1,720,976 research outputs found
L'uso di tecniche di microanalisi strumentale per la caratterizzazione di malte storiche con proprietà idrauliche
Production, characterization, and toxicology of environmentally relevant nanoplastics: a review
Nanoplastic pollution is poorly known, in particular because research is actually mainly done using synthetic polymeric nanospheres that are not representative of environmental nanoplastics, which are very diverse in their composition, size, and shape. Here we review environmentally relevant nanoplastics with focus on their production, characterization, quantification, stability, aggregation, and toxicity. Production of environmentally relevant nanoplastics can be done by mechanical and physicochemical methods. Toxicological studies focus on internalization and toxicity on human cell lines, and bioaccumulation and systemic effects on model organisms
Thermodynamics of mechanical transduction of surface confined receptor/ligand reactions
Chemomechanics of surface stress is discussed in terms of interfacial thermodynamics. In the first section the paper shows how to quantitatively describe the chemical equilibrium of a receptor/ligand binding reaction confined at a solid-liquid interface and how the overall work of the reaction splits into chemical and surface work, that appears as a surface pressure. In the second section this thermodynamic model is applied to describe the experimental results of microcantilever bending induced by DNA hybridization occurring onto one of its face
Erbium incorporation in LiNbO3 crystals obtained by ion-exchange process
Erbium local doping of LiNbO3 single crystal by the ion-exchange has been performed. The role of the process parameters such as exchange time and temperature, crystal cut direction, composition and heating rate of the Er ions liquid source has been investigated by means of secondary ion mass spectrometry, X-ray diffraction and micro-lumi- nescence techniques. A theoretical model has been presented for describing the ion-exchange process and has been successfully applied to fit the experimental data. We have demonstrated that the method is suitable for Er-doping of LiNbO3 crystals, with the possibility of tailoring the optical performances of the material through the preparation parameters
Going Beyond Counting First Authors in Author Co-citation Analysis
The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Application of benchtop total-reflection X-ray fluorescence spectrometry and chemometrics in classification of origin and type of Croatian wines
The contents of selected metals (K, Ca, Fe, Cu, Zn, Mn, Sr, Rb, Ba, Pb, Ni, Cr and V) in 70 wine samples from Continental and Adriatic part of Croatia and different types of wine (red and white) were determined by TXRF. The aim of this study was to compare the elemental composition of wines from two different regions and to determine the discriminant ability of each variable and to indicate which variables discriminate between the four categories considered. Principal component analysis and cluster analysis showed that K, Mn, Ba and Ni can be considered as the most important characteristics to distinguish between Continental red and white wines, Rb, Ni and Ba for Continental red and Adriatic red wines while Sr is the only metal that completely distinguishes the samples of each category. Finally, linear discriminant analysis showed good recognition (100%) and prediction abilities (96.43%) using these selected elements
Appropriate Similarity Measures for Author Cocitation Analysis
We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
AN INVESTIGATION OF THE CRYSTALLINE AND ELECTRONIC-STRUCTURES OF A 4-3-3-4 LAYERED BI-CA-SR-CU OXIDE
- …
