20 research outputs found

    Fast model predictive control for hydrogen outflow regulation in ethanol steam reformers

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    © 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In the recent years, the presence of alternative power sources, such as solar panels, wind farms, hydropumps and hydrogen-based devices, has significantly increased. The reasons of this trend are clear: contributing to a reduction of gas emissions and dependency on fossil fuels. Hydrogen-based devices are of particular interest due to their significant efficiency and reliability. Reforming technologies are among the most economic and efficient ways of producing hydrogen. In this paper we consider the regulation of hydrogen outflow in an ethanol steam reformer (ESR). In particular, a fast model predictive control approach based on a finite step response model of the process is proposed. Simulations performed using a more realistic non-linear model show the effectiveness of the proposed approach in driving the ESR to different operating conditions while fulfilling input and output constraints.Peer ReviewedPostprint (author's final draft

    Changes in drought tolerance of Pinus radiata in Chile associated with provenance and breeding generation

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    International audienceAbstractKey messageIn Chile, breeding radiata pine for growth has led to drifts in the degree of drought tolerance of the seedlings. Interior provenances gained a larger tolerance to drought after three breeding generations as shown by larger survival and root/shoot ratio under water shortage, while coastal provenance displayed an opposite trend.•Context Given that rainfall is predicted to decrease and to affect establishment and early survival of radiata pine (Pinus radiata D. Don) in Chile, there is a need to identify more drought tolerant genotypes at seedling stage.•Aims The aim of this study was to test whether provenances of P. radiata originating from interior or from coastal provenances, displayed different responses to short-term water shortage, and whether these responses differed from the first to the third breeding generation.•Methods Three generations of breeding families from two sites in Central Chile were compared. The seedlings were grown during 100 days and subjected to two watering regimes for 45 days. Survival, growth, and biomass allocation to roots and shoots were recorded.•Results The two provenances displayed different responses to drought. Biomass allocation to shoots and survival were significantly reduced by water shortage. The first generation seedlings from the coastal provenance displayed a larger survival rate when exposed to water shortage (i.e., 60 %); this rate decreased in the following breeding generations. On the contrary, the survival rate increased from the first to the third generation in the interior provenance.•Conclusions We observed an important local adaptation to water shortage in the interior provenance. This response may be due to the fact that parent tree populations of the interior provenance have successfully adapted to sites with periodic drought

    Differential adaptations in nursery seedlings from diverse Chilean provenances of Peumus boldus Mol.

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    Seed germination, seedling growth and biomass allocation of the endemic species Peumus boldus Mol. (Boldo) were studied in four provenances (two northern and two southern provenances) from central Chile. Seeds collected from five different mother plants for each provenance were sowed in plastic pots and placed in an ambient nursery. Germinated seeds were transplanted to 130-mL containers and cultivated under nursery conditions during one growing season. Germination capacity, seed weight, morphological traits of seedlings (root collar diameter, height, number of leaves, foliar area, root length), their biomass allocation pattern (dry mass of leaves, shoots and roots) and survival were analyzed. Results showed significant differences among provenances and mother plants for most traits. Northern provenances showed slower germination, smaller size, higher root biomass, lesser leaf area, and higher survival, while seedlings from southern provenances were taller, with more body mass, larger leaf area and lower root biomass. We concluded that northern provenances of Peamus boldus are more tolerant to drought and therefore are suitable for ecological restoration of drought-prone Mediterranean sites, while the use of southern provenances must be restricted to restoration of more humid environments

    Fast model predictive control for hydrogen outflow regulation in ethanol steam reformers

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    © 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In the recent years, the presence of alternative power sources, such as solar panels, wind farms, hydropumps and hydrogen-based devices, has significantly increased. The reasons of this trend are clear: contributing to a reduction of gas emissions and dependency on fossil fuels. Hydrogen-based devices are of particular interest due to their significant efficiency and reliability. Reforming technologies are among the most economic and efficient ways of producing hydrogen. In this paper we consider the regulation of hydrogen outflow in an ethanol steam reformer (ESR). In particular, a fast model predictive control approach based on a finite step response model of the process is proposed. Simulations performed using a more realistic non-linear model show the effectiveness of the proposed approach in driving the ESR to different operating conditions while fulfilling input and output constraints.Peer Reviewe

    The Recruitment of the Recalcitrant-Seeded <i>Cryptocarya alba</i> (Mol.) Looser, Established via Direct Seeding Is Mainly Affected by the Seed Source and Forest Cover

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    Natural regeneration of recalcitrant-seeded tree species is strongly limited in Mediterranean-type climate zones due to increasing droughts imposed by climate change. Direct seeding can be a low-cost alternative to seedling establishment, but there is still limited information for some species. This study aimed to assess the effects of the seed source and forest cover on the germination and survival of the endemic Cryptocarya alba Mol. established through direct seeding. Three habitat types differing in forest cover were identified within the natural park Reserva Natural Altos de Cantillana, Metropolitan Region, Chile. The forest cover corresponded to open (canopy density 75%). All forest cover had C. alba as one of the dominant species. At each habitat type, 38 families from four seed sources (Cuesta La Dormida (CD), Antumapu (AN), Cantillana (CA, local seed source) and Cayumanque (CY)) were directly seeded. Germination (Germin) and survival (Surv) were evaluated weekly during one growing season. There were significant differences between seed sources in Germin and Surv, with means values varying from 7.8% to 37% for Germin and 0% to 20% for Surv. The local seed source CA had the highest values in both traits. A significant variation was also observed between families within seed sources only for Germin. The dense forest cover had the highest Germin (22%) and Surv (55%) results compared to the other forest cover types, which was partially associated with differences in soil moisture, temperature, and bulk density. Due to the most frequent droughts in these Mediterranean-type climate zones, the use of local seeds on dense forest cover is recommended for the direct seeding of the species in the initial recruitment

    Effect of crop management intensity on energy and carbon dioxide balance of two bioenergy Sorghum bicolor hybrids

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    Although bioenergy sorghum has many traits that make it ideal for biofuel production, management conditions that can affect the productivity and sustainability of these systems are still poorly understood. This paper estimated the energy and CO2 balance of two bioenergy sorghum (Sorghum bicolor L. Moench.) hybrids (H128 and H133) cultivated during two growing seasons and under two different levels of crop management, high and low input. At the end of both growing season, sorghum was harvested for biomass yield determination. Calorific value and net energy production were also estimated. Crop management had important effects on sorghum CO2 and energy balance. The energy produced varied between 126 and 365 GJ ha–1 depending on crop management, hybrid and growing season. Regarding of the CO2 balance, the high level of crop management had a superior CO2 emission. However, the energy produced per kg of CO2 emitted was higher (>300%) than the energy produced with the use of fossil fuels. The use of bioenergy sorghum can contribute to better energy sustainability and reduced CO2 emission in Mediterranean ecosystems

    Effect of the Soil Matric Potential on the Germination Capacity of <i>Prosopis chilensis</i>, <i>Quillaja saponaria</i> and <i>Cryptocarya alba</i> from Contrasting Geographical Origins

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    As a consequence of the megadrought in Central Chile, it is expected that most of the distribution of woody species will be narrowed in the northern limits because of restrictions imposed by soil matric potential on seed germination. In this study, we analyzed the effect of the soil matric potential on seed germination and initial recruitment of the sclerophyllous species Prosopis chilensis, Quillaja saponaria and Cryptocarya alba from contrasting geographic origins (i.e., seed sources). We evaluated the germination capacity (%) under different matric potentials (i.e., 0, −6, −33, −750 and −1250 kPa) for 100 days. Soil matric potential of −1250 kPa negatively affected the germination capacity of the three species. P. chilensis seeds stopped germinating under soil matric potential close to −1200 kPa, whereas in Q. saponaria and C. alba the complete inhibition of germination was under −1000 kPa. Seed sources also differed in their germination capacity by soil matric potential: northern seed sources of P. chilensis germinated with the lowest soil matric potential. There was no clear trend in Q. saponaria and C. alba, but in general, southern seed sources performed better than the northern ones. The results showed that Ѱm in the soil played an important role in the germinative capacity against different seed source origins, but not in soils with a north–south gradient

    NNPDF/nnpdf: Version 4.0.7

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    &lt;h2&gt;What's Changed&lt;/h2&gt; &lt;ul&gt; &lt;li&gt;run black isort on recently edited files (#1848) @RoyStegeman&lt;/li&gt; &lt;li&gt;N3LO fits with IHOU (#1698) @giacomomagni&lt;/li&gt; &lt;li&gt;Raise an exception when use_pdferr is used together with plot_fancy (#1844) @scarlehoff&lt;/li&gt; &lt;li&gt;some cosmetic fixes of things that bothered me (#1845) @RoyStegeman&lt;/li&gt; &lt;li&gt;update pineappl dependency to 0.6.2 (#1842) @RoyStegeman&lt;/li&gt; &lt;li&gt;remove qed input from &lt;code&gt;ekobox.apply.apply_pdf&lt;/code&gt; (#1841) @RoyStegeman&lt;/li&gt; &lt;li&gt;Generic hessian PDF covmat (#1831) @comane&lt;/li&gt; &lt;li&gt;update postivity commondata (#1839) @RoyStegeman&lt;/li&gt; &lt;li&gt;Remove NNLO specific cuts (#1835) @andreab1997&lt;/li&gt; &lt;li&gt;Restart hyperopt (#1824) @Cmurilochem&lt;/li&gt; &lt;li&gt;nFONLL theory indices up to and including 721 (#1810) @andreab1997&lt;/li&gt; &lt;li&gt;Remove unused functions in photon module (#1833) @niclaurenti&lt;/li&gt; &lt;li&gt;Update PLOTTING_ATLAS_Z_TOT_13TEV.yaml (#1827) @enocera&lt;/li&gt; &lt;li&gt;add scale variations IDs for theory 600 (#1823) @t7phy&lt;/li&gt; &lt;li&gt;Exa couplings2 (#1806) @niclaurenti&lt;/li&gt; &lt;li&gt;Miscelaneous bugfixes (matplotlib &amp; futuretests) (#1809) @scarlehoff&lt;/li&gt; &lt;li&gt;Allow added cuts (#1745) @Zaharid&lt;/li&gt; &lt;li&gt;Documentation for reportengine (#1804) @comane&lt;/li&gt; &lt;li&gt;Test with less tests (#1805) @scarlehoff&lt;/li&gt; &lt;li&gt;Add &lt;code&gt;--lite&lt;/code&gt; option to vp-comparefits for quick comparisons (#1801) @scarlehoff&lt;/li&gt; &lt;li&gt;Raise an exception if after many tries the replicas are still negative (#1790) @scarlehoff&lt;/li&gt; &lt;li&gt;Use evolven3fit_new with the fitbot (#1789) @scarlehoff&lt;/li&gt; &lt;li&gt;Fix regression tests for arclengths (#1791) @scarlehoff&lt;/li&gt; &lt;li&gt;Add produce_eko_photon to evolven3fit_new (#1778) @niclaurenti&lt;/li&gt; &lt;li&gt;Intermediate merge of Aron's stuff (#1775) @goord&lt;/li&gt; &lt;li&gt;Refactoring model creation code (#1734) @APJansen&lt;/li&gt; &lt;li&gt;Change fiatlux_dis_F{2,L} -&gt; FIATLUX_DIS_F{2,L} (#1774) @niclaurenti&lt;/li&gt; &lt;li&gt;Alpha variation but same thcovmat (#1768) @andreab1997&lt;/li&gt; &lt;li&gt;Change also luxset with vp-nextfitruncard (#1767) @niclaurenti&lt;/li&gt; &lt;li&gt;Add theory 527 and extend comments in theories 522, 523, 524, 525, 526 (#1766) @niclaurenti&lt;/li&gt; &lt;li&gt;Separate DY_CC and DY_NC from DY in nnpdf31_process (#1760) @andreab1997&lt;/li&gt; &lt;li&gt;Avoid using resources at the module level (#1763) @niclaurenti&lt;/li&gt; &lt;li&gt;Add luminosity channels (#1762) @Zaharid&lt;/li&gt; &lt;li&gt;QED tests (#1738) @niclaurenti&lt;/li&gt; &lt;li&gt;Allow categorical variables in smpdf plots (#1715) @Zaharid&lt;/li&gt; &lt;li&gt;Enable nf=3 with &lt;code&gt;evolven3fit_new&lt;/code&gt;. (#1754) @scarlehoff&lt;/li&gt; &lt;li&gt;Getting latest master changes (#1759) @goord&lt;/li&gt; &lt;li&gt;Allow different matching scale for the photon (#1751) @niclaurenti&lt;/li&gt; &lt;li&gt;Hessian PDF Covariance Matrix for theory predictions (#1743) @comane&lt;/li&gt; &lt;li&gt;Tests for &lt;code&gt;evolven3fit_new&lt;/code&gt; and lhapdf &lt;code&gt;.info&lt;/code&gt; files. (#1746) @scarlehoff&lt;/li&gt; &lt;li&gt;Fixes to prepare the code for pandas 2.0 (#1747) @scarlehoff&lt;/li&gt; &lt;li&gt;Evolven3fit new w eko 0.13 (#1742) @giacomomagni&lt;/li&gt; &lt;li&gt;Re-style codebase: validphys (#1737) @scarlehoff&lt;/li&gt; &lt;li&gt;add .git-blame-ignore-revs (#1736) @RoyStegeman&lt;/li&gt; &lt;li&gt;Add photon (#1643) @niclaurenti&lt;/li&gt; &lt;li&gt;Make pineparser handle optimized fktables (#1716) @andreab1997&lt;/li&gt; &lt;li&gt;Closure test L1 consistency in random noise generation (#1695) @comane&lt;/li&gt; &lt;li&gt;nnpdf without pyplot imports (#1723) @comane&lt;/li&gt; &lt;li&gt;Fixing logs of evolven3fit_new (#1731) @andreab1997&lt;/li&gt; &lt;li&gt;Change the fitbot solver to libmamba (#1725) @scarlehoff&lt;/li&gt; &lt;li&gt;futureproofing: make dropna keyword based (#1713) @RoyStegeman&lt;/li&gt; &lt;li&gt;Positivity constraints for c and cbar (#1697) @enocera&lt;/li&gt; &lt;li&gt;Remove replica selector functionality (#1703) @Zaharid&lt;/li&gt; &lt;li&gt;Update recommended pylintrc (#1701) @Zaharid&lt;/li&gt; &lt;li&gt;Added EXA theory (250) (#1689) @enocera&lt;/li&gt; &lt;li&gt;k-factors for new theories (#1677) @giacomomagni&lt;/li&gt; &lt;li&gt;Fix label of absolute uncertainty plots (#1692) @Zaharid&lt;/li&gt; &lt;li&gt;Remove libNNPDF from python (#1680) @scarlehoff&lt;/li&gt; &lt;li&gt;vp-comparefit issue, due to arclength errors (#1681) @comane&lt;/li&gt; &lt;li&gt;Keep name of target dataset (avoid reutilizing fktables) (#1688) @scarlehoff&lt;/li&gt; &lt;li&gt;Move xgrid back to n3fit (#1686) @scarlehoff&lt;/li&gt; &lt;li&gt;Update to the plot (#1685) @scarlehoff&lt;/li&gt; &lt;li&gt;Python closure sampling (with the only python commondata branch) (#1660) @scarlehoff&lt;/li&gt; &lt;li&gt;Substitution of apfel with eko in evolven3fit (#1537) @andreab1997&lt;/li&gt; &lt;li&gt;Use ndata instead of len (#1675) @scarlehoff&lt;/li&gt; &lt;li&gt;Tensorflow in macos (#1673) @scarlehoff&lt;/li&gt; &lt;li&gt;only build docs for 3.9 (#1671) @scarlehoff&lt;/li&gt; &lt;li&gt;Build for Python 3.10 (#1628) @Zaharid&lt;/li&gt; &lt;li&gt;Save pseudodata by default (#1669) @RoyStegeman&lt;/li&gt; &lt;li&gt;Fix penalties and add tests (#1668) @scarlehoff&lt;/li&gt; &lt;li&gt;Use python &lt;code&gt;CommonData&lt;/code&gt; (#1650) @scarlehoff&lt;/li&gt; &lt;/ul&gt; &lt;h2&gt;New Features&lt;/h2&gt; &lt;ul&gt; &lt;li&gt;FTDY maxTau cuts in runcard (#1733) @andreab1997&lt;/li&gt; &lt;li&gt;Add a &lt;code&gt;pyproject.toml&lt;/code&gt; (#1710) @scarlehoff&lt;/li&gt; &lt;li&gt;Mix bands and replicas (#1607) @scarlehoff&lt;/li&gt; &lt;li&gt;read NN output size for hyperscan from runcard (#1696) @RoyStegeman&lt;/li&gt; &lt;li&gt;Evolve n3fit with eko 0.12 (#1694) @giacomomagni&lt;/li&gt; &lt;/ul&gt; &lt;h2&gt;Bug fixes&lt;/h2&gt; &lt;ul&gt; &lt;li&gt;bugfix with stopping (#1820) @APJansen&lt;/li&gt; &lt;li&gt;correct sorting and indexing of level1 data (#1765) @comane&lt;/li&gt; &lt;li&gt;don't print msr layer summary if msr not enforced (#1795) @RoyStegeman&lt;/li&gt; &lt;li&gt;Fix custom_group processing (#1753) @Zaharid&lt;/li&gt; &lt;li&gt;Fix &lt;code&gt;Q2grid&lt;/code&gt; in &lt;code&gt;evolven3fit_new&lt;/code&gt; (#1750) @giacomomagni&lt;/li&gt; &lt;li&gt;Fix calling of fiatlux (#1749) @niclaurenti&lt;/li&gt; &lt;li&gt;multiclosure internal dataset loader should use t0_covmat_from_systematics (#1719) @comane&lt;/li&gt; &lt;li&gt;reintroduce AlphaS_* attributes in the PDF class and add a test of alpha_s_bundle_pdf (#1714) @RoyStegeman&lt;/li&gt; &lt;/ul&gt; &lt;h2&gt;Documentation&lt;/h2&gt; &lt;ul&gt; &lt;li&gt;remove mention that vp-setupfit doesn't always have to be the first step (#1771) @RoyStegeman&lt;/li&gt; &lt;li&gt;Update styling docs (#1740) @RoyStegeman&lt;/li&gt; &lt;li&gt;add use_scalevar_uncertainties to loading custom comvat docs (#1712) @RoyStegeman&lt;/li&gt; &lt;li&gt;add version 4.0.6 to releases list in docs (#1670) @RoyStegeman&lt;/li&gt; &lt;/ul&gt; &lt;h2&gt;Workflow&lt;/h2&gt; &lt;ul&gt; &lt;li&gt;use mamba in docker construction (#1850) @RoyStegeman&lt;/li&gt; &lt;li&gt;add skip_magic_trailing_comma to black config (#1828) @RoyStegeman&lt;/li&gt; &lt;li&gt;Mamba ci (#1793) @APJansen&lt;/li&gt; &lt;/ul&gt; &lt;h2&gt;Refactoring&lt;/h2&gt; &lt;ul&gt; &lt;li&gt;Refactor stopping (#1792) @APJansen&lt;/li&gt; &lt;li&gt;Refactor msr (#1781) @APJansen&lt;/li&gt; &lt;li&gt;Refactor rotations (#1780) @APJansen&lt;/li&gt; &lt;li&gt;Refactor preprocessing (#1777) @APJansen&lt;/li&gt; &lt;li&gt;Refactor xintegrator (#1779) @APJansen&lt;/li&gt; &lt;li&gt;Implement FkRotation as subclass of Rotation by rewriting using a rotation tensor (#1772) @APJansen&lt;/li&gt; &lt;/ul&gt
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