Bicarbonate or Carbonate Processes for Coupling Carbon Dioxide Capture and Electrochemical Conversion

Designing a scalable system to capture CO₂ from the air and convert it into valuable chemicals, fuels, and materials could be transformational for mitigating climate change. Climate models predict that negative greenhouse gas emissions will be required by the year 2050 in order to stay below a 2 °C change in global temperature. The processes of CO₂ capture, CO₂ conversion, and finally product separation all require significant energy inputs; devising a system that simultaneously minimizes the energy required for all steps is an important challenge. To date, a variety of prototype or pilot-level CO₂ capture and/or conversion systems have been designed and built targeting the individual objectives of either capture or conversion. One approach has focused on CO₂ removal from the atmosphere and storage of pure pressurized CO₂. Other efforts have concentrated on CO₂ conversion processes, such as electrochemical reduction or fermentation. Only a few concepts or analyses have been developed for complete end-to-end processes that perform both CO₂ capture and transformation

What is New or Different about the Scholarship of Teaching?

SCHOLARSHIP Reconsidered (Boyer, 1990) summarized a new way of approaching higher education. This report presented higher education as a set of four scholarships, four means of accomplishing the goals of academe. The purpose of our report is to address the scholarship of teaching, both as an activity and as an assessment of such activity. This report will focus on the scholarship of teaching by addressing: What is the scholarship of teaching? What qualities exist in this form of scholarship? What are the requirements of this scholarship? How does one accomplish this scholarship? And finally, how can the scholarship of teaching be assessed

Learning spaces in academic libraries: a review of the evolving trends

This paper presents a review of the professional discourse regarding the evolution of information and learning spaces in academic libraries, particularly in the first decade of the twenty-first century. It investigates the evolution of academic libraries and the development of learning spaces focusing on the use of the terms which have evolved from the information commons concept. The literature review is primarily guided by an effort to make clearly visible the connections and distinctions between different models for the use of space in academic libraries for delivering information and learning services, up to the very recent occurrence of "maker spaces". Attention is given to the language used to describe the different models and to changing historical factors, purposes, pedagogical influences, and attributes of each model for better recognition of shifts and emerging trends

Influence of supercoiling on the disruption of dsDNA

We propose that supercoiling energizes double-stranded DNA (dsDNA) so as to facilitate thermal fluctuations to an unzipped state. We support this with a model of two elastic rods coupled via forces that represent base pair interactions. Supercoiling is shown to lead to a spatially localized higher energy state in a small region of dsDNA consisting of a few base pairs. This causes the distance between specific base pairs to be extended, enhancing the thermal probability for their disruption. Our theory permits the development of an analogy between this unzipping transition and a second order phase transition, for which the possibility of a new set of critical exponents is identified

Optical Excitation of a Nanoparticle Cu/p-NiO Photocathode Improves Reaction Selectivity for CO₂ Reduction in Aqueous Electrolytes

We report the light-induced modification of catalytic selectivity for photoelectrochemical CO₂ reduction in aqueous media using copper (Cu) nanoparticles dispersed onto p-type nickel oxide (p-NiO) photocathodes. Optical excitation of Cu nanoparticles generates hot electrons available for driving CO₂ reduction on the Cu surface, while charge separation is accomplished by hot-hole injection from the Cu nanoparticles into the underlying p-NiO support. Photoelectrochemical studies demonstrate that optical excitation of plasmonic Cu/p-NiO photocathodes imparts increased selectivity for CO₂ reduction over hydrogen evolution in aqueous electrolytes. Specifically, we observed that plasmon-driven CO₂ reduction increased the production of carbon monoxide and formate, while simultaneously reducing the evolution of hydrogen. Our results demonstrate an optical route toward steering the selectivity of artificial photosynthetic systems with plasmon-driven photocathodes for photoelectrochemical CO₂ reduction in aqueous media

Anomalous increase in nematic-isotropic transition temperature in dimer molecules induced by magnetic field

We have determined the nematic-isotropic transition temperature as a function of applied magnetic field in three different thermotropic liquid crystalline dimers. These molecules are comprised of two rigid calamitic moieties joined end to end by flexible spacers with odd numbers of methylene groups. They show an unprecedented magnetic field enhancement of nematic order in that the transition temperature is increased by up to 15K when subjected to 22T magnetic field. The increase is conjectured to be caused by a magnetic field-induced decrease of the average bend angle in the aliphatic spacers connecting the rigid mesogenic units of the dimers

Light scattering study of the “pseudo-layer” compression elastic constant in a twist-bend nematic liquid crystal

The nematic twist-bend (TB) phase, exhibited by certain achiral thermotropic liquid crystalline (LC) dimers, features a nanometer-scale, heliconical rotation of the average molecular long axis (director) with equally probable left- and right-handed domains. On meso to macroscopic scales, the TB phase may be considered as a stack of equivalent slabs or “pseudo-layers”, each one helical pitch in thickness. The long wavelength fluctuation modes should then be analogous to those of a smectic-A phase, and in particular the hydrodynamic mode combining “layer” compression and bending ought to be characterized by an effective layer compression elastic constant Beff and average director splay constant Keff1. The magnitude of Keff1 is expected to be similar to the splay constant of an ordinary nematic LC, but due to the absence of a true mass density wave, Beff could differ substantially from the typical value of ∼10⁶ Pa in a conventional smectic-A. Here we report the results of a dynamic light scattering study, which confirms the “pseudo-layer” structure of the TB phase with Beff in the range 10³–10⁴ Pa. We show additionally that the temperature dependence of Beff at the TB to nematic transition is accurately described by a coarse-grained free energy density, which is based on a Landau-deGennes expansion in terms of a heli-polar order parameter that characterizes the TB state and is linearly coupled to bend distortion of the director