1,034 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
Recovery Courses of Patients Who Return to Work by 3, 6 or 12 Months After Total Knee Arthroplasty
Purpose This study compared the preoperative levels and postoperative recovery courses of physical and mental impairments, activity limitations and participation restrictions of working-age patients who return to work (RTW) by 3, 6 or 12 months after total knee arthroplasty (TKA). Methods A prospective survey study including TKA patients (aged < 65) (n = 146) who returned to work (RdTW) in the first postoperative year. Three groups were compared: those who returned by 3 (n = 35), 6 (n = 40) or 12 (n = 29) months. Surveys were completed preoperatively and at 6 weeks and 3, 6 and 12 months postoperatively. Outcomes represented domains of the International Classification of Functioning, i.e. physical impairments (pain, stiffness, vitality), mental impairments (mental health and depressive symptoms), activity limitations (physical functioning) and participation restrictions (social and work functioning). Results Preoperative knee-specific pain and physical functioning levels were better among patients who RdTW by 3 months, compared to those who returned by 12 months. Patients who RdTW by 3 months experienced significantly better recovery from physical impairments than those who returned by 6 months (on general pain) or 12 months (on general and knee-specific pain and on stiffness). Patients returning by 3 months experienced significantly better recovery from activity limitations (on knee-specific physical functioning). Conclusions To optimize return to work outcome after TKA surgery, the focus should lie on physical impairments (general and knee-specific pain, stiffness) and activity limitations (knee-specific physical functioning) during recovery
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