Molecular Hospitality: The Interactions of Brooker’s Merocyanine with Modified Cyclodextrins

The binding of a guest molecule to a host system occurs through weak molecular interactions instead of through the formation of chemical bonds. The relative strength of these interactions can be understood by comparing the binding constant in related host-guest systems. Β-cyclodextrin (β-CD) is a seven-membered ring of glucose units which was used as the host molecule due to its basket-like shape. This shape allows Brooker’s merocyanine (BM), a highly conjugated guest molecule that is sensitive to its environment, to enter the cavity and interact with substituents located along the primary and secondary rims of the CD. This project measured the changes in the equilibrium binding constant due to different modifications to the CD, as well as the isomerization of BM within the cavity using UV-Vis and fluorescence spectroscopy. Binding constants were determined for different CD modifications, including β-CD, hydroxypropyl-β-CD, hydroxyethyl-β-CD, and sulfated β-CD (sodium salt). The largest effect of these substituents was the hindrance of the binding by the sulfate groups due to either steric effects or ionic interactions. A better understanding of these factors that affect binding and how molecules behave within the cavity will allow for more accurate predictions of their behavior under different conditions

Two-dimensional flow of foam around a circular obstacle: local measurements of elasticity, plasticity and flow

We investigate the two-dimensional flow of a liquid foam around circular obstacles by measuring all the local fields necessary to describe this flow: velocity, pressure, bubble deformations and rearrangements. We show how our experimental setup, a quasi-2D "liquid pool" system, is adapted to the determination of these fields: the velocity and bubble deformations are easy to measure from 2D movies, and the pressure can be measured by exploiting a specific feature of this system, a 2D effective compressibility. To describe accurately bubble rearrangements, we propose a new, tensorial descriptor. All these quantities are evaluated via an averaging procedure that we justify showing that the fluctuations of the fields are essentially random. The flow is extensively studied in a reference experimental case; the velocity presents an overshoot in the wake of the obstacle, the pressure is maximum at the leading side and minimal at the trailing side. The study of the elastic deformations and of the velocity gradients shows that the transition between plug flow and yielded regions is smooth. Our tensorial description of T1s highlight their correlation both with the bubble deformations and the velocity gradients. A salient feature of the flow, notably on the velocity and T1 repartition, is a marked asymmetry upstream/downstream, signature of the elastic behaviour of the foam. We show that the results do not change qualitatively when various control parameters vary, identifying a robust quasistatic regime. These results are discussed in the frame of the actual foam rheology literature, and we argue that they constitute a severe test for existing rheological models, since they capture both the elastic, plastic and fluid behaviour of the foam.Comment: 41 pages, 25 figures, submitted to Journal of Fluid Mechanics (but not in JFM style), short version of the abstrac

Benchmarking news recommendations: the CLEF NewsREEL use case

The CLEF NewsREEL challenge is a campaign-style evaluation lab allowing participants to evaluate and optimize news recommender algorithms. The goal is to create an algorithm that is able to generate news items that users would click, respecting a strict time constraint. The lab challenges participants to compete in either a "living lab" (Task 1) or perform an evaluation that replays recorded streams (Task 2). In this report, we discuss the objectives and challenges of the NewsREEL lab, summarize last year's campaign and outline the main research challenges that can be addressed by participating in NewsREEL 2016

CLEF NewsREEL 2016: Comparing Multi-Dimensional Offline and Online Evaluation of News Recommender Systems

Running in its third year at CLEF, NewsREEL challenged participants to develop news recommendation algorithms and have them benchmarked in an online (Task 1) and offline setting (Task 2), respectively. This paper provides an overview of the NewsREEL scenario, outlines this year’s campaign, presents results of both tasks, and discusses the approaches of participating teams. Moreover, it overviews ideas on living lab evaluation that have been presented as part of a “New Ideas” track at the conference in Portugal. Presented results illustrate potentials for multi-dimensional evaluation of recommendation algorithms in a living lab and simulation based evaluation setting

Planning the Future of North American Cold-Formed Steel Design Standards

Growth in cold-formed steel structures has long been tied to developing and advancing the engineering standards that govern their use in construction. The American Iron and Steel Institute (AISI) has taken a leadership role in this activity in North America since 1946. Conventional standards providing closed-formed solutions to member capacity, such as the recently completed suite of AISI Standards in 2015 and 2016. These standards have reached an impressive level of maturity given the complexity of designing entire (building) structural systems out of steel that is rarely greater than 2mm thick. However, the demands on the structural engineer designing cold-formed steel have evolved. System performance, resilience, and sustainability all present new challenges, while changing processes in construction and the integration of simulation tools in design alter engineering workflows and open up new opportunities. Cold-formed steel standards need to evolve to meet these demands and leverage new workflows. The Strategic Planning Committee of the AISI Standards Council facilitated a process that defined areas of focus (vision statements) for the AISI specification writing committees and then facilitated a process to generate prioritized issues for the subcommittees to address. Taken together the lists provide a snapshot of the needed work to evolve cold-formed steel standards, and in turn enable next-generation cold-formed steel structural systems. This paper provides a description of the strategic planning process and its significant outcomes, which will guide the efforts of AISI standards development over the next code development cycle and beyond

One-Litter Outdoor Farrowing System by using Artificial Insemination and Hoop Structures

The one−litter outdoor system of pork production may be improved with advanced technology. Artificial insemination and low cost gestation housing allow replacement gilts to be produced at a lower cost. Electric fencers, all terrain vehicles, and improved management all provide the hog producer an opportunity to raise more hogs at lower cost and with reduced labor. This article provides a budget for a one-litter system in which three groups of 100 sows each are farrowed annually. Seven hundred-fifty pigs are raised to 50 lb from each farrowing. Then, 300 pigs per group are saved from the maternal cross as well as six terminal boars and are finished in hoop structures. Of 900 pigs finished, 390 (130 per group) are kept for replacement gilts (using the hoops for gestation). The remaining are sold as market hogs. Of 130 gilts, 30 are assumed to be non breeders and are sold as open gilts. The remaining 100 gilts are farrowed the following year and sold immediately after weaning. This system farrows 300 litters and markets 2,250 feeder pigs, 500 market hogs, 90 cull gilts, and 300 cull sows per year. Based on current prices (1997) and 7.5 pigs weaned per litter, the cost of production was $41 per 50 lb–pig for all costs; or$32 per 50 lb–pig excluding labor. The system budget is competitive with more capital-intensive confinement systems