Holographic optical elements recorded on spherical surfaces with photopolymers

A method for recording of holograms on spherical substrates is presented. As recording material we used a photopolymer placed between two spherical glass plates that are concentric.     

An enzootic with pseudo-tumoral manifestations in Vipera lebetina in captivity

The authors report the clinical and epizootic evolution of an epizooty, characterized by pseudo-tumours, observed on some vipers (Vipera lebetina) maintained in captivity at the "institut Pasteur de Tunis". The disease was characterized by 2.3 cm size nodules, scattered under the skin or into splanchnic cavities. These ones, spherical and well capsuled, were formed by a mass of clear rounded cells (histiocytes or monocytes), the necrotic central area of which contained innumerable bacteria. Several reviewed works show that this appearance of chronic abcess is a common and univocal reaction to various pathogenic factors, such as bacteria and parasites. As to etiology, the authors have doubt about the pathological role of the germs which they have identified (Salmonella and other anterobacteria) because these latter belong to the normal microbial flora of snakes and are, in the present case, probably occasional infective agents only.     

A Methodological Approach for Object-Relational Database Design using UML

The most common way of designing databases is by means of a conceptual model, such as E/R, without taking into account other views of the system. New object-oriented design languages, such as UML (Unified Modelling Language), allow the whole system, including the database schema, to be modelled in a uniform way. Moreover, as UML is an extendable language, it allows for any necessary introduction of new stereotypes for specific applications. Proposals exist to extend UML with stereotypes for database design but, unfortunately, they are focused on relational databases. However, new applications require complex objects to be represented in complex relationships, object-relational databases being more appropriate for these requirements. The framework of this paper is an Object-Relational Database Design Methodology, which defines new UML stereotypes for Object-Relational Database Design and proposes some guidelines to translate a UML conceptual schema into an object-relational schema. The guidelines are based on the SQL:1999 object-relational model and on Oracle8i as a product example. Initial submission: 22 January 2002 / Revised submission: 10 June 2002 Published online: 7 January 2003 This paper is a revised and extended version of Extending UML for Object-Relational Database Design, presented in the UML’2001 conference [17].     

Humidity-Sensing Characteristics of Divalent-Metal-Doped Indium Oxide Thin Films

Metal-doped indium oxide thin films that have been prepared on glass substrates via a dip-coating method from an aqueous sol show a rapid decrease in electrical conductivity at room temperature (by approximately three orders of magnitude) when brought into contact with moist air. This observation is in contrast to the conductivities of nondoped indium oxide films that are independent of moisture. Thus, the doped films can be applied as a humidity sensor. The film thickness has no substantial effect on the sensing properties, probably because of the porous nature of the films that are prepared by a sol-gel process. To examine the effects of film morphology, a comparison between the humidity-sensing properties of the films that have been prepared from organic and aqueous sols also has been conducted. The roles of the doped metal ions are also discussed.     

Specific roof behavior in the southern wing of the Upper Kama potash salt deposit

The authors consider a number of geomechanical monitoring methods for the underworked salt rock behavior, including visual control of its specific structural features, measurement of displacements using contour and depth reference points, and assessment of stresses in the surrounding rock mass. It is proposed to assess stresses in salt rocks using long spacing measurement methods without modeling-based recovery of stresses from measured strains if possible.     

Multidisciplinary approach to the assessment of historic structures based on the case of a masonry bridge in Galicia (Spain)

The paper presents a general method to evaluate a masonry structure with a complex geometry and unknown material properties. This multidisciplinary approach integrates close range digital photogrammetry, ground probing radar (GPR) and finite elements analysis (FEM) to analyse a masonry bridge. The resulting information from photogrammetry and radar is applied to define a 3D model, which is then used to simulate the behaviour of the bridge using FEM. Two different approaches to model the internal composition of the bridge with finite elements are presented. Sensitivity analysis is applied to study the reasons of the structural damage.     

Detection of potentially mycotoxigenic Aspergillus species in Capsicum powder by a highly sensitive PCR-based detection method

The objective of this study was to gain information about the toxigenic Aspergillus species present in a wide survey of retail samples of paprika and chilli collected in Spain. Detection of these mycotoxigenic species was performed with an optimized protocol for paprika and chilli which includes a set of species-specific PCR assays. Occurrence of toxigenic Aspergillus species was higher in paprika than in chilli samples (83.9% and 64.5%, respectively). Paprika showed also the highest percentage of co-occurrence of two or more different species (43.6%) in comparison with chilli (35.5%). The most common aspergilli were Aspergillus niger aggregate (67.7%), followed by Aspergillus flavus (49.5%). Aspergillus carbonarius, Aspergillus parasiticus and Aspergillus steynii were detected at lower frequency (1.1%). The high co-occurrence of Aspergillus species able to produce ochratoxin A and aflatoxins, particularly in paprika, suggested the need of a more efficient control during processing and storage to reduce fungal contamination, and additional legislation to consider the simultaneous presence of both toxins in these matrices.     

Recent advances in the meshless simulation of aluminium extrusion and other related forming processes

Summary In this paper we review some recent results in the field of numerical simulation of extrusion and other forming processes obtained by the authors by using a meshless approach, together with a wide review of the existing bibliography on the topic. Three main alternatives exist in the literature, namely (updated) Lagrangian, Eulerian and arbitrary Lagrangian-Eulerian (ALE) methods. A review of the most important characteristics of each of these three approaches is here presented and their possible advantages are pointed out. Finally, an updated Lagrangian approach over a meshless approximation, based on a class of methods globally coined as natural element methods (also as natural neighbour Galerkin methods) is analysed and its relative advantages studied. Some numerical examples are included that clearly show the potential capabilities of the proposed method.