• Journal of the Mineralogical Society of Korea
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• v.11 no.1
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• pp.1-12
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• 1998

In Pohang area, basaluminite accompanying a little amounts of hydrobasalumnite, super-genetically occurs as whitish cryptocrystalline (2-4 $\mu\textrm{m}$) clay-like aggregates in the vicinity of altered carbonate concretions embedded within mudstones of the Tertiary Yeonil Group. A hydrobasaluminite changed readily into a basaluminite at room temperature in air, and, in turn, into a metabasaluminite when heating to 150$^{\circ}$~30$0^{\circ}C$. For the basaluminite, a monoclinic unit-cellparameters (a=14.845$\AA$, b=10.006$\AA$, c=11.082$\AA$, $\beta$=122.15$^{\circ}$) were calculated by X-ray powder diffraction data. Its basal reflections (001 and 002) are XRD analyses strongly indicate that the aluminum sulphate mineral has a layer structure and, at least, three types of water, i.e., (1) interlayer water (9.0 wt %), (2) crystal water (8.0 wt %), and (3) structural water (19.0 wt %). may present in its lattice. Based on TG-DTG data combined with EDS and IR analyses, a new chemical formula of Al5SO4(OH)134H2O was given to the basaluminite. Field occurrence and stable isotope data ($\delta$18O, $\delta$D, $\delta$34S) for the basaluminite seem to reflect that it was formed by the leached meteoric solution from surrounding mudstones during or after uplifting. An interaction of the acid solution with carbonate concretion and the resultant local neutralization of the fluid rich in Al3+ and SO42- are major controls on the basaluminite formation.

• Economic and Environmental Geology
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• v.25 no.3
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• pp.275-282
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• 1992

Mineral chemistry and stable isotope compositions of sericites from the Sangdong mine in the Kimhae area, Kyungsangnamdo, were studied. The Sangdong sericite deposit occurs in rhyolitic tuff of late Cretaceous age and considers to have been fonned by the hydrothennal alteration. The sericites are classified as $2M_1$ polytype and are characterized by less celadonite substitution indicating muscovite-phengite series. Their compositions are very close to that of the ideal muscovite but net layer charge ranges 1.71~1.91 which is less than 2 per formula unit of ideal muscovite. Predominant interlayer cation is K and K/(K+Na) ratio ranges 0.91 and 0.93. ${\delta}^{18}O$ values of sericites and quartz separated from the ore range 7.70~9.07 and 8.20~10.87‰, respectively. The formation temperature of sericite can be estimated as $315{\sim}340^{\circ}C$( based on ${\delta}^{18}O$ value of sericite and ${\delta}D$ value of of Cretaceous meteoric water. Their formation temperature discrepancy between coexisting sericite and quartz indicates that they are in isotopically inequilibrium. Two types of quartz, coarse grained phenocrysts and micrcrystalline aggregates are observed and the former must have been formed during volcanic eruption and remained isotopically unexchanged during hydrothermal alteration period. ${\delta}^{14}S$ values of pyrites range 1.9~4.5‰ which is within a range of volcanogenic sulfur, indicating magmatic source.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.4
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• pp.255-261
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• 2007

Soil aggregates, resulting from physico-chemical and biological interactions, are important to understand carbon dynamics and material transport in soils. The objective of this study is to investigate stable macro-aggregate (> 0.25mm diameter) in wet sieving (SM) and their relation to soil properties in 15 sites. The clay contents of soils were ranged from 1% to 33%, and their land uses included bare and cultivated lands of annual upland crops, orchard, and grass. Undisturbed 3 inch cores with five replicates were sampled at topsoil (i.e., 0- to 10-cm depth), for analyzing SM and physico-chemical properties, after in situ measurement of air permeability. SM of sandy soils, with clay content less than 2%, was observed as 0%. Except the sandy soils, SM of soils mainly depended on land uses, showing 27%~35% in soils with annual plants such as vegetable and corn, 51% in orchard, and 75% in grass. This sequence of SM is probably due to the different strength of soil disturbance like tillage with different land uses. SM had significant correlation with cation exchange capacity, organic matter content, sand, clay, silt, bulk density, and exchangeable potassium (K) and magnesium (Mg), whereas fluctuating properties with fertilization such as pH, EC, and water soluble phosphorus weren't significantly correlated to the SM. Particularly, exchangeable calcium (Ca) had significant relation with SM, only except soils with oversaturating Ca. This study, therefore, suggested that SM could perceive different land uses and the change of soil properties in soils, necessarily considering soil textures and Ca over-saturation.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.4
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• pp.345-352
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• 2017

Heavy weight concrete can be used in marine concrete structure to improve resistance against high wave energy. However, heavy weight aggregate, which is an indispensable material for heavy weight concrete, is difficult to be supplied in large quantities because its use is limited due to its high cost. In this work, the applicability of heavy weight by-products, copper and 3 month aged steelmaking slags, were evaluated as sources of heavy weight aggregate for marine concrete structures. Experimental results showed that copper slag was found to be a stable material for marine concrete structure. However, 3 month aged steelmaking slag showed significant expansion by $80^{\circ}$ water immersion test and ASTM C 1260 test. In addition, depth of chloride ion penetration in concrete was higher at which steelmaking slags were located. It was associated with porosity of steelmaking slag, and for this reason, steelmaking slag was not found to be suitable for marine concrete structure.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.480-488
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• 2016

Soil microbes are widely well known to play an important role for sustainable agriculture in terms of crop healthy cultivation and environmental conservation. In this context, the distributional characteristics of soil microbes according to cropping systems were investigated under rice (R)-rice (R), rice (R)-barley (B)-rice (R), and soybean (S)-barley (B)-soybean (S) cropping condition to get basic informations for sustainable agriculture, where barley was grown for winter, in mid-mountainous loam paddy located at the altitude of 285 m above sea level in Sangju area from 2014 to 2015. Estimating from microbial communities by fatty acid methyl ester (FAME) method, a total biomass of bacteria, actinomycetes, and fungi in R-B-R plot was 37% and 40% higher than that in S-B-S and R-R plots, respectively (p < 0.05). In especial, bacteria and fungi were more in R-B-R plot than those in any other ones. B. japonicum, AMF, and mesophilic Bacillus sp. were also greater in S-B-S plot than those. In the community distribution, however, bacteria and actinomycetes showed comparatively high values in S-B-S plot relative to either R-R or R-B-R plot including rice, in which fungi outstanding. In the correlation between microbial biomass and soil properties changed by the cropping, bacteria was positively correlated with C:N ratio; actinomycetes with exchangeable Ca; fungi with available $P_2O_5$ (p < 0.05). While these microbes showed negative response to water stable aggregates of soil.

• Ocean Science Journal
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• v.40 no.3
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• pp.167-176
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• 2005

A time-series sediment trap was deployed at 1,034 m water depth in the eastern Bransfield Strait for a complete year from December 25, 1998 to December 24, 1999. About 99% of total mass flux was trapped during an austral summer, showing distinct seasonal variation. Biogenic particles (biogenic opal, particulate organic carbon, and calcium carbonate) account for about two thirds of annual total mass flux $(49.2\;g\;m^{-2})$, among which biogenic opal flux is the most dominant (42% of the total flux). A positive relationship (except January) between biogenic opal and total organic carbon fluxes suggests that these two variables were coupled, due to the surface-water production (mainly diatoms). The relatively low $\delta^{13}C$ values of settling particles result from effects on C-fixation processes at low temperature and the high $CO_2$ availability to phytoplankton. The correspondingly low $\delta^{l5}N$ values are due to intense and steady input of nitrates into surface waters, reflecting an unlikely nitrate isotope fractionation by degree of surface-water production. The $\delta^{l5}N$ and $\delta^{l3}C$ values of sinking particles increased from the beginning to the end of a presumed phytoplankton bloom, except for anomalous $\delta^{l5}N$ values. Krill and the zooplankton fecal pellets, the most important carriers of sinking particles, may have contributed gradually to the increasing $\delta^{l3}C$ values towards the unproductive period through the biomodification of the $\delta^{l3}C$ values in the food web, respiring preferentially and selectively $^{12}C$ atoms. Correspondingly, the increasing $\delta^{l5}N$ values in the intermediate-water trap are likely associated with a switch in source from diatom aggregates to some remains of zooplankton, because organic matter dominated by diatom may be more liable and prone to remineralization, leading to greater isotopic alteration. In particular, the tendency for abnormally high $\delta^{l5}N$ values in February seems to be enigmatic. A specific species dominancy during the production may be suggested as a possible and speculative reason.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.119-123
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• 2010

This experiment was conducted at Sinheung series (fine loamy, mixed, nonacid, mesic family of Fluvaquentic Endoaquepts) in 2007 to 2008 at the National Institute of Crop Science (NICS), RDA, Suwon, Gyeonggi province, Korea. Three kinds of green manure crops (hairy vetch, barley, rye) incorporated in soil for rice cultivation. 6.3 kg N $10a^{-1}$, and3.2 kg $P_2O_5$ $10a^{-1}$ were applied to rye and barley plot before rice transplanting. Chemical fertilizers had not been applied to hairy vetch plot. Glomalin concentration, soil bulk density, and porosity were measured in soil from different green manure crops incorporation after rice harvesting in paddy. Soil bulk density and porosity after rice harvesting improved at surface soil of hairy vetch incorporation plot. Degree of water stable aggregates increased all green manure incorporation plots. Glomalin concentrations significantly increased at hairy vetch incorporation treatment. In barley plot, the concentration of glomalin increased at 10-20 soil depth. There were no differences relationship between soil carbon, and glomalin concentration, but relationship between soil aggregate stability, and glomalin concentration significantly positive under green manure crop-rice cropping system. Rice yield decreased at hairy vetch incorporation plot because of field lodging. We suggested that hairy vetch incorporation should be considered about application amount, and water management using rice cultivation because of soil properties changes.

• The Journal of Engineering Geology
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• v.17 no.2 s.52
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• pp.187-196
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• 2007

The Dalseong acid mine drainage were studied focused on the characters of schwertmannite that controls geochemistry of the stream. Besides chemical analysis of stream water, particle size analysis, XRD SEM and TEM were performed on precipitates of streams and on wasted metalliferous ores. The AMD discharged from the abandoned mine reveals a decrease of pH and EC downward stream. Euhedral sulfur occurs as equigranular aggregates on the altered pyrite while fine acicula goethite coalesces to form cross, star, or starfish-like shapes. Water chemistry plotted on the Eh-pH diagram shows that schwertmannite and ferrihydrite are stable phases. Reddish brown precipitates consist of mostly schwertmannite with less goethite, whereas yellowish brown precipitates are composed of geothite with less schwertmannite. The particle size of precipitates ranges $d(0.1)\;0.861{\mu}m{\sim}3.769{\mu}m,\;d(0.5)\;3.984{\mu}m{\sim}15.255{\mu}m,\;and\;d(0.9)\;9.875{\mu}m{\sim}56.726{\mu}m$. Schwertmannite is characterized by equigranular spheric form. Pincushion or spicule with 100nm width and $200{\sim}300nm$length form on schwertmannite sphere with radial growth patterns. It is highly probable that reddish or yellowish brown precipitates formed in many AMDs may contain schwerhnannite. Because it can serve as sink for removing heavy elements by adsorption in AMD system, there is a need to correctly identify schwertmannite in precipitates and to characterize its phase stability.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.2
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• pp.90-95
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• 1984

To improve the physico-mechanical characteristics of heavy clayey paddy soils(Hwadong series) on Diluvial terrace after application of fine sand and briquette ashes, barley and rice were cultivated for 2 years. The influences of sand and briquette ashes on soil properties and on the crops were summarized as follows: 1. Application of the adding materials could not affect the yield of rice but barley yields were increased significantly about 18-19% in the plots of sand 100t/10a(clay 15% adjusted) and in the plots of briquette ashes. 2. The porosity and the content of water stable aggregates were decreased in the plots of sand and briquette ash adding. The chemical properties were slightly decreased in the plots of sands while the contents of av. $SiO_2$: and extr K were increased in the plots of briquette ashes. 3. Soil mechanical properties such as cone penetration resistance, shearing resistance and plastic index etc. were decreased while the friction resistance increased in the plots of sand and briquette ash treatments. Consequently, the adaptability to mechanization was increased. 4. The content of rice roots in subsoils (10-20cm) were increased in the plots of sand and briquette ash treatments.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.4
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• pp.296-300
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• 1989

This study was carried out to evaluate the effects of clay loam soil, zeolite, and high molecular organic compounds on the improvement of soil physico-chemical properties and soybean yield in a sandy loam soil. Soybean was cultivated from 1987 to 1988. CEC, moisture retention of soil were increased, but soil bulk density and hardness were decreased by soil conditioners. Clay loam soil addition enhanced the soybean yield by 5% at 10ton 10a plot, 7% at 20ton/10a plot. Also zeolite application increased the soybean yield by 6~10%. Effects of soil conditioner application of the 1rst year were greater than that of 2nd year. Some experiments were conducted in laboratory for the effect of soil conditioners on soil physical properties. The nutrient and water holding capacity were highest by K-SAM treatment, but the soil aggregates was most stable by AN-905SH and Primal treatments.