The Capillary Flow Experiments Aboard the International Space Station: Increments 9-15

This report provides a summary of the experimental, analytical, and numerical results of the Capillary Flow Experiment (CFE) performed aboard the International Space Station (ISS). The experiments were conducted in space beginning with Increment 9 through Increment 16, beginning August 2004 and ending December 2007. Both primary and extra science experiments were conducted during 19 operations performed by 7 astronauts including: M. Fincke, W. McArthur, J. Williams, S. Williams, M. Lopez-Alegria, C. Anderson, and P. Whitson. CFE consists of 6 approximately 1 to 2 kg handheld experiment units designed to investigate a selection of capillary phenomena of fundamental and applied importance, such as large length scale contact line dynamics (CFE-Contact Line), critical wetting in discontinuous structures (CFE-Vane Gap), and capillary flows and passive phase separations in complex containers (CFE-Interior Corner Flow). Highly quantitative video from the simply performed flight experiments provide data helpful in benchmarking numerical methods, confirming theoretical models, and guiding new model development. In an extensive executive summary, a brief history of the experiment is reviewed before introducing the science investigated. A selection of experimental results and comparisons with both analytic and numerical predictions is given. The subsequent chapters provide additional details of the experimental and analytical methods developed and employed. These include current presentations of the state of the data reduction which we anticipate will continue throughout the year and culminate in several more publications. An extensive appendix is used to provide support material such as an experiment history, dissemination items to date (CFE publication, etc.), detailed design drawings, and crew procedures. Despite the simple nature of the experiments and procedures, many of the experimental results may be practically employed to enhance the design of spacecraft engineering systems involving capillary interface dynamics

Accounting for both electron--lattice and electron--electron coupling in conjugated polymers: minimum total energy calculations on the Hubbard--Peierls hamiltonian

Minimum total energy calculations, which account for both electron--lattice and electron--electron interactions in conjugated polymers are performed for chains with up to eight carbon atoms. These calculations are motivated in part by recent experimental results on the spectroscopy of polyenes and conjugated polymers and shed light on the longstanding question of the relative importance of electron--lattice vs. electron--electron interactions in determining the properties of these systems.Comment: 6 pages, Plain TeX, FRL-PSD-93GR

Excited states of linear polyenes

We present density matrix renormalisation group calculations of the Pariser- Parr-Pople-Peierls model of linear polyenes within the adiabatic approximation. We calculate the vertical and relaxed transition energies, and relaxed geometries for various excitations on long chains. The triplet (3Bu+) and even- parity singlet (2Ag+) states have a 2-soliton and 4-soliton form, respectively, both with large relaxation energies. The dipole-allowed (1Bu-) state forms an exciton-polaron and has a very small relaxation energy. The relaxed energy of the 2Ag+ state lies below that of the 1Bu- state. We observe an attraction between the soliton-antisoliton pairs in the 2Ag+ state. The calculated excitation energies agree well with the observed values for polyene oligomers; the agreement with polyacetylene thin films is less good, and we comment on the possible sources of the discrepencies. The photoinduced absorption is interpreted. The spin-spin correlation function shows that the unpaired spins coincide with the geometrical soliton positions. We study the roles of electron-electron interactions and electron-lattice coupling in determining the excitation energies and soliton structures. The electronic interactions play the key role in determining the ground state dimerisation and the excited state transition energies.Comment: LaTeX, 15 pages, 9 figure

The nature of singlet exciton fission in carotenoid aggregates.

Singlet exciton fission allows the fast and efficient generation of two spin triplet states from one photoexcited singlet. It has the potential to improve organic photovoltaics, enabling efficient coupling to the blue to ultraviolet region of the solar spectrum to capture the energy generally lost as waste heat. However, many questions remain about the underlying fission mechanism. The relation between intermolecular geometry and singlet fission rate and yield is poorly understood and remains one of the most significant barriers to the design of new singlet fission sensitizers. Here we explore the structure-property relationship and examine the mechanism of singlet fission in aggregates of astaxanthin, a small polyene. We isolate five distinct supramolecular structures of astaxanthin generated through self-assembly in solution. Each is capable of undergoing intermolecular singlet fission, with rates of triplet generation and annihilation that can be correlated with intermolecular coupling strength. In contrast with the conventional model of singlet fission in linear molecules, we demonstrate that no intermediate states are involved in the triplet formation: instead, singlet fission occurs directly from the initial 1B(u) photoexcited state on ultrafast time scales. This result demands a re-evaluation of current theories of polyene photophysics and highlights the robustness of carotenoid singlet fission.This work was supported by the EPSRC (UK) (EP/G060738/ 1), the European Community (LASERLAB-EUROPE, grant agreement no. 284464, EC’s Seventh Framework Programme; and Marie-Curie ITN-SUPERIOR, PITN-GA-2009-238177), and the Winton Programme for the Physics of Sustainability. G.C. acknowledges support by the European Research Council Advanced Grant STRATUS (ERC-2011-AdG No. 291198). J.C. acknowledges support by the Royal Society Dorothy Hodgkin Fellowship and The University of Sheffield’s Vice- Chancellor’s Fellowship scheme.This is the final published version. It was first made available by ACS at http://pubs.acs.org/doi/abs/10.1021/jacs.5b01130

The incidence of major cardiovascular events relied coronary vessels after angioplasty and stent types complications

Background: Cardiovascular diseases alone have become the leading cause of death worldwide. One of the treatment methods cardiovascular disease is angioplasty. This study aimed to investigate the clinical results after coronary artery angioplasty, based on the incidence of major cardiovascular events with emphasis on stent types. Methods: In this retrospective cross-sectional study, the prevalence of risk factors (age, history of previous illness and previous surgery) was assessed by using a case file for patients undergoing coronary angioplasty and stent placement during the years 2006 to 2016 and found during the follow-up. The place of the study was the Imam Ali Hospital's educational center affiliated to Kermanshah University of Medical Sciences, Iran, from July to September 2017. Results: In this study, 1188 patients undergone to stent containing 909 non-drug stents, 504 sirolimus-eluting stents and 316 paclitaxel-eluting stents. Patients were followed-up one to five years. During follow-up, 98 patients involved major cardiovascular events, six cases involved with death and 91 patients involved with myocardial infarction. 1729 of patients undergone angioplasty and during follow-up, 91 patients had stent restenosis. In this study stent restenosis showed the highest correlation with the incidence of major cardiovascular events. With a view to stent type in lesions with stent restenosis, 61.7 was in non-drug stent, 23.5 was in paclitaxel-eluting stent and 14.8 was in sirolimus-eluting stent. This study also showed that despite the superiority of sirolimus-stained stents, there was no difference between paclitaxel-stained stents and non-drug stents in clinical outcomes and restenosis. Conclusion: The results showed that the syringes impregnated with sirolimus have better quality. Also, stents that have a smaller diameter or need dilatation in the procedure have a worse prognosis and cause more complications in the patient. © 2018, Tehran University of Medical Sciences. All rights reserved

Investigating the validity and reliability of the GLFS-25 questionnaire by factor analysis in the elderly hospitalized at the intensive and cardiac care units

INTRODUCTION: Geriatric Locomotive Function Scale-25 (GLFS-25) is a 25-item tool most commonly used to diagnose locomotive syndrome in the elderly. The purpose of the present study was to investigate the validity and reliability of the GLFS-25 questionnaire using factor analysis. MATERIALS AND METHODS: This descriptive-analytical study was conducted on 186 elderly people. The GLFS-25 questionnaire contains 25 items, and each item is scored on a five-point Likert scale from 0 to 4. Data were analyzed by SPSS V.19 software. Descriptive (frequency, percentage, mean, and standard deviation) and inferential (Cronbach's alpha, correlation coefficient, Bartlett test, KMO index, scree plot, and factor analysis) statistics were used to present the findings. RESULTS: Factor analysis revealed two hidden factors in the four dimensions of the questionnaire (i.e., pain, daily activities, social relations, and mental health). The first factor, named mobility and its consequential concerns), with a variance percentage of 74.323, had an effect on questions No. 19, 11, 25, 16, 6, 24, 5, 4, and 3. The second factor, named the problems and risks associated with daily and social activities, with a variance percentage of 78.680, had an effect on questions No. 17, 22, 7, 18, 14, 20, 13, 9, 12, 8, 10, 21, 2, 15, 1, and 23. Cronbach's alpha coefficient among the questionnaire's dimensions was 78.4. CONCLUSION: The GLFS-25 questionnaire can be used as a valid and reliable tool to diagnose locomotive syndrome in the elderly

Effect of Lens-Induced Myopia on Visual Cortex Activity: A Functional MR Imaging Study

BACKGROUND AND PURPOSE: Myopia is a type of refractive error that blurs retinal image and in turn can change neural signals transferred from retina to visual cortex. The purpose of this study was to evaluate the effect of induced myopia on occipital visual cortex activity by fMRI results

The frequency of arrhythmias in COVID-19 patients, a study in the Shahid Mostafa Khomeini Hospital of Ilam from March to August 2020

Introduction: Cardiac arrhythmias are important causes of death among populations and always responsible for a high percentage of mortality in hospitalized patients. The aim of this study was to evaluate the frequency of arrhythmias in COVID-19 patients in the Shahid Mostafa Khomeini Hospital of Ilam from March to August 2020. Materials and Methods: In this descriptive-analytical study, all the COVID-19 patients with a cardiac condition admitted to the intensive care unit were enrolled by census. Electrocardiography (ECG) and Holter monitoring were used to diagnose arrhythmias. Data analysis was performed in Microsoft Excel using descriptive statistics (frequency and percentage). Results: The total number of eligible patients was 45, of whom 26 (57.8) were men, and 19 (42.2) were women. The mortality rate of arrhythmias among COVID-19 patients was 17.77 (8 out of 45 patients), and the recovery rate was 82.13 (37 out of 45 patients). Conclusion: Tachycardia and the lack of response to heart rate reducing drug be observed in patients with COVID-19.Owing to an overlap between these symptoms and those of heart diseases, there is a need to further evaluate patients with arrhythmias. Although arrhythmias are not common in COVID-19 patients, they can be fatal and inflict a high mortality rate, which can be prevented by early detection