Drag Force Measurements of Vegetation Elements

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

The hydrodynamic drag of full scale trees

River hydrodynamicsOverbank flows and vegetatio

Novel Hybrid Electrode Using Transparent Conductive Oxide and Silver Nanoparticle Mesh for Silicon Solar Cell Applications

AbstractTransparent conductive oxides (TCOs) have been widely used as the front electrodes for various solar cell structures, including heterojunction silicon wafer solar cells and the vast majority of thin-film solar cells. For heterojunction silicon wafer solar cells, the front TCO layer not only serves as a top electrode (by enhancing the lateral conductance of the underlying amorphous silicon film), but also as an antireflection coating. These requirements make it difficult to simultaneously achieve excellent conductivity and transparency, and thus only high-quality indium tin oxide (ITO) has as yet found its way into industrial heterojunction silicon wafer solar cells. For thin-film solar cells, in order to provide efficient lateral conductance of the charge carriers, normally a TCO layer of a few hundred nanometers thickness is used which impedes the optical transparency due to the enhanced free carrier absorption. To reduce the conflict between conductivity and transparency, and to separately engineer the electrical and optical properties, a hybrid electrode is proposed and fabricated by us which consists of a TCO layer (optical layer) and a silver nanoparticle mesh (electrical layer). This hybrid electrode is demonstrated to have a 10 times higher lateral conductance compared to a single TCO layer, while maintaining high light transmission in a wide wavelength range. Due to the excellent performance of the hybrid electrode, it is demonstrated that such an electrode is suitable for various solar cell structures

Excellent Silicon Surface Passivation Achieved by Industrial Inductively Coupled Plasma Deposited Hydrogenated Intrinsic Amorphous Silicon Suboxide

We present an alternative method of depositing a high-quality passivation film for heterojunction silicon wafer solar cells, in this paper. The deposition of hydrogenated intrinsic amorphous silicon suboxide is accomplished by decomposing hydrogen, silane, and carbon dioxide in an industrial remote inductively coupled plasma platform. Through the investigation on CO2 partial pressure and process temperature, excellent surface passivation quality and optical properties are achieved. It is found that the hydrogen content in the film is much higher than what is commonly reported in intrinsic amorphous silicon due to oxygen incorporation. The observed slow depletion of hydrogen with increasing temperature greatly enhances its process window as well. The effective lifetime of symmetrically passivated samples under the optimal condition exceeds 4.7 ms on planar n-type Czochralski silicon wafers with a resistivity of 1 Ωcm, which is equivalent to an effective surface recombination velocity of less than 1.7 cms−1 and an implied open-circuit voltage (Voc) of 741 mV. A comparison with several high quality passivation schemes for solar cells reveals that the developed inductively coupled plasma deposited films show excellent passivation quality. The excellent optical property and resistance to degradation make it an excellent substitute for industrial heterojunction silicon solar cell production

Level 1-to-2 Data Processor Version 3.0: A Major Upgrade of the GOME/ERS-2 Total Ozone Retrieval Algorithm,

Abstract The Global Ozone Monitoring Experiment (GOME) was launched in April 1995, and the GOME Data Processor (GDP) retrieval algorithm has processed operational total ozone amounts since July 1995. GDP Level 1-to-2 is based on the two-step Differential Optical Absorption Spectroscopy (DOAS) approach, involving slant column fitting followed by Air Mass Factor (AMF) conversions to vertical column amounts. We present a major upgrade of this algorithm to Version 3.0. GDP 3.0 was implemented in July 2002, and the 9-year GOME data record from July 1995 to December 2004 has been processed using this algorithm. The key component in GDP 3.0 is an iterative approach to AMF calculation, in which AMFs and corresponding vertical column densities are adjusted to reflect the true ozone distribution as represented by the fitted DOAS effective slant column. A neural networkensemble is used to optimize the fast and accurate parameterization of AMFs. We describe results of a recent validation exercise for the operational version of the total ozone algorithm; in particular, seasonal and meridian errors are reduced by a factor of two. On a global basis, GDP 3.0 ozone total column results lie between -2% and +4% of ground-based values for moderate solar zenith angles lower than 70°. A larger variability of about +5% and -8% is observed for higher solar zenith angles up to 90°. Copyright OCIS codes 01

RNA editing signature during myeloid leukemia cell differentiation

Adenosine deaminases acting on RNA (ADARs) are key proteins for hematopoietic stem cell self-renewal and for survival of differentiating progenitor cells. However, their specific role in myeloid cell maturation has been poorly investigated. Here we show that ADAR1 is present at basal level in the primary myeloid leukemia cells obtained from patients at diagnosis as well as in myeloid U-937 and THP1 cell lines and its expression correlates with the editing levels. Upon phorbol-myristate acetate or Vitamin D3/granulocyte macrophage colony-stimulating factor (GM-CSF)-driven differentiation, both ADAR1 and ADAR2 enzymes are upregulated, with a concomitant global increase of A-to-I RNA editing. ADAR1 silencing caused an editing decrease at specific ADAR1 target genes, without, however, interfering with cell differentiation or with ADAR2 activity. Remarkably, ADAR2 is absent in the undifferentiated cell stage, due to its elimination through the ubiquitin–proteasome pathway, being strongly upregulated at the end of the differentiation process. Of note, peripheral blood monocytes display editing events at the selected targets similar to those found in differentiated cell lines. Taken together, the data indicate that ADAR enzymes play important and distinct roles in myeloid cells

Impaired protein translation in Drosophila models for Charcot–Marie–Tooth neuropathy caused by mutant tRNA synthetases

Dominant mutations in five tRNA synthetases cause Charcot–Marie–Tooth (CMT) neuropathy, suggesting that altered aminoacylation function underlies the disease. However, previous studies showed that loss of aminoacylation activity is not required to cause CMT. Here we present a Drosophila model for CMT with mutations in glycyl-tRNA synthetase (GARS). Expression of three CMT-mutant GARS proteins induces defects in motor performance and motor and sensory neuron morphology, and shortens lifespan. Mutant GARS proteins display normal subcellular localization but markedly reduce global protein synthesis in motor and sensory neurons, or when ubiquitously expressed in adults, as revealed by FUNCAT and BONCAT. Translational slowdown is not attributable to altered tRNA[superscript Gly] aminoacylation, and cannot be rescued by Drosophila Gars overexpression, indicating a gain-of-toxic-function mechanism. Expression of CMT-mutant tyrosyl-tRNA synthetase also impairs translation, suggesting a common pathogenic mechanism. Finally, genetic reduction of translation is sufficient to induce CMT-like phenotypes, indicating a causal contribution of translational slowdown to CMT.National Institutes of Health (U.S.) (Grant GM17151