• Journal of Sensor Science and Technology
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• v.12 no.3
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• pp.103-111
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• 2003

A chromel-alumel thermoelectric flow sensor using $Si_3N_4/SiO_2/Si_3N_4$ thermal isolation membrane was fabricated. Temperature coefficient of resistance of thin film Pt-heater was about $0.00397/^{\circ}C$, and Seebeck coefficient of chromel-alumel thermocouple was about $36\;{\mu}V/K$. The sensor showed that thermoelectric voltage decreased as thermal conductivity of gas increased, and $N_2$-flow sensitivity increased as heater voltage increased or the distance between heater and thermocouple decreased. When heater voltage was about 2.5 V, $N_2$-flow sensitivity and thermal response time of the sensor were about $1.5\;mV/sccm^{1/2}$ and 0.18 sec., respectively. Linear range in flow sensitivity of the flow sensor was wider than that of Bi-Sb flow sensor.

• Korean Journal of Clinical Laboratory Science
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• v.36 no.2
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• pp.110-114
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• 2004

Apolipoprotein E is the major lipid-carrier protein in the brain, and several studies provided evidence that apolipoprotein E(ApoE) epsilon4 allele can be considered a genetic risk factor for Alzheimer's disease(AD). Inheritance of the APOE gene has three alleles: ${\varepsilon}2$, ${\varepsilon}3$ and ${\varepsilon}4$. There are six possible genotypes: ${\varepsilon}2/{\varepsilon}2$, ${\varepsilon}3/{\varepsilon}3$, ${\varepsilon}4/{\varepsilon}4$, ${\varepsilon}2/{\varepsilon}3$, ${\varepsilon}2/{\varepsilon}4$, ${\varepsilon}3/{\varepsilon}4$. AD is characterized by a progressive loss of function and death of nerve cells in several areas of the brain. The ${\varepsilon}4$ allele is associated with a risk for developing AD. People with the ${\varepsilon}4/{\varepsilon}4$ genotype have the highest risk, but people with the ${\varepsilon}2/{\varepsilon}4$ or ${\varepsilon}3/{\varepsilon}4$ genotypes are also likely to develop the disease. 64.3% of people carry the is ${\varepsilon}3/{\varepsilon}3$ genotype, 22.1% carry the second ${\varepsilon}3/{\varepsilon}4$ genotype but, ${\varepsilon}2/{\varepsilon}2$ genotype is not usually found of people carry the 3.6% is ${\varepsilon}4/{\varepsilon}4$ genotype in a total of a test group of 140 people. The ratio of ${\varepsilon}4/{\varepsilon}4$ genotype related directly with AD is less than the ${\varepsilon}3/{\varepsilon}3$ genotype, but the ${\varepsilon}2/{\varepsilon}4$ and ${\varepsilon}3/{\varepsilon}4$ genotype ratio of indirect AD risk is 25.7% in the group of people, regardless. Thus, we have referred to the benefit from the treatment of AD through apoE genotype diagnosis.

• Korean Journal of Food Science and Technology
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• v.21 no.4
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• pp.468-479
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• 1989

The oxidative stability of the ramyon prepared with rapeseed oil fortified with antioxidants or blended with palm oil was studied to explore the possibility of substituting it for Imported frying fats and oils. Natural tocopherols, butylated hydroxyanisole(BHA), tertiarybutyl hydroquinone(TBHQ), and ascorbyl palmitate with citric acid were used at a level of 0.02 percent. Blended oils were prepared by adding a palm oil to the rapeseed oil at ratios of 7:3, 5:5, and 3:7(w/w), respectively. Ramyon samples were stored at $35.0{\pm}0.5^{\circ}C$. for 90 days. The values of parameters, such as peroxide value, unsaturation ratio, and dielectric constant, of the extracted oils were regularly determined. An organoleptic test for the flavor of the samples was also performed. The oxidative stability of the samples was estimated on the basis of the changes of the parameter values. The effectiveness of the antioxidants was in the order of TBHQ ${\gg}$ ascorbyl palmitate with citric acid>BHA>natural tocopherols. The oxidative stability of the ramyon prepared with the rapeseed oil containing 0.02 percent TBHQ was almost as good as that of the ramyon prepared with the palm oil. The stability of the ramyon prepared with the blended oil containing 70 percent palm oil was also as good as that of the ramyon prepared with the palm oil.

• Applied Chemistry for Engineering
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• v.28 no.5
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• pp.597-600
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• 2017

$(C_{10}H_8N_2H)_2Cr_2O_7$ was synthesized by reacting 4,4'-bipyridine and chromium (VI) trioxide. The structure of the product was characterized with FT-IR (infrared spectroscopy) and elemental analysis. The oxidation of benzyl alcohol using $(C_{10}H_8N_2H)_2Cr_2O_7$ in various solvents showed that the reactivity increased with the increase of the solvent dielectric constant, in the order of DMF (N,N'-dimethylformamide) > acetone > chloroform > cyclohexane. In the presence of DMF, an acidic catalyst such as $H_2SO_4$ $(C_{10}H_8N_2H)_2Cr_2O_7$ oxidized benzyl alcohol (H) and its derivatives ($p-OCH_3$, $m-CH_3$, $m-OCH_3$, m-Cl, $m-NO_2$). Electron donating substituents accelerated the reaction rate, whereas electron acceptor groups retarded the reaction rate. Hammett reaction constant (${\rho}$) was -0.70 (308 K). The observed experimental data were used to rationalize the hydride ion transfer in the rate determining step.

• Journal of Life Science
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• v.30 no.7
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• pp.614-624
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• 2020

The recent development of next-generation sequencing technology has enabled increased genomic analysis, but very few single nucleotide polymorphism (SNP) markers applicable to sweet persimmon (Diospyros kaki Thunb.) cultivars have been identified. In this study, SNP primers developed from five pollination-constant astringent (PCA) persimmons native to Korea were applied to discriminate between cultivars and verify their usability. The polymerase chain reactions of 19 SNP primers developed by Jung et al. were checked, with 11 primers finally selected. The other eight were very difficult to analyze in the agarose gel electrophoresis and QIAxcel Advanced System used in this experiment and were therefore excluded. The 11 SNP primers were applied through first and second verification to 76 cultivars and collection lines including 20 pollination-variant non-astringent (PVNA), 30 pollination-constant non-astringent (PCNA), 20 PCA, and six pollination-variant astringent (PVA). Of these, 38 were indistinguishable (eight PVNA, 18 PCNA, nine PCA, and three PVA). However, the results of applying the 11 SNP primers to new sweet persimmon cultivars, namely Gamnuri, Dannuri, Hongchoo, Jamisi, and Migamjosaeng, showed that they have the potential to be used as a unique marker for simultaneously determining between them.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.3
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• pp.374-380
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• 2010

Treacher Collins syndrome(TCS) is a rare, incurable condition occurring in approximately 1 of 25,000 to 50,000 births. It may occur as a spontaneous mutation out of genetically normal parents or it may be manifested as an autosomal dominant pattern. TCS is characterized by facial deformities such as, underdevelopment of the maxilla, mandible and zygoma, malocclusion, bilateral deformities of auricles, antimongoloid slant of the palpebral fissures. The syndrome is often associated with cleft lip and palate, ear malformations and hearing loss, short stature, and anomalies of the heart and skeleton. Respiratory difficulty associated with air way obstruction may also be observed, and there is considerable difficulty in airway management during general anesthesia. It is necessary that dentists provide safe dental treatments and guidelines to TCS patients by providing adequate understanding about the characteristics of the syndrome and proper ways of managements. The purpose of this study is to report the dental and medical characteristics of the patient who visited the Department of Pediatric Dentistry, Yonsei University for multiple dental caries treatment and to review the literatures of TCS.

• Journal of the Korean Ceramic Society
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• v.38 no.9
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• pp.806-810
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• 2001

$La_{2/3}TiO_3$, $La_2Ti_2O_7$ are used in various parts by dielectric properties. The purpose of the present study is to understand the photoluminescence properties of $Al^{3+}\;and\;Pr^{3+}$ doped perovskite-type $La_{2/3}TiO_3$ and pyrochlore-type $La_2Ti_2O_7$ phosphor, which characterized by the red emission $(^1D_2{\rightarrow}^3H_4)\;of\;Pr^{3+}$ of $Pr^{3+}$ ion. The explanation for the energy transfer and the corresponding critical distance were proposed on the role of Al^3+ ions as energy transfer mediates in perovskite-type $La_{2/3}TiO_3$:Pr phosphor. In order to clarify the distinction of photoluminescence propoerties between the perovskite-type $La_{2/3}TiO_3$ and the pyrochlore $La_2Ti_2O_7$, the trap-involved process and the charge transfer band have been investigated.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.2 s.117
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• pp.151-157
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• 2007

We have presented a compact two-wire helical antenna adopted an open stub in opposite to a feeding point, which is for a T-DMB antenna of mobile devices. By adjusting the length of the open stub or pasting a dielectric material on the open stub, the input impedance around 200 MHz, bands of the T-DMB, can be easily control, even though the total height of the antenna is less than 8 cm(0.053 $\lambda$ at 200 MHz). The operating mechanism of the antenna is explained by using equivalent circuits of two modes, an unbalanced mode and a balanced mode. Based on the analysis of the equivalent circuits, the effects of using the open stub are validated. Several proposed antennas have been fabricated and measured. One of the fabricated antennas has -10 dB impedance bandwidth of $196{\sim}204$ MHz(8 MHz) whose value covers one channel of the T-DMB(6 MHz). The measured $S_{21}$ of the antenna is -38.6 dB which is about 17 dB higher than that of a monopole antenna whose height is same with the proposed antenna.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.41-56
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• 2018

The purpose of this study was to provide clinical recommendations for restoration with selection of the most similar zirconia crown by 3-dimensional analysis of the shape of the maxillary primary central and lateral incisors in Korean individuals and prefabricated zirconia crowns. The average shape of the sound maxillary primary central and lateral incisors in 300 children was reproduced by 3-dimensional scanning. Zirconia crowns of 4 manufacturers (NuSmile $ZR^{(R)}$ Crown, Cheng $Crowns^{(R)}$, Kinder $Krowns^{(R)}$, and EZ $Pedo^{(R)}$ Crown) were scanned 3-dimensionally, and coordinates for comparison of the shape were measured to evaluate the similarity between the teeth and crowns. The most similar crowns were selected by comparing the mesiodistal length, crown height, crown shape ratio, distance between the same coordinates of a tooth and crown, the radius of curvature of the labial surface, and the volume. As a result of analysis, Cheng $Crowns^{(R)}$ size 3 and NuSmile $ZR^{(R)}$ Crown size 2 were the most similar crowns in the maxillary primary central and lateral incisors, respectively. Scanning the inner surface of the crowns and evaluating the amount of tooth reduction required suggested that an overall lesser amount of tooth reduction compared to that presented by the manufacturer's guidelines should be performed.

• Korean Journal of Environment and Ecology
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• v.30 no.2
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• pp.261-270
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• 2016

The concept of Eco-welfare emerged in the process of discovering the relationship between a healthy ecosystem and human wellbeing. The objective of this study is to offer basic data for eco-welfare policy realization by conceptualizing the 'National Park Eco-welfare' since national parks are appropriate places for eco-welfare to be optimally implemented. A pre-workshop and two rounds of Delphi surveys were conducted to determine the concept of the 'National Park Eco-welfare ' and the main elements to be included in ecosystem service. Through this study, the concept of 'National Park Eco-welfare' was defined as efforts to conserve the biodiversity and sustainability of the ecosystem and create harmony between 'National Park Ecosystem Welfare' and 'National Park Human Welfare'. To establish the direction of the National Park Eco-welfare policy, we identified the main elements of ecosystem services which are appropriate for the National Park. These are comprised of 3 elements (food, fresh water and genetic resources) from supply service, all elements from regulating service and supporting/habitat service and 4 elements (aesthetic information, recreation-based ecotourism, healing, and knowledge systems with educational values) from culture service. In this study, the concept of National Park Eco-welfare was established, and its policy objectives and scope were suggested. However, further studies are necessary to develop action plans areand thereby realize the policy.