• Journal of Oral Medicine and Pain
• /
• v.32 no.4
• /
• pp.421-429
• /
• 2007

Some researchers suggested that tactile sensor system would be useful in evaluating masticatory muscles of TMD patients, but there were few studies on the effects of chewing with time. The aim of this study was to investigate the change of elasticity and stiffness for masseter and temporal muscles of normal subjects before, during and after gum chewing and to obtain the baseline data for further researches on the elasticity and stiffness for masticatory muscles of TMD patients. Stiffness and elasticity of their anterior temporalis and inferior masseter muscle were measured bilaterally by a tactile sensor system. Each subject was instructed to sit on a chair for evaluation of masticatory muscles. Before operating the sensor, the thickest skin area over anterior temporalis and inferior masseter muscles were selected as the points to be pressed by a tactile sensor, and marked with a pen. While the teeth of subjects were lightly contacted, the probe of the tactile sensor was placed perpendicularly over the marked point over the skin, followed by computer-controlled movement including gently pressing straight down on the muscle for a second and retracting. All subjects were instructed to chew gum (Excellent Breath, Taiyo Co., Japan) bilaterally with a velocity of 2 times per second for 40 minutes after the first measurement had been performed for the baseline data of all subjects. The measurements had been repeated during chewing with 10 minutes of interval and continued for 40 minutes with same interval after chewing. Resultantly, the decrease of elasticity and the increase of stiffness in masticatory muscles can be seen significantly within 10 minutes after chewing and those were maintained during chewing without significant change with chewing time. The elasticity of muscles was recovered within 10 minutes after stopping chewing, but the stiffness was recovered more lately than elasticity by about 10 minutes. Based on these results, it can be concluded that elasticity and stiffness of muscles would be good indicators to evaluate the masticatory muscles objectively, when more supported by further researches.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.44 no.5
• /
• pp.59-67
• /
• 2016

In landscape design by public institutions, although the costs and species of landscape trees stipulated by the Korean Public Procurement Service(PPS) are generally adhered to, the PPS regulations about planting trees with well-developed rootlets are almost entirely neglected. This study aimed to evaluate the performance of buried container modules, which are a new technology and product in landscape production that is able to reduce the defect rate while complying with regulations. To this end, this study measured rootlet density, rootlet development length, rootlet survival rate on excavation, and impairments of tree growth for 3 months after root pruning, and compared these variables for the container modules with those for trees that underwent root pruning in bare ground, and those that were cultivated in a container above ground. The results were as follows: First, the rootlet density was 88% for the trees in container modules, which was very high. Trees that underwent standard root pruning in bare ground had a somewhat lower density of 64%. Meanwhile, the trees that were cultivated in pots above ground died, invalidating measurement. Second, in terms of rootlet development and rootlet survival rate, the trees in container modules showed a mean length of 10.4cm, and 100% survival rate, indicating that there was no rootlet damage caused by excavation. For the trees that only underwent root pruning in bare ground, the mean length was 25.6cm and the rootlet survival rate was only half that of the trees in container modules, at 56%, demonstrating considerable damage. Rootlet development did not occur at all in the trees grown in pots. Third, the trees in container modules and those that underwent root pruning in bare ground did not show any deaths during the root pruning process, or any impairments such as stunted leaf growth. Conversely, the trees grown in pots nearly all died, and severe impairments of tree growth were observed. As shown by the results above, when we evaluated the performance of buried container modules, they showed the most outstanding performance of the three models tested in this study. The container modules prevent defects by stimulating early rooting in environments that with poor conditions for growth, or in trees that are not suited to the summer environment Therefore, it is expected that they would be an optimal means by which to enable compliance with rules such as the regulation presented by the PPS.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.19 no.1
• /
• pp.139-146
• /
• 2015

The amount of by-product from sulphur increases in domestic industrial facilities. However, the amount of its consumption is limited so that the amount of unused sulphur continues to increase. Therefore, in this study, the use sulfur polymer as the concrete surface protecting material was conducted. The compressive strength showed that as the substitution ratio of filler increased up to 40%, the compressive strength also increased. A high compressive strength was shown at the curing temperature of $40^{\circ}C$ (SS, FA) and $60^{\circ}C$ (OPC) according to the type of filler. The difference of compressive strength between air dry curing and water curing was insignificant so that there was no significant influence of moisture during curing process. The evaluation result of bond strength showed that the highest bond strength was shown at the air-dry condition of $40^{\circ}C$ regardless of type of filler. Bonding didn't occur properly during water curing in comparison to air dry curing. Also, in case of the specimen cured at $60^{\circ}C$, discoloration and hair cracks appeared due to the influence of temperature, and the highest bond strength was shown at the substitution ratio of 20% (SS, FA) and 30% (OPC) according to the type of filler. The releasing test result of harmful substance showed that no harmful substance was released, so there is no harmfulness in the surface protecting material using sulfur polymer. As a conclusion drawn in this study, it is most appropriate to substitute silica by approximately 20%, mix and cure at the air-dry condition of $40^{\circ}C$ in order to use sulfur polymer as the surface protecting material.

• Journal of Korean Ophthalmic Optics Society
• /
• v.17 no.3
• /
• pp.255-264
• /
• 2012

Purpose: In this study, the effect of lens fitting status on the contact area between spherical/aspherical RGP lens and the cornea having different astigmatic degree and corneal type was investigated for guiding the proper selection of RGP lens. Methods: Spherical and aspherical RGP lenses were applied on ninety eyes $(25.12{\pm}3.52years)$ having with-the-rule astigmatism by different fitting status. Then, their central, mid-peripheral and peripheral areas of fluorescein pattern were calculated and compared for the quantitative evaluation of the contact area between spherical/aspherical RGP lens. Results: The central and peripheral areas with the alignment fitting was significant different based on lens design. However, the central area didn't show any significant difference by lens design and corneal type when fitted in steep or flat. When analyzed by the corneal shape, both lenses with alignment and flat fitting had significant difference in central and peripheral areas. However, the central, mid-peripheral and peripheral areas with steep fitting didn't show the difference by corneal types. When analyzed by the astigmatic degree, the central and peripheral areas with alignment fitting changed proportionally to the increase of corneal astigmatism regardless of corneal shape. With steep and flat fitting, however, the central, mid-peripheral and/or peripheral areas in round- and symmetric bowtie-typed corneas showed the conflicting result when compared to those of alignment fitting when analyzed by the astigmatic degree. Conclusions: In this study, it was confirmed that the contact areas of cornea and RGP lens fitted steep and flat status were largely affected by the corneal type and corneal astigmatism rather than RGP lens fitted in alignment status. Also, this result commonly occurred in both spherical and aspherical RGP lenses.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.9
• /
• pp.1464-1470
• /
• 2005

To assure the safety of the major edible seaweeds, we collected the 176 samples of seaweeds such as laver(Porphyra sp.), sea mustard (Undaria pinnatifida), sea tangle (Laminaria japonica) and sea lettuce (Enter-omorph sp.) from Korean coast. We investigated the contents of the trace metals in the edible seaweeds, and the values were expressed as the dry weight of sea weeds. The mean levels of the trace metals were high in the oder of Zn ($36.19{\pm}27.14 \;{\mu}g/g$), Mn ($28.75{\pm}28.03\;{\mu}g/g$), and Cu ($6.82{\pm}7.62\;{\mu}g/g$), which are necessary metals in the human body, and then followed by Cr ($1.54{\pm}2.07\;{\mu}g/g$), Ni ($1.29{\pm}2.57\;{\mu}g/g$), Pb ($0.89{\pm}1.11\;{\mu}g/g$), Cd ($0.72{\pm}0.80\;{\mu}g/g$) and Hg ($0.01{\pm}0.02\;{\mu}g/g$). The contents of Cd and Zn were high in the laver, Cr, Ni and Pb were detected highly in sea lettuce, and Hg was detected highly in sea tangle. Significant linear correlations were obtained among 28 different pairs of metals, some of them highly correlated (r>0.5, p<0.05),such as Ni-Mn, Zn-Ni, Cu-Pb and Cu-Zn in laver, Ni-Zn in sea mustard, Cu-Pb, Cu-Zn and Mn-Pb in sea tangle, and Ni-Cr in sea lettuce. And, the trace metal contents of seaweeds varied with parts and kinds of samples. The average weekly intakes of Hg, Cd and Pb from seaweeds were about $0.07{\~}3.57\%$ of PTWI (Provisional Tolerable Weekly Intakes) which has set by FAO/WHO to evaluate the safeties of trace metals in food. Therefore, it was found that they showed very safe levels in the edible seaweeds.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.6
• /
• pp.791-800
• /
• 2006

This study examined the effects of gromwell (Lithospermum erythrorhizon) extracts on the storage characteristics of Kangjung. At an increase of $0{\sim}0.25%$, there was no significant difference in the moisture content of wild and cultivated gromwell extract added to Kangjung, whereas there was a significant difference when increased to 0.5%. When compared, the occurrence of lipid oxidation among the controlled gromwell extract group stored at $60^{\circ}C$, resulted in peroxide values exceeding 40 meq/kg which is a maximum value for Hankwa within 12 hours of storage. However, at an increase of 0.25%, the cultivated gromwell extract added group reached limits within 16 hours. Furthermore, at a 0.5% increase in cultivated gromwell and 0.25% in wild gromwell, extract added groups exceeded this limit within 20 hours of storage. Gromwell added Kangjung, a fried food, showed efficiency in suppressing oxidation of fat, more so in the wild gromwell than the cultivated gromwell. In addition, efficiency in suppressing oxidation of fat increased at the 0.5% level than the 0.25% level. In conclusion, it is believed that an unused pigment resource called Lithospermum erythrorhizon, normally reserved for medicinal use, can be distributed as a safe food additive. In addition, as Lithospermum erythrorhizon is a natural antioxidant in fried foods, we believe this satisfies the demand for natural food.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.31 no.6
• /
• pp.791-798
• /
• 1998

To develop natural flavoring substances. optimal hydrolysis conditions for two stage enzyme hydrolysates (TSEH) using low-utilized shellfishes such as purplish clam and frozen oyster stored at $-20^{\circ}C$ for 60 days. The optimal conditions for TSEH method were revealed in temperature at $50^{\circ}C$ 3 hours digestion with alcalase (Aroase AP-10, $0.3%$ w/v, pH 8.0) at the 1st stage and $45^{\circ}C$ 2 hours digestion with neutrase (Pandidase NP-2, $0.3\%$ w/v, pH 6.0) at the 2nd stage. Among water extracts, autolytic extracts and 4 kinds of enzyme hydrolysates tests, TSEH method was superior to other methods on the aspect of yields, nitrogen contents, taste such as umami and control of off-flayer formation, and transparency of extracts. From the results of chemical experiments and sensory evaluation, we may conclude that TSEH from low-utilized marine products is more flavorable compared the conventional enzyme hydrolysates, it could be commercialized as the seasoning substances.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.19 no.3
• /
• pp.187-194
• /
• 1986

For the purpose of obtaining basic data which can be applied to evaluate the quality of the retortable pouch and tin-plated canned product, the canned sardine and the retort pouched sardine were prepared and compared in terms of thermal sterilization times required and product duality during storage. Retort pouched sardine required $20\%$ less thermal sterilization time than the canned sardine. Volatile basic nitrogen (VBN) and amino nitrogen ($NH_2-N$) contents in both canned and retort pouched sardine showed little difference during processing and storage. During storage, peroxide value (POV) and thiobarbituric acid (TBA) value of the canned sardine had a slightly higher value compared to the retort pouched sardine, but acid value (AV) revealed little difference between both canned and retort pouched sardine. Trimethylamine (TMA) content of the both canned and retort pouched sardine showed little difference during processing and storage. The inosinic acid (IMP) content in canned and retort pouched sardine was $8.39{\sim}9.80{\mu}mole/g$ range, and had no significant change during processing and storage. The retort ponched sardine revealed a smaller reduction in polyenoic acid than the canned sardine during processing and storage. Among the TPA (texture profile analysis) parameters, hardness maintained a slightly higher value in the retort pouched sardine than in the canned sardine. Color values showed that the retort pouched sardine was generally lighter than the canned sardine. In sensory evaluation, the retort pouched sardine was scored slightly higher, in most cases, for color, flavor, texture, taste and overall acceptance than the canned sardine. It was concluded from the results that the retort pouched sardine was at least equal to the canned sardine in product quality.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.12 no.4
• /
• pp.225-234
• /
• 1979

For the effective utilization of diverse and abundant resource of seaweeds in Korea as a food protein supplment, extraction conditions of water, salt, and alkali soluble proteins were investigated in previous work(Ryu and Lee, 1977: Lee et al., 1977: Lee et al., 1978). The present study as a part of the serial work was thus aimed to find the conditions of isolation and purification of extracted proteins, and to evaluate the nutritional quality of the isolated seaweed proteins in terms of amino acid composition, chemical score, protein score, modified essential amino acid index(MEAAI), and in vitro digestibility presented as pepsin-pancreatin digest residue index (PPDRI). As for the isolation of extracted proteins, TCA treatment was more effective for the proteins from rhodophyceae and Chlorophyceae while the precipitation at isoelectric point was more desirable for Phaeophyceae proteins. In amino acid composition, water soluble protein fraction was superior to the other fractions in Porphyra suborbiculata whereas both water and alkali soluble fractions seemed to bo more benefitial for Enteromorpha linza and Ulva pertusa; the extraction with alcohol-alkali mixed solvent for Undaria pinnatifida and Sargassum fulvellum. Glutamic acid and aspartic acid content was particularly high in all protein fractions examined. The total amino acid content of Porphyra suborbiculata and Enteromorpha linza was almost equivalent to that of dried whole egg although the essential amino acid content was lower. A comparative analysis was made on the inedexes between raw seaweed powder and isolated protein. Chemical score of Porphyra suborbiculata and Ulva pertusa was approximately 35 and 56 in cafes of raw powder and isolated protein respectively while only 10 to 16 for raw powder of Undaria pinnatifida and Sargassum fulvellum and 30 to 35 for their isolated proteins. Protein score of all isolated proteins was in the range of 63 to 73 which indicates that isolated protein would be mere valuable than the fern of raw seaweed powder. Digestibility by means of PPDRI was found to be extremely low in case of raw powder but it could be doubled in case of isolated protein yielding 67 to 70 for Porphyra suborbiculata and Ulva pertusa.

• Journal of Korean Society of Environmental Engineers
• /
• v.29 no.4
• /
• pp.404-411
• /
• 2007

Adsorption performance of odorous compounds such as geosmin and 2-MIB on granular activated carbon were evaluated in this study. The coal-based activated carbon was found more effective than other carbons in adsorption of geosmin and 2-MIB. The wood-based virgin activated carbon was less effective than coconut- and coal-based carbon in adsorption nevertheless having larger pore volume and specific surface area than others carbons. The maximum adsorption capacity(X/M) of coal-based activated carbon for geosmin and 2-MIB was $1.2\sim1.9$ and $2.1\sim2.6$ times larger than coconut- and wood-based virgin activated carbon, respectively. Carbon usage rate (CUR) of coal-, coconut- and wood-based virgin activated carbons for geosmin and 2-MIB were 1.72 and 1.44 g/day, 1.72 and 2.05 g/day and 2.12 and 1.90 g/day, respectively. In the evaluation of adsorption isotherm of geosmin and 2-MIB for coal-, coconut- and wood-based virgin activated carbons, k value of 2-MIB was lower than geosmin, It menas 2-MIB is more difficult to remove by activated carbon adsorption than geosmin. The relationship of max. adsorption versus total pore volume of coconut- and wood-based virgin and used activated carbon for geosmin and 2-MIB were $y=264,459\times-79,047(R^2=0.95)$, $y=319,650\times-101,762(R^2=0.93)$.