280 research outputs found
Project PROMETHEUS: Design and Construction of a Radio Frequency Quadrupole at TAEK
The PROMETHEUS Project is ongoing for the design and development of a 4-vane
radio frequency quadrupole (RFQ) together with its H+ ion source, a low energy
beam transport (LEBT) line and diagnostics section. The main goal of the
project is to achieve the acceleration of the low energy ions up to 1.5 MeV by
an RFQ (352 MHz) shorter than 2 meter. A plasma ion source is being developed
to produce a 20 keV, 1 mA H+ beam. Simulation results for ion source,
transmission and beam dynamics are presented together with analytical studies
performed with newly developed RFQ design code DEMIRCI. Simulation results
shows that a beam transmission 99% could be achieved at 1.7 m downstream
reaching an energy of 1.5 MeV. As the first phase an Aluminum RFQ prototype,
the so-called cold model, will be built for low power RF characterization. In
this contribution the status of the project, design considerations, simulation
results, the various diagnostics techniques and RFQ manufacturing issues are
discussed.Comment: 4 pages, 8 figures, Proceedings of the 2nd International Beam
Instrumentation Conference 2013 (IBIC'13), 16-19 Sep 2013, WEPC02, p. 65
A new approach to switch fabrics based on mini-router grids and output queueing
A number of switch fabric architectures based on mini-router grids (MRG) have been proposed as a replacement of buses for system-on-chip communication, as well as a replacement of crossbars for network routers. The rationale for using MRGs in switch fabrics is that they provide high delivery ratios, low latencies, high degree of parallelism and pipelining, load balancing properties, and sub-quadratic cost growth for their implementation. The traditional approaches to switch fabrics are based on input queuing (IQ) or virtual output queueing (VOQ), because output queuing (OQ) solutions to date are unscalable and expensive due to the speedup problem. However, we show that the speedup problem introduced by OQ can be bounded by 3 by using MRGs.We present the design of a switch fabric based on OQ MRGs that offers high delivery ratios, smaller queue sizes, and QoS guarantees. Queueing and scheduling are distributed over the MRs, where each MR is a pipestage, thus allowing MRGs to provide high throughput by nature. We present the first in-depth analytical model of switch fabric architectures based on OQ MRG, and support our model with register-transfer level (RTL) simulations in SystemC. The analytical and simulation results are shown to have close correlation over a range of design parameters and evaluation metrics
Pituitary Insufficiency and Hyperprolactinemia Associated with Giant Intra- and Suprasellar Carotid Artery Aneurysm
Pituitary insufficiency secondary to internal carotid artery (ICA) aneurysm is a very rare condition. Its prevalence is reported as 0.17% (Heshmati et al., 2001). We present a case of pituitary insufficiency and hyperprolactinemia secondary to suprasellar giant intracranial aneurysm. A 71-year-old man was admitted to our clinic with symptoms of hypopituitarism, hyperprolactinemia, and visual field defect. His pituitary MRI and cerebral angiography revealed a giant saccular aneurysm filling suprasellar cistern arising from the ophthalmic segment of the right ICA. Endovascular treatment was performed on the patient to decrease the mass effect of aneurysm and improve the hypophysis dysfunction. After treatment, his one-year follow-up showed the persistence of hypophysis insufficiency, decrease of prolactin (PRL) level, and normal visual field. An intracranial aneurysm can mimic the appearance and behavior of a pituitary adenoma. Intracranial aneurysms should be taken into consideration in the situation of hypopituitarism and hyperprolactinemia. It is important to distinguish them because their treatment approach is different from the others
Conceptual design of a hydroelectric power plant for a rehabilitation project
This study presents the conceptual design of a hydroelectric
power plant, as a part of a large scale rehabilitation project for an
existing power plant in Antalya, Turkey. The aim of the
rehabilitation project is to increase the power and efficiency of
the plant and its scope includes CFD aided turbine design, model
production and tests, the design, production and implementation
of the turbine, generator and the SCADA system. This study is
the first attempt, as a preliminary study, to handle the problem
and perform a conceptual design of the hydroelectric power
plant. The existing plant is modeled to estimate the head and flow
rate characteristics at various sections of the system. The net
head and flow rate of the turbine are estimated. Transient
analyses of the system are also performed to evaluate water
hammer characteristics. The results of the transient analyses
provide the inputs for the design of by-pass pipeline and pressure
relief valve. The estimated net head and flow rate from the
simulations are used as inputs for the preliminary design. The
dimensions of the spiral case, the diameter of the stay vanes and
guide vanes, wicket gate heights, runner diameter and rotational
speed, runaway characteristics and preliminary output power are
determined. The best efficiency point and the design point of the
turbine are also obtained as the net head versus the flow rate.
These results provide an idea on the feasibility of the increase in
power.Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016
Exploring TPACK among pre-service teachers in Australia and Israel
The ubiquitous nature of technology in the world has not yet translated into the ubiquitous use of technology to transform learning and teaching. Teachers lack the confidence and competence to integrate technology across a broad range of tools within a range of contexts. Technological Pedagogical Content Knowledge (TPACK) has become a common framework to explore technology within teaching and teacher education. However, little research exists to explore the similarities and differences of TPACK between different teacher education programs, within different countries or even different disciplines, especially in a secondary context. Using a self-report online survey, this study sought to compare and contrast TPACK results from pre-service teachers studying in secondary teacher education programs in Australia and Israel. Findings suggest that TPACK is higher in Australia, and in both countries for those students who were aged over 26. There were no significant differences between gender or disciplines reported. The paper also discusses broad-scale implications for the future of research in TPACK
ERS International Congress 2022: highlights from the Respiratory Clinical Care and Physiology Assembly
It is a challenge to keep abreast of all the clinical and scientific advances in the field of respiratory medicine. This article contains an overview of the laboratory-based science, clinical trials and qualitative research that were presented during the 2022 European Respiratory Society International Congress within the sessions from the five groups of Assembly 1 (Respiratory Clinical Care and Physiology). Selected presentations are summarised from a wide range of topics: clinical problems, rehabilitation and chronic care, general practice and primary care, mobile/electronic health (m-health/e-health), clinical respiratory physiology, exercise and functional imaging
A Large Hadron Electron Collider at CERN
This document provides a brief overview of the recently published report on
the design of the Large Hadron Electron Collider (LHeC), which comprises its
physics programme, accelerator physics, technology and main detector concepts.
The LHeC exploits and develops challenging, though principally existing,
accelerator and detector technologies. This summary is complemented by brief
illustrations of some of the highlights of the physics programme, which relies
on a vastly extended kinematic range, luminosity and unprecedented precision in
deep inelastic scattering. Illustrations are provided regarding high precision
QCD, new physics (Higgs, SUSY) and electron-ion physics. The LHeC is designed
to run synchronously with the LHC in the twenties and to achieve an integrated
luminosity of O(100) fb. It will become the cleanest high resolution
microscope of mankind and will substantially extend as well as complement the
investigation of the physics of the TeV energy scale, which has been enabled by
the LHC
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