Solcore: A multi-scale, python-based library for modelling solar cells and semiconductor materials

Computational models can provide significant insight into the operation mechanisms and deficiencies of photovoltaic solar cells. Solcore is a modular set of computational tools, written in Python 3, for the design and simulation of photovoltaic solar cells. Calculations can be performed on ideal, thermodynamic limiting behaviour, through to fitting experimentally accessible parameters such as dark and light IV curves and luminescence. Uniquely, it combines a complete semiconductor solver capable of modelling the optical and electrical properties of a wide range of solar cells, from quantum well devices to multi-junction solar cells. The model is a multi-scale simulation accounting for nanoscale phenomena such as the quantum confinement effects of semiconductor nanostructures, to micron level propagation of light through to the overall performance of solar arrays, including the modelling of the spectral irradiance based on atmospheric conditions. In this article we summarize the capabilities in addition to providing the physical insight and mathematical formulation behind the software with the purpose of serving as both a research and teaching tool.Comment: 25 pages, 18 figures, Journal of Computational Electronics (2018

Continuity properties for linear commutators of Calderón-Zygmund operators

It is known that the linear commutator [$b, T$] of a Calderón-Zygmund operator $T$ with a $BMO$ function $b$ does not satisfy some of the continuity properties typical of a Calderón-Zygmund operator, for instance, continuity from the Hardy space $H^p$ into $L^p$ for $p\leq 1$ large enough, and weak type (1, 1). We obtain in this paper alternative results. Indeed, we prove in the first part of the paper that [$b, T$] is continuous from $H^p_b$ into $L^p$, where $H^p_b$ denotes an atomic space with atoms satisfying an extra cancellation condition involving the function $b$. In the second part of the paper we define a weak version $H^{p,\infty}_b$ of this atomic space and we prove that [$b, T$] maps continuously $H^{p,\infty}_b$ into $L^{p,\infty}$

Effects of adenotonsillectomy on plasma inflammatory biomarkers in obese children with obstructive sleep apnea: A community-based study.

BackgroundObesity and obstructive sleep apnea syndrome (OSA) are highly prevalent and frequently overlapping conditions in children that lead to systemic inflammation, the latter being implicated in the various end-organ morbidities associated with these conditions.AimTo examine the effects of adenotonsillectomy (T&A) on plasma levels of inflammatory markers in obese children with polysomnographically diagnosed OSA who were prospectively recruited from the community.MethodsObese children prospectively diagnosed with OSA, underwent T&A and a second overnight polysomnogram (PSG) after surgery. Plasma fasting morning samples obtained after each of the two PSGs were assayed for multiple inflammatory and metabolic markers including interleukin (IL)-6, IL-18, plasminogen activator inhibitor-1 (PAI-1), monocyte chemoattractant protein-1 (MCP-1), matrix metalloproteinase-9 (MMP-9), adiponectin, apelin C, leptin and osteocrin.ResultsOut of 122 potential candidates, 100 obese children with OSA completed the study with only one-third exhibiting normalization of their PSG after T&A (that is, apnea-hypopnea index (AHI) ≤1/hour total sleep time). However, overall significant decreases in MCP-1, PAI-1, MMP-9, IL-18 and IL-6, and increases in adropin and osteocrin plasma concentrations occurred after T&A. Several of the T&A-responsive biomarkers exhibited excellent sensitivity and moderate specificity to predict residual OSA (that is, AHI⩾5/hTST).ConclusionsA defined subset of systemic inflammatory and metabolic biomarkers is reversibly altered in the context of OSA among community-based obese children, further reinforcing the concept on the interactive pro-inflammatory effects of sleep disorders such as OSA and obesity contributing to downstream end-organ morbidities

Strain balanced quantum posts

Quantum posts are assembled by epitaxial growth of closely spaced quantum dot layers, modulating the composition of a semiconductor alloy, typically InGaAs. In contrast with most self-assembled nanostructures, the height of quantum posts can be controlled with nanometer precision, up to a maximum value limited by the accumulated stress due to the lattice mismatch. Here we present a strain compensation technique based on the controlled incorporation of phosphorous, which substantially increases the maximum attainable quantum post height. The luminescence from the resulting nanostructures presents giant linear polarization anisotropy.Comment: Submitted to Applied Physics Letters (7th March 2011). 4 pages, 4 figure

Cider Proteins and Foam Characteristics: A Contribution to Their Characterization

A capillary sieving electrophoretic method for protein analysis and molecular weight determination was used to characterize ciders from Asturias, northern Spain. The total protein content (Bradford method) and the foam parameters (Bikerman method) were also analyzed to complete this characterization. The polypeptide profile, based on the molecular weight, together with exploratory and classification techniques, that is, principal component analysis (PCA) or linear discriminant analysis (LDA), allowed ciders to be differentiated on the basis of their foam assessment and the apple juice extraction technology used in the cidermaking process. In addition, the application of correlation analysis, that is, canonical correlations (CCA) or partial least-squares (PLS), revealed that the proteins with higher molecular weight were more relevant with respect to cider foamability. PLS analysis also provided a mathematical equation that is able to predict the stabilization time of foam from the polypeptide profile of the cider, because this is the foam parameter most influenced by these compounds

Characterisation of sparkling cider by the yeast type used in taking foam on the basis of polypeptide content and foam characteristics

This paper describes the characterisation of sparkling ciders from Asturias, northern Spain, by means of the analysis of their protein content and their foam characteristics. A capillary sieving electrophoretic method was used in the protein analysis to determine molecular mass and the Bradford method to determine total protein content. The foam parameters were measured using the Bikerman method. Chemometric techniques, such as principal component analysis (PCA) and soft independent modelling of class analogy analysis (SIMCA), allowed the sparkling cider to be differentiated on the basis of the yeast strain used in their manufacture. As a result, feasible models for classifying sparkling ciders were computed (classification hits higher than 96%). Furthermore, the relationship between polypeptides and foam was demonstrated with a prediction equation of foam stability time, which was computed using the partial least square (PLS) regression technique. This mathematical equation confirmed that the polypeptides of high molecular mass are especially related to this foaming parameter