Bladder psoas hitch. Report of 11 cases

Bladder psoas hitch is an surgical technique which, in very complicated cases, like repeated failures of vesico-ureteral re-implants or undiversions, allow us to bridge the shortness of the ureter and obtain a good vesico-ureteral reimplant. The surgical maneuver is described and several of the 11 cases operated by this technique are commented. The results are presented.     

Plasma enhanced chemical vapor deposition of SiO2 films at low temperatures using SiCl4 and O2

Silicon dioxide films have been deposited by Plasma-Enhanced Chemical Vapor Deposition (PECVD) technique using SiCl₄ and O₂ as reactive materials. Infra-red transmittance, Auger electron spectroscopy analysis, ellipsometry, electrical, and chemical etch measurements have been used to characterize these films. It is possible to obtain good quality oxides at a substrate temperature of 200° C using a low flow of reactant gases. High flow of reactant gases results in highly non-homogeneous porous films. The best oxide films obtained show destructive breakdown at electrical fields above 4 MV/cm and a fixed charge density of the order of 2.6 × 10¹¹ charges/cm².     

All-optical AND gate implementation using cross-polarizationmodulation in a semiconductor optical amplifier

We demonstrate experimentally a new design for an all-optical AND gate operating in the gigahertz regime. The efficiency of this effect was estimated by measuring the conversion coefficients C_TETM/ and C_TMTE/ indicating the TE to TM mode conversion and vice versa when the amplifier is perturbed with a wavelength tunable control beam. The all-optical gate here described differ from others developed before using semiconductor optical amplifiers in its ability to operate on nondegenerate input signals and to produce an output signal with an independent wavelength from the wavelengths of the input signals     

Physical Reasoning to Synchronize Electrical Signals and Related Diagnostics in Plasma Focus Devices

Plasma Focus (PF) devices as well as other similar pulsed discharge devices requires a variety of diagnostics for their proper control and optimization, including the voltage between electrodes, the time derivative of the discharge current, detection of X-rays and neutron emissions, and pulsed laser images (Shadow, Schlieren, interferograms). This article discusses the problem of the time reference of all these outputs and proposes specific techniques for synchronizing them based on sound physical grounds. The foundations of synchronization criterion are verified in several experiments on PF devices.     

Long term storage of virus templated fluorescent materials for sensing applications

Wild type, mutant, and chemically modified Cowpea mosaic viruses (CPMV) were studied for long term preservation in the presence and absence of cryoprotectants. Viral complexes were reconstituted and tested via fluorescence spectroscopy and a UV/vis-based RNase assay for structural integrity. When viruses lyophilized in the absence of cryoprotectant were rehydrated and RNase treated, UV absorption increased, indicating that the capsids were damaged. The addition of trehalose during lyophilization protected capsid integrity for at least 7 weeks. Measurements of the fluorescence peak maximum of CPMV lyophilized with trehalose and reconstituted also indicate that the virus remained intact. Microarray binding assays indicated that CPMV particles chemically modified for use as a fluorescent tracer were intact and retained binding specificity after lyophilization in the presence of trehalose. Thus, we demonstrate that functionalized CPMV nanostructures can be stored for the long term, enabling their use in practical sensing applications.     

An efficient fluid-solid coupled finite element scheme for weapon fragmentation simulations

An efficient finite element (FE) scheme to deal with a class of coupled fluid-solid problems is presented. The main ingredients of such methodology are: an accurate Q1/P0 solid element (trilinear in velocities and constant piecewise-discontinuous pressures); a large deformation plasticity model; an algorithm to deal with material failure, cracking propagation and fragment formation; and a fragment rigidization methodology to avoid the possible numerical instabilities that may produce pieces of material flying away from the main solid body. All the mentioned schemes have been fully parallelized and coupled using a loose-embedded procedure with a well-established and validated computational fluid dynamics (CFD) code (FEFLO). A CSD and a CFD/CSD coupled case are presented and analyzed.     

Classifying unlabeled short texts using a fuzzy declarative approach

Web 2.0 provides user-friendly tools that allow persons to create and publish content online. User generated content often takes the form of short texts (e.g., blog posts, news feeds, snippets, etc). This has motivated an increasing interest on the analysis of short texts and, specifically, on their categorisation. Text categorisation is the task of classifying documents into a certain number of predefined categories. Traditional text classification techniques are mainly based on word frequency statistical analysis and have been proved inadequate for the classification of short texts where word occurrence is too small. On the other hand, the classic approach to text categorization is based on a learning process that requires a large number of labeled training texts to achieve an accurate performance. However labeled documents might not be available, when unlabeled documents can be easily collected. This paper presents an approach to text categorisation which does not need a pre-classified set of training documents. The proposed method only requires the category names as user input. Each one of these categories is defined by means of an ontology of terms modelled by a set of what we call proximity equations. Hence, our method is not category occurrence frequency based, but highly depends on the definition of that category and how the text fits that definition. Therefore, the proposed approach is an appropriate method for short text classification where the frequency of occurrence of a category is very small or even zero. Another feature of our method is that the classification process is based on the ability of an extension of the standard Prolog language, named Bousi~Prolog , for flexible matching and knowledge representation. This declarative approach provides a text classifier which is quick and easy to build, and a classification process which is easy for the user to understand. The results of experiments showed that the proposed method achieved a reasonably useful performance.     

IEEE 802.21: Media independence beyond handover

The IEEE 802.21 standard facilitates media independent handovers by providing higher layer mobility management functions with common service primitives for all technologies. Right after the base specification was published, several voices rose up in the working group advocating to broaden the scope of IEEE 802.21 beyond handovers. This paper aims at updating the reader with the main challenges and functionalities required to create a Media Independence Service Layer, through the analysis of scenarios which are being discussed within the working group: 1) Wireless Coexistence, and 2) Heterogeneous Wireless Multihop Backhaul Networks.     

Cell formation in group technology using constraint programming and Boolean satisfiability

Cell formation consists in organizing a plant as a set of cells, each of them containing machines that process similar types or families of parts. The idea is to minimize the part flow among cells in order to reduce costs and increase productivity. The literature presents different approaches devoted to solve this problem, which are mainly based on mathematical programming and on evolutionary computing. Mathematical programming can guarantee a global optimal solution, however at a higher computational cost than an evolutionary algorithm, which can assure a good enough optimum in a fixed amount of time. In this paper, we model and solve this problem by using state-of-the-art constraint programming (CP) techniques and Boolean satisfiability (SAT) technology. We present different experimental results that demonstrate the efficiency of the proposed optimization models. Indeed, CP and SAT implementations are able to reach the global optima in all tested instances and in competitive runtime.