A major constraint to the use of biomass sorghum varieties (Sorghum bicolor (L.) Moench) to generate electricity by direct combustion is the high biomass moisture content at harvest that, under ...unfavourable weather conditions during field drying limits the possibility to achieve a suitable moisture content for baling.
In this work, the CropSyst model was calibrated and validated with data collected in experimental trials conducted in the Po Valley (northern Italy). It was then used to simulate biomass production of three sorghum varieties of contrasting earliness (early, medium-late, and late). In order to simulate the dynamics of biomass moisture content during field drying, a specific model, “sorghum haying model”, was developed and validated.
The two models combined were used to simulate, for three sorghum varieties of contrasting earliness (early, medium-late and late), biomass production and the probability to achieve during field drying a biomass moisture content suitable for baling.
In a long term simulation (140 years), the late sorghum variety achieved the highest dry biomass production (16.5 Mg ha−1) followed by the medium-late (15.4 Mg ha−1) and early (15.1 Mg ha−1) variety. The early variety had the highest probability (0.66) of being baled at a moisture content ≤ 18%, followed by the medium-late (0.53) and late (0.37) varieties. The early variety, also having the shortest average field drying (9.2 days), was considered the most suitable for the selected environmental conditions.
•A model to simulate field drying of sorghum was developed, calibrated and validated.•Late sorghum variety had the highest dry matter production at harvest.•Duration and dynamics of field drying were affected by variety earliness.•Early variety had the highest probability to be baled at suitable moisture content.•Early variety had the shorted drying period and permanence in the field.
The reform of the European sugar market in 2006 paved the way for the development of new agricultural value chains in the Po Valley (Italy). A value chain based on the use of biomass sorghum (Sorghum ...bicolor (L.) Moench) to produce electricity in a medium-scale power plant was investigated. A Life Cycle Assessment was carried out to explore the environmental impact and energy performance of power generation from three biomass sorghum genotypes characterized by different earliness (early, medium-late and late) in the Po Valley (Italy). To fully cover the plant needs, sorghum was complemented by winter wheat straw. Productivity and losses of sorghum for the past 39 years as simulated in Serra et al. (2017) were used to produce a probability distribution of environmental impacts. Soil organic carbon change relative to the straw removal and sorghum incorporation in soil as well as indirect land use change CO2 emissions for the substitution of sugar crops with energy crops were also accounted for. To test the influence of the assumptions an extensive sensitivity analysis over several parameters was performed. The lowest average GHG emissions (68.9 g CO2eq.MJ−1) were achieved with the late genotype while medium-late and early genotypes emitted 73.5 g CO2eq. MJ−1 and 76.8 g CO2eq.MJ−1, respectively. Despite the conservative assumptions, the bioenergy system contributed on average 47.7% less GHG than a natural gas power plant. In the lowest productivity years the sorghum based energy system emitted 52% less GHG than the Italian electricity mix.
Overall, when harvesting and bailing failed due to unfavourable weather conditions, the lowest GHG emissions were found, thanks to the increased replacement of sorghum with straw. In fact, soil incorporation of sorghum biomass resulted in more nutrients added to the soil than with incorporation of wheat straw. Considering that GHG emissions decreased linearly when sorghum biomass yield increased, the highest reductions of GHG were found with late genotypes, that produced the highest yields. The lowest GHG emissions were found when harvesting failed, as the fertilizer debit of straw is lower than the fertilizer credit of sorghum. However, since carbon and nutrients storage in the soil is not rewarded monetarily, this option will not correspond to an optimal profit as the risk of failures are highest with late genotype.
All other environmental impacts assessed were higher for the sorghum based system than for the fossil alternatives. It was found that the presence of DeNOx SNCR (Selective Non-Catalytic Reduction) technology achieved the expected mitigation of acidification potential and photochemical oxidant formation but at the expenses of an increased climate change impact, due to additional N2O emissions.
•Sorghum electricity on average emits 47.7% less GHG than natural gas.•Non-GHG impacts of bioenergy systems are always higher than fossil alternatives.•The late genotype showed on average the lowest GHG emissions.•Haymaking failures mitigate global warming potential by increasing soil nutrients.•DeNOx SNCR causes a trade-off between decreased NOx and increased N2O and NH3 emissions.
Considering the high levels of materials used in the fields of electronics and energy storage systems, it is increasingly necessary to take into consideration environmental impact. Thus, it is ...important to develop devices based on environmentally friendlier materials and/or processes, such as additive manufacturing techniques. In this work, poly(vinylidene fluoride) (PVDF) and poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) are prepared by direct‐ink‐writing (DIW) by varying solvent evaporation temperature and fill density percentage. Different morphologies for both polymers are obtained, including dense films and porous membranes, as well as different electroactive β‐phase content, thermal and mechanical properties. The dielectric constant and piezoelectric d33 coefficient for dense films reaches up to 16 at 1 kHz and 4 pC N−1, respectively for PVDF‐HFP with a fill density of 80 and a solvent evaporation temperature of 50 °C. Porous structures are developed for battery separator membranes in lithium‐ion batteries, with a highest ionic conductivity value of 3.8 mS cm−1 for the PVDF‐HFP sample prepared with a fill density of 100 and a solvent evaporation temperature of 25 °C, the sample showing an excellent cycling performance. It is demonstrated that electroactive films and membranes can be prepared by direct‐ink writing suitable for sensors/actuators and energy storage systems.
Direct‐ink‐writing (DIW) is an additive manufacturing process that allows one to obtain any desired pattern for the development of devices and in this present work presents the development of PVDF and PVDF/HFP based thick films and membranes printed by DIW, the materials being suitable for sensing and energy storage, respectively. It is shown that electroactive PVDF‐based films and membranes can be prepared by DIW, suitable to be implemented in a variety of applications.
Super duplex stainless steels are widely used in harsh environments due to their high corrosion resistance. However, the improvement of their tribological properties can contribute to a better ...performance of these materials in service. In this regard, this study aimed to evaluate the application influence of duplex treatment on the tribological properties of the UNS S32760 super duplex stainless steel. Two treatment times, 2 h and 4 h, were studied for both the nitriding step and the cathodic cage plasma deposition step. The results showed that the combination of the nitrided layer and the TiN film, confirmed with the application of Rietveld refinement on the XRD data, contributes to the wear volume decrease by up to 9.41 times. This behaviour was associated with the increase in surface microhardness and the excellent adhesion conditions (HF1) presented by the film deposited over the nitrided layer. The film provided a change in the wear mechanism, evidenced by the reduction in the tendency to wear by scratches. Additionally, was observed the presence of lower oxygen content in the wear region of the treated samples, that can be associated a lower heating of the samples during the test. Thus, the duplex treatment has a great application potential for improving the wear resistance of UNS S32760 steel.
Display omitted
•UNS S32760 samples were plasma nitrided and then received TiN films.•The coatings composition was confirmed by Rietveld Refinement method.•The nitriding step provided excellent adhesion conditions, HF1, for TiN films.•Wear volumes were significantly reduced with the duplex treatment application.•The treatments contributed to decrease the tendency to wear by scratching.
•A more economical approach to LIFT is proposed using long laser pulses.•We prove the feasibility of LIFT with long pulses for printing low viscosity inks.•Three different transfer mechanisms are ...found as a function of the laser fluence.•The evolution of printing outcomes is explained in terms of transfer mechanisms.
Laser-induced forward transfer (LIFT) is a laser-based printing technique which has been revealed as an interesting alternative to inkjet printing for the deposition of inks in direct writing applications. The principle of operation of the technique relies on the focusing of a laser beam on a thin film of the ink and the release of a tiny fraction of material through the action of a laser pulse, being usually assumed that such pulse should be very short, of the order of ns and below. However, with the aim of reducing production costs it would be desirable to operate with longer pulses (hundreds of ns and above), so that less expensive lasers could be employed.
In this work we prove that it is feasible to carry out the LIFT of liquids with relatively long laser pulses (a few hundreds of ns). To that aim we have investigated the influence of laser fluence on the printed droplets and identified an evolution of their morphology with that parameter somewhat different from the one characteristic of the LIFT of liquids with much shorter pulses. A further time-resolved imaging study has revealed the onset of up to three different transfer mechanisms which correlate well with the deposition outcomes.
•High viscosity Ag nanopaste voxels were congruently laser printed.•Effect of laser fluence and donor-receiver gap on voxel transfer was studied.•Demonstrated voxel transfer with areas spanning 4 ...decades (25 to 250,000μm2).•Several methods of conjoining voxel chains were explored.•Low loss coplanar waveguides using Ag voxel chains up to 3mm long were fabricated.
We explore the effect of variations in laser fluence and donor-receiver substrate distance on the laser-induced forward transfer technique for high viscosity Ag nanopaste. By transferring 50μm×50μm voxels with thicknesses between 0.8 and 8.7μm at different laser fluences, we are able to systematically determine a thickness-fluence regime for successful transfer that widens with increasing voxel thickness. We use these results to study congruent transfer of square voxels with lateral dimensions spanning 2 orders of magnitude: 5μm×5μm, 50μm×50μm, and 500μm×500μm. We conclude by linking a multitude of voxels together in 1mm and 3mm lines to fabricate the center conductor in coplanar waveguides (CPWs) with relatively low loss up to 10GHz.
ABSTRACT
We present results from neutral atomic hydrogen (H i) observations of Hydra I, the first cluster observed by the Widefield ASKAP L-band Legacy All-sky Blind Survey (WALLABY) on the ...Australian Square Kilometre Array Pathfinder. For the first time, we show that WALLABY can reach its final survey sensitivity. Leveraging the sensitivity, spatial resolution, and wide field of view of WALLABY, we identify a galaxy, ESO 501−G075, that lies near the virial radius of Hydra I and displays an H i tail. ESO 501−G075 shows a similar level of morphological asymmetry as another cluster member, which lies near the cluster centre and shows signs of experiencing ram pressure. We investigate possible environmental processes that could be responsible for producing the observed disturbance in the H i morphology of ESO 501−G075. We rule out tidal interactions, as ESO 501−G075 has no nearby neighbours within ∼0.34 Mpc. We use a simple model to determine that ram pressure can remove gas from the disc at radii r ≳ 25 kpc. We conclude that, as ESO 501−G075 has a typical H i mass compared to similar galaxies in the field and its morphology is compatible with a ram pressure scenario, ESO 501−G075 is likely recently infalling into the cluster and in the early stages of experiencing ram pressure.
The widespread application of AISI 304 austenitic stainless steel is mainly due to its high corrosion resistance. However, its field of application can be expanded by improving its tribological ...properties. This work deposited thin films on AISI 304 steel substrates through different plasma treatments using a titanium cathodic cage to evaluate which configuration best combines the films' mechanical, tribological, and corrosion resistance properties. The samples were analyzed by X-ray diffraction, Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, Vickers microhardness, Rockwell C adhesion, fixed-sphere micro-abrasion wear, and Electrochemical Impedance Spectroscopy. The simultaneous duplex treatment sample exhibited the best wear resistance results. It was the film with the lowest loss of corrosion resistance compared to the untreated substrate, highlighting the efficiency of this technique in obtaining surfaces with good mechanical, tribological, and corrosion properties obtained in treatment times shorter than conventional duplex treatment.
ABSTRACT
This paper presents the results of 475h of interferometric observations with the Australia Telescope Compact Array towards the Spiderweb protocluster at z=2.16. We search for large, extended ...molecular gas reservoirs among 46 previously detected CO(1−0) emitters, employing a customised method we developed. Based on the CO emission images and position–velocity diagrams, as well as the ranking of sources using a binary weighting of six different criteria, we have identified 14 robust and 7 tentative candidates that exhibit large extended molecular gas reservoirs. These extended reservoirs are defined as having sizes greater than 40 kpc or supergalactic scale. This result suggests a high frequency of extended gas reservoirs, comprising at least 30 percent of our CO-selected sample. An environmental study of the candidates is carried out based on Nth nearest neighbour and we find that the large molecular gas reservoirs tend to exist in denser regions. The spatial distribution of our candidates is mainly centred on the core region of the Spiderweb protocluster. The performance and adaptability of our method are discussed. We found 13 (potentially) extended gas reservoirs located in eight galaxy (proto)clusters from the literature. We noticed that large extended molecular gas reservoirs surrounding (normal) star-forming galaxies in protoclusters are rare. This may be attributable to the lack of observations low-J CO transitions and the lack of quantitative analyses of molecular gas morphologies. The large gas reservoirs in the Spiderweb protocluster are potential sources of the intracluster medium seen in low redshift Virgo- or Coma-like galaxy clusters.
PDF
