Search results for "VOLUME"
showing 10 items of 1932 documents
Numerical analysis of a new cross-flow type hydraulic turbine for high head and low flow rate
2021
Cross-flow turbines have recently been proposed for energy recovery in aqueducts when the outlet pressure is greater than zero, owing to their constructive simplicity and good efficiency within a large range of flow rates and head drops. In the case of high head drop (higher than 150 m) and relatively small discharge (lower than 0.2 m3/s), the traditional design of these turbines leads to very small widths of the nozzle and the runner; as a consequence, friction losses grow dramatically and efficiency drops down to very low values. Standard Pelton turbines require zero outlet pressure and cannot be used as alternatives. A new counter-pressure hydraulic turbine for high head and low flow rat…
A novel pressure regulation system based on Banki hydro turbine for energy recovery under in-range and out-range discharge conditions
2021
Abstract Efficiency improvement of water distribution networks needs to be in place to guarantee a long life period under suitable operating conditions. Excessive pressure is among the well-known issues encountered in water distribution networks which can cause strength damages to the piping system. In order to overcome this drawback and to reach a suitable water pressure delivery, the present work suggests a novel pressure regulation system. This regulation system is consisting of a Banki turbine equipped with a mobile flap as a control device. The suggested pressure regulation system was experimentally and numerically investigated under in-range i.e. like actual water distribution network…
Conservative swept volume boundary approximation
2010
We present a novel technique for approximating the boundary of a swept volume. The generator given by an input triangle mesh is rendered under all rigid transformations of a discrete trajectory. We use a special shader program that creates offset geometry of each triangle on the fly, thus guaranteeing a conservative rasterization and correct depth values. Utilizing rasterization mechanisms and the depth buffer we then get a conservative voxelization of the swept volume (SV) and can extract a triangle mesh from its surface. This mesh is simplified maintaining conservativeness as well as an error bound measured in terms of the one-sided Hausdorff distance. For this we introduce a new techniqu…
Dental anatomy portrayed with microscopic volume investigations
1993
The clinical treatment of the root canal of teeth--called endodontics--assumes a precise idea of the spatial arrangement of the anatomy of teeth and their inner structure. By using computer-assisted data acquisition from filmed sequences of histologic serial sections and a special kind of magnetic resonance microscope--the Stray Field Imaging (STRAFI)--volume investigations were carried out using special functions of a newly developed 3D software. Possible applications and future perspectives are discussed.
Cutting Temperatures Evaluation in Ceramic Tools: Experimental Tests, Numerical Analysis and SEM Observations
1994
The authors propose a multiple approach for the evaluation of cutting temperatures in ceramic tools. The first approach was the experimental evaluation of equitemperature lines, obtained in three-dimensional cutting by employing constant melting point powders scattered on planes parallel to rake face. In the second approach, a numerical finite element analysis was performed. At this step the determination of the percentage of total heat produced in the operation that flows into the tool was considered and, consequently, the temperature distribution within the whole volume of the insert. Finally, the examination of the crater zone with SEM microscopy confirmed the temperature levels as previ…
Part program automatic check for three axis CNC machines
2001
Abstract The simulation and verification of NC codes for CNC machining is a very important task. The aim of this work is to limit the number of cutting tests needed to verify the right writing of the part program for a CN milling machine in the intent of saving time, human resources and money. This is obtained through the Boolean operation among solids, in AutoCAD environment, of the volume covered by the tool during the operations ruled by the part program.
Why Must Everything Be So Complicated? Demands and Challenges on Methods for Analyzing School Improvement Processes
2021
AbstractIn the recent years, awareness has risen by an increasing number of researchers that we need studies that appropriately model the complexity of school improvement if we want to increase our knowledge about school improvement substantially and to close the identified research gaps within this field (Feldhoff T, Radisch F, Klieme E, J Educ Admin 52(5):565–736, 2014; Hallinger P, Heck RH, School Effect School Improv 22(2):149–173, 2011; Sammons P, Davis S, Day C, Gu Q, J Educ Admin 52(5):565–589, 2014). So far, respective quantitative studies, that appropriately consider those complexities, have hardly been realized because of the high efforts of current methods and costs involved (Fel…
<title>Textures from stereo-based IR imaging for industrial tire inspection</title>
2000
A conceptual system to produce 3D thermal models of tires for tire inspection and defect characterization is proposed. The system uses registered range and thermal information to build highly detailed 3D models using either a volumetric or mech-based approach. To achieve this goal, two narrow bandpass filters are used in conjunction with two IR cameras to obtain the true temperature of the target body. The thermal information is then translated to texture data and mapped as an overlay onto a 3D model. The textures are realizable through the use of three-component texture maps that include rgb values to specify the texture coordinates in the plane. The objective is to generate a movie loop d…
A mathematical model to evaluate apparent losses due to meter under-registration in intermittent water distribution networks
2013
Apparent losses consist of water volume drawn from the network, consumed by users but not paid for. Those due to water meter under-registration were evaluated by means of a mathematical model able to analyse the complexity of intermittent supply systems with private tanks. This supply scheme is very common in the Mediterranean area where unexpected water shortage often happens and intermittent water supply is a common practice. In order to analyse such complex systems, a demand model, reproducing the effect of private tanks, and an apparent losses module were developed and coupled with an hydraulic network model based on the Global Gradient Algorithm (GGA). In distribution networks pressure…
Machine Learning and Creative Methods Used to Classify Customers in a CRM Systems
2013
Considering the fact that business processes are becoming more and more customer-oriented, marketing and connecting top management to the customers are extremely important, which should be given a special attention, taking into account the globalization and the increasing market competition. Due to the exponential growth of data volume, in any field, it was necessary to use and develop new methods and techniques for discovering hidden information in data, information almost impossible to be detected by traditional means, based on human analysis skills. This paper presents a pre-processing method for mining data in order to support decision makers in developing coherent and saleable strategi…