Control considerations for high frequency, resonant, power processing equipment used in large systems

Addressed is a class of resonant power processing equipment designed to be used in an integrated high frequency (20 KHz domain), utility power system for large, multi-user spacecraft and other aerospace vehicles. It describes a hardware approach, which has been the basis for parametric and physical data used to justify the selection of high frequency ac as the PMAD baseline for the space station. This paper is part of a larger effort undertaken by NASA and General Dynamics to be sure that all potential space station contractors and other aerospace power system designers understand and can comfortably use this technology, which is now widely used in the commercial sector. In this paper, we will examine control requirements, stability, and operational modes; and their hardware impacts from an integrated system point of view. The current space station PMAD system will provide the overall requirements model to develop an understanding of the performance of this type of system with regard to: (1) regulation; (2) power bus stability and voltage control; (3) source impedance; (4) transient response; (5) power factor effects, and (6) limits and overloads

Systemic Lupus Erythematosus:Electron Microscopic Localization Of In Vivo Bound Globulins at the Dermal-Epidermal Junction**From the 1st Department of Dermatology, University of Vienna, A-1090 Vienna, Austria.

An anti-human globulin antibody-peroxidase conjugate has been used to demonstrate the ultrastructural localization of globulins at the dermal-epidermal junction in the skin of a patient with systemic lupus erythematosus. The globulin deposits are confined to the most superficial layers of the dermis immediately subjacent to the basal cells; they spare the epidermis and exhibit no preferential affinity to preexisting structures but they do coat collagen fibres. The basal lamina is, therefore, not the only antigenic site to which these globulins are directed

Thermophysical and Electrochemical Properties of Ethereal Functionalised Cyclic Alkylammonium-based Ionic Liquids as Potential Electrolytes for Electrochemical Applications

International audienceA series of hydrophobic room temperature ionic liquids (ILs) based on ethereal functionalised pyrrolidinium, piperidinium and azepanium cations bearing the bis[(trifluoromethyl)sulfonyl]imide, [TFSI]−, anion were synthesized and characterized. Their physicochemical properties such as density, viscosity and electrolytic conductivity, and thermal properties including phase transition behaviour and decomposition temperature have been measured. All of the ILs showed low melting point, low viscosity and good conductivity and the latter properties have been discussed in terms of the IL fragility, an important electrolyte feature of the transport properties of glass‐forming ILs. Furthermore, the studied [TFSI]−‐based ILs generally exhibit good electrochemical stabilities and, by coupling electrochemical experiments and DFT calculations, the effect of ether functionalisation at the IL cation on the electrochemical stability of the IL is discussed. Preliminary investigations into the Li‐redox chemistry at a Cu working electrode are also reported as a function of ether‐functionality within the pyrrolidinium‐based IL family. Overall, the results show that these ionic liquids are suitable for electrochemical devices such as battery systems, fuel cells or supercapacitors

ELECtric Tibial nerve stimulation to Reduce Incontinence in Care homes: protocol for the ELECTRIC randomised trial

Background Urinary incontinence (UI) is highly prevalent in nursing and residential care homes (CH) and profoundly impacts on residents’ dignity and quality of life. Care homes predominantly use absorbent pads to contain UI rather than actively treat the condition. Transcutaneous posterior tibial nerve stimulation (TPTNS) is a non-invasive, safe, low-cost intervention with demonstrated effectiveness for reducing UI in adults. However, the effectiveness of TPTNS to treat UI in older adults living in care homes is not known. The ELECTRIC Trial aims to establish if a programme of TPTNS is a clinically effective treatment for UI in care home residents and investigate the associated costs and consequences. Methods This is a pragmatic, multicentre, placebo controlled randomised parallel group trial comparing effectiveness of TPTNS (target n=250) with sham stimulation (target n=250) in reducing volume of UI in CH residents. CH residents (men and women) with self- or staff- reported UI of more than once per week are eligible to take part, including those with cognitive impairment. Outcomes will be measured at 6, 12 and 18 weeks post randomisation using the following measures: 24-hour pad weight tests (PWT), post void residual urine (bladder scans), Patient Perception of Bladder Condition (PPBC), Minnesota Toileting Skills Questionnaire (MTSQ) and Dementia Quality of Life (DEMQOL). Economic evaluation based on a bespoke Resource Use Questionnaire will assess the costs of providing a programme of TPTNS. A concurrent process evaluation will investigate fidelity to the intervention and influencing factors and qualitative interviews will explore the experiences of TPTNS from the perspective of CH residents, family members, CH staff and managers. Discussion TPTNS is a non-invasive intervention that has demonstrated effectiveness in reducing UI in adults. The ELECTRIC Trial will involve CH staff delivering TPTNS to residents and establish whether TPTNS is more effective than sham stimulation for reducing the volume of UI in CH residents. Should TPTNS be shown to be an effective and acceptable treatment for UI in older adults in CHs, it will provide a safe, low-cost and dignified alternative to the current standard approach of containment and medication. Trial registration Clinical Trials.gov. NCT03248362. Registered on 14/08/2017. https://clinicaltrials.gov/ ISRCTN, ISRCTN 98415244. Registered on 25/04/2018. https://www.isrctn.com

Mehrwert und Impetus bei Petrus Johannis Olivi: Wissenschaftlicher Paradigmenwechsel im Kontext gesellschaftlicher Veränderungen im späten Mittelalter

Wolff M. Mehrwert und Impetus bei Petrus Johannis Olivi: Wissenschaftlicher Paradigmenwechsel im Kontext gesellschaftlicher Veränderungen im späten Mittelalter. In: Miethke J, Schreiner K, eds. Sozialer Wandel im Mittelalter: Wahrnehmungsformen, Erklärungsmuster, Regelungsmechanismen. Sigmaringen: Thorbecke; 1994: 413-423

SISTER CHROMATID EXCHANGES IN PHOTOCHEMOTHERAPY

Sister chromatid exchanges (SCE), presently considered highly sensitive indicators for chromosomal effects of potential mutagens and carcinogens in mammalian cells, were studied in circulating white blood cells from patients with widespread psoriasis who were being treated with 8-methoxy-psoralen and long-wavelength ultraviolet light (UVA) photo-chemotherapy (PUVA). SCE counts of patients with psoriasis treated with PUVA neither differed from SCE counts of those treated with topical dithranol and corticosteroids, nor from SCE of nonpsoriatic, clinically healthy individuals. The duration of PUVA treatment (up to 2 years) and the total cumulative dose of UVA energy given to the patients also had no effect on the number of SCE of circulating lymphocytes. However, the SCE counts of patients with psoriatic arthropathy were higher than those of patients with psoriasis without joint involvement or normal controls, irrespective of the type of treatment given. There was no difference between SCE counts obtained before and after PUVA treatment sessions, but when white blood cells removed from patients after treatment were reirradiated with UVA in vitro there was a significant increase of SCE. It is concluded that, whereas the principle of PUVA does induce an increased number of SCE in human lymphocytes in vitro, the same principle, employed as a clinical form of therapy, does not result in similar alterations in circulating lymphocytes in vivo. This study has therefore failed to detect harmful effects of PUVA on the genome of circulating lymphocytes in patients subjected to this treatment