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Showing 1 to 20 of 145 for “"CHF"”.
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High pressure counterflow CHF.
… be expected for up to 20% void. Beyond this, the CHF value decreases uniformly with void. Void fractions up to 70% were investigated, with the results being slightly conservative compared to a similar experiment carried out at atmospheric pressure by Avedisian.
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CHF Education and Readmission Reduction
… To improve patient care and help reduce CHF readmissions by addressing CHF patient education among nursing staff.</p> <p><strong>Specific Aim: </strong>We aim to improve patient self-care and safety, and decrease the readmission rate for persons admitted with CHF at MSJMC by enhancing the …
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A Percolation Model for Boiling and Predicting CHF
… coefficient (HTC) and critical heat flux (CHF). Exceeding CHF can result in catastrophic failure of a system, making it an important value to understand; however, there is no universal model for predicting it. A recently investigated way to model CHF uses percolation theory, which states …
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Transient flow boiling CHF under exponentially escalating heat inputs
… power escalation period on critical heat flux (CHF). The results show that, for our flow conditions, the CHF value does not depend on the escalation period for periods longer than 100 ms, and is essentially the same as in steady-state boiling. For shorter periods, CHF increases as the escalation …
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Community health fund (CHF) in Tanzania : predictors of and barriers to enrolment
… introduction of voluntary Community Health Fund (CHF) in 1996. The aim of the CHF was to mobilize resources through collection prepayments from households on a voluntary basis to fund primary health care for people in the informal sector operating in rural areas. However, CHF membership …
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Experimental Investigation of Subcooled Flow Boiling and CHF at Prototypical Pressures of Light Water Reactors
Boiling crisis is an important phenomenon that affects the performance and safety of pressurized water reactors (PWRs). Accurate predictions of the boiling crisis are difficult to make because they require a clear understanding of the physical mechanisms leading to the boiling crisis combined with …
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Experimental investigation of liquid contact in the developing post-dryout CHF flow boiling regime using surface mounted thermistors
… heat transfer in the post-critical heat flux (CHF) flow boiling regime is important for determining the performance of the heat transfer equipment for various industrial applications requiring high heat transfer rates, e.g., heat exchangers, boilers, chemical and nuclear reactors. Liquid can be …
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Experimental investigation of effects of surface roughness, wettability and boiling-time on steady state and transient CHF for nanofluids
Critical Heat Flux (CHF) is one of the primary design constraints in a nuclear reactor. Increasing the CHF of water can enhance the safety margins of the current fleet of Light Water Reactors (LWRs) and/or increase their power output. It has been shown that a suspension of nanoparticles called …
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The fabrication of nano-scale engineered surfaces to investigate the enhancement of boiling heat transfer and CHF in nuclear reactors
… heat flux limit, i.e., the critical heat flux (CHF), resulting in a boiling crisis. That allows for improvement on the safety margins and operation at higher power. The exact procedure for growing the nanowires will be delineated such that the results can be replicated exactly. A variety of ZnO …
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Effects of pentoxifylline on exercising skeletal muscle vascular control in rats with chronic heart failure
… exercise intolerance in chronic heart failure (CHF). The pharmaceutical TNF-[alpha] synthesis suppressor pentoxifylline (PTX) reduces plasma [TNF-[alpha]] and improves left ventricular (LV) function in CHF rats, but the effects of PTX on skeletal muscle blood flow (BF) and vascular conductance …
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Effects of nitrite infusion on skeletal muscle vascular control during exercise in rats with chronic heart failure
Chronic heart failure (CHF) reduces nitric oxide (NO) bioavailability and impairs skeletal muscle vascular control during exercise. Reduction of nitrite (NO[subscript]2-) to NO may impact exercise-induced hyperemia particularly in muscles with pathologically-reduced O[subscript]2 delivery. We …
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An experimental study of critical heat flux with surface modification and its analytic prediction model development
The critical heat flux (CHF) condition causes a drastic reduction of heat transfer coefficient and sometimes involves physical failure of the heating surface in heat flux-controlled systems. Understanding of CHF phenomena and reliable CHF prediction model development are necessary to design various …
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Critical heat flux enhancement via surface modification using colloidal dispersions of nanoparticles (Nanofluids)
… (HTC) and boiling critical heat flux (CHF) than that of the respective base fluid. Nanofluids have been found to exhibit a very significant enhancement up to 200% of the boiling CHF at low nanoparticle concentrations. In this study, nanofluids were investigated as an agent to modify a …
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Insulin resistance, chronic heart failure and potential treatment
… correlates with the severity and mortality of CHF. The pathophysiology of IR in CHF has yet to be fully defined. Activation of sympathetic nervous system, abnormal regulation of adipocytokines systems, activation of inflammatory and coagulation cascade, accumulation of glycated products, …
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Desing of the high Pressure HIgh temperature annuLUS flow (PHILUS) Facility
Critical heat flux (CHF) and post-CHF are two critical phenomena in light water-cooled nuclear power plants regarding safety. Even though the general trends of CHF and post- CHF are known, the exact mechanisms are still unknown. To better understand CHF and post-CHF, experimental flow boiling …
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The effects of congestive heart failure and functional overload on rat skeletal muscle
… capacity during congestive heart failure (CHF) are not simply due to changes in myocardial function. In fact, recent evidence has indicated that reductions in skeletal muscle strength and endurance during CHF significantly impact exercise capacity of the CHF patient. Currently, it is …
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Effects of surface parameters on boiling heat transfer phenomena
… have been shown to enhance pool and flow boiling CHF. The CHF enhancement was due to nanoparticle deposited on the heater surface, which was verified in pool boiling. However, no such work has been done for flow boiling. Using a cylindrical tube pre-coated with Alumina nanoparticles coated via …
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Study of chemistry and irradiation effects on nanofluids to be used in light water reactor accident cooling
… boiling and flow boiling critical heat flux (CHF) in laboratory tests. The applicability of this aspect to nuclear reactor post-accident cooling is promising. This study investigates various parameters that should be considered for such applications. Dilute alumina nanofluids were tested in …
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Two-phase CFD analyses in fuel assembly sub-channels of Pressurized Water Reactors under swirl conditions
… realistic description of the critical heat flux (CHF)-phenomena and identification of two-phase indicators characterizing CHF-phenomena. The numerical simulations were conducted with a 3-D CFD code (STAR CD) for various types of swirl generating components in FA. New insights regarding local void …
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Tumor necrosis factor induced oxidative stress in the central nervous system contributes to sympathoexcitation in heart failure
… ultimately develop congestive heart failure (CHF), rendering the disease a major cause of death in the United States. MI is associated with an acute increase in sympathetic nervous system activity, becoming persistent in CHF patients. Increased pro-inflammatory cytokines (PICs) following MI …
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