• Weed & Turfgrass Science
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• v.2 no.4
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• pp.348-351
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• 2013

Weedy rice is one of the major problems in direct-seeded rice field, resulting in poor rice quality and low grain yield. This study was carried out to evaluate the conversion effect to machine transplanting after wet-direct- seeding for 3 years on weedy rice occurrence, in comparison of repeated wet-direct-seeding. Occurrence of weedy rice in the continuous wet-hill-seeded and broadcasted field for 3 years increased 4 folds, when compared with that in machine transplanted rice paddy. In the first year of wet-direct-seeded field converted from machine transplanting, weedy rice occurrence did not increase, demonstrating lesser weedy rice in wet-hill-seeded than broadcasted field. These results indicate that alternate cultivation of wet-hill-seeding and machine transplanting is more effective to prevent weedy rice occurrence than the repeated wet-direct-seeding method for 3 years.

• Analytical Science and Technology
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• v.9 no.1
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• pp.98-106
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• 1996

The concentration of sulfur dioxide in Wonju City was predicted using TCM (Texas Climatological Model). We have studied the transportation and wet deposition of $SO_2$ using the TCM and the analysis of rainfalls. The results are as follows : At the Hak-Sung Dong site in Wonju city, the correlation coefficient between the measured and calculated concentrations were 0.904. Sulfur dioxide was washed out by wet deposition. The wet deposition ratio to total amount of emitted sulfur dioxide was higher in summer than in autumn and winter seasons due to heavy rainfall in summer. The correlation coefficient between the precipitation and wet deposition of sulfur dioxide was 0.68. The months with greater rainfall showed that the measured concentrations of sulfur dioxide were much lower than the predicted ones. Although the amount of precipitation in April was smaller than in summer, the wet deposition ratio in April was much higher than any other months, due to the sulfur dioxide that was adsorbed on particulate matter and moisture was transported during the period of yellow sand phenomena from China.

• Food Science of Animal Resources
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• v.33 no.6
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• pp.752-756
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• 2013

This study was carried out to investigate the effect of cooking condition on the water-soluble flavor precursors relevant to postmortem glycogen metabolisms in various beef muscles from Hanwoo (Korean cattle). The loins, striploins, top rounds, and eye of rounds from 40-mon-old heifers were cooked in either with $100^{\circ}C$ water bath (wet-cooking) or $180^{\circ}C$ household electric oven (dry-cooking) until attained to about $80^{\circ}C$ of internal temperature before the measurements of amounts of macroglycogen, proglycogen, free glucose, and lactate. The macroglycogen and proglycogen contents were not significant differences in all beef muscles between the wet-cooking and dry-cooking treatments. Regardless of cooking condition, the both loin and top round had higher (p<0.05) two types of glycogen than the eye of round. The free glucose and lactate contents presented higher trends in the dry-cooking treatment compared with the wet-cooking treatment. The wet-cooked top round had higher (p<0.05) free glucose than the wet-cooked eye of round. Moreover, the top round contained the highest lactate content regardless of cooking condition. Consequently, it is considered that the dry-cooking treatment would be more beneficial to the flavor of cooked beef muscles than the wet-cooking treatment.

• Food Science of Animal Resources
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• v.39 no.4
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• pp.655-667
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• 2019

The present study aimed at investigating the effects of dry- and wet-aging methods on flavor compounds and sensory properties of low fat Hanwoo beef muscles. All the beef samples were obtained from 2-grade carcasses of Hanwoo cows. The beef samples used in the dry- and wet-aging methods were prepared in the forms of quarter beef (bone-in) and cuts (boneless), respectively. The dry-aging was carried out at $2^{\circ}C-4^{\circ}C$ and humidity of 65%-85%, while the wet-aging was done at $1^{\circ}C$ for 0, 20, 40, and 60 d. At each aging time, three muscles: longissmus thoracis (LT), glutaeusmedus (GM) and semimembranosus (SM) were taken from the corresponding quarters and cuts, and used for the flavor compounds and sensory analyses. Results showed that both aging methods significantly increased the concentrations of flavor compounds and total amount of all classes of the flavor compounds as the aging time increased (p<0.05). In the dry-aging method, the GM and SM muscles presented significantly higher total amounts of pyrazines and sulfur-containing compounds compared to the LT muscle (p<0.05). Both the aging methods improved the eating quality attributes, indicating by increased scores of sensorial attributes with increased aging time for all the muscles studied (p<0.05). However, compared to the wet-aging, the dry-aging method resulted in significantly higher scores of tenderness and flavor for the GM and SM muscles after 40 to 60 d. Thus, postmortem aging, especially the dry-aging method could be used to improve eating quality attributes (tenderness and flavor) of low fat beef muscles such as GM and SM.

• Journal of the Korean Chemical Society
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• v.55 no.5
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• pp.842-845
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• 2011

Wet air oxidation (WAO) of oily sludge was carried out using $Fe^{3+}$ as catalyst, placed in a 0.5 L batch autoclave in the temperature range of $250-330^{\circ}C$. Experiments were conducted to investigate the effects of temperature, the initial COD, reaction time, concentration of catalyst and $O_2$ excess (OE) on the oxidation of the oily sludge. The results showed that in the WAO 88.4% COD was achieved after 9 min reaction at temperature of $330^{\circ}C$, OE of 0.8 and the initial COD of 20000 mg/L. Temperature was found to have a significant impact on the oxidation of oily sludge. Adding a catalyst significantly improved the COD removal. Homogenous catalyst, $Fe^{3+}$, showed effective removal for pollutants. COD removal was 99.7% in the catalytic wet air oxidation (CWAO) over $Fe^{3+}$ catalyst. The results proved that the CWAO was an effective pretreatment method for the oily sludge.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.154-156
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• 2008

A prototype of the desiccant cooling system with a regenerative evaporative cooler was built and tested for the performance evaluation. The regenerative evaporative cooler is to cool a stream of air using evaporative cooling effect without an inc6rease in the humidity ratio. It is comprised of multiple pairs of dry and wet channels and the evaporation water is supplied only to the wet channels. By redirecting a portion of the air flown out of the dry channel into the wet channel, the air can be cooled down to a temperature lower than its inlet wet-bulb temperature at the outlet end of the dry channels. Incorporating a regenerative evaporative cooler eliminates the need for deep dehumidification in the desiccant rotor that is necessary to achieve low air temperature in the system with a direct evaporative cooler. Subsequently, the regenerative evaporative cooler enables the use of low temperature heat source to regenerate the dehumidifier permitting the desiccant cooling system more beneficial compared with other thermal driven air conditioners. At the ARI condition with the regeneration temperature of $60^{\circ}C$, the prototype showed the cooling capacity of 4.4 kW and COP of 0.75.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.5
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• pp.581-587
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• 2007

In order to suggest the methodology for improving the equality of flow distribution in a distribution channel, wet tests were carried out for pilot plant which was scaled down to 1/8 of full scale distribution channel being operated in domestic K_water treatment plant. The correlation between various hydraulic variables and their effects on the equality of flow distribution was evaluated through wet tests using pilot plant. From the results of wet tests, the longitudinal baffle with orifices was installed in the distribution channel, the equality of flow distribution was improved on the condition that the Froude number in pilot plant was similar with that in the full scale channel. Also, the opening ratio of the orifices on the longitudinal baffled did not have influence on the performance of the equality of flow distribution when the average flow velocity and Froud number were relatively low (Froude number ${\fallingdotseq} 0.01$). In the other hand, the performance of the equality of flow distribution was improved with increasing the opening ration of on the longitudinal baffle under conditions of relatively high average flow velocity and high Froud number(${\gtrsim}0.1$)

• The Korean Journal of Ecology
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• v.23 no.2
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• pp.181-185
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• 2000

This study was carried out to see whether Gastrophysa viridula (Degeer) (Coleoptera : Chrysomelidae) could be used as a biological control agent for Rumex obtusifolius L., with human manipulation of the beetle population. The study was consisted of three experimental sets : Wet-Dry experiment (the wet weight Vs dry weight relationship of Rumex obtusifolius L.), Greenhouse feeding experiment, and Field experiment. There was a significant correlation between the total wet and dry weight of Rumex obtusifolius as follows : Total dry weight : -0.23542+ (0.17514${\times}$Total wet weight) ($R^2$=0.9317, p=0.047, T=16.927 (dF=21)). In the Greenhouse feeding experiment, the result was very promising. The relationship between the density unit of the beetles and the growth of the plant is given below (20 day) : Plant growth =105.8+(-34.4${\times}$Density unit) ($R^2$=0.76, p=0.13). A repeated introduction of the beetle population into the field vegetation of R. obtusifolius from April to October is suggested to see the beetle's grazing ability on the plant. This study shows that the potential grazing power of the beetle on Rumex obtusifolius was enough to defoliate the plants, but it was able to recover from its root reserves. The practical question remains as to whether repeated additions (by man) of the beetles to Rumex obtusifolius could eliminate them.

• Corrosion Science and Technology
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• v.2 no.4
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• pp.165-170
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• 2003

Atmospheric corrosion behaviors of Zn, Zn-5%Al and Zn-55%A l coated steels have been investigated under cyclic wet-dry environments containing chloride ions. The wet-dry cycle was carried out by alternate exposure to immersion in 0.5 M (or 0.05 M) NaCl solutions and drying at $25^{\circ}C$ and 60 %RH. The polarization resistance $R_p$ and solution resistance $R_s$ were monitored by AC impedance technique. From the obtained $1/R_p$ and $1/R_s$ values, the corrosion rate of the coatings and the Time of Wetness (TOW) were estimated, respectively. Effects of chloride ions and TOW on the corrosion rates of Zn, Zn-5%Al, Zn-55%Al coatings and appearance of red rust (onset of underlying steel corrosion) under wet-dry cycles are discussed on the basis of the corrosion monitoring data.

• Journal of Energy Engineering
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• v.18 no.2
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• pp.93-100
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• 2009

An exergy analysis is carried out for the regenerative wet-compression Brayton cycle which has a potential of enhanced thermal efficiency owing to the reduced compression power consumption and the recuperation of exhaust energy. Using the analysis model, the effects of pressure ratio and water injection ratio are investigated on the exergy efficiency of system, exergy destruction ratio for each component of the system, and exergy loss ratio due to exhaust gas. The results of computation for the typical cases show that the regenerative wet-compression gas turbine cycle can make a notable enhancement of exergy efficiency. The injection of water results in a decrease of exergy loss of exhaust gas and an increase of net power output.