Performance characteristics of concrete based on a ternary calcium sulfoaluminate–anhydrite–fly ash cement

This paper reports an assessment of the performance of concrete based on a calcium sulfoaluminate–anhydrite–fly ash cement combination. Concretes were prepared at three different w/c ratios and the properties were compared to those of Portland cement and blast-furnace cement concretes. The assessment involved determination of mechanical and durability properties. The results suggest that an advantageous synergistic effect between and ettringite and fly ash (Ioannou et al., 2014) was reflected in the concrete’s low water absorption rates, high sulfate resistance, and low chloride diffusion coefficients. However, carbonation depths, considering the dense ettringite-rich microstructure developed, were higher than those observed in Portland cement concretes at a given w/c ratio. It was concluded that the amount of alkali hydroxides present in the pore solution is as important factor as the w/c ratio when performance of this type of concrete is addressed.     

油酸钠作捕收剂时变性淀粉对赤铁矿、石英可浮性的影响

以油酸钠为捕收剂,以木薯原淀粉、取代度为0.026和0.21的羧甲基淀粉、取代度为0.0065和0.055的磷酸酯淀粉作为抑制剂,考察了赤铁矿和石英的可浮性。重点研究了变性淀粉基团取代度对其抑制性能的影响。浮选试验结果表明,原淀粉与变性淀粉对赤铁矿的抑制作用规律一致,提高变性淀粉的取代度可增强其对赤铁矿的抑制能力;对于Ca~(2+)活化的石英,在较低的Ca~(2+)用量时,原淀粉和变性淀粉均没有明显的抑制作用,但是随着Ca~(2+)用量的增加,变性淀粉表现出一定的抑制作用、且取代度越高越显著。这种抑制作用与油酸钠、Ca~(2+)及变性淀粉三者的用量有关。Ca~(2+)以Ca(OH)+的形式吸附于石英表面,油酸钠或变性淀粉再与Ca(OH)+作用,如果油酸钠用量较大,全部Ca(OH)+优先与油酸钠作用,则石英被捕收;如果油酸钠用量相对较小,变性淀粉与剩余的Ca(OH)+作用,则对石英产生抑制作用。控制Ca~(2+)和油酸钠的用量在最佳范围,增加变性淀粉的取代度可提高其在赤铁矿脱硅反浮选中的抑制性能。     

Determination of biomass accumulation in mixed belts of Salix,Corylus and Alnus species in combined food and energy production system

Given the energetic, demographic and the climatic challenges faced today, we designed a combined food and energy (CFE) production system integrating food, fodder and mixed belts of Salix, Alnus and Corylus sp. as bioenergy belts. The objective was to assess the shoot dry weight-stem diameter allometric relationship based on stem diameter at 10 (SD₁₀) and 55 cm (SD₅₅) from the shoot base in the mixed bioenergy belts. Allometric relations based on SD₁₀ and SD₅₅ explained 90–96% and 90–98% of the variation in shoot dry weights respectively with no differences between the destructive and the non-destructive methods. The individual stool yields varied widely among the species and within willow species with biomass yield range of 37.60–92.00 oven dry tons (ODT) ha⁻¹ in 4-year growth cycle. The biomass yield of the bioenergy belt, predicted by allometric relations was 48.84 ODT ha⁻¹ in 4-year growth cycle corresponding to 12.21 ODT ha⁻¹ year⁻¹. The relatively high biomass yield is attributed to the border effects and the ‘fertilizing effect’ of alder due to nitrogen fixation, benefitting other SWRC components. On termination of 4-year growth cycle, the bioenergy belts were harvested and the biomass yield recorded was 12.54 ODT ha⁻¹ year⁻¹, in close proximity to the biomass yield predicted by the allometric equations, lending confidence and robustness of the model for biomass yield determination in such integrated agro-ecosystem.     

Properties of a ternary calcium sulfoaluminate–calcium sulfate–fly ash cement

In this paper, cement combinations based on calcium sulfoaluminate cement (CSAC) were developed and the effect of fly ash and the hemihydrate form of calcium sulfate on the properties of the systems was studied. Fly ash (FA), anhydrite (ANH), flue-gas desulfurization gypsum (FGDG) and plaster gypsum (PL) were used to develop appropriate CSAC/calcium sulfate and CSAC/calcium sulfate/addition systems, the hydration of which was studied. Tested properties of cements were the compressive strength and the setting times. The results suggest that the use of fly ash in the presence of anhydrite accelerates the formation of a strong ettringite-rich matrix that firmly accommodated unreacted fly ash particles, both synergistically contributing to a dense microstructure. At a given sulfate content, the use of anhydrite was shown to be favourable in terms of the setting times, heat patterns and strength development compared to the hemihydrate-based formulations.     

Effect of dietary supplementation of Spirulina (Arthrospira platensis) and Thyme (Thymus vulgaris) on rabbit meat appearance,oxidative stability and fatty acid profile during retail display

The objective of this study was to evaluate the effect of Spirulina and Thyme supplementation on rabbit meat during retail display. At weaning 294 rabbits were allocated to 7 different treatments (42 rabbits/treatment). Rabbits of the control group (C) received a diet without any supplementation throughout the experiment (5–11 weeks of age). The other groups were fed diets containing 5% Spirulina (S), 3% Thyme (T) or both supplements (ST) for the whole trial (5–11 weeks; treatments S, T and ST), or for a part of the growing period (8–11 weeks; treatments C–S, C–T and C–ST). Colour parameters, pH, water holding capacity and drip loss were determined on fresh and stored Longissimus dorsi muscle of 5 rabbits/treatment. Spirulina- and Thyme-supplemented diets had a significant effect on redness and yellowness of Longissimus dorsi. Drip loss was significantly reduced in C–T and T groups that also showed the highest content of α-tocopherol and n − 3 fatty acids content and the lower lipid oxidation.     

Mapping actual thermal properties to building elements in gbXML-based BIM for reliable building energy performance modeling

The ability to import building geometric and construction thermal data from building information models (BIM) has significant potential to reduce the time and uncertainty in building energy modeling process. In today's BIM-based energy modeling practice, thermal properties are mainly derived from generic building construction types in BIM. However, for energy modeling of existing buildings, such assumptions are often inaccurate as they do not account for diminishing thermal resistances of building materials instigated by their deteriorations. To improve the reliability of BIM-based energy modeling, we present a system, together with new methods for automated association and updating of actual thermal property measurements with BIM elements in gbXML schema. By leveraging collections of digital and thermal images and based on environmental measurements, our system first produces a 3D thermal model for the building under inspection and then derives the actual thermal resistances of the building assemblies at the level of 3D vertexes. By associating these measurements with their corresponding elements in gbXML, thermal properties of the BIM elements are automatically updated. Our experiments in real-world residential and instructional buildings show how actual thermal properties can be automatically associated with BIM elements and updated in gbXML. The proposed method shortens the gap between architectural information in BIM and the actual data needed for energy performance simulation, and enables reliable BIM-based energy analysis for retro-commissioning, continuous commissioning, and retrofit.     

Non-thermal plasma effects on the lipoxygenase enzyme activity,aroma and phenolic profiles of olive oil

Effects of non-thermal plasma (NTP) technology on the aroma and phenolic compositions and inactivation of lipoxygenase (LOX) enzyme activity of extra virgin olive oil were investigated for the first time. A short non-thermal plasma treatment with pure argon gas (2 standard liters per minute and an average voltage of 7 kV) was applied for 135 s on the olive oil sample. The LOX activity in the NTP treated oil was inhibited up to 42.9% in comparison with untreated oil. Mean values of the peroxides in both samples, expressed in meq oxygen/kg of oil, did not show any statistically significant difference. The values of the antioxidant potentials in the samples proved a mild reduction after NTP treatment. A total of 14 phenols and 31 volatiles were found in both samples with same profile. Although there was a slight difference in the test samples with regard to the concentration of individual phenolic and aroma compounds, this difference was not statistically significant. Therefore, NTP treatment had no statistically significant influence on the antioxidant activity, peroxide value, phenols and volatiles, except LOX activity.     

Image-based measurement of the dimensions and of the axis straightness of hot forgings

Non-contact measurement of shapes and dimensions is currently quite a common issue. A lot of systems with different speeds and accuracies are in the market. Measurement of high temperature objects is, however, a very special task which ensures a specific solution. This paper presents a measurement system composed of two high resolution single-lens reflex cameras and a software application, which is designed for the fast measurement of shapes and dimensions of rotationally symmetric forgings. The software computes the length, diameter, and straightness of the axis, based on a 3D model constructed from four boundary curves of the forging captured in two images. Experimental measurements have shown an error of up to 2% for the length measurement and 1% for the diameter measurement. Results are available in a few seconds. The proposed measurement approach based on boundary curves shows a great potential for practical use in forging plants.