8 resultados para Ceramic raw materials

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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This article attempts to analyse and investigate the implications of the approach to the applicability of Article XX GATT adopted in the recent China – Raw Materials. Using the decision on the non-availability of Article XX defences for violations of China’s WTO-plus commitments on export duties as a backdrop, it scrutinizes the more general, ‘systemic’ approach to the applicability of Article XX exceptions developed by theWTO dispute settlement bodies, and sheds light on the implications of such approach with respect to the relationship between GATT 1994 andWTO obligations arising from different instruments of theWTOAgreement, such as new members’ accession protocols. It also suggests that an exception to this general approach could be envisaged when the fundamental environmental goals protected under Article XX b) and g) are at stake.

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INTRODUCTION: This investigation was designed to compare the histomorphometric results from sinus floor augmentation with anorganic bovine bone (ABB) and a new biphasic calcium phosphate, Straumann Bone Ceramic (BCP). MATERIALS AND METHODS: Forty-eight maxillary sinuses were treated in 37 patients. Residual bone width was > or =6 mm and height was > or =3 mm and <8 mm. Lateral sinus augmentation was used, with grafting using either ABB (control group; 23 sinuses) or BCP (test group; 25 sinuses); sites were randomly assigned to the control or test groups. After 180-240 days of healing, implant sites were created and biopsies taken for histological and histomorphometric analyses. The parameters assessed were (1) area fraction of new bone, soft tissue, and graft substitute material in the grafted region; (2) area fraction of bone and soft tissue components in the residual alveolar ridge compartment; and (3) the percentage of surface contact between the graft substitute material and new bone. RESULTS: Measurable biopsies were available from 56% of the test and 81.8% of the control sites. Histology showed close contact between new bone and graft particles for both groups, with no significant differences in the amount of mineralized bone (21.6+/-10.0% for BCP vs. 19.8+/-7.9% for ABB; P=0.53) in the biopsy treatment compartment of test and control site. The bone-to-graft contact was found to be significantly greater for ABB (48.2+/-12.9% vs. 34.0+/-14.0% for BCP). Significantly less remaining percentage of graft substitute material was found in the BCP group (26.6+/-5.2% vs. 37.7+/-8.5% for ABB; P=0.001), with more soft tissue components (46.4+/-7.7% vs. 40.4+/-7.3% for ABB; P=0.07). However, the amount of soft tissue components for both groups was found not to be greater than in the residual alveolar ridge. DISCUSSION: Both ABB and BCP produced similar amounts of newly formed bone, with similar histologic appearance, indicating that both materials are suitable for sinus augmentation for the placement of dental implants. The potential clinical relevance of more soft tissue components and different resorption characteristics of BCP requires further investigation.

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Our workshop aims at a deeper understanding of various itineraries of pottery and dif-ferent forms of human mobilities in which pottery is relevant, bringing together archae-ological and anthropological perspectives. For thousands of years, pottery has been an important part of many societies’ material culture and therefore a major research topic in both disciplines. In past and present societies the material existence of ceramic vessels is informed by various movements across time and space but also by periods of stasis: from the mo-ment of their production until their exclusion from daily practices, either disposed as waste, excluded as funerary objects or stored as collectibles. In their seemingly endless material durability, ceramic vessels might outlive their human producers, distributors or consumers and travel farther and longer. Still they are embedded in the regimes of human mobility, ranging from daily subsistence-based mobility to long-term migrations. In such processes, pottery shifts between spatial, temporal, social, economic and cultural contexts. Thereby ceramic vessels are appropriated and integrated in new contexts of action and meaning, sometimes leading to material transformations. This workshop takes place in the context of our archaeological research project „Mobili-ties, Entanglements and Transformations in Neolithic Societies on the Swiss Plateau (3900-3500 BC)“ to which our PhDs are connected. We address the above outlined topic by analysing the production of pottery. Based on dendrochronologically dated settle-ments between 3900 and 3500 BC, two regional pottery styles and their local variations are well known, Pfyn and Cortaillod. The vessels share the same habitus and were made of clays and temper deriving from the settlements’ surroundings. However, some vessels specific to other pottery styles are also present on the sites. They are characteristic for pottery styles known from more or less far off regions (Michelsberg, Munzingen or Néo-lithique Moyen Bourguignon). Some of them were travelling objects, as their non local raw materials show. Others seem to have been produced locally, pointing to long-term mobility and a change of residence from neighbouring social groups.

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This study evaluated how applicable European Life Cycle Inventory (LCI) data are to assessing the environmental impacts of the life cycle of Brazilian triple superphosphate (TSP). The LCI data used for the comparison were local Brazilian LCI data, European LCI data in its original version from the ecoinvent database and a modified version of the European LCI data, which had been adapted to better account for the Brazilian situation. We compared the three established datasets at the level of the inventory as well as for their environmental impacts, i.e. at the level of Life Cycle Environmental Assessment (LCIA). The analysis showed that the European LCIs (both the original and the modified ones) considered a broader spectrum of background processes and environmental flows (inputs and outputs). Nevertheless, TSP production had in all three cases similar values for the consumption of the main raw materials. The LCIA results obtained for the datasets showed important differences as well. Therefore we concluded that the European data in general lead to much higher environmental impacts than the Brazilian data. The differences between the LCIA results obtained with the Brazilian and the European data can be basically explained by the methodological differences underlying the data. The small differences at the LCI level for selected inputs and outputs between the Brazilian and the European LCIs from ecoinvent indicate that the latter can be regarded as applicable for characterizing the Brazilian TSP.

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The paper deals with batch scheduling problems in process industries where final products arise from several successive chemical or physical transformations of raw materials using multi–purpose equipment. In batch production mode, the total requirements of intermediate and final products are partitioned into batches. The production start of a batch at a given level requires the availability of all input products. We consider the problem of scheduling the production of given batches such that the makespan is minimized. Constraints like minimum and maximum time lags between successive production levels, sequence–dependent facility setup times, finite intermediate storages, production breaks, and time–varying manpower contribute to the complexity of this problem. We propose a new solution approach using models and methods of resource–constrained project scheduling, which (approximately) solves problems of industrial size within a reasonable amount of time.

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Neolithic wetland sites in the Swiss Plateau provide an extraordinary database for the study of mobilities, entanglements and transformations in material culture. Based on dendrochronologically dated settlements between 3900 and 3500 BC, two regional pottery styles and their local variations are well known, Pfyn and Cortaillod. The vessels share the same habitus and were made of local raw materials. However, some vessels specific to other pottery styles are also present in the sites. By focusing on itineraries of vessels and shifts in pottery knowledge, their appropriation in different contexts and the resulting material entanglements, we want to approach the multiple regimes of mobility: At Lake Constance - known for Pfyn pottery - specific Michelsberg vessels like tulip beakers and lugged jars occur in small numbers. These travelling objects were produced with exogenous raw materials and transported to the sites from Southern Germany. At Concise (Lake Neuchâtel) besides the local Cortaillod pottery the whole repertoire of NMB pottery, characteristic for Eastern France, was also produced. Further cases from the same space-time frame point to other regimes of mobility. In our two PhD-projects we compare pottery practices - styles, techniques, raw materials - from over 20 key sites in the region. Based on Bourdieu’s reflexive anthropology, we apply different qualitative and quantitative archaeological and archaeometrical methods, thus striving for a deeper understanding of habitus and the transformative potential of moving people, objects and ideas on local and regional scales and related social contexts.

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Pottery is one of the most common and stylistically differentiated sources in prehistoric archaeology. This might be the reason why it served as a waste projection surface for archaeological notions about culture, identity, and mobility in the past. As we do not have access to emic categorisations of Neolithic societies we focus on contexts of practice in which pottery was incorporated. It is the moment of production, which left some of the clearest traces on the vessels. Different ways of using raw materials, specific techniques, and characteristic pottery styles can be observed. We understand them as a result of habitus, as socially shared internalized schemes, patterns and habits in pottery production. Taking this as a staring point, two main pottery groups can be differed on the Swiss Plateau between 3900 and 3500 BC: the Mediterranean influenced Cortaillod pottery in Western Switzerland and the Danubian influenced Pfyn pottery in North-Eastern Switzerland. These pottery styles were not only entangled to some degree. Furthermore, in some settlements vessels made in “foreign” styles - Michelsberg, Munzingen, Néolithique Moyen Bourguignon - are present too. Some of them were travelling objects, as their nonlocal raw materials show. Others were locally made, indicating long-term mobility of their producers. To analyse these phenomena of mobilites and entanglements in our PhDs we plan to apply different archaeological and archaeometrical methods, thus striving for a deeper understanding of the transformative potential of moving people, objects and ideas in Neolithic societies on the Swiss Plateau.

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This paper examines concerns about the impact that TTIP could have on existing and future climate policies and laws from the inclusion of provisions on investment protection including investor-to-State dispute settlement (ISDS), the reduction of non-tariff barriers and the introduction of rules for trade in energy and raw materials. It argues that from an environmental perspective, ISDS should not necessarily be seen as a regime that goes against the defence of the environment or prevention of climate change. Although it might be used to challenge policies of an EU home State that increase levels of environmental protection, it can also be used to contest changes in an EU home State’s environmental policies that would reduce the protection of the environment, if foreign investment is affected. To a large extent, this also holds true for other areas of TTIP negotiations. While the achievement of a balance between rules that promote trade and those that maintain policy space for governments to respond to environmental concerns has to be closely monitored, benefits for climate could be seized from harmonisation of carbon laws at the level of the strictest regulations of two parties, provisions that promote trade in low carbon technologies and renewable energy and bilateral cooperation on climate change.