2,847 research outputs found
Rapa Nui (Easter Island)’s Stone Worlds
No full textThis article explores the spatial, architectural and conceptual relationships between landscape places, stone quarrying, and stone moving and building during Rapa Nui’s statue-building period. These are central themes of the ‘Rapa Nui Landscapes of Construction Project’ and are discussed using aspects of the findings of our recent fieldwork. The different scales of expression, from the detail of the domestic sphere to the monumental working of quarries, are considered. It is suggested that the impressiveness of Rapa Nui’s stone architecture is its conceptual coherence at the small scale as much as at the large scale. </div
The influence of flow acceleration on stone stability
No full textThe stability of a bed of stones subject to a flow is often described in terms of a critical velocity or shear stress generated by the flow. These classical design methods like for example Shields, do not take the influence of flow acceleration into account. In experiments and practice, it appeared that when a flow is accelerated, stones start to move at a point where the so-called critical velocity is not reached yet. The movement of stones must have a second cause beside the velocity of flow. Only a little information is known on the influence of flow acceleration on stone stability of the bed. The objective of this thesis is to obtain more insight into the influence of acceleration of flow on the stability of stones. By carrying out experiments in a flume containing a local contraction, the stone stability in an accelerated flow is investigated. In the contraction the stability of two different stone sizes, subject to different velocity-acceleration combinations, is analysed. If the hypothesis is correct, than for some velocity-acceleration combinations movement occurs while for the same velocity combined with a lower acceleration no movement occurs. The shear stress occurring in the accelerated flow is determined using the shear velocity. According to the classical Shields method the shear velocity is responsible for the movement of the stones. Movement is detected for lower shear velocities then expected. According to the hypothesis this is a result of the extra generated force on the stones due to acceleration. After analysing the data it appeared that combinations of the same velocity and different accelerations showed differences in movement. The amount of movement goes up for an increase in acceleration combined with a constant or slightly decreasing velocity. This proves that there is a relation between the stability of the stones and a combination of the velocity and acceleration generated forces. The Morison equation is used to describe the relation between the forces acting on a stone. It combines the force generated by acceleration and the force generated by the peak velocities due to turbulence, as the sum of both forces. The extra force due to acceleration appeared to be of the same order as the force due to the velocity. Therefore, when looking at the stone stability in an accelerated flow, it is important to take the force generated by the acceleration into account. The resulting Morison force acting on a stone is proved to be responsible for the stability of the stones. Finally, a unique relation, valid for both stone diameters, between the force acting on the stone and the entrainment is found. This power relation consists of a dimensionless Morison-Shields parameter representing the force on a stone and a dimensionless entrainment parameter. The relation does not depend on stone size and is therefore expected to be universal in use.Civil Engineering and Geoscience
Scrivere di pietra | Writing about stone
No full textIl lavoro è uno degli 8 capitoli, dei quali 5 dell’autore, risultato di un’attività di ricerca commissionata dal Consorzio Produttori Pietra Piasentina di Torreano (Ud), responsabile scientifico il prof. Mauro Bertagnin. In questo caso viene fornita una bibliografia ragionata, che si auspica esaustiva, sulla pietra piasentina, brecciola calcarea eocenica usata in tutta l’area del Friuli orientale, partendo dai primi studi geologici di fine ‘800 e arrivare ai contributi più recenti, di carattere tanto geologico-tecnico che storico-etnografico. | This work is one of eight chapters, including five by the author, resulting from research commissioned by the Consortium of Producers of Piasentina Stone in Torreano (Ud), directed by prof. Mauro Bertagnin. This chapter contains an annotated bibliography, meant to be exhaustive, on Piasentina stone, the Eocene breccia used throughout the area of eastern Friuli, beginning with the early geological studies of the late 1800s and concluding with the most recent contributions, be they of a geological or historical and ethnographic nature
Tacit knowledge, learning and expertise in dry stone walling
No full textThis is a detailed study of learning in the context of dry stone walling. It examines
what happens in the learning situation. The aim of this work was:
'To understand the nature of expertise in dry stone walling, how it is understood
by those practising the craft, and how it is transmitted to others'.
The main research questions were, therefore:
What happens when dry stone wallers are learning their craft?
How do they acquire expertise in dry stone walling?
How is this learning communicated?
This process necessitated developing a way of engaging with the practitioners,
eliciting descriptive data about what they were doing, and why they were doing it,
through interviews (or conversations) with both individuals and groups, whilst
they practiced their skill. Twenty three wailers were interviewed as they worked,
building walls.
The material obtained was analysed under seven different themes:
'Knowing how'
The use of tacit knowledge or intuition
'Flow'
Constant decision making, reflection and learning from mistakes
Individual and subjective variations and experiences
The relevance of emotion
The use of 'rules of thumb' or maxims.
Learning walling does not fit simply into any of the seven themes. It is
contextualised, complex and individual. It demonstrates tacit knowledge and
intuition. It involves emotion, sometimes consciously, sometimes not. It involves
memory, problem solving, and learning from mistakes, and reflection. Maxims or
'rules of thumb' were a key element in the learning process at all stages. Linear
stages of learning were not evidenced. Deep understanding of the practice is
evidenced, and the wider learning and teaching implications are explored
Description of a new mutation in rhodopsin, Pro23Ala, and comparison with electroretinographic and clinical characteristics of the Pro23His mutation
No full textOBJECTIVES: To report the clinical characteristics of a family with autosomal dominant retinitis pigmentosa caused by a proline-to-alanine mutation at codon 23 (Pro23Ala) of the rhodopsin gene and to compare this phenotype with that associated with the more common proline-to-histidine mutation at codon 23 (Pro23His).METHODS: We examined 6 patients within a single pedigree. The electroretinograms (ERGs) of 35 patients with known Pro23His mutations and of 22 healthy individuals were reviewed. Scotopic dim flash-response amplitudes, maximum combined-response amplitudes, and photopic-response amplitudes from the ERGs of these patients were plotted against age. The ERG indices of 5 individuals in the Pro23Ala family were compared with those of the patients with Pro23His mutations and of healthy individuals. Multiple linear regression was performed to evaluate the effect of age and mutation type on amplitudes. Mutation detection was performed using single-strand conformation polymorphism analysis, followed by automated DNA sequencing.RESULTS: Patients with the Pro23Ala mutation have a clinical phenotype characterized by onset of symptoms in the second to fourth decades of life, loss of superior visual field with relatively well-preserved inferior fields, and mild nyctalopia. Comparison with patients with the Pro23His mutation demonstrates statistically significant differences (P<.001) in responses to dim flash, maximum combined, and photopic responses between patients with these mutations after controlling for the effects of age. Patients with Pro23Ala mutations were less affected by ERG criteria than patients with Pro23His mutations. Patients with Pro23Ala mutations also differed significantly from healthy patients in all ERG indices examined (P<.001), after controlling for age.CONCLUSION: We describe a rare mutation in codon 23 of rhodopsin causing autosomal dominant retinitis pigmentosa. The retinal dystrophy associated with the Pro23Ala mutation is characteristically mild in presentation and course, with greater preservation of ERG amplitudes than the more prevalent Pro23His mutation<br/
Life cycle assessment of stone buildings in the Taihang mountains of Hebei province: Evolution towards cleaner production and operation
No full textThe building sector has gained significant attention due to its remarkably high energy consumption and greenhouse gas emissions. In China's rural areas, stone is a popular building material, but there are unprecedented demands to improve the life-cycle performance of stone buildings. It is essential to preserve the original architectural features while evolving towards a cleaner production and operation. This study implements a field survey in the Taihang Mountains of Hebei province. The improvement of stone extraction methods and the evolution of three stone wall styles are collected and developed. Thermal transmittances of three stone walls are measured and modeled. A cradle-to-grave life cycle assessment is conducted, and the results are compared to show their environmental performance in the embodiment and operation phases. Their life cycle inventories, including stone extraction, are developed. One representative building style sample is developed for the cooling and heating energy requirement simulation in the DesignBuilder. Based on the inventories, conducting life cycle impact assessment shows various environmental profiles in their whole life cycles. From the outcomes, the stone cladding wall (SCW) outperforms the other stone walls in both the embodiment and operation phases. However, its relatively high cost is a challenge for an individual house owner. This study proves the SCW is more sustainable, providing a basis for the choice of stone wall style in the future construction.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.Architectural Technolog
Relationship between Urolithiasis and Nutrition in Patients with Urinary Stones in Ardabil City
No full textBackground & Objectives: Urolithiasis is the third common urinary disease. While,
relationship between the urinary stones and diet is known to some extent, but there are
controversies about it. The aim of this study was to determine the association between food
habit, nutrients intake and kinds of urinary stone disease.
Methods: This cross-sectional and descriptive analytical study was performed on 150 patients
(91 male and 59 females) with urinary stone disease in Ardabil during 2008-2009. Data of
urinary stones analysis, type of stone in the graph, type of stone, preventive emprise and type
of drinking water were recorded. Food data were recorded using 24-hour dietary recalls three
days in week and food frequency questionnaires. Data were analyzed using SPSS, Food
Processor III software, and ANOVA Statistical program.
Results: Findings showed that the most common and lowest form of urinary stone disease in
men and women were calcium oxalate and ammonium phosphate, respectively. There was
significant inverse association between beta-carotene intake and the percentage of uric acid
stone disease (p<0.05). We observed significant relationship between vitamin A and folacin
intake with percentage of uric acid stone disease (p<0.05). There was significant relationship
between consumption of cheese and pickles with calcium phosphate stone disease (p<0.05).
There was no significant association between other foods and nutrients intake with types of
urinary stone disease.
Conclusion: This study showed the consumption of some nutrients including folacin, vitamin
A and some foods such as cheese was associated with the incidence of urinary stone disease.
Therefore, taking accurate diet could possibly prevent the incidence of urinary stone diseases
Allelic variation in ABCR associated with Stargardt disease but not age-related macular degeneration
No full text"Where now the harp?" Listening for the sounds of Old English verse, from Beowulf to the twentieth century
No full textAdditional multimedia to accompany this article is available from http://journal.oraltradition.org/issues/24ii/jonesThis essay examines the representation or staging of oral performance and poetic composition within Beowulf, in order to argue that poem thematizes and mythologizes its own origins, and is as much interested in recovering the sounds of oral performances that pre-date its own manuscript inscription as modern Anglo-Saxon scholarship has been. The second half of the essay considers the recovery and reimagining of an Anglo-Saxon “soundscape” in the work of two twentieth-century poets, W. S. Graham and Edwin Morgan. The invocation of this “Saxonesque” patterning of sound invokes or triggers a historically constituted set of associations with the whole body of Old English poetry; that is, an allusion to a corpus, rather than to a specific text, is made through sound patterning.Peer reviewe
Correction to: Ceftaroline Fosamil for Treatment of Pediatric Complicated Skin and Soft Tissue Infections and Community-Acquired Pneumonia (Pediatric Drugs, (2021), 23, 6, (549-563), 10.1007/s40272-021-00468-w)
No full textThe article “Ceftaroline Fosamil for Treatment of Pediatric Complicated Skin and Soft Tissue Infections and Community-Acquired Pneumonia”, written by Susanna Esposito,Timothy J, Carrothers ,Todd Riccobene , Gregory G. Stone and Michal Kantecki was originally published electronically on the publisher’s internet portal on 31st August 2021 without open access. With the author(s)’ decision to opt for Open Choice the copyright of the article changed on 20th September 2021 to © The Author(s) 2021 and the article is forthwith distributed under a Creative Commons Attribution-Noncommercial 4.0 International License, which permits any non-commercial 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 license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license 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 license, visit http://creativecommons.org/licenses/by-nc/4.0/. The original article has been corrected
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