490 research outputs found

    Exploring a human-centred design of possessions

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    Understanding the idea of possession is essential for creating successful products and services, particularly in digital and access contexts. This paper examines current shortcomings in conceptualising ownership and possessions before presenting a framework for the process of developing user possession. The framework is grounded in psychological ownership theory and informed by interviews with thirteen participants. The theory considers ownership as a mental state in which users feel the object is theirs. The interviews explored this mental state under three contexts: traditional material possession, digital possession, and access-based possession. This work helps inform the meaning of possessions, and can aid designers and policy makers in how to approach the notion of designing possessions from a human-centered viewpoint

    The appraisal of sustainable materials

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    This paper seeks to understand how users appraise and perceive sustainable material s . Using th inking aloud sessions , appraisals of sustainable materials embodied in commercial products were collected from users and categorised . To account for the appraisal of systemic features of materials w e have extended a previous categorisation of material appraisals . We have also investigated the relationships between the appraisal themes of sustainable materials . The results stress the influence of material origin in the appraisal. This understanding is useful to facilitate the uptake of the materials

    Design and control of 3-DOF needle positioner for MRI-guided laser ablation of liver tumours

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    This article presents the design and control of a pneumatic needle positioner for laser ablation of liver tumours under guidance by magnetic resonance imaging (MRI). The prototype was developed to provide accurate point-to-point remote positioning of a needle guide inside an MR scanner with the aim of evaluating the potential advantages over the manual procedure. In order to minimise alterations to the MR environment, the system employs plastic pneumatic actuators and 9 m long supply lines connecting with the control hardware located outside the magnet room. An improved sliding mode control (SMC) scheme was designed for the position control of the device. Wireless micro-coil fiducials are used for automatic registration in the reference frame of the MR scanner. The MRI-compatibility and the accuracy of the prototype are demonstrated with experiments in the MR scanner

    Contaminated interaction: another barrier to circular material flows

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    Contamination poses a significant problem to the circular economy (CE), which derives much of its value from maintaining pure material flows. The aim of this article is to frame contaminated interaction among other forms of contamination and investigate its effects on the CE. The research is based on a review of the contamination literature and case studies. We differentiate between three types of contamination influencing circular material flows: technical, which deals with fitness for use; systemic, which deals with efficiency in processing; and interaction, which deals with user-object interaction and decision making. Our focus is on developing a foundational understanding of contaminated interaction and how it influences circular processes. Through multiple examples, contaminated interaction is shown to create three barriers to the CE: downcycling, disposal, and hindered circulation. Among other proposals to address contaminated interaction, the research calls for the development of experientially transferrable design—products that can move between users and uses without negative consequences

    Optimal logistics planning for modular construction using two-stage stochastic programming

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    The construction sector is currently undergoing a shift from stick-built construction to modular building systems that take advantage of modern prefabrication techniques. Long established in-situ construction practices are thus being replaced by processes imported from the manufacturing sector, where component fabrication takes place within a factory environment. As a result of this transformation, current construction supply chains, which have focused on the delivery of raw materials to sites, are no longer apt and need to make way to new, strengthened, and time-critical logistics systems. The aim of this study is to establish a mathematical model for the optimisation of logistics processes in modular construction covering three tiers of operation: manufacturing, storage and assembly. Previous studies have indicated that construction site delays constitute the largest cause of schedule deviations. Using the model outlined in this paper we seek to determine how factory manufacturing and inventory management should react to variations in the demand on construction sites. A two-stage stochastic programming model is developed to capture all possible demand variations on site. The model is evaluated using a case study from the residential construction sector. The application shows that the model is effective and can serve as decision support to optimise modular construction logistics

    Identification of the Thyroid Transcription Factor-1 as a Target for Rat MST2 Kinase

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    Abstract Thyroid transcription factor-1 (TTF-1) is a homeodomain-containing transcription factor that is required for thyroid-specific expression of the thyroglobulin and thyroperoxidase genes as well as for lung-specific expression of the surfactant protein A, B, and C and the CC10 and the HNF-3α genes. TTF-1 is a phosphoprotein, and the phosphorylation of TTF-1 has been studied already. However, the kinase(s) that could be responsible for this phosphorylation have not been known. In this paper we report the identification by in-gel kinase assay of a 56-kDa serine/threonine kinase that is able to phosphorylate TTF-1 in thyroid cells. The cloning of this kinase revealed that we had identified the rat homolog of the human MST2 kinase. The pathway in which human MST2 functions is not known; however, it does not appear to involve either mitogen-activated protein kinases such as Erk1 and Erk2 nor the stress-activated protein kinases such as JNK and p38. We show that the activity responsible for TTF-1 phosphorylation is constitutive in thyroid cells. Furthermore, we demonstrate that TTF-1 is phosphorylatedin vivo by rMST2 at the same residues that had been identified previously as the major phosphorylation sites. Thus, TTF-1 represents the first identified target of this class of protein kinases

    AN UNUSUAL TOURMALINE COMPOSITION FROM SITHONIA PENINSULA (NORTHERN GREECE)

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    Η ποικιλία και το εύρος των υποκαταστάσεων που παρουσιάζονται στην ομάδα του τουρμαλίνη, κυρίως στις θέσεις Ζ, Υ και Χ, καθιστά δυνατό τον προσδιορισμό ενός σημαντικού αριθμού πραγματικών και υποθετικών ακραίων μελών. Βέβαια σε μερικές περιπτώσεις αυτό δεν είναι τόσο εύκολο. Ωστόσο, ο προσδιορισμός της % χημικής σύστασης του βοηθά στον καθορισμό παραμέτρων που σχετίζονται με το περιβάλλον γέννεσής του. Σε αυτή την εργασία παρατίθεται η μεθοδολογία που ακολουθήθηκε για τον προσδιορισμό των συστατικών μιας σύνθετης μορφής τουρμαλίνη που απαντά στη χερσόνησο της Σιθωνίας. Ο τουρμαλίνης αυτός, που έχει υπιδιόμορφο ή πιο συχνά αλλοτριόμορφο σχήμα, εντοπίστηκε να γεμίζει με πλήθος μικρών κρυστάλλων του παράλληλες μικρο-διακλάσεις στον χαλαζιακό πυρήνα πηγματιτικής φλέβας. Η σύσταση του οδηγεί στο συμπέρασμα ότι πρόκειται μάλλον για μέλος ασυνήθους στερεού διαλύματος. Χαρακτηρίζεται από σημαντικό έλλειμμα ΑΙ ( ΑΙ Fe και Να που υπερτερεί στη θέση Χ. Με βάση τη σύσταση και το χημισμό του κρυστάλλου, θεωρείται ότι το Mg και ο Fe σχετίζονται με μέλος της σειράς ουβίτη - φερουβίτη, ενώ ένα σημαντικό μέρος του ολικού σιδήρου σε τρισθενή μορφή δίνει ένα ποβονδραϊτικό συστατικό, σύμφωνα επίσης και με το Να στην θέση Χ. Αυτά τα δεδομένα, σε συνδυασμό με το θεωρητικό υπολογισμό του αθροίσματος των δεσμών σθένους που επιτρέπει τον προσδιορισμό της παρουσίας ανιόντων OH στη θέση W, μας ενισχύει την άποψη ότι ο τουρμαλίνης της Σιθωνίας ανήκει σε νέα ποικιλία με ονομασία νατρούχος ποβονδραϊτικός υδροξυλ- ουβίτης-φερουβίτης. Με βάση τη σύσταση, τη δομή και τις τάσεις ζώνωσης που παρουσιάζουν τα κύρια στοιχεία των θέσεων Υ και Χ, αυτός ο τουρμαλίνης μπορεί να θεωρηθεί ως μετα-μαγματικής γένεσης, πιθανά με τη συνδρομή υδροθερμικών ρευστών.The variety and wideness of substitutions shown by tourmaline group, mainly in the Ζ, Y and X sites, make possible a high number of real and hypothetical endmembers. However in some cases it is not so obvious to determine to what endmembers to refer to, but the wide stability field of tourmaline and its occurrence in different geological environments make useful to define the composition as percentages of end-members to trace back to its genesis. In this paper the followed procedure to identify the components of a complex tourmaline is given. During a study on the granitoid intrusions outcropping on Sithonia, Chalkidiki Peninsula (Northern Greece), a swarm of very small crystals of tourmaline, subhedral or more often allotriomorphic, has been found as stuffing of subparallel micro fractures in the quartz core of a pegmatite dike. Their composition, analysed by EMPA, turns out to be rather unusual and not satisfactorily referable to so far proposed solid solutions. It is characterized by remarkable Al deficiency (ZAl Fe and Να dominating X site. On the basis of compositional and crystal-chemical evidences, supported by previous literature, it was hypothesized that Mg and Fe have to be referred to an uvite — feruvite component, while the considerable part of total iron in its trivalent oxidation state yields a povondraitic component according also with Na in X site. These data, coupled with a theoretical evaluation of bond valence sum (B VS) that allowed inferring the presence of OFT anions in the W site, make reasonable to consider Sithonia tourmaline as the new variety sodian povondraitic hydroxil uviteferuvite. On the basis of its composition, of its fabric and of the oscillatory trends shown by the main elements of Y and X sites, this tourmaline may be considered post magmatic likely of hydrothermal genesis
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