Safety effects of low-cost engineering measures. An observational study in a Portuguese multilane road

Single carriageway multilane roads are not, in general, a very safe type of road, mainly because of the high number of seriously injured victims in head-on collisions, when compared with dual carriageway multilane roads, with a median barrier.     

Environmental performance assessment of a provider of logistical services in an industrial supply chain

This paper presents a method for assessing environmental performance in industrial operations. The method was applied to three logistical operations in an industrial supply chain performed by a single operator: road transportation, warehousing, and urban transportation. Environmental performance was treated as a complex object and was structured according to the following five criteria: atmospheric emissions, liquid effluents, solid waste, natural and energy resources, and managerial and legal regulations. The first four criteria address a direct impact on the environment, whereas the last is a necessary condition for the first four to have a satisfactory performance. Six experts in environmental management prioritized the criteria and defined sets of indicators for the field appraisal. The indicators were expected to be correlated for the same criteria. The validity of the indicators was assessed through questionnaires answered by six managers of the operation. Finally, three overall indices corresponding to the environmental performance of the three logistical operations were calculated for the operations and were found to be 73.58, 79.21, and 76.28% (higher is better). These indicate good results because the maximum performance is expected to be 100%. This environmental performance assessment can aid in reformulating the environmental strategies embedded in the operational strategy of the company.     

Digitalisation and employment in manufacturing

The present work tackles the issue of the effects of digitalisation on employment. This issue has been attracting a growing interest, in particular because of the anxiety generated by the idea that digital technologies could cancel a large number of jobs. Although I agree with argument put forward in opposition to the existence of a causal link between technological innovation and increased productivity at the macroeconomic level, I believe that the novelty and pervasiveness of digital technologies require more in-depth micro-level analysis in order to understand the extent to which new digital technologies are currently employed by leading manufacturing companies and the ways new technologies are affecting employment. The empirical findings show that among the different technologies included under the umbrella of Industry 4.0, mainly robots have received a great deal of attention so far, while the current application and employment impact for other emerging technological opportunities such as 3D printing, Internet of Things, Augmented reality, Big data Analytics have not been studied yet. In relation to the qualitative changes of the labour market, our empirical research confirms that there are new types of skills that will be demanded in the future in manufacturing, in particular in relation to service provision and software development.     

Influence of mesostasis in volcanic rocks on the alkali-aggregate reaction

Mesostasis material present in the interstices of volcanic rocks is the main cause of the alkali-aggregate reaction (AAR) in concretes made with these rock aggregates. Mesostasis often is referred to as volcanic glass, because it has amorphous features when analyzed by optical microscopy. However, this study demonstrates that mesostasis in the interstitials of volcanic rocks most often consists of micro to cryptocrystalline mineral phases of quartz, feldspars, and clays. Mesostasis has been identified as having different characteristics, and, thus, this new characterization calls for a re-evaluation of their influence on the reactivity of the volcanic rocks. The main purpose of this study is to correlate the characteristics of mesostasis with the AAR in mortar bars containing basalts and rhyolites.     

Determination of pyrethroids in chicken egg samples: development and validation of a confirmatory analytical method by gas chromatography/mass spectrometry

The aim of this study was to develop and validate an efficient analytical method based on gas chromatography/tandem mass spectrometry (GC/MS/MS) for detection and quantification of six pyrethroids residues (Phenothrin, Permethrin, Cyfluthrin, Cypermethrin, Deltamethrin and Fenvalerate) in chicken eggs. The method was based on a preliminary liquid–liquid extraction of albumen‐free yolk samples, followed by a clean‐up by solid‐phase extraction. GC/MS/MS analyses were carried out in the selected reaction monitoring mode. Validation parameters such as specificity, detection capability, decision limit, precision, recovery, stability and ruggedness were determined, resulting in compliance with Decision 2002/657/EC. No complicated apparatus are required; moreover, low volumes of organic solvents and a nonintensive manual labour are required. These low costs and simple procedure, based on rapid and safe operations, may represent a useful tool in the routine analysis of pyrethroids pesticides, in the place of the currently used conventional techniques.     

Adaptive tracking control of Euler–Lagrange systems with bounded controls

We solve the simultaneous closed‐loop identification and tracking‐control problems for fully‐actuated Euler–Lagrange systems under input constraints. We use a nonlinear adaptive controller reminiscent of computed‐torque‐type controllers in which linear correction terms are saturated in order to comply with the imposed bounds on the control inputs. Adaptation, reminiscent of gradient methods, is used also with saturation. With respect to related literature, our contribution consists in establishing uniform global asymptotic stability. Therefore, our control scheme ensures robustness with respect to bounded perturbations and uniform convergence of the estimation errors for any initial conditions. Copyright © 2016 John Wiley & Sons, Ltd.     

Modification of coconut fibers with polyaniline for manufacture of pressure‐sensitive devices

This article studies the modification of coconut fibers with polyaniline (PAni) with help of statistical experimental design techniques. The main factors studied here were the techniques used for particle dispersion (sonication vs. magnetic stirring) and the type of initiator (ammonium persulfate, APS, vs. ammonium cerium sulfate dihydrate, Ce(IV)). The obtained materials were characterized through low field nuclear magnetic resonance, small‐and wide‐angle X‐ray scattering, scanning electron microscopy, fourier transform infrared spectroscopy, and ultraviolet–visible spectroscopy. Additionally, the electrical resistivities and respective sensitivities to variations of the applied pressure were evaluated for all obtained samples, with help of standard volume resistivity measurements and electro‐mechanical tests. The materials prepared through magnetic stirring with APS presented the best electrical and electromechanical properties, although materials prepared through sonication with Ce(IV) also presented good electrical and electromechanical properties and could be prepared much faster. As a consequence, modification of coconut fibers with PAni, using sonication as the particle dispersion technique and Ce(IV) as initiator, constitutes a very promising procedure for manufacture of pressure‐sensitive devices. POLYM. ENG. SCI., 54:2887–2895, 2014. © 2014 Society of Plastics Engineers