Στην περιοχή της Ελευσίνας, στη Δυτική Αττική, υπάρχει το Ιερό της Δήμητρας στο οποίο τελούνταν για αιώνες τα Ελευσίνια Μυστήρια. Η ιστορία του Ιερού χρονολογείται ότι ξεκινά ήδη από τους προϊστορικούς χρόνους, τουλάχιστον από τις αρχές της 2ης π.Χ. χιλιετηρίδας και τελειώνει τον 4ο αιώνα μ.Χ. Τα ερείπια του Ναού είδαν το φως σταδιακά μετά τις πρώτες ανασκαφές (1812). Από το 1875 και έπειτα, λόγω της θέσης της, η πόλη μετατράπηκε σε βιομηχανικό κέντρο με πολύ υψηλές τιμές ρύπανσης στο θαλάσσιο και το ατμοσφαιρικό περιβάλλον της περιοχής. Συγκεκριμένα, η ατμοσφαιρική ρύπανση αντανακλάται στα λίθινα στοιχεία του αρχαιολογικού χώρου. Σκοπός της εργασίας είναι να αναγνωρίσει και να καταγράψει τις μορφές διάβρωσης που επικρατούν στο χώρο και να τις συνδέσει με πιθανά αίτια που τις προκάλεσαν. Αρχικά, γίνεται πλήρης περιγραφή των 5 κύριων λιθοτύπων (3 ασβεστόλιθοι και 2 μάρμαρα) που χρησιμοποιήθηκαν στις διάφορες φάσεις ανέγερσης του Ιερού και των χώρων που το περιβάλλουν, μακροσκοπικά και με τη βοήθεια της οπτικής και ηλεκτρονικής μικροσκοπίας. Έτσι, προκύπτει ότι οι κυριότεροι ενδογενείς παράγοντες φθοράς των δομικών λίθων του Ιερού της Δήμητρος είναι το υψηλό πορώδες, η ορυκτολογική σύσταση και κυρίως η παρουσία αργιλικών ορυκτών. Στη συνέχεια, καταγράφονται μακροσκοπικά οι φθορές που έχουν υποστεί οι δομικοί λίθοι του μνημείου με κυριότερη τη δημιουργία τσιμεντιτικών κρουστών σε επίπεδες επιφάνειες. Σημαντικές είναι και οι διάφορες πάτινες βιολογικής και άλλης προέλευσης που αλλοιώνουν χρωματικά τα λίθινα στοιχεία καθώς και οι επιφάνειες με έντονα φαινόμενα κυψέλωσης και γυψοποίησης. Δε λείπουν περιπτώσεις εκλεκτικής διάβρωσης λόγω ορυκτολογικής ετερογένειας. Η μελέτη των διαβρωσιγενών μορφών που οφείλονται σε περιβαλλοντικούς παράγοντες συνεχίζεται μικροσκοπικά όπου παρατηρούνται αλλοιώσεις των επιφανειών βάσει της σύστασης, της μορφολογίας και της μικροδομής. Έτσι, εντοπίζονται αποθέσεις οργανικού υλικού, θραυσμάτων SiC και άλλων βιομηχανικών ρύπων με υψηλή περιεκτικότητα σε βαρέα μέταλλα, αποικίες βακτηρίων και άλλων μικροοργανισμών, πάτινες αργιλοπυριτικής σύστασης, σκληρές τσιμεντιτικές κρούστες, γύψος, οξειδωμένες σιδηρούχες φάσεις, μικροκαρστικά φαινόμενα και τέλος, φερτά αντικείμενα θαλάσσιας και ατμοσφαιρικής προέλευσης. Η ακτινογραφική μελέτη επιβεβαιώνει το φαινόμενο της γυψοποίησης σε σημεία των λίθων που δεν υπάρχει ελεύθερη ροή νερού και διαφοροποιεί τα δείγματα λάσπης ή σκόνης που προέρχονται από κοιλότητες πετρωμάτων που εγκλωβίζουν νερό και αυτά που ελήφθησαν από ωμές πλίνθους ως προς το κυρίαρχο ορυκτό που στην πρώτη περίπτωση είναι ο ασβεστίτης και ακολουθεί ο χαλαζίας, ενώ στη δεύτερη περίπτωση συμβαίνει το αντίστροφο. Η γνώση των λιθοτύπων και των διαβρωσιγενών μορφών αποτελούν κλειδιά για την επιλογή μεθόδων αποκατάστασης των φθορών που συναντώνται στο χώρο της μελέτης. Έτσι, προτείνονται μηχανικές μέθοδοι για σκληρές κρούστες, πάστες και κομπρέσες για αδιάλυτα και διαλυτά άλατα και βιοκτόνα για βιολογικές επικαθίσεις. Για ρωγμές με διάμετρο μικρότερη των 0,2mm απαιτούνται εργασίες στερέωσης και αδιαβροχοποίησης με οργανικά ή ανόργανα υλικά που εφαρμόζονται ανάλογα με το είδος του λίθου. Για μεγαλύτερα ανοίγματα τα κενά συμπληρώνονται με κονίαμα, ενώ τέλος η αισθητική αποκατάσταση περιλαμβάνει τη συγκόλληση τεμαχίων ή απωλεσθέντων κομματιών, ενίοτε με τη χρήση συνδέσμων. / In Eleusis, a town in western Attica, lies the site of the Demeter Sanctuary, the sacred temple where the Mysteries of Eleusis took place in the antiquity. The history of the Sanctuary starts in the beginning of the 2nd millennium B.C. and ends during the 4th century A.C. The first time that some of the ruins came into light was in 1812, the year when the excavations started. Since 1875 the town got industrialized because of its geographical position with very high levels of marine and atmospheric pollution. In particular, atmospheric pollution reflects on the weathered stones of the ruins. This work aims to recognize and record the weathering forms that exist in the Demeter Sanctuary and to connect them with possible causes that engendered them. Primarily, 5 lithotypes (3 limestones and 2 marbles) got described macroscopically and microscopically (optical and electronic microscopy). From that, one can conclude that high pororsity, mineralogical composition and mostly clay minerals are the main intrinsic factors that play an important role in stone weathering. Thereinafter, the weathering forms that are observed macroscopically on the stones of the monument are written down. The most important of those forms is the case of the cementitious crusts in horizontal surfaces. Also important are the different patinas of biological or other origin as well as surfaces with intense phenomena of alveolization and gypsum formation. Preferential deterioration attributed to mineralogical heterogeneity can’t be omitted. The research on the weathering forms is continued microscopically where one can observe alterations due to composition and due to morphology or microstrusture. Thus, we note depositions of organic matter, SiC and other industrial pollutants such as heavy metals, biological activity attributed to bacterial and other microorganisms colonies, patinas rich in Al and Si, hard cementitious crusts, gypsum, oxidized ferrous phases, microcarstic phenomena and specific objects imported from the nearby marine environment or the atmpsphere (shells or rounded particulate matter). The study of the X-ray diffraction results confirms the gypsum formation in places protected against rainfall, and also demarcates the samples that were collected from water enclaving stone cavities and those that were picked from raw plinths, as far as their mineralogical composition is concerned˙ in the first case calcite is the main mineral and quartz follows, while in the second case, quartz is in abundance and calcite happens in a smaller percentage. Recognizing the lithotypes and the weathering forms and combining them, constitutes the key to choose the conservation methods for the treatment of the decay patterns that are encountered in the ruins of the Demeter Sanctuary. Thus, mechanical and chemical methods can be proposed for the hard crusts, different pastes and compresses for soluble and isoluble salts and biocides for biological deposits. Ultimately, consolidation with organic or inorganic material and water repellents applying is proposed for application in cracks with diameter less than 0,2mm, always taking the lithotype into consideration. For larger gaps, the voids are supplemented with mortars.

abstract: Pavement management systems and performance prediction modeling tools are essential for maintaining an efficient and cost effective roadway network. One indicator of pavement performance is the International Roughness Index (IRI), which is a measure of ride quality and also impacts road safety. Many transportation agencies use IRI to allocate annual maintenance and rehabilitation strategies to their road network. The objective of the work in this study was to develop a methodology to evaluate and predict pavement roughness over the pavement service life. Unlike previous studies, a unique aspect of this work was the use of non-linear mathematical function, sigmoidal growth function, to model the IRI data and provide agencies with the information needed for decision making in asset management and funding allocation. The analysis included data from two major databases (case studies): Long Term Pavement Performance (LTPP) and the Minnesota Department of Transportation MnROAD research program. Each case study analyzed periodic IRI measurements, which were used to develop the sigmoidal models. The analysis aimed to demonstrate several concepts; that the LTPP and MnROAD roughness data could be represented using the sigmoidal growth function, that periodic IRI measurements collected for road sections with similar characteristics could be processed to develop an IRI curve representing the pavement deterioration for this group, and that pavement deterioration using historical IRI data can provide insight on traffic loading, material, and climate effects. The results of the two case studies concluded that in general, pavement sections without drainage systems, narrower lanes, higher traffic, or measured in the outermost lane were observed to have more rapid deterioration trends than their counterparts. Overall, this study demonstrated that the sigmoidal growth function is a viable option for roughness deterioration modeling. This research not only to demonstrated how historical roughness can be modeled, but also how the same framework could be applied to other measures of pavement performance which deteriorate in a similar manner, including distress severity, present serviceability rating, and friction loss. These sigmoidal models are regarded to provide better understanding of particular pavement network deterioration, which in turn can provide value in asset management and resource allocation planning. / Dissertation/Thesis / Masters Thesis Civil Engineering 2016

Made available in DSpace on 2014-06-11T19:27:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-06-10Bitstream added on 2014-06-13T20:56:22Z : No. of bitstreams: 1 vittori_j_me_jabo.pdf: 179453 bytes, checksum: ba26e6c54868af1d8a37acaf9f491fe1 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Visando suplementar ruminantes no período seco, a cana-de-açúcar nos últimos anos tem sido bastante pesquisada e empregada como volumoso alternativo, principalmente na forma de silagem. Na ensilagem desta forrageira, principalmente quando utilizada após queima do canavial, ocorre uma alta atividade de leveduras epífitas que convertem os carboidratos solúveis da forragem em etanol, gás carbônico e água, levando a elevadas perdas de matéria seca, aumento no teor de fibra em detergente neutro e diminuição de consumo. Buscando amenizar esses problemas temse pesquisado inoculantes bacterianos compostos por bactérias ácido-produtoras, tais como o Lactobacillus buchneri. Sendo assim, objetivando avaliar os efeitos antimicrobianos e químicos na silagem de cana-de-açúcar queimada e inoculada com Lactobacillus buchneri, quatro silos de superfície foram analisados por meio dos seguintes tratamentos: cana-de-açúcar crua sem aditivo; cana-de-açúcar crua inoculada com L. buchneri; cana-de-açúcar queimada sem aditivo e cana-de-açúcar queimada e inoculada com L. buchneri. As amostragens foram efetuadas após 0, 21, 49, 77 e 105 dias de utilização dos silos, sendo retiradas do centro e superfície do painel. Houve redução na população de leveduras e fungos filamentosos nas silagens inoculadas e aumento nas queimadas. Constatou-se maior população de microrganismos na camada superficial, além de maiores valores de pH e nitrogênio amoniacal. Ocorreram menores perdas de matéria seca na silagem de cana-de-açúcar queimada e inoculada em relação ao seu controle. As silagens apresentaram os fungos filamentosos Aspergillus, Penicillium, Trichoderma, Rhizopus e Neurospora após abertura, verificando-se redução na frequência dos mesmos ao longo do período. O inoculante exerceu um efeito redutor na população de leveduras e na perda de MS sendo esse efeito potencializado pela... / In order to supplement ruminants’s diets in dry period, sugarcane in the last years has been researched and processed as silage to used as an alternative food. In this ensilage process, mainly after sugar cane plantation have been set on fire, occurs a high activity of yeasts that convert the soluble carbohydrates of the forage in ethanol, carbon dioxide and water, leading to dry matter losses, increase in fiber content and decrease in the intake. In a way to solve those problems bacterial inoculants produced with acid-producers bacteria’s, such as Lactobacillus buchneri, have been researched. Considering this the aim of the present study was to evaluate the microbiological and chemical effects on burned sugarcane silage when inoculated with Lactobacillus buchneri. Four silos type surface were analyzed using the following treatments: sugarcane without additives; sugarcane inoculated with L. buchneri; burned sugarcane without additives; and burned sugarcane inoculated with L. buchneri. The samples were taken after 0, 21, 49, 77 and 105 days after opening the silos and they were taken from the center and the surface of the panel. There was a reduction in the population of yeasts and filamentous fungi in inoculated silages and an increase of them in burned silages. There was a greater population of microorganisms in the superficial layer, in addition to higher pH values and ammoniacal nitrogen. The burned silage inoculated with L. buchneri showed the least amount of losses of dry matter in comparison to the control sample. The fungi Aspergillus, Penicillium, Trichoderma, Rhizopus and Neospora were found in the silages after opening the silos and the frequency of these microorganisms decreased with the passing of time. The inoculating had an reduccing effect in the yeast's population and in the loss of DM, and this effect was enhanced by the burn of the sugarcane... (Complete abstract click electronic access below)

Governments and municipalities in the developing world face the challenge of rapid environmental deterioration in the growing informal settlements along the urban fringes. Waste management, its efficiency, or lack thereof, is becoming an increasingly urgent issue. In this thesis, Winterveld, located approx. 50 km north of Pretoria, is studied as a typical example of the problems and bottlenecks related to solid domestic waste management in a mixed urban fringe settlement. While the formal parts of Winterveld receive waste removal services, the – much larger - informal parts are not being provided with such services. A wide range of methodologies was employed to assess the current status of waste management and related environmental problems. Policies and actual service delivery by the City of Tshwane, responsible for providing waste removal service to the area, were investigated; surveys were conducted among waste removal contractors in and around Winterveld, and the residents from both formal and informal settlements. Field surveys were conducted to identify environmental problems on site, dumping sites and their change over time were mapped and digitized on orthophotos. Vegetation surveys complemented the fieldwork, as illegal dumping sites often are masked by vegetation. The following aspects were investigated: 1) the efficiency of governmental and municipal efforts regarding waste removal in informal Winterveld; 2) environmental and health problems caused by improper handling of waste; 3) the residents' attitudes towards waste management; 4) possible solutions to the problems. The findings revealed that Winterveld is not an exception from other informal settlements with regards to waste management. People are of the opinion that waste management is the sole responsibility of the government thus the residents are doing little to improve their own area. Government initiatives which include provision of facilities for waste management are misused and vandalised by the residents. Dumping along the roads, according to some residents is used as a call to the government to attract attention that the residents need removal services. The initiatives by the municipality should ensure that solid waste management facilities are socially acceptable and environmentally and economically sound. It is therefore very important to involve the community when investigate technologies that will benefit the economy and the environment maximally. Informing people may encourage them to change their negative attitudes by making them feel as an important part of waste management, this will eventually compel them to cooperate and play a positive role in waste management. Until such time that they change their attitudes, there is little hope that they will appreciate and protect the facilities provided. / Dissertation (MSc)--University of Pretoria, 2007. / Geography, Geoinformatics and Meteorology / MSc / Unrestricted

Mole-rats from the family Bathyergidae are endemic to Africa, this family exhibits a continuum of sociality, comprising both solitary and social species. Sociality is related to the degree of aridity and the distribution of the underground food resource. All the members of the bathyergid family are strictly subterranean, and occur in a niche which is devoid of light cues and thermally buffered from ambient and surface extremes. Since vision is redundant in a lightless environment, mole-rats have subsequently undergone ocular regression over evolutionary time. As a consequence of the minute eyes, the visual system of mole rats is severely regressed and, in addition, the proportional retinal innervation to different structures is modified. The classical visual system is reduced while the circadian system is expanded. Retinal projection studies on the giant Zambian mole-rat, Cryptomys mechowi and an albino highveld mole-rat, Cryptomys hottentotus pretoriae, confirmed sparse contralateral retinal projections to structures of the visual system, while the circadian system received relatively dense bilateral innervation. The innervation pattern of an albino Damaraland mole-rat, Cryptomys damarensis differed from the other animals. Investigations of Fos expression in neurons over circadian time suggested that the phase response curve of the solitary mole rat, Georychus capensis, resembles that of aboveground mammals whereas the social Cryptomys hottentotus pretoriae, does not display differential sensitivity to light in the subjective day and night. The influence of increasing light intensities showed that higher light intensities elicit a more pronounced Fos expression in SCN of all the species investigated. In addition, longer light pulses also increases the Fos induction in the SCN. A preliminary investigation into the effect of temperature on the Fos induction in the SCN of three mole-rat species, demonstrated that a higher Fos response could be expected with higher ambient temperatures. However the sample size was very small, and could have influenced the outcome of the experiment. Behavioural locomotor activity rhythms of the solitary species, Georychus capensis, and the social species Cryptomys hottentotus pretoriae and Cryptomys damarensis, confirmed that activity patterns correlate with trends displayed in Fos expression. The solitary species exhibited much more defined rhythmicity than the social species and a higher percentage of the animals displayed distinct endogenous rhythms. African mole rats provide an interesting model to study not only the features of the circadian system in a group of animals with a naturally regressed visual system, but also the influence of sociality on the degree of regression. / Dissertation (MSc (Zoology))--University of Pretoria, 2005. / Zoology and Entomology / unrestricted

No description available.

Reinforcement corrosion is the most common deterioration problem observed in reinforced concrete (RC) structures located at coastal or cold regions. The corrosion process can impact the performance of these structures by inducing damage on the bonding action between concrete and steel, either by the splitting of the concrete cover due to the volumetric expansion of corrosion products or the lubricant effect at the steel/concrete interface as the corrosion by-products accumulate. The current research aims at investigating corrosion-induced deterioration of bond between steel and concrete through finite element (FE) analysis of the flexural behaviour of corroded RC components. By treating the concrete cover as a thick-wall cylinder subjected to internal pressure, the analytical evaluation of impaired bond capacity is studied first and verified against published bonding tests. Then, the formulation of a numerical model is performed using ABAQUS, wherein a link element to simulate the bond behaviour is formulated and implemented through the ABAQUS user-subroutine (UEL) feature according to the validated analytical model. By introducing corrosion-induced damages, i.e., smaller cross-sectional area of reinforcement, splitting of concrete and bond deterioration, in the FE analyses, the results of the numerical model show good agreement with experimental observations. Upon validation of the analytical and FE models, a parametric investigation is conducted, wherein the effects of concrete strength, dimension of reinforcing bars, properties of oxide products, different corrosion damage mechanisms and the corrosion location along the longitudinal reinforcement on the flexural behaviour of RC beams are studied. The results show that the analytical evaluation for bond degradation is impacted by the selection of the post-cracking material model and the thickness of cover that determine the ‘holding capacity’ after cracking initiation. Also, the density of rust by-products affects the results of the analytical model at high corrosion levels. From the FE model results, it was observed that each damage mechanism due to corrosion contribute to different levels of flexural degradation, although the flexural strength degradation is mainly due to the loss of bonding action. The parametric study also demonstrates that flexural members which have reinforcement corrosion initiated near the supports suffer greater deterioration in flexural capacity than those with damages at mid span. Finally, based on these observations, suggestions for the application of both analytical and numerical models are made.

BACKGROUND: Late identification of deteriorating children undermines timely implementation of life-saving measures to prevent cardiopulmonary arrest (CPA) or death. The Pediatric Early Warning System (PEWS) has been validated for use in pediatric acute care settings for early identification of children at increased risk of physiologic deterioration, yet there is a dearth of evidence of the use of PEWS in primary care. Implementing the PEWS in primary care could guide rural primary care practitioners to early detection and prompt management of deteriorating children. This DNP project evaluated the attitudes and perceptions of rural practitioners towards the implementation of the PEWS scoring tool. METHODS: A cross-sectional descriptive design was conducted using an anonymous online survey via an email listserv. RESULTS: Seventeen practitioners responded to the survey, but only 14 participants met criteria for inclusion – 2 males and 11 females. The sex of one participant was not reported. Participants areas of specialization include 79% specialized in family practice, 79% pediatric specialists 14% and (7%) listed as "Other." Thirty-one percent of participants reported a travel distance of over 60 miles, while 39% reported a travel distance of over 60 miles lasting over 60 minutes via ground from a place of care to a hospital that specializes in the pediatric emergency care, and pediatric care respectively. Although 92% reported they have not heard of the PEWS tool prior to this survey, 54% strongly agree that the PEWS could help prevent cardiopulmonary arrest or death. Similarly, 54% of respondents reported they strongly agree that the PEWS can help identify deteriorating children, while 39% somewhat agree. Over 62% strongly agree that implementing the PEWS is appropriate in primary care, while 31% somewhat agree. Fifty-four percent of participants strongly agree they could use the PEWS tool in their practice. DISCUSSION: Participants have a positive view of the PEWS tool and perceive implementation of the PEWS to be a vital clinical decision support tool that could lead pediatric primary care providers to early detection of deteriorating children before the occurrence of an adverse event. Further study could determine the generalizability of implementing the PEWS in primary care.

O presente trabalho tem como objetivo quantificar estatisticamente a ocorrência de falhas geradas pelos erros de projeto e execução das construções. Para isso, elaborou-se um checklist que se subdividiu em duas partes: a primeira contendo informações desde a concepção à geração de um edifício e a segunda para verificação da estrutura \"in loco\" em edifícios habitacionais em construção na cidade de São Carlos. Quantificou-se as incidências patológicas observadas por elemento estrutural e finalmente se traçou um panorama da atual realidade dos edifícios sob a ponto de vista das patologias geradas pela falta de controle de qualidade nas construções. Através dos dados obtidos pôde-se verificar a existência de várias patologias, destacando-se a segregação do concreto de pilares e paredes, cobrimento inadequado do concreto em vigas e problemas advindos da falta de estanqueidade de fôrmas em lajes. / The goal of this work is the quantify statistically the occurrance of failure generated by carelessness with the project and execution of the constructions. A check-list was proposed was subdivided in two parts: the first with information since the conception to generation of a building and the second by the verification of the building structure \"in loco\" in São Carlos town. It was quantified the pathological incidences observed by structural element and finally it was designed a panorama of the actual reality of the buildings under the view of the pathologies generated by the lack of control and quality in the constructions. Through the obtained data it could be verified the existence of several patologies, highlighting the segregation of concrete in pillars and walls, inadequate covering of concrete in beams and problems from the lack of stanching of moulds in flagstone.

No description available.