Catalytic Dehydrogenation of Tetradecanol over Copper/Barium Oxide Catalysts

The liquid phase dehydrogenation of tetradecanol to tetradecanal has been studied over a series of CuO/BaO catalysts. Catalytic activity and selectivity to tetradecanal was found to depend on the ratio of easily reducible copper sites to less easily reducible copper sites. The catalysts have been characterized by X-ray diffraction, temperature programmed reduction, and thermo-gravimetric analysis. TPR results have shown that there were at least two types of copper oxides with varying reducibility. The relationship between the activity and area ratio of various copper oxide sites and a scheme for the conversion of tetradecanol were discussed

Two flavors of dynamical quarks on anisotropic lattices

We report on our study of two-flavor full QCD on anisotropic lattices using $O(a)$-improved Wilson quarks coupled with an RG-improved glue. The bare gauge and quark anisotropies corresponding to the renormalized anisotropy $\xi=a_s/a_t = 2$ are determined as functions of $\beta$ and $\kappa$, which covers the region of spatial lattice spacings $a_s\approx 0.28$--0.16 fm and $m_{PS}/m_V\approx 0.6$--0.9. The calibrations of the bare anisotropies are performed with the Wilson loop and the meson dispersion relation at 4 lattice cutoffs and 5--6 quark masses. Using the calibration results we calculate the meson mass spectrum and the Sommer scale $r_0$. We confirm that the values of $r_0$ calculated for the calibration using pseudo scalar and vector meson energy momentum dispersion relation coincide in the continuum limit within errors. This work serves to lay ground toward studies of heavy quark systems and thermodynamics of QCD including the extraction of the equation of state in the continuum limit using Wilson-type quark actions.Comment: 16 pages, 23 figures, Version accepted for publication in Physical Review

Renormalization group improved action on anisotropic lattices

We study a block spin transformation in the SU(3) lattice gauge theory on anisotropic lattices to obtain Iwasaki's renormalization group improved action for anisotropic cases. For the class of actions with plaquette and $1\times2$ rectangular terms, we determine the improvement parameters as functions of the anisotropy $\xi= a_s/a_t$. We find that the program of improvement works well also on anisotropic lattices. From a study of an indicator which estimates the distance to the renormalized trajectory, we show that, for the range of the anisotropy $\xi \approx 1$--4, the coupling parameters previously determined for isotropic lattices improve the theory considerably.Comment: 15 pages, 10 figure

GoalD: A Goal-Driven Deployment Framework for Dynamic and Heterogeneous Computing Environments

Context: Emerging paradigms like Internet of Things and Smart Cities utilize advanced sensing and communication infrastructures, where heterogeneity is an inherited feature. Applications targeting such environments require adaptability and context-sensitivity to uncertain availability and failures in resources and their ad-hoc networks. Such heterogeneity is often hard to predict, making the deployment process a challenging task. Objective: This paper proposes GoalD as a goal-driven framework to support autonomous deployment of heterogeneous computational resources to fulfill requirements, seen as goals, and their correlated components on one hand, and the variability space of the hosting computing and sensing environment on the other hand. Method: GoalD comprises an offline and an online stage to fulfill autonomous deployment by leveraging the use of goals. Deployment configuration strategies arise from the variability structure of the Contextual Goal Model as an underlying structure to guide autonomous planning by selecting available as well as suitable resources at runtime. Results: We evaluate GoalD on an existing exemplar from the selfadaptive systems community – the Tele Assistance Service provided by Weyns and Calinescu [1]. Furthermore, we evaluate the scalability of GoalD on a repository consisting of 430,500 artifacts. The evaluation results demonstrate the usefulness and scalability of GoalD in planning the deployment of a system with thousands of components in a few milliseconds

From linear to circular economy: The role of BS 8001:2017 for green transition in small business in developing economies

Implementing Circular Economy (CE) strategies has recently become one of the essential strategies for sustainable development and corporate social responsibility. However, despite the promising role and potential benefits of the CE for companies and society, there has still been insufficient analysis examining the challenges for circular transition faced by micro, small, and medium-sized enterprises (MSMEs) and the role that standards, such as British Standard (BS) 8001:2017, play during the transition process from linear to circular economy practices. Given this context and to further increase our understanding of the factors preventing the transition from linear to CE, this study aims to assess the CE implementation in MSMEs in developing economies in light of BS 8001:2017 through a survey with Brazilian MSMEs. The primary findings emphasize that CE practices from the Administration dimension occupied top positions in the ranking of implementation, along with one practice from the Innovation dimension. However, the results show that several practices associated with Transparency and Product Optimization in the value chain held the last level of evidence of implementation. Findings suggest that assessing MSMEs through BS 8001:2017 is beneficial for aiding them in analysing and reconsidering their practices related to the conventional linear business models of take-use-dispose. Collectively, the findings improve our understanding of the level of adoption of CE components implementation, the most and the least adopted practices during the CE transition. The study also provides implications for policy, theory, and practical applications in cases where there is an interest in assessing the maturity of CE implementation within MSMEs in developing economies

Thermodynamics of SU(3) gauge theory on anisotropic lattices

Finite temperature SU(3) gauge theory is studied on anisotropic lattices using the standard plaquette gauge action. The equation of state is calculated on $16^{3} \times 8$, $20^{3} \times 10$ and $24^{3} \times 12$ lattices with the anisotropy $\xi \equiv a_s / a_t = 2$, where $a_s$ and $a_t$ are the spatial and temporal lattice spacings. Unlike the case of the isotropic lattice on which $N_t=4$ data deviate significantly from the leading scaling behavior, the pressure and energy density on an anisotropic lattice are found to satisfy well the leading $1/N_t^2$ scaling from our coarsest lattice, $N_t/\xi=4$. With three data points at $N_t/\xi=4$, 5 and 6, we perform a well controlled continuum extrapolation of the equation of state. Our results in the continuum limit agree with a previous result from isotropic lattices using the same action, but have smaller and more reliable errors.Comment: RevTeX, 21 pages, 17 PS figures. A quantitative test about the benefit of anisotropic lattices added, minor errors corrected. Final version for PR

The flavour singlet mesons in QCD

We study the flavour singlet mesons from first principles using lattice QCD. We explore the splitting between flavour singlet and non-singlet for vector and axial mesons as well as the more commonly studied cases of the scalar and pseudoscalar mesons.Comment: 12 pages, LATEX, 4 ps figure

Charmonium Spectrum from Quenched Anisotropic Lattice QCD

We present a detailed study of the charmonium spectrum using anisotropic lattice QCD. We first derive a tree-level improved clover quark action on the anisotropic lattice for arbitrary quark mass. The heavy quark mass dependences of the improvement coefficients, i.e. the ratio of the hopping parameters $\zeta=K_t/K_s$ and the clover coefficients $c_{s,t}$, are examined at the tree level. We then compute the charmonium spectrum in the quenched approximation employing $\xi = a_s/a_t = 3$ anisotropic lattices. Simulations are made with the standard anisotropic gauge action and the anisotropic clover quark action at four lattice spacings in the range $a_s$=0.07-0.2 fm. The clover coefficients $c_{s,t}$ are estimated from tree-level tadpole improvement. On the other hand, for the ratio of the hopping parameters $\zeta$, we adopt both the tree-level tadpole-improved value and a non-perturbative one. We calculate the spectrum of S- and P-states and their excitations. The results largely depend on the scale input even in the continuum limit, showing a quenching effect. When the lattice spacing is determined from the $1P-1S$ splitting, the deviation from the experimental value is estimated to be $\sim$30% for the S-state hyperfine splitting and $\sim$20% for the P-state fine structure. Our results are consistent with previous results at $\xi = 2$ obtained by Chen when the lattice spacing is determined from the Sommer scale $r_0$. We also address the problem with the hyperfine splitting that different choices of the clover coefficients lead to disagreeing results in the continuum limit.Comment: 43 pages, 49 eps figures, revtex; minor changes, version to appear in Physical Review

Magnetic string contribution to hadron dynamics in QCD

Dynamics of a light quark in the field of static source (heavy-light meson) is studied using the nonlinear Dirac equation, derived recently. Special attention is paid to the contribution of magnetic correlators and it is found that it yields a significant increase of string tension at intermediate distances. The spectrum of heavy-light mesons is computed with account of this contribution and compared to experimental and lattice data.Comment: 10 pages Revte

Parallel tempering in full QCD with Wilson fermions

We study the performance of QCD simulations with dynamical Wilson fermions by combining the Hybrid Monte Carlo algorithm with parallel tempering on $10^4$ and $12^4$ lattices. In order to compare tempered with standard simulations, covariance matrices between sub-ensembles have to be formulated and evaluated using the general properties of autocorrelations of the parallel tempering algorithm. We find that rendering the hopping parameter $\kappa$ dynamical does not lead to an essential improvement. We point out possible reasons for this observation and discuss more suitable ways of applying parallel tempering to QCD.Comment: 16 pages, 3 figure