Solving identity delegation problem in the e-government environment

At present, many countries allow citizens or entities to interact with the government outside the telematic environment through a legal representative who is granted powers of representation. However, if the interaction takes place through the Internet, only primitive mechanisms of representation are available, and these are mainly based on non-dynamic offline processes that do not enable quick and easy identity delegation. This paper proposes a system of dynamic delegation of identity between two generic entities that can solve the problem of delegated access to the telematic services provided by public authorities. The solution herein is based on the generation of a delegation token created from a proxy certificate that allows the delegating entity to delegate identity to another on the basis of a subset of its attributes as delegator, while also establishing in the delegation token itself restrictions on the services accessible to the delegated entity and the validity period of delegation. Further, the paper presents the mechanisms needed to either revoke a delegation token or to check whether a delegation token has been revoked. Implications for theory and practice and suggestions for future research are discussed.     

A technique for defining agent-oriented engineering processes with tool support

The formalization of engineering processes is necessary for guaranteeing the quality and cost of the products involved. Agent-oriented engineering has already proposed development processes that still need to be further formalized to be applicable by non-researchers. This paper proposes a technique to instantiate processes for specific agent-oriented methodologies. This technique is based on three orthogonal views that are respectively related with lifecycles, disciplines and guidances. In addition, processes are modeled with a tool, which is automatically generated from a process metamodel inspired by the software & systems process engineering metamodel. Accordingly, engineers can choose the methodology–process pair best-suited for the characteristics of their project. The paper illustrates the approach based on the unified development process and the scrum process for the INGENIAS methodology and compares the results with other existing alternatives.     

A framework for the definition of metamodels for Computer-Aided Software Engineering tools

Computer-Aided Software Engineering (CASE) tools support modeling-related activities in development projects. Given the variety of tools and functionalities, it is quite common to work with several tools in the same project. However, data cannot usually be exchanged between these tools without loss of information. Recent approaches address this model interchange problem using metamodels to characterize the involved information and transformations to export/import it. Nevertheless, most of these solutions focus on the abstract syntax of models. They fail to consider aspects such as the presentation of models or tool-specific information, which are either disregarded or represented in ad-hoc ways that make difficult their processing. In order to overcome these limitations, this paper introduces a framework to define metamodels of CASE tools and a process to carry out the model interchange using them. The proposed metamodels have a modular organization with several internal metamodels. Each of them is aimed at describing some specific information about content, structure and presentation for both models and tools. The paper illustrates this approach with a case study used for comparison with existing works for this problem.     

Biodegradation of 4-methylaniline in a sequencing batch reactor

The biodegradation of the aromatic amine 4-methylaniline (4MA) using an aerobic sequencing batch reactor was evaluated. The specific degradation rate showed an exponential increase during the acclimation of the microorganisms reaching a maximal value of 34 mg 4MA/VSS/h. After the acclimation, the process showed a stable operation. A high similarity index was observed, indicating a low variation in the population diversity. During this period, the physicochemical parameters demonstrated a stable operation of the reactor.     

On the Plasma-Chemical Synthesis of Nanopowders

This paper presents an overview of nanopowders preparation using low-temperature plasma (LTP). LTP with its unique processing capabilities provides an attractive and chemically unspecific route for powder synthesis. Nanopowders such as oxides, nitrides, carbides, catalysts and other nanopowders have been successfully synthesized in LTP reactors based on high intensity arcs, plasma jets and radio-frequency (r. f.) inductively coupled discharges.     

Crude oil aggregation by microscopy and dynamic light scattering

This research is focused on establishing a methodology to evaluate the aggregation state of Mexican crude oil solutions from two different sources and SARA compositions, by using Dynamic Light Scattering (DLS). Different crude oil concentrations were established and monitored through time in order to determine their effects on the aggregation state. DLS results indicate that the aggregation state of the studied solutions is influenced by crude oil composition, specifically by the amount of resins. Particle size and elemental analysis of the aggregates were performed by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX), respectively. Results from these techniques reveal particulated low-porosity smooth surfaces due to the presence of resin, as well as the determination of the characteristic elements found in asphaltenes. High-Resolution Transmission Electron Microscopy (HTEM) indicated the presence of asphaltene aggregates constituted by nanometric particles and asphaltene stacking as well as ultrafine nanocrystalline-oriented structures.     

A smartphone-based system for detecting hand tremors in unconstrained environments

The detection of tremors can be crucial for the early diagnosis and proper treatment of some disorders such as Parkinson’s disease. A smartphone-based application has been developed for detecting hand tremors. This application runs in background and distinguishes hand tremors from common daily activities. This application can facilitate the continuous monitoring of patients or the early detection of this symptom. The evaluation analyzes 1770 accelerometer samples with cross-validation for assessing the ability of the system for processing unknown data, obtaining a sensitivity of 95.8 % and a specificity of 99.5 %. It also analyzes continuous data for some volunteers for several days, which corroborated its high performance.     

PDMS microfluidics developed for polymer based photonic biosensors

In this work, advances in the fabrication technology and functional analysis of a polymer microfluidic system—as a significant part of a developed polymer photonic biosensor—are reported. Robust and cost-effective microfluidics in PDMS including sample preparation functions is designed and realized by using SU-8 moulding replica. Surface modification strategies using Triton X-100 and PDMS-PEO and their effect on device sealing and non-specific protein adsorption are investigated by contact angle measurement and in situ fluorescence microscopy.