IMPACTOS AMBIENTAIS CAUSADOS POR ATIVIDADE DE MINERAÇÃO DE AREIA EM DUNAS FIXAS, CAUCAIA, CEARÁ

2019 ◽  
Vol 21 (2) ◽  
pp. 1060-1069
Author(s):  
Letícia De Freitas Vieira ◽  
Antonio Jeovah De Andrade Meireles ◽  
Henrique Sampaio De Castro
Keyword(s):  
Environmental Impact ◽  
Construction Industry ◽  
Interaction Matrix ◽  
Office Work ◽  
Check List ◽  
Landscape Characterization ◽  
High Magnitude ◽  
Negative Impacts

Este trabalho propõe-se em trazer uma discussão acerca da mineração, enfocando nos impactos ambientais causados pela extração de agregados para a construção civil. A área de estudo é uma poligonal de 44,8 hectares, licenciada para extrair areia até 2018. Localizada em uma duna fixa, foi possível constatar os impactos relacionados com o desmatamento, retirada do solo e do minério, mudança topográfica e o afloramento do lençol freático. A metodologia consistiu em trabalho de campo, gabinete e aplicações de métodos da Avaliação de Impactos Ambientais que foram a Metodologia de listagem (Check-list) e Matrizes de interações. Através dessas metodologias, alguns dos resultados obtidos foram a descaracterização da paisagem, a determinação dos processos evolutivos do campo de dunas com a extração mineral e o afloramento do lençol freático. Por meio do check-list, foram elencados os impactos positivos e negativos, e a matriz de interações relacionou os impactos do empreendimento com o meio ambiente. Baseado nos resultados, concluiu-se que os impactos da mineração são 44% negativos e apenas 6% positivos e que, na maioria dos casos, o impacto ambiental foi de elevada magnitude, representando atividade nitidamente insustentável no âmbito social e ambiental.Palavras-chave: Mineração; Descaracterização da paisagem; Impacto ambiental. ABSTRACTThe present work proposes a discussion about mining, with emphasis on the environmental impacts caused by the extraction of aggregates for the construction industry. The study area is a 44.8 hectare polygon that was auctioned for sand extraction until 2018. Located on a fixed dune, Related to: deforestation, removal of vegetation, soil and ore, topographic change and outcropping of groundwater . The methodology consisted of fieldwork, office work and the applications Environmental Impact Assessment Methods that were the List Methodology (Checklist) and Interaction Matrices. Through these methodologies, some of the results obtained were the de-characterization of the landscape,The determination of the evolutionary processes of the dune field with the mineral extraction and the outcrop of the water table Positive and negative impacts were listed throughout the checklist and the interaction matrix related to development impacts within the environment. Based on the results, it was concluded that the impacts of mining are 44% negative and only 6% positive and that in most cases, the environmental impact was of high magnitude, representing a clearly unsustainable social and environmental activity.Keywords: Mining; Landscape characterization; Environmental impact.

scholarly journals Effect of type cement on the mechanical strength of copper slag mortars

2013 ◽  
Vol 66 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Amin Nazer ◽  
Osvaldo Pavez ◽  
Ithamar Toledo
Keyword(s):  
Environmental Impact ◽  
Flexural Strength ◽  
Construction Industry ◽  
Mechanical Characteristics ◽  
Copper Slag ◽  
Cement Mortars ◽  
Alternative Material ◽  
Binder Type ◽  
Initial Resistance

Copper slag is a massive metallurgist waste. Annual production rises up to 24.6 million tons, approximately, and the main environmental impact derived from slag disposal is the usage of great soil extensions and the resulting visual contamination of the landscape. Along time, copper slag has been used in the manufacture of concrete and cement mortars. Thus, with the aim of verifying binder-type influence in the final hardness of mortars, two types of cement were used: regular cement and high initial resistance cement. Copper slag was characterized from the chemical, mineralogical and grading viewpoints. Official Chilean regulations were used in the applied methodology for the determination of some important slag parameters. Compression and flexural strength trials were carried out on cement mortars in specialized laboratories. The obtained results showed that mortars manufactured with copper slag presented a better resistance to compression and flexural strength than mortars manufactured with normal sand, and those made with high initial resistance cement were even better. It can be concluded from this work that copper slag offers optimal mechanical characteristics to be used in the manufacturing of cement mortars, becoming a sustainable and adequate alternative material for usage in the construction industry.

scholarly journals Recycling Construction and Demolition Residues in Clay Bricks

2021 ◽  
Vol 11 (19) ◽  
pp. 8918
Author(s):  
Chiara Zanelli ◽  
Elena Marrocchino ◽  
Guia Guarini ◽  
Alice Toffano ◽  
Carmela Vaccaro ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Environmental Impact ◽  
Construction Industry ◽  
Mineralogical Composition ◽  
Processing Plant ◽  
Fine Grained ◽  
Technical Performance ◽  
Clay Bricks ◽  
Compositional Properties

In recent years, the management of construction and demolition residues (CDRs) has become a major challenge for the construction industry due to the increasing volume of waste produced and its associated environmental impact. The aim of this article is to assess the effect of fine-grained fractions (<0.125 mm–0.6–0.125 mm) of construction and demolition residues, obtained by industrial sorting in a CDR processing plant in Rovigo (Italy), on the technological behavior and technical performance of clay bricks. Simulating the brickmaking process on a laboratory scale, it was appraised whether the CDR additions determined any change in the main properties of both fired and unfired bricks, taking a CDR-free brick body as a reference. The results indicated that the use of CDR is technologically feasible. It is possible to obtain, through proper crushing and sorting operations, grain-sized fractions with quite homogenous chemical and mineralogical composition. The residues did affect the compositional properties, porosity and water absorption of the clay bricks. Nevertheless, the characterization of the residual-added semi-finished and fired products highlighted their good technological and mechanical properties, which allowed them to provide performances similar to those of standard bricks manufactured with raw natural materials.

scholarly journals PERFIL AMBIENTAL QUALITATIVO DE UMA MARCENARIA NA CIDADE DE VIÇOSA, MG

FLORESTA ◽  
2011 ◽  
Vol 41 (3) ◽  
Author(s):  
Michele Karina Cotta Walter ◽  
Ricardo Ribeiro Alves ◽  
Elias Silva ◽  
Laércio Antônio Gonçalves Jacovine ◽  
Naisy Silva Soares ◽  
...  
Keyword(s):  
Environmental Impacts ◽  
Negative Impact ◽  
Minas Gerais ◽  
Qualitative Assessment ◽  
Check List ◽  
Forestry Sector ◽  
Quality Profile ◽  
Local Medium ◽  
Negative Impacts

O ramo de marcenaria se insere no setor florestal, sendo que diversos impactos positivos e negativos advêm desse tipo de indústria. Assim, o presente estudo teve como objetivo avaliar o perfil ambiental qualitativo de uma marcenaria na cidade de Viçosa, Minas Gerais. A identificação e a caracterização dos impactos ambientais foram realizadas utilizando-se o método do “check-list” e a avaliação qualitativa dos impactos por meio do método das matrizes de interação. Foram identificadas treze atividades impactantes referentes à fase de operação da marcenaria. A maioria dos impactos foi classificada como Negativo, Direto, Local, de Médio Prazo, Temporário e Reversível (NDLMTV), estando 41% relacionados ao meio físico, 35% ao meio biótico, e 24% ao meio antrópico. Foram delineadas 39 medidas mitigadoras e potencializadoras para o empreendimento. Conclui-se que os impactos ambientais identificados na marcenaria podem ser mitigados ou potencializados por meio de ações relativamente simples, visto que foram classificados, na maior parte dos casos, como temporários e reversíveis.Palavras-chave: Impacto ambiental; meio ambiente; produção de móveis. AbstractQualitative environmental profile of a joinery company at Viçosa, MG. The branch of joineries is one of activities impacting on the forestry sector. Several positive and negative impacts arise from this kind of industry. This study aimed to evaluate the environmental quality profile of a joinery company in the city of Viçosa, Minas Gerais. The identification and characterization of the environmental impacts were done according to the "check-list 'and qualitative assessment of impacts using the method of interaction matrices. We identified fifteen impacting activities on the stage of operation of the woodwork. Most of the impacts were classified as a negative impact, Direct, Local, Medium Term, Temporary and Reversible (NDLMTV), as well as 41% related to physical environment, 35% to biota, and 24% to man. We outlined 39 mitigating and potential actions to the venture. It concludes that environmental impacts identified in joinery can be mitigated or enhanced by relatively simple actions, which had been classified in a large amount of situations as temporary and reversible.Keywords: Environmental impact; environment; furniture production.

Characterization of Impressed Current Technique to Model Corrosion of Reinforcement in Concrete

2020 ◽  
Vol 11 (1) ◽  
pp. 93-99
Author(s):  
Abu Zakir Morshed ◽  
Sheikh Shakib ◽  
Tanzim Jahin
Keyword(s):  
Immersion Time ◽  
Chloride Content ◽  
Engineering Science ◽  
Coastal Regions ◽  
Faraday’S Law ◽  
Current Technique ◽  
Corrosion Cell ◽  
Impressed Current

Corrosion of reinforcement is an important durability concern for the structures exposed to coastal regions. Since corrosion of reinforcement involves long periods of time, impressed current technique is usually used to accelerate the corrosion of reinforcement in laboratories. Characterization of impressed current technique was the main focus of this research,which involved determination of optimum chloride content and minimum immersion time of specimens for which the application of Faraday’s law could be efficient. To obtain optimum chloride content, the electrolytes in the corrosion cell were prepared similar to that of concrete pore solutions. Concrete prisms of 200 mm by 200 mm by 300 mm were used to determine the minimum immersion time for saturation. It was found that the optimum chloride content was 35 gm/L and the minimum immersion time for saturation was 140 hours. Accounting the results, a modified expression based on Faraday’s law was proposed to calculate weight loss due to corrosion. Journal of Engineering Science 11(1), 2020, 93-99

The Determination of Sense via Deleuze and Blanchot: Paradoxes of the Habitual, the Immemorial, and the Eternal Return

2008 ◽  
Vol 2 (2) ◽  
pp. 155-177 ◽  
Author(s):  
Eugene Brently Young
Keyword(s):  
Eternal Return

Eternal return is the paradox that accounts for the interplay between difference and repetition, a dynamic at the heart of Deleuze's philosophy, and Blanchot's approach to this paradox, even and especially through what it elides, further illuminates it. Deleuze draws on Blanchot's characterisations of difference, forgetting, and the unlivable to depict the ‘sense’ produced via eternal return, which, for Blanchot, is where repetition implicates or ‘carries’ pure difference. However, for Deleuze, difference and the unlivable are also developed by the living repetition or ‘contraction’ of habit, which results in his distinctive characterization of ‘force’, ‘levity’, and sense in eternal return.

SEM/EDS Characterization of Uncommon Metal Whiskers and Determination of Underlying Growth Mechanisms

2018 ◽  
Author(s):  
D. Basak ◽  
L. H. Ponce
Keyword(s):  
Reliability Analysis ◽  
Case Studies ◽  
Whisker Growth ◽  
Innovation Systems ◽  
Growth Mechanisms ◽  
Crystal Oscillator ◽  
Analysis Laboratory ◽  
Investigative Techniques

Abstract Two case-studies on uncommon metals whiskers, performed at the Reliability Analysis Laboratory (RAL) of Northrop Grumman Innovation Systems, are presented. The components analyzed are an Oven Controlled Crystal Oscillator (OCXO) and an Electromechanical Relay. Investigative techniques were used to determine the chemical and physical makeup of the metal whiskers and develop an understanding of the underlying effects and mechanisms that caused the conditions conducive to whisker growth.

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