Search results for "Scientific method"

Status of independent yield measurements

1996

Recent progress in the measurement of independent yields in low energy nuclear fission is presented. Different experimental approaches are discussed and a survey of the most important experimental results obtained is given. Physical consequences for the understanding of the fission process are briefly referred.

Structural flexibility of bis(phenoxyimine) titanium complexes in the early stages of olefin polymerization process: a DFT study

2010

The behaviors of three structurally similar salan- and phenoxyimine-based catalysts activated by perfluorophenylborate were compared in the early stages of ethylene polymerization. It was found that moderate modification of the ligand structure can dramatically reduce the interactions between the cationic active site and the counteranion and, as a result, decrease the theoretically calculated upper bound to the ion separation barrier from 15 to 2 kcal/mol. The interactions between the ions in the ion pair have further repercussions on the structure of the active sites (octahedral vs square pyramid), transition states and thus the insertion barriers.

Thermal and Hydrodynamic Analysis of the Melting Process in the Cold Crucible Using 3D Modeling

2008

Boosting the methanolysis of polycarbonate by the synergy between ultrasound irradiation and task specific ionic liquids

2021

In an attempt to perform polycarbonate chemical recycling in a more sustainable way, we took into consideration the combined use of ultrasound irradiation and task specific ionic liquids. Towards this aim, the methanolysis of polycarbonate, into dimethylcarbonate and bisphenol A, was carried out in the presence of cholinium-based ionic liquids featuring anions derived from amino acids and other eco-friendly species. The target process was optimized in terms of both energy and material amounts as well as in terms of the nature of the catalysts used. The proposed protocol allowed high conversion and yields of bisphenol A to be obtained, under milder conditions compared to the ones so far repo…

Photocatalytic Processes in Membrane Reactors

2010

Conversion and degradation processes of various substrates in various types of matrices using both artificial and solar light are today very attractive by considering the scarcity and the expensiveness of the conventional energy sources. Coupling of membrane with light has shown to be very powerful and promising hybrid process, especially because a synergistic effect has been often observed. Some examples of reactions carried out to produce useful chemicals or to degrade noxious species in the framework of the green chemistry approach are reported. Fundamentals of heterogeneous photocatalysis, in general, and photocatalytic reactions in membrane reactors, in particular, are treated with a f…

Closer to nature: an ATP-driven bioinspired catalytic oxidation process

2013

The capability of DNA to acquire enzyme-like properties has led to the emergence of the so-called DNAzyme field; herein, we take a further leap along this nature-inspired road, demonstrating that a template assembled synthetic G-quartet (TASQ) can act as a pre-catalyst for catalytic peroxidase-mimicking oxidation reactions, whatever its nature (guanine or guanosine-based G-quartets), in an ATP-dependent manner, thereby bringing this bioinspired TASQzyme process even closer to nature.

An Anthropological Insight on the Commonalities between Tourism and Archaeology

2019

Over the years, archaeology maturated towards something else than a scientific discipline. Archaeological sites are culturally showed as emerging and recycled tourist attractions (Robb 1998; Bateman 2006; Rowan & Baram 2004; Karlsson & Gustafsson, 2006). At a closer look, tourism is understood as a leisure activity which is enrooted in the needs of relaxing and evasion while archaeology -as a knowledge platform which is based on scientific method- explores the history of ancient cultures. This raises a more than interesting question respecting the commonalities and differences between archaeology and tourism. To some extent, archaeologists find ancient relics and objects whi…

Application of gas separation membranes to detritiation systems

2002

The use of gas separation membranes in tritium removal systems has been studied to develop a new detritiation process. The main advantage of this new process is to reduce the number and/or the size of equipments in comparison to conventional detritiation systems. The objective of this study is to choose the best suited membrane for this application. The hydrogen or its isotopes recovery performance of several commercial hollow fiber organic membranes has been analyzed thanks to three devices. Experiments are performed with small quantities of hydrogen gas or deuterium gas or tritium gas in the range representative of the radioactive contamination level in tritium handling gloveboxes. A math…

Features of the in-situ experiments on studying of tritium release from lithium ceramic Li2TiO3 using vacuum extraction method

2021

Abstract The paper presents the results of reactor experiments with lithium ceramic Li2TiO3 performed at the WWR-K research reactor (Almaty, Kazakhstan). A qualitative analysis of the experimental results is presented. The following general results are obtained from the experiments performed by the vacuum extraction method: • Almost no tritium is released in the form of tritium water vapor, and the processes associated with tritium interaction with water vapor can be excluded from the consideration; • a significant amount of tritium is released as T2 molecule; • in long-term irradiation, a significant growth of tritium release in the form of T2 molecule with the time of irradiation is obser…

Information Technologies and Social Media: New Scientific Methods for the Anthropocene

2022

The development of technology during the Anthropocene has affected science and the ways of “doing science”. Nowadays, new technologies help scientists of several disciplines by facilitating knowledge and how to manage it, but also allow for collaborative science, the so-called “Social Science”, where everyone can be a scientist and be involved in providing data and knowledge by using a computer or a smartphone without being a specialist. But is it really that simple? Actually, the daily and integrated use of different digital technologies and sharing platforms, such as social media, requires important reflections. Such reflections can lead to a rethinking of epistemologies and scientific pa…