Classification of the phases of 1D spin chains with commuting Hamiltonians

We consider the class of spin Hamiltonians on a 1D chain with periodic boundary conditions that are (i) translational invariant, (ii) commuting and (iii) scale invariant, where by the latter we mean that the ground state degeneracy is independent of the system size. We correspond a directed graph to a Hamiltonian of this form and show that the structure of its ground space can be read from the cycles of the graph. We show that the ground state degeneracy is the only parameter that distinguishes the phases of these Hamiltonians. Our main tool in this paper is the idea of Bravyi and Vyalyi (2005) in using the representation theory of finite dimensional C^*-algebras to study commuting Hamiltonians.Comment: 8 pages, improved readability, added exampl

Protocolos para extração de DNA genômico de amostras de pêlo de bovinos.

Descreve uma experiência de padronização de protocolo de extração de DNA de células do bulbo capilar de pêlos coletados da vassoura da cauda de bovinos visando a utilização em análises por PCR.bitstream/item/24672/1/ct87-protocolos-extracaoDNA.pd

Graph Concatenation for Quantum Codes

Graphs are closely related to quantum error-correcting codes: every stabilizer code is locally equivalent to a graph code, and every codeword stabilized code can be described by a graph and a classical code. For the construction of good quantum codes of relatively large block length, concatenated quantum codes and their generalizations play an important role. We develop a systematic method for constructing concatenated quantum codes based on "graph concatenation", where graphs representing the inner and outer codes are concatenated via a simple graph operation called "generalized local complementation." Our method applies to both binary and non-binary concatenated quantum codes as well as their generalizations.Comment: 26 pages, 12 figures. Figures of concatenated [[5,1,3]] and [[7,1,3]] are added. Submitted to JM

Bath Adsorption Study of Methylene Blue Dye Onto Sunflower Seeds Husks Activated Carbon

Mesoporous activated carbon prepared from sunflower seeds husks (SSH) using physiochemical activation (potassium hydroxide treatment and carbon dioxide gasification). The optimum conditions for preparing activated carbon from (SSH) were found to be activation temperature of 500 oC, activation time of 1.0 h and chemical impregnation ratio of 1:1. The adsorptions of methylene blue (MB) onto sunflower seed husks activated carbon (SSHAC) were studied with respect to initial MB concentration. The experimental data were analyzed by the Langmuir isotherm, the Freundlich isotherm and the Temkin isotherm. Equilibrium data fitted well with the Langmuir model with maximum adsorption capacity of 410 mg/g at 30 oC for MB concentration range of 50-300 mg/L. Desorption-adsorption studies for the spent SSHAC (saturated with MB) using ethanol as solvent showed that regeneration efficiency around 85%. The results indicated that the SSHAC is very effective for the adsorption of MB from aqueous solutions and can be regenerate to use for more than two adsorption cycles

Ultra-Stretchable Interconnects for High-Density Stretchable Electronics

The exciting field of stretchable electronics (SE) promises numerous novel applications, particularly in-body and medical diagnostics devices. However, future advanced SE miniature devices will require high-density, extremely stretchable interconnects with micron-scale footprints, which calls for proven standardized (complementary metal-oxide semiconductor (CMOS)-type) process recipes using bulk integrated circuit (IC) microfabrication tools and fine-pitch photolithography patterning. Here, we address this combined challenge of microfabrication with extreme stretchability for high-density SE devices by introducing CMOS-enabled, free-standing, miniaturized interconnect structures that fully exploit their 3D kinematic freedom through an interplay of buckling, torsion, and bending to maximize stretchability. Integration with standard CMOS-type batch processing is assured by utilizing the Flex-to-Rigid (F2R) post-processing technology to make the back-end-of-line interconnect structures free-standing, thus enabling the routine microfabrication of highly-stretchable interconnects. The performance and reproducibility of these free-standing structures is promising: an elastic stretch beyond 2000% and ultimate (plastic) stretch beyond 3000%, with 10 million cycles at 1000% stretch with <1% resistance change. This generic technology provides a new route to exciting highly-stretchable miniature devices.Comment: 13 pages, 5 figure, journal publicatio

PARTICLE DEGRADATION

A linear air gun was used to examine the effect of particle velocity, impact angle, particle diameter, the number of impacts, target thickness and target material on the degradation of three types of spherical particles (Aluminum oxide, Polystyrene and Glass)

Simulations and cosmological inference: A statistical model for power spectra means and covariances

We describe an approximate statistical model for the sample variance distribution of the non-linear matter power spectrum that can be calibrated from limited numbers of simulations. Our model retains the common assumption of a multivariate Normal distribution for the power spectrum band powers, but takes full account of the (parameter dependent) power spectrum covariance. The model is calibrated using an extension of the framework in Habib et al. (2007) to train Gaussian processes for the power spectrum mean and covariance given a set of simulation runs over a hypercube in parameter space. We demonstrate the performance of this machinery by estimating the parameters of a power-law model for the power spectrum. Within this framework, our calibrated sample variance distribution is robust to errors in the estimated covariance and shows rapid convergence of the posterior parameter constraints with the number of training simulations.Comment: 14 pages, 3 figures, matches final version published in PR