• Geomechanics and Engineering
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• v.19 no.1
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• pp.11-20
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• 2019

The use of electrokinetic dissipation method to study the fluid flow law in micro-pores is of great significance to reservoir rock microfluidics. In this paper, the micro-capillary theory was combined with the coupling model of the seepage field and the current field under the excitation of the harmonic signal, and the coupling theory of the electrokinetic effect under the first-order approximation condition was derived. The dissipation equation of electrokinetic dissipation and viscous resistance dissipation and its solution were established by using Green's function method. The physical and mathematical models for the electrokinetic dissipation of reservoir rocks were constructed. The microscopic mechanism of the electrokinetic dissipation of reservoir rock were theoretically clarified. The influencing factors of the electrokinetic dissipation frequency of the reservoir rock were analyzed quantitatively. The results show that the electrokinetic effect transforms the fluid flow profile in the pores of the reservoir from parabolic to wavy; under low-frequency conditions, the apparent viscosity coefficient is greater that one and is basically unchanged. The apparent viscosity coefficient gradually approaches 1 as the frequency increases further. The viscous resistance dissipation is two orders of magnitude higher than the electrokinetic effect dissipation. When the concentration of the electrolyte exceeds 0.1mol/L, the electrokinetic dissipation can be neglected, while for the electrolyte solution (<$10^{-2}M$) in low concentration, the electrokinetic dissipation is very significant and cannot be ignored.

• Journal of Trauma and Injury
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• v.18 no.2
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• pp.161-171
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• 2005

Background: The management of hepatic injuries has changed dramatically during the past two decade after the technologic breakthroughs in radiologic imaging techniques. Recently, the non-operative management of blunt hepatic trauma has become the standard of care in hemodynamically stable patients. We reviewed our experience of the non-operative management of blunt hepatic trauma. And the purpose of this study was to examine the prognostic factors and indicators affecting the decision for treatment modality of emergent hepatic trauma. Methods: The medical records of 84 patients who were treated for blunt hepatic injury at Masan Samsung Hospital from January 2002 to December 2003. The patients were divided two groups, non-operative(Non-OP) and operative(OP), according to the treatment modality. The two groups were compares for age, sex, mechanism of injury, grade of liver injury scale, combined injury, systolic blood pressure, pulse rate, hemoglobin, hematocrit, WBC count, S-GOT, S-GPT, ALP, transfusion amount during initial 24 hours, amount of infused crystalloid fluid, length of ICU stay, length of ward care, morbidity and mortality. The grade of the liver injury were determined by using the organ injury scale(OSI). Results: Among the 84 patients, 46 cases(54.8%) were managed non-surgically, and 3 cases of Non-OP group were treated by transarterial embolization. Between the two groups, there were significant difference in age, injury grade, combined injury, hemoglobin, hematocrit, initial systolic blood pressure, amount of infused crystalloid fluid, amount of transfusion during the first 24 hours, and length of ICU care, morbidity and mortality.(p<0.05) The overall mortality rate was 8.3%, but 2.2% mortality in the non-operative group. Conclusion: Non-operative management may be considered as a first choice in hemodynamic stable patients with blunt liver trauma. The reliable indicators affecting the treatment modality of blunt hepatic trauma were systolic BP, Hb, Hct, amount of infused crystalloid fluid, amount of transfusion during the first 24 hours, liver injury grade and combined injury. Strict selection of treatment madality and aggresive monitoring with intensive care unit were more important.

• The Korean Journal of Pain
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• v.26 no.4
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• pp.336-346
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• 2013

Intrathecal drug delivery is an effective and safe option for the treatment of chronic pathology refractory to conventional pain therapies. Typical intrathecal administered drugs are opioids, baclofen, local anesthetics and adjuvant medications. Although knowledge about mechanisms of action of intrathecal drugs are every day more clear many doubt remain respect the correct location of intrathecal catheter in order to achieve the best therapeutic result. We analyze the factors that can affect drug distribution within the cerebrospinal fluid. Three categories of variables were identified: drug features, cerebrospinal fluid (CSF) dynamics and patients features. First category includes physicochemical properties and pharmacological features of intrathecal administered drugs with special attention to drug lipophilicity. In the second category, the variables in CSF flow, are considered that can modify the drug distribution within the CSF with special attention to the new theories of liquoral circulation. Last category try to explain inter-individual difference in baclofen response with difference that are specific for each patients such as the anatomical area to treat, patient posture or reaction to inflammatory stimulus. We conclude that a comprehensive evaluation of the patients, including imaging techniques to study the anatomy and physiology of intrathecal environment and CSF dynamics, could become essential in the future to the purpose of optimize the clinical outcome of intrathecal therapy.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.5
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• pp.712-717
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• 2013

The gas management system for a vertical launching system must be safely managed within a ship. The plenum and uptake are capable of containing and surviving a full-burning restrained firing without loss of gas management integrity. To secure the safety, the pressure characteristics with a supersonic under-expanded jet on a gas management system are numerically investigated using computational fluid dynamics. The results of present analysis and the preliminary design of the gas management system are described in this paper.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.1
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• pp.23-33
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• 2015

This study was carried out for the purpose of minimizing the area of rapid flow inside the water tank. And the shape of incurrent canal was improved, and then the characteristics of fluid flow occurring inside the water tank was analyzed by using the Computational Fluid Dynamics (CFD) simulation method. better multiple hoe screw nozzle incurrent canal was used instead of conventional drop current canal used for the water tank. And according to the results of analyzing the characteristics of fluid flow, in case a screw blade was installed inside the nozzle, fluid flow was sprayed wide. And wide fluid flow was shown inside the cylindrical water tank too. Besides, a tracer simulation was carried out, in case of installing 1 and 2 multiple hoe screw nozzle incurrent canals at the cubic water tank. As a result, MODAL, MODAL index value was close to 1, in case of installing 2 canals. Therefore, it was possible to obtain the results of being close to the characteristics of plug flow.

• Journal of Korean Society for Quality Management
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• v.10 no.1
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• pp.13-15
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• 1982

A device is said to have three states if it has one good state and two mutually exclusive failure modes ; e. g., in one failure mode, it operates when it should not, in the other it doesn't operate when it Should. Some examples of such device include a fluid flow valve, an automatic machine, and an explosive. A Markov model is developed to obtain the availability Function of a 2-unit standby redundant system of such devices.

• Childhood Kidney Diseases
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• v.25 no.1
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• pp.8-13
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• 2021

Pediatric kidney transplantation is the best option since it can achieve near normal glomerular filtration rate, adequate fluid balance, and autonomic endocrine function of the kidney in end-stage kidney disease. However, pediatric kidney transplantation is difficult because children are developing and growing, management and complications of pediatric kidney transplantation are different from those of adults. This review covers the current status of pediatric kidney transplantation in Korea, key considerations that must be taken before kidney transplantation in children, and management strategy of immunosuppression and common complications.

• Journal of Sensor Science and Technology
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• v.23 no.4
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• pp.266-271
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• 2014

Chemical sensors are used in various industrial facilities such high-risk and prevent the leakage of substances, important in life and environmental protection and the safe use of industry, used for management. In particular, high-temperature environments such as power generation equipment of the rotating part due to leakage generated by the various oil, power plants Shut Down, fire, work environment (exposure to various chemical solution and gas leak) and various water, air and soil pollution causes. Thus, over the long term through various channels such as crops and groundwater contamination caused by the slow, serious adverse effect on the ecosystem. In this paper, synthetic lube oil and high pressure hydraulic fluid leakage and immediately detect a new Printed Electronic implementation of technology-based film-type sensors, and its performance test. Thus, industrial accidents and environmental pollution and for early detection of problems, large accidents can be prevented. Experimental results of the synthetic lube oil and high pressure hydraulic fluid solution after the contact time depending on the experiment and the oil solution of the sensor material of the conductive porous PE resistance value by a chemical reaction could be confirmed that rapid increase. Also implemented in the film-type oil sensor electrical resistance change over time of the reaction rate and the synthetic lube oil is about 2 minutes or less, the high pressure hydraulic fluid is less than about 1 minute was. Therefore, more high-pressure hydraulic fluid such as a low volatility synthetic lube oils are the resistance change and the reaction rate was confirmed to be the slowest.

• Journal of Korean Institute of Industrial Engineers
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• v.43 no.2
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• pp.90-99
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• 2017

As the importance of R&D has increased, there have been various efforts to apply the quality management principles and tools to R&D activities in order to manage them effectively. The R&D sector differs from other value chains, so it may be difficult to apply quality management without proper considerations of R&D characteristics. This study describes the characteristics of R&D as high uncertainty and risk, diversity of R&D types, project-based activities, importance of strategic goals and business models, and importance of intangible assets. Three well accepted R&D quality management models are reviewed and implications for quality management and R&D characteristics are summarized. Based on these findings, the management targets of R&D quality management are classified into management level (organization, project) and management focus (process, output), and the contexts of R&D quality management are classified into R&D type (research, development) and market/customer requirement clarity (fluid, specific), and appropriate R&D quality management activities in each situations have been suggested.

• Journal of Pharmaceutical Investigation
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• v.39 no.1
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• pp.29-36
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• 2009

Since the quality of final products is significantly affected by the homogeneity of powder mixture, the powder blending process has been regarded as one of the critical pharmaceutical unit processes, especially for solid dosage forms. Accordingly, the monitoring to determine a blending process' end-point based on a faster and more accurate in-line/on-line analysis has attracted enormous attentions recently. Among various analytical tools, NIR (near-infrared) spectroscopy has been extensively studied for PAT (process analytical technology) system due to its many advantages. In this study, NIR spectroscopy was employed with an optical fiber probe for the in-line monitoring of fluid-bed blending process. The position of the probe, the ratio of binary powder mixture, the powder size differential and the back-flush period of the shaking bag were examined as principal process parameters. During the blending process of lactose and mannitol powders, NIR spectra were collected, corrected, calibrated and analyzed using MSC and PLS method, respectively. The probe position was optimized. A reasonable end-point was predicted as 1,500 seconds based on 5% RSD value. As a consequence, it was demonstrated that the blending process using a fluid-bed processor has several advantages over other methods, and the application of NIRS with an optical fiber probe as PAT system for a fluid-bed blending process could be high feasible.