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Abstract In this paper we calibrate the strength of the soundness of a set theory KP ω + (Π 1 -Collection) with the assumption that 'there exists an uncountable regular ordinal' in terms of the existence of ordinals. [ABSTRACT FROM AUTHOR]

We describe a new quantifier elimination algorithm for real closed fields based on Thom encoding and sign determination. The complexity of this algorithm is elementary recursive and its proof of correctness is completely algebraic. In particular, the notion of connected components of semialgebraic sets is not used. [ABSTRACT FROM AUTHOR]

In 2007 Cortés and Peña introduced a pivoting strategy for the Neville elimination of nonsingular sign regular matrices and called it two-determinant pivoting. Neville elimination has been very useful for obtaining theoretical and practical properties for totally positive (negative) matrices and other related types of matrices. A real matrix is said to be almost strictly sign regular if all its nontrivial minors of the same order have the same strict sign. In this paper, some nice properties related with the application of Neville elimination with two-determinant pivoting strategy to almost strictly sign regular matrices are presented. [ABSTRACT FROM AUTHOR]

The sports elimination problem asks whether a team participating in a competition still has a chance to win, given the current standings and the remaining matches to be played among the teams. This problem can be viewed as a graph labelling problem, where arcs receive labels that contribute to the score of both endpoints of the arc, and the aim is to label the arcs in a way that each vertex obtains a score not exceeding its capacity. We investigate the complexity of this problem in detail, using a multivariate approach to examine how various parameters of the input graph (such as the maximum degree, the feedback vertex/edge number, and different width parameters) influence the computational tractability. We obtain several efficient algorithms, as well as certain hardness results. [ABSTRACT FROM AUTHOR]

Underwater acoustic communications have found a growing interest because of its variety usages both in military and commercial applications. But, for ocean environment, the channel has an extended time varying multipath due to acoustic propagation. These phenomena cause pulse spreading and time varying inter-symbol interference (ISI). To overcome the interference caused by this harsh environment, equalizers with Passive Phase Conjugation (PPC) have been widely used in coherent communications. In this paper, we have proposed a combined scheme of PPC followed by an iteratively ISI cancelation algorithm to remove the residual ISI remained at the output of the PPC processor. By using a coarse estimation of the channel along with the ISI alleviated PPC output symbols; we can eliminate residual ISI from the received data signal. We have conducted extensive simulations and some experimental tests at the coastal environment of the Persian Gulf to investigate the performance of the proposed scheme. The advantages of the proposed combined scheme are using the channel probe signal for both frame synchronization and coarse estimation of the channel impulse response to using it in the iteratively ISI cancellation and the PPC processing block. The results showed the effectiveness of the combined method. [ABSTRACT FROM AUTHOR]

This paper deals with the computational modeling and numerical simulation of contact problems at finite deformations using the finite element method. Quasi-static and dynamic problems are considered and two particular frictional conditions, full stick friction and frictionless cases, are addressed. Lagrange multipliers and regularized formulations of the contact problem, such as penalty or augmented Lagrangian methods, are avoided and a new direct elimination method is proposed. Conserving algorithms are also introduced for the proposed formulation for dynamic contact problems. An assessment of the performance of the resulting formulation is shown in a number of selected benchmark tests and numerical examples, including both quasi-static and dynamic contact problems under full stick friction and frictionless contact conditions. Conservation of key discrete properties exhibited by the time stepping algorithm used for dynamic contact problems is also shown in an example. [ABSTRACT FROM AUTHOR]

This paper presents an algorithm called “volume & neighbors” for finding elimination trees for multifrontal solver algorithm applied to three dimensional h -adaptive finite element method computations. The algorithm is described in a pseudo-code and explained on exemplary h -refined grids. The algorithm is implemented in three dimensional h -adaptive finite element method code and tested on a sequence of representative grids, namely uniform grid, grid with point singularity, grid with edge singularity and grid with face singularity. The number of floating point operations for the multifrontal solver algorithm working with the elimination trees generated by the volume & neighbors algorithm is compared with the number of floating-point operations resulting from execution of the state-of-the-art multifrontal direct solver MUMPS with state-of-the-art algorithms for constructing elimination trees like nested-dissection from METIS library and approximate minimum degree AMD algorithm as well as PORD algorithm. In all the cases the volume & neighbors algorithm outperforms other state-of-the art algorithms. The only exception is the case of the uniform grid, where the algorithm results in a similar number of FLOPs than nested dissection algorithm. [ABSTRACT FROM AUTHOR]

Abstract: Perfect vertex elimination schemes are part of the characterizations for several classes of graphs, including chordal and cop-win. Partial elimination schemes reduce a graph to an important subgraph, for example, -cores and robber-win graphs. We are interested in those partial elimination schemes, in which once a vertex is ready to be eliminated, it stays in that state regardless of which other vertices are eliminated. We show that in such a scheme, the sets of subsets of eliminated vertices, when ordered by inclusion, form an upper locally distributed lattice. We also show that (a) unless they contain a specific induced subgraph, the cop-win orderings have this property, and that (b) the process of cleaning graphs also leads to upper locally distributed lattices. Finally, we ask for an elimination scheme, which graphs are associated with distributive lattices? [Copyright &y& Elsevier]

Abstract: In Gaussian elimination it is often desirable to preserve existing zeros (sparsity). This is closely related to perfect elimination schemes on graphs. Such schemes can be found in polynomial time. Gaussian elimination uses a pivot for each column, so opportunities for preserving sparsity can be missed. In this paper we consider a more flexible process that selects a pivot for each nonzero to be eliminated and show that recognizing matrices that allow such perfect partial elimination schemes is NP-hard. [Copyright &y& Elsevier]

Abstract: We present an alternative explicit expression for the Moore–Penrose inverse of a matrix. Based on this expression, we propose a Gauss–Jordan elimination method for the computation of . Its computational complexity indicates that this method is more efficient than the existing Gauss–Jordan elimination method in the literature for a large class of problems. An example is included to illustrate the new method. [Copyright &y& Elsevier]

Abstract: Neville elimination is a direct method for the solution of linear systems of equations with advantages for some classes of matrices and in the context of pivoting strategies for parallel implementations. The growth factor is an indicator of the numerical stability of an algorithm. In the literature, bounds for the growth factor of Neville elimination with some pivoting strategies have appeared. In this work, we determine all the matrices such that the minimal upper bound of the growth factor of Neville elimination with those pivoting strategies is reached. [Copyright &y& Elsevier]

Abstract: Partial Granger causality was introduced by who showed that it could better eliminate the influence of latent variables and exogenous inputs than conditional G-causality. In the recent literature we can find some reviews and applications of this type of Granger causality (e.g. ). These articles apparently do not take into account a serious flaw in the original work on partial G-causality, being the negative F values that were reported and even proven to be plausible. In our opinion, this undermines the credibility of the obtained results and thus the validity of the approach. Our study is aimed to further validate partial G-causality and to find an answer why negative partial Granger causality estimates were reported. Time series were simulated from the same toy model as used in the original paper and partial and conditional causal measures were compared in the presence of confounding variables. Inference was done parametrically and using non-parametric block bootstrapping. We counter the proof that partial Granger F values can be negative, but the main conclusion of the original article remains. In the presence of unknown latent and exogenous influences, it appears that partial G-causality will better eliminate their influence than conditional G-causality, at least when non-parametric inference is used. [Copyright &y& Elsevier]

Abstract: The paper discusses a general methodology to the design of recursive Gaussian filters to be used for separating the form, waviness and roughness components of the surface texture. By selecting appropriate initial values for the filter difference equations, it is possible to eliminate the so-called edge effect and evaluate the whole registered profile. Two ways of filter implementation were considered: series and parallel. The incremental difference operator is applied in place of the usual shift operator z to describe the filter transfer function. This increases the accuracy of the representation of filter parameters and decreases the number of rounding errors. The results of the analysis were illustrated using 2D and 3D roughness profiles of a ball bearing race. The data show that the mean line and the mean surface were correctly determined for the whole area of the measured profile. [Copyright &y& Elsevier]

Abstract: We present a method for finding optimal controlled variables, which are polynomial combinations of measurements. Controlling these variables gives optimal steady state operation. Our work extends the concept of self-optimizing control; starting from the first-order necessary optimality conditions, any unknown variables are eliminated using elimination theory for polynomial systems to obtain invariant variable combinations, which contain only known variables (measurements). If a disturbance causes the active constraints to change, the invariants may be used to identify, and switch to the right region. This makes the method applicable over a wide disturbance range with changing active sets. The procedure is applied to two case studies of continuous stirred tank reactors. [Copyright &y& Elsevier]

Abstract: In this paper we present two new algorithmic variants to compute the Neville elimination, with and without pivoting, which improve data locality and cast most of the computations in terms of high-performance Level 3 BLAS. The experimental evaluation on a state-of-the-art multi-core processor demonstrates that the new blocked algorithms exhibit a much higher degree of concurrency and better cache usage, yielding higher performance while offering numerical accuracy akin to that of the traditional columnwise variant in most cases. [Copyright &y& Elsevier]

Abstract: Elimination methods are highly effective for the solution of linear and nonlinear systems of equations, but reversal of the elimination principle can be beneficial as well: competent incorporation of additional independent constraints and variables or more generally immersion of the original computational problem into a larger task, defined by a larger number of independent constraints and variables can improve global convergence of iterative algorithms, that is their convergence from the start. A well known example is the dual linear and nonlinear programming, which enhances the power of optimization algorithms. We believe that this is just an ad hoc application of general Principle of Expansion with Independent Constraints; it should be explored systematically for devising iterative algorithms for the solution of equations and systems of equations and for optimization. At the end of this paper we comment on other applications and extensions of this principle. Presently we show it at work for the approximation of a single zero of a univariate polynomial of a degree . Empirical global convergence of the known algorithms for this task is much weaker than that of the algorithms for all zeros, such as Weierstrass–Durand–Kerner’s root-finder, which reduces its root-finding task to Viète’s (Vieta’s) system of polynomial equations with unknowns. We adjust this root-finder to the approximation of a single zero of , preserve its fast global convergence and decrease the number of arithmetic operations per iteration from quadratic to linear. Together with computing a zero of a polynomial , the algorithm deflates this polynomial as by-product, and then could be reapplied to the quotient to approximate the next zero of . Alternatively by using processors that exchange no data, one can concurrently approximate up to zeros of . Our tests confirm the efficiency of the proposed algorithms. Technically our root-finding boils down to computations with structured matrices, polynomials and partial fraction decompositions. Our study of these links can be of independent interest; e.g., as by-product we express the inverse of a Sylvester matrix via its last column, thus extending the celebrated result of Gohberg and Sementsul (1972) from Toeplitz to Sylvester matrix inverses. [Copyright &y& Elsevier]

Abstract: In this paper we show that the intuitionistic theory for finitely many iterations of strictly positive operators is a conservative extension of Heyting arithmetic. The proof is inspired by the quick cut-elimination due to G. Mints. This technique is also applied to fragments of Heyting arithmetic. [Copyright &y& Elsevier]

Abstract: The elimination of whip using electromagnetic exciters (EEs) is investigated in this paper. First, mathematical models of a rotor-bearing system are derived. The threshold of instability determining if the rotor-bearing system experiences fluid-induced instability is obtained. Then, an experimental rotor-bearing system is designed and constructed to justify the elimination of whip, and orbit, spectrum, and spectrum cascade plots are obtained from the experimental data. The proposed procedure applies root locus plots to simulate the threshold of instability, and the spring model is used to compute the stiffness that the system needs to address the whip problem. Moreover, design examples are illustrated to explain the calculation process that tackles the proportional (simulating stiffness) and derivative (simulating damping) parameters of the EE to improve the stiffnesses of the rotor-bearing system. The main contribution of the present experimental work is that by using the EE it is possible to increase the stiffness of the rotor-bearing system and lead to the rotor-bearing system with a higher threshold of stability and eliminate the whip instability. [ABSTRACT FROM AUTHOR]

Abstract: Neville elimination is a direct method for solving linear systems. Several pivoting strategies for Neville elimination, including pairwise pivoting, are analyzed. Bounds for two different kinds of growth factors are provided. Finally, an approximation of the average normalized growth factor associated with several pivoting strategies is computed and analyzed using random matrices. [ABSTRACT FROM AUTHOR]

Abstract: We propose an elimination mechanism in the study of the evolutionary prisoner’s dilemma games on evolving networks. It assumes that after each round of playing, players whose payoffs are below a certain threshold will be eliminated from the game and the same number of new nodes will be added to the network to maintain the size of the network constant. Numerical results show that moderate values of elimination threshold can result in a maximum cooperation level in the evolutionary prisoner’s dilemma game. Moreover, the elimination mechanism can make the network structure evolve into a high heterogeneity in degree distribution, which is considered to be helpful in promoting cooperation in evolutionary games. The present study may provide new insight for understanding the evolution of cooperation in light of the law ‘survival of the fittest’ in nature. [Copyright &y& Elsevier]

Abstract: Neville elimination is an elimination procedure alternative to Gaussian elimination. It is very useful when dealing with totally positive matrices, for which nice stability results are known. Here we include examples, most of them test matrices used in MATLAB which are not totally positive matrices, where Neville elimination outperforms Gaussian elimination. [Copyright &y& Elsevier]

Abstract: An important property of chordal graphs is that these graphs are characterized by the existence of perfect elimination orderings on their vertex sets. In this paper, we generalize the notion of perfect elimination orderings to signed graphs, and give a characterization for graphs admitting such orderings, together with characterizations restricted to some subclasses and further properties of those graphs. The definition of our generalized perfect elimination orderings is motivated by a generalization of the classical result that a so-called graphic hyperplane arrangement is free if and only if the corresponding graph is chordal. [Copyright &y& Elsevier]

Abstract: This paper studies the forward kinematics of a symmetrical 6-6 Stewart platform, in which both the base and the mobile platform are hexagons and the joint centers satisfy some conditions. A concise algebraic elimination algorithm to solve the closed-form forward kinematics of the Stewart platform is presented. Based on the presented algebraic method, an interesting result that comes out of our study is that the forward kinematics problem is reduced to solve a univariate polynomial equation of degree at most 14. The 14th degree univariate polynomial is derived from the determinant of the 15×15 Sylvester’s matrix, which is relatively small in size, without factoring out or deriving the greatest common divisor. The algorithm is comparatively concise and requires fairly less computation time. The result is verified by a numerical example. [Copyright &y& Elsevier]

Abstract: We first look at an existing infinitary sequent system for common knowledge for which there is no known syntactic cut-elimination procedure and also no known non-trivial bound on the proof-depth. We then present another infinitary sequent system based on nested sequents that are essentially trees and with inference rules that apply deeply inside these trees. Thus we call this system “deep” while we call the former system “shallow”. In contrast to the shallow system, the deep system allows one to give a straightforward syntactic cut-elimination procedure. Since both systems can be embedded into each other, this also yields a syntactic cut-elimination procedure for the shallow system. For both systems we thus obtain an upper bound of on the depth of proofs, where is the Veblen function. [Copyright &y& Elsevier]

Abstract: In the paper we propose a new algorithm for the determination of peaks containing regions and their separation from peak-free regions. Further based on this algorithm we propose a new background elimination algorithm which allows more accurate estimate of the background beneath the peaks than the algorithms known so far. The algorithm is based on a clipping operation with the window adjustable automatically to the widths of identified peak regions. The illustrative examples presented in the paper prove in favor of the proposed algorithms. [Copyright &y& Elsevier]

Abstract: Elimination Game is a well-known algorithm that simulates Gaussian elimination of matrices on graphs, and it computes a triangulation of the input graph. The number of fill edges in the computed triangulation is highly dependent on the order in which Elimination Game processes the vertices, and in general the produced triangulations are neither minimum nor minimal. In order to obtain a triangulation which is close to minimum, the Minimum Degree heuristic is widely used in practice, but until now little was known on the theoretical mechanisms involved. In this paper we show some interesting properties of Elimination Game; in particular that it is able to compute a partial minimal triangulation of the input graph regardless of the order in which the vertices are processed. This results in a new algorithm to compute minimal triangulations that are sandwiched between the input graph and the triangulation resulting from Elimination Game. One of the strengths of the new approach is that it is easily parallelizable, and thus we are able to present the first parallel algorithm to compute such sandwiched minimal triangulations. In addition, the insight that we gain through Elimination Game is used to partly explain the good behavior of the Minimum Degree algorithm. We also give a new algorithm for producing minimal triangulations that is able to use the minimum degree idea to a wider extent. [Copyright &y& Elsevier]

Abstract: The reactions of Pd+ and Pt+ with CS2 have been investigated at B3LYP, CCSD(T) and QCISD(T) levels of theory. Both Pd+ and Pt+ are found to be able to activate the C–S bond in CS2 and produce the products PdS+ and PtS+ through insertion–elimination mechanism. For both Pd+ and Pt+ the spin-forbidden reaction 2M+ +CS2 → 4MS+ +CS is found to be energetically more favorable than the spin-allowed reaction 2M+ +CS2 → 2MS+ +CS. According to the identified reaction mechanisms and PESs, the doublet–quartet surface-crossing is presumed to occur at the exit channel of the reaction. The reactions of Ni+, Pd+ and Pt+ with CS2 are systematically compared in reaction mechanism and potential energy surface. Although all these reactions exhibit obvious endothermic feature, comparisons of these reactions indicate that the reaction of Pt+ with CS2 is energetically much more favorable. The calculated results well rationalize the experimental observations. [Copyright &y& Elsevier]

Abstract: This paper proves the strong normalization of classical natural deduction with disjunction and permutative conversions, by using CPS-translation and augmentations. Using them, this paper also proves the strong normalization of classical natural deduction with general elimination rules for implication and conjunction, and their permutative conversions. This paper also proves that natural deduction can be embedded into natural deduction with general elimination rules, strictly preserving proof normalization. [Copyright &y& Elsevier]

Abstract: A simple cut elimination proof for arithmetic with the epsilon symbol is used to establish the termination of a modified epsilon substitution process. This opens a possibility of extension to much stronger systems. [Copyright &y& Elsevier]

Abstract: The role of the base in the synthesis of 3′-deoxy-3′-[18F]fluorothymidine, [18F]FLT, via nucleophilic substitution of the nosyl group with [18F]fluoride was investigated. The rate of 18F-incorporation into the molecule dramatically changed as a function of the precursor-to-base ratio. In the presence of excess base, the precursor was consumed by elimination before substitution was complete. When the precursor-to-base ratio was optimal, an overall [18F]FLT yield of 30–40% was achieved even if the precursor amount was as small as 8–13mg. [Copyright &y& Elsevier]

Abstract: For a tree T and an integer , it is well known that the kth power of T is strongly chordal and hence has a strong elimination ordering of its vertices. In this note we obtain a complete characterization of strongly simplicial vertices of , thereby characterizing all strong elimination orderings of the vertices of . [Copyright &y& Elsevier]

Abstract: N-Mannich bases have been widely applied as prodrugs of amine drugs. The analogous C-Mannich bases (β-aminoketones) have received rather less attention probably because they are not sufficiently susceptible to elimination at pHs encountered in vivo. Compounds in which there is a thermodynamic advantage to elimination may be an exception. In this study, the physicochemical characteristics of a series of Michael amino addition adducts of chalcone and other carbonyl compounds is explored. The ketone adducts rapidly eliminate at around pH 7.4 (t 1/2 <15min) releasing the amine and the ketone but they are stable under acidic conditions. The Michael adducts are more lipophilic than the parent amines and have significantly suppressed ionisation characteristics at biologically relevant pH values. [Copyright &y& Elsevier]

Abstract: A pivoting strategy of operations for the Neville elimination of n × n nonsingular sign regular matrices is introduced. Among other nice properties, it is proved that it preserves sign regularity. It is also shown its relationship with scaled partial pivoting strategies for Neville elimination. [Copyright &y& Elsevier]

Abstract: The molecular mechanism of the Hoffmann elimination involving (N-Cl),N-methylethanolamine and HO− to yield 2-methyleneamino-ethanol has been theoretically characterized by using DFT at the B3LYP/6-31++G∗∗ computing level. The role of water as a solvent was analyzed by using both discrete and hybrid discrete-continuum models. The rearrangement proceeds along a water-assisted asynchronous concerted mechanism. The Gibbs free energy reaction barrier decreases when two water molecules are included in the reaction, one of them acting simultaneously as H+ donor/acceptor to/from the nitrogen/oxygen atom of (N-Cl),N-methylethanolamine, although not involved in a proton relay mechanism, it favours the elimination. [Copyright &y& Elsevier]

Abstract: In this paper we apply the recently introduced Random Forest-Recursive Feature Elimination (RF-RFE) algorithm to the identification of relevant features in the spectra produced by Proton Transfer Reaction-Mass Spectrometry (PTR-MS) analysis of agroindustrial products. The method is compared with the more traditional Support Vector Machine-Recursive Feature Elimination (SVM-RFE), extended to allow multiclass problems, and with a baseline method based on the Kruskal–Wallis statistic (KWS). In particular, we apply all selection methods to the discrimination of nine varieties of strawberries and six varieties of typical cheeses from Trentino Province, North Italy. Using replicated experiments we estimate unbiased generalization errors. Our results show that RF-RFE outperforms SVM-RFE and KWS on the task of finding small subsets of features with high discrimination levels on PTR-MS data sets. We also show how selection probabilities and features co-occurrence can be used to highlight the most relevant features for discrimination. [Copyright &y& Elsevier]

Abstract: We present a Gröbner basis associated with the symmetric group of degree , which is determined by a strong generating set of the symmetric group and is defined by means of a term ordering with the elimination property. [Copyright &y& Elsevier]

Abstract: The formation and fragmentation of the indene dication is studied using synchrotron radiation. The double-ionization energy of indene amounts to 21.8±0.1eV. The appearance energies of the fragments and are 25.8±0.1eV and 25.7±0.2eV, respectively. Although the appearance energies are almost the same, the dicationic fragment is formed in a higher yield than . It is suggested that the elimination of atomic hydrogen is associated with a considerable energy barrier, whereas the H2 elimination proceeds via very small barrier or is barrier-less process with respect to the reaction endothermicity. [Copyright &y& Elsevier]

Abstract: For an important class of organic reactions in which a fragment of the reactants, the leaving group (LG) or nucleofuge (Z), is detached of the substrate bearing the bonding electron pair, the global electrophilicity index of the CH3LG system is proposed as a reliable descriptor of the intrinsic nucleofugality of the LG. The model is illustrated by ranking within a unique relative scale, the LG ability of 28 functional groups commonly involved in substitution and elimination reactions in organic chemistry. [Copyright &y& Elsevier]

Abstract: Epistasis is the interaction between two or more genes to control a single phenotype. We model epistasis with a two-locus two-allele problem. The resulting model allows us to examine both population sizes as well as genotypic and phenotypic frequencies. In the context of an example, we show that if epistasis results in an undesirable phenotype, such as a genetically transmitted disease or condition, elimination of undesirable phenotypes from the population through selective breeding may be possible, although such selective breeding could lead to an increase in less desirable phenotypes and possibly the elimination of desirable phenotypes. [Copyright &y& Elsevier]

Abstract: The component structure of a generic supersymmetric nonlinear sigma-model (NLSM) defined in the four-dimensional (Euclidean) nonanticommutative (NAC) superspace is investigated in detail. The most general NLSM is described in terms of arbitrary Kähler potential, and chiral and antichiral superpotentials. The case of a single chiral superfield gives rise to splitting of the NLSM potentials, whereas the case of several chiral superfields results in smearing (or fuzziness) of the NLSM potentials, while both effects are controlled by the auxiliary fields. We eliminate the auxiliary fields by solving their algebraic equations of motion, and demonstrate that the results are dependent upon whether the auxiliary integrations responsible for the fuzziness are performed before or after elimination of the auxiliary fields. There is no ambiguity in the case of splitting, i.e., for a single chiral superfield. Fully explicit results are derived in the case of the supersymmetric NAC-deformed NLSM in four dimensions. Here we find another surprise that our results differ from the supersymmetric NLSM derived by the quotient construction from the supersymmetric NAC-deformed gauge theory. We conclude that an supersymmetric deformation of a generic NLSM from the NAC superspace is not unique. [Copyright &y& Elsevier]

Abstract: We introduce a system of simply typed lambda terms (with fixed point combinators) and show that a rather comprehensive class of (co-)recursion equations on streams or non-wellfounded trees can be solved in our system. Moreover certain conditions are presented which guarantee that the defined functionals are primitive recursive. As a major example we give a co-recursive treatment of Mints’ continuous cut-elimination operator. [Copyright &y& Elsevier]

Abstract: The dynamics of initial decomposition of gas phase 1,3,3-trinitroazetidine (TNAZ) is investigated by using B3LYP/6-31+G(d,p) method and microcanonical variational transition state theory. Three initial decomposition pathways, NO2 fission, HONO elimination, and direct ring-opening reaction are considered. The calculated rate constants indicate that the rate constants of NO2 fission reaction are larger than those of both HONO elimination and ring-opening reaction in gas phase. However, HONO elimination and ring-opening channels may be important for the decomposition reaction of TNAZ in solid state. These results provide new understanding of the dynamics of the initial decomposition steps of TNAZ. [Copyright &y& Elsevier]

Abstract: We give geometric axioms for existentially closed Hasse fields. We prove a quantifier elimination result for existentially closed -truncated Hasse fields and characterize them as reducts of existentially closed Hasse fields. [Copyright &y& Elsevier]

Abstract: The rotating-wave approximation (RWA) is a formalism of great utility in the description of the coherent excitation of atoms and molecules by laser light. Not only does it give results in agreement with experiment, it also provides a simple framework allowing the Hamiltonian of a system to be written down from inspection of the state-linkage diagram. Recent interest in systems with a two-photon coupling prompted an investigation of the structure of two-photon terms in RWA Hamiltonians. In carrying through the derivation, an interaction with adiabatic elimination was discovered. It is shown that adiabatic elimination must be performed before application of the RWA, else terms are dropped that ought to be retained. RWA Hamiltonians for three-state systems with one and two two-photon linkages are displayed. [Copyright &y& Elsevier]

Abstract: This paper examines the synthesis of the five degree-of-freedom robot formed by links connected by a revolute, prismatic and spherical joint to form an RPS serial chain. The reachable workspace of this robot is a right circular hyperboloid that defines a constraint equation with 10 dimensional parameters. Evaluating this equation on 10 arbitrary spatial positions yields a polynomial system of total degree 262,144. Polynomial continuation yields as many as 1024 RPS chains for a general 10 position task. The number of task positions and constraint equations can be reduced by specifying some of the dimensional parameters. For the cases of six through eight task positions, analytical solutions are provided using both a resultant elimination strategy as well as a generalized eigenvalue elimination procedure. The generalized eigenvalue method has been implemented using Java and integrated into our design software. A numerical example of the solution for eight design positions is presented. [Copyright &y& Elsevier]

Abstract: We report here the effect of annealing temperature (750–850°C), when annealing in air for 50h, on the structural, mechanical and superconducting properties of Bi2Sr2CaCu2O8+ δ (Bi:2212) system. X-ray diffraction, bulk density and microhardness measurements for sintered and annealed Bi:2212 are presented in details. The superconducting critical temperature T c, the residual resistivity and the resistivity slope corresponding to the linear -T region are extracted from electrical resistivity measurements. It is found that the amount of low-T c phase (2212) is gradually increasing with increasing annealing temperature up to 850°C. Interestingly, the critical temperature T c is found to be increased from 78 up to 100K by increasing the annealing temperature, along with sharpening of the transition. The sharpest transition may be attributed to a high homogeneity of the superconducting grains. Moreover, the Vickers microhardness (VHN) and the bulk density are also increased with annealing temperature increase. This behavior reflects the improvement of the coupling between superconducting grains. From these observations, one can see clearly that the improvement of electrical resistivity and micro-hardness is caused by elimination, by annealing, of oxygen disorder and microcracks elimination. [Copyright &y& Elsevier]

The ground-state intramolecular gas-phase dissociation pathways of ethyl fluoroformate radical cation (FCOOCH2CH·3+) are studied using density functional molecular orbital methods. Initial geometries are optimized using the 6-31G* basis set. Electron correlation is incorporated by optimizing the geometries at the B3LYP level using the 6-31G** basis set. Stationary points are characterized by frequency calculation at the same level of theory and basis set. In the first installment of this paper, the existence of so-called enol pathway was reported and the dissociation mechanism was described in detail. In this installment, a new dissociation mechanism, a supposed keto pathway, is proposed. In this reaction channel, the ester linkage is immediately broken in a rate-determining E1 step producing FCOOꔷ and C2H·5+ which reacts further in a bimolecular elimination mechanism to yield the same intermediates (FCOOH + C2H·4+ as the enol pathway. In a similar manner as the enol pathway, the keto pathway is terminated by a slow elimination of a proton from C2H·4+ by FCOOH which acts as a base in an E2 elimination scheme. The keto pathway is more accessible than the enol pathway explaining the relative heights of the MS peaks in the EI spectrum of ethyl fluoroformate. [Copyright &y& Elsevier]

Abstract: The biochemical paradigm for carbon monoxide (CO) is driven by the century-old Warburg hypothesis: CO alters O2-dependent functions by binding heme proteins in competitive relation to 1/oxygen partial pressure (PO2). High PO2 thus hastens CO elimination and toxicity resolution, but with more O2, CO-exposed tissues paradoxically experience less oxidative stress. To help resolve this paradox we tested the Warburg hypothesis using a highly sensitive gas-reduction method to track CO uptake and elimination in brain, heart, and skeletal muscle in situ during and after exogenous CO administration. We found that CO administration does increase tissue CO concentration, but not in strict relation to 1/PO2. Tissue gas uptake and elimination lag behind blood CO as predicted, but 1/PO2 vs. [CO] fails even at hyperbaric PO2. Mechanistically, we established in the brain that cytosol heme concentration increases 10-fold after CO exposure, which sustains intracellular CO content by providing substrate for heme oxygenase (HO) activated after hypoxia when O2 is resupplied to cells rich in reduced pyridine nucleotides. We further demonstrate by analysis of CO production rates that this heme stress is not due to HO inhibition and that heme accumulation is facilitated by low brain PO2. The latter becomes rate limiting for HO activity even at physiological PO2, and the heme stress leads to doubling of brain HO-1 protein. We thus reveal novel biochemical actions of both CO and O2 that must be accounted for when evaluating oxidative stress and biological signaling by these gases. [Copyright &y& Elsevier]

Abstract: An easy and general sequenced elimination/reduction or elimination/cyclopropanation process promoted by samarium diiodide or/and CH2I2/Sm provide an efficient method for synthesising 2,3-dideuterioamides 3 or cyclopropanamides 8, respectively. The transformations take place in high yields and with total or high selectivity from the easily available 2,3-epoxyamides. [Copyright &y& Elsevier]

We introduce the new notion of additive “multibox” for linear logic proof-nets. Thanks to this notion, we define a cut-elimination procedure which associates with every proof-net of multiplicative and additive linear logic a unique cut-free one. [Copyright &y& Elsevier]