Characterization of a Limestone Powder Residue for Recycling as a Concrete Block Incorporation

2014 ◽  
Vol 798-799 ◽  
pp. 3-8 ◽  
Author(s):  
Jonas Alexandre ◽  
Afonso Rangel Garcez de Azevedo ◽  
Gustavo de Castro Xavier ◽  
Leonardo Gonçalves Pedroti ◽  
Carlos Maurício Fontes Vieira ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Physical Properties ◽  
Construction Material ◽  
Concrete Block ◽  
Limestone Powder ◽  
Small Particles ◽  
Microstructural Characteristics ◽  
Physical Chemical ◽  
Concrete Blocks

The mining and processing of limestone in the state of Rio de Janeiro, southeast of Brazil, generates a considerable amount of small particles, like a powder ,which is commercialized as a by product. In principle, this inert limestone powder could be recycled as part of another civil construction material. Thus, the objective of this work was to characterize a limestone powder by its physical properties, chemical analysis and microstructural aspects. The results were compared with the characteristics of a common cement and a conventional sand to be possibly applied in the fabrication of limestone incorporated concrete blocks. It was found that the limestone powder has physical, chemical and microstructural characteristics satisfactory for concrete blocks incorporation.

Effect of Banana Fibers on Mechanical and Physical Properties of Light Weight Concrete Blocks

2018 ◽  
Vol 879 ◽  
pp. 151-155 ◽  
Author(s):  
Woranuch Deelaman ◽  
Kantima Chaochanchaikul ◽  
Kitiyot Tungsudjawong
Keyword(s):  
Physical Properties ◽  
Water Absorption ◽  
Water Immersion ◽  
Concrete Block ◽  
Light Weight ◽  
Banana Fiber ◽  
Banana Fibers ◽  
Precursor Material ◽  
Mechanical And Physical Properties ◽  
Concrete Blocks

This work was to investigate the mechanical and physical properties of light weight block with addition of banana fiber. The formulation series of concrete block were divided into two groups: banana fiber for replacing cement and sand, respectively. Banana fibers were varied from 0.0 to 7.5 %wt. and were evaluated by compressive testing, density and water absorption and changing length at water immersion of 28 days. Optimum formulation of concrete adding banana fiber is ratio of sand: cement: lime: gypsum: aluminum powder: banana fibers: 50: 27.5: 9: 9: 2: 2.5, respectively. The increase of water absorption and changing length were found with increase of fiber content whereas the density decreased. However, the mechanical and physical properties of banana fiber/concrete block were subject to standard according to Thai Industrial Standard 1505-2541. From this study, it indicates that banana fiber can be used as an alternative precursor material for producing the light weight and cost effectiveness block.

Physical properties of La0.8Sr0.2MnO3nanotubes and fibers

2013 ◽  
Vol 1507 ◽  
Author(s):  
Daniel Felipe Simião ◽  
Alessandra Zenatti ◽  
Marcia T. Escote
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Physical Properties ◽  
Perovskite Structure ◽  
Physical Characterization ◽  
External Diameter ◽  
Ferromagnetic Transition ◽  
Microstructural Characteristics ◽  
Scanning Electron

ABSTRACTThis work describes the study of synthesis and physical characterization of nanostructured manganite oxides. The La0.8Sr0.2MnO3 (LSM) nanotubes and fibers have been prepared by electrospinning and pore wetting technique. The samples were characterized by Xray diffraction (XRD), scanning electron microscopy (SEM) and magnetization as a function of temperature (M(T)). XRD results of LSM fibers and nanotubes revealed that both samples crystallize in a rhombohedra-distorted perovskite structure. SEM pictures of these samples revealed ultrafine grains assembled in fibers and nanotubes samples. Analysis of these images revealed samples with external diameter ranging from 300 to 1.4 mm, and 7 μm to hundreds of mm in length. The M(T) measurements of samples La0.8Sr0.2MnO3 revealed a paramagnetic/ferromagnetic transition with decreasing temperature. Such transition occurs at temperatures of Tc ≈ 337 K and Tc ≈ 360 K for the nanotubes and fibers, respectively. Furthermore, this variation of the Tc values is also reported in literature for other manganite nanostructures. Such variation can be related to the microstructural characteristics observed for both LSM samples produced in this work. In general, it is believed that both methodologies allowed the production of nanostructures LSM. Also, these results suggest that the dimensionality of the samples seems to interfere in the physical properties of LSM manganite.

scholarly journals Side-scan sonar techniques for the characterization of physical properties of artificial benthic habitats

2011 ◽  
Vol 59 (spe1) ◽  
pp. 77-90 ◽  
Author(s):  
Wen-Miin Tian
Keyword(s):  
Physical Properties ◽  
Concrete Block ◽  
Artificial Reefs ◽  
Artificial Habitat ◽  
Benthic Habitats ◽  
Side Scan Sonar ◽  
Resources Management ◽  
Database Structure ◽  
Site Identification

Side-scan sonar observations conducted at Mito artificial habitat site in the southwest coast off Taiwan, documented the locations of both concrete cubic blocks (more than 10,000 units) and scrapped steel boats (39 units) deployed previously. Based on their geographic locations, the concrete cubic artificial reefs could be grouped into 14 reef sets. About 30% of the reefs were deployed out of the promulgated site area. For the purpose of artificial habitat site identification and fishery resources management, a database structure was designed to accommodate types and positions of reefs, information of reef sets, bathymetric contours, textures of bottom sediments and geomorphological characteristics. The effectiveness of Mito artificial habitat site was evaluated to be positive after the deployment of both concrete block reefs and steel boat reefs.

Characterization of Particulates Accompanying Laser Ablation of NaNO3

1997 ◽  
Vol 51 (5) ◽  
pp. 707-717 ◽  
Author(s):  
R. L. Webb ◽  
J. T. Dickinson ◽  
G. J. Exarhos
Keyword(s):  
Laser Ablation ◽  
Chemical Analysis ◽  
Single Crystal ◽  
Electric Charge ◽  
Atmospheric Pressure ◽  
Charged Particles ◽  
High Fluence ◽  
Small Particles ◽  
Many Particles

We present observations of submicrometer- to micrometer-sized particles generated by high-fluence (≥10 J/cm2) 248-nm laser ablation of single-crystal NaNO3 in vacuum and at atmospheric pressure. Small particles (50–200 nm in diameter) are ejected by hydrodynamic sputtering. Larger particles (1–20 μm in diameter) are produced by cavitation and spallation in the melt. Many particles formed in air carry electric charge, with roughly equal numbers of positively and negatively charged particles. The particle composition is consistent with substantial nitrate decomposition. The implications of these observations with respect to laser-based chemical analysis are discussed.

scholarly journals Application of Lignite Combustion Waste Slag Generated in Heating Plants as a Partial Replacement for Cement. Part II: Physical–Mechanical and Physical–Chemical Characterization of Mortar and Concrete

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 925
Author(s):  
Milan Kragović ◽  
Nenad Ristić ◽  
Jelena Gulicovski ◽  
Andrijana Nedeljković ◽  
Snežana Pašalić ◽  
...  
Keyword(s):  
Construction Material ◽  
Chemical Characterization ◽  
Physical And Mechanical Properties ◽  
Partial Replacement ◽  
Test Results ◽  
Cement Replacement ◽  
Physical Chemical ◽  
Standard Procedures ◽  
Concrete Production

The presented study is a continuation of the research with the aim of finding a useful value of hazardous waste slag generated by the combustion of lignite in heating plants and its application in the construction industry. The different amounts of cement (10, 15, 20 and 25%) were replaced with waste slag and silica fumes in mortars and concrete production. Detailed physical–mechanical characterization was performed on the mortar and concrete samples according to standard procedures. Test results indicated that the replacement of cement with slag and silica fumes reduces the physical and mechanical properties of mortar and concrete, but cement composites retained the required structural properties. If 15–20% is considered an acceptable level of compressive strength decrease, then it can be concluded that waste slag can be implemented in practice and be used as a construction material, with cement replacement in the maximal amount of 20% (17.8% of slag and 2.2% of silica fumes). On hardened mortar samples with maximal possible cement replacement (20%), physical–chemical characterizations were performed and included X-ray and infrared spectrophotometry, scanning electron microscopy, and thermal analysis. Results showed the absence of new phases and the presence of only those which were characteristic for starting samples, predominantly portlandite, quartz, calcite and calcium silicate-oxide.

scholarly journals ELABORATION AND PHYSICAL-CHEMICAL AND SENSORIAL CHARACTERIZATION OF DRIED BANANA FLAVORED WITH SPICES

2021 ◽  
Vol 36 (1) ◽  
pp. 145-154
Author(s):  
Alissandra de Oliveira Souza ◽  
Rosane Liege Alves de Souza ◽  
Emanuel Neto Alves de Oliveira ◽  
Natieli Piovesan
Keyword(s):  
Chemical Analysis ◽  
Water Content ◽  
Sensory Evaluation ◽  
Water Activity ◽  
Room Temperature ◽  
Reducing Sugars ◽  
Osmotic Dehydration ◽  
Rio Grande ◽  
Physical Chemical

ELABORATION AND PHYSICAL-CHEMICAL AND SENSORIAL CHARACTERIZATION OF DRIED BANANA FLAVORED WITH SPICES   ALISSANDRA DE OLIVEIRA SOUZA1, ROSANE LIÉGE ALVES DE SOUZA2, EMANUEL NETO ALVES DE OLIVEIRA3, NATIELI PIOVESAN4   1 Instituto de Educação, Ciência e Tecnologia do Rio Grande do Norte, BR 405, Km 154, Chico Cajá, 59900-000, Pau dos Ferros, RN, Brasil, [email protected]. 2 Departamento de Gastronomia, Universidade Federal da Paraíba, Rua dos Escoteiros, s/n - Mangabeira, 58058-600, João Pessoa, PB, Brasil, [email protected]. 3 Instituto de Educação, Ciência e Tecnologia do Rio Grande do Norte, BR 405, Km 154, Chico Cajá, 59900-000, Pau dos Ferros, RN, Brasil, [email protected]. 4 Instituto de Educação, Ciência e Tecnologia do Rio Grande do Norte, BR 405, Km 154, Chico Cajá, 59900-000, Pau dos Ferros, RN, Brasil, [email protected].   ABSTRACT: Brazil is the fifth largest producer of banana. However, there are significant losses due to transportation and its high perishability and. The osmotic dehydration followed by drying can add value to the product, reduce transportation costs, decrease the acidity, and heighten the taste of the original fruit. Therefore, the work aimed to elaborate dried banana using osmotic dehydration followed by drying, flavored with spices, and to evaluate the physical-chemical and sensorial characteristics. The fresh and flavored bananas were submitted to the physical-chemical analysis. The final product also underwent a sensory evaluation. The water content parameter was according to the legislation for dehydrated fruit. The water activity of the treatments decreased compared to the fresh product, favoring the conservation at room temperature. The reducing sugars increased and were entirely accounted for in the dried banana seasoned with clove and cinnamon. Treatments with clove and fennel were accepted for the attributes of appearance, color, and firmness, but did not present sensory characteristics superior to traditional bananas. Only the dried banana flavored with cinnamon-presented acceptability index higher than 70% for the flavor attribute. However, it is worth noting that this refers to the new food with a peculiar taste.   Keywords: Pacovan, flavorization, osmotic dehydration.   ELABORAÇÃO E CARACTERIZAÇÃO FÍSICO-QUÍMICA E SENSORIAL DE BANANA PASSA SABORIZADA COM ESPECIARIAS   RESUMO: O Brasil é o quinto maior produtor de banana, porém as perdas pela alta perecibilidade e transporte são significativas. A desidratação osmótica seguida de secagem, pode agregar valor, reduzir custos com transporte, diminuir a acidez e elevar o sabor da fruta original. Desta forma, o objetivo do trabalho foi elaborar bananas passa por desidratação osmótica seguida de secagem, saborizadas com especiarias e avaliar as características físico-química e sensoriais. A banana in natura e as saborizadas foram submetidas a análises físico-químicas. O produto final também passou por avaliação sensorial. A umidade concordou com a legislação para fruta desidratada, já a atividade de água diminuiu do produto in natura para os tratamentos, favorecendo a conservação a temperatura ambiente. Já os açúcares redutores se elevaram, sendo totalmente contabilizados na banana passa com cravo-da-índia e canela. Os tratamentos com cravo-da-índia e erva-doce foram aceitos nos atributos de aparência, cor e firmeza, porém não apresentaram características sensoriais superiores a banana passa tradicional. Apenas a saborizada com canela teve índice de aceitabilidade maior do que 70% para o atributo sabor. No entanto, vale salientar que refere-se a alimento novo com sabor peculiar.   Palavras-chave: Pacovan, saborização, desidratação osmótica.

High-resolution electron microscopy of nanostructured materials

1995 ◽  
Vol 53 ◽  
pp. 172-173
Author(s):  
M. José-Yacamán
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Grain Boundaries ◽  
Nanostructured Materials ◽  
High Resolution Electron Microscopy ◽  
Hrem Image ◽  
Small Particles ◽  
Resolution Electron ◽  
Nanophase Materials

Electron microscopy is a fundamental tool in materials characterization. In the case of nanostructured materials we are looking for features with a size in the nanometer range. Therefore often the conventional TEM techniques are not enough for characterization of nanophases. High Resolution Electron Microscopy (HREM), is a key technique in order to characterize those materials with a resolution of ~ 1.7A. High resolution studies of metallic nanostructured materials has been also reported in the literature. It is concluded that boundaries in nanophase materials are similar in structure to the regular grain boundaries. That work therefore did not confirm the early hipothesis on the field that grain boundaries in nanostructured materials have a special behavior. We will show in this paper that by a combination of HREM image processing, and image calculations, it is possible to prove that small particles and coalesced grains have a significant surface roughness, as well as large internal strain.

ALGOMA AR225

Alloy Digest ◽  
2003 ◽  
Vol 52 (12) ◽  
Keyword(s):  
Carbon Steel ◽  
Chemical Analysis ◽  
Physical Properties ◽  
Carbon Content ◽  
Brinell Hardness ◽  
Low Cost ◽  
Heat Treating ◽  
Rolled Plate ◽  
High Carbon ◽  
High Carbon Content

Abstract Algoma AR225 is a carbon steel developed primarily to supply a low-cost material for high-abrasion applications. It is furnished in the form of as-rolled plate with a relatively high carbon content (0.35-0.45%). AR-225 is sold on the basis of chemical analysis only; the number 225 signifies the approximate Brinell hardness. On thicknesses one-half inch and over, this Brinell value may be lower than 225 because of higher finishing temperatures. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, machining, and joining. Filing Code: CS-138. Producer or source: Algoma Steel Corporation Ltd.

New Coordination Compounds of Fe(III) with Organic Ligands

2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Mihaela Flondor ◽  
Ioan Rosca ◽  
Doina Sibiescu ◽  
Mihaela-Aurelia Vizitiu ◽  
Daniel-Mircea Sutiman ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Complex Compounds ◽  
Organic Ligands ◽  
X Ray Diffraction ◽  
X Ray ◽  
Elemental Chemical Analysis ◽  
Structural Formulae ◽  
Paramagnetic Properties

In this paper the synthesis and the study of some complex compounds of Fe(III) with ligands derived from: 2-(4-chloro-phenylsulfanyl)-1-(2-hydroxy-3,5-diiodo-phenyl)-ethanone (HL1), 1-(3,5-dibromo-2-hydroxy-phenyl)-2-phenylsulfanyl-ethanone(HL2), and 2-(4-chloro-phenylsulfanyl)-1-(3,5-dibromo-2-hydroxy-phenyl)-ethanone (HL3) is presented. The characterization of these complexes is based on method as: the elemental chemical analysis, IR and ESR spectroscopy, M�ssbauer, the thermogravimetric analysis and X-ray diffraction. Study of the IR and chemical analysis has evidenced that the precipitates form are a complexes and the combination ratio of M:L is 1:2. The central atoms of Fe(III) presented paramagnetic properties and a octaedric hybridization. Starting from this precipitation reactions, a method for the gravimetric determination of Fe(III) with this organic ligands has been possible. Based on the experimental data on literature indications, the structural formulae of the complex compounds are assigned.

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