22,320 research outputs found
CE Challenges: Work to Do
No full textCE has been used for more than two decades now. Despite many successes and advantages, there are still many challenges to be addressed. These challenges are both technical and organisational. In the paper we will address the current challenges of CE. Many challenges are related to the exchange of data and knowledge and to the systems that make data and knowledge exchange possible. Although much progress has been made in enabling extensive data and knowledge exchange and use, much remains to be wished. For example, there are still barriers to data exchange. Technically, these barriers may consist of different formats, differences in infrastructures and systems, and different semantics. There are also organisational and political barriers. For example, investment in information system may heavily impact upstream suppliers, while revenues of better information exchange may predominantly be gained by downstream actors. Without sharing costs and revenues, chain-wide information exchange will not be easily realised. Another barrier is the possible lack of willingness to share information, because of potential misuse of knowledge and loss of power. The paper is organised as follows. First we will describe the current manifestation of CE as described in a recent book. Second, we will list current trends in CE. Third, we will present some Critical Success Factors (CSFs) that are considered relevant for implementing and adapting CE practices. Last, we indicate some research and practical questions to be addressed, especially for areas that have a high potential and actual impact. </p
Synthesis optimization and charge carrier transfer mechanism in LiLuSiO<sub>4</sub>:Ce, Tm storage phosphor
No full textLiLuSiO4:Ce and LiLuSiO4:Ce, Tm show very efficient charge carrier storage properties upon beta irradiation after samples have received treatment in vacuum. They outperform the commercial storage phosphor BaFBr(I):Eu2+ in many aspects. The influence of the synthesis conditions, Ce and Tm concentration, nonstoichiometry and codoping with Ca, Hf, Al and Ge are reported. Based on the results of the synthesis optimization, thermoluminescence (TL) emission and TL excitation spectra a mechanism of charge carrier transfer, storage, and recombination during irradiation and thermal or optical readout is proposed.Accepted Author ManuscriptRST/Fundamental Aspects of Materials and EnergyRST/Luminescence Material
The impact of P(NDI2OD-T2) crystalline domains on the open-circuit voltage of bilayer all-polymer solar cells with an inverted configuration
No full textWe fabricated P(NDI2OD-T2)/PTB7 bilayer all-polymer solar cells with an inverted configuration, where the annealing temperature was systematically varied. The current density-voltage behavior was investigated and the structural properties of the P(NDI2OD-T2) layers were characterized. Absorption spectroscopy, surface morphology, and crystallite analysis showed that increasing phase segregation of P(NDI2OD-T2) films occurred as the annealing temperature increased. We found that, as the P(NDI2OD-T2) stacking improved, with larger domains, the open-circuit voltage decreased and the saturation dark current density increased. This work provides a guide for the processing of P(NDI2OD-T2) layers to maximize the power conversion efficiency of all-polymer solar cells. (C) 2015 Author(s).open1186sciescopu
Data and code for: Variational Graph Author Topic Modeling
No full textThis is the tensorflow implementation of KDD-2022 paper "Variational Graph Author Topic Modeling" by Delvin Ce Zhang and Hady W. Lauw.
VGATM is a Graph Neural Network model that extracts interpretable topics for documents with authors and venues. Topics of documents then fulfill document classification, citation prediction, etc.
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Updated analytical solutions of continuity equation for electron beams precipitation – I. Pure collisional and pure ohmic energy losses
No full textWe present updated analytical solutions of continuity equations for power-law beam electrons precipitating in (a) purely collisional losses and (b) purely ohmic losses. The solutions of continuity equation (CE) normalized on electron density presented in Dobranskis & Zharkova are found by method of characteristics eliminating a mistake in the density characteristic pointed out by Emslie et al. The corrected electron beam differential densities (DD) for collisions are shown to have energy spectra with the index of −(γ + 1)/2, coinciding with the one derived from the inverse problem solution by Brown, while being lower by 1/2 than the index of −γ/2 obtained from CE for electron flux. This leads to a decrease of the index of mean electron spectra from −(γ − 2.5) (CE for flux) to −(γ − 2.0) (CE for electron density). The similar method is applied to CE for electrons precipitating in electric field induced by the beam itself. For the first time, the electron energy spectra are calculated for both constant and variable electric fields by using CE for electron density. We derive electron DD for precipitating electrons (moving towards the photosphere, μ = +1) and ‘returning’ electrons (moving towards the corona, μ = −1). The indices of DD energy spectra are reduced from −γ − 1 (CE for flux) to −γ (CE for electron density). While the index of mean electron spectra is increased by 0.5, from −γ + 0.5 (CE for flux) to −γ + 1(CE for electron density). Hard X-ray intensities are also calculated for relativistic cross-section for the updated differential spectra revealing closer resemblance to numerical Fokker–Planck (FP) solutions
Introduction and Author Biographical Notes
No full textThe Introductory Notes include The Cutting EDge\u27s mission statement, editorial board, founder\u27s note, and author\u27s biographies
From the Editors and Author Biographical Notes
No full textLetter from the Editors and Author Biographical Note
Surface modification with MK-2 organic dye in a ZnO/P3HT hybrid solar cell: Impact on device performance
No full textThe photovoltaic performance of a hybrid ZnO/P3HT heterojunction was improved by modifying the device surface with the MK-2 dye. This organic dye enhanced the compatibility between the polymer and the metal oxide, increased the exciton separation efficiency, and improved the molecular ordering in the charge transport network. The resulting device displayed a substantial enhancement in the photocurrent, open circuit voltage, and fill factor, leading to a 12-fold increase in the power conversion efficiency relative to the unmodified device, from 0.13% to 1.53%. (C) 2014 Author(s).open1145sciescopu
Creating transparency and guidance in Circular Economy indicators: Tools for assisting circular consultants with choosing the right CE indicators for manufacturing companies
No full textBusinesses are being increasingly pressured to start making the transition from their current polluting economy towards a circular economy (CE) to pursuit a sustainable industry. Indicators for CE play a key role in this transition, enabling the measurement and control of this development. However, the scattered landscape of micro level CE indicators, which varies in purpose and scope, and their ambiguity in measuring environmental and social impact, complicates this transition. Circular consultants are being faced with these challenges when advising the right CE indicator to companies.This study aims to provide CE consultants the tools to find an indicator that measures CE holistically and that fit their client’s profile. A literature review and interviews with 5 different circular consultants shows that many CE indicators are focused on material efficiency, leaving out aspects that are key for measuring environmental impact such as emissions and pollution. Additionally, social aspects are often not included in CE indicators even though the social dimension of CE is crucial for reaching a sustainable industry. At last, the literature review shows that CE indicators differ in characteristics such as purpose (such as learning or decision-making), their maturity in CE (from beginner to advanced), and data requirements.Insights from the literature review and from the five interviews with different circular consultants, have led to the development of three tools: a checklist of sub-indicators for CE indicators to analyse their contribution to measuring environmental impact, a checklist of social indicators that are relevant for CE, and a framework to categorize CE indicators on six categories: measurement level, purposes of measuring, company’s maturity in CE, life cycle focus, ease of application and data requirements. The checklist for environmental impact and the categorization framework are applied to five CE indicators chosen from literature. The checklist provides an overview of sub-indicators present and missing in the CE indicators of analysis. Additionally, the sub-indicators in the checklist is translated into a questionnaire for a hypothetical company, to check its practicality. The framework shows that there are notable differences between the five CE indicators: in their purpose, life cycle focus, data requirements and ease of application.Further work is required to investigate the tension between the CE indicator checklist for environmental impact and the ability of organizations to pick and choose CE indicators – which can be financially driven. Secondly, future case studies could help validate the effectiveness of the indicator checklist for environmental impact and the framework in assisting circular consultants in choosing a suitable and holistic CE indicator for a manufacturing company.https://lnkd.in/d2HYgY4 The author published blog under the wing of Circle Economy, related to this master thesis research.Industrial Ecolog
Vascular endothelial growth factor restores delayed tumor progression in tumors depleted of macrophages
No full textGenetic depletion of macrophages in Polyoma Middle T oncoprotein (PyMT)-induced mammary tumors in mice delayed the angiogenic switch and the progression to malignancy. To determine whether vascular endothelial growth factor A (VEGF-A) produced by tumor-associated macrophages regulated the onset of the angiogenic switch, a genetic approach was used to restore expression of VEGF-A into tumors at the benign stages. This stimulated formation of a high-density vessel network and in macrophage-depleted mice, was followed by accelerated tumor progression. The expression of VEGF-A led to a massive infiltration into the tumor of leukocytes that were mostly macrophages. This study suggests that macrophage-produced VEGF regulates malignant progression through stimulating tumor angiogenesis, leukocytic infiltration and tumor cell invasion
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