891 resultados para Concrete products industry


Relevância:

30.00% 30.00%

Publicador:

Resumo:

A vida da sociedade atual é dependente dos recursos fósseis, tanto a nível de energia como de materiais. No entanto, tem-se verificado uma redução das reservas destes recursos, ao mesmo tempo que as necessidades da sociedade continuam a aumentar, tornando cada vez mais necessárias, a produção de biocombustíveis e produtos químicos. Atualmente o etanol é produzido industrialmente a partir da cana-de-açúcar e milho, matérias-primas usadas na alimentação humana e animal. Este fato desencadeou o aumento de preços dos alimentos em todo o mundo e, como consequência, provocou uma série de distúrbios sociais. Os subprodutos industriais, recursos independentes das cadeias alimentares, têm-se posicionado como fonte de matérias-primas potenciais para bioprocessamento. Neste sentido, surgem os subprodutos gerados em grande quantidade pela indústria papeleira. Os licores de cozimento da madeira ao sulfito ácido (SSLs) são uma matériaprima promissora, uma vez que durante este processo os polissacarídeos da madeira são hidrolisados originando açúcares fermentáveis. A composição dos SSLs varia consoante o tipo de madeira usada no processo de cozimento (de árvores resinosas, folhosas ou a mistura de ambas). O bioprocessamento do SSL proveniente de folhosas (HSSL) é uma metodologia ainda pouco explorada. O HSSL contém elevadas concentrações de açúcares (35-45 g.L-1), na sua maioria pentoses. A fermentação destes açúcares a bioetanol é ainda um desafio, uma vez que nem todos os microrganismos são capazes de fermentar as pentoses a etanol. De entre as leveduras capazes de fermentar naturalmente as pentoses, destaca-se a Scheffersomyces stipitis, que apresenta uma elevada eficiência de fermentação. No entanto, o HSSL contém também compostos conhecidos por inibirem o crescimento de microrganismos, dificultando assim o seu bioprocessamento. Neste sentido, o principal objetivo deste trabalho foi a produção de bioetanol pela levedura S. stipitis a partir de HSSL, resultante do cozimento ao sulfito ácido da madeira de Eucalyptus globulus. Para alcançar este objetivo, estudaram-se duas estratégias de operação diferentes. Em primeiro lugar estudou-se a bio-desintoxicação do HSSL com o fungo filamentoso Paecilomyces variotii, conhecido por crescer em resíduos industriais. Estudaram-se duas tecnologias fermentativas diferentes para a biodesintoxicação do HSSL: um reator descontínuo e um reator descontínuo sequencial (SBR). A remoção biológica de inibidores do HSSL foi mais eficaz quando se usou o SBR. P. variotii assimilou alguns inibidores microbianos como o ácido acético, o ácido gálico e o pirogalol, entre outros. Após esta desintoxicação, o HSSL foi submetido à fermentação com S. stipitis, na qual foi atingida a concentração máxima de etanol de 2.36 g.L-1 com um rendimento de 0.17 g.g-1. P. variotti, além de desintoxicar o HSSL, também é útil na produção de proteína microbiana (SCP) para a alimentação animal pois, a sua biomassa é rica em proteína. O estudo da produção de SCP por P. variotii foi efetuado num SBR com HSSL sem suplementos e suplementado com sais. A melhor produção de biomassa foi obtida no HSSL sem adição de sais, tendo-se obtido um teor de proteína elevado (82,8%), com uma baixa concentração de DNA (1,1%). A proteína continha 6 aminoácidos essenciais, mostrando potencial para o uso desta SCP na alimentação animal e, eventualmente, em nutrição humana. Assim, a indústria papeleira poderá integrar a produção de bioetanol após a produção SCP e melhorar a sustentabilidade da indústria de pastas. A segunda estratégia consistiu em adaptar a levedura S. stipitis ao HSSL de modo a que esta levedura conseguisse crescer e fermentar o HSSL sem remoção de inibidores. Operou-se um reator contínuo (CSTR) com concentrações crescentes de HSSL, entre 20 % e 60 % (v/v) durante 382 gerações em HSSL, com uma taxa de diluição de 0.20 h-1. A população adaptada, recolhida no final do CSTR (POP), apresentou uma melhoria na fermentação do HSSL (60 %), quando comparada com a estirpe original (PAR). Após esta adaptação, a concentração máxima de etanol obtida foi de 6.93 g.L-1, com um rendimento de 0.26 g.g-1. POP possuía também a capacidade de metabolizar, possivelmente por ativação de vias oxidativas, compostos derivados da lenhina e taninos dissolvidos no HSSL, conhecidos inibidores microbianos. Por fim, verificou-se também que a pré-cultura da levedura em 60 % de HSSL fez com que a estirpe PAR melhorasse o processo fermentativo em HSSL, em comparação com o ensaio sem pré-cultura em HSSL. No entanto, no caso da estirpe POP, o seu metabolismo foi redirecionado para a metabolização dos inibidores sendo que a produção de etanol decresceu.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Every can of tuna purchased by the consumer has taken a long journey before reaching the supermarket shelves. For each can bought there is a lengthy process from sea to shelf. A large proportion of the tuna cans purchased in the European Union come all the way from West Africa; a developing region with a high dependency on fisheries. Amidst an ever-increasing demand for tuna products the global tuna fisheries are set to continue expanding, apparently one of the last natural resource based industries fit to do so in West Africa. Tuna is the biggest fisheries export and dominates the fisheries sector in Ghana, a country situated in West Africa. This thesis aims to understand how this globally important industrial fisheries functions in terms of procedures, practices, Governance and finance. Socioeconomic influences, in the setting of a developing country, were also examined. For these purposes a Value Chain Analysis was employed. A Value Chain Analysis is a tool commonly used to understand how different companies and organizations participate in a domestic policy environment, which directs conclusion in the global economy. This analysis has the potential to allow researchers to fully understand a commodity chain and hence identify realistic opportunities for consequential improvements. Interviews and questionnaires were employed in-field Ghana along with secondary data collection techniques. It was found that the fisheries functions at the production level under influences from large multinational companies and tends to operate with a certain degree of lawlessness. Governance over the value chain is well defined, however implementation is poor or non-existent. The processors, whom are also dominated by multinationals, exert some control over the producers and their sales, however the high value links which are highlighted occur at the retail stage. Socioeconomic dynamics acting in the chain included the lack of communication between the public and private sector, power imbalances amongst players at production, the role of local businesswomen as actors in the chain and the general characteristics of the workers in the industry. Value addition and upgrading are needed the most in Governance over the chain, especially within Monitoring, Control and Surveillance. The results of the study provide a wealth of material about the components of a cost-heavy fishing industry in a developing country; an industry on which many eyes have recently turned due to illegal fishing activities. It highlights clearly where funding and future focus are needed. This value chain can be used as a guide for those that need to comprehend the financial complexities and real life dynamics of the Ghanaian tuna fishing industry today.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Making more money involves more than targeting new customer segments and offering new services.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In this study, efforts were made in order to put forward an integrated recycling approach for the thermoset based glass fibre reinforced polymer (GPRP) rejects derived from the pultrusion manufacturing industry. Both the recycling process and the development of a new cost-effective end-use application for the recyclates were considered. For this purpose, i) among the several available recycling techniques for thermoset based composite materials, the most suitable one for the envisaged application was selected (mechanical recycling); and ii) an experimental work was carried out in order to assess the added-value of the obtained recyclates as aggregates and reinforcement replacements into concrete-polymer composite materials. Potential recycling solution was assessed by mechanical behaviour of resultant GFRP waste modified concrete-polymer composites with regard to unmodified materials. In the mix design process of the new GFRP waste based composite material, the recyclate content and size grade, and the effect of the incorporation of an adhesion promoter were considered as material factors and systematically tested between reasonable ranges. The optimization process of the modified formulations was supported by the Fuzzy Boolean Nets methodology, which allowed finding the best balance between material parameters that maximizes both flexural and compressive strengths of final composite. Comparing to related end-use applications of GFRP wastes in cementitious based concrete materials, the proposed solution overcome some of the problems found, namely the possible incompatibilities arisen from alkalis-silica reaction and the decrease in the mechanical properties due to high water-cement ratio required to achieve the desirable workability. Obtained results were very promising towards a global cost-effective waste management solution for GFRP industrial wastes and end-of-life products that will lead to a more sustainable composite materials industry.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The development and applications of thermoset polymeric composites, namely fiber reinforced polymers (FRP), have shifted in the last decades more and more into the mass market [1]. Production and consume have increased tremendously mainly for the construction, transportation and automobile sectors [2, 3]. Although the many successful uses of thermoset composite materials, recycling process of byproducts and end of lifecycle products constitutes a more difficult issue. The perceived lack of recyclability of composite materials is now increasingly important and seen as a key barrier to the development or even continued used of these materials in some markets.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In this study, a new waste management solution for thermoset glass fibre reinforced polymer (GFRP) based products was assessed. Mechanical recycling approach, with reduction of GFRP waste to powdered and fibrous materials was applied, and the prospective added-value of obtained recyclates was experimentally investigated as raw material for polyester based mortars. Different GFRP waste admixed mortar formulations were analyzed varying the content, between 4% up to 12% in weight, of GFRP powder and fibre mix waste. The effect of incorporation of a silane coupling agent was also assessed. Design of experiments and data treatment was accomplished through implementation of full factorial design and analysis of variance ANOVA. Added value of potential recycling solution was assessed by means of flexural and compressive loading capacity of GFRP waste admixed mortars with regard to unmodified polymer mortars. The key findings of this study showed a viable technological option for improving the quality of polyester based mortars and highlight a potential cost-effective waste management solution for thermoset composite materials in the production of sustainable concrete-polymer based products.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The World Business Council for Sustainable Development (WBCSD) defines Eco-Efficiency as follows: ‘Eco- Efficiency is achieved by the delivery of competitively priced-goods and services that satisfy human needs and bring quality of life, while progressively reducing ecological impacts and resource intensity throughout the life-cycle to a level at least in line with the earth’s estimated carrying capacity’. Eco-Efficiency is under this point of view a key concept for sustainable development, bringing together economic and ecological progress. Measuring the Eco-Efficiency of a company, factory or business, is a complex process that involves the measurement and control of several and relevant parameters or indicators, globally applied to all companies in general, or specific according to the nature and specificities of the business itself. In this study, an attempt was made in order to measure and evaluate the eco-efficiency of a pultruded composite processing company. For this purpose the recommendations of WBCSD [1] and the directives of ISO 14301 standard [2] were followed and applied. The analysis was restricted to the main business branch of the company: the production and sale of standard GFRP pultrusion profiles. The main general indicators of eco-efficiency, as well as the specific indicators, were defined and determined according to ISO 14031 recommendations. With basis on indicators’ figures, the value profile, the environmental profile, and the pertinent eco-efficiency’s ratios were established and analyzed. In order to evaluate potential improvements on company eco-performance, new indicators values and ecoefficiency ratios were estimated taking into account the implementation of new proceedings and procedures, both in upstream and downstream of the production process, namely: a) Adoption of new heating system for pultrusion die in the manufacturing process, more effective and with minor heat losses; b) Implementation of new software for stock management (raw materials and final products) that minimize production failures and delivery delays to final consumer; c) Recycling approach, with partial waste reuse of scrap material derived from manufacturing, cutting and assembly processes of GFRP profiles. In particular, the last approach seems to significantly improve the eco-efficient performance of the company. Currently, by-products and wastes generated in the manufacturing process of GFRP profiles are landfilled, with supplementary added costs to this company traduced by transport of scrap, landfill taxes and required test analysis to waste materials. However, mechanical recycling of GFRP waste materials, with reduction to powdered and fibrous particulates, constitutes a recycling process that can be easily attained on heavy-duty cutting mills. The posterior reuse of obtained recyclates, either into a close-looping process, as filler replacement of resin matrix of GFRP profiles, or as reinforcement of other composite materials produced by the company, will drive to both costs reduction in raw materials and landfill process, and minimization of waste landfill. These features lead to significant improvements on the sequent assessed eco-efficiency ratios of the present case study, yielding to a more sustainable product and manufacturing process of pultruded GFRP profiles.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The development and applications of thermoset polymeric composites, namely fibre reinforced plastics (FRP), have shifted in the last decades more and more into the mass market [1]. Despite of all advantages associated to FRP based products, the increasing production and consume also lead to an increasing amount of FRP wastes, either end-of-lifecycle products, or scrap and by-products generated by the manufacturing process itself. Whereas thermoplastic FRPs can be easily recycled, by remelting and remoulding, recyclability of thermosetting FRPs constitutes a more difficult task due to cross-linked nature of resin matrix. To date, most of the thermoset based FRP waste is being incinerated or landfilled, leading to negative environmental impacts and supplementary added costs to FRP producers and suppliers. This actual framework is putting increasing pressure on the industry to address the options available for FRP waste management, being an important driver for applied research undertaken cost efficient recycling methods. [1-2]. In spite of this, research on recycling solutions for thermoset composites is still at an elementary stage. Thermal and/or chemical recycling processes, with partial fibre recovering, have been investigated mostly for carbon fibre reinforced plastics (CFRP) due to inherent value of carbon fibre reinforcement; whereas for glass fibre reinforced plastics (GFRP), mechanical recycling, by means of milling and grinding processes, has been considered a more viable recycling method [1-2]. Though, at the moment, few solutions in the reuse of mechanically-recycled GFRP composites into valueadded products are being explored. Aiming filling this gap, in this study, a new waste management solution for thermoset GFRP based products was assessed. The mechanical recycling approach, with reduction of GFRP waste to powdered and fibrous materials was applied, and the potential added value of obtained recyclates was experimentally investigated as raw material for polyester based mortars. The use of a cementless concrete as host material for GFRP recyclates, instead of a conventional Portland cement based concrete, presents an important asset in avoiding the eventual incompatibility problems arisen from alkalis silica reaction between glass fibres and cementious binder matrix. Additionally, due to hermetic nature of resin binder, polymer based concretes present greater ability for incorporating recycled waste products [3]. Under this scope, different GFRP waste admixed polymer mortar (PM) formulations were analyzed varying the size grading and content of GFRP powder and fibre mix waste. Added value of potential recycling solution was assessed by means of flexural and compressive loading capacities of modified mortars with regard to waste-free polymer mortars.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Glass fibre-reinforced plastics (GFRP) have been considered inherently difficult to recycle due to both: crosslinked nature of thermoset resins, which cannot be remoulded, and complex composition of the composite itself. Presently, most of the GFRP waste is landfilled leading to negative environmental impacts and supplementary added costs. With an increasing awareness of environmental matters and the subsequent desire to save resources, recycling would convert an expensive waste disposal into a profitable reusable material. In this study, efforts were made in order to recycle grinded GFRP waste, proceeding from pultrusion production scrap, into new and sustainable composite materials. For this purpose, GFRP waste recyclates, were incorporated into polyester based mortars as fine aggregate and filler replacements at different load contents and particle size distributions. Potential recycling solution was assessed by mechanical behaviour of resultant GFRP waste modified polymer mortars. Results revealed that GFRP waste filled polymer mortars present improved flexural and compressive behaviour over unmodified polyester based mortars, thus indicating the feasibility of the GFRP industrial waste reuse into concrete-polymer composite materials.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Mestrado em Engenharia Química - Ramo Otimização Energética na Indústria Química

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dissertation presented to obtain the Ph.D. degree in “Biology” at the Institute of Chemical and Biological Technology of the New University of Lisbon

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Logoplaste is a specialist in operating in-house industrial sites for manufacturing rigid plastic packaging containers. In developing countries, especially in Africa, the low income of consumers does not allow a widespread adoption of products typically sold in rigid plastic containers. In these countries the flexible packages are usually adopted as they allow for better ratios of cost/litter of product, particularly in smaller packages. Should Logoplaste offer this type of technology in order to expand into developing countries?

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This paper studies operating profitability drivers in the Four Main Tobacco Manufacturers for the period 2004-2014. The operating profitability is analyzed as return on assets (ROA) based on the DuPont Extended Model breakdown in degree of operational risk, gross sales margin and assets turnover. The sources of ROA are market share and price strategies appraised through the drivers: firm-size, global value and strategic choices. Using consolidated data, results suggest that firm-size and global value holds a positive relationship with ROA. Also innovation through less harmful tobacco products can lead to better ROA despite no correlation between R&D and ROA.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This project aims to explore the Portuguese Beauty and Cosmetics market, and to discuss the usage and purchase behaviour of young female adults, between 18 and 26 years old. After a market analysis based on secondary data, it evaluates the results of qualitative and quantitative research based on 9 interviews and 126 online questionnaires to explore the consumers’ reasoning when choosing products from this category – fragrances, skin care or make-up – as well as their attitude towards brands, with a special focus on the premium cosmetics brand Lancôme. Contrary to our expectations there was no statistically significant positive influence of the online touchpoints within this age segment’s purchase intention. However, results indicate that Lancôme is already being perceived by some as young and modern, but is still suffering the threat of Mass Market brands that are valued by this target, mainly due to a price sensitivity towards premium beauty brands.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

L’Organisation mondiale de la santé animale (OIE) est l’institution internationale responsable de la mise en place des mesures sanitaires associées aux échanges commerciaux d’animaux vivants. Le zonage est une méthode de contrôle recommandée par l’OIE pour certaines maladies infectieuses, dont l’influenza aviaire. Les éclosions d’influenza aviaire été extrêmement coûteuses pour l’industrie avicole partout dans le monde. Afin d’évaluer la possibilité d’user de cette approche en Ontario, les données sur les sites de production avicole ont été fournies par les fédérations d’éleveurs de volailles ce cette province. L’information portant sur les industries associées à la production avicole, soit les meuneries, les abattoirs, les couvoirs, et les usines de classification d’œufs, a été obtenue par l’entremise de plusieurs sources, dont des représentants de l’industrie avicole. Des diagrammes de flux a été crée afin de comprendre les interactions entre les sites de production et les industries associées à ceux-ci. Ces industries constituaient les éléments de bas nécessaires au zonage. Cette analyse a permis de créer une base de données portant sur intrants et extrants de production pour chaque site d’élevage avicole, ainsi que pour les sites de production des industries associées à l’aviculture. À l’aide du logiciel ArcGIS, cette information a été fusionnée à des données géospatiales de Statistique Canada de l’Ontario et du Québec. La base de données résultante a permis de réaliser les essais de zonage. Soixante-douze essais ont été réalisés. Quatre ont été retenus car celles minimisaient de façon similaire les pertes de production de l’industrie. Ces essais montrent que la méthode utilisée pour l’étude du zonage peut démontrer les déficits et les surplus de production de l’industrie avicole commerciale en Ontario. Ceux-ci pourront servir de point de départ lors des discussions des intervenants de l’industrie avicole, étant donné que la coopération et la communication sont essentielles au succès du zonage.