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Construction Material (construction + material)
Selected AbstractsCeramic Matrix Composites: A Challenge in Space-Propulsion Technology ApplicationsINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 2 2005Stephan Schmidt Various technology programs in Europe are concerned, besides developing reliable and rugged, low-cost, throwaway equipment, with preparing for future reusable propulsion technologies. One of the key roles for realizing reusable engine components is the use of modern and innovative materials. One of the key technologies that concerns various engine manufacturers worldwide is the development of fiber-reinforced ceramics,CMCs (ceramic matrix composites). The advantages for the developers are obvious,the low specific weight, the high specific strength over a large temperature range, and their great damage tolerance compared with monolithic ceramics make this material class extremely interesting as a construction material. Over the past few years, the EADS-ST Company (formerly DASA) has, together with various partners, worked intensively on developing components for hypersonic engines and liquid rocket propulsion systems. In the year 2000, various hot-firing tests with subscale (scale 1:5) and full-scale nozzle extensions were conducted. In this year, a further decisive milestone was achieved in the sector of small thrusters, and long-term tests served to demonstrate the extraordinary stability of the C/SiC material. Besides developing and testing radiation-cooled nozzle components and small-thruster combustion chambers, EADS-ST worked on the preliminary development of actively cooled structures for future reusable propulsion systems. In order to get one step nearer to this objective, the development of a new fiber composite was commenced within the framework of a regionally sponsored program. The objective here is to create multidirectional (3D) textile structures combined with a cost-effective infiltration process. Besides material and process development, the project also encompasses the development of special metal/ceramic and ceramic/ceramic joining techniques as well as studying and verifying nondestructive investigation processes for the purpose of testing components. [source] Conservation of forage resources for increasing livestock production in traditional forage reserves in TanzaniaAFRICAN JOURNAL OF ECOLOGY, Issue 2008A. J. Mwilawa Abstract Traditional reserved pastures namely ,Olopololi/Alalili' for Maasai, ,Ngitili' for Sukuma and ,Milaga' for Gogo have been in use among the pastoral and agropastoral communities for many years. These reserves provide dry season feed for ruminant livestock especially cattle, sheep and goats. Apart from the provision of forage materials, these reserves provide fuel wood, construction material and medicinal plants. These traditional forage conservation practices also contribute to soil conservation and forage species biodiversity. However, studies conducted in these traditional forage reserves at Tingatinga (Maasai), Makang'wa (Gogo) and in Mwamishali/Mwanyanhina (Sukuma) in Tanzania show limitations of the reserves especially, in providing adequate dry matter and proteins for both maintenance and production of livestock. Nevertheless, there are opportunities for improvement on these traditional practices through introduction of improved grasses, legumes and tree/shrub species as well as proper maintenance of the superior local species and cultivars. [source] Aerated autoclaved concrete: Stochastic structure model and elastic propertiesPROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2005Ilja Kadaschewitsch Aerated autoclaved concrete (AAC) is a modern and important construction material, whose elastic properties are primarily defined by its porosity. The possibility to predict elastic properties of AAC based on the voids distribution is very important. The report describes simulations of the mechanical properties of AAC, based on a stochastic-geometric model of its structure. The model is the well-known "cherry-pit" model, which presents a random system of partially overlapping spheres. In the mechanical analysis the solid phase is approximated by a network model with the help of the so-called radical tessellation with respect to the hard spheres of the "cherry-pit" model. The network edges are modelled in ANSYS as 3D beams. In this approach, the discretized elements (the edges) have in distinction to FE calculations with small polyhedral same dimension as the air voids and so the numerical costs can be drastically reduced. The FE simulations calculate the elastic constants and energy concentrations, which are responsible for the material failures, in large samples. Comparisons with fracture tests showed good matching between simulations and experiments. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Winning back more than words?THE CANADIAN GEOGRAPHER/LE GEOGRAPHE CANADIEN, Issue 1 2005Power, discourse, quarrying on the Niagara Escarpment This paper explores the controversy and public hearing on the proposed extension of the largest limestone quarry in Canada, operated by Dufferin Aggregates at Milton, Ontario. The quarry constitutes an important source of construction material for the nearby Greater Toronto Area. However, the quarry is protected by the provincial Niagara Escarpment Planning and Development Act and located inside the UNESCO-designated Niagara Escarpment Biosphere Reserve. The proposal has therefore attracted considerable opposition from the public institution charged with its protection, the Niagara Escarpment Commission, as well as environmental groups and local residents. To make sense of the tensions, conflicts and outcome of the Dufferin case, we consult and apply several critical literatures. We see the conflict as part of a transformation of the countryside from a space of production to a space of consumption, where there is a shift in emphasis from resource extractive to scenic and ecological landscape values, and the displacement of productive classes, farmers and workers, in favour of a service class of professionals and retirees. Within this transformation, we identify a ,power geometry' of actor networks of different coalition groups that form allegiances and engage in struggles at different geographic scales. These actor networks operate within the set frames of a dominant development discourse and a popular environmentalist discourse that both include and exclude other ways of seeing and managing the escarpment. Cet article examine la controverse et l'audience publique sur l'aggrandissement projetée de la plus vaste carrière de calcaire au Canada, operée par Dufferin Aggregates à Milton, Ontario. La carrière constitue une source importante de matériaux de construction pour la région métropolitaine de Toronto. Toutefois, cette carrière est non seulement protégée par la loi du développement et de l'aménagment de l'Escarpement du Niagara, mais elle est également située dans la Réserve Biosphère désignée par l'UNESCO. Cette proposition d'aggrandissement de la carrière a donc suscité l'opposition de la Commission de l'Escarpement du Niagara, institution publique désignée pour la protection, ainsi que de certains groupes environnementaux et résidents locaux. Afin d'examiner les tensions, conflits et résultat du cas de la carrière Dufferin, nous avons consulté et appliqué plusieurs littératures critiques. Nous considérons d'abord ce conflit comme faisant partie de la transformation de la campagne d'un site de production en un site de consommation, où l'emphase passe de l'extraction d'une resource à la revalorisation aesthétique et écologique du paysage, accompagnée par le déplacement des classes productives, agriculteurs et ouvriers, en faveur de la classe de services professionnels et retraités. Émergeant de cette transformation, nous identifions une ,géométrie de pouvoir , des réseaux d'acteurs issus de différentes coalitions formant des allégeances et s'engageant dans des formes de résistances à différentes échelles géographiques. Ces réseaux d'acteurs opèrent dans les paramètres d'un discours dominant de développement et d'un discours populaire d'environnementalisme qui tout à la fois inclus et exclus d'autres façons de voir et de gérer l'escarpement. [source] Timberfabric: Applying Textile Principles on a Building ScaleARCHITECTURAL DESIGN, Issue 4 2010Yves Weinand Abstract Timber is coming to the fore as a contemporary construction material. Not only sustainable, its suppleness, adaptability and strength make it highly attractive for experimental designers. Yves Weinand founded the interdisciplinary timberfabric research project at IBOIS, the Laboratory for Timber Fabric, at the École Polytechnique Fédérale de Lausanne (EPFL), in order to fully explore innovative timber construction techniques. Here Yves Weinand and Markus Hudert describe the Textile Module, which Hudert developed, in order to investigate timber's ability for ,social behaviour', or greater structural strength, once woven into a textile-like form. Copyright © 2010 John Wiley & Sons, Ltd. [source] Innovation zur Bestimmung der Erdstoff-Geokunststoff-Wechselwirkung , Pullout-, Scher- und ReibungsversucheBAUTECHNIK, Issue 9 2004Taner Aydogmus Dipl.-Ing. Der Einsatz des ökonomischen und ökologischen Baumaterials "Geokunststoff" hat sich in den letzten Jahren in der Geotechnik für das Bauwesen, den Bergbau und den Umweltschutz stark verbreitet. In Form von Geotextilien, Geogittern, Geomembranen und verwandten Produkten ermöglichen sie technisch einfache, preisgünstige alternative Lösungsmöglichkeiten. Für die Berechnung der Standsicherheit von Konstruktionen mit Geokunststoffen, die für Bewehrungszwecke verwendet werden, ist die Ermittlung der "Reibungseigenschaften" in den Schichtgrenzen zwischen verschiedenen Geokunststoffen sowie zwischen Geokunststoffen und Erdstoffen unerläßlich. Zur Einschätzung der Hauptversagensmechanismen eines kunststoffbewehrten Erdkörpers werden üblicherweise Scher- und Reibungsversuche sowie nun auch verstärkt Pullout-Versuche durchgeführt. In diesem Beitrag wird ein neu entwickeltes und gebautes vollautomatisches Großrahmenschergerät mit integrierter Herausziehversuchseinrichtung vorgestellt, welches die Durchführung von vielfältigen innovativen Versuchen, mit leicht reproduzierbaren , den in-situ-Verhältnissen anpaßbaren , Randbedingungen, dem aktuellen Stand der Versuchstechnik entsprechend und nach den Vorgaben der neuen Normen (z. B. DIN 18137-3) ermöglicht. Innovation for the determination of the soil-geosynthetic interaction , pullout-, shear- and friction tests. The use of the economical and ecological construction material "geosynthetic" plays a rapidly increasing role in a variety of civil engineering, mining and environmental protection applications. Geosynthetics captured their own place as construction material due to their diversity and their specific characteristics. The applications of geosynthetics are many-sided. In the form of geotextiles, geogrids, geomembranes and related products, they make technically simple and low-priced alternative solution concepts possible. For the stability analysis of geosynthetic constructions knowledge of the friction behaviour in the geosynthetic interfaces is essential. For the assessment of the main failure mechanisms of a geosynthetic reinforced construction shear- and friction tests are usually performed as well as now also Pullout tests. In the following, a novel experimental apparatus for the examination of the interaction behaviour of soil-geosynthetic compound systems capable of performing both pullout and direct shear tests is described. In comparison with known geosynthetic testing practice, the novel testing apparatus offers the special advantage that a wide range of innovative shear and pullout test procedures can be carried out in the same device with negligible influence of test device configurations on friction test results. [source] Verbundverhalten von vorgespannten Litzen in UHPCBETON- UND STAHLBETONBAU, Issue 6 2010Teil 1: Versuche zur Verbundfestigkeit und zur Übertragungslänge Spannbeton; Versuche; Bewehrung; Baustoffe Abstract Ultra-Hochfester Beton (UHPC = Ultra-High Performance Concrete) ist hervorragend geeignet für vorgespannte Bauteile. Um eine sichere und dennoch wirtschaftliche Bemessung von vorgespannten Trägern mit sofortigem Verbund vornehmen zu können, muss das Verankerungsverhalten der Litzen bekannt sein. Die hohen Verbundfestigkeiten führen zu kurzen Übertragungslängen und verbessern dadurch die Querkrafttragfähigkeit. Bei Vorspannung mit sofortigem Verbund ist eine Mindestbetondeckung entscheidend, um Längsrisse im Verankerungsbereich zu vermeiden, die einen erheblichen Verlust an Verbundfestigkeit und im Extremfall ein Verankerungsversagen zur Folge haben. In diesem Beitrag, der im Rahmen des von der Deutschen Forschungsgemeinschaft geförderten Schwerpunktprogramms SPP 1182 entstand, werden die Untersuchungsergebnisse zum Verbundverhalten von Litzen in UHPC vorgestellt. Teil 1 behandelt die experimentellen Untersuchungen und Teil 2 die Herleitung eines Verbundmodells zur Berechnung der Übertragungslänge. Bond Behavior of prestressed Strands in UHPC. Part 1: Tests on Bond Strength and Transfer Length Ultra-High Performance Concrete (UHPC) is an appropriate construction material for pretensioned girders. To ensure an economic and safe design a detailed knowledge of the behavior of pretensioned strands in the anchorage zone is essential. The dimension of the bond anchorage zone favors the cost-effective design of pretensioned girders, especially when the shear resistance is decisive. However, a minimum concrete cover has to be maintained to avoid splitting cracks in the transmission zone, since they lead to an uncontrolled increase in transfer length and may cause a premature anchorage failure. This paper, which resulted from the priority program SPP 1182 funded by the German Research Foundation, presents the results of investigations on the bond behavior of strands in UHPC. Part 1 deals with the experimental investigations and in part 2 a bond model is derived to design the transfer length. [source] Herstellung und Eigenschaften eines neuen Leichtbetons: AerogelbetonBETON- UND STAHLBETONBAU, Issue 4 2008Lorenz Ratke Prof. Dr.-Ing. Die Dispergierung von superhydrophobem Aerogelgranulat in konventionelle Zement- oder Betonmischungen erzeugt einen Leichtbeton mit außergewöhnlichen Eigenschaften: gute Wärmedämmung, schallisolierend, Brandschutz der Klasse F120 und besser, bewehrbar und leicht mechanisch zu bearbeiten. Der Aufsatz beschreibt die Herstellung und einige Eigenschaften dieses neuartigen Baustoffs. Fabrication and Properties of a New Light Weight Concrete: Aerogel Concrete The distribution of super hydrophobic aerogel in particulate form into conventional cement or concrete mixtures produces a light weight concrete with extraordinary properties: good heat and sound insulation, fire protection of the class F120 and better, armorable und easy workable. The paper describes the fabrication and some properties of this new construction material. [source] Mechanisms driving the specificity of a myrmecophyte,ant associationBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2009JULIEN GRANGIER In the understory of pristine Guianese forests, the myrmecophyte Hirtella physophora almost exclusively shelters colonies of the plant-ant Allomerus decemarticulatus in its leaf pouches. We experimentally tested three non-mutually exclusive hypotheses concerning phenomena that can determine the species specificity of this association throughout the foundation stage of the colonies: (1) interspecific competition results in the overwhelming presence of A. decemarticulatus queens or incipient colonies; (2) exclusion filters prevent other ant species from entering the leaf pouches; and (3) host-recognition influences the choice of founding queens, especially A. decemarticulatus. Neither interspecific competition, nor the purported exclusion filters that we examined play a major role in maintaining the specificity of this association. Unexpectedly, the plant trichomes lining the domatia appear to serve as construction material during claustral foundation rather than as a filter. Finally, A. decemarticulatus queens are able to identify their host plant from a distance through chemical and/or visual cues, which is rarely demonstrated in studies on obligatory ant,plant associations. We discuss the possibility that this specific host-recognition ability could participate in shaping a compartmentalized plant-ant community where direct competition between ant symbionts is limited. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 90,97. [source] Thermal properties of lightweight-framed construction components at elevated temperaturesFIRE AND MATERIALS, Issue 3 2005Noureddine Bénichou Abstract Fire resistance behaviour of lightweight-framed assemblies is determined by defining the thermal and structural performances of the assembly when exposed to fire. To adequately model thermal behaviour in a lightweight wood-framed assembly, thermal properties of the components of the assembly at elevated temperatures must be well defined. This paper presents results of measurements of thermal properties at elevated temperatures of construction materials commonly used to build lightweight wood-framed assemblies that were conducted at the National Research Council of Canada since 1990. The test results, in graphical form, are given as a function of temperature for thermal conductivity, specific heat, mass loss and thermal expansion/contraction for wood, gypsum and insulation. In addition, the effects of temperature on the thermal conductivity, specific heat, mass loss and thermal expansion/contraction of these materials are discussed. Finally, in addition to providing a resource of information, this paper also identifies the additional thermal property tests required to complete the matrix of information. Copyright © 2005 Crown in the right of Canada. Published by John Wiley & Sons, Ltd. [source] Surface temperature of decomposing construction materials studied by laser-induced phosphorescenceFIRE AND MATERIALS, Issue 1 2005Alaa Omrane Abstract Measurements of surface temperature and mass loss of decomposing construction materials during rapid pyrolysis are presented. Experiments have been performed with samples of low-density fiberboard, medium-density fiberboard, particleboard and poly(methyl methacrylate) in a single particle reactor at temperatures between 300° and 600°C. Ultraviolet laser light was used to excite micrometer-sized thermographic phosphor particles that were deposited on the investigated materials, and the temperature was obtained from temporally resolved measurements of the laser-induced emission. The wood-based materials show a similar behavior, with small differences being attributed to differences in material properties. The surface temperature rapidly increases to about 400°C when a particle is introduced to the hot reactor. The initial phase is followed by rapid decomposition during which the surface temperature is 380°,540°C. The heating rate is slowed down during the rapid pyrolysis, and again increases as the remaining char is heated to the reactor temperature. The poly (methyl methacrylate), however, melts and at high temperatures can be characterized as a liquid with a boiling point of about 400°C. Thermographic phosphors are concluded to be suitable for high precision remote measurements of the surface temperature of decomposing construction materials, and possibilities for further studies and developments of the technique are discussed. Copyright © 2004 John Wiley & Sons, Ltd. [source] Analysis of adobe wall composition at the Chaves-Hummingbird Site, New Mexico, by diffuse reflectance spectrophotometryGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 8 2007William Balsam This article investigates adobe wall construction materials utilized by prehistoric inhabitants of Chaves-Hummingbird Pueblo, an ancestral Pueblo village located ,20 miles west of Albuquerque, New Mexico. The walls were constructed with native clay-rich soils some time between approximately 1275,1450 A.D. Samples were analyzed with a diffuse reflectance spectrophotometer from the near ultraviolet (NUV) through the visible (VIS) and into the near infrared (NIR) region of the electromagnetic spectrum. Cluster analysis of samples from 275 adobe walls and 36 soil locations surrounding the pueblo room blocks indicates four clusters. Comparison of typical samples from the four clusters indicates that they are very similar and are distinguished by minor variations in the three primary spectrally determined components, Na-Ca montmorillonite, bentonite, and goethite. In general, clusters correspond with room construction episodes that are discernible through patterns of wall bonding and abutment recorded during the archaeological investigation of the site. This suggests that during different phases of construction the source of the wall adobe changed. Many of the soil samples are included in wall clusters and therefore reveal a potential source of material used for adobe, adjacent soils. However, not all the soil surrounding the pueblo grouped with wall clusters indicating a preference for certain soil types and that some soils were probably unsuitable for making adobe. Therefore, diversity in spectrally identified construction materials provides insights into source locations and possible construction preferences of the site inhabitants. © 2007 Wiley Periodicals, Inc. [source] Pool boiling on a superhydrophilic surfaceINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 2 2003Y. Takata Abstract Titanium Dioxide, TiO2, is a photocatalyst with a unique characteristic. A surface coated with TiO2 exhibits an extremely high affinity for water when exposed to UV light and the contact angle decreases nearly to zero. Inversely, the contact angle increases when the surface is shielded from UV. This superhydrophilic nature gives a self-cleaning effect to the coated surface and has already been applied to some construction materials, car coatings and so on. We applied this property to the enhancement of boiling heat transfer. An experiment involving the pool boiling of pure water has been performed to make clear the effect of high wettability on heat transfer characteristics. The heat transfer surface is a vertical copper cylinder of 17 mm in diameter and the measurement has been done at saturated temperature and in a steady state. Both TiO2 -coated and non-coated surfaces were used for comparison. In the case of the TiO2 -coated surface, it is exposed to UV light for a few hours before experiment and it is found that the maximum heat flux (CHF) is about two times larger than that of the uncoated surface. The temperature at minimum heat flux (MHF) for the superhydrophilic surface is higher by 100 K than that for the normal one. The superhydrophilic surface can be an ideal heat transfer surface. Copyright © 2002 John Wiley & Sons, Ltd. [source] Small,scale mining in South Africa: Past, present and futureNATURAL RESOURCES FORUM, Issue 4 2002Nellie Mutemeri Mining is an important part of the South African economy and has been the driver of much of the economic development of the country. However, the small,scale mining subsector still has to realise its full potential. A small,scale mine has been defined as a mining activity employing less than 50 people and with an annual turnover of less than 7.5 million Rand and includes artisanal mines. Small,scale miners are involved in many commodities but there appears to be a bias towards gold, diamonds and quarrying for construction materials, including brickclays. Small,scale mining is regulated by the same legislation (i.e., for the environment, labour, mineral rights, exploration and mining permitting, and skills development) as large,scale mining, though compliance is low, particularly where artisanal mining in concerned. The effective participation of small,scale miners in the mining sector is hampered by their lack of skills, i.e., technical, business and management, and their limited access to mineral deposits, capital and markets. Some of these hindrances have been inherited from the imbalances of the colonial and apartheid eras and continue to act as barriers, making entrance to the industry difficult. For those who have entered the industry out of desperation, as is the case with most artisanal miners, their activities result in negative impacts evident in the inefficient, unsafe and environmentally unfriendly operations. With the advent of the new political dispensation in South Africa, a new era is dawning for the country's small,scale mining subsector. This has resulted in a change of attitude and new government policies which have led to special programmes being put in place to promote the subsector. Intervention strategies for the support of small,scale mining (some of which are already in operation) include programmes for kickstarting mineral beneficiation and value,addition projects, development of appropriate technologies and skills and technology transfer. Proponents of small,scale mining see a well,regulated industry as being the cornerstone of future rural economic development, particularly for previously disadvantaged communities in the poverty nodes. [source] Mining and sustainable development: considerations for minerals supplyNATURAL RESOURCES FORUM, Issue 4 2001Ian B. Lambert Abstract Sustainable development involves meeting the needs of human societies while maintaining viable biological and physical Earth systems. The needs include minerals: metals, fuels, industrial and construction materials. There will continue to be considerable demand for virgin mineral resources, even if levels of recycling and efficiency of use are optimal, and rates of population growth and globalisation decrease significantly. This article aims to stimulate debate on strategic issues for minerals supply. While the world has considerable stocks of mineral resources overall, international considerations of the environmental and social aspects of sustainable development are beginning to result in limitations on where mining will be conducted and what types of deposits will be mined. Current and emerging trends favour large mines in parts of the world where mining can be conducted within acceptable limits of environmental and social impact. Finding new deposits that meet such criteria will be all the more challenging given a disturbing global decline in the rate of discovery of major economic resources over the last decade, and the decreasing land area available for exploration and mining. To attract responsible exploration and mining, governments of mining nations will need to provide: regional-scale geo-scientific datasets as required to attract and guide future generations of exploration; resource access through multiple and sequential land use regimes, and frameworks for dealing with indigenous peoples' issues; and arrangements for consideration of mining proposals and regulation of mines that ensure responsible management of environmental and social issues. The minerals industry will need to continue to pursue advances in technologies for exploration, mining, processing, waste management and rehabilitation, and in public reporting of environmental and social performance. [source] Generation, Capture, and Utilization of Industrial Carbon DioxideCHEMSUSCHEM CHEMISTRY AND SUSTAINABILITY, ENERGY & MATERIALS, Issue 3 2010Andrew Abstract As a carbon-based life form living in a predominantly carbon-based environment, it is not surprising that we have created a carbon-based consumer society. Our principle sources of energy are carbon-based (coal, oil, and gas) and many of our consumer goods are derived from organic (i.e., carbon-based) chemicals (including plastics, fabrics and materials, personal care and cleaning products, dyes, and coatings). Even our large-volume inorganic-chemicals-based industries, including fertilizers and construction materials, rely on the consumption of carbon, notably in the form of large amounts of energy. The environmental problems which we now face and of which we are becoming increasingly aware result from a human-induced disturbance in the natural carbon cycle of the Earth caused by transferring large quantities of terrestrial carbon (coal, oil, and gas) to the atmosphere, mostly in the form of carbon dioxide. Carbon is by no means the only element whose natural cycle we have disturbed: we are transferring significant quantities of elements including phosphorus, sulfur, copper, and platinum from natural sinks or ores built up over millions of years to unnatural fates in the form of what we refer to as waste or pollution. However, our complete dependence on the carbon cycle means that its disturbance deserves special attention, as is now manifest in indicators such as climate change and escalating public concern over global warming. As with all disturbances in materials balances, we can seek to alleviate the problem by (1),dematerialization: a reduction in consumption; (2),rematerialization: a change in what we consume; or (3),transmaterialization: changing our attitude towards resources and waste. The "low-carbon" mantra that is popularly cited by organizations ranging from nongovernmental organizations to multinational companies and from local authorities to national governments is based on a combination of (1) and (2) (reducing carbon consumption though greater efficiency and lower per capita consumption, and replacing fossil energy sources with sources such as wind, wave, and solar, respectively). "Low carbon" is of inherently less value to the chemical and plastics industries at least in terms of raw materials although a version of (2), the use of biomass, does apply, especially if we use carbon sources that are renewable on a human timescale. There is however, another renewable, natural source of carbon that is widely available and for which greater utilization would help restore material balance and the natural cycle for carbon in terms of resource and waste. CO2, perhaps the most widely discussed and feared chemical in modern society, is as fundamental to our survival as water, and like water we need to better understand the human as well as natural production and consumption of CO2 so that we can attempt to get these into a sustainable balance. Current utilization of this valuable resource by the chemical industry is only 90,megatonne per year, compared to the 26.3,gigatonne CO2 generated annually by combustion of fossil fuels for energy generation, as such significant opportunities exist for increased utilization of CO2 generated from industrial processes. It is also essential that renewable energy is used if CO2 is to be utilized as a C1 building block. [source] | |||||||||||||||||||