cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Minimizing Energy Storage Requirement for PV Power Ramp-Rate Limitation Controlling the Inverters MPPT
Creators: name: De La Parra, I.
name: Marcos, J.
name: García, M.
name: Marroyo, L.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
Operation of PV Systems and Plants

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2376-2379
description: Short-term variability in the power generated by large grid-connected PV plants can negatively affect power quality and the network reliability. New grid-codes require combining the PV generator with some form of energy storage technology in order to reduce short-term PV power fluctuation. Herein, an effective control is proposed to comply with the maximum allowable ramp-rate limitation with the minimum energy storage capacity. This works presents a new state of charge (SOC) control involving some changes in the the maximum power point tracking (MPPT) algorithm of the inverters. The solution is corroborated with 1-year 5 second power measurements which were recorded at the output of 550 kW inverters at the 38.5 MW Amareleja (Portugal) PV plant.
Operads of Wiring Diagrams
Creators: name: Yau, Donald
Publisher: name: arXiv
Year: 2015
Subjects: subject: Category Theory (math.CT)
subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 08A70, 18B20, 18D50, 68Q05, 37C60

description: This monograph is a comprehensive study of the combinatorial structure of various operads of wiring diagrams and undirected wiring diagrams. Our first main objective is to prove a finite presentation theorem for each operad of wiring diagrams, describing each one in terms of just a few operadic generators and a small number of generating relations. For example, the operad of wiring diagrams has 8 generators and 28 generating relations, while the operad of undirected wiring diagrams has 6 generators and 17 generating relations. Our second main objective is to prove a corresponding finite presentation theorem for algebras over each operad of wiring diagrams. As applications we provide finite presentations for the propagator algebra, the algebra of discrete systems, the algebra of open dynamical systems, and the (typed) relational algebra. We also provide a partial verification of Spivak's conjecture regarding the quotient-freeness of the relational algebra. Our third main objective is to construct explicit operad maps among the several operads of wiring diagrams. In particular, there is a surjective operad map from the operad of all wiring diagrams, including delay nodes, to the operad of undirected wiring diagrams. This monograph is intended for graduate students, mathematicians, scientists, and engineers interested in operads and wiring diagrams. Assuming no prior knowledge of categories, operads, and wiring diagrams, this monograph is self-contained and can be used as a supplement in a graduate course and for independent study. There are over 100 graphical illustrations and a chapter with a list of problems.
description: 302 pages. Substantially revised. New material includes: (i) a reading guide in the introduction of each of the three parts; (ii) a chapter summary at the end of each chapter from Ch.2 to Ch.13; (iii) new Ch.15 on Further Reading; (iv) 30 new examples, 36 new pictures, and 27 new paragraphs of motivation
Distributed PV Power Generation Forecasting for Distribution Management
Creators: name: Carter, C.
name: Fletcher, J.
name: Kostylev, V.
name: Mahoney, C.
name: Palmer, M.
name: Daye, T.
name: Pavlovski, A.
name: Cormier, D.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
Operation of PV Systems and Plants

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2371-2375
description: High penetration of distributed PV generation (DG-PV) assets has created a new energy management
and control landscape in the power industry as it has substantially changed operating conditions in the distribution
grid. In 2013, Green Power Labs (GPL) and San Diego Gas and Electric (SDG&E) developed an approach to
integrate distributed PV generation forecasts with SDG&E’s existing distribution management system (DMS) to help
account for this growth. The developed technology provides forecasts for the over 20,000 DG-PV assets currently in
the SDG&E service area for near real-time forecast horizons at the “electrical resolution” level of service
transformers. Enabling distribution management systems with high “electrical” resolution DG-PV forecasting
achieves improvement in the performance of existing grid assets and a reduction in the limitations on distributed PV
penetration.
Enabling High Amounts of PV Systems in Low Voltage Grids Using Storage Systems
Creators: name: Von Appen, J.
name: Stetz, T.
name: Idlbi, B.
name: Braun, M.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
Operation of PV Systems and Plants

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2380-2386
description: As the business case for home-scaled PV storage systems emerges in Germany, the impact of different control strategies for such systems on the distribution grid has to be evaluated. This paper assesses the economic performance of two different control strategies for PV storage systems (optimization- and rule-based) regarding their ability to minimize grid reinforcement costs, grid losses and PV energy losses accompanied by lower feed-in limits. The results show that an optimization-based control strategy is able to reduce PV energy losses further than a rulebased storage operation. Grid reinforcement costs depend on the limitation of the maximum grid feed-in which is mainly determined by PV systems and not storage operation. However, as smart storage operation allows to minimize PV energy losses for the lower feed-in limits the DSO also benefits as grid reinforcement cost decreases.
Observed Fluctuations in Output From a Regional Fleet of PV Power Plants Used To Compute Hourly Schedules of Spinning Reserve Requirements
Creators: name: Cormode, D.
name: Richardson, W.
name: Lorenzo, T.
name: Holmgren, W.
name: Cronin, A.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
Operation of PV Systems and Plants

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2387-2392
description: We examine fluctuations in power from an 80 MW fleet of utility scale power plants deployed around Tucson, Arizona, and a 500MW fleet deployed throughout Arizona and New Mexico. We observe that individual plants exhibit frequent rapid changes in power, greater than 50% of nameplate capacity in less than one minute. The aggregate fleet generally has slower ramps. Local utilities face the challenge of addressing this variability in a cost effective manner. We present a method to use historical data to estimate appropriate spinning reserves for variability mitigation for each hour of the day for different seasons. We contrast the results for recommended reserves when calculated on a fleet wide basis or when summed from a plant by plant basis.
The Local Potential Distribution as Driver of PID & "Live PID Monitoring" Method
Creators: name: Pingel, S.
name: Janke, S.
name: Seydewitz, J.
name: Alam, R.
name: Koch, S.
name: Kupke, J.
name: Berghold, J.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
Performance and Reliability of Solar Cells

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2335-2341
description: In the last few years many research addressed the root cause of Potential Induced Degradation (PID), many issues became clearer but today it is still a topic for industry & institutes. This paper brings some new aspects in the discussion for better understanding of the occurrence of PID. In the field PID occurs typically either (i) laterally spread over the module surface or (ii) close to the frame or a mixture of both. Case (i) is simulated with a new method call “Live PID Monitoring” that was developed to track PID of a solar module “in situ” with an EL camera. This gives valuable information of local degradation with high time resolution. The second case (ii) is simulated in the laboratory with a furnace test where high temperature & low humidity conditions together with applied potential are enough for PID to occur in case of sensitive modules. One important aspect of PID on module level is the encapsulation material that has a dominant influence on the leakage current. Here the new aspect of lamination process influence is presented that partly may explain why PID sometimes happens so fast. Industry relevant module configurations are simulated with a simple 1D model. The model calculates the local potential distribution and leakage current herewith the stress for each cell is estimated. To verify the calculations the local electric potential was measured and the data was analyzed with the model. Fit results are in good agreement with the expectations.
Relation between Indoor Flash Testing and Outdoor Performance of Bifacial Modules
Creators: name: Van Aken, B.B.
name: Jansen, M.J.
name: Carr, A.
name: Janssen, G.J.M.
name: Mewe, A.A.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
PV Modules

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2399-2402
description: Flash tests under standard test conditions yield lower power for bifacial modules due to transmittance of the transparent back sheet or glass. Nevertheless, these bifacial modules are expected to outperform their monofacial equivalents in terms of yearly energy output in the field, depending on local climate conditions, albedo, orientation (relative to South) and tilt angle. Modules with transparent back sheet on the rear give very similar power output in standard test conditions and with extra background scattering when compared to bifacial modules with AR-glass as rear cover. This gives the freedom to design either a glass-glass or a glass-back sheet bifacial module, depending on other considerations. For a location with low albedo, bifacial modules produces more kWh/Wp than monofacial modules in the early and late hours of the day, when the sun is more or less parallel to the plane of the modules. With increasing albedo, the bifacial gain increases from 5% to 20%; the gain is constant for a broad range of irradiation conditions.
Cutkosky Rules for Superstring Field Theory
Creators: name: Pius, Roji
name: Sen, Ashoke
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Superstring field theory expresses the perturbative S-matrix of superstring theory as a sum of Feynman diagrams each of which is manifestly free from ultraviolet divergences. The interaction vertices fall off exponentially for large space-like external momenta making the ultraviolet finiteness property manifest, but blow up exponentially for large time-like external momenta making it impossible to take the integration contours for loop energies to lie along the real axis. This forces us to carry out the integrals over the loop energies by choosing appropriate contours in the complex plane whose ends go to infinity along the imaginary axis but which take complicated form in the interior navigating around the various poles of the propagators. We consider the general class of quantum field theories with this property and prove Cutkosky rules for the amplitudes to all orders in perturbation theory. Besides having applications to string field theory, these results also give an alternative derivation of Cutkosky rules in ordinary quantum field theories.
description: LaTeX, 52 pages; v2: minor additions in section 5.4; v3: corrections added to section 5.2.3, no change in the final results
Optimized PV Modules for Tropical, Mountain and Desert Climates
Creators: name: Verlinden, P.J.
name: Zhang, Y.
name: Xu, J.
name: Shu, Y.
name: Yang, Y.
name: Chen, Y.
name: Quan, P.
name: Zhang, S.
name: Xu, G.
name: Mao, J.
name: Ping, F.
name: Feng, Z.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
Quality and Sustainability in Manufacturing and Recycling

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2267-2271
description: PV modules are optimized for particular climates in terms of reliability and energy efficiency, instead of being optimized for a standard testing condition of 1000W/m2, 25°C cell temperature. A dual-glass PV module has been designed and developed for harsh climates, such as desert hot-dry, tropical hot-humid and mountain cold-sunny climates. The dual-glass module is optimized to deliver the highest amount of annual energy, i.e. optimized for energy efficiency instead of power efficiency at STC, as well as optimized for best reliability for the particular climatic conditions. Reliability test sequences must be adapted to the particular climatic environment. Dual Glass modules present excellent reliability for the harshest climatic environment such as desert, tropical and mountain climates. Dual Glass modules have shown the best resistance to reliability tests, up to more than three times the standard IEC 61215, as well as an excellent resistance to the System Voltage Durability test or commonly called PID test for 600 hours under 85% R.H., 85°C, 1500V, or even the most stringent test for 600 hours under 85% R.H., 85°C, 1000V with Cu foil, with a degradation of less than 3%.
Influence of Photovoltaic-Module Handling on Solar Cell Cracking
Creators: name: Köntges, M.
name: Siebert, M.
name: Illing, R.
name: Wegert, F.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
Quality and Sustainability in Manufacturing and Recycling

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2276-2282
description: Before a PV module is integrated into a PV system it has to be handled and transported. This handling and transport is a critical stage of the PV-modules life. In order to identify critical handling steps we accompanied the installation of PV systems and compiled a list of typical and exceptional handling situations. From these observations we developed test to be performed in the laboratory. The tests are designed to account for the mechanical installation conditions as well as for the module temperature during the installation. As a result we find that the most critical handling step is the lay down of the PV module with sunny side up. During the lay down of the module one might let drop the module on one side from a low height. For one module type we found even for a 5 cm drop height more than 5 cracked cells after the drop. In contrast a vertical drop of a framed PV module results in no cell breakage at all. Additionally the risk of cell breakage rises for static loads by at least factor two with PV module temperature of -5°C compared to 25°C. Therefore one should avoid installing PV modules below the freezing point.
Scheduling meets n-fold Integer Programming
Creators: name: Knop, Dušan
name: Koutecký, Martin
Publisher: name: arXiv
Year: 2016
Subjects: subject: Data Structures and Algorithms (cs.DS)
subject: FOS: Computer and information sciences
subject: I.2.8; F.2.2; G.1.6

description: Scheduling problems are fundamental in combinatorial optimization. Much work has been done on approximation algorithms for NP-hard cases, but relatively little is known about exact solutions when some part of the input is a fixed parameter. In 2014, Mnich and Wiese initiated a systematic study in this direction. In this paper we continue this study and show that several additional cases of fundamental scheduling problems are fixed parameter tractable for some natural parameters. Our main tool is n-fold integer programming, a recent variable dimension technique which we believe to be highly relevant for the parameterized complexity community. This paper serves to showcase and highlight this technique. Specifically, we show the following four scheduling problems to be fixed-parameter tractable, where p max is the maximum processing time of a job and w max is the maximum weight of a job: - Makespan minimization on uniformly related machines $(Q||C_{max} )$ parameterized by $p_{max}$, - Makespan minimization on unrelated machines $(R||C_{max} )$ parameterized by $p_{max}$ and the number of kinds of machines, - Sum of weighted completion times minimization on unrelated machines $(R|| \sum w_i C_i )$ parameterized by $p_{max} + w_{max}$ and the number of kinds of machines, - The same problem, $(R|| \sum w_i C_i),$ parameterized by the number of distinct job times and the number of machines.
description: 14 pages, 3 figures
A Bayesian Generalized CAR Model for Correlated Signal Detection
Creators: name: Brown, D. Andrew
name: Datta, Gauri S.
name: Lazar, Nicole A.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Over the last decade, large-scale multiple testing has found itself at the forefront of modern data analysis. In many applications data are correlated, so that the observed test statistic used for detecting a non-null case, or signal, at each location in a dataset carries some information about the chances of a true signal at other locations. Brown, Lazar, Datta, Jang, and McDowell (2014) proposed in the neuroimaging context a Bayesian multiple testing model that accounts for the dependence of each volume element on the behavior of its neighbors through a conditional autoregressive (CAR) model. Here, we propose a generalized CAR model that allows for inclusion of points with no neighbors at all, something that is not possible under conventional CAR models. We consider also neighborhoods based on criteria other than physical location, such as genetic pathways in microarray determined from existing biological knowledge. This generalization provides a unified framework for the simultaneous modeling of dependent and independent cases, resulting in stronger Bayesian learning in the posterior and increased precision in the estimates of interesting signals. We justify the selected prior distribution and prove that the resulting posterior distribution is proper. We illustrate the effectiveness and applicability of our proposed model by using it to analyze both simulated and real microarray data in which the genes exhibit dependence that is determined by physical adjacency on a chromosome or predefined gene pathways.
description: Statistica Sinica, 2017
Characterisation of New Generation of Solar Concentrators
Creators: name: Sellami, N.
name: Meng, X.
name: Knox, A.R.
name: Mallick, T.
Publisher: name: WIP
Year: 2014
Subjects: SOLAR CELLS / ASSEMBLIES / MODULES FOR TERRESTRIAL CONCENTRATOR SYSTEMS AND FOR SPACE SOLAR GENERATORS
Terrestrial Concentrator Modules and Systems

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2166-2169
description: The cost of the Concentrated Photovoltaic CPV modules could be reduced by increasing the output per unit solar cell and this could be done by replacing expensive solar cells with a low cost optical material. The problem remains with the increase of the temperature of the solar cell assembled to the concentrators. One of the key requirements of the CPV system is to keep the temperature minimum of the solar cells. The current study aims to provide a solution to increase the total efficiency of the CPV system by decreasing the temperature of the solar cell and extend the duration of the utilisation of the concentrator. The Crossed Compound Parabolic Concentrator (CCPC) is one of the most efficient non-imaging solar concentrators to be used as a stationary solar concentrator or second stage solar concentrator. The CCPC is modified to generate for the first time a new generation of solar concentrator working as CPV/thermal system and thermal solar collector at the same time. The CCPC is designed to have two complementary surfaces, one reflective and one absorbent. Usually, the height of the CCPC is truncated with a minor sacrifice to the geometric concentration. In the current study, these truncated surfaces, to be eliminated, are replaced with absorbent surfaces instead to collect heat from solar radiation. The studied CCPC has an acceptance angle of 60° and is able to collect sunrays for 6 hours during the day. The optical, thermal and total efficiency of the modified CCPC (absorbent and reflective) is simulated and compared for different geometric concentration ratios varying from 3.6x to 4x. Results show that the total efficiency of the novel modified CCPC remains constant and high all day long and that the 3.6x CCPC has the highest total efficiency compared to the other concentrators. These preliminary results are very promising and significant for the enhancement of low solar concentrator systems.
Non-Equilibrium Steady States in Kac's Model Coupled to a Thermostat
Creators: name: Evans, Josephine
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: This paper studies the existence, uniqueness and convergence to non-equilibrium steady states in Kac's model with an external coupling. We work in both Fourier distances and Wasserstein distances. Our methods work in the case where the external coupling is not a Maxwellian equilibrium. This provides an example of a non-equilibrium steady state. We also study the behaviour as the number of particles goes to infinity and show quantitative estimates on the convergence rate of the first marginal.
description: 17 pages, no figures
DH Test of a Femtogrid Power Optimizer and Microinverter under Operation
Creators: name: Dekker, N.J.J.
name: Jansen, M.J.
name: Eerenstein, W.
name: Schaacke, R.
name: Kockelkoren, R.
name: Jonkman, R.
name: Van Der Sanden, R.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
Balance of System Components

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2239-2242
description: In order to facilitate the installation of PV systems, it is expected that power optimizers and microinverters will be integrated in the PV module, the so-called Smart PV module. For integrated electronics in PV modules no IEC standard is available yet, but it is likely that the damp heat test at 85°C and 85% relative humidity of the IEC 61215 standard for type approval of PV modules will be part of a future standard for PV modules with integrated electronics.
In this paper the results are given of the add-on power optimizer PO310 of Femtogrid and SMI-300 microinverter of Heliox as tested at 85°C and 85% relative humidity, without power and under power conversion. The test under power conversion appeared to be even more severe for part of the components. The power optimizer of Femtogrid passed the damp test without power conversion for 1000 hours, followed by 500 hours with power conversion. The Heliox microinverter also passed the damp heat test during 500 hours with power conversion as no power degradation was observed.
XStruct
Creators: name: Hegewald, Jan
name: Naumann, Felix
name: Weis, Melanie
Publisher: name: Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II
Year: 2006
Subjects: subject: Metadata
subject: XML Schema
subject: 004 Informatik

description: XML is the de facto standard format for data exchange on the Web. While it is fairly simple to generate XML data, it is a complex task to design a schema and then guarantee that the generated data is valid according to that schema. As a consequence much XML data does not have a schema or is not accompanied by its schema. In order to gain the benefits of having a schema - efficient querying and storage of XML data, semantic verification, data integration, etc.- this schema must be extracted. In this paper we present an automatic technique, XStruct, for XML Schema extraction. Based on ideas of [5], XStruct extracts a schema for XML data by applying several heuristics to deduce regular expressions that are 1-unambiguous and describe each element’s contents correctly but generalized to a reasonable degree. Our approach features several advantages over known techniques: XStruct scales to very large documents (beyond 1GB) both in time and memory consumption; it is able to extract a general, complete, correct, minimal, and understandable schema for multiple documents; it detects datatypes and attributes. Experiments confirm these features and properties.
Outdoor Characterization of Three PV Architectures under Clear and Shaded Conditions
Creators: name: Sinapis, K.
name: Litjens, G.B.M.A.
name: Van Den Donker, M.N.
name: Folkerts, W.
Publisher: name: WIP
Year: 2014
Subjects: OPERATIONS, PERFORMANCE AND RELIABILITY OF PHOTOVOLTAICS (from Cells to Systems)
Balance of System Components

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2249-2254
description: Building Integrated and Building Applied Photovoltaic (BIPV, BAPV) systems often suffer from low
performance due to partial shading. New system architectures have been proposed to optimize the energy yield. The
common approach of these new architectures is to track the Maximum Power Point (MPP) of every solar module
individually. Three independent PV systems were installed in Eindhoven, a reference string inverter system, a power
optimizer (PO) system and a micro inverter system. We designed a sophisticated monitoring system that allows for a
detailed comparison of the three PV systems. We calculated system and component efficiencies and found a good
agreement with data sheets provided by the manufacturers. Additionally, we analyzed the performance ratio for DC
and AC of the systems for different weather types based on the clearness index. A pole shading covering 1 to 2% of
the total system surface has been used to evaluate system performance under a specific type of partial shading.
Module Level Power Electronics (MLPE) are capable of increasing the Performance Ratio (PR) up to 35% under
certain partial shading conditions. However, the string inverter system outperformed MLPE under unshaded
operation conditions.
La guerra contro l'arte. Dall'Associazione Nazionale per il Restauro dei Monumenti Danneggiati dalla Guerra alla ricostruzione del patrimonio artistico in Italia
Creators: name: Ciancabilla, Luca
Publisher: name: La Rivista di Engramma
Year: 2008
Subjects: WW2
Monuments
Distructions
Restoration

description: 22 October 1942 the Palace of San Giorgio in Genoa. 19 July 1943 San Paolo fuori le mura in Rome. August 1943 Santa Chiara in Naples. 13 August 1943 Santa Maria delle Grazie and the Castello Sforzesco in Milan. 15 February 1944 the Abbey of Montecassino. 11 March 1944 the Church of the Eremitani in Padua. March 1944 the Malatesta Temple in Rimini. 13 May 1944 the Teatro Farnese in Parma. 29 May 1944 the Palazzo dell'Archiginnasio in Bologna. 22nd June 1944 the Temple of Augustus in Pula. These are some, and the list is very partial, of the most important Italian monuments destroyed or severely mutilated by Anglo-American bombs during the Second World War.

After the war, in just five years, most of the monuments had been brought back to life thanks to the constant efforts of the regional superintendencies to ensure the technical and historical scientificity of each restoration operation of consolidation or recomposition.

What is certain is that this immense reconstruction work, as well as the destruction and devastation that preceded it, are little known to the new generations.
Circadian variation on oxygen consumption in preterm infants
Creators: name: Bauer, Jacqueline
name: Janecke, Andreas
name: Gerss, Joachim
name: Masjosthusmann, Katja
name: Werner, Claudius
name: Hoffmann, Georg
Publisher: name: Kooperation de Gruyter
Year: 2009

description: Objective: We investigated the diurnal variation in oxygen consumption to determine the optimal time periods of calorimetry in preterm infants. Methods: Oxygen consumption (VO2) was measured continuously for 24 h using indirect calorimetry. Twenty-two premature infants with gestational age of 27–31 (31±1.7) weeks were enrolled in the study. Heart rate, respiratory rate, oxygen saturation, skin and rectal temperature and physical activity were monitored continuously. Results: The averaged values of VO2 showed a significant pattern (P<0.0001) of circadian rhythm with a peak in the afternoon and a nadir during the night with significantly differences between the mean VO2 values. A circadian variation of VO2 was found in more than 80% of preterm infants and was unrelated to gestational age, physical activity or environmental stress. The infants spent 90.4% of their time sleeping. Conclusions: These findings indicate the possible existence of an endogenous circadian rhythm of VO2 in preterm infants beginning shortly after birth. Day-night variations of VO2 should be considered when VO2 values are extrapolated from short measurement periods to prevent overestimation of values.
New High Concentration Photovoltaic Power Plant for Training, Research and Electricity Production
Creators: name: Barhdadi, A.
name: Benazzouz, A.
name: Jaziri, H.
name: Borelli, G.
name: Carpanelli, M.
name: Fabrizio, B.
name: Verdilio, D.
Publisher: name: WIP
Year: 2014
Subjects: SOLAR CELLS / ASSEMBLIES / MODULES FOR TERRESTRIAL CONCENTRATOR SYSTEMS AND FOR SPACE SOLAR GENERATORS
Terrestrial Concentrator Modules and Systems

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2125-2127
description: In this paper, performance monitoring program is applied to a grid-connected high concentration photovoltaic power plant in order to identify any operational problem and to make sure of its optimal and continuous power generation working conditions. A preventive maintenance plan was also established and proposed for the whole system.
Optical Performances of Refractive Crossed Compound Parabolic Concentrator CCPC
Creators: name: Sellami, N.
name: Mallick, T.
Publisher: name: WIP
Year: 2014
Subjects: SOLAR CELLS / ASSEMBLIES / MODULES FOR TERRESTRIAL CONCENTRATOR SYSTEMS AND FOR SPACE SOLAR GENERATORS
Terrestrial Concentrator Modules and Systems

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2146-2149
description: The design of solar concentrators depends on its application (thermal or PV) and on the tracking system that will be used. Low geometrical concentration ratios (Cg) are <10x and generally tend to be static concentrators; in this case they have to be nonimaging concentrators. Nonimaging concentrators allow the collection of sunrays for a certain period of time during the day depending on their acceptance angle. Static concentrators are used in order to avoid using tracking systems especially for use in Building Integrated Photovoltaic (BIPV) applications. This research work discusses the optical performances of the refractive Crossed Compound Parabolic Concentrator (CCPC) for photovoltaic application and compares it with reflective CCPC performances. The CCPC was manufactured and the electrical and optical performance analysed using indoor characterisation instruments. A maximum power concentration of 2.5× was achieved compared to a similar type of non-concentrating module. The developed CCPC system, being static and truncated, achieved a 65° acceptance angle with a high optical efficiency of 75%. The refractive CCPC proved a better performance than the reflective CCPC built from a hollow 3-D geometry with reflective surfaces. In addition to the optical performances, the refractive CCPC is built from cheaper material and uses a cheaper manufacturing process.
Flat Photovoltaic Modules at Ultra High Concentration
Creators: name: Pérez-Higueras, P.
name: Fernández, E.F.
name: Almonacid, F.
name: Rodrigo, P.
Publisher: name: WIP
Year: 2014
Subjects: SOLAR CELLS / ASSEMBLIES / MODULES FOR TERRESTRIAL CONCENTRATOR SYSTEMS AND FOR SPACE SOLAR GENERATORS
Terrestrial Concentrator Modules and Systems

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2090-2093
description: Nowadays, High Concentrator Photovoltaic (HCPV) technology has shown a great potential and has emerged as a promising source of green energy that could play an important role in the energy generation market soon. However, despite the great efforts made, there are not systems that can compete on price with conventional photovoltaic technology yet. Because of this, important efforts are needed in research and development to get this technology more competitive and to promote its market expansion. Two key issues have been identified to address this issue: Develop modules with higher concentration ratios that the current HCPV modules and obtain modules more compacts and with small dimensions and weights. These two issues cannot be reached with the current HCPV technology at the same time. Reach ultra-high concentrator factors above 2000 suns implies a significant increase of the area and the focal length of the primary concentrator of the module and therefore an increase of the size, weight and cost of the module. To achieve these goals, a new approach based on new optical configurations will be presented. These optical configurations allow developing ultra-high concentrator photovoltaic (UHCPV) modules with dimensions similar to the conventional flat photovoltaic PV modules.
Concentrator PV System Prototype with Water Heating
Creators: name: Yurchenko, A.
name: Okhorzina, A.
Publisher: name: WIP
Year: 2014
Subjects: SOLAR CELLS / ASSEMBLIES / MODULES FOR TERRESTRIAL CONCENTRATOR SYSTEMS AND FOR SPACE SOLAR GENERATORS
Terrestrial Concentrator Modules and Systems

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2101-2103
description: The paper reports on a choice a facilities of realization a new solar station with water heating and concentration. Estimation of tracker system was presented. The consumer was selected.
LBIC Measurements as a Defect Mapping Tool for Multi-Junction Solar Cells
Creators: name: Kwarikunda, N.
name: Van Dyk, E.E.
name: Vorster, F.J.
name: Okullo, W.
Publisher: name: WIP
Year: 2014
Subjects: SOLAR CELLS / ASSEMBLIES / MODULES FOR TERRESTRIAL CONCENTRATOR SYSTEMS AND FOR SPACE SOLAR GENERATORS
Electrical Characterisation and Modeling of Cells and Modules

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2084-2087
description: The presence of current reducing defects such as inclusions, local optical blockages or strong local shunts may adversely affect the performance of solar cells. Experimental techniques can be used to map the spatial distribution of such defects and thus help to improve the production technology. Light Beam Induced Current (LBIC) measurements were used to obtain photo-response maps of an InGaP/InGaAs/Ge triple junction solar cell from which local current reducing defects were mapped. Incorporation of a reflection detector into the LBIC system allowed us to distinguish between optical blockages present on the cell surface and current reducing features within the device. By dynamically biasing the solar cell, point-by-point current and the corresponding voltage values were obtained to extract spot illuminated I-V curves and compared with full cell solar illumination I-V characteristics.
Concentrator PV Modules with III-V Multijunction Solar Cells for Different Geographic Locations: Output Energy Predictions
Creators: name: Vlasov, A.S.
name: Aronova, E.S.
name: Emelyanov, V.M.
name: Shvarts, M.Z.
Publisher: name: WIP
Year: 2014
Subjects: SOLAR CELLS / ASSEMBLIES / MODULES FOR TERRESTRIAL CONCENTRATOR SYSTEMS AND FOR SPACE SOLAR GENERATORS
Terrestrial Concentrator Modules and Systems

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2110-2114
description: In the work, power generation by concentrator photovoltaic modules based on III-V multijunction solar cells in different geographic regions has been investigated. Simulation of the dependence of III-V PV cell operating parameters on variation of the sunlight spectral composition in different climatic conditions has been performed. PV converter production in several geographic locations has been estimated. On the basis of the rated power production values, evaluation of the annual power generation prediction accuracy has been carried out with accounting for the effects of the PV converter variation in changing the radiation spectral composition and also in neglecting these effects. It has been established that the error of prediction being performed by the “simplified” scheme depends substantially on the number of photoactive p-n junctions in a solar cell and can reach 10–16 % for PV modules based on triple-junction GaInP/Ga(In)As/Ge solar cells, 18 % and 21 % for modules based on 4- and 6-junction cells, correspondingly. Evaluation of productivity of PV modules based on optimized for a specified geographic region triple-junction GaInP/GaAs/Ge solar cells has been performed. It has been shown that the error in predicting the power production of the modules with optimized solar cells is lower and their annual generation is higher by 2–4 %.
The Necessity of Measuring the System Characteristic of a Concentrator PV System at Installation
Creators: name: Kemmoku, Y.
name: Oke, S.
name: Araki, K.
Publisher: name: WIP
Year: 2014
Subjects: SOLAR CELLS / ASSEMBLIES / MODULES FOR TERRESTRIAL CONCENTRATOR SYSTEMS AND FOR SPACE SOLAR GENERATORS
Terrestrial Concentrator Modules and Systems

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2115-2118
description: Issues related to solar tracking and optical systems and the deterioration of solar cells are generally considered as factors that degrade the performance of a concentrator photovoltaic (CPV) system. In order to maintain a satisfactory system performance over a long time period, it is important to develop method for non-destructively evaluating the factors contributing to degradation and the level of degradation of the system performance. To assess a degradation factor of the performance of a CPV system, this paper emphasizes the need for measuring the characteristic values of the system such as short-circuit current, open-circuit voltage, and the fill factor under various conditions when installing a CPV system.
Quantum signature for laser-driven correlated excitation of Rydberg atoms
Creators: name: Wu, Huaizhi
name: Li, Yong
name: Yang, Zhen-Biao
name: Zheng, Shi-Biao
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The excitation dynamics of a laser-driven Rydberg gas exhibits a cooperative effect due to the interatomic Rydberg-Rydberg interaction, but the large many-body system with inhomogeneous Rydberg coupling is hard to exactly solved or numerically study by density matrix equations. In this paper, we find that the laser-driven Rydberg gas with most of the atoms being in the ground state can be described by a simplified interaction model resembling the optical Kerr effect if the distance-dependent Rydberg-Rydberg interaction is replaced by an infinite-range coupling. We can then quantitatively study the effect of the quantum fluctuations on the Rydberg excitation with the interatomic correlation involved and analytically calculate the statistical characteristics of the excitation dynamics in the steady state, revealing the quantum signature of the driven-dissipative Rydberg gas. The results obtained here will be of great interest for other spin-1/2 systems with spin-spin coupling.
description: Main text (8 pages, 8 figures)
A two-component model for fitting light-curves of core-collapse supernovae
Creators: name: Nagy, Andrea P.
name: Vinkó, József
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present an improved version of a light curve model, which is able to estimate the physical properties of different types of core-collapse supernovae having double-peaked light curves, in a quick and efficient way. The model is based on a two-component configuration consisting of a dense, inner region and an extended, low-mass envelope. Using this configuration, we estimate the initial parameters of the progenitor via fitting the shape of the quasi-bolometric light curves of 10 SNe, including Type IIP and IIb events, with model light curves. In each case we compare the fitting results with available hydrodynamic calculations, and also match the derived expansion velocities with the observed ones. Furthermore, we also compare our calculations with hydrodynamic models derived by the SNEC code, and examine the uncertainties of the estimated physical parameters caused by the assumption of constant opacity and the inaccurate knowledge of the moment of explosion.
Influence of Surfactants on the Recombination and Diffusion Processes in GaAs Solar Cells
Creators: name: Vlasov, A.S.
name: Karlina, L.B.
name: Shvarts, M.Z.
name: Timoshina, N.K.
name: Ber, B.Y.
name: Kazantsev, D.Y.
Publisher: name: WIP
Year: 2014
Subjects: SOLAR CELLS / ASSEMBLIES / MODULES FOR TERRESTRIAL CONCENTRATOR SYSTEMS AND FOR SPACE SOLAR GENERATORS
III-V-based Multi-junction Solar Cells, Concentrator Solar Cells and Space Solar Cells

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2054-2057
description: Influence of phosphorous and indium on GaAs cell properties has been studied. A comparative study of Zn diffused GaAs cells with and without P and In pre-exposure is presented. Zn diffusion was performed from the gas phase in the hydrogen flow atmosphere at 670 °C. The aim of the current research was to study the effects of In and P surfactants on Zn diffusion processes in the GaAs substrate. In and P were introduced in a separate chamber by annealing in their vapors. The annealing conditions were modeling the memory effect of a MOVPE reactor, which exists in the multilayer structure. The results obtained by secondary –ion- mass spectrometry show that In and P surfactants helped to increase both the incorporation efficiency of Zn atoms and the diffusion rate at low (670 °C) temperature. Raman spectroscopy measurements confirm the increase of free hole concentration in the sub-surface layers in pre-annealed samples. Influence of surfactants on the diffusion process was observed at In, P concentrations higher than 1017@cm-3.Optical characterization of the cells (photoluminescence, spectral photoresponse) reveal changes in defect distribution in the bulk and on the surface of the cells. It has been shown that presence of In and P in GaAs layers changes the recombination processes and ensures passivation of the emitter.
Estimation of Thermal Stress in Concentrator Solar Cell under Thermal Cycle Test and Outdoor Operation
Creators: name: Ota, Y.
name: Nishioka, K.
Publisher: name: WIP
Year: 2014
Subjects: SOLAR CELLS / ASSEMBLIES / MODULES FOR TERRESTRIAL CONCENTRATOR SYSTEMS AND FOR SPACE SOLAR GENERATORS
Electrical Characterisation and Modeling of Cells and Modules

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2081-2083
description: We developed a simple geometry model for the heat transfer calculation in the CPV receiver and cell and estimated the temperature and thermal stress of solar cell using a heat transfer simulator COMSOL. The thermal parameters of the model were modified by the simulated result of CPV receiver. We assumed two thermal conditions in this study. One is the thermal cycle test condition. Other is the outdoor operating condition. The thermal stresses of Ag electrode were estimated. In the case of both thermal cycle conditions, the maximum thermal stresses were generated at the bus-bar. The tensile stresses occurred at higher than 25°C, and the compressive stress occurred at lower than 25°C. The maximum thermal stress was generated at finger-electrode in the case of outdoor operation condition. The thermal stress of outdoor operation condition was lower than that of thermal cycle condition.
On the Calibration of Multilevel Monte Carlo Ensemble Forecasts
Creators: name: Gregory, Alastair
name: Cotter, Colin
Publisher: name: arXiv
Year: 2016
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Multilevel Monte Carlo can efficiently compute statistical estimates of discretized random variables, for a given error tolerance. Traditionally, only a certain statistic is computed from a particular implementation of multilevel Monte Carlo. This paper considers the multilevel case when one wants to verify and evaluate a single ensemble that forms an empirical approximation to many different statistics, namely an ensemble forecast. We propose a simple algorithm that, in the univariate case, allows one to derive a statistically consistent single ensemble forecast from the hierarchy of ensembles that are formed during an implementation of multilevel Monte Carlo. This ensemble forecast then allows the entire multilevel hierarchy of ensembles to be evaluated using standard ensemble forecast verification techniques. We demonstrate the case of evaluating the calibration of the forecast in this paper.
description: 6 pages, 2 figures. Accepted to Quarterly Journal of the Royal Meteorological Society
Optical and Electrical Characterization of High-Efficiency InGaP/InGaAs/Ge Triple-Junction Solar Cell Incorporated with InGaAs/GaAs QDs Layers in Middle Cell
Creators: name: Ho, W.-J.
name: Yang, G.-C.
name: Chan, C.-M.
name: Liu, J.-J.
name: Lee, Y.-Y.
name: Shiao, H.-P.
Publisher: name: WIP
Year: 2014
Subjects: SOLAR CELLS / ASSEMBLIES / MODULES FOR TERRESTRIAL CONCENTRATOR SYSTEMS AND FOR SPACE SOLAR GENERATORS
III-V-based Multi-junction Solar Cells, Concentrator Solar Cells and Space Solar Cells

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 2046-2049
description: In this study, the MOCVD grown InGaP/InGaAs/Ge triple-junction (3-J) solar cell incorporated with the InGaAs/GaAs quantum dots (QDs) layers in the middle cell to achieve 33.5% conversion efficiency () under one-sun AM1.5 G illumination is demonstrated. Optical reflective spectrum, dark and photo current-voltage (I-V) characteristics, external quantum efficiency (EQE) response, and capacitance as a function of frequency under dark and illuminated conditions were measured and characterized. With 50 layers of In0.7Ga0.3As (QD)/GaAs (Barrier) QDs-structure, an impressive EQE enhancement of 35% at 900-930 nm was observed in the middle cell. Thus, the short-circuit current-density (JSC) of 15.43 mA/cm2, open-circuit voltage (VOC) of 2.54 V, fill factor (FF) of 84.7%, and  = 33.5% were obtained as the cell with the QDs layer. In addition, the capacitance dependence of frequency result shows that using 50 pairs In0.7Ga0.3As/GaAs QD-structure in the middle cell exhibited a strain-balanced high quality epitaxy film and extended the spectral bandwidth of the middle cell.