2,731 research outputs found
Examples of heterogeneous catalytic processes for fine chemistry
Fine chemicals are highly pure substances that are commercially produced by chemical reactions for highly specialized applications. In most cases, however, these reactions involve stoichiometric and
highly polluting steps. A possible solution is the development of processes using enzymatic, homogeneous or heterogeneous catalysts. In this review, selected examples of clean heterogeneously-catalyzed reactions applied to the synthesis of fine chemicals are reported for the purpose of highlighting the growing need for more sustainable industrial processes, i.e., processes that produce minimal waste and avoid as much as possible the use of toxic and/or hazardous
reagents and solvents. A thorough knowledge of catalyst properties, reaction conditions and interactions with the reacting substrate are essential for optimizing the synthesis, thus making it possible to move on from laboratory to industrial production
Using normative ethics for building a good evaluation of research practices: towards the assessment of researcher’s virtues
In this paper, we propose the adoption of moral philosophy and in particular normative ethics, to clarify the concept of “good” evaluation of “research practices”. Using MacIntyre (1985)’s notion of a practice we argue that research is a form of social practice. As a result of this characterization, we claim that research practice typically requires three typologies of researcher: the leader, the good researcher and the honest researcher. Reflecting on what is a “good” research practice and on what is the role of researchers in it provides insight into some aspects of both the self-assessment process and how this promotes individual improvement. Moreover, this kind of reflection helps us to describe the functions (missions) of the research practices. A “good” evaluation should take into account all the building constituents of a “good” research practice and should be able to discriminate between good and bad research practices, while enforcing the functions of good research practices. We believe that these reflections may be the starting point for a paradigm shift in the evaluation of research practices which replaces an evaluation centred on products with an evaluation focused on the functions of these practices. In the last sections of the paper, we introduce and discuss an important aspect for the implementation of the proposed framework. This relates to the assessment of the virtues of researchers involved in a good research practice. Some examples of questions and preliminary items to include in a questionnaire for the assessment of Virtues in Research Practices are also provided
SR-FTIR microscopy for the study of residues on Palaeolithic stone tools: Looking for a methodological protocol
In this paper, we use SR-FTIR microscopy to analyse residues identified on seven
lithic artefacts from the Evolved Epigravettian layer 9c2 of the cave site of Grotta Paglicci
(Apulia, southern Italy). Synchrotron radiation, thanks to its properties that particularly increase
the sensitivity of FTIR microscopy, allows the analysis of samples of microscopic size and the
characterisation of even highly degraded compounds, such as the residues of materials worked
by Palaeolithic stone tools or complex compounds used for hafting. This pilot study has been
carried out in the framework of a project concerning the reconstruction of hunting technologies
between the Middle and Upper Palaeolithic. The preliminary results allowed us to focus on the
issues of our methodological approach and to show the potential of the SR-FTIR microscopy for
the analysis of residues on lithic implements
Accidental exposure to politics on social media as online participation equalizer in Germany, Italy, and the United Kingdom
We assess whether and how accidental exposure to political information on social
media contributes to citizens\u2019 online political participation in comparative perspective.
Based on three online surveys of samples representative of German, Italian, and British
Internet users in the aftermath of the 2014 European Parliament elections, we find that
accidental exposure to political information on social media is positively and significantly
correlated with online participation in all three countries, particularly so in Germany
where overall levels of participation were lower. We also find that interest in politics
moderates this relationship so that the correlation is stronger among the less interested
than among the highly interested. These findings suggest that inadvertent encounters
with political content on social media are likely to reduce the gap in online engagement
between citizens with high and low interest in politics, potentially broadening the range
of voices that make themselves heard
FT-IR Investigation of Methoxy Substituted Benzenes Adsorbed on Solid Acid Catalysts
The nature of the interaction on two different catalysts (zeolite BEA and
\u3b3-alumina) of some aromatic substrates, 1,2-methylendioxybenzene, 1,2-ethylendioxybenzene,
and 1,2-dimethoxybenzene, have been investigated by FT-IR spectroscopy.
FT-IR data suggest that the adsorption of 1,2-methylendioxybenzene occurs through
oxygen atoms and the molecule maintains the original puckered conformation, whereas
the planar structure due to the absence of a fused ring in the case of 1,2-
dimethoxybenzene and the twisted conformation of 1,2-ethylendioxybenzene cause an
orientation of the molecules parallel to the catalyst surface, with the benzene ring
directly interacting to it. The puckered conformation of MDB leads the benzene ring to
be electron-deficient, then deactivated toward alkylation, such as confirmed by the obtained catalytic results, which show that
MDB is totally not reactive using the investigated heterogeneous catalysts, while in the traditional homogeneous system shows a
reactivity comparable to the other considered substrates
Geopolymers: A new and smart way for a sustainable development
“Geopolymers” is a general term that describes a wide variety of inorganic and composite materials with limited restrictions on alumina and silica content. In the last decades, they have been also defined as “low-temperature aluminosilicate glasses”, “hydroceramics”, “inorganic polymer concrete” or “alkali bonded ceramics”. Recently, an updated definition has been proposed by the RILEM Technical Committee 224-AAM: “geopolymer materials are essential aluminosilicates activated with alkaline solution, excluding any other alkali-activated materials that should be classified apart” [1]
Evaluation of Linear and Nonlinear Site Effects for the MW 6.3, 2009 L’Aquila Earthquake
An effective strategy for the seismic risk mitigation needs the use of advanced seismological
methodologies for a realistic estimate of the seismic hazard and, consequently, to reduce
earthquake damage through a preventive evaluation of vulnerability and actions for
structure safety. Prediction of earthquakes and their related effects (expressed in terms of
ground shaking) can be performed either by a probabilistic approach or by using modelling
tools based, on one hand, on the theoretical knowledge of the physics of the seismic source
and of wave propagation and, on the other hand, on the rich database of geological, tectonic,
historical information already available. Strong earthquakes are very rare phenomena and it
is therefore statistically very difficult to assemble a representative database of recorded
strong motion signals that could be analyzed to define ground motion parameters suitable
for seismic hazard estimations. That is, the probabilistic estimation of the seismic hazard is a
very gross approximation, and often a severe underestimation, of reality.
A realistic and reliable estimate of the expected ground motion can be performed by using
the Neo-Deterministic Seismic Hazard Analysis (NDSHA), an innovative modelling
technique that takes into account source, propagation and local site effects (for a recent
review see Panza et al., 2011). This is done using basic principles of physics about wave
generation and propagation in complex media, and does not require to resort to
convolutive approaches, that have been proven to be quite unreliable, mainly when
dealing with complex geological structures, the most interesting from the practical point
of view
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