• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.9 no.3
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• pp.19-25
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• 2013

A new type axial flow fan with centrifugal sub-blades has been designed and fabricated in the present study. We investigated velocity and pressure distributions in downstream flow fields of the fan experimentally to detect the detailed flow characteristics of new axial flow fan and an existing axial flow fan. Two-dimensional velocity components were probed by applying a particle image velocimetry system and pressure distributions were measured by Pitot tube and micro-manometer. Our results show that the velocity and pressure distributions at the flow fields of the new fan are quite different from the existing fan, and that the centrifugal sub-blades in the new fan can improve the performance characteristics in view of kinetic energy.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.2
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• pp.30-35
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• 2006

The purpose of this study is to develop a new cuff to improve the accuracy of blood pressure measurement, and to evaluate the performance of the developed system. We added a small bladder to the normal cuff, which we refer to as the double bladder system. The system that we developed for blood pressure measurement was based on the oscillometric method using a double bladder. This system was developed in order to reduce the oscillation noise and to amplify the signal of pure blood pressure. An oscillometric signal database based on the developed system was evaluated according to the ANSI/AAMI/SP10-1992 standard. The correlation coefficients between the cuff of the double bladder and the normal cuff were 0.98 for systolic pressure and 0.94 for diastolic pressure. The mean differences and the standard deviations between the average blood pressure obtained from a mercury manometer and that obtained from an automated sphygmomanometer were -0.7mmHg and 4.9mmHg for systolic, and -1.4mmHg and 5.4mmHg for diastolic pressure. We conclude that the proposed double bladder-based cuff system improves the accuracy of oscillometric blood pressure measurement. The developed system reduces the range of error by about $44{\sim}62%$ for systolic pressure and about $6{\sim}21%$ for diastolic pressure compared to the most recently developed, commercially available sphygmomanometers.

• The Korean Journal of Pharmacology
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• v.2 no.1 s.2
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• pp.99-109
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• 1966

It has been known that the pronounced hypotension resulting from hemorrhage gives rise to compensatory stimulation of the adrenosympathetic system, which leads to an increase of liberation of catecholamines from sympathetic nervous system and adrenal medulla. It is obvious, therefore, that numerous physiological and biochemical changes during the hemorrhagic hypotention might be mediated through the increased liberation of catecholamines. Although an extensive studies have been reported on changes of protein and carbohydrate metabolism in hemorrhagic shock a few studies on the changes of lipid metabolism have been reported. Levenson(1961) observed a marked increase of serum lipids content during hemorrhagic shock and also noticed a marked elevation of serum free fatty acids. He suggested that these effects were due to mobilization and accelerated metabolic breakdown of lipids which might be resulted by sympathetic stimulation as a cause. To elucidate the mechanism of this, author studied the change of serum free fatty acids and blood sugar with relation to catecholamines during experimentally induced hemorrhagic shock in dog. Healthy male mongrel dogs weighing approximately 15kg were used. Under the general anesthesia with pentobarbital, rapid hemorrhage was produced from the femoral artery maintaining blood pressure level of 40 mmHg measured by the manometer connected with the opposite femoral artery throughout the experiment. Serum free fatty acids(FFA) and blood sugar were measured by the methods of Dole(1956) and Folin-wu,(1920) respectively. Tissue catecholamine was measured by Shore and Olin method(1958) using Aminco-Bowman spectrophotofluorometer.

• Applied Science and Convergence Technology
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• v.23 no.4
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• pp.192-199
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• 2014

The electronic property of graphene was investigated by hydrazine treatment. Hydrazine ($N_2H_4$) highly increases electron concentrations and up-shifts Fermi level of graphene based on significant shift of Dirac point to the negative gate voltage. We have observed contact resistance and channel length dependent mobility of graphene in the back-gated device after hydrazine monohydrate treatment and continuously monitored electrical characteristics under Nitrogen or air exposure. The contact resistance increases with hydrazine-treated and subsequent Nitrogen-exposed devices and reduces down in successive Air-exposed device to the similar level of pristine one. The channel conductance curve as a function of gate voltage in hole conduction regime keeps analogous value and shape even after Nitrogen/Air exposure specially whereas, in electron conduction regime change rate of conductance along with the level of conductance with gate voltage are decreased. Hydrazine could be utilized as the highly effective donor without degradation of mobility but the stability issue to be solved for future application.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.2
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• pp.200-211
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• 1998

Heat transfer performance improvement by fin and groovs is studied for condensation of R-11 on integral-fin tubes. Eight tubes with trapczodially shaped integral-fins having fin density from 748 to 1654fpm(fin per meter) and 10, 30 grooves are tested. A plain tube having the same diameter as the finned tubes is also used for comparison. R-11 condensates at saturation state of 32 $^{\circ}C$ on the outside tube surface coded by inside water flow. All of test data are taken at steady state. The heat transfer loop is used for testing singe long tubes and cooling is pumped from a storage tank through filters and folwmeters to the horizontal test section where it is heated by steam condensing on the outside of the tubes. The pressure drop across the test section is measured by menas pressure gauge and manometer. The results obtained in this study is as follows : 1. Based on inside diameter and nominal inside area, overall heat transfer coefficients of finned tube are enhanced up to 1.6 ~ 3.7 times that of a plain tube at a constant Reynolds number. 2. Friction factors are up to 1.6 ~ 2.1 times those of plain tubes. 3. The constant pumping power ratio for the low integral-fin tubes increase directly with the effective area to the nominal area ratio, and with the effective area diameter ratio. 4. A tube having a fin density of 1299fpm and 30 grooves has the best heat transfer performance.

• Korean Journal of Occupational Health Nursing
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• v.4
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• pp.30-38
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• 1995

The purpose of this study was to evaluate the effect of health services on workers with hypertension in small and medium sized enterprises (20-300 employees). One hundred seventy three workers among 296 workers with hypertension were responded to the questionnaire on general and occupational characteristics, health habits and anti-hypertensive medications. Blood pressure was obtained while seated using a calibrated standard manometer before and after 4 months health services. Statistical analysis was performed using $X^2$-test and logistic regression analysis. The results were as follows ; 1. No significant differences were noted in variables of smoking, glucose intake and sleeping time, while significant differences were showed in variables of exercise time, frequency and amount of drinking and intake of salt, protain, lipid, calcium, vegetable and fruits between groups which was provided and not provided health services. 2. The rate of anti-hypertensive medication was increased and the blood pressure was decreased significantly in group which was provided health services compared with those of group which was not provided. 3. With the logistic regression analysis, significant variables affecting blood pressure change were smoking and anti-hypertensive medication. The results of this study suggested that health services on workers with hypertension in small and medium sized enterprises was effective, and the role of health professionals for health promotion movement in enterprises was important.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.340-343
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• 2011

장대 케이블 교량의 풍응답을 계측할 수 있는 무선센서네트워크 기반의 풍응답 계측시스템을 개발하고, 이를 사용하여 인천대교의 시공단계별로 고유진동수, Mode Shape과 같은 Modal Parameters의 변화를 추정하고 보강형에서의 풍압분포와 보강형, 주탑, 케이블의 가속도를 계측하여 내풍 성능을 분석하였다. 개발된 계측 시스템은 인천대교 사장교의 전체 거동을 계측할 수 있도록, 1.5km 범위에 넓게 분포된 최대 55 Nodes에서 최대 1kHz의 동기화된 계측을 수행할 수 있으며, 각 Node별로 3축가속도나 풍압을 측정할 수 있다. 전체 Node에서 가속도를 계측하는 경우에는 최대 165 Channel을 1kHz로 측정할 수 있다. Modal 해석의 경우에, 고가교, 접속교, 사장교 주탑, 보강형, 케이블의 시공 단계별 동특성의 변화를 추정하였으며, 고가교에서는 모드해석을 통해 역추정한 구조계수를 정적재하실험 및 실험실에서의 Mold 시험결과와 비교하였으며 사장교 케이블에서는 케이블 댐퍼의 성능을 분석하였다. 또한 인천대교 보강형에서의 풍압분포를 계측하였으며, 풍압의 공간상관관계를 분석하였고, 풍하중 및 풍진동 특성을 분석하여 가속도 계측 결과와 비교하였다. 계측 및 분석 결과를 바탕으로 장대교량의 내풍성능을 확보하고 향상시키는데 활용할 수 있을 것으로 기대한다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.2
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• pp.185-192
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• 1999

Effective thermal conductivities and pressure-drop-related properties of aluminum foam metals have been measured. The effects of porosity and cell size in the aluminum foam metal are investigated in detail. The porosity of the foam metal, considered in the present study, varies from 0.89 to 0.96 and the cell size from 0.65㎜ to 2.5㎜. The effective thermal conductivity is evaluated by comparing the temperature gradient of the foam metal with that of the thermal conductivity-known material. The pressure drop in the foam metal is measured by a highly precise electric manometer while air is flowing through the aluminum foam metal in the channel. The results obtained indicate that the effective thermal conductivities are found to be increased with a decrease in the porosity while the effective thermal conductivities ire little affected by the cell size at a fixed porosity. However, the pressure drop is strongly affected by the cell size as well as the porosity. It is seen that the pressure drop is increased as the cell size becomes smaller, as expected. The minimum pressure drop is obtained in the porosity 0.94 at a fixed cell size. A new correlation of the pressure drop is proposed based on the permeability and Ergun's coefficient for the aluminum foam metal.

• Journal of Korean Academy of Nursing
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• v.45 no.4
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• pp.576-586
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• 2015

Purpose: The purpose of this study was to develop a self-management program applying Dongsasub training based on self-efficacy theory, and to verify the program effectiveness on self-esteem as well as self-efficacy, self-management behaviors, and blood pressure. Methods: The study design was a non-equivalent, pre-post controlled quasi-experiment study. Thirty-eight patients aged 65 and older from a senior welfare center in Seoul participated in this study (20 patients in the experimental group and 18 patients in the control group). The self-management program applying Dongsasub training consisted of eight sessions. After development was complete the program was used with the experimental group. Outcome variables included self-efficacy, self-esteem, self-management behaviors measured by questionnaires, and blood pressure measured by electronic manometer. Results: Self-efficacy (t=2.42, p=.021), self-esteem (t=2.57, p=.014) and self-management behaviors (t=2.21, p=.034) were significantly higher and systolic blood pressure (t=-2.14, p=.040) was significantly lower in the experimental group compared to the control group. However, diastolic blood pressure (t=-.85, p=.400) was not significantly different between the two groups. Conclusion: The results indicate that the self-management program applying Dongsasub training can be used as a nursing intervention in community settings for improving self-management behaviors for older adults with hypertension.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.359-365
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• 2020

Sasang Constitution data that were classified by the QSCCII (Questionnaire for the Sasang Constitution Classification II) and artery pulse waves of Chon, Guan, and Chuck data measured using an electronic manometer, were obtained from 732 subjects who visited an oriental hospital. The pulse width, peak height, and number of peaks were extracted from the pulse waves as feature variables. Validity and reliability analyses were performed to obtain the feature variables. The feature variables with high validity and reliability were selected as the discriminant variables. The pulse wave data were divided into training and predicting samples by applying a fivefold cross-validation technique. Discriminant analysis was performed for the training sample, and discriminant functions were obtained. The discriminant functions were applied to the predicting sample and the Sasang Constitution was predicted. The accuracy of prediction was estimated by comparing the predicted Sasang Constitution and that obtained by QSCCII. The accuracy of the predicted Sasang Constitution before (after) age and sex calibration was 73.6 % (70.4 %), 68.4 % (84.2 %), and 74.2 % (67.7 %) for Taeumin, Soumin, and Soyangin, respectively, and 72.5 % (73.8 %) in total.