Interfacial kinetics in a model emulsion polymerisation system using microelectrochemical measurements at expanding droplets (MEMED) and time lapse microscopy

Physicochemical processes that take place at the oil-water interface of an epoxy-amine emulsion polymerisation system influence the properties and structural morphology of the polymeric microparticles formed. Investigating these processes, such as the transport of monomers across the liquid/liquid interface brings new understanding which can be used to tune polymeric morphology. Two different approaches are used to provide new insights on these processes. Microelectrochemical measurements at expanding droplets (MEMED) are used to measure the transfer of amine from an organic phase comprised of epoxide and amine into an aqueous receptor phase. The rate of amine transfer across the liquid/liquid interface is characterised using MEMED and finite element method modelling and kinetic values are reported. Time lapse microscopy of epoxide droplets held in deionised water or an aqueous amine solution heated to different temperatures is further used to characterise epoxide dissolution into the aqueous phase. Mass-transport of epoxide into the aqueous phase is shown to be temperature-dependent. Epoxide homopolymerisation at the droplet-water interface is found to influence the rate of epoxide droplet dissolution. The rate of the epoxy- amine cure reaction is shown to be faster than the rate of the epoxide homopolymerisation reaction

Seed priming enhances early growth and improves area of soil exploration by roots

Introduction: Seed priming has been conducted for centuries with growth advantages reported for a variety of different crops. Previous work has suggested priming does not offer a yield advantage despite an increased early growth if grown under ideal conditions. However, how these advantages unfold in regards to early root development is largely unknown.Results: We observed accelerated germination speed in primed seeds regardless of applied seed enhancement technology i.e. coating or pelleting. Additionally, we found significant differences in lateral root development in primed seeds vs non-primed seeds. Furthermore, we recorded an increase in volume and surface of embryo and perisperm indicating a distinct morphological change during the germination process of primed seeds compared to non-primed seeds.Conclusions: We attribute the enhanced early plant development in primed seeds to increased root development and thus enhanced volume of the soil resource mined for nutrients. This improvement can be detected four days after emergence within the root system throughout the early plant development despite an early transition from seed reserves to soil based growth. The understanding of below ground root architecture characteristics can improve the selection of appropriate seed enhancement technologies and seedbed management practices

Kinetic and Desorption Study of Selected Bioactive Compounds on Mesoporous Starbons : A Comparison with Microporous-Activated Carbon

A series of experiments were conducted to determine the chemical and physical differences between varieties of Starbon and activated carbon (AC). The adsorption process for all materials followed pseudo second order kinetics. High levels of adsorption were obtained for all materials; AC showed low levels of desorption for all bioactives over multiple washings, whereas the Starbons showed elevated desorption over the course of multiple washings

Zero tillage has important consequences for soil pore architecture and hydraulic transport: A review

Following the adoption of zero-tillage (ZT) from conventional tillage (CT), the soil pore network undergoes immediate and significant changes. As soil remains undisturbed for an extended period, a soil structure emerges that is primarily generated and stabilised by both biotic and abiotic processes. There is limited understanding concerning how the adoption of ZT influences the soil porous architecture and associated soil hydraulic properties, and specifically over what timeframe these changes occur. Since a previous synthesis of such information over 20-years ago, there has been a substantial number of new investigations aimed at addressing this knowledge gap. Here we review 34 papers that illustrate ZT can influence porosity depending on soil texture, pore size class, depth and time, and also influence important transport mechanisms likely to impact the fate of agrochemicals in soils. We found decreased macroporosity in surface layers of soil under ZT when compared with CT. In addition, soil pore connectivity tended to increase in soil under ZT though the associated effects on hydraulic transport were less clear. Our investigation reveals the value of a prospective examination of an evolving ZT pore network both visually and functionally across temporal and spatial scales. We also highlight the necessity for standardised methodology to aid in future data compatibility and quantitative analysis

Quantification of differences in germination behaviour of pelleted and coated sugar beet seeds using X-ray Computed Tomography (X-ray CT)

Seed enhancement technologies i.e. priming, pelleting and coating have been extensively9 used throughout the last century to improve crop yield and to reduce losses associated with pest infestation. However, until recently, it has not been possible to non-destructively assess the effect of seed enhancement technologies belowground due to the opacity of soil. Using X- ray Computed Tomography (X-ray CT) we undertook a 4D visualisation of the germination process of four different sugar beet seed enhancement treatments (untreated / naked, coated, pelleted and pelleted + coated) in soil. The aim of this study was to improve the understanding of the germination process in the natural environment of the seed to inform future soil management and seed enhancement processes. Using X-ray CT we were able to quantify the germination and establishment process of different seed enhancement technologies in soil non-destructively for the first time. We observed a delay in seedling growth posed by the addition of a physical barrier, i.e. the seed coating. However, an enhanced radicle growth rate was observed in pelleted, as well as pelleted and coated seeds, after overcoming the physical barrier. The disadvantage posed by the addition of seed coating was overcome after four days of seedling growth. Further work should focus on refinements to the type and composition of the pelleting which we observed to have a retarded effect on seed germination

Quantification of seed-soil contact of sugar beet (Beta vulgaris) using X-ray Computed Tomography

© 2017 The Author(s). Background: Seed-soil contact is important to ensure successful germination, however, there is a paucity of reported studies that have quantified the microstructure at and around this critical interface, mainly due to the opacity of soil. Results: Here we describe a novel methodology to non-destructively calculate the seed-soil contact area using X-ray Computed Tomography. Under controlled conditions, we observed that seed-soil contact was strongly influenced by the size and type of seed, with a seed-soil contact of ca. 15% for naked sugar beet seeds compared to ca. 32% for pelleted and coated seeds. Similar results were obtained for seeds sampled from the field albeit with a higher spatial variability. Conclusions: By application of this new quantification method it is hoped seed enhancement technologies can be optimised and ultimately seedbed preparation improved to ensure better germination

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Combinations of single-top-quark production cross-section measurements and vertical bar f(LV)V(tb)vertical bar determinations at root s=7 and 8 TeV with the ATLAS and CMS experiments

This paper presents the combinations of single-top-quark production cross-section measurements by the ATLAS and CMS Collaborations, using data from LHC proton-proton collisions at = 7 and 8 TeV corresponding to integrated luminosities of 1.17 to 5.1 fb(-1) at = 7 TeV and 12.2 to 20.3 fb(-1) at = 8 TeV. These combinations are performed per centre-of-mass energy and for each production mode: t-channel, tW, and s-channel. The combined t-channel cross-sections are 67.5 +/- 5.7 pb and 87.7 +/- 5.8 pb at = 7 and 8 TeV respectively. The combined tW cross-sections are 16.3 +/- 4.1 pb and 23.1 +/- 3.6 pb at = 7 and 8 TeV respectively. For the s-channel cross-section, the combination yields 4.9 +/- 1.4 pb at = 8 TeV. The square of the magnitude of the CKM matrix element V-tb multiplied by a form factor f(LV) is determined for each production mode and centre-of-mass energy, using the ratio of the measured cross-section to its theoretical prediction. It is assumed that the top-quark-related CKM matrix elements obey the relation |V-td|, |V-ts| << |V-tb|. All the |f(LV)V(tb)|(2) determinations, extracted from individual ratios at = 7 and 8 TeV, are combined, resulting in |f(LV)V(tb)| = 1.02 +/- 0.04 (meas.) +/- 0.02 (theo.). All combined measurements are consistent with their corresponding Standard Model predictions.Peer reviewe