cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Development of Outdoor Research Platforms and Tests on Photovoltaic Modules in the Green Energy Park in Morocco
Creators: name: Malik, S.
name: Ebert, M.
name: Naimi, Z.
name: Ikken, B.
Publisher: name: WIP - Renewable Energies and ETA-Florence Renewable Energies
Year: 2014
Subjects: subject: design outdoor research platform; outdoor module characterization; desert module
subject: 1. PV Technologies, Cells, Modules, Systems

description: The Moroccan Solar Program aims to install 2000 MW of solar power production by 2020. In this context the paper intends to introduce the concept of the PV outdoor test platform that will be set up in the “Green Energy Park” as part of cooperation between the Moroccan IRESEN Rabat and the German Fraunhofer CSP Halle (Saale). The “Green Energy Park” has been established by IRESEN and OCP S.A in Ben Guerir. These outdoor test platforms are designed, combining a multitude of test-set-ups, in order to investigate and characterize PV modules in harsh weather conditions and to get valuable data about their performances in situ. The aims of the different test-set-ups as well as the recorded parameters are defined. Furthermore the systematic tests that are focusing on the outdoor behavior of PV modules are described. Some aspects of module improvements in design, in materials for hot regions like Morocco are introduced. The results that will be obtained in this platform after its realization will help to implement a new adapted certification process for the outdoor measurement and characterization.
description: 1st Africa Photovoltaic Solar Energy Conference and Exhibition Proceedings, AfricaPVSEC 2014
Tailoring Band Gap in 2D Nanolayers for Photovoltaic Applications: In2Se3 Films
Creators: name: Minnings, R.
name: Shkrebtii / Chkrebtii, A.I.
name: Perinparajah, G.
name: Arzate, N.
name: Anderson, S.
name: Mendoza, B.
name: Cho, Y.
name: Downer, M.
name: Zahn, D.R.T.
Publisher: name: WIP
Year: 2020
Subjects: New Materials and Concepts for Photovoltaic Devices
New Materials and Concepts for Cells and Modules

description: 37th European Photovoltaic Solar Energy Conference and Exhibition; 51-55
description: We demonstrate that the atomic structure dependent electron and optical properties of In2Se3 2D nanofilms are promising for application in photovoltaic-based devices. The In2Se3 nanolayers are constructed from vertically stacked semiconducting quintuple layers (QLs), which also exhibit spontaneous out of plane polarization (as well as in-plane polarization, not considered here). We investigated from first principles within Density Functional Theory (DFT), the impact of a different number of stacked QLs, and various combinations of out of plane polarization, either up () or down (), on the band gap in those layers, that can either render the stacked QL combination with a net or zero out of plane polarization. The band structure and dielectric response of the 2D In2Se3 nanomaterials were also modelled for a various number of stacked QLs with varying combinations of out of plane polarization of each individual QL layer within the stack.
System Technology for the Next Generation Village Energy Supply
Creators: name: Eberlin, M.
name: Franz, S.
name: Reiners, F.
name: Stalter, O.
Publisher: name: WIP - Renewable Energies and ETA-Florence Renewable Energies
Year: 2014
Subjects: subject: PV hybrid; villages; off grid systems; turn key; energy supply
subject: 1. PV Technologies, Cells, Modules, Systems

description: According to the newest IEA World Energy Outlook, 1.2 billion people do not have access to electricity. Most of them live in remote areas where a connection to the public grid is not economically feasible. On the other hand, almost all of these areas are located within the “Sun Belt” region around the equator and have high solar resources. Offgrid solar energy systems have always been an interesting option for these remote areas and the continuing drop of solar panel prices as well as the low carbon emission of photovoltaic (PV) electricity makes them an even more attractive option. So far, in the field of remote PV energy systems, only low power components are available on the market. In order to supply larger consumers, different kinds of technical solutions allow parallelizing multiple small inverters or battery chargers in the range of a few kilowatts (kW) to reach a few hundreds of kW. Although this is a well-proven approach, it makes PV off-grid systems more complex and foremost more expensive. The Fraunhofer Institute for Solar Energy Systems has developed, in the frame of a research project funded by the German Ministry for Environment (BMU), the architecture and framework of the next generation village energy supply system (BMU key number 0325121). In this paper the focus is on the power electronic components developed within the project. Firstly the common system topology for PV-based off-grid applications is presented. Then a very advanced 125 kVA off-grid inverter, which is designed to challenge large diesel generators in their well-established market, is introduced. In a second part the associated highly innovative high voltage PV battery charger with its hybrid lead-acid (Pb) and lithium-ion (Li) battery will be presented. Also the energy management system and the used communication architecture will be introduced.
description: 1st Africa Photovoltaic Solar Energy Conference and Exhibition Proceedings, AfricaPVSEC 2014
Fabrication and Characterization of Inversion Layer Solar Cell using PEDOT:PSS on n-Si
Creators: name: Diale, M.M.
name: Erickson, A.S.
name: Cahen, D.
Publisher: name: WIP - Renewable Energies and ETA-Florence Renewable Energies
Year: 2014
Subjects: subject: inversion-layer; Si solar cell; PEDOT:PSS
subject: 1. PV Technologies, Cells, Modules, Systems

description: -
description: 1st Africa Photovoltaic Solar Energy Conference and Exhibition Proceedings, AfricaPVSEC 2014
Perspectives on Solar PV project commissioning procedures: International comparisons, improvements and lessons learnt from solar PV plants in South Africa and the United Kingdom
Creators: name: Quarta, N.
name: Santoni, L.
name: Lukins, T.
name: Dufton, D.
name: Wright, J.G.
name: Van Der Merwe, S.
Publisher: name: WIP - Renewable Energies and ETA-Florence Renewable Energies
Year: 2014
Subjects: subject: defects; design; energy performance; large grid-connected PV systems; pyranometer
subject: 2. Implementation (Technical) and Standardisation

description: With the first round of renewable energy projects in South Africa’s Renewable Energy Independent Power Producer Programme (REIPPPP) reaching commercial operation, this paper aims to provide insight into what was learnt from the commissioning processes and what can be improved for the next REIPPPP rounds. We outline and compare the commissioning processes for a solar PV plant in South Africa to existing solar PV plants in the UK with regards to weather instrumentation, thermal imagery testing, performance ratio testing, contracted capacity vs. achieved capacity, and grid interface.  Suggestions are made to improve the current commissioning procedures in South Africa looking towards the commissioning of future projects under the REIPPPP rounds.
description: 1st Africa Photovoltaic Solar Energy Conference and Exhibition Proceedings, AfricaPVSEC 2014
Effective Theory of WIMP Dark Matter supplemented by Simplified Models: Singlet-like Majorana fermion case
Creators: name: Matsumoto, Shigeki
name: Mukhopadhyay, Satyanarayan
name: Tsai, Yue-Lin Sming
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We enumerate the set of simplified models which match onto the complete set of gauge invariant effective operators up to dimension six describing interactions of a singlet-like Majorana fermion dark matter with the standard model. Tree level matching conditions for each case are worked out in the large mediator mass limit, defining a one to one correspondence between the effective operator coefficients and the simplified model parameters for weakly interacting models. Utilizing such a mapping, we compute the dark matter annihilation rate in the early universe, as well as other low-energy observables like nuclear recoil rates using the effective operators, while the simplified models are used to compute the dark matter production rates at high energy colliders like LEP, LHC and future lepton colliders. Combining all relevant constraints with a profile likelihood analysis, we then discuss the currently allowed parameter regions and prospects for future searches in terms of the effective operator parameters, reducing the model dependence to a minimal level. In the parameter region where such a model-independent analysis is applicable, and leaving aside the special dark matter mass regions where the annihilation proceeds through an s-channel Z or Higgs boson pole, the current constraints allow effective operator suppression scales ($Λ$) of the order of a few hundred GeV for dark matter masses $m_χ>$ 20 GeV at $95\%$ C.L., while the maximum allowed scale is around $3$ TeV for $m_χ\sim \mathcal{O}(1\,{\rm TeV})$. An estimate of the future reach of ton-scale direct detection experiments and planned electron-positron colliders show that most of the remaining regions can be probed, apart from dark matter masses near half of the Z-boson mass (with $500\,{\rm GeV} < Λ< 2\,{\rm TeV} $) and those beyond the kinematic reach of the future lepton colliders.
description: 30 pages, 6 figures
Encapsulant-Integrated Interconnection of Bifacial Solar Cells for BIPV Applications: Latest Results in the Twill-BIPV Project
Creators: name: Govaerts, J.
name: Borgers, T.
name: Van Dyck, R.
name: Andries, N.
name: Meyers, P.
name: Van Der Heide, A.
name: Vastmans, L.
name: Moors, R.
name: Doumen, G.
name: Nivelle, P.
name: Daenen, M.
name: Voroshazi, E.
name: Arnett, C.
name: Labie, R.
name: Van Den Storme, M.
name: Van Den Storme, G.
name: Vandebroek, S.
name: Schroyen, P.
name: Smeers, K.
name: Vavilkin, T.
name: Dewallef, S.
name: Abgrall, F.
name: Jousset, D.
name: Poortmans, J.
Publisher: name: WIP
Year: 2020
Subjects: New Materials and Concepts for Photovoltaic Devices
New Materials and Concepts for Cells and Modules

description: 37th European Photovoltaic Solar Energy Conference and Exhibition; 33-37
description: In this work, we present our progress on the multi-wire interconnection approach that we are developing, based on a contact sheet that integrates the interconnect wiring into the encapsulant. After a brief motivation and explanation of the concept, the latest results are indicated in terms of manufacturing of the contact sheets via 2 routes, and the potential in varying encapsulant formulation, wire diameter and solder coating thickness. After this, we discuss also our efforts in upscaling and automation of the technology, as well as the reliability testing and the application of the technology towards a BIPV environment.
title: Between prediction and reality: top-down propagation, communication and modulation
Creators: name: Yan, Yuening
Publisher: name: University of Glasgow
Year: 2022

description: Expectations predict the upcoming visual information, facilitating its disambiguation from the noisy input to speed up behavior. However, the neural mechanisms that support such dynamic feature flow and how they facilitate behavior remain unclear. In this thesis, I will trace the propagation, communication and modulation effect related to the prediction. In the first study (Chapter 2), I initiated a cueing-categorization design and validated its feasibility. I first detected the sensibility of participants in distinguishing auditory pitches (i.e., the cues) by estimating their d-primes. Next, in two phases, I instructed participants to build the coupling relationship between auditory cues and stimuli, then proved that compared with non-informative prediction, informative ones can significantly reduce the reaction time. Recognizing confounding factors in the first study, I further improved the design by manipulating two specific and separate predicted contents. I used a prediction experiment that cued participants (N = 11) to the spatial location (left vs. right) and spatial frequency (SF, Low, LSF, vs. High, HSF) contents of an upcoming Gabor patch. I reconstructed two networks (prediction network and categorization network) in the following two studies with simultaneous MEG recordings of each participant’s neural activity. In the second study (Chapter 3), focusing on the pre-stimulus prediction stage, I answered when, where and how predictions dynamically propagate through a network of brain regions. I traced the dynamic neural representation of predictive cues and reconstructed the communications about predicted contents in a functional network, sequentially from temporal lobe at 90-120ms, to occipital cortex after 200ms, with modulatory supervision of frontal regions at 120-200ms. In the third study (Chapter 4), turning to the post-stimulus stage, I reconstructed the communication network propagating the stimulus feature from occipital-ventral regions (150-250ms) to parietal lobe (250-350ms), finally arriving premotor cortex (>350ms) which modulates behavioral categorization. I found the previous prediction previewed and then sharpen stimulus representation across the categorization network, leading to a faster reaction time. I discussed the generalization of the findings to other stimulus features and sensory modalities. Putting forward the plans about developing a series of structured studies on predicting higher-dimensional features, in the future, I aim to understand the neural mechanisms about how prediction tunes perception and to trace the concrete predicted contents in laminar layers with the fusion of E/MEG and fMRI.
Gebete und Gesänge der Menschenfamilie heute
Creators: name: Bilotti, Domenico
name: O´Laoghaire, Diarmuid
Publisher: name: Concilium
Year: 1970

description: Concilium, Bd. 6 Nr. 2 (1970): Concilium: Internationale Zeitschrift für Theologie, Band 6, Heft 2
Contamination-Free Measures and Algebraic Operations
Creators: name: Mani, A
Publisher: name: arXiv
Year: 2015
Subjects: subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences
subject: 03E99, 06F30, 03C90

description: An open concept of rough evolution and an axiomatic approach to granules was also developed recently by the present author. Subsequently the concepts were used in the formal framework of rough Y-systems (RYS) for developing on granular correspondences by her. These have since been used for a new approach towards comparison of rough algebraic semantics across different semantic domains by way of correspondences that preserve rough evolution and try to avoid contamination. In this research paper, new methods are proposed and a semantics for handling possibly contaminated operations and structured bigness is developed. These would also be of natural interest for relative consistency of one collection of knowledge relative other.
description: Preprint of FUZZIEEE'2013 Conference Paper
Enabling the In-Situ Stress and Temperature Measurement by Silicon Solar Cell Integrated Stress and Temperature Sensors for Photovoltaic Modules
Creators: name: Beinert, A.J.
name: Imm, M.
name: Benick, J.
name: Becker, F.
name: Seitz, S.
name: Heinrich, M.
name: Paul, O.
name: Glunz, S.W.
name: Aktaa, J.
name: Eitner, U.
name: Neuhaus, H.
Publisher: name: WIP
Year: 2020
Subjects: New Materials and Concepts for Photovoltaic Devices
New Materials and Concepts for Cells and Modules

description: 37th European Photovoltaic Solar Energy Conference and Exhibition; 38-43
description: We propose silicon solar cell integrated stress and temperature sensors as a new approach for the stress and temperature measurement in PV modules. The solar cell integrated sensors enable a direct and continuous in-situ measurement of mechanical stress and temperature of solar cells within PV modules. In this work, we present a proof of concept for stress and temperature sensors on a silicon solar cell wafer. Both sensors were tested in a conventional PV module setup. For the stress sensor, a sensitivity of (-47.41 ± 0.14) %/GPa and for the temperature sensor a sensitivity of (3.557 ± 0.008) × 10-3K-1 has been reached. These sensors can already be used in research for increased measurement accuracy of the temperature and the mechanical stress in PV modules due to the implementation at the precise location of the solar cells within a laminate stack, for process evaluation, in-situ measurements in reliability tests and the correlation with real exposure to climates.
Securitization of PV-Power Plant Performance - Experience of 1,5 GWp Field Inspections, Failure Analysis, Minimization of Risks
Creators: name: Vaassen, W.
name: Hupach, U.
name: Becker, H.
name: Van Rensburg, L.
Publisher: name: WIP - Renewable Energies and ETA-Florence Renewable Energies
Year: 2014
Subjects: subject: degradation; electroluminescence; large grid-connected PV systems; performance; qualification and testing; system performance
subject: 2. Implementation (Technical) and Standardisation

description: The economic success in operating photovoltaic systems depends essentially on the possibility of their long-term operation and delivery of the expected energy yield. Twenty to twenty-five years are often presupposed. These are high demands. A precondition is the good quality and long-term stability of the employed products, in particular the PV modules, as well as all other components and materials, and the non-appearance of damages to these items during transport and handling. In addition, the PV systems must be professionally planned, properly implemented and professionally operated with appropriate maintenance measures. Not only the quality of the PV modules is important, but also the quality of planning and installation of the overall system that pose high risks for long-term protection of profitability. The influential factors for the financial risk are not limited to the technical and safety-relevant risks. The risk assessment of photovoltaic projects must include an evaluation of the location regarding on-site risks and evaluation of the logistical risks in connection with the installation of the system.
description: 1st Africa Photovoltaic Solar Energy Conference and Exhibition Proceedings, AfricaPVSEC 2014
The Use of Copper in Solar Cells and Modules
Creators: name: Gawlinska-Necek, K.
name: Panek, P.
name: Starowicz, Z.
name: Socha, R.P.
name: Putynkowski, G.
name: Stodolny, M.K.
name: Van Aken, B.B.
Publisher: name: WIP
Year: 2020
Subjects: New Materials and Concepts for Photovoltaic Devices
New Materials and Concepts for Cells and Modules

description: 37th European Photovoltaic Solar Energy Conference and Exhibition; 25-28
description: The most expensive non-silicon component of solar cells remain silver used for front contact. We propose a single step deposition of Cu/Ni metallization by screen printing method. It was achieved by coating the copper powder with a barrier layer mainly consisting of nickel, in a simple electroless process and then mixing it with a commercial silver paste at 30 wt%. Produced solar cells were fired at high temperature (940°C), which so far was unattainable due to the high diffusion coefficient of copper in elevated temperatures. Manufactured solar cells with an active area 243 cm2 were soldered into 4-solar cells mini module and laminated. Subsequently, the module was subjected to a thermal cycling test for 400 cycles. No signs of module delamination or visual degradation were observed. The I-V measurement results indicate that the power drop of the module is 3.3%, which meets the IEC 61215 standard requirements and confirms that nickel is an effective barrier and prevents copper diffusion into space charge region. For the reference sample with silver front metallization the power decrease was 1.5%. No significant difference in electrical parameters of test modules proves that the proposed copper-silver metallization is comparably stable as standard silver electrode.
Testing PV Central Inverters' Compliance with International Grid Codes
Creators: name: Grab, R.
name: Rogalla, S.
name: Singer, R.
name: Doetter, G.
Publisher: name: WIP - Renewable Energies and ETA-Florence Renewable Energies
Year: 2014
Subjects: subject: electrical properties; grid integration; grid stability; inverter; large grid-connected PV systems
subject: 2. Implementation (Technical) and Standardisation

description: In many electrical grids worldwide, the rising amount of installed PV power entails a considerable influence of PV systems on grid quality and stability. Consequently, in the wake of the revised German medium voltage directives issued in 2009, new requirements for PV inverters have been established internationally. At Fraunhofer ISE’s Inverter Laboratory, more than 25 large PV inverters with a nominal power of up to 880 kVA have been characterised in the past three years. In this period, the focus of many inverter manufacturers has begun to shift from traditional European markets towards a truly international perspective. Therefore, experiences with numerous different grid codes have been gained by our team. This work summarises the similarities and differences between these grid codes. Additionally, several requirements that have proved to be critical will be examined in detail. In conclusion, the adequacy of these grid codes to guarantee the safe and reliable operation of electrical grids is discussed.
description: 1st Africa Photovoltaic Solar Energy Conference and Exhibition Proceedings, AfricaPVSEC 2014
Theory of valley-dependent transport in graphene-based lateral quantum structures
Creators: name: Chen, Feng-Wu
name: Chou, Mei-Yin
name: Chen, Yiing-Rei
name: Wu, Yu-Shu
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Modulation of electronic states in two-dimensional (2D) materials can be achieved by using in-plane variations of the band gap or the average potential in lateral quantum structures. In the atomic configurations with hexagonal symmetry, this approach makes it possible to tailor the valleytronic properties for potential device applications. In this work, we present a multi-band theory to calculate the valley-dependent electron transport in graphene-based lateral quantum structures. As an example, we consider the structures with a single interface that exhibits an energy gap or potential discontinuity. The theoretical formalism proceeds within the tight-binding description, by first deriving the local bulk complex band structures in the regions of a constant gap or potential and, next, joining the local wave functions across the interface via a cell-averaged current operator to ensure the current continuity. The theory is applied to the study of electron reflection off and transmission through an interface. Both reflection and transmission are found to exhibit valley-contrast behavior that can be used to generate valley-polarized electron sources. The results vary with the type of interfaces, as well as between monolayer and bilayer graphene based structures. In the monolayer case, the valley contrast originates from the band warping and only becomes sizable for incident carriers of high energy; whereas in AB-stacked bilayer graphene, the vertical interlayer coupling emerges as an additional important cause for valley contrast, and the favorable carrier energy is also found to be drastically lower. Our numerical results clearly demonstrate the propitious valleytronic properties of bilayer graphene structures.
description: 36 pages, 7 figures
The Evolution of Planet-Disk Systems That Are Mildly Inclined to the Orbit of a Binary Companion
Creators: name: Lubow, Stephen H.
name: Martin, Rebecca G.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We determine the evolution of a giant planet-disk system that orbits a member of a binary star system and is mildly inclined with respect to the binary orbital plane. The planet orbit and disk are initially mutually coplanar. We analyze the evolution of the planet and the disk by analytic means and hydrodynamic simulations. We generally find that the planet and the disk do not remain coplanar unless the disk mass is very large or the gap that separates the planet from the disk is very small. The relative planet-disk tilt undergoes secular oscillations whose initial amplitudes are typically of order the initial disk tilt relative to the binary orbital plane for disk masses ~1% of the binary mass or less. The effects of a secular resonance and the disk tilt decay enhance the planet-disk misalignment. The secular resonance plays an important role for disk masses greater than the planet mass. At later times, the accretion of disk gas by the planet causes its orbit to evolve towards alignment, if the disk mass is sufficiently large. The results have several implications for the evolution of massive planets in binary systems.
description: Accepted for publication in ApJ
Low Temperature Lead Free Solder Pastes for Shingling Interconnection
Creators: name: Pujari, N.S.
name: Krithika, P.M.
name: Vishwanath, P.
name: Sarkar, S.
name: Bilgrien, C.
Publisher: name: WIP
Year: 2020
Subjects: New Materials and Concepts for Photovoltaic Devices
New Materials and Concepts for Cells and Modules

description: 37th European Photovoltaic Solar Energy Conference and Exhibition; 29-32
description: We present solder paste as an alternative interconnection material for shingling assembly. Two tin-bismuth based lead free low temperature solder pastes with one eutectic and other non eutectic alloy were studied. These pastes were evaluated for printing, stability, and rapid reflowing properties to make them suitable for existing automated shingling machines. We found that solder paste based assemblies yield reliable interconnection joints with uniform intermetallic compound (IMC) formation and no loss of power output. The modules pass thermal-cycling and damp heat reliability testing according to IEC 61215 and static mechancal load test as per IEC 61215-2:2016 Clause 4.16.
Meeting Utility Step Voltage Change Requirements by Providing Precise Voltage Control for a PV Plant on a Distribution Feeder
Creators: name: Diaz De Leon II, J.A.
name: Managoli, J.
name: Agrawal, B.L.
Publisher: name: WIP - Renewable Energies and ETA-Florence Renewable Energies
Year: 2014
Subjects: subject: voltage fluctuation; STATCOM; power factor control
subject: 2. Implementation (Technical) and Standardisation

description: For well over 100 years now, distribution systems have served industrial, commercial, and residential customers. The generation to serve these customers for the most part has always been from some type of centralized station power source. As renewable generation becomes more distributed in the US, becoming more like Europe, it is being added to distribution networks. Most utilities have a voltage flicker limit, which is usually set at a 2% step voltage change. Often, utilities use this step change in voltage limit to set the largest size of capacitor banks on their distribution systems, but it can also be used to size the amount of renewable generation allowed on the distribution system. The renewable generation is capped at a MW size where the sudden loss of this generation keeps voltage dip no greater than 2%. Thus, a utility’s goal is to minimize the impact of variation in or the loss of the renewable generation power output on its other customers served from the distribution system. This paper presents a method for designing and sizing a STATCOM installation on a utility distribution system such that the loss of the renewable generation will not exceed the utility’s voltage dip requirements.
description: 1st Africa Photovoltaic Solar Energy Conference and Exhibition Proceedings, AfricaPVSEC 2014
Fabrication of Erbium Doped GaAs Intermediate-Band Solar Cell
Creators: name: Sogabe, T.
name: Hung, C.-Y.
name: Tamaki, R.
name: Tomic, S.
name: Ekins-Daukes, N.
name: Okada, Y.
Publisher: name: WIP
Year: 2020
Subjects: New Materials and Concepts for Photovoltaic Devices
New Materials and Concepts for Cells and Modules

description: 37th European Photovoltaic Solar Energy Conference and Exhibition; 13-19
description: In this work, we proposed an alternative approach to form IB for intermediate band solar cell by using Er-doped GaAs. AFM and RHEED were used to measure and characterize the structural properties and surface morphology of the Er-doped GaAs. SIMS has been used to study the concentration of erbium incorporated into GaAs as a function of erbium cell temperature. Photoluminescence characteristics were performed to confirm the 4f transition from Er. J-V characteristics along with voltage dependent EQE of Er-doped GaAs solar cells were measured to evaluate the energy collection ability. By means of wavelength specific spectral response voltage measurement, it was found that the illumination at 970 nm and 1550 nm result in an increase in photocurrent under bias voltage. The photovoltaic response increases monotonically with increasing bias voltage, providing supporting evidence that the intended twophoton process for IB solar cells may be occurring in the Er-doped GaAs device. It also suggests that IB solar cell efficiency may be improved under higher Er concentration cell, indicating that these devices may further benefit from solar concentration.
Installing Solar Systems on the Face of Existing African Dams for Additional Energy Production
Creators: name: Kougias, I.
name: Bódis, K.
name: Jäger-Waldau, A.
name: Szabó, S.
Publisher: name: WIP - Renewable Energies and ETA-Florence Renewable Energies
Year: 2014
Subjects: subject: developing countries; hybrid; storage; sustainable; water-pumping
subject: 2. Implementation (Technical) and Standardisation

description: Recognizing the issues of land shortage and growing concerns for protecting natural lands, installers, project developers with the help of scientists and engineers try to locate alternative spots for PV-systems installations. In the present paper the authors describe a novel approach, installing PV systems on the outside face of dams. This approach, although currently applied very moderately, has certain advantages that favor even large-scale systems with a capacity of several MWs. In the case of energy-producing hydroelectric dams, the created hybrid system can be notably efficient. The intermittent solar energy will be counterbalanced by hydropower. At the same time, peak demand will be partially covered by PV energy production, ensuring energy availability. Recent research reviewed by the authors has revealed that a notable number of water reservoirs in African continent are under-utilized or don't serve any energy production purpose. That unexploited energy potential apart from being utilized through hydropower development can also be amplified by simultaneous solar system installation. Supplementary power capacity will increase the total energy production and result to economic and environmental benefits.
description: 1st Africa Photovoltaic Solar Energy Conference and Exhibition Proceedings, AfricaPVSEC 2014
Free fall and cellular automata
Creators: name: Arrighi, Pablo
name: Dowek, Gilles
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cellular Automata and Lattice Gases (nlin.CG)
subject: Computational Complexity (cs.CC)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Three reasonable hypotheses lead to the thesis that physical phenomena can be described and simulated with cellular automata. In this work, we attempt to describe the motion of a particle upon which a constant force is applied, with a cellular automaton, in Newtonian physics, in Special Relativity, and in General Relativity. The results are very different for these three theories.
description: In Proceedings DCM 2015, arXiv:1603.00536
Photonic Reflectors with Point Contact Approach for Cu(In,Ga)(S,Se)2 Solar Cells
Creators: name: Balestrieri, M.
name: Lakhdar Chaouche, S.
name: Jimenez, C.
name: Bellet, D.
name: Foldyna, M.
name: Roca I Cabarrocas, P.
name: Lincot, D.
Publisher: name: WIP
Year: 2020
Subjects: New Materials and Concepts for Photovoltaic Devices
New Materials and Concepts for Cells and Modules

description: 37th European Photovoltaic Solar Energy Conference and Exhibition; 20-24
description: In this work, we propose an innovative solution to fabricate a photonic back reflector layer prototype for Cu(In,Ga)(S,Se)2 (CIGS) solar cells that is optically rough, physically flat and electrically associated to molybdenum point contacts. This combination should lead to significant improvement in the efficiency of CIGS solar cells and favor the use of thinner CIGS layers. The nanostructured pattern is obtained using polystyrene beads self-assembly, followed by Ag evaporation and polystyrene beads lift-off. Stacks comprising a nanostructured multilayer of silver, molybdenum and an alumina layer deposited conformally by ALCVD, are successfully stacked. The optical characterization of the samples (in air) during the last steps before polishing, including angular resolved measurements, shows that these layers present very large haze factors (around 50%) over a large region of the solar spectrum. Preliminary attempts to planarize the substrate and to reveal the point contacts by chemical etching are reported.
title: Comparison of handheld and echelle spectrometer to assess copper in ores by means of laser-induced breakdown spectroscopy (LIBS)
Creators: name: Brinkmann, Pia
name: Köllner, Nicole
name: Merk, Sven
name: Beitz, Toralf
name: Altenberger, Uwe
name: Löhmannsröben, Hans-Gerd
Publisher: name: Universität Potsdam
Year: 2023
Subjects: subject: 550 Geowissenschaften

description: Its properties make copper one of the world’s most important functional metals. Numerous megatrends are increasing the demand for copper. This requires the prospection and exploration of new deposits, as well as the monitoring of copper quality in the various production steps. A promising technique to perform these tasks is Laser Induced Breakdown Spectroscopy (LIBS). Its unique feature, among others, is the ability to measure on site without sample collection and preparation. In this work, copper-bearing minerals from two different deposits are studied. The first set of field samples come from a volcanogenic massive sulfide (VMS) deposit, the second part from a stratiform sedimentary copper (SSC) deposit. Different approaches are used to analyze the data. First, univariate regression (UVR) is used. However, due to the strong influence of matrix effects, this is not suitable for the quantitative analysis of copper grades. Second, the multivariate method of partial least squares regression (PLSR) is used, which is more suitable for quantification. In addition, the effects of the surrounding matrices on the LIBS data are characterized by principal component analysis (PCA), alternative regression methods to PLSR are tested and the PLSR calibration is validated using field samples.
description: Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe; 1311
312 kW Solar PV-Diesel Minigrid in Bambadinca, Guinea-Bissau
Creators: name: Arsénio, J.
name: Afonso, D.
name: Dourado, S.
name: Maia Alves, J.
name: Centeno Brito, M.
Publisher: name: WIP - Renewable Energies and ETA-Florence Renewable Energies
Year: 2014
Subjects: subject: design; developing countries; hybrid; PV hybrid; rural electrification; sizing
subject: 2. Implementation (Technical) and Standardisation

description: Bambadinca is a village in Guinea Bissau, a developing country, in West Africa, with about 7,000 people with no reliable access to electricity, where 70% of the population lives with less than 2US$/day. The purpose of this project, funded by the European Commission - as part of the ACP-EU Energy Facility budget line IPAD - Portuguese cooperation Agency, is the village rural electrification through a microgrid, providing good quality, reliable and affordable electricity to the population, to fight extreme poverty increasing educational opportunities, improving health conditions and supporting fundamental economic activities. To accomplish these objectives and to ensure economical and financial sustainability, a three-party participatory management model for the Decentralized System for Production and Distribution of Electricity from Renewable Energy, will be implemented by a local association in cooperation with national authorities. In this paper we discuss the sizing of the PV hybrid power plant, micro-grid design options and layout, management model and project deployment challenges.
description: 1st Africa Photovoltaic Solar Energy Conference and Exhibition Proceedings, AfricaPVSEC 2014
Off-grid Rooftop Solar System with Solar-first and Virtual Grid Features
Creators: name: Dutta, V.
name: Mudgal, A.
name: Pandya, D.
Publisher: name: WIP - Renewable Energies and ETA-Florence Renewable Energies
Year: 2014
Subjects: subject: design; developing countries; PV hybrid; PV system; rooftop
subject: 2. Implementation (Technical) and Standardisation

description: Solar rooftops, particularly for urban area where availability of land can be an issue, have been aggressively pursued by introducing specific incentives like net metering or feed in tariff or for diesel abatement. In case of a grid interactive Solar Photo-Voltaic (SPV) generator, use of diesel generator may be needed under grid outages. This paper proposes a rooftop solar system topology which ensures continued solar power evacuation to the load even in load shedding scenarios. This arrangement has the potential for replacement/ reduction of Diesel generators (DGs) used for backup power. In this system photovoltaic energy serves as the primary source of electricity and utility grid serves as the secondary source. ‘Solar First’ operation ensures that the solar power generated is always evacuated first and any excess requirement of power is supplied by the grid/battery via a Bi -directional inverter. This concept finds high relevance in solar city program in India as well as other countries, as such a topology doesn’t require any change in the existing power infrastructure and will decrease the load on the utility grid and increases the overall energy efficiency.
description: 1st Africa Photovoltaic Solar Energy Conference and Exhibition Proceedings, AfricaPVSEC 2014
Mobile Solar Power Delivery System for Rural Applications
Creators: name: Lakeou, S.
name: Tadiwose Zewdie, T.
Publisher: name: WIP - Renewable Energies and ETA-Florence Renewable Energies
Year: 2014
Subjects: subject: stand-alone PV systems; water-pumping
subject: 2. Implementation (Technical) and Standardisation

description: The paper describes the design and implementation of a mobile Solar Power Delivery System for use in rural areas. The work is undertaken jointly by the University of the District of Columbia in Washington, DC, USA, (UDC)  and Bahir Dar University (BDU) in Ethiopia. This UDC-BDU partnership was initially supported by a Seed Grant from the US Embassy in Ethiopia. The design introduces novel features providing versatility and mobility and has beneficial applications to the rural populations whose need in potable water and water for small scale irrigation is very acute. The design is performed with the help of graduate and undergraduate students at BDU and has contributed to the infusion renewable energy in the engineering curriculum.
description: 1st Africa Photovoltaic Solar Energy Conference and Exhibition Proceedings, AfricaPVSEC 2014
Compound Parabolic Concentrator Design for Equatorial Africa
Creators: name: Naman, G.Z.
name: SellamiS, N.
name: Sarmah, N.
name: Ivaturi, A.
name: Senthilarasu, S.
name: Bobbili, P.R.
name: Upadhyaya, H.M.
name: Mallick, T.K.
Publisher: name: WIP - Renewable Energies and ETA-Florence Renewable Energies
Year: 2014
Subjects: subject: compound parabolic concentrator; concentration ratio; concentrator; entrance aperture; absorber length; acceptance angle; height of CPC
subject: 2. Implementation (Technical) and Standardisation

description: Compound Parabolic Concentrators (CPC) design uses interposed optical devices (such as parabolic trough, parabolic dish, linear Fresnel reflectors, etc) between the source of radiation (Sun in this case) and the energy absorbing surface (solar cell). The CPCs can be either symmetric or asymmetric. Nigeria lies between latitude 4°N to 14°N and Longitude 2°E to 15°E  while Abuja where this project will be experimented lies between 9.176°N and longitude 7.181°E. Nigeria is close to the Equator and has lower altitude unlike the United Kingdom that has higher altitudes to the sun. Asymmetric CPC is best applicable in countries with higher altitudes like the UK while symmetric CPC is best applicable in countries having lower altitudes. There are majorly two motivations of using concentration in solar collectors The first is to improve performance such as effective geometric concentration ratio, concentration ratio and optical efficiency  the second motivation is reducing the cost by the optimization of the concentrator profile such as the solar incident angle and height of the concentrator. There are two related approaches that are possible for CPC design. The first one is the use of non-imaging concentrators and the second one is the use of imaging concentrators. The focus of the present work is to design and develop  solar concentrator that is stationary and able to harness solar energy in the maximum.  It is symmetric 3D CPC with a concentration ratio of 3X. It is a non-imaging concentrator to achieve high energy generation for stand-alone or mini-grids for built environment. The approximate factors that are to be optimized to increase the radiation flux on the energy absorbing surfaces are – i) the ray distribution on the concentrator, ii) ray focusing on the solar cell, and iii) the CPC design to reduce ray leakage or energy loss. This is approached by the method of using coordinate systems, solid works, solid edge and optics work software. The calculated acceptance apertures and CPC heights for the chosen acceptance half angles obtained after Intensive modelling indicate that the height of CPC could be truncated without losing the required concentration ratio of 3X thereby reducing the material cost. The CPC system designed in the present study is expected to have low cost, high efficiency with reliable improved performance to generate power that will contribute to addressing power demand in the equatorial countries like Nigeria and Africa at large.
description: 1st Africa Photovoltaic Solar Energy Conference and Exhibition Proceedings, AfricaPVSEC 2014
4D Photoluminescence Imaging for Advanced Characterization of Photovoltaic Absorber
Creators: name: Legrand, M.
name: Bercegol, A.
name: Duchatelet, A.
name: Lombez, L.
name: Guillemoles, J.-F.
name: Ory, D.
Publisher: name: WIP
Year: 2020
Subjects: New Materials and Concepts for Photovoltaic Devices
Fundamental Studies

description: 37th European Photovoltaic Solar Energy Conference and Exhibition; 9-12
description: In this work, we present the principle of a new multidimensional photoluminescence imaging set-up allowing the extraction of carriers recombination and transport properties. For this purpose, the reconstruction of spatial information from non-imaging detector is performed by Single Pixel Imaging, an approach based on light modulation. In that way, we built a hyperspectral imager from a spectrometer in parallel with a time-resolved imaging branch. We demonstrate the use of this set-up to study light-soaking of halide perovskite. Indeed, the illumination induces both changes in the spectrum and in the photoluminescence dynamic as illustrated in the literature. These two measures are complementary and investigate a wide range of characteristics of the sample as its optical, transport and electronic properties. They offer together a valuable feedback in order to elaborate new performant and innovative materials for photovoltaics. This set-up constitutes a first step toward a 4D-PL imaging based on single pixel imaging providing the local temporal evolution of the sample spectrum.
Dynamics following a linear ramps in the $O(N)$ model: dynamical transition and statistics of excitations
Creators: name: Maraga, Anna
name: Smacchia, Pietro
name: Silva, Alessandro
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: Non-thermal dynamical critical behavior can arise in isolated quantum systems brought out of equilibirum by a change in time of their parameters. While this phenomenon has been studied in a variety of systems in the case of a sudden quench, here we consider its sensitivity to a change of protocol by considering the experimentally relevant case of a linear ramp in time. Focusing on the $O(N)$ model in the large $N$ limit, we show that a dynamical phase transition is always present for all ramp durations and discuss the resulting crossover between the sudden quench transition and one dominated by the equilibrium quantum critical point. We show that the critical behavior of the statistics of the excitations, signaling the non-thermal nature of the transition are robust against changing protocol. An intriguing crossover in the equal time correlation function, related to an anomalous coarsening is also discussed.
description: 12 pages; 8 figures
RISK MANAGEMENT IN COMESA'S CROSS-BORDER SUPPLY CHAINS
Creators: name: Mbonigaba Celestin*, A. Dinesh Kumar** & M. Vasuki***
Publisher: name: Zenodo
Year: 2024

description: This study examines the risk management strategies within the cross-border supply chains of the Common Market for Eastern and Southern Africa (COMESA) from July 2020 to June 2024. The research addresses the primary risks affecting cross-border supply chains, including political instability, logistical challenges, regulatory inconsistencies, and environmental factors. These risks have significantly impacted key industries such as agriculture, manufacturing, and transport, leading to disruptions and economic losses across the region. The study adopts a mixed-methods approach, combining qualitative case studies and quantitative analyses to assess the effectiveness of various risk management strategies. Key findings highlight the importance of diversification of supply sources, investment in technology, and the implementation of flexible contracts. Additionally, public-private partnerships and contingency planning have been critical in mitigating the adverse effects of unforeseen disruptions. Despite these strategies, the study identifies several challenges in implementing effective risk management practices, such as regulatory inconsistencies, resource constraints, and coordination issues among stakeholders. To address these challenges, the study recommends standardizing risk management frameworks across COMESA member states, incentivizing technology adoption, and enhancing training programs for firms, particularly small and medium-sized enterprises (SMEs). Future research should focus on the intersection of climate risks and supply chain management, the digitalization of supply chains, and the impact of regional conflicts on supply chain resilience. The findings underscore the need for robust risk management practices to ensure the stability and growth of COMESA's cross-border supply chains, contributing to the region's overall economic development.
Green Immersive Education for ALL: Green Week Workshop
Creators: name: Orero, Pilar
Publisher: name: Zenodo
Year: 2023
Subjects: Education for sustainable development, eco-school, environmental education, sustainability, sustainability competences, GreenComp

description: This presentation aims to explore the history of efforts to reduce the use of plastic bags and promote the use of totes as a tool for environmental awareness in Catalonia and Japan.