• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.8
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• pp.331-336
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• 2016

This study presents a coolant density calculation device and its corresponding method by using a mass flowmeter and the LabVIEW program. The method can be easily measured with a mixture of coolant and by calculating the percentage of ethylene-glycol without additional investment. The cooling water is very important in a vehicle to protect the engine, and the cooling performance is affected by the mixture concentration and coolant density. The coolant density calculation device measures the mixed concentration in the anti-freeze cooling mixture made from distilled water and ethylene-glycol in real time with the mass flowmeter that is commonly attached to the radiator or heater core. The calculation program for the mixture concentration percentage was developed using the LabVIEW software. The correlation between experimental results and the calculation was conducted for a range of temperature from 40 to $90^{\circ}C$ and by varying the mixture ratio of distilled water and ethylene-glycol. As a result, the anti-freeze coolant concentration in the volume percentage is able to monitor the coolant density in a timely basis by implementing a mixture concentration calculation program without the need for additional equipment investment. The results of the calculation for the mixture concentration level show a maximum 2.7% deviation compared to the experimental results.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.160-165
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• 1999

Osmotic pressure induced by semi-permeability of hardened cement pasts and cement mortar was studied, which was considered to be a cause of failure such as separation and blistering of floor coatings or wall coatings from the concrete substrate. The specimens with a water cement ratio of 45, 60 and 75% were installed between the solution of sodium chloride and distilled water. First, we measured water flux from distilled water to sodium chloride and the ion flux of Na+ and Cl- through the specimens. Then, we measured osmotic pressure induced by semi-permeability of the specimens using an apparatus which was specially developed for this study. It was made clear that hardened cement paste and cement mortar have properties of semipermeability, and the osmotic pressure is closely related to their water cement ratio. Finally, we calculated the osmotic pressure according to Staverman's equation, which was obtained for organic membranes, and tried to explain quantitatively the observed pressure.

• Preventive Nutrition and Food Science
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• v.6 no.4
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• pp.224-229
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• 2001

We investigated the effects of bean sprouts (Glycine max), dropwort (Oenanthe javanica), and radish (Raphanus sativus var. hortensis for. acanthiformis) extracts on alcohol dehydrogenase (ADH). The extracts from three kinds of vegetables were prepared by extracting with boiling water, distilling water, and ethyl alcohol. Among extracts, boiling water extract showed the highest activating effect on ADH, respectively and distilled water extract had a greater effect on ADH activation than that of alcohol extract. The ADH facilitating effect of bean sprout extract by distilled water was significantly higher than dropwort or radish, hut the effect of the bean sprout extract by ethyl alcohol was lower than others. The facilitating effect on ADH of mixture extracts of bean sprout and dropwort were mixed at 1 : 1 mixture of boiled-water extract showed the highest effectiveness. And bean sprout extract separated below 3000 molecular weight (MW) range of extract fraction had greater ADH activity than large MW parts.

• Journal of the Korean Society of Visualization
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• v.20 no.3
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• pp.117-127
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• 2022

The present study has investigated the performance of hydrogen gas generators for inhalation purposes based on polyelectrolyte membrane water electrolysis (PEMWE). The system applied two watering methods. One is pumped water (pumping system) and the other is gravity-fed water without a pump (non-pumping system). The cell efficiencies were compared by measuring the cell voltage and temperature in the hydrogen gas generator, respectively. The results show that the cell voltage and temperature increase with the cell current. The cell temperature is lower in the pumping system than that in the non-pumping system at a given cell current. Even though the amount of hydrogen production is the same regardless of the pumping system, the cell efficiency of the hydrogen gas generator in the non-pumping system is better than that in the pumping system.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.06a
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• pp.302-302
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• 2011

• The Journal of Advanced Prosthodontics
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• v.8 no.5
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• pp.333-338
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• 2016

PURPOSE. The aim of this study was to compare the effects of different denture cleansers on the surface roughness and microhardness of various types of posterior denture teeth. MATERIALS AND METHODS. 168 artificial tooth specimens were divided into the following four subgroups (n=42): SR Orthotyp PE (polymethylmethacrylate); SR Orthosit PE (Isosit); SR Postaris DCL (double cross-linked); and SR Phonares II (nanohybrid composite). The specimens were further divided according to the type of the denture cleanser (Corega Tabs (sodium perborate), sodium hypochlorite (NaOCl), and distilled water (control) (n=14)) and immersed in the cleanser to simulate a 180-day immersion period, after which the surface roughness and microhardness were tested. The data were analyzed using the Kruskal-Wallis test, Conover's nonparametric multiple comparison test, and Spearman's rank correlation analysis (P<.05). RESULTS. A comparison among the denture cleanser groups showed that NaOCl caused significantly higher roughness values on SR Orthotyp PE specimens when compared with the other artificial teeth (P<.001). Furthermore, Corega Tabs resulted in higher microhardness values in SR Orthotyp PE specimens than distilled water and NaOCl (P<.005). The microhardness values decreased significantly from distilled water, NaOCl, to Corega Tabs for SR Orthosit PE specimens (P<.001). SR Postaris DLC specimens showed increased microhardness when immersed in distilled water or NaOCl when compared with immersion in Corega Tabs (P<.003). No correlation was found between surface roughness and microhardness (r=0.104, P=.178). CONCLUSION. NaOCl and Corega Tabs affected the surface roughness and microhardness of all artificial denture teeth except for the new generation nanohybrid composite teeth.

• Polymer(Korea)
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• v.26 no.2
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• pp.185-192
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• 2002

Rigid polyurethane foams (PUFs) were prepared from polymeric 4.4'-diphenyl-methane diisocyanate (PMDI), polyether polyol, 1,4-butane diol, silicone surfactant, and distilled water. The density of the PUF was decreased from 173.7 to 41.7 kg/㎥ with an increase in distilled water from 0.5 to 3.0 php (parts per hundred polyol by weight), respectively, at the 0 php butane diol. The cell size of the PUF increased from 115 to 258 $mu extrm{m}$ with an increase in the amount of distilled water from 0.5 to 3.0 php, respectively, at the 10 php butane diol. It was found that the compressive strength of the PUF increased with the content of distilled water, at the same density. Out of the study for the surfactant effect on the properties of the PUF, it was observed that the cell site of the PUF decreased from 360 to 146 $mu extrm{m}$ with an increase in the amount of the surfactant from 0 to 0.33 php, respectively, but the tell size did not change significantly when the amount of the surfactant exceeded 0.33 php.

• Horticultural Science & Technology
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• v.17 no.6
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• pp.758-760
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• 1999

This experiment was carried out to investigate the effect of pretreatments and holding solutions on quality and vase life of cut 'Saphir' rose (Rosa hybrida L.). Pulsing with aluminum sulfate or NaOCl prolonged vase life held in HQS+sucrose+ethionine. Solution absorption held in distilled water were more increased than held in HQS+sucrose+ethionine. Holding solution with 8-hydroxyquinoline sulfate (HQS)+sucrose+ethionine increased fresh weight compared with distilled water except pulsing with STS+sucrose. Pulsing with aluminium sulfate delayed bent-neck held in HQS+sucrose+ethionine. Flower diameter and dry weight of petal held in HQS+sucrose+ethionine were more increased than held in distilled water except pulsing with STS+sucrose. There were no significance in Hunter color value 'L' and value 'a', but value 'b' was decreased held in distilled water.

• Journal of Korean Medicine Rehabilitation
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• v.25 no.2
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• pp.73-80
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• 2015

Objectives To assess the safety of Shinbaro3 Pharmacopuncture by analyzing the potential single-dose intramuscular toxicity of Shinbaro3 Pharmacopuncture at various dose levels in SD (Spraque-Dawley) rats and Beagle dogs. Methods For evaluation of single-dose intramuscular toxicity of Shinbaro3 Pharmacopuncture, 40 SD rats (20 male and 20 famale) and 4 Beagle dogs (2 male and 2 female) were used. The rats were divided in four groups of 10 each, and treated intramuscularly with Shinbaro3 Pharmacopuncture at doses of 0.3, 0.6 and 1.2 mg/kg in distilled water, and distilled water as a vehicle control group, respectively. The Beagle dogs were divided into two groups of 2 each, and treated intramuscularly with Shinbaro3 Pharmacopuncture at doses of 0.15, and 0.3 mg/kg in distilled water, respectively, and signs of toxicity were observed. After a wash-out period of 3 days, the procedure was repeated with Shinbaro3 Pharmacopuncture at doses of 0.6, and 1.2 mg/kg in distilled water, respectively. Mortality, body weight changes, and necropsy findings were examined during the study period. Results There were no mortalities in either the SD rats or Beagle dogs. There were also no significant differences in adverse effects, body weight, or necropsy findings between the Shinbaro3 Pharmacopuncture and control groups. Conclusions There results suggest that the lethal dose 50 ($LD_{50}$) and approximate lethal dose (ALD) value of the test substance Shinbaro3 Pharmacopuncture are higher than 1.2 mg/kg in SD rats and Beagle dogs.

• Macromolecular Research
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• v.17 no.1
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• pp.44-50
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• 2009

Rigid polyurethane foams (PUF)s were synthesized with environmentally friendly blowing agents such as a cyclopentane/distilled water (10.0/1.0, pphp) mixture and distilled water only for four different silicone surfactants having different silicone/polyether ratios. An attempt was made to reduce the thermal conductivities of the PUF samples by varying the concentration and the silicone/polyether ratio of the various silicone surfactants. The scanning electron microscopy (SEM) results indicated an optimum concentration of the silicone surfactant of about 1.5 to 2.5 phpp for various surfactants to reduce the cell size and lower the thermal conductivity. The silicone surfactant having a higher silicone/polymer ratio showed a smaller cell size and, therefore, demonstrated the lower thermal conductivity of the PUF samples. From the relation between the thermal conductivity and the cell size of the PUF samples, the smaller cell size improved the thermal insulation property of the rigid PUF for both the PUF samples blown by the cyclopentane/distilled water (10.0/1.0, pphp) mixture and distilled water only. If the blowing agent is fixed, then the cell size is an important factor to decrease the thermal conductivity of the PUF samples. These results indicated that rigid PUF samples having lower thermal conductivity can be obtained by choosing a silicone surfactant containing a higher silicone/polyether ratio, as well as an optimum content of the surfactant.