Influence of Ageing on Electrothermal Condition of Low Current Contact

2021 ◽  
Author(s):  
Gideon Gwanzuwang DANKAT ◽  
Alin Alexandru DOBRE ◽  
Laurentiu Marius DUMITRAN
Keyword(s):  
Current Contact

The Model of a Homopolar Electric Motor with High-Temperature Superconductors

2021 ◽  
Vol 7 (7) ◽  
pp. 19-25
Author(s):  
Andrey V. NAUMOV ◽  
◽  
Alexey V. POLYAKOV ◽  
Mikhail I. SURIN ◽  
Vladimir I. SHCHERBAKOV ◽  
...  
Keyword(s):  
High Temperature ◽  
Electric Motor ◽  
Pid Controller ◽  
Magnetic System ◽  
High Temperature Superconductors ◽  
Liquid Nitrogen Temperature ◽  
Design Solution ◽  
Analysis Model ◽  
Current Contact ◽  
Motor Operation

The electromechanical model for analyzing a homopolar electric motor with a magnetic system made using second-generation high-temperature superconductors (HTSC 2G) is described. Homopolar electric motors made with a disk-shaped rotor have the simplest design of their magnetic system and heavy-current contact. Owing to the use of HTSC 2G conductors for producing constant magnetic field in the rotor area, it becomes possible to achieve a higher current density in the windings, thereby increasing the motor power capacity. Due to the HTSC ability to operate at the liquid nitrogen temperature (77 K), it becomes possible to have a simpler cryostat design in comparison with magnetic systems based on low-temperature superconductors. For large-capacity homopolar motors, the use of liquid metal contacts for supplying current to the rotating rotor seems to be the most promising design solution. The advantage of motors of this type is that their torque depends linearly on the rotor current. The homopolar motor operation governed by a proportional-integral-differentiating (PID) controller was simulated using the SciLab Xcos software. The application of the analysis model for selecting the optimal PID-controller coefficients is demonstrated. The electric motor dynamic operation modes are analyzed. The numerical simulation results are compared with the previously obtained experimental data.

scholarly journals Association of Breast Surgeons at the British Association of Surgical Oncology (ABS AT BASO)

2006 ◽  
Vol 9 (S1) ◽  
pp. 28-33
Author(s):  
Keyword(s):  
Clinical Trials ◽  
Ductal Carcinoma ◽  
Randomised Trial ◽  
Surgical Oncology ◽  
British Association ◽  
List Type ◽  
Current Contact ◽  
Trial Testing ◽  
Er Positive

This section provides current contact details and a summary of recent or ongoing clinical trials being coordinated by Association of Breast Surgeons at the British Association of Surgical Oncology (ABS at BASO). Clinical trials include: BASO DCIS II TRIAL: Randomised trial testing observation (no radiotherapy) against radiotherapy in women with low-risk completely excised ER positive ductal carcinoma in situ (DCIS) of the breast on adjuvant endocrine therapy.Neoadjuvant trial of preoperative exemestane or letrozole ± celecoxib in the treatment of ER positive postmenopausal early breast cancer.

X-ray diffraction study of the transient structure of sliding charge density waves in NbSe3

2002 ◽  
Vol 12 (9) ◽  
pp. 181-182
Author(s):  
H. Requardt ◽  
D. Rideau ◽  
R. Danneau ◽  
A. Ayari ◽  
F. Ya Nad ◽  
...  
Keyword(s):  
Charge Density ◽  
Density Wave ◽  
Charge Density Waves ◽  
X Ray Diffraction ◽  
X Ray ◽  
Slowing Down ◽  
Current Contact ◽  
Decay Profile ◽  
Stretched Exponential Decay ◽  
Transient Structure

We present high resolution X-ray diffraction measurements on NbSe3 of the charge-density-wave (CDW) relaxation from the deformation created by the sliding of the CDW. The data are taken in the temperature range 75 K < T < 105 K in the upper-CDW phase of NbSe, and cover spatial positions up to $8OO~\mu$m from the current contact. Convenient fits to the data are obtained by a stretched exponential decay profile yielding exponents μ in the range of 0.4–0.7 and relaxation time-scales τ of the order of 1–150 ms. becoming faster with increasing sample temperature and slowing down with increasing distance from the current contact.

scholarly journals 2457. Data Science for Outbreak Investigation: Identifying Risk Factors, Tracing Contacts, and Eliciting Transmission Pathways in a Vancomycin-Resistant Enterococci (VRE) Outbreak

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S850-S850
Author(s):  
Stefan Zahnd ◽  
Theus Hossmann ◽  
Andrew Atkinson ◽  
Sabine Herbel ◽  
Luisa Salazar-Vizcaya ◽  
...  
Keyword(s):  
Risk Factors ◽  
Medical Devices ◽  
Data Science ◽  
Length Of Hospital Stay ◽  
Contact Tracing ◽  
Healthcare Personnel ◽  
Vancomycin Resistant Enterococci ◽  
Current Contact ◽  
Vancomycin Resistant ◽  
Transmission Pathways

Abstract Background In 2018 we experienced a nosocomial outbreak due to vancomycin-resistant enterococci (VRE) in our hospital network. Our goals were to characterize risk factors for VRE acquisition, elicit potential hot spots of transmission, and delineate an optimized approach to tracing contacts. Methods We assembled diverse datasets of variable quality and covering different aspects of care from electronic medical records generated during the outbreak period (1/2018–9/2018). Patients who tested VRE-positive during this period were compared with controls with up to 3 negative screenings. First, we identified risk factors for VRE colonization by means of uni- and multivariate analyses. Next, we elicited transmission pathways by detecting commonalities between VRE cases, and determined whether patients with characteristics and connections similar to VRE cases were missed by our current contact tracing strategy. Results We compared 221 VRE patients to 33,624 controls. Independent predictors of VRE colonization were ICU admission (OR 4.9, with 95% confidence interval [3.7–6.5], P < 0.001)], number of records in the database (a proxy for severity-of-illness, OR 1.1 [1.1–1.1], P < 0.001), length of hospital stay (OR 2.7 [2.0–3.5], P < 0.001), age (OR 1.3 [1.2–1.4], P < 0.001), and weeks of antibiotics (OR 1.2 [1.1–1.3], P < 0.001). By using complex network analysis, we were able to establish three main pathways by which the 221 VRE cases are connected: healthcare personnel, medical devices, and patient rooms. This multi-dimensional network extends beyond our current contact tracing strategy, which captures inpatients based on geographical proximity (cf. figure). Conclusion In this outbreak investigation based on a large electronic healthcare data collection, we found three main risk factors for being a VRE carrier (ICU admission, length of hospital stay, antibiotic exposure), along with three important links between VRE cases (healthcare personnel, medical devices, patient rooms). Data science is likely to provide a better understanding of outbreaks, but interpretations should take data maturity, the scope of included sources, and potential confounding factors into account. Disclosures All authors: No reported disclosures.

Archival and Research Resources in Conakry, Guinea

2009 ◽  
Vol 36 ◽  
pp. 439-445
Author(s):  
Graeme Counsel
Keyword(s):  
West Africa ◽  
Archival Research ◽  
Contact Information ◽  
The Arts ◽  
Current Contact ◽  
Significant Damage ◽  
First Republic ◽  
Basic Infrastructure ◽  
First Time ◽  
Research Resources

Archival research in West Africa can present many challenges. In one of the poorest regions of the world, governments struggle to maintain funding for the most basic infrastructure; thus archives and their holdings can often reside in a neglected state. Moreover, research materials may be spread over many departments and buildings, creating a labyrinthine network of officialdom, and requisite access requirements. This paper provides a brief overview of the principal archives located in Conakry, capital of Guinea. It includes current contact information and descriptions of holdings, and expands upon earlier articles by Klein (1981), Ford (1987), Conrad (1993), and Sampson (2002).On 2 October 2008 Guinea celebrated 50 years of independence. Earlier that year many new ministries were created, including the Ministère de la Culture, des Arts et Loisirs. For the first time in the nation's history, Guinea had its own dedicated ministry of the arts, thus potentially streamlining academic and archival research. The new Ministry faced many hurdles, however, for the story of Guinea's archives during the last 50 years is a tale of both marvel and neglect.During the nation's First Republic (1958-1984), Guinea's archives became established under the Presidency of Sékou Touré. The Archives Nationale, the Bibliothèque Nationale, and Radiodiffusion Télévision de Guinée were all created during his reign, and Guinea's archival resources were said to be among the best in West Africa. As Touré's grip on power strengthened, the nation's economic malaise grew, and Klein (1981:333) reported that in the early 1980s, when he conducted research in Conakry, he had been warned to expect significant damage to the archival contents.

Calculation Method of Pure Resistance and Inductance of Ore-Thermal Furnaces Electrode Holder Tubes

2014 ◽  
Vol 698 ◽  
pp. 35-39 ◽  
Author(s):  
L.P. Goreva ◽  
A.Yu. Ignatenko ◽  
A.V. Bordunova
Keyword(s):  
3D Models ◽  
Iteration Algorithm ◽  
Calculation Error ◽  
Electrical Parameters ◽  
Secondary Current ◽  
Electrode Holder ◽  
Straight Line ◽  
Current Contact ◽  
Calculation Results ◽  
Magnetic Flux Compensation

While designing an ore-thermal furnace it is necessary to minimize and balance its secondary current contact jaw electrical parameters. The study deals with the method of calculating pure resistance and inductance of ore-thermal furnace electrode holder tubes. It is significant because the tubes have complicated wires configuration and their resistance is noticeable in current contact jaw total impedance because of the same half-phase currents flow in tube bundles and absence of magnetic flux compensation. Real bent wires are suggested to be approximated by broken lines. After that both existing and proposed by the authors formulas can be used for calculating inductance and mutual inductance of two straight-line wires arbitrary placed in space. Current distribution non-uniformity along separate tubes is taken into account in an iterative algorithm. Currents in wires are assumed to be equal at the first iteration. Then they are corrected at following steps of the iteration algorithm with respect to wires resistances calculation results. Skin effect and closure effect between wires segments are taken into account when pure resistance is calculated. The proposed method has been applied in the development of the software for calculating ore-thermal furnace secondary current-contact jaw electrical parameters. The method has been approbated in the design of the 60 MVA ore-thermal furnace made by ZAO “Electroterm”, Novosibirsk, Russia. The results obtained have been tested with numeric 3D models created in ANSYS environment. Inductance calculation error is 10%, pure resistance error is 25%.

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