[en] Recent coordination of thermometry with optical images has shown that obvious defects at specific locations produce heat or even quench superconducting radio frequency (SRF) cavities, imposing a significant limit on the overall accelerating gradient produced by the cavity. Characterization of the topography at such locations provides clues about how the defects originated, from which schemes for their prevention might be devised. Topographic analyses also provide understanding of the electromagnetic mechanism by which defects limit cavity performance, from which viability of repair techniques might be assessed. In this article we discuss how a variety of two-component silicone-based room-temperature vulcanizing agents can be routinely used to make replicas of the cavity surface and extract topographic details of cavity defects. Previously, this level of detail could only be obtained by cutting suspect regions from the cavity, thus destroying the cavity. We show 3-D profiles extracted from several different 1.3 GHz cavities. The defect locations, which were all near cavity welds, compelled us to develop extraction techniques for both equator and iris welds as well as from deep inside long 9-cell cavities. Profilometry scans of the replicas yield micrometer-scale information, and we describe various curious features, such as small peaks at the bottom of pits, which were not apparent in previous optical inspections. We also discuss contour information in terms of electromagnetic mechanisms proposed by others for local cavity heating. We show that production of the replica followed by high-pressure rinsing dose not adversely affect the cavity RF performance.

[en] The effects of the two lowest-order uniaxial anisotropy fields on the phase diagrams of the classical m-vector spin glass are analyzed. The model is defined in terms of infinite-range interactions and the replica approach is used to study the system. The replica-symmetric phase diagrams present qualitative modifications with respect to those with no uniaxial anisotropies; new features, in particular, reentrance effects arise. In some cases, the reentrant critical frontiers are totally inside the region of instability of the replica-symmetric solution and may disappear within more general parametrizations, whereas in other cases, they coincide with the limit of stability of such a solution and should persist under replica-symmetry breaking

[en] The influence of time-dependent impurity on the electronic and transport properties of the tilted superlattices modeled by the tight-binding Hamiltonian is investigated. The quasienergies of the system are calculated in two methods: exact diagonalization and Floquet replica technique, the subtle effects of the impurity on the dynamics of the system are discussed in detail. Through a perturbative analysis in terms of the inverse of the time-dependent impurity frequency, we obtain the time-independent effective Hamiltonian, whose reliability and physical implication are discussed

[en] Extraction replicas provide a powerful extension of AEM techniques for analysis of fine precipitates. In many cases, replicas allow more accurate analyses to be performed and, in some cases, allow unique analyses which cannot be performed in-foil. However, there are limitations to the use of extraction replicas in AEM, of which the analyst must be aware. Many can be eliminated by careful preparation. Often, combined AEM studies of precipitates in-foil and on extraction replicas provide complementary and corroborative information for the fullest analysis of precipitate phases

[en] Following a general introduction to the rationale and physical events of 'shadowing' (a method common to virtually all replica techniques) the coating-unit and details of its use, and the shadowing technique are described. Attention is focused particularly upon the means of observing small isolated particles, particularly macromolecules. A general introduction to the concept of the replica, as used in examining bulk specimens is presented and replica techniques in the materials sciences and the biological sciences are outlined. Freeze-etching is described. Finally the resolution limits of the shadowing technique (by means of which the detail in replicas is usually revealed) is explored. Some notes on quantitative methods, particularly on the estimation of particle size in shadowed specimens, are also included. (Auth.)

[en] In this paper we show that in systems where the probability distribution of the the overlap is non trivial in the infinity volume limit, the property of ultrametricity can be proved in general starting from two very simple and natural assumptions: each replica is equivalent to the others (replica equivalence or stochastic stability) and all the mutual information about a pair of equilibrium configurations is encoded in their mutual distance or overlap (separability or overlap equivalence). (author)

[en] Recent coordination of thermometry with optical images has shown that obvious defects at specific locations produce heat or even quench superconducting radio-frequency (SRF) cavities, imposing a significant limit on the overall accelerating gradient produced by the cavity. Characterization of the topography at such locations provides clues about how the defects originated, from which schemes for their prevention might be devised. Topographic analyses also provide understanding of the electromagnetic mechanism by which defects limit cavity performance, from which viability of repair techniques might be assessed. In this paper we discuss how a variety of two-component silicone-based room-temperature vulcanizing agents can be routinely used to make replicas of the cavity surface and extract topographic details of cavity defects. Previously, this level of detail could only be obtained by cutting suspect regions from the cavity, thus destroying the cavity. We show 3D profiles extracted from several different 1.3 GHz cavities. The defect locations, which were all near cavity welds, compelled us to develop extraction techniques for both equator and iris welds as well as from deep inside long 9-cell cavities. Profilometry scans of the replicas yield micrometre-scale information, and we describe various curious features, such as small peaks at the bottoms of pits, which were not apparent in previous optical inspections. We also discuss contour information in terms of electromagnetic mechanisms proposed by others for local cavity heating. We show that production of the replica followed by high-pressure rinsing does not adversely affect the cavity RF performance.

[en] A connection between fractional supersymmetric quantum mechanics and ordinary supersymmetric quantum mechanics is established in this Letter

[en] We study the saddle points of the SYK model, formulated in terms of the replica bilocal fields, beyond the replica-diagonal assumption. We find a family of replica-nondiagonal saddle points in the IR limit, where the saddle point equations are separable. We use the Parisi Ansatz to find the replica- nondiagonal solutions and take the replica limit. The free energy on these solutions is computed, and we find that some of the replica-nondiagonal saddles have lower free energy than the replica-diagonal saddle point. (authors)

[en] Full Text: Implementation of the metallographic methods can be done by removal of samples or non destructively by replication. The replica method is one of a number of on-site metallurgical techniques used to establish the physical condition and properties of a material. It is used to evaluate the microstructure condition and in crack detection, hence can be applied for periodic monitoring in ascertaining creep-life expenditure. (Author)