In a hydraulic jump, the turbulent flow region between the upstream supercritical flow and downstream subcritical flow is called the jump roller. The turbulence development in the jump roller leads to substantial energy dissipation as well as free-surface fluctuations, oscillations of jump position, air entrainment and unstationary velocity field. The time scales of these motions cover a broad ...

Vacuum-assist venous drainage (VAVD) can increase venous blood return during cardiopulmonary bypass (CPB) procedures. However, the negative pressure created in the closed cardiotomy reservoir can be transmitted to the oxygenator if a nonocclusive or centrifugal arterial pump is used, resulting in bubble transgression (BT) from the gas to blood compartment of the oxygenator. We analyzed the vacu...

Forced hydraulic jump in a horizontal stilling basin with one and two continuous sills at the downstream end of an ogee standard weir was investigated. Experiments were completed on sills of five different heights which were fixed at two different distances from the toe of the weir. The main characteristics of the jump such as the sequent depth ratio, relative roller length, and relative ener...

In order to improve the service life of needle roller bearing used in a precision cycloid reducer, and reveal skew collision phenomenon bearing, based on force analysis transmission mechanism reducer considering friction between wheel, roller, cage, crank shaft, dynamic contact rolling bodies is simulated by Hertz elastic contact, where cage pocket hole equivalent spring damping, nonlinear mode...

The feasibility of a purified, inactivated dengue (DEN) vaccine made in Vero cells was explored. A DEN-2 virus candidate was chosen for production of a monotypic, purified, inactivated vaccine (PIV). Virus was harvested from roller bottle culture supernatants, concentrated, and purified on sucrose gradients. The purified virus was inactivated with 0.05% formalin at 22 degrees C. After inactivat...

This study investigated changes in technique and efficiency after high-intensity exercise to exhaustion in elite cross-country skiers. Twelve elite male skiers completed 4 min submaximal exercise before and after a high-intensity incremental test to exhaustion with the G3 skating technique on a 5% inclined roller-ski treadmill. Kinematics and kinetics were monitored by instrumented roller skis,...

OBJECTIVES To describe a cohort of significantly injured roller coaster riders and the likely levels of acceleration at which the injuries occurred, and to compare these data with contemporary efforts to define a lower limit of acceleration below which no significant spinal injury is likely to occur. DESIGN A retrospective case series of roller coaster ride-induced significant spinal injuries...

OBJECTIVE This study was carried out to evaluate whether the type of pump used for cardiopulmonary bypass (CPB; roller vs. centrifugal) can affect mortality or the neurological outcomes of adult cardiac surgery patients. METHODS Between 1994 and June 1999, 4000 consecutive patients underwent coronary and/or valve surgery at our hospital; of these, 2213 (55.3%) underwent surgery with centrifug...