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Thin Mereological Sums, Abstraction, and Interpretational Modalities
No full textSome tools introduced by Linnebo to show that mathematical entities are thin objects can also be applied to non-mathematical entities, which have been thought to be thin as well for a variety of reasons. In this paper, I discuss some difficulties and opportunities concerning the application of abstraction and interpretational modalities to mereological sums. In particular, I show that on one hand some prima facie attractive candidates for the role of an explanatory plural abstraction principle for mereological sums (in terms of pluralities of summed entities) are not really explanatory; on the other hand, singular abstraction principles (in terms of single summed entities) are materially inadequate. Nonetheless, explanatory criteria of identity and conditions of existence for mereological sums are provided by classical extensional mereology independent of abstraction principles. Thus, given classical extensional mereology, the reasons why, according to Linnebo, mathematical abstracted entities are thin also hold for mereological sums. Finally, I contend that interpretational modalities can be used to characterise the process by which a subject adds sums of previously admitted entities to the domain of quantification
Differenze di genere nel Disturbo Ossessivo Compulsivo in pazienti in trattamento con fluvoxamina.
No full textSequestering ability of aminopolycarboxylic (APCs) and aminopolyphosphonic (APPs) ligands toward palladium(II) in aqueous solution
No full textThe binding capacity of three aminopolycarboxylates [nitrilotriacetic acid (NTA), ethylene-glycol-bis(2-aminoethyl ether)-N,N,N,N-tetraacetic acid (EGTA), and diethylenetriamine-N,N,N,NN-pentaacetic acid (DTPA)] and two aminopolyphosphonates {(1-hydroxyethane-1,1-diyl)bis(phosphonic acid) (HEDP) and [[(phosphonomethyl)imino]bis[2,1-ethanediylnitrilobis(methylene)]] tetrakis-phosphonic acid (DTPP)} toward palladium(II) ion was studied by potentiometric and spectrophotometric titrations at different temperatures (283.15 ≤ T/K ≤ 318.15) and ionic strengths (0.1 ≤ I/mol·dm -3 ≤ 1.0) in NaClO4. The hydrolysis of Pd2+ and the protonation of ligands were always taken into account in the speciation models of Pd2+/L systems investigated. Equilibrium reaching experiments were performed to check and confirm the reaching of the equilibrium state. Owing to the high stability of the PdL species (K > 1020), for EGTA, HEDP, and DTPP it was determined using exchange measurements with auxiliary ligands, such as iodide (I-) and ammonia (NH3). For the other ligands the stability of the PdL species was reported in the literature. The general speciation scheme consisted of mononuclear differently protonated species with general formula PdHiL and only in the case of the NTA ligand the formation of the PdL2 species was found. The stability of the PdL species is high: as an example we have log KML = 17.82, 22.60, 36.31, 23.49, and 27.27 for NTA, EGTA, DTPA, HEDP, and DTPP, respectively. Among the ligands, DTPA shows the highest formation constants and sequestering ability, evaluated using the pL0.5 parameter, as well. The complex formation reaction is always exothermic and in general the entropic contribution to the stability is dominant. Some empirical relationships were found to model the dependence of the formation constants on the number of protons and of the sequestering ability on pH
Contingent composition as identity
Full text linkWhen the necessity of identity (NI) is combined with composition as identity (CAI), the contingency of composition (CC) is at risk. In the extant literature, either NI is seen as the basis for a refutation of CAI or CAI is associated with a theory of modality, such that: either NI is renounced (if counterpart theory is adopted); or CC is renounced (if the theory of modal parts is adopted). In this paper, we investigate the prospects of a new variety of CAI, which aims to preserve both NI and CC. This new variety of CAI (CCAI, contingent composition as identity) is the quite natural product of the attempt to make sense of CAI on the background of a broadly Kripkean view of modality, such that one and the same entity is allowed to exist at more than one possible world. CCAI introduces a world-relative kind of identity, which is different from standard identity, and claims that composition is this kind of world-relative identity. CCAI manages to preserve NI and CC. We compare CCAI with Gibbard’s and Gallois’ doctrines of contingent identity and we show that CCAI can be sensibly interpreted as a form of Weak CAI, that is of the thesis that composition is not standard identity, yet is significantly similar to it
Evaluation of the sequestering ability of different complexones towards Ag+ ion
No full textThe interaction between Ag+ cation and different ligands was evaluated as a function of temperature and ionic strength by means of potentiometric techniques. Six aminopolycarboxylic (APCs) and aminopolyphosphonic (APPs) ligands were chosen, namely four APCs: nitrilotriacetic acid (NTA), ethylene-glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA), ethylenediamine-N,N,N',N'-tetraacetate (EDTA) and diethylenetriamine-N,N,N',N",N"-pentaacetic acid (DTPA)] and two APPs: [(1-hydroxyethane-1,1-diyl)bis(phosphonic acid) (HEDP) and [[(Phosphonomethyl)imino]bis[2,1-ethanediylnitrilobis(methylene)]] tetrakis-phosphonic acid (DTPP). Different mononuclear species with general formula AgHiL and different number of protons were found. For example in the case of the DTPP, six species with i = 0 to 5 were determined. The ionic strength dependence of the formation constants was studied for all the six ligands, whereas the temperature dependence only for the EDTA, HEDP and DTPP. Among these ligands, DTPP shows the highest formation constant values for the AgL species. The stability trend is: DTPP > DTPA > EDTA ~ EGTA > HEDP > NTA. It was found that the formation constant values decrease with increasing temperature and ionic strength. All the complex formation reactions are endothermic and enthalpic driven. The sequestering ability was evaluated using a useful tool, named pL0.5, which uses a Boltzmann type equation to determine the percentage of metal bound to the ligand as a function of the ligand concentration and other chemico physical parameters (e.g. pH, temperature, ionic strength). Also in this case, the trend traces that of the formation constants, although the difference between DTPP and DTPA is lower
Protonation Constants of Halloysite Clay Nanotubes
No full textHalloysite is one of the most interesting nano-structured clay materials. It is similar to kaolin but has a hollow tubular structure that
can be attributable to particular crystallization conditions. Typically, halloysite nanotubes (HNTs) are formed by 15 – 20
aluminosilicate layers, has a length of 1 ± 0.5 μm and inner and outer diameters of 1 - 30 and 30 - 50 nm, respectively [1,2]. In each
layer the SiOH and the AlOH groups are disposed on the external and the internal surfaces, respectively.
The particular structure of HNTs makes this kind of material very useful for different purposes in several fields. Among the various
applications, worth of mention are: i) their use as additive for devices in the capture tumor cells in blood; ii) nanoparticles for the
entrapment and controlled release of active molecules; ii) additive agents in wound and personal care; iv) sorbents for water
contaminants etc [1,2]. In all these applications, the knowledge of the acid-base properties of HNTs is of fundamental importance.
The acid-base properties of HNTs have been studied by ISE-H+ potentiometric titrations in NaCl medium, in the range 0.025 ≤ I /
mol L-1 ≤ 0.750 and at T = 25°C. Two functional groups indicated with HNT1 (SiOH) and HNT2 (AlOH) were considered in the analysis of the experimental data. Potentiometric data were processed with four different models previously used for the study of the acid - base properties of natural and synthetic polyelectrolytes: Högfeldt, Linear, modified Henderson-Hasselbalch and diprotic like models [3]. The results obtained with the four models for the protonation constants of HNT1 groups of HNTs were in good
accordance, whilst the acid-base properties of HNT2 groups were well defined by one protonation constant calculated by
processing the potentiometric titration data with the computer programs STACO and BSTAC
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
Variations on the Author
Full text link“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
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