• Title/Summary/Keyword: primary fluid

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Primary Purulent Pericarditis with Cardiac Tamponade due to Oropharyngeal Polymicrobial Infection: A Case Report and Literature Review

  • Bhatarai, Mukul;Yost, Gregory;Good, Christopher W.;White, Charles F.;Nepal, Hitekshya
    • Journal of Chest Surgery
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    • v.47 no.2
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    • pp.155-159
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    • 2014
  • Cardiac tamponade due to purulent pericarditis with a characteristic greenish fluid is rare in this antibiotic era. It is highly fatal despite early diagnosis and advanced treatment. Gram-positive cocci are the leading cause of purulent pericarditis, which usually results from a direct or hematogenous spread of organisms to the pericardium from the primary foci of infection. We describe an index case of rapidly developing pericardial tamponade caused by oropharyngeal polymicrobial infection in the absence of a primary source of infection in a 62-year-old man, who was successfully managed with emergency large-volume pericardiocentesis followed by pericardiectomy.

EFFECTS OF CHANNEL ASPECT RATIO ON FLOW AND HEAT TRANSFER CHARACTERISTICS OF PRIMARY SURFACE HEAT EXCHANGER FOR ORC (유기랭킨사이클(ORC)을 위한 주전열면 열교환기의 채널 종횡비에 따른 유동 및 열전달 특성)

  • Sung, M.J.;Ahn, J.
    • Journal of computational fluids engineering
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    • v.18 no.4
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    • pp.35-40
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    • 2013
  • A series of numerical simulation has been carried out to study thermo-hydraulic characteristics of a primary surface type heat exchanger, which is designed for the evaporator and condenser of a geothermal ORC. Working fluid is geothermal water at hot side and R-245fa, which is a refrigerant designed for ORC, at cold side. Aspect ratio of the channel and Reynolds number are considered as design parameters. Nusselt number is presented for the Reynolds number ranging from 50 to 150 and compared to existing correlations. The result shows that higher aspect ratio channel gives better heat transfer performance within the range of investigation.

Design of an Organic Simplified Nuclear Reactor

  • Shirvan, Koroush;Forrest, Eric
    • Nuclear Engineering and Technology
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    • v.48 no.4
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    • pp.893-905
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    • 2016
  • Numerous advanced reactor concepts have been proposed to replace light water reactors ever since their establishment as the dominant technology for nuclear energy production. While most designs seek to improve cost competitiveness and safety, the implausibility of doing so with affordable materials or existing nuclear fuel infrastructure reduces the possibility of near-term deployment, especially in developing countries. The organic nuclear concept, first explored in the 1950s, offers an attractive alternative to advanced reactor designs being considered. The advent of high temperature fluids, along with advances in hydrocracking and reforming technologies driven by the oil and gas industries, make the organic concept even more viable today. We present a simple, cost-effective, and safe small modular nuclear reactor for offshore underwater deployment. The core is moderated by graphite, zirconium hydride, and organic fluid while cooled by the organic fluid. The organic coolant enables operation near atmospheric pressure and use of plain carbon steel for the reactor tank and primary coolant piping system. The core is designed to mitigate the coolant degradation seen in early organic reactors. Overall, the design provides a power density of 40 kW/L, while reducing the reactor hull size by 40% compared with a pressurized water reactor while significantly reducing capital plant costs.

SORET, HALL CURRENT, ROTATION, CHEMICAL REACTION AND THERMAL RADIATION EFFECTS ON UNSTEADY MHD HEAT AND MASS TRANSFER NATURAL CONVECTION FLOW PAST AN ACCELERATED VERTICAL PLATE

  • VENKATESWARLU, M.;LAKSHMI, D. VENKATA;RAO, K. NAGA MALLESWARA
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.20 no.3
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    • pp.203-224
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    • 2016
  • The heat and mass transfer characteristics of the unsteady hydromagnetic natural convection flow with Hall current and Soret effect of an incompressible, viscous, electrically conducting, heat absorbing and optically thin radiating fluid flow past a suddenly started vertical infinite plate through fluid saturated porous medium in a rotating environment are taken into account in this paper. Derivations of exact analytical solutions are aimed under different physical properties. The velocity, concentration and temperature profiles, Sherwood number and Nusselt number are easily examined and discussed via the closed forms obtained. Soret effect and permeability parameter tends to accelerate primary and secondary fluid velocities whereas hall current, radiation and heat absorption have reverse effect on it. Radiation and heat absorption have tendency to enhance rate of heat transfer at the plate. The results obtained here may be further used to verify the validity of obtained numerical solutions for more complicated transient free convection fluid flow problems.

Should Workers Avoid Consumption of Chilled Fluids in a Hot and Humid Climate?

  • Brearley, Matt B.
    • Safety and Health at Work
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    • v.8 no.4
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    • pp.327-328
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    • 2017
  • Despite provision of drinking water as the most common method of occupational heat stress prevention, there remains confusion in hydration messaging to workers. During work site interactions in a hot and humid climate, workers commonly report being informed to consume tepid fluids to accelerate rehydration. When questioned on the evidence supporting such advice, workers typically cite that fluid absorption is delayed by ingestion of chilled beverages. Presumably, delayed absorption would be a product of fluid delivery from the gut to the intestines, otherwise known as gastric emptying. Regulation of gastric emptying is multifactorial, with gastric volume and beverage energy density the primary factors. If gastric emptying is temperature dependent, the impact of cooling is modest in both magnitude and duration (${\leq}5$ minutes) due to the warming of fluids upon ingestion, particularly where workers have elevated core temperature. Given that chilled beverages are most preferred by workers, and result in greater consumption than warm fluids during and following physical activity, the resultant increased consumption of chilled fluids would promote gastric emptying through superior gastric volume. Hence, advising workers to avoid cool/cold fluids during rehydration appears to be a misinterpretation of the research. More appropriate messaging to workers would include the thermal benefits of cool/cold fluid consumption in hot and humid conditions, thereby promoting autonomy to trial chilled beverages and determine personal preference. In doing so, temperature-based palatability would be maximized and increase the likelihood of workers maintaining or restoring hydration status during and after their work shift.

Impact of Clinical, Laboratory and Fluid Therapy Variables on Hospital Length of Stay for Children with Acute Pancreatitis

  • Shahein, Abdul R.;Quiros, J. Antonio;Arbizu, Ricardo A.;Jump, Candi;Lauzon, Steven D.;Baker, Susan S.
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.23 no.4
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    • pp.356-365
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    • 2020
  • Purpose: There have been many efforts to develop generalizable severity markers in children with acute pancreatitis (AP). Expert opinion panels have developed consensus guidelines on management but it is unclear if these are sufficient or valid. Our study aims to assess the effect of clinical and laboratory variables, in addition to treatment modality on hospital length of stay (LOS) as a proxy variable for severity in pediatric patients admitted with AP. Methods: We conducted a retrospective chart review of patients between ages of 0-18 years, who were admitted with AP at 2 institutions between 2013-2018, John R. Oishei Children's Hospital (Buffalo, NY, USA) and Medical University of South Carolina Children's Hospital (Charleston, SC, USA). We constructed three linear regression models to analyze the effect of clinical signs of organ dysfunction, laboratory markers and fluid intake on hospital LOS. Results: Ninety-two patients were included in the study. The mean age was 12 years (range, 7.6-17.4 years), 55% were females, and median LOS was 3 days. The most frequent cause of AP was idiopathic. Our study showed that elevated blood urea nitrogen (BUN) on admission (p<0.005), tachycardia that lasted for ≥48 hours (p<0.001) and need for fluid resuscitation were associated with increase LOS. Total daily fluid intake above maintenance did not have a significant effect on the primary outcome (p=0.49). Conclusion: Elevated serum BUN on admission, persistent tachycardia and need for fluid resuscitation were associated with increase LOS in pediatric AP. Daily total fluid intake above recommended maintenance did not reduce LOS.

Cerebrospinal Fluid Pressure Changes Following the Injection of Saline into the Epidural Space (경막외강(硬膜外腔)에 주입(注入)한 생리식염수(生理食鹽水)가 뇌척수액압(腦脊髓液壓)에 미치는 영향(影響))

  • Jeon, Jae-Kyu;Lee, Suck-Kang;Choo, Young-Eun
    • The Korean Journal of Physiology
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    • v.11 no.1
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    • pp.21-26
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    • 1977
  • Many cases have been reported that a post spinal headache can be relieved immediately by an epidural injection of saline; and autologous blood also has recently been used successfully instead of saline. The changes of the cerebrospinal fluid pressure in 40 cases were observed in the present study in support of the concept; that a continuous leakage in association with hypovolemia and hypotension of the cerebrospinal fluid is the primary cause of a post spinal headache. Subarachnoid pressure increased immediately with saline injection into the lumber epidural space. A spinal needle was inserted into the subarachnoid space at the level of $L2{\sim}3$ and opening pressure of the cerebrospinal fluid was read. An epidural Tuohy needle was insertad at the$L3{\sim}4$ and 25m1 of saline was injected into the epidural space and the cerebrospinal fluid pressure was read in the sitting position. $\underline{Sitting\;Position:}$ Mean pressure after injection $555{\pm}(110.9)mm\;H_2O$, Pressure rise rise (%) 51.3%, Mean opening pressure $366{\pm}(52.2)mm\;H_{2}O$, $\underline{Lateral\;position:}$ Mean pressure after injection $308{\pm}(70.8)mm\;H_{2}O$, Pressure(%) 86.7%, Mean opening pressure $165{\pm}(42.6)mm\;H_{2}O$. These pressure changes responded almost simultaneously as saline was injected. This pressure rise of 51.3% in the sitting position and 86.7% in the lateral position are clinically very significant. Therefore, it is most possible that the immediate relieve of post, spinal headache by injection of fluid into the epidural space is simultaneous with the increase of the cerebrospinal fluid pressure.

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An Experimental Study of Water Vapor Pressure Change by Ambient Temperature at the Interface between Concrete and Fluid-Applied Membrane Layer

  • Ko, Jin-Soo;Kim, Byung-Yun;Park, Sung-Woo;Lee, Mun-Hwan;Lee, Sung-Bok
    • International Journal of Concrete Structures and Materials
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    • v.3 no.1
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    • pp.15-23
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    • 2009
  • Over about 30% of problems in construction is related to water-leaking, and the loss from this problem can incur as much as three times the cost of initial construction. Thus, water vapor pressure is known to be the primary cause of defective waterproofing. Accordingly, the theories on the relationship between water pressure and temperature as well as damp-proofing volume of concrete and the change in vapor pressure volume were reviewed and analyzed in this study by making test samples after spraying a dampness remover and applying waterproofing materials to the prepared test specimens. The result of measuring water vapor pressure with the surface temperature of the waterproofing (fluid-applied membrane) layer at the experimental temperature setting of about $10^{\circ}C$, which is the annual average temperature of Seoul, indicated that (1) the temperature of the fluid-applied membrane elevated to about $40^{\circ}C$, and the water vapor pressure generated from the fluid-applied membrane was about 0.03 N/mm 2 when the surface temperature of the waterproofing layer was raised to about $80^{\circ}C$. (2) when the temperature of the fluid-applied membrane of the waterproofing layer was raised from $30^{\circ}C$ to $35^{\circ}C$, water vapor pressure of about 0.01 N/mm 2 was generated, and (3) when a thermal source was applied to the fluid-applied membrane (waterproofing) layer, the temperature increased from $35^{\circ}C$ to $40^{\circ}C$, and approximately $0.005\;N/mm^2$ of water vapor pressure was generated.

An Experimental Study of Water Vapor Pressure that occurs at the Interface of a Fluid-Applied Membrane and Concrete (콘크리트와 도막 방수층 계면에 발생되는 수증기압에 관한 실험적 연구)

  • Ko, Jin-Soo;Kim, Mun-Hee;Lee, Sung-Bok;Shin, Yun-Ho
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2006.11a
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    • pp.147-150
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    • 2006
  • Of the total defects that have occurred recently in the Korean construction market, over 30% are caused by the construction of defective waterproofing, and the phenomenon of air pockets in the waterproofing layer, which is caused by the concrete vapor pressure, is known to be the primary cause of defective waterproofing. Accordingly, in this study the theory about the relationship between water pressure and temperature as well as the damp-proofing volume of concrete and, then, the change of vapor pressure volume was measured and analyzed by making a test sample after spraying a dampness remover and a waterproofing material to a prepared test body. As a result of measuring the water vapor pressure for the surface temperature of the waterproofing layer with the fluid-applied membrane temperature based on about $10^{\circ}C$, which is the average temperature of Seoul, it was found that first, the fluid-applied membrane elevated up to about $40^{\circ}C$, and the water vapor pressure generated from the fluid-applied membrane was about $0.3kgf/cm^2$ when the surface temperature of the waterproofing layer was raised up to about $80^{\circ}C$. Second, when the fluid-applied membrane temperature of the waterproofing layer was raised from $30^{\circ}C\;to\;35^{\circ}C,\;about\;0.1kgf/cm^2$ of water vapor pressure was generated, and when supplying a thermal source to raise the fluid-applied membrane temperature of the waterproofing layer from $35^{\circ}C\;to\;40^{\circ}C$, approximately $0.05kgf/cm^2$ of water vapor pressure was generated.

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Thermal-hydraulic Design of A Printed-Circuit Steam Generator for Integral Reactor (일체형원자로 인쇄기판형 증기발생기 열수력학적 설계)

  • Kang, Han-Ok;Han, Hun Sik;Kim, Young-In
    • The KSFM Journal of Fluid Machinery
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    • v.17 no.6
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    • pp.77-83
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    • 2014
  • The vessel of integral reactor contains its major primary components such as the fuel and core, pumps, steam generators, and a pressurizer, so its size is proportional to the required space for the installation of each component. The steam generators take up the largest volume of internal space of reactor vessel and their volumes is substantial for the overall size of reactor vessel. Reduction of installation space for steam generators can lead to much smaller reactor vessel with resultant decrease of overall cost for the components and related facilities. A printed circuit heat exchanger is one of the compact types of heat exchangers available as an alternative to conventional shell and tube heat exchangers. Its name is derived from the procedure used to manufacture the flat metal plates that form the core of the heat exchanger, which is done by chemical milling. These plates are then stacked and diffusion bonded, converting the plates into a solid metal block containing precisely engineered fluid flow passages. The overall heat transfer area and pressure drops are evaluated for the steam generator based on the concept of the printed circuit heat exchanger in this study. As the printed circuit heat exchanger is known to have much larger heat transfer area density per unit volume, we can expect significantly reduced steam generator compared to former shell and tube type of steam generator. For the introduction of new steam generator, two design requirements are considered: flow area ratio between primary and secondary flow paths, and secondary side parallel channel flow oscillation. The results show that the overall volume of the steam generator can be significantly reduced with printed circuit type of steam generator.