• Journal of Surface Science and Engineering
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• v.56 no.5
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• pp.335-340
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• 2023

Quinary component of 3㎛ thick Ti-Al-Si-Cu-N films were deposited onto WC-Co and Si wafer substrates by using an arc ion plating(AIP) system. In this study, the influence of copper(Cu) contents on the mechanical properties and microstructure of the films were investigated. The hardness of the films with 3.1 at.% Cu addition exhibited the hardness value of above 42 GPa due to the microstructural change as well as the solid-solution hardening. The instrumental analyses revealed that the deposited film with Cu content of 3.1 at.% was a nano-composites with nano-sized crystallites (5-7 nm in dia.) and a thin layer of amorphous Si₃N₄ phase.

• Journal of Soil and Groundwater Environment
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• v.28 no.5
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• pp.68-77
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• 2023

The effect of soil damage on the physicochemical characteristics and activity of the soil microbial community is not well known. This study investigates this relationship by analyzing 11 soil samples collected from various points of soil damage across Gyeonggi-do. Soil damage resulted from forest fires, landslides, and development areas, with their impacts most severe on the topsoil layer (0-30 cm). Dehydrogenase and β-glucosidase activities were notably higher at locations damaged by forest fires compared to other sites. While enzyme activities in soils influenced by landslides and development areas were relatively low, sites with a pollution history exhibited elevated dehydrogenase activity, likely due to past microbial response to the pollution. Additionally, an assessment of carbon substrate usability by soil microorganisms indicated higher substrate availability in areas impacted by forest fires, contrasting with lower availability in landslide and development sites. Statistical analysis revealed a positive correlation between organic content of sand and clay and microbial activity. These findings provide valuable insights into soil damage and associated restoration research, as well as management strategies.

• Food Science of Animal Resources
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• v.44 no.1
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• pp.119-131
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• 2024

BIOVITA 3 bacterial species (BIOVITA 3), a probiotic blend powder containing Clostridium butyricum IDCC 1301, Weizmannia coagulans IDCC 1201, and Bacillus subtilis IDCC 1101, has been used as a food ingredient for gut health. However, its efficacy in improving constipation has not been reported. Therefore, we aimed to investigate the functional effects of oral administration of BIOVITA 3 as well as its component strains alone (at 1.0×10⁹ CFU/day) in Sprague-Dawley (SD) rats with loperamide-induced constipation. The study included fecal analysis, gastrointestinal transit ratio, histopathological analysis, short chain fatty acids (SCFAs), and metagenome analysis. As results, the BIOVITA 3 group showed significant improvements in fecal number, water content, gastrointestinal transit ratio, and thickening of the mucosal layer. In the SCFAs analysis, all probiotic-treated groups showed an increase in total SCFAs compared to the loperamide-constipated group. Changes in microbial abundance and the diversity index of three groups (normal, constipated, and BIOVITA 3) were also defined. Of these, the BIOVITA 3 showed a significant improvement in loperamide-constipated SD-rats. This study suggests the possibility that BIOVITA 3 can be applied as an ingredient in functional foods to relieve constipation.

• Corrosion Science and Technology
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• v.23 no.4
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• pp.302-309
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• 2024

The purpose of this study was to elucidate effects of a thin (tens to hundreds of nanometers) Ni-flash coating layer on hydrogen embrittlement (HE) and liquid metal embrittlement (LME) in ultra-high-strength electrogalvanized steel with a tensile strength of more than 1 GPa. Various experimental and analytical methods, including thermal desorption spectroscopy, slow strain rate testing, resistance spot welding, X-ray diffraction, and metallographic observation, were employed. Results showed that an increase in Ni target amount for flash coating resulted in a decrease in diffusible hydrogen content during electrogalvanizing, resulting in a significant decrease in HE sensitivity. Moreover, a Ni target amount of more than 1000 mg/m² drastically reduced the occurring frequency and average depth of LME. This reduction could be primarily attributed to formation of Zn-Ni intermetallic phases during the welding process that could inhibit liquefaction of intermetallic phases in the heat-affected zone. This study provides a desirable Ni target amount for Ni-flash coating on ultra-high-strength steels conducted in a continuous galvanizing line or a high-speed batch line to achieve high resistance to both HE and LME.

• Journal of the Korean GEO-environmental Society
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• v.13 no.12
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• pp.5-16
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• 2012

The second scientific antarctic station of South Korea is under construction at Terra Nova Bay located in eastern Antarctica. Ground condition in the Antarctica is frozen in general, but there are seasonal frozen grounds with active layers sporadically. When the active layer is frozen, frost heaving occurs that might cause the differential movement of frozen ground and the failure of structures. Therefore, it is necessary to determine the frost heaving susceptibility of soils at Terra Nova Bay before starting antarctic station construction. This study presents experimental investigation of the frost heaving susceptibility of soil samples with variation of particle sizes and unfrozen water contents. The soil samples were taken from five different locations at Terra Nova Bay and physical properties, unfrozen water content, and frost heaving tests were performed. For the frost heaving tests, soil specimens were frozen with constant freezing temperatures at the top and with drainage at the bottom in order to stimulate the frost heaving. The frost heaving tests provide volume expansion, volumetric strain, and heaving rate which can be used to analyze the relationship between the frost heaving vs. particle size and the frost heaving vs. unfrozen water content. Experimental results show that the more the fine contents exist in soils, the more frost heaving occurs. In addition, the frost heaving depends on unfrozen water content. Experimental data can be used to evaluate the frost heaving susceptibility of soils at the future construction site in the Antarctica.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.3
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• pp.176-180
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• 2000

The higher sugar and lower starch in super sweet corn may be due to modified endosperm genes sh, bt series, but its seeds have major limiting factors causing low germination and low seedling vigor, This study was conducted to determine what measurable kernel characteristics during the grain tiling period might be more useful as a guide to optimize harvest date for good seed quality in hybrid super sweet corn production. Artificial crossing in super sweet corn hybrid (Chodangok 1) was made on the same day, and ears were harvested from 18 days to 53 days after pollination at weekly intervals. Kernel weight, moisture content, hardness, endosperm rate, seedling height and storage nutrients such as sugars, protein, starch, and germination rate were measured for the kernels at each harvest. Super sweet corn hybrid, Chodangok 1 presented satisfactory germination rate above 70% when harvested on 39 to 46 days after pollination. Its storage nutrients at that time were 23.7-24.2% in starch content 5.5-5.9% in total sugars, 38.9-46.6% in kernel moisture, and 62.7-64.2% in endosperm rate. Germination rate was extremely high when harvested on 39 days after pollination. The black layer of Chodangok 1 could not be used as an indicator for seed harvest. These results suggested that optimum harvest date seems to be 39 days, and kernel moisture and starch content could be used as indications of kernel maturity in deciding when to harvest fer good seed quality in super sweet corn.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.60-68
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• 2007

This study was perform to examine the feasibility of cooking processing using the rice added the 70% ethanol extract of pigmented rice bran layer. Four rice samples, including normal rice, glutinous rice, pigmented-normal rice, and pigmented-glutinous rice were compared the properties of physico-chemical, texture, and sensory evaluation. Pigmented rice varieties had a higher amylose content, but shorter length in glucose chains than non-pigmented rice varieties. The enthalpy for gelatinization was found to increase in pigmented rice, which need more energy for gelatinization of starch in cooking. The hydrolysis rate by glucoamylase in rice added pigmented bran extract was higher than pigmented rice. Rice with pigmented bran extract had higher glutamine content, but lower asparagine content and no difference in fatty acid composition, which affect palatability. Cooked rice added pigmented bran extract was less retrograded than pigmented rice during the storage period. Moreover, cooked rice added pigmented bran extract was more acceptable in sensory evaluation. Based on the results, the use of rice added pigmented bran extract instead of pigmented rice in grain processed food have advantageous effects in palatability of polished rice and phytochemicals of pigmented non-polished rice. This study will help develop new health-promoting rice products.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.139-145
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• 2011

The practice of asphalt pavement recycling has grown rapidly over the decade, one of which is the cold in-place recycling with the foamed asphalt (CIR-foam) or the emulsified asphalt (CIR-emulsion). Particularly, in Iowa, the CIR has been widely used in rehabilitating the rural highways because it significantly increases the service life of the existing pavement. The CIR layer is typically overlaid by the hot mix asphalt (HMA) to protect it from water ingress and traffic load and obtain the required pavement structure and texture. Most public agencies have different curing requirements based on the number of curing days or the maximum moisture contents for the CIR before placing the overlay. The main objective of this study is to develop a moisture loss index that the public agency can use to monitor the moisture content of CIR layers in preparation for a timely placement of the wearing surface. First, the moisture contents were measured in the field using a portable time domain reflectometry (TDR) device. Second, the weather information in terms of rain fall, air temperature, humidity and wind speed was collected from the same location. Finally, a moisture loss index was developed as a function of initial moisture content, air temperature, humidity and wind speed. The developed moisture loss index based on the field measurements would help the public agency to determine an optimum timing of an overlay placement without continually measuring moisture conditions in the field.

• Journal of the Korean Wood Science and Technology
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• v.4 no.1
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• pp.38-47
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• 1976

This study was carried out to exploit and utilize American sycamore (Platanus occidentalis) and poplar grown in Korea as veneer species for plywood manufacture. At this study to save the imported lauan logs and dollars, the effects affecting to the properties of plywood constructed by sycamore, poplar and lauan veneers were studied. Important items dealt with this study were dry and wet shear strength, moisture content, and specific gravities By the results and discussion it may be summarized as followings. 1) Sycamore core lauan plywood (A-II type) was shown best dry shear strength, and the next were all lauan veneer plywood (A-I type), poplar core lauan plywood (B-I type), lauan core sycamore plywood (A-III type) in order. There are no differences between dry shear strength of A-II type and A-I type, A-II type and B-I type plywood. 2) Wet shear strength showed the same order with dry shear strength. A-II type plywood showed best wet shear strength and it showed more difference than other plwoods. A-I type, B-I type and A-III type plywood were all very good without significant difference in wet shear strength. 3) B-I type plywood showed highest moisture content of all type plywood and the next were all sycamore(A-IV type) all poplar plywood (B-III type), A-III type, B-II type, A-II type pllywood in order. Generally high moisture content showed when two or three veneers were same species in the three layer plywood. 4) A-III type plywood showed highest specific gravity of all and the next was A-IV type plywood without a difference to A-I type plywood on the whole. plywoods constructed by lauan and sycamore were shown high specific gravities and the next was lauan, sycamore and poplar, lauan and poplar. It seemed to be that connected wi th the specific gravity of veneer itself in different species. 5) The plywood manufactured by extension of potato flour is not only superior but also profitable in the price aspect than the plywood manufactured by extension of wheat flour.

• Korean Journal of Oriental Medicine
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• v.12 no.3 s.18
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• pp.101-115
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• 2006

The purpose of this study was to introduce the differential standard of the types of Angelicae Pubescentis Radix. We established the classificatory standard according to the external and internal morphology and the physicochemistrical pattern for the four types of Aucklandiae Radix. The results follow: 1. At the external shape, Angelica pubescens f. biserrata has rising lenticel and dark brown surface, Its section is light gray and its xylem is yellow gray. Aralia continentalis has big stem mark in upper portion, its section has no dense tissue with yellow gray. Heracleum hemsleyanum has dark brown surface and little lenticel, its cortical layer is white yellow and xylem is isabella and powdered. 2. At the internal shape, Angelica pubescens f. biserrata has phloem with half of the root and rare vessel. Aralia continentalis has phloem with two-thirds of the root and it has broad cutting and putting vessel that formed 1-2 row. Heracleum hemsleyanum also has phloem with half of the root and wide scattered latex tube and many large vessel. 3. At the TLC pattern, Heracleum hemsleyanum has remarkable dark spot at $R_{f}$ 0.23 on the sulphuric acid color pattern test, but others have faint. 4. At the HPLC pattern, all samples have generally patterns. But Angelica pubescens f. biserrata shows diminutive continentalic acid content and the peak at Rt 20.278min comes out on Heracleum hemsleyanum, but do not come out on Aralia continentalis and Angelica pubescens f. biserrata. Heracleum hemsleyanum has remarkable peak at Rt 20.278min, but shows no peak at Rt 29.023min unlike Aralia continentalis or Angelica pubescens f. biserrata. Also Aralia continentalis and Angelica pubescens f. biserrata show one remarkable peak at Rt 29.023, but Heracleum hemsleyanum do not show. Consequently, Aralia continentalis and Angelica pubescens f. biserrata are comparable whit continentalic acid content and Heracleum hemsleyanum is comparable with the peak at Rt 20.273 and Rt 29.023. So it is thought that content of continentalic acid and the peaks at Rt 20.278 and Rt 29.023 can apply to differentiate a species from other. It is considered the results of this study will be furnished the basis to succeeding studies and it is needed to extensive comparative study for the same genus-degree of relatedness.