• Wind and Structures
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• 제24권2호
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• pp.145-169
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• 2017

The auxiliary structures of a high-rise building, such as balconies, ribs, and grids, are usually much smaller than the whole building; therefore, it is difficult to simulate them on a scaled model during wind tunnel tests, and they are often ignored. However, they may have notable effects on the local or overall wind loads of the building. In the present study, a series of wind pressure wind tunnel tests and high-frequency force balance (HFFB) wind tunnel tests were conducted on rigid models of an actual super high-rise building with vertical ribs protruding from its facades. The effects of the depth and spacing of vertical ribs on the mean values, fluctuating values and the most unfavorable values of the local wind pressure coefficients were investigated by analyzing the distribution of wind pressure coefficients on the facades and the variations of the wind pressure coefficients at the cross section at 2/3 of the building height versus wind direction angle. In addition, the effects of the depth and spacing of vertical ribs on the mean values, fluctuating values and power spectra of the overall aerodynamic force coefficients were studied by analyzing the aerodynamic base moment coefficients. The results show that vertical ribs significantly decrease the most unfavorable suction coefficients in the corner recession regions and edge regions of facades and increase the mean and fluctuating along-wind overall aerodynamic forces.

• Wind and Structures
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• 제11권6호
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• pp.479-496
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• 2008

In this paper, computer simulation of wind flow around a single cooling tower with louver support at the base in the KAZERUN power station in south part of IRAN is presented as a case study. ANSYS FLOTRAN, an unstructured finite element incompressible flow solver, is used for numerical investigation of wind induced pressure load on a single cooling tower. Since the effects of the wind ribs on external surface of the cooling tower shell which plays important role in formation of turbulent flow field, an innovative relation is introduced for modeling the effects of wind ribs on computation of wind pressure on cooling tower's shell. The introduced relation which follows the concept of equivalent sand roughness for the wall function is used in conjunction with two equations ${\kappa}-{\varepsilon}$ turbulent model. In this work, the effects of variation in the height/spacing ratio of external wind ribs are numerically investigated. Conclusions are made by comparison between computed pressure loads on external surface of cooling tower and the VGB (German guideline for cooling tower design) suggestions.

• 한국항공우주학회지
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• 제33권4호
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• pp.71-78
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• 2005

초임계 상태의 질소 유동 환경에서 헵탄 액적의 기화 특성을 수치적으로 연구하였다. 더불어 실기체 효과와 액적 내부 순환, 다양한 열역학적 물성치 및 고압 효과를 고려하였다. 또한 헵탄 액적 바로 근처에서의 저속 유동 문제를 풀기 위하여 예조건화 스킴을 적용한 시간 전진법을 수치 코드에 적용하였다. 주위 유동 속도와 주위 압력을 변화 시켜가면서 액적의 거동을 살펴보았다. 유동 속도 증가로 인한 레이놀즈수의 증가에 따라 액적의 변형이 활발히 이루어졌고, 동일한 레이놀즈수에 대해서는 압력이 높아질수록 액적의 변형이 약화되었다.

• 약학회지
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• 제28권5호
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• pp.249-256
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• 1984

The effects of $Ca^{2+}-antagonist$, cinnarizine, on the antihypertensive effects of propranolol and metoprolol were investigated in normal cat (i. v.) and SHR (p. o.). Cinnarizine increased the antihypertensive effect of propranolol, but not of metoprolol. It inhibited the heart rate decreasing effects of propranolol and metoprolol slightly. It decreased the norepinephrine-induced blood pressure increasing effect and isoproterenol-induced blood pressure decreasing effect when coadministered with metoprolol orally for 4 weeks in SHRs.

• 설비공학논문집
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• 제16권9호
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• pp.855-862
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• 2004

This study reports pressure drops during evaporation for R-l34a, R-407C (a mixture of 23 wt% R-32, 25 wt% R-125, and 52 wt% R-l34A) and R-410A (a mixture of 50 wt% R-32 and 50 wt% R-125) in the oblong shell and Plate heat exchanger. The effects of the mass fluxes, heat fluxes, refrigerant saturation temperatures and vapor quality of refrigerants on the measured data were explored in detail. The present data showed that pressure drops of all refrigerants increase with the vapor quality. At a higher mass flux, pressure drops are higher for the entire range of the vapor quality A rise in the heat flux doesn't show significant effects on the pressure drops. Finally, at a higher saturation temperature the pressure drops are found to be lower. The pressure drops for R-407C were approximately 20% lower than those of R-l34a. R-410A had 33% lower pressure drops than R-l34a. Correlation is also provided for the measured pressure drops in terms of the friction factor.

• Structural Engineering and Mechanics
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• 제27권3호
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• pp.277-292
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• 2007

Based on the composite finite element simulation and a series of hydrostatic pressure and burst tests, autofrettage effects on strength and deformation of fiber reinforced pressure vessel with metallic liners have been studied in the paper (autofrettage: during the course of one pressure taking effect, the increasing internal stress in metallic liner can surpass the yielding point and the plastic deformation will happen, which result in that when there is no internal pressure, there are press stress in liner while tensile stress in fiber lamination). By making use of a composite finite element Ansys code and a series of experiments, the autofrettage pressure is determined in order to make the aluminium liner be totally in elastic state, under given hydrostatic test pressure. The stress intensity factors of the longitudinal crack in aluminum liner end under internal pressure and thermal loads have been computed and analyzed before and after the autofrettage processing. Through numerical calculation and experiment investigations, it is found that a correct choice for autofrettage pressure can improve the gas-tightness and fatigue strength of FRP vessel.

• 대한간호학회지
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• 제36권7호
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• pp.1123-1134
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• 2006

Purpose: The purpose of this study was to identify the effects of aromatherapy on blood pressure and stress responses of clients with essential hypertension. Method: There were fifty-two subjects divided into an essential oil group, placebo group, and control group by random assignment. The application of aromatherapy was the inhalation method of blending oils with lavender, ylangylang, and bergamot once daily for 4 weeks. To evaluate the effects of aromatherapy, blood pressure and pulse were measured two times a week and serum cortisol levels, catecholamine levels, subjective stress, and state anxiety were measured before and after treatment in the three groups. Data was analyzed by repeated measures of ANOVA, one-way ANOVA, and $X^2-test$ using the SPSS 10.0 program. Results: The blood pressure, pulse, subjective stress, state anxiety, and serum cortisol levels among the three groups were significantly statistically different. The differences of catecholamine among the three groups were not significant statistically Conclusion: The results suggest that the inhalation method using essential oils can be considered an effective nursing intervention that reduces psychological stress responses and serum cortisol levels, as well as the blood pressure of clients with essential hypertension.

• 한국임상수의학회지
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• 제21권3호
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• pp.291-297
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• 2004

Aminoglycosidic antibiotics have multiple effects on muscle. For example, they have been shown to block L-type $Ca^{2+}$ channels in vascular smooth muscle, cardiac muscle and skeletal muscle. Possibly as a consequence of this effect on $Ca^{2+}$ influx, they have been shown to decrease the contractility of cardiac muscle (gentamicin). The present study evaluated the effects of gentamicin on blood pressure, vasorelaxation and left ventricular pressure. Gentamicin(10, 20, 40mg/kg) produced dose-dependent blood pressure lowering in rat. The pretreatment of MgSO$_4$ and imipramine (Na$^{+}$-Mg$^{2+}$ exchange inhibitor) had no effect in gentamicin-induced hypotension. However, the gentamicin-induced hypotension was significantly potentiated in the preincubation of verapamil or nifedipine (L-type $Ca^{2+}$ channel blockers), and was significantly attenuated by CaCl$_2$ and was slightly attenuated by caffeine (phosphodiesterase inhibitor). Gentamicin (10, 30, 100$\mu$g/m1) did not have an effect on relaxation of phenylephrine-precontracted aortic rings but high concentration of gentamicin(100, 300$\mu$g/ml) relaxed KCl-precontracted aortic rings, which relaxation was potentiated by treatment of nifedipine. Whereas gentamicin markedly decreased left ventricular developed pressure (LVDP) in perfused heart. These data suggest that gentamicin has significant blood pressure lowering of the rat, which seems to be mediated by calcium channel-sensitive pathway and blood $Ca^{2+}$ level may be important role in this response.

• Structural Engineering and Mechanics
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• 제50권5호
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• pp.617-633
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• 2014

Because the elevated temperature degrades the mechanical properties of materials used in containments, the global behavior of containments subjected to the internal pressure under high temperature is remarkably different from that subjected to the internal pressure only. This paper concentrates on the nonlinear finite element analyses of the nuclear power plant containment structures, and the importance for the consideration of the elevated temperature effect has been emphasized because severe accident usually accompanies internal high pressure together with a high temperature increase. In addition to the consideration of nonlinear effects in the containment structure such as the tension stiffening and bond-slip effects, the change in material properties under elevated temperature is also taken into account. This paper, accordingly, focuses on the three-dimensional nonlinear analyses with thermal effects. Upon the comparison of experiment data with numerical results for the SNL 1/4 PCCV tested by internal pressure only, three-dimensional analyses for the same structure have been performed by considering internal pressure and temperature loadings designed for two kinds of severe accidents of Saturated Station Condition (SSC) and Station Black-out Scenario (SBO). Through the difference in the structural behavior of containment structures according to the addition of temperature loading, the importance of elevated temperature effect on the ultimate resisting capacity of PCCV has been emphasized.

• 동서간호학연구지
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• 제16권1호
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• pp.11-18
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• 2010

Purpose: The aim of this study was to examine the characteristics of hypertension-related nursing intervention programs and their effects on systolic and diastolic blood pressure. Methods: Fifteen studies were selected from four databases (Korean studies, Riss4U, RICHIS, and JKAN) published as of 2009. They were analyzed by meta-analysis method. The selected studies contained a control group with pre-test and post-test design, measured blood pressure as a dependent variable, and used a reported statistical value for blood pressure to measure the size of effects. Results: The hypertension-related nursing intervention programs were relatively effective in lowering both systolic and diastolic blood pressure, although they were more efficient to decrease diastolic pressure. Among the hypertension-related intervention programs, complementary and alternative therapies were more effective in lowering blood pressure compared to lifestyle change intervention. Conclusions: To acquire substantial data of intervention effects, and complementary and alternative therapy, subjects in pre-hypertensive stage, and elderly people, better industrial and scholastic research methods need to be developed for future research. Further studies are needed to establish complementary and alternative therapies. Studies with different group of participants and studies using effective research design are in need as well.