not significantly higher than those of chemical fertilizer use. Contents of heavy metals in leaves of the crops did not show significant difference among treatments. The levels of copper and zinc, plant essential elements, in leaves were in the range of optimum plant growth. Yields of tomato and cucumber for swine liquid manures were not significantly different from that of chemical fertilizer. The results implied that the three types of swine slurry may not deteriorate soil chemical properties including phosphate and trace elements in greenhouse soils when they are applied as a basal fertilization at a recommended nitrogen rate based on soil testing.

• Analytical Science and Technology
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• v.35 no.5
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• pp.205-211
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• 2022

Deuterium (D) is an isotope with one more neutron number than hydrogen (H). Heavy elements rarely change their chemical properties with little effect even if the number of neutrons increases, but low-mass elements change their vibration energy, diffusion rate, and reaction rate because the effect cannot be ignored, which is called an isotope effect. Recently, in the semiconductor and display industries, there is a trend to replace hydrogen gas (H₂) with deuterium gas (D₂) in order to improve process stability and product quality by using the isotope effect. In addition, as the demand for D₂ in industries increases, domestic gas producers are making efforts to produce and supply D₂ on their own. In the case of high purity D₂, most of them are produced by electrolysis of heavy water (D₂O), and among D₂, hydrogen deuteride (HD) molecules are present as isotope impurities. Therefore, in order to maximize the isotope effect of hydrogen in the electronic industry, HD, which is an isotope impurity of D₂ used in the process, should be small amount. To this end, purity analysis of D₂ for industrial processing is essential. In this study, HD quantitative analysis of D₂ for high purity D₂ purity analysis was established and hydrogen isotope RM (Reference material) was developed. Since hydrogen isotopes are difficult to analyze with general gas analysis instrument, they were analyzed using a high-precision mass spectrometer (Gas/MS, Finnigan MAT271). High purity HD gas was injected into Gas/MS, sensitivity was determined by a signal according to pressure, and HD concentrations in two bottles of D₂ were quantified using the corresponding sensitivity. The amount fraction of HD in each D₂ was (4518 ± 275) μmol/mol, (2282 ± 144) μmol/mol. D₂, which quantifies HD amount using the developed quantitative analysis method, will be manufactured with hydrogen isotope RM and distributed for quality management and maintenance of electronic industries and gas producers in the future.

• Journal of Conservation Science
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• v.31 no.3
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• pp.181-192
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• 2015

This study aims to examine production technique of twelve white wares from the Gangneung Namyang-ri and Donghae Balhan-dong2(Samun-dong) kiln sites, Kangwon Province and characteristics of the used materials, and to find a correlation among materials of the excavated white wares. X-ray fluorescence sequential spectroscopy(XRF), X-ray diffraction(XRD), Dilatometer and Inductively coupled plasma mass spectrometry(ICP-MS), Inductively coupled plasma automic emission spectrometer(ICP-AES) were applied to determine the chemical composition, crystalline phase of samples, firing temperatures, trace elements and rare earth elements. When analyzing body crystalline phases of the white wares using the XRD method, quartz and mullite were extracted from all the samples. Though firing temperature of each sample was different, they were mostly fired at a temperature below $1200^{\circ}C$. Analyzing the excavated white wares using the Seger formula, compositional properties of white wares in Gangneung Namyang-ri kiln showed diffrently from the Donghae Balhan-dong2(Samun-dong) kiln. The body of white wares from Gangneung Namyang-ri kiln have higher raito of $RO_2$ and $RO+R_2O$ than of white wares from Donghae Balhan-dong2(Samun-dong) kiln site. The white wares from Gangneung Namyang-ri kiln and Donghae Balhan-dong2(Samun-dong) kiln were made of host rocks of the different geological origin, according to the result of rare earth elements analysis.

• Economic and Environmental Geology
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• v.26 no.3
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• pp.337-347
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• 1993

Mineralogical and geochemical studies on some pyrophyllite deposits in Milyang area, Kyeongnam Province (Milyang and Sungjin mine) were carried out in order to investigate dispersion patterns of chemical elements in altered volcanic wallrocks, and to interpret genetic environments of the pyrophyllite deposits. Cretaceous andesitic and tuffaceous rocks, and pyrophyllite ore specimens were collected from the dumps and drilling cores. Andesitic wallrocks were grouped as unaltered and altered rocks in the order of pyrophyllitization. Vertical dispersion patterns and relative mobilities of chemical elements in volcanic wallrocks were discussed. Geochemical environment in the Milyang area is characterized by the occurrence of boron minerals such as dumortierite coexisting with pyrophyllite ores, and tourmaline in granitic rocks. Unaltered andesitic rocks are mainly composed of plagioclase, pyroxene and hornblende, and were propylitized and saussuritized. Altered andesitic rocks are bleached and consist of quartz, sericite, pyrophyllite, kaolinite, chlorite and disseminated pyrite. Pyrophyllite ores are mainly composed of quartz, pyrophyllite, dumortierite, dissemianted pyrite and some diaspore. Enrichment of $SiO_2$, $Al_2O_3$, LOI (loss on ignition), As and Cr, and depletion of $K_2O$, $Na_2O$, CaO, MgO and total Fe are characteristic during alteration process. The REE patterns show that the pyrophyllite deposits could be originated from the continental margin volcanics. The $(La/Lu)_{cn}$ ratios of the pyrophyllite ores increase from 4.2~23.2 to 2.67~128.8 owing to strong acidic hydrothermal alteration. Vertical dispersion patterns of $Al_2O_3$, $K_2O$, $Na_2O$, CaO, MgO, $Fe_2O_3$ (total Fe), As, Au, Sb, Cr and Sr in the wallrocks show the location of orebodies. Particularly dispersion patterns of $Al_2O_3$ and Cr indicate the extension of orebodies. Anomalous distribution of Au, As and Sb in wallrocks shows potential for gold occurrence below the pyrophyllite deposits. Judging from the relative mobilities of elements in wallrocks, $Al_2O_3$ could be added from hydrothermal solution, and the silicified rone be formed from the excess of $SiO_2$.

• Bulletin of the Korean Chemical Society
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• v.35 no.11
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• pp.3289-3293
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• 2014

Femtosecond laser ablation (fs LA) was used in this study to identify pollution by heavy metals and the distribution of elemental nutrients at different rice milling ratios. Polished rice (degrees of milling of 3, 5, 7, 9, and 11) was collected from major Korean supermarkets and one sample thereof was selected. An internal quality control experiment was conducted using a rice flour certified reference material from the Korea Research Institute of Standards and Science (KRISS CRM) for the evaluation of the efficacy. To assess the effectiveness of the analysis method, the reliability was validated using a food analysis performance assessment scheme (FAPAS), with chili powder serving as an external quality control. The results of the analysis of the inorganic elements Ti, Ca, Al, Fe and Mn in white and brown rice with degrees of milling of 3, 5, 7, 9 and 11 using ICP-MS, ICP-OES and AAS revealed contents of 0.40, 49.2, 2.43, 5.36 and 10.3 mg/kg in white rice and 0.59, 78.0, 7.52, 11.0 and 18.5 mg/kg in brown rice, respectively. Among the elements, there were remarkable differences in the measured contents. By comparing the contents of the elements at different degrees of milling, Ti, Co, As, Ca, Al, Cu, Fe, and Mn were determined to be distributed on the surface of the rice grains, whereas the contents of Cd and Pb increased toward the center of the rice grains, and Si was evenly distributed. After the quantitative analysis of rice samples polished to different degrees of milling, Ca and Al, which were contained in large amounts, and Si were analyzed with specificity by fs LA. The results show that Ca and Al were distributed in the rice husk (protective covering of rice) and Si was distributed in all parts of the rice.

• Journal of the Korean Chemical Society
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• v.38 no.9
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• pp.667-675
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• 1994

The precipitate flotation using $La(OH)_3$ as a coprecipitant was studied for the simultaneous determination of trace three elements in a sea water. Several experimental conditions such as pH, coprecipitant and surfactant were investigated with an artificial sea water. To remove the influence of Cr(VI) the Cr(VI) was reduced to Cr(III) using $NaBH_4$ prior to the flotation. Trace amounts of Cu(II), Co(II) and total Cr in 1.0 l sea water was coprecipitated together with the precipitation of $La(OH)_3$ in the solution of pH 9.8 adjusted with 3.OM NaOH solution. The precipitate was floated by using a mixed surfactant (1 to 8 of each 0.5% ethanolic sodium oleate and sodium dodecylsulfate solution) by bubbling a nitrogen gas. The floats was separated and filtrated from the mother liquor by suction. The precipitate was dissolved in 7.0 M $HNO_3$ solution and then marked to 25.0 ml with a deionized water. These elements were determined by graphite fumace atomic absorption spectrophotometry. This method was applied to determine the elements in the sea water of the Eastern and Western coasts. And the recoveries were over 90.0% in the samples into which given amounts of the analyte elements were spiked.