52 research outputs found
Away with the basics? Exhibition design, experience economy and polyphony
No full textToday’s market economy effaces the operational divide between museums as financial entities and as educational–cultural institutions. With the retraction of public funding and in a highly competitive neoliberal context, museums are pressed into creating new investment opportunities, which range from renting out facilities and services to high-end architecture and bespoke design that fuel an experience economy. In 2017, the Stedelijk Museum Amsterdam undertook an entrepreneurial experiment by redesigning the display of its permanent collection as Stedelijk BASE. The museum’s largest space, its 1,350-m2 open-plan basement, was filled with bespoke-design partition walls and transformed into a labyrinth where the collection was exhibited both chronologically and thematically. According to the institution, the intention was to create an experimental, open-ended, non-hierarchical and non-traditional display, which resembled the experience of browsing and invited multiple perspectives and unexpected connections. In practice, the endeavour was costly, overwhelming and entangled in an official enquiry for conflict of interest, resulting in the resignations of the museum’s directors and managing boards, as well as the withdrawal of many private donors.
This chapter provides a close examination of the exhibition design of Stedelijk’s BASE I in relation to institutional rhetoric and marketing. It suggests two frameworks for understanding and evaluating museum entrepreneurial practices – experience economy and polyphony – and demonstrates the extent to which space participates in meaning-making. Experience economy concerns the commoditisation of experiences themselves, and polyphony the different voices, agencies and capitals (cf. Pierre Bourdieu) that entrepreneurship introduces in a museum setting and which can be selectively employed in order to best define and market a museum’s assets. Working with these two concepts allows us to address the different ways by which the logic of the market enters the field of culture (and therefore the commons) and transforms its production, organisation and distribution. As this chapter demonstrates, BASE sought to capitalise on a new type of museum visit experience, which the author qualifies as the “art fair experience”. Yet, this ultimately failed to be meaningful because its staging was permeable and created dissonance with the museum’s identity, shifting focus from learning to entertainment
Electrical response from nanocomposite PDMS–Ag NPs generated byin situlaser ablation in solution
No full textLaser ablation technique is employed in order to generate polydimethylsiloxane (PDMS)/Ag NPs in situ, starting from a silver target in a solution of PDMS prepolymer and toluene. The produced surfactant-free nanoparticles are characterized by high resolution transmission electron microscopy (HRTEM) and scanning TEM-high angle annular dark field (STEM-HAADF) imaging modes, showing the majority of them to be of the order of 4 nm in diameter with a small percentage of larger Ag-AgCl multidomain NPs, embedded into a PDMS matrix. Low concentrations of carbon onion-like nanoparticles or larger fibers are also formed in the toluene-PDMS prepolymer solution. In accordance with this, UV-vis spectra shows no peak from silver NPs; their small size and their coverage by the PDMS matrix suppresses the signal of surface plasmon absorption. Inductively coupled plasma measurements reveal that the concentration of silver in the polymer is characteristically low, ∼0.001% by weight. The electrical properties of the PDMS nanocomposite films are modified, with current versus voltage (I-V) measurements showing a low current of up to a few tenths of a pA at 5 V. The surface resistivity of the films is found to be up to ∼1010 Ω/sq. Under pressure (e.g. stress) applied by a dynamic mechanical analyzer (DMA), the I-V measurements demonstrate the current decreasing during the elastic deformation, and increasing during the plastic deformation
Fate of pharmaceuticals in the environment - A review-
No full textThe occurrence of pharmaceuticals in environment originating from human consumption has received increased scientific attention during the last decades due to concerns regarding their combined environmental effects in aquatic and terrestrial environments, in flora and biota and by extent in human health. In this review, I summarized the existing knowledge on the entire life cycle of pharmaceutical substances, from their exposure (sources) and fate to their effects on the natural environment. Since the negative effects of several drugs along with the environmental damage they entail are now known, it can be suggested that pharmaceutical companies make greener pharmaceutical products to reduce these effects to the terrestrial and aquatic environment. The present review could provide suggestions to improve the pharmaceutical environmental management globally, such as methodologies for monitoring systems, that need to be put in place for consistent data collection. Another area of research that is important is the release of pharmaceutical compounds in manufacturing plants as well as from landfill effluent. Finally, one more area with need for further research is green chemistry which could reduce or even eliminate the potential hazards of pharmaceutical compounds that enter the environment, irrespective to the source of entry
Fate of pharmaceuticals in aquatic environments in Northern Sweden
No full textThe occurrence of pharmaceuticals in aquatic environments originating from human consumption has received increased scientific attention during the last decades due to concerns regarding their combined environmental effects. This concerns stress the need of studies quantifying dissipation rates of pharmaceutical in aquatic ecosystems. The aims of this study were: i) to assess the degradation rates of trimethoprim (TPR), diphenhydramine (DPH), diclofenac (DCL), oxazepam (OXZ) and hydroxyzine (HDZ) in laboratory incubations, and ii) to compare laboratory assessment of dissipation rates with previously measured in situ half-lives of these drugs in a pond ecosystem. I hypothesized that the dissipation of these five drugs dissolved, in laboratory incubations, is affected by common environmental parameters such as temperature, UV-light, organic solutes and presences of sediments. In line with my hypothesis, all substances were affected by my treatments. Here, main parameters affecting the dissipation of the drugs were UV light and to a lesser temperature (i.e. through microbial degradation). All drugs were found to be affected by sediment sorption, especially HDZ where 95 % of the applied pharmaceutical was adsorbed. Laboratory estimate with highest environmental relevance (low TOC and 3 °C water temperature or low TOC, sediments and UV light) seemed to predict field estimates fairly well for all of the drugs beside OXZ and DCL. Given the strong adsorption for sediments seen in the laboratory incubations, it seems likely that the mismatch between laboratory inferred half-lives and the in situ half-lives for OXZ was likely caused by sediment exchange processes releasing drugs initially adsorbed to the sediments into water column over time
Redefining the relation between human factor and nature through residence: the example of Fallingwater
No full textImage and text juxtapositions in conceptual art in Britain 1967-1972
No full textEThOS - Electronic Theses Online ServiceGBUnited Kingdo
Experimental studies of structural and electronic properties of photo-sensitive chalcogenide compounds
No full textAmorphous, are a wide category of materials with significant properties thatdo not occur in their respective crystalline phase. In this work, a special category ofselected amorphous chalcogenide compounds (chalcogenides) in the form of thin(1μm) films, is studied experimentally. Chalcogens are the elements from Group VIA,namely Sulfur (S), selenium (Se) and tellurium (Te) and therefore compoundscontaining one or more of these elements together with elements such as As, Ge, P,Bi, Si, Sb, Ga, Ag, etc. form chalcogenide compounds. The fact that their energy gapis within the range of visible light and near infrared has given rise to numerous ofphoto-induced (non-thermal) phenomena when these materials are irradiated withlight of appropriate wavelength and power density.The photo-induced effects include changes in structural, mechanical,chemical, optical, electrical, etc. properties. More specifically, through the study ofphoto-induced effects it is possible to control micro-structural changes andmacroscopic properties of the material. Therefore these materials have a strongtechnological interest for applications in optics, in microelectronics and as elements incircuits for optical data storage (optical memories). The aim of this work is to studyand understand at a basic level the micro-structural characteristics of chalcogenidefilms of selected compounds under the influence of various external stimuli as well asto achieve a correlation between microscopic characteristics and useful forapplications macroscopic properties.In the present work the electronic surface structure of AsxSe100-x filmsprepared by thermal evaporation (TE) and by pulsed laser deposition (PLD) wasstudied systematically with surface sensitive techniques such as X-ray and UltravioletPhotoelectron Spectroscopies ( XPS, UPS). X-ray photoelectron spectroscopy is usedto determine the chemical composition of the surface of a solid. The multiplicity ofchemical states for a specific type of atom suggests the existence of a variety of localindividual arrangements on the surface of the film. Therefore, the changes ofelectronic properties on the surface can be directly correlated with changes on thesurface structure, which are caused either by altering various parameters such as thecomposition of the material or by imposing an external stimulus such as annealingand irradiation, or by photo-dissolution of silver atoms (Ag) in their structure. Changing the composition of PLD AsxSe100-x films and submitting them toannealing below the Tg, the most pronounced changes occurred in the electronicenvironment of atoms in films with intermediate compositions (As50Se50, As60Se40).The symmetrical composition As50Se50 was chosen and studied thoroughly because ofthe great diversity and heterogeneity of its micro-structural units in nano-scale. Theresults showed that irradiation and annealing lead the film to two different amorphousstates, with different percentage of structural units. The phenomenon is reversible andrepeatable in successive cycles of annealing and irradiation for the PLD films whilethis is not true for the TE films. The determination of the refractive index usingspectroscopic ellipsometry in PLD and TE As50Se50 films, in successive irradiationand annealing stimuli, revealed the correlation of the changes in the microstructure offilms with the changes in this macroscopic property.Furthermore, the photo-induced diffusion and dissolution of silver (Αg) atomsin the structure of PLD and TE As50Se50 films induced by x-rays and visible light(laser energy comparable to the energy gap of semiconductor) was studied. Thepurpose of these experiments was to follow the chemical species formed during thevarious stages of the diffusion procedure with XPS in contrast to most studies so farfocusing mainly on the mechanism of kinetics of the diffusion reaction. Depth profileanalysis by XPS and SIMS took place in order to investigate the concentration profileof the metal atoms in depth of the films, before and after the induction of the effect.Τα άμορφα υλικά είναι μια ευρεία κατηγορία υλικών με σημαντικές ιδιότητεςπολλές από τις οποίες δεν απαντώνται όταν αυτά βρίσκονται στην αντίστοιχηκρυσταλλική τους φάση. Στην παρούσα εργασία μελετώνται επιλεγμένα υμένια(πάχους ~ 1μm) από μια ειδική κατηγορία άμορφων υλικών, τις χαλκογονούχεςενώσεις (chalcogenides). “χαλκογενή” (chlacogens) αναφέρονται τα στοιχεία τηςομάδας VIA του περιοδικού πίνακα, δηλαδή το Θείο (S), το Σελήνιο (Se) και τοΤελλούριο (Te) και συνεπώς οι ενώσεις που περιέχουν ένα ή περισσότερα από αυτάτα στοιχεία μαζί με στοιχεία όπως τα As, Ge, P, Bi, Si, Sb, Ga, Ag, κλπ. σχηματίζουντις χαλκογονούχες ενώσεις. Το γεγονός ότι το ενεργειακό χάσμα των ενώσεων αυτόεμπίπτει στην φασματική περιοχή του ορατού φωτός και του κοντινού υπερύθρου έχειως αποτέλεσμα την εμφάνιση πλήθους φωτο-επαγόμενων (μη-θερμικών) φαινομένωνόταν τα υλικά αυτά ακτινοβοληθούν με φως κατάλληλου μήκους κύματος καιπυκνότητας ισχύος.Τα φωτο-επαγόμενα φαινόμενα περιλαμβάνουν αλλαγές σε δομικές,μηχανικές, χημικές, οπτικές, ηλεκτρικές κ.α. ιδιότητες. Πιο συγκεκριμένα, μέσω τηςμελέτης των φωτο-επαγόμενων φαινομένων παρέχεται η δυνατότητα για ελεγχόμενημεταβολή δομικών (μικροσκοπικών) αλλά και μακροσκοπικών ιδιοτήτων του υλικού.Επομένως τα υλικά αυτά έχουν έντονο τεχνολογικό ενδιαφέρον, σε εφαρμογές όπωςστην οπτική, στην μικροηλεκτρονική και στην ανάπτυξη στοιχείων αποθήκευσηςπληροφορίας (οπτικές μνήμες). Στόχος της παρούσας εργασίας είναι η μελέτη και ηκατανόηση σε βασικό επίπεδο των μικρο-δομικών χαρακτηριστικών, υμενίωνεπιλεγμένων άμορφων χαλκογονούχων ενώσεων υπό την επίδραση διαφόρωνεξωτερικών ερεθισμάτων καθώς και η επίτευξη συσχετισμού μεταξύμικροσκοπικών χαρακτηριστικών και χρήσιμων για εφαρμογές μακροσκοπικώνιδιοτήτων. Πιο συγκεκριμένα, μελετήθηκε συστηματικά η επιφανειακή ηλεκτρονιακή δομήυμενίων του συστήματος AsxSe100-x, παρασκευασμένων με θερμική εναπόθεση(thermal evaporation, TE) και εναπόθεση με παλμικό laser (pulsed laser deposition,PLD) με επιφανειακά ευαίσθητες τεχνικές όπως Φασματοσκοπία Φωτοηλεκτρονίωναπό Ακτίνες-x (XPS) και από Υπεριώδες (UPS). H ΦασματοσκοπίαΦωτοηλεκτρονίων από Ακτίνες-x (XPS) χρησιμοποιείται για τον καθορισμό τηςχημικής σύστασης της επιφάνειας του στερεού. Η πολλαπλότητα των χημικών καταστάσεων για ένα συγκεκριμένο είδος ατόμου υποδηλώνει την ύπαρξη μιαςποικιλίας τοπικών ατομικών διατάξεων στην επιφάνεια του υμενίου. Επομένως οιαλλαγές των ηλεκτρονιακών ιδιοτήτων στην επιφάνεια μπορούν να συσχετιστούνάμεσα με αλλαγές που αφορούν στην επιφανειακή δομή, οι οποίες προκαλούνται είτεμεταβάλλοντας διάφορες παραμέτρους όπως η σύσταση του υλικού είτε με τηνεπιβολή κάποιου εξωτερικού ερεθίσματος όπως η θέρμανση και η ακτινοβόληση, είτεμε τη φωτο-διάλυση ατόμων μετάλλου (Ag) στο εσωτερικό τους.Μεταβάλλοντας την σύσταση σε PLD υμένια AsxSe100-x και υποβάλλοντας τασε θέρμανση, σε θερμοκρασία 150ºC (δηλαδή λίγο πιο κάτω από το Τg) οι πιοέντονες αλλαγές παρατηρήθηκαν στο ηλεκτρονικό περιβάλλον των ατόμωναρσενικού στα υμένια με ενδιάμεσες συστάσεις (As50Se50, As60Se40). Στην συνέχεια,η συμμετρική σύσταση As50Se50 μελετήθηκε διεξοδικότερα λόγω της μεγάληςποικιλομορφίας και ετερογένειας σε νανο-κλίμακα. Τα αποτελέσματα έδειξαν ότι ηακτινοβόληση και η θέρμανση οδηγούν την δομή σε δύο διαφορετικές άμορφεςκαταστάσεις με διαφορετικό ποσοστό δομικών μονάδων. Το φαινόμενο είναιαντιστρεπτό και επαναλήψιμο σε διαδοχικούς κύκλους θέρμανσης και ακτινοβόλησηςγια τα PLD υμένια ενώ δεν ισχύει το ίδιο για τα ΤΕ υμένια. Ο προσδιορισμός τουδείκτη διάθλασης με την χρήση φασματοσκοπικής ελλειψομετρίας σε PLD και ΤΕAs50Se50 υμένια, σε διαδοχικές διεγέρσεις ακτινοβόλησης και θέρμανσης, αποκάλυψετην συσχέτιση των αλλαγών στη μικροδομή των υμενίων με τις μεταβολές σε αυτήτην μακροσκοπική ιδιότητα του υμενίου.Επιπλέον, εκπονήθηκε μελέτη του φωτο-επαγόμενου φαινομένου της διάχυσηςκαι διάλυσης ατόμων μετάλλου όπως ο Ag στην δομή των υμενίων PLD και ΤΕAs50Se50 με ακτινοβόληση ακτίνων- x και ορατού φωτός (laser ενέργειας συγκρίσιμηςμε το ενεργειακό χάσμα του ημιαγωγού). Σκοπός ήταν η μελέτη της εξέλιξης τωνσχηματιζόμενων χημικών ειδών κατά τα διάφορα στάδια του φαινομένου σε αντίθεσημε την έως τώρα υπάρχουσα πρακτική που εστιάζει κυρίως στον μηχανισμό τηςκινητικής του φαινομένου. Μετρήσεις ανάλυσης σε βάθος με XPS και SIMS έλαβανχώρα με σκοπό την διερεύνηση του προφίλ της συγκέντρωσης του μετάλλου στοεσωτερικό του υμενίου, πριν και μετά την επαγωγή του φαινομένου
Ανάπτυξη συστημάτων εγκλεισμού δραστικών ουσιών με στόχο την εφαρμογή τους σε προστατευτικές επικαλύψεις
No full textΕθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Επιστήμη και Τεχνολογία Υλικών
Study of the electrodeposition of Zn-Ni alloy on O-6 work steel with the addition of ZrO2 microparticles and estimation of the improvement of the mechanical properties and corrosion resistance.
No full textThe influence of teaching experience and professional development on Greek teachers' attitudes towards inclusion
No full textThis is a postprint of an article whose final and definitive form has been published in the European Journal of Special Needs Education© 2007 Copyright Taylor & Francis; European Journal of Special Needs Education is available online at http://www.informaworld.comOn the assumption that the successful implementation of any inclusive policy is largely dependent on educators being positive about it, a survey was undertaken into the attitudes of Greek teachers to inclusion. The 155 respondents were general education primary teachers drawn from one region of Northern Greece, with a proportion deliberately selected from schools identified as actively implementing inclusive programmes. The analysis revealed positive attitudes towards the general concept of inclusion but variable views on the difficulty of accommodating different types of disabilities in mainstream classrooms. Teachers who had been actively involved in teaching pupils with SEN held significantly more positive attitudes than their counterparts with little or no such experience. The analysis also demonstrated the importance of substantive long-term training in the formation of positive teacher attitudes towards inclusion. The paper concludes with recommendations for developing critical professional development courses that can result in attitudinal change and the formulation of genuinely inclusive practices
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