118,183 research outputs found
Efficienza energetica degli edifici scolastici pugliesi: un’indagine basata sulla rilevazione dei consumi reali
No full textSilica shelling of Quantum Dots and gold film development
No full textColloidal Quantum Dots (QDs) are an established class of optoelectronic materials thanks to their tunable and highly efficient emission. The encapsulation of QDs in silica shells is a well-known procedure to protect them from the external environment and obtain dispersibility in polar solvents. Here, we have coated different types of QDs (CdSe@CdS [1] and InP@ZnS [2]) with silica shells of controlled thickness. The silica shells were obtained exploiting the Reverse Microemulsion reaction combined with an experimental design approach [3,4]. In addition to this, we deposited a uniform gold film over the silica shell. The combination of the QDs emission with the gold plasmon resonance enables an improvement in the optical properties, as already demonstrated [5]. As a first step to achieve this goal, the functionalization of the silica shell for further gold seeds attachment is required. With such aim, we employed (3-Aminopropyl)trimethoxysilane (APTMS), with an amino group binding to the gold seed, helping in the development of the film. Instead, the silicon of the APTMS binds strongly to the silica surface through a covalent bond. Thanks to the 1H and two-dimensional NOESY (Nuclear Overhauser Effect Spectroscopy) NMR analyses, we assessed the bonding of the APTMS to the silica surface and determined the best ratio of injected molecules to the surface area of the nanoparticle to obtain complete coverage. Then, we attached gold seeds to the silica surface, and we merged them by adding gold precursor through a slow injection, employing a syringe pump. In this way, we avoided self-nucleation of gold nanoparticles in the chemical environment, achieving uniform gold coverage. As a further development, by exploiting the variable thickness of the silica shell, the gold film could also be employed to build an optical microcavity around the QD (increasing the QD-gold film distance through a thicker silica shell). In general, silica shells around QDs can be used as a template to colloidally grow more sophisticated optical structures able to impart additional effects to tune the emitter properties.
Bibliography
(1) Carbone, L.; Nobile, C.; De Giorgi, M.; Sala, F. D.; Morello, G.; Pompa, P.; Hytch, M.; Snoeck, E.; Fiore, A.; Franchini, I. R.; Nadasan, M.; Silvestre, A. F.; Chiodo, L.; Kudera, S.; Cingolani, R.; Krahne, R.; Manna, L. Nano Lett. 2007, 7 (10), 2942–2950.
(2) Tessier, M. D.; Dupont, D.; De Nolf, K.; De Roo, J.; Hens, Z. Chem. Mater. 2015, 27 (13), 4893–4898.
(3) Fiorito, S.; Silvestri, M.; Cirignano, M.; Marini, A.; Di Stasio, F. ACS Appl. Nano Mater. 2024, 7 (4), 3724–3733
(4) Leardi, R. Analytica Chimica Acta 2009, 652 (1), 161–172.
(5) Ji, B.; Giovanelli, E.; Habert, B.; Spinicelli, P.; Nasilowski, M.; Xu, X.; Lequeux, N.; Hugonin, J.-P.; Marquier, F.; Greffet, J.-J.; Dubertret, B. Nature Nanotech 2015, 10 (2), 170–175
The Influence of American Economists on the Clayton and Federal Trade Commission Acts
No full textThe aim of this paper is to analyze American economists’ influence in the passing of the Clayton and Federal Trade Commission Acts (1914). Specifically, it is argued and documented that American economists were important in this process in two ways. Many economists exercised an “indirect” influence by discussing in academic journals and books problems concerning trusts, combinations, and the necessary measures to preserve the working of competitive markets. At least as importantly, if not more so, some economists took an active role in the reform movement both contributing to draft proposals for the amendment of existing antitrust legislation and providing help and advice during the Congressional debates which led to the passing of the FTC and Clayton Acts. Among these, we will focus primarily, albeit not exclusively, on the contribution of John Bates Clark
Frank H. Knight, pragmatism, and American institutionalism: A note
No full textThis note deals with the debated question of whether, and to what extent, Frank Knight's epistemology was consistent with the general philosophy of American pragmatism. First, in accord with recent interpretations, I provide new evidence illustrating that Knight's views on science, knowledge and related philosophical topics present some important similarities with the pragmatic tradition. Second, I attempt to demonstrate that Knight's unsympathetic reading of Dewy and pragmatism was, to a relevant extent, a consequence of his aversion to the so-called scientific wing of American interwar institutionalism.Frank H. Knight, behaviourism, American institutionalism, positivism, empiricism, John Dewey,
BETWEEN PROGRESSIVISM AND INSTITUTIONALISM: ALBERT BENEDICT WOLFE ON EUGENICS
No full textAlbeit concerned with the biological element in social evolution, Albert B. Wolfe was among the very few economists of the progressive era who openly expressed their concerns about certain implications of eugenic rhetoric for the social science. Specifically, Wolfe questioned the strong hereditary boundaries that more extreme eugenicists suggested about human beings. A careful examination of Wolfe's writings reveals that his reaction was rooted in the belief that many of the social problems that eugenicists attributed to hereditary limitations were actually imputable to the influence that the social, economic, and physical environment exercised on the individuals
Autoimmune features in atherosclerotic ischemic cardiomyopathy.
No full textAn high frequency of antimitochondrial autoantibodies has been reported in subjects affected with primary cardiomyopathies and it has been hypothesized that they could be involved in the pathogenesis of these diseases. In order to find out whether such autoantibodies could on the contrary represent an epiphenomenon of myocardial cell damage, we searched for antimitochondrial (AMA), antinuclear (ANA) and antismooth-muscle (SMA) non-organ specific autoantibodies in a group of 50 subjects (47 females and 3 males), over 65 years of age, affected with ischemic cardiomyopathy (ICM) due to atherosclerosis, a condition resembling other cardiomyopathies as it concerns ultrastructural aspects of myocardial tissue. The frequency of the autoantibodies tested in our patients resulted quite similar to that occurring in our healthy elderly control subjects (AMA: 14% vs 5.7%; ANA: 28% vs 23%; SMA: 12% vs 11.4%) and in normal aged population. On the basis of our data, the myocardial cell damage "per se" does not seem to influence significatively the production of non-organ specific autoantibodies
On john maynard keynes's anti-semitism once again: A documentary note
No full textThis note presents new archival evidence about John Maynard Keynes' attitudes toward Jews. The relevant material is composed of two letters sent by Robert G. Wertheimer to Bertrand Russell and Richard F. Kahn along with their replies. Between 1963 and 1964, Wertheimer - An Austrian-born Jewish immigrant then professor of economics at Babson College - wrote to Russell and Kahn asking for their personal reminiscences concerning Keynes' anti-Semitic utterances. In their brief but still significant responses, both Russell and Kahn firmly denied any hint of anti-Semitism in Keynes, thereby providing significant first-hand testimonies from two of his closest acquaintances
Il disturbo da Ansia e da Stress post Catastrofe o Attacco Terroristico (Post Traumatic Stress Disorder). Linee Guida nella pratica Clinica per la Diagnosi ed il Management degli Operatori Coinvolti nelle Maxi-Emergenze.
No full textNon organ-specific autoantibodies in healthy and in cardiomyopathic elderly subjects
No full textThe presence of non organ-specific autoantibodies ( anti-nuclear, anti-mitochondrial, anti smooth-muscle, anti gastric parietal cells) was determined in two groups of elderly subjects: in 36 subjects over 65 years age, affected by ischemic cardiomyopathy due to atherosclerosis and in 29 healthy subjects matched for age and sex. The frequency of the autoantibodies tested resulted quite similar in both the populations examined. We conclude that the observed increase of non organ-specific autoantibodies in aging does not depend on age-associated pathologies but on the immunological senescence itsel
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