Procedimento de operação, manutenção e verificação de thermomixer.

bitstream/CENARGEN/29576/1/ct060.pd

Procedimento de operação, manutenção e verificação da centrífuga refrigerada de bancada Eppendorf, Modelo 5810 R.

bitstream/CENARGEN/29583/1/ct063.pd

Procedimento de operação, manutenção e verificação da estufa ELETROLAB modelo 112FC.

bitstream/CENARGEN/29586/1/ct065.pd

Procedimento de operação, manutenção e verificação do Espectrofotômetro.

bitstream/CENARGEN/29588/1/ct067.pd

Spin-glass phase transition and behavior of nonlinear susceptibility in the Sherrington-Kirkpatrick model with random fields

The behavior of the nonlinear susceptibility $\chi_3$ and its relation to the spin-glass transition temperature $T_f$, in the presence of random fields, are investigated. To accomplish this task, the Sherrington-Kirkpatrick model is studied through the replica formalism, within a one-step replica-symmetry-breaking procedure. In addition, the dependence of the Almeida-Thouless eigenvalue $\lambda_{\rm AT}$ (replicon) on the random fields is analyzed. Particularly, in absence of random fields, the temperature $T_f$ can be traced by a divergence in the spin-glass susceptibility $\chi_{\rm SG}$, which presents a term inversely proportional to the replicon $\lambda_{\rm AT}$. As a result of a relation between $\chi_{\rm SG}$ and $\chi_3$, the latter also presents a divergence at $T_f$, which comes as a direct consequence of $\lambda_{\rm AT}=0$ at $T_f$. However, our results show that, in the presence of random fields, $\chi_3$ presents a rounded maximum at a temperature $T^{*}$, which does not coincide with the spin-glass transition temperature $T_f$ (i.e., $T^* > T_f$ for a given applied random field). Thus, the maximum value of $\chi_3$ at $T^*$ reflects the effects of the random fields in the paramagnetic phase, instead of the non-trivial ergodicity breaking associated with the spin-glass phase transition. It is also shown that $\chi_3$ still maintains a dependence on the replicon $\lambda_{\rm AT}$, although in a more complicated way, as compared with the case without random fields. These results are discussed in view of recent observations in the LiHo$_x$Y$_{1-x}$F$_4$ compound.Comment: accepted for publication in PR

Control of state and state entanglement with a single auxiliary subsystem

We present a strategy to control the evolution of a quantum system. The novel aspect of this protocol is the use of a \emph{single auxiliary subsystem}. Two applications are given, one which allows for state preservation and another which controls the degree of entanglement of a given initial state

Synchronism in electoral cycles : how united are the United States?

The role of national, sectional, state, and local forces in driving electoral outcomes in the United States has remained a matter of considerable indeterminacy in the American politics literature. In what concerns House elections, different approaches and methods have yielded widely divergent results. In what concerns presidential elections, considerable doubts remain about the timing and the plausible causes of a long-term trend towards homogeneity. In this paper, we take a new look at the nationalization of politics in the United States. We are particularly interested in the dynamic nationalization in presidential elections, i.e., the extent to which swings and shifts from one election to the next have been similar across states and whether or not that similarity has increased through time. We treat this problem as one of similarity or dissimilarity — and convergence or divergence of — electoral cycles, and use wavelets analysis in order to ascertain the degree to which the national and state election cycles have been synchronized and the degree to which that synchronization has increased or decreased. We determine, first, the states where electoral change has been more in sync with the national cycle and clusters of states defined in terms of the mutual synchronization of their own electoral cycles. Second, we analyze how the degree of synchronization of electoral cycles in the states has changed through time, answering questions as to when, to what extent, and where has the tendency towards a “universality of political trends” in presidential elections been more strongly felt. We present evidence strongly in favor of an increase in the dynamic nationalization of presidential elections taking place in the 1950s, showing that alternative interpretations concerning the historical turning point in this respect are not supported by empirical evidence.Fundação para a Ciência e a Tecnologia (FCT

An Ultra-Stable Referenced Interrogation System in the Deep Ultraviolet for a Mercury Optical Lattice Clock

We have developed an ultra-stable source in the deep ultraviolet, suitable to fulfill the interrogation requirements of a future fully-operational lattice clock based on neutral mercury. At the core of the system is a Fabry-P\'erot cavity which is highly impervious to temperature and vibrational perturbations. The mirror substrate is made of fused silica in order to exploit the comparatively low thermal noise limits associated with this material. By stabilizing the frequency of a 1062.6 nm Yb-doped fiber laser to the cavity, and including an additional link to LNE-SYRTE's fountain primary frequency standards via an optical frequency comb, we produce a signal which is both stable at the 1E-15 level in fractional terms and referenced to primary frequency standards. The signal is subsequently amplified and frequency-doubled twice to produce several milliwatts of interrogation signal at 265.6 nm in the deep ultraviolet.Comment: 7 pages, 6 figure