• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.4
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• pp.457-463
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• 2024

(Bi_1/2Na_1/2)TiO₃(BNT) piezoelectric ceramics are one of the promising materials that can replace Pb(Zr, Ti)O₃(PZT) piezoelectric ceramics due to the high electromechanical strain properties. However, it is still difficult to use practical applications because the required electric field for inducing electromechanical strain is relatively higher than that of PZT ceramics. To overcome this problem, it has been intensively studied on doping impurity or modifying other ABO₃ for BNT-based piezoelectric ceramics. Therefore, this study investigated the effects of La₂O₃ doping on the phase transition behavior and electromechanical strain properties in BNT-SrTiO₃ (BNT-ST) lead-free piezoelectric ceramics. In the case of the temperature-dependent dielectric properties, it was confirmed that a phase transition from ferroelectrics to relaxors is induced with increasing La₂O₃ content. As a result, the electromechanical strain properties of BNT-ST ceramics were improved. The highest S_max/E_max value corresponding to 300 pm/V was obtained at 2 mol% La₂O₃-dopped BNT-ST ceramics. Accordingly, this study successfully demonstrated that La₂O₃ doping is effective on the inducing phase transition from ferroelectrics to relaxors and the improving electromechanical strain properties of BNT-ST lead-free piezoelectric ceramics.

• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.173-184
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• 2019

BACKGROUND: This study was carried out to investigate pesticide residues from fifty streams in Korea. Water samples were collected at two times. Thee first sampling was performed from april to may, which was the season for start of pesticide application and the second sampling event was from august to september, which was a period for spraying pesticides multiple times. METHODS AND RESULTS: The 136 pesticide residues were analyzed by LC-MS/MS and GC/ECD. As a result, eleven of the pesticide residues were detected at the first sampling. Twenty eight of the pesticide residues were detected at the second sampling. Seven pesticides were frequently detected from more than 10 water samples. Ecological risk assessment (ERA) was carried out by using residual and toxicological data. Four scenarios were applied for the ERA. Scenario 1 and 2 were performed using LC50 values and mean and maximum concentrations. Scenarios 3 and 4 were conducted by NOEC values and mean and maximum concentrations. CONCLUSION: Frequently detected pesticide residues tended to coincide with the period of preventing pathogen and pest at paddy rice. As a result of ERA, five pesticides (butachlor, carbendazim, carbofuran, chlorantranilprole, and oxadiazon) were assessed to be risks at scenario 4. However, only oxadiazon was assessed to be a risk at scenario 3 for the first sampling. Oxadiazon was not assessed to be a risk at the second sampling. It seems to be temporary phenomenon at the first sampling, because usage of herbicides such as oxadiazon increased from April to march for preventing weeds at paddy fields. However, this study suggested that five pesticides which were assessed to be risks need to be monitored continuously for the residues.

• Journal of Life Science
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• v.20 no.3
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• pp.430-436
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• 2010

In this study, the effects of dibenzocyclooctadiene on seed germination were investigated in pepper. Four $C_{18}$ dibenzocyclooctadiene lignans - schisandrin (1143.7 mg), schisandrin C (317.3 mg), gomisin A (261.4 mg) and gomisin N (213.4 mg) - were isolated from hexane extracts of the fruits of Schisandra chinensis. The molecular structures of the four lignans were elucidated based on spectroscopic analyses including 1D NMR experiments, and bi comparing their spectroscopic data with those of previous literatures. Seeds were immersed in $10^{-5}\;M$ schisandrin, $10^{-6}\;M$ schisandrin C and $10^{-7}\;M$ gomisin A and gomisin N for 1 hr and incubated at $25^{\circ}C$ in the dark for germination. Compared to untreated control, treatment with schisandrin C and gomisin A suppressed seed germination at 48 hrs after incubation, whereas treatment with gomisin N increased germination rate at 48 hrs after incubation. The results of the germination activity of the lignans from S. chinensis confirm their potential plant growth role, and the relative natural abundances of these metabolites suggest their potential use as natural plant growth regulators.

• Journal of Applied Biological Chemistry
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• v.62 no.2
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• pp.187-193
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• 2019

The newly bred Picnic apple was extracted using water and ethanol for extracting solvent. Each water and ethanol extract showed relatively high phenolic compound of 3.69 and 5.55 mg/g. Each water and ethanol extract of Picnic apple showed 1,1-diphenyl-2-picrylhydrazyl of 88.10 and 88.07%, 2,2'-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) of 98.79 and 97.25%, antioxidant protection factor of 2.07 and 2.00 PF and thiobarbituric acid reactive substances showed anti-oxidation effect of 9.69 and 19.83% all at $100{\mu}g/mL$ phenolics concentration. Therefore extract of Picnic apple can be considered as anti-oxidant for anti-aging. The anti-inflammatory effect (hyaluronidase inhibition) of extract of Picnic apple were 4.62% with water extract and 4.39% with ethanol extract both at $200{\mu}g/mL$ phenolics concentration. Both water and ethanol extract showed low ${\alpha}$-amylase inhibition effect but each showed 67.37 and 79.16% of ${\alpha}$-glucosidase inhibition effect at $200{\mu}g/mL$ phenolics concentration. In anti-wrinkle effect, water extract showed each 23.70 and 66.29% in elastase inhibition and collagenase inhibition and ethanol extract showed 64.83 and 65.70% each. These result show high potential for functional food and cosmetic source. Picnic apple was identified to have various functions of anti-oxidation, anti-inflammation, anti-wrinkle effect, and anti-diabetic effect. Therefore, Picnic apple is qualified as a source for new functional cosmetics and functional foods.

• Journal of the Korean Society of Costume
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• v.41
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• pp.95-105
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• 1998

SOO-BAL(Hair Style) is a method Which match hair style to face and clothes with using hair covering and protecting the head. Also SOO-BAL includes personal ornaments using to avoid one's hair be disheveled. In a standpoint of beauty and spirit, etiquette SOO-BAL is a very important thing as one being dressed up. Until now, since just a form of hair style have been studied, hair styling process is nothing to be known and studied. Time after time, our unique traditional SOO-BAL is forgotten with clothes and then this th-esis will be classified hair styling form follow-ing a form of hair style in royal palace of the C-hosun dynasty. According to the record of HAE DONG HISTORY, it shows the same of attire between Ko-rean and chinese style in ae of the chosun. The reason in that there were no any certain boundary border and the interaction of culture between two countries was happened spontaneously at ancient time like the GOCHO-SUN age. Until the period of the three states, the korean attire be changed had gone with chinese one s-imilarly. The chinese form gave to influence on the EONJIN MEURI·POON-GI-MYEONG MEURI·JJO-CJIN MEURI·MOOK-EUN GOONG-BAL MEURI·OL-LIN MEURI·SSANGSANG-TU ME-URI be drawn wall painting in the KOKUR-YU. And a gold chignon accesso-ry unearthed in a MOO-RYOUNG royal mausoleum is proof of the korean attrire be changed with chinese. In the shilla dynasty at three years after Cjin-Deuk(A.D. 649) reign. It was recorded that the dynasty let women wear the form of chinese attire. Also in the koryo dyn-asty, a rod-like hairpin (BIN-YEU) and DANG-GI employing EON-JIN MEURI was used. The SOO-BAL based on the Confucianism had lots of regulations which limited to use ornaments with classes of society in the CHOSUN dynasty. Until YOUNG CHO and CHUNG CHO period. EONJIN MEURI be decorated GACHAE was announced by dynasty as ind-ulging in luxury. Women of yangban used a rod-like hairpin and a chignon accessory made by jewerly. And 1-owly women weared a rod-like hairpin made of born and wood to perfom EONJIN MEURI with PUNCHAE. Most unmarried women decorated with DDA-AH-NEULIN MEURI, GUI-MIT MEURI, specially in palace with SAE-ANG MEURI. At palace, one put on a full dress with KEUN MEURI, and a simple dress with ER-YEO MEURI be decorated DDERL-JAM The CHOP-JI MEURI manifested social rank, class. Kids at CHO-SUN age had BA-DUK-PANMEURI and JONG-JONG MEURI. The ornament things are GACHE, DDERL JAM with EON-JIN M-EURI, and all kinds of rod-like hairpin and chignon accessory used in JJOK MEURI. IN DANGGE, JE-BI-BURI DANGGI used by ummarried women. DO-TOO-RAK DANGGI and AP DANGGI on a dress suit, and BE-SSI DANGGI used by 3∼4 years ungrown kids etc. were used. And at palace, kinds of CHUPJI used with JJOK MEURI showed social rank. In CHOSUN age, women want to keep shiny hair washed at TA-NO festival day, a treatment of bald hair used a forked remedy. In CHOSUN age, woman Soo-Bal hair style has DAE-SOO·DDEU-KOO-JI MEURI·CHO-P-GI MEURI·EON-JIN MEURI·SAE-ANG MEURI· and so on. We could find out Soo-Bal was developed very well by these variety hair styles. I attatched all of the hair style pictures step by step, and also explained detail my research foll owing these pictures.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.737-747
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• 1999

To estimate biomass and distribution of the Antarctic krill (Euphausia superba), hydroacoustic survey was conducted on board of R/V Yuzhmorgeologiya, which was chartered by Korea Antarctic Research Program (KARP) group from 18 to 21 December 1998, in the northern part of the South Shetland Islands, Antarctic Ocean, The scientific echo sounder (towing body type) used was EK- 500 (SIMRAD, Norway) with echo integrator (BI-500) at 38 kHz frequency and recorded mean backscattering cross-section coefficient (SA) per 1 $mile^2$ of sea surface. Also, Bongo net sampling was carried out to determine the size of krill and CTD (Conductivity, Temperature and Depth) casting to understand physical structure. Water column was divided into 5 layers (22$\~$65 m, 65$\~$115 m, l15$\~$65 m, 165$\~$215 m and 215$\~$315 m) to know vertical distribution of krill biomass. The standard length of krill collected was between 30 mm and 51 mm, and adult krill had single mode (41 mm). Maximum horizontal length of krill patch was about 35 nautical mile and vertical thickness was about 275 m. High density of krill was appeared in frontal area between Circumpolar Deep Water (>$1^{\circ}C$) and very low temperature water mass (< $-0.5^{\circ}C$) that originate from Weddell Sea. According to the results calculated using target strength equation, krill density was totally higher in continental slope and open water areas than in coastal area. In the study area, krill seems to distribute in depth; density was low at first layer ($\={\rho}=17.0\;g/m^2$) and higher at fourth layer ($\={\rho}=40.19\;g/m^2$). The estimated krill biomass at total survey area and water column was about 2.77 million metric ion ($\={\rho}=151.0\;g/m^2$) and coefficient of valiance ( CV, $\%$) was 19.92. The proportions and biomass of krill biomass at each layer were as follows; layer 1 ($11.3\%$, 0.31 million metric ton, CV=16.24), layer 2 ($13.3\%$, 0.37 million metric ton, CV=34.91), layer 3 ($23.7\%$, 0.66 million metric ton, CV=41.5), layer 4 ($26.6\%$, 0.74 million metric ton, CV=27.84) and layer 5 ($25\%$, 0.69 million metric ton, CV= 26.83).

• Korean journal of applied entomology
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• v.57 no.2
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• pp.97-104
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• 2018

The larva of the white-spotted flower chafer, Protaetia brevitarsis seulensis (Coleoptera: Cetoniidae), is known to have important medicinal properties, such as anti-cancer activity. However, the consumer market for the larvae is depressed because of its high production cost which needs to be reduced. This study was carried out to evaluate two spent mushroom substrates as food source for chafer larvae to improve the productivity and reduce production cost. The larvae were fed with spent substrates of king oyster mushroom (Pleurotus eryngii) (P-SMS) and shiitake mushroom (Lentinula edodes) (L-SMS), with a control of fermented oak sawdust. Effects of the diets on the development of P. brevitarsis seulensis and contents of minor nutrient components in the larvae produced were examined. In the P-SMS diet, the larval rearing period was shorter at 16.2 days, while the rate of larval weight gain and the cocoon weight were higher at 156.3% and 4.1 g, respectively, than that in the L-SMS diet. The pupation rate was 100% and the adult emergence was higher at 93.3% in the P-SMS diet than in the L-SMS diet with no difference to the control diet. In the P-SMS diet, the total nitrogen content during rearing was higher at 10.28% and the minor nutrient component, particularly Fe (145.8 mg/kg), was higher than that in other diets. The oviposition preference of adults showed no significant difference among the diets. Economic analysis showed that P-SMS costs approximately 667,960 Won less per 100 kg of larvae produced, compared to that of the control diet.

• Economic and Environmental Geology
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• v.50 no.6
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• pp.435-443
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• 2017

The Hanae deposit is located within the Cretaceous Gyeongsang Basin. The Cu-bearing hydrothermal quartz vein formed by narrow open-space filling along fracture in the sedimentary rocks as Jindong Formation. The Hanae Cu-bearing hydrothermal deposit shows a paragenetic sequence of pyrrhotite-pyrite $\rightarrow$ pyrite-chalcopyrite-sphalerite(${\pm}$Bi-bearing tellurides) $\rightarrow$ Ag-bearing telluride mineralization $\rightarrow$ secondary mineralization. Fluid inclusion data indicate that the Hanae Cu-bearing hydrothermal mineralization occurred from dominantly aqueous fluids at temperatures of $400^{\circ}C-200^{\circ}C$. Equilibrium thermodynamic interpretation of the mineral paragenesis and assemblages combined with fluid inclusion data indicate that early main Cu-bearing ore mineralization in the vein starts at about $350^{\circ}C$ which corresponds to sulfur fugacity from about $10^{-9.2}$ to $10^{-8.7}bar$ with oxygen fugacity of about $10^{-32.1}$ to $10^{-29.8}bar$. Late main Cu-bearing ore mineralization in the vein occurs at about $250^{\circ}C$ which corresponds to sulfur fugacity from about $10^{-13.5}$ to $10^{-11.7}bar$ with oxygen fugacity of about $10^{-38.4}$ to $10^{-35.2}bar$. The late Ag-bearing telluride mineralization in the Hanae hydrothermal system occurs at about $200^{\circ}C$ which corresponds to minium Tellirium fugacity value of about $10^{-18}bar$ with sulfur fugacity of about $10^{-14.0}$ to $10^{-10.9}bar$.

• Journal of the Korean Wood Science and Technology
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• v.45 no.1
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• pp.43-52
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• 2017

This study was fulfilled to verify the durations of cambial activity and analyze the associations of degree days and precipitation with the initiation of cambial activity and intra-annual wood formation for Pinus koraiensis and Chamaecyparis pisifera planted at Mt. Worak, respectively, by monitoring of their intra-annual cambial activities. And more, the reason was also analyzed why the DBH of Chamaecyparis pisifera known as planted in the same year could be classified as two groups (CPL: ${\phi}30cm$, CPS: ${\phi}15cm$). The intra-annual cambial activity was monitored using mini-cores (${\phi}2mm$) and they were collected in 2-week interval between April and October. However, between April and May and between middle September and October expected as the initiation and cessation of the cambial activity, respectively, it was fulfilled in 1-week interval. The average number of tree rings for PK (30) was less than CPS (37) and CPL (38), whereas the average ring width of PK (4.12 mm) was wider than CPS (1.84 mm) and CPL (3.97 mm). In the comparison of ring widths between CPL and CPS, CPL was 2.13 mm wider than CPS, however, excepting CPS 1 (0.83 mm), the average ring widths of CPS 2 (2.42 mm) and CPS 3 (2.73 mm) in the last 3 years were close to the average of CPL (2.71 mm). The initiation of cambial activity for PK was between 1 and 21 April, which was 1 week earlier than CPL and CPS (excepting CPS 1) and the cessation was between 1 and 22 September. The longest growing season therefore was 157.3 days (${\pm}3.3$) and it was longer than CPL ($145.7{\pm}6.6days$) and CPS ($148.0{\pm}15.1days$). In CP groups there were wide variations for the cessation of cambial activity and also there were the meaningful linear relationship between the growing seasons and the ring widths (r = 0.69, p < 0.064). The cambial activity in PK was initiated when degree days were between 99 and 134 and in CPS (excepting PCS 1) and CPL between 134 and 200. Excepting CPS 3, the false ring was observed in all samples collected on 21 July when drought stress was high due to low precipitation from June to the beginning of July.

• Journal of Life Science
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• v.16 no.2 s.75
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• pp.339-344
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• 2006

The aim of this study was to examine the timing and magnitude of growth spurt in skinfold, body musle and bone related variables aligned on peak height velocity in boys and girls. In the study design, the subjects and the method were used by the cross-sectional investigation. The subjects participated in this study were 7 through 18 years of age belonged to typical primary, junior, senior high school students, and about 250 males and 250 females in each age group. The total subjects were 2,798 males and 2,762 females. All subjects of this study were lived in Pusan metropolitan city, Korea. The growth velocity magnitudes of sum of the four sites sknfold thickness, body musle and bone related variables. Velocity curve chart of physique was the smoothed according to an approximation of splines by the Sigma Plot-2001 graphic program. In this study, age at PHV of girls occurred eariler about 2 years than boys. In sum of four sites skinfold thickness, PV occurred -2 years from PHV in boys, and PV occurred +2 years from PHV in girls, respectively. In humerus breadth, two PV occurred before and after PHV in boys, whereas PV occurred -1 year from PHV in girls, respectively. In femur breadth, PFV and PHV appeared to occure the same time in boys, PV occurred -2 years from PHV in girls, respectively, In arm circumference, PV occurred after PHV in both sexes. In calf circumference, PV occurred +2 years from PHV in boys, PCCV and PHV appeared to occure the same time in girls, respectively. In magnitudes of peak velocity of body height, humerus breadth, femur breadth, arm circumference and calf circumfence, boys obtained higher than girls, on the other hand, girls obtained higher than boys in sum of four sites skinfold variable. we need to longitudinal and scientific investigation by Korean government level in adolescent growth spurt study, because childhood and adolescence achive higher positive physical education effect than the other ages.