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We propose an on-the-fly statistical learning method to make a qualitative reduced-order model of the dynamics of a premixed flame quantitatively accurate. This physics- informed data-driven method is based on the statistically optimal combination of (i) a reduced-order model of the dynamics of a premixed flame with a level-set method, (ii) high-quality data, which can be provided by experiments and/or high-fidelity simulations, and (iii) assimilation of the data into the reduced-order model to improve the prediction of the dynamics of the premixed flame. The reduced-order model learns the state and the parameters of the premixed flame on the fly with the ensemble Kalman filter, which is a Bayesian filter used in the data assimilation of high-dimensional dynamical systems, e.g., in weather forecasting. The proposed method and algorithm are applied to two test cases with relevance to reacting flow and instability. First, the capabilities of the framework are demonstrated in a twin experiment, where the assimilated data are produced from the same model as that used in prediction. Second, the assimilated data are extracted from a high-fidelity reacting-flow direct numerical simulation (DNS). The results are analyzed by using Bayesian statistics, which provide the uncertainties of the calculations. This method opens up new possibilities for on-the-fly optimal calibration of computationally cheap reduced-order models when experimental data become available, for example, from sensors.

ON 16 NOVEMBER 2000, the final report of the World Commission on Dams (WCD) was launched in London, in the presence of South Africa’s former president Nelson Mandela. This represented a remarkable milestone in the history of dam policy and politics. During its two-year existence, WCD had conducted the most extensive review of research and evidence regarding the planning, impacts, and management of large dams. It had engaged with numerous stakeholders around the globe. It also made comprehensive recommendations about how to improve dam planning and management.

This paper presents a research work carried out under the umbrella of the CASCADE project, which is a European FP7 research project which is developing facility-specific measurement-based energy action plans for the airport energy managers that are underpinned by Fault Detection Diagnosis (FDD). The paper first describes the context of the project then it focuses on Building Management Systems describing the current status of the technology and presenting an outlook on their future development. Then a Strengths Weakness Opportunity and Treads (SWOT) framework is defined with the aim of verifying the suitability of an installed BMS system to incorporate Fault Detection and Diagnosis (FDD) tools

The thin film (TF) solar market is challenged to produce solar modules with higher energy conversion efficiency while at the same time reducing the manufacturing cost. One way to improve the energy efficiency is to move to higher performance systems like Cadmiumtellurid (CdTe) or Cu(In,Ga)(S,Se)2 (CIGS) in comparison to TF Silicon (Si) based technologies. As today’s a-Si and CdTe structuring technology for module development is based on laser scribing, the technology for CIGS modules is mostly dominated by mechanical scribing. As inexpensive as the mechanical scribing technology seems, it has its drawbacks when it comes to high precision scribing of TF materials and, subsequently, the reliability in the manufacturing process. Bringing together a high speed, high accuracy motion system with ultra short pulse laser sources opens up new ways CIGS solar cell production can be perceived. We present with this work an in depth evaluation of the influences of the laser pulse width and wavelength to the CIGS scribing process on glass substrate. A variation of the pulse width in the range of 10 ps to 100 ps and 1 ns up to 30 ns is studied and monitored to determine the influences on the scribing quality. At the end, a functional mini-module is presented featuring a dead zone of less than 200 μm. Incorporating the results into a scribing tool an innovative industrial concept is developed for future integration. An outlook is given on the possible impact on cell efficiency, manufacturing costs, and cost of ownership implementing such a concept into production. 26th European Photovoltaic Solar Energy Conference and Exhibition; 2986-2991

In order to develop the technology of carbon dioxide at so-called supercritical state (sCO2) further, quick and reliable design tools for the different system components, e.g. centrifugal compressors, are required. In this study, a computer program is developed to predict the performance of centrifugal compressors with sCO2 as working fluid. This computer program is based on mean-line analysis, calculates the fluid parameters at selected sections of the meridional plane and plots the performance maps. So-called enthalpy loss coefficients are utilized to describe the difference between the isentropic and the polytropic process. In addition to previous studies, the presented model intends to predict the performance of sCO2 centrifugal compressor with a shrouded impeller and a vaneless diffuser. For this purpose, corresponding loss coefficients are incorporated. Subsequently, the predicted results of this work are compared and validated with computational fluid dynamics (CFD) and experimental results from the EU-project sCO2-HeRo. The prediction of the computer program fits within 5% deviation to the CFD results, and about 4% to the experimental results regarding to pressure ratio. Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 68

Upconversion (UC) of sub-band-gap photons is a promising approach to increase solar cell efficiencies, because it makes these sub-band-gap photons useful as well. We investigate the application of -NaYF4:20% Er3+ to silicon solar cells. We determine the external quantum efficiency of an UC silicon solar cell, both under monochromatic excitation and under white light illumination. We demonstrate that an UC silicon solar cell responds under white light with an average UC efficiency of 1.07 ± 0.13% in the spectral range from 1460 to 1600 nm. Concepts are discussed how the narrow absorption range of the UC material can be overcome. 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 229-233

CEOCOR 2021 Madrid

Over the past few years, remarkable developments in piezoelectric materials have motivated many researchers to work in the field of vibration energy harvesting by using piezoelectric beam like smart structures. This paper aimed to present the most recent application of a dual function piezoelectric device which can suppress vibration and harvest vibration energy simultaneously and a brief illustration of conventional mechanical and electrical TVAs (Tuned Vibration Absorber). It is shown that the proposed dual function device combines the benefits of conventional mechanical and electrical TVAs and reduces their relative disadvantages. Conversion of mechanical energy into electrical energy introduces damping and, hence, the optimal damping required by this TVA is generated by the energy harvesting effects. This paper presents the methodology of implementing the theory of 'electromechanical' TVAs to suppress the response of any real world structure. The work also illustrates the prospect of extensive applications of such novel "electromechanical" TVAs in defence and industry. The results show that the optimum degree of vibration suppression of an electronic box is achieved by this dual function TVA through suitable tuning of the attached electrical circuitry