Reutilização de imóveis de interesse patrimonial, voltados para a ahabitação: um estudo de caso na Ribeira-Natal/RN

This work analyzes the reutilization of real estate of patrimonial interest, come back toward habitation. One understands as real estate of patrimonial interest the old ones that present relevant architectural typologies that must be preserved; some buildings that represent characteristic architectural styles of a determined period; some valued real estates for the history of the city (historical, memory and image signification that has of certain places) and buildings with exceptional artistic elements. In short, real estate of patrimonial interest. The place or site to be studied will be the neighborhood of the Ribeira, because is an area that protects a bigger interest for the historic patrimony of the city. The habitation use was thought as a booster element of revitalization processes of degradable historic site, contributing to the preservation of artistic, architectural and historic patrimony, and thus to stimulate the accomplishment of the re-qualification of the neighborhood of the Ribeira. It is intended with the present study to examine alternatives to make possible habitation re (uses) in the historical quarter of the Ribeira in old constructions of patrimonial value

Desenvolvimento de cerâmica vermelha utilizando rejeitos da construção civil

The Industry of the Civil Construction has been one of the sectors that most contribute to the pollution of the environment, due to the great amount of residues generated by the construction, demolition and the extraction of raw material. As a way of minimizing the environmental impacts generated by this industry, some governmental organizations have elaborated laws and measures about the disposal of residues from the building construction (CONAMA - resolution 307). This work has as objective the reutilization of residues compound of sand, concrete, cement, red bricks and blocks of cement and mortar for the production of red ceramic, with the objective of minimizing costs and environmental impacts. The investigated samples contained 0% to 50% of residues in weight, and they were sintered at temperatures of 950°C, 1000°C, 1050°C, 1100°C and 1150°C. After the sinterization, the samples were submitted to tests of absorption of water, linear retraction, resistance to bending, apparent porosity, specific density, XRD and SEM. Satisfactory results were obtained in all studied compositions, with the possible incorporation of up to 50% of residues in ceramic mass without great losses in the mechanical strength, giving better results to the incorporation of 30% of residues in the fabrication of ceramic parts, such as roofing tiles, bricks masonry and pierced bricks

Copper Nanoparticles in Click Chemistry

Conspectus: The challenges of the 21st century demand scientific and technological achievements that must be developed under sustainable and environmentally benign practices. In this vein, click chemistry and green chemistry walk hand in hand on a pathway of rigorous principles that help to safeguard the health of our planet against negligent and uncontrolled production. Copper-catalyzed azide–alkyne cycloaddition (CuAAC), the paradigm of a click reaction, is one of the most reliable and widespread synthetic transformations in organic chemistry, with multidisciplinary applications. Nanocatalysis is a green chemistry tool that can increase the inherent effectiveness of CuAAC because of the enhanced catalytic activity of nanostructured metals and their plausible reutilization capability as heterogeneous catalysts. This Account describes our contribution to click chemistry using unsupported and supported copper nanoparticles (CuNPs) as catalysts prepared by chemical reduction. Cu(0)NPs (3.0 ± 1.5 nm) in tetrahydrofuran were found to catalyze the reaction of terminal alkynes and organic azides in the presence of triethylamine at rates comparable to those achieved under microwave heating (10–30 min in most cases). Unfortunately, the CuNPs underwent dissolution under the reaction conditions and consequently could not be recovered. Compelling experimental evidence on the in situ generation of highly reactive copper(I) chloride and the participation of copper(I) acetylides was provided. The supported CuNPs were found to be more robust and efficient catalyst than the unsupported counterpart in the following terms: (a) the multicomponent variant of CuAAC could be applied; (b) the metal loading could be substantially decreased; (c) reactions could be conducted in neat water; and (d) the catalyst could be recovered easily and reutilized. In particular, the catalyst composed of oxidized CuNPs (Cu2O/CuO, 6.0 ± 2.0 nm) supported on carbon (CuNPs/C) was shown to be highly versatile and very effective in the multicomponent and regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles in water from organic halides as azido precursors; magnetically recoverable CuNPs (3.0 ± 0.8 nm) supported on MagSilica could be alternatively used for the same purpose under similar conditions. Incorporation of an aromatic substituent at the 1-position of the triazole could be accomplished using the same CuNPs/C catalytic system starting from aryldiazonium salts or anilines as azido precursors. CuNPs/C in water also catalyzed the regioselective double-click synthesis of β-hydroxy-1,2,3-triazoles from epoxides. Furthermore, alkenes could be also used as azido precursors through a one-pot CuNPs/C-catalyzed azidosulfenylation–CuAAC sequential protocol, providing β-methylsulfanyl-1,2,3-triazoles in a stereo- and regioselective manner. In all types of reaction studied, CuNPs/C exhibited better behavior than some commercial copper catalysts with regard to the metal loading, reaction time, yield, and recyclability. Therefore, the results of this study also highlight the utility of nanosized copper in click chemistry compared with bulk copper sources.

Reutilização de imóveis de interesse patrimonial, voltados para a ahabitação: um estudo de caso na Ribeira-Natal/RN

This work analyzes the reutilization of real estate of patrimonial interest, come back toward habitation. One understands as real estate of patrimonial interest the old ones that present relevant architectural typologies that must be preserved; some buildings that represent characteristic architectural styles of a determined period; some valued real estates for the history of the city (historical, memory and image signification that has of certain places) and buildings with exceptional artistic elements. In short, real estate of patrimonial interest. The place or site to be studied will be the neighborhood of the Ribeira, because is an area that protects a bigger interest for the historic patrimony of the city. The habitation use was thought as a booster element of revitalization processes of degradable historic site, contributing to the preservation of artistic, architectural and historic patrimony, and thus to stimulate the accomplishment of the re-qualification of the neighborhood of the Ribeira. It is intended with the present study to examine alternatives to make possible habitation re (uses) in the historical quarter of the Ribeira in old constructions of patrimonial value