• The Journal of Korean Academy of Prosthodontics
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• v.54 no.3
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• pp.306-313
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• 2016

Tooth wear is known as a normal physiological process which gradually progresses. It is reported that vertical dimension can be kept stable because amount of physiologically worn loss could be compensated by growth of alveolar bone and tooth eruption. However, excessive tooth wear as pathologic wear can cause pathologic pulp, disharmony with occlusal plane, functional disorders and esthetic problems so that full mouth rehabilitation could be needed in these cases. Recovery of function and esthetic improvement should be considered for alteration of the vertical dimension. Determination of the vertical dimension of occlusion is needed to be in harmony with the neuromuscular system. This clinical report describes 36 year-old female patient who had chief complaint of severely worn dentition and esthetic discomfort. An increase of 2.0 mm at maxillary incisal edge was done to restore vertical dimension. It was based on the degree of tooth wear and esthetics.

• Horticultural Science & Technology
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• v.33 no.6
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• pp.854-859
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• 2015

This experiment was performed to develop a model for nutrition ion concentration and EC in regard to change in pH from 4.0 to 8.0 in nutrient solution. The pH changes according to the variation of $HPO_4{^{-2}}$ and $H_2PO_4{^-}$ in the nutrient solution while variation of EC increased from pH 4.0 to 5.0, stabilized from pH 5.0 to 7.0 and increased again from pH 7.0 to 8.0. For the variance of major elements in the nutrient solution, K, Ca, N and P increased while pH was higher, especially the variables for K and P were increased largely. On the other hand, variables of Mg and S were stable. Based on analysis of the ion balance model of nutrient solution, the cation increased than anion over rising the variation of pH while balance point of ion moved from a-side to d-side. In addition, the imbalance increased while it moved away from the EC centerline as variance of pH increased. It was larger than effect of EC variance to correction values of equivalence ratios of K and Ca about variation of $HPO_4{^{-2}}$ and $H_2PO_4{^-}$ while as variance of pH increased, K decreased but Ca increased. These showed the result that variance of pH about correction values of equivalence ratios of K and Ca gave a second-degree polynomial model rating of 0.97. Through this research, it was identified the pH variable model about variance among pH, ion and EC according to gradient of phosphate.

• Korean journal of applied entomology
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• v.16 no.4 s.33
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• pp.229-234
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• 1977

The experiments were carried out to investigate the selection effects on the drug resistance to Agrepto in Xanthomonas oryzae, the causal bacteria of rice bacterial leaf blight. The results obtained were as follows. 1, The Agrepto was stable at the heat treatment of $105^{\circ}C$ for 20 minutes, when the drug was added in the media. 2. The local isolates of the bacteria, 75-6 and 75-9, showed the different resistante reaction, when they were selected by the Agrepto contained media which concentrations of 10r9/m1 and 100ug/ml. 3. The individuals shelving high degree of resistance, which can grow on the media contained 10,000ug/m1 of Agrepto, could selected by the concentrations as low as 10ug/ml and 100ug/m1, in one generation. 4. The highly resistant isolates which selected by 3-stepwise selections such as 100ug/ml, 3,000ug/ml and 10,000/ml plots, showed nearly normal growth at the media contained 100ug/ml of Agrepto 5. When the isolate 75-9 was selected at the 100ug/m1 of concentration, showed various degrees of resistance, indicating that the isolate may be composed of resistance groups that lower than 500ug/ml, between 500-1,000ug/ml and 1,000-3,000ug/ml, to the Agrept.

• Phonetics and Speech Sciences
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• v.5 no.1
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• pp.109-121
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• 2013

This study examined several kinematic properties of the primary articulator (the tongue dorsum) and the supplementary articulator (the jaw) in the articulation of the voiceless velar stop (/k/) within nonassimilating contexts. We examined in particular the spatiotemporal properties (constriction duration and constriction maxima) from the constriction onset to the constriction offset by analyzing a velar (/k/) followed by the coronal fricative (/s/), the coronal stop (/t/), and the labial (/p/) in across-word boundary conditions (/k#s/, /k#t/, and /k#p/). Along with these measurements, we investigated intergestural temporal coordination between C1 and C2 and the jaw articulator in relation to its coordination with the articulation of consonant sequences. The articulatory movement data was collected by means of electromagnetic midsagittal articulometry (EMMA). Four native speakers of Seoul Korean participated in the laboratory experiment. The results showed several characteristics. First, a velar (/k/) in C1 was not categorically reduced. Constriction duration and constriction degree of the velar (/k/) were similar within nonassimilating contexts (/k#s/=/k#t/=/k#p/). This might mean that spatiotemporal attributes during constriction duration were stable and consistent across different contexts, which might be subsequently associated with the nontarget status of the velar in place assimilation. Second, the gestural overlap could be represented as the order of /k#s/ (less) < /k#p/ (intermediate) < /k#t/ (more) as we measured the onset-to-onset lag (a longer lag indicated shorter gestural overlap.). This indicates a gestural overlap within nonassimilating contexts may not be constrained by any of the several constraints including the perceptual recoverability constraint (e.g., more overlap in Front-to-Back sequences compared to the reverse order (Back-to-Front) since perceptual cues in C1 can be recovered anytime during C2 articulation), the low-level speech motor constraint (e.g., more overlap in lingual-nonlingual sequences as compared to the lingual-lingual sequences), or phonological contexts effects (e.g., similarity in gestural overlap within nonassimilating contexts). As one possible account for more overlap in /k#t/ sequences as compared to /k#p/, we suspect speakers' knowledge may be receptive to extreme encroachment on C1 by the gestural overlap of the coronal in C2 since it does not obscure the perceptual cue of C1 as much as the labial in C2. Third, actual jaw position during C2 was higher in coronals (/s/, /t/) than in the labial (/p/). However, within the coronals, there was no manner-dependent jaw height difference in C2 (/s/=/t/). Vertical jaw position of C1 and C2 was seen as inter-dependent as higher jaw position in C1 was closely associated with C2. Lastly, a greater gap in jaw height was associated with longer intergestural timing (e.g., less overlap), but was confined to the cluster type (/kp/) with the lingual-nonlingual sequence. This study showed that Korean jaw articulation was independent from coordinating primary articulators in gestural overlap in some cluster types (/k#s/, /k#t/) while not in others (e.g., /k#p/). Overall, the results coherently indicate the velar stop (/k/) in C1 was robust in articulation, which may have subsequently contributed to the nontarget status of the velar (/k/) in place assimilation processes.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.6
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• pp.573-582
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• 2010

In this paper, X-band transceiver for high resolution wideband SAR systems is designed and fabricated. Also as a technique for enhancing the performance, error compensation algorithm is presented. The transceiver for SAR system is composed of transmitter, receiver, switch matrix and frequency generator. The receiver especially has 2 channel mono-pulse structure for ground moving target indication. The transceiver is able to provide the deramping signal for high resolution mode and select the receive bandwidth for receiving according to the operation mode. The transceiver had over 300 MHz bandwidth in X-band and 13.3 dBm output power which is appropriate to drive the T/R module. The receiver gain and noise figure was 39 dB and 3.96 dB respectively. The receive dynamic range was 30 dB and amplitude imbalance and phase imbalance of I/Q channel was ${\pm}$0.38 dBm and ${\pm}$3.47 degree respectively. The transceiver meets the required electrical performances through the individual tests. This paper shows the pulse error term depending on SAR performance was analyzed and range IRF was enhanced by applying the compensation technique.

• KSBB Journal
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• v.14 no.1
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• pp.96-102
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• 1999

Marine bacterium Bacillus cereus ASK202 produced an extracellular agarase (E.C.3.2.1.81) which showed a high level of enzyme activity in the presence of agar and agarose. In the optimal culture conditions, the agarase production increased 7.7 folds compared with the one obtained from the basal medium. Agarase production reached upto 160 units/L after 24hr of cultivation in a modified marine medium at $25^{\circ}C$. The degree of purification increased 31.5 folds with 27.8% yield through freeze drying, DEAE Sepharose CL-6B and Superose 6HR 10/30 column chromatography. The molecular weight of the purified agarase was determined to be 90,000 daltons by gel-permeation filteration. Optimal temperature and pH for the enzyme activity were $40^{\circ}C$ and 7.8, respectively. The enzyme was stable up to $50^{\circ}C$ and at a broad pH range of 5.0-10.0. The $\beta$-agarase was activated by $Zn(NO_3)_2$, and was inhibited by $CuSO_4$ and $SnCl_2$. The Km and Vmax values of this enzyme for agarose as a substrate was $2.4mg/m\ell$ and 13.6 mg/m$\ell$, respectively.

• Journal of Sensor Science and Technology
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• v.29 no.2
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• pp.93-99
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• 2020

A colorimetric paper sensor was used to detect volatile nitrogen-containing compounds emitted from spoiled salmon filets to determine their freshness. The sensing mechanism was based on acid-base reactions between acidic pH-indicating dyes and basic volatile ammonia and amines. A sensing layer was simply fabricated by drop-casting a dye solution of bromocresol green (BCG) on a polyvinylidene fluoride substrate, and its color-change response was enhanced by optimizing the amounts of additive chemicals, such as polyethylene glycol, p-toluene sulfonic acid, and graphene oxide in the dye solution. To avoid the adverse effects of water vapor, both faces of the sensing layer were enclosed by using a polyethylene terephthalate film and a gas-permeable microporous polytetrafluoroethylene sheet, respectively. When exposed to basic gas analytes, the paper-like sensor distinctly exhibited a color change from initially yellow, then to green, and finally to blue due to the deprotonation of BCG via the Brønsted acid-base reaction. The use of ammonia analyte as a test gas confirmed that the sensing performance of the optimized sensor was reversible and excellent (detection time of < 15 min, sensitive naked-eye detection at 0.25 ppm, good selectivity to common volatile organic gases, and good stability against thermal stress). Finally, the coloration intensity of the sensor was quantified as a function of the storage time of the salmon filet at 28℃ to evaluate its usefulness in monitoring of the food freshness with the measurement of the total viable count (TVC) of microorganisms in the food. The TVC value increased from 3.2 × 10⁵ to 3.1 × 10⁹ cfu/g in 28 h and then became stable, whereas the sensor response abruptly changed in the first 8 h and slightly increased thereafter. This result suggests that the colorimetric response could be used as an indicator for evaluating the degree of decay of salmon induced by microorganisms.

• Economic and Environmental Geology
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• v.43 no.5
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• pp.443-453
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• 2010

The Samsung gold-silver deposit consists of quartz veins that fill along the fault zone within Cretaceous shale and sandstone. Mineralization is occurred within fault-breccia zones and can be divided into two stages. Stage I is main ore mineralization and stage II is barren. Stage I is associated with wall-rock alteration minerals(sericite, pyrite, chlorite, quartz), rutile, base-metal sulfides(pyrrhotite, pyrite, sphalerite, chalcopyrite, galena), and electrum. Stage II occur quartz, calcite and pyrite. Fluid inclusion data indicate that homogenization temperatures and salinities of stage I range from 145 to $309^{\circ}C$ and from 0.4 to 12.4 wt.% NaCl, respectively. It suggests that hydrothermal fluids were cooled and diluted with the mixing of meteoric water. The main deposition of base-metal sulfides and electrum occurred as a result of cooling and dilution at temperature between $200^{\circ}C$ and $300^{\circ}C$. Sulfur(9.3~10.8‰) isotope composition indicates that ore sulfur was mainly derived from a magmatic source as well as the host rocks. The calculated oxygen[-2.3~0.9‰(quartz: 0.3‰, 0.9‰, calcite: -2.3‰)] and hydrogen[-86~-76‰(quartz: -86‰, -82‰, calcite: -76‰)] isotope compositions indicate that hydrothermal fluids may be meteoric origin with some degree of mixing of another meteoric water for paragenetic time.

• Korean Journal of Clinical Laboratory Science
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• v.44 no.1
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• pp.24-30
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• 2012

In this study, we have examined the effects of the storage time and temperature on DNA quality and have also studied the effects of the hydration buffer in which DNA is dissolved. This study was performed using 160 human blood samples collected with informed consent from 2007 to 2008 in the hospital where this cohort study was performed. The DNA extracted was dissolved using distilled water (DW) or Tris-EDTA (TE) buffer, and stored in the deep freezer or refrigerator for up to 10 weeks at $-70^{\circ}C$, $-20^{\circ}C$, $4^{\circ}C$, and $25^{\circ}C$, respectively. DNA integrity was determined by the degree of smearing of DNA on the gel. After four weeks, all of the 20 DNA samples dissolved in DW and stored at $25^{\circ}C$ were entirely degraded. After 10 weeks, 6 of the 20 DNA samples dissolved in TE buffer and stored at $25^{\circ}C$ were fairly degraded, and 4 of the 20 DNA samples dissolved in DW and stored at $4^{\circ}C$ were fairly degraded. The 20 DNA samples dissolved in TE buffer and stored at $4^{\circ}C$ were stable for 10 weeks. DNA samples stored at $-20^{\circ}C$ and $-70^{\circ}C$ did not appear to degrade in either DW or TE buffer, even at the 10-week point. We suggest that TE buffer should use for DNA elution, in order to protect against degradation and to preserve DNA for a long period of time, and the samples should be stored at $-20^{\circ}C$ or $-70^{\circ}C$.

• Applied Biological Chemistry
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• v.46 no.1
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• pp.39-45
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• 2003

This study was conducted to investigate the effect of ash contents of bread flour on the rheology of frozen dough In making frozen dough by measuring amylograph, flrinograph and extensograph. The quality of frozen-stored dough under freezing condition ($-20^{\circ}C$, 12 weeks) was evaluated by measuring final proof time, moisture content, baking loss, loaf volume and hardness of bread with storage time. In bread flour with high ash content farinogram showed that water absorption, degree of softening increased but valorimeter value decreased. In bread flour with low ash content amylogram showed that gelatinization temperature and maximum viscosity increased and extensogram showed that the area and resistance of the bread flour increased. As the proof time increased the extensibility decreased. Final proof time of frozen dough was shortened at the bread flour with low ash content with storage time. In bread using the flour with high ash content, moisture content, increased but baking loss rate decreased while the hardness of product increased slowly with time. But in bread using the flour with low ash content, the loaf volume of baking increased but the hardness of product decreased. As the frozen storage time was shortened, the product was more stable and better in quality.