193 research outputs found
Correction: Do chemistry and rheology follow the same laboratory ageing trends in bitumen?
No full text Correction to: Materials and Structures (2022) 55:146 https://doi.org/10.1617/s11527-022-01986-w The article “Do chemistry and rheology follow the same laboratory ageing trends in bitumen?”, written by Georgios Pipintakos, Caitlin Lommaert, Aikaterini Varveri and Wim Van den bergh, was originally published in volume 55, issue 5, ID 146 without open access. With the society's decision to grant Open Choice the copyright of the article changed in February 2023 to © The Author(s) 2022 and the article is forthwith distributed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0. Open access funding enabled and organized by RILEM.Pavement Engineerin
Effects of different aging methods on chemical and rheological properties of bitumen
No full textBitumen undergoes ageing, which leads to changes in its chemical and rheological properties, causing it to become harder and more brittle with time. This study aims to compare the effects of different laboratory ageing methods on the chemistry and rheology of three bitumen types: a Pen 40=60, a Pen 70=100, and a polymer-modified bitumen (PmB). Four ageing protocols were applied: ageing at room temperature, oven ageing, pressure ageing vessel (PAV), and rolling thin-film oven test (RTFOT) combined with PAVageing. The effects of temperature, pressure, and ageing time were studied using dynamic shear tests and infrared spectroscopy. The results highlight the relationship between chemistry and rheology of bitumen. Bitumen hardening, which was revealed by an increase in complex modulus and a decrease in phase angle, was reflected in the growth of specific chemical functional groups. Among all materials, soft bitumen showed the greater tendency to oxidize. Different behavior was observed for PmB, which presented the highest resistance against oxidation among the studied bitumens, even though the reaction with oxygen caused the deterioration of the added polymer modifiers.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Pavement Engineerin
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Contractual renegotiations and international investment arbitration ::a relational contract theory interpretation of investment treaties /
No full text"In Contractual Renegotiations and International Investment Arbitration, Aikaterini Florou explores the tangible and sensitive problem of the renegotiation of state contracts, and the relationship between those contracts and the overarching international investment treaties. By bringing novel insights from economics, the author deconstructs and decodes the contract-treaty interaction by showing that it is not only treaties that have an impact on the underlying contracts, but also those contracts have an effect on the way the open-textured treaty standards are interpreted. The originality of the argument is combined with an innovative interpretative methodology based on relational contract theory and transaction cost economics. Departing from the traditional emphasis of international lawyers on the text of investment contracts, the author shows instead that such contracts are first and foremost "economic animals" and the theory of obsolescing bargaining does not paint a full picture of the contract-treaty interaction"-
Recommended from our members
Contractual renegotiations and international investment arbitration ::a relational contract theory interpretation of investment treaties /
No full text"In Contractual Renegotiations and International Investment Arbitration, Aikaterini Florou explores the tangible and sensitive problem of the renegotiation of state contracts, and the relationship between those contracts and the overarching international investment treaties. By bringing novel insights from economics, the author deconstructs and decodes the contract-treaty interaction by showing that it is not only treaties that have an impact on the underlying contracts, but also those contracts have an effect on the way the open-textured treaty standards are interpreted. The originality of the argument is combined with an innovative interpretative methodology based on relational contract theory and transaction cost economics. Departing from the traditional emphasis of international lawyers on the text of investment contracts, the author shows instead that such contracts are first and foremost "economic animals" and the theory of obsolescing bargaining does not paint a full picture of the contract-treaty interaction"
Examining Inferred Author and Textual Correlates of Harmful Language Annotation
No full textThis study examines whether the psycholinguistic and demographic characteristics of authors of online texts are correlated with the way harmful language, such as toxicity and hate speech, is judged. We apply artificial intelligence models to two harmful language datasets, Jigsaw’s Special Rater Pool dataset and the Measuring Hate Speech dataset, to generate probabilities for different text aspects, namely inferring demographic information of the author behind the suspicious text in terms of age and gender, as well as the expressed emotions, emotionality, sentiment and communication style. We then perform a statistical regression analysis to examine how these text aspects correlate with the perception of hate speech and toxicity during the annotation process. The study shows that while the frequency of the psycholinguistic text aspects that can be derived from the author’s personality does not differ significantly between harmful and non-harmful classes, the inferred text aspects are statistically associated with the annotators’ perception of harmful language and could potentially influence the way annotators label the texts
Effect of filler properties on the hydrothermal ageing of bituminous mastics
No full textMoisture sorption can significantly influence hydrothermal ageing and alter the chemical and rheological properties of bituminous mastics. Mineral filler particles are added to bituminous binders to form mastics with increased stiffness. The addition of fillers can considerably change the moisture sorption and the physico-chemical properties of binders by surface interactions and physical presence. This study aims to investigate the effect of filler type on the moisture-induced changes of bituminous mastics after wetting-drying cycles by means of sorption, rheological and infrared spectrometry tests. The results show that mineral fillers with higher diffusivity increase the overall capacity of mastics to absorb moisture, but at the same time allow for moisture desorption during drying. Nevertheless, it has been found that it is not the diffusivity properties but rather the bitumen and filler interactions that control the hydrothermal ageing of the mastics.Pavement Engineerin
From the ‘Small but Smart State’ to the ‘Small and Entrepreneurial State’: Introducing a Framework for Effective Small State Strategies within the EU and Beyond
No full textAs the current international system is leaning towards multipolarity, small states face the danger of their influence being diminished and their interests being ignored. Small states in Europe and within the European Union might find themselves in such a predicament. In order to overcome it, they are in need of effective strategies. Literature on the international relations of small states suggests that, despite their limitations, small states are able to pursue their goals and succeed in the international system. Small state studies employ the ‘small but smart state’ concept for a small state that can maximize its influence. Despite being widely used, the latter lacks analytical value and remains a cliché. The objective of this article is to pin down the ‘small but smart’ state strategy and based on that to provide a comprehensive framework for the analysis and the design of effective small state strategies. We suggest that the ‘small but smart’ state strategy shares many elements with the entrepreneurial action, as the latter is extended from its business origins to include a specific strategy. We draw on the field of entrepreneurship to explore the ways it can enhance our understanding of the international relations of small states and we introduce a framework for the ‘small and entrepreneurial state’ strategy. The notion of the ‘small and entrepreneurial state’ adds more depth and rigor into our small state analyses as well as reinvigorates a fragmented and repetitive literature. Last but not least, our ‘small and entrepreneurial state’ approach can be of use for both small state scholars and policy makers.9131
Factors (besides cytogenetic ones) with importance to CLL behavior
No full textChronic Lymphocytic leukemia is an indolent leukemic B-cell lymphoproliferative disorder involving peripheral blood, bone marrow, spleen and lymph nodes. Patients usually enjoy a favorable outcome as the majority of them remain asymptomatic for years without needing treatment. However, some patients have a more aggressive course and shorter survival; clinical manifestations, when present, include anaemia, peripheral lymphadenopathy, splenomegaly and autoimmune manifestations. Treatment should be immediately initiated in the presence of a lymphocytic doubling time of less than 6 months, very enlarged or rapidly growing lymph nodes or spleen, anaemia, thrombocytopenia and B symptoms. For symptomatic patients adverse prognostic factors include classical staging ( according to Rai or Binet ), unmutated VH genes, ZAP-70 and CD-38 expression, cytogenetic alterations such as deletion of 11q, deletion of 17p, and/or presence of TP53 mutation. Additional prognostic factors are needed for asymptomatic patients to predict whether they will remain stable for years or not, so this was the purpose of our study. Serum free light chains ( sFLC ) are the most commonly detected paraprotein in CLL and were recently proposed as a useful tool for the prognostication of CLL patients. In our study we confirmed the significance of sFLC in CLL with regard to both treatment and overall survival and showed their relationship with adverse prognostic clinical and laboratory parameters.In an effort to identify other important disease markers, we studied the impact of BLyS and one of its receptors sTACI. B-Lymphocyte Stimulator is a member of the TNF superfamily mainly produced by myeloid cells, monocytes, dendritic cells and osteoclasts in the bone marrow .It is involved in normal or malignant B cell differentiation, proliferation, survival and immunoglobulin production. It may be proteolytically cleaved from the cell membrane and circulate as a soluble protein. TACI ( transmembrane activator and CAML interactor ) is one of the 3 BLyS ( BAFF ) receptors and it is expressed by T and B cells. Serum BLyS levels were found considerably low in CLL patients and their low concentration related to shorter time to first treatment and overall survival. It was suggested that low BLyS levels in aggressive CLL were reflecting its binding to its receptors on B-cell surface, sequestrating it from circulation. TACI can be shed from cell surface and circulate in its soluble form ( sTACI ). It was found in our study that sTACI concentrations at diagnosis is a powerfull prognostic marker, related to parameters of disease activity and stage and more importantly to time to first treatment and overall survival. This particular finding has never been mentioned in other studies, to the best of our knowledge.Η Χρόνια Λεμφογενής Λευχαιμία είναι μια σχετικά αργά εξελισσόμενη Β λεμφουπερπλαστική νόσος στην οποία συμμετέχουν το περιφερικό αίμα, ο μυελός των οστών, ο σπλήνας και οι λεμφαδένες. Οι ασθενείς συνήθως διατρέχουν ομαλή πορεία καθώς η πλειοψηφία αυτών παραμένουν ασυμπτωματικοί και χωρίς ανάγκη για θεραπεία για χρόνια. Όμως, σε μερικούς ασθενείς, η νόσος διατρέχει μια δυσμενέστερη και επιθετικότερη πορεία, με συντομότερο χρόνο συνολικής επιβίωσης. Κλινικές εκδηλώσεις της νόσου, όπου εμφανίζονται, είναι αναιμία, περιφερική λεμφαδενοπάθεια, σπληνομεγαλία και αυτοάνοσες εκδηλώσεις. Θεραπεία πρέπει να ξεκινάει αμέσως όταν ο χρόνος διπλασιασμού των λεμφοκυττάρων είναι μιικρότερος των 6 μηνών, υπάρχει ογκώδης λεμφαδενοπάθεια, σημαντική σπληνομεγαλία ή ταχύτατη διόγκωση του σπληνός, αναιμία, θρομβοπενία και ύπαρξη Β συμπτωματολογίας. Για τους συμπτωματικούς ασθενείς, δυσμενείς προγνωστικοί παράγοντες είναι το στάδιο της νόσου ( κατά Rai και Binet ), αμετάλλαχτη μεταβλητή περιοχή βαριάς αλύσου της ανοσοσφαιρίνης, η παρουσία του ZAP-70, η έκφραση του CD-38 και κυτταρογενετικές ανωμαλίες όπως η απώλεια του μακρύ σκέλους του χρωμοσώματος 11 ( 11q ), η απώλεια του βραχύ σκέλους του χρωμοσώματος 17 ( 17p ) καθώς και η παρουσία του p53.Επιπρόσθετοι προγνωστικοί παράγοντες χρειάζονται για τους ασυμπτωματικούς ασθενείς προκειμένου να προβλεφθεί η πορεία της νόσου σε αυτούς, ο οποίος ήταν ο σκοπός της μελέτης μας. Οι ελεύθερες ελαφρές αλυσίδες ορού ( sFLC ), είναι οι πιο συχνά ανιχνεύσιμες παραπρωτείνες της ΧΛΛ και πρόσφατα προτάθηκαν ως ένα σημαντικό διαγνωστικό εργαλείο για την πρόγνωση της νόσου. Η μελέτη μας επιβεβαίωσε τη σημασία των sFLC σε ότι αφορά το χρόνο έναρξης θεραπείας και τη συνολική επιβίωση των ασθενών και ανέδειξε το συσχετισμό τους με κλινικοεργαστηριακούς παράγοντες.Σε μια προσπάθεια ανεύρεσης άλλων δεικτών της νόσου, μελετήσαμε τον παράγοντα BLyS και ενός από τους υποδοχείς του, τον TACI. Ο BLyS είναι μία κυτταροκίνη που ανήκει στην υπεροικογένεια του παράγοντα νέκρωσης όγκου ( TNF ) και παράγεται κυρίως από μυελοειδή κύτταρα, μονοκύτταρα, δενδριτικά κύτταρα και οστεοκλάστες του μυελού των οστών. Συμμετέχει στη διαφοροποίηση των Β λεμφοκυττάρων, φυσιολογικών και μη, στον πολλαπλασιασμό τους, στην επιβίωσή τους καθώς και στην παραγωγή ανοσοσφαιρίνης. Μπορεί να αποκοπεί πρωτεολυτικά από την κυτταρική μεμβράνη και να κυκλοφορεί σαν διαλυτή πρωτείνη. Ο TACI είναι ένας από τους 3 υποδοχείς του και εκφράζεται και από τα Β και από τα Τ λεμφοκύτταρα. Τα επίπεδα ορού του BLyS βρέθηκαν χαμηλότερα σε ασθενείς με ΧΛΛ και η χαμηλή συγκέντρωση συσχετίσθηκε με συντομότερο χρόνο έναρξης θεραπείας και ολική επιβίωση. Προτάθηκε ότι τα χαμηλά επίπεδα του BLyS σε ασθενείς με επιθετική ΧΛΛ, αντικατοπτρίζει τη δέσμευσή του από τους υποδοχείς των Β λεμφοκυττάρων, αποσύροντάς τον με αυτό τον τρόπο από την κυκλοφορία. Ο TACI μπορεί να κυκλοφορήσει και στη διαλυτή του μορφή ( sTACI ), αφού αποκοπεί από την κυτταρική επιφάνεια. Από τη μελέτη μας προέκυψε ότι η συγκέντρωση του sTACI στη διάγνωση είναι ισχυρός προγνωστικός παράγοντας, ενώ συσχετίσθηκε με παράγοντες της νόσου, το στάδιο, αλλά πιο σημαντικά με το χρόνο έναρξης θεραπείας και τη συνολική επιβίωση. Το εύρημα αυτό δεν έχει αναφερθεί εώς τώρα από όσο γνωρίζουμε
Punching shear in prestressed concrete deck slabs: a comprehensive study
No full textA large number of bridges in the Netherlands have transversely post tensioned deck slabs cast in-situ between flanges of precast girders and were found to be critical in shear when evaluated by Eurocode 2. To investigate the bearing (punching shear) capacity of such bridges, a 1:2 scale bridge model was constructed in the laboratory and static tests were performed by varying the transverse prestressing level (TPL). A 3D solid, 1:2 scale model of the real bridge, similar to the experimental model, was developed in the finite element software DIANA and several nonlinear analyses were carried out. It was observed that the experimental and numerical ultimate load carrying capacity was much higher than predicted by the governing codes due to lack of consideration of compressive membrane action (CMA). In order to incorporate CMA in the Model Code 2010 (fib 2012) punching shear provisions for prestressed slabs, numerical and theoretical approaches were combined. As a result, sufficient factor of safety was observed when the real bridge design capacity was compared with the design wheel load of Eurocode 1. It was concluded that the existing bridges still had sufficient residual bearing capacity with no problems of serviceability and structural safety.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Concrete Structure
Shear and punching capacity predictions for slabs under concentrated loads aided by lefea
No full textOne-way slabs under concentrated loads may fail by one-way shear, punching, flexure or a mixed-mode between them. This study examines the benefits of using Linear Elastic Finite Element Analyses (LEFEA) combined with analytical expressions to predict the shear and punching capacities of such slabs. Besides, the determination of the most critical shear failure mechanism is also addressed. A simplified approach is proposed to predict the shear and punching capacity without numerical models. Forty-eight tests of simply supported slabs under concentrated loads were evaluated. The LEFEA was conducted with ABAQUS. The analytical expressions are based on the Critical Shear Crack Theory (CSCT). The coupling of the CSCT-expressions with the LEFEA accurately predicts the governing shear failure mechanism and the shear capacity of most test results. In this study, it was also found that the punching capacity predictions may be improved by considering the influence of the slab width and load size on the governing failure mechanism. A similar level of precision was achieved using only analytical expressions when properly calibrated. Therefore, the CSCT expressions can be used at different stages of design and assessment of existing structures according to the Level of Approximation required.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Concrete Structure
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