A new behavioural model for performance evaluation of common mode chokes

A galvanically isolated three-phase AC/AC converter with a high-frequency AC-link has been analyzed from an EMC point of view. This is a special configuration because of a large number of switches, a high frequency transformer, and a fourwire output. The essential coupling paths are identified. Corresponding suppression remedies are given. The results, before and after measures, have been presented to demonstrate the improvement in EMC. Keywords: AC/AC converter; electromagnetic interference; galvanically isolate

Performance optimization aspects of common mode chokes

Optimization aspects of common mode chokes are presented. These are based on a behavioral model for common mode chokes and its sensitivity study. Results are used to show the influence of the designable parameters on the final performance of the choke placed in a circuit

Limits on the Mixing of Tau Neutrino to Heavy Neutrinos

Limits at 90 % c.l. on the square of the mixing strength |U_tau4|^2 between nu_tau and a mostly isosinglet heavy neutrino with mass in the range 10-290 MeV/c^2 are reported. The results were derived using the negative result of a search for neutral particles decaying into two electrons conducted by the CHARM collaboration in a neutrino beam dump experiment. Upper limits ~10^-4 were obtained for neutrino masses larger than 160 MeV/c^2.Comment: 10 pages, 3 figure

An overview of existing head supports for people with reduced or altered head mobility: current solutions and future developments

The first objective of this research was to create an overview of existing assistive devices for supporting the head of people with decreased or altered head mobility. The second objective was to identify future research opportunities, also by investigating what functionalities are still missing in the current head support solutions. A systematic literature review was performed, combined with searches in technology manufacturer databases and websites, to get an overview of existing head support solutions. Expert opinions were gathered, as well as feedback from a number of head support users by means of semi-structured interviews. A database was constructed from the assistive devices that were found. Devices were categorized with respect to type of interface with the user, functionality and amount of adjustability in the system. Existing solutions that stabilize the head are mainly static, meaning that the head can only be stabilized in one position. Some systems offer freedom of movement but do not really support the head. Additionally, some systems can be configured such that there is a certain level of adaptability to the user. However, if head support systems are adjustable, most often it are systems which enable the caregiver and/or end user to manually change the head support to another position. Based on feedback from experts and users it can be concluded that there is a need for assistive devices that provide independent adjustability in such a way that changes in position of the trunk and head are combined with continuous stabilization. Combining this need with current developments in robotic assistive devices, recommendations are given for future research on head supports

Rethinking Plato’s Theory of Art: Aesthetics and the Timaeus

The Timaeus presents a fascinating account of the cosmos. It includes a creation myth that introduces the figure known as the Demiurge who, despite the fact that he is the cause of the sensible world, is reverently attributed with reason, and whose creation – the cosmos – is actually beautiful and good. In this dialogue Plato offers his readers a panorama of the universe. But just what are his intentions for this? Is his approach a precursor to the methods of natural science,1 or does the Timaeus fall under the category of theology? This thesis will discuss the outcome Plato wished to achieve by finally writing on cosmology and how the methods used to accomplish these ends reveal a more existential attitude towards aesthetics

Model comportemental pour l`evaluation des performances de chokes de mode commun

Un model comportemental pour l’évaluation des performances de choke de mode commun (CMC) est proposé : la topologie et les méthodes utilisés pour modéliser les différentes propriétés de la CMC sont décrites. Il s’agit de la combinaison d’une modélisation précise de la perméabilité complexe du matériau, de la saturation, des inductances de fuite et des capacités parasites. Les données necessaries fournies par le designer sont les valeurs de courants, tensions et impédances du système actuel sans CMC et des paramètres disponibles dans la littérature et /ou des manufacturiers en ce qui concerne la CMC modélisée. Ce model comportemental s’avère essentiel dans la simulation des effets des interférences électromagnétiques (EMI)

An overview of head support solutions for people with reduced or altered head mobility

Objective: To create an overview of existing assistive devices for supporting the head of people with decreased or altered head mobility. Additionally, to investigate if there are any functionalities missing in the current head support solutions. Search strategy: A systematic literature review was performed, combined with searches in technology manufacturer databases and websites, to get an overview of existing head support solutions. Expert opinions were gathered, as well as feedback from a number of head support users by means of semi-structured interviews. Selection of articles: A database was constructed from the assistive devices that were found. Evaluation of articles and results: Devices were categorized with respect to type of interface with the user, functionality and amount of adjustability in the system. Conclusion: Existing solutions that stabilize the head are mainly static, meaning that the head can only be stabilized in one position. Some systems offer freedom of movement but do not really support the head. Additionally, some systems can be configured such that there is a certain level of adaptability to the user. However, if head support systems are adjustable, most often it are systems which enable the caregiver and/or end user to manually change the head support to another position. Based on feedback from experts and users there can be concluded that there is a need for assistive devices that provide independent adjustability in such a way that changes in position of the trunk and head are combined with continuous stabilization

The Modular Socket System as Rural Solution in Indonesia

INTRODUCTION: The majority of the people in low-income countries, who need assistive technology do not have access to prosthetic devices [1]. Instead of these people having to make a long journey to one of the few prosthetic workshops, solutions like the Modular Socket System (MSS, Össur®) may be useful, because potentially they could be delivered and manufactured on site, at the location of the person [2]. This could make it suitable for application in a Community Based Rehabilitation (CBR) setting.The aim of this study was to evaluate the technical feasibility of the MSS for implementation in a CBR setting in terms of required tools, skills and required production time. METHODS: The study was performed at the Department of Prosthetics & Orthotics of the Jakarta I Polytechnic School of Health Science (JSPO). Four JSPO students received a three days training in manufacturing of the MSS. Lower limb amputees were recruited to participate in this study from the region of Jakarta (n = 5) and Bali (n = 10). A set of standardized instruments including the two minutes’ walking test (2MWT) and Prosthesis Evaluation Questionnaire (PEQ) were used to measure performance and satisfaction with the prosthesis. Production and maintenance logbooks were filled out by the involved prosthetists to evaluate the technical feasibility of the MSS. RESULTS AND DISCUSSION: Performance (2MWT) and satisfaction (PEQ) scores were comparable to that of similar studies with other lower leg prostheses [3,4]. Both measures did not decrease significantly over time (Figure 1). This suggest that the JSPO students were able to reach sufficient quality.It took the prosthetists 3.5 to 10.5 hours to fit an amputee with a MSS prosthesis. Mean socket production time was 2.0±0.6 hours and mean prosthesis assembly and fitting time was 4.1±2.6 hours. The only non-portable machine needed for the production of the prosthesis was a grinding machine (router). Smaller portable machines used were a cast cutter/jigsaw, Icecast® Compact and resin injection tool. If in the future the grinding machine will be replaced by a handheld tool, production of the MSS could be performed on site, making it suitable for use in a rural setting. Figure 1: The results of the 2MWT at the moment of fitting (t0), at 1-3 months post fitting (t1), and at the end evaluation at 4-6 months post fitting (t2). CONCLUSIONS: Patients who normally have to travel long distances to access prosthetic services were only required to make one visit to the health facility in order to receive a prosthesis. From a technical and quality perspective the method seems feasible, although, high costs remain an issue.ACKNOWLEDGEMENTSMaterials and training for the production of all prostheses were sponsored by Össur®. REFERENCES: 1.Borg J, et al. Assistive Technology for Children with Disabilities: Creating Opportunities for Education, Inclusion and Participation - a discussion paper. 20152.Normann E, et al., Prosthetics and orthotics international. 35(1):76-80, 20113.Boonstra AM, et al. Prosthetics and orthotics international. 17(2):78-82, 19934.Zidarov D, et al. Archives of Physical Medicine and Rehabilitation. 90(4):634-645, 200

Opportunities and challenges for antisense oligonucleotide therapies

Antisense oligonucleotide (AON) therapies involve short strands of modified nucleotides that target RNA in a sequence-specific manner, inducing targeted protein knockdown or restoration. Currently, 10 AON therapies have been approved in the United States and Europe. Nucleotides are chemically modified to protect AONs from degradation, enhance bioavailability and increase