• Journal of Food Hygiene and Safety
• /
• v.32 no.5
• /
• pp.434-442
• /
• 2017

The UV light in sunlight breaks down the chemical bonds in a polyolefin polymer through a process called photodegradation, ultimately causing cracking, chalking, colour changes, and loss of physical properties such as impact strength, tensile strength, elongation, and others. UV absorbers are used to prevent or terminate the oxidation of plastics by UV light. They are receptive to UV radiation and dissipate the energy harmlessly as heat. Benzotriazoles and benzophenones are used mainly in polyolefins such as polyethylene and polypropylene. In this study, we have developed a method for the analysis of 12 UV absorbers, which are Uvinul 3000, Cyasorb UV 24, Uvinul 3040, Tinuvin 312 and P, Seesorb 202, Chimassorb 81, Tinuvin 329, 234, 326, 328 and 327, migrated from the food packaging materials into four food simulants for aqueous, acidic, alcoholic and fatty foods. The UV absorbers in food simulants were determined by reversed-phase high performance liquid chromatograph-ultraviolet detector with 310 nm after solid-phase extraction with a hydrophilic-lipophilic balance (HLB) cartridge or dilution with isopropanol. The analytical method showed a good linearity of coefficient ($R^2{\geq}0.99$), limits of detection (0.049~0.370 mg/L), and limits of quantification (0.149~1.120 mg/L). The recoveries of UV absorbers spiked to four food simulants ranged from 70.05% to 110.13%. The developed method would be used as a reliable tool to determine concentrations of the migrated UV absorbers.

• Economic and Environmental Geology
• /
• v.26 no.4
• /
• pp.433-444
• /
• 1993

Electrum (32~73 atom. % Ag)-sulfide mineralization of the Bodeok mine in the Boseong area was deposited in two stages of mineralogically simple, massive quartz veins that fill the fractures along fault shear zones in Precambrian gneiss. Radiometric dating indicates that mineralization is Late Jurassic age ($155.9{\pm}2.3$ Ma). Fluid inclusion data show that ore mineralization was formed from $H_2O-CO_2$ fluids with variable $CO_2$ contents ($X_{CO_2}=0.0$ to 0.7) and low salinities (0.0 to 7.4 wt. % eq. NaCl) at temperatures between $200^{\circ}$ and $370^{\circ}C$. Evidence of fluid unmixing ($CO_2$ effervescence) indicates pressures up to 1 kbar. Gold-silver deposition occurred later than base-metal sulfide deposition, at temperatures near $250^{\circ}C$ and was probably a result of cooling and decreasing sulfur activity caused by sulfide precipitation and/or $H_2S$ loss (through fluid unmixing). Calculated sulfur isotope compositions of ore fluids (${\delta}^{34}S_{{\Sigma}S}=1.7$ to 3.3‰) indicate an igneous source of sulfur in hydrothermal fluids. Measured and calculated O and H isotope compositions of ore fluids (${\delta}^{18}O_{water}=4.8$ to 7.2‰, ${\delta}D_{water}=-73$ to -76‰) indicate that mesothermal auriferous fluids at Bodeok were likely mixtures of $H_2O-rich$, isotopically evolved meteoric waters and magmatic $H_2O-CO_2$ fluids.

• Korean Journal of Food Science and Technology
• /
• v.32 no.3
• /
• pp.590-597
• /
• 2000

The rheological properties of ${\beta}-glucans$ isolated from non-waxy and waxy barley were investigated. ${\beta}-Glucan$ solutions showed pseudoplastic properties and their behaviors were explained by applying Power law model in the range of concentrations$(1{\sim}4%)$ and temperatures$(20{\sim}65^{\circ}C)$. The effects of temperature and concentration on the apparent viscosity at $700\;s^{-1}$ shear rate were examined by applying Arrhenius equation and power law equation, and their effect was more pronounced in waxy ${\beta}-glucan$ solutions. The activation energy for flow of ${\beta}-glucan$ solutions decreased with the increase of concentration, and the concentration-dependent constant A increased with the increase of temperature. The intrinsic viscosity of waxy ${\beta}-glucan$ was higher than that of non-waxy ${\beta}-glucan$. The transition from dilute to concentrate region occurred at a critical coil overlap parameter $C^*[{\eta}]=0.02.$ The slopes of non-waxy and waxy ${\beta}-glucan$ at $C[{\eta}] were similar, but the slope of waxy ${\beta}-glucan$ at $C[{\eta}]>C^*[{\eta}]$ was higher than that of non-waxy ${\beta}-glucan$. Dynamic viscoelasticity measurement showed that cross-over happened, and storage modulus was higher than loss modulus at frequency range above cross-over. ${\beta}-Glucan$ solutions formed weak gels after stored for 24 hr.

• Journal of Bio-Environment Control
• /
• v.29 no.3
• /
• pp.209-218
• /
• 2020

This paper investigated actual crop evapotranspiration (ET_c) of tomato and paprika planted in test beds of the greenhouse. Crop water requirement (CWR) is the amount of water required to compensate ET_c loss from the crop. The main objectives of the study are to assess whether the actual crop watering (ACW) was adequate CWR of tomato and paprika and which amount of ACW should be irrigated to each crop. ET_c was estimated using the Penman-Monteith model (P-M) for each crop. ACW was calculated from the difference of amount of nutrient supply water and amount of nutrient drainage water. ACW and CWR of each crop were determined, compared and assessed. Results indicated CWR-tomato was around 100 to 1,200 ml/day, while CWR-paprika ranged from 100 to 500 ml/day. Comparison of ACW and CWR of each crop found that the difference of ACW and CWR are fluctuated following day of planting (DAP). However, the differences could divide into two phases, first the amount of ACWs of each crop are less than CWR in the initial phase (60 DAP) around 500 ml/day and 91 ml/day, respectively. Then, ACWs of each crop are greater than the CWR after 60 DAP until the end of cultivation approximately 400 ml/day in tomato and 178 ml/day in paprika. ET_c assessment is necessary to correctly quantify crop irrigation water needs and it is an accurate short-term estimation of CWR in greenhouse for optimal irrigation scheduling. Thus, reducing ACW of tomato and paprika in the greenhouse is a recommendation. The amount of ACW of tomato should be applied from 100 to 1,200 ml/day and paprika is 100 to 500 ml/day depend on DAP.

• The Journal of Korean Medicine
• /
• v.17 no.1 s.31
• /
• pp.374-406
• /
• 1996

This study has been carried out to investigate the types of differential diagnosis of amnesia. The results are as follows; 1. Amnesia has various types of differential diagnosis(辨證分型) ; deficiency of both the heart and spleen(心脾兩虛型), deficiency of the heart(心虛型), deficiency of the kidney(腎虛型), breakdown of the coordination between the heart and the kidney(心腎不交型), mental confusion due to phlegm(痰迷心竅型), accumulation of stagnant blood(蓄血型), internal injury by seven emotion (七情所傷型). 2. The type of deficiency of both the heart and spleen(心脾兩虛型) occurs when the heart and spleen is injured by overthinking(思慮過度), The symptoms are heart palpitation(心悸), continuous palpitation(??), insomnia(少寐), hypochondric discomfort(心煩), dream disturbed sleep(多夢), being easy to be scared(易驚), dizziness(眩暈), these are caused by blood deficiency of the heart(心血不足), poor appetite(飮食不振), loss of appetite(納?), short breath(氣短), sense of turgid abdormen(腹部膨滿感), loose stool(泥狀便), these are caused by deficiency of the spleen(脾虛), lassitude and weakness (身倦乏力), lassitude of the extremities (四肢無力), dim complexion (面色少華), pale lips(舌質淡), thready and feeble(脈細弱無力), these are caused by deficiency of both qi and the blood(氣血虛損). The remedy is nourishing the heart-blood(養心血) and regulating the spleen(理脾土). I can prescribe the recipes such as Guibitang(歸脾湯), Gagambosimtang(加減補心湯), Seongbitang(醒脾湯), Insin-guisadan(引神歸舍丹), Insamyangyoungtang(人蔘養榮湯), Sojungjihwan(小定志丸), Yungjigo(寧志膏), Palmijungjihwan(八味定志丸), etc., 3. The type of deficiency of the heart(心虛型) occurs when the heart-blood is injured by the mental tiredness(神勞) and so blood cannot nourish the heart. The symptoms are amnesia(健忘), short breath(氣短), heart palpitation(心悸), perspire spontaneously(自汗), facial pallidness(顔面蒼白), pale lips (舌質淡白), feeble pulse and lassitude(脈虛無力), intermittent pulse(結代脈). The remedy is nourishing the hart and blood and allaying restlessness(補心益血安神). I can prescribe the recipes such as Chenwangbosimdan(天王補心丹), Jeongji-hwan(定志丸), Gaesimhwan(開心丸), Youngjigo(寧志膏), Chilseonghwan(七聖丸), Baegseogyoungtang(白石英湯), Oseohwan(烏犀丸), Yangsinhwan(養神丸), Guisindan(歸神丹), Bogsinsan(茯神散), Jinsamyohyangsan(辰砂妙香散), Cheongeumboksinsan(千金茯神散), Samjotang(蔘棗湯), jangwonhwan(壯元丸), Sa gunjatang(四君子湯) minus rhizoma atractylodis macrocephalae(白朮) plus rhizoma acori graminei(石菖蒲), radix polygalae(遠志), cinnabaris(朱砂), etc. 4. The type of deficiency of the kidney(腎虛型) occurs when the kidney-qi and kidney-essence is deficient(腎氣腎精不足) and so it cannot nourish the brain. The symptoms arc amnesia(健忘), ache at the waist and lassitude in the lower extremities(腰산腿軟), dizziness and tinnitus(頭暈耳嗚), emmission and premature ejaculation(遺精早泄), burning sensation of the five centres(五心煩熱), flushed tongue(舌紅), rapid and small palse(脈細數). The remedy is nourishing the kidney and strengthen the essence(補腎益精). I can prescribe the recipes such as Gagamgobonhwan(加減固本丸), Jeongjihwan(定志丸), Gongseongchlmjungdan(孔聖枕中丹), Yugmigihwanghwan(六味地黃丸) plus ra-dix polygalae(遠志), fructus schizandrae(五味子), Yugmigihwanghwan(六味地黃丸) plus radix polygalae(遠志), fructus schizandrae(五味子), rhizoma acori graminei(石菖蒲), semen zizyphi spinosae(酸棗仁), Palmihwan(八味丸) plus fructus schizandrae(五味子), semen zizyphi spinosae(酸棗仁). etc., 5. The type of breakdown of the coordination between the heart and the kidney (心腎不交型) occurs when the heart-fire(心火) and kidney-fluid(腎水) are imbalanced. The symptoms are amnesia(健忘), hypochondric discomfort(心煩), insomnia(失眠), dizziness and tinnitus(頭最耳嗚), feverish sensation m the palms and soles(手足心熱), emmision(遺精), ache at the waist and lassitude in the lower extremities(腰?腿軟), flushed tongue(舌紅), rapid pulse(脈數). The remedy is coordinating each other(交通心腎). I can prescribe the recipes such as Gangsimdan(降心丹), Jujaghwan(朱雀丸), Singyotang(神交湯), Simsinyang- gyotang(心腎兩交湯), Yugmihwan(六味丸) plus fructus schizandrae(五味子), radix polygalae(遠志), Yugmihwan(六味丸) plus fructus schizandrae(五味子), radix polygalae(遠志), rhizoma acari graminei(石菖蒲), semen zizyphi spinosae(酸棗仁), etc., 6. The type of mental confusion due to phlegm(痰迷心竅型) occurs when the depressed vital energy(氣鬱) create phlegm retention(痰飮) and phlegm stagnancy(痰濁) put the heart and sprit(心神) out of order. The symptoms arc amnesia(健忘), dizziness(頭暈), chest distress(胸悶), nausea(惡心), dull(神思欠敏), dull and slow facial expression(表情遲鈍), tongue with yellow and greasy fur(舌苔黃?), sliperry pulse(脈滑). The remedy is removing heat from the heart to restore consciousness and dispersing phlegm(淸心化痰開竅) I can prescribe the recipes such as Gamibogryeongtang(加味茯?湯), Goa-rujisiltang(瓜蔞枳實湯), Jusaansinhwan(朱砂安神丸), Dodamtang(導痰湯) plus radix saussurea(木香), Yijintang(二陳湯) plus succus phyllostachyos(竹瀝), rhizoma zingiberis(生薑) Ondamtang(溫膽湯) plus rhizoma acori graminei(石菖蒲), rhizoma curcumae aromaticae(鬱金), etc., 7. The type of accumulation of stagnant blood(蓄血型) occurs when the blood is accumulated in the lower part of body. The symptoms are amnesia(健忘), chest distress(胸悶), icteric skin(身黃), rinsing the mouth but don't wanting eat(漱水不欲燕), madness(發狂), black stool(屎黑), pain in the lower abdomen(小腹硬痛). The remedy is dispersing phlegm and absorb clots (化痰化瘀), I can prescribe the recipes such as Jeodangtang(抵當湯), Daejeodanghwan(代抵當丸), Hyeolbuchugeotang (血府逐瘀湯) plus rhizoma acori graminei (石菖蒲), rhizoma curcumae aromaticae(鬱金), Jusaansinhwan(朱砂安神丸) plus rhizoma curcumae aromaticae(鬱金), radix polygalae(遠志), semen persicae(桃仁), cortex moutan radicis(收丹皮), etc., 8. The type of internal injury by seven emotion(七情所傷型) occurs when the anger injures the will stored in the kidney(腎志). The symptoms are amnesia(健忘), heart palpitation(心悸). hot temper(易怒), being easy to be scared(善驚), panic(易恐). The remedy is relieving the depressed liver and regulating the circulation of qi(疏肝解鬱). I can prescribe the recipes such as Tongultang(通鬱湯), Sihosogantang(柴胡疏肝湯) plus rhizoma acari graminei(石菖蒲), rhizoma curcumae aromaticae(鬱金), etc.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.9
• /
• pp.1208-1214
• /
• 2011

Caffeine, a psychoactive stimulant, has been implicated in the modulation of learning and memory functions due to its action as a non-selective adenosine receptors antagonist. On the contrary, some side effects of caffeine have been reported, such as an increased energy loss and metabolic rate, decrease DNA synthesis in the spleen, and increased oxidative damage to exerted on LDL particles. Therefore, the aim of this study was to develop a safe stimulant from natural plants mixture (Aralia elata, Acori graminei Rhizoma, Chrysanthemum, Dandleion, Guarana, Shepherd's purse) that can be used as a substitute for caffeine. Thirty SD rats were divided into three groups; control group, caffeine group (15.0 mg/kg, i.p.), and natural plants mixture group (NP, 1 mL/kg, p.o.). The effect of NP extract on stimulant activity was evaluated with open-field test (OFT) and plus maze test for measurement of behavioral profiles. Plasma lipid profiles, lipid peroxidation in LDL (conjugated dienes), total antioxidant capacity (TRAP) and DNA damage in white blood, liver, and brain cells were measured. In the OFT, immobility time was increased significantly by acute (once) and chronic (3 weeks) supplementation of NP and showed a similar effect to caffeine treatment. Three weeks of caffeine treatment caused plasma lipid peroxidation and DNA damage in liver cells, whereas there were no changes in the NP group. NP group showed a higher plasma HDL cholesterol concentration compared to the caffeine group. The results indicate that the natural plants mixture had a stimulant effect without inducing oxidative stress.

• Journal of dental hygiene science
• /
• v.16 no.1
• /
• pp.53-61
• /
• 2016

Eating supports to gain energy and nutrition and improves quality of life. Ageing affects the food intake ability due to loss of natural teeth and the progressive muscle degeneration. Our objective was to investigate how the food intake ability (FIA) and the remaining teeth could influence on oral health related quality of life in the elderly. This study was performed with 503 elderly subjects living in Daejeon, Korea. The questionnaire with the FIA with 30 Korean food and Oral Health Impact Profile 14 (OHIP-14) and oral examination were surveyed. The five groups according to cluster analysis of FIA had the different numbers of remaining teeth and functional posterior teeth with opposing teeth or prosthesis significantly: group 1, $21.78{\pm}8.27$ and $2.80{\pm}2.63$; group 2, $16.75{\pm}7.87$ and $2.16{\pm}2.44$; group 3, $14.68{\pm}9.77$ and $1.73{\pm}2.30$; group 4, $9.93{\pm}8.13$ and $0.78{\pm}1.68$; group 5, $10.18{\pm}8.37$ and $0.51{\pm}1.22$. The more foods the subjects could masticate, the better oral health related quality of life they had. The medium FIA, soft FIA and the number of remaining teeth could explain 46% of OHIP-14, but hard FIA could not in the multiple regression model. We suggested to develop the oral health program for the elderly to be able to eat the food with medium physical property at least be helpful to improve oral health related quality of life.

• Restorative Dentistry and Endodontics
• /
• v.36 no.4
• /
• pp.290-299
• /
• 2011

Objectives: The usage of fluoride varnish for a moderate to low caries-risk group has not been well validated. This study aimed to evaluate the preventive and therapeutic efficacies of fluoride varnish on the initiated root caries. Materials and Methods: Ten premolars were sectioned into quarters, further divided into two windows, one of which was painted with Fluor Protector (1,000 ppm fluoride, Ivoclar Vivadent). An initial lesion with a well-preserved surface layer was produced by pH cycling. Scanned line analysis using energy dispersive spectrometry determined the weight percentages of Ca and P in the demineralized layer. Scanning Electron microscopy and confocal laser scanning microscopy (CLSM) evaluated the varnish-applied root surfaces. Results: The mean lesion depth (SD) was 12.3 (2.6) ${\mu}m$ (single cycling) and 19.6 (3.8) ${\mu}m$ (double cycling). Double cycling extended the lesion depth, but induced no more mineral loss than single cycling (p < 0.05). The mean weight percentages of Ca and P between groups with and without varnish were not significantly different (p < 0.05). A CLSM showed varnish remained within 15 ${\mu}m$ of the surface layer. Conclusions: When a mild acid challenge initiated root tissue demineralization, the application of low-concentration fluoride varnish did not influence the lesion depth or the mineral composition of the subsurface lesion.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.64 no.4
• /
• pp.414-421
• /
• 2019

Pod shattering during the maturing stage causes a serious yield loss in soybean. It is the main limiting factor of soybean cultivation and mechanization. It is important to develop varieties suitable for mechanical harvesting and to develop energy-efficient agricultural machinery to save labor and costs. 'Daewonkong,' developed by the National Institute of Crop Science (NICS) in 1997, is an elite cultivar that occupies more than 80% of the soybean cultivation area in Korea because of its strong tolerance to pod shattering. The objectives of this study were to investigate the variation in pod shattering degree in a RIL population developed from a 'Daewonkong' parent and to select promising lines with pod shattering tolerance. 'Daewonkong' demonstrated a high level of tolerance to pod shattering compared to the 'Tawonkong' and 'Saeolkong' varieties, with no shattered pods after 72 hours of drying. Screening of pod shattering showed a clear distinction between the tolerant and susceptible varieties. Also, the distribution of shattering pod ratio in the two populations showed a similar pattern for three years. The promising lines with pod shattering tolerance included 27 lines in the 'Daewonkong'×'Tawonkong' population and 21 lines in the 'Daewonkong'×'Saeolkong' population. The promising lines are expected to be widely used as breeding parents for creating soybean cultivars with pod shattering tolerance.

• Economic and Environmental Geology
• /
• v.27 no.6
• /
• pp.557-561
• /
• 1994

Q estimates are made by direct measurements of energy loss per cycle from primary P and S waves, as a function of frequency. Assuming that intrinsic Q is frequency independent and scattering Q is frequency dependent over the frequencies of interest, the relative contributions of each, to a total observed Q, may be estimated. Test examples are produced by computing viscoelastic synthetic seismograms using a pseudo spectral solution with inclusion of relaxation mechanisms (for intrinsic Q) and a fractal distribution of scatterers (for scattering Q). The composite theory implies that when the total Q for S-waves is smaller than that for P-waves (the usual situation), intrinsic Q is dominating; when it is larger, scattering Q is dominating. In the inverse problem, performed by a global least squares search, intrinsic $Q_p$ and $Q_s$ estimates are reliable and unique when their absolute values are sufficiently low that their effects are measurable in the data. Large $Q_p$ and $Q_s$ have no measurable effect and hence are not resolvable. Standard deviation of velocity $({\sigma})$ and scatterer size (A) are less unique as they exhibit a tradeoff as predicted by Blair's equation. For the P-waves, intrinsic and scattering contributions are of approximately the same importance, for S-waves, the intrinsic contributions dominate.