Comparative Study on Pantothenic Acid Separation by Reactive Extraction with Tri-n-octylamine and Di-(2-ethylhexyl) Phosphoric Acid

The mechanism of reactive extraction of pantothenic acid with tri-n-octylamine and di-(2-ethylhexyl) phosphoric acid was analysed for three solvents in the presence or absence of 1-octanol. In the absence of 1-octanol, the stoichiometric ratio between the solute and tri-n-octylamine was 1:1 for dichloromethane, 1:2 for butyl acetate, and 1:4 for n-heptane. In the presence of 1-octanol, the formation of aminic adducts was restricted, the stoichiometries for the interfacial reaction between the acid and tri-n-octylamine becoming 1:1 for dichloromethane and butyl acetate, 1:2 for n-heptane. A similar effect has been observed for extraction with di-(2-ethylhexyl) phosphoric acid, the structure of the interfacial compound being changed for n-heptane and butyl acetate from HAE2 in the absence of 1-octanol to HAE by addition of this alcohol. The highest extraction constants were obtained when extractant associates were formed. However, when the extraction mechanism was the same, the increase in organic phase polarity influenced positively the value of extraction constant

Sustainability and climate resilience metrics and trade-offs in transport infrastructure asset recovery

Copyright © 2023 The Author(s). Climate change exacerbates natural hazards and continuously challenges the performance of critical infrastructure. Thus, climate resilience and sustainable adaptation of infrastructure are of paramount importance. This paper puts forward a novel framework and metrics for optimising sustainability (Greenhouse Gas emissions - GHG), climate resilience (restoration time), and cost. The framework aims to facilitate decision-making by operators and stakeholders and communicate actionable trade-offs between these principles. It describes approaches for quantifying ex-ante adaptation and ex-post recovery from the lenses of sustainability and resilience using relevant metrics. This paper concludes with an application of the framework on a bridge, where normalised metrics are integrated into one unique index (ISRC), which can be used in the recovery prioritisation for portfolios of similar assets. The optimisation program includes a bridge recovery, while reducing GHG emissions. The impact of climate change on the sustainability and resilience indexes is examined and the results show how the optimum solutions are adversely affected by different climate projections. In all scenarios examined, more sustainable solutions leading to reduced GHG emissions (tCO2e) are the optimum solutions when weighing resilience and cost. Based on the case study analysed in this paper, the low carbon restoration strategy resulted in up to 50% higher ISRC, which can justify investments for low GHG adaptation strategies in transport assets.The authors received funding by the UK Research and Innovation (UKRI) under the UK government’s Horizon Europe funding guarantee [grant agreement No: 101086413, EP/Y003586/1, EP/Y00986X/1, EP/X037665/1]. This is the funding guarantee for the European Union HORIZON-MSCA-2021-SE-01 [grant agreement No: 101086413] ReCharged - Climate-aware Resilience for Sustainable Critical and interdependent Infrastructure Systems enhanced by emerging Digital Technologies. The first author would also like to acknowledge funding by the UK Research and Innovation (UKRI) under the UK government’s Horizon Europe funding guarantee [grant agreement No: 10062091]. This is the funding guarantee for the European Union HORIZON-MISS-2021-CLIMA-02 [grant agreement No: 101093939] RISKADAPT - Asset-level modelling of risks in the face of climate-induced extreme events and adaptation

‘Deliberate Preparation’ as an evidence-based focus for primary physical education

There is substantial scientific research suggesting the physical and psychological health benefits of a physically active lifestyle. Consequently, governments worldwide prioritize policies, finances, and resources in healthcare, education, and sports sectors to increase mass participation in physical activity. However, practices in physical activity promotion are often not underpinned by evidence-based standardization that is requisite in other domains of epidemiology. The aim of this article is to examine critically the available scientific research on promoting life-long physical activity participation and to propose an evidence-based model for implementation in school physical education. Reasons are discussed as to why programs that integrate physical, psychological, and behavioral skills have been long acknowledged in physical education and physical activity domains but remain lacking in empirical validation. Finally, future directions are suggested that are required to examine the application of this approach to practice in primary-level physical education

Stretching the spines of gymnasts: a review

Gymnastics is noted for involving highly specialized strength, power, agility and flexibility. Flexibility is perhaps the single greatest discriminator of gymnastics from other sports. The extreme ranges of motion achieved by gymnasts require long periods of training, often occupying more than a decade. Gymnasts also start training at an early age (particularly female gymnasts), and the effect of gymnastics training on these young athletes is poorly understood. One of the concerns of many gymnastics professionals is the training of the spine in hyperextension-the ubiquitous 'arch' seen in many gymnastics positions and movements. Training in spine hyperextension usually begins in early childhood through performance of a skill known as a back-bend. Does practising a back-bend and other hyperextension exercises harm young gymnasts? Current information on spine stretching among gymnasts indicates that, within reason, spine stretching does not appear to be an unusual threat to gymnasts' health. However, the paucity of information demands that further study be undertaken

SYNERGIC EXTRACTION OF PANTOTHENIC ACID WITH TWO DIFFERENT EXTRACTANTS

Abstract -The influences of extractants concentrations and solvent polarity on the efficiency of pantothenic acid separation by synergic extraction with tri-n-octylamine (TOA) and di(2-ethylhexyl) phosphoric acid (D2EHPA) mixture have been analyzed. The results indicated the formation of an interfacial compound which includes one molecule of pantothenic acid and one of D2EHPA, its hydrophobicity being increased by solvation with additional TOA molecules. For solvents with lower dielectric constants, n-heptane and n-butyl acetate, the number of amine molecules participating in the interfacial complex formation was controlled by solvent polarity and D2EHPA concentration, decreasing with the increase of these two parameters. For dichloromethane, the chemical structure of the extracted compound remained the same regardless of D2EHPA concentration. The most important synergic effect corresponded to the extractant mixture dissolved in nheptane, at low D2EHPA concentration in the organic phase (5 g/l)

Experimental in-plane cyclic response of dry and wet masonry walls incorporating lime mortar and clay bricks

This paper investigates the in-plane response of ambient-dry and wet clay-brick/lime-mortar masonry walls under lateral cyclic loading and co-existing compressive gravity load, as well as of square masonry panels under diagonal compression. The properties of the constituent materials were selected to resemble those of existing heritage masonry structures in Historic Cairo. After describing the specimen details and testing arrangements, the main results and observations are provided and discussed. The full load-deformation behaviour of the large-scale wall members is also evaluated , including their ductility and failure modes, and compared with the predictions of available assessment models. It is shown that moisture has a detrimental effect on the main material properties, including the diagonal tension and compression strengths as well as brick-mortar interaction parameters. For the large-scale wall specimens, the wet-to-dry reduction was found to between 8-11% for the lateral strength and around 10% in terms of ductility. The response of diagonal walls was relatively brittle with a reduction between wet-to-dry strengths of around 33%, suggesting that the reduction ratio is dependent on the compression stress level. Provided that the key moisture-dependent masonry properties are appropriately evaluated, it is also shown that analytical assessment methods can be reliably adapted for predicting the response