159 research outputs found
Monitoring and Failure Analysis of Corroded Bridge Cables under Fatigue Loading Using Acoustic Emission Sensors
Cables play an important role in cable-stayed systems, but are vulnerable to corrosion and fatigue damage. There is a dearth of studies on the fatigue damage evolution of corroded cable. In the present study, the acoustic emission (AE) technology is adopted to monitor the fatigue damage evolution process. First, the relationship between stress and strain is determined through a tensile test for corroded and non-corroded steel wires. Results show that the mechanical performance of corroded cables is changed considerably. The AE characteristic parameters for fatigue damage are then established. AE energy cumulative parameters can accurately describe the fatigue damage evolution of corroded cables. The failure modes in each phase as well as the type of acoustic emission source are determined based on the results of scanning electron microscopy. The waveform characteristics, damage types, and frequency distribution of the corroded cable at different damage phases are collected. Finally, the number of broken wires and breakage time of the cables are determined according to the variation in the margin index
The composition and oxidative stability of vegetarian omega-3 algal oil nanoemulsions suitable for functional food enrichment
Background: Long chain omega-3 polyunsaturated fatty acid (LCn3PUFA) nanoemulsion enriched foods offer potential to address habitually low oily fish intakes. Nanoemulsions increase LCn3PUFA bioavailability, but may cause lipid oxidation. This study examined oxidative stability of LCn3PUFA algal oil-in-water nanoemulsions created by ultrasound using natural and synthetic emulsifiers during 5-weeks of storage at 4, 20 and 40°C. Fatty acid composition, droplet size ranges and volatile compounds were analysed. Results: No significant differences were found for fatty acid composition at various temperatures and storage times. Lecithin nanoemulsions had significantly larger droplet size ranges at baseline and during storage regardless of temperatures. While combined Tween 40 and lecithin nanoemulsions had low initial droplet size ranges, there were significant increases at 40°C after 5-weeks storage. Gas chromatograms identified hexanal and propanal as predominant volatile compounds, along with 2-ethylfuran; propan-3-ol; valeraldehyde. The Tween 40 only nanoemulsion sample showed formation of lower concentrations of volatiles compared to lecithin samples. Formation of hexanal and propanal remained stable at lower temperatures although higher concentrations were found in nanoemulsions than bulk oil. The lecithin only sample had formation of higher concentrations of volatiles at increased temperatures despite having significantly larger droplet size ranges than the other samples. Conclusions: Propanal and hexanal were the most prevalent of five volatile compounds detected in bulk oil and lecithin and/or Tween 40 nanoemulsions. Oxidation compounds remained more stable at lower temperatures indicating suitability for enrichment of refrigerated foods. Further research to evaluate the oxidation stability of these systems within food matrices is warranted
Dietary fibre intake and risk of ischaemic and haemorrhagic stroke in the UK Women’s Cohort Study
BACKGROUND: Stroke risk is modifiable through many risk factors, one being healthy dietary habits. Fibre intake was associated with a reduced stroke risk in recent meta-analyses; however, data were contributed by relatively few studies, and few examined different stroke types. METHODS: A total of 27 373 disease-free women were followed up for 14.4 years. Diet was assessed with a 217-item food frequency questionnaire and stroke cases were identified using English Hospital Episode Statistics and mortality records. Survival analysis was applied to assess the risk of total, ischaemic or haemorrhagic stroke in relation to fibre intake. RESULTS: A total of 135 haemorrhagic and 184 ischaemic stroke cases were identified in addition to 138 cases where the stroke type was unknown or not recorded. Greater intake of total fibre, higher fibre density and greater soluble fibre, insoluble fibre and fibre from cereals were associated with a significantly lower risk for total stroke. For total stroke, the hazard ratio per 6 g/day total fibre intake was 0.89 (95% confidence intervals: 0.81–0.99). Different findings were observed for haemorrhagic and ischaemic stroke in healthy-weight or overweight women. Total fibre, insoluble fibre and cereal fibre were inversely associated with haemorrhagic stroke risk in overweight/obese participants, and in healthy-weight women greater cereal fibre was associated with a lower ischaemic stroke risk. In non-hypertensive women, higher fibre density was associated with lower ischaemic stroke risk. CONCLUSIONS: Greater total fibre and fibre from cereals are associated with a lower stroke risk, and associations were more consistent with ischaemic stroke. The different observations by stroke type, body mass index group or hypertensive status indicates potentially different mechanisms
The development of vegetarian omega-3 oil in water nanoemulsions suitable for integration into functional food products
Global trends show that habitual omega-3 intakes are short of recommended guidelines, particularly among vegetarians and vegans. The potential health implications of low long chain omega-3 polyunsaturated fatty acids (LC3PUFA) intakes coupled with concerns about sustainability of fish stocks call for innovative approaches to provide food based solutions to this problem. Nanoemulsions are systems with extremely small droplet sizes that could provide a solution whilst improving the bioavailability of LC3PUFA. Oil in water nanoemulsion systems were successfully created using ultrasound with oil loads of up to 50 vol % using vegetarian LC3PUFA oils. Nanoemulsions containing 50 vol % flaxseed and algae oil were created with mean droplet size measurements of 192 and 182nm respectively using combinations of the emulsifiers Tween 40 and lecithin. This technique could be applied to create vegetarian LC3PUFA nanoemulsions suitable for integration into enriched functional food products with the potential to increase LC3PUFA intakes and bioavailability
Universality of Thermodynamic Constants Governing Biological Growth Rates
Background: Mathematical models exist that quantify the effect of temperature on poikilotherm growth rate. One family of such models assumes a single rate-limiting ‘master reaction ’ using terms describing the temperature-dependent denaturation of the reaction’s enzyme. We consider whether such a model can describe growth in each domain of life. Methodology/Principal Findings: A new model based on this assumption and using a hierarchical Bayesian approach fits simultaneously 95 data sets for temperature-related growth rates of diverse microorganisms from all three domains of life, Bacteria, Archaea and Eukarya. Remarkably, the model produces credible estimates of fundamental thermodynamic parameters describing protein thermal stability predicted over 20 years ago. Conclusions/Significance: The analysis lends support to the concept of universal thermodynamic limits to microbial growth rate dictated by protein thermal stability that in turn govern biological rates. This suggests that the thermal stability of proteins is a unifying property in the evolution and adaptation of life on earth. The fundamental nature of this conclusion has importance for many fields of study including microbiology, protein chemistry, thermal biology, and ecological theory including, for example, the influence of the vast microbial biomass and activity in the biosphere that is poorly described in current climate models
A nontoxic polypeptide oligomer with a fungicide potency under agricultural conditions which is equal or greater than that of their chemical counterparts
Research ArticleThere are literally hundreds of polypeptides described in the literature which exhibit fungicide
activity. Tens of them have had attempted protection by patent applications but none,
as far as we are aware, have found application under real agricultural conditions. The reasons
behind may be multiple where the sensitivity to the Sun UV radiation can come in first
place. Here we describe a multifunctional glyco-oligomer with 210 kDa which is mainly composed
by a 20 kDa polypeptide termed Blad that has been previously shown to be a stable
intermediary product of β-conglutin catabolism. This oligomer accumulates exclusively in
the cotyledons of Lupinus species, between days 4 and 12 after the onset of germination.
Blad-oligomer reveals a plethora of biochemical properties, like lectin and catalytic activities,
which are not unusual per si, but are remarkable when found to coexist in the same protein
molecule. With this vast range of chemical characteristics, antifungal activity arises
almost as a natural consequence. The biological significance and potential technological
applications of Blad-oligomer as a plant fungicide to agriculture, its uniqueness stems from
being of polypeptidic in nature, and with efficacies which are either equal or greater than the
top fungicides currently in the market are addressedinfo:eu-repo/semantics/publishedVersio
Application of anthocyanins from blackcurrant (Ribes nigrum L.) fruit waste as renewable hair dyes
There is much concern about the toxicological effects of synthetic hair dyes. As an alternative approach, renewable waste blackcurrant (Ribes nigrum L.) fruit skins from the fruit pressing industry were extracted using acidified water with a solid-phase purification stage. Anthocyanins colorants were isolated in good yields (2-3% w/w) and characterized by HPLC. Sorption of anthocyanins onto hair followed a Freundlich isotherm; anthocyanin-anthocyanin aggregation interactions enabling high build-up on the substrate. Sorption energy of cyanidin-3-O-glucoside (monosaccharide) > cyanidin-3-O-rutinoside (disaccharide), but sorption properties of different anthocyanin glucosides were very similar. Intense blue-colored dyeings on hair could be achieved with λmax-vis at 580 nm, typical of the anionic quinonoid base – it is suggested that the hair provides an environment that enables the stabilization of the anionic quinonoid base on adsorption through association with cations in the hair and copigmentation effects. Dyeings were stable to multiple washes
Computational shelf-life dating : complex systems approaches to food quality and safety
Shelf-life is defined as the time that a product is acceptable and meets the consumers expectations regarding food quality. It is the result of the conjunction of all services in production, distribution, and consumption. Shelf-life dating is one of the most difficult tasks in food engineering. Market pressure has lead to the implementation of shelf-life by sensory analyses, which may not reflect the full quality spectra. Moreover, traditional methods for shelf-life dating and small-scale distribution chain tests cannot reproduce in a laboratory the real conditions of storage, distribution, and consumption on food quality. Today, food engineers are facing the challenges to monitor, diagnose, and control the quality and safety of food products. The advent of nanotechnology, multivariate sensors, information systems, and complex systems will revolutionize the way we manage, distribute, and consume foods. The informed consumer demands foods, under the legal standards, at low cost, high standards of nutritional, sensory, and health benefits. To accommodate the new paradigms, we herein present a critical review of shelf-life dating approaches with special emphasis in computational systems and future trends on complex systems methodologies applied to the prediction of food quality and safety.Fundo Europeu de Desenvolvimento Regional (FEDER) - Programa POS-ConhecimentoFundação para a Ciência e a Tecnologia (FCT) - SFRH/BPD/26133/2005, SFRH/ BPD/20735/200
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