• Journal of Environmental Science International
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• v.5 no.3
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• pp.387-398
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• 1996

Granular sludge formation and it's activity change are the most important factors in achieving successful start-up and operation of UASB reactor. Nevertheless, the detailed mechanism is still unknown. On the basic of the experiments in laboratory-scale UASB reactor, the effect of hydrogen partial pressure on sludge granulation was evaluated. Size distribution method and specific metabolic activity of the sludge with the operation time were used as a means for estimating the degree of the sludge granulation. At the constant hydrogen loading, the granulation increased as starvation periods in hydrogen supply increased, resulting in high organic removal efficiency. It was evidient that hydrogen play very important role in granulation and sludge granulation was achieved through mutual symbiosis between hydrogen utilizing bacteria and hydrogen producing bacteria under the hydrogen dificient conditions. Key words : granular sludge, UASB reactor, hydrogen partial pressure.

• Journal of Powder Materials
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• v.17 no.4
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• pp.281-288
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• 2010

A carbon doped $TiO_2$ (C-$TiO_2$) photocatalyst, which shows good photocatalytic activity to Ultraviolet irradiation and visible irradiation, was successfully prepared by co-grinding of $TiO_2$ with ethanol or Activated Carbon(C), followed by heat treatment at $200^{\circ}C$ in air for 60 min. Ethanol and C were used as a representative agent of liquid and solid for carbon doping. Their influence on improving photocatalytic ability and carbon doping degree was studied with degradation of methyl orange and XPS analysis. The product prepared by co-grinding of $TiO_2$ with Ethanol had Ti-C and C-O chemical bonds and showed higher photocatalytic activity than the product prepared by co-grinding of $TiO_2$ with C, where just C-O chemical bond existed. As a result, mechanochemical route is useful to prepare a carbon doped $TiO_2$ photocatalyst activating to visible irradiation, where the solid-liquid operation is more effective than solid-solid operation to obtain a carbon doped $TiO_2$.

• Health Policy and Management
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• v.8 no.2
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• pp.88-109
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• 1998

The main purpose of this study is to compare the traditional cost system and ABC(Activity Based Cost) system of clinical laboratory department in a hospital. The study subject was 296 services in clinical laboratory from March, 1997 to August, 1997. In a new costing system, cost for a lab test consist of direct cost element, activity based cost element, and allocated common cost element. In a traditional cost system, cost elements included direct cost element and indirect cost allocated based on test volumes The major findings of this research were as follows. 1. In the application of ABC system, total cost was analyzed as follows. Direct cost was 39.3% of total cost. Activity cost and allocation were 20.9% and 39.8%, respectively. The results of analysis to use traditional cost system were as follows. Direct cost was 39.3% and it was as same as the result of direct cost of ABC system. Indirect cost was 60.7%. 2. Activities of clinical laboratory of subject hospital were registration, pre-test operation, test, test result handling, delivery, culture, post-test operation, technical support, management support, and educational support. 3. The differences of the case of higher number of test case being carried out, the cost of ABC system was lower than the cost of traditional cost system. Otherwise in the case of lower number of test case being carried out, the rests have not been appropriately evaluated, and effective management were needed in clinical laboratory.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.400-408
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• 2009

Simulation applications for analyzing the productivity of construction operations at operation level and project schedules at project level are crucial methods in project management. The application at two different levels should be very tightly linked to each other in practice. However, appropriate integration at the levels is not achieved in that existing systems do not support to integrate operation models into a schedule model. This paper presents a new approach named to Discrete Event Simulation-Nesting modeling approach, which supports not only productivity analysis at operation level but also schedule management at a project level. The system developed by the authors allows creating operation models at the operation level, maintaining them in operation model library, executing sensitivity analysis to find the behaviors of the operation models when different combination of resources are used as existing DES systems do. On top of the conventional functions, the new system facilitates to find the optimum solution of resource combinations which satisfy the user's interest by computing the hourly productivity and the hourly cost of the operation. By drag-and-dropping an operation model kept in the operation model library, the operation models are integrated into an activity of the schedule model. When a complete schedule model is established by nesting operation models into the schedule model, stochastic simulation based scheduling is executed. A case study is presented to demonstrate the new simulation system and verify the validity of the system.

• Journal of Life Science
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• v.10 no.1
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• pp.7-13
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• 2000

The purpose of this study was to investigate whether the extracts of Daucus carota L. could lead to a beneficial outcomes on serum lipid and antioxidative enzyme activity in ovariectomized rats. Sprague-Dawley rats were randomly assigned to one control and three diet groups; carrot seed, carrot root and estrogen after ovariectomy operation. Experimental diets were fed for 8 weeks. The GOT activity was decreased in the carrot extracts treated group than in the control group. The carrot seed extracts treated group showed the lowest SOD and catalase activities compare to other groups. Serum total cholesterol and LDL cholesterol decreased in the carrot seed extracts group than in the control group. From these results, it suggest that carrot seed extracts positively influenced on serum lipid and antioxidative enzyme activity.

• Nuclear Engineering and Technology
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• v.34 no.1
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• pp.9-21
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• 2002

Recently each domestic NPP has achieved zero release in liquid effluent activity. However, when looking back past experiences in world nuclear power operation, it is thought that another maximum activity reduction in the released liquid effluent just prior to falling it into environment, if possible, will bring a good effect in PA viewpoint. As the intent of applying the safety concept of diversity to conducting the above activity reduction measure, a scheme passing that effluent through the Deposition Bed just before discharging it into ocean environment was divised. Both Zeolite and ＂the mixed ＂Anthracite-sand＂ were derived as the main activity adsorption medium used in the Deposition Bed, and the schematic drawings of this Bed were presented.

• Nuclear Engineering and Technology
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• v.56 no.4
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• pp.1250-1253
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• 2024

Activity measurement of the primary circuit water of fission reactors is one method that can provide early detection of a damaged fuel assembly in the reactor core. This is an important aspect in the safe operation of the reactor and for radiation protection of staff. Radionuclides in the primary circuit water are produced by the activation of stable nuclides and the fission of fissile nuclides, mainly the isotope ²³⁵U. In the LVR-15 research reactor, measurement of the activity of the primary circuit water has been regularly undertaken since 1996. A water sample is taken from the primary circuit every week and the activities are measured four days later using gamma spectrometry. The results of these long-term measurements from 1996 to 2022 are presented. The activity time dependences of the individual radionuclides are discussed in relation to fuel assembly damage and for events connected to contamination of the water by objects inserted into the primary circuit during experiments carried out near the reactor core.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.5
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• pp.67-76
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• 2003

The principal operation rule of irrigation reservoir is to accelerate the water use and supply water actively when water is sufficient, and to restrict water use and supply water deficiently in order not to stop the irrigation activity when water is scarce. In drought seasons. water should be saved in order to keep the reservoir not to be dried up during the irrigation season. It is important to know how much water should be saved, depending on the rice-growing season and water storage volume. For the drought control of irrigation reservoirs. the rotational irrigation scheduling in paddy with the operation rule curve developed in this study could be utilized as a software program to install TM/TC system for irrigation water supply by automation facilities.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.445-448
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• 2001

Noise radiated from pile driving operation is one of major sources of community noise pollution and thus its operation method is strictly restricted by regulations. Although the drilling method is now used been commonly used in urban areas because of its activity, the benefit of low noise decreases due to high working cost. In the present work, noise characteristics of pile driving operation are carried out. Based on the study result, a low-noise pile cap for driven piles is developed in order to satisfy both the noise level restriction and the economical efficiency. Effects of pile cap are investigated by a scale model experiment, which is focused on the variation of impact force and sound pressure level. The results show a good possibility of noise reduction by an appropriately designed pile cap.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.840-842
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• 2003

Recent satellite data have revealed a correlation between the Sun’s activities and the Earth’s atmosphere . Many scientists have been conjectured a more direct connections between solar variability and the Earth’s atmosphere from satellite data analysis. During solar storms, more energetic particles reach the Earth’s atmosphere and this phenomenon have effects on the Earth’s atmospheric environment. Consequently, scientists suggest that these variations will affect a global climate change. In this study, we investigate the confirmative research results of atmospheric effects due to solar activities, especially solar storms.