Four Years of Unmediated Demand-Driven Acquisition and 5,000 E-Books Later: We Gave ‘Em What They Wanted

As one of ebrary’s largest academic library DDA customers, the program at the University of Iowa Libraries has been highly successful, though not without challenges. This presentation will present detailed findings from analyzing Iowa’s demand-driven acquisition e-book usage data from over 5,000 titles purchased over 4 years, including examining subject areas, prices, publishers, and other relevant metrics. This presentation will serve as update to a popular session at Charleston in 2010 (Give ‘Em What They Want: Patron-Driven Collection Development), where the University of Iowa Libraries presented data from a 1-year pilot program. Now, with 4 years of experience under our belts, a lot more data, and over a half-million dollars spent from our coffers, Iowa will share what we have learned, gained, and changed as a result of our experiences

The Preservation of Florida\u27s Public Trust Doctrine

In recent years, the State of Florida found itself embroiled in what has become the most massive sovereignty lands dispute in [its] history

Assessing the association between pre-course metrics of student preparation and student performance in introductory statistics: Results from early data on simulation-based inference vs. nonsimulation based inference

The recent simulation-based inference (SBI) movement in algebra-based introductory statistics courses (Stat 101) has provided preliminary evidence of improved student conceptual understanding and retention. However, little is known about whether these positive effects are preferentially distributed across types of students entering the course. We consider how two metrics of Stat 101 student preparation (pre-course performance on concept inventory and math ACT score) may or may not be associated with end of course student performance on conceptual inventories. Students across all preparation levels tended to show improvement in Stat 101, but more improvement was observed across all student preparation levels in early versions of a SBI course. Furthermore, students' gains tended to be similar regardless of whether students entered the course with more preparation or less. Recent data on a sample of students using a current version of an SBI course showed similar results, though direct comparison with non-SBI students was not possible. Overall, our analysis provides additional evidence that SBI curricula are effective at improving students' conceptual understanding of statistical ideas post-course regardless student preparation. Further work is needed to better understand nuances of student improvement based on other student demographics, prior coursework, as well as instructor and institutional variables.Comment: 16 page

Futterwert von Mais-Bohnen-Silagen: Stangen- und Feuerbohnen im Vergleich

Maize for silage is a major forage source for dairy cows with its high energy density, but the protein concentration is low. Therefore intercropping systems with maize and climbing beans, which have the potential to improve the protein- and energy supply from regional grown roughage, were investigated since 2014 in field experiments. Four cultivars of Phaseolus vulgaris and two cultivars of P. coccineus were evaluated for their potential in intercropping with maize and their crude nutrient contents were evaluated in comparison with maize. Furthermore defined mixtures of two cultivars of P. vulgaris and two cultivars of P. coccineus with maize were produced to assess their digestibility in sheep. All intercrop silages (IS) had higher crude protein values than maize. The in vivo organic matter digestibility were higher for IS when compared to maize. The metabolisable energy for IS were also higher than for maize silage

A Coagulation Method to Prepare Single-Walled Carbon Nanotube/PMMA Composites and Their Modulus, Electrical Conductivity, and Thermal Stability

A coagulation method that provides better dispersion of SWNT in the polymer matrix has been used to produce single-walled carbon nanotube (SWNT)/poly(methyl methacrylate) (PMMA) composites. Optical microscopy and SEM show improved dispersion of SWNT in the PMMA matrix, which is a key factor in composite performance. Aligned and unaligned composites were made with purified SWNT with different SWNT loadings, from 0.1 to 7 wt%. Comprehensive testing shows improved elastic modulus, electrical conductivity, and thermal stability with addition of SWNT. The electrical conductivity of a 2 wt% SWNT composite decreases significantly (\u3e105), when the SWNT is aligned and this result is discussed in terms of percolation

Effect of nanotube alignment on percolation conductivity in carbon nanotube/polymer composites

Percolation conductivity of a stick network depends on alignment as well as concentration. We show that both dependences exhibit critical (power-law) behavior, and study the alignment threshold in detail. The highest conductivity occurs for slightly aligned, rather than isotropic, sticks. Experiments on single wall carbon nanotube composites are supported by Monte Carlo simulations. These results should be broadly applicable to percolating networks of anisotropic conductors

The morphology and dynamics of subducting lithosphere

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1989.Vita.Includes bibliographical references (leaves 175-189).by Karen Marie Fischer.Ph.D

Interfacial in situ polymerization of single wall carbon nanotube/nylon 6,6 nanocomposites

An interfacial polymerization method for nylon 6,6 was adapted to produce nanocomposites with single wall carbon nanotubes (SWNT) via in situ polymerization. SWNT were incorporated in purified, functionalized or surfactant stabilized forms. The functionalization of SWNT was characterized by FTIR, Raman spectroscopy and TGA and the SWNT dispersion was characterized by optical microscopy before and after the in situ polymerization. SWNT functionalization and surfactant stabilization improved the nanotube dispersion in solvents but only functionalized SWNT showed a good dispersion in composites, whereas purified and surfactant stabilized SWNT resulted in poor dispersion and nanotube agglomeration. Weak shear flow induced SWNT flocculation in these nanocomposites. The electrical and mechanical properties of the SWNT/nylon nanocomposites are briefly discussed in terms of SWNT loading, dispersion, length and type of functionalization

Microfluidics: Continuous‐Flow Synthesis of Nanoparticle Dispersions for the Fabrication of Organic Solar Cells

State-of-the-art solvents for the fabrication of organic solar cells are mostly toxic or hazardous. First attempts to deposit light-harvesting layers from aqueous or alcoholic nanoparticle dispersions instead have been successful on laboratory scale, enabling future eco-friendly production of organic solar cells. In this work, a scalable high-throughput continuous-flow microfluidic system is employed to synthesize surfactant-free organic semiconductor dispersions by nanoprecipitation. By adjusting the differential speed of the syringe pumps, the concentration of the initial solute and the irradiation of the microfluidic chip, the synthesis can be controlled for tailored dispersion concentrations and nanoparticle sizes. The resulting dispersions are highly reproducible, and the semiconductor inks are stable for at least one year. The synthesis of the dispersions is exemplified on a polymer/fullerene combination with large-scale availability