Irrigation of Sand-based Creeping Bentgrass Putting Greens with Nanobubble-oxygenated Water

Cultural and environmental factors can place creeping bentgrass (Agrostis stolonifera) under extreme stress during the summer months. This stress, coupled with the growth adaptation of creeping bentgrass, can result in shallow, poorly rooted stands of turf. To enhance root zone oxygen and rooting of creeping bentgrass, golf courses use methods such as core and solid-tine aerification, and sand topdressing. An additional method of delivering oxygen to the soil could be irrigation with nanobubble-oxygenated water. The properties of nanobubbles (NBs) allow for high gas dissolution rates in water. Irrigating with NB-oxygenated water sources may promote increased rooting of creeping bentgrass putting greens during high-temperature periods and lead to a more resilient playing surface. The objectives of this study include comparing the effects of irrigation with NB-oxygenated water sources with untreated water sources on creeping bentgrass putting green root zone and plant health characteristics using field and controlled environment experiments. Treatments included NB-oxygenated potable water and irrigation pond water, and untreated potable and irrigation pond water. In the field, NB-oxygenated water did not enhance plant health characteristics of creeping bentgrass. In 1 year, NB-oxygenated water increased the daily mean partial pressure of soil oxygen from 17.48 kPa to 18.21 kPa but soil oxygen was unaffected in the other 2 years of the trial. Subsurface irrigation with NB-oxygenated water did not affect measured plant health characteristics in the greenhouse. NB-oxygenation of irrigation water remains an excellent means of efficiently oxygenating large volumes of water. However, plant health benefits from NB-oxygenated irrigation water were not observed in this research

Consumer electronics devices for DNA genotyping based on loop-mediated isothermal amplification and array hybridisation

[EN] Consumer electronic technologies offer practical performances to develop compact biosensing systems intended for the point-of-care testing of DNA biomarkers. Herein a discrimination method for detecting single nucleotide polymorphisms, based on isothermal amplification and on-chip hybridisation, was developed and integrated into user-friendly optical devices: e.g., USB digital microscope, flatbed scanner, smartphone and DVD drive. In order to adequately identify a single base change, loop-mediated isothermal amplification (LAMP) was employed, with high yields (8 orders) within 45 min. Subsequently, products were directly hybridised to the allele-specific probes attached to plastic chips in an array format. After colorimetric staining, four consumer electronic techniques were compared. Sensitive precise measurements were taken (high signal-to-noise ratios, 10-mu m image resolution, 99% scan-to-scan reproducibility). These features confirmed their potential as analytical tools, are a competitive alternative to fluorescence scanners, and incorporate additional advantages, such as user-friendly interface and connectivity for telemedicine needs. The analytical performances of the integrated platform (assay and reader) in the human samples were also excellent, with a low detection limit (100 genomic DNA copies), and reproducible (< 15%) and cheap assays (< 10 (sic)/test). The correct genotyping of a genetic biomarker (single-nucleotide polymorphism located in the GRIK4 gene) was achieved as the assigned genotypes agreed with those determined by using sequencing. The portability, favourable discriminating and read-out capabilities reveal that the implementation of mass-produced low-cost devices into minimal-specialised clinical laboratories is closer to becoming a reality.The authors acknowledge the financial support received from the Generalitat Valenciana, Spain (GVA-PROMETEOII/2014/040 Project and GRISOLIA/2014/024 Ph.D. grant) and the Spanish Ministry of Economy and Competitiveness, Spain (MINECO CTQ2016-75749-R project) by U. E. FEDER funds. The authors also thank J. Carrascosa for supporting the DVD reader measurements.Tortajada-Genaro, LA.; Yamanaka, ES.; Maquieira Catala, A. (2019). Consumer electronics devices for DNA genotyping based on loop-mediated isothermal amplification and array hybridisation. Talanta. 198:424-431. https://doi.org/10.1016/j.talanta.2019.01.124S42443119

The seeds of divergence: the economy of French North America, 1688 to 1760

Generally, Canada has been ignored in the literature on the colonial origins of divergence with most of the attention going to the United States. Late nineteenth century estimates of income per capita show that Canada was relatively poorer than the United States and that within Canada, the French and Catholic population of Quebec was considerably poorer. Was this gap long standing? Some evidence has been advanced for earlier periods, but it is quite limited and not well-suited for comparison with other societies. This thesis aims to contribute both to Canadian economic history and to comparative work on inequality across nations during the early modern period. With the use of novel prices and wages from Quebec—which was then the largest settlement in Canada and under French rule—a price index, a series of real wages and a measurement of Gross Domestic Product (GDP) are constructed. They are used to shed light both on the course of economic development until the French were defeated by the British in 1760 and on standards of living in that colony relative to the mother country, France, as well as the American colonies. The work is divided into three components. The first component relates to the construction of a price index. The absence of such an index has been a thorn in the side of Canadian historians as it has limited the ability of historians to obtain real values of wages, output and living standards. This index shows that prices did not follow any trend and remained at a stable level. However, there were episodes of wide swings—mostly due to wars and the monetary experiment of playing card money. The creation of this index lays the foundation of the next component. The second component constructs a standardized real wage series in the form of welfare ratios (a consumption basket divided by nominal wage rate multiplied by length of work year) to compare Canada with France, England and Colonial America. Two measures are derived. The first relies on a “bare bones” definition of consumption with a large share of land-intensive goods. This measure indicates that Canada was poorer than England and Colonial America and not appreciably richer than France. However, this measure overestimates the relative position of Canada to the Old World because of the strong presence of land-intensive goods. A second measure is created using a “respectable” definition of consumption in which the basket includes a larger share of manufactured goods and capital-intensive goods. This second basket better reflects differences in living standards since the abundance of land in Canada (and Colonial America) made it easy to achieve bare subsistence, but the scarcity of capital and skilled labor made the consumption of luxuries and manufactured goods (clothing, lighting, imported goods) highly expensive. With this measure, the advantage of New France over France evaporates and turns slightly negative. In comparison with Britain and Colonial America, the gap widens appreciably. This element is the most important for future research. By showing a reversal because of a shift to a different type of basket, it shows that Old World and New World comparisons are very sensitive to how we measure the cost of living. Furthermore, there are no sustained improvements in living standards over the period regardless of the measure used. Gaps in living standards observed later in the nineteenth century existed as far back as the seventeenth century. In a wider American perspective that includes the Spanish colonies, Canada fares better. The third component computes a new series for Gross Domestic Product (GDP). This is to avoid problems associated with using real wages in the form of welfare ratios which assume a constant labor supply. This assumption is hard to defend in the case of Colonial Canada as there were many signs of increasing industriousness during the eighteenth and nineteenth centuries. The GDP series suggest no long-run trend in living standards (from 1688 to circa 1765). The long peace era of 1713 to 1740 was marked by modest economic growth which offset a steady decline that had started in 1688, but by 1760 (as a result of constant warfare) living standards had sunk below their 1688 levels. These developments are accompanied by observations that suggest that other indicators of living standard declined. The flat-lining of incomes is accompanied by substantial increases in the amount of time worked, rising mortality and rising infant mortality. In addition, comparisons of incomes with the American colonies confirm the results obtained with wages— Canada was considerably poorer. At the end, a long conclusion is provides an exploratory discussion of why Canada would have diverged early on. In structural terms, it is argued that the French colony was plagued by the problem of a small population which prohibited the existence of scale effects. In combination with the fact that it was dispersed throughout the territory, the small population of New France limited the scope for specialization and economies of scale. However, this problem was in part created, and in part aggravated, by institutional factors like seigneurial tenure. The colonial origins of French America’s divergence from the rest of North America are thus partly institutional

A design of a high temperature x-ray furnace /

The goal of this thesis is to design a furnace to be used in in-situ time-resolved x-ray scattering studies of processes such as crystallization in 25 mum thick metallic ribbons. Two approaches are tested thoroughly. The first is to use forced convection to heat the sample. This is tested experimentally up to about 500 K with 1.5 mm thick samples and theoretical calculations are used to resolve these data and to predict the behaviour of the thin ribbons at higher temperatures. The results show that the ideal configuration for this heating mechanism involves heating the ends of the samples while allowing hot gas to flow over the surface. Despite its expected advantages, such as small thermal gradients within the sample, this system should have poor long term stability and require a difficult calibration in order to couple the gas heater to the heaters at the ends of the sample. (Abstract shortened by UMI.

Novel complex stacking of fully-ordered transition metal layers in Li [sub] 4 FeSbO [sub] 6 materials

As part of a broad project to explore Li4MM′O6 materials (with M and M′ being selected from a wide variety of metals) as positive electrode materials for Li-ion batteries, the structures of Li4FeSbO6 materials with both stoichiometric and slightly deficient lithium contents are studied here. For lithium content varying from 3.8 to 4.0, the color changes from yellow to black and extra superstructure peaks are seen in the XRD patterns. These extra peaks appear as satellites around the four superstructure peaks affected by the stacking of the transition metal atoms. Refinements of both XRD and neutron scattering patterns show a nearly perfect ordering of Li, Fe, and Sb in the transition metal layers of all samples, although these refinements must take the stacking faults into account in order to extract information about the structure of the TM layers. The structure of the most lithium rich sample, where the satellite superstructure peaks are seen, was determined with the help of HRTEM, XRD, and neutron scattering. The satellites arise due to a new stacking sequence where not all transition metal layers are identical but instead two slightly different compositions stack in an AABB sequence giving a unit cell that is four times larger than normal for such monoclinic layered materials. The more lithium deficient samples are found to contain metal site vacancies based on elemental analysis and Mössbauer spectroscopy results. The significant changes in physical properties are attributed to the presence of these vacancies. This study illustrates the great importance of carefully determining the final compositions in these materials, as very small differences in compositions may have large impacts on structures and properties

Synthesis of Boroxine and Dioxaborole Covalent Organic Frameworks via Transesterification and Metathesis of Pinacol Boronates

Boroxine and dioxaborole are the first and some of the most studied synthons of Covalent Organic Frameworks (COFs). Despite their wide application in the design of functional COFs over the last 15 years, their synthesis still relies on the original Yaghi’s condensation of boronic acids (with itself or with polyfunctional catechols), some of which are difficult to prepare, poorly soluble, or unstable in the presence of water. Here we propose a new synthetic approach to boroxine COFs (based on transesterification of pinacol aryl boronates (ArBpin) with methyl boronic acid (MBA) and dioxaborole COFs (through the metathesis of pinacol boronates with methylboryl-protected catechols). The ArBpin and MBA-protected catechols are easy to purify, highly soluble, and bench-stable. Furthermore, kinetic analysis of the two model reactions reveals high reversibility (Keq~1) and facile control over the equilibrium. Unlike the conventional condensation which eliminates water by-products, the by-product of the metathesis (MBA pinacolate) allows for easy kinetic measurements of the COF formation by conventional 1H NMR. We show the generality of this approach by synthesis of seven known boroxine/dioxaborole COFs whose crystallinity is better or equal to those reported by conventional condensation. We also apply metathesis polymerization to obtain two new COFs, Py4THB and B2HHTP, whose synthesis was previously precluded by their insolubility and hydrolytic instability, respectively, of the boronic acid precursors.<br /

Combinatorial Investigation of the Impact of Systematic Al Substitution into LiNi_{1–<i>x</i>–<i>y</i>}Mn_<i>x</i>Co_<i>y</i>O₂ Materials

State-of-the-art Li-ion batteries in long-range electric vehicles increasingly rely on LiNi1–x–yMnxCoyO2 (NMC) cathodes with a trend toward higher Ni content. While high-Ni compositions can increase capacity, they also decrease the material’s stability and therefore battery lifetime. Though aluminum has been substituted into a few NMC compositions, to date, no systematic study has been performed. In this study, the impact of different levels of Al substitution was explored across the full range of NMC compositions by preparing a total of 320 materials with varying aluminum content from 0 to 15%. Both X-ray diffraction (XRD) and cyclic voltammetry were performed on all samples. The single-phase layered oxide region is quite large when no Al is present and decreases slightly in size as aluminum content increases. The nickel-rich region (1 – x – y > 0.8) was entirely single phase for 0 and 5% Al levels, while at higher Al content small amounts of Li–Al–O phases were found as contaminants detrimental to the electrochemistry, indicating an optimal Al level in high-Ni materials. Key battery metrics including discharge capacity, average voltage, and diffusion coefficients were obtained for all materials and correlated to structural changes seen in the XRD. It was found that Al suppressed the detrimental hexagonal phase transitions at high voltage (∼4.3 V) in Ni-rich compositions. Increased Al content also improved the diffusion coefficients in the Ni-rich materials. Overall, this study provides the first generalized view of the effects of Al substitution on NMC cathode materials. This work can serve as a base for further exploration into Al substitution on less-studied NMC compositions

The intriguing question of anionic redox in high-energy density cathodes for Li-ion batteries

International audienceThe energy density delivered by a Li-ion battery is a key parameter that needs to be significantlyincreased to address the global question of energy storage for the next 40 years. This quantity is directlyproportional to the battery voltage (V) and the battery capacity (C) which are difficult to improvesimultaneously when materials exhibit classical cationic redox activity. Recently, a cumulative cationic4+ 5+ 2À nÀ(M /M ) and anionic (2O /(O2) ) redox activity has been demonstrated in the Li-rich Li2 MO3 familyof compounds, therefore enabling doubling of the energy density with respect to high-potentialcathodes such as transition metal phosphates and sulfates. This paper aims to clarify the origin of thisextra capacity by addressing some fundamental questions regarding reversible anionic redox inhigh-potential electrodes for Li-ion batteries. First, the ability of the system to stabilize the oxygen holes2À nÀgenerated by Li-removal and to achieve a reversible oxo- to peroxo-like (2O /(O2) ) transformation iselucidated by means of a metal-driven reductive coupling mechanism. The penchant of the system forundergoing this reversible anionic redox or releasing O2 gas is then discussed with regards toexperimental results for 3d- and 4d-based Li2MO3 phases. Finally, robust indicators are built as tools topredict which materials in the Li-rich TM-oxide family will undergo efficient and reversible anionicredox. The present finding provides insights into new directions to be explored for the development ofhigh-energy density materials for Li-ion batteries