• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.231-237
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• 2017

This paper presents an implementation of a smart flowerpot which can adjust humidity and illumination automatically after monitoring the temperature, humidity, and illumination. We made a container of the flowerpot with a 3D printer and embedded a NodeMCU micro controller in it. We attached a temperature sensor, a humidity sensor, an illumination sensor, and a water pump to the NodeMCU. We developed a control program that adjusts humidity and illumination and ran it on the NodeMCU. Also we developed an Android application and set up an MQTT server. Using the MQTT server, the NodeMCU and the Android application can exchange messages which keep sensor values and commands. Using the Android application. the user can send the proper temperature, humidity, and illumination to the smart flowerpot and monitor the sensor values.

• Journal of the Korea Concrete Institute
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• v.20 no.6
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• pp.827-832
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• 2008

This study evaluated fire resistance performance for hybrid (polypropylene+steel) fiber reinforced high strength concrete column. Full-size columns were constructed and tested with or without fibers using ISO-834 fire curve. As the result of test, Control specimen occurred serious spalling and indicated rapidly internal temperature increasing. Specimen with polypropylene fiber occurred not spalling but steady internal temperature increasing. Specimen with hybrid fiber occurred not spalling as well as does not propagated temperature distribution. Therefore, hybrid fiber reinforced column specimen indicated a good fire resistance performance than other cases.

• Journal of Technologic Dentistry
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• v.27 no.1
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• pp.79-88
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• 2005

This study was performed to investigate the surface properties of electrochemically oxidized pure niobium by anodic oxide and hydrothermal treatment technique. Niobium specimens of $10\times10mm$ in dimension were polished sequentially from #600, #800, #1000 emery paper. The surface pure niobium specimens were anodized in an electrolytic solution that was dissolved calcium and phosphate in water. The electrolytic voltage was set in the range of 250 V and the current density was 10 $mA/cm^2$. The specimen was hydrothermal treated in high-pressure steam at 300$^{\circ}C$ for 2 hours using an autoclave. Then, specimens were immersed in the Hanks' solution with pH 7.4 at 37$^{\circ}C$ for 30 days. The surface of specimen was characterized by scanning electron microscope(SEM), energy dispersive X-ray microanalysis(EDX), potentiostat/galvanostat test, and cytotoxicity test. The results obtained was summarized as follows; According to the result of measuring corrosion behavior at 0.9% NaCl, corrosion resistance was improved more specimens treated with anodic oxide than in hydrothermal treated ones. The multi-porous oxide layer on surface treated through anodic oxidation showed a structure that fine pores overlap one another, and the early precipitation of apatite was observed on the surface of hydrothermal treated samples. According to the result of EDX after 30 days deposition in Hanks' solution, Ca/P was 1.69 in hydrothermal treated specimens. In MTT test, specimens treated through anodic oxidation and hydrothermal treated ones showed spectrophotometer similar to that of the control group. Thus no significant difference in cytotoxicity was observed (P>0.05).

• Journal of Forest and Environmental Science
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• v.11 no.1
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• pp.61-71
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• 1995

From Salix maximowiczii of the Korean Salix, morphological and palynological characters were investigated by stereoscopic, light, and scanning electron microscopes. Also, this study was eonducted to investigate the effect of meteorological factors on the disjunct distribution in Salix maximowiczii forests grown within the restricted region. 1. Morphological characters of S. maximowiczii clarified with the descriptions and figures. 2. The palynological description was made to the S. maximowiczii and identified distinctly species. 3. S. maximowiczii is distributed only in Baekdam and Hangyeryong valley of Mt. Sorak in Kangwon-do, and valley of height region in Kyeongseong-gun (Hamgyongbuk-do), Sinhueng-gun, and Pungsan-gun (Hamgyongnam-do) in North Korea. 4. Water factors was better than temperature factors in the influence of meteorological factors for disjunct distribution. 5. These ecological and taxonomical informations could be used in practical application for silvicultural prescription, such as erosion control forest, timber production, and development of green area in river bank.

• Journal of Environmental Health Sciences
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• v.12 no.2
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• pp.1-9
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• 1986

The purpose of this study is to determine the antidotal effects of thiamine in phenylmercury poisoning rats. Sixty-six rats were divided into six groups the control group, the $40{\gamma}$ thiamine-only-dosed group, the 6 ppm phenylmercury-only-dosed group, the simultaneously-dosed-group with 6 ppm mercury & $20{\gamma}$ thiamine, and with 6 ppm mercury & $40{\gamma}$ thiamine, and with 6 ppm mercury & $80{\gamma}$ thiamine. The thiamine was put into pellet by various concentrations, and phenylmercury was mixed in drinking water by 6 ppm concentration. The rats were sacrificed for observing the histopathological changes of brain, liver and kidney. The remits summarized are as follows 1. In the group dosed with only $40{\gamma}$ thiamine, the tissues of brain, liver and kidney did not show any abnormal architecture. 2. The phenyhnercury-only-dosed group and the simultaneoulsy-dosed group with mercury and $20{\gamma}$ thiamine showed remarkable degenerative or necrotic hepatic cells. In addition, a remarkable swelling and necrosis on epithelium of proximal tubules in kidney were found. 3. The simultaneously-dosed group with mercury and $40{\gamma}$ thiamine showed moderate degeneration and necrosis of Purkinje cells in cerebellum. A moderate necrosis and swelling on epithelium of proximal tubules and a large amount of tubular casts were found as well. 4. The simultaneously-dosed group with mercury and $80{\gamma}$ thiamine showed a slight degenerative change of Purkinje cells. A slight degenerative change on epithelium of proximal tubules and a small amount of tubular casts were also found.

• KSBB Journal
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• v.19 no.1
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• pp.1-11
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• 2004

Chlorella contains a rich source of biochemical products with applications in the feed, food, nutritional, cosmetic, pharmaceutical and even fuels industries. Chlorella is one of unicellular green algae and is mostly grown in fresh water such as pond and lake. It grows in a manner of nonsexual reproduction so that it multiplies 4~16 times overnight. Large-scale culture is conducted by open pond culture or pure culture using fermenter. Chlorella has various efficacies such as heavy metal removal, degradation of toxic materials, control of arteriosclerosis, immunoprotective effects, anticancer activity and growth-stimulating activity of intestinal bacteria. Chlorella can be used as a taste enhancer and foodstuff, as it has a plenty of essential amino acids, polyunsaturated fatty acids, sterols and chlorella growth factor (CGF). Chlorella is a potential organism which can be utilized for CO$_2$ removal and H$_2$ Production in environmental area and energy Production.

• Journal of Aquaculture
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• v.3 no.1
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• pp.25-30
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• 1990

Adult channel catfish, Ictalurus punctatus, mature but do not ovulate and spawn in ponds in Korea. Ovulation and natural spawning were induced in the breeding season by increasing water temperature or injecting one to three doses of both 4.4 mg dried carp pituitary or 1,100 IU human chorionic gonadotropin(HCG) per kg body weight at 24 hours intervals when plural doses were employed. The increasing higher temperature (from $24^{\circ}C$ to $30^{\circ}C$) resulted in 4 times greater ovulation than lower increase of temperature (from $24^{\circ}C$ to $27^{\circ}C$). In overall performance, dried carp pituitary gave $78.6\%$ ovulation and HCG induced $66.6\%$ ovulation. None of the control fish spawned in any of the experiments.

• Culinary science and hospitality research
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• v.16 no.3
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• pp.250-258
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• 2010

This study was performed to find the most desirable mixing formula for Sulgidduk added with Cheongkukjang powder for various benefits. The optimal mixing formulas were identified by evaluations of ingredients, the color, and the sensory and textual characteristics. As the amount of Cheongkukjang powder increased, the rice cake appeared redder, yellower and less luminous. The amount of crude ash was significantly smaller in the experimental groups than in the control group, and the amount of crude protein and crude fat was significantly high. The change in texture according to the amount of Cheongkukjang powder was not statistically significant, but hardness, adhesiveness, and cohesiveness showed significant differences(p<0.05). It was also found that chewiness increased while adhesiveness decreased as storage time increased. According to the results of the sensory evaluation, scores in the color and aroma decreased as the amount of Cheongkukjang powder increased. Overall acceptability score was highest in the 5% group, consisting of 68% of rice powder, 5% of Cheongkukjang powder, 10% of sugar, and 17% of water.

• Membrane and Water Treatment
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• v.11 no.1
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• pp.59-68
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• 2020

The study objective was to evaluate the enhanced removal of high concentrations of phosphorus from synthetic wastewater (solely phosphorus-containing) and real wastewater (pig manure) by using carbon nanotube (CNT)-coated steel slag. Generally, phosphorus removal by steel slag is attributed to Ca²⁺ eluted from the slag. However, in this study, CNT was used to control the excess release of Ca²⁺ from steel slag and increase the phosphorus removal. The phosphorus removal rate by the uncoated steel slag was lower than that of the CNT-coated steel slag, even though the Ca²⁺ concentrations were higher in the solution containing the uncoated steel slag. Therefore, the phosphorus removal could be attributed to both precipitation with Ca²⁺ eluted from steel slag in aqueous solution and adsorption onto the surface of the CNT-coated steel slag. Furthermore, the protons released from the CNT surface by exchanging with divalent cations acted to reduce the pH increase of the solution, which is attributed to the OH^- eluted from the steel slag. The adsorption isotherm and kinetics of the CNT-coated steel slags followed the Freundlich isotherm and pseudo-second-order model, respectively. The maximum adsorption capacity of the uncoated and CNT-coated steel slags was 6.127 and 9.268 mg P g^-1 slag, respectively. In addition, phosphorus from pig manure was more effectively removed by the CNT-coated steel slag than by the uncoated slag. Over 24 hours, the PO₄-P removal in pig manure was 12.3% higher by the CNT-coated slag. This CNT-coated steel slag can be used to remove both phosphorus and metals and has potential applications in high phosphorus-containing wastewater like pig manure.

• Earthquakes and Structures
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• v.19 no.5
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• pp.347-359
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• 2020

The Mega-Sub Controlled Structure System (MSCSS), an innovative vibration passive control system for building structures, is improved by adding lead rubber bearings (LRBs) on top of the substructure. For the new system, a genetic algorithm is used to optimize the dynamic parameters and distributions of dampers and LRBs. The program uses various seismic performance indicators as optimization objectives, and corresponding results are compared. It is found that the optimization procedure for maximizing the energy dissipation ratio yields the best solutions, and optimized models have consistent seismic performances under different earthquakes. Seismic performances of optimized MSCSS models with and without LRBs, as well as the traditional Mega-Sub Structure model, are evaluated and compared under El Centro wave, Taft wave and 20 other artificial waves. In both elastic and plastic analysis, the model with LRBs shows significantly smaller story drift and horizontal acceleration than those of the other two models, and fewer plastic hinges are developed during severe earthquakes. Energy analysis also shows that LRBs installed in proper locations increase the deformation and energy dissipation of dampers, thereby significantly reduce the kinetic, potential, and hysteretic energy in the structure. However, LRBs do not have to be mounted on all the additional columns. It is also demonstrated that LRBs at unfavorable locations can decrease the energy dissipation for dampers. After LRBs are installed, the optimal damping coefficient and the optimal damping exponent of dampers are reduced to produce the best damping effect.