• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.1
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• pp.28-37
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• 2022

The burning rate estimation method of solid propellants, based on closed bomb tests, has been introduced. The composition of the combustion gas is determined by using CEA and the Noble-Abel equation of state for high pressure operation conditions. Covolume taking into account the collision among molecules due to the actual volume of the molecule is modeled by LJ potential. A cubic form function is applied to calculate the volume change of propellant grains during combustion. The estimated burning rates of five different grain configuation at high pressure are fairly compared with BRLCB results within the maximum error of 6%.

• Journal of Korean Biological Nursing Science
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• v.24 no.3
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• pp.171-180
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• 2022

Purpose: The purpose of this study was to investigate the nutritional intake status, according to the risk of diabetic complications in Type 2 diabetes patients. Methods: This was a secondary data analysis study that included 83 patients. The nutritional intake was assessed, using 24-hour dietary recall. The risk of diabetic complications was measured, using the Framingham Risk Score (FRS) and Michigan Neuropathy Screening Instrument Questionnaire (MNSIQ). The nutritional intake was analyzed using the CAN-pro 4.0 program. Data were analyzed using descriptive statistics, Chi-square test, and Independent t-test, using the SPSS WIN 26.0 program. Results: The mean FRS and MNSIQ scores for the participants was 14.46± 4.09 and 2.30± 2.22, respectively. Thirty two participants (38.6%) were in the high-risk groups for cardiovascular disease and peripheral neuropathy. The participants consumed high amounts of grain and low amounts of vegetables, fruits, and dairy products when compared to the recommended intake. However, the nutritional intake did not differ according to FRS or MNSIQ levels. Consumption of vegetables and fruits were significantly different between high and low risk groups of MNSIQ. Conclusion: It is necessary to consider the composition of dietary intake to improve the imbalanced diet in Type 2 diabetes patients and prevent diabetic complications. Type 2 diabetes patients should reduce the intake of grains and sodium, and increase vegetable intake. More deliberate future studies are needed, to investigate the relationship between food intake and the risk status for diabetic complication.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.1-7
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• 2002

This study deals with physical properties of Larch(Larix kaemferi Carr.) treated by steaming at temperatures above 100℃. Treatment conditions of this experiment were operated at regular intervals of 10℃ at temperature up to 130℃ for 10, 30 and 60 minutes by using the auto-clave. The Bending strength and compressive strength along the grain were slightly decreased with increasing the treating temperatures. There was no significant relations between wood strength and steaming temperatures. At the range from 120℃ to 130℃ of steaming temperature, it was considered that the change of composition and structure in cell wall was changed due to release of stresses. Water absorption characteristics were not affected by steaming temperature. In this experiment limits, it was concluded that physical properties of wood by steaming treatment were affected more largely by wood density than by treating temperature.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.s01
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• pp.39-47
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• 1988

Soybean grain is most widely used and soybean crop produces most high protein per area among crops. To meet rapid increase of human population and supply protein in safety. soybean has considered more and more important crop. And it has been emphasizing that high quality and high protein soybean breeding must be made efforts in future. Many papers related to soybean breeding for high quality and protein and soybean protein composition have suggested the problems to do in future. Soybean germplasm collection. classification and conservation should be continuously performed, and it is emphasized that wild type of soybeans (G. soja) be considered to use in breeding for high protein varieties. Selections would be better emphasized in first yield and therefore high yield of protein per area. Selection for high protein would be secondary criterion. High protein lines with high yielding potential could be selection from certain populations, and breeders should consider this phenomenon in procedure of selection. Heritability of protein percent is relatively high and genetic gain of increment of protein percent is large. Soybean protein which is comprised 70 to 90% of globulin is constituted mostly 11S and 7S proteins. Sulfur-containing amino acids, methionine and cysteine, are identified to contain more in 11S protein than 7S protein. High 11S germplasm should be desirable to use in crossing plan, and selection of high ratio of 11S/7S lines be better in development of high quality varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.5
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• pp.403-412
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• 1990

Soybean grain, the main source of protein and lipid, has been used for various purposes in our food resources. Therefore, to abtain and supply protein in safety, soybean must be considered as more and more important and it must be made many efforts in breeding for good quality and high protein. Contents of seed protein of the recommeded soybean cultivars in Korea were above 40 persents. Soybean seed protein was divided four fractions by solubility differences. Contents of fraction-albumines, globulines, prolamines and glutelines- were 7.59%, 71.43%, 1.32%, and 9.11% to total protein in Jangyeobkong. The major components of amino acids were glutamic acid, aspartic acid and arginine in order, cystein, methionine, and tyrosine were the minor components in soybean seed protein. Soybean seed protein is constituted mostly of 11s and 7s proteins. Contents of methionine and cystein, sulfur containing amino acid, in 11s protein has already identified higher than 7s protein's The yields of soybean curd were positively correlated with the soluble protein contents of the soybean varieties.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2001.11a
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• pp.37-37
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• 2001

TiN coatings were applied for VarIOUS application fields, because of a good wear-resistance and a high hardness. Typically, TiN thin films show the hardness of 25GPa and friction coefficient of 0.6. However, in many field, one is looking for a more improved tool which has low friction coefficient and high wear resistance. The main motivation of this study is to characterize the influence of copper dopant content on TiN thin films. Ti-Cu-N thin films were deposited onto D2 steel substrates by PVD processing with various magnetron current densities (Cu contents). In this work, we synthesized titanium nitride films similar with reported typical titanium nitride films and synthesized Ti-Cu-N thin films with the addition of elemental copper which is measured improved hardness more than pure TiN films with copper content variables. This films has preferred oriented films of (111) direction. In addition, It was found that there is a strong correlation between content of various metal and film characteristics such as preferred orientation, grain size, hardness and friction coefficient and so, in future study, improved mechanical properties of TiN films can be controlled by change in target current density. The Ti-Cu-N film will show apparent hardness improvement and mechanical properties enhancement, when doping element is added onto TiN thin films. Film structure, chemical composition, mechanical properties were investigated by means of X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy(EDS), wear resistance tester and nanohardness tester.

• Journal of the Korean Society for Heat Treatment
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• v.36 no.3
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• pp.153-160
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• 2023

The use of biogas is an industrially necessary means to achieve resource circulation. However, since biogas obtained from waste frequently causes corrosion in pipes, it is important to elucidate corrosion mechanisms of the pipes used for biogas transportation. Recently, corrosion failure occurred in a pipe which supplied for the biogas at the speed of 12.5 m/s. Pinholes and pits were found in a straight line along the seamline of the pipe. By using corrosion-damaged samples, residual thickness, microstructure, and composition of oxide film and inclusion were examined to analyze the cause of the failure. It was revealed that the thickness reduction of biogas pipe was ~0.11 mm per year. A thin sulfuric acid film was formed on the surface of the interior of a pipe due to moisture and hydrogen sulfide contained in a biogas. Near the seamline, microstructure was heterogeneous and manganese sulfide (MnS) was found. Pits were generated by micro-galvanic corrosion between the manganese sulfide and the matrix in the interior of the pipe along the seamline. In addition, microcracks formed along the grain boundaries beneath the pits revealed that hydrogen-induced cracking (HIC) also contributed to accelerating the pitting corrosion.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.1
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• pp.57.2-57.2
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• 2021

Variability in Young Stellar Objects (YSOs) can be caused by time-dependent accretion rates, geometric changes in the circumstellar disks, the stochastic hydromagnetic interactions between stellar surfaces and inner disk edges, reconnections within the stellar magnetosphere, and hot/cold spots on stellar surfaces. We uncover ~1400 variables from a sample of ~5300 YSOs in nearby low-mass star-forming regions using mid-IR light curves obtained from the 5.5-years NEOWISE All Sky Survey. The mid-IR variability traces a wide range of dynamical, physical, and geometrical phenomenon. We classify six types of YSO variability based on their light curves: secular variability (Linear, Curved, Periodic) and stochastic variability (Burst, Drop, Irregular). YSOs in earlier evolutionary stages have higher fractions of variables at all types and higher amplitudes for the variability. Along with brightness variability, we also find a diverse range of secular color variations, which can be attributed to a competitive interplay between the variable accretion luminosity of the central source and the variable extinction by material associated with the accretion process. We compare the variability of known FUors/EXors and VeLLOs/LLSs, which represent two extreme ends (burst versus quiescent) of the episodic accretion process; FUors/EXors have a higher fraction of variables (65%) than VeLLOs/LLSs (41%). Short-term (few day) and long-term (decades) variability, as well as possible AGB contamination in the YSO catalogues, are also discussed.molecules become more complex by surface chemistry induced directly by high energy photons or by the thermal energy diffused over heated grain surface. Therefore, the ice composition is an

• The Korean Journal of Food And Nutrition
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• v.36 no.5
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• pp.395-402
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• 2023

As the consumption of corn increases, the production of by-products is also increasing. In this study, functional substances and antioxidant activities of corn by-products were investigated to determine their applicability as functional materials. Total polyphenol, flavonoid contents, and ABTS antioxidant activity were the highest in leaves. The total phenolic acid content was the highest in cobs; p-coumaric and ferulic acid were the main components. Phytosterol content in leaves and stems was high at 64 and 50 days after sowing, 261.4 and 274.7 mg/100 g, respectively. β-sitosterol of the leaves and stems was the highest, 149.2 and 138.7 mg/100 g. The total phytosterol content of grains and by-products harvested 106 days after sowing was in the order of: corn silk, husk, grain, leaf, stem, and cob. Among the phytosterols, β-sitosterol was the highest, followed by stigmasterol and campesterol, and the composition was different depending on part. The total phytosterol content was the highest in husk and corn silk, but the stems and leaves, which account for 50% of the total corn biomass, also contained high phytosterol content. Therefore, corn leaves and stems are expected to be used as functional raw materials for the development of functional materials in the future.

• The Journal of the Petrological Society of Korea
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• v.25 no.4
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• pp.373-388
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• 2016

To understand human activity in the past, the information about past environmental change including geomorphological and climatic conditions is essential and this can be traced by using age dating and geochemical analysis of sediments from the prehistoric sites. The sedimentary sequence of Seokgwan-dong Paleolithic Site located in Seoul was 5m long unconsolidated sediments and consists of lower part bedrock weathering sediments, slope deposits and upper-part fluvial deposits. In this study, upper part sediments were used to reconstruct past environmental change through age dating and various physical and chemical analyses including grain size, magnetic susceptibility and mineral and elements. The fluvial sediments can be divided into 4 units including three organic layers. Grain size analysis results showed that the sediments were very poorly sorted with fining upward features. Magnetic susceptibility was relatively high in the organic layers, indicating environmental changes causing mineral composition change at that times. The mineral and major element composition are similar to Jurassic biotite granite which mainly consists of quartz, K-feldspar, biotite and muscovite. The radiocarbon age of $14,240{\pm}80yr$ BP was obtained from the lower most organic layer of Unit III(O), suggesting that the fluvial sediments formed at least from the early stage of deglacial period after the end of Last Glacial Maximum. Subsequent wet and warm climates and resultant fluvial process including slope sedimentation during the Holocene may have been responsible for the sedimentary sequence in Seokgwan-dong paleolithic site and surrounding area. The observed organic layers suggests frequent wetland occurrence combined with natural levee changes in this area.