• Preventive Nutrition and Food Science
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• v.9 no.2
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• pp.150-155
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• 2004

The free radical scavenging activities and the protective effects of Rhus javanica extracts against oxidative damage induced by reactive oxygen species (ROS) were investigated. n-Hexane, ethyl acetate and water fractions were prepared from a methanol extract. DPPH radical, superoxide anion and hydroxyl radical scavenging activities were estimated. Intracellular ROS formation was quantified using fluorescent probes, 2', 7'-dichlorofluorescin diacetate (DCFH-DA) for hydroxyl radical and dihydroethidium (DHE) for superoxide anion. The oxidative DNA damage was investigated by the comet assay in HepG$_2$ cells exposed either to $H_2O$$_2$ or to menadione. The highest $IC_{50}$/ values for DPPH radical scavenging activity was found in the ethyl acetate fraction with a value of 5.38 $\mu\textrm{g}$/mL. Cells pretreated with $\geq$ 1 $\mu\textrm{g}$/mL of the ethyl acetate extract had significantly increased cell viability compared to control cells, which were not pretreated with the extract. Intracellular ROS formation and DNA damage in HepG$_2$ cells, which were pretreated with the various concentrations of Rhus javanica ethyl acetate extract and then incubated either with $H_2O$$_2$ or with menadione, reduced in a dose-dependent manner. These findings suggest that Rhus javanica might have biologically active components which have strong protective effects against ROS induced oxidative damages to the biomolecules, such as cell membranes and DNA.

• Korean Journal of Environmental Agriculture
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• v.42 no.1
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• pp.1-7
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• 2023

Super absorbent polymers (SAPs) are hydrophilic molecules that can absorb large amounts of water. This study was conducted to investigate the enhancement of the physicochemical properties of sand soil blended with three SAPs imbibed with 100, 150, and 200-fold water. Three treatments were applied, namely, 100SAP, 150SAP, and 200SAP. The three SAPs were blended at concentrations of 0% (control), 3%, 5%, 7%, and 10% with sand. The pH, electrical conductivity, and cation exchangeable capacity (CEC) of soil blended with the three SAPs were pH 6.35-6.46, 0.09-0.65 dS/m, and 1.42-1.92 cmol_c/kg, respectively, and their capillary porosity, total porosity, and saturated hydraulic conductivity were 21.0-29.3%, 39.2-48.7%, and 272-470 mm/hr. CEC, capillary porosity, total porosity, and saturated hydraulic conductivity of soil were positively correlated with the ratio of the SAPs (p<0.01). These results indicate that blending sand soil with SAPs increased CEC, capillary porosity, and saturated hydraulic conductivity, thus improving the nutrient-retention capacity, water-retention capacity, and permeability of the soil.

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.457-464
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• 2023

The rendering residue generated by rendering disposal, an eco-friendly livestock carcass disposal method, is a useful agricultural resource. Methods for recycling this are being actively researched, and this study investigated the impact of applying rendered residue directly to soil on crop productivity and the agricultural environment. The chemical properties of the rendering residue were examined. The pH, OM, T-N, T-P, CaO, K₂O, and MgO content values were 5.47%, 59.8%, 9.22%, 2.96%, 2.16%, 0.51% and 0.10%, respectively. Treatment conditions were divided into control, inorganic fertilizer, and rendering residue, and rendering residue corresponding to 50, 100, and 200% nitrogen content was applied based on the amount of inorganic fertilizer nitrogen input. Greenhouse gases and ammonia were collected during the cultivation period. Rendering residue increased both the yield and growth of peppers and was effective in improving nutrients such as pH and OM of the soil after harvest. However, compared to inorganic fertilizer treatment, it increased emissions of nitrous oxide and methane as well as ammonia. It is judged that the direct agricultural use of rendering residue is difficult, and a utilization method is needed.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.4
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• pp.129-134
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• 2018

Recently, the artificial neural network (ANN) model is a promising technique in the prediction, numerical control, robot control and pattern recognition. We predicted the outside temperature of greenhouse using ANN and utilized the model in greenhouse control. The performance of ANN model was evaluated and compared with multiple regression model(MRM) and support vector machine (SVM) model. The 10-fold cross validation was used as the evaluation method. In order to improve the prediction performance, the data reduction was performed by correlation analysis and new factor were extracted from measured data to improve the reliability of training data. The backpropagation algorithm was used for constructing ANN, multiple regression model was constructed by M5 method. And SVM model was constructed by epsilon-SVM method. As the result showed that the RMSE (Root Mean Squared Error) value of ANN, MRM and SVM were 0.9256, 1.8503 and 7.5521 respectively. In addition, by applying the prediction model to greenhouse heating load calculation, it can increase the income by reducing the energy cost in the greenhouse. The heating load of the experimented greenhouse was 3326.4kcal/h and the fuel consumption was estimated to be 453.8L as the total heating time is $10000^{\circ}C/h$. Therefore, data mining technology of ANN can be applied to various agricultural fields such as precise greenhouse control, cultivation techniques, and harvest prediction, thereby contributing to the development of smart agriculture.

• Reproductive and Developmental Biology
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• v.28 no.4
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• pp.211-219
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• 2004

The effects of adenosine 5'-triphosphate (ATP) and ATP analogs, P/sub 2y/ purinoceptor agonists, on growth of normal mouse mammary epithelial cells (NMuMG) were examined. Cells were plated onto 24 well plates in DMEM supplemented with 10 % fetal calf serum. After serum starvation for 24 hours, ATP, P/sub 2y/ purinoceptor agonists (AdoPP[NH]P, ATP-α-S, ATP-γ-S, β, γ-me-ATP and 2me-S-ATP), P/sub 2u/ purinoceptor agonist (UTP) and P/sub 2y/ purinoceptor antagonists (Reactive Blue 2, more selective to P/sub 2y/ receptor than PPADS; PPADS) were added. DNA synthesis was estimated as incorporation of 3H-thymidine into DNA (1 hour pulse with 1 μ Ci/ml, 18～19 hours after treatment). ATP, Adopp[NH]P, ATP-α-S or ATP-γ-S, significantly increased DNA synthesis at 1, 10 and 100 μM concentrations with dose-dependency (P<0.05), and the maximum responses of ATP and ATP analogs were shown at 100 μM concentration (P<0.05). The potency order of DNA synthesis was ATP≥ATP- γ -S>Adopp [NH]P>ATP-α-S. β, γ -me-ATP, 2me-S-ATP and UTP did not increase DNA synthesis. In autoradiographic analysis of percentage of S-phase cells, similar results were observed to those of DNA synthesis. Addition of 1, 10 or 100 μM Reactive Blue 2 or PPADS significantly decreased ATP (100 μM)-induced DNA synthesis, however, PPADS was less effective than Reactive Blue 2. In Elvax 40P implant experiment, ATP directly stimulated mammary endbud growth in situ suggesting the physiological regulator of ATP in mammary growth. ATP 100 μM rapidly increased MAPK activity, reaching a maximum at 5 min and then gradually decreasing to the base level in 30 min. ATP analogs, Adopp[NH]P and ATP-γ-S also increased MAPK activity, however, β, γ-me-ATP and 2me-S-ATP did not. The inhibitor of the upstream MAPK kinase (MEK), PD 98059 (25 μM), effectively reduced ATP (100 μM) or EGF(10 ng/ml, as positive control)-induced MAPK activity and DNA synthesis (P<0.05). These results indicate that ATP-induced DNA synthesis was prevented from the direct inhibition of MAPK kinase pathway. Overall results support the hypothesis that the stimulatory effects of normal mouse mammary epithelial growth by addition of ATP or ATP analogs are mediated through mammary tissue specific P/sub 2y/ purinoceptor subtype, and MAPK activation is necessary for the ATP-induced cell growth.

• Fisheries and Aquatic Sciences
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• v.20 no.11
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• pp.30.1-30.10
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• 2017

Small-scale fish farmers in developing countries are faced with challenges owing to their limited information on aquaculture management. Nile tilapia farmers in Teso North Sub-County recorded lower yields than expected in 2009 despite having been provided with required inputs. Water quality was suspected to be the key factor responsible for the low yields. This study sought to assess the effects of earthen pond water physico-chemical parameters on the growth of Nile tilapia in six earthen fish ponds under semi-intensive culture system in Teso North Sub-County. The study was longitudinal in nature with pond water and fish being the units of analysis. Systematic sampling was used to select five ponds while a control pond was purposively selected based on its previously high harvest. Four ponds were fed by surface flow and two by underground water. Each pond was fertilized and stocked with 900 fry of averagely 1.4 g and 4.4 cm. Physico-chemical parameters were measured in-situ using a multi-parameter probe. Sixty fish samples were randomly obtained from each pond fortnightly for four months using a 10 mm mesh size and measured, weighed and returned into the pond. Mean range of physico-chemical parameters were: dissolved oxygen (DO) 4.86-10.53 mg/l, temperature $24-26^{\circ}C$, pH 6.1-8.3, conductivity $35-87{\mu}S/cm$ and ammonia 0.01-0.3 mg/l. Temperature (p = 0.012) and conductivity (p = 0.0001) levels varied significantly between ponds. Overall Specific Growth Rate ranged between 1.8% (0.1692 g/day) and 3.8% (1.9 g/day). Ammonia, DO and pH in the ponds were within the optimal levels for growth of tilapia, while temperature and conductivity were below optimal levels. As temperature and DO increased, growth rate of tilapia increased. However, increase in conductivity, pH and ammonia decreased fish growth rate. Temperature and DO ranging between 27 and $30^{\circ}C$ and 5-23 mg/l, respectively, and SGR of 3.8%/day and above are recommended for higher productivity.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.229-234
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• 2002

Under the hostile influence of the extreme space environmental conditions due to the deep space and direct solar flux, the thermal control in space applications is especially of major importance. There are tight temperature range restrictions for electro-optical elements while on the other hand there are low power consumption requirements due to the limited energy sources on the spacecraft. So, we usually have strong requirement of thermal and power control module in space applications. In this paper, the design concept of a thermal and power control module in the MSC(Multi-Spectral Camera) system which will be a payload on KOMPSATII is described in terms of H/W & S/W. This thermal and power control module, called THTM(Thermal and Telemetry Module) in MSC, resides inside the PMU(Payload Management Unit) which is responsible for the proper management of the MSC payload for controlling and monitoring the temperature insides the EOS(Electro-Optic System) and gathering all the analog telemetry from all the MSC sub-units, etc. Particularly, the designed heater controller has the special mode of "duty cycle" in addition to normal closed loop control mode as usual. THTM controls heaters in open loop according to on/off set time designed through analysis in duty cycle mode in case of all thermistor failure whereas it controls heaters by comparing the thermistor value to temperature based on closed loop in normal mode. And a designed THTM provides a checking and protection method against the failure in thermal control command using the test pulse in command itself.

• Applied Chemistry for Engineering
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• v.8 no.5
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• pp.709-714
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• 1997

$TiO_2$ hydrate coating on mica in an aqueous solution of $TiOSO_4$ by the hydrolysis using ammonia water studied with emphasis on coating conditions for a uniform coating. For the uniform coating of $TiO_2$ film on mica surface, it was found that smaller mica particles were coated more uniformly compared to larger particles. It was necessary to suppress the rate of formation of hydrated $TiO_2$ particles in solution, which were deposited on mica and generate irregular coating. It was also necessary to control precipitation yield by varying the reaction temperature to obtain uniform coating. More uniform coating was obtained with higher precipitation yield. A uniform dense film was formed when mica particles of average size of $14.7{\mu}m$ is used for mica slurry solution, of which pH is 2.5, and the factor of acidity of $TiOSO_4$ solution is 291, and the solution was kept at $80^{\circ}C$ for 3 hours. The morphology of $TiO_2$ film formed on mica was little affected by firing at $900^{\circ}C$.

• Applied Chemistry for Engineering
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• v.25 no.1
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• pp.84-89
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• 2014

In this work, Ag-$TiO_2$ nanocomposites were prepared via the sonochemical deposition of Ag nanometals on $TiO_2$ nanoparticles. The size of deposited Ag nanometals was ranged in 1~3 nm and the number of Ag nanometals deposited on $TiO_2$ increased in proportion to the dosage amounts of Ag precursors. As-prepared Ag-$TiO_2$ was loaded on the sterilized agar plate together with an aliquot volume of diluted E-coli, followed by 30 min irradiation of the solar simulated light ($600{\sim}1800{\mu}w/cm^2$). Finally, the agar plate was incubated for 24 h at $37^{\circ}C$ and the number of survived colonies were counted. It was experimentally confirmed that Ag-$TiO_2$ exhibited the higher antimicrobial activity than that of pure $TiO_2$, based on measuring the colony number of control sample. The survived colony numbers on the agar plate decreased with the increase of dosage amounts of Ag-$TiO_2$ and the irradiated intensity of solar simulated light for 30 min before incubating. The increase of Ag nanometal doposition induced the progressive enhancement of antimicrobial activity, but rather reduced the photocatalytic activity of Ag-$TiO_2$ probably due to the excessive presence of Ag nanometals on $TiO_2$ matrix.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.867-873
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• 2023

In this study, for the purpose of standardized quality control of a cold medicine, we simultaneous analyzed four main chemical components of a cold medicine: acetaminophen, caffeine, methyl paraben, and propyl paraben. The sample was subjected to quantitative analysis using high performance liquid chromatography (HPLC), after pretreatment of four components. The experiment was carried out by using Isocratic elution at wavelength of 270nm. Acetonitrile and water (H₂O) were used as a mobile phase at a flow rate of 1.0mL/min in a commercial C18 reversed-phase column. A volume of 10uL cold medicine were injected into the column with column oven temperature at 35℃. As a result of the experiment, the values of Resolution were 4.983, 1.596, 5.519, and 1.678 respectively-well over Rs >1.5, which indicates that the separation of four components were efficient. In addition, value of symmetry factor of the components was 1.056, 1.069, 1.032, and 1.133 respectively, to show its symmetrical stability. The calibration curve of all four components exhibits good linearity with R² >0.9995 to 0.9999. Furthermore, the limit of detection(LOD) were between 0.0118 to 1.5973 mg/mL, while the limit of quantification (LOQ) were between 0.0353 to 4.7919 ㎍/mL with the recovery rate of 79.6% ~ 120.5%. The results of this study showed an efficient quality evaluation of a simultaneous analysis method for cold medicine components.