Recycled Polyolefin Blends: Effect of Modified Natural Zeolite on their Properties and Morphology

The purpose of this study is to investigate the effect of treated natural zeolite on the flow behavior, morphology, thermal, and mechanical properties in recycled polyolefin blends. A model polymer blend consisting of 95 wt% polyolefines and 5 wt% polystyrene was studied. Compositions from this recycled blend and dehydrated zeolite in a narrow concentration range (0–5 wt%) were treated with maleic anhydride-grafted polypropylene and initiator dicumyl peroxide. The compositions were characterized by capillary rheometry, wide-angle X-ray scattering, differential scanning calorimetry, scanning electron microscopy, and mechanical tests. The results show a compatibilizing effect of treated zeolite expressed by increase of shear viscosity and improvement of interfacial interactions and impact strength. The results can open wide possibilities for utilization of treated zeolite in recycling of unsorted polymer wastes.     

Sustainability assessment of dwellings – a comparison of methodologies

Building sustainability assessment tools (BSATs) aim to promote and rank the sustainability of building stock. This paper makes a deep comparative analysis on how dwellings are evaluated by five BSAT and one performance-based design tool. The comparison is based on: (i) the purpose of assessment; (ii) sustainability dimensions considered; (iii) indicators addressed; (iv) life cycle phases considered by the indicators; (v) type of indicators; (vi) measurements; (vii) aggregation processes; and (vii) life cycle phases during which the assessment was carried out. The evaluation showed that the scope of BSAT varies significantly as well as the life cycle phases addressed in the assessment. Financial issues are often excluded from the assessment. None of the schemes is totally quantitative or qualitative in their measurement system; all have different types of indicators and different ways to assess them. This research provides researchers and stakeholders with important inside knowledge on the tools that allow the development and construction of more sustainable buildings.     

Improved Accuracy of the Inherent Shrinkage Method for Fast and More Reliable Welding Distortion Calculations

This paper describes the implementation of a simple strategy adopted for the inherent shrinkage method (ISM) to predict welding-induced distortion. This strategy not only makes it possible for the ISM to reach accuracy levels similar to the detailed transient analysis method (considered the most reliable technique for calculating welding distortion) but also significantly reduces the time required for these types of calculations. This strategy is based on the sequential activation of welding blocks to account for welding direction and transient movement of the heat source. As a result, a significant improvement in distortion prediction is achieved. This is demonstrated by experimentally measuring and numerically analyzing distortions in two case studies: a vane segment subassembly of an aero-engine, represented with 3D-solid elements, and a car body component, represented with 3D-shell elements. The proposed strategy proves to be a good alternative for quickly estimating the correct behaviors of large welded components and may have important practical applications in the manufacturing industry.     

Terahertz emission at impurity electrical breakdown in Si(Li)

Terahertz electroluminescence caused by impurity-induced breakdown in lithium-doped silicon crystals is studied. The spectrum of the terahertz emission exhibits lines corresponding to intracenter electronic transitions between excited states of the impurity and sublevels of the ground state of the lithium donor. The spectrum also shows a background signal, which, apparently, is a manifestation of the effects due to heating at electric excitation.     

Complex approach to the tribotechnical processing of elements for automobile and tractor engines

It has been shown that the addition of a geotribomodifier to engine oil and the processing of rubbing surfaces by metal-cladding agent substantially reduce the mechanical loss (up to 45%) and the heat generation in the contact zone (by 38%) and increases the load-carrying ability (by 61%). The optimal concentration of the friction geotribomodifier additive in oil has been established.     

Effect of Blanching Treatments on Antioxidant Activity and Thiosulfinate Degradation of Garlic (Allium sativum L.)

The degradation kinetics of thiosulfinates and the reduction of antioxidant activity of garlic bulbs cut in slices were studied during steam at 100 °C and in water at 80 and 90 °C. Blanching process led to significant reduction of the antioxidant activity and thiosulfinate contents. The reaction rate constants for loss of thiosulfinate species and antioxidant activity increased with blanching temperature, with activation energies of 7.67 and 89.75 kJ/mol, respectively. The antioxidant activity showed a significant correlation with thiosulfinates (R?=?0.7604), and both the antioxidant activity and thiosulfinate contents decreased with increasing blanching time. The antioxidant activity did not show significant differences after 6 min of steam blanching and 8 min of water blanching at 90 and 80 °C. Regarding the thiosulfinate concentration, there was no significant difference after 8 min of blanching for all temperatures.