923 resultados para Calcarenite stone


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The San Julián’s stone is the main material used to build the most important historical buildings in Alicante city (Spain). This paper describes the analysis developed to obtain the relationship between the static and the dynamic modulus of this sedimentary rock heated at different temperatures. The rock specimens have been subjected to heating processes at different temperatures to produce different levels of weathering on 24 specimens. The static and dynamic modulus has been measured for every specimen by means of the ISRM standard and ultrasonic tests, respectively. Finally, two analytic formulas are proposed for the relationship between the static and the dynamic modulus for this stone. The results have been compared with some relationships proposed by different researchers for other types of rock. The expressions presented in this paper can be useful for the analysis, using non-destructive techniques, of the integrity level of historical constructions built with San Julián’s stone affected by fires.

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This research in Cordoba's mosque tower main objective was to analyze and characterize the foundations and the underlying soil, calculating the stability of the monument as well as the settlement and deformations performed, using traditional calculation methods and also by finite elements, and to determine differences between both, as well as the stability factor of the Minaret Tower. The works done to study the soil, were drill bores and dynamic penetration tests, classification of samples by size, Atterberg limits, physical and chemical analysis, showing the typical geotechnical composition of the Guadalquivir valley: an alluvial material composed by sand, gravels and silt clays. To study the foundations, inclined bore samples were extracted with 10-65º, showing calcarenite stone ashlars and lime concrete alternating with stone and brick masonry.

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This work discusses the results from tests which were performed in order to study the effect of high temperatures in the physical and mechanical properties of a calcarenite (San Julian's stone). Samples, previously heated at different temperatures (from 105 °C to 600 °C), were tested. Non-destructive tests (porosity and ultrasonic wave propagation) and destructive tests (uniaxial compressive strength and slake durability test) were performed over available samples. Furthermore, the tests were carried out under different conditions (i.e. air-cooled and water-cooled) in order to study the effect of the fire off method. The results show that uniaxial compressive strength and elastic parameters (i.e. elastic modulus and Poisson's ratio), decrease as the temperature increases for the tested range of temperatures. A reduction of the uniaxial compressive strength up to 35% and 50% is observed in air-cooled and water-cooled samples respectively when the samples are heated to 600 °C. Regarding the Young's modulus, a fall over 75% and 78% in air-cooled and water-cooled samples respectively is observed. Poisson's ratio also declines up to 44% and 68% with the temperature in air-cooled and water-cooled samples respectively. Slake durability index also exhibits a reduction with temperature. Other physical properties, closely related with the mechanical properties of the stone, are porosity, attenuation and propagation velocity of ultrasonic waves in the material. All exhibit considerable changes with temperature.

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Informed by Kristeva's formulation of affect and Winnicott's Holding Environment, this practice-led visual art project is an exploration into how sensitivity to the physical sensation of trembling can sustain a creative practice. Building upon this is a further enquiry into what the significance of the affective experience of trembling is for an ethics of affect in contemporary art. I have done this through object and video-based installations informed by my own experience of trembling. This has been further informed by the work of artists like Louise Bourgeois, Dennis Del Favero and Willie Doherty. The creative outcomes contribute to the discourse around ethical responses to affect by extending and developing on the works of these artists.

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1 Five experiments were conducted during 1995-99 in stone fruit orchards on the Central Coast and in inland New South Wales, Australia, on the use of synthetic aggregation pheromones and a coattractant to suppress populations of the ripening fruit pests Carpophilus spp. (Coleoptera: Nitidulidae). 2 Perimeter-based suppression traps baited with pheromone and coattractant placed at 3m intervals around small fruit blocks, caught large numbers of Carpophilus spp. Very small populations of Carpophilus spp. occurred within blocks, and fruit damage was minimal. 3 Carpophilus spp. populations in stone fruit blocks 15-370m from suppression traps were also small and non-damaging, indicating a large zone of pheromone attractivity. 4 Pheromone/coattractant-baited suppression traps appeared to divert Carpophilus spp. from nearby (130 m) ripening stone fruit. Ten metal drums containing decomposing fruit, baited with pheromone and treated with insecticide, attracted Carpophilus spp. and appeared to reduce populations and damage to ripening fruit at distances of 200-500 m. Populations and damage were significantly greater within 200m of the drums and may have been caused by ineffective poisoning or poor quality/overcrowding of fruit resources in the drums. 5 Suppression of Carpophilus spp. populations using synthetic aggregation pheromones and a coattractant appears to be a realistic management option in stone fruit orchards. Pheromone-mediated diversion of beetle populations from ripening fruit may be more practical than perimeter trapping, but more research is needed on the effective range of Carpophilus pheromones and the relative merits of trapping compared to attraction to insecticide-treated areas.

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Traps baited with synthetic aggregation pheromones of Carpophilus hemipterus (L.), Carpophilus mutilatus Erichson and Carpophilus davidsoni Dobson and fermenting bread dough were used to identify the fauna and monitor the seasonal abundance of Carpophilus spp. in insecticide treated peach and nectarine orchards in the Gosford area of coastal New South Wales. In four orchards 67 178 beetles were trapped during 1994–1995, with C. davidsoni (82%) and Carpophilus gaveni (Dobson) (12.2%) dominating catches. Five species (C. hemipterus, C. mutilatus, Carpophilus marginellus Motschulsky, Carpophilus humeralis (F.) and an unidentified species) each accounted for 0.2–3.2% of trapped beetles. Carpophilus davidsoni was most abundant during late September–early October but numbers declined rapidly during October, usually before insecticides were applied. Spring populations of Carpophilus spp. were very large in 1994–1995 (1843–2588 per trap per week). However, despite a preharvest population decline of approximately 95% and 2–11 applications of insecticide, 14–545 beetles per trap per week (above the arbitrary fruit damage threshold of 10 beetles per trap per week) were recorded during the harvest period and fruit damage occurred at three of the four orchards. Lower preharvest populations in 1995–1996 (< 600 per trap per week) and up to six applications of insecticide resulted in < 10 beetles per trap per week during most of the harvest period and minimal or no fruit damage. The implications of these results for the integrated management of Carpophilus spp. in coastal and inland areas of southeastern Australia are discussed.

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Traps baited with synthetic aggregation pheromone and fermenting bread dough were used to monitor seasonal incidence and abundance of the ripening fruit pests, Carpophilus hemipterus (L.), C. mutilatus Erichson and C. davidsoni Dobson in stone fruit orchards in the Leeton district of southern New South Wales during five seasons (1991-96). Adult beetles were trapped from September-May, but abundance varied considerably between years with the amount of rainfall in December-January having a major influence on population size and damage potential during the canning peach harvest (late February-March). Below average rainfall in December-January was associated with mean trap catches of < 10 beetles/trap/week in low dose pheromone traps during the harvest period in 1991/92 and 1993/94 and no reported damage to ripening fruit. Rainfall in December-January 1992/93 was more than double the average and mean trap catches ranged from 8-27 beetles/week during the harvest period with substantial damage to the peach crop. December-January rainfall was also above average in 1994/95 and 1995/96 and means of 50-300 beetles/trap/week were recorded in high dose pheromone traps during harvest periods. Carpophilus spp. caused economic damage to peach crops in both seasons. These data indicate that it may be possible to predict the likelihood of Carpophilus beetle damage to ripening stone fruit in inland areas of southern Australia, by routine pheromone-based monitoring of beetle populations and summer temperatures and rainfall.

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The prominent roles of birds, often mentioned in historical sources, are not well reflected in archaeological research. Absence or scarcity of bird bones in archaeological assemblages has been often seen as indication of a minor role of birds in the prehistoric economy or ideology, or explained by taphonomic loss. Few studies exist where birds form the basis for extensive archaeological interpretation. In this doctoral dissertation bird bone material from various Stone Age sites in the Baltic Sea region is investigated. The study period is approximately 7000-3400 BP, comprising mainly Neolithic cultures. The settlement material comes from Finland, Åland, Gotland, Saaremaa and Hiiumaa. Osteological materials are used for studying the economic and cultural importance of birds, fowling methods and principal fowling seasons. The bones were identified and earlier identifications partially checked with help of a reference material of modern skeletons. Fracture analysis was used in order to study the deposition history of bones at Ajvide settlement site. Birds in burials at two large cemeteries, Ajvide on Gotland and Zvejnieki in northern Latvia were investigated in order to study the roles of birds in burial practices. My study reveals that the economic importance of birds is at least seasonally often more prominent than usually thought, and varies greatly in different areas. Fowling has been most important in coastal areas, and especially during the breeding season. Waterbirds and grouse species were generally the most important groups in Finnish Stone Age economy. The identified species composition shows much resemblance to contemporary hunting with species such as the mallard and capercaillie commonly found. Burial materials and additional archaeological evidence from Gotland, Latvia and some other parts of northern Europe indicate that birds –e.g., jay, whooper swan, ducks – have been socially and ideologically important for the studied groups (indicating a place in the belief system, e.g. clan totemism). The burial finds indicate that some common ideas about waterbirds (perhaps as messengers or spirit helpers) might have existed in the northern European Stone Age.

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Since 1997 the Finnish Jabal Haroun Project (FJHP) has studied the ruins of the monastery and pilgrimage complex (Gr. oikos) of Aaron located on a plateau of the Mountain of Prophet Aaron, Jabal an-Nabi Harûn, ca. 5 km to the south-west of the UNESCO World Heritage site of Petra in Jordan. The state of conservation and the damaging processes affecting the stone structures of the site are studied in this M.A. thesis. The chapel was chosen as an example, as it represents the phasing and building materials of the entire site. The aim of this work is to act as a preliminary study with regards to the planning of long-term conservation at the site. The research is empirical in nature. The condition of the stones in the chapel walls was mapped using the Illustrated Glossary on Stone Deterioration, by the ICOMOS International Scientific Committee for Stone. This glossary combines several standards and systems of damage mapping used in the field. Climatic conditions (temperature and RH %) were monitored for one year (9/2005-8/2006) using a HOBO Microstation datalogger. The measurements were compared with contemporary measurements from the nearest weather station in Wadi Musa. Salts in the stones were studied by taking samples from the stone surfaces by scraping and with the “Paper Pulp”-method; with a poultice of wet cellulose fiber (Arbocel BC1000) and analyzing what main types of salts were to be found in the samples. The climatic conditions on the mountain were expected to be rapidly changing and to differ clearly from conditions in the neighboring areas. The rapid changes were confirmed, but the values did not differ as much as expected from those nearby: the 12 months monitored had average temperatures and were somewhat drier than average. Earlier research in the area has shown that the geological properties of the stone material influence its deterioration. The damage mapping showed clearly, that salts are also a major reason for stone weathering. The salt samples contained several salt combinations, whose behavior in the extremely unstable climatic conditions is difficult to predict. Detailed mapping and regular monitoring of especially the structures, that are going remain exposed, is recommended in this work.

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Tutkielmassa käsitellään kiviesineiden käytön jatkumista kivikauden jälkeen Itä-Afrikassa. Rautakauden alku Itä- ja Etelä-Afrikassa liitetään perinteisesti bantuheimojen migraatioon näille alueille. Tämä vallitseva teoria otettiin tässä tutkimuksessa lähtökohdaksi. Afrikasta tunnetaan runsaasti sekä etnografisia että arkeologisia esimerkkejä kiviteknologian säilymisestä paikoin 1900-luvun loppupuolelle. Nämä liittyvät usein perimätiedon perusteella "kivikautisten" metsästäjä-keräilijöiden ja rautakautisten maanviljelijä- ja karjanhoitajayhteisöjen rinnakkaiseloon. Tutkimuskysymystä lähestytään sekä julkaistun että primääriaineiston kautta. Alussa esitellään kirjallisuudesta löytyviä esimerkkejä myöhäisestä kiviesineiden käytöstä, minkä jälkeen käydään tarkemmin läpi Malawin alueelta julkaistu aiheeseen liitettävissä oleva arkeologinen aineisto. Tätä käytetään vertailuaineistona tutkimuksen pääasiallista tapaustutkimusta käsiteltäessä. Pääasiallisena tapaustutkimuksena toimii Viktoria-järven läheisyydessä sijaitsevan Wadh Lang'o:n asuinpaikan kiviesineistön analyysi. Wadh Lang'o:sta tunnetaan pitkä kulttuurisekvenssi, joka kattaa alueen myöhäiskivikautiset ja rautakautiset kulttuurivaiheet. Stratigrafisen aineiston perusteella kiviesineet ovat säilyneet asuinpaikalla käytössä ainakin keskisen rautakauden alkuun. Varhaisimmassa vaiheessa asuinpaikkaa on asuttanut Oltome-kulttuuriin kuuluva väestö. Suurimmat muutokset materiaalisessa kulttuurissa analyysin kattamana aikana ovat aiheutuneet seuraavan kulttuurivaiheen, Elmenteitan-kulttuurin, myötä. Kiviesineistön perusteella Elmenteitan-keramiikan ilmaantuminen asuinpaikalle on liitettävissä idästäpäin Itä-Afrikan hautavajoaman suunnalta tapahtuneeseen migraatioon. Jatkuvuuden puolesta puhuvat esimerkiksi tehdyt kiviraaka-aine valinnat. Vaikuttaa, että edeltänyt Oltome-keraaminen väestö on säilyttänyt vaikutuksensa asuinpaikalla vielä tänäkin aikana. Varhaisrautakautisen Urewe-keramiikan ilmestymiseen asuinpaikalle ei näyttäisi olevan liitettävissä mitään suurisuuntaista migraatiota, toisin kuin vallalla oleva teoria bantumigraatiosta antaisi olettaa. Mahdollisesti uusi keramiikka on omaksuttu spesialistien, esimerkiksi seppien, muuton myötä tai vaeltavien kauppiaiden vaikutuksesta. Kiviesineistö osoittaa jatkuvuutta esimerkiksi mikroliittien morfologisten piirteiden ja käytettyjen raaka-aineiden perusteella. Mahdollisesti Elmenteitan-kulttuurin karjanhoitoa harjoittanut väestö on kyennyt estämään bantusiirtolaisten muuton alueelleen. Rauta ei vaikuta olleen asuinpaikalla missään vaiheessa erityisen yleistä, eikä paikalta tunneta merkkejä raudanvalmistuksesta. Tutkielman lopussa esitellään kaksi vaihtoehtoista mallia, joiden pohjalta myöhäinen kiviesineiden käyttö voisi selittyä. Niistä ensimmäinen perustuu konventinaaliseen käsitykseen, jossa rautakauden alku nähdään bantumigraation seurauksena. Toinen malli perustuu varhaisrautakautisten kulttuuripiirteiden leviämiseen diffuusion avulla. Wadh Lang'o:n tapaustutkimus näyttäisi puhuvan diffuusion puolesta, mutta toisilla alueilla, esimerkiksi Malawissa, migraatio vaikuttaa olevan todennäköisin selitysmalli. Avainsanat: arkeologia, kiviteknologia, Itä-Afrikka, Oltome, Elmenteitan, Urewe, bantumigraatio, myöhäiskivikausi, rautakausi

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There are many reports of efficient embryo germination and the method has been optimized to suit subtropical low chill genotypes. However the subsequent growth, vigor, and ability of germinated embryos to develop and survive acclimatization is rarely reported. Many germinated embryos do not survive acclimatization, develop slowly, or fail to develop normally. Methods to improve plant development from in vitro embryo cultures are needed to improve the number of plants that survive to be useful in breeding programs. This paper describes an improved method of embryo rescue that significantly increases embryo shoot and root development that leads to increased plant survival. Four treatments: Woody Plant Media (WPM) solidified with agar, vermiculite with liquid WPM, vermiculite with WPM plus agar, and conventional stratification, were evaluated for embryo growth and subsequent plantlet development and survival for two low-chill peach and one low-chill nectarine cultivar. Highly significant improvements were found for shoot and root development of seedlings germinated in vermiculite based media compared to embryos germinated in conventional agar-based media. Vermiculite with WPM and agar improved plantlet growth subsequent to in vitro culture and significantly increased survival of germinated embryos resulting in more plants reaching the field.

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