• Title/Summary/Keyword: pressure reduction

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Gigantomastia as a Cause of Pulmonary Hypertension

  • Castillo, Juan Pablo;Robledo, Ana Maria;Torres-Canchala, Laura;Roa-Saldarriaga, Lady
    • Archives of Plastic Surgery
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    • v.49 no.3
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    • pp.369-372
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    • 2022
  • Reduction mammaplasty is the gold standard treatment for gigantomastia. We report one female patient with juvenile gigantomastia associated with severe pulmonary hypertension where her pulmonary pressure decreased significantly after the surgery, improving her quality of life. A 22-year-old female patient with gigantomastia since 10 years old, tricuspid regurgitation, and pulmonary thromboembolism antecedent was admitted to the emergency department. Her oxygen saturation was 89%. Acute heart failure management was initiated. An echocardiogram reported left ventricle ejection fraction (LVEF) of 70% with severe right heart dilation, contractile dysfunction, and arterial pulmonary pressure (PASP) of 110 mm Hg. A multidisciplinary team considered gigantomastia could generate a restrictive pattern, so a Thorek reduction mammoplasty with Wise pattern was performed. Presurgical measurements were: sternal notch to nipple-areola complex, right 59 cm, left 56 cm. Three days after surgery, the patient could breathe without oxygen support. In the outpatient follow-up, patient referred reduction of her respiratory symptoms and marked improvement in her quality of life. Six months after surgery, a control echocardiogram showed a LVEF of 62% and PASP of 85 mm Hg. Pulmonary hypertension may be present in patients with gigantomastia. Reduction mammoplasty may be a feasible alternative to improve the cardiac signs and symptoms in patients with medical refractory management.

A study on the sheet drawing using the Matrix method (Matrix법을 이용한 판재 인발에 관한 연구)

  • 유홍균;전병희
    • Journal of the korean Society of Automotive Engineers
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    • v.13 no.6
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    • pp.90-100
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    • 1991
  • This paper represents the analysis of the sheet drawing by applying the Matrix method to Hill's slip-line field for small reduction and indirect type slip-line field in case of large reduction. Results of the analysis represent the relation between the reduction ratio and the die wall pressure, mean drawing stress through rough die. The limitation on the use of this slip-line field is described. When the reduction ratio is given, the optimum die angle is analyzed in this paper.

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Waterproofing Mechanism of Hardened Cement Paste with Waterproofing Materials (구체방수제가 혼입된 시멘트 경화체의 방수 메카니즘)

  • Kang, Hyun Ju;Song, Myong Shin;Park, Jong Hun;Jeon, Se Hoon;Lee, Sung Hyun
    • Journal of the Korean Ceramic Society
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    • v.50 no.1
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    • pp.25-30
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    • 2013
  • The pore volume of hardened cement with waterproofing materials is lower compared to that of hardened cement without waterproofing materials. Thus, fewer gaps will appear by means of chemical reactions between $Ca^{2+}$ ions in hardened cement and water, solutes, and other ions. Due to the selective permeability, the osmotic pressure of hardened cement can change due to physical effects such as the reduction of the pore volume and the reduction in the number of pores, as well as by the electrochemical reaction between water, solutes, other ions and $Ca^{2+}$ ions in hardened cement. Of course, these factors do not have independent effects but instead a combined complex effect. Accordingly, we studied changes in the osmotic pressure due to the difference in the pore structure of hardened cement. A pore size smaller than 1 nm in hardened cement had only a slight effect on the osmotic pressure, whereas a pore size larger than 1 nm had a direct effect on the osmotic pressure.

Effects of Aqua-Acupuncture of Jibaikjihwangtang on the Blood Pressure in Hypertensive Rats (지백지황탕(知柏地黃湯) 약침(藥鍼)이 혈압(血壓)에 미치는 영향(影響))

  • Shim, Yang-soo;Jeon, Moon-ki;Kim, Kyung-sik;Sohn, In-chul
    • Journal of Acupuncture Research
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    • v.21 no.4
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    • pp.1-18
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    • 2004
  • Objective : This study was performed to investigate the effects of aqua-acupuncture of Jibaikjihwangtang in two-kidney one clip Goldblatt hypertensive rats and spontaneously hypertensive rats. Methods : we injected aqua-acupuncture solution into Shin-Soo ($BL_{23}$) which corresponds to human acupuncture point in two-kidney one clip Goldblatt hypertensive rats and spontaneously hypertensive rats. Systolic blood pressure, renin activity, aldosterone and atrial natriuretic peptide (ANP) plasma levels were tested. Results : Systolic blood pressure decreased significantly after aqua-acupuncture of jibaikjihwangtang. Acupuncture group in two-kidney one clip Goldblatt hyper-tensive rats had deference with control group. In plasma levels of atrial natriuretic peptide, acupuncture group of spontaneously hypertensive rats increased meaningfully but to two-kidney one clip Goldblatt hypertensive rats it was decreased meaningfully. In Serum Aldosterone density, the acupuncture group of spontaneously hypertensive rats had significant alteration than control group, but the acupuncture group of two-kidney one clip Goldblatt hypertensive rats had decreased alteration than control group. Conclusion : According to these results, after Aqua-Acupuncture of Jibaikjihwangtang blood pressure decreased significantly and data suggest that blood pressure reduction activity connected with renin activity reduction in renal hypertensive rat.

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Experimental investigation of Reynolds number effects on 2D rectangular prisms with various side ratios and rounded corners

  • Wang, Xinrong;Gu, Ming
    • Wind and Structures
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    • v.21 no.2
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    • pp.183-202
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    • 2015
  • Experiments on two-dimensional rectangular prisms with various side ratios (B/D=2, 3, and 4, where B is the along-wind dimension, and D is the across-wind dimension) and rounded corners (R/D=0%, 5%, 10%, and 15%, where R is the corner radius) are reported in this study. The tests were conducted in low-turbulence uniform flow to measure the wind pressures on the surfaces of 12 models for Reynolds numbers ranging from $1.1{\times}10^5$ to $6.8{\times}10^5$. The aerodynamic force coefficients were obtained by integrating the wind pressure coefficients around the model surface. Experimental results of wind pressure distributions, aerodynamic force coefficients, and Strouhal numbers are presented for the 12 models. The mechanisms of the Reynolds number effects are revealed by analyzing the variations of wind pressure distributions. The sensitivity of aerodynamic behavior to the Reynolds number increases with increasing side ratio or rounded corner ratio for rectangular prisms. In addition, the variations of the mean pressure distributions and the pressure correlations on the side surfaces of rectangular prisms with the rounded corner ratio are analyzed at $Re=3.4{\times}10^5$.

Study on Loss Reduction for Tilting Disk Check Valve Installed in Piping System (배관용 틸팅디스크 체크밸브의 손실저항 절감에 관한 연구)

  • Kim, J.H.;Park, J.H.;Lee, H.S.;Nam, S.H.;Hwang, S.H.
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2006.06a
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    • pp.327-328
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    • 2006
  • In generally, under the influence of over-pressure drop, serious problems such as cavitation, choked flow, flashing and vibration has been coming around the tilting disk check valve. A PIV experiment to examine the cause of energy loss has been performed and the improvement configuration of valve seat based on this visualization results is proposed. In the visualization results, flows in the piping system became instability under the influence of the shape of boss. This unstable flows induces sudden pressure drop in the piping system. So, we change the configuration of boss as a streamlined design to be stabilized the flows. A pressure measurement has been performed to know that the influence of the configuration change. In result, the rate of pressure loss reduction is about 22% at the position of No. 2 and 24.2% at the position of No. 6 in comparison with pre-improved shape.

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Inactivation Kinetics of Listeria innocua ATCC 33090 at Various Temperature Heating-up and Pressure Building-up Rates

  • Ahn, Ju-Hee;Balasubramaniam, V.M.
    • Food Science and Biotechnology
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    • v.16 no.2
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    • pp.255-259
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    • 2007
  • The effects of temperature heating-up rate and pressure building-up phase on the inactivation of Listeria innocua ATCC 33090 were evaluated in buffered peptone water. The number of L. innocua was reduced by 5.57 and 6.52 log CFU/mL during the nonisothermal treatment (the come-up time followed by isothermal process) and the isothermal treatment, respectively, at $60^{\circ}C$. When compared to the isothermal treatment (0.76$33.2^{\circ}C/min$ of temperature heating-rate. The effect of the combined high pressure and thermal processing on the inactivation of L. innocua increased with increasing pressure and temperature. At all temperature levels from 40 to $60^{\circ}C$ under 700 MPa, L. innocua was not detected by enrichment culture (>7 log reduction).

Gate Design to Reduce Porosity in High Pressure Die Cast Impeller Blade (임펠러 블레이드용 다이캐스팅 금형의 게이트 방안 설계)

  • Jung, S.K.;Cho, I.H.;Lee, J.H.;Kim, D.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.05a
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    • pp.435-436
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    • 2009
  • In the effort on cost reduction in marine equipment company, the medium sized impeller blade ($500mm{\times}200mm{\times}20mm$) of an axial flow pan was manufactured by the high pressure die casting, with which was replaced the gravity die casting. High pressure die casting is a practical alternative because of some advantages such as excellent accuracy and smooth cast surface as well as cost reduction if a certain amount of porosity in the parts can be minimized. In order to reduce the porosity in the center of the neck which is thickest region of the impeller blade, the several gate designs were proposed in this work. The flow simulations for each gate design were performed and then the optimal design was determined by considering the air pressure distribution in neck section. Finally, the size of porosity in the neck of the die cast impeller blade for optimal design was less than 1mm, which satisfied the requirement.

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Robust Design of Gate Locations and Process Parameters for Minimizing Injection Pressure of an Automotive Dashboard (자동차 대시보드의 사출압력 최소화를 위한 게이트 위치와 공정조건의 강건설계)

  • Kim, Kwang-Ho;Park, Jong-Cheon
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.13 no.6
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    • pp.73-81
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    • 2014
  • In this paper, multiple gate locations and process conditions under concern are automatically optimized by considering robustness to minimize the injection pressure required to mold an automotive dashboard. Computer simulation-based experiments using orthogonal arrays(OA) and a design-range reduction algorithm are consolidated into an iterative search scheme, which is then used as a tool for the optimization process. The robustness of a design is evaluated using an OA-based simulation of process fluctuations due to noise as well as the signal-to-noise ratio. The optimal design solution for the automotive dashboard shows that the robustness of the injection pressure is significantly improved when compared to the initial design. As a result, both the die clamping force and the pressure distribution in the part cavity are also much improved in terms of their robustness.

A PIV Study on Loss Reduction for Tilting Disk Check Valve Installed in Piping System of Water Supply by PIV (PIV에 의한 상수도 배관용 틸팅디스크 체크 밸브의 손실저감에 관한 연구)

  • Kim, B.S.;Kim, J.H.;Lee, J.Y.;Kim, J.G.;Lee, Y.H.
    • 유체기계공업학회:학술대회논문집
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    • 2003.12a
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    • pp.577-582
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    • 2003
  • In generally, under the influence of over-pressure drop, serious problems such as cavitation, choked flow, flashing and vibration has been coming around the tilting disk check valve. A PIV experiment to examine the cause of energy loss has been performed and the improvement configuration of valve seat based on this visualization results is proposed. In the visualization results, flows in the piping system became instability under the influence of the shape of boss. This unstable flows induces sudden pressure drop in the piping system. So, we change the configuration of boss as a streamlined design to be stabilized the flows. A pressure measurement has been performed to know that the influence of the configuration change. In result, the rate of pressure loss reduction is about 22% at the position of No. 2 and 24.2% at the position of No. 6 in comparison with pre-improved shape.

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