• International Journal of Vascular Biomedical Engineering
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• 제2권2호
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• pp.16-26
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• 2004

The object of this study is to develop a mathematical model of the hemodialysis system including the mechanism of solute kinetics, water exchange and also cardiovascular dynamics. The cardiovascular system model used in this study simulates the short-term transient and steady-state hemodynamic responses such as hypotension and disequilibrium syndrome (which are main complications to hemodialysis patients) during hemodialysis. It consists of a 12 lumped-parameter representation of the cardiovascular circulation connected to set-point models of the arterial baroreflexes, a kinetic model (hemodialysis system model) with 3 compartmental body fluids and 2 compartmental solutes. We formulate mathematically this model in terms of an electric analog model. All resistors and most capacitors are assumed to be linear. The control mechanisms are mediated by the information detected from arterial pressoreceptors, and they work on systemic arterial resistance, heart rate, and systemic venous unstressed volume. The hemodialysis model includes the dynamics of urea, creatinine, sodium and potassium in the intracellular and extracellular pools as well as fluid balance equations for the intracellular, interstitial, and plasma volumes. Model parameters are largely based on literature values. We have presented the results on the simulations performed by changing some model parameters with respect to their basal values. In each case, the percentage changes of each compartmental pressure, heart rate (HR), total systemic resistance (TSR), ventricular compliance, zero pressure filling volume and solute concentration profiles are represented during hemodialysis.

• 한국환경과학회지
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• 제24권7호
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• pp.947-954
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• 2015

Dielectric barrier discharge plasma is a new technique in water pollutant degradation, which that is characterized by the production of chemically active species such as hydroxyl radicals, ozone, hydrogen peroxide, etc. If dissolving of plasma gas generated in the plasma reaction has increased, it is possible to increase the contaminant removal capacity. In this study, the improvement on the dissolving performance of plasma gas was evaluated by the indirect method measuring the overall oxygen transfer coefficient. Experiments were conducted to examine the effects of nozzle type, distance from water surface, air supply rate and liquid circulation rate. The experimental results showed that the $K_{La}$ value of the 3-prong nozzle is 2.67 times higher than the diffuser. The order of $K_{La}$ value with nozzle type ranked in the following order: 3-prong nozzle (inner diameter, less 1 mm) > circular nozzle (inner diameter, 1.5 mm) > ellipse nozzle (short diameter 1 mm, long diameter 2.5 mm) > circular nozzle (inner diameter, 3 mm). Optimal liquid circulation rate was appeared to be 1.7 L/min, the value of $K_{La}$ was 0.510 1/min. The value of $K_{La}$ with increasing air supply rate was revealed in the form of an exponential such as $K_{La}=0.3581e^{0.2919^*air\;flow\;rate}$.

• 교육시설
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• 제16권5호
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• pp.27-33
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• 2009

The existing universities enlarged the scope, filled up the facilities. And many new universities are founded by increase of university students, the change of curriculum and extension of installations for new curriculum. However, the planning for university campus hinders desirable activities in campus and also the origin function of university, because of the problems caused by an application of a uniform planning standard that lacks in logical analysis and such a short step as the occasion demands for the growth and the change of the university campus changing more rapidly than any other field in society. This dissertation is for space program beginning from architectural explanation and basic planning concluding a general structure-planning for land utility, circulation planning, and building layout planning in order to find the practical solution for the applicable campus plan. The contents of this dissertation is summarized below. First, I studied the characteristics of the university, the structure of the university facilities and the expansion the development process of the campus. Second, through the case study of domestic campus planning, I analyzed the characteristics and the problems about space programming, facility layout planning, circulation planning and exterior space planning. Third, in the basis of the above analyses, I set up the directions of comprehensive campus master plan.

• 지역사회간호학회지
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• 제19권4호
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• pp.622-635
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• 2008

Purpose: The purpose of this study was to measure the level of job stress and health status and find out factors affecting the health status among circulation enterprise workers. Method: This study was a cross-sectional descriptive study. The subjects were 128 workers whose mean age was 33.2 years. Korean occupational stress questionnaire Short Form was used to measure job stress. Todai Heath Index that was made by Aoki in 1977 and translated by Kim(1997) was used to measure the health status. Results: The total job stress scores of men and woman fell in the lower 50% of Korean workers. Job autonomy and interpersonal conflicts as a subcategories fell in upper level 50% in both men and women and job insecurity fell in the upper level 50% in women. The mean score of health status was 51.47, indicating slightly higher frequency of complains of health symptoms. There was no significant correlation between total job stress and total health status. Finally, factors influencing the health status were organizational system and age. Conclusion: Based on the results of this study, it is necessary to develop comprehensive stress management programs including interventions of personal and organizational levels for promoting workers' health.

• The Journal of Korean Physical Therapy
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• 제12권3호
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• pp.497-507
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• 2000

This study was performed to understanding on guidelines for using therapeutic modalities according to injury phases of soft tissue. Clinical decisions on how and when therapeutic modalities may be used should be based on recognition of signs and symptoms. as well as some awareness of the time frames associated with the various phases of the Healing process. The physical therapist must have a sound understanding of that process in terms of the sequence of the various process of healing stage. The results of this study are as follows: 1. Once an acute injury has occured, the healing process consists of the imflammatory response phase, the fibroblastic-repair phase, and the maturation-remodeling phase and can impede by various pathologic factors. 2. Modality use in the initial acute injury phase and the inflammatory response phase should be directed toward limiting the amount of swelling and reducing pain. 3. Modality use in the Fibroblastic repair phase may be change from cold to heat. The purpose of heat is to increase circulation to the injured area to promote healing. 4. During the Maturation-Remodeling phase, some type of heating modalities, ultrasound, or short wave and microwave diathermy should be used to increase circulation to the deeper tissue. In this phases, physical therapists must control training and conditioning habits to allow the injury to heal sufficiently.

• Journal of Mechanical Science and Technology
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• 제17권10호
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• pp.1507-1519
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• 2003

The two-phase flow patterns for both non-loop and loop type oscillating capillary tube heat pipes (OCHPs) were presented in this study. The detailed flow patterns were recorded by a high-speed digital camera for each experimental condition to understand exactly the operation mechanism of the OCHP. The design and operation conditions of the OCHP such as turn number, working fluid, and heat flux were varied. The experimental results showed that the representative flow pattern in the evaporating section of the OCHP was the oscillation of liquid slugs and vapor plugs based on the generation and growth of bubbles by nucleate boiling. As the oscillation of liquid slugs and vapor plugs was very speedy, the flow pattern changed from the capillary slug flow to a pseudo slug flow near the annular flow. The flow of short vapor-liquid slug-train units was the flow pattern in the adiabatic section. In the condensing section, it was the oscillation of liquid slugs and vapor plugs and the circulation of working fluid. The oscillation flow in the loop type OCHP was more active than that in the non-loop type OCHP due to the circulation of working fluid in the OCHP. When the turn number of the OCHP was increased, the oscillation and circulation of working fluid was more active as well as forming the oscillation wave of long liquid slugs and vapor plugs in the OCHP. The oscillation flow of R-142b as the working fluid was more active than that of ethanol and the high efficiency of the heat transfer performance of R -142b was achieved.

• 한국환경과학회지
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• 제27권8호
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• pp.621-629
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• 2018

Many chemically active species such as ${\cdot}H$, ${\cdot}OH$, $O_3$, $H_2O_2$, hydrated $e^-$, as well as ultraviolet rays, are produced by Dielectric Barrier Discharge (DBD) plasma in water and are widely use to remove non-biodegradable materials and deactivate microorganisms. As the plasma gas containing chemically active species that is generated from the plasma reaction has a short lifetime and low solubility in water, increasing the dissolution rate of this gas is an important challenge. To this end, the plasma gas and water within reactor were mixed using the air-automizing nozzle, and then, water-gas mixture was injected into water. The dissolving effect of plasma gas was indirectly confirmed by measuring the RNO (N-Dimethyl-4-nitrosoaniline, indicator of the formation of OH radical) solution. The plasma system consisted of an oxygen generator, a high-voltage power supply, a plasma generator and a liquid-gas mixing reactor. Experiments were conducted to examine the effects of location of air-automizing nozzle, flow rate of plasma gas, water circulation rate, and high-voltage on RNO degradation. The experimental results showed that the RNO removal efficiency of the air-automizing nozzle is 29.8% higher than the conventional diffuser. The nozzle position from water surface was not considered to be a major factor in the design and operation of the plasma reactor. The plasma gas flow rate and water circulation rate with the highest RNO removal rate were 3.5 L/min and 1.5 L/min, respectively. The ratio of the plasma gas flow rate to the water circulation rate for obtaining an RNO removal rate of over 95% was 1.67 ~ 4.00.

• 한국응급구조학회지
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• 제9권1호
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• pp.79-87
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• 2005

Purpose: Investigates the results of CPR operation in visited patients with arrest state, and element to affect the results, and it is checks a problem, and it is made to promote. Methods: As for this study, analysis studied the results that operation CPR with the object arrest patients of 69 visited Jecheon Seoul hospital emergency center for during the period from January 2002 to February 2005. It was played writing partly changed In-hospital Utstein Style, and to stick a record in it. Paramedic which participated in CPR directly did the record of a variable, As for the data processing, use SPSS Version 12.0 for Windows. Results: It was male 68.1% female 31.9% for 69 people, and the sex ratio didn't affect return of spontaneous circulation, with female 8 people to male 16 people for ROSC(Return of spontaneous circulation) 24 people. with female 14 people to male 31 people for NROSC(Non-return of spontaneous circulation) 45 people(p>0.05). The initial EKG rhythm was asystole 34.8%, VF 31.9%, The case that initial EKG was VF compared it to a patient of asystole, and a survivor had a lot of VF and there were a lot of survivors(p<0.05). The wasn't relativity between VF and PEA(p>0.05), The CPR lead time was short in ROSC with NROSC $25.0{\pm}15.0$ minutes, ROSC $11.9{\pm}10.7$ minutes(p<0.01). Epinephrine administer time was NROSC $3.0{\pm}4.1$ minutes, ROSC $2.1{\pm}1.9$ minutes(p>0.05). It was survivor 18 people(21.1%) than 24 hours and the PAM Index affected in ROSC. with $9.0{\pm}1.2$ points NROSC, with $1.6{\pm}1.7$ points ROSC(p<0.01). A correlation was high between a CPR lead time and PAM Index(p<0.02), a correlation was examined by being high between ROSC and a CPR lead time, PAM Index(p<0.01).

• 한국수산과학회지
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• 제45권5호
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• pp.465-471
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• 2012

To compare the accumulation of paralytic shellfish poison (PSP) in different marine organisms, the occurrence and variation of PSP were surveyed in blue mussel Mytilus edulis, oyster Crassostrea gigas, short neck clam Ruditapes philippinarum, bay scallop Argopecten irradians, and warty sea squirt Styela clava collected from Jinhae Bay, Korea, in 2005 and 2006 year. We also investigated the ability of the blue mussel to detoxify PSP by relaying and depuration (via the water flow or water circulation system). In the marine organisms examined, PSP levels were the highest in blue mussel, followed in order by bay scallop, oyster, short neck clam, and warty sea squirt. Comparing the maximum PSP levels in the bivalve species examined in 2005 and 2006, PSP in blue mussel was 1.6-2.0, 4.0-5.9, and 5.1-6.0 times higher than in bay scallop, oyster, and short neck clam, respectively. Therefore, blue mussel could be useful as a bioindicator for PSP monitoring. With the increasing PSP levels in blue mussel in 2006, the proportion of PSP in its digestive gland increased to 95.1% when the maximum level was detected from the whole tissues of blue mussel on May 29. Subsequently, the PSP proportion in the digestive gland decreased as the PSP level in whole tissue decreased. The detoxification of PSP in blue mussel was greatest with relaying, followed by the water flow, and water circulation systems. Relaying decreased the PSP level below the regulatory limit of $80{\mu}g$/100 g after 2 days in low toxic sample with $124{\mu}g$/100 g, and after 7 days in high toxic sample with $401{\mu}g$/100 g. During depuration in the blue mussel with $401{\mu}g$/100 g via the water flow system, the PSP amounts in the digestive gland decreased by about 50% after 1 day, and about 77% after 7 days. In contrast, the PSP amounts in the soft body, gill, and mantle did not change significantly with depuration.

• Journal of Chest Surgery
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• 제10권2호
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• pp.274-280
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• 1977

As a major cause for postoperative hypoxia, the importance of increased physiological shunting is increasingly emphasized. This study is a review and analysis of postoperative physiological shunting following open heart surgery with the aid of extracorporeal circulation. Sixteen patients were selected from among 21 patients who underwent elective open heart surgery at the Department of Thoracic and Cardiovascular Surgery, Kyungpook National University, School of Medicine, from December, 1975 to September, 1977. The results were as follows: 1. The degree of postoperative physiological shunt was progressively increased from 18.8% mean value one hour after surgery to 22.7% mean value, reaching a peak on the second postoperative days. 2. For up to one week, large physiological shunt[15%] was persisted in one patient. 3. Comparing long[more than 90 minutes] with short[less than 90 minutes] perfusion time group using pump oxygenator, it was found that the physiological shunt increased about 3% in the long as compared with the short perfusion time group. 4. The mean blood pressure was 70-80 mmHg without a remarkable causal relationship between physiological shunt and mean blood pressure. 5. On elevated $PaO_2$[>200 torr], the physiological shunt was decreased less than 20% of cardiac output, but on diminished $PaO_2$[102 torr] after two days, it was 22.7% of cardiac output. From above results, a contrary causal relationship between $PaO_2$ and physiological shunt was obtained. Co Reviewing chest X-rays postperfusion, it was demonstrated that no remarkable causal relationship between roentgen-ray evidence and physiological shunt could be obtained.