Search results for "Head"

Cost Reduction in Irrigation Networks by an Efficient Use of Pressure Reducing Valves

1992

The cost effective design of hydraulic networks has been traditionally studied from the point of view of the relationship between hydraulic variables and economic parameters, with piping being the main element studied. The reason is clear: the piping is by far the most costly item of a projected network. However it is not usual to find an explicit consideration of the influence that pipe thickness has on the cost of the network because of the added difficulty that this aspect poses to formulating the problem of optimization. In irrigation networks, which are typically branched, it is advisable to place Pressure Reducing Valves (PRV’s) to fulfil three main goals: 1) to control the flow rate …

Transition from self tilt to object tilt during maintained lateral tilt in parabolic flight.

1991

Abstract 19 young healthy subjects were subjected to parabolic rollercoaster flight. A horizontal luminous line was seen by the subjects in a headfixed goggle device. During the hypergravic phases of parabolic flight the luminous line seemed to rotate into and during the hypogravic phase against the direction of static head tilt. Ocular counter rotation and activity of the neck position receptors cannot explain these subjective rotations. We conclude that information from the otolith system, converging with visual information within the brain, dislocated the headfixed visual target line. While the retinal image of the luminous line remains unchanged, loading and unloading the otoliths in pa…

Measurement of Head Motion during Double-Poling Technique in Cross-Country Ski Classical Race using Kinematic GNSS

2019

Energy recovery from rectangular weirs in wastewater treat-ment plants

2022

Hydraulic turbines for energy recovery in wastewater treatment plants, with relatively large discharges and small head jumps, are usually screw or Kaplan types. In the specific case of a small head jump (about 3 m) underlying a rectangular weir in the major Palermo (Italy) treat-ment plant, a traditional Kaplan solution is compared with two other ones: a Hydrostatic Pres-sure Machine (HPM) located in the upstream channel and a cross-flow turbine located in a specif-ic underground room downstream the same channel.

Cross-flow Turbine Design for Variable Operating Conditions

2014

Abstract The potential energy hidden in water resources is becoming more and more a significant economic value. The value of the hydroelectric energy is often magnified by the proximity of the turbine to pumps or other energy sinks owned by the same water manager. Cross-flow or Banki-Michel turbines are a very efficient and economic choice that allows a very good cost/benefit ratio for energy production located at the end of conduits carrying water from a water source to a tank. In the paper the optimum design of a cross-flow turbine is sought after, assuming a flow rate variable in time. Regulation of the discharge entering in the turbine is a key issue, which is faced adopting a shaped se…

An improved goniometer head for high-temperature single-crystal X-ray diffraction

1999

A reliable and inexpensive goniometer head has been designed. Its stability, resulting from its compact construction, makes it very suitable for accurate measurements. Moreover, its space-saving design facilitates its application in X-ray data collection using charge-coupled device (CCD) detectors. This head has been improved for high-temperature measurements and has been tested by comparison of accurate K0.88Rb0.12TiOPO4data collected both at room temperature and at 973 K on the same crystal. The excellent structure results obtained at 973 K during the 360 h of measurements prove the stability of the goniometer head.

Head-to-tail connected double calix[4]arenes

1997

New macrotricyclic compounds consisting of two calix[4]arene substructures connected by aliphatic chains of various length (three to five carbon atoms) between two oppositep-positions and two distal phenolic oxygens have been synthesized. Starting withp-tert-butyl-calix[4]arene, two O-protected phenolic units are attachedvia ether links in 1,3-position by reaction with the corresponding tosylates. After deprotection, the new calix[4]arene is formed by fragment condensation with 2,6-bisbromomethylated 4-alkylphenols. The structure of one example (8c) has been confirmed by single crystal X-ray analysis. Both calixarene parts assume the cone conformation, a molecule of acetonitrile being inclu…

The more you move, the more action you construct : a motion capture study on head and upper-torso movements in constructed action in Finnish Sign Lan…

2020

Abstract This paper investigates, with the help of motion capture data processed on corpus principles, the characteristics of head and upper-torso movements in constructed action and regular narration (i.e., signing without constructed action) in FinSL. Specifically, the paper evaluates the validity of two arguments concerning constructed action: that constructed action forms a continuum with regular narration, and that constructed action divides into three subtypes (i.e., overt, reduced, and subtle). The results presented in the paper support the first argument but not directly the second one. Because of the ambiguous position of reduced constructed action in between subtle and overt const…

Evidence of the origin of specific spontaneous head turns during intertrial intervals.

1997

Direction and the frequency of spontaneous head movements during the ITIs following forward and backward paired trials were compared to an acquisition of a conditioned orienting (alpha) response directed to the side of the tone source. The head movements were analyzed from video recordings using classification of head turns to preferred and to nonpreferred directions. The results showed a significant increase in the alpha responses during the forward paired conditioning to the preferred direction and rapid extinction during the subsequent backward conditioning sessions. Spontaneous head movements during the ITIs increased to the same preferred direction as the conditioned alpha responses. T…

Test system for trifunctional antibodies in 3D MCTS culture.

2009

The aim of the present study was to assess the feasibility of a 3D tumor cell culture model, that is, multicellular tumor spheroids (MCTSs) as an adequate model for micrometastases and therefore as a pharmacological model for efficacy testing of trifunctional therapeutic antibodies. Unlike conventional monolayer cultures, spheroids allow researchers to study parameters, such as 3D cell shape, 3D cell arrangement and microenvironment, and penetration efficiency of defense cells that may largely influence the efficacy of antibody treatment in vivo. The authors established a long-term coculture of human MCTSs with peripheral blood mononuclear cells (PBMCs) to test the anticancer effect of the …