Influence of strain localization on reliability based design of bridge abutments using pseudo-dynamic method

The paper focuses on reliability based design of bridge abutments when subjected to earthquake loading. Planar failure surface has been used in conjunction with pseudo-dynamic approach to compute the seismic active earth pressures on the bridge abutment. The proposed pseudo dynamic method, considers the effects of strain localization in the backfill soil and associated post-peak reduction in the shear resistance from peak to residual values along a previously formed failure plane, phase difference in shear waves and soil amplification along with the horizontal seismic accelerations. Four modes of stability viz. sliding, overturning, eccentricity and bearing capacity of the foundation soil are considered for the reliability analysis. The influence of various design parameters on the seismic reliability indices against four modes of failure is presented, following the suggestions of Japan Road Association, Caltrans Bridge Design Specifications and U.S Department of the Army.

Pseudo-Static and Pseudo-Dynamic Stability Analysis of Tailings Dam Under Seismic Conditions

In this paper the seismic slope stability analyses are performed for a typical section of 44 m high water retention type tailings earthen dam located in the eastern part of India, using both the conventional pseudo-static and recent pseudo-dynamic methods. The tailings earthen dam is analyzed for different upstream conditions of reservoir like filled up with compacted and non-compacted dumped waste materials with different water levels of the pond tailings portion. Phreatic surface is generated using seepage analysis in geotechnical software SEEP/W and that same is used in the pseudo-static and pseudo-dynamic analyses to make the approach more realistic. The minimum values of factor of safety using pseudo-static and pseudo-dynamic method are obtained as 1.18 and 1.09 respectively for the chosen seismic zone in India. These values of factor of safety show clearly the demerits of conventional pseudo-static analysis compared to recent pseudo-dynamic analysis, where in addition to the seismic accelerations, duration, frequency of earthquake, body waves traveling during earthquake and amplification effects are considered.

On piercing (pseudo)lines and boxes

We say a family of geometric objects C has (l;k)-property if every subfamily C0C of cardinality at most lisk- piercable. In this paper we investigate the existence of g(k;d)such that if any family of objects C in Rd has the (g(k;d);k)-property, then C is k-piercable. Danzer and Gr̈ unbaum showed that g(k;d)is infinite for fami-lies of boxes and translates of centrally symmetric convex hexagons. In this paper we show that any family of pseudo-lines(lines) with (k2+k+ 1;k)-property is k-piercable and extend this result to certain families of objects with discrete intersections. This is the first positive result for arbitrary k for a general family of objects. We also pose a relaxed ver-sion of the above question and show that any family of boxes in Rd with (k2d;k)-property is 2dk- piercable.

P3F92-: An All-Pseudo-pi* 2 pi-Aromatic

A qualitative MO analysis suggests (PH3)(3)(2-) as a candidate for an all-pseudo-pi* 2 pi-aromatic; however computational studies rule out its existence. Fluorine substitution which increases the contribution of p orbitals on P in the pseudo-pi* MO makes (PF3)(3)(2-) a minimum and an aromatic. The 2 pi aromaticity arising from the bonding combination of the three pseudo-pi* fragment MOs is comparable to that in C3O32- and is another example for the analogy between CO and PF3. The dianion (PF3)(3)(2-) forms the first example of a three-membered ring with all the vertices constituted by pentacoordinate phosphorus. The ability of PF3 to form the all-pseudo-pi* 2 pi-aromatic system is not shared by the heavier analogues, AsF3 and SbF3.

On Hermite pseudo-multipliers

In this article we deal with a variation of a theorem of Mauceri concerning the L-P boundedness of operators M which are known to be bounded on L-2. We obtain sufficient conditions on the kernel of the operator M so that it satisfies weighted L-P estimates. As an application we prove L-P boundedness of Hermite pseudo-multipliers. (C) 2014 Elsevier Inc. All rights reserved.

A pseudo-binary interdiffusion study in the beta-Ni(Pt)Al phase

Interdiffusion study is conducted in the Ni-rich part of the beta-Ni(Pt)Al phase following the pseudo-binary approach. Interdiffusion coefficients over the whole composition range considered in this study increases with increase in Pt content, which is in line with the theoretical study predicting the decrease in vacancy formation and migration energy because of Pt addition. The trend of change in diffusion coefficient with the increase in Ni and Pt contents indicates that Pt preferably replaces Ni antisites.

Estimation of intrinsic diffusion coefficients in a pseudo-binary diffusion couple

Major drawback of studying diffusion in multi-component systems is the lack of suitable techniques to estimate the diffusion parameters. In this study, a generalized treatment to determine the intrinsic diffusion coefficients in multi-component systems is developed utilizing the concept of a pseudo-binary approach. This is explained with the help of experimentally developed diffusion profiles in the Cu(Sn, Ga) and Cu(Sn, Si) solid solutions. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Synthesis, reactivity and structural characterisation of bicyclic tetraphosphapentazanes

The diphenoxy bicyclic tetraphosphapentazane derivatives (EtN)(5)P-4(OPh)(2) 2 and its monoxide (EtN)(5)P-4(O)(OPh)(2) 3 have been prepared. Both 2 and 3 exist as a mixture of two isomers. One isomer of (EtN)(5)P-4(O)(OPh)(2) 3a has been isolated and its reaction with tetrachloro-1,2-benzoquinone yielded (EtN)(5)P-4(O)(OPh)(2)(O2C6Cl4) 5 in which the junction phosphorus atom becomes five-co-ordinated. Treatment of 2 or 3a with [Mo(CO)(4)(nbd)] (nbd = norbornadiene, bicyclo[2.2.1]hepta-2,5-diene), on the other hand, yielded the chelate complex [Mo(CO)(4){(EtN)(5)P-4(O)(n)(OPh)(2)}] (n = 0 or 1; 6 or 7) in which the peripheral phosphorus atoms are bonded to the metal. The structures of 3a and 5-7 have been confirmed by single-crystal X-ray diffraction studies. The two P3N3 rings in 3a and 5 adopt twist/twist and irregular/twist conformations respectively; the phenoxy substituents occupy the 'pseudo axial' positions. However, an ideal chair conformation is observed for the P3N3 rings in 6 and 7 with the phenoxy substituents taking up the 'pseudo equatorial' positions. The NMR spectroscopic data for the compounds are discussed.

Adenosine-5'-carboxylic Acid

The two molecules in the asymmetric unit of adenosine-5'-carboxylic acid, C10H11N5O5, exist as zwitterions with N1 protonated and the carboxyl groups ionized. Both molecules are in an anti conformation with glycosyl torsion angles of -161.4(3) and -155.5(3)degrees. The ribose moieties adopt a C3-endo-C2-exo twist conformation. The pseudo-rotation parameters are P = 0.01(1) and 6.58(1)degrees, and tau(m) = 36.2(2) and 34.6(2)degrees, for molecules A and B, respectively. The carboxyl groups of A and B are not in the standard g(+), g(-) or t conformations. Both Watson-Crick sites, N1 and N6, of the adenine bases are involved in a pair of hydrogen bonds with the dissociated carboxyl groups, forming a cyclic tetramer. The adenine base of molecule A stacks on the ribose O4' atom of a symmetry-related B molecule at a distance of 2.88 Angstrom; the adenine base of B stacks in an analogous way at a distance of 2.91 Angstrom.

Transonic Properties of Accretion Disk Around Compact Objects

An accretion flow is necessarily transonic around a black hole.However, around a neutron star it may or may not be transonic, depending on the inner disk boundary conditions influenced by the neutron star. I will discuss various transonic behavior of the disk fluid in general relativistic (or pseudo general relativistic) framework. I will address that there are four types of sonic/critical point. possible to form in an accretion disk. It will be shown that how the fluid properties including location of sonic point's vary with angular momentum of the compact object which controls the overall disk dynamics and outflows.

Synthesis, structure and spectroscopic studies on hydroxo-bridged heterotrinuclear complexes of cobalt(m) with ethane-l,2-diamine and ammonia as terminal ligands

Hydroxo-bridged homo- and hetero-trinuclear cobalt(III) complexes of the type [MII(H2O)2{(OH)2CoIII(N4)}2]X2·nH2O [MII= a divalent metal ion such as CoII, NiII or ZnII; N4=(en)2(en = ethane-1,2-diamine) or (NH3)4; X = SO4 or (ClO4)2; n= 3 or 5] have been prepared and spectroscopically characterized. The structure of [Cu{(OH)2Co(en)2}2][SO4]2·2H2O 1 has been determined. The geometry around copper atom is a pseudo-square-based pyramid, with the basal sites occupied by four bridging hydroxide oxygens and the apical site is occupied by a weakly co-ordinated sulfate anion [Cu–O 2.516(4)Å]. The hydroxo groups bridge pairs of cobalt(III) ions which are in near-octahedral environments. The ethylenediamine chelate rings have the twist conformation. In the crystal structure of [Cu{(OH)2Co(en)2}2][ClO4]4·2H2O 2 the perchlorate ion is not co-ordinated and the en ligands have envelope conformations. The sulfate ion in [Cu{(OH)2Co(NH3)4}2][SO4]2·4H2O 3 is not co-ordinated to the central copper ion. Electronic, infrared and variable-temperature EPR spectral data are discussed.

Structure of a thionucleoside: 5'-deoxy-5',6-epithio-5,6-dihydro-2',3'-O-isopropylidene-3-methyluridine

C13HlsN205 S, M r = 314.35, orthorhombic, P212121 with a = 39.526 (4), b = 6.607 (2), c = 5.661 (2) A, Z = 4, V = 1478.36 A 3, D c = 1.412 Mg m -3, Cu Ka radiation. Final R = 0.073 for 1154 observed counter reflections. The sulphur atom is in a pseudo-equatorial position with respect to the dihydrouracil ring. The sugar pucker is predominantly O(l')-exo unlike the C(3')-exo,C(4')-endo observed for 2',3'-O-isopropylideneuridine (ISPU). The fivemembered dioxolane ring has C(7) displaced by 0.497 (7)A from the best plane through atoms 0(2'), C(2'), C(3'), 0(3'), in contrast to ISPU where 0(3') shows the maximum deviation.

Adsorption isotherms for neutral organic compounds-A hierarchy in modelling: Part III

A simple three-state model permitting two different configurational states for the solvent, together with one for the organic adsorbate, is analysed to derive the adsorption isotherm. The implications of this model regarding pseudo-two-state and pseudo-Frumkin adsorption isotherms are indicated. A critique of the earlier theory of Bockris, Devanathan and Müller is presented in brief.

Watson-Crick pairing, the Heisenberg group and Milnor invariants

We study the secondary structure of RNA determined by Watson-Crick pairing without pseudo-knots using Milnor invariants of links. We focus on the first non-trivial invariant, which we call the Heisenber invariant. The Heisenberg invariant, which is an integer, can be interpreted in terms of the Heisenberg group as well as in terms of lattice paths. We show that the Heisenberg invariant gives a lower bound on the number of unpaired bases in an RNA secondary structure. We also show that the Heisenberg invariant can predict allosteric structures for RNA. Namely, if the Heisenberg invariant is large, then there are widely separated local maxima (i.e., allosteric structures) for the number of Watson-Crick pairs found.

Technicolor

The need for reexamination of the standard model of strong, weak, and electromagnetic interactions is discussed, especially with regard to 't Hooft's criterion of naturalness. It has been argued that theories with fundamental scalar fields tend to be unnatural at relatively low energies. There are two solutions to this problem: (i) a global supersymmetry, which ensures the absence of all the naturalness-violating effects associated with scalar fields, and (ii) composite structure of the scalar fields, which starts showing up at energy scales where unnatural effects would otherwise have appeared. With reference to the second solution, this article reviews the case for dynamical breaking of the gauge symmetry and the technicolor scheme for the composite Higgs boson. This new interaction, of the scaled-up quantum chromodynamic type, keeps the new set of fermions, the technifermions, together in the Higgs particles. It also provides masses for the electroweak gauge bosons W± and Z0 through technifermion condensate formation. In order to give masses to the ordinary fermions, a new interaction, the extended technicolor interaction, which would connect the ordinary fermions to the technifermions, is required. The extended technicolor group breaks down spontaneously to the technicolor group, possibly as a result of the "tumbling" mechanism, which is discussed here. In addition, the author presents schemes for the isospin breaking of mass matrices of ordinary quarks in the technicolor models. In generalized technicolor models with more than one doublet of technifermions or with more than one technicolor sector, we have additional low-lying degrees of freedom, the pseudo-Goldstone bosons. The pseudo-Goldstone bosons in the technicolor model of Dimopoulos are reviewed and their masses computed. In this context the vacuum alignment problem is also discussed. An effective Lagrangian is derived describing colorless low-lying degrees of freedom for models with two technicolor sectors in the combined limits of chiral symmetry and large number of colors and technicolors. Finally, the author discusses suppression of flavor-changing neutral currents in the extended technicolor models.