894 research outputs found

    Special issue “metal nanoparticles as catalysts for green applications”

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    This Special Issue of Processes on “Metal Nanoparticles as Catalysts for Green Applications” collects recent works of researchers on metal nanoparticles as catalysts for green applications [...

    Catalytic Production of Levulinic Acid (LA) from Actual Biomass

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    Catalytic conversion of actual biomass to valuable chemicals is a crucial issue in green chemistry. This review discusses on the recent approach in the levulinic acid (LA) formation from three prominent generations of biomasses. Our paper highlights the impact of the nature of different types of biomass and their complex structure and impurities, different groups of catalyst, solvents, and reaction system, and condition and all related pros and cons for this process

    Au/ZrO2 catalysts for LT-WGSR: active role of sulfates during gold deposition

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    Two studies examined the effect of acculturation-contact discrepancies on well-being. Specifically, we tested the prediction that well-being will be compromised when cultural minorities' acculturation preferences are not met by the intergroup and intragroup contact in a new society. Study 1 found that for Polish immigrants (n=55) acculturation-contact discrepancies were associated with compromised well-being. Study 2 followed a cohort of international students (n=106) for a period of two academic years. Results suggested that discrepancies in students' acculturation-contact in their first year had harmful consequences for their well-being 1 year later. Overall, the two studies show that discrepancies between acculturation preferences and actual contact have negative implications for the psychological adaptation of acculturating individuals.info:eu-repo/semantics/publishedVersio

    A review on the efficient catalysts for algae transesterification to biodiesel

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    The depletion of fossil fuel resources and increasing environmental pollution led to a trend for using alternative, clean, green, and sustainable fuel and energy resources. To attain this aim, using biomass as an alternative resource for diesel production has been a hotspot among researchers. Biodiesel has several advantages, such as being lower toxic and more renewable, and eco-friendlier than diesel from fossil fuel resources. Several edible and non-edible bio-sources were used for the production of biodiesel from the transesterification process. Algal oil as a non-edible source is considered an abundant, low cost and green substrate for biodiesel production. Various factors such as reaction conditions and the type of catalyst affect the biodiesel production process. Different catalytic systems such as basic and acidic homogeneous and heterogeneous catalysts and biocatalysts were introduced for the process in the literature, and each proposed catalyst has its own advantages and disadvantages. For instance, in spite of the lower cost and better mass transfer of base and acid homogeneous catalysts, reaction system corrosion, non-reusability, and soap formation are serious challenges of these catalysts at an industrial scale. On the other hand, acid and base heterogenous catalysts overcame the issues of corrosion and recovery, but some matters such as mass transfer limitation, high cost, and weak performance in catalyzing both esterification of FFAs and transesterification of lipids must be taken into account. In addition, bio-catalysis as a high-cost process led to a purer product formation with less side reaction. Therefore, several significant factors should be considered for transesterification catalysts such as availability, cost, reusability, stability, mass transfer, and the possibility to manage both the transesterification of triglycerides and the esterification of FFAs, selecting a catalyst with predominant pros is viable. Here, a review of the biodiesel production from algal biomass focusing on the efficient catalyst of the process is presented

    The application of the Boolean Stochastic Generation Method to model seepage under levees in heterogeneous soils

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    Soil heterogeneity plays an important role in incrementing the uncertainty about the reliability of geotechnical engineering works, especially levees. The presence of thin layers of soils more permeable than the surrounding matrix significantly changes the seepage flow net below and within the dike. However, the detection of these layers is extremely difficult. Consequently, to evaluate the overall safety of dikes it may be useful to adopt stochastic computation methods. The paper presents the calibration of a seepage model of an operational river embankment subject to sand boils. The levee, located along the Adige River (South Tyrol, Italy), has been monitored since 2016. Piezometers and spot temperature sensors are installed in the lateral banks while a distributed fiber optic sensors (FOS), buried in a 350 m long trench at the toe of the levee, is used to check temperature distribution in the subground. The Boolean Stochastic Generation (BoSG) method addresses the influence of layers of material with different properties with respect of the surrounding soil. 360 soil configurations were generated for a two-dimensional groundwater flow model of the levee and confronted with the monitoring data of two piezometers. This analysis permits to identify the configuration that has effects more congruent with piezometers data, which in this case is a configuration with a major presence of lenses on the waterside respect the field-side. This evidence could guide strategies for remedial works
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