• Journal of the Korea Concrete Institute
• /
• v.28 no.3
• /
• pp.309-316
• /
• 2016

In this study, performance of hardening accelerator types which promote setting and hardening of cement has been reviewed in order to develop early age strength of concrete with compressive strength of 21~27 MPa after examination of strength development of the concrete at early age according to curing temperature and unit cement(binder) content. As results, soluble mineral salt showed better hardening acceleration effect than organic salt in the scope of this study. Also, hydration reaction accelerating effect of $C_3S$ by Soluble mineral salt is effective on development of early age compressive strength and it was shown that the Pt's hydration reaction accelerating effect was the best. Construction duration reduction can be expected by securing compressive strength for prevention of early aged freezing damage in 25hour-curing time under curing temperature at $15^{\circ}C$. Also, it was shown that compressive strength of specimen cured at $5^{\circ}C$ was similar with plain specimen cured at $10^{\circ}C$. Therefore, it is expected that fuel costs and carbon dioxide can be reduced when the same construction duration is considered.

• Journal of Mushroom
• /
• v.13 no.3
• /
• pp.250-255
• /
• 2015

In this study spent mushroom substrate has ingredient raising rice bed soil. spent mushroom substrates are organic content is 60.72% were nitrogen - phosphoric acid - potassium is 1.39 - 0.89 - 0.81% of the chemical characteristics determine. Post-harvested mushroom substrates of the stabilization process, the temperature of the 20 days time progress in the pH of the rise and fall of temperature down were germination index also 77, as identified, Spent mushroom substrate bed soil for raising rice Ingredient to take advantage of the 20 days or more stabilization process needed to be investigated. Rice seed germination characteristic is in the common bed soil for raising rice ingredients manufactured control group and the comparison in spent mushroom substrate is 10% or less of a mixed experimental population of the germination rate is 82% was more than average days to germination and germination energy, even a statistical significant difference is or control group than good level was ok. Growth initial also spent mushroom substrate is 10% or less of a mixed experimental population of shoot dry matter (top) and grave less than control group higher as confirmed spent mushroom substrates are bed soil for raising rice ingredients are likely to take advantage of the high, as was the judge.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.356-356
• /
• 2017

A field experiment was performed to evaluate the effects of tillage systems and fertilizer management on yield and nutrient uptake in Soybean. The plant height, fresh weight and dry weight of conventional tillage were much higher those observed for no-tillage. Significant differences in plant height were observed under tillage practices combined with fertilizer treatment. However, the greatest plant height (128.47 cm) was observed in conventional tillage with chemical fertilizer, and the lowest (45.4 cm) was observed in the no-tillage with green manure treatment. The highest fresh weight (172.4 g) and dry weight (44.1 g) were observed from the no-tillage chemical treatment in the late flowering stage of soybean. The plant concentration of nitrate was higher (2.29%) in no-tillage with green manure than it was with chemical fertilization. However, nitrogen increased steadily in all treatments, and the highest quantity of total nitrogen (476.7 Kg/ha) was observed in no-tillage with green manure. The N content in the soil decreased gradually just after the vegetative stage. Tillage practices and additional fertilizer application had an adverse effect on the uptake of N, P and K in soybean seeds. The nitrogen concentration in seeds was found to be increased in the no-tillage with green manure treatment. The uptake of more nitrogen induced a better yield. Thus, the no-tillage with green manure treatment had the greatest yield, although no significant difference was observed among foliar-applications and additional fertilization. Additionally, the phosphorus and potassium concentrations in seeds remained the same between the conventional tillage and no-tillage treatments. The results obtained in this study indicate that no-tillage strategies with fertilizers may influence the growth characteristics and mineral uptake in soybean.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.16 no.1
• /
• pp.193-206
• /
• 2013

This study was to provide the base data on the status of vegetations and soils in green roofs by analyzing the soil and vegetation characteristics of 4 green roofs in Dongguk University in September 2012. Sanglokwon(SW), Dongguk Hall(DH), University Library(UL), and Information and Culture Hall P(IC) were established in 2005, 2008, 2009, and 2010, respectively. The areas of green roofs were $700m^2$, $2,300m^2$, $1,240m^2$, and $640m^2$ in SW, DH, UL, and IC respectively. The investigated floras of vascular plants were 26 families, 55 genera, 65 species in Sanglokwon(SW), 53 families, 99 genera, 112 species in Dongguk Hall(DH), 43 families, 77 genera, 84 species in University Library(UL), and 41 families, 71 genera, 75 species in Information and Culture Hall P(IC), respectively. A positive correlation is shown between the number of plant species and planting area. Total nitrogen, organic matter, and potassium in soil have positive correlation with the number of plant species. The number of plant species was proportional to area and increased more than twice after planting. About a quarter of the invaded plants (including native and naturalized species) were naturalized plants. The total soil depths including vegetation soil and drainage soil at SW, DH, UL, and IC were 20cm, 10cm, 10cm, and 8cm, respectively. The depths of vegetation soil at SW, DH, UL, and IC were <7cm, <3cm, <2cm, and <2cm respectively. The soil pH in vegetation soil ranged from 5.22 to 5.36, and from 6.13 to 6.39 in drainage soil. Available-P concentration ranged from 10.17 to 189.77mg/kg in vegetation soil and from 6.70 to 81.17mg/kg in drainage soil. Carbon concentration in vegetation soil ranged from 2.93 to 9.70%, and 2.93 to 9.70% in drainage soil. Carbon contents in 20cm, 10cm, 10cm, and 8cm soil depths were $2.62kg/m^2$, $1.89kg/m^2$, $0.50kg/m^2$, and $0.53kg/m^2$ at SW, DH, UL, and IC, respectively.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.09a
• /
• pp.121-121
• /
• 2004

The groundwater in the Pocheon area occurs from both a fractured bedrock aquifer in igneous and metamorphic rocks and an alluvial aquifer with a thickness of <50 m, and forms a major source of domestic and agricultural water supply. In this study, we performed a hydrogeochemical study in order to identify the control of geochemical processes on groundwater quality. For this study, groundwater level and physicochemical parameters (EC, Eh, pH, alkalinity) were monitored once a month from a total of 150 groundwater wells between June 2003 to August 2004. A total of 153 water samples (13 surface water, 66 alluvial groundwater, 74 bedrock groundwater) were also collected and analyzed in February 2004. Groundwater chemistry in the study area is very complex, depending on a number of major factors such as geology, degree of chemical weathering, and quality of recharge water. Hydrochemical reactions such as the leaching of surficial and near-solace soil salts, dissolution of calcite, cation exchange, and weathering of silicate minerals are proposed to explain the chemistry of natural groundwater. Alluvial groundwaters locally have very high TDS concentrations, which are characterized by their chloride(nitrate)-sulfate-bicabonate facies and low Na/Cl ratio. Their grondwater levels are highly fluctuated according to rainfall event. We suggest that high nitrate content and salinity in such alluvial groundwaters originates from the local recharge of sewage effluents and/or fertilizers. Likewise, high concentrations of nitrate were also locally observed in some bedrock groundwaters, suggesting their effect of anthropogenic contamination. This is possibly due to the bypass flow taking place through macropores. Tile degree of the weathering of silicate minerals seems to be a major control of the distribution of major cations (sodium, calcium, magnesium, potassium) in bedrock groundwaters, which show a general increase with increasing depth of wells. Thermodynamic interpretation of groundwater chemistry shows that the groundwater in the study area is in chemical equilibrium with kaolinite and Na-montmorillonite, which indicates that weathering of plagioclase to those minerals is a major control of hydrochemistry of bedrock groundwater. The interpretation of the molar ratios among major ions, as well as the mass balance calculation, also indicates the role of both dissolution/precipitation of calcite and Ca-Na cationic exchange as bedrock groundwaters evolves progressively.

• Korean Journal of Soil Science and Fertilizer
• /
• v.15 no.3
• /
• pp.199-206
• /
• 1982

A field experiment was conducted to compare the effects of compost and rice straw application on the growth of soybean, chemical properties and soil microorganism in newly reclaimed silty clay loamy upland soil. Application rates of the arganic materials were 750 Kg, 1,500 Kg and 3,000 Kg/10a in compost, and 340 Kg, 680 Kg and 1,360 Kg/10a in rice straw. The differences of N.P.K. application rates caused by the two different organic materials were balanced by chemical fertilizers of N.P.K. The results can be summarized as follows; 1. The yield of soybean was increased upon compost application, but no significant difference on yield was observed except luxuriant plant growth upon rice straw application. 2. There was highly possitive correlation between concentration of phosphorous, potassium in soybean plant at 71 days after planting and dry weight of grain vs. stem plus bean chaff of harvest plant in compost applied plots, but no correlation was found in rice straw applied plots. 3. In greneral, the soil water contents in organic material applied plots, expecially in plots of rice straw, were higher than in no organic material plots. However, at wilting point, the soil water content in organic material applied plot was lower compare to no organic material plot. 4. The weight of nodules per soybean plant was heavier notwithstanding the fewer number of soil bacteria and fungi in compost application plots than rice straw application plots.

• Journal of Aquaculture
• /
• v.10 no.3
• /
• pp.255-260
• /
• 1997

In order to investigate the effects of phosphorus and iron levels in the diets containing fish meal as only protein source on the growth, feed conversion, body composition and blood characteristics of juvenile Korean rockfish, either graded monobasic potassium phosphate (MPP) of 1% (MPP-1), 2% (MPP-2), 3% (MPP-3) and 4% (MPP-4), or Fe-citrate (FC) of 0.022% (FC-1), 0.044% (FC-2), 0.066% (FC-3) and 0.088% (FC-4) was added to fish meal-based diet (MMP-0 or FC-0), respectively. Duplicate groups of 40 fish weighing 7g were fed the diets for 21 weeks. Weight gain, feed efficiency and nutrient retention of fish fed diets with different MPP levels were not significantly different (P>0.05). Lipid content of whole body decreased with an increase in dietary MMP (P<0.05). No significant differences were found in the Ht, Hb, total protein, or total glucose in serum among diets containing different MMP levels (P>0.05). Weight gain of fish fed the FC-0, FC-1 adn FC-3 diets was significantly higher than that of FC-4 diet (P>0.05), whereas feed efficiency, nutrient retention, hematological values (Ht, Hb, total protein, and total glucose), and whole body composition were not affected by dietary FC levels (P>0.05). The present results revealed that phosphate or iron supplementation to the diet containing 65% fish meal for juvenile Koran rockfish was not necessary.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.9
• /
• pp.1210-1218
• /
• 2000

Four experiments were conducted to evaluate the effect of temperature and humidity on biochemical indices of Arbor Acres broilers at different weeks of age. The alkaline phosphatase (AKP), acid phosphatase (ACP), lactic dehydrogenase (LD), creatine kinase (CK), plasma glucose (Glu), calcium (Ca), potassium (K), chloride (Cl), urea nitrogen (UN), uric acid (UA), plasma thyroxin (T4), triiodothyronine (T3) and insulin levels were determined in all the four experiments. In experiment 1, the plasma Glu, LD and CK levels were increased by heat exposure ($35{^{\circ}C}$ and 35, 60, or 85% RH, 2 h) and this effect was aggravated by longer exposure (24 h). No significant changes (p>0.05) were found in Ca concentration, activity of AKP and ACP. In experiment 2, temperature (10, 20, 30, $33{^{\circ}C}$) had significant effect on the levels of K, Cl, UN, UA levels and the activity of LD (p<0.01), but had no significant influence on the activity of CK (p>0.05). The UN, UK and LD levels were elevated by low temperature $(10{^{\circ}C})$ (p<0.01), Cl content was increased by high temperature ($(33{^{\circ}C})$ (p<0.01), and K level was decreased by high ($(33{^{\circ}C})$ or low $(10{^{\circ}C})$ temperature and increased by medium temperature $(30{^{\circ}C})$ (p<0.01). The humidity (35, 85% RH) only had significant effect on Cl concentration which was decreased by high humidity (p<0.01). In experiment 3, the result showed that only the LD and CK activity were significantly increased (p<0.01) by high temperature (7, 24, 28, $32{^{\circ}C}$) or high humidity (35, 85% RH). Temperature and humidity had no significant effect on K, Cl, UA, UN and Glu levels (p>0.05). In experiment 4 (24, 27, 30, $33{^{\circ}C}$; 30, 45, 60, 75, 90% RH), plasma T3 level was declined by high temperature $(33{^{\circ}C})$, and this phenomena disappeared in birds under high temperature and high humidity environment. T4 concentration in plasma was not affected by temperature (p>0.05), but was increased by high or low humidity (p<0.01). Neither temperature nor humidity had significant effect on plasma insulin concentration (p>0.05). The results of the four experiments suggested that broilers at different growth periods might have different thermal requirements and would response differently to heat exposure. The plasma biochemical indices themselves had big variation; the reaction of the indices to thermal exposure treatment differed with the age of broilers. The big variation of biochemical indices themselves might cover the response of indices to temperature and humidity treatments.

• Nutritional Sciences
• /
• v.9 no.2
• /
• pp.124-130
• /
• 2006

To examine the effects of alcohol consumption on body fluid restoration and fat mobilization following exercise induced dehydration, nine healthy collegiate men ($24{\pm}2yrs,\;177{\pm}5cm,\;72{\pm}8kg,\;10.5{\pm}2.3%$ body fat) underwent three experiments. In each experiment, subjects ran on a treadmill to reduce individual body mass to $2.2{\pm}0.1%$ and consumed one of three beverages containing 0, 4, or 8% alcohol over 60 min followed by 4 hr of resting recovery. They consumed approximately 150% of weight loss $(2053{\pm}204,\;2091{\pm}149,\;and\;1943{\pm}295mL)$ and content of alcohol was $9.9{\pm}1.0(0%),\;71.9{\pm}5.1(4%)$, and $132.2{\pm}20.1g$ (8% trial). Body weight, urine volume and samples, blood samples, and thirst sensation were measured five times; at baseline, immediately after exercise, and 0, 1st, and 4th hr of recovery. Blood alcohol concentration after ingestion was $0.0{\pm}0.0(0%),\;0.1{\pm}0.02(4%)$, and $0.2{\pm}0.03%$ (8% trial). No differences in blood sodium and potassium concentrations, and urine specific gravity were noticed over time periods and trials. Thirst sensation tended to be elevated in all trials immediately after exercises and urine output was elevated during the recovery. The magnitude of changes in these variables was proportional to the alcohol concentrations, but not statistically significant. While serum osmolality was not different among trials and time periods in 0 and 4% trials, it was higher during recovery than the baseline in the 8% trial (P<0.01). Triglycerides did not change throughout the time period and among trials. Free fatty acids were elevated after exercise in all trials and 4th hr of recovery in 0% (P<0.05). Subjects' net body fluid balance at 4th hr of recovery was negatively maintained and proportional to alcohol concentrations. Only 8% trials showed a significant reduction at 1st and 4th hr of recovery compared to 0 hr. The results suggested that diuretic effect of alcohol after moderate level of dehydration appeared dose dependent, but beverage containing alcohol up to 4% did not induce impaired rehydration than alcohol free drinks. Alcohol effects on fat mobilization during recovery appeared to be minimal and the mechanism is unclear.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.5
• /
• pp.732-738
• /
• 2015

Quality characteristics of Korean cabbage treated with red clay-processed materials (RCPM) were evaluated. Two different types of RCPM treatments including a control were applied for the cultivation of cabbage. General components, nutrients, antioxidant activities, textures, and sensory evaluation were assessed. For the nutrition components analysis, RCPM-treated cabbage showed higher contents of potassium and riboflavin along with lower content of sodium compared to the control. RCPM-treated cabbage exhibited higher total polyphenol contents than those of the control, indicating higher antioxidant activities. For the textural analysis under refrigeration over 4 weeks, RCPM-treated samples showed more stable textures based on higher hardness values than the control and RC. Results of this study indicate that RCPM would be of benefit to produce high-value added cabbage of premium quality.