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Статті в журналах з теми "Stoppers exchange":
1
Starygina, Natalya. "EXTRALINGUISTIC STOPPERS AS THE BASIS OF CROSS-CULTURAL SPACE WITHIN A LANGUAGE FOR SPECIFIC PURPOSES." Bulletin of Chelyabinsk State University 475, no. 5 (August 17, 2023): 121–30. http://dx.doi.org/10.47475/1994-2796-2023-475-5-121-130.
Анотація:
This article discusses the features of linguistic and cultural accents within the language for special purposes of the forest cluster. The most functional and productive markers in this sense are linguistic and extralinguistic stoppers involved in the special spaсе of the profile text. Stoppers participate in the process of information exchange based on ethnic realities, strengthen communication in the field of forestry, nature management, logging and woodworking with precedent fragments of a specific geolocative linguistic and cultural environment.
2
Rowan, Stuart J., Stuart J. Cantrill, J. Fraser Stoddart, Andrew J. P. White, and David J. Williams. "Toward Daisy Chain Polymers: “Wittig Exchange” of Stoppers in [2]Rotaxane Monomers." Organic Letters 2, no. 6 (March 2000): 759–62. http://dx.doi.org/10.1021/ol9913587.
3
Frumence, Etienne, Sandrine Genetet, Pierre Ripoche, Achille Iolascon, Immacolata Andolfo, Caroline Le Van Kim, Yves Colin, Isabelle Mouro-Chanteloup, and Claude Lopez. "Rapid Cl−/HCO3−exchange kinetics of AE1 in HEK293 cells and hereditary stomatocytosis red blood cells." American Journal of Physiology-Cell Physiology 305, no. 6 (September 15, 2013): C654—C662. http://dx.doi.org/10.1152/ajpcell.00142.2013.
Анотація:
Anion exchanger 1 (AE1) or band 3 is a membrane protein responsible for the rapid exchange of chloride for bicarbonate across the red blood cell membrane. Nine mutations leading to single amino-acid substitutions in the transmembrane domain of AE1 are associated with dominant hereditary stomatocytosis, monovalent cation leaks, and reduced anion exchange activity. We set up a stopped-flow spectrofluorometry assay coupled with flow cytometry to investigate the anion transport and membrane expression characteristics of wild-type recombinant AE1 in HEK293 cells, using an inducible expression system. Likewise, study of three stomatocytosis-associated mutations (R730C, E758K, and G796R), allowed the validation of our method. Measurement of the rapid and specific chloride/bicarbonate exchange by surface expressed AE1 showed that E758K mutant was fully active compared with wild-type (WT) AE1, whereas R730C and G796R mutants were inactive, reinforcing previously reported data on other experimental models. Stopped-flow analysis of AE1 transport activity in red blood cell ghost preparations revealed a 50% reduction of G796R compared with WT AE1 corresponding to a loss of function of the G796R mutated protein, in accordance with the heterozygous status of the AE1 variant patients. In conclusion, stopped-flow led to measurement of rapid transport kinetics using the natural substrate for AE1 and, conjugated with flow cytometry, allowed a reliable correlation of chloride/bicarbonate exchange to surface expression of AE1, both in recombinant cells and ghosts and therefore a fine comparison of function between different stomatocytosis samples. This technical approach thus provides significant improvements in anion exchange analysis in red blood cells.
4
Caruana, Ralph J., Kenneth L. Smith, Charlene P. Hess, John Charles Perez, and Patricia L. Cheek. "Dialysate Dumping: A Novel Cause of Inadequate Dialysis in Continuous Ambulatory Peritoneal Dialysis (CAPD) Patients." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 9, no. 4 (October 1989): 319–20. http://dx.doi.org/10.1177/089686088900900418.
Анотація:
Inadequate control of serum chemistries and extracellular fluid volume may result in patients being changed from continuous ambulatory peritoneal dialysis (CAPD) to another form of dialysis. We report 2 patients in whom apparent inadequacy of CAPD resulted from dialysate dumping. The first patient could not control her fluid intake and required frequent hypertonic exchanges. She felt too full with these exchanges and drained a substantial portion of each exchange 30 to 60 min after infusion. Patient 2 had similar complaints but simply drained a large portion of each fresh bag directly into the drain bag at the start of the fiush-before-fill step. Both patients had improved results from CAPD once they stopped their dialysate dumping. Partial wasting of each exchange because of abdominal discomfort should be added to the causes of inadequate dialysis in CAPD.
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Bárány, Michael, and Pieter P. de Tombe. "Rapid exchange of actin-bound nucleotide in perfused rat heart." American Journal of Physiology-Heart and Circulatory Physiology 286, no. 4 (April 2004): H1394—H1401. http://dx.doi.org/10.1152/ajpheart.00866.2003.
Анотація:
In the rat heart the actin-bound nucleotide contained both ATP and ADP. The ratio of bound ATP to bound ADP depended on the functional state of the heart; it was higher in hearts stopped reversibly in diastole (low Ca2+, high Mg2+, or high K+), than in stimulated (inotropic agents or pacing) hearts. Immunoblotting and gel electrophoresis showed the existence of G-actin (30% of total actin) in the cytoplasm of the heart. Pure actin was isolated from rat hearts: in G-actin the bound nucleotide readily exchanged with ATP or ADP, and in F-actin the bound nucleotide did not exchange with ATP or ADP. The free and bound nucleotides were separated in the intact heart by extraction with 75% methanol at –15°C. In rat hearts perfused with 32P-labeled orthophosphate the actin-bound nucleotide rapidly exchanged with the cytoplasmic ATP. The full exchange of the bound ATP was immediate, whereas the full exchange of the bound ADP was slower. The full exchange of the bound ATP was independent of the heartbeat frequency, whereas the full exchange of the bound ADP was frequency dependent. The data suggest that the transformation of actin monomer-ATP to actin polymer-ADP is a part of the normal contraction-relaxation cycle of the rat heart.
6
Gray, William Glenn. "“Number One in Europe”: The Startling Emergence of the Deutsche Mark, 1968–1969." Central European History 39, no. 1 (March 2006): 56–78. http://dx.doi.org/10.1017/s0008938906000033.
Анотація:
The dollars—and pounds, and francs—came pouring in. Speculators and small savers across Western Europe raced to exchange their currencies for the Deutsche Mark. “Hot money” flowed into Germany at astounding rates. The reserves of West Germany's central bank, the Bundesbank, shot up by DM 9.4 billion ($2.15 billion) in the first three weeks of November 1968—with DM 7.3 billion arriving in just three days of trading. Airports in Germany barred exchanges of more than one hundred francs at a time; train stations in Zurich stopped accepting French notes altogether.
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Nair, R., H. S. Plendl, E. P. Gavathas, L. C. Liu, R. J. Estep, B. J. Dropesky, J. D. Bowman, et al. "Pion-nucleus single charge exchange induced by stopped negative pions." Physical Review C 53, no. 2 (February 1, 1996): 811–14. http://dx.doi.org/10.1103/physrevc.53.811.
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Amin, Mona Ahmed, Mohamed Mommtaz, Nashwa Al-Saraf, Ahmed Fathy, Dina Farouk, Ahmed Nageeb, Rana Sherif, and Mina Adel Ragheb. "Case of hypertriglyceridemia-induced subacute pancreatitis and hypertriglyceridemia-triggered transverse sinus thrombosis in a recently diagnosed diabetic patient and the efficacy of management of hypertriglyceridemia with continuous insulin infusion." International Journal of Noncommunicable Diseases 9, no. 1 (2024): 42–45. http://dx.doi.org/10.4103/jncd.jncd_57_23.
Анотація:
ABSTRACT A 28-year-old single female diagnosed with transverse sinus thrombosis; she was also discovered to be diabetic with severe hyperlipidemia. She presented by recurrent episodes of diffuse dull aching abdominal pain referred to the back; she was diagnosed with acute pancreatitis with markedly elevated triglyceride (TG) levels. She started medical treatment for hypertriglyceridemia with no improvement. She started four sessions of plasma exchanges with marked improvement of the general condition, abdominal pain and appetite, and TGs declined.While the patient was on plasma exchange she developed catheter related infection so it is stopped and soon triglycerides raised again with recurrence of the abdominal pain and we started insulin infusion with improvement of her condition
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Nierengarten, Iwona, Eric Meichsner, Michel Holler, Pauline Pieper, Robert Deschenaux, Béatrice Delavaux-Nicot, and Jean-François Nierengarten. "Preparation of Pillar[5]arene-Based [2]Rotaxanes by a Stopper-Exchange Strategy." Chemistry - A European Journal 24, no. 1 (November 23, 2017): 169–77. http://dx.doi.org/10.1002/chem.201703997.
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Hilczer, Maria, A. V. Barzykin, and M. Tachiya. "Theory of the Stopped-Flow Method for Studying Micelle Exchange Kinetics." Langmuir 17, no. 14 (July 2001): 4196–201. http://dx.doi.org/10.1021/la001285w.
Дисертації з теми "Stoppers exchange":
1
Becharguia, Nihed. "Préparation de rotaxanes incorporant une sous-unité pillar[5]arène." Electronic Thesis or Diss., Strasbourg, 2023. http://www.theses.fr/2023STRAF058.
Анотація:
Les rotaxanes constituent un domaine de recherche particulièrement actif en chimie. Dans cette thèse, nous décrivons le potentiel de la stratégie de synthèse développée dans notre groupe pour la synthèse de rotaxanes par des réactions d’échange de bouchons. Nous avons ainsi montré qu’un [2]rotaxane possédant deux bouchons activés peut être mono-fonctionnalisé avec des rendements quasi-quantitatifs. Les dérivés de [2]rotaxanes mono-fonctionnalisés peuvent alors être utilisés pour conduire soit à des [2]rotaxanes, soit à des [3]rotaxanes, suivant la nature de la diamine utilisée. Ces méthodes de synthèse ont alors été utilisées pour la préparation de machines moléculaires. Nous avons montré que la position de macrocycle peut être contrôlée par un stimulus acide-baseRotaxanes are a particularly active field of research in chemistry. In this thesis we describe the potential of the synthesis strategy developed in our group for the synthesis of new rotaxanes by the stopper exchange method. We have shown that a [2]rotaxane with two activated stoppers can be mono-functionalized in almost quantitative yields. To further explore the potential of mono-functionalized [2]rotaxane derivatives, we then used to give either [2]rotaxanes or [3]rotaxanes, depending on the nature of the diamine used. These synthetic methods were then used to prepare molecular machines. We have shown that the position of the macrocycle can be controlled by an acid-base stimulus
2
Skinner, J. G. "Optimisation of xenon-rich stopped-flow spin-exchange optical pumping for functional lung imaging." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/41416/.
Анотація:
Spin-exchange optical pumping (SEOP) is a hyperpolarisation method used in the hyperpolarisation of noble gases and can enhance nuclear spin polarisation by five orders of magnitude. Hyperpolarised (HP) 129-Xe has many properties that make it ideally suited to clinical lung imaging, but since its first demonstration in animals in 1994 and humans in 1996, translation to the clinic has been hampered by challenges associated with scaling up production. Within this thesis, construction and demonstration of a clinical-scale stopped-flow hyperpolariser is described, the design of which is based on the record holding XeUS and XeNA polarisers developed previously by our consortium, which had aimed to address the issue of production scale-up. Modifications enhancing the ease of operation and utility in-clinic are presented, as are modifications that reduce the capital cost of such a system. These include a re-design of the gas manifold and the development of a low-cost low-field NMR spectrometer which achieved an SNR of 125 at a cost of ~$300, a 13-fold improvement in cost/SNR compared with the existing spectrometer at a saving of ~$19,000. In continuous-flow 129-Xe polarisers there has long been a discrepancy in the polarisation achieved and that predicted by the standard model of SEOP which was shown recently to be due to the presence of rubidium clusters. Here, the standard model is applied to- and validated for the first time against the stopped-flow regime. The validated model is used to explore parameter space to identify the most effective ways to increase production yield in future stopped-flow polarisers. Stopped-flow SEOP in the xenon-rich regime presents unique thermal management problems due to the absence of gas flow and abundance of poorly thermally conductive, Rb spin destroying Xe. Raman spectroscopy is used to spatially examine in-cell thermal behaviour under steady-state and turbulent 'rubidium runaway' conditions as a function of temperature and Xe density and the beneficial impact of adding thermally conductive helium to the standard N2-Xe gas mix is demonstrated. Hybrid Rb-Cs-Xe SEOP is demonstrated for the first time and examined using in-situ NMR and Raman spectroscopies. High polarisations of ~50% were obtained. Finally, progress on the HP-Xe clinical trial is presented to illustrate the impact of the 4-fold increase in SNR that will come with the installation of the new N-XeUS stopped-flow polariser.
3
Ranta, Kaili. "Clinical-Scale Hyperpolarization of 129Xe and 131Xe via Stopped-Flow Spin Exchange Optical Pumping." OpenSIUC, 2016. https://opensiuc.lib.siu.edu/dissertations/1282.
Анотація:
The fundamental physics of spin-exchange optical pumping (SEOP) has been explained in detail by many brilliant scientists since its discovery in the 50’s and 60’s. Although some interactions remain only tenuously understood, mathematical relationships have been mapped across many trajectories with meticulous care. Despite these foundational descriptions, many of the larger scale dynamics remain capricious in practice, especially as SEOP strives to take advantage of rapidly developing laser technologies. This presents a difficulty for implementing the large-scale production of hyperpolarized gases that is required for clinical and some specific experimental applications. This research, performed over the past four years, was designed to shed light on some of the practical effects that become critical for scaling up production while keeping polarizations high, particularly in a “stopped-flow” polarizer environment. This dissertation is divided into eight main chapters. The first chapter is written to provide a historical context for the SEOP field and summarize the evolutionary stages that have led to current methodologies. The second chapter provides a brief summary of SEOP theory and mathematically outlines the transfer of quantum order from photon polarization, to electron polarization via optical pumping, and finally to long-lived nuclear polarizations via spin-exchange. Chapter 3 discusses the practical implementation of SEOP, and the specific designs and techniques used throughout this project to create and monitor polarization. Chapter 4 presents data with some unexpected trends collected by Dr. Nicholas Whiting and Dr. Peter Nikolaou using high densities of xenon and high resonant laser powers. This data inspired a set of simulations designed to locate the cause of these trends, and map the expected trajectory for further studies. Chapter 5 features a clinical-scale polarizer with 170 W of highly resonant cw laser power, capable of producing >0.8 L of hyperpolarized gas per SEOP cycle with 129Xe polarization values of ~30-90% (depending on the xenon density). Multidimensional data maps were created over various temperatures, gas mixes, and laser powers; the results are used to guide optimal performance and describe the conditions that cause SEOP to fail. Chapter 6 reintroduces helium into stopped-flow gas mixes to help mitigate the central difficulties found in Chapter 5 with thermal regulation, and discusses the improvements and difficulties observed as a result. Chapter 7 contrasts the tactics for high 129Xe polarization with the strategies that lead to high 131Xe polarization. Specifically this study is designed to assess whether 131Xe is capable of becoming polarized via SEOP to sufficient levels—and in sufficient amounts—to be used for some specific fundamental physics studies and other biomedical applications. Finally Chapter 8 presents a short proof of concept for the use of an aluminum optical pumping cell instead of the glass optical pumping cells predominantly used for SEOP.
4
Molway, Michael Jhon. "EXPERIMENTAL ADVANCES IN CLINICAL-SCALE PRODUCTION OF HYPERPOLARIZED 129XE AND 131XE VIA STOPPED-FLOW SPIN-EXCHANGE OPTICAL PUMPING." OpenSIUC, 2018. https://opensiuc.lib.siu.edu/theses/2360.
Анотація:
Spin-exchange optical pumping (SEOP) produces hyperpolarized noble gases (e.g. 129Xe and 131Xe) that have been used to improve spatial resolution and speed of biological magnetic resonance imaging, enhance NMR signals of molecules and materials, and utilized in fundamental physics experiments. In SEOP, circularly polarized laser light optically pumps an alkali metal vapor (e.g. Cs or Rb) into an electronically spin-polarized ground state. This electronic spin polarization can then be transferred to the nucleus of a noble gas during gas phase collisions. Over time, a bulk nuclear spin polarization begins to accumulate, resulting in hyperpolarized (HP) gases. The research presented in this thesis is concerned with the optimization of experimental aspects in clinical-scale HP 129Xe and high-density HP 131Xe production by stopped-flow SEOP—specifically with respect to alkali metal choice, laser technology, SEOP cell design and experimental conditions. This thesis is divided into five main chapters. The first chapter is written to provide an introduction into the field of NMR, giving both historical context and relevant NMR phenomenon to help understand nuclear spin hyperpolarization. The second chapter gives a brief introduction into SEOP and how the evolution of laser technology has given rise to current methodologies. Secondly, this chapter includes a brief summary of SEOP theory as well as mathematically outlines the process of how electron spin polarization via optical pumping leads to long-lived nuclear spin polarizations via spin-exchange. Furthermore, this chapter provides a description of the stopped-flow (i.e. batch-mode) SEOP setup and how in situ measurements of HP noble gases are made. Chapters 3 and 4 are concerned with hyperpolarization of 129Xe and 131Xe, respectively. In both of these chapters, the physical and chemical properties of the respective isotope of xenon are given followed by how to calculate their bulk nuclear spin polarizations using in situ measurements. Exploration to the changes in experimental conditions (i.e. alkali metal choice, temperature, laser technology, etc.) allowed for a comparison of the resulting spin dynamics and polarizations to be made in both chapters. In addition, Chapter 3 includes a brief description of the continuing efforts to implement an aluminum optical pumping cell for use in SEOP. Finally, Chapter 5 will cover preliminary work towards transferring the polarization from HP 129Xe to that of a target molecule. While other groups have shown that this ‘xenon induced polarization’ is possible, we have yet to replicate this phenomenon; However, Chapter 5 will show our work towards ex situ measurements of HP 129Xe and how this will act as a stepping stone towards transferring the polarization to a target molecule.
Частини книг з теми "Stoppers exchange":
1
Desmond, Adrian. "6. Founding the Museum." In Reign of the Beast, 175–200. Cambridge, UK: Open Book Publishers, 2024. http://dx.doi.org/10.11647/obp.0393.06.
Анотація:
In 1831 Saull moved his business to larger premises at 15 Aldersgate Street. That April he bought James Sowerby’s fossils, added them to his own, and in June declared his wine-depot museum open. In these months, Reform Bill fever was running high. Henry Hetherington started his class-conscious Poor Man’s Guardian, and the museum fossils, arranged stratigraphically, were to show Hetherington’s dispossessed “scum” how life’s perfecting principle promised a brighter future. Accordingly, where Sowerby’s museum had had a hefty entrance fee, Saull’s was free; nor were letters of introduction needed. He invited radical artisans (men and women), Rotunda dissidents and Trades’ Union activists. Thus the museum, in its clientele and accessibility, broke all precedents, while in its rationalist explanation of life, to ready the “productive classes” for power, it was unique. Meanwhile Saull’s political lobbying, at the Guildhall and in the National Political Union, continued in support of the Reform Bill. To coincide with the museum opening, Saull, still on bail and under threat of prosecution for blasphemy, stopped publicly attacking Christianity, but continued it under the rubric of his newly-started geology lectures. He now moved completely into Robert Owen’s camp. Saull helped establish Owen’s Labour Exchange, and sat on the council of Owen’s “Institution of the Industrious Classes”, where he delivered geology courses.
2
Moir, Nathaniel L. "After the Shooting Stopped." In Reporting World War II, 234–58. Fordham University Press, 2023. http://dx.doi.org/10.5422/fordham/9781531503093.003.0012.
Анотація:
The Nuremberg Trials marked a watershed moment in the history and development of international law. Journalists reporting on the trials recorded substantial evidence and recounted complex proceedings, such as the testimony of the Third Reich’s top leaders and their exchanges with prosecutor Robert H. Jackson. In addition, journalists at the trials also played a significant role in documenting the Holocaust and Nazi war crimes that led to much of Europe’s destruction. This chapter assesses how reporters covered the trials, described the proceedings’ legal origins, maintained day-to-day operations covering the unprecedented event, and how they struggled to keep readers interested as Europe began to rebuild and as a new post-war order emerged.
3
"Stop and Frisk." In Advances in Religious and Cultural Studies, 140–51. IGI Global, 2023. http://dx.doi.org/10.4018/978-1-6684-8541-5.ch008.
Анотація:
This chapter focuses on the topic of stop-and-frisk. Stop-and-frisk describes an encounter where one (i.e., a civilian) is stopped and frisked without giving consent for the exchange with an officer. Stops-and-frisks are related to the Fourth Amendment and the 14th Amendment, respectively. With that being said, civilians and/or citizens who are stopped are astronomically people of color, and there has been protest and legal contest regarding the matter. After exploring those issues, a brief discussion of solutions and recommendations will take place.
4
Adams, Olga Y. "State approaches to non-state interactions." In Shadow Exchanges along the New Silk Roads. Nieuwe Prinsengracht 89 1018 VR Amsterdam Nederland: Amsterdam University Press, 2020. http://dx.doi.org/10.5117/9789462988934_ch08.
Анотація:
The chapter focuses on cross-border relations between the Republic of Kazakhstan and Xinjiang-Uyghur Autonomous Region of China, examining the attempts of respective states to intervene in and/or co-opt long-established traditions of transborder flows. Despite having existed on opposite sides of closely guarded borders for most of the 20th century, the two adjoining regions managed to keep alive long-established traditions of cross-border interactions thanks to shared ethnic, cultural, and linguistic features. The frontier societies there today have lived through multiple challenges – the indiscriminate border policy of the Soviet era on Kazakhstan’s side and the tumultuous early years of socialist China engendered exoduses of people across semi-controlled borders. Almost all official interactions stopped until the 1990s when new challenges and opportunities presented themselves and, with them, the revival of informal cross-border exchanges and states’ attempts to co-opt and control them.
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Obermeier, Sebastian, and Stefan Böttcher. "Protecting a Distributed Voting Schema for Anonymous and Secure Voting Against Attacks of Malicious Partners." In Mobile Opportunities and Applications for E-Service Innovations, 283–301. IGI Global, 2013. http://dx.doi.org/10.4018/978-1-4666-2654-6.ch016.
Анотація:
A distributed protocol is presented for anonymous and secure voting that is failure-tolerant with respect to malicious behavior of individual participants and that does not rely on a trusted third party. The proposed voting protocol was designed to be executed on a fixed group of N known participants, each of them casting one vote that may be a vote for abstention. Several attack vectors on the protocol are presented, and the detection of malicious behavior like spying, suppressing, inventing, and modifying protocol messages or votes by the protocol is shown. If some participants stop the protocol, a fair information exchange is achieved in the sense that either all votes are guaranteed to be valid and accessible to all participants, or malicious behavior has been detected and the protocol is stopped, but the votes are not disclosed.
6
"The International Dignitary Caps a Distinguished Career." In Let America Be America Again, edited by Christopher C. De Santis, 217–302. Oxford University PressOxford, 2022. http://dx.doi.org/10.1093/oso/9780192855046.003.0006.
Анотація:
Abstract Hughes was highly regarded throughout the world in the final years of his career, and although he was the subject of critiques by some younger writers, who perceived his later work as lacking in complexity and, at times, out of step with Black nationalist political commitments and aesthetics, he was frequently sought after for his perspectives on art, race, politics, and the role and responsibilities of Black writers. In the 1960s, his fifth decade working as a professional writer, Hughes still perceived himself primarily as a propaganda writer, and he retained a belief in the power of literature to effect some change in prevailing problems of racial intolerance, bigotry, and discrimination. Hughes emphasized the importance of cross-cultural and transnational exchange among artists and writers, but he never lost sight of—or stopped speaking boldly about—the specific struggles of Black people in the United States against entrenched systems of racial oppression and the racist violence that continued even in the context of the gains achieved during the Civil Rights Movement.
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Pinto, Marcus V. R., and P. James B. Dyck. "Difficult-to-Treat Polyradiculoneuropathy." In Mayo Clinic Cases in Neuroimmunology, edited by Andrew McKeon, B. Mark Keegan, and W. Oliver Tobin, 135–37. Oxford University Press, 2021. http://dx.doi.org/10.1093/med/9780197583425.003.0043.
Анотація:
A 51-year-old healthy man sought care for a 6-month history of progressive, distal, lower extremity weakness, imbalance, and numbness in the feet. Neurologic examination showed a steppage gait, upper and lower extremity weakness, distal greater than proximal, absent tendon reflexes, and large fiber–predominant sensation loss in the feet. Nerve conduction studies showed marked temporal dispersion and slowed conductions. Cerebrospinal fluid analysis showed an increased protein concentration, 1 white blood cell/µL, and normal glucose level. Lumbar spine magnetic resonance imaging showed enlargement and enhancement of the nerve roots in the cauda equina, along with hypointensity in lumbar vertebral bodies. He underwent right sural nerve biopsy that showed an inflammatory demyelinating process. The patient was diagnosed with chronic inflammatory demyelinating polyradiculoneuropathy and started on intravenous immunoglobulin. He was markedly worse at 12-week follow-up, with severe proximal and distal weakness and requiring the use of a walker. The diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy was revisited. Lumbar spine magnetic resonance imaging again showed enhancement of the nerve roots. Because of concern for neurolymphomatosis, a proximal fascicular nerve biopsy of the right sciatic nerve was performed. It showed the hallmark pathologic features of chronic inflammatory demyelinating polyradiculoneuropathy: endoneurial inflammation and signs of long-standing demyelination and remyelination with stacks on Schwann cell processes. The diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy was confirmed. Intravenous immunoglobulin was stopped, and the patient was started on an aggressive plasma exchange regimen. He had modest improvement. Azathioprine was also started. The patient continued to improve. He remained on this regimen for 2 years. Over the next year, the intravenous methylprednisolone dose was reduced. He was weaned off plasma exchange and intravenous methylprednisolone. At the last follow-up the disease was still in remission. Chronic inflammatory demyelinating polyradiculoneuropathy was described and named in 1975. It is a fairly symmetric peripheral neuropathy that usually presents with proximal and distal weakness, imbalance, and large fiber sensory dysfunction. Cerebrospinal fluid analysis shows albuminocytologic dissociation in 80% to 95% of those with typical chronic inflammatory demyelinating polyradiculoneuropathy.
8
Clark, Peter. "Organization." In British Clubs and Societies 1580-1800, 234–73. Oxford University PressOxford, 2000. http://dx.doi.org/10.1093/oso/9780198203766.003.0007.
Анотація:
Abstract Riven by disputes, the Royal Society erupted in 1783, complaints against the president, Sir Joseph Banks, being ‘stopped by a clamour more worthy of a Covent Garden rabble than the fellows of a learned society’. A decade later An Authentic Narrative of the Dissensions and Debates in the Royal Society recorded renewed faction fighting over admissions and elections? Despite all the rhetoric of associational solidarity and the mechanisms for controlling admission and enhancing cohesion, societies often experienced internal conflict. The Royal Academy of Arts was set up in 1768 following a schism within the Incorporated Society of Artists of Great Britain, but the Academy proved equally prone to division. At the close of the century the professor of painting, James Barry, launched a noisy attack on the president, Benjamin West, and other members of the Council, making allegations of financial abuse. Nor were smaller societies immune. Exeter’s Literary Society suffered acrimonious exchanges in the 1790s, while Tiverton’s corporation club descended to family feuds and personal invective.1 2 The New England minister William Bentley remarked on the ‘many mortifications in such associations’, which led to animosities and division. On occasion, disputes might turn violent. In the 1730s we hear of an East Anglian ringing club, split over sharing the profits from ringing the peals at a wedding, where the members ‘fought till one died on the spot and another was desperately wounded’.
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Nelson, Scott Reynolds, and Carol Sheriff. "War’s Miseries The Confederate Home Front." In A People at War, 260–91. Oxford University PressNew York, NY, 2007. http://dx.doi.org/10.1093/oso/9780195146547.003.0012.
Анотація:
Abstract On a late April day in 1862, forty-year-old Leah Black was tidying up after the midday meal when the alarmed squawks and cries of the farm animals sent her to the window. If she at first suspected that her four young sons were up to mischief, the reality proved much worse: Twenty to thirty Union infantrymen, maybe more, were scattered across her southwestern Tennessee farmyard, trying to corral her livestock. With her husband away from the house, Black huddled inside with her children while some of the men outside scooped up chickens and geese, slaughtered hogs, prodded cows, and harnessed a horse to each of the family’s two wagons. Others raided the barn, flinging sacks of corn and bales of hay onto the wagons. Returning home not long after the soldiers had fled, James Black gave quick chase and soon caught up to the men, whose retreat was slowed by the burden of their plunder. We cannot know for sure what exchange took place, but Jim Black probably breathlessly pleaded his case: There never was a more loyal Union man than he, and he was willing to do his part for the boys in blue, but he had four youngsters, the oldest of whom was ten, who needed to eat but couldn’t yet do much to help out. Those horses had cost him nearly every last penny—$150 each in greenbacks—and who could afford to buy food at wartime prices anyway? The soldiers barely stopped to listen—they had heard it all before. They didn’t feel good about it, but soldiers can’t be starving either. They instructed Jim Black that if on Wednesday next he came to Bolivar, the nearby Union-garrisoned town, he could retrieve his horses then.
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Rosenstein, Donald L., and Justin M. Yopp. "The Wrong Parent Died." In The Group. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780190649562.003.0009.
Анотація:
“Absolutely. One-hundred percent,” Neill answered without hesitation. Karl repeated his question. “Do you really believe your children would be better off if you had died instead of your wife?” “It’s not even close,” Neill said. He quickly counted off all the things Deanna had done for their family, detailing her involvement in just about every aspect of their children’s lives. She was simply a much more important cog in the family wheel. “You guys helped me out with my daughter and the hockey game situation, but Deanna would have handled it on her own.” Neill concluded, “So, yes, for my children’s sake, there’s no question that the wrong parent died.” The discussion leading up to the exchange between Neill and Karl had coalesced around the familiar topic of parental competence—or, as the men often saw it, parental incompetence. Karl had shared his latest blunder, which occurred when he took his two children on a family trip to Connecticut for a wedding. As they were leaving their hotel room for the ceremony, Karl noticed for the first time how his children were dressed. “So, there’s my ten-year-old son wearing this pair of khakis that don’t come close to fitting him. The pant legs stopped about three inches above his ankles and he couldn’t even button the pants because the waistband was so tight. He looked ridiculous, but they were the only pair of pants I’d brought for him to wear.” Yet another instance of being unprepared, something Karl hated. “I’m standing there looking at my son in the hallway of this hotel and I think to myself, ‘No way this happens if Susan were still here.’ ” “I know just what you mean,” Neill said. “Deanna did so many things better than I’m doing them now. I feel like I’m screwing up pretty much all the time.” Then he said the words that caught Karl by surprise: “The wrong parent died.” Neill had never been comfortable opening up about his feelings. He joined the support group only for his children’s sake.
Тези доповідей конференцій з теми "Stoppers exchange":
1
Shelby, Jason L., and Krishna Kota. "Design of a High-Effective Wavy Channel Heat Exchanger for Cryogenic Applications." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-52833.
Анотація:
Long duration thermal control of cryogenic propellants is a high priority mission activity for NASA. A 20 K cryocooler capable of 20 W of refrigeration would offer a significant mass savings in cryogen storage by facilitating propellant zero boil-off and hence long term cryogen storage, which would provide scope for long duration missions beyond low Earth orbit (LEO). For direct current (DC) type cryocoolers, as well as open cycle liquefaction systems, effective recuperative heat exchange is a highly critical function. Coefficient of Performance (COP) of cryocoolers is greatly sensitive to heat recuperator effectiveness, more so than to the efficiencies of other key components such as compressor, turbine and cold head. A heat recuperator with high effectiveness is extremely important for achieving a high COP for cryocoolers. Current recuperators tend to be the heaviest and largest components in space cooling systems. Primary issues in miniaturization of a heat recuperator that adversely affect the performance are the longitudinal/axial heat conduction in the wall and insufficient flow length (size) to achieve complete heat transfer between the hot and cold fluids. Further, frictional pressure drops are usually large as a result of decreased size of the flow channels. In addition, it is worth noting that, in general, attempts to improve heat transfer would almost always result in increasing the pressure drop (or otherwise, attempts to decrease pressure drop usually result in lowering the heat transfer performance). This paper discusses a split wavy channel heat recuperator design to overcome the above mentioned technical show-stoppers. A split wavy channel design has the advantage of increased flow length and improved heat transfer in the same form factor as a heat exchanger with straight channels without causing a large increase in the pressure drop. So far, this concept has never been studied and exploited for a cryogenic heat recuperator. High fidelity numerical simulations were used to study the three-dimensional flow of working fluid through hot and cold wavy channels of the heat recuperator separated by a wall. A two channel scheme was modeled for the analysis. Wavy geometry consisting of two sinusoidal parallel channels was built in a pre-processor for the solver. Governing equations in mass, momentum and energy at steady-state were implicitly solved on a computational grid using a commercial finite element solver to obtain the pressure, velocity and temperature fields. The developed numerical model was employed to perform a systematic parametric study. Two working fluids (helium and nitrogen) were considered addressing both liquid oxygen and liquid hydrogen propellant boil-off temperatures. Wavy wall amplitude was varied between 125 μm, 250 μm, and 500 μm with a goal of identifying optimal configuration that will have maximum effectiveness for the size. Entrance Reynolds numbers of 300 and 600 were considered. The performance of various configurations were compared using a performance factor, and traditional recuperator effectiveness. The results showed that wavy channels, due to a unique fundamental physical phenomenon of geometry governed boundary layer thinning, help in augmenting heat transfer and in realizing a compact cryogenic heat exchanger. An interesting observation was that wavy channels which were previously found by researchers to enhance heat transfer substantially (up to 55% or more) at room temperature for liquids were found to improve heat transfer performance only by up to 10% for gases at cryogenic temperatures, which could be attributed to the drastic variation in thermo-physical properties of gases at these temperatures suggesting the consideration of a different design methodology compared to design for room temperature applications.
2
Aspect, Alain. "Laser Manipulation of Atoms." In The European Conference on Lasers and Electro-Optics. Washington, D.C.: Optica Publishing Group, 1994. http://dx.doi.org/10.1364/cleo_europe.1994.tutorial.b.
Анотація:
Momentum exchange between atoms and photons allow laser physicists to control atomic motion. It is possible to decelerate and/or focus an atomic beam, to stop it. The average velocity of the almost stopped atoms can be decreased to very small values close to or even below the one photon recoil velocity V R = ħk L /M, corresponding to temperatures in the microkelvin range or below. Laser manipulation of atoms is also essential for the recently developing field of atom optics.
3
Funabiki, Ayako, Taisei Yabuki, and Masahito Oguma. "Optimum Heating Pattern of a Ground Source Heat Reference Map." In ASME 2015 9th International Conference on Energy Sustainability collocated with the ASME 2015 Power Conference, the ASME 2015 13th International Conference on Fuel Cell Science, Engineering and Technology, and the ASME 2015 Nuclear Forum. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/es2015-49117.
Анотація:
A ground source heat reference map (GSHRM) shows the minimum necessary thermal performance of the ground heat exchanger (GHE) of a ground source heat pump (GSHP) system. Thermal performance depends on thermal properties of the ground, the ground temperature profile, heat advection by groundwater flow, and the GHE operating pattern. This study modeled optimum heating and cooling modes for a GSHRM. First, continuous and intermittent operation modes were compared, and a standard operation time was defined. In a standard household GSHP system, the quantity of heat transferred from the ground depends on household energy demand, which is relatively constant. Once the demand is known, an operation mode is selected that can meet it. Continuous operation increased the total amount of heat exchanged over a period of time but lowered the heat flux at the GHE, whereas intermittent operation with relatively long stopped periods decreased the total amount of heat but did not greatly decrease the heat flux at the GHE. Second, energy-saving efficiency and cost factors were compared among intermittent operation modes. Operation costs consist of the electrical energy supplied to the heat and circulation pumps. At a given operation time, the energy supplied to the heat pump depends on its coefficient of performance (COP), whereas that supplied to the circulation pump depends on its pressure loss, hence on the GHE length. A long GHE has a higher initial cost. Thus, the optimum heating pattern must consider the configuration of the GSHP system, including energy-saving efficiency and cost factors.
4
Bausseron, Thomas, Philippe Baucour, Raynal Glises, Sylvain Verschelde, and Didier Chamagne. "Heat Modeling of the Catenary’s Contact Wire During the Electrical Power Supply of Trains in Station." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-36745.
Анотація:
The overheating problem of the railroad catenary at the contact with the pantograph when the train is stopped and electrically fed is responsible of many incidents. This paper describes an experimental study and a numerical model of a catenary/pantograph system used during the preconditioning of the train. Several incidents of wire breakage have highlighted the importance of the catenary/pantograph heating problem, in those incidents the contact wire had melted and broke itself. The experimental setups consists of estimating the contact’s thermal resistance and area in order to calculate which part of the interface heat flux go throught the catenary’s contact wire and which part go throught the pantograph’s collector strip. The numerical model is based on several phenomena as heat conduction into the wires, heat exchange with ambiance through convection, Joule effects and heat flux from the interface.
5
Pint, Bruce A., Bruce N. Anderson, Wendy J. Matthews, Chris M. Waldhelm, and William Treece. "Evaluation of NiCrAl Foil for a Concentrated Solar Power Application." In ASME Turbo Expo 2013: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gt2013-94939.
Анотація:
A NiCrAl-type foil (alloy 214) was selected for evaluation for heat exchanger applications for a concentrated solar power (CSP) system. Due to the formation of a protective alumina surface oxide, this class of alloys can operate at higher temperatures than conventional stainless steels or even Ni-base alloys, such as alloy 625. Laboratory testing is being conducted at 1000° and 1050°C in dry air using 10 h thermal cycles in order to simulate the CSP duty cycle at a high temperature to accelerate the degradation process. Mass change data showed indications of degradation of the foils with exposures up to 8,000 h. Foil specimens also were stopped after 2,400 h to measure the loss of Al in the foil as a method to predict lifetime. Previous lifetime modeling results for 1h cycles in air with 10%H2O provided an initial basis to predict lifetime for this material to >100,000 h operating times as a function of foil thickness and exposure temperature for this application.
6
Aoshima, Atsushi, and Kazuhiko Tanaka. "Vitrification Technology Development Plan in Tokai Reprocessing Plant." In 14th International Conference on Nuclear Engineering. ASMEDC, 2006. http://dx.doi.org/10.1115/icone14-89430.
Анотація:
The Tokai Vitrification Facility (TVF) is the only operating vitrification plant in Japan, constructed and operated by JAEA, to vitrify concentrated high radioactive liquid waste (HALW) in the Tokai Reprocessing Plant (TRP). JAEA started TVF hot operation in 1995 and produced 218 canisters as of March, 2006. An existing melter is the second melter, which was installed from 2002 to 2004 in place of the first melter stopped its operation by damage of a main electrode. JAEA has estimated that the damage was caused by accumulation of noble metal. Therefore, melter bottom structure was improved to get better drain ability of glass containing noble metal. Completing the melter replacement, vitrification operation was restarted in October 2004 and produced 88 canisters successfully until the end of March 2006. Through these experiences, JAEA made basic strategy to achieve stable TVF operation: keeping stable operation of the existing melter preventing adverse effect by noble metal accumulation and developing a new advanced melter with long lifetime preparing for future exchange as the third melter. Based on the basic strategy, JAEA made a decade development plan of necessary key technologies and has started the development since 2005.
7
Jerković, Emina. "LEGAL ASPECTS OF THE INTRODUCTION OF THE EURO AS THE OFFICIAL CURRENCY IN THE REPUBLIC OF CROATIA." In The recovery of the EU and strengthening the ability to respond to new challenges – legal and economic aspects. Faculty of Law, Josip Juraj Strossmayer University of Osijek, 2022. http://dx.doi.org/10.25234/eclic/22414.
Анотація:
The 1992 Maastricht Treaty defined the conditions for the introduction of the euro as a common currency in the European Union. These are macroeconomic indicators that measure the level of nominal convergence achieved and thus the state’s readiness to participate in monetary union. These conditions (convergence criteria) relate to price stability, stability and sustainability of public finances, which includes budget deficits and public debt, exchange rate stability and convergence of long-term interest rates. In addition to nominal convergence, the degree of legal convergence is also assessed - the provisions of national legislation relating to the independence of the central bank, the ban on monetary financing and preferential access to state financing, and integration into the European System of Central Banks are assessed. Among the member states that have not yet adopted the euro, only the Republic of Croatia is fully harmonized in this regard. On July 10, 2020, the Croatian kuna was included in the European Exchange Rate Mechanism (ERM II). Accessing the ERM II mechanism is often referred to as the euro waiting room. Despite the fact that the pandemic caused by the COVID-19 virus has not abated, the Republic of Croatia has not stopped its efforts to become a full member of the euro area. The paper will present the benefits of the introduction of the euro, but also the inevitable costs incurred during the conversion process. As the pandemic has not slowed down the conversion process and the moment of conversion is approaching, on the other hand, there are conflicting views on the introduction of the euro as the official currency, which are trying to be implemented through a referendum. The paper will discuss the legal aspects of Croatia’s accession to the euro area and what measures are envisaged when exchanging the Croatian kuna for the euro, especially from the aspect of consumer protection, given the fact that Croatia has one of the highest euroization rates of all non-euro area EU member states.
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Orynyak, Igor, Maksym Zarazovskii, and Mykhaylo Borodii. "The Method for Structural Reliability Estimation of the Heat Exchanger Tubes of Steam Generator of WWER NPPs." In ASME 2016 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/pvp2016-63710.
Анотація:
After the replacement due to the well known problem of weld seam #111 the steam generators (SG) of the Ukrainian WWER-1000 type nuclear power plants (NPP) have been in operation for almost 25 years. So now, the main practical problem related to the SG is the leakage/breaking of heat exchanger tubes (HET). If the leakage criterion is not satisfied the NPP Unit has to be stopped until the corresponding HET is plugged, which leads to unexpected huge financial losses. Every year at least 12.5% of the SG HETs are controlled by eddy current inspection, after which some of the HETs are plugged according to the appropriate plugging criteria (in most cases – 65% loss of tube wall thickness). Thus, every SG has its own statistics of plugging. From the practical point of view the Utility is interested in the following questions: whether the failure of the HET happens during the normal operation mode (NOM) up to the next NPP stop or not; what is the probability of this event; what is the defect growth rate? Answers on these questions could give us the opportunity to increase the effectiveness of the HET in-service inspection and to improve the plugging criterion. A simple statistically-based method for HET integrity assessment is proposed. The method based on an exponent distribution law and HET plugging statistics of specific SG, taking into account defect growth. Based on the history of the tubes plugging (year of operation versus quantity of pluggings) the three statistical parameters inherent to this specific SG have to be found: initial number of defects, parameter of the exponential distribution (initial defect size) and the defect growth rate. The developed method was used for the prediction of HET leak/break number for all Ukrainian WWER-1000 SG. It is shown that for those SG which has less than 2% HET pluggings the accumulated pluggings as of the end of the next year of NOM will not exceed this value. Based on the Ukrainian history of WWER-1000 SG operation the database of HET plugging is presented. This method is also used for justification of pressure reduction of periodic hydrostatic test (HT) for primary circuit of WWER-1000 and WWER-440 NPPs from 24.5 MPa to 20.3 MPa and from 19.1 MPa to 15.7 MPa, correspondingly. To justify a reduction of the HT pressure, a quantitative, risk-informed assessment of HT effectiveness has been performed with taking into account the HT pressures change. The HET failure probability is calculated as the proportion of defects which exceed critical sizes for NOM and HT. Limit load models are used for the determination of the critical defects size. The variation of reliability is calculated as the difference between fracture probability during NOM after HT at routine and reduced pressures. It is shown that HT pressure reduction does not practically increase the fracture probability during operation, and satisfies the criteria of risk change.
9
Altinay, Mehmet. "INTEGRATION OF ONLINE EDUCATION TO TOURISM EDUCATION: CROSS CULTURAL STUDENT VOICES." In eLSE 2021. ADL Romania, 2021. http://dx.doi.org/10.12753/2066-026x-21-044.
Анотація:
Covid-19 pandemics had great impacts both in the manufacturing and service industries. Tourism is one of the service industries that had been affected in all its dimensions. Tourism services were heat as all modes of transport to a great extend have stopped after covid-19, but education continued by introducing on line systems all over the world including tourism education. Just before covid-19 the developments in tourism contributed to foreign exchange earnings, growth of the economies and also to employment. This paper aims to evaluate perceptions of tourism education students on online education. Self-reflection task was conducted to gather data from 98 tourism students. It is revealed that students had difficulty in using technological facilities, coping with project-based activities and in using new modes of teaching and learning. As a result of covid-19 higher education systems together with tourism and hospitality education has moved to non-traditional tourism education such as hybrid and online education from traditional classroom settings. The resent changes have significantly changed the way instructors teach and engage students to this education environment. Innovative, cooperative strategies and technologies are needed to remove barriers on online education. This study aims to answer the questions on the perceptions of students regarding online education from students that have different cultures and also shed a light on the challenges and opportunities of online education in tourism. Qualitative research design was used for reflection report. Despite student life has become difficult online education contributed a lot to the student's academic life for personal development.
10
Di Piazza, I., M. Tarantino, P. Agostini, and P. Gaggini. "HELENA: A Heavy Liquid Metal Multi-Purpose Loop for Thermal-Hydraulics, Corrosion and Component Test." In 2014 22nd International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/icone22-30784.
Анотація:
Since the Lead-cooled Fast Reactor (LFR) has been conceptualized in the frame of GEN IV International Forum (GIF), ENEA is strongly involved on the HLM technology development. Currently ENEA has implemented large competencies and capabilities in the field of HLM thermal-hydraulic, coolant technology, material for high temperature applications, corrosion and material protection. In this frame, the HELENA facility is well instrumented and it represents a loop working in pure lead for experiments in the field of corrosion for LFR structural materials, component test, and thermal-hydraulic investigations. The components and the process of the facility has been also depicted in some details. The scheduled working activities has been described and the main steps focused. A prototypical mechanical pump has been designed and manufactured to properly work in pure lead at high temperatures. The long-run test on the component will be isothermal at 400°C with low oxygen content <10−8 % in weight; the oxygen content will be monitored continuously. The pump will be gradually driven to the reference mass flow rate 35 kg/s and this mass flow rate will be maintained for 1500 h, i.e. 2 months about. After this, the pump is stopped and the loop is drained. Then, the pump impeller is disassembled by the body and it is analyzed for corrosion. Then, a test on the ball valves is carried out for a few months. At the end of 2014, the facility is upgraded with the insertion of the FPS in the heating section and with the secondary side. A 19-pin wire-spaced Fuel Pin bundle Simulator (FPS) is installed to measure clad temperature and heat transfer coefficients in different conditions in the different ranks of sub-channels of the MYRRHA bundle. Therefore a test matrix on the forced convection condition in the wire-spaced bundle will be carried out. A 7 tube/shell-and-tube Heat Exchanger couples the primary lead loop with the secondary side with water in pressure at 100 bar. The tube-in-tube technology with lead tube side, water shell side, steel powder in the gap is adopted. Bubble tubes with flowing Argon are adopted to measure pressure losses in the different branches of the loop. Several thermocouples monitor the loop in different points. An ancillary gas system ensures the cover gas. The paper reports the description of the experiments, the proposed test matrix and description the technological solution adopted for the HELENA implementation.
Звіти організацій з теми "Stoppers exchange":
1
Carrasquilla-Barrera, Alberto, Arturo José Galindo-Andrade, Gerardo Hernández-Correa, Ana Fernanda Maiguashca-Olano, Carolina Soto, Roberto Steiner-Sampedro, and Juan José Echavarría-Soto. Report of the Board of Directors to the Congress of Colombia - July 2020. Banco de la República de Colombia, February 2021. http://dx.doi.org/10.32468/inf-jun-dir-con-rep-eng.07-2020.
Анотація:
In Colombia, as well as in the rest of the world, the Covid-19 pandemic has seriously damaged the health and well-being of the people. In order to limit the damage, local and national authorities have had to order large sectors of the population to be confined at their homes for long periods of time. An inevitable consequence of isolation has been the collapse of economic activity, expenditure, and employment, a phenomenon that has hit many countries of the world affected by the disease. It is an unprecedented crisis in modern times, not so much for its intensity (which is undoubtedly immense), but because its origin is not economic. That is what makes it so unpredictable and difficult to manage. Naturally, its economic consequences are enormous. Governments and central banks from all over the world are struggling to mitigate them, but the final solution is not in the hands of the economic authorities. Only science can provide a way out. In the meantime, the economic indicators in Colombia and in the rest of the world cause concern. The output falls, the massive loss of jobs, and the closure of businesses of all sizes have become daily news. Added to this, there is the deterioration in global financial conditions and the increase in the risk indicators. Financial volatility has increased and stock indexes have fallen. In the face of the lower global demand, export prices of raw materials have fallen, affecting the terms of trade for producing countries. Workers’ remittances have declined due to the increase of unemployment in developed countries. This crisis has also generated a strong reduction of global trade of goods and services, and effects on the global value chains. Central banks around the world have reacted decisively and quickly with strong liquidity injections and significant cuts to their interest rates. By mid-July, such determined response had succeeded to revert much of the initial deterioration in global financial conditions. The stock exchanges stopped their fall, and showed significant recovery in several countries. Risk premia, which at the beginning of the crisis took an unusual leap, recorded substantial corrections. Something similar happened with the volatility indexes of global financial markets, which exhibited significant improvement. Flexibilization of confinement measures in some economies, broad global liquidity, and fiscal policy measures have also contributed to improve global external financial conditions, albeit with indicators that still do not return to their pre-Covid levels.