scholarly journals The formation of authigenic deposits during Paleogene warm climatic intervals: a review

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Santanu Banerjee ◽  
Tathagata Roy Choudhury ◽  
Pratul Kumar Saraswati ◽  
Sonal Khanolkar
Keyword(s):  
Oxygen Deficiency ◽  
Close Correspondence ◽  
Rapid Rise ◽  
Review Of The Literature ◽  
Tropical Zone ◽  
Shallow Marine ◽  
Sedimentary Deposits ◽  
Shallow Seas ◽  
Organic Productivity ◽  
Low Rate

Abstract Although Paleogene warm climatic intervals have received considerable attention for atmospheric and oceanographic changes, the authigenic mineralization associated with these time spans remains overlooked. An extensive review of the literature reveals a close correspondence between the high abundance of glauconite and warm climatic intervals during the Paleogene period. The abundance of phosphorite, ironstone, lignite and black shale deposits reveals similar trends. Although investigated thoroughly, the origin of these authigenic deposits is never understood in the background of Paleogene warming climatic intervals. A combination of factors like warm seawater, hypoxic shelf, low rate of sedimentation, and enhanced rate of continental weathering facilitated the glauconitization. The last factor caused the excess supply of nutrients, including Fe, Si, K, Mg and Al through the rivers, the cations needed for the formation of glauconite. The excessive inflow of nutrient-rich freshwater into the shallow seas further ensured high organic productivity and stratification in shallow shelves, causing hypoxia. The consequent rapid rise in sea-level during the warm periods created extensive low-relief shallow marine shelves starved in sediments. Oxygen-deficiency in the shallow marine environment facilitated the fixation of Fe into the glauconite structure. The inflow of nutrient-rich water during the warm climatic intervals facilitated the formation of phosphorite, ironstone, and organic-matter-rich sedimentary deposits as well. Although global factors primarily controlled the formation of these authigenic deposits, local factors played significant roles in some of the deposits. Therefore, phosphorites formed in marine conditions with open circulation within the tropical zone. While lush growth of rainforest covers in the tropical belt facilitated the formation of coastal lignite.

Influence of deposition rate on the properties of thick YBa2Cu3O7–δ films

1997 ◽  
Vol 12 (11) ◽  
pp. 2941-2946 ◽  
Author(s):  
S. R. Foltyn ◽  
E. J. Peterson ◽  
J. Y. Coulter ◽  
P. N. Arendt ◽  
Q. X. Jia ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Deposition Rate ◽  
Current Density ◽  
Oxygen Deficiency ◽  
Lattice Parameter ◽  
High Rate ◽  
Superconducting Transition ◽  
And Performance ◽  
Low Rate

To investigate potential limits to the rate at which high-quality YBa2Cu3O7–δ can be deposited, we have produced a series of 1 μm thick films by pulsed laser deposition on single-crystal SrTiO3 substrates at average rates ranging from 2 Å/s to 240 Å/s. The critical current density of low-rate films was over 2 MA/cm2 at 75 K, self field, but dropped linearly with rate to about 1 MA/cm2 at the upper end of the range. In addition, the superconducting transition temperature, resistivity above the transition, and performance in an applied magnetic field were all degraded by increasing the deposition rate. A change in c-axis lattice parameter suggests that possible causes for this degradation are oxygen deficiency or cation disorder with the latter being the more likely. Annealing high-rate films at 790 °C for as little as 20 min improved critical current density to within 20% of low-rate values, and resulted in dramatic improvements in other film properties as well.

scholarly journals SLEEVE GASTRECTOMY IN PATIENTS WITH MORBID OBESITY AND HIV

2016 ◽  
Vol 29 (suppl 1) ◽  
pp. 124-127 ◽  
Author(s):  
José Máximo Costa PINTO ◽  
Marianna Gomes Cavalcanti Leite de LIMA ◽  
Ana Luiza Melo Cavalcanti de ALMEIDA ◽  
Marcelo Gonçalves SOUSA
Keyword(s):  
Morbid Obesity ◽  
Continuous Improvement ◽  
Critical Appraisal ◽  
Antiretroviral Drugs ◽  
Review Of The Literature ◽  
Vertical Gastrectomy ◽  
Quality Scale ◽  
Immunodeficiency Virus ◽  
Critical Appraisal Skills ◽  
Low Rate

ABSTRACT Introduction: It is estimated that there are nearly 40 million people with the human immunodeficiency virus (HIV) worldwide. Due to the advent of antiretroviral drugs, it has been observed increasing in obesity and metabolic rates among patients undergoing treatment. Thus, numerous surgical therapies for weight loss are proposed for continuous improvement in health of patients with HIV, being the vertical gastrectomy an option for intact intestinal transit. Objective: To evaluate the applicability of the vertical gastrectomy in patients with morbid obesity and HIV. Methods: Was conducted a systematic review of the literature, in the electronic databases Scopus, Pubmed, Cinahl, Scielo, Cochrane and Lilacs, from 1998 to 2015. MeSH headings used in data collection were "Gastrectomy" and "Morbid obesity" being combined with the descriptor "HIV". Were found 2148 articles in Scopus, 1234 in PubMed and 784 in Cinahl. The articles were analyzed by the Jadad Quality Scale, being reduced to 40 articles, subsequently reassessed using an elaborated form by the Critical Appraisal Skills Programme (CASP), reaching 12 articles in the end. Conclusion: It was found that vertical gastrectomy constitutes a safe and effective method, with low mortality and low rate of postoperative complications, being recommended as surgical technique in patients with obesity, HIV and comorbidities.

China-based logistics research: a review of the literature and implications

2014 ◽  
Vol 44 (5) ◽  
pp. 392-411 ◽  
Author(s):  
Xiaohong Liu
Keyword(s):  
Design Methodology ◽  
Methodological Approach ◽  
Research Needs ◽  
Review Of The Literature ◽  
Research Focus ◽  
Research Setting ◽  
Content Type ◽  
Methodological Rigor ◽  
Practical Implications ◽  
Low Rate

Purpose – The purpose of this paper is to investigate the extent to which research opportunities on China's logistics have been identified in the field. Design/methodology/approach – In order to fulfill the research objective, a literature-based survey was executed in eight peer-reviewed logistics and supply chain management journals during the 2001-2012 timeframe. In total, 91 articles were examined and analyzed from three perspectives: research focus, theoretical base and methodological approach. A content analysis was used to classify and assess the analytical units with selected examples from the articles surveyed. Findings – The analysis reveals that a number of research foci have been addressed, but there are some fertile areas that researchers could explore in view of the evolution of logistics and transitional trends in present-day China. Theory applications were applied in few papers, showing a low rate of usage of theories. Different research techniques have been applied, but greater methodological rigor is expected to be achieved, given the unique research setting in China. Research limitations/implications – While the study has consulted the major logistics journals in the logistics field in which researchers aim to pursue their publications regarding China-based logistics research, it should be noted that contributions in other journals may have been missed. Practical implications – The study sheds new light on the research needs and opportunities for advancing China-based logistics research; for those researchers interested in China's logistics, it provides options which may lead to further, valuable research in this area. Originality/value – This paper represents the first attempt to examine a body of literature on China-based logistics research. It provides implications for future study.

scholarly journals Early Sarmatian paleoenvironments in the easternmost Pannonian Basin (Borod Depression, Romania) revealed by the micropaleontological data

2014 ◽  
Vol 65 (1) ◽  
pp. 67-81 ◽  
Author(s):  
Sorin Filipescu ◽  
Angela Miclea ◽  
Martin Gross ◽  
Mathias Harzhauser ◽  
Kamil Zágoršek ◽  
...  
Keyword(s):  
Sea Level ◽  
Pannonian Basin ◽  
Active Tectonics ◽  
Sea Level Changes ◽  
Sedimentary Record ◽  
Relative Sea Level ◽  
Shallow Marine ◽  
Apuseni Mountains ◽  
Shallow Seas

Abstract The Sarmatian sedimentary record of the Borod Depression (eastern Pannonian Basin) consists of a marine sequence with continental influence. The investigated section, located near Vârciorog, was biostratigraphically and paleoenvironmentally analysed. The micro- and macrofossil assemblages include dasycladaceans, characeans, foraminifera, molluscs, polychaetes, ostracods, crabs, bryozoans, fish and vertebrate remains, which are characteristic for a shallow marine setting with local transitions to continental facies. The microfossil assemblages are characteristic for the Elphidium reginum Zone and Mohrensternia Zone of the early Sarmatian (Serravallian). The succession of populations correlates with the sedimentological trend, allowing the separation of several genetic units. The relative sea-level changes and the progradational trend from the top of the section suggest active tectonics in the hinterland (Apuseni Mountains). The shallow seas surrounding the emerging islands (Apuseni Mountains) provided the connections between the Pannonian and Transylvanian basins during the early Sarmatian

Suicide in the Greek Penal System and the Problem of Various Limitations in Relevant Studies

Crisis ◽  
2006 ◽  
Vol 27 (3) ◽  
pp. 135-139 ◽  
Author(s):  
Olga Themeli
Keyword(s):  
Missing Data ◽  
Suicide Prevention ◽  
Intervention Strategies ◽  
European Countries ◽  
High Rate ◽  
Penal System ◽  
Review Of The Literature ◽  
Official Statistics ◽  
Cry For Help ◽  
Low Rate

Suicides in prison are not merely self-destructive acts or a “cry for help.” They reflect the inherent need for freedom and the repercussions of imprisonment. SPACE statistics on suicides in prison reveal a rate above 10 per 10,000 in 10 European countries, 4 of which have a rate above 20. Greek data do not appear in all SPACE statistics. This fact has stimulated the present paper. Unpublished data obtained from the Greek Ministry of Justice reveal that Greece belongs to the group of countries with a rate below 10 in 1995 (the year of SPACE statistics). However, the suicide rates fluctuated widely in Greece from a low rate of 3.2 per 10,000 prisoners (convicted, on remand, or hospitalized) in 1982 to the incredibly high rate of nearly 40 in the year 1979 (11 suicides, 10 of which occurred in prison hospitals). A review of the literature indicates that various limitations mentioned in relevant studies lie in the unreliability of data (doubts about the validity of official statistics, missing data in archives, missing files on the victims, suicide in juvenile institutions not always recorded separately, etc.). The research emphasizes the importance of improving suicide statistics (recording, clearing up the incidents of deaths that are recorded without specification of cause, etc.) in order to plan and enforce suicide prevention and intervention strategies that seem to “work” in a particular milieu and are not debatable (e.g., the use of “suicide proof” cells).

Surface reconstructions of (001) cleaved GdBa2Cu3O7-δ

1992 ◽  
Vol 50 (1) ◽  
pp. 106-107
Author(s):  
H.W. Zandbergen ◽  
M.R. McCartney
Keyword(s):  
Electron Microscopy ◽  
Copper Oxide ◽  
Grain Boundaries ◽  
Atomic Structure ◽  
Oxygen Deficiency ◽  
Surface Layers ◽  
Layer Sequence ◽  
Surface Reconstructions ◽  
Good Agreement

Very few electron microscopy papers have been published on the atomic structure of the copper oxide based superconductor surfaces. Zandbergen et al. have reported that the surface of YBa2Cu3O7-δ was such that the terminating layer sequence is bulk-Y-CuO2-BaO-CuO-BaO, whereas the interruption at the grain boundaries is bulk-Y-CuO2-BaO-CuO. Bursill et al. reported that HREM images of the termination at the surface are in good agreement with calculated images with the same layer sequence as observed by Zandbergen et al. but with some oxygen deficiency in the two surface layers. In both studies only one or a few surfaces were studied.

Crystal chemistry of high-Tc superconductors

1990 ◽  
Vol 48 (4) ◽  
pp. 1118-1119
Author(s):  
Maryvonne Hervieu
Keyword(s):  
Oxygen Deficiency ◽  
Large Family ◽  
Copper Oxides ◽  
High Tc Superconductors ◽  
High Tc ◽  
Single Mechanism ◽  
Square Planar ◽  
History Of ◽  
Bismuth Cuprates ◽  
New Compounds

Four years after the discovery of superconductivity at high temperature in the Ba-La-Cu-O system, more than thirty new compounds have been synthesized, which can be classified in six series of copper oxides: La2CuO4 - type oxides, bismuth cuprates, YBa2Cu3O7 family, thallium cuprates, lead cuprates and Nd2CuO4 - type oxides. Despite their quite different specific natures, close relationships allow their structures to be simply described through a single mechanism. The fifth first families can indeed be described as intergrowths of multiple oxygen deficient perovskite slabs with multiple rock salt-type slabs, according to the representation [ACuO3-x]m [AO]n.The n and m values are integer in the parent structures, n varying from 0 to 3 and m from 1 to 4; every member of this large family can thus be symbolized by [m,n]. The oxygen deficient character of the perovskite slabs involves the existence or the co-existence of several types of copper environment: octahedral, pyramidal and square planar.Both mechanisms, oxygen deficiency and intergrowth, are well known to give rise easily to nonstoichiometry phenomena. Numerous and various phenomena have actually been characterized in these cuprates, strongly depending on the thermal history of the samples.

Telepractice for Adult Speech-Language Pathology Services: A Systematic Review

2020 ◽  
Vol 5 (1) ◽  
pp. 326-338 ◽  
Author(s):  
Kristen Weidner ◽  
Joneen Lowman
Keyword(s):  
Systematic Review ◽  
Primary Progressive Aphasia ◽  
Future Research ◽  
Service Delivery Model ◽  
Speech Language Pathology ◽  
Review Of The Literature ◽  
Research Designs ◽  
Assessment And Treatment ◽  
Language Pathology ◽  
Screening Assessment

Purpose We conducted a systematic review of the literature regarding adult telepractice services (screening, assessment, and treatment) from approximately 2014 to 2019. Method Thirty-one relevant studies were identified from a literature search, assessed for quality, and reported. Results Included studies illustrated feasibility, efficacy, diagnostic accuracy, and noninferiority of various speech-language pathology services across adult populations, including chronic aphasia, Parkinson's disease, dysphagia, and primary progressive aphasia. Technical aspects of the equipment and software used to deliver services were discussed. Some general themes were noted as areas for future research. Conclusion Overall, results of the review continue to support the use of telepractice as an appropriate service delivery model in speech-language pathology for adults. Strong research designs, including experimental control, across multiple well-described settings are still needed to definitively determine effectiveness of telepractice services.

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