• 약학회지
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• 제44권6호
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• pp.572-577
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• 2000

The effects of ibuprofen on bioavailability of ciprofloxacin were studied in rabbits. Animals were divided into three groups ; group A received 60 mg/kg of ciprofloxacin; group B and C received 60 mg/kg of ciprofloxacin with 60 and 240 mg/kg of ibuprofen, respectively. Ciprofloxacin and ibuprofen were given by single oral administration. Serum concentrations of ciprofloxacin were measured by high performance liquid chromatography with UV detector and pharmacokinetic parameters were calculated. Area under the serum concentrations versus time curve (${\pm}\;S.E.$) of ciprofloxacin were decreased in group B and C compared with group A ($12.26\;{\pm}\;0.94$ and $12.57\;{\pm}\;0.94$ vs. $15.71\;{\pm}\;1.06\;{\mu}g{\cdot}hr/ml$, p<0.05), whereas total clearances were increased ($1.81\;{\pm}\;0.13$ and $1.76\;{\pm}\;0.12$ vs. $1.40\;{\pm}\;0.09\;l/hr/kg$, p<0.05). No significant differances in these parameters were observed between group B and C. Relative bio-availability of group B and C to group A were 78 and 80%, respectively. These results suggest that the coadministration of ibuprofen with ciprofloxacin may reduce the bioavailability of ciprofloxacin.

• 대한조선학회논문집
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• 제36권1호
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• pp.37-46
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• 1999

덕트 로터 추진장치에서 덕트와 로터 날개끝 사이의 간극변화가 날개끝 보오텍스 캐비테이션 초기발생 특성에 미치는 영향을 실험적으로 연구하였다. 허브 보오텍스 캐비테이션과 날개끝 보오텍스 캐비테이션 초기발생특성의 상관관계를 살펴보기 위해서 추진장치 하류에서 축방향과 원주방향유속을 L.D.V.로 계측하였다. 날개끝 및 허브 보오텍스 캐비테이션 초기발생 관찰결과와 유속분포로부터 해석된 유동변화가 정성적으로 잘 일치하고 있으며, 날개끝 보오텍스 캐비테이션 초기발생 지연을 최대화할 수 있는 최적의 간극량을 도출하였다.

• 대한인간공학회지
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• 제34권2호
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• pp.135-143
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• 2015

Objective: The purposes of this study are to investigate ergonomic problems and to propose their improving measures in office environment of big general hospitals. Background: Office tasks have varying risk factors of work-related musculoskeletal disorders (WMSDs). The first symptom resulted from the office work was recognized as an occupational disease in Korea in 1986. Although the symptoms have increased since its first recognition, there has been few study on the effect of office work environment settings. Method: First, the author took pictures of working scenes performed in three big university hospitals. Next, the pictures were analyzed in view point of ergonomics. Based on the analysis, their improving measures were proposed for reducing work stress. Results: The results showed that most physical office environment settings such as dimensions of tables/desks and chairs, leg room, thigh, knee and foot clearances, and chairs used did not satisfy the ergonomically recommended design guidelines. In addition, some clerks placed personal belongings under their desks, put monitors in high position and did not lean against the backrest of chairs in seated tasks, which resulted in poor working postures of leg, back, neck etc. It is recommended that the hospital management should provide their clerks with ergonomically designed office furniture and continuously perform ergonomics training program for raising clerks' recognition for office ergonomics. Conclusion: Most office environment settings investigated in this study were not in good condition in view point of ergonomic design for the settings. Application: It would be useful as basic data for establishing ergonomically good office environment in hospitals.

• 약학회지
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• 제34권2호
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• pp.88-101
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• 1990

Captopril, angiotensin converting enzyme (ACE) inhibitor, when given intravenously in dog, elicited the diuretic action along with the increases of glomerular filtration rates (GFR), renal plasma flow (RPF) and osmolar clearances (Cosm) with no changes of free water clearnces ($C_{H_2O}$), and then captopril produced the enlargement of excretion rates of electrolytes in urine and the reduction of reabsorption rates of electrolytes in renal tubles. Captopril, when given into a renal artery, exhibited no changes of renal function in the experinental kidney, whereas diuretic action with the same mechanism as shown in intravenous captopril in control kidney. Captopril, when injected into a carotid artery, showed increases in rates of urine flow in a small does which did not affect on renal action when it was administered intravenusly. Diuretic action induced by captopril was not influenced by renal artery denervation, propranolol and angiotensin II inhibiters. Above results suggest that captopril produced diuretic action along with renal hemodynamic changes by slight contraction of vas efferense and reduction of reabsorption rate of electrolytes in renal tubules, especilly distal tubules, that may be mediatedby endogenous substances.

• 약학회지
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• 제35권2호
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• pp.85-98
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• 1991

Verapamil, $Ca^{2+}$-channel blocker, when given into vein or into carotid artery, produced the decrease of urine flow accompanied with the decreased amounts of Na$^{+}$ and $K^{+}$ excreted in urine ($E_{Na}, E_{K}$) and with the decreased clearances of free water (C$_{H_2O}$) and osmolar substance (C$_{osm}$), and then increased reabsorption of Na$^{+}$ and $K^{+}$ in renal tubules (R$_{Na}$, R$_{N}$), glomeruler filtration rate (GFR) and renal plasma flow (RPF) were inhibited when verapamil was given into carotid artery, but were only tendency of reduction when given intravenously. Verapamil, when infused into a renal artery, exhibited diuresis accompanied with the increased GER, RPF, E$_{Na}$ and E$_{K}$, with the decreased filtration fraction (FF) in only infused kidney. At the same time, $C_{H_2O}$ was not changed, R$_{Na}$ and R$_{K}$ were reduced. Antidiuretic action by verapamil administered into vein or into carotid artery in normal kidney was reversed to diuretic action in denervated kidney. At this time, parameters of renal function exhibited the opposite phenomena compared to that elicited by verapamil in normal kidney, wherease renal denervation did not influence the action of verapamil infused into a renal artery. Above results suggest that verapamil produce both antidiuresis through nervous system centrally, not endogenous substances and diuresis by direct action in the kidney. Diurectic action are caused by hemodynamic improvement through dilatioon of vas efferense and by greatly inhibited reabsorption of electrolytes in distal tubules.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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• pp.209-215
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• 2001

The head-capacity curves for pumps developed by the pump manufacturer are based on tests of a single pump operating in a semi-infinite pool with no nearby walls or floors and no stray currents, Hence, flow into the Pump suction is symmetrical with no vortices or swirling. Pump station designers rely on these curves to define the operating conditions for the pump selected. But various constraints such as size, cost, and limitations on storage time require walls, floors, and pump intakes to be close proximity to each other. From this background, the authors are carrying out a systematic study on the flow characteristics of intakes within a sump found in pump stations. Model pump intake basin is designed and PIV is adopted as a measuring tool to capture the instantaneous flow patterns. Special attention is paid to investigate the flow patterns near the free surface, side-wall and back-wall due to different clearances from back-wall to vertical in take pipe. Moreover, the locations and vorticities of the various types of vortices that were found in the examinations are discussed.

• 한국유체기계학회 논문집
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• 제14권5호
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• pp.18-23
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• 2011

A CFD analysis method is developed and applied for investigating the gas flow and the byproduct particle trajectory in Roots type vacuum pump. The internal fluid flow and thermal fields between the rotors and the housing of vacuum pump are analyzed by using the dynamic mesh, the numerical methods for unsteady 2-D Navier-Stokes equation and the standard k-$\varepsilon$ turbulence model of the Fluent code. Coupled with the flow simulation results, the particle trajectory of the byproduct flowing into the pump with gas stream is analyzed by using discrete phase modeling technique. The CFD analysis results show the pressure, the velocity and the temperature distributions in pump change abruptly due to the rotation of rotors, and back flows are produced due to the strong reverse pressure gradients at rotor/rotor and rotor/housing clearances. The predicted byproduct particle trajectory results also show the particles impinge on the clearance surfaces between the housing and the rotor of pump and then may form the deposit layer causing the failure of pump.

• 대한기계학회논문집A
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• 제20권5호
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• pp.1508-1515
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• 1996

The method of utilizing sensitivity linkages for the analysis of mechanical errors are proposed. As sources of the mechanical error, tolerances in the link length and clearances in thejoints are considered. It is demonstrated that the problem of calculating mechanical errors of a 4-bar mechanism can be transformed into a problem of conventeional velocity analysis of a sensitivity linkage. As a result of the present study, it is found and proved that the mechanical error of the output angle in the 4-Bar mechaism is represented as a simple harmonic function with respect to the relative position of the pin on the clearance circle. Also the vector representing the mechanical error of a coupler point makes, in general, an ellipse as the relative angle varies on the clearance circle. With these results we can better identify the characteristic of the mechanical errors in linkages.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.563-569
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• 2001

The head-capacity curves for pumps developed by the pump manufacturer are based on tests of a single pump operating in a semi-infinite pool with no nearby walls or floors and no stray currents, Hence, flow into the pump suction is symmetrical with no vortices or swirling. Pump station designers rely on these curves to define the operating conditions for the pump selected. But various constraints such as size, cost, and limitations on storage time require walls, floors, and pump intakes to be close proximity to each other. From this background, the authors are carrying out a systematic study on the flow characteristics of intakes within a sump found in pump stations. Model pump intake basin is designed and PIV is adopted as a measuring tool to capture the instantaneous flow patterns. Special attention is paid to investigate the flow patterns near the free surface, side-wall and back-wall due to different clearances from back-wall to vertical in take pipe. Moreover, the locations and vorticities of the various types of vortices that were found in the examinations are discussed.

• 한국임상약학회지
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• 제10권3호
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• pp.120-124
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• 2000

Diltiazem inhibits calcium channels and leads to vascular smooth muscle relaxation and negative inotroic and chronotropic effects in the heart. Diltiazem (DTZ) is almost completely absorbed after oral administration, but its bioavailability is reduced because of considerable hepatic first-pass metabolism. The main metabolite of DTZ is deacetyldiltiazem. The purpose of this study was to report the pharmacokinetic changes of DTZ and its metabolite, deacetyldiltiazem (DAD) after intravenous administration of diltiazem to control rabbits and rabbits with mild and medium folate-induced renal failure (FIRRs). The area under the plasma concentration-time curves (AUC) of DTZ were significantly increased in mild and medium FIRRs. The metabolite ratio of the DAD to DTZ were significantly decreased in mild and medium FIRRs. The elimination rate constant $(\beta)$ and total body clearances (CLt) of DTZ were significantly decreased in mild and medium FIRRS. These findings suggest that the hepatic metabolism of diltiazem was inhibited and CLt and ${\beta}$ of DTZ were significantly decreased in mild and in rabbits with medium folate-induced renal failure.