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H. Cifuentes,F. Montero-Chacón,J. Galán,J. Cabezas,A. Martínez-De la Concha 한국콘크리트학회 2019 International Journal of Concrete Structures and M Vol.13 No.6
This paper presents a general procedure based on fracture mechanics models in order to analyze the level of crack-ing and structural safety in reinforced concrete elements at early ages, depending on the stripping time. Our proce-dure involves the development of a thermo-mechanical numerical model based on the finite element method that accounts for the change in the mechanical properties of concrete with time. Moreover, fracture mechanisms are analyzed by means of a material damage model, which is characterized via specific experimental results obtained for standard specimens and notched beams under three-point bending testing. The loading conditions are both thermal and mechanical, and are obtained from the hydration process for a given concrete dosage. The presented methodol-ogy allows for the determination of the optimal stripping time, whereas it helps assessing the analysis of the cracking and the stress states of the elements under consideration. A practical application, namely the analysis of a retaining wall, is used to validate our methodology, showing its suitability in engineering practice.
Gholamhossein Davarynejad,Shadan Khorshidi,J?zsef Ny?ki,Zolt?n Szab?,Judit Gal-Remennyik 한국원예학회 2010 Horticulture, Environment, and Biotechnology Vol.51 No.6
The study was undertaken to elucidate the understanding of biochemical and physical properties of nine fresh and dried apricot cultivars (‘Jumbo cot’, ‘Tom cot’, ‘Goldstrike’, ‘Goldbar’, ‘Bergeron’, ‘Bergarouge’, ‘Sweet cot’, ‘Yellow cot’ and ‘Zebra’) cultivated at the Boldogk?v?ralja Commercial Orchard of Debrecen, Hungary. Flesh firmness, skin color, total soluble solid content, titratable acidity, and antioxidant capacity were measured by ferric reducing antioxidant power (FRAP) method and chemiluminescence assay. Fruits were harvested at commercial maturity stages. Fresh apricot and the stoned, non sulphurated fruits dried with hot air for 24 hours were used for measuring antioxidant activity. The contents of antioxidant compounds were analyzed according to a factorial experiment with completely randomized design. All measured characteristics were significantly different among cultivars. ‘Goldbar’ had the highest lipophilic antioxidant capacity (ACL), hydrophilic antioxidant capacity (ACW) and FRAP value. Drying changed the correlation between assays.
Asteroid pairs: A complex picture
Pravec, P.,Fatka, P.,Vokrouhlický,, D.,Scheirich, P.,Ď,urech, J.,Scheeres, D.J.,Kuš,nirá,k, P.,Hornoch, K.,Galá,d, A.,Pray, D.P.,Krugly, Yu. N.,Burkhonov, O.,Ehgamberdiev, Elsevier 2019 Icarus Vol.333 No.-
<P><B>Abstract</B></P> <P>We studied a sample of 93 asteroid pairs, i.e., pairs of genetically related asteroids that are on highly similar heliocentric orbits. We estimated times elapsed since separation of pair members (i.e., pair age) that are between 7 × 10<SUP>3</SUP> yr and a few 10<SUP>6</SUP> yr. With photometric observations, we derived the rotation periods <I>P</I> <SUB>1</SUB> for all the primaries (i.e., the larger members of asteroid pairs) and a sample of secondaries (the smaller pair members). We derived the absolute magnitude differences of the studied asteroid pairs that provide their mass ratios <I>q</I>. For a part of the studied pairs, we refined their WISE geometric albedos and collected or estimated their taxonomic classifications. For 17 asteroid pairs, we also determined their pole positions. In two pairs where we obtained the spin poles for both pair components, we saw the same sense of rotation for both components and constrained the angles between their original spin vectors at the time of their separation. We found that the primaries of 13 asteroid pairs in our sample are actually binary or triple systems, i.e., they have one or two bound, orbiting secondaries (satellites). As a by-product, we found also 3 new young asteroid clusters (each of them consisting of three known asteroids on highly similar heliocentric orbits). We compared the obtained asteroid pair data with theoretical predictions and discussed their implications. We found that 86 of the 93 studied asteroid pairs follow the trend of primary rotation period vs mass ratio that was found by Pravec et al. (2010). Of the 7 outliers, 3 appear insignificant (may be due to our uncertain or incomplete knowledge of the three pairs), but 4 are high mass ratio pairs that were unpredicted by the theory of asteroid pair formation by rotational fission. We discuss a (remotely) possible way that they could be created by rotational fission of flattened parent bodies followed by re-shaping of the formed components. The 13 asteroid pairs with binary primaries are particularly interesting systems that place important constraints on formation and evolution of asteroid pairs. We present two hypotheses for their formation: The asteroid pairs having both bound and unbound secondaries could be “failed asteroid clusters”, or they could be formed by a cascade primary spin fission process. Further studies are needed to reveal which of these two hypotheses for formation of the paired binary systems is real.</P>