640 research outputs found

    Iterated cyclic homology

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    ArticleKODAI MATHEMATICAL JOURNAL. 30(1): 19-40 (2007)journal articl

    Crystallographic Stability of Metastable Phase Formed by Containerless Processing in REFeO3 (RE: Rare-Earth Element)

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    Undercooling a melt often facilitates a metastable phase to nucleate preferentially. Although the classical nucleation theory shows that the most critical factor for forming a metastable phase is the interface free energy, the crystallographic stability is also indispensable for the phase to be frozen at ambient temperature. In compound materials such as oxides, authors have suggested that the decisive factors for forming a critical nucleus are not only the free energy difference but also the difference of the entropy of fusion between stable and metastable phases. In the present study, using REFeO3 (RE: rare-earth element) as a model material, we investigate the formation of a metastable phase from undercooled melts with respect to the competitive nucleation and crystallographical stabilities of both phases

    Towards a realistic estimation of the powering performance of a ship with a gate rudder system

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    This paper presents an investigation on the scale effects associated with the powering performance of a Gate Rudder System (GRS) which was recently introduced as a novel energy-saving propulsion and maneuvring device. This new system was applied for the first time on a 2400 GT domestic container ship, and full-scale sea trials were conducted successfully in Japan, in 2017. The trials confirmed the superior powering and maneuvring performance of this novel system. However, a significant discrepancy was also noticed between the model test-based performance predictions and the full-scale measurements. The discrepancy was in the power-speed data and also in the maneuvring test data when these data were compared with the data of her sister container ship which was equipped with a conventional flap rudder. Twelve months after the delivery of the vessel with the gate rudder system, the voyage data revealed a surprisingly more significant difference in the powering performance based on the voyage data. The aim of this paper, therefore, is to take a further step towards an improved estimation of the powering performance of ships with a GRS with a specific emphasis on the scale effect issues associated with a GRS. More specifically, this study investigated the scale effects on the powering performance of a gate rudder system based on the analyses of the data from two tank tests and full-scale trials with the above-mentioned sister ships. The study focused on the corrections for the scale effects, which were believed to be associated with the drag and lift characteristics of the gate rudder blades due to the low Reynolds number experienced in model tests combined with the unique arrangement of this rudder and propulsion system. Based on the appropriate semi-empirical approaches that support model test and full-scale data, this study verified the scale effect phenomenon and presented the associated correction procedure. Also, this study presented an enhanced methodology for the powering performance prediction of a ship driven by a GRS implementing the proposed scale effect correction. The predicted powering performance of the subject container vessel with the GRS presented an excellent agreement with the full-scale trials data justifying the claimed scale effect and associated correction procedure, as well as the proposed enhanced methodology for the practical way of predicting the powering performance of a ship with the GRS

    Riemann Surfaces of genus g with an automorphism of order p prime and p>g

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    The present work completes the classification of the compact Riemann surfaces of genus g with an analytic automorphism of order p (prime number) and p > g. More precisely, we construct a parameteriza- tion space for them, we compute their groups of uniformization and we compute their full automorphism groups. Also, we give affine equations for special cases and some implications on the components of the singular locus of the moduli space of smooth curves of genus g.Comment: 28 pages, 5 figure

    On hydrogen bond correlations at high pressures

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    In situ high pressure neutron diffraction measured lengths of O H and H O pairs in hydrogen bonds in substances are shown to follow the correlation between them established from 0.1 MPa data on different chemical compounds. In particular, the conclusion by Nelmes et al that their high pressure data on ice VIII differ from it is not supported. For compounds in which the O H stretching frequencies red shift under pressure, it is shown that wherever structural data is available, they follow the stretching frequency versus H O (or O O) distance correlation. For compounds displaying blue shifts with pressure an analogy appears to exist with improper hydrogen bonds.Comment: 12 pages,4 figure

    Abnormal left ventricular wall rotation in patients with complete left bundle branch block: analysis using magnetic resonance imaging tagging images

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    The ideal vaccine is a simple and stable formulation which can be conveniently administered and provides life-long immunity against a given pathogen. The development of such a vaccine, which should trigger broad and strong B-cell and T-cell responses against antigens of the pathogen in question, is highly dependent on tailored vaccine delivery approaches. This review addresses vaccine delivery in its broadest scope. We discuss the needs and challenges in the area of vaccine delivery, including restrictions posed by specific target populations, potentials of dedicated stable formulations and devices, and the use of adjuvants. Moreover, we address the current status and perspectives of vaccine delivery via several routes of administration, including non-or minimally invasive routes. Finally we suggest possible directions for future vaccine delivery research and development. (C) 2012 Elsevier B.V. All rights reserved

    Anthropometric evaluation and micronutrients intake in patients submitted to laparoscopic Roux-en-Y gastric bypass with a postoperative period of ≥1 year

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    Backgroung - Bariatric surgery is indicated as the most effective treatment for morbid obesity; the Roux-en-Y gastric bypass (RYGB) is considered the procedure of choice. However, nutritional deficiency may occur in the postoperative period as a result of reduced gastric capacity and change in nutrients absorption in the gastrointestinal tract. The prescription of vitamin and mineral supplementation is a common practice after RYGB; however, it may not be sufficient to prevent micronutrient deficiencies. The aim of this study was to quantify the micronutrient intake in patients undergoing RYGB and verify if the intake of supplementation would be enough to prevent nutritional deficiencies. Methods - The study was conducted on 60 patients submitted to RYGB. Anthropometric, analytical, and nutritional intake data were assessed preoperatively and 1 and 2 years postoperatively. The dietary intake was assessed using 24-h food recall; the values of micronutrients evaluated (vitamin B12, folic acid, iron, and calcium) were compared to the dietary reference intakes (DRI). Results - There were significant differences (p < 0.05) between excess weight loss at the first and second year (69.9 ± 15.3 vs 9.6 ± 62.9 %). In the first and second year after surgery, 93.3 and 94.1 % of the patients, respectively, took the supplements as prescribed. Micronutrient deficiencies were detected in the three evaluation periods. At the first year, there was a significant reduction (p < 0.05) of B12, folic acid, and iron intake. Conclusions - Despite taking vitamin and mineral supplementation, micronutrient deficiencies are common after RYGB. In the second year after surgery, micronutrient intake remains below the DRI

    Shimura varieties in the Torelli locus via Galois coverings of elliptic curves

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    We study Shimura subvarieties of Ag\mathsf{A}_g obtained from families of Galois coverings f:CCf: C \rightarrow C' where CC' is a smooth complex projective curve of genus g1g' \geq 1 and g=g(C)g= g(C). We give the complete list of all such families that satisfy a simple sufficient condition that ensures that the closure of the image of the family via the Torelli map yields a Shimura subvariety of Ag\mathsf{A}_g for g=1,2g' =1,2 and for all g2,4g \geq 2,4 and for g>2g' > 2 and g9g \leq 9. In a previous work of the first and second author together with A. Ghigi [FGP] similar computations were done in the case g=0g'=0. Here we find 6 families of Galois coverings, all with g=1g' = 1 and g=2,3,4g=2,3,4 and we show that these are the only families with g=1g'=1 satisfying this sufficient condition. We show that among these examples two families yield new Shimura subvarieties of Ag\mathsf{A}_g, while the other examples arise from certain Shimura subvarieties of Ag\mathsf{A}_g already obtained as families of Galois coverings of P1\mathbb{P}^1 in [FGP]. Finally we prove that if a family satisfies this sufficient condition with g1g'\geq 1, then g6g+1g \leq 6g'+1.Comment: 18 pages, to appear in Geometriae Dedicat

    Experimental infection of dogs with a brazilian strain of Rickettsia rickettsii: clinical and laboratory findings

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    The bacterium Rickettsia rickettsii is the etiological agent of an acute, severe disease called Rocky Mountain spotted fever in the United States or Brazilian spotted fever (BSF) in Brazil. In addition to these two countries, the disease has also been reported to affect humans in Mexico, Costa Rica, Panama, Colombia and Argentina. Like humans, dogs are also susceptible to R. rickettsii infection. However, despite the wide distribution of R. rickettsii in the Western Hemisphere, reports of R. rickettsii-induced illness in dogs has been restricted to the United States. The present study evaluated the pathogenicity for dogs of a South American strain of R. rickettsii. Three groups of dogs were evaluated: group 1 (G1) was inoculated ip with R. rickettsii; group 2 (G2) was infested by R. rickettsii-infected ticks; and the control group (G3) was infested by uninfected ticks. During the study, no clinical abnormalities, Rickettsia DNA or R. rickettsii-reactive antibodies were detected in G3. In contrast, all G1 and G2 dogs developed signs of rickettsial infection, i.e., fever, lethargy, anorexia, ocular lesions, thrombocytopenia, anemia and detectable levels of Rickettsia DNA and R. rickettsii-reactive antibodies in their blood. Rickettsemia started 3-8 days after inoculation or tick infestation and lasted for 3-13 days. Our results indicate that a Brazilian strain of R. rickettsii is pathogenic for dogs, suggesting that canine clinical illness due to R. rickettsii has been unreported in Brazil and possibly in the other South American countries where BSF has been reported among human

    Constraining symmetron fields with atom interferometry

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    We apply the new constraints from atom-interferometry searches for screening mechanisms to the symmetron model, finding that these experiments exclude a previously unexplored region of the parameter space. We discuss the possibility of networks of domain walls forming in the vacuum chamber, and how this could be used to discriminate between models of screening
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