Development of a human-structure dynamic interaction model for human sway for use in permanent grandstand design

This paper details a first attempt to develop a simple human-structure dynamic interaction (HSDI) model for vibration serviceability design of permanent grandstands subject to crowd sway. To date, extensive research has been conducted on vertical crowd-induced vibrations to understand interaction mechanisms and enable engineers to account for them. Similar mechanisms have not yet been fully understood or researched in the lateral plane. This, alongside the limited, verified measured response data has led to incomplete design assessment methods. In this work, an effective two-degree-of-freedom spring-mass-damper-actuator system is developed to represent co-ordinated spectators swaying laterally in the side-to-side direction on a real grandstand. The dynamic properties attributed in the constituents of the model are determined by curve fitting of laboratory-scale human sway data and the modal analysis of the grandstand’s finite element model. The comparison of the modelling output against existing serviceability criteria approaches illustrates potential conservatism in current practice. Namely, when the maximum responses and forces were examined as part of the integrated dynamic system a notable drop-out effect was observed. Although further research is required to validate and calibrate the proposed simple human-structure sway model for individuals and crowds, the observations qualitatively determine the significance of explicitly considering human-structure interaction in the design and assessment of permanent grandstands. Such effects may lead to construction cost savings in addition to unwanted limitations on architecture, hospitality areas and spectator circulation

Η σχέση του Δαρβινισμού με τον Μαρξισμό και η «αλληλογραφία» του Μαρξ με τον Δαρβίνο

Η αλληλογραφία Μαρξ Δαρβίνου διερευνήθηκε από δύο οπτικές. Η μία ήταν η καταγραφή των γεγονότων δηλαδή το περιεχόμενο των επιστολών, ο χρόνος που στάλθηκαν, οι πιθανές προθέσεις, η αυθεντικότητα και πιθανές ερμηνείες για τη στάση που κράτησαν οι δύο σπουδαίοι διανοητές του 18ου αιώνα. Η άλλη οπτική ήταν η εξέταση των θεωριών των Μαρξ και Δαρβίνου ως προς τις βασικές αρχές της κάθε θεωρίας, την τεκμηρίωση των θέσεων του καθενός, την αναζήτηση πιθανών σημείων «συνάντησης» μεταξύ τους καθώς και το κοινωνικοπολιτικό πλαίσιο στο οποίο διαμορφώθηκαν. Θεωρήθηκε σκόπιμο η εργασία αυτή να περιέχει όσο γίνεται περισσότερο αυθεντικά αποσπάσματα από το έργο του καθενός, από την αλληλογραφία τους ή ακόμα απόψεις τρίτων για να περιοριστεί η απόκλιση ανάμεσα σε αυτό που γράφεται από τον εκάστοτε μελετητή και των γραφόμενων από τους ίδιους τους διανοητές, Μαρξ και Δαρβίνο. Ο Μαρξ επιδίωξε την επικοινωνία με τον Δαρβίνο διότι τα δεδομένα των συλλογών του Δαρβίνου και τα συμπεράσματα που προέκυπταν από τις ερμηνείες του στην Καταγωγή των ειδών θεμελίωναν τον διαλεκτικό υλισμό, γεγονός που συμπλήρωνε την μαρξική θεωρία. Ο Δαρβίνος θεωρούσε ότι δεν υπήρχε σημείο συνάντησης αφού το έργο του Μαρξ αφορούσε το πεδίο της πολιτικής οικονομίας για το οποίο ο εκείνος δήλωνε άγνοια και επιπλέον δεν έβλεπε την συσχέτιση που θα μπορούσε να έχει το Κεφάλαιο με την εξέλιξη των ειδών. Το έργο του Δαρβίνου ήταν τόσο επαναστατικό, καινοτόμο και τεκμηριωμένο που ξεπέρασε ακόμα και τον ίδιο. Αμφισβήτησε την σταθερότητα των ειδών, επινόησε τη διακλαδιζόμενη εξέλιξη, και πρότεινε τρόπους να τροποποιούνται τα χαρακτηριστικά των ειδών και να προκύπτουν νέα. Η κοινή καταγωγή των ειδών ως συμπέρασμα από τις παρατηρήσεις θεωρείται τομή για τις επιστήμες της ζωής. Η φυσική επιλογή των ικανότερων ή των ικανοτήτων ξεσήκωσε θύελλες που είναι ενεργές και σήμερα. Τροφοδοτεί τις κοινωνιοβιολογικές προσεγγίσεις αλλά και τις αντιμαχόμενες απόψεις διαμορφώνοντας δύο διακριτά ρεύματα μέσα στους επιστήμονες. Οι βιοεπιστήμες όσο πλησιάζουν την υλιστική φύση τους με τις νέες ανακαλύψεις, τόσο περισσότερο καταρρέουν δογματικές θέσεις που έχουν ως αφετηρία τους, αναπόδεικτες παραδοχές όπως συμβαίνει με την κοινωνιοβιολογία. Η φιλοσοφία της επιστήμης και ο διαλεκτικός υλισμός αποτελούν μια ευρετική εξελικτική θεωρία του υλικού κόσμου η οποία εξελίσσεται και η ίδια. Σύμφωνα με την παρούσα εργασία αυτό αποτελεί το σημείο συνάντησης του μαρξισμού με τον δαρβινισμό.The Marx Darwin correspondence was explored from two perspectives. One was the recording of the facts, i.e. the content of the letters the time they were sent, the possible intentions, the authenticity and possible interpretations of the attitude taken by the two great intellectuals of the 18th century. The other perspective was the examination of the theories of Marx in terms of the basic principles of each theory, the documentation of the positions of each, the search for possible points of “meeting” between them as well as the socio – political context in which they were formed. It was considered appropriate for this work to contain as much as possible authentic excerpts from each individual’s work, from their correspondence or even the views of third parties in order to limit the discrepancy between what is written by the intellectual themselves, Marx and Darwin. Marx sought communication with Darwin because the data of Darwin’s collections and the conclusions derived from his interpretations in the Origin of species founded dialectical materialism, which complemented Marxian theory. Darwin believed that there was no meeting point since Marx’s work concerned the field of political economy of which he professed ignorance and moreover he did not see the correlation that Capital could have with the evolution of species. Darwin’s work was so revolutionary, innovative and documented that it surpassed even himself. He questioned the constancy of species, invented branching evolution and suggested ways the characteristics of species are modified and new ones are created. Common descent of species as inferred from observations is considered cutting edge for the life sciences. Natural selection of the fittest or abilities raised storms that are still active today. It feeds the sociobiological approaches but also the conflicting views forming two distinct currents within the scientists. The closer the life sciences get to their materialistic nature with new discoveries the more doctrinal positions that have unprovable assumptions as their starting point collapse, as is the case with sociobiology. The philosophy of science and dialectical materialism constitute a heuristic evolutionary theory of the material world which is itself evolving. According to this work is this is the meeting point between Marxism and Darwinism

Ο διευρυνόμενος ρόλος των Δήμων στην άσκηση κοινωνικής πολιτικής. Νέες τάσεις και προοπτικές. Η περίπτωση των δημοτικών βρεφονηπιακών σταθμών.

Αντικείμενο της παρούσας εργασίας συνιστά ο διευρυνόμενος ρόλος των δήμων στην άσκηση της κοινωνικής πολιτικής και ιδίως στον τομέα της κοινωνικής προστασίας και αλληλεγγύης. Πρωταρχικός σκοπός είναι η αποτίμηση της συμβολής της πρωτοβάθμιας τοπικής αυτοδιοίκησης στο εν λόγω πεδίο, και πιο συγκεκριμένα: ο προσδιορισμός του κοινωνικού ρόλου των δήμων, τόσο σε όρους θεσμικών προβλέψεων όσο και σε όρους διοικητικής πρακτικής. Η μεθοδολογία που ακολουθείται περιλαμβάνει βιβλιογραφική έρευνα, έρευνα της οικείας νομοθεσίας, στατιστική επεξεργασία δεδομένων καθώς και μελέτη περίπτωσης που εστιάζεται στην εξέταση του θεσμού του δημοτικού βρεφονηπιακού σταθμού. Στα κύρια συμπεράσματα περιλαμβάνεται η διαπίστωση ότι μολονότι οι πρόσφατες μεταρρυθμίσεις του νομοθετικού πλαισίου στόχευαν στη θεσμική ενδυνάμωσή τους και στην ανάδειξη του ρόλου των δήμων ως βασικών διαχειριστών των κοινωνικών αναγκών στο τοπικό επίπεδο, η πραγμάτωση της αποστολής τους συναντά σοβαρά εμπόδια, το οποία ενισχύθηκαν τα τελευταία χρόνια εξαιτίας της οικονομικής κρίσης. Ειδικότερα όσον αφορά στους βρεφονηπιακούς σταθμούς είναι αναγκαία η μετατόπιση από την προσχολική φροντίδα στην έννοια της ολοκληρωμένης προσχολικής αγωγής και στην προσπάθεια δημιουργίας ενός δικτύου δημοτικών παιδικών σταθμών με υψηλή ποιότητα παρεχόμενων υπηρεσιών με στόχο τη σταδιακή κάλυψη του συνόλου των αναγκών του πληθυσμού, καθόσον αποτελεί μεγάλης σημασίας υπηρεσία για τη στήριξη και ενίσχυση της σύγχρονης οικογένειας.This working paper attempts to analyze the growing role of municipalities in advancing social policy measures, namely in the field of social protection and solidarity. The main purpose of this study is to review how the municipalities responded to recent social policy challenges: determining its involvement in implementing social policies, both in terms of institutional forecasts and of best administrative practices. Methodology used in this paper includes bibliographic research, relevant legislation, statistical data processing as well as a case study focusing on the municipal preschool educational institution. Among the most important findings is that despite the recent reforms of the legislative framework enhancing the role of municipalities as key managers of social needs at the local level, these authorities did not manage to accomplish that mission. Among the impediments which resulted in that failure were the lasting effects of the recent financial crisis. As far as preschools are concerned, it seems more and more necessary to shift from the notion of preschool nursery to the concept of integrated preschool education and to the creation of a network of high quality municipal day care centers. The ultimate goal is to serve the overall needs of the population for preschool education and offer tangible support to the families of the modern world

Quantitative assessment of the variability in chemical profiles from source apportionment analysis of PM10 and PM2.5 at different sites within a large metropolitan area

The study aims to assess the differences between the chemical profiles of the major anthropogenic and natural PM sources in two areas with different levels of urbanization and traffic density within the same urban agglomeration. A traffic site and an urban background site in the Athens Metropolitan Area have been selected for this comparison. For both sites, eight sources were identified, with seven of them being common for the two sites (Mineral Dust, non-Exhaust Emissions, Exhaust Emissions, Heavy Oil Combustion, Sulfates & Organics, Sea Salt and Biomass Burning) and one, site-specific (Nitrates for the traffic site and Aged Sea Salt for the urban background site). The similarity between the source profiles was quantified using two statistical analysis tools, Pearson correlation (PC) and Standardized Identity Distance (SID). According to Pearson coefficients five out of the eight source profiles present high (PC > 0.8) correlation (Mineral Dust, Biomass Burning, Sea Salt, Sulfates and Heavy Oil Combustion), one presented moderate (0.8 > PC > 0.6) correlation (Exhaust) and two low/no (PC < 0.6) correlation (non-Exhaust, Nitrates/Aged Sea Salt). The source profiles that appear to be more correlated are those of sources that are not expected to have high spatial variability because there are either natural/secondary and thus have a regional character or are emitted outside the urban agglomeration and are transported to both sites. According to SID four out of the eight sources have high statistical correlation (SID < 1) in the two sites (Mineral Dust, Sea salt, Sulfates, Heavy Oil Combustion). Biomass Burning was found to be the source that yielded different results from the two methodologies. The careful examination of the source profile of that source revealed the reason for this discrepancy. SID takes all the species of the profile equally into account, while PC might be disproportionally affected by a few numbers of species with very high concentrations. It is suggested, based on the findings of this work, that the combined use of both tools can lead the users to a thorough evaluation of the similarity of source profiles. This work is, to the best of our knowledge, the first time a study is focused on the quantitative comparison of the source profiles for sites inside the same urban agglomeration using statistical indicators.The study was supported by “CALIBRA/EYIE” (MIS 5002799) and “PANhellenic infrastructure for Atmospheric Composition and climatE change” (MIS 5021516) implemented under the Action “Reinforcement of the Research and Innovation Infrastructure”, funded by the Operational Programme “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014–2020) and co-financed by Greece and the European Union (European Regional Development Fund). Collection and chemical analysis of samples were supported by LIFE + AIRUSE EU project (ENV/ES/584). Partial support was also received by H2020 ERAPLANET/SMURBS ERANET GA No 689443.Peer reviewe

Comparing black-carbon- and aerosol-absorption-measuring instruments

We report on an inter-comparison of black-carbon- and aerosol-absorption-measuring instruments with laboratory-generated soot particles coated with controlled amounts of secondary organic matter (SOM). The aerosol generation setup consisted of a miniCAST 5201 Type BC burner for the generation of soot particles and a new automated oxidation flow reactor based on the micro smog chamber (MSC) for the generation of SOM from the ozonolysis of α-pinene. A series of test aerosols was generated with elemental to total carbon (EC  TC) mass fraction ranging from about 90 % down to 10 % and single-scattering albedo (SSA at 637 nm) from almost 0 to about 0.7. A dual-spot Aethalometer AE33, a photoacoustic extinctiometer (PAX, 870 nm), a multi-angle absorption photometer (MAAP), a prototype photoacoustic instrument, and two prototype photo-thermal interferometers (PTAAM-2λ and MSPTI) were exposed to the test aerosols in parallel. Significant deviations in the response of the instruments were observed depending on the amount of secondary organic coating. We believe that the setup and methodology described in this study can easily be standardised and provide a straightforward and reproducible procedure for the inter-comparison and characterisation of both filter-based and in situ black-carbon-measuring (BC-measuring) instruments based on realistic test aerosols

Real-time pollen monitoring using digital holography

We present the first validation of the SwisensPoleno, currently the only operational automatic pollen mon-itoring system based on digital holography. The device pro-vides in-flight images of all coarse aerosols, and here wedevelop a two-step classification algorithm that uses theseimages to identify a range of pollen taxa. Deterministiccriteria based on the shape of the particle are applied toinitially distinguish between intact pollen grains and othercoarse particulate matter. This first level of discriminationidentifies pollen with an accuracy of 96 %. Thereafter, in-dividual pollen taxa are recognized using supervised learn-ing techniques. The algorithm is trained using data obtainedby inserting known pollen types into the device, and out ofeight pollen taxa six can be identified with an accuracy ofabove 90 %. In addition to the ability to correctly identifyaerosols, an automatic pollen monitoring system needs to beable to correctly determine particle concentrations. To fur-ther verify the device, controlled chamber experiments us-ing polystyrene latex beads were performed. This providedreference aerosols with traceable particle size and numberconcentrations in order to ensure particle size and samplingvolume were correctly characterized

Role of Secondary Organic Matter on Soot Particle Toxicity in Reconstituted Human Bronchial Epithelia Exposed at the Air-Liquid Interface.

Secondary organic matter (SOM) formed from gaseous precursors constitutes a major mass fraction of fine particulate matter. However, there is only limited evidence on its toxicological impact. In this study, air-liquid interface cultures of human bronchial epithelia were exposed to different series of fresh and aged soot particles generated by a miniCAST burner combined with a micro smog chamber (MSC). Soot cores with geometric mean mobility diameters of 30 and 90 nm were coated with increasing amounts of SOM, generated from the photo-oxidation of mesitylene and ozonolysis of α-pinene. At 24 h after exposure, the release of lactate dehydrogenase (LDH), indicating cell membrane damage, was measured and proteome analysis, i.e. the release of 102 cytokines and chemokines to assess the inflammatory response, was performed. The data indicate that the presence of the SOM coating and its bioavailability play an important role in cytotoxicity. In particular, LDH release increased with increasing SOM mass/total particle mass ratio, but only when SOM had condensed on the outer surface of the soot cores. Proteome analysis provided further evidence for substantial interference of coated particles with essential properties of the respiratory epithelium as a barrier as well as affecting cell remodeling and inflammatory activity

Importance of size representation and morphology in modelling optical properties of black carbon: comparison between laboratory measurements and model simulations

Black carbon (BC) from incomplete combustion of biomass or fossil fuels is the strongest absorbing aerosol component in the atmosphere. Optical properties of BC are essential in climate models for quantification of their impact on radiative forcing. The global climate models, however, consider BC to be spherical particles, which causes uncertainties in their optical properties. Based on this, an increasing number of model-based studies provide databases and parameterization schemes for the optical properties of BC, using more realistic fractal aggregate morphologies. In this study, the reliability of the different modelling techniques of BC was investigated by comparing them to laboratory measurements. The modelling techniques were examined for bare BC particles in the first step and for BC particles with organic material in the second step. A total of six morphological representations of BC particles were compared, three each for spherical and fractal aggregate morphologies. In general, the aggregate representation performed well for modelling the particle light absorption coefficient σabs, single-scattering albedo SSA, and mass absorption cross-section MACBC for laboratory-generated BC particles with volume mean mobility diameters dp,V larger than 100nm. However, for modelling Ångström absorption exponent AAE, it was difficult to suggest a method due to size dependence, although the spherical assumption was in better agreement in some cases. The BC fractal aggregates are usually modelled using monodispersed particles, since their optical simulations are computationally expensive. In such studies, the modelled optical properties showed a 25% uncertainty in using the monodisperse size method. It is shown that using the polydisperse size distribution in combination with fractal aggregate morphology reduces the uncertainty in measured σabs to 10% for particles with dp,V between 60-160nm. Furthermore, the sensitivities of the BC optical properties to the various model input parameters such as the real and imaginary parts of the refractive index (mre and mim), the fractal dimension (Df), and the primary particle radius (app) of an aggregate were investigated. When the BC particle is small and rather fresh, the change in the Df had relatively little effect on the optical properties. There was, however, a significant relationship between app and the particle light scattering, which increased by a factor of up to 6 with increasing total particle size. The modelled optical properties of BC are well aligned with laboratory-measured values when the following assumptions are used in the fractal aggregate representation: mre between 1.6 and 2, mim between 0.50 and 1, Df from 1.7 to 1.9, and app between 10 and 14nm. Overall, this study provides experimental support for emphasizing the importance of an appropriate size representation (polydisperse size method) and an appropriate morphological representation for optical modelling and parameterization scheme development of BC