Web-GIS models: accomplishing modularity with aspects

Spatial concerns of Web geographical information systems (Web-GIS) are inherently crosscutting and volatile: crosscutting because they affect multiple functionalities of Web-GIS systems, and volatile because their status may change often. If these concerns are not modularized properly, the quality of Web-GIS services, particularly with regard to adaptation and evolution, can be severely compromised. This paper uses aspect-orientation to model crosscutting and volatile spatial concerns. By modeling both types of concerns, crosscutting and volatile, as candidate aspects, one can use dynamic weaving to add or remove them from a system at runtime. The aspect-oriented approach proposed starts with the identification and specification of crosscutting concerns and follows by composing these using modeling aspects using a transformation approach, an aspect-oriented modeling technique. The conflicts that can emerge due to the composition order are also taken into consideration. Finally, this paper proposes a set of reusable GIS crosscutting concerns, documenting them in a concern catalogue.     

Structural,optical and electrical properties of silicon nanocrystals embedded in SixC1−x/SiC multilayer systems for photovoltaic applications

In this work we present a structural, optical and electrical characterization of Si_xC_1?x/SiC multilayer systems with different silicon content. After the deposition process, an annealing treatment was carried out in order to induce the silicon nanocrystals formation. By means of energy-filtered transmission electron microscopy (EFTEM) we observed the structural morphology of the multilayers and the presence of crystallized silicon nanoprecipitates for samples annealed up to 1100 °C. We discuss the suitability of optical techniques such as Raman scattering and reflectance and transmittance (R&T) for the evaluation of the crystalline fraction of our samples at different silicon excess ranges. In addition, the combination of R&T measurements with simulation has proved to be a useful instrument to confirm the structural properties observed by EFTEM. Finally, we explore the origin of the extremely high current density revealed by electrical measurements, probably due to the presence of an undesired defective SiC_yO_z ternary compound layer, already supported by the structural and optical results. Nevertheless, the variation of the electrical measurements with the silicon amount indicates a small but significant contribution from the multilayers.     

TBARs distillation method: Revision to minimize the interference from yellow pigments in meat products

The aim was to study the effect of the incubation method and TBA reagent (concentration/solvent) on yellow pigment interference in meat products. Distillates from red sausage, sucrose, malondialdehyde and a mixture of sucrose–malondialdehyde were reacted with four different TBA solutions at five different temperature/time relations. Two TBA solutions were prepared at 20 mM using 90% glacial acetic acid or 3.86% perchloric acid. In addition, an 80 mM TBA solution was prepared using distilled water adjusted to pH 4 and another using 0.8% TBA in distilled water. The temperature/time relations were: (1) 35 min in a boiling water bath; (2) 70 °C/30 min; (3) 40 °C/90 min; (4) room temperature (r.t.) (24 °C) in dark conditions for 20 h; and (5) 60 min in a boiling water bath. The results showed that aqueous or diluted acid solutions of TBA reagent and the application of 100 °C for less than 1 h provided the best conditions to minimize the presence of yellow pigments and maximize pink pigment formation in meat products.     

Stability Analysis of a Human Arm Interacting with a Force Augmenting Device

This paper presents a stability analysis of the interaction between a human and a linear moving Force Augmenting Device (FAD). The analysis employs a mathematical model of the human arm, the FAD and their interaction. As a depart from past works, this article presents a stability analysis considering time-delays in the human model. A key ingredient in the analysis is the use of the Rekasius substitution for replacing the time-delay terms. It is proved that the human machine interaction is stable when the human model has no delays. When delays are considered in the human model, the analysis provides an upper bound for the time-delays preserving a stable interaction. Numerical simulations allow to assess the human-FAD interaction. An experiment is performed with a laboratory prototype, where a human operator lifts a load. It is observed that the human machine interaction is stable and the human operator is able to move the load to a desired position by experiencing very little effort.     

Analysis of coding risks in progressive transmission

In progressive image transmission, there exist some risks which may appear during the processing. A first class of risks is the diminishing coding performance when the occurrence of insignificant coefficients at each transmission time is a small-probability event. It may be a catastrophic transmission risk which can lead to major and irreversible bit losses. In a second class of risks, the performance of the transmission technique diminishes though the occurrence of insignificant sample is still a large-probability event.This paper shows a “Test of Transmission Risks” which can be used to analyze, for a given image, the performance of the state of the art in progressive transmission from the viewpoint of the catastrophic transmission risks. To this aim we make use of a decision making tool based on axioms requiring sensitivity to coding situations where the occurrence of insignificant sample at the transmission time may be either a small-probability or a large-probability event.     

Ethyl group as matrix modifier and inducer of ordered domains in hybrid xerogels synthesised in acidic media using ethyltriethoxysilane (ETEOS) and tetraethoxysilane (TEOS) as precursors

Hybrid silica xerogels favourably combine the properties of organic and inorganic components in one material; consequently these materials are useful for multiple applications. The versatility and mild synthetic conditions provided by the sol-gel process are ideal for the synthesis of hybrid materials. The specific aims of this study were to synthesise hybrid xerogels in acidic media using tetraethoxysilane (TEOS) and ethyltriethoxysilane (ETEOS) as silica precursors, and to assess the role of the ethyl group as a matrix modifier and inducer of ordered domains in xerogels. All xerogels were synthesised at pH 4.5, at 60 °C, with 1:4.75:5.5 TEOS:EtOH:H₂O molar ratio. Gelation time exponentially increased with the ETEOS molar ratio. Incorporation of the ethyl groups into the structure of xerogels reduced cross-linking, increased the average siloxane bond length, and promoted the formation of ordered domains. As a result, a transition from Qⁿ to Tⁿ signals detected in the ²⁹Si NMR spectra, the Si–O structural band in the FTIR spectra shifted to lower wavelength, and a new peak in the XRD pattern at 2θ < 10° appeared in the XRD patterns. Mass spectroscopy detected fragments with high numbers of silicon atoms and a polymeric distribution.     

Physiological compliance for social gaming analysis: Cooperative versus competitive play

We report the results of an empirical study demonstrating the value of using physiological compliance as a measure of social presence during digital game playing. The physiological activity (facial EMG, electrodermal activity, cardiac activity and respiration) of 21 dyads were acquired synchronously while they were playing a digital game either cooperatively or competitively and either at home or in the laboratory. Physiological compliance was defined as the correlation between the physiological signals of the dyad members. The results of this study confirm that physiological compliance is higher in a conflicting situation than when playing cooperatively. Importantly, the results also demonstrate that physiological compliance is related to self-reported social presence. This suggests that physiological compliance is not limited to negative situations but rather increases due to rich interactions. Only minor differences in physiological compliance were observed between home play and laboratory play, suggesting the ecological validity of laboratory measures. Finally, we propose that compliance measures can be considered as objective indices of social presence in digital gaming.     

Crude glycerine inclusion in Limousin bull diets: Animal performance,carcass characteristics and meat quality

Three hundred and six Limousin young bulls (7 ± 1 months of age, initial body weight 273 ± 43 kg) were used to evaluate the effect of crude glycerine supplementation on animal performance, carcass characteristics and meat quality. Animals were assigned to three different diets: Control (0% of crude glycerine), G2 and G4 (2 and 4% of crude glycerine, respectively). The diets were administrated ad libitum for 240 days (final body weight 644 ± 24 kg). Average daily weight gain, average daily feed intake, the gain:feed ratio, ultrasound measures in vivo, carcass characteristics, pH, water holding capacity, drip losses, and cooking losses were not affected (P > 0.05) by diets. Diet decreased C16:0 (P < 0.01) and C16:1 (P < 0.05) contents in meat. The G4 meat showed lower C12:0, C14:0, C17:0, C18:0, C18:1, C18:2, C18:3, c9,t11-c18:2, C20:0 and C20:4 levels (P < 0.05) than control. Glycerine increased desirable fatty acid percentages (P < 0.05) in intramuscular fat.