140 research outputs found

    Liquid crystalline properties of unsymmetrically substituted phthalocyanines: structural features leading to nematic mesophase materials

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    A novel homologous series of four 1,4,8,11,15,18-hexakis(pentyl)-22-methyl-25-hydroxyalkylphthalocyanine derivatives with the hydroxyalkyl chain varying from hydroxynonyl through to hydroxydodecyl has been synthesized to investigate the role of the hydroxyalkyl chain in promoting thermotropic liquid crystalline behavior. Polarizing optical miscoscopy reveals that the compound with the shortest hydroxyalkyl chain (hydroxynonyl) exhibits a mesophase with a texture characteristic of a columnar mesophase, common among liquid crystalline phthalocyanine derivatives. However, as the chain is lengthened along the series, there appears a second type of mesophase that shows a schlieren texture. Such a texture is characteristic of a nematic phase and rare among liquid crystalline phthalocyanine derivatives. A fifth compound, the novel 1,4,8,11,15,18-hexakis(pentyl)-22-methyl-25- dodecylphthalocyanine, exhibits only columnar mesophase behavior suggesting that the hydroxyl group at the end of the longer chains of the former compounds is important in developing the nematic phase

    The Net Effect of Exchange Rates on Agricultural Inputs and Outputs

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    For more than thirty years, studies about the effect of the exchange rate on exports have been conducted. However, few have considered the combined effect of the exchange rate on imported inputs into the agricultural system and the exports of final agricultural products those inputs produce. A current concern is for the net effect as the total value and quantity of inputs imported has increased. This research examines the effect of exchange rate changes on imported inputs into the corn, wheat, and beef cattle production systems. Effects on cost of production budgets are calculated, examining affects on profitability. Vector Autoregression (VAR) and Bayesian Averaging of Classical Estimates (BACE) models were estimated to evaluate those effects. Daily and weekly price data were used for corn, wheat, feeder steers, ethanol, diesel, ammonia, urea, di-ammonium phosphate, and the exchange rate. A VAR model was estimated to model the relationship between the variables. After having incongruous test results in determining the lag length structure it was decided that a BACE model would be approximated. After estimating the BACE model the price responses of the commodities to the exchange rates was estimated. The price responses were used in demonstrating the effect of the exchange rate on a producer’s profitability. It was determined that, generally, a strengthening exchange rate has a negative impact on prices. It was also found that the exchange rate has a greater impact on prices now than it did 14 years ago, implying that the exchange rate now has a greater affect on profitability. A one percent increase in the value of the dollar led to a decline in profitability ranging from 0.02/buinwheatto0.02/bu in wheat to 0.56/cwt in feeder steers. However, agricultural producers should not be overly concerned about a lower valued dollar from the perspective of their agricultural business.Agricultural and Food Policy, Crop Production/Industries, International Relations/Trade, Livestock Production/Industries,

    Structural Dynamic Stability of Noah\u27s Ark

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    If the Genesis Flood was a catastrophic event that induced large scale wind driven waves, then the ark that carried Noah and his family needed to be very stable upon large, sometimes random loads. This particular study has several research components that give greater insight into the structural dynamic stability of the ark: (1) a combined numerical-experimental modal analysis on a 1/200th scale ark structure quantifying the first three fundamental resonance frequencies and associated mode shapes: 528 Hz in pitch bending, 800 Hz in yaw bending, and 1000 Hz in torsion; (2) a computational modal analysis that links the 1/200th scale ark structure with the full scale structure of Noah’s Ark showing that the first fundamental frequency ranges from 1–4.5 Hz below the range of human resonances that typically range between 5–10 Hz; and (3) a 1/200th scale ark experimental study on turbulent, random loads with waves that scaled as high as 500 ft (152 m) showing that Noah’s Ark would be stable even under these extreme loads. This combined computational-experimental study clearly shows the stability of the ark under extremely large scale, deleterious conditions

    Taking deliberative research online:Lessons from four case studies

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    Researchers using deliberative techniques tend to favour in-person processes. However, the covid-19 pandemic has added urgency to the question of whether meaningful deliberative research is possible in an online setting. This paper considers the reasons for taking deliberation online, including bringing people together more easily; convening international events; and reducing the environmental impact of research. It reports on four case studies: a set of stakeholder workshops considering greenhouse gas removal technologies, convened online in 2019, and online research workshops investigating local climate strategies; as well as two in-person processes which moved online due to covid-19: Climate Assembly UK, a Citizens’ Assembly on climate change, and the Lancaster Citizens’ Jury on Climate Change. It sets out learnings from these processes, concluding that deliberation online is substantively different from in-person meetings, but can meet the requirements of deliberative research, and can be a rewarding and useful process for participants and researchers alike

    A whole system approach to increasing children’s physical activity in a multi-ethnic UK city:a process evaluation protocol

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    BACKGROUND: Engaging in regular physical activity requires continued complex decision-making in varied and dynamic individual, social and structural contexts. Widespread shortfalls of physical activity interventions suggests the complex underlying mechanisms of change are not yet fully understood. More insightful process evaluations are needed to design and implement more effective approaches. This paper describes the protocol for a process evaluation of the JU:MP programme, a whole systems approach to increasing physical activity in children and young people aged 5–14 years in North Bradford, UK. METHODS: This process evaluation, underpinned by realist philosophy, aims to understand the development and implementation of the JU:MP programme and the mechanisms by which JU:MP influences physical activity in children and young people. It also aims to explore behaviour change across wider policy, strategy and neighbourhood systems. A mixed method data collection approach will include semi-structured interview, observation, documentary analysis, surveys, and participatory evaluation methods including reflections and ripple effect mapping. DISCUSSION: This protocol offers an innovative approach on the use of process evaluation feeding into an iterative programme intended to generate evidence-based practice and deliver practice-based evidence. This paper advances knowledge regarding the development of process evaluations for evaluating systems interventions, and emphasises the importance of process evaluation. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-021-12255-w

    The SAMI Galaxy Survey: Shocks and Outflows in a normal star-forming galaxy

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    We demonstrate the feasibility and potential of using large integral field spectroscopic surveys to investigate the prevalence of galactic-scale outflows in the local Universe. Using integral field data from SAMI and the Wide Field Spectrograph, we study the nature of an isolated disk galaxy, SDSS J090005.05+000446.7 (z = 0.05386). In the integral field datasets, the galaxy presents skewed line profiles changing with position in the galaxy. The skewed line profiles are caused by different kinematic components overlapping in the line-of-sight direction. We perform spectral decomposition to separate the line profiles in each spatial pixel as combinations of (1) a narrow kinematic component consistent with HII regions, (2) a broad kinematic component consistent with shock excitation, and (3) an intermediate component consistent with shock excitation and photoionisation mixing. The three kinematic components have distinctly different velocity fields, velocity dispersions, line ratios, and electron densities. We model the line ratios, velocity dispersions, and electron densities with our MAPPINGS IV shock and photoionisation models, and we reach remarkable agreement between the data and the models. The models demonstrate that the different emission line properties are caused by major galactic outflows that introduce shock excitation in addition to photoionisation by star-forming activities. Interstellar shocks embedded in the outflows shock-excite and compress the gas, causing the elevated line ratios, velocity dispersions, and electron densities observed in the broad kinematic component. We argue from energy considerations that, with the lack of a powerful active galactic nucleus, the outflows are likely to be driven by starburst activities. Our results set a benchmark of the type of analysis that can be achieved by the SAMI Galaxy Survey on large numbers of galaxies.Comment: 17 pages, 15 figures. Accepted to MNRAS. References update
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