Some practical considerations for economical back contact formation on high efficiency solar cells

The back contact can detract from solar cell performance in a number of ways: high recombination, barrier, photovoltaic, minority carrier collection, resistance. These effects may act in a nonuniform fashion over the cell area, and complicate the analysis of photovoltaic performance aimed at a better understanding of the effects of device geometry and material and/or processing parameters. The back contact is tested by reproducing it on both sides of a substrate. The objective is to find a back contact which performs well as a back contact, can be applied cheaply to large area solar cells, fits well into a practical process sequence, does not introduce structural damage or undesirable impurities into the silicon substrate, is compatible with an effective front contact technology, permits low temperature solder contacting, adheres well to silicon, and is reliable

Phase 1 of the automated array assembly task of the low cost silicon solar array project

The state of technology readiness for the automated production of solar cells and modules is reviewed. Individual process steps and process sequences for making solar cells and modules were evaluated both technically and economically. High efficiency with a suggested cell goal of 15% was stressed. It is concluded that the technology exists to manufacture solar cells which will meet program goals

Creating Artful Thinkers - Transforming Research into Practice, Onsite to Online Learning

National Gallery of Art educators Julie Carmean and Sara Lesk propose presenting about their process of transforming research into practice through creating the National Gallery’s first Massive Open Online Course (MOOC), specifically for K-12 educators, using the pedagogy of Harvard’s Artful Thinking Routines and the National Gallery’s art collection. This free, international, online learning experience aims to democratize the opportunity for teachers to bring critical thinking through art to their students around the world. Participants will experience a combined onsite/online demonstration of one of their MOOC modules by, first, engaging with a work of art, using an Artful Thinking routine; second, watching a produced video of students responding to the same work, using the same routine as participants; and third, discussing the experience and the documentation of student learning, as would happen on a discussion forum. The presenters will then invite participants to give actionable feedback to course creators

RIBFIND: a web server for identifying rigid bodies in protein structures and to aid flexible fitting into cryo EM maps

Motivation: To better analyze low-resolution cryo electron microscopy maps of macromolecular assemblies, component atomic structures frequently have to be flexibly fitted into them. Reaching an optimal fit and preventing the fitting process from getting trapped in local minima can be significantly improved by identifying appropriate rigid bodies in the fitted component. Results: Here we present the RIBFIND server, a tool for identifying rigid bodies in protein structures. The server identifies rigid bodies in proteins by calculating spatial proximity between their secondary structural elements. Availability: The RIBFIND web server and its standalone program are available at http://ribfind.ismb.lon.ac.uk

Minimum message length inference of secondary structure from protein coordinate data

Motivation: Secondary structure underpins the folding pattern and architecture of most proteins. Accurate assignment of the secondary structure elements is therefore an important problem. Although many approximate solutions of the secondary structure assignment problem exist, the statement of the problem has resisted a consistent and mathematically rigorous definition. A variety of comparative studies have highlighted major disagreements in the way the available methods define and assign secondary structure to coordinate data

Non-perturbative renormalization of vector and axial vector currents in quenched QCD for a renormalization group improved gauge action

Renormalization constants of vector ($Z_V$) and axial-vector ($Z_A$) currents are determined non-perturbatively in quenched QCD for an RG-improved gauge action and a tadpole-improved clover quark action using the Schr\"odinger functional method. Meson decay constants $f_\rho$ and $f_\pi$ show much better scaling when $Z_V$ and $Z_A$ estimated for infinite physical volume are used instead of $Z$-factors from tadpole-improved one-loop perturbation theory.Comment: Lattice2003(improve), 3 page

I=2 Pion Scattering Length and Phase Shift with Wilson Fermions

We present preliminary results of scattering length and phase shift for I=2 S-wave $\pi\pi$ system with the Wilson fermions in the quenched approximation. The finite size method presented by L\"uscher is employed, and calculations are carried out at $\beta=5.9$ on a $24^3\times 60$ and $32^3\times 60$ lattice.Comment: Lattice2001(spectrum

I=2 pion-pion scattering phase shift in the continuum limit calculated with two-flavor full QCD

We present a calculation of the scattering phase shift for the I=2 S-wave pion-pion system in the continuum limit with two-flavor full QCD. Calculations are made at three lattice spacings, using the finite volume method of L\"uscher in the center of mass frame, and its extension to the laboratory frame.Comment: Lattice2003(spectrum), 3 page

Dynamical fermions on anisotropic lattices

We report on our study of two-flavor full QCD on anisotropic lattices using $O(a)$-improved Wilson quarks coupled with an RG-improved glue. The bare gauge and quark anisotropies corresponding to the renormalized anisotropy $\xi=a_s/a_t = 2$ are determined as functions of $\beta$ and $\kappa$, using the Wilson loop and the meson dispersion relation at several lattice cutoffs and quark masses.Comment: Lattice2002(improve), 3 pages, 3 figure

I=2 Pion Scattering Phase Shift with Wilson Fermions

We present a lattice QCD calculation of the scattering phase shift for the I=2 $S$-wave two-pion system using the finite size method proposed by L\"uscher. We work in the quenched approximation employing the standard plaquette action at $\beta=5.9$ for gluons and the Wilson fermion action for quarks. The phase shift is extracted from the energy eigenvalues of the two-pion system, which are obtained by a diagonalization of the pion 4-point function evaluated for a set of relative spatial momenta. In order to change momentum of the two-pion system, calculations are carried out on $24^3\times 60$, $32^3\times 60$, and $48^3\times 60$ lattices. The phase shift is successfully calculated over the momentum range $0 < p^2 < 0.3 {\rm GeV}^2$.Comment: LaTeX, 28 pages, 10 eps figures, uses revtex and epsfi