551 results on '"A. Robert Armstrong"'
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2. Solvothermal Synthesis of a Novel Calcium Metal-Organic Framework: High Temperature and Electrochemical Behaviour
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Russell M. Main, David B. Cordes, Aamod V. Desai, Alexandra M. Z. Slawin, Paul Wheatley, A. Robert Armstrong, and Russell E. Morris
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MOF ,calcium MOF ,electrochemistry ,scXRD ,VTXRD ,bioMOF ,Organic chemistry ,QD241-441 - Abstract
The rapid growth in the field of metal-organic frameworks (MOFs) over recent years has highlighted their high potential in a variety of applications. For biological and environmental applications MOFs with low toxicity are vitally important to avoid any harmful effects. For this reason, Ca-based MOFs are highly desirable owing to their low cost and high biocompatibility. Useful Ca MOFs are still rare owing to the ionic character and large size of the Ca2+ ion tending to produce dense phases. Presented here is a novel Ca-based MOF containing 2,3-dihyrdoxyterephthalate (2,3-dhtp) linkers Ca(2,3-dhtp)(H2O) (SIMOF-4). The material undergoes a phase transformation on heating, which can be followed by variable temperature powder X-ray diffraction. The structure of the high temperature form was obtained using single-crystal X-ray diffraction. The electrochemical properties of SIMOF-4 were also investigated for use in a Na ion battery.
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- 2021
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3. Li(V0.5Ti0.5)S2 as a 1 V lithium intercalation electrode
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Steve J. Clark, Da Wang, A. Robert Armstrong, and Peter G. Bruce
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Science - Abstract
Lithium sulfides have been previously investigated as 1 V anodes for Li-ion batteries, but suffered from significant performance issues. Here, the authors report on a 1 V lithium sulfide electrode with noteworthy performance, demonstrating that sulfide-based electrodes may merit further exploration.
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- 2016
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4. Global consensus statement on simulation-based practice in healthcare
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Cristina Diaz-Navarro, Robert Armstrong, Matthew Charnetski, Kirsty J. Freeman, Sabrina Koh, Gabriel Reedy, Jayne Smitten, Pier Luigi Ingrassia, Francisco Maio Matos, and Barry Issenberg
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Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
Abstract Simulation plays a pivotal role in addressing universal healthcare challenges, reducing education inequities, and improving mortality, morbidity and patient experiences. It enhances healthcare processes and systems, contributing significantly to the development of a safety culture within organizations. It has proven to be cost-effective and successful in enhancing team performance, fostering workforce resilience and improving patient outcomes. Through an international collaborative effort, an iterative consultation process was conducted with 50 societies operating across 67 countries within six continents. This process revealed common healthcare challenges and simulation practices worldwide. The intended audience for this statement includes policymakers, healthcare organization leaders, health education institutions, and simulation practitioners. It aims to establish a consensus on the key priorities for the broad adoption of exemplary simulation practice that benefits patients and healthcare workforces globally. Key recommendations Advocating for the benefits that simulation provides to patients, staff and organizations is crucial, as well as promoting its adoption and integration into daily learning and practice throughout the healthcare spectrum. Low-cost, high-impact simulation methods should be leveraged to expand global accessibility and integrate into system improvement processes as well as undergraduate and postgraduate curricula. Support at institutional and governmental level is essential, necessitating a unified and concerted approach in terms of political, strategic and financial commitment. It is imperative that simulation is used appropriately, employing evidence-based quality assurance approaches that adhere to recognized standards of best practice. These standards include faculty development, evaluation, accrediting, credentialing, and certification. We must endeavor to provide equitable and sustainable access to high-quality, contextually relevant simulation-based learning opportunities, firmly upholding the principles of equity, diversity and inclusion. This should be complemented with a renewed emphasis on research and scholarship in this field. Call for action We urge policymakers and leaders to formally acknowledge and embrace the benefits of simulation in healthcare practice and education. This includes a commitment to sustained support and a mandate for the application of simulation within education, training, and clinical environments. We advocate for healthcare systems and education institutions to commit themselves to the goal of high-quality healthcare and improved patient outcomes. This commitment should encompass the promotion and resource support of simulation-based learning opportunities for individuals and interprofessional teams throughout all stages and levels of a caregiver’s career, in alignment with best practice standards. We call upon simulation practitioners to champion healthcare simulation as an indispensable learning tool, adhere to best practice standards, maintain a commitment to lifelong learning, and persist in their fervent advocacy for patient safety. This statement, the result of an international collaborative effort, aims to establish a consensus on the key priorities for the broad adoption of exemplary simulation practice that benefits patients and healthcare workforces globally.
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- 2024
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5. Global consensus statement on simulation-based practice in healthcare
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Cristina, Diaz-Navarro, Robert, Armstrong, Matthew, Charnetski, Kirsty, Freeman J., Sabrina, Koh, Gabriel, Reedy, Jayne, Smitten, Pier, Ingrassia Luigi, Francisco, Matos Maio, and Barry, Issenberg
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- 2024
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6. KFe(C2O4)F: A Fluoro‐oxalate Cathode Material for Li/Na‐Ion Batteries
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Dr. Atin Pramanik, Alexis G. Manche, Megan T. Smeaton, Dr. Moulay‐Tahar Sougrati, Prof. Philip Lightfoot, and Dr. Anthony Robert Armstrong
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cathode materials ,electrochemistry ,Na-ion/Li-ion ,oxalate ,rechargeable battery ,Industrial electrochemistry ,TP250-261 ,Chemistry ,QD1-999 - Abstract
Abstract The iron‐based polyanionic fluoro‐oxalate material, KFe(C2O4)F (KFCF), has been synthesized by hydrothermal methods. This compound shows promising reversible lithium and sodium insertion properties as a cathode material. The material delivered a first‐cycle discharge capacity of 120 mAh g−1 at ∼3.3 V (Li+/Li) and 97.4 mAh g−1 at ∼3.0 V (Na+/Na) in LIB and NIB, respectively. Stable cycling performance was observed in both cases. The involvement of reversible Fe2+/Fe3+ redox was confirmed by ex‐situ Mössbauer spectroscopy supported by first‐principles calculations. This study reveals promising performance from a mixed oxalate‐fluoride based polyanionic material thereby opening up further possibilities for materials discovery in the design of new electrode materials.
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- 2023
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7. Metadetection Weak Lensing for the Vera C. Rubin Observatory
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Erin S. Sheldon, Matthew R. Becker, Michael Jarvis, Robert Armstrong, and LSST Dark Energy Science Collaboration
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Astronomy ,QB1-991 ,Astrophysics ,QB460-466 - Abstract
Forthcoming astronomical imaging surveys will use weak gravitational lensing shear as a primary probe to study dark energy, with accuracy requirements at the 0.1% level. We present an implementation of the Metadetection shear measurement algorithm for use with the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). This new code works with the data products produced by the LSST Science Pipelines, and uses the pipeline algorithms when possible. We tested the code using a new set of simulations designed to mimic LSST imaging data. The simulated images contained semi-realistic galaxies, stars with representative distributions of magnitudes and galactic spatial density, cosmic rays, bad CCD columns and spatially variable point spread functions. Bright stars were saturated and simulated "bleed trails" were drawn. Problem areas were interpolated, and the images were coadded into small cells, excluding images not fully covering the cell to guarantee a continuous point spread function. In all our tests the measured shear was accurate within the LSST requirements.
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- 2023
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8. Child disability and family-centred care in East Africa: Perspectives from a workshop with stakeholders and health practitioners
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Pauline Samia, Susan Wamithi, Amina Kassam, Melissa Tirkha, Edward Kija, Ayalew Moges, Arnab Seal, Peter Rosenbaum, and Robert Armstrong
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cerebral palsy ,rehabilitation ,quality of life ,africa ,family-centred ,Vocational rehabilitation. Employment of people with disabilities ,HD7255-7256 ,Communities. Classes. Races ,HT51-1595 - Abstract
Background: Our understanding of child disability has undergone major changes over the last three decades transforming our approach to assessment and management. Globally there are significant gaps in the application of these 21st century models of care. There is recognition that economic, cultural, and social factors influence transitions in care and there is need to consider contextual factors. Objectives: A two-day workshop brought together key stakeholders to discuss current models of care and their application in the East African context. This article summarises workshop proceedings and identifies a broadly supported set of recommendations that serve to set a direction for health professionals, families, family-based disability organisations, communities and government. Method: Presentations followed by facilitated round-table sessions explored specific themes with participants reporting their responses communally. Future actions were agreed upon by relevant stakeholders. Results: Many barriers exist to care for children with disabilities in East Africa, including stigma and a lack of human and infrastructural resources. In addition, significant disparities exist with regard to access to medication and specialist care. The International Classification of Functioning framework needs to be translated to clinical practice within East Africa, with due recognition of the importance of family-centred care and emphasis on the life course theory for disability care. Family-centred care, educational initiatives, advocacy on the part of stakeholders and involvement of government policymakers are important avenues to improve outcomes. Conclusion: Further education and data are needed to inform family-centred care and multidisciplinary team implementation across East African care contexts for children with disabilities.
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- 2022
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9. Role-taking and robotic form: an exploratory study of social connection in human-robot interaction.
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Jenny L. Davis, Robert Armstrong, Anne Groggel, Sharni Doolan, Jake Sheedy, Tony P. Love, and Damith C. Herath
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- 2023
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10. An augmented reality approach for ADL support in Alzheimer’s disease: a crossover trial
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Nina Rohrbach, Philipp Gulde, Alan Robert Armstrong, Linda Hartig, Anas Abdelrazeq, Stefan Schröder, Johanne Neuse, Timo Grimmer, Janine Diehl-Schmid, and Joachim Hermsdörfer
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ADL, Augmented reality, Alzheimer’s disease, Usability, Assistive technology, Mixed methods ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Abstract Background Dementia of the Alzheimer’s type can impair the performance of activities of daily living and therefore severely impact independent living. Assistive technologies can support such patients when carrying out daily tasks. Methods In this crossover study, we used an augmented reality approach using a Microsoft HoloLens to support patients in a tea making task. During task execution, subjects received three-dimensional dynamic holograms of the sub-steps necessary to complete the task. Ten patients suffering from Alzheimer’s disease were tested and post-hoc semi-structured interviews were conducted to assess usability. Results The patients committed errors when executing the task with and without holographic assistance. No differences in success rates or error frequencies were observed (psuccess = .250, perrors = .887). Patients revealed prolonged trial durations (Glass’ Δ = 1.475) when wearing the augmented reality headset. A model of multiple linear regression (R2 adjusted = .958) revealed an influence of the errors in the control condition and a moderation by the errors in the experimental condition. Patients with more severe problems in the natural performance of the task showed lower increases in trial durations when wearing the HoloLens. Conclusions We assume that the application was a secondary task requesting its own resources and impairing performance on its own. The regression suggests however that the given assistance was compensating these additional costs in patients with stronger needs of support. Interview data on usability revealed an overall positive feedback towards the application although the hardware was considered uncomfortable and too large. We conclude that the approach proved feasible and the acceptability was overall high, although advances in hardware and the patient-interface are necessary to assist patients suffering from Alzheimer’s disease in daily activities. Trial registration DRKS, DRKS00014870. Registered 11 June 2018 - Retrospectively registered, TrialID = DRKS00014870.
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- 2019
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11. Les barbares numériques : résister à l’invasion des GAFAM. Par Alain Saulnier
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Robert Armstrong
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Communication - Published
- 2023
12. Sodium Layered Oxide Cathode Materials
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A. Robert Armstrong, Stephanie F. Linnell, Philip A. Maughan, Begoña Silván, and Nuria Tapia‐Ruiz
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- 2022
13. Virtual care exercise interventions in multidisciplinary chronic pain clinics: a qualitative study of perspectives of adults living with chronic pain
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Kiren Kaloty, Julia Rudecki, Vanessa Craine, Alexander Moyes, Robert Armstrong, Megan Baxter, Judith Hunter, Nida Mustafa, Gillian Grant, Kyle Vader, and Rachael Bosma
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Rehabilitation - Abstract
Chronic pain affects 1 in 4 Canadians and is a leading contributor of disability. Although virtual care has become more prevalent, it is unclear how adults living with chronic pain perceive virtual delivery of exercise interventions within multidisciplinary chronic pain clinics (MCPC). This study explores the perspectives of adults living with chronic pain regarding their perceived barriers and facilitators and recommendations when implementing virtual care exercise interventions within MCPCs.We conducted an interpretive description qualitative study based on semi-structured interviews with adults (age ≥18 years) living with chronic pain from a MCPC in Toronto, Canada, between March 1 and April 30, 2021.We completed fifteen (Our results reveal that adults living with chronic pain view virtual care exercise interventions positively however, the implementation of these interventions must be carefully considered within MCPCs. Specifically, virtual care was considered an excellent adjunct to in-person care but should not replace it completely.Implications for RehabilitationChronic pain is a leading contributor of disability.Exercise interventions are recommended component of comprehensive pain management.Virtual delivery of exercise interventions are becoming more prevalent.Adults living with chronic pain view virtual care exercise interventions positively as they can supplement in-person care and improve access to this type of care.
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- 2022
14. Cosmological constraints from cosmic shear two-point correlation functions with HSC survey first-year data
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Takashi Hamana, Masato Shirasaki, Satoshi Miyazaki, Chiaki Hikage, Masamune Oguri, Surhud More, Robert Armstrong, Alexie Leauthaud, Rachel Mandelbaum, Hironao Miyatake, Atsushi J Nishizawa, Melanie Simet, Masahiro Takada, Hiroaki Aihara, James Bosch, Yutaka Komiyama, Robert Lupton, Hitoshi Murayama, Michael A Strauss, and Masayuki Tanaka
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- 2020
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15. Weak lensing shear calibration with simulations of the HSC survey
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Rachel Mandelbaum, François Lanusse, Alexie Leauthaud, Robert Armstrong, Melanie Simet, Hironao Miyatake, Joshua E Meyers, James Bosch, Ryoma Murata, Satoshi Miyazaki, and Masayuki Tanaka
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- 2018
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16. Erratum: Cosmological constraints from cosmic shear two-point correlation functions with HSC survey first-year data
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Takashi Hamana, Masato Shirasaki, Satoshi Miyazaki, Chiaki Hikage, Masamune Oguri, Surhud More, Robert Armstrong, Alexie Leauthaud, Rachel Mandelbaum, Hironao Miyatake, Atsushi J Nishizawa, Melanie Simet, Masahiro Takada, Hiroaki Aihara, James Bosch, Yutaka Komiyama, Robert Lupton, Hitoshi Murayama, Michael A Strauss, and Masayuki Tanaka
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Space and Planetary Science ,Astronomy and Astrophysics - Published
- 2022
17. Azo-functionalised metal-organic framework for charge storage in sodium-ion batteries
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Aamod V. Desai, Valerie R. Seymour, Romy Ettlinger, Atin Pramanik, Alexis G. Manche, Daniel N. Rainer, Paul S. Wheatley, John M. Griffin, Russell E. Morris, A. Robert Armstrong, EPSRC, University of St Andrews. School of Chemistry, University of St Andrews. University of St Andrews, and University of St Andrews. EaSTCHEM
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MCC ,Materials Chemistry ,Metals and Alloys ,Ceramics and Composites ,NDAS ,QD ,General Chemistry ,QD Chemistry ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Abstract
Funding: This work was supported by Faraday Institution (Grant-FIRG018). We are grateful to Engineering and Physical Sciences Research Council (EPSRC) for the Light Element Facility Grant (EP/T019298/1) and Strategic Equipment Resource Grant (EP/R023751/1). Sodium-ion batteries (NIBs) are emerging as promising devices for energy storage applications. Porous solids, such as metal–organic frameworks (MOFs), are well suited as electrode materials for technologies involving bulkier charge carriers. However, only limited progress has been made using pristine MOFs, primarily due to lack of redox-active organic groups in the materials. In this work a azo-functional MOF, namely UiO-abdc, is presented as an electrode compound for sodium-ion insertion. The MOF delivers a stable capacity (∼100 mA h g−1) over 150 cycles, and post-cycling characterisation validates the stability of the MOF and participation of the azo-group in charge storage. This study can accelerate the realisation of pristine solids, such as MOFs and other porous organic compounds, as battery materials. Publisher PDF
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- 2023
18. Second data release of the Hyper Suprime-Cam Subaru Strategic Program
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Hiroaki Aihara, Yusra AlSayyad, Makoto Ando, Robert Armstrong, James Bosch, Eiichi Egami, Hisanori Furusawa, Junko Furusawa, Andy Goulding, Yuichi Harikane, Chiaki Hikage, Paul T P Ho, Bau-Ching Hsieh, Song Huang, Hiroyuki Ikeda, Masatoshi Imanishi, Kei Ito, Ikuru Iwata, Anton T Jaelani, Ryota Kakuma, Kojiro Kawana, Satoshi Kikuta, Umi Kobayashi, Michitaro Koike, Yutaka Komiyama, Xiangchong Li, Yongming Liang, Yen-Ting Lin, Wentao Luo, Robert Lupton, Nate B Lust, Lauren A MacArthur, Yoshiki Matsuoka, Sogo Mineo, Hironao Miyatake, Satoshi Miyazaki, Surhud More, Ryoma Murata, Shigeru V Namiki, Atsushi J Nishizawa, Masamune Oguri, Nobuhiro Okabe, Sakurako Okamoto, Yuki Okura, Yoshiaki Ono, Masato Onodera, Masafusa Onoue, Ken Osato, Masami Ouchi, Takatoshi Shibuya, Michael A Strauss, Naoshi Sugiyama, Yasushi Suto, Masahiro Takada, Yuhei Takagi, Tadafumi Takata, Satoshi Takita, Masayuki Tanaka, Tsuyoshi Terai, Yoshiki Toba, Hisakazu Uchiyama, Yousuke Utsumi, Shiang-Yu Wang, Wenting Wang, and Yoshihiko Yamada
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- 2019
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19. Cosmology from cosmic shear power spectra with Subaru Hyper Suprime-Cam first-year data
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Chiaki Hikage, Masamune Oguri, Takashi Hamana, Surhud More, Rachel Mandelbaum, Masahiro Takada, Fabian Köhlinger, Hironao Miyatake, Atsushi J Nishizawa, Hiroaki Aihara, Robert Armstrong, James Bosch, Jean Coupon, Anne Ducout, Paul Ho, Bau-Ching Hsieh, Yutaka Komiyama, François Lanusse, Alexie Leauthaud, Robert H Lupton, Elinor Medezinski, Sogo Mineo, Shoken Miyama, Satoshi Miyazaki, Ryoma Murata, Hitoshi Murayama, Masato Shirasaki, Cristóbal Sifón, Melanie Simet, Joshua Speagle, David N Spergel, Michael A Strauss, Naoshi Sugiyama, Masayuki Tanaka, Yousuke Utsumi, Shiang-Yu Wang, and Yoshihiko Yamada
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- 2019
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20. Novel Framework for Treatment Response Evaluation Using PSMA PET/CT in Patients with Metastatic Castration-Resistant Prostate Cancer (RECIP 1.0): An International Multicenter Study
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Andrei Gafita, Isabel Rauscher, Manuel Weber, Boris Hadaschik, Hui Wang, Wesley Robert Armstrong, Robert Tauber, Tristan R. Grogan, Johannes Czernin, Matthew B. Rettig, Ken Herrmann, Jeremie Calais, Wolfgang A. Weber, Matthias Benz, Wolfgang P. Fendler, and Matthias Eiber
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Male ,Urologic Diseases ,Aging ,PSMA PET ,Urology ,Clinical Sciences ,Medizin ,radionuclide treatment ,Lutetium ,Castration-Resistant ,Heterocyclic Compounds, 1-Ring ,Heterocyclic Compounds ,Positron Emission Tomography Computed Tomography ,Humans ,interim PET ,Radiology, Nuclear Medicine and imaging ,radionuclide ,Retrospective Studies ,Cancer ,1-Ring ,treatment ,Prostate Cancer ,Prostatic Neoplasms ,Dipeptides ,Prostate-Specific Antigen ,interimPET ,177Lu-PSMA ,Lu-177-PSMA ,Prostatic Neoplasms, Castration-Resistant ,Nuclear Medicine & Medical Imaging ,Treatment Outcome ,Good Health and Well Being ,metastatic castration-resistant prostate cancer ,Biomedical Imaging ,Radiopharmaceuticals - Abstract
Our objective was to develop version 1.0 of a novel framework for response evaluation criteria in prostate-specific membrane antigen (PSMA) PET/CT (RECIP) and a composite response classification that combines responses by prostate-specific antigen (PSA) measurements and by RECIP 1.0 (PSA + RECIP). Methods: This was an international multicenter, retrospective study. One hundred twenty-four men with metastatic castration-specific prostate cancer (mCRPC) who underwent 177Lu-PSMA therapy and received PSMA PET/CT at baseline and at an interim time point of 12 wk were included. Pairs of baseline interim PET/CT scans were interpreted by consensus among 3 masked readers for appearance of new lesions. Tumor lesions were segmented, and total PSMA-positive tumor volume (PSMA-VOL) was obtained. Appearance of new lesions and changes in PSMA-VOL were combined to develop RECIP 1.0, which included classifications of complete response (RECIP-CR: absence of any PSMA-ligand uptake on interim PET/CT), partial response (RECIP-PR: decline ≥ 30% in PSMA-VOL and no appearance of new lesions), progressive disease (RECIP-PD: increase ≥ 20% in PSMA-VOL and appearance of new lesions), and stable disease (RECIP-SD: any condition but RECIP-PR or RECIP-PD). Changes in PSA levels at 12 wk by Prostate Cancer Working Group Criteria 3 were recorded. PSA + RECIP results were defined as response (PSA decline ≥ 50% or RECIP-PR/CR) or progression (PSA increase ≥ 25% or RECIP-PD). The study's primary outcome measure was the prognostic value of RECIP 1.0 for overall survival (OS). The secondary outcome measure was the prognostic accuracy (C-index) of PSA + RECIP versus PSA responses. Results: Patients with RECIP-PD (n = 39; 8.3 mo) had a shorter OS than patients with stable disease (RECIP-SD) (n = 47; 13.1 mo; P < 0.001) or RECIP-PR (n = 38; 21.7 mo; P < 0.001). In identifying responders and progressors, PSA + RECIP had C-indices superior to those of PSA only: 0.65 versus 0.62 (P = 0.028) and 0.66 versus 0.63 (P = 0.044), respectively. Conclusion: PSMA PET/CT by RECIP 1.0 is prognostic for OS and can be used as a response biomarker to monitor early efficacy of 177Lu-PSMA in men with mCRPC. PSA + RECIP may be used as a novel composite endpoint in mCRPC clinical trial design.
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- 2022
21. The LSST DESC DC2 Simulated Sky Survey
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Bela Abolfathi, David Alonso, Robert Armstrong, Éric Aubourg, Humna Awan, Yadu N. Babuji, Franz Erik Bauer, Rachel Bean, George Beckett, Rahul Biswas, Joanne R. Bogart, Dominique Boutigny, Kyle Chard, James Chiang, Chuck F. Claver, Johann Cohen-Tanugi, Céline Combet, Andrew J. Connolly, Scott F. Daniel, Seth W. Digel, Alex Drlica-Wagner, Richard Dubois, Emmanuel Gangler, Eric Gawiser, Thomas Glanzman, Phillipe Gris, Salman Habib, Andrew P. Hearin, Katrin Heitmann, Fabio Hernandez, Renée Hložek, Joseph Hollowed, Mustapha Ishak, Željko Ivezić, Mike Jarvis, Saurabh W. Jha, Steven M. Kahn, J. Bryce Kalmbach, Heather M. Kelly, Eve Kovacs, Danila Korytov, K. Simon Krughoff, Craig S. Lage, François Lanusse, Patricia Larsen, Laurent Le Guillou, Nan Li, Emily Phillips Longley, Robert H. Lupton, Rachel Mandelbaum, Yao-Yuan Mao, Phil Marshall, Joshua E. Meyers, Marc Moniez, Christopher B. Morrison, Andrei Nomerotski, Paul O’Connor, HyeYun Park, Ji Won Park, Julien Peloton, Daniel Perrefort, James Perry, Stéphane Plaszczynski, Adrian Pope, Andrew Rasmussen, Kevin Reil, Aaron J. Roodman, Eli S. Rykoff, F. Javier Sánchez, Samuel J. Schmidt, Daniel Scolnic, Christopher W. Stubbs, J. Anthony Tyson, Thomas D. Uram, Antonio Villarreal, Christopher W. Walter, Matthew P. Wiesner, W. Michael Wood-Vasey, and Joe Zuntz
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- 2021
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22. Sthreepura cave at Kiriwanagama, south central Sri Lanka: A network cave in saprolite and proterozoic quartzite
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Pathmakumara Jayasingha, Robert Armstrong .L. Osborne, and Ross E Pogson
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sri lanka ,gneiss ,network cave ,saprolite ,arenization ,Petrology ,QE420-499 ,Stratigraphy ,QE640-699 - Abstract
Sthreepura Cave at Kiriwanagama consists of an upper level of cavities in quartzite formed by arenization and a lower level developed in a saprolite formed from the weathering of gneiss sandwiched between two layers of quartzite. The lower level cave is not like most arenization and phantom rock caves as the walls are composed of saprolite, not exhumed unweathered rock. The cave is not a soil pipe as it is not in soil, lacks the characteristic features of soil pipes and has formed directly below, not above an aquiclude. Sthreepura Cave at Kiriwanagama is a network cave in saprolite. Speleogenesis in the lower level began with the development of joint-guided tubes in the saprolite directly below the upper layer of quartzite, probably under phreatic conditions. Later erosion under vadose conditions removed the saprolite to produce a network of passages with a rectangular profile. Widening of the passages ultimately caused ceiling failure producing breakdown chambers, but fallen slabs of quartzite armoured the walls of the Main Passage of the cave protecting them from undercutting. Key words: Sri Lanka, gneiss, network cave, saprolite, arenization. Jama Sthreepura pri Kiriwanagami, južni del osrednje Šri Lanke: Mreža rovov v saprolitu in proterozojskem kvarcitu Jamo St hreepura pri Kiriwanagami sestavljata gornji nivo arenizacijskih votlin v kvarcitu ter spodnji nivo v saprolitu, ki je nastal s preperevanjem gnajsa med plastmi kvarcita. Tudi stene rovov spodnjega nivoja so iz saprolita, kar kaže na drugačen razvoj od znanih arenizacijskih in fantomskih jam. Jama nima lastnosti preperinskih cevi in je v nasprotju s temi nastala neposredno pod (in ne nad) akvikludom. Jama Sthreepura pri Kiriwanagami predstavlja mrežo kanalov nastalih v saprofitu.. Speleogeneza se je začela z razvojem cevi vzdolž razpok v saprolitu, neposredno pod gornjo plastjo kvarcita, verjetno v freatičnih pogojih. Kasnejša erozija v vadozni coni je saprolit odstranila in tako ustvarila mrežo rovov pravokotnega profila. Širjenje rovov je privedlo do rušenja stropa in nastanka podornih dvoran. V glavnem rovu so padli bloki kvarcita zaščitili stene in preprečili nadaljnje spodkopavanje v glavnem rovu jame. Ključne beside: Šri Lanka, gnajs, mreža rovov, saprolit, arenizacija.
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- 2018
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23. Safety and Efficacy of Natalizumab as Adjunctive Therapy for People With Drug-Resistant Epilepsy
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Jacqueline A, French, Andrew J, Cole, Edward, Faught, William H, Theodore, Annamaria, Vezzani, Kore, Liow, Jonathan J, Halford, Robert, Armstrong, Jerzy P, Szaflarski, Sarah, Hubbard, Jagdish, Patel, Kun, Chen, Wei, Feng, Marco, Rizzo, Jacob, Elkins, Gabrielle, Knafler, Kimberly A, Parkerson, and Jose, Rafecas
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Adult ,Drug Resistant Epilepsy ,medicine.medical_specialty ,business.industry ,Seizure types ,Natalizumab ,Phases of clinical research ,Odds ratio ,Placebo ,medicine.disease ,Epilepsy ,Treatment Outcome ,Seizures ,Internal medicine ,Humans ,Medicine ,Anticonvulsants ,Neurology (clinical) ,business ,Adverse effect ,medicine.drug - Abstract
Background and ObjectivesTo explore efficacy/safety of natalizumab, a humanized monoclonal anti–α4-integrin antibody, as adjunctive therapy in adults with drug-resistant focal epilepsy.MethodsParticipants with ≥6 seizures during the 6-week baseline period were randomized 1:1 to receive natalizumab 300 mg IV or placebo every 4 weeks for 24 weeks. Primary efficacy outcome was change from baseline in log-transformed seizure frequency, with a predefined threshold for therapeutic success of 31% relative reduction in seizure frequency over the placebo group. Countable seizure types were focal aware with motor signs, focal impaired awareness, and focal to bilateral tonic-clonic. Secondary efficacy endpoints/safety were also assessed.ResultsOf 32 and 34 participants dosed in the natalizumab 300 mg and placebo groups, 30 (94%) and 31 (91%) completed the placebo-controlled treatment period, respectively (one participant was randomized to receive natalizumab but not dosed due to IV complications). Estimated relative change in seizure frequency of natalizumab over placebo was −14.4% (95% confidence interval [CI] –46.1%–36.1%; p = 0.51). The proportion of participants with ≥50% reduction from baseline in seizure frequency was 31.3% for natalizumab and 17.6% for placebo (odds ratio 2.09, 95% CI 0.64–6.85; p = 0.22). Adverse events were reported in 24 (75%) and 22 (65%) participants receiving natalizumab vs placebo.DiscussionAlthough the threshold to demonstrate efficacy was not met, there were no unexpected safety findings and further exploration of possible anti-inflammatory therapies for drug-resistant epilepsy is warranted.Trial Registration InformationThe ClinicalTrials.gov registration number is NCT03283371.Classification of EvidenceThis study provides Class I evidence that IV natalizumab every 4 weeks, compared to placebo, did not significantly change seizure frequency in adults with drug-resistant epilepsy. The study lacked the precision to exclude an important effect of natalizumab.
- Published
- 2021
24. Exploiting anion and cation redox chemistry in lithium-rich perovskite oxalate : a novel next-generation Li/Na-ion battery electrode
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Atin Pramanik, Alexis G. Manche, Rebecca Clulow, Philip Lightfoot, A. Robert Armstrong, EPSRC, University of St Andrews. School of Chemistry, and University of St Andrews. EaSTCHEM
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Fysikalisk kemi ,Inorganic Chemistry ,MCC ,Oorganisk kemi ,Materials Chemistry ,NDAS ,Materialkemi ,QD ,QD Chemistry ,Physical Chemistry - Abstract
Authors thank EPSRC EP/R030472/1 for financial support. AGM wishes to thank the Faraday Institution for financial support and training (Grant Number FITG033). The authors are also grateful to EPSRC Light Element Analysis Facility Grant EP/T019298/1 and the EPSRC Strategic Equipment Resource Grant EP/R023751/1. The fundamental understanding of electrochemical reaction kinetics for lithium/sodium-ion batteries (LIBs & NIBs) is a significant criterion for advancing new-generation electrode materials. Herein, we demonstrate a novel lithium-rich perovskite oxalate KLi3Fe(C2O4)3 (KLFC) cathode with the combination of cation and anion redox delivering discharge capacities of 86 and 99 mA h g−1 after 100 cycles for a LIB and NIB, respectively, with good cyclability. Experimental Raman spectroscopy analysis combined with DFT calculations of charged/discharged samples illustrate the oxalate anion redox activity. Further, first-principles calculations of the partial density of states and Bader charges analysis have also characterised the redox behaviour and charge transfer during the potassium extraction processes. Publisher PDF
- Published
- 2022
25. Enhanced Cycling Stability in the Anion Redox Material P3‐Type Zn‐Substituted Sodium Manganese Oxide
- Author
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Stephanie F. Linnell, Moritz Hirsbrunner, Saki Imada, Giannantonio Cibin, Aaron B. Naden, Alan V. Chadwick, John T. S. Irvine, Laurent C. Duda, A. Robert Armstrong, EPSRC, University of St Andrews. School of Chemistry, University of St Andrews. Institute of Behavioural and Neural Sciences, University of St Andrews. Centre for Energy Ethics, University of St Andrews. Centre for Designer Quantum Materials, and University of St Andrews. EaSTCHEM
- Subjects
Layered compounds ,Anion redox chemistry ,Transition metal vacancies ,Sodium ,NDAS ,Positive electrode material ,Materials Chemistry ,Electrochemistry ,Materialkemi ,QD ,QD Chemistry ,Catalysis - Abstract
Funding: Faraday Institution (Grant Number(s): FIRG018), Diamond Light Source (Grant Number(s): SP14239), Engineering and Physical Sciences Research Council (Grant Number(s): EP/L017008/1, EP/R023751/1, EP/T019298/1), SPRing8 (Grant Number(s): 2021A1425). Sodium layered oxides showing oxygen redox activity are promising positive electrodes for sodium‑ion batteries (SIBs). However, structural degradation typically results in limited reversibility of the oxygen redox activity. Herein, the effect of Zn‑doping on the electrochemical properties of P3-type sodium manganese oxide, synthesised under air and oxygen is investigated for the first time. Air‑Na 0.67 Mn 0.9 Zn 0.1 O 2 and Oxy‑Na 0.67 Mn 0.9 Zn 0.1 O 2 exhibit stable cycling performance between 1.8 and 3.8 V, each maintaining 96% of their initial capacity after 30 cycles, where Mn 3+ /Mn 4+ redox dominates. Increasing the voltage range to 1.8‑4.3 V activates oxygen redox. For the material synthesised under air, oxygen redox activity is based on Zn, with limited reversibility. The additional transition metal vacancies in the material synthesised under oxygen result in enhanced oxygen redox reversibility with small voltage hysteresis. These results may assist the development of high‑capacity and structurally stable oxygen redox‑based materials for SIBs. Publisher PDF
- Published
- 2022
26. Nanostructured TiO2(B): the effect of size and shape on anode properties for Li-ion batteries
- Author
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Liu, Zheng, Andreev, Yuri G., Robert Armstrong, A., Brutti, Sergio, Ren, Yu, and Bruce, Peter G.
- Published
- 2013
- Full Text
- View/download PDF
27. Kung Fu Panda 3: mandarin lip-sync reanimation process and pipeline.
- Author
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Mark Edwards, Dave Walvoord, Robert Armstrong, Geoff Parkhill, Dagan Potter, Eli Bocek-Rivele, Tsun Chuen Ho, Jingxiang Li, and Kyle Wood
- Published
- 2016
- Full Text
- View/download PDF
28. Crop Seed Phenomics: Focus on Non-Destructive Functional Trait Phenotyping Methods and Applications
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Gokhan Hacisalihoglu and Paul Robert Armstrong
- Subjects
Ecology ,Plant Science ,Ecology, Evolution, Behavior and Systematics - Abstract
Seeds play a critical role in ensuring food security for the earth’s 8 billion people. There is great biodiversity in plant seed content traits worldwide. Consequently, the development of robust, rapid, and high-throughput methods is required for seed quality evaluation and acceleration of crop improvement. There has been considerable progress in the past 20 years in various non-destructive methods to uncover and understand plant seed phenomics. This review highlights recent advances in non-destructive seed phenomics techniques, including Fourier Transform near infrared (FT-NIR), Dispersive-Diode Array (DA-NIR), Single-Kernel (SKNIR), Micro-Electromechanical Systems (MEMS-NIR) spectroscopy, Hyperspectral Imaging (HSI), and Micro-Computed Tomography Imaging (micro-CT). The potential applications of NIR spectroscopy are expected to continue to rise as more seed researchers, breeders, and growers successfully adopt it as a powerful non-destructive method for seed quality phenomics. It will also discuss the advantages and limitations that need to be solved for each technique and how each method could help breeders and industry with trait identification, measurement, classification, and screening or sorting of seed nutritive traits. Finally, this review will focus on the future outlook for promoting and accelerating crop improvement and sustainability.
- Published
- 2023
29. Ambient base-free glycerol oxidation over bimetallic PdFe/SiO2 by in situ generated active oxygen species
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Ricci Underhill, Peter J. Miedziak, Richard J. Lewis, David J. Morgan, Simon J. Freakley, Damien Martin Murphy, Mark Douthwaite, Robert Armstrong, Qian He, Jennifer K. Edwards, Graham J. Hutchings, Andrea Folli, Ouardia Akdim, and Thomas E. Davies
- Subjects
inorganic chemicals ,chemistry ,Alcohol oxidation ,chemistry.chemical_element ,Reactivity (chemistry) ,Dehydrogenation ,General Chemistry ,Leaching (metallurgy) ,Photochemistry ,Bimetallic strip ,Carbon ,Decomposition ,Catalysis - Abstract
Low temperature oxidation of alcohols over heterogeneous catalysts is exceptionally challenging, particularly under neutral conditions. Herein, we report on an efficient, base-free method to oxidise glycerol over a 0.5%Pd-0.5%Fe/SiO2 catalyst at ambient temperature in the presence of gaseous H2 and O2. The exceptional catalytic performance was attributed to the in situ formation of highly reactive surface-bound oxygenated species, which promote the dehydrogenation on the alcohol. The PdFe bimetallic catalyst was determined to be significantly more active than corresponding monometallic analogues, highlighting the important role both metals have in this oxidative transformation. Fe leaching was confirmed to occur over the course of the reaction but sequestering experiments, involving the addition of bare carbon to the reactions, confirmed that the reaction was predominantly heterogeneous in nature. Investigations with electron paramagnetic resonance spectroscopy suggested that the reactivity in the early stages was mediated by surface-bound reactive oxygen species; no homogeneous radical species were observed in solution. This theory was further evidenced by a direct H2O2 synthesis study, which confirmed that the presence of Fe in the bimetallic catalyst neither improved the synthesis of H2O2 nor promoted its decomposition over the PdFe/SiO2 catalyst.
- Published
- 2021
30. Synthesis, Structure, and Electrochemical Properties of Some Cobalt Oxalates
- Author
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Yongbing Tang, Yuanqi Lan, Wenjiao Yao, Xinyuan Zhang, Haiyan He, A. Robert Armstrong, Philip Lightfoot, and Cai Jinghua
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010405 organic chemistry ,Rietveld refinement ,chemistry.chemical_element ,010402 general chemistry ,Electrochemistry ,01 natural sciences ,Oxalate ,Hydrothermal circulation ,Cathode ,0104 chemical sciences ,law.invention ,Inorganic Chemistry ,chemistry.chemical_compound ,Crystallography ,Octahedron ,chemistry ,law ,Physical and Theoretical Chemistry ,Polarization (electrochemistry) ,Cobalt - Abstract
Transition-metal oxalates have wide applications in magnetics, photoemission, electrochemistry, etc. Herein, using hydrothermal reactions, five cobalt(II) oxalates, Na2Co2(C2O4)3·2H2O (I), Na2Co(C2O4)2·8H2O (II), KLi3Co(C2O4)3 (III), Li4Co(C2O4)3 (IV), and (NH4)2Co2(C2O4)F4 (V) have been synthesized, and their structures are determined from single-crystal X-ray diffraction or Rietveld refinement of powder X-ray diffraction data. Notably, IV and V are identified for the first time. The structures of these cobalt oxalates are versatile, covering 0D, 1D, 2D, and 3D frameworks, while the coordination environments of Co2+ centers are uniquely distorted octahedra. As representative examples, I and III are investigated as cathode materials for secondary batteries. Both exhibited electrochemical activity despite large cell polarization. The present study enriches the transition-metal oxalate family and provides new options for energy storage materials.
- Published
- 2020
31. Advances in Organic Anode Materials for Na‐/K‐Ion Rechargeable Batteries
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Robert Armstrong, Aamod V. Desai, and Russell E. Morris
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Battery (electricity) ,Global energy ,anode ,Materials science ,General Chemical Engineering ,Structural diversity ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,Electrochemistry ,01 natural sciences ,Ion ,Molecular engineering ,Environmental Chemistry ,General Materials Science ,potassium-ion ,Electrode material ,Minireviews ,021001 nanoscience & nanotechnology ,organic electrode ,0104 chemical sciences ,Anode ,General Energy ,battery ,Minireview ,sodium-ion ,0210 nano-technology - Abstract
Electrochemical energy storage (EES) devices are gaining ever greater prominence in the quest for global energy security. With increasing applications and widening scope, rechargeable battery technology is gradually finding avenues for more abundant and sustainable systems such as Na‐ion (NIB) and K‐ion batteries (KIB). Development of suitable electrode materials lies at the core of this transition. Organic redox‐active molecules are attractive candidates as negative electrode materials owing to their low redox potentials and the fact that they can be obtained from biomass. Also, the rich structural diversity allows integration into several solid‐state polymeric materials. Research in this domain is increasingly focused on deploying molecular engineering to address specific electrochemical limitations that hamper competition with rival materials. This Minireview aims to summarize the advances in both the electrochemical properties and the materials development of organic anode materials., Sustainable electrodes: Sodium‐ion and potassium‐ion batteries are likely to contribute significantly in the upcoming years to global energy security. Sustainable electrode materials must be developed to enable this growth. Organic molecules are at the core of this technology and materials offering low‐voltage redox are improving. This Minireview tracks the progress and remaining challenges in this domain.
- Published
- 2020
32. Local Health Department Interest in Implementation of a Jail-Based Human Papillomavirus Vaccination Program in Kansas, Iowa, Missouri, and Nebraska
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Molly Allison, Catherine L. Satterwhite, Robert Armstrong, Brynne Musser, Megha Ramaswamy, and Patricia J. Kelly
- Subjects
medicine.medical_specialty ,Cross-sectional study ,Staffing ,Context (language use) ,Article ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Papillomavirus Vaccines ,030212 general & internal medicine ,Local Government ,Missouri ,030505 public health ,Health Policy ,Public health ,Papillomavirus Infections ,Public Health, Environmental and Occupational Health ,Nebraska ,social sciences ,Kansas ,Iowa ,Vaccination ,Cross-Sectional Studies ,Prisons ,Family medicine ,Local government ,Public Health ,Implementation research ,0305 other medical science ,Psychology ,Health department - Abstract
Context Local health departments (LHDs) play a vital role in community vaccination programs for human papillomavirus (HPV) infection, but little research has been done to assess LHD interest in cross-sectoral partnerships to vaccinate high-risk groups, specifically incarcerated persons. Objective To describe factors associated with interest in a novel implementation strategy linking LHDs with jails in 4 Midwestern states to deliver HPV vaccine. Design Survey based on the Consolidated Framework for Implementation Research (CFIR) model given to LHD administrators. A modified Poisson relative risk regression was used to assess the relationship between independent variables and LHD interest in implementation of a jail-based HPV vaccination program. Setting LHDs in Kansas, Missouri, Iowa, and Nebraska. Participants From September 2017 to April 2018, two-thirds (237/344) of invited LHD administrators from the 4 states responded to the survey. Main outcome measure LHD interest in implementation of a jail-based HPV vaccination program. Results Forty-five percent of LHDs were interested in learning more about implementing a jail-based HPV vaccination program, and 2% already offered or had plans to offer HPV vaccine in their jails. Barriers to implementation were cost (66%), inmates' short incarcerations (47%), and availability of medical staffing (43%). LHD characteristics associated with interest in implementation of a jail-based HPV vaccination program included "inner setting" CFIR variables, which capture the structural and cultural context for program implementation: 7 or more employees (odds ratio [OR] = 2.22; 95% confidence interval [CI], 1.24-3.95), perception of importance to provide HPV vaccine in jails (OR = 3.70; 95% CI, 2.00-6.84), and already providing any vaccines in jails (OR = 2.62; 95% CI, 1.18-5.80). Conclusions Nearly half of LHDs in the region expressed interest in partnering with local entities to meet HPV vaccination needs of high-risk groups. Research on cross-sectoral partnerships and what these collaborations look like in practice is needed for public health impact.
- Published
- 2020
33. Sustainable production of glucaric acid from corn stover via glucose oxidation: An assessment of homogeneous and heterogeneous catalytic oxidation production routes
- Author
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David W. Knight, Nilay Shah, Graham J. Hutchings, Robert Armstrong, David Chadwick, Vaishali Thaore, and Engineering & Physical Science Research Council (EPSRC)
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food.ingredient ,Adipic acid ,Strategic, Defence & Security Studies ,010405 organic chemistry ,General Chemical Engineering ,Food additive ,0904 Chemical Engineering ,Biomass ,0914 Resources Engineering and Extractive Metallurgy ,General Chemistry ,Chemical Engineering ,010402 general chemistry ,01 natural sciences ,Glucaric Acid ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,food ,Corn stover ,Catalytic oxidation ,chemistry ,0911 Maritime Engineering ,Nitric acid ,0102 Applied Mathematics ,Organic chemistry - Abstract
Glucaric acid is being used increasingly as a food additive, corrosion inhibitor, in deicing, and in detergents, and is also a potential starting material for the production of adipic acid, the key monomer for nylon-66. This work describes a techno-economic analysis of a potential bio-based process for the production of pure glucaric acid from corn stover (biomass). Two alternative routes for oxidation of glucose to glucaric acid are considered: via heterogeneous catalytic oxidation with air, and by homogeneous glucose oxidation using nitric acid. Techno-economic and lifecycle assessments (TEA, LCA) are made for both oxidation routes and cover the entire process from biomass to pure crystalline glucaric acid that can be used as a starting material for the production of valuable chemicals. This is the first TEA of pure glucaric acid production incorporating ion exchange and azeotropic evaporation below 50 °C to avoid lactone formation. The developed process models were simulated in Aspen Plus V9. The techno-economic assessment shows that both production routes are economically viable leading to minimum selling prices of glucaric acid of ∼ $2.53/kg and ∼ $2.91/kg for the heterogeneous catalytic route and the homogeneous glucose oxidation route respectively. It is shown that the heterogeneous catalytic oxidation route is capable of achieving a 22% lower environmental impact than the homogeneous glucose oxidation route. Opportunities for further improvement in sustainable glucaric acid production at industrial scale are identified and discussed.
- Published
- 2020
34. Author response for 'A Structural Investigation of Organic Battery Anode Materials by NMR Crystallography'
- Author
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null Tommy Whewell, null Valerie R. Seymour, null Kieran Griffiths, null Nathan R. Halcovitch, null Aamod V. Desai, null Russell E. Morris, null A. Robert Armstrong, and null John M. Griffin
- Published
- 2022
35. A structural investigation of organic battery anode materials by NMR crystallography
- Author
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Tommy Whewell, Valerie R. Seymour, Kieran Griffiths, Nathan R. Halcovitch, Aamod V. Desai, Russell E. Morris, A. Robert Armstrong, John M. Griffin, The Faraday Institution, EPSRC, University of St Andrews. School of Chemistry, and University of St Andrews. EaSTCHEM
- Subjects
General Materials Science ,DAS ,QD ,General Chemistry ,QD Chemistry - Abstract
V.R.S., A.V.D., A.R.A. R.E.M. and J.M.G.are indebted to the Faraday Institution NEXGENNA project (FIRG018) for financial support. We acknowledge the support of the Leverhulme Doctoral Scholarships Programme in “Material Social Futures” (grant number DS-2017-036) for the provision of a PhD studentship to T.W. We acknowledge the support from CCP-NC, funded by the EPSRC (EP/M022501/1), and the UKCP consortium, funded by the EPSRC (EP/P025561/1). K.G. acknowledges the Leverhulme Trust (Research Project Grant Number RPG-2018-395). We are grateful to the UK Materials and Molecular Modelling Hub for computational resources, which is partially funded by the EPSRC (EP/P020194). The UK High-Field Solid-State NMR Facility used in this research was funded by EPSRC and BBSRC (EP/T015063/1) as well as, for the1 GHz instrument, EP/R029946/1. Conjugated alkali metal dicarboxylates have recently received attention for applications as organic anode materials in lithium and sodium-ion batteries. In order to understand and optimise these materials, it is important to be able to characterise both the long-range and local aspects of the crystal structure, which may change during battery cycling. Furthermore, some materials can display polymorphism or hydration behaviour. NMR crystallography, which combines long-range crystallographic information from diffraction with local information from solid-state NMR via interpretation aided by DFT calculations, is one such approach, but this has not yet been widely applied to conjugated dicarboxylates. In this work, we evaluate the application of NMR crystallography for a set of model lithium and sodium dicarboxylate salts. We investigate the effect of different DFT geometry optimisation strategies and find that the calculated NMR parameters are not systematically affected by the choice of optimisation method, although the inclusion of dispersion correction schemes is important to accurately reproduce the experimental unit cell parameters. We also observe hydration behaviour for two of the sodium salts, and provide insight into the structure of an as-yet uncharacterised structure of sodium naphthalenedicarboxylate. This highlights the importance of sample preparation and characterisation for organic sodium-ion battery anode materials in particular. Publisher PDF
- Published
- 2022
36. Enhanced oxygen redox reversibility and capacity retention of titanium-substituted Na-4/7[1/7Ti1/7Mn5/7]O-2 in sodium-ion batteries
- Author
-
Stephanie F. Linnell, Eun Jeong Kim, Yong-Seok Choi, Moritz Hirsbrunner, Saki Imada, Atin Pramanik, Aida Fuente Cuesta, David N. Miller, Edoardo Fusco, Bela E. Bode, John T. S. Irvine, Laurent C. Duda, David O. Scanlon, A. Robert Armstrong, EPSRC, University of St Andrews. School of Chemistry, University of St Andrews. Biomedical Sciences Research Complex, University of St Andrews. Centre of Magnetic Resonance, University of St Andrews. EaSTCHEM, University of St Andrews. Centre for Energy Ethics, and University of St Andrews. Centre for Designer Quantum Materials
- Subjects
Renewable Energy, Sustainability and the Environment ,NDAS ,Materials Chemistry ,Materialkemi ,QD ,General Materials Science ,General Chemistry ,QD Chemistry - Abstract
L. D. gratefully acknowledges financial support from the Swedish Energy Agency (contract 2020-005246). Y.C. and D.O.S. are grateful to the Faraday Institution for funding the MICHAEL computing cluster hosted at University College London (UCL). Our membership of the UKs HEC Materials Chemistry Consortium, which is funded by EPSRC (EP/L000202, EP/R029431), this work used the ARCHER2 UK National Supercomputing Service(http://www.archer2.ac.uk). We are also grateful to the UK Materials and Molecular Modelling Hub for computational resources, which is partially funded by EPSRC (EP/P020194/1 and EP/T022213/1). We are grateful to the Engineering and Physical Sciences Research Council (EPSRC) Light Element Facility Grant (EP/T019298/1) for funding the acquisition of the Raman spectrometer. EF is grateful for an EaStCHEM studentship. This work was supported by the Faraday Institution (grant number FIRG018). Anion redox reactions offer a means of enhancing the capacity of layered sodium transition metal oxide positive electrode materials. However, oxygen redox reactions typically show limited reversibility and irreversible structural changes upon cycling, resulting in rapid capacity loss. Here, the Ti substituted Na4/7[□1/7Ti1/7Mn5/7]O2 (where □ represents a transition metal vacancy) is presented as a positive electrode material for sodium ion batteries. Na4/7[□1/7Ti1/7Mn5/7]O2 delivers a reversible capacity of 167 mAh g -1 after 25 cycles at 10 mA g -1 within the voltage range of 1.6 – 4.4 V and presents enhanced stability compared with Na4/7[□1/7Mn6/7]O2 over the voltage range 3.0 – 4.4 V. The structural and electronic structural changes of this Ti4+ substituted phase are investigated by powder X-ray diffraction, X ray absorption spectroscopy, electron paramagnetic resonance and Raman spectroscopy, supported by density functional theory calculations. These results show that the Na4/7[□1/7Mn6/7]O2 structure is maintained between 3.0 – 4.4 V, and the presence of TiO6 octahedra in Na4/7[□1/7Ti1/7Mn5/7]O2 relieves structural distortions from Jahn Teller distorted Mn3+O6 between 1.6 – 4.4 V. Furthermore, Ti4+ substitution stabilises the adjacent O 2p orbitals and raises the ionicity of the Mn O bonds, increasing the operating potential of Na4/7[□1/7Ti1/7Mn5/7]O2. Thereby providing evidence that the improved electrochemical performance of Na4/7[□1/7Ti1/7Mn5/7]O2 can be attributed to Ti4+ substitution. This work provides insight and strategies for improving the structural stability and electrochemical performance of sodium layered oxides. Publisher PDF
- Published
- 2022
37. Effect of Ti-Substitution on the Properties of P3 Structure Na2/3Mn0.8Li0.2O2 Showing a Ribbon Superlattice
- Author
-
Stephanie F. Linnell, Eun Jeong Kim, Le Anh Ma, Aaron B. Naden, John T. S. Irvine, Reza Younesi, Laurent C. Duda, A. Robert Armstrong, EPSRC, University of St Andrews. Institute of Behavioural and Neural Sciences, University of St Andrews. School of Chemistry, University of St Andrews. Centre for Energy Ethics, University of St Andrews. Centre for Designer Quantum Materials, and University of St Andrews. EaSTCHEM
- Subjects
Superstructure ,Layered compounds ,Anion redox chemistry ,Sodium ,Electrochemistry ,NDAS ,Positive electrode material ,Materials Chemistry ,Materialkemi ,QD ,SDG 7 - Affordable and Clean Energy ,QD Chemistry ,Catalysis - Abstract
Funding: Faraday Institution (Grant Number(s): FIRG018); Engineering and Physical Sciences Research Council (Grant Number(s): EP/T019298/1, EP/L017008/1, EP/R023751/1); Energimyndigheten (Grant Number(s): 2020-005249); Spring 8 (Grant Number(s): 2019B1604). Oxygen anion redox offers an effective strategy to enhance the energy density of layered oxide positive electrodes for sodium- and lithium-ion batteries. However, lattice oxygen loss and irreversible structural transformations over the first cycle may result in large voltage hysteresis, thereby impeding practical application. Herein, ribbon superstructure ordering of Li/transition-metal-ions was applied to suppress the voltage hysteresis combined with Ti-substitution to improve the cycling stability for P3-Na0.67Li0.2Ti0.15Mn0.65O2. When both cation and anion redox reactions are utilized, Na0.67Li0.2Ti0.15Mn0.65O2 delivers a reversible capacity of 172 mA h g−1 after 25 cycles at 10 mA g−1 between 1.6–4.4 V vs. Na+/Na. Ex-situ X-ray diffraction data reveal that the ribbon superstructure is retained with negligible unit cell volume expansion/contraction upon sodiation/desodiation. The performance as a positive electrode for Li-ion batteries was also evaluated and P3-Na0.67Li0.2Ti0.15Mn0.65O2 delivers a reversible capacity of 180 mA h g−1 after 25 cycles at 10 mA g−1 when cycled vs. Li+/Li between 2.0–4.8 V. Publisher PDF
- Published
- 2022
38. Importance of Superstructure in Stabilizing Oxygen Redox in P3-Na0.67Li0.2Mn0.8O2
- Author
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Eun Jeong Kim, Philip A. Maughan, Euan N. Bassey, Raphaële J. Clément, Le Anh Ma, Laurent C. Duda, Divya Sehrawat, Reza Younesi, Neeraj Sharma, Clare P. Grey, A. Robert Armstrong, The Faraday Institution, and University of St Andrews. School of Chemistry
- Subjects
oxygen redox ,Renewable Energy, Sustainability and the Environment ,NDAS ,layered structures ,Materialkemi ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,QD Chemistry ,01 natural sciences ,P3 structure ,0104 chemical sciences ,superstructures ,Materials Chemistry ,sodium-ion batteries ,General Materials Science ,QD ,0210 nano-technology - Abstract
Funder: Powder Diffraction at the Australian Synchrotron, Funder: Australian Nuclear Science and Technology Organization, Funder: Engineering Physical Sciences Research Council, Funder: National Productivity Interest Fund, Funder: Center for Functional Nanomaterials, Funder: Brookhaven National Laboratory; Id: http://dx.doi.org/10.13039/100006231, Activation of oxygen redox represents a promising strategy to enhance the energy density of positive electrode materials in both lithium and sodium‐ion batteries. However, the large voltage hysteresis associated with oxidation of oxygen anions during the first charge represents a significant challenge. Here, P3‐type Na0.67Li0.2Mn0.8O2 is reinvestigated and a ribbon superlattice is identified for the first time in P3‐type materials. The ribbon superstructure is maintained over cycling with very minor unit cell volume changes in the bulk while Li ions migrate reversibly between the transition metal and Na layers at the atomic scale. In addition, a range of spectroscopic techniques reveal that a strongly hybridized Mn 3d–O 2p favors ligand‐to‐metal charge transfer, also described as a reductive coupling mechanism, to stabilize reversible oxygen redox. By preparing materials under three different synthetic conditions, the degree of ordering between Li and Mn is varied. The sample with the maximum cation ordering delivers the largest capacity regardless of the voltage windows applied. These findings highlight the importance of cationic ordering in the transition metal layers, which can be tuned by synthetic control to enhance anionic redox and hence energy density in rechargeable batteries.
- Published
- 2022
39. 'Better Together': achieving a global professional network for childhood disability
- Author
-
Robert Armstrong, Diane Damiano, and Hans Forssberg
- Subjects
Developmental Neuroscience ,Developed Countries ,Interprofessional Relations ,Pediatrics, Perinatology and Child Health ,Humans ,Neurology (clinical) ,Congresses as Topic ,Child ,Disabled Children ,Societies, Medical - Published
- 2021
40. Data Warehousing: Dealing with the Growing Pains.
- Author
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Robert Armstrong
- Published
- 1997
- Full Text
- View/download PDF
41. Commodity Clusters: Performance Comparison Between PC's and Workstations.
- Author
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Russell Carter, John Laroco, and Robert Armstrong
- Published
- 1996
- Full Text
- View/download PDF
42. Rapid Microwave-Assisted Synthesis and Electrode Optimization of Organic Anode Materials in Sodium-Ion Batteries
- Author
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Anthony Robert Armstrong, Daniel N. Rainer, Atin Pramanik, Joel M. Cabañero, Russell E. Morris, Aamod V. Desai, EPSRC, The Faraday Institution, University of St Andrews. School of Chemistry, and University of St Andrews. EaSTCHEM
- Subjects
Materials science ,Sodium carboxylate ,General Chemistry ,3rd-DAS ,QD Chemistry ,Engineering physics ,Microwave assisted ,Rapid synthesis ,Engineering and Physical Sciences ,Anode ,Research council ,Electrode ,Organic anode ,General Materials Science ,QD ,Sodium-ion batteries ,Microwave - Abstract
This work was supported by the Faraday Institution (Grant number—FIRG018). The authors also acknowledge the Engineering and Physical Sciences Research Council (EPSRC) Light Element Facility Grant (EP/T019298/1) and the EPSRC Strategic Equipment Resource Grant (EP/R023751/1). D.N.R. acknowledges the EPSRC (grant: EP/N509759/1) for funding. Sodium-ion batteries are commanding increasing attention owing to their promising electrochemical performance and sustainability. Organic electrode materials (OEMs) complement such technologies as they can be sourced from biomass and recycling them is environmentally friendly. Organic anodes based on sodium carboxylates have exhibited immense potential, except the limitation of current synthesis methods concerning upscaling and energy costs. In this work, a rapid and energy efficient microwave-assisted synthesis for organic anodes is presented using sodium naphthalene-2,6-dicarboxylate as a model compound. Optimizing the synthesis and electrode composition enables the compound to deliver a reversible initial capacity of ≈250 mAh g–1 at a current density of 25 mA g–1 with a high initial Coulombic efficiency (≈78%). The capacity is stable over 400 cycles and the compound also exhibits good rate performance. The successful demonstration of this rapid synthesis may facilitate the transition to preparing organic battery materials by scalable, efficient methods. Publisher PDF
- Published
- 2021
43. Child disability and family-centred care in East Africa: Perspectives from a workshop with stakeholders and health practitioners
- Author
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Pauline Samia, Susan Wamithi, Amina Kassam, Melissa Tirkha, Edward Kija, Ayalew Moges, Arnab Seal, Peter Rosenbaum, and Robert Armstrong
- Subjects
cerebral palsy ,quality of life ,Rehabilitation ,Africa ,Physical Therapy, Sports Therapy and Rehabilitation ,rehabilitation ,family-centred - Abstract
Background: Our understanding of child disability has undergone major changes over the last three decades transforming our approach to assessment and management. Globally there are significant gaps in the application of these 21st century models of care. There is recognition that economic, cultural, and social factors influence transitions in care and there is need to consider contextual factors.Objectives: A two-day workshop brought together key stakeholders to discuss current models of care and their application in the East African context. This article summarises workshop proceedings and identifies a broadly supported set of recommendations that serve to set a direction for health professionals, families, family-based disability organisations, communities and government.Method: Presentations followed by facilitated round-table sessions explored specific themes with participants reporting their responses communally. Future actions were agreed upon by relevant stakeholders.Results: Many barriers exist to care for children with disabilities in East Africa, including stigma and a lack of human and infrastructural resources. In addition, significant disparities exist with regard to access to medication and specialist care. The International Classification of Functioning framework needs to be translated to clinical practice within East Africa, with due recognition of the importance of family-centred care and emphasis on the life course theory for disability care. Family-centred care, educational initiatives, advocacy on the part of stakeholders and involvement of government policymakers are important avenues to improve outcomes.Conclusion: Further education and data are needed to inform family-centred care and multidisciplinary team implementation across East African care contexts for children with disabilities.
- Published
- 2021
44. Effect of Cu substitution on anion redox behaviour in P3-type sodium manganese oxides
- Author
-
Stephanie F Linnell, Alexis G Manche, Yingling Liao, Moritz Hirsbrunner, Saki Imada, Aaron B Naden, John T S Irvine, Laurent C Duda, A Robert Armstrong, EPSRC, University of St Andrews. School of Chemistry, University of St Andrews. Institute of Behavioural and Neural Sciences, University of St Andrews. Centre for Energy Ethics, University of St Andrews. Centre for Designer Quantum Materials, and University of St Andrews. EaSTCHEM
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MCC ,General Energy ,Layered oxides ,Cathode materials ,Anion redox ,Materials Science (miscellaneous) ,NDAS ,Materials Chemistry ,Materialkemi ,QD ,QD Chemistry ,Sodium-ion batteries - Abstract
Funding information: This work was supported by the Faraday Institution (Grant No. FIRG018). The authors gratefully acknowledge support from the Engineering and Physical Sciences Research Council (EPSRC), Grant Nos. EP/L017008/1, EP/R023751/1 and EP/T019298/1. Sodium layered oxides which display oxygen anion redox behaviour are considered promising positive electrodes for sodium-ion batteries because they offer increased specific capacities. However, they suffer from irreversible structural changes resulting in significant capacity loss and limited oxygen redox reversibility. Here the effect of Cu substitution on the electrochemical performance of P3-type sodium manganese oxide is examined by evaluating the structural and electronic structural evolution upon cycling, supported by density functional theory (DFT) calculations. Over the voltage range 1.8–3.8 V vs. Na/Na+, where the redox reactions of the transition metal ions contribute entirely towards the charge compensation mechanism, stable cycling performance is maintained, showing a capacity retention of 90% of the initial discharge capacity of 166 mA h g−1 after 40 cycles at 10 mA g−1. Over an extended voltage range of 1.8–4.3 V vs. Na/Na+, oxygen anion redox is invoked, with a voltage hysteresis of 110 mV and a greater initial discharge capacity of 195 mA h g−1 at 10 mA g−1 is reached. Ex-situ powder x-ray diffraction patterns reveal distortion of the P3 structure to P'3 after charge to 4.3 V, and then transformation to O'3 upon discharge to 1.8 V, which contributes towards the capacity fade observed between the voltage range 1.8–4.3 V. DFT with projected density of states calculations reveal a strong covalency between the copper and oxygen atoms which facilitate both the cationic and anionic redox reactions in P3-type Na0.67Mn0.9Cu0.1O2. Publisher PDF
- Published
- 2022
45. The E-Myth Attorney: Why Most Legal Practices Don't Work and What to Do About It
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Michael E. Gerber, Robert Armstrong, Sanford Fisch and Michael E. Gerber, Robert Armstrong, Sanford Fisch
- Published
- 2010
46. Seven Steps to Optimizing Data Warehouse Performance.
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Robert Armstrong
- Published
- 2001
- Full Text
- View/download PDF
47. The LSST DESC DC2 Simulated Sky Survey
- Author
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Kevin Reil, Adrian Pope, Kyle Chard, Mustapha Ishak, D. Boutigny, Humna Awan, H. Kelly, Laurent Le Guillou, W. Michael Wood-Vasey, Eli S. Rykoff, Stéphane Plaszczynski, Rahul Biswas, Richard Dubois, Saurabh Jha, Danila Korytov, C. W. Walter, J. Anthony Tyson, Katrin Heitmann, T. Glanzman, Fabio Hernandez, François Lanusse, F. Javier Sánchez, Joe Zuntz, Željko Ivezić, Marc Moniez, Yadu Babuji, HyeYun Park, Christopher W. Stubbs, Franz E. Bauer, Phillipe Gris, Chuck Claver, Paul O'Connor, J. Meyers, Christopher B. Morrison, George Beckett, Joseph Hollowed, Seth Digel, Andrew Rasmussen, Céline Combet, Phil Marshall, Éric Aubourg, Rachel Mandelbaum, J. Perry, Mike Jarvis, Thomas D. Uram, K. Simon Krughoff, Johann Cohen-Tanugi, Scott F. Daniel, Yao-Yuan Mao, Matthew P. Wiesner, James Chiang, Bela Abolfathi, Daniel Scolnic, Craig S. Lage, Ji Won Park, Steven M. Kahn, Eric Gawiser, Antonio Villarreal, A. Roodman, E. Gangler, Nan Li, Rachel Bean, David Alonso, Emily Phillips Longley, Andrei Nomerotski, Andrew P. Hearin, Salman Habib, Daniel Perrefort, Andrew J. Connolly, J. Peloton, J. Bryce Kalmbach, Eve Kovacs, Patricia Larsen, Alex Drlica-Wagner, Renée Hložek, Robert Armstrong, J.R. Bogart, Samuel Schmidt, Robert H. Lupton, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Particules de Montpellier (LUPM), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de Clermont (LPC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Centre de Calcul de l'IN2P3 (CC-IN2P3), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), LSST Dark Energy Science, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
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Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Data products ,media_common.quotation_subject ,FOS: Physical sciences ,Image processing software ,Sky surveys ,01 natural sciences ,Field (computer science) ,Observatory ,0103 physical sciences ,N-body simulations ,[PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det] ,Deep drilling ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,010303 astronomy & astrophysics ,media_common ,Remote sensing ,Physics ,010308 nuclear & particles physics ,Testbed ,Astronomy and Astrophysics ,Cosmology ,Space and Planetary Science ,Sky ,Simulated data ,Astrophysics - Instrumentation and Methods for Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We describe the simulated sky survey underlying the second data challenge (DC2) carried out in preparation for analysis of the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) by the LSST Dark Energy Science Collaboration (LSST DESC). Significant connections across multiple science domains will be a hallmark of LSST; the DC2 program represents a unique modeling effort that stresses this interconnectivity in a way that has not been attempted before. This effort encompasses a full end-to-end approach: starting from a large N-body simulation, through setting up LSST-like observations including realistic cadences, through image simulations, and finally processing with Rubin's LSST Science Pipelines. This last step ensures that we generate data products resembling those to be delivered by the Rubin Observatory as closely as is currently possible. The simulated DC2 sky survey covers six optical bands in a wide-fast-deep (WFD) area of approximately 300 deg^2 as well as a deep drilling field (DDF) of approximately 1 deg^2. We simulate 5 years of the planned 10-year survey. The DC2 sky survey has multiple purposes. First, the LSST DESC working groups can use the dataset to develop a range of DESC analysis pipelines to prepare for the advent of actual data. Second, it serves as a realistic testbed for the image processing software under development for LSST by the Rubin Observatory. In particular, simulated data provide a controlled way to investigate certain image-level systematic effects. Finally, the DC2 sky survey enables the exploration of new scientific ideas in both static and time-domain cosmology., 39 pages, 19 figures, version accepted for publication in ApJS
- Published
- 2021
48. Some Remarks on Keats and His Friends
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Robert, Armstrong-Jones
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Articles - Published
- 2021
49. Sodium Naphthalene‐2,6‐dicarboxylate: An Anode for Sodium Batteries
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A. Robert Armstrong, Kieran C. Cannon, Vanessa Pimenta, Russell E. Morris, Joel M. Cabañero, EPSRC, The Leverhulme Trust, University of St Andrews. School of Chemistry, and University of St Andrews. EaSTCHEM
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Organic redox ,Materials science ,General Chemical Engineering ,Sodium ,NDAS ,Carbon Additive ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Electrochemical cell ,Batteries ,chemistry.chemical_compound ,Environmental Chemistry ,QD ,General Materials Science ,Thermal stability ,SDG 7 - Affordable and Clean Energy ,Anodes ,Na ions ,Naphthalene ,QD Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Anode ,General Energy ,chemistry ,Electrode ,0210 nano-technology ,Metal-organic frameworks (MOFs) ,Monoclinic crystal system ,Nuclear chemistry - Abstract
We thank the EPSRC (EP/K025112/1) and the Leverhulme Trust (RPG-2016-323) for funding and Diamond Light Source for rapid access to synchrotron radiation facilities. The conjugated dicarboxylate, sodium naphthalene-2,6-dicarboxylate (Na2NDC), has been prepared by a low energy consumption reflux method and its performance as a negative electrode for sodium-ion batteries evaluated in electrochemical cells. The structure of Na2NDC was solved for the first time (monoclinic P21/c) from powder X-ray diffraction data and consists of π-stacked naphthalene units separated by sodium-oxygen layers. Through an appropriate choice of binder and conducting carbon additive Na2NDC exhibits a reversible two electron sodium insertion at around 0.4 V vs. Na+/Na with remarkably stable capacities of ca. 200 mA h g-1 at a rate of C/2 and good rate capability (~133 mA h g-1 at 5C). In parallel the high thermal stability of the material is demonstrated by HT-X-ray diffraction, the framework remaining intact to above 500 °C. Postprint
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- 2019
50. An oxalate cathode for lithium ion batteries with combined cationic and polyanionic redox
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Hui-Ming Cheng, Philip Lightfoot, Suchinda Sattayaporn, Chenghua Sun, Xiaolong Zhou, Wenjiao Yao, Moulay Tahar Sougrati, Chunlei Jiang, Yongbing Tang, Nanzhong Wu, A. Robert Armstrong, Bifa Ji, Sarayut Tunmee, Pinit Kidkhunthod, University of St Andrews. School of Chemistry, University of St Andrews. EaSTCHEM, School of Chemistry [University of St Andrews], University of St Andrews [Scotland], Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Shenyang National Laboratory for Materials Science, Institute of Metal Research [Chinese Academy of Sciences] (IMR), and Chinese Academy of Sciences [Beijing] (CAS)-Chinese Academy of Sciences [Beijing] (CAS)
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0301 basic medicine ,Science ,Inorganic chemistry ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,7. Clean energy ,Redox ,General Biochemistry, Genetics and Molecular Biology ,Oxalate ,Article ,law.invention ,Ion ,03 medical and health sciences ,chemistry.chemical_compound ,Batteries ,law ,QD ,SDG 7 - Affordable and Clean Energy ,lcsh:Science ,R2C ,Electrode material ,Multidisciplinary ,Chemistry ,Gas evolution reaction ,Cationic polymerization ,DAS ,General Chemistry ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,QD Chemistry ,Cathode ,030104 developmental biology ,Lithium ,lcsh:Q ,0210 nano-technology ,BDC - Abstract
The growing demand for advanced lithium-ion batteries calls for the continued development of high-performance positive electrode materials. Polyoxyanion compounds are receiving considerable interest as alternative cathodes to conventional oxides due to their advantages in cost, safety and environmental friendliness. However, polyanionic cathodes reported so far rely heavily upon transition-metal redox reactions for lithium transfer. Here we show a polyanionic insertion material, Li2Fe(C2O4)2, in which in addition to iron redox activity, the oxalate group itself also shows redox behavior enabling reversible charge/discharge and high capacity without gas evolution. The current study gives oxalate a role as a family of cathode materials and suggests a direction for the identification and design of electrode materials with polyanionic frameworks., Polyoxyanion compounds are alternative cathodes to conventional oxides, but their reliance on the transition metal redox limits the performance. Here the authors report an oxalate system which possesses additional polyanionic redox reactivity, suggesting a new direction for cathode materials design.
- Published
- 2019
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