In an open channel, a hydraulic jump is a sudden transition from a high-velocity to slower, fluvial flow motion. The impinging flow forms a turbulent roller with a highly fluctuating free-surface, while a large amount of air bubbles is entrapped at the jump toe. The present work presents some physical investigations of hydraulic jumps based upon a wide range of inflow Froude numbers (3.8 < Fr1 ...

The internal leakage has a great effect on the performance of a rotary compressor. In this paper a leakage model as a part of a complete simulation model is developed. The leakage model analyzes the oil/refrigerant mixture leakage flow through the roller radial clearance caused by the motion of roller relative to cylinder wall and the pressure difference and considers the effect of the motion o...

With 300,000,000 riders annually, roller coasters are a popular recreational activity. Although the number of roller coaster injuries is relatively low, the precise effect of roller coaster rides on our brains remains unknown. Here we present the quantitative characterization of brain displacements and deformations during roller coaster rides. For two healthy adult male subjects, we recorded he...

Tubing circuits primed with water were constructed on two roller pumps to characterize and compare two static methods of setting the occlusion on roller pumps (fluid drop rate and pressure drop rate). Twelve separate experiments were performed in which PVC boot tubing diameters (1/2 in, 3/8 in and 1/4 in), roller position (each roller alone on a two roller pump) and roller occlusion (total occl...

Introduction The Rodale Institute (Kutztown, PA) began experimenting with an Organic No–Till Plus system in 2004, where commercial crops (corn, soybean, pumpkin) were no-till drilled or planted into cover crops that were rolled with a roller/crimper. The roller consists of a large steel cylinder (10.5 ft. wide x 16 in. diameter) filled with water to provide 2,000 lb. of weight. The Rodale Insti...

Centrifugal pumps are considered to be less destructive to blood elements (1) when compared to roller pumps. However, their large prime volumes render them unsuitable as arterial pumps in heart lung machine (HLM) circuitry for children. In November of 2014, the circuit at Arnold Palmer Hospital, a Biomedicus BP-50 with kinetic assist venous drainage (KAVD) and 1/4″ tubing was converted to a rol...

Samples of Lepidoptera genus Bebearia Hemming, 1960 deposited in their majority the MUHNAC collection are studied; they proceed especially from Guinea-Bissau, Angola and Mozambique. Five new subspecies described, three northern one north-eastern Mozambique belong to “group mardania”; a further one, north-western Angola, includes sophus”.

Roller skis are used by cross-country skiers for snow-free training, with the aim of imitating skiing on snow. The roller skis on the market that are constructed for use in the classical style are equipped with a front and a back wheel, one of which has a ratchet to enable it to grip the surface when diagonal striding and kick double poling. A new type of roller ski was constructed with a funct...

compared to other methods of vaccine production, (e.g. culture flask and bioreactor system), the roller culture method for producing rabies vaccine is simpler, and the equipment easier to install and maintain, and also in the event of contamination of one roller, the entire batch need not be discarded. this system provides a much larger surface area than the culture flask, and also ensures a mu...

Rollers crimpers have been used in conservation agriculture to terminate cover crops; however, excessive vibration generated by the original straight-bar roller design has delayed adoption of this technology in the United States. To avoid excessive vibration, producers generally reduce operating speeds that increase the time needed to perform the field operation. The objectives of this research...