43 research outputs found
First Row Transition Metal Aminopyridinates – the Missing Complexes
No full textLithiated 4-methyl-2-[(trimethylsilyl)amino]pyridine (Ap(TMS)H) undergoes a salt metathesis reaction with [SCCl(3)(thf)(3)] and FeCl(3), at low temperature in thf, to yield the homoleptic complexes [Sc(Ap(TMS))(3)] (1) and [Fe(Ap(TMS))(3)] (2). An analogous reaction with MnCl(2), CoCl(2) and FeCl(2) using two equivalents of 4-tert-butylpyridine (tBuPy) as additional donor ligand affords the structurally analogous cis complexes [Mn(Ap(TMS))(2)(tBuPy)(2)] (3), [Co(Ap(TMS))(2)(tBuPy)(2)] (4) and [Fe(Ap(TMS))(2)(tBuPy)(2)] (5). If FeCl(3), is used without tBuPy, the highly symmetric trinuclear complex [Fe(3)(Ap(TMS))((6)Li(2)O] (6) is obtained. Furthermore, the use of ZnCl(2) in a reaction with lithiated Ap(TMS)H yields the dimeric complex [Zn(Ap(TMS))(4)] (7) in which two Ap(TMS) ligands bridge the two metals. All complexes have been characterised by X-ray crystal structure analysis. To the best of our knowledge, complexes 1 and 2 and 5 are the first scandium and iron aminopyridinates, respectively, and complex 3 is the first manganese aminopyridinate complex which contains no additional anionic ligand. Complexes 4 and 7 are rare examples of cobalt and zinc aminopyridinates. This study proves that aminopyridinato ligands are highly universal ligands since they are able to stabilize early and late transition metals. Aminopyridinates of every first row transition metal are now available. The magnetic properties of all paramagnetic complexes were investigated. All complexes are high-spin complexes and the trinuclear iron complex 6 exhibits a weak antiferromagnetic coupling. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)Deutsche Forschungsgerneinschaft (DFG
Enhanced electromagnetic microwave absorption properties of SiCN(Fe) ceramics produced by additive manufacturing via in-situ reaction of ferrocene
No full textThinking the unthinkable: Facing maternal abuse.
No full textThis paper describes how the radical concept of maternal perversion first presented by Estela Welldon (1988) informs the psychotherapeutic assessment and treatment of female inpatients within forensic services and of women in the community who commit acts of violence. It presents a model of the psychology of female violence that the author describes as 'crimes against the body'. The paper offers clinical evidence for Welldon's model of female perversion in forensic settings and provides an extended clinical illustration of psychotherapeutic work, when the therapist was pregnant, with a woman who killed her child
23.3 A 51A Hybrid Magnetic Current Sensor with a Dual Differential DC Servo Loop and 43mA<sub>rms</sub>Resolution in a 5MHz Bandwidth
No full textMagnetic current sensors are widely used in applications where galvanic isolation and wide bandwidth (BW) are desired, such as in switched-mode power supplies and motor drivers. By using Hall plates for low frequencies and pick-up coils for high frequencies, hybrid magnetic sensors can achieve high resolution (tens of textmA) over a wide frequency range (up to 15MHz) [1]-[3]. However, previous designs exhibit either poor gain flatness over frequency or limited energy efficiency. This work presents a hybrid magnetic current sensor that textachievespm 1. 1% gain flatness, which is 3times better than prior art [1]-[3]. Its energy efficiency is also 11times better than the state-of-the-art [1], [4], [5].Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Microelectronic
A Hybrid Magnetic Current Sensor With a Dual Differential DC Servo Loop
No full textThis article presents a hybrid magnetic current sensor for contactless current measurement. Pick-up coils and Hall plates are employed to sense the high and low-frequency fields, respectively, generated by a current-carrying conductor. Due to the differentiating characteristic of the pick-up coils, a flat frequency response can then be obtained by summing the outputs of the coil and the Hall paths and passing the result through a 1st-order low-pass filter (LPF). For maximum resolution, the LPF corner frequency (2 kHz) is set such that the noise contribution of each path is equal. To suppress the coil-path offset without the use of large ac coupling capacitors, an area-efficient dual dc servo loop (D3SL) is used. This effectively suppresses the coil-path offset, resulting in a total offset of 73 μT , which is mainly dominated by the Hall path. Fabricated in a standard 0.18-μm CMOS process, the current sensor occupies 3.9 mm2 and draws 7.1 mA from a 1.8 V supply. It achieves 43 mA resolution in a 5 MHz bandwidth, which is 1.5 × better than the state-of-the-art hybrid sensors. It also achieves the lowest energy efficiency FoM (3.5 ×) among CMOS magnetic current sensors.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationElectronic Components, Technology and MaterialsMicroelectronic
A 25A Hybrid Magnetic Current Sensor with 64mA Resolution, 1.8MHz Bandwidth, and a Gain Drift Compensation Scheme
No full textMagnetic current sensors are used in switched-mode power supplies and motor drivers, where both galvanic isolation and wide bandwidth (BW) are desired. In CMOS, Hall-effect sensors are widely used, but their resistance results in a fundamental trade-off between BW and resolution. Coils have a differentiating characteristic and so can achieve much wider BW and resolution, but cannot sense DC.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A Hybrid Magnetic Current Sensor With a Multiplexed Ripple-Reduction Loop
No full textThis article presents a hybrid magnetic current sensor for galvanically isolated measurements. It consists of a CMOS chip that senses the magnetic field generated by current flowing through a lead-frame-based current rail. Hall plates and coils are used to sense low-frequency (dc to 10 kHz) and high-frequency (10 kHz to 5 MHz) magnetic fields, respectively. With the help of on- chip calibration coils, the biasing current of the Hall plates is trimmed to match the sensitivity of the Hall and coil signal paths. The sensitivity drift of the coil path with temperature is compensated by using temperature-dependent gain-setting resistors, while the drift of the Hall path is compensated by biasing the Hall plates with a proportional- to-absolute-temperature (PTAT) current. The resulting sensitivity drift is less than 9% from-40 °C to 80 °C. The offset of the Hall plates is reduced by the current spinning technique, and the resulting ripple is suppressed by a multiplexed ripple-reduction loop (MMRL). Fabricated in a standard 0.18-μm CMOS process, the current sensor occupies 4.6 mm2 and draws 7.8 mA from a 1.8-V supply. It achieves a gain variation of only ±2% in a 5-MHz BW. It also achieves high energy efficiency, with an figure of merit (FoM) of 1.6 fW/Hz.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
Patient Safety and Communication in the Operating Room
No full textHospitals, and in particular the operating room, have not universally adopted a checklist system as a way to increase communications and decrease errors. Analyses showed that communication at Navy Hospital Twenty-nine Palms was less than optimal, leading to errors, such as delayed surgical start times and equipment errors, although patient safety was not affected. After thorough research, including a comprehensive literature review, and investigation by the author and operating room director, it was decided that the World Health Organization/The Joint Commission comprehensive surgical checklist and the Team STEPPS communication technique would be adapted and implemented to increase communication. Implementation of these programs would undergo evaluation through monitoring and staff interviews on a continual basis by committee members and process adjustments if needed after committee member agreement. This checklist would flatten the hierarchy and improve the operating room process, increasing patient safety. This checklist to increase communication in the operating room is not expected to prevent all errors but could increase safety by creating a shared mental model and increased distribution of responsibility to all health care personnel involved. By empowering every team member, from technicians to surgeons, the ability to raise concerns raises the standards for patient safety.Doctor of Anesthesia Practice (DAP)Doctor of Anesthesia PracticeUniversity of Michigan-Flinthttps://deepblue.lib.umich.edu/bitstream/2027.42/136781/1/Owens2015.pdfDescription of Owens2015.pdf : Thesi
Barriers Faced by Nurse Anesthetist Entrepreneurs Wishing to Implement an Office-based Anesthesia Practice
No full textPurpose: Certified Registered Nurse Anesthetists (CRNAs) are highly trained anesthesia professionals with a minimum of seven calendar years of nurse anesthesia education and clinical experience, who safely administer more than 40 million anesthetics in the United States every year. CRNAs may encounter barriers to full practice authority that limit their ability to practice anesthesia to the full scope of training and experience, and to meet the needs of the patients they serve. The removal of practice barriers remains a high priority requiring legislative changes at various levels of government. State regulatory restrictions of practice, and the requirement of physician supervision, may restrict nurse anesthetist entrepreneurs wishing to establish an office-based anesthesia practice (OBA). The purpose of this project was to determine what barriers exist for the CRNA when implementing an OBA practice, and develop a practice guide for CRNA entrepreneurs wishing to establish an OBA practice.
Methods: An extensive literature review informed the formulation of a descriptive survey instrument to gather data on the barriers experienced by CRNAs when transitioning into autonomous OBA practices. The questionnaire was distributed online using Qualtrics® via social media venues, Facebook and Yahoo, to groups of CRNAs in autonomous OBA practices, yielding a sample size of 86 CRNAs .The survey data was analyzed to determine the perceived barriers encountered by CRNAs administering anesthesia in the physician office setting.
Results: The analyses of the survey results revealed the following three primary barriers; (1) state statutes prevent CRNAs from practicing to the full extent of their education and training, (2) fair reimbursement for CRNA services by third party payers, and (3) challenges related to other disciplines recognition of the CRNA scope of practice. Of the 86 participants surveyed, 90% perceived state statutes to be the greatest barrier to OBA practice.
Conclusions: Barriers to CRNA OBA practice are complicated and multi-factorial. CRNAs need to continue advocating for patient safety in physician office settings, and obtain support from federal and state governments, health insurers, healthcare professionals, and consumers of health services. This may assist in overcoming barriers faced by CRNAs establishing autonomous OBA practices. Continued research aimed at outcome data related to CRNA effectiveness and quality in providing anesthesia independently at an office location, is necessary to aid in the successful reduction of the perceived barriers to practice. As a conclusion of this project the author intends to publish a guide to assist CRNAs considering establishing an OBA practice, to overcome some of the barriers identified in this project.
Data Sources: ProQuest, Medscape, PubMed, Cochrane Library, CINAHL, and Google Scholar.
Keywords: Certified Registered Nurse Anesthetist (CRNA), nurse anesthetist entrepreneurs, office-based anesthesia practice, barriers faced by nurse anesthetists.Doctor of Anesthesia Practice (DAP)Anesthesia PracticeUniversity of Michigan - Flinthttps://deepblue.lib.umich.edu/bitstream/2027.42/137656/1/Mwaura2017.pdfDescription of Mwaura2017.pdf : Thesi
