Eulerian quasisymmetric functions and cyclic sieving

It is shown that a refined version of a q-analogue of the Eulerian numbers together with the action, by conjugation, of the subgroup of the symmetric group $S_n$ generated by the $n$-cycle $(1,2,...,n)$ on the set of permutations of fixed cycle type and fixed number of excedances provides an instance of the cyclic sieving phenonmenon of Reiner, Stanton and White. The main tool is a class of symmetric functions recently introduced in work of two of the authors.Comment: 30 page

Module Homomorphisms and Topological Centres Associated with Weakly Sequentially Complete Banach Algebras

AbstractThis paper is a contribution to the theory of weakly sequentially complete Banach algebrasA. We require them to have bounded approximate identities and, for the most part, to be ideals in their second duals, so that examples are the group algebrasL1(G) for compact groupsGor the Fourier algebrasA(G) for discrete amenable groupsG. In Section 2 we present our main result, that the topological centre (or set of weak* bicontinuous elements) ofA** is identifiable withA. As a corollary, we deduce in Section 3 that each leftA-module homomorphism fromA* toA*Acan be realized as right translation by an element ofA. These conclusions generalise recent advances in the subject. In Section 4 we take a special algebra,l1(S) for a commutative discrete semigroupS, and show that if its second dual has an identity then that identity must lie inl1(S)

Teaching in China: Reflections on Higher Education, Student Learning, and Teacher Training

In spring and summer 2013, four faculty members from Bridgewater State University taught courses on history, business, education, American studies, and second language acquisition in several universities in Hong Kong, Shanghai, Beijing, and a workshop for teachers in an international school in Xiamen. These opportunities offer our faculty new perspectives on the current state of higher education, student learning, and teacher training in China and Hong Kong. Wing-kai To taught history, culture, immigration, and ethnicity to graduate students and undergraduate students in the spring semester at the Chinese University of Hong Kong and University of Hong Kong and in a three-week intensive summer course at Beijing Jiaotong University. Chien-wen Yu taught a one-month summer session on business and strategic management to students in the College of Business at Shanghai Normal University. John Marvelle offered his expertise in a 2-week workshop for teachers at the Xiamen International School (XIS) and taught a three-week intensive summer session about American culture and literature at Beijing Jiaotong University. Ryan LaBrozzi taught theories and practices of second language acquisition for English learners in the same three-week intensive session in Beijing. These faculty members will share their experiences about the rewards and challenges of teaching in China, issues of student learning in higher education and K-12 education there, and US-China cooperation in educational exchanges. We will examine the opportunities and constraints in curricular issues, pedagogy, academic freedom, and student success in China. We welcome participation from the audience to share their teaching experiences in Asia as well

Facile Synthesis of Nitrogen-doped Porous Carbon for Selective CO2 Capture

AbstractSolid-state post-combustion CO2 sorbents have certain advantages over traditional aqueous amine systems, including reduced regeneration energy since vaporization of liquid water is avoided, tunable pore morphology, and greater chemical variability. We report here an ordered mesoporous nitrogen-doped carbon made by the co- assembly of a modified-pyrrole and triblock copolymer through a soft-templating method, which is facile, economic, and fast compared to the hard-template approach. A high surface area mesoporous carbon was achieved, which is comparable to the silica counterpart. This porous carbon, with a Brunauer–Emmett–Teller (BET) specific surface area of 804.5 m2 g-1, exhibits large CO2 capacities (298K) of 1.0 and 3.1 mmol g-1 at 0.1 and 1bar, respectively, and excellent CO2/N2 selectivity of 51.4. The porous carbon can be fully regenerated solely by inert gas purging without heating. It is stable for multiple adsorption/desorption cycles without reduction in CO2 capacity. These desirable properties render the nitrogen-doped hierarchical porous carbon a promising material for post-combustion CO2 capture

Design and testing of sorbents for CO2 separation of post-combustion and natural gas sweetening applications

In post-combustion processes, sorbents with both high capacity and selectivity are required for reducing the cost of carbon capture. Although physisorbents have the advantage of low energy consumption for regeneration, it remains a challenge to obtain both high capacity and sufficient CO2/N2 selectivity at the same time. A novel N-doped hierarchical carbon has been developed, which exhibits record-high Henry’s law CO2/N2 selectivity among physisorptive carbons while having a high CO2 adsorption capacity. Specifically, the synthesis involves the rational design of a modified pyrrole molecule that can co-assemble with the soft Pluronic template via hydrogen bonding and electrostatic interactions to give rise to mesopores followed by carbonization. The low-temperature carbonization and activation processes allow for the development of ultra-small pores (d2 affinity. Furthermore, the described work provides a strategy to initiate the development of rationally-designed porous conjugated polymer structures and carbon-based materials for various potential applications. In addition to post-combustion capture, natural gas sweetening is another topic of interest. Natural gas, having the lowest carbon intensity compared to coal and petroleum, is projected to increase in production and consumption in the coming decades. However, a drawback associated with natural gas is that it contains considerable amounts of CO2 at the recovery well, making on-site CO2 capture necessary. Solid sorbents are advantageous over traditional amine scrubbing due to their relatively low regeneration energies and non-corrosive nature. However, it remains a challenge to improve the sorbent’s CO2 capacity at elevated pressures relevant to natural gas purification. A series of porous carbons have been developed, which were derived from an intrinsic 3D hierarchical nanostructured polymer hydrogel, with simple and effective tunability over the pore size distribution. The optimized surface area reached a record-high of 4196 m2 g-1 among carbon-based materials. This high surface area along with the abundant micro/narrow mesopores (1.94 cm3 g-1 with d \u3c 4 nm) results in a record-high CO2 capacity (28.3 mmol g-1 at 25 °C and 30 bar) among carbons. This carbon also showed reasonable CO2/CH4 selectivity and excellent cyclability. In addition, this work for the first time combines experimental studies with first-principle molecular simulations for high-pressure CO2 adsorption on porous sorbents. It was found that at elevated pressures, the CO2 density in the adsorbed phase is significantly enhanced in the micro- and narrow mesopores with quantitative values provided for CO2 density. Furthermore, surface nitrogen functionalities have a trivial contribution to the CO2 uptake at high pressures. These findings emphasize the importance of being able to tune a sorbent’s pore size to achieve high CO2 uptake. Thus, the simulation studies help in our understanding of our sorbent’s superior performance as well as provides useful insight into future sorbent development

Inkjet Patterned Anodic Aluminum Oxide for Rear Metal Contacts of Silicon Solar Cells

AbstractLocal rear metal contacting through passivating dielectric layers has the ability to increase silicon solar cell efficiencies to over 20%. To-date most contact schemes have involved the formation of localised aluminium-alloyed regions through patterned AlOx or SiNx passivating layers. Recently electrochemically-formed anodic aluminium oxide (AAO) layers have been shown to enhance minority carrier lifetimes of phosphorus–diffused p-type CZ wafers when formed over an intervening layer of SiO2 or SiNx, suggesting that these layers may find applications as passivation layers for cells. We report here on the inkjet patterning of AAO layers formed over a thermally-grown thin oxide layer on p-type silicon surfaces. The process, which involves the inkjet printing of 50% (w/w) phosphoric acid, was used to form well-resolved arrays of holes with a diameter as small as 20-40μm in the dielectric stack. Alloying of aluminium, which was evaporated over the patterned dielectric stack, resulted in the formation of localised back surface field (BSF) regions having a thickness up to 8μm. Future work will focus on adapting this process for use in local rear metal contacting of silicon solar cells

Should there be a future for Tablet PCs in schools?

Tablet PCs are a relatively new format of computer, which seem to offer features which may be beneficial to schools. The uptake of Tablet PCs by schools has been somewhat limited, not least due to their greater cost than laptops of a 'similar' specification. This paper explores the key question of the extent to which schools should be investing in Tablet PCs, if at all, in preference to other formats of fully functional PCs, drawing on evidence from a Becta funded evaluation of the use of Tablet PCs in schools in England conducted in 2004-2005. The Computer Practice Framework was used to develop a set of questions which helped structure a meta-analysis of the data from 12 case studies that formed part of this evaluation. The methodology used and some limitations of the evaluation are outlined, and the key findings are described. The paper concludes that Tablet PCs do appear to offer significant potential to schools, though this potential was not being fully realised in most of the case study schools. A number of specific circumstances in which Tablet PCs do appear to be the most cost effective option are also identified

Erratum to: Genetic alterations of m6A regulators predict poorer survival in acute myeloid leukemia

Abstract Methylation of N6 adenosine (m6A) is known to be important for diverse biological processes including gene expression control, translation of protein, and messenger RNA (mRNA) splicing. However, its role in the development of human cancers is poorly understood. By analyzing datasets from the Cancer Genome Atlas Research Network (TCGA) acute myeloid leukemia (AML) study, we discover that mutations and/or copy number variations of m6A regulatory genes are strongly associated with the presence of TP53 mutations in AML patients. Further, our analyses reveal that alterations in m6A regulatory genes confer a worse survival in AML. Our work indicates that genetic alterations of m6A regulatory genes may cooperate with TP53 and/or its regulator/downstream targets in the pathogenesis and/or maintenance of AML