• Journal of the Korean Society of Tobacco Science
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• v.16 no.2
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• pp.128-133
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• 1994

This study was carried out to get agronomic information about the tobacco culture in paddy soil where incidence of grey tobacco leaves used to appearly uptake of iron, manganese and chlorine due to soil acidity and high water level. Application of lime to paddy soil(pH5.4-5.6) reduced content of iron, manganese known as proceeding materials giving rise to variegated grey tobacco after curing, compared with non-treatment. Grey leaves were found mainly at lower and middle stalk positions, and incidence of grey tobacco was lowered by application of lime in the well drained field but was not affected by level of fertilizer application. Amendment of soil acidity by lime tended to decrease chlorine and manganese content in leaves. Nicotine and mangenese content of leaves were lowered by reduction of one-quarter fertilizer level. In case of lime treatment, increase of yield reached to 4-6% comparing with those of non-treatment but price per kg was not affected. Reduction of N fertilizer level to three-quarters had the equal yield but high quality of leaf comparing with standard fertilization in paddy field.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.3
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• pp.310-316
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• 1999

Physiological responses (cortisol, glucose, GPT, GOT, total protein, hematocrit, sodium, chloride, potassium, total calcium and osmolality), growth and survival rates of grey mullet (Mugil cephalus) and Nile tilapia (Oreochromis niloticus) by the manipulation of salinity were studied. Salinity was increased directly from freshwater to $33\%_{\circ}$ and remained for 15 days. Then, salinity was decreased directly from seawater to freshwater and remained for other 15 days. All tilapias were dead at the third day, but $96.5\%$ of grey mullet were survived at the 30th day. The grey mullet showed no significant differences for cortisol and glucose concentrations in the seawater and freshwater. However, those of the Nile tilapia were increased in seawater. The grey mullet showed no significant differences for sodium, chloride and potassium concentrations during experimental period. However, those of the Nile tilapia were significantly increased when exposed to seawater. The osmolality of grey mullet ranged between 293.5 mOsm/kg and 335.0 mOsm/kg for the whole experimental period.

• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1321-1335
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• 2022

This study was conducted to investigate the effect of absorption coefficient models on the P1 radiation model for a premixed hydrogen flame containing the water vapor. A CFD combustion simulation analysis was performed using XiFoam, one of the open-source CFD solvers in OpenFOAM. The solver using the flamelet combustion model has been modified to implement radiative heat transfer. The absorption coefficient models used in this study the grey-mean model and constant model, and for comparison, case without radiation was added. This CFD simulation study consisted of benchmarking the THAI HD-15 and HD-22 experiments. The difference between the two tests is the inclusion of water vapor in the condition before ignition. In the case of the HD-22 experiment containing water vapor in the initial condition, the simulation results show that the grey-mean absorption coefficient model has a strong influence on the temperature decrease of the flame and on the change in pressure inside the vessel.

• Smart Structures and Systems
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• v.7 no.4
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• pp.241-262
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• 2011

Cast iron pipe has been used as a water distribution technology in North America since the early nineteenth century. The first cast iron pipes were made of grey cast iron which was succeeded by ductile iron as a pipe material in the 1940s. These different iron alloys have significantly different microstructures which give rise to distinct mechanical properties. Insight into the non-destructive structural condition assessment of aging pipes can be advantageous in developing mitigation strategies for pipe failures. This paper examines the relationship between the small-strain and large-strain properties of exhumed cast iron water pipes. Nondestructive and destructive testing programs were performed on eight pipes varying in age from 40 to 130 years. The experimental program included microstructure evaluation and ultrasonic, tensile, and flexural testing. New applications of frequency domain analysis techniques including Fourier and wavelet transforms of ultrasonic pulse velocity measurements are presented. A low correlation between wave propagation and large-strain measurements was observed. However, the wave velocities were consistently different between ductile and grey cast iron pipes (14% to 18% difference); the ductile iron pipes showed the smaller variation in wave velocities. Thus, the variation of elastic properties for ductile iron was not enough to define a linear correlation because all the measurements were practically concentrated in single cluster of points. The cross-sectional areas of the specimens tested varied as a result of minor manufacturing defects and levels of corrosion. These variations affect the large strain testing results; but, surface defects have limited effect on wave velocities and may also contribute to the low correlations observed. Lamb waves are typically not considered in the evaluation of ultrasonic pulse velocity. However, Lamb waves were found to contribute significantly to the frequency content of the ultrasonic signals possibly resulting in the poor correlations observed. Therefore, correlations between wave velocities and large strain properties obtained using specimens manufactured in the laboratory must be used with caution in the condition assessment of aged water pipes especially for grey cast iron pipes.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.1
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• pp.1-8
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• 2005

In order to find out the environmental factors influencing movement of common grey mullet, Mugil cephalus in funnel net fishing ground of the Dolsan-do, Yeosu southern sea area, the oceanographic factor such as the water temperature, isobath and tidal current were observed respectively, the water temperature was compared with the amount of common grey mullet caught by funnel net. Also, to investigate the movement direction of common grey mullet in same sea area, 160 common grey mullets of body length 22 to 51cm caught at funnel nets of the Dolsan-do southern sea area were marked and then released at 5 positions in 5 times. The results obtained are summarized as follows : 1. The water temperature at the funnel net fishing ground of Dolsan-do in 2002 was ranged from 6.9 to 27.4$^{\circ}C$. The water temperature was displayed a maximum value in August to increase from March and a minimum value in February of the ensuing year to decrease from September. The catches of gray mullet caught by funnel net were generally abundant from March to September, but decreased sharply from October. The optimum range of water temperature for the funnel nets fishing was situated between 15.0 to 25.0$^{\circ}C$. 2. The isobath from 6m to 13m in coast sea set up funnel nets were densely distributed and the depth more than 14m of isobath were widely spreaded to the open sea at Dolsan-do southern sea area. 3. The tidal current of the coast sea set up funnel nets flowed southward and northward along the coast ato ebb and flood tide respectively. The direction of tidal current to the open sea was southeast at ebb tide with the mean speed 43cm/sec, but northwest at flood with the mean speed 25cm/sec. 4. The recapture rate through the experiment duration showed 9.4%. The recapture rate in Gyedong area was very high value with 33.3% as compared with others. The movement of common grey mullet in Dolsan-do southern sea area trended toward a inner bay and north bound mainly.

• Food Science of Animal Resources
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• v.22 no.3
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• pp.218-221
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• 2002

A total of 40 domestic-fed imported beef cattle were used to determine meat quality traits. Sirloin was taken from each 10 of Hereford, Angus, Hurray Grey(MG), Cross breed(Hereford$\times$Angus) and objective and subjective meat quality were assessed after a 7 days ageing(0$\pm$1$\^{C}$). Results showed that ultimate pH and fat hardness was not affected by breeds. MG showed a higher water holding capacity and consequently a lower cooking loss(%) than the other breeds(p<0.05). Angus sirloin was shown to be the toughest meat(assessed by WB-shear force), Hereford and MG resulted in the most tender meat(p<0.05). Objective meat color and sensory properties did not differ between the breeds. The current study indicated that the breeds had a similar characteristics in meat quality. However, further research on consumer preference including Hanwoo needs to be undertaken.

• Geomechanics and Engineering
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• v.18 no.5
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• pp.515-525
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• 2019

A karst collapse, as a natural hazard, is totally different to a normal collapse. In recent years, karst collapses have caused substantial economic losses and even threatened human safety. A risk assessment model for karst collapse was developed based on the fuzzy analytic hierarchy process (FAHP) and grey relational analysis (GRA), which is a simple and effective mathematical algorithm. An evaluation index played an important role in the process of completing the risk assessment model. In this study, the proposed model was applied to Jiaobai village in southwest China. First, the main controlling factors were summarized as an evaluation index of the model based on an investigation and statistical analysis of the natural formation law of karst collapse. Second, the FAHP was used to determine the relative weights and GRA was used to calculate the grey relational coefficient among the indices. Finally, the relational sequence of evaluation objects was established by calculating the grey weighted relational degree. According to the maximum relational rule, the greater the relational degree the better the relational degree with the hierarchy set. The results showed that the model accurately simulated the field condition. It is also demonstrated the contribution of various control factors to the process of karst collapse and the degree of collapse in the study area.

• Journal of the Korean Solar Energy Society
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• v.31 no.5
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• pp.126-133
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• 2011

The current world wide interest in environmental issues has moved from energy conservation to $CO_2$emission reduction. Recently, according to the increase in demand for water resources, insufficient potable water circumstance is supposed, unless there are corresponding in crease in water conservation and water recycling. This study has attempted to analyze $CO_2$emission reduction by water saving strategies like installation water saving devices, rain water harvesting and grey water system. To do this, this research investigates applicable water conservative strategies by literature review and calculated total water saving. The results show that (1) firstly, the water usage and $CO_2$ emission could be reduced up to 44%, (2) $CO_2$ emission reduction by water saving devices and rainwater harvesting system is about 47.7%, and (3) water usage and $CO_2$ emission reduction by grey water system is about 66%. In the future, this paper will be utilized for water management from the early design stage to maintenance stage of water glutton building.

• Geomechanics and Engineering
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• v.19 no.5
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• pp.447-462
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• 2019

The vacuum preloading method has been used in many countries for ground improvement and land reclamation works. A sand cushion is required as a horizontal drainage channel for conventional vacuum preloading. In terms of the dredged-fill foundation soil, the treatment effect of the conventional vacuum preloading method is poor, particularly in Tianjin, China, where a shortage of sand exists. To solve this problem, straight-line vacuum preloading without sand is widely adopted in engineering practice to improve the foundation soil. Based on the engineering properties of dredged fill in Lingang City, Tianjin, this paper presents field instrumentation in five sections and analyzes the effect of a prefabricated vertical drain (PVD) layout and a vacuum pumping method on the soft soil ground treatment. Through the arrangement of pore water pressure gauges, settlement marks and vane shear tests, the settlement, pore water pressure and subsoil bearing capacity are analyzed to evaluate the effect of the ground treatment. This study demonstrates that straight-line vacuum preloading without sand can be suitable for areas with a high water content. Furthermore, the consolidation settlement and consolidation degree system is developed based on the grey model to predict the consolidation settlement and consolidation degree under vacuum preloading; the validity of the system is also verified.

• Korean Journal of Ichthyology
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• v.26 no.3
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• pp.194-201
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• 2014

Age and growth of flathead grey mullet Mugil cephalus were estimated using samples collected by a two-side fyke net in the coastal water off Taean in 2008. Age was determined by examination of annuli in otoliths and total lengths at ages were back-calculated from otolth-body size relationship. Total length ranged from 239 to 605 mm and mainly between 400 and 550 mm. Observed ages ranged from 1 to 7 years old and mainly between 3 and 5 years old. Total length (L, mm) was linearly related to otolith radius (R, mm); L=15.3+87.9 R. Total lengths at the annulus formation in otolith were back-calculated by Frazer-Lee method. Estimated length at the age 1 was $316{\pm}40.6mm$ ($mean{\pm}SD$) showing a fast growth rate during the early growth stage. Total length at each age (t) showed a wide range indicating the big difference in growth rate among individuals. Growth in total length can be expressed by a Von Bertalanffy growth curve as $L_t=542[1-{\exp}\{-0.493 (t+0.769)\}]$.