| 1. |
- Achilles, Silvio, et al.
(författare)
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GPU-Accelerated Coupled Ptychographic Tomography
- 2022
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Ingår i: Developments in X-Ray Tomography XIV. - : SPIE. - 0277-786X .- 1996-756X. - 9781510654686 ; 12242
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Konferensbidrag (refereegranskat)abstract
- Scanning coherent X-ray microscopy (ptychography) has gained considerable interest during the last decade since the performance of this indirect imaging technique does not necessarily rely on the quality of the X-ray optics and, in principle, can achieve highest spatial resolution in X-ray imaging. The method can be easily extended to 3D by adding standard tomographic reconstruction schemes. However, the tomographic reconstruction is often applied in a subsequent step using a sequence of aligned ptychographic 2D projections. In this contribution, we outline current developments of a GPU-accelerated framework for direct 3D ptychography, coupling 2D ptychography and tomography. The program utilizes a custom GPU-accelerated framework for ptychography that offers three distinct ptychographic reconstruction algorithms. The tomographic reconstruction runs simultaneously and uses numerical routines of the ASTRA Toolbox. This parallel-computing approach results in a high performance increase considerably reducing the reconstruction time of 3D ptychographic datasets.
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| 2. |
- Bauwens, Maite, et al.
(författare)
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Recent past (1979-2014) and future (2070-2099) isoprene fluxes over Europe simulated with the MEGAN-MOHYCAN model
- 2018
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Ingår i: Biogeosciences. - : Copernicus GmbH. - 1726-4170 .- 1726-4189. ; 15:12, s. 3673-3690
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Tidskriftsartikel (refereegranskat)abstract
- Isoprene is a highly reactive volatile organic compound emitted by vegetation, known to be a precursor of secondary organic aerosols and to enhance tropospheric ozone formation under polluted conditions. Isoprene emissions respond strongly to changes in meteorological parameters such as temperature and solar radiation. In addition, the increasing CO2 concentration has a dual effect, as it causes both a direct emission inhibition as well as an increase in biomass through fertilization. In this study we used the MEGAN (Model of Emissions of Gases and Aerosols from Nature) emission model coupled with the MOHYCAN (Model of HYdrocarbon emissions by the CANopy) canopy model to calculate the isoprene fluxes emitted by vegetation in the recent past (1979-2014) and in the future (2070-2099) over Europe at a resolution of 0.1° × 0.1°. As a result of the changing climate, modeled isoprene fluxes increased by 1.1%yr-1 on average in Europe over 1979-2014, with the strongest trends found over eastern Europe and European Russia, whereas accounting for the CO2 inhibition effect led to reduced emission trends (0.76%yr-1). Comparisons with field campaign measurements at seven European sites suggest that the MEGAN-MOHYCAN model provides a reliable representation of the temporal variability of the isoprene fluxes over timescales between 1h and several months. For the 1979-2014 period the model was driven by the ECMWF ERA-Interim reanalysis fields, whereas for the comparison of current with projected future emissions, we used meteorology simulated with the ALARO regional climate model. Depending on the representative concentration pathway (RCP) scenarios for greenhouse gas concentration trajectories driving the climate projections, isoprene emissions were found to increase by +7% (RCP2.6), +33% (RCP4.5), and +83% (RCP8.5), compared to the control simulation, and even stronger increases were found when considering the potential impact of CO2 fertilization: +15% (RCP2.6), +52% (RCP4.5), and +141% (RCP8.5). However, the inhibitory CO2 effect goes a long way towards canceling these increases. Based on two distinct parameterizations, representing strong or moderate inhibition, the projected emissions accounting for all effects were estimated to be 0-17% (strong inhibition) and 11-65% (moderate inhibition) higher than in the control simulation. The difference obtained using the two CO2 parameterizations underscores the large uncertainty associated to this effect.
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| 3. |
- Bech, Martin, et al.
(författare)
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Dual-binary phase gratings for x-ray interferometry
- 2022
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 9781510654686
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Konferensbidrag (refereegranskat)abstract
- X-ray phase-contrast imaging by grating interferometry has in the past decades been established both at synchrotron radiation sources and at conventional x-ray tubes. Due to the sensitivity to x-ray phase shifting, contrast in soft tissue has been improved significantly and the possibilities to do virtual histology of tissue biopsies are being pioneered. Constraints in the design of a grating interferometer are dominated by the phase-shifting structures of the gratings. Typically, binary gratings are used, with alternating regions of shift and no shift. However, other structures are also possible, leading to different patterns of intensity modulations. Here we simulate the possibility of using multiple binary structures in the phase grating, to utilize Moiré effects and avoid the use of attenuating grating structures. In particular the parameters for grating-based phase-contrast imaging using a single optical element are discussed, with focus on laboratory-based x-ray imaging using microfocus sources.
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| 4. |
- Bergamaschi, Peter, et al.
(författare)
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High-resolution inverse modelling of European CH4emissions using the novel FLEXPART-COSMO TM5 4DVAR inverse modelling system
- 2022
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 22:20, s. 13243-13268
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Tidskriftsartikel (refereegranskat)abstract
- We present a novel high-resolution inverse modelling system ("FLEXVAR") based on FLEXPARTCOSMO back trajectories driven by COSMO meteorological fields at 7 km×7 km resolution over the European COSMO-7 domain and the four-dimensional variational (4DVAR) data assimilation technique. FLEXVAR is coupled offline with the global inverse modelling system TM5-4DVAR to provide background mole fractions ("baselines") consistent with the global observations assimilated in TM5-4DVAR. We have applied the FLEXVAR system for the inverse modelling of European CH4 emissions in 2018 using 24 stations with in situ measurements, complemented with data from five stations with discrete air sampling (and additional stations outside the European COSMO-7 domain used for the global TM5-4DVAR inversions). The sensitivity of the FLEXVAR inversions to different approaches to calculate the baselines, different parameterizations of the model representation error, different settings of the prior error covariance parameters, different prior inventories, and different observation data sets are investigated in detail. Furthermore, the FLEXVAR inversions are compared to inversions with the FLEXPART extended Kalman filter ("FLExKF") system and with TM5-4DVAR inversions at 1° × 1° resolution over Europe. The three inverse modelling systems show overall good consistency of the major spatial patterns of the derived inversion increments and in general only relatively small differences in the derived annual total emissions of larger country regions. At the same time, the FLEXVAR inversions at 7 km × 7 km resolution allow the observations to be better reproduced than the TM5-4DVAR simulations at 1° × 1°. The three inverse models derive higher annual total CH4 emissions in 2018 for Germany, France, and BENELUX compared to the sum of anthropogenic emissions reported to UNFCCC and natural emissions estimated from the Global Carbon Project CH4 inventory, but the uncertainty ranges of top-down and bottom-up total emission estimates overlap for all three country regions. In contrast, the top-down estimates for the sum of emissions from the UK and Ireland agree relatively well with the total of anthropogenic and natural bottom-up inventories.
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| 5. |
- Bert, Valérie, et al.
(författare)
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How to manage plant biomass originated from phytotechnologies? : Gathering perceptions from end-users
- 2017
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Ingår i: International journal of phytoremediation. - : Taylor & Francis. - 1522-6514 .- 1549-7879. ; 19:10, s. 947-954
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Tidskriftsartikel (refereegranskat)abstract
- A questionnaire survey was carried out in 4 European countries to gather end-user's perceptions of using plants from phytotechnologies in combustion and anaerobic digestion (AD). 9 actors of the wood energy sector from France, Germany and Sweden, and 11 AD platform operators from France, Germany and Austria were interviewed. Questions related to installation, input materials, performed analyses, phytostabilization and phytoextraction. Although the majority of respondents did not know phytotechnologies, results suggested that plant biomass from phytomanaged areas could be used in AD and combustion, under certain conditions. As a potential advantage, these plants would not compete with plants grown on agricultural lands, contaminated lands being not suitable for agriculture production. Main limitations would be related to additional controls in process' inputs and end-products and installations that might generate additional costs. In most cases, price of phytotechnologies biomass was mentioned as a driver to potentially use plants from metal-contaminated soils. Plants used in phytostabilisation or phytoexclusion were thought to be less risky and, consequently, benefited from a better theoretical acceptance than those issued from phytoextraction. Results were discussed according to national regulations. One issue related to the regulatory gap concerning the status of the plant biomass produced on contaminated land.
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| 6. |
- Dreier, Till, et al.
(författare)
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Radiopaque dyes allow vessel imaging in lung tissue using laboratory phase contrast micro-CT
- 2022
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. ; 12242
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Konferensbidrag (refereegranskat)abstract
- Phase contrast micro-CT is a powerful technique allowing imaging of soft tissue at synchrotrons or using lab- oratory sources. The use of contrast agents is a useful approach when imaging vascular structures. However, common x-ray contrast agents typically rely on heavy metals to increase absorption, which may affect the phase contrast and cause artifacts in the reconstructed volumes. Thus, utilizing an agent with lower attenuation similar to soft tissue is clearly advantageous. Here, we evaluated different colored radiopaque solutions (tissue marking dyes) which had been injected into the vascular system of bovine lung samples, prior to embedding in paraffin. Scans were performed using a micro-focus x-tube calibrated to 10 µm spot size at 70 kV and a photon counting detector with a silicon sensor and 75 µm pixels. The resulting volumes have a voxel size of (25 µm)3, limited by the size of the samples, but sufficient to resolve the vascular system. Experiments confirmed that sufficient perfusion of the vessels with the dyes could be achieved, and the different dyes could be clearly discerned in the reconstructed volumes without causing artifacts allowing to clearly identify features in the soft tissue. Further, the findings were confirmed by histology.Keywords:
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| 7. |
- Kumpiene, Jurate, et al.
(författare)
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Selecting chemical and ecotoxicological test batteries for risk assessment of trace element-contaminated soils (phyto)managed by gentle remediation options (GRO)
- 2014
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 496, s. 510-522
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Tidskriftsartikel (refereegranskat)abstract
- During the past decades a number of field trials with gentle remediation options (GRO) have been established on trace element (TE) contaminated sites throughout Europe. Each research group selects different methods to assess the remediation success making it difficult to compare efficacy between various sites and treatments. This study aimed at selecting a minimum risk assessment battery combining chemical and ecotoxicological assays for assessing and comparing the effectiveness of GRO implemented in seven European case studies. Two test batteries were pre-selected; a chemical one for quantifying TE exposure in untreated soils and GRO-managed soils and a biological one for characterizing soil functionality and ecotoxicity. Soil samples from field studies representing one of the main GROs (phytoextraction in Belgium, Sweden, Germany and Switzerland, aided phytoextraction in France, and aided phytostabilization or in situ stabilization/phytoexclusion in Poland, France and Austria) were collected and assessed using the selected test batteries. The best correlations were obtained between NH4NO3-extractable, followed by NaNO3-extractable TE and the ecotoxicological responses. Biometrical parameters and biomarkers of dwarf beans were the most responsive indicators for the soil treatments and changes in soil TE exposures. Plant growth was inhibited at the higher extractable TE concentrations, while plant stress enzyme activities increased with the higher TE extractability. Based on these results, a minimum risk assessment battery to compare/biomonitor the sites phytomanaged by GROs might consist of the NH4NO3 extraction and the bean Plantox test including the stress enzyme activities.
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| 8. |
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| 9. |
- Mollenhauer, Jan, et al.
(författare)
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Carcinogen inducibility in vivo and down-regulation of DMBT1 during breast carcinogenesis.
- 2004
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Ingår i: Genes, chromosomes & cancer. - : Wiley. - 1045-2257. ; 39:3, s. 185-94
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Tidskriftsartikel (refereegranskat)abstract
- Deleted in malignant brain tumors 1 (DMBT1) has been proposed as a candidate tumor suppressor for brain and epithelial cancer. Initial studies suggested loss of expression rather than mutation as the predominant mode of DMBT1 inactivation. However, in situ studies in lung cancer demonstrated highly sophisticated changes of DMBT1 expression and localization, pointing to a chronological order of events. Here we report on the investigation of DMBT1 in breast cancer in order to test whether these principles might also be attributable to other tumor types. Comprehensive mutational analyses did not uncover unambiguous inactivating DMBT1 mutations in breast cancer. Expression analyses in the human and mouse mammary glands pointed to the necessity of DMBT1 induction. While age-dependent and hormonal effects could be ruled out, 9 of 10 mice showed induction of Dmbt1 expression after administration of the carcinogen 7,12-dimethybenz(alpha)anthracene prior to the onset of tumorigenesis or other histopathological changes. DMBT1 displayed significant up-regulation in human tumor-flanking tissues compared to in normal breast tissues (P < 0.05). However, the breast tumor cells displayed a switch from lumenal secretion to secretion to the extracellular matrix and a significant down-regulation compared to that in matched normal flanking tissues (P < 0.01). We concluded that loss of expression also is the predominant mode of DMBT1 inactivation in breast cancer. The dynamic behavior of DMBT1 in lung carcinoma is fully reflected in breast cancer, which suggests that this behavior might be common to tumor types arising from monolayered epithelia.
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| 10. |
- Moosmann, Julian, et al.
(författare)
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A load frame for in situ tomography at PETRA III
- 2019
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Ingår i: Developments in X-Ray Tomography XII. - : SPIE. - 0277-786X .- 1996-756X. - 9781510629196 ; 11113
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A load frame for in situ mechanical testing is developed for the microtomography end stations at the imaging beamline P05 and the high-energy material science beamline P07 of PETRA III at DESY, both operated by the Helmholtz- Zentrum Geesthacht. The load frame is fully integrated into the beamline control system and can be controlled via a feedback loop. All relevant parameters (load, displacement, temperature, etc.) are continuously logged. It can be operated in compression or tensile mode applying forces of up to 1 kN and is compatible with all contrast modalities available at IBL and HEMS i.e. conventional attenuation contrast, propagation based phase contrast and differential phase contrast using a grating interferometer. The modularity and flexibility of the load frame allows conducting a wide range of experiments. E.g. compression tests to understand the failure mechanisms in biodegradable implants in rat bone or to investigate the mechanics and kinematics of the tessellated cartilage skeleton of sharks and rays, or tensile tests to illuminate the structure-property relationship in poplar tension wood or to visualize the 3D deformation of the tendonbone insertion. We present recent results from the experiments described including machine-learning driven volume segmentation and digital volume correlation of load tomography sequences.
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| 11. |
- Poutanen, Markku, et al.
(författare)
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DynaQlim – Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas
- 2010
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Ingår i: New Frontiers in Integrated Solid Earth Sciences. - Dordrecht : Springer. - 9789048127368 - 9789048127375 ; , s. 349-372
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The isostatic adjustment of the solid Earth to the glacial loading (GIA, Glacial Isostatic Adjustment) with its temporal signature offers a great opportunity to retrieve information of Earth’s upper mantle to the changing mass of glaciers and ice sheets, which in turn is driven by variations in Quaternary climate. DynaQlim (Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas) has its focus to study the relations between upper mantle dynamics, its composition and physical properties, temperature, rheology, and Quaternary climate. Its regional focus lies on the cratonic areas of northern Canada and Scandinavia.Geodetic methods like repeated precise levelling, tide gauges, high-resolution observations of recent movements, gravity change and monitoring of postglacial faults have given information on the GIA process for more than 100 years. They are accompanied by more recent techniques like GPS observations and the GRACE and GOCE satellite missions which provide additional global and regional constraints on the gravity field. Combining geodetic observations with seismological investigations, studies of the postglacial faults and continuum mechanical modelling of GIA, DynaQlim offers new insights into properties of the lithosphere. Another step toward a better understanding of GIA has been the joint inversion of different types of observational data – preferentially connected with geological relative sea-level evidence of the Earth’s rebound during the last 10,000 years.Due to the changes in the lithospheric stress state large faults ruptured violently at the end of the last glaciation in large earthquakes, up to the magnitudes MW = 7–8. Whether the rebound stress is still able to trigger a significant fraction of intraplate seismic events in these regions is not completely understood due to the complexity and spatial heterogeneity of the regional stress field. Understanding of this mechanism is of societal importance.Glacial ice sheet dynamics are constrained by the coupled process of the deformation of the viscoelastic solid Earth, the ocean and climate variability. Exactly how the climate and oceans reorganize to sustain growth of ice sheets that ground to continents and shallow continental shelves is poorly understood. Incorporation of nonlinear feedback in modelling both ocean heat transport systems and atmospheric CO2 is a major challenge. Climate-related loading cycles and episodes are expected to be important, hence also more short-term features of palaeoclimate should be explicitly treated.Within this Chapter View ChapterIntroductionObservational BasisCurrent Models and Problems to be SolvedClimateChallenges with DynaQlimReferencesReferencesOther actionsExport citationsAbout this BookReprints and Permissions
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| 12. |
- Quintela-Sabarís, Celestino, et al.
(författare)
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Assessing phytotoxicity of trace element-contaminated soils phytomanaged with gentle remediation options at ten European field trials
- 2017
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 599-600, s. 1388-1398
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Tidskriftsartikel (refereegranskat)abstract
- Gentle remediation options (GRO), i.e. in situ stabilisation, (aided) phytoextraction and (aided) phytostabilisation, were implemented at ten European sites contaminated with trace elements (TE) from various anthropogenic sources: mining, atmospheric fallout, landfill leachates, wood preservatives, dredged-sediments, and dumped wastes. To assess the performance of the GRO options, topsoil was collected from each field trial, potted, and cultivated with lettuce (Lactuca sativa L.) for 48 days. Shoot dry weight (DW) yield, photosynthesis efficiency and major element and TE concentrations in the soil pore water and lettuce shoots were measured.GRO implementation had a limited effect on TE concentrations in the soil pore water, although use of multivariate Co-inertia Analysis revealed a clear amelioration effect in phytomanaged soils. Phytomanagement increased shoot DW yield at all industrial and mine sites, whereas in agricultural soils improvements were produced in one out of five sites. Photosynthesis efficiency was less sensitive than changes in shoot biomass and did not discriminate changes in soil conditions.Based on lettuce shoot DW yield, compost amendment followed by phytoextraction yielded better results than phytostabilisation; moreover shoot ionome data proved that, depending on initial soil conditions, recurrent compost application may be required to maintain crop production with common shoot nutrient concentrations.
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| 13. |
- Rodriguez-Palmero, Agusti, et al.
(författare)
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DLG4-related synaptopathy : a new rare brain disorder
- 2021
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Ingår i: Genetics in Medicine. - : Elsevier BV. - 1098-3600 .- 1530-0366. ; 23:5, s. 888-899
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Tidskriftsartikel (refereegranskat)abstract
- PurposePostsynaptic density protein-95 (PSD-95), encoded by DLG4, regulates excitatory synaptic function in the brain. Here we present the clinical and genetic features of 53 patients (42 previously unpublished) with DLG4 variants.MethodsThe clinical and genetic information were collected through GeneMatcher collaboration. All the individuals were investigated by local clinicians and the gene variants were identified by clinical exome/genome sequencing.ResultsThe clinical picture was predominated by early onset global developmental delay, intellectual disability, autism spectrum disorder, and attention deficit–hyperactivity disorder, all of which point to a brain disorder. Marfanoid habitus, which was previously suggested to be a characteristic feature of DLG4-related phenotypes, was found in only nine individuals and despite some overlapping features, a distinct facial dysmorphism could not be established. Of the 45 different DLG4 variants, 39 were predicted to lead to loss of protein function and the majority occurred de novo (four with unknown origin). The six missense variants identified were suggested to lead to structural or functional changes by protein modeling studies.ConclusionThe present study shows that clinical manifestations associated with DLG4 overlap with those found in other neurodevelopmental disorders of synaptic dysfunction; thus, we designate this group of disorders as DLG4-related synaptopathy.
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| 14. |
- Shaker, Kian
(författare)
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Preclinical X-ray imaging beyond attenuation contrast
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Medical imaging is a cornerstone of modern clinical practice. Here, X-ray imaging is the given choice for rapid morphological imaging with excellent spatial resolution, albeit with sensitivity often insufficient for resolving subtle pathological changes to soft tissues. Fundamentally, the sensitivity issue is due to the image contrast traditionally being based on differential X-ray attenuation (i.e., absorption and scattering) where attenuation properties of soft tissues are often very similar. Improving the sensitivity of clinical X-ray imaging therefore requires moving beyond conventional attenuation contrast.Motivated by the above, this Thesis explores two alternative contrast mechanisms in the preclinical domain, yet with a clinical outlook: X-ray fluorescence and X-ray phase contrast. These mechanisms are demonstrated both experimentally on animal models (in vivo) and computationally on virtual anatomical phantoms (in silico). Specifically, we developed instrumentation for in vivo X-ray fluorescence imaging of mice injected with nanoparticle contrast agents, demonstrating a path towards molecular X-ray imaging with higher spatial resolution (< 0.5 mm) than established molecular modalities (e.g., PET & SPECT) and roughly 10× higher sensitivity (~ 0.1 mM) compared to conventional attenuation contrast. Furthermore, we showed that the terminal bronchioles (diameters down to ~ 60 μm) could be resolved in free-breathing mice under anesthesia using X-ray imaging boosted by phase contrast. Lastly, we showed through in silico modeling that the extension of X-ray phase contrast to human lungs could potentially enable visualization of small airways (diameters below 2 mm) which are invisible to attenuation contrast alone. In summary, this Thesis provides experimental and computational demonstrations indicating that both X-ray fluorescence and X-ray phase contrast could provide a path towards clinical X-ray imaging with improved sensitivity.
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| 15. |
- Stridh, Bengt, Universitetslektor, 1957-, et al.
(författare)
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Uncertainties in Yield Assessments and PV LCOE : Report IEA-PVPS T13-18:2020 November 2020
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Yield assessments (YA) and Long-Term Yield Predictions (LTYP) are a prerequisite for business decisions on long term investments into photovoltaic (PV) power plants. Together with cost data (CAPEX, OPEX and discount rate), the output of a YA and LTYP (utilisation rate, performance loss rate and lifetime) provides to the financial investors the parameters needed for the calculation of the Levelised Cost of Electricity (LCOE) and to assess the cash flow model of an investment with relative Internal Rate of Return (IRR) and Net Present Value (NPV).YA and LTYP outputs should be provided with a related exceedance probability. This gives the right tool to stakeholders involved in PV projects to take the best decision in terms of riskaversion. A reduction in the uncertainty of the energy yield can lead to higher values for a given exceedance probability and hence a stronger business case. Various efforts in the literature show the importance of having a common framework that can assess the impact of technical risks on the economic performance of a PV project.The most important parameter influencing the energy yield assessment is the site-specific insolation. Several aspects need to be considered: reliability of the database, interannual variability, long term trends.Site adaptation techniques combine short-term measured data and long-term satellite estimates. Short periods of measured data but with site-specific seasonal and diurnal characteristics are combined with satellite-derived data having a long period of record with not necessarily site-specific characteristics. Upon completion of the measurement campaign, which is typically around one-year, different methodologies can be applied between the measured data at the target site, spanning a relatively short period, and the satellite data, spanning a much longer period. The complete record of satellite data is then used in this relationship to predict the long-term solar resource at the target site. Assuming a strong correlation, the strengths of both data sets are captured and the uncertainty in the long-term estimate can be reduced. In Müller et al [1] an analysis on long-term trends for measured in-plane irradiance, Performance Ratio and energy yield for 44 rooftop installations in Germany was performed showing an average increase of in-plane irradiance of 1.1 %/year or about 11 %/decade over the period 2008 to 2018 for these systems. The increase in irradiance was especially higher than the observed Performance Loss Rate so that the energy yields of the systems analysed increased over the years with an average trend of 0.3 %/year. The typical output of Yield Assessments should report the contribution to each derating factor, starting from the Global Horizontal Irradiation to the energy injected in the grid. The starting point of PR = 100 is considered after applying the horizon shading as this become the annual insolation seen by the PV modules. The following table shows a best practice in providing an overview of gains/losses along each modelling step and the related uncertainty. The uncertainty related to each modelling step can be provided already referred to the irradiation/yield value or to the parameter that is modelled. The value in the table for the specific yield (including its uncertainty) is to be understood as an average value over the entire operating period. The possible deviations between the yields for individual recorded years and the specific yield calculated can be assessed by including interannual variability. For example, for temperature-dependent losses, the value of uncertainty could be referred to the temperature variability of the profile used in the assessment or to the temperature model used in the assessment. The ambient temperature variability and the various temperature models will lead to a different contribution in terms of yield loss and in terms of uncertainty.An emerging challenge in YAs is also due to the deployment of novel technologies (e.g. bifacial PV modules) with a contribution in terms of uncertainty that needs to be properly assessed.Building upon the knowledge available in the literature and the previous IEA PVPS Task 13 report [2], in this report we have moved forward from the uncertainty framework in yield assessment to two real implementations of it and the impact that uncertainties can have on lifetime yield predictions, on the LCOE and on the cash-flow.One of the most relevant question that we have tried to answer is also the following: How reliable are YA’s?This is an apparently simple question; however, the answer is not equally simple. Typically, investors require one YA. In some cases, more YAs might be requested if results are unclear. The various YAs can be averaged to assign a purchase value to a given project. In any case the question remains unanswered: why different assessors obtain different answers? Is one YA more reliable than others?
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