• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.4
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• pp.1-14
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• 2017

In Korea, the soil series derived from sedimentary rocks are classified into seven soil series of coarse loamy soil such as Dain, Danbug, Dongam, Imdong, Jeomgog, Maryeong, and Yonggog; seventeen soil series of fine loamy soil such as Angye, Anmi, Banho, Bigog, Deoggog, Dogye, Dojeon, Gamgog, Gugog, Jincheon, Maji, Mungyeong, Oggye, Samam, Yanggog, Yeongwol, and Yulgog; six soil series of fine silty soil such as Goryeong, Bonggog, Juggog, Gyeongsan, Yuga, and Yugog; and four soil series of clayey soil such as Mitan, Pyeongan, Pyeongjeon, and Uji. All thirty-four soil series have different drainage rates and topography. However, the soil texture depends on the parent rock. The buffer functions in GIS (Geographic Information System) techniques were used to calculate adjacent soil series from a soil series. The length of the adjacent soil series was adjusted because a side of the buffer area was one meter long. The cluster analysis was conducted using the CCC (Cubic Clustering Criterion) method, in which the number of clusters is calculated based on the individual soil series ratio. Soil survey has been carried out since 1964 as "The reconnaissance soil survey", and 1:5,000 detailed soil survey was completed in 1999 with a five-years plan in Korea. Today, all the soil survey information has been computerized. GIS techniques were used to establish a digital soil map; however, there have not been any studies to interpret pedogenesis using the GIS technique. In this study, the area of the adjacent soil series were obtained using the GIS technique. The area of the adjacent soil series can be calculated based on the information area. The similarities of soil originated from sedimentary rocks were estimated using the length. As a result, the distribution of grain size was different based on the types of sedimentary rocks and the location. The clusters were distinguished into limestone, sandstone, and shale. In addition, the soil derived from shale was divided into red shale and gray shale. This means that quantitative interpretation of the catena and this established method can be used to interpret the relationship between soil series.

• Economic and Environmental Geology
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• v.26 no.3
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• pp.327-335
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• 1993

Phase relations in the system Pd-Sb-Te were investigated at $1000^{\circ}$, $800^{\circ}$, and $600^{\circ}C$, using the sealed-capsule technique; the quenched products were studied by reflected light microscopy, X-ray diffraction, and electron microprobe analysis. At $1000^{\circ}C$, the solid phases Pd, $Pd_{20}Sb_7$, $Pd_8Sb_3$, $Pd_{31}Sb_{12}$, and $Pd_5Sb_2$ are stable with a liquid phase that occupies most of the isothermal diagram. Additional solid phases at $800^{\circ}C$ are $Pd_5Sb_3$, PdSb, $Pd_8Te_3$, $Pd_7Te_3$, and a continuous $Pd_{20}Te_7-Pd_{20}Sb_7$ solid solution becomes stable. At $600^{\circ}$, $PdSb_2$, $Pd_{17}Te_4$, $Pd_9Te_4$, PdTe, $PdTe_2$, $Sb_2Te_3$, and Sb and continuous PdSb-PdTe and $PdTe-PdTe_2$ solid solutions are stable. All the solid phases exhibit solid solution, mainly by substitution between Sb and Te to an extent that varies with temperature of formation. The maximum substitution (at.%) of Te for Sb in the Pd-Sb phases is: 44.3 in $Pd_8Sb_3$, 52.0 in $Pd_{31}Sb_{12}$, 46.2 in $Pd_5Sb_2$ at $800^{\circ}C$; 15.3 in $Pd_5Sb_3$, 68.3 in $PdSb_2$ at $600^{\circ}C$. The maximum substitution (at.%) of Sb for Te in the Pd-Te phases is 34.5 in $Pd_5Sb_3$ at $800^{\circ}C$, and 41.6 in $Pd_7Te_3$, 5.2 in $Pd_{17}T_4$, 12.4 in $Pd_9Te_4$, and 19.1 in $PdTe_2$ at $600^{\circ}C$. Physical properties and X-ray data of the synthetic $Pd_9Te_4$, PdTe, $PdTe_2$, $Pd_8Sb_3$, PdSb, and $Sb_2Te_3$ correspond very well with those of telluropalladinite, kotulskite, merenskyite, mertieite II, sudburyite, and tellurantimony, respectively. Because X-ray powder diffraction data consistently reveal a 310 peak ($2.035{\AA}$), the $PdSb_2$ phase is most probably of cubic structure with space group $P2_13$. The X-ray powder pattern of a phase with PdSbTe composition, synthesized at $600^{\circ}C$, compares well with that of testibipalladite. Therefore, testibiopalladite may be a member of the $PdSb_2-Pd(Sb_{0.32}Te_{0.68})$ solid solution series which is cubic and $P2_13$ in symmetry. Thus the ideal fonnula for testibiopalladite, presently PdSbTe, must be revised to PdTe(Sb, Te). Borovskite($pd_3SbTe_4$) has not been found in the synthetic system in the temperature range $1000^{\circ}-600^{\circ}C$.

• Membrane Journal
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• v.25 no.2
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• pp.191-201
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• 2015

We have studied on the preparation of $TiCo_xFe_{1-x}$(x=0.50~1.00) system alloy, the characteristics of $TiCo_xFe_{1-x}$(x=0.50~1.00) system alloy by X-ray diffractometer (XRD), pressure composition temperature (PCT) curve, scanning electron microscopy (SEM) and the $H_2-N_2$ gas mixture separation of $TiCo_xFe_{1-x}$(x=0.50~1.00)- stainless steel (SS) composite membranes. The formation of $TiCo_xFe_{1-x}$(x=0.50~1.00) system alloys with cubic crystal same as TiCo was confirmed by X-ray diffractometer. $TiCo_xFe_{1-x}$(x=0.50~1.00) system alloys showed the hysteresis at $120^{\circ}C$. As the Fe content of $TiCo_xFe_{1-x}$(x=0.50~1.00) system alloys increased, the hysteresis was increased both range x=0.90~1.00 and x=0.55~0.60, and the range x=0.55~0.90 gave decreased hysteresis. $TiCo_{0.55}Fe_{0.45}$ alloy was the one showed the lowest hysteresis among them. The lowest value of hydrogen permeation pressure of $TiCo_xFe_{1-x}$(x=0.50~1.00)-SS composite membrane was $TiCo_{0.55}Fe_{0.45}$-SS composite membrane with the value of 2.5 atm at $120^{\circ}C$; otherwise, $TiCo_{0.90}Fe_{0.10}$-SS composite had the highest pressure value among the membranes with the value of 10 atm. $TiCo_{0.55}Fe_{0.45}$-SS composite membrane was the best to separate the $H_2-N_2$ gas mixture excellently among the $TiCo_xFe_{1-x}$(x=0.50~1.00)-SS composite membranes since $TiCo_{0.55}Fe_{0.45}$ had the least hysteresis, and hydrogen permeation pressure was the lowest with value of 2.5 atm.

• Journal of the Korean Electrochemical Society
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• v.11 no.2
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• pp.109-114
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• 2008

Though ethanol can theoretically generate 12 electrons during oxidation to carbon dioxide, the complete oxidation of ethanol is hard to achieve due to the strong bond between the two carbons in its molecular structure. Therefore, development of high activity catalyst for ethanol oxidation is necessary for the commercialization of direct ethanol fuel cell. In this study, some binary and ternary electrocatalysts of PtSn/C and PtSnAu/C have been synthesized and characterized. The catalysts were fabricated with modified polyol method with the amounts of 20 wt%, where the Pt : Sn ratios in the PtSn/C were 1 : 0, 4 : 1, 3 : 1, 2 : 1, 1.5 : 1, 1 : 1, 1 : 1.5 and Pt:Sn:Au ratios in the PtSnAu/C were 5 : 5 : 0, 5 : 4 : 1, 5 : 3 : 2, 5 : 2 : 3. From the XRD and TEM analysis results, the catalysts were found to have face centered cubic structure with particle size of around $1.9{\sim}2.4\;nm$. The activity in the ethanol oxidation was examined with cyclic voltammetry and the results indicated that PtSn(1.5 : 1)/C and PtSnAu(5 : 2 : 3)/C had the highest activity in each catalyst system. Further tests with single cell were performed with those catalysts. It was found that PtSn/C(1.5 : 1) exhibited the best performance while the long term stability of PtSnAu/C(5 : 2 : 3) is better than PtSn/C(1.5 : 1).

• The Journal of Engineering Geology
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• v.23 no.4
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• pp.447-455
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• 2013

A micro-mechanical pipe network model with the shape of a cube was developed to simulate the behavior of fluid flow through a porous medium. The fluid-flow mechanism through the cubic pipe network channels was defined mainly by introducing a well-known percolation theory (Stauffer and Aharony, 1994). A non-uniform flow generally appeared because all of the pipe diameters were allocated individually in a stochastic manner based on a given pore-size distribution curve and porosity. Fluid was supplied to one surface of the pipe network under a certain driving pressure head and allowed to percolate through the pipe networks. A percolation condition defined by capillary pressure with respect to each pipe diameter was applied first to all of the network pipes. That is, depending on pipe diameter, the fluid may or may not penetrate a specific pipe. Once pore pressures had reached equilibrium and steady-state flow had been attained throughout the network system, Darcy's law was used to compute the resultant permeability. This study investigated the sensitivity of network size to permeability calculations in order to find out the optimum network size which would be used for all the network modelling in this study. Mean pore size and pore size distribution curve obtained from field are used to define each of pipe sizes as being representative of actual oil sites. The calculated and measured permeabilities are in good agreement.

• Journal of the Korean Magnetics Society
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• v.11 no.2
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• pp.58-62
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• 2001

The L $i_{0.5}$F $e_{2.5-x}$A $l_{x}$ $O_4$ systems (x=0, 0.3, 0.6, 0.9, 1.2, 1.5) were investigated by X-ray diffraction and Mossbauer spectroscopy. The structure of all the samples is cubic spinel type and lattice constant decrease with increasing Al content x. The Moissbauer spectra reveal two sextet for 0$\leq$x$\leq$0.6, two sextet and a doublet for 0.9$\leq$x$\leq$1.2, and a doublet for x=1.5. The cation distribution of the samples is (L $i_{1-a}$$^{+}$F $e_{a}$ $^{3+}$)$^{A}$[L $i_{a-0.5}$$^{+}$A $l_{2.5-a-x}$$^{+}$F $e_{2.5-a-x}$$^{3+}$]$^{B}$ $O_4$$^{2-}$ and substituted $Al^{3+}$ ions decrease the covalency of F $e^{3+}$- $O^{2-}$ bond in B-sites and A-B super-exchange interactions.tions.s.tions.ons.s.

• Journal of Korean Society of Rural Planning
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• v.23 no.1
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• pp.85-96
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• 2017

Existing agricultural reservoirs are considered as alternative source for the water welfare of rural area. In this study, domestic water supply potential of 476 reservoirs, which has storage capacity more than one million cubic meter, out of 3,377 agricultural reservoirs managed by Korean Rural Community Corporation (KRC) were investigated. Among them water quality of 136 reservoirs met the criteria of domestic water source which show less than COD 3 ppm. Available amount for domestic water of reservoirs, which meet the water quality, for ten year return period of drought was analyzed with reservoir water balance model. The results showed that 116 reservoirs has potential for supplementary domestic water supply while satisfying irrigation water supply. Finally, economic analysis using Net Present Value (NPV), Benefit-Cost (B/C) ratio, Internal Rate of Return (IRR), and Profitability Index (PI) methods was also conducted. The analysis showed that 19 reservoirs satisfied economic feasibility when water is provided from reservoir outlet but only 9 reservoirs meet the economic feasibility if water delivered from a reservoir to treatment plant by newly built conveyance canal. In order to supply the domestic water through the agricultural reservoirs managed by KRC, it is necessary to flexibly interpret and operate the 'Rearrangement of Agricultural and Fishing village Act'. Also, it is reasonable to participate in the water service business when there is a supply request from other Ministries. In addition, the KRC requires further effort to change the crop system for saving water and improve efficiency of irrigation systems.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.3
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• pp.259-273
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• 1998

The hydroacoustic surveys to provide the essential information for the assessment, management and utilization of fishery resources in the southern waters of Korea were carried out during five research cruises between October 1996 and October 1997 by the training ship KAYA of Pukyong National University. These hydroacoustic investigations were designed to obtain more precise estimates of the geographic distribution, absolute abundance and biological characteristics of the fishery resources, and the vertically integrated densities of fish in terms of volume backscattering strength(SV) by survey region and depth bins, such as the entire water column and the 0~ 10 m from bottom fraction, were measured separately. Hydroacoustic data were collected by using a Simrad EK 500 Scientific echo sounder operating at two frequencies of 38kHz and 120kHz and the data stored in field were later processed on a HP PC using a Simrad EP 500 echo integration and target strength analysis system. The biological compositions of echo signal were identified and sampled using a demersal trawl during daylight hours. The mean target strength to scale the echo integration data for hydroacoustic surveys was derived from the relationship between the SV and the weight of trawl catch per unit volume of the water column sampled by demersal trawls. The results obtained can be summarized as follow : 1. The mean volume backscattering strength for the entire water column in the southern waters of Korea between 1996 and 1997 were -67.2 dB and -70.9 dB at two frequencies of 38 kHz and 120 kHz , respectively, and for the bottom layer of the 0-10 m from bottom friction were -68.8 dB, -70.2 dB, respectively. That is, the volume backscattering strength for the entire water column at low frequency was higher than that at high frequency. 2. The relationship between the mean backscattering strength (〈SV〉, dB) for the depth strata of trawl hauls and the weight (C, kg/m3) per cubic meter of the catch sampled by bottom trawling in the southern waters of Korea in January and July 1997 were expressed by the following equations: 38 kHz : 〈SV〉= -28.2 + 10 log(C), 120 kHz : 〈SV〉= -32.4 + 10 log(C). The mean weight -normalized target strengths derived from these equitions were -28.2 dB/ kg, -32.4 dB/ kg at 38 kHz and 120 kHz , respectively. That is, the mean weight -normalized target strength at 38 kHz was 4.2 dB higher than that at 120 kHz. 3. The distribution density of fish in terms of biomass per unit volume in the southern waters of Korea were estimated to be 125.9 $\times$ 10-6 kg/m3 and 141.3 $\times$ 10-6 kg/m3 at 38 kHz and 120 kHz , respectively.

• The Journal of Engineering Geology
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• v.9 no.3
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• pp.187-206
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• 1999

A computer program to numerically predict the permeability tensor of fractured rocks is developed using information on discontinuities which Borehole Televiewer and Borehole Image Processing System (BIPS) provide. It uses orientation and thickness of a large number of discontinuities as input data, and calculates relative values of the 9 elements consisting of the permeability tensor by the formulation based on the EPM model, which regards a fractured rock as a homogeneous, anisotropic porous medium. In order to assess feasibility of the program on field sites, the numerically calculated tensor was obtained using BIPS logs and compared to the results of pumping test conducted in the boreholes of the study area. The degree of horizontal anisotropy and the direction of maximum horizontal permeability are 2.8 and $N77^{\circ}CE$, respectively, determined from the pumping test data, while 3.0 and $N63^{\circ}CE$ from the numerical analysis by the developed program. Disagreement between two analyses, especially for the principal direction of anisotropy, seems to be caused by problems in analyzing the pumping test data, in applicability of the EPM model and the cubic law, and in simplified relationship between the crack size and aperture. Aside from these problems, consideration of hydraulic parameters characterizing roughness of cracks and infilling materials seems to be required to improve feasibility of the proposed program. Three-dimensional assessment of its feasibility on field sites can be accomplished by conducting a series of cross-hole packer tests consisting of an injecting well and a monitoring well at close distance.

• Bulletin of the Korean Chemical Society
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• v.30 no.8
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• pp.1703-1710
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• 2009

The single-crystal structure of |$Ca_{35.5}$|[$Si_{121}Al_{71}O_{384}$]-FAU, $Ca_{35.5}Si_{121}Al_{71}O_{384}$ per unit cell, a = 24.9020(10) $\AA$, dehydrated at 673 K and 2 ${\times}\;10^{-6}$Torr, has been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd$\overline{3}$m at 294 K. The large single crystals of zeolite Y (Si/Al = 1.70) were synthesized up to diameters of ${\mu}m\;and\;Ca^{2+}$-exchanged zeolite Y were prepared by ion exchange in a batch method of 0.05 M aqueous Ca($NO_3)_2$ for 4 hrs at 294 K. The structure was refined using all intensities to the final error indices (using only the 971 reflections for which $F_o\;>\;4{\sigma}(F_o))\;R_1$ = 0.038 (based on F) and $R_2$ = 0.172 (based on $F^2$). About 35.5 $Ca^{2+}$ ions per unit cell are found at an unusually large number of crystallographically distinct positions, four. Nearly filling site I (at the centers of the double 6-rings), 14.5 octahedrally coordinated $Ca^{2+}$ ions (Ca-O = 2.4194(24) $\AA$ and O-Ca-O = 87.00(8) and 93.00($8^o$) are found per unit cell. One $Ca^{2+}$ ion per unit cell is located at site II’ in the sodalite cavity and extends 0.50 $\AA$ into the sodalite cavity from its 3-oxygen plane (Ca-O = 2.324(13) $\AA$ and O-Ca-O = 115.5(10)o). The remaining twenty $Ca^{2+}$ ions are found at two nonequivalent sites II (in the supercages) with occupancies of 10 and 10 ions, respectively. Each of these $Ca^{2+}$ ions coordinates to three framework oxygens, either at 2.283(3) or 2.333(5) $\AA$, respectively, and extends either 0.24 or 0.54 $\AA$, respectively, into the supercage from the three oxygens to which it is bound. In this crystal, site I is the most populated; sites II’ and II are only sparsely occupied.$Ca^{2+}$+ appears to fit the octahedral site I best. No cations are found at sites III or III’, which are clearly less favorable for $Ca^{2+}$ ions in dehydrated zeolite Y.