820 research outputs found
Varkenshouderij in niet-concentratiegebieden : op weg naar duurzaamheid
In opdracht van de vakgroepen varkenshouderij van de N LTO en WLTO is onderzoek uitgevoerd naar de voorwaarden om een duurzame varkenshouderij in de niet-concentratiegebieden mogelijk te maken. Met behulp van gegevens uit de CBS-Landbouwtelling, een analyse van de inhoud van Streek- en Bestemmingsplannen en de resultaten van een enquĂŞte onder varkenshouders is nagegaan op welke wijze gekomen kan worden tot: 1) een verantwoorde en duurzame afzet van de geproduceerde mest; 2) een optimale afstemming tussen opfokzeugen, zeugen en vleesvarkens in het gebied; 3) ontwikkelingsmogelijkheden voor individuele bedrijven. Hiervoor zijn oplossingsrichtingen aangegeven en worden beleidsaanbevelingen gedaa
Mechanical Design of the SMC (Short Model Coil) Dipole Magnet
The Short Model Coil (SMC) working group was set in February 2007 within the Next European Dipole (NED) program, in order to develop a short-scale model of a NbSn dipole magnet. The SMC group comprises four laboratories: CERN/TE-MSC group (CH), CEA/IRFU (FR), RAL (UK) and LBNL (US). The SMC magnet was originally conceived to reach a peak field of about 13 T on conductor, using a 2500 A/mm2 Powder-In-Tube (PIT) strand. The aim of this magnet device is to study the degradation of the magnetic properties of the NbSn cable, by applying different level of pre-stress. To fully satisfy this purpose, a versatile and easy-to-assemble structure has to be realized. The design of the SMC magnet has been developed from an existing dipole magnet, the SD01, designed, built and tested at LBNL with support from CEA. In this paper we will describe the mechanical optimization of the dipole, starting from a conceptual configuration based on a former magnetic analysis. Two and three-dimensional Finite Element Method (FEM) models have been implemented in ANSYS™ and in CAST3M, aiming at setting the mechanical parameters of the dipole magnet structure, thus fulfilling the design constraints imposed by the materials
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Detection of Extracochlear Electrodes in Cochlear Implants with Electric Field Imaging/Transimpedance Measurements: A Human Cadaver Study.
OBJECTIVES: Extracochlear electrodes in cochlear implants (CI), defined as individual electrodes on the electrode array located outside of the cochlea, are not a rare phenomenon. The presence of extracochlear electrodes frequently goes unnoticed and could result in them being assigned stimulation frequencies that are either not delivered to, or stimulating neurons that overlap with intracochlear electrodes, potentially reducing performance. The current gold-standard for detection of extracochlear electrodes is computed tomography (CT), which is time-intensive, costly and involves radiation. It is hypothesized that a collection of Stimulation-Current-Induced Non-Stimulating Electrode Voltage recordings (SCINSEVs), commonly referred to as "transimpedance measurements (TIMs)" or electric field imaging (EFI), could be utilized to detect extracochlear electrodes even when contact impedances are low. An automated analysis tool is introduced for detection and quantification of extracochlear electrodes. DESIGN: Eight fresh-frozen human cadaveric heads were implanted with the Advanced Bionics HiRes90K with a HiFocus 1J lateral-wall electrode. The cochlea was flushed with 1.0% saline through the lateral semicircular canal. Contact impedances and SCINSEVs were recorded for complete insertion and for 1 to 5 extracochlear electrodes. Measured conditions included: air in the middle ear (to simulate electrodes situated in the middle ear), 1.0% saline in the middle ear (to simulate intraoperative conditions with saline or blood in the middle ear), and soft tissue (temporal muscle) wrapped around the extracochlear electrodes (to simulate postoperative soft-tissue encapsulation of the electrodes). Intraoperative SCINSEVs from patients were collected, for clinical purposes during slow insertion of the electrode array, as well as from a patient postoperatively with known extracochlear electrodes. RESULTS: Full insertion of the cochlear implant in the fresh-frozen human cadaveric heads with a flushed cochlea resulted in contact impedances in the range of 6.06 ± 2.99 kΩ (mean ± 2SD). Contact impedances were high when the extracochlear electrodes were located in air, but remained similar to intracochlear contact impedances when in saline or soft tissue. SCINSEVs showed a change in shape for the extracochlear electrodes in air, saline, and soft tissue. The automated analysis tool showed a specificity and sensitivity of 100% for detection of two or more extracochlear electrodes in saline and soft tissue. The quantification of two or more extracochlear electrodes was correct for 84% and 81% of the saline and soft tissue measurements, respectively. CONCLUSIONS: Our analysis of SCINSEVs (specifically the EFIs from this manufacturer) shows good potential as a detection tool for extracochlear electrodes, even when contact impedances remain similar to intracochlear values. SCINSEVs could potentially replace CT in the initial screening for extracochlear electrodes. Detecting migration of the electrode array during the final stages of surgery could potentially prevent re-insertion surgery for some CI users. The automated detection tool could assist in detection and quantification of two or more extracochlear electrodes
New high level application software for the control of the SPS-LEP beam transfer lines
New high level application software is being developed for the control of the SPS and LEP Transfer Lines. This paper briefly describes the model for the operation of these Transfer Lines, which is largely based on previous experience gained during the development and upgrades of the SPS and LEP control systems. The software system is then presented, followed by a description of the high level applications for the control room operators. Tools and methods used for the design and implementation of the system are mentioned
Stakeholder perspectives on primary school pupils and sickness absence:Exploring opportunities and challenges
School absenteeism and its underlying causes can have negative effects on the cognitive, psychosocial and health development of a child. Research in primary education shows high rates of sickness absence. Many stakeholders are involved in addressing school absenteeism, including primary school professionals, child and youth healthcare physicians, school attendance officers and parents. This study explores these stakeholders’ perspectives, their approaches and what they envisage to be necessary in order to improve. It also aims to unveil opportunities and challenges in addressing sickness absence among primary school pupils. Qualitative research was performed with six semi-structured focus group interviews and involving 27 participants from the West-Brabant and Amsterdam regions of the Netherlands. Thematic analysis was used. The overarching theme was aiming for the child’s wellbeing. Each focus group interview started with low awareness of sickness absence as a threat to this wellbeing, but awareness grew during the interviews. The participating stakeholders regarded problematic sickness absence as complex due to a wide variety of causes, and felt that each other’s expertise was necessary to reduce sickness absence. Schools registered absence, but only occasionally used planned steps; they based the identification of problematic sickness on gut feeling rather than any agreed-upon criteria. To be able to systematically address sickness absence and thus improve the wellbeing of children, stakeholders felt the need for a clearly structured approach, including monitoring of sickness absence of all pupils, identifying problematic absence and promoting collaboration with other stakeholders. An approach should allow for tailoring solutions to the individual child
The effects of LHC civil engineering on the SPS and LEP machines
The LHC will utilise much of the existing LEP infrastructure but will require many new surface buildings and several smaller underground structures, two new transfer tunnels from the SPS to the LHC an d two huge cavern complexes to house the ATLAS and CMS experiments. Excavation for the underground structures will start while LEP and SPS are running, causig the existing tunnels in close proximity t o move. The predicted movements are of sufficient amplitude to prevent machine oepration if no precautions are taken
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