• Animal Bioscience
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• v.36 no.5
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• pp.810-817
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• 2023

Objective: The aim was to compare the behavioral response to full separation of cows and calves maintained together for 100 days or 24 h. Methods: Twelve Holstein-Friesian cow-calf pairs were enrolled into either treatment or industry groups (n = 6 cow-calf pairs/group). The treatment cows and calves were maintained on pasture together for 106±8.6 d and temporarily separated twice a day for milking. The Industry cows and their calves, were separated within 24 h postpartum. Triaxial accelerometer neck-mounted sensors were fitted to cows 3 weeks before separation to measure hourly rumination and activity. Before separation, cow and calf behavior was observed by scan sampling for 15 min. During the separation process, frequency of vocalizations and turn arounds were recorded. At separation, cows were moved to an observation pen where behavior was recorded for 3 d. A CCTV camera was used to record video footage of cows within the observation pens and behavior was documented from the videos in 15 min intervals across the 3 d. Results: Before separation, industry calves were more likely to be near their mother than Treatment calves. During the separation process, vocalization and turn around behavior was similar between groups. After full separation, treatment cows vocalized three times more than industry cows. However, the frequency of time spent close to barrier, standing, lying, walking, and eating were similar between industry and treatment cows. Treatment cows had greater rumination duration, and were more active, than industry cows. Conclusion: These findings suggest a similar behavioral response to full calf separation and greater occurrence of vocalizations, from cows maintained in a long-term, pasture-based, cow-calf rearing system when ompared to cows separated within 24 h. However, further work is required to assess the impact of full separation on calf behavior.

• Journal of the Korean Chemical Society
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• v.39 no.4
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• pp.257-265
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• 1995

Free amino acids were isolated from milk and their absolute amounts were determined by reversed phase high performance liquid chromatography after derivatization with dansyl chloride. The determination of D- and L-amino acids was based on achiral separation on a C18 column. It was found that milk contained totally 41.00 mg DL-amino acids in 100 mL milk. The level of D-amino acids to L-amino acids was determined by a column-switching system combining an achiral reversed phase separation and chiral chelate additive. The chiral separation was carried out with addition of the chiral Cu(N-benzyl-L-proline)2 chelate to the mobile phase in reversed phase liquid chromatography. It was found that the determination of 16 different amino acids is feasible in the milk sample with a C18 column separation and 12 D-amino acids out of the 16 amino acids can be determined via the column-switching system with chiral separation. 2.05% of D-glutamic acid and 2.93% of D-alanine were found in milk.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.8
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• pp.1071-1076
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• 2020

The importance of network separation is due to the use of the Internet with existing business PCs, resulting in an internal information leakage event, and an environment configured to allow servers to access the Internet, which causes service failures with malicious code. In order to overcome this problem, it is necessary to use network virtualization to separate networks and network interconnection systems. Therefore, in this study, the construction area was constructed into the network area for the Internet and the server farm area for the virtualization system, and then classified and constructed into the security system area and the data link system area between networks. In order to prove the excellence of the proposed method, a network separation construction study using network virtualization was conducted based on the basis of VM Density's conservative estimates of program loads and LOBs.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.72_73
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• 2009

The industrial power system has the radial plant distribution system and domestic generators to supply the essential loads. When the system is isolated from the utility tie line, the system frequency drops resulting in the trip of generators. The load shedding scheme shall be properly designed to secure the essential load. In this paper two kinds of load shedding schemes, those are, the Fast Act Load Shedding(FALS) and Under Frequency Load Shedding(UFLS) are simulated and compared taking an example of petrochemical gas separation plant.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.95-98
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• 2004

The present work has been developed the study of interpretation of separation behavior in gas expansion separation(GES) bolt which has the separation characteristic without fragmentation and minimum pyre-shock during the operation of the explosive bolt. In order to obtain the performance of minimum pyro-shock, the present work used non-compressive material instead of separation explosives. The use of the interpretation processor could be extensively helped to design the shape and the amount of explosives in the explosive bolt having complex geometry, and to analyse the separation behavior during the operation. It is also proved that the GES bolt is the most suitable the separation system necessary to minimum pyro-shock and non fragmentation compare to others.

• Journal of Hydrogen and New Energy
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• v.27 no.2
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• pp.211-219
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• 2016

To develop an ash separator for the solid fuel chemical looping combustion system, effects of operating variables such as solid injection nozzle velocity, diameter of solid injection nozzle, gap between solid injection line and vent line, vent line inside diameter, and solid intake height on solid separation rate and solid separation efficiency were measured and discussed using heavy and coarse particle and light and fine particles mixture as bed material in an acrylic fluidized bed apparatus. The solid separation rate increased as the solid injection nozzle velocity and the diameter of solid injection nozzle increased. However, the solid separation rate decreased as the gap between solid injection line and vent line, the vent line inside diameter, and the solid intake height increased. The solid separation efficiency was in inverse proportion to the solid separation rate. In this study, we could get high solid separation rate up to 2.39 kg/hr with 91.6% of solid separation efficiency.

• Journal of Soil and Groundwater Environment
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• v.18 no.5
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• pp.56-64
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• 2013

After the law has been enacted for the prevention and recovery of mining damage in 2005, efforts of remediation have been started to recover heavy metal contaminated soils in agricultural land near mining sites. As part of an effort, the upper part of cultivation layer has been treated through covering up with clean soil, but the heavy metal contamination could be still spreaded to the surrounding areas because heavy metals may be remained in the lower part of cultivation layers. In this study, the most frequently occurring arsenic (As) contamination was selected to study in agricultural land nearby an abandoned metal mining site. We applied separation technologies considering the differences in the physical characteristics of soil particles (particle size, density, magnetic properties, hydrophobicity, etc.). Based on physical and chemical properties of arsenic (As) containing particles in agricultural lands nearby mining sites, we applied sieve separation, specific gravity separation, magnetic separation, and flotation separation to remove arsenic (As)-containing particles in the contaminated soil. Results of this study show that the removal efficiency of arsenic (As) were higher in the order of the magnetic separation, flotation separation, specific gravity separation and sieve separation.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.2
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• pp.147-152
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• 2014

In this research, polysulfone hollow fiber membrane was used to recover $CO_2$ which is one of greenhouse gases from flue gas stream being emitted after the combustion of fossil fuels. The prerequisite requirement is to design the membrane process producing high-purity $CO_2$ from flue gas. For separation of $CO_2$, a membrane module and flue gas containing 10% carbon dioxide was used. The effects of operating conditions such as pressure, temperature, feed gas composition and multi-stage membrane on separation performance were examined at various stage cuts. Higher operating pressure and temperature increased carbon dioxide concentration and recovery ratio in permeate. Recovery ratio and separation efficiency increased if a higher content of $CO_2$ injection gas composition. Three-stage membrane system was producing a 95% $CO_2$ with 90% recovery from flue gas. The separation efficiency of three-stage membrane system was higher than one-stage system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.9
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• pp.828-837
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• 2004

The present study investigated two-phase flow distribution, phase separation and pressure drop in multi-microchannel tubes under adiabatic condition. The test section consisted of inlet and outlet headers with the inner diameter of 19.4㎜ and 15 parallel microchannel tubes. Each microchannel tube brazed to the inlet and outlet headers and had 8 rectangular ports with the hydraulic diameter of 1.32㎜. The key experimental parameters were orientation of header (horizontal and vertical), flow direction of refrigerant into the inlet header (in-line, parallel and cross flow) and inlet quality (0.1, 0.2 and 0.3). It was found that the orientation of the header had relatively large effect on the flow distribution and phase separation, while the inlet quality didn't affect much on them. The horizontal header showed the better flow distribution and phase separation characteristics than the vertical one. The parallel flow condition with the horizontal header showed the best performance for the flow distribution and phase separation characteristics under the test conditions. Two-phase pressure drops through the microchannel tubes with the horizontal header were higher than those of the microchennel tubes with the vertical header due to gravitational effect.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.6
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• pp.715-722
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• 2020

This paper proposes a design verification method based on system dynamics for offshore separation systems. Oil and gas separation systems are key components of offshore oil platforms; these systems determine the competitiveness of engineering, procurement, and construction (EPC) projects, especially in terms of added value. However, previous research on design verification has been limited to the process and deliverables of design. To address this, the study aims to develop a comprehensive design verification method and the associated functions from the perspective of project management, for the entire project life-cycle of offshore structures. The proposed methodology for design verification is expected to contribute toward effective and detailed designs as well as improve the competitiveness of EPC companies in constructing of shore structures during the early design stages. We first analyzed the separation system of the FPSO using the design verification method adopted by advanced countries and compared it with the system dynamics process formalized as ISO 15288. Subsequently, a tailored process for the design verification of the offshore structure was derived. It is shown that the proposed design verification method can be applied to the front-end engineering design process of of shore structures. Moreover, it can contribute toward the successful performance of offshore projects in the future and also minimize design changes and critical risks during the construction of these offshore structures.