1,721,628 research outputs found
Foreword, in CONTE P., FIMIANI F., WEEMANS M. (eds.), Je est un autre. Mimicries in nature, art and society
No full textBy investigating mimetism as a fundamental and polymorphic aesthetic performance,
this issue of «Aisthesis» aims to rethink the concept, value, and function of mimesis and its
media in the context of camouflage, simulation, and dissimulation, where images do not
reveal themselves as such, but are to be perceived unambiguously as what they are not – as
hieroglyphs or puzzles. In the animal kingdom, as well as in war or in ordinary public life,
camouflage consists in taking on the traits, colours, and shapes of a given form or
environment. This is a twofold process: on the one hand, by blending two or more shapes in
one, the camoufleur seeks to remain hidden and to mislead the others in order to keep a
vital secret or an ephemeral whim; on the other hand, however, he/she aims to be
recognized by a specific milieu or group, thus betraying a craving for communication and
familiarity, as well as a need to convey an agreeable appearance and to share a way of life
Applications of fast field cycling NMR relaxometry
No full textFast field cycling (FFC) NMR relaxometry is emerging as a powerful tool to investigate physical chemistry properties of many systems in a number of different scientific fields. As an example, it is used to investigate environmental issues such as soil erosion, water, and nutrient dynamics in environmentally relevant porous systems, to discriminate among different kinds of foodstuff in order to understand possible source of adulteration and fraud, to evaluate the properties of new materials, and much more. In the present study, an overview about the possible applications of FFC NMR relaxometry is given. The paper is not intended to be exhaustive. Rather, it is thought to provide an ensemble of information as wider as possible in order to allow scientists from different cultural extractions to “open their eyes” in fields to which they are not familiar, thereby hoping that new and inspirational ideas can emerge from the reading of this paper
Measuring hydrological connectivity inside soils with different texture by fast field cycling nuclear magnetic resonance relaxometry
No full textThe locution “hydrological connectivity inside the soil” is generally used to disclose how the spatial patterns inside the soil affect the physical–chemical processes at a molecular level to influence water transfer into the soil, the surface runoff and related sediment transport. Fast Field Cycling (FFC) Nuclear Magnetic Resonance (NMR) relaxometry has been used to measure both structural and functional connectivity by two indexes indicated as structural (SCI) and functional (FCI) connectivity index. Here, FFC-NMR relaxometry has been applied to analyze three samples: two non-degraded soils, having different grain-size distribution, and a degraded soil sampled in a badland area. Proton Larmor frequencies (νL) ranging in the 0.015–35 MHz interval were used on water suspended samples. The relaxograms (i.e., the distributions of the longitudinal relaxation times, T1) obtained by the FFC-NMR investigations were integrated. The resulting S-shaped curves were handled to obtain the aforementioned FCI and SCI parameters. Results showed that the empirical frequency distribution of the SCI index is related to soil texture and structure, while soils having similar SCI revealed different functional connectivity values. This approach allowed (i) to distinguish SCI values of degraded soils from those of non-degraded ones and (ii) to verify whether the structural connectivity index is related to soil texture and structure. The analysis also showed that the variation coefficient of SCI and FCI, achieved from the measurements done at different νL values, is minimum in the measurement range 0.015–1 MHz. The frequency of 1 MHz can be considered the optimal value to have accurate measured connectivity indexes. For the investigated samples, the obtained relationship between FCI and SCI allowed to conclude that high structural connectivity values correspond to a better functional connectivity. Finally, the hydrological connectivity inside a soil was defined as the sum of the two components representing structural and functional perspective
Advanced CPMAS-13C NMR techniques for molecular characterization of size-separated fractions from a soil humic acid
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Nuclear magnetic resonance with fast field-cycling setup: A valid tool for soil quality investigation
Full text linkNuclear magnetic resonance (NMR) techniques are largely employed in several fields. As an example, NMR spectroscopy is used to provide structural and conformational information on pure systems, while affording quantitative evaluation on the number of nuclei in a given chemical environment. When dealing with relaxation, NMR allows understanding of molecular dynamics, i.e., the time evolution of molecular motions. The analysis of relaxation times conducted on complex liquid-liquid and solid-liquid mixtures is directly related to the nature of the interactions among the components of the mixture. In the present review paper, the peculiarities of low resolution fast field-cycling (FFC) NMR relaxometry in soil science are reported. In particular, the general aspects of the typical FFC NMR relaxometry experiment are firstly provided. Afterwards, a discussion on the main mathematical models to be used to “read” and interpret experimental data on soils is given. Following this, an overview on the main results in soil science is supplied. Finally, new FFC NMR-based hypotheses on nutrient dynamics in soils are described
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