171,582 research outputs found
Life Cycle Design for Lightweight Skin
No full textThe typical membranes for building are polymer-based and have origin from fossil fuel but become very lightweight building components, compared with other typical ones. Structural elements stiffen them (bio-based or not) and, due to the lightness, involve fewer structural materials than other components. Through a multidisciplinary experimental design path—focused on the weight factor at the level of the constructive system and the efficiency factor at the level of primary material—it is possible to enhance the efficiency and the aesthetic of lightweight skins and distill the eco-design concepts which can be transferable to the whole construction sector. In other words, the author tries to demonstrate the impacts of reducing weight firstly in textile skins and also other lightweight and hybrid architectures. Coming from this significant weight awareness through experimental knowledge, the author discusses the opportunity to apply multidisciplinary design approaches to reduce energy consumption and environmental loads during the life cycle. This chapter aims to elaborate on those concepts and systematize the obtained results demonstrating the advantages of the Life Cycle Design strategy in the environmental sustainability of novel lightweight skins
Flussi di acqua e soluti attraverso n membrane in serie, con trasporto attivo
No full textTrasporto di acqua e soluti attraverso n membrane in serie in presenza di trasporto "attivo" di soluto. L'esperienza mostra che le relazioni fra i flussi di materia attraverso membrane, e le forze generalizzate che li sostengono sono non lineari. Ciò è vero sia per il trasporto attraverso singole membrane biologiche sia per quello attraverso barriere complesse, come gli epiteli, che si possono ritenere costituiti da più membrane semplici in serie. Il modello più semplice, ma poco realistico, costituito da due sole membrane, già consente di spiegare l'accoppiamento fra il trasporto "attivo" (accoppiato a reazioni chimiche) di soluto e il trasporto d'acqua (1-2). La generalizzazione a un sistema costituito da n membrane in serie, ma puramente passivo (3-4) viene ora estesa con l'introduzione del trasporto attivo. Lo studio teorico del modello e la simulazione al calcolatore di tale sistema hanno mostrato che: 1. la non linearità del flusso volumetrico si osserva solo in presenza di soluto e l'equazione si riduce alla legge lineare di Darcy per il solvente puro, 2. la non linearità richiede comunque l'asimmetria del sistema ed è dovuta all'accumulo di soluto nei compartimenti interni, 3. i coefficienti non costanti che correlano i flussi alle loro forze traenti sono funzione, oltre che del flusso stesso, anche delle variabili operative, 4. il comportamento non lineare di membrane semplici può venire spiegato con il fatto che gli strati limite di fluido non mescolato si comportano come membrane non selettive. (1) C. S. Patlack, D. A. Goldstein, J. F. Hoffman: J. Theor. Biol. 5, 426-442 (1963). (2) G. Monticelli, F. C. Celentano: Bull. Math. Biol. 45, 1073-1096 (1983). (3) F. C. Celentano, G. Monticelli: Atti VI Congresso SIBPA, Camogli, 1983, pp 6062. (4) F. C. Celentano, G. Monticelli in V. Capasso, E. Grosso, S. L. Paveri Fontana: Mathematics in Biology and Medicine, Springer Berlino, 1985, pp 293-299
Material saving and building component efficiency as main eco-design principles for membrane architecture: case - studies of ETFE enclosures
No full textCompared to the traditional materials, textile membrane and foil structural enclosures use minimal quantity of materials to cover spaces or close façades, thanks especially to their tensioning ability, by shaping themselves to the forces ways, with a few additional stiffening components. However the environmental compatibility, due to their actual fossil fuel origin, together with the thermal, optical, and acoustic performances are crucial factors to be verified during the design phase. The need of understanding their potentials and limits in terms of ecoefficiency is on the debate. Starting from these concepts, the aim of the research is to demonstrate the advantages of the Life Cycle Design strategy answering to the environmental sustainability of membrane building components.The authors found out two eco-efficiency principles for the application of membranes and foils, orienting the designers towards a more sustainable whole life spanned lightweight technology’s choice. The main advancement of this research is presented adding new ETFE membranes case studies to the initial analysis (Monticelli, Zanelli, 2016). The aim of this ex-post application of the principles on built examples is the demonstration of their validness for the designer’s need and the intention is to spread their use during the early design stage. The calculation on a wider and different use of membranes allowed to sketch benchmark reference rates. The results of the data analysis show how lightweight technologies offer a high degree of freedom in shaping geometries and forms, while only their optimized application can guarantee a sustainable and LCA effective result
Prefazione
No full textLa Fisiologia è una delle scienze della vita e si occupa di come funzionano, in
condizioni normali, gli organismi viventi e le loro parti; di particolare importanza
nella Fisiologia sono le relazioni fra le varie strutture, le relative funzioni e l’integrazione di queste.
Lo studio della Fisiologia riguarda tutti i livelli dimensionali e organizzativi: dall’atomico-molecolare al sistemico. La Fisiologia è, quindi, strettamente correlata
a varie discipline. Oltre a far uso della Chimica, della Fisica e della Matematica,
la Fisiologia necessita della conoscenza dell’Anatomia come base strutturale per
la comprensione delle funzioni, della Biochimica e della Biologia molecolare per
capire le reazioni chimiche che hanno luogo dentro e fuori le cellule, della Biofisica
per spiegare i fenomeni elettrici e meccanici dell’organismo, della Genetica e
dell’Embriologia per interpretare l’ereditarietà, la crescita, la differenziazione e lo sviluppo. In questo modo la Fisiologia unifica, in un insieme integrato, le informazioni fornite da molte altre discipline.
Quando riguarda l’organismo umano, come nel nostro caso, la Fisiologia diventa
insostituibile per chiarire i processi di sviluppo e di invecchiamento, per comprendere
come si instaurano i processi patologici – ovvero le alterazioni dei meccanismi
che, modificando le funzioni, portano alla malattia – e per definire l’approccio farmacologico atto a ripristinare la funzionalità. Peraltro, anche i processi
di ideazione, sintesi e sviluppo di molecole, agenti come possibili farmaci,
non possono fare a meno delle conoscenze, a vario livello strutturale, dei meccanismi
di funzionamento dell’organismo e delle sue parti.
Per realizzare questo testo sei docenti di Fisiologia nei Corsi di Laurea magistrale
a ciclo unico in Farmacia, di sette Università in Italia e all’estero, si sono coordinati tra loro e avvalsi dell’esperienza e della collaborazione di colleghi fisiologi, docenti in altri corsi di laurea della Facoltà di Farmacia e di altre Facoltà o, comunque, di affermati ricercatori della disciplina.
Pensata inizialmente per studenti di Farmacia, l’opera può risultare quindi utile anche per studenti di altri corsi di laurea. Del resto non ci sono diverse “Fisiologie”, ma il taglio dato alla materia può variare notevolmente in dipendenza delle finalità formative che ci si prefigge.
Il presente testo è proposto, primariamente, come uno strumento didattico, scritto con l’intenzione di unire rigore scientifico e chiarezza espositiva. Gli autori si augurano di avere raggiunto tali obiettivi e, inoltre, che i lettori possano trovare, attraverso il succedersi dei capitoli, una sempre maggiore comprensione del funzionamento in toto dell’organismo umano, conseguendo una conoscenza non nozionistica, ma predittiva, attraverso un chiaro divenire logico.
Nonostante il rigore nella stesura dei testi e la meticolosità nella correzione delle bozze, l’opera presenterà sicuramente
errori o imprecisioni. Gli autori ringraziano sin da ora chiunque vorrà inviare commenti, suggerimenti,
critiche o, semplicemente, segnalare errori di stampa.
Gianluigi Monticelli
Milano, ottobre 200
ERYTHROCYTE MEMBRANE. EFFECTS OF AGE AND CHRONIC ETHANOL TREATMENT
No full textChronic ethanol consumption was demostrated to affect cell membrane lipid composition and fluidity.
Studies on red blood cell (RBC) membrane of alcoholics showed a decrease in sialic acid content and a disorganization of the outer membrane leaflet. In addition ageing seems to affect RBC survival in circulating blood and to modify the presence of sialic acid on the outer surface of RBC membrane.
In order to study the biochemical and biophysical properties of RBC membrane and the possible differences in the adaptive capability to ethanol chronic exposure during ageing we considered the membrane composition and the surface electric charge density.
Albino male rats (Crl:(WI)BR Charles River Italiana), aged 2 months (young) and 7 months (adult) at the time of the experiment, were divided in two groups (ethanol-treated and control) and fed for 24 days a liquid diet (Lieber - DeCarli formula), in which ethanol or carbohydrates represented 36 % of the caloric content. RBC membranes were prepared and analyzed as previously reported
(Monticelli et al. 1992). To estimate the membrane glycoprotein content, the defatted residue was assayed for neutral sugars and for sialic acid. Cell electrophoretic mobility measurements (MEF) were performed on RBC immediately after collected in a horizontal cylindrical capillary by the microscope method; electric surface charge density was calculated both assuming RBC to be spherical and using a flat plate model.
Our experiments showed that ethanol treatment does not affect the electrophoretic mobility and the electric surface charge density of RBC, which increase in adult animals aside from treatment.
Since electric surface charge is due to the presence of sialic acid on the outer surface of the membrane as expected after MEF experiments, gangliosidic sialic acid resulted not affected by ethanol treatment but it seems to be lower in adult treated animals than in the other groups. Nevertheless our data seem to indicate an increase of glycoprotein sialic acid in adult rats. According to the decreased galactosyltranspherase activity found in the enterocyte microsomes and in sinaptosomes of the same animals (Omodeo-Salè et al. 1994, Lindi et al. 1995), the glycoprotein neutral hexose content of RBC decreases while glycolipid neutral hexose content increases indicating that ethanol affects differently the various enzymatic systems.
In conclusion our experiments underlined the ethanol effect on membrane composition suggesting adult rat membranes react more than the young. It is not the ethanol but ageing exerting effects on RBC electrophoretic mobility.
Lindi et al. (1995) Alcohol: in press.
Monticelli et al. (1992) Riv. It. Sostanze Grasse 67: 507.
Omodeo-Salè et al. (1994) Alcohol 11: 301
Eco-design principles for a preliminary eco-efficiency assessment in the design phase: application on membrane envelopes
No full textStating the necessity of increasing the designers’ awareness of both lightweight and flexible materials and their performances, in a life cycle thinking perspective, this contribute is based on the updated identified needs of the membrane sector (Cost Action TU1303, 2017): Life Cycle Assessment, durability aspects, recyclability, social acceptability, thermal, optical, acoustic comforts. Into the frame of the Tensinet association activity, the Textile Architecture Network of Politecnico di Milano is continuing the search of Eco-design strategies and enlarging the mapping of case studies, by the application ex-post of two eco-efficiency principles in order to verify their validness and their efficacy for the designer’s need, during the design process of a membrane system. The main advancement of this work is here presented adding new membranes case studies to the initial analysis. The aim is to verify the applicability of the principles to a wider and different uses of membranes and the identification of reference rates. The results demostrate relations between the rate of the eco- efficiency, the year of construction and the evolution of the technology and the impostance to take into account in the design phases the environmental impact of membrane structures
On Temnocephala axenos Monticelli, 1898 (Platyhelminthes, Temnocephalida): Taxonomic status and designation of a neotype
No full textTemnocephala axenos Monticelli, 1898 was described based on specimens from an unidentified host collected in Blumenau, Santa Catarina, Brazil. Information about type locality was imprecise and the host was later identified as Aegla laevis (Latreille, 1818). However, it is known that A. laevis is not present on the eastern side of the Andes. Also, only histological preparations from one specimen studied by Monticelli are currently available in the Museum für Naturkunde Berlin, but it showed none of the taxonomic characters needed for the characterization of the species. Although the updated description of the species based on Uruguayan specimens, neither the author nor the several previous studies about the species showed a search for the type material, a resolution for the misidentification of the type host or the imprecise type locality due to the subsequent geographical division of the municipality cited in the description. The Uruguayan specimens were not even geographically close to the type locality and a neotype was not designed to validate the species' taxonomic status again. Specimens from Santa Catarina and Paraná States, Brazil, were studied, as well as restudied Argentinean specimens. The new data were compared with the update description of the species. The historical background and the discussion about geographical origins and hosts of the species, as well as a designation of a neotype, allow comparative material of the type locality and type host to exist, eliminating doubts about the identification of T. axenos.Fil: Alves Seixas, Samantha. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División de Zoología Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Amato, Suzana. Universidade Federal do Rio Grande do Sul; BrasilFil: Amato, J. F. R.. Universidade Federal do Rio Grande do Sul; BrasilFil: Daut, L. C. C.. Universidade Federal do Rio Grande do Sul; BrasilFil: Damborenea, Maria Cristina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División de Zoología Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
PHENOMENOLOGY TODAY: A GOOD TRAVEL MATE FOR ANALYTIC PHILOSOPHY?
No full textOn the basis of a short summary of phenomenological aims and methods, this essay
describes the present state of relationships between phenomenology and analytic
philosophy, pointing out the progress done in the last years on the way of their
rapprochement, after a long time of reciprocal scorn and misunderstandings. In the way
of a presentation of the Phenomenology Lab and Center’s present and future research
program, it recalls some relevant chapters of past and present phenomenological
research in Europe, and quite particularly in Italy. After discussing some aspects
of contemporary debates in phenomenology and philosophy of mind, it attempts at
establishing a convergent line of argument toward the assessment of an anti-reductive
ontology of concreteness, or the life world
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