• Parasites, Hosts and Diseases
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• v.48 no.1
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• pp.43-48
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• 2010

Cryptosporidium and Giardia are 2 protozoan parasites responsible for waterborne diseases outbreaks worldwide. In order to assess the prevalence of these protozoans in drinking water samples in the northern part of Portugal and the risk of human infection, we have established a long term program aiming at pinpointing the sources of surface water, drinking water, and environmental contamination, working with the water-supply industry. Total 43 sources of drinking water samples were selected, and a total of 167 samples were analyzed using the Method 1623. Sensitivity assays regarding the genetic characterization by PCR and sequencing of the genes, 18S SSU rRNA, for Cryptosporidium spp. and $\beta$, -giardin for G. duodenalis were set in the laboratory. According to the defined criteria, molecular analysis was performed over 4 samples. Environmental stages of the protozoa were detected in 25.7% (43 out of 167) of the water samples, 8.4% (14 out of 167) with cysts of Giardia, 10.2% (17 out of 167) with oocysts of Cryptosporidium and 7.2% (12 out of 167) for both species. The mean concentrations were 0.1-12.7 oocysts of Cryptosporidium spp. per 10 L and 0.1-108.3 cysts of Giardia duodenalis per 10 L. Our results suggest that the efficiency in drinking water plants must be ameliorated in their efficiency in reducing the levels of contamination. We suggest the implementation of systematic monitoring programs for both protozoa. To authors' knowledge, this is the first report evaluating the concentration of environmental stages of Cryptosporidium and Giardia in drinking water samples in the northern part of Portugal.

• Journal of the Korean Graphic Arts Communication Society
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• v.25 no.1
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• pp.43-52
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• 2007

Offset printing is one of the well known printing technique of lithographic process and consists of image area and 'non-image area on a flat image carrier. The surface tension of dampening water can be controlled by adding IPA after mixing of raw water and etching solution. The etching solution contains a surfactant for reducing surface energy, a clean agent for non-imaging area, wetting agent for protecting non-imaging area from oil components like ink and also an emulsifying agent for controlling emulsification. In this study, the present situation of dampening water maintenance has examined by collecting dampening water using at domestic companies. The pH related to dampening water, conductivity, contact angle, emulsification curve are measured to define the current situation of dampening water control of each companies and to analyze the relationship among measured properties. In the study most of companies among 16 printing companies tested controlling dampening water through pH value. However, the quality of printing has varied depending upon conductivity, contact angle, IPA content, and emulsification value. The control of dampening water should be carry at the state of the standard when adding proper ratio of etching solution. It would be more effective when pH or conductivity control carries out in parallel with controlling dampening water. Therefore the concept that pH5.5 is correct is based concept. Based on these initial tests it is defined that the standardization of dampening water control is required.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.2
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• pp.123-134
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• 2012

A typical cooling system of an engine relies on a water pump that circulates the coolant through the system. The pump is typically driven by the crankshaft through a mechanical link with engine starting. In order to reduce the friction and warm-up time of an engine, the clutch-type water pump (CWP) was applied in 2.0 liter diesel vehicle. The clutch-type water pump can force cooling water to supply into an engine by the operation of an electromagnetic clutch equipped as the inner part of pump system. The onset of CWP is decided by temperature of cooling water and engine oil. And, the control logic for an optimal operation of the clutch-type water pump was developed and applied in engine and vehicle tests. In this study, the warm-up time was measured with the conventional water pump and clutch-type water pump in engine tests. And the emission and the fuel consumption were evaluated under NEDC mode in vehicle tests. Also, tests were carried out for the various temperature conditions starting the operation of CWP. From the results of the study, the application of CWP can improve the fuel consumption and $CO_2$ reduction by about 3%.

• Journal of Korean Society on Water Environment
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• v.34 no.6
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• pp.669-677
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• 2018

Torrential rain and drought are repeated due to the increase in the unpredictable fluctuating of rainfall patterns. It is time for stabilize water resource management in terms of disaster prevention. Distributed control from sources is needed to minimize damages caused by torrential rains and droughts. Rain barrel can be used to reduce the runoff as they collect and store rainwater. In response to this situation, Seoul Metropolitan Government and other local governments implemented a project to support the installation of rain barrel and provided 90% of the cost of installing it in private areas. However, with limited budget, it is difficult to distribute rainwater to the city which is mostly covered by private areas. In this study, Samho-dong, Ulsan, where pilot projects of water cycle leading city are underway, analyzed the effects of reducing the runoff with respect to the amount of rainwater that can be used, and analyzed the economics of recoverable investment cost when installed. From the analysis, it was established that it is possible to show sufficient efficiency with a small capacity without the need to install large rain barrel effectively in the private sector, and to support the installation cost of less than 70 percent of the rainwater can be recovered.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.5
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• pp.983-990
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• 2024

Water quality management is an important element of aquaculture, and digitization of water quality information can be said to be the starting point of smart aquaculture. The complex water quality sensor is an IoT device that automatically measures arrow items such as pH, DO, water temperature, and salinity. However, due to the high price of the water quality sensor, it is economically burdensome to apply it to all aquaculture tanks, and it requires specialized knowledge to maintain them, making it difficult for small-scale aquaculture providers to apply them. In this paper, we propose a multi-channel complex water quality sensor to solve this problem. The proposed system is a device that measures the water quality of multiple tanks with a single sensor through valve control with a pump, thereby reducing sensor purchase costs for fish farms. In addition, we aimed to extend the service life of the sensor and improve the convenience of management by providing an automatic cleaning function using fresh water after measurement.

• Korean Journal of Medicinal Crop Science
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• v.19 no.6
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• pp.501-507
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• 2011

This experiment was carried out in order to collect the basic data on the standardization of the manufacturing process of Rehmannia glutinosa Libosch. var. purpurea Makino drying. By the drying methods of R. glutinosa, the content of water, inorganic components, reducing sugar, catalpol and benzo[${\alpha}$]pyrene were investigated. The water content was 15.6~17.2% when R. glutinosa was dried by cold-warm air moisture absorption drying method (CAMAD) at $60^{\circ}C$ during 6 days. Among of the inorganic components of R. glutinosa the K content was the most followed by P, Na, Ca and Mg. The reducing sugar content of R. glutinosa by the hot air drying method (HAD) was much more than that by the CAMAD. The catalpol content of R. glutinosa was not different by the drying temperature when it was dried by the CAMAD. The catalpol content of the large size tuber (about 50.0 g/unit) showed a tendency to increase from $60^{\circ}C$ until $70^{\circ}C$ drying temperature, but that of the small size tuber(about 4.0 g/unit) was decreased as being a trend as the drying temperature high when R. glutinosa was dried by the HAD, But the catalpol content R. glutinosa had a tendency to drop significantly at drying temperature above $80^{\circ}C$. The benzo[${\alpha}$]pyrene content was little detected when R. glutinosa was dried by both the SLD and the CAMAD, and the sampling by the HAD indicated within the scope of 5 ${\mu}g/kg$ which was the scope to regulate by Korean food and drug administration. In conclusion, it seemed that an appropriate drying temperature of R. glutinosa by the CAMAD and the HAD was about $60^{\circ}C$ and about $70^{\circ}C$, respectively, when we consider the catalpol content and benzo[${\alpha}$]pyrene detection in the manufacturing process of drying R. glutinosa.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.622-632
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• 2018

The aim of the present study was to evaluate of turmeric (Curcuma longa L.) on the physiological activities and oxidation inhibitory action. The effects of various solvents (distilled water DW, 70% ethanol and n-butanol) on the total phenolics content (TPC) of turmeric and their corresponding biological activity were studied. Bioactive compound of total saponin $7.506{\pm}0.349mg\;SE/g$ dry weight. Turmeric extracts yield were DW (17.11%), 70% ethanol (15.26%) and n-butanol (4.12%), respectively. Oxidation inhibitory action of the samples exhibited a dose-dependent increase. However, in the current study, none of the samples evaluated showed activity as strong as the BHA, ascorbic acid and EDTA. Results showed that extraction solvent had significant effects on TPC and oxidation inhibitory action (DPPH radical scavenging activity, ABTS radical scavenging activity, reducing power and ferric reducing antioxidant power) of n-butanol. Turmeric exhibited the antioxidant properties, which suggests that the plant material could be used for further studies as a potential source for bioactive and natural antioxidant.

• Food Science and Preservation
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• v.18 no.1
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• pp.59-64
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• 2011

This study was performed to investigate antioxidant activity of various solvent extracts (methanol, ethanol, acetone and water) from canola meal. As the concentration of all extracts increased, antioxidant activities increased gradually. Among solvent extracts from canola meal, methanol extract showed the highest antioxidant activities with $EC_{50}$ values of 0.9, 3.5, 1.3, and 8.5 mg/mL for DPPH radical scavenging ability, ABTS radical scavenging ability, reducing power, and chelating ability, respectively, and it had the highest total phenolics and total flavonoids contents. Furthermore, methanol extract was fractionated into three fractions (MF 1, MF 2, and MF 3) using Sephadex LH-20 column. The highest antioxidant activity was found on MF 2 for DPPH radical scavenging ability, on MF 3 for ABTS radical scavenging ability and reducing power, and on MF 1 for chelating ability at the same concentration of 1.5 mg/mL. The results indicated that each fraction containing various antioxidant materials seemed to have different influence at each antioxidant activity.

• Journal of Life Science
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• v.22 no.11
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• pp.1507-1514
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• 2012

Oxidative stress leads to damage in all components of the cell, including proteins, lipids, and DNA due to imbalance between reactive oxygen species production and cellular detoxification. Phytochemicals are well-known to contain antioxidants, and their physiological role has been intensively studied. The fruit of Cornus officianalis has been used in oriental medicine and has been reported to have many functions. In this study, four different extraction techniques were applied to extract functional components from the fruit of Cornus officianalis, and the content of loganin, which is an antioxidant having DPPH radical and hydrogen peroxide scavenging activity and reducing power, was analyzed in each extract. Extraction techniques employed in this study were heat extraction by water, 70% ethanol extraction, enzyme treatment, and combination of enzyme treatment and heat extraction by water. All extracts contained 11.8-18.0 mg/g loganin and showed antioxidation function assayed by measuring DPPH radical and hydrogen peroxide scavenging activity and reducing power. Among them, heat extraction was the most effective technique, showing a maximum amount of loganin (18.0 mg/g) and antioxidative activity at 100 mg/ml concentration. Each extract showed very low cytotoxicity up to at 500 mg/ml but 10-20% cytotoxicity at 1,000 mg/ml by in vitro MTT assay.

• Journal of agriculture & life science
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• v.44 no.2
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• pp.57-66
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• 2010

The antioxidant and neuronal cell protective effects of water extract from purple sweet potato were investigated. The total phenolics and monomeric anthocyanin contents of purple sweet potato extract were 44.25 mg/g and 2,394 mg/L, respectively. The antioxidant activities of purple sweet potato extract were evaluated using various antioxidant tests, including 1,1-diphenyl- 2-picrylhydrazyl (DPPH), 2,2'-azino- bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activities, ferric reducing/antioxidant power (FRAP) and reducing power. In these assays, the extract of purple sweet potato presented significant radical scavenging activities, FRAP, and reducing power in a dose-dependent manner. MTT {3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyl- tetrazoliumbromide} reduction assay showed significantly increase in cell viability when PC12 cells were pretreated with purple sweet potato extract. Because oxidative stress is also known to increase neuronal cell membrane breakdown, we further investigated by lactate dehydrogenase (LDH) and neutral red uptake assay. Purple sweet potato extract inhibited oxidative stress-induced membrane damage in neuronal cells. Therefore, these data results demonstrated that water extract of purple sweet potato have antioxidant activity and neuronal cell protective effect thus it has great potential as a natural source for human health.