Mechanical spectroscopy in commercial Fe–6 wt.% Si alloys between 400 and 1000 K

Mechanical spectroscopy, neutron diffraction and differential scanning calorimetry (DSC) were performed on commercial Fe–6 wt.% Si alloy after quenching from high temperature. The damping spectrum shows a peak at around 800 K and an associated modulus defect. The modulus shows an increase during the second and subsequent heating runs. In addition, an anomaly in the modulus behavior has been found at around 400 K. Different thermal treatments allows to obtain two different recovery degrees of the quenched-in defects. The influence of the recovery degree on the 800 K internal friction peak and on the anelastic modulus has been evaluated and confirm the validity of the grain boundary mechanism associated to this peak. Experimental results are discussed on the basis of recovery and ordering processes.     

Structural Changes in EPDM Subjected to Ageing in High Voltage Transmission Lines

This work presents a study of the structural changes in aged EPDM (ethylene-propylene-diene monomer) from outdoor high voltage transmission lines. Samples were taken from failed and non-failed insulators after up to ten years in service on a 33 kV line. Infrared absorption, hydrophobicity index, dynamical mechanical analysis (DMA) and dielectric relaxation (DR) were employed as experimental techniques. The same experimental techniques were also applied to new samples of EPDM that were subjected to high electric fields (up to 14 kV/mm) for several hours. Results from DMA and DR techniques are in good agreement and, together with previous results from neutron irradiation techniques, suggest that the experimental data obtained from outdoor-aged and laboratory tested samples may be explained by a decrease in the degree of crystallinity due to the interaction between electrical and mechanical effects in the dielectric. The proposed model is based on the disentanglement of the crystallites by forces originated in the interaction of the electric field with the polar groups located in the amorphous phase of the polymer matrix. An alternative explanation, based on a relaxation process appearing at the interfaces between the filler (ATH) and the polymer matrix conflicts with several experimental results presented in this work.     

The impact of computer‐based instruction on the development of EFL learners' writing skills

The current study investigated the application and effectiveness of computer assisted language learning (CALL) in teaching academic writing to Iranian EFL (English as a Foreign Language) learners by means of Microsoft Word Office. To this end, 44 sophomore intermediate university students majoring in English Language and Literature at an Iranian university who had enrolled in a course called Advanced Writing were randomly divided into two groups. As a pre‐test, a pen‐and‐paper writing task was given to both groups at the beginning of the semester. The control group including 24 male and female students was taught based on traditional approach while the experimental group including 20 male and female students was taught based on CALL. At the end of one semester, a pen‐and‐paper writing task was given to both groups. The results of the post‐test revealed that the students who were exposed to computer‐based instruction outperformed their counterparts in terms of using appropriate articles, tense, plural forms and spelling. Moreover, the students in the experimental group produced paragraphs of higher quality. The findings of this study confirmed the efficacy of computer‐based instruction in the development of EFL learners' writing skills.     

Comparing the impact of bentonite addition for both must clarification and wine fining on the chemical profile of wine from Chambave Muscat grapes

The impact of bentonite fining is generally studied on final wines, and few studies have evaluated it throughout the winemaking process. This work studied the fate of proteins and terpenols, the main targets of bentonite addition, during the processing of Chambave Muscat aromatic grapes. The experimental trials were performed in two vintages (2006 and 2007) and included the following processes: bentonite addition to must only (100 g hL^?1 in both vintages), fining of wine only (100 g hL^?1 in both vintages), double bentonite treatment on must and wine (200 and 150 g hL^?1 in 2006 and in 2007, respectively) and no treatment (control). The results demonstrated that the treatment allowing the best removal of protein was the addition of bentonite to must only. Moreover, a lower removal of free terpenols was observed in samples from double treatment compared with wines fined with bentonite only after alcoholic fermentation.     

Food uses of pineapple waste and by-products: a review

Waste from fruits and vegetable processing industry is produced in large quantities worldwide and it contains high levels of lignocellulose, fibre, sugar, bioactive and functional compounds. Their utilisation has become one of the main important and challengeable aspects due to the generation of large quantities of by-products including peels, seeds, leaves and unused flesh in different steps of processing chain. Many researches have validated the waste utilisation as novel, low-cost, economical and natural sources of dietary fibre, antioxidants, pectin, enzymes, organic acids, food additives, essential oils, etc. through different methods of extractions, purifications and fermentations. Though, obtaining these by-products from such a variable substrate requires an understanding of the composition of the polysaccharides and their associations within the overall substrate. Focus on the pineapple fruit, scientific and technological studies have already highlighted and confirmed the potential of better and more profitable markets for pineapple wastes. This review is first of all the collection of previous reports about valorisation of food processing waste, deepening the possibilities of pineapple waste utilisation and to promote the integral exploitation of the by-products rich in bioactive compounds, even as multifunctional food ingredients. More in detail, this review aims at identifying those processes that can be implemented even in disadvantaged areas by means of technologies that allow recovering waste directly on site, thus reducing pollution and providing ingredients/food products with high nutritional values that could be integrated into the diet.     

Changes in the elasticity modulus and mechanical dynamical spectroscopy of nitrogen and argon implanted copper

The effect of pulsed ion implantation of nitrogen and argon on copper was studied by means of mechanical dynamical spectroscopy.

A new peak of internal friction at about 800 K (grain boundary relaxation), which is not present in unimplanted samples, was found only in nitrogen ion implanted cases.

Nevertheless, a strong increase in the shear modulus was found in the same manner for ion implanted samples with both species of ions.