Experimental Simulation of Volatile Organic Contributions to Planetary Atmospheres and Surfaces

We present the results of a new simulation of the atmospheric entry heating experienced by extraterrestrial dust particles, quantifying their volatile loss into the early Earth atmosphere and characterising their organic volatile components

Heart enhancers with deeply conserved regulatory activity are established early in zebrafish development.

During the phylotypic period, embryos from different genera show similar gene expression patterns, implying common regulatory mechanisms. Here we set out to identify enhancers involved in the initial events of cardiogenesis, which occurs during the phylotypic period. We isolate early cardiac progenitor cells from zebrafish embryos and characterize 3838 open chromatin regions specific to this cell population. Of these regions, 162 overlap with conserved non-coding elements (CNEs) that also map to open chromatin regions in human. Most of the zebrafish conserved open chromatin elements tested drive gene expression in the developing heart. Despite modest sequence identity, human orthologous open chromatin regions recapitulate the spatial temporal expression patterns of the zebrafish sequence, potentially providing a basis for phylotypic gene expression patterns. Genome-wide, we discover 5598 zebrafish-human conserved open chromatin regions, suggesting that a diverse repertoire of ancient enhancers is established prior to organogenesis and the phylotypic period

Using the Scanning Fluid Dynamic Gauging Device to Understand the Cleaning of Baked Lard Soiling Layers.

Extended or repeated heating of food fats promotes polymerisation reactions that produce difficult-to-remove soil layers. Cleaning of these baked-on/burnt-on fat deposits was investigated using model layers generated by baking lard on 316 stainless steel discs. Rigorous characterisation of the layer material was difficult, as it was insoluble in most solvents. Cleaning was studied using the scanning fluid dynamic gauging technique developed by Gordon et al. (Meas Sci Technol 21:85-103, 2010), which provides non-contact in situ measurement of layer thickness at several sites on a sample in real time. Tests at 50 [Formula: see text]C with alkali (sodium hydroxide, pH 10.4-11) and three surfactant solutions indicated two removal mechanisms, related to the (1) roll-up and (2) dispersion mechanisms reported for oily oils, namely (1) penetration of solvent at the soil-liquid interface, resulting in detachment of the soil layer as a coherent film, observed with linear alkylbenzene sulfonic acid (LAS) and Triton X-100 and aqueous sodium hydroxide at pH 10.4-11; and (2) the breakdown promoted by the agent penetrating through the layer, observed with cetyl trimethyl ammonium bromide (CTAB), in which CTAB antagonised the cleaning action of LAS.An EPSRC studentship for AA and project support from Procter and Gamble Ltd is gratefully acknowledged.This is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1007/s11743-015-1737-

Comparison of fouling of raw milk and whey protein solution on stainless steel and fluorocarbon coated surfaces: Effects on fouling performance, deposit structure and composition

Fouling from raw milk and from whey protein solutions mimicking the protein content of milk have been performed at two length scales, using a microfluidic heat transfer cell and a bench-scale device with hydraulic diameters 1:0mm and 16:1 mm, respectively. The microfluidic cell allows raw milk to be studied in once-through mode and was used to identify polymer coated surfaces to test against stainless steel. Several of the fluorocarbon coated surfaces reduced the mass deposition but the pressure drop and thermal resistance did not match these directly, indicating that the nature and structure of the deposit is affected by the surface. A fluorinated ethylene propylene coating was identified as a promising candidate for large scale tests. At the interface with apolar surfaces, raw milk fouling layers were high in protein whereas a strongly attached mineral-rich layer was present at the interface with steel. The attraction of denatured protein towards apolar surfaces and the formation of a calcium phosphate layer on steel at later stages of fouling are explained with arguments based on the interfacial free energy of these materials in water.The work was funded by Chemours Belgium BVB

Quantifying Implications of Deposit Aging from Crude Refinery Preheat Train Data

Heat exchanger fouling has been studied for some time in the petroleum industry. As understanding of fouling dynamics and mitigation methods improves, refinery fouling mitigation strategies are changing. The implications of deposit aging in refinery units have not been addressed in detail: aging refers to where the deposit undergoes physical and chemical conversion over time. In the 2009 Heat Exchanger Fouling and Cleaning conference, Wilson et al. [Ageing: Looking back and looking forward] presented a simple framework illustrating how deposit aging impacts heat exchanger thermal and hydraulic performance. This paper presents insights into deposit aging gained from analysis of refinery monitoring data. Two case studies are presented: (i) one from the Preem refinery in Sweden where stream temperature, flow and gauge pressure measurements indicated a higher deposit thermal conductivity in exchangers located in the hotter section of the preheat train. (ii) US refinery stream temperature, flow and plant cleaning log data, showing an increased resistance to cleaning when deposits are exposed to high temperature for a prolonged period. The use of deposit aging analysis to improve exchanger operation is discussed.I am a co-author on this paper. The work reported was undertaken for a Swedish company by another company, HTRI.I advised on the results

Development of a single droplet freezing apparatus for studying crystallisation in cocoa butter droplets

The single droplet freezing apparatus described by Pore et al. (J. Am. Oil. Chem. Soc., 86, 215-225), which allows crystallisation to be monitored in situ by X-ray diffraction, was modified to allow rapid switching of coolant gas and monitoring by video microscopy. The apparatus was used to study drops of cocoa butter undergoing simulated spray freezing at high cooling rates, e.g. 130 K/min. The transformation of an Ivory Coast cocoa butter to the Form V polymorph was significantly faster in drops (~40 h) than in static bulk samples (10 days) crystallised under isothermal conditions. Phase transformation was observed from Forms I/II → III → IV → melt → V, with Form V crystallising directly from the melt at 28.6°C. Numerical simulations of the temperature evolution within the droplet established that the drops are not isothermal, explaining why nucleation was initially observed in the lower (upstream) part of the droplet.The provision of an EPSRC studentship for AMT and project support from Nestlé PTC York is gratefully acknowledged. The apparatus was constructed by Lee Pratt, Gary Chapman, Kevin Swan and Wei-Yao Ma. Assistance with the DSC testing from Zlatko Saraçevic, video microscopy from Dr Simon Butler, and general X-ray analysis from Dr Joanna Stasiak are all gratefully acknowledged.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.jfoodeng.2015.02.01

Interfacial band-edge energetics for solar fuels production

Photoelectrochemical (PEC) water splitting has received growing attention as a potential pathway to replace fossil fuels and produce a clean, renewable, and sustainable source of fuel. To achieve overall water splitting and the associated production of solar fuels, complex devices are needed to efficiently capture light from the sun, separate photogenerated charges, and catalyze reduction and oxidation reactions. To date, the highest performing solar fuels devices rely on multi-component systems, which introduce interfaces that can be associated with further performance loss due to thermodynamic and kinetic considerations. In this review, we identify several of the most important interfaces used in PEC water splitting, summarize methods to characterize them, and highlight approaches to mitigating associated loss mechanisms.The authors thank Dr Eric Miller for the inspiration to compile this review, and the members of the U.S. Department of Energy’s Photoelectrochemical Working Group and Task 35 (Renewable Hydrogen) of the International E nergy Agency’s Hydrogen Imple- menting Agreement for helpful comments, suggestions, and dis- cussions, specifically Prof. Shane Ardo, Dr John Turner, Prof. Dunwei Wang, and Prof. Shannon Boettcher. WAS greatly acknowl- edges funding support from the FOM/NWO/Shell Program on CO 2 - neutral Fuels (Project – APPEL). IDS was supported by the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the U.S. Department of Energy under Award Number DE-SC0004993. NCS acknowledges start-up funds from Lehigh University. JB thanks financial support from GeneralitatValenciana (ISIC/ 2012/008). A summary version of this review paper (DOI: 10.2172/1209498), and associated summary tables that will be updated as the field progresses, will be available on the working group website (http://energy.gov/eere/fuelcells/ photoelectrochemical-working-group)

Medical student wellbeing - a consensus statement from Australia and New Zealand

Abstract Background Medical student wellbeing – a consensus statement from Australia and New Zealand outlines recommendations for optimising medical student wellbeing within medical schools in our region. Worldwide, medical schools have responsibilities to respond to concerns about student psychological, social and physical wellbeing, but guidance for medical schools is limited. To address this gap, this statement clarifies key concepts and issues related to wellbeing and provides recommendations for educational program design to promote both learning and student wellbeing. The recommendations focus on student selection; learning, teaching and assessment; learning environment; and staff development. Examples of educational initiatives from the evidence-base are provided, emphasising proactive and preventive approaches to student wellbeing. Main recommendations The consensus statement provides specific recommendations for medical schools to consider at all stages of program design and implementation. These are:Design curricula that promote peer support and progressive levels of challenge to students.Employ strategies to promote positive outcomes from stress and to help others in need.Design assessment tasks to foster wellbeing as well as learning.Provide mental health promotion and suicide prevention initiatives.Provide physical health promotion initiatives.Ensure safe and health-promoting cultures for learning in on-campus and clinical settings.Train staff on student wellbeing and how to manage wellbeing concerns. Conclusion A broad integrated approach to improving student wellbeing within medical school programs is recommended. Medical schools should work cooperatively with student and trainee groups, and partner with clinical services and other training bodies to foster safe practices and cultures. Initiatives should aim to assist students to develop adaptive responses to stressful situations so that graduates are prepared for the realities of the workplace. Multi-institutional, longitudinal collaborative research in Australia and New Zealand is needed to close critical gaps in the evidence needed by medical schools in our region

RAZINE LIPIDNE PEROKSIDACIJE U DIJELOVIMA SJEMENA SOJE (Glycine max (L.) Merr.) KAO POSLJEDICA STRESA PRI USVAJANJU VODE

High rainfall and rapid water uptake by dry seed after sowing in the field can result in so-called seed imbibitional damage. Here, lipid peroxidation levels were evaluated in seed testa, embryos and cotyledons of three soybean cultivars (Podravka 95, Tisa and Vita), after 3, 6, 12 and 24 h of seed imbibition in water at 20oC. In general, lipid peroxidation was enhanced in soybean embryos and the lowest vales were observed in seed testa. With respect to imbibition duration, the highest lipid peroxidation was observed after 3 h of imbibition and decreased thereafter in seed of Podravka 95 and Vita, with similar trend regarding seed of the same age.Intenzivne oborine i intenzivno usvajanje vode suhoga sjemena nakon sjetve u polju mogu rezultirati takozvanim imbibicijskim oštećenjem sjemena. U ovom istraživanju analiziran je intenzitet lipidne peroksidacije u sjemenjači, klici i kotiledonima sjemena tri sorte soje (Podravka 95, Tisa i Vita), nakon 3, 6, 12 i 24 imbibicije u vodi pri 20oC. U cjelini, lipidna peroksidacija bila je povećana u klici soje, a najslabije izražena u sjemenjači. S obzirom na dužinu imbibicije, najveći intenzitet lipidne peroksidacije utvrđen je nakon 3 h imbibicije, nakon čega se smanjivao kod sorata Podravka 95 i Vita, uz sličan trend, s obzirom na sjeme iste starosti