• Korean Journal of Construction Engineering and Management
• /
• v.16 no.1
• /
• pp.110-118
• /
• 2015

The standard production unit system is the most basic element in our country construction. However, this standard production unit system shows a large difference in the actual amount of labor input for works at the Apartment housing construction, Therefore, it may be a reasonable alternative to estimate the cost of construction by historical cost data, works will be calculated the cost of labor must determine the exact amount and It is necessary to determine the exact amount of labor input for the construction progress management. This study examines the results of comparing the standard production unit system and the actual amount of labor counting in apartment housing construction was completed in the metropolitan area since 2000, the following results were obtained. the actual amount of labor input are looked for 1.184person/1000 of masonary, $0.084persons/m^2$ of plaster, $0.039persons/m^2$ of Waterproofing, $0.059persons/m^2$ of tile at the Apartment housing construction. in the actual amount of labor counting Compared with standard production unit system, masonry ratio of 59.8%, plaster ratio of 41.3%, waterproofing ratio of 31.5%, tile ratio of 34.3% and The labor rate in the works was the lowest in the plaster. was relatively high in the masonary. Therefore, the amount of labor country apartment housing construction is preferably calculated on historical cost data. But it seems that the amount of labor necessary complement ongoing close enough to the actual standard production unit system a major variable in construction management.

• Applied Chemistry for Engineering
• /
• v.23 no.3
• /
• pp.302-307
• /
• 2012

Advanced oxidation processes (AOP) such as O3/activated carbon process and O3/catalysts process were used to compare the decomposition of phenol. Catalysts such as Pd/activated carbon (Pd/AC), Mn/activated carbon (Mn/AC), Co/activated carbon (Co/AC) and Fe/activated carbon (Fe/AC) were prepared by impregnation of Pd, Mn, Co and Fe into the activated carbon of pellet form, respectively. Based on an hour of reactions, the following descending order for the decomposition ratios of dissolved O3 to the 1.48 mg/L of saturated dissolved O3 was observed: Mn/AC (45%) > Pd/AC (42%) > Co/AC (33%) > AC (31%) > Fe/AC (27%). The removal efficiencies of phenol were also arranged in the descending order of AOP as follows: Mn/AC (89%) > Pd/AC (85%) > Co/AC (77%) > AC (76%) > Fe/AC (71%). The remaining ratios (C/Co) of TOC (total organic carbon) after an hour of experiments were arranged in the ascending order of AOP as follows : Pd/AC (0.29) < Mn/AC (0.36) < AC (0.40) < Co/AC (0.49) < Fe/AC (0.51). However, the catalytic effects in the Co/AC and the Fe/AC processes were little in comparison with O3/AC process. The maximum concentrations of intermediates such as hydroquinone and catechol formed from the decomposition of phenol were arranged in the ascending order of AOP as follows: Pd/AC < Fe/AC < Co/AC < AC < Mn/AC. In the case of Pd/AC process, these intermediates were almost disappeared after an one hour of reaction.

• Journal of Aquaculture
• /
• v.16 no.3
• /
• pp.151-158
• /
• 2003

This study was conducted to estimate the effects of residual chlorine dioxide ($CIO_2$) in chlorinated seawater on survival and physiological responses (hematocrit: Ht, hemoglobin: Hb, serum electrolyte and glucose levels, and osmolality) of olive flounder, Paralichthys olivaceus. All the flounders were exposed for 10 min to different concentrations of residual $CIO_2$ just after chlorination for 1 min in each experimental aquarium (EA). ClO$_2$-free seawater was continuously supplied to each EA after 10 min exposure to $CIO_2$. By means of probit analysis, the median lethal times (LT$_{50}$, min) of flounder exposed to 0.43 and 0.51 ppm $CIO_2$, were at 103 and 32 min, respectively. In the range from 0.34 to 0.51 ppm $CIO_2$, the values of Ht, Hb, electrolytes and osmolality of fish exposed to $CIO_2$ were significantly elevated as elapsed time and residual concentrations of $CIO_2$ increased after chlorination. The levels of Ht, Hb, electrolytes and osmolality in flounder exposed to 0.27 ppm $CIO_2$ were not significantly different compared to control fish, which were maintained in $CIO_2$-free seawater; however, the levels of serum glucose were significantly increased with elapse times.

• Korean Journal of Environmental Biology
• /
• v.31 no.4
• /
• pp.486-492
• /
• 2013

Recently, a new disease showing symptoms such as epidermal exfoliation and muscular necrosis occurred in cultured Korean catfish. Although the mortality of fishes was low but the economic damages owing to loss of commercial value were severe. The authors isolated the causative agent from diseased fish and observed pathological changes both in naturally and artificially infected fish. The causative bacteria was identified as Aeromonas veronii. Subsequently we observed the daily death and pathological symptoms of artificially infected fish with Aeromonas veronii. Symptoms of artificially infected fish were similar to those of naturally infected fish and all fish died within 7 days after infection. Histopathological changes on the naturally infected fish revealed severe congestion and necrotic degeneration in the liver, spleen and kidney. Some bacterial aggregates with inflammatory degeneration were observed in the heart, and congestion and fibrosis in the lamina propria of digestive tube were predominant. In artificially infected fish, skin erosion and necrotic degeneration of muscle tissue around injected region were particularly manifested. Degeneration of hepatocytes in liver and hyalic degeneration around ellipsoids in spleen were partially observed. However, there were no predominant signs in digestive tube in artificially infected fish.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.23 no.2
• /
• pp.43-50
• /
• 2021

Growth tests on the Yuldo, Supum1 and Supum2 cultivars of Pyropia dentata were performed at the Eoran and Imha aquafarm, Haenam in Jeollanamdo, from October to December in 2017. The mean water temperature ranged from 5.4 to 26.4 ℃. In Eoran aquafarm (flating raft method), dissolved total nitrogen (DTN), dissolved total phosphorus (DTP), total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (COD) ranged from 0.091 to 0.181 mg/L, 0.007 to 0.019 mg/L, 0.114 to 0.187 mg/L, 0.008 to 0.033 mg/L and 0.200 to1.000 mg/L, respectively. In Imha aquafarm (fixed pold method), DTN, DTP, TN, TP and COD ranged from 0.118 to 0.276 mg/L, 0.005 to 0.024 mg/L, 0.155 to 0.305 mg/L, 0.009 to 0.042 mg/L and 0.300 to1.400 mg/L, respectively. In order to investigate the number of conchospores attached on the Pyropia net, which was cut into about 4cm long. The mean number of conchospores of Yuldo, Supum1 and Supum2 cultivars were 39.5, 26.5, 72.5, respectively. Young thalli were harvested two times at Eoran aquafarm, and three times at Imha aquafarm. In eoran aquafarm, the mean thallus length of Yuldo, Supum1 and Supum2 cultivars were 49.9, 46.0, 42.0 cm on October and 163, 126.0, 263.0 cm on November, respectively. The mean thallus width of Yuldo, Supum1 and Supum2 cultivars were 5.8, 4.6, 11.5 cm on October and 20.9, 11.5, 14.0 cm on November, respectively. In Imha aquafarm, the mean thallus length of Yuldo, Supum1 and Supum2 cultivars were 119.0, 60.9, 71.0 cm on October, 196.0, 132.0, 262.0 cm on November and 187.0, 281.0, 296.0 cm on December, respectively. The mean thallus width of Yuldo, Supum1 and Supum2 cultivars were 4.2, 3.4, 3.1 cm on October, 8.9, 6.2, 6.6 cm on November and 11.7, 11.6, 9.4 cm on December, respectively. In eoran aquafarm, contents of moisture, crude ash, crude lipid, crude protein and carbohydrate of three cultivars ranged from 11.64 to 20.15, 19.54 to 21.19, 0.00 to 0.18, 29.78 to 37.81, 29.16 to 29.71, respectively. In Imha aquafarm, contents of moisture, crude ash, crude lipid, crude protein and carbohydrate of three cultivars ranged from 8.43 to 9.15, 11.42 to 17.49, 0.00 to 0.00, 31.90 to 37.54, 36.30 to 42.24, respectively.

• Korean Journal of Soil Science and Fertilizer
• /
• v.21 no.4
• /
• pp.386-408
• /
• 1988

A study was conducted to develop a model for estimating evapotranspiration and yield of Chinese cabbages from meteorological factors from 1981 to 1986 in Suweon, Korea. Lysimeters with water table maintained at 50cm depth were used to measure the potential evapotranspiration and the maximum evapotranspiration in situ. The actual evapotranspiration and the yield were measured in the field plots irrigated with different soil moisture regimes of -0.2, -0.5, and -1.0 bars, respectively. The soil water content throughout the profile was monitored by a neutron moisture depth gauge and the soil water potentials were measured using gypsum block and tensiometer. The fresh weight of Chinese cabbages at harvest was measured as yield. The data collected in situ were analyzed to obtain parameters related to modeling. The results were summarized as followings: 1. The 5-year mean of potential evapotranspiration (PET) gradually increased from 2.38 mm/day in early April to 3.98 mm/day in mid-June, and thereafter, decreased to 1.06 mm/day in mid-November. The estimated PET by Penman, Radiation or Blanney-Criddle methods were overestimated in comparison with the measured PET, while those by Pan-evaporation method were underestimated. The correlation between the estimated and the measured PET, however, showed high significance except for July and August by Blanney-Criddle method, which implied that the coefficients should be adjusted to the Korean conditions. 2. The meteorological factors which showed hgih correlation with the measured PET were temperature, vapour pressure deficit, sunshine hours, solar radiation and pan-evaporation. Several multiple regression equations using meteorological factors were formulated to estimate PET. The equation with pan-evaporation (Eo) was the simplest but highly accurate. PET = 0.712 + 0.705Eo 3. The crop coefficient of Chinese cabbages (Kc), the ratio of the maximum evapotranspiration (ETm) to PET, ranged from 0.5 to 0.7 at early growth stage and from 0.9 to 1.2 at mid and late growth stages. The regression equation with respect to the growth progress degree (G), ranging from 0.0 at transplanting day to 1.0 at the harvesting day, were: $$Kc=0.598+0.959G-0.501G^2$$ for spring cabbages $$Kc=0.402+1.887G-1.432G^2$$ for autumn cabbages 4. The soil factor (Kf), the ratio of the actual evapotranspiration to the maximum evapotranspiration, showed 1.0 when the available soil water fraction (f) was higher than a threshold value (fp) and decreased linearly with decreasing f below fp. The relationships were: Kf=1.0 for $$f{\geq}fp$$ Kf=a+bf for f$$I{\leq}Esm$$ Es = Esm for I > Esm 6. The model for estimating actual evapotranspiration (ETa) was based on the water balance neglecting capillary rise as: ETa=PET. Kc. Kf+Es 7. The model for estimating relative yield (Y/Ym) was selected among the regression equations with the measured ETa as: Y/Ym=a+bln(ETa) The coefficients and b were 0.07 and 0.73 for spring Chinese cabbages and 0.37 and 0.66 for autumn Chinese cabbages, respectively. 8. The estimated ETa and Y/Ym were compared with the measured values to verify the model established above. The estimated ETa showed disparities within 0.29mm/day for spring Chinese cabbages and 0.19mm/day for autumn Chinese cabbages. The average deviation of the estimated relative yield were 0.14 and 0.09, respectively. 9. The deviations between the estimated values by the model and the actual values obtained from three cropping field experiments after the completion of the model calibration were within reasonable confidence range. Therefore, this model was validated to be used in practical purpose.