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Photovoltaic yield prediction using an irradiance forecast model based on multiple neural networks

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Journal of Modern Power Systems and Clean Energy 2018年第2期6卷 255-267页

作者： Saad Parvaiz DURRANI Stefan BALLUFF Lukas WURZER Stefan KRAUTER Paderborn University Bosch Thermotechnik gmbh

In order to develop predictive control algorithms for efficient energy management and monitoring for residential grid connected photovoltaic systems, accurate and reliable photovoltaic(PV) power forecasts are required.A PV yield prediction system is presented based on an irradiance forecast model and a PV model. The PV power forecast is obtained from the irradiance forecast using the PV model. The proposed irradiance forecast model is based on multiple feed-forward neural networks. The global horizontal irradiance forecast has a mean absolute percentage error of 3.4% on a sunny day and 23% on a cloudy day for Stuttgart. PV power forecasts based on the neural network irradiance forecast have performed much better than the PV power persistence forecast model.

关键词： Grid connected photovoltaic(GCPV) Photovoltaic(PV) PV power prediction Irradiance forecast Neural network(NN)

Understanding the corrosion of Mg alloys in in vitro urinary tract conditions: A step forward towards a biodegradable metallic ureteral stent

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Journal of Magnesium and Alloys 2023年第11期11卷 4301-4324页

作者： Margarida Pacheco Ivo M.Aroso Joana M.Silva Sviatlana V.Lamaka Jan Bohlen Maria Nienaber Dietmar Letzig Estêvão Lima Alexandre A.Barros Rui L.Reis 3B’s Research Group-Research Institute on Biomaterials Biodegradables and BiomimeticsUniversity of MinhoGuimarãesPortugal ICVS/3B’s-PT Government Associate Laboratory Braga/GuimarãesPortugal Institute of Surface Science Helmholtz-Zentrum hereon GmbHGermany Institute of Material and Process Design Helmholtz-Zentrum hereon GmbHGermany School of Health Sciences Life and Health Sciences Research Institute(ICVS)University of MinhoBragaPortugal

Ureteral stents play a fundamental role in modern time urology. However, following the deployment, stent-related symptoms are frequent and affect patient health and quality of life. Using biodegradable metals as ureteral stent materials have emerged as a promising strategy, mainly due to the improved radial force and slower degradation rate expected. Therefore, this study aimed to characterize different biodegradable metals in urinary tract environment to understand their propensity for future utilization as base materials for ureteral stents. The corrosion of 5 Mg alloys - AZ31, Mg-1Zn, Mg-1Y, pure Mg, and Mg-4Ag - under simulated urinary tract conditions was accessed. The corrosion layer of the different alloys presented common elements, such as Mg(OH)_(2), MgO, and phosphate-containing products, but slight variations in their chemical compositions were detected. The corrosion rate of the different metals varied, which was expected given the differences in the corrosion layers. On top of this, the findings of this study highlighted the significant differences in the samples' corrosion and corrosion layers when in stagnant and flowing conditions. With the results of this study, we concluded that Mg-1Zn and Mg-4Ag presented a higher propensity for localized corrosion, probably due to a less protective corrosion layer;Mg-4Ag corroded faster than all the other four alloys,and Mg-1Y stood out due to its distinct corrosion pattern, that showed to be more homogeneous than all the other four samples, making this one more attractive for the future studies on biodegradable metals.

关键词： Biodegradable metals Magnesium alloys Localized corrosion Biodegradable metallic ureteral stent

Provision of Ramp-rate Limitation as Ancillary Service from Distribution to Transmission System:Definitions and Methodologies for Control and Sizing of Central Battery Energy Storage System

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Journal of Modern Power Systems and Clean Energy 2023年第5期11卷 1507-1518页

作者： Spyros I.Gkavanoudis Kyriaki-Nefeli D.Malamaki Eleftherios O.Kontis Aditya Shekhar Umer Mushtaq Sagar Bandi Venu Charis S.Demoulias Department of Electrical&Computer Engineering Aristotle University of ThessalonikiThessalonikiGreece Electrical Engineering Mathematics&Computer Science DepartmentDelft University of TechnologyDelftNetherlands FENECON gmbh DeggendorfGermany

The variability of the output power of distributed renewable energy sources(DRESs)that originate from the fastchanging climatic conditions can negatively affect the grid ***,grid operators have incorporated ramp-rate limitations(RRLs)for the injected DRES power in the grid *** the DRES penetration levels increase,the mitigation of high-power ramps is no longer considered as a system support function but rather an ancillary service(AS).Energy storage systems(ESSs)coordinated by RR control algorithms are often applied to mitigate these power ***,no unified definition of active power ramps,which is essential to treat the RRL as AS,currently *** paper assesses the various definitions for ramp-rate RR and proposes RRL method control for a central battery ESS(BESS)in distribution systems(DSs).The ultimate objective is to restrain high-power ramps at the distribution transformer level so that RRL can be traded as AS to the upstream transmission system(TS).The proposed control is based on the direct control of theΔP/Δt,which means that the control parameters are directly correlated with the RR requirements included in the grid *** addition,a novel method for restoring the state of charge(So C)within a specific range following a high ramp-up/down event is ***,a parametric method for estimating the sizing of central BESSs(BESS sizing for short)is *** BESS sizing is determined by considering the RR requirements,the DRES units,and the load mix of the examined *** BESS sizing is directly related to the constant RR achieved using the proposed ***,the proposed methodologies are validated through simulations in MATLAB/Simulink and laboratory tests in a commercially available BESS.

关键词： Battery energy storage system distributed renewable energy resource sizing distribution system transmission system ramp-rate limitation state of charge

Efficient Noninvasive FHB Estimation using RGB Images from a Novel Multiyear,Multirater Dataset

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Plant Phenomics 2023年第3期5卷 533-545页

作者： DominikRößle LukasPrey LudwigRamgraber AnjaHanemann DanielCremers Patrick OleNoack TorstenSchön AImotion Bavaria Technische Hochschule IngolstadtIngolstadtGermany Hochschule Weihenstephan-Triesdorf WeidenbachGermany Saatzucht Josef Breun gmbh and Co.KG HerzogenaurachGermany Technical University of Munich MunichGermany

Fusarium head blight(FHB)is one of the most prevalent wheat diseases,causing substantial yield losses and health *** phenotyping of FHB is crucial for accelerating resistance breeding,but currently used methods are time-consuming and *** present article suggests a noninvasive classification model for FHB severity estimation using red–green–blue(RGB)images,without requiring extensive *** model accepts images taken from consumer-grade,low-cost RGB cameras and classifies the FHB severity into 6 ordinal *** addition,we introduce a novel dataset consisting of around 3,000 images from 3 different years(2020,2021,and 2022)and 2 FHB severity assessments per image from independent *** used a pretrained EfficientNet(size b0),redesigned as a regression *** results demonstrate that the interrater reliability(Cohen’s kappa,κ)is substantially lower than the achieved individual network-to-rater results,e.g.,0.68 and 0.76 for the data captured in 2020,*** model shows a generalization effect when trained with data from multiple years and tested on data from an independent ***,using the images from 2020 and 2021 for training and 2022 for testing,we improved the F_(1)^(w) score by 0.14,the accuracy by 0.11,κ by 0.12,and reduced the root mean squared error by 0.5 compared to the best network trained only on a single year’s *** proposed lightweight model and methods could be deployed on mobile devices to automatically and objectively assess FHB severity with images from low-cost RGB *** source code and the dataset are available at https://***/cvims/FHB_classification.

关键词： network consuming breeding

Microstructure and Mechanical Properties of Cold Metal Transfer Welding Similar and Dissimilar Aluminum Alloys

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Acta Metallurgica Sinica(English Letters) 2015年第6期28卷 715-724页

作者： Ahmed Elrefaey Nigel G.Ross LKR Leichtmetallkompetenzzentrum Ranshofen gmbh Austrian Institute of Technology

Integrating structures made from aluminum alloys in automotive industry requires a large amount of joining. As a consequence, the properties of the joints have a significant influence on the overall performance of the whole structure. Robot cold metal transfer welding is a relatively new joining technique and has been used in this work to join 6082-T4 and 5182-O aluminum alloy sheets by using ER5356 and ER4043 filler metals. Microstructure characterization was performed by optical microscopy and energy dispersive X-ray spectroscopy, and the mechanical properties were measured by tensile and hardness tests. A correlation is made between welding variables, mechanical properties and the microstructure of welded joints. Results indicate that robot cold metal transfer welding provides good joint efficiency with high welding speed, good tensile strength, and ductility. Owing to the low heat input of robot cold metal transfer welding process, the heat affected zone microstructure was quite similar to base metals, and weld metal microstructure was the controlling factor of joint efficiency. The best performing were the 5182/5182 joints welded with ER5356 and these had mechanical property coefficients of 100%, 98%, and 85% for yield strength, ultimate tensile strength, and elongation, respectively.

关键词： Aluminum CMT Welding Microstructure Tensile property

Protective and Regenerative Anti-Pollution Efficacy of a Plant Oil-Based Day and Night Cream: Investigated by a Novel Approach to Reveal the Impact of Pollutants on Epidermal Barrier Integrity and Lipid Matrix

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Journal of Cosmetics, Dermatological Sciences and Applications 2023年第4期13卷 302-321页

作者： Dorothee Dähnhardt Stephan Dähnhardt-Pfeiffer Isabel Simon Dana Ditgen Inge Holland Dörte Segger Jürgen Blaak Peter Staib Microscopy Services Dä hnhardt GmbH Flintbek Germany Research & Development and Regulatory Affairs Kneipp GmbH Wuerzburg Germany SGS INSTITUT FRESENIUS gmbh Hamburg Germany

In the wake of ever-increasing environmental pollution, human skin in the modern urban world is exposed to increased levels of harmful environmental pollutants. Many studies have shown that these pollutants can weaken the epidermal skin barrier and thus facilitate the penetration of these substances into the skin. An important goal of modern skin care against harmful environmental influences should therefore be to protect and strengthen the epidermal barrier and to repair occurring damage quickly and efficiently. With this in mind, in the present study we investigated what damage cigarette smoke causes to the epidermal barrier and 1) whether the regular application of a O/W emulsion (Day Cream) can protectively strengthen the epidermal barrier against environmental damage and 2) whether a cigarette smoke-induced disruption of the epidermal barrier is restored faster and better by the regular application of a another O/W emulsion (Night Cream) than in product-untreated skin. The two products are slightly different in plant-oil, active ingredient composition and texture. Firstly, the study has shown that the Lipbarvis? method is suitable for measuring the effect of cigarette smoke, in contrast to conventional biophysical measurement methods (transepidermal water loss, skin hydration). Secondly, both products were able to improve skin barrier function in the corresponding test scenario. This was demonstrated for both test products by a significantly reduced TEWL, significantly increased skin hydration and significantly improved length of the lipid lamellae in the intercellular space, as well as the protective effect of the day cream on the epidermal skin barrier and the regenerative properties of the tested night cream. .

关键词： Skin Care Anti-Pollution Skin Barrier Intercellular Lipid Lamellae Cigarette Smoke

Characterization and modeling of the temperature-dependent thermal conductivity in sintered porous silicon-aluminum nanomaterials

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Nano Research 2022年第6期15卷 5663-5670页

作者： Danny Kojda Tommy Hofmann Natalia Gostkowska-Lekner Klaus Habicht Department Dynamics and Transport in Quantum Materials Helmholtz-Zentrum Berlin für Materialien und Energie GmbHBerlin D-14109Germany Institute of Physics and Astronomy University of PotsdamPotsdam D-14476Germany

Nanostructured silicon and silicon-aluminum compounds are synthesized by a novel synthesis strategy based on spark plasma sintering(SPS)of silicon nanopowder,mesoporous silicon(pSi),and aluminum *** interplay of metal-assisted crystallization and inherent porosity is exploited to largely suppress thermal *** and temperaturedependent thermal conductivity studies allow us to elucidate the impact of porosity and nanostructure on the macroscopic heat *** electron microscopy along with quantitative image analysis is applied to characterize the sample morphology in terms of domain size and interpore distance *** demonstrate that nanostructured domains and high porosity can be maintained in densified mesoporous silicon *** contrast,strong grain growth is observed for sintered nanopowders under similar sintering *** observe that aluminum agglomerations induce local grain growth,while aluminum diffusion is observed in porous silicon and dispersed nanoparticles.A detailed analysis of the measured thermal conductivity between 300 and 773 K allows us to distinguish the effect of reduced thermal conductivity caused by porosity from the reduction induced by phonon scattering at nanosized *** a modified Landauer/Lundstrom approach the relative thermal conductivity and the scattering length are *** relative thermal conductivity confirms the applicability of Kirkpatrick’s effective medium *** extracted scattering lengths are in excellent agreement with the harmonic mean of log-normal distributed domain sizes and the interpore distances combined by Matthiessen’s rule.

关键词： thermal conductivity mesoporous silicon porosity spark plasma sintering nanoscale modeling

Model of an iron ore sinter plant with selective waste gas recirculation

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Carbon Resources Conversion 2022年第1期5卷 71-83页

作者： Johannes Niel Bernd Weiss Walter Wukovits TU Wien Institute of ChemicalEnvironmental and Bioscience EngineeringGetreidemarkt 9/1661060 ViennaAustria Primetals Primetals Technologies Austria GmbHLinzAustria

The use of sinter influences hot metal production substantially and significantly affects an integrated steel mill’s total emissions. Sintering of iron ores is an enormousenergy-intensive and resources consuming process. Introducing a selective waste gas recirculation (SWGR) to the sintering process reduces the energy consumption,stack gas volume flow, and sulfur dioxide emissions of an iron sinter production. Simulating this complex process in flowsheet simulations of integrated iron andsteelworks is a fast and cost-effective opportunity to validate new operation settings. The implementation of a sinter plant in gPROMS ModelBuilder®characterizesthe sintering processes by three main sub-models. A burner model describes the gas combustion, a black-box model consider the main sintering processes, and a windbox model divides the total off-gas into a recycle gas and a stack gas. A specific temperature polynomial represents the temperature distribution across the wind boxesto allow detailed investigations on SWGR in complex flowsheet simulations. Implementing SWGR to the sintering process, the model shows a reduction of cokeconsumption, stack gas flow rate, and sulfur dioxide emissions by 11%, 27%, and 27%, respectively. In the SWGR scenario, the utilization rate of carbon monoxideincreases and less coke is consumed. The chlorine emissions of the sintering process differ with and without SWGR insignificantly.

关键词： dioxide monoxide consuming

Potential Application of a Wine Extract in Skin Care: How to Benefit from the Antibacterial, Antioxidant and Elastase Inhibiting Properties

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Journal of Cosmetics, Dermatological Sciences and Applications 2023年第2期13卷 136-155页

作者： Lisa-Marie Sittek Thomas Michael Schmidts Peggy Schlupp Novigo gmbh Grünberg Germany

Since plant polyphenols have many beneficial properties on health, the aim of this study was to evaluate the potential use of a phenolic wine extract, a by-product of wine production, for skin care on HaCaT cells. In these studies, a significant reduction of reactive oxygen species formation in HaCaT cells and severe elastase inhibition was observed. In contrast, the wine extract caused a major increase in lipase activity. The extract showed no influence on cell proliferation, but an immunomodulatory effect on the release of the interleukins IL-6 and IL-8 was found. The phenolic wine extract demonstrated a strong activity against gram-positive and gram-negative pathogens, yeasts, and fungi. Overall, our results show that the investigated phenolic wine extract is a promising ingredient for anti-aging skin care, could contribute to the improvement of skin appearance and health, and may positively affect cellulite.

关键词： Phenolic Wine Extract Skin Care HaCaT Cells Elastase Lipase IL-6 IL-8 Cell Proliferation Reactive Oxygen Species Antimicrobial Antimycotic