Geodetic vertical velocities derived from data as short as 3 yr are often assumed to be representative of linear deformation over past decades to millennia. We use two decades of surface loading ...deformation predictions due to variations of atmospheric, oceanic and continental water mass to assess the effect on secular velocities estimated from short time-series. The interannual deformation is time-correlated at most locations over the globe, with the level of correlation depending mostly on the chosen continental water model. Using the most conservative loading model and 5-yr-long time-series, we found median vertical velocity errors of 0.5 mm yr−1 over the continents (0.3 mm yr−1 globally), exceeding 1 mm yr−1 in regions around the southern Tropic. Horizontal velocity errors were seven times smaller. Unless an accurate loading model is available, a decade of continuous data is required in these regions to mitigate the impact of the interannual loading deformation on secular velocities.
The preparation of non‐isocyanate polyurethanes (NIPUs) by polyaddition of (poly)cyclic carbonates to (poly)amines represents one of the most optimistic alternatives for replacing conventional ...polyurethanes prepared by the toxic isocyanate chemistry. However, the limited reactivity of conventional five membered cyclic carbonates even in the presence of catalysts restricts their industrial implementation. One way to mitigate this lack of reactivity is to combine with other chemistries to create hybrid‐NIPUs with superior performance. In this article the combination of the adhesive promoter, dopamine, and the fast‐curing promoter, an aminopropyl trimethoxysilane, is found to create a synergetic effect on the rheological and adhesive properties of NIPUs. After demonstrating the importance of adjusting soft/hard ratios to obtain lap‐shear strength adhesion values up to 21 MPa on stainless steel, these values are retained when adding dopamine and silane compounds. Importantly, the adhesive properties of NIPU are preserved at high temperature (T > 200 °C) for optimal compositions. Finally, adhesion tests on various substrates (polyamide, high density polyethylene, poly(methyl methacrylate), oak wood, and aluminum) show best performances on polar substrates confirming the strong interactions of hydroxyl groups of NIPU and dopamine.
Hybrid non‐isocyanate polyurethanes are prepared through polyaddition of dicarbonates and an aromatic diamine. Dopamine and an alkoxysilane compound are added, enhancing the adhesive, lap‐shear strength, as well as shear adhesion failure temperature, and rheological properties. Moreover, the importance of the hard/soft monomer balance in the formulation to obtain optimal performances is demonstrated.
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•The catalysis contributions to biorefineries was reviewed.•A techno-economic analysis of a biorefinery with catalytic processes is shown.•The use of enzymes and catalytic ways for ...biomass conversion is discussed.•The successful application of catalysis into biorefineries is presented.
The use of crude oil as energy source and raw material to produce chemicals has deteriorated the environment. For this reason, biomass is a representative renewable energy source that has been researched to obtain different products and energy vectors through biochemical and thermochemical pathways. However, the inclusion of catalytic processes is an opportunity to obtain a great variety of value-added products and fuel additives. The objective of the present paper is to compare from a techno-economic point of view the influence of the implementation of catalytic processes to upgrade biomass components and its derivatives into compounds of interest through the biorefinery concept. The simulation of two biorefineries with and without heterogeneous catalysis was performed to compare and elucidate the catalytic processes impact into economic indicators. It was observed that the inclusion of heterogeneous catalysis is feasible from an economical perspective. The capital cost of each biorefinery were 56.13M.USD and 64.93M.USD, respectively. As a conclusion, the application of catalysis into biorefineries increases the number of valuable products that can be obtained from lignocellulosic biomass. Finally, the techno-economic assessment showed that the addition of catalysis into biorefineries is a feasible possibility that must be analyzed in future biorefineries.
We investigate the effect of an in-plane ac electric field coupled to electrons in the honeycomb lattice and show that it can be used to manipulate the Dirac points of the electronic structure. We ...find that the position of the Dirac points can be controlled by the amplitude and the polarization of the field for high-frequency drivings, providing a new platform to achieve their merging, a topological transition which has not been observed yet in electronic systems. Importantly, for lower frequencies we find that the multiphoton absorptions and emissions processes yield the creation of additional pairs of Dirac points. This provides an additional method to achieve the merging transition by just tuning the frequency of the driving. Our approach, based on Floquet formalism, is neither restricted to specific choice of amplitude or polarization of the field, nor to a low-energy approximation for the Hamiltonian.
•The psychological impact of COVID-19 crisis has remained stable during the lockdown.•Symptoms of frequent mental disorders were reported by 35-50% of participants.•Anxiety, depression and above all ...stress levels have risen from the COVID-19 outbreak.•Daily physical activity may be included as a complement to reduce symptomatology.
Strict confinement and social distancing measures have been imposed due to the COVID-19 pandemic in many countries. The aim was to assess the temporal evolution of the psychological impact of the COVID-19 crisis and lockdown from two surveys, separated by one month, performed in Spain.
Symptoms of depression, anxiety and stress, and the psychological impact of the situation were longitudinally analyzed using the Depression Anxiety and Stress Scale (DASS-21) and the Impact of Event Scale (IES) respectively.
There was a total of 4,724 responses from both surveys. Symptomatic scores of anxiety, depression and stress were exhibited by 37.22%, 46.42% and 49.66% of the second survey respondents, showing a significant increase compared to the first survey (32.45%, 44.11% and 37.01%, respectively). There was no significant longitudinal change of the IES scores, with 48.30% of the second survey participants showing moderate to severe impact of the confinement. Constant news consumption about COVID-19 was found to be positively associated with symptomatic scores in the different scales, and daily physical activity to be negatively associated with DASS-21 scores.
Results indicated a temporal increase of anxiety, depression and stress scores during the COVID-19 lockdown. Factors such as age, consumption of information about COVID-19 and physical activity seem to have an important impact on the evolution of psychological symptoms.
The transition towards safer and more sustainable production of polymers has led to a growing body of academic research into non-isocyanate polyurethanes (NIPUs) as potential replacements for ...conventional, isocyanate-based polyurethane materials. This perspective article focuses on the opportunities and current limitations of NIPUs produced by the reaction between biobased cyclic carbonates with amines, which offers an interesting pathway to renewable NIPUs. While it was initially thought that due to the similarities in the chemical structure, NIPUs could be used to directly replace conventional polyurethanes (PU), this has proven to be more challenging to achieve in practice. As a result, and in spite of the vast amount of academic research into this topic, the market size of NIPUs remains negligible. In this perspective, we will emphasize the main limitations of NIPUs in comparison to conventional PUs and the most significant advances made by others and us to overcome these limitations. Finally, we provide our personal view of where research should be directed to promote the transition from the academic to the industrial sector.
The transition towards safer and more sustainable production of polymers has led to a growing body of academic research into non-isocyanate polyurethanes (NIPUs) as potential replacements for conventional, isocyanate-based polyurethane materials.
Sex differences in 116 local gray matter volumes (GM
) were assessed in 444 males and 444 females without correcting for total intracranial volume (TIV) or after adjusting the data with the scaling, ...proportions, power-corrected proportions (PCP), and residuals methods. The results confirmed that only the residuals and PCP methods completely eliminate TIV-variation and result in sex-differences that are "small" (∣d∣ < 0.3). Moreover, as assessed using a totally independent sample, sex differences in PCP and residuals adjusted-data showed higher replicability (Formula: see text 93%) than scaling and proportions adjusted-data Formula: see text 68%) or raw data (Formula: see text 45%). The replicated effects were meta-analyzed together and confirmed that, when TIV-variation is adequately controlled, volumetric sex differences become "small" (∣d∣ < 0.3 in all cases). Finally, we assessed the utility of TIV-corrected/ TIV-uncorrected GM
features in predicting individuals' sex with 12 different machine learning classifiers. Sex could be reliably predicted (> 80%) when using raw local GM
, but also when using scaling or proportions adjusted-data or TIV as a single predictor. Conversely, after properly controlling TIV variation with the PCP and residuals' methods, prediction accuracy dropped to Formula: see text 60%. It is concluded that gross morphological differences account for most of the univariate and multivariate sex differences in GM
.
•Four different lignin production processes are evaluated and compared.•Economic and environmental technical evaluations are performed.•Importance of the quality of lignin for high value-added ...products.
This paper presents the technical–economic and environmental assessment of four lignin extraction processes from two different raw materials (sugarcane bagasse and rice husks). The processes are divided into two categories, the first processes evaluates lignin extraction with prior acid hydrolysis step, while in the second case the extraction processes are evaluated standalone for a total analysis of 16 scenarios. Profitability indicators as the net present value (NPV) and environmental indicators as the potential environmental impact (PEI) are used through a process engineering approach to understand and select the best lignin extraction process. The results show that both economically and environmentally process with sulfites and soda from rice husk presents the best results; however the quality of lignin obtained with sulfites is not suitable for high value-added products. Then, the soda is an interesting option for the extraction of lignin if high quality lignin is required for high value-added products at low costs.
The selection of the location of a biomass plant is a critical concern because biomass feedstocks are geographically and spatially dispersed. Geographic Information System-Multi-Criteria Decision ...Analysis (GIS-MCDA) techniques are powerful methods that have been applied to various disciplines using suitable criteria. These methods can be used to solve power planning problems, such as determining the optimal locations of biomass plants in the context of renewable energy. In response to the promotion of renewable energy in European strategy, Extremadura (Spain) is boosting energy generation from biomass as an alternative to traditional generation to protect the environment. This study presents a combined application of GIS-MCDA and the Fuzzy-DEcision-MAking Trial and Evaluation Laboratory (F-DEMATEL) technique to identify suitable and favorable sites for biomass facilities in terms of long-term sustainability. The main criteria established in this approach are outlined, evaluated, weighted and allocated to three criteria groups: environmental, geophysical and socio-economic groups. In the F-DEMATEL participatory method, constraints and their weight coefficients, with regard to their influence, are calculated. The most suitable locations are obtained after applying the Weighted Linear Combination (WLC) method. In the final stage of the decision-making problem, a sensitivity analysis of the criteria set is conducted, and the weights are determined for four implementation strategies. The model is applied in a case study of Extremadura where forest and agriculture are the typical land uses. The results of the F-DEMATEL/GIS-MCDA analysis suggest that the optimal sites for the locations of biomass plants are situated near forests and in zones with low transport costs, which comprise only 9.247% (Sh) of the total study area. Currently, five plants are installed in this area; however, they are not located in the most suitable areas (Sh). The most influential criteria of the model are the vegetation cover, agricultural area, transport cost and potential demand criteria. This methodology can be used in other studies to verify suitable locations for biomass plants in areas with similar geographical and spatial characteristics and available spatial data. Additionally, the proposed method of renewable energy policy planning can be applied to decision-making problems in the private sector and at various government levels.
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•An integrated model for determining the locations of sustainable biomass plants is developed.•The operational method considers energy and land use issues based on spatial assessment.•The five biomass plants in the case study area are not located in the most suitable areas.•A sensitivity analysis of the modified weight coefficients of criteria demonstrates the high stability of the model.•The optimal locations for biomass plants are near forested areas with low transport costs.
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