• Journal of the Korea Institute of Building Construction
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• v.2 no.4
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• pp.145-152
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• 2002

High fluid concrete unlike OPC concrete is made with various material, and the phase of fresh concrete is considerably different. In order to understand fluidity phase and mix properties of high fluid concrete, concrete is required to access as suspension structure which consists of aggregate and paste. The focus of this paper is to analyze the test results and quantify the effect of mix proportions of mortar and fineness modulus of sand on the properties of fresh mortar. The effect of water-binder ratio. sand-binder ration. contents of ggbs (by mass of total cementitious materials). and various contents of water reducing agent on the yield stress and plastic viscosity of the mix is studied. Based on the experimental results, the fellowing conclusions can be drawn: (1) The mixing time needed for high fluid mortar was approximately two times more than that of ordinary portland mortar. (2) The fluidity phase of mortar could be explained by yield stress of mix and the fluidity of mortar. (3) As the content of ggbs increased, yield stress of mortar was decreased and plastic viscosity of it was increased. (4) For the high fluid mortar, it was appeared that sand-binder ratio should be below 1.5.

• Research in Plant Disease
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• v.29 no.2
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• pp.137-144
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• 2023

Exserohilum turcicum is a fungus that causes northern corn leaf blight (NCLB) and has deleterious effects on maize production globally. Therefore, it is prudent to mitigate the effects of NCLB using genetic diversity. The objective of this research was to assess the severity of NCLB disease on the growth and yield of various maize genotypes. A randomized complete block design field experiment, replicated three times, was conducted to evaluate the effect of E. turcicum on 10 maize hybrids. Percent disease index, plant height, and leaf area were recorded at the silk stage. Cob weight, grain fresh weight, and grain yields were determined at harvest maturity. All measured parameters were significantly different (P<0.05) between the maize hybrids. Of the 10 genotypes, four (PAN 4R-528R, PAN 4R-728BR, PAN 3R-724BR, and P1788BR) were susceptible, five (DKC74-74BR, PAN 5R-582R, PAN 5R-890R, PAN 5R-854R, and PAN 5R-590R) were moderately susceptible, and one (DKC80-40BR) was moderately resistant. DKC80-40BR exhibited greater cob weight, while DKC74-74BR was superior in all other plant growth and yield components. Interestingly, although not significant (P>0.05) and high, maize growth and yield parameters had negative correlations with disease incidence, except for grain fresh weight. Therefore, DKC80-40BR may be selected for cultivation in areas prone to NCLB to reduce maize susceptibility to the disease, while DKC74-74BR may improve crop performance. These hybrids could be considered as potential sources of resistance or tolerance to NCLB for further validation by plant breeders.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.110-110
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• 2022

According to the statistics of the Ministry of Environment, the amount of food waste generated in Korea is 15,903 tons, which accounts for about 30% of the daily household waste. Food waste in Korea is on the rise, and various odors, greenhouse gases, and leachate generated in the process of discharging, transporting, and processing are emerging as social problems. Accordingly, there is a need for a method for recycling food waste. Therefore, this study was carried out to establish an appropriate limiting dose by manufacturing fertilizer mixed with food waste powder and treating it on tomatoes to investigate the growth and yield of crops. The experiment was carried out with continuous cultivation in 2021 (1st year) and 2022 (2nd year), and the treatment groups were set to No Treatment (NT), Chemical Fertilizer (CF), Mixed Fertilizer (MF), and Mixed Fertilizer×2 (MF×2). As a result of the 1st year growth survey, shoot and root length did not show a significant difference between the treatment groups, and the fresh weight showed a significant difference between the MF and MF×2. As a result of the 2nd year growth survey, there was no significant difference in shoot length, root length, and dry weight between the treatment groups, and the fresh weight of the CF was significantly greater than that of the MF×2. The yield of 1st year, MF×2 increased significantly compared to other treatment groups. In the case of 2nd year, CF, and MF×2 show significantly high values compared to NT. Judging from these results, continuous cultivation using food waste powder mixed fertilizer did not have a significant effect on crop growth and yield. However, it is considered that several studies including continuous cultivation experiments are needed to accurately set the appropriate application amount and limit the application amount of the mixed fertilizer for food waste.

• Korean Journal of Agricultural Science
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• v.20 no.2
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• pp.117-124
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• 1993

This study was conducted to determine the effects of alternating planting systems of soybean and tillering hybrid corn on yield of both crops. The planting systems included monocultures of both crops. 1 to 1 row ratio, 1 to 2 row ratio, 1 to 3 row ratio, 2 to 1 row ratio, 2 to 3 row ratio, 3 to 1 row ratio, 3 to 2 row ratio and 3 to 3 row ratio of soybean and corn. The results obtained are summarized as follows : The plant height of soybean was increased as the number of planting rows of corn increased. But the plant, height of soybean was quite stabilized when the ratio of soybean planting rows increased. When the plant height of soybean was increased due to the increased row number of corn, the branch number and diameter of soybean decreased and lodging ratio increased. Total fresh weight of soybean per 10a was decreased as the ratio of soybean planting decreased and it was increased when the ratio of soybean planting increased over monoculture of soybean. Dry weight of soybean per 10a showed the same tendency of the fresh weight. But the highest grain yield of soybean was obtained in the monoculture of soybean and it was 276 kg/10a. Comparatively high yield of soybean was obtained in the systems of 2 to 1 and 3 to 3 ratios. The plant height, number of tillers and number of ears per plant of tillering corn were greatly affected by the alternating planting of soybean and they were 208.9cm, 2.1 and 4 per plant, respectively. The fresh and dry weights and yield of corn per 10a showed significant differences among systems. The average fresh and dry weight of corn in the systems of 3 to 1 and 2 to 1 were 1000 kg and 100 kg higher than those of monoculture of corn. The kernel yields of corn per 10a were 438 kg in the monoculture system and 530 kg in the systems of 3 to 2 and 2 to 1. The total fresh weights of corn and soybean in systems of 3 to 1, 3 to 2 and 2 to 1 were higher than 5721 kg of soybean and 4358 kg of corn in the monoculture. Combined dry weight was high in the order of monoculture, 2 to 1 and 3 to 1 row ratios. Combined grain yield was high in the systems of 2 to 1 and 3 to 1 row ratios and it was over 430 kg per 10a.

• Plant Resources
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• v.1 no.1
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• pp.49-52
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• 1998

This study confirmed that the initiation time of tuberization was well consistent with the cativation time of JA. The consistency was also cinfirmed in the tuberization of yam plants under the altered condition of natural day length. The final yield of JA from 500g fresh leaves was $89.3{\mu}g$.

• Journal of the Korean Solar Energy Society
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• v.30 no.3
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• pp.33-38
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• 2010

The evaporative desalination system using solar thermal energy would be the efficient and attractive method to get fresh water from brine due to low carbon dioxide generation. In this research the solar desalination system as a heating source of refrigerant R123 in the evaporator was considered. The circulation of refrigerant in the evaporator can reduce the energy consumption of the system, because of using the latent heat of the refrigerant 123 instead of the sensible heat of present hot water. The system was comprised of the single-stage fresh water production unit on the capacity of 1ton/day with shell and tube type evaporator, heaters instead of solar collector to supply the proper heat to refrigerant, and refrigerant and brine circulation systems. Various operating flowrate and temperature ranges were varied in the experiments to get the optimum design data. The results showed that the optimum flow rate of brine feed rate to evaporator was 1.2Liter/min, and the yield of fresh water was increased as higher temperature of feed brine. It was confirmed that the circulation flowrate of heating source of refrigerant was decrease of one fifth of the present warm water system, and very efficient system for solar desalination.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.262-265
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• 2009

This study was carried out to evaluate the clear day operating performances for the decentralized desalination system with the solar thermal system and the photovoltaic power system. In a clear day, we used a solar thermal system as heat source of the single-stage fresh water generator with plate-type heat exchangers and a photovoltaic power system as electric source for hydraulic pumps. The demonstration system generation was designed and installed at Jeju-island in 2006. The system was comprised of the desalination unit with daily fresh water capacity designed as $2m^3$, a $120m^3$ evacuated tubular solar collector to supply the heat, a $6m^3$ heat storage tank, and a 5.2kW photovoltaic power generation to supply the electricity of hydraulic pumps for the heat medium fluids. In a clear day, solar irradiance daily averaged was measured $518W/m^3$, the daily fresh water yield showed that about 565 liter.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.250-255
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• 2009

This study was analyzed the long term performance of the demonstration system for solar energy desalination in Jeju. we used a solar thermal system as heat source of the single-stage fresh water generator with plate-type heat exchangers and a photovoltaic power system as electric source for hydraulic pumps. The demonstration system was designed and installed at Jeju-island in 2006. The system was comprised of the desalination unit with daily fresh water capacity designed as $2m^3$ a $120m^2$ evacuated tubular solar collector to supply the heat, a $6m^3$ heat storage tank, and a 5kW photovoltaic power generation to supply the electricity of hydraulic pumps for the heat medium fluids. Through the operation during about 3 years, In a clear day more than $400W/m^2$, the daily fresh water showed to produce more than about 500liter, and from January, 2007 to March, 2009 for 3 years, solar irradiance daily averaged was measured $370W/m^2$, the daily fresh water yield showed that can be produced about 330liter.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.333-341
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• 1999

This study was conducted to investigate physicochemical and functional properties of turnip. The concentrations of antocyanin in the rind of root was 3.24mg%, which was about 3.5 times higher than those in the flesh. Among free amino acids in each part of turnip, glutamic acid showed the highest concentrations(132.5mg%) in the root followed by alanine(25.0mg%), valine (23.3mg%), and serine (20.7mg%). Contents of minerals in the root of turnip were 395.7mg% for potassium, 187mg% for calcium, 53.6mg% for phosphate, and 40.7mg% for magnesium. According to dynamic heasdspace analysis, dimethyl disulfide was the most abundant flavor components from the juice of fresh turnip and other volatile components such as dimethyl trisulfide, 1 hexanal, 2 methyl 1 butamine, and 1 penten 3 ol were also identified. From the blanched turnip, however, 3 isothiocyanato 1 propene and 4 isothiocyanato 1 butene were mainly detected. Fresh and blanched turnips were extracted with water or 70% acetone to investigate percent yield. The concentrations of total polyphenols in the extracts of fresh turnip were higher than those of blanched turnip. The nitrite scavenging effects of water and 70% acetone extracts from fresh or blanched turnip were decreased as pH was increased. Between two water extracts, the 30oC water extracts showed the higher values of electron donating ability than 95$^{\circ}C$ water extracts.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.2
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• pp.155-159
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• 1992

This study was carried out to know the effects of two kinds of peper mill sludge manure compost(SMC-1 and SMC-2) on the growth and chemical comments of carrot(Daucus carota L.) : SMC-1 contained 18% of swine manure and 8 % of sawdust on a fresh weight basis and SMC-2 contained swine manure without sawdust a third of the total weight of the manure and S-0(control) was treated with chemical fertilizer only, S-1 and S-2 was with SMC-1 and SMC-2 respectively, in addition to the chemical fertilizer. Carrot treated with S-1 and S-2 showed the increasing tendency of fresh weight per root and fresh yield of carrot per unit area than control(S-0), and the contents of nitrogen(N), phosporus(P), potassium(K) and calcium(Ca) in carrot grown on SMC treatments were higher than those on control(S-0), The S-2 treatment tended to increase values of the fresh weight of live leaves, root diameter, fresh weight per root and fresh yield of carrot per unit area than S-1 treatment. The contents in carrot were higher in the order of K>Ca, N. P>Mg, and the contents of aluminium, zinc, copper and chromium were below the level of toxicity for plant growth, and the contents of cadmium and lead were negligible. From the results obtained, it can be said that SMC application showed favorable effects on the growth of carrot when compared to control(S-0), and with the SMC treatments SMC-2 aplication was favorable.