• The korean journal of orthodontics
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• v.21 no.2 s.34
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• pp.287-307
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• 1991

This study aimed at examining speech defects of openbite patients, which were analized in terms of formant frequency for vowels and word pronunciation length for consonants. In addition, the upper and lower lip (perioral m.) activity was tested by the EMG. The tongue force was measured by the strain gauge, and the speech discrimination test was carried out. One experimental group and one control group were used for this study and they were respectively composed of six female openbite patients and six normal-occlusion females. Eight monophthongs, two fricatives and two affricatives were chosen for speech analysis. Speeches of the above-mentioned groups were recorded and then analized by the ILS/PC-1 software. Four hundred most frequently used monosyllables were also chosen for discrimination score. Openbite patients showed the following characteristics: 1. Abnormality in case of /a/, $/\varepsilon/$, /e/, /i/ $F_2$ and /e/, /a/ $F_1$. 2. Significantly elongated length in their pronunciation of /h/ and $/C^h/$ and somewhat elongated length also in their pronunciation of /s/ and /c/. 3. Significant upper lip activity according to the EMG test during pronunciation of the bilabial consonants. 4. Relatively weak tongue force according to the strain gauge measurement. 5. According to the speech discrimination test, high rate of misarticulation in case of (a) initial /p/ /s'/ and /ts'/, (b) /a/,$/\varepsilon/$,/e/,/je/,/o/, $/\phi/$,/jo/,/u/,/we/, and /i/ (c) final (equation omitted).

• Journal of the Korean Society of Combustion
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• v.20 no.2
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• pp.36-39
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• 2015

The combustion characteristics of metal fiber burner fueled natural gas with tail gas produced from reforming process were analyzed on the point of flame stability and excess air conditions. Also, it was analyzed the effect of energy efficiency improvement due to decrease the fuel input in reforming system by using residue gases. As a results, it was confirmed that tail gas including hydrogen, CO and $CO_2$ could be directly injected without any change of air control system in natural gas burner and also energy efficiency was increased up to 30% maintained stable combustion.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.7
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• pp.622-627
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• 2005

In this study, electrical properties of self-assembled dipyridinium dithioacetate molecule onto the Au(111) substrate is observed using Scanning Tunneling Microscopy(STM) by vortical structure of STM probe. At first, the Au(111) substrate is cleaned by piranha solution$(H_2SO_4:H_2O_2\;=\;3:1)$. Subsequently, 1 mM/ml of dipyridinium dithioacetate molecule is self-assembled onto the Au(111) surface. Using STM, the images of dipyridinium dithioacetate molecule which is self-assembled onto the Au(111) substrate, can be observed. In addition, the electrical properties(I-V) of dipyridinium dithioacetate can also be examined by using Scanning Tunneling Spectroscopy(STS). From the results of the measurement of the current-voltage(I-V), the property of Negative Differential Resistance(NDR) that shows the decreases of current according to the increases of voltage is observed. We found the NDR voltage of the dipyridinium dithioacetate is -1.42 V(negative region) and 1.30 V(positive region), respectively.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.81.1-81.1
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• 2017

L1251B is an excellent example of a small group of pre- and protostellar objects in low-mass star-forming region. Previous interferometer data with a high angular resolution resolved the outflows associated with L1251B into a few components. To understand the physical conditions of the protostellar outflows in L1251B, we mapped this region spectroscopically with Spitzer/IRS and obtained spectral line data from Herschel/PACS. Spitzer/IRS provides the S(0)-S(7) pure rotational lines of H2 as well as fine-structure emissions produced in shocks such as S, [Si II], and [Fe II] and it is a powerful tool for studying shocked interstellar gas. In addition, [O I] lines observed with Herschel/PACS are described well by J-type shock models expected in the outflows from protostars. We will present an analysis of the L1251B protostellar outflow in the H2 pure rotational lines and fine-structure emissions.

• The Korean Journal of Community Living Science
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• v.14 no.2
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• pp.63-70
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• 2003

In this experiment, the curd was made from soybean and cow's milk in the ratio of 7 to 3, and coagulated with Glucono-delta-lacton(GDL) and $CaSO_4&.$2H_{2}O& in the 1:1 ratio. During the procedure, the mulberry leaf powder was added. The amount of the added powder varied from 0.1 % to 0.5 %. This experiment aimed to show the change of yield, general components, minerals, amino acid, changes of pH, sensory properties of these products. As mulberry leaf powder addition increased, crude protein, crude fat, crude ash content, minerals and amino acids increased. Whereas moisture content decreased, and in particular,$Ca^{++}$, $K^+$ and $Na^+$ increased. On the other hand, in the sensory properties, the levels of satisfaction about the color, appearance, flavor, texture and savory were lower in mulberry leaf powder added than under control.

• Journal of the Korean Chemical Society
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• v.64 no.2
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• pp.67-73
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• 2020

The study aimed to investigate in vitro lipid deposition of oleic acid, oleic acid methyl ester and cholesterol on a daily disposable (1-day lenses) and 3-days lenses over 3 days and changes of optical characteristics is also investigated. Artificial tear solutions were prepared to simulate actual tear compositions. Two types of contact lenses (1-day lenses (Senofilcon A) and 3-days lenses (silicone tripolymer)) were soaked in the artificial tear solutions within an incubator at 37 ℃ with 150 rpm for 8, 16, 24 hours. Lipid deposition (oleic acid, oleic acid methyl ester and cholesterol) were measured using high performance liquid chromatography (HPLC) instrument. In addition, measurements of oxygen transmissibility, light transmittance and observation of lens surface were conducted. The amount of lipid deposition on the 1-day lenses were 127.55 ㎍/lens for Day 1, 302.96 ㎍/lens, for Day 2, and 353.30 ㎍/lens for Day 3. The 3-days lenses were 46.22 ㎍/lens for Day 1, 66.07 ㎍/lens for Day 2, and 67.45 ㎍/lens for Day 3. Oxygen transmissibility were 81×10^-9(cm/sec)(ml O₂/ml×mmHg)(Baseline) and 48×10^-9(cm/sec)(ml O₂/ml×mmHg) (Day 3) for the 1-day lenses, it were 13.23×10^-9(cm/sec)(ml O₂/ml×mmHg)(Baseline) and 9.6×10^-9(cm/sec)(ml O₂/ml×mmHg) (Day 3) for the 3-days lenses. Transmittance of each lenses were 97.21% (Baseline) and 94.25% (Day 3) for the 1-day lenses, 97.65% (Baseline) and 95.15% (Day 3) for the 3-days lenses. Observation of surface deposition indicated greatest deposition for the 3-days lenses type on Day 3. Lipid deposition for both lens types increased by day and was greater for the 1-day lenses type. Surface deposition appeared to differ as it was greatest for the 3 days lens type, which may suggest other deposits such as protein may be present.

• Journal of Life Science
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• v.34 no.6
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• pp.426-433
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• 2024

The environmental stress that plants are most susceptible to is water stress. Abscisic acid (ABA) is a plant hormone synthesized by plants to counteract environmental stress. The role of stomata in plants is to allow the synthesis of sucrose by absorbing CO₂, which greatly affects photosynthetic activity. In addition, stomata are pathways for transpiration, which releases H₂O and help establish a water potential gradient that allows plant roots to continuously absorb water and inorganic substances from the soil. Plants have a mechanism to minimize water loss by closing their stomata when exposed to water-stressed environments. The most well-studied hypothesis concerning the mechanism of stomatal closure is the response to water stress. When a plant receives sufficient water, its stomata open during the day and close at night due to its circadian rhythm. In addition, stomatal closure occurs when the concentration of CO₂ in the intercellular space increases. However, the mechanism of stomatal closure due to circadian rhythm and increased CO₂ concentration in the intercellular space is not well understood. When plants undergo water stress, the increased concentration of ABA in the guard cell cytoplasm induces an increase in Ca²⁺ concentration, resulting in cytoplasmic depolarization. As a result, the outward K⁺-channel of the tonoplast and the slow-type anion channels SLAC1 and SLAH3 are activated, releasing K⁺, Cl^-, and malate^2-, causing the stomata to close. Therefore, in this paper, the mechanism of stomatal closure caused by water stress was investigated.

• Korean Journal of Food Science and Technology
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• v.14 no.2
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• pp.151-155
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• 1982

Effects of vitamins, metabolic intermediates and several inorganic mineral salts on the biomass and lipid accumulation of Mucor plumbeus were investigated after 15 days of incubation at $37^{\circ}C$ under static culture condition. The optimum concentrations of various vitamins were ${\gamma}/l$ for biotin, and 0.01 g/l for nicotinic acid, pyridoxine, thiamine and riboflavin. Among them pyridoxine was the most stimulatory. The maximum felt weight and lipid content per 50ml medium were $2.82{\pm}0.14\;g$ and 62.8%. Triglyceride content of neutral lipid produced under this condition was 64.9%. The major fatty acids were oleic acid (50.0%), linoleic (23.8%) and palmitic acid (13.9%). Malonic acid was considered not to be desirable even though it stimulated the biomass and lipid accumulation because triglyceride content was lowered considerably comparing with control. $MgSO_4{\cdot}7H_2O$ was the most stimulatory among the various magnesium salts and its optimum concentration was 5 g/l. Mucor plumbeus did not require $NaH_2PO_4$ for the stimulation of felt and lipid production. However, the addition of $MnCl_2$ at the concentration of 2 g/l was stimulatory to show $2.76{\pm}0.28\;g$ of felt/50 ml and 56.4% lipid content, and 73.9% triglyceride in the neutral lipid.

• Journal of Life Science
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• v.24 no.8
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• pp.873-879
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• 2014

The constituents from the needles of the pine tree, Pinus densiflora, were purified and investigated for antithrombotic activity. The needles were initially extracted three times with 70% ethanol, and the extract was sequentially fractionated with chloroform and n-butanol. The aqueous layer formed after n-butanol fractionation was subjected to purification by medium pressure and high pressure liquid chromatography. The two neolignans, 2, 3-dihydro-7-hydroxyl-3-hydroxymethyl-2-(4'-hydroxyl -3-methoxyphenyl)-5-benzofuranpropanol-3-O-${\alpha}$-rhamnopyranoside (a neolignan glycoside) and 2, 3-dihyro-3-hydroxymethyl-7-methoxy-2-(4'-hydroxyphenyl-3'-methoxy)-5-benxofuran propanol 4'-O-${\alpha}$-rhamnopyranoside (icariside $E_4$) were identified by $^1H$ and $^{13}C$ NMR spectra. The effect of the purified compounds, the neolignan glycoside and icariside $E_4$ on thrombin inhibition were investigated by measuring thrombin clotting time in plasma. As a result, the clotting of the neolignan glycoside was delayed four times compared to that of icariside $E_4$. In addition, an analysis of the inhibition effect by changing the concentration showed that the clotting time was delayed in accordance with an increase in the concentration of the neolignan glycoside. Furthermore, we examined the interaction of thrombin and fibrinogen to clarify the action mechanism. As a result, the delay of clotting time in the response of thrombin and pure fibrinogen may indicate that neolignan glycosides inhibit the thrombin action in a direct manner, leading to the suppression of fibrin generation.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.2
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• pp.89-95
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• 2021

Research on the production of lithium hydroxide (LiOH) has been actively conducted in response to the increasing demand for high nickel-based positive electrode materials for lithium-ion batteries. Herein we studied the conversion of lithium oxide (Li2O) through thermal decomposition of lithium carbonate for the production of lithium hydroxide from lithium carbonate (Li2CO3). The reaction mechanism of lithium carbonate with alumina, quartz and graphite crucible during heat treatment was confirmed. When graphite crucible was used, complete lithium oxide powder was obtained. Based on the TG analysis results, reagent-grade lithium carbonate was heat-treated at 700℃, 900℃ and 1100℃ for various time and atmosphere conditions. XRD analysis showed the produced lithium oxide showed high crystallinity at 1100℃ for 1 hour in a nitrogen atmosphere. In addition, several reagent-grade lithium oxides were reacted at 100℃ to convert to lithium hydroxide. XRD analysis confirmed that lithium hydroxide (LiOH) and lithium hydroxide monohydrate (LiOH·H2O) were produced.