Efficiency data for MVG trays with truncated downcomers are presented for the first time. Various operating conditions including vacuum and high pressure are considered. While 7 bar and 11 bar data are very promising it has been possible to show that a uniform liquid flow pattern does indeed affect the efficiency at atmospheric pressure positively. A special downcomer outlet device has been dev...

In this article, turbulent flow heat transfer in the air gap between rotor and stator of a generator under nonhomogeneous heat flux is studied experimentally. The rotor consists of four symmetrical triangular grooves. The stator surface is smooth and does not include any grooves. The relative heat flux between the rotor and the stator is 1 to 3. Temperature and heat flux are measured locally at...

Transcranial Doppler ultrasound monitoring of cerebral blood flow velocity (CBFV) was performed on 17 children (age range 8 days to 6 years) with pyogenic meningitis. Serial measurements of the peak systolic, end diastolic, mean flow velocity, and resistance index (equal to peak systolic velocity minus end diastolic velocity divided by peak systolic velocity) were obtained over the period of th...

Due to methodologic difficulties, few investigations have been made on the blood flow velocity in the cerebral microcirculation. Using a newly developed video camera method, we simultaneously measured the blood flow velocity and diameter of pial arteries during hemorrhagic hypotension, after blood pressure recovery, and during CO2 inhalation in cats. When the mean arterial blood pressure was lo...

BACKGROUND Intracoronary physiology techniques have been validated extensively for the assessment of epicardial stenoses but not for the lone study of coronary microcirculation. We performed a comparison between 4 intracoronary physiological indices with the actual structural microcirculatory changes documented in transplanted hearts. METHODS AND RESULTS In 17 cardiac allograft patients witho...

BACKGROUND Intermittent negative pressure (INP) applied to the lower leg and foot increases foot perfusion in healthy volunteers. The aim of the present study was to describe the effects of INP to the lower leg and foot on foot macro- and microcirculation in patients with lower extremity peripheral arterial disease (PAD). METHODS In this experimental study, we analyzed foot circulation during...

Here, u(t,x) ∈ R3 denotes the velocity of the fluid at a point x ∈ and time t ∈ [0,T ]; w(t,x) ∈ R3, b(t,x) ∈ R3 and p(t,x) ∈ R denote, respectively, the micro-rotational velocity, the magnetic field and the hydrostatic pressure; the constants μ,χ,α,β,γ,j , and ν are positive numbers associated to properties of the material; f (t,x), g(t,x) ∈ R3 are given external fields. We assume that on the ...

Twenty-nine patients with a patent ductus arteriosus (PDA) in isolation (n = 17) or in combination with other lesions (n = 12) underwent simultaneous hemodynamic assessment and evaluation of PDA flow velocity by the Doppler method. The accuracy with which Doppler velocity across the PDA predicted pulmonary arterial pressure and the influence of PDA size and shape on the Doppler velocity-pressur...

In this paper, we develop and analyze mixed finite element methods for the Stokes and Navier-Stokes equations. Our mixed method is based on the pseudostress-pressure-velocity formulation. The pseudostress is approximated by the Raviart-Thomas, Brezzi-Douglas-Marini, or Brezzi-DouglasFortin-Marini elements, the pressure and the velocity by piecewise discontinuous polynomials of appropriate degre...