974 resultados para Leather of scrap


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This article describes a new approach of recycling the leather waste (shavings) using it as filler in natural rubber foams composites. The foams were prepared using different amounts of leather waste (0-60 parts per hundred of rubber) and submitted to morphological (SEM microscopy) and mechanical analyses (cyclic stress-strain compression). The increase of leather shavings on the composite causes an increase of viscosity in the mixture, which reflects in the foaming process. This results in smaller and fairly uniform cells. Furthermore, expanded rubber has the biggest cell size, with more than 70% of cell with 1000 mu m, while the composite with the higher concentration of leather has around 80% of total number of cells with 100-400 mu m. The mechanical parameters were found to depend on the leather dust concentration. Moreover, the stiffness rises with the increase of leather shavings; consequently, the compression force for expanded rubber was 0.126 MPa as well as the composite with higher concentration of leather was 7.55 MPa. (c) 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41636.

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Automotive heat shields are usually composed of two metal sheets enclosing an insulating material with a paper-like texture that contains refractory ceramic particles. This article discusses the results achieved by recycling the scrap automotive insulation that is discarded in landfills, using the same concept as paper recycling. For comparison with the original product, tests of thickness, bulk density, weight loss on ignition, tensile strength, compressibility, and recovery were performed on recycled materials produced in a so-called "manual" process (involving little automation and performed in adapted facilities) without pressing, and pressed once, twice, and four times. Materials recycled in a so-called "industrial" process (in a paper recycling plant) without pressing, and pressed once were also tested. The recycled materials can be considered approved with respect to the main requirement, thermal insulation, since they dissipated the under-hood temperature by more than 300 A degrees C (like the original product). Like the heat insulation tests, the thermogravimetric analysis suggested that the recycled materials showed higher stability than the original product. Thermogravimetric, microscopy, and energy dispersive spectroscopy analyses indicated that the structural and compositional characteristics of the original product were preserved after recycling.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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This work addresses the synthesis of carbon nanomaterials (CNMs) by up-cycling common solid wastes. These feedstocks could supersede the use of costly and often toxic or highly flammable chemicals, such as hydrocarbon gases, carbon monoxide, and hydrogen, which are commonly used as feedstocks in current nanomanufacturing processes for CNMs. Agricultural sugar cane bagasse and corn residues, scrap tire chips, and postconsumer polyethylene (PE) and polyethylene terephthalate (PET) bottle shreddings were either thermally treated by sole pyrolysis or by sequential pyrolysis and partial oxidation. The resulting gaseous carbon-bearing effluents were then channeled into a heated reactor. CNMs, including carbon nanotubes, were catalytically synthesized therein on stainless steel meshes. This work revealed that the structure of the resulting CNMs is determined by the feedstock type, through the disparate mixtures of carbon-bearing gases generated when different feedstocks are pyrolyzed. CNM characterization was conducted by scanning and transmission electron microscopy as well as by Raman spectroscopy and by thermogravimetric analysis. Gas chromatography was used to characterize the gases in the synthesis chamber. This work demonstrated an alternative method for efficient manufacturing of CNMs using both biodegradable and nonbiodegradable agricultural and municipal carbonaceous wastes.

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When Huxley proposed, Blythe imagined herself fifty years into the future at his funeral. He was such a good man, they’d say. Seventy-two is too young, they’d say. She’d nod and, she had imagined, remember this moment – them lounging in her bed during the early afternoon with the sunlight threatening to burst from behind the drawn shades, him lying on his side with his left arm anchored around her waist, and the tickle of his thumb as he traced circles on her bellybutton. She rubbed her nose against his neck and breathed. His scent was different from that of Walter. Huxley smelled of pears and basil. Walter smelled of leather and soap. She didn’t smell Walter intentionally, of course. He walked into the White Dog the prior day while she was drinking a mint-mocha cappuccino and studying for an exam on medical physiology. The wind whiffed his odor towards her. She didn’t look at him, but she couldn’t stop from inhaling. “People get married after college,” Huxley swung his right leg over and straddled her, forcing her to look at him. “It’s almost been a year since we graduated. It’s what we should do.” She had wondered if he could donate organs if he were seventy-two years old. Not his liver or heart or anything like that, of course, but maybe his eyes. It’d be a shame if they couldn’t preserve his eyes. She noticed them first: they were alert and misty blue, like Santa’s. But then she wondered if eye characteristics like color were even changed during cornea transplants. Walter had plain brown eyes. She hated brown eyes. She told people that she had brown eyes, because they were dark and no one ever looked close enough. Except Huxley. They were at dinner with mutual friends and were talking about eye color, and how they all wished that theirs were like those of the young Afghan girl on the 1985 cover of National Geographic.

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Waterproofing agents are widely used to protect leather and textiles in both domestic and occupational activities. An outbreak of acute respiratory syndrome following exposure to waterproofing sprays occurred during the winter 2002-2003 in Switzerland. About 180 cases were reported by the Swiss Toxicological Information Centre between October 2002 and March 2003, whereas fewer than 10 cases per year had been recorded previously. The reported cases involved three brands of sprays containing a common waterproofing mixture, that had undergone a formulation change in the months preceding the outbreak. A retrospective analysis was undertaken in collaboration with the Swiss Toxicological Information Centre and the Swiss Registries for Interstitial and Orphan Lung Diseases to clarify the circumstances and possible causes of the observed health effects. Individual exposure data were generated with questionnaires and experimental emission measurements. The collected data was used to conduct numeric simulation for 102 cases of exposure. A classical two-zone model was used to assess the aerosol dispersion in the near- and far-field during spraying. The resulting assessed dose and exposure levels obtained were spread on large scales, of several orders of magnitude. No dose-response relationship was found between exposure indicators and health effects indicators (perceived severity and clinical indicators). Weak relationships were found between unspecific inflammatory response indicators (leukocytes, C-reactive protein) and the maximal exposure concentration. The results obtained disclose a high interindividual response variability and suggest that some indirect mechanism(s) predominates in the respiratory disease occurrence. Furthermore, no threshold could be found to define a safe level of exposure. These findings suggest that the improvement of environmental exposure conditions during spraying alone does not constitute a sufficient measure to prevent future outbreaks of waterproofing spray toxicity. More efficient preventive measures are needed prior to the marketing and distribution of new waterproofing agents.

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The purpose of this research was to continue the work of Thomas Parker, who worked on the recovery of copper and zinc from brass during the school year l934 - 1935. Since there is such a wide variety of brasses made with usually a third alloying constituent, remelt­ed scrap is suitable only for castings of wide tolerance in specifications.

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The reclamation of metals from scrap is becoming increasingly important in the metallurgical industry. Copper, because it does not corrode readily and is electronegative to most common metals, is peculiarly adapted to reclamation.

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There is a long tradition of river monitoring using macroinvertebrate communities to assess environmental quality in Europe. A promising alternative is the use of species life-history traits. Both methods, however, have relied on the time-consuming identification of taxa. River biotopes, 1-100 m**2 'habitats' with associated species assemblages, have long been seen as a useful and meaningful way of linking the ecology of macroinvertebrates and river hydro-morphology and can be used to assess hydro-morphological degradation in rivers. Taxonomic differences, however, between different rivers had prevented a general test of this concept until now. The species trait approach may overcome this obstacle across broad geographical areas, using biotopes as the hydro-morphological units which have characteristic species trait assemblages. We collected macroinvertebrate data from 512 discrete patches, comprising 13 river biotopes, from seven rivers in England and Wales. The aim was to test whether river biotopes were better predictors of macroinvertebrate trait profiles than taxonomic composition (genera, families, orders) in rivers, independently of the phylogenetic effects and catchment scale characteristics (i.e. hydrology, geography and land cover). We also tested whether species richness and diversity were better related to biotopes than to rivers. River biotopes explained 40% of the variance in macroinvertebrate trait profiles across the rivers, largely independently of catchment characteristics. There was a strong phylogenetic signature, however. River biotopes were about 50% better at predicting macroinvertebrate trait profiles than taxonomic composition across rivers, no matter which taxonomic resolution was used. River biotopes were better than river identity at explaining the variability in taxonomic richness and diversity (40% and <=10%, respectively). Detailed trait-biotope associations agreed with independent a priori predictions relating trait categories to near river bed flows. Hence, species traits provided a much needed mechanistic understanding and predictive ability across a broad geographical area. We show that integration of the multiple biological trait approach with river biotopes at the interface between ecology and hydro-morphology provides a wealth of new information and potential applications for river science and management.

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The Iranian textile industry still remains important as one of the largest sources of employment within the non-petroleum sector, although it no longer plays the large role it used in the country's economy (having been replaced by petroleum as the economy's primary industry). The subject of this study are middlemen known as namayande in the Iranian textile industry who plays a very important role in the operations of the innumerable small and medium-sized private firms. When private firms import materials from abroad, namayande make the connections between them and foreign sellers. These middlemen are not local sales agents of foreign companies as is usually the case; rather the namayande specialize in purchasing goods for local buyers. This study will point out some of the reasons why the namayande exist, and examine the present state of Iran's textile industry along with the particular management problems found within the firms' operations.

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Sheepskin market in Ethiopia seems to enjoy the benefits of the economic liberalization policy since 1991, such as price deregulation or liberalization of economic activities. The close observation on the profiles and activities of each actor in the marketing channel, however, illustrates that the actors have tried to complement the lack of appropriate infrastructure and legal protection, which should be provided by the government, through utilizing their social and blood ties. While these ties have implemented the role of the government, there are risks that the marketing channel might be developed based on coalition with social network and the poor without the network would be excluded.

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This paper sheds light on the iron and steel (IS) scrap trade to examine how economic development affects the quality demanded of recyclable resource. A simple model is presented that show a mechanism of how scrap quality impacts the direction of trade due to comparative advantage. We find that economic development in both importing and exporting countries has a positive effect on the quality of traded recyclables. Developed countries that intend to improve the domestic recovery of recyclables should raise the quality of separating recyclables while developing countries should tighten environmental regulations to help decrease the import of recyclables that cause pollution.

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Natural coral reefs are in a state of serious decline worldwide. The pressures of over fishing, recreational activities, environmental pollutants, and global warming have stressed these marine ecosystems to the breaking point. One of the oldest methods of augmenting natural reef systems is the implementation of artificial reefs. These projects are not as simple as dumping waste or scrap materials in offshore areas. Proper material selection is vital to produce a healthy artificial marine habitat that is completed on schedule and on budget. This Capstone Project will evaluate the most commonly used materials and provide a comparison of their strengths and weaknesses. This comparison provides a valuable tool for project managers as they begin the reef planning process.

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The leather-bound volume contains accounts for the Classes of 1650-1663 and Fellows. Many of the student bills were settled with payment in kind, often in the form of grain, apples, or livestock. The Steward's accounts with the College from 1656-1659 were entered on pages 295-303 and listed as "The steward is Creditor" and "The steward is Debitor." Credit entries include food, fuel, corn, and wages; debit entries list purchases and often identify the sellers.

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The volume, bound in a modern leather binding, contains accounts for the Classes of 1723-1731. Leaves 108-118 list the Steward's account with Harvard College arranged monthly for the years 1721-1729.