Prediction of a double-antireflection coating made solely with SiN x in a single, directional deposition step

Silicon solar cell modules, where the EVA layer is replaced by an air gap, are able to produce the same electric power as standard modules with EVA only if their anti-reflective properties are enhanced. We propose a method to do this by exploiting the fact that, on Si surfaces textured with random pyramids, light incident from near normal angle always hits at least two pyramidal faces before being reflected back toward the sun. If these two faces are covered with an anti-reflective coating (ARC) made of one and the same material but with two different thicknesses, the coating acts as a double ARC. Such a coating can be produced by depositing the SiNx layer from an oblique angle, optimally from 14.7°. Our detailed raytracing analysis predicts that J sc can then be improved by 0.2 mA/cm2 for normal incident sunlight and AM1.5g standard illumination, and is improved for all angles within a cone with an apex angle of approximately 64°. Furthermore, the coating can be optimized for modules in vertical mounting, where a Jsc gain of 0.1 mA/cm2 is predicted for an angle of incidence of 40°

Numerical Modeling of c-Si PV Modules by Coupling the Semiconductor with the Thermal Conduction, Convection and Radiation Equations

Commonly, the thermal behavior of solar cell modules is calculated with analytical approaches using non wavelength-dependent optical data. Here, we employ ray tracing of entire solar modules at wavelengths of 300-2500 nm to calculate heat sources. Subsequently, finite element method (FEM) simulations are used to solve the semiconductor equations coupled with the thermal conduction, thermal convection, and thermal radiation equations. The implemented model is validated with measurements from an outdoor test over the period of an entire year. Our ray tracing analysis of different solar modules under the AM.15G spectrum shows that, for a standard module about 18.9% of the sun's intensity becomes parasitically absorbed. A loss analysis shows that the biggest parasitic heat source is the cell's full-area rear side metallization. We hence propose the use of a SiNx layer as rear side mirror to reduce the parasitic absorption to 11.7%. This change can lead to a 3.2 °C lower module operating temperature, which results in an about 5 W higher electrical power output when considering a typical 260 W module

Ghrelin receptor (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database

The ghrelin receptor (nomenclature as agreed by the NC-IUPHAR Subcommittee for the Ghrelin receptor [18]) is activated by a 28 amino-acid peptide originally isolated from rat stomach, where it is cleaved from a 117 amino-acid precursor (GHRL, Q9UBU3). The human gene encoding the precursor peptide has 83% sequence homology to rat prepro-ghrelin, although the mature peptides from rat and human differ by only two amino acids [70]. Alternative splicing results in the formation of a second peptide, [des-Gln14]ghrelin with equipotent biological activity [48]. A unique post-translational modification (octanoylation of Ser3, catalysed by ghrelin Ο-acyltransferase (MBOAT4, Q96T53) [127] occurs in both peptides, essential for full activity in binding to ghrelin receptors in the hypothalamus and pituitary, and for the release of growth hormone from the pituitary [56]. Structure activity studies showed the first five N-terminal amino acids to be the minimum required for binding [4], and receptor mutagenesis has indicated overlap of the ghrelin binding site with those for small molecule agonists and allosteric modulators of ghrelin function [43]. In cell systems, the ghrelin receptor is constitutively active [44], but this is abolished by a naturally occurring mutation (A204E) that results in decreased cell surface receptor expression and is associated with familial short stature [88]

Ghrelin receptor in GtoPdb v.2021.3

The ghrelin receptor (nomenclature as agreed by the NC-IUPHAR Subcommittee for the Ghrelin receptor [19]) is activated by a 28 amino-acid peptide originally isolated from rat stomach, where it is cleaved from a 117 amino-acid precursor (GHRL, Q9UBU3). The human gene encoding the precursor peptide has 83% sequence homology to rat prepro-ghrelin, although the mature peptides from rat and human differ by only two amino acids [74]. Alternative splicing results in the formation of a second peptide, [des-Gln14]ghrelin with equipotent biological activity [49]. A unique post-translational modification (octanoylation of Ser3, catalysed by ghrelin Ο-acyltransferase (MBOAT4, Q96T53) [133] occurs in both peptides, essential for full activity in binding to ghrelin receptors in the hypothalamus and pituitary, and for the release of growth hormone from the pituitary [58]. Structure activity studies showed the first five N-terminal amino acids to be the minimum required for binding [4], and receptor mutagenesis has indicated overlap of the ghrelin binding site with those for small molecule agonists and allosteric modulators of ghrelin function [44]. An endogenous antagonist and inverse agonist called Liver enriched antimicrobial peptide 2 (Leap2), expressed primarily in hepatocytes and in enterocytes of the proximal intestine [35, 68] inhibits ghrelin receptor-induced GH secretion and food intake [35]. The secretion of Leap2 and ghrelin is inversely regulated under various metabolic conditions [71]. In cell systems, the ghrelin receptor is constitutively active [45], but this is abolished by a naturally occurring mutation (A204E) that results in decreased cell surface receptor expression and is associated with familial short stature [93]

Ghrelin receptor in GtoPdb v.2023.1

The ghrelin receptor (nomenclature as agreed by the NC-IUPHAR Subcommittee for the Ghrelin receptor [19]) is activated by a 28 amino-acid peptide originally isolated from rat stomach, where it is cleaved from a 117 amino-acid precursor (GHRL, Q9UBU3). The human gene encoding the precursor peptide has 83% sequence homology to rat prepro-ghrelin, although the mature peptides from rat and human differ by only two amino acids [75]. Alternative splicing results in the formation of a second peptide, [des-Gln14]ghrelin with equipotent biological activity [50]. A unique post-translational modification (octanoylation of Ser3, catalysed by ghrelin Ο-acyltransferase (MBOAT4, Q96T53) [134] occurs in both peptides, essential for full activity in binding to ghrelin receptors in the hypothalamus and pituitary, and for the release of growth hormone from the pituitary [59]. Structure activity studies showed the first five N-terminal amino acids to be the minimum required for binding [4], and receptor mutagenesis has indicated overlap of the ghrelin binding site with those for small molecule agonists and allosteric modulators of ghrelin function [45]. An endogenous antagonist and inverse agonist called Liver enriched antimicrobial peptide 2 (Leap2), expressed primarily in hepatocytes and in enterocytes of the proximal intestine [36, 69] inhibits ghrelin receptor-induced GH secretion and food intake [36]. The secretion of Leap2 and ghrelin is inversely regulated under various metabolic conditions [72]. In cell systems, the ghrelin receptor is constitutively active [46], but this is abolished by a naturally occurring mutation (A204E) that results in decreased cell surface receptor expression and is associated with familial short stature [94]

Application of a new ray tracing framework to the analysis of extended regions in Si solar cell modules

While ray tracing of solar cells was established decades ago, ray tracing of entire modules has met obstacles, mainly because module optics are affected by geometric structures varying over a large scale of dimensions. In this paper, we introduce a ray tracing framework that is based on a modular structure made up of separate plugins. While existing plugins can be used for common effects such as light sources, absorption in materials, etc., specialized plug-ins can be written by users to handle problem-specific properties. We demonstrate the functionality of our approach by ray tracing a test module containing 9 crystalline Si solar cells. Good agreement between light-beam induced current (LBIC) measurements and ray tracing is achieved

Urban Atmospheric Boundary-Layer Structure in Complex Topography: An Empirical 3D Case Study for Stuttgart, Germany

Investigation of the atmospheric boundary-layer structure in urban areas can be challenged by landscape complexity and the heterogenous conditions this instills. Stuttgart, Germany, is a city situated in a bowl-shaped basin and troubled by the accumulation of pollutants during weak-wind conditions. The center of Stuttgart is surrounded by steep slopes up to 250m above the basin floor, except for an opening to the northeast that allows runoff towards the Neckar river. Urban planning and regulation of air quality require advanced monitoring and forecasting skills, which in turn require knowledge about the structure of the atmospheric boundary layer (ABL), down to the surface. Three dimensional observations of the ABL were collected in the City Centre of Stuttgart in 2017. A laser ceilometer and a concerted network of Doppler lidar systems were deployed on roof-tops, providing continuous observations of the cloud base, the mixing-layer height and the three-dimensional wind field. The impact of weak-wind conditions, the presence of shear layers, properties of convective cells and the impact of nocturnal low-levels jets were studied for representative days in winter and summer. The observations revealed the development of distinctive layers with high directional deviation from the flow aloft, reoccurring as a dominant diurnal pattern. Our findings highlight the influence of topography and surface heterogeneity on the structure of the ABL and development of flow regimes near the surface that are relevant for the transport of heat and pollutants

Urban atmospheric boundary-layer structure in complex topography: an empirical 3D case study for Stuttgart, Germany

Investigation of the atmospheric boundary-layer structure in urban areas can be challenged by landscape complexity and the heterogenous conditions this instills. Stuttgart, Germany, is a city situated in a bowl-shaped basin and troubled by the accumulation of pollutants during weak-wind conditions. The center of Stuttgart is surrounded by steep slopes up to 250 m above the basin floor, except for an opening to the northeast that allows runoff towards the Neckar river. Urban planning and regulation of air quality require advanced monitoring and forecasting skills, which in turn require knowledge about the structure of the atmospheric boundary layer (ABL), down to the surface. Three-dimensional observations of the ABL were collected in the City Centre of Stuttgart in 2017. A laser ceilometer and a concerted network of Doppler lidar systems were deployed on roof-tops, providing continuous observations of the cloud base, the mixing-layer height and the three-dimensional wind field. The impact of weak-wind conditions, the presence of shear layers, properties of convective cells and the impact of nocturnal low-levels jets were studied for representative days in winter and summer. The observations revealed the development of distinctive layers with high directional deviation from the flow aloft, reoccurring as a dominant diurnal pattern. Our findings highlight the influence of topography and surface heterogeneity on the structure of the ABL and development of flow regimes near the surface that are relevant for the transport of heat and pollutants