scholarly journals Characterization of a New Lightened Gypsum-Based Material Reinforced with Fibers

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1203
Author(s):  
Manuel Álvarez ◽  
Daniel Ferrández ◽  
Carlos Morón ◽  
Evangelina Atanes-Sánchez
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Statistical Analysis ◽  
Chemical Analysis ◽  
Polyvinyl Acetate ◽  
Boric Acid Solution ◽  
Polymeric Compound ◽  
Physico Chemical ◽  
The Mean

This paper shows the characterization of a new lightened gypsum-based material for use in buildings. A plaster material has been designed with a polymeric compound based on polyvinyl acetate, bicarbonate and a boric acid solution, which reduce the density and thermal conductivity by up to 20% and 30%, respectively. In addition, tests have been carried out with the lightened plaster material reinforced with glass (GF), basalt (BF), polypropylene (PPF) and wood (WF) fibers. A significant improvement in mechanical properties was achieved. All samples obtained resistance values greater than 2 MPa in flexion and 3 MPa in compression. Physico-chemical analysis were also carried out. The study is completed with a statistical analysis, where confidence intervals have been obtained for the mean at 95% confidence for each of the physical properties studied.

Preparation and Characterization of In Situ Nanocomposites of Graphene Nanosheets/Polyurethane

2019 ◽  
Vol 814 ◽  
pp. 90-95 ◽  
Author(s):  
Guang Lei Lv ◽  
Yuan Yuan Li ◽  
Chen Fei ◽  
Zhi Hao Shan ◽  
Jing Gan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Tensile Strength ◽  
Graphene Nanosheets ◽  
Graphene Sheets ◽  
Microstructural Properties ◽  
Wear Performance ◽  
Polyurethane Composites

Graphene nanosheets/polyurethane (GNS/PU) was prepared in situ by polymerization technique for the manufacture of PU safety shoes soles. The graphene nanosheets/polyurethane composites were characterized for their mechanical properties, thermal conductivity and abrasion resistance, and comparison is made with those of the neat polyurethane. The microstructural properties of GNS/PU were characterized by SEM. The results show that with the increase of the amount of graphene within the range of weight-percentages analyzed, the tensile strength of the composites gradually increases. The tensile strength of the GNS/PU composites increased to 64.14 MPa with 2 wt% GNS, compared with 55.1 MPa for neat PU. When the graphene sheets reached 2 wt%, the abrasion volume reached 71 mm3. Compared with the pure PU, the wear performance of GNS/PU composites was significantly improved.

Preparation and characterization of surface modified boron nitride epoxy composites with enhanced thermal conductivity

RSC Advances ◽  
2014 ◽  
Vol 4 (83) ◽  
pp. 44282-44290 ◽  
Author(s):  
Jun Hou ◽  
Guohua Li ◽  
Na Yang ◽  
Lili Qin ◽  
Maryam E. Grami ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Boron Nitride ◽  
High Thermal Conductivity ◽  
Epoxy Composites ◽  
Surface Modified ◽  
Enhanced Thermal Conductivity ◽  
Electrical Insulation Properties

The fabricated surface modified boron nitride epoxy composites exhibit high thermal conductivity, superior thermal stability and good mechanical properties while retaining good electrical insulation properties.

scholarly journals Sensoryal and Physico-chemical Analysis of Curd Used for Cheese Production

2012 ◽  
Vol 69 (2) ◽  
Author(s):  
Mirela JIMBOREAN ◽  
Dorin Å¢IBULCÄ‚ ◽  
Adriana PÄ‚UCEAN
Keyword(s):  
Statistical Analysis ◽  
Chemical Analysis ◽  
Water Content ◽  
Dry Matter ◽  
Chemical Characteristics ◽  
Physico Chemical ◽  
Taste And Smell ◽  
Cheese Production

The present work aim was to assess the sensorial characteristics (colour, taste and smell) and also the physico-chemical characteristics (acidity, fat, dry matter and water content) of ripened curd. A total of 100 samples of curd were analyzed. The curd samples were collected seasonally, 25 samples each season. The obtained data were subjected to statistical analysis.

Preparation and characterization of phenolic foam reinforced with expandable graphite and expanded graphite

2017 ◽  
Vol 54 (3) ◽  
pp. 545-559 ◽  
Author(s):  
Kejing Yu ◽  
Xia Luo ◽  
Menglei Wang ◽  
Kun Qian
Keyword(s):  
Mechanical Properties ◽  
Expanded Graphite ◽  
Expandable Graphite ◽  
Test Results ◽  
Compressive Test ◽  
Compression Performance ◽  
Phenolic Foam ◽  
Mean Diameter ◽  
The Mean

In this paper, two kinds of phenolic foams modified with expandable graphite and expanded graphite were prepared and the effect of particles on the mechanical properties and structure of the foams has been discussed. The mechanical properties, density and morphology of reinforced phenolic foams were studied. The images of scanning electron microscope showed that the size of the modified phenolic foams was smaller and more complete. The mean diameter of the expanded graphite-reinforced phenolic foams was smaller than that of the expandable graphite-reinforced phenolic foams due to the specific surface area of the expanded graphite. The compressive test results showed that the expandable graphite and expanded graphite could enhance the mechanical properties of the foams obviously. And the smaller cell size of the expanded graphite-reinforced foams provided them better mechanical properties. When the addition of the reinforcement reached to 0.8 wt%, the reinforced phenolic foams showed the best compression performance. The compressive strength and modulus with the 0.8 wt% expandable graphite were increased by 70% and 48% and that with the 0.8 wt% expanded graphite were increased by 80% and 69%.

Preparation and Characterization of GNP/Nylon Composites

2014 ◽  
Vol 556-562 ◽  
pp. 339-342 ◽  
Author(s):  
Bao Feng Xu ◽  
Zhi Dan Lin ◽  
Jiang Ming Chen ◽  
Jun Lin
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Graphene Nanoplatelets ◽  
Melt Blending ◽  
Blending Method

Graphene nanoplatelets (GNP) and nylon (PA) have been often used as thermal filler and matrix and respectively to produce composites. In this work, PA6/PA66/GNP thermal composites were prepared via a melt blending method. Mechanical properties, morphology, and thermal properties of PA6/PA66/GNP composites were investigated. Because the GNP is very expensive, we investigated to use Al2O3 and graphite and examined the characteristics of the prepared composites. Thermal conductivity values of PA6/PA66/GNP composites remarkably increased with increase of GNP contents mainly via layered dispersion in nylon matrix. The thermal conductivity of composite containing 50 wt % of GNP was measured as 5.03 W·m–1·K–1 at 30 °C, indicating an increase of more than 15 times compared with that of the neat PA6. When the Al2O3 was replaced for GNP, the thermal conductivity of composites decreased, but the mechanical properties improved. When graphite was used to replace for GNP, thermal conductivity basically remained unchanged but mechanical properties decreased.

scholarly journals Influence of the Cooling Rate on the Morphology of Spheroidic Graphite Obtained by the CO2 Process

2013 ◽  
Vol 8 (22) ◽  
pp. 37
Author(s):  
Mauro Carlos Souza ◽  
Antonio Carlos de Araújo Santos ◽  
Wilma Clemente de Lima Pinto ◽  
Mila Rosendal Avelino
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Chemical Analysis ◽  
Cooling Rate ◽  
Processing Parameters ◽  
Mechanical Resistance ◽  
Metallic Materials ◽  
Metallurgical Processing ◽  
Resistance Tests

The mechanical properties of cast metallic materials are strongly influenced by processing parameters, such as percentage of silicate, sand granulometry, and metallurgical processing. The ductile iron cast produced by the CO2 process depends on variables that determine the behavior of the material in service, such as the cooling rate and chemical composition. This study evaluated the influence of the cooling rate on the spheroidic graphite. In order to determine this effect, a simulation was performed in specimens with 20, 25, and 30 mm in thickness, through the characterization of type, measurement of nodule size, and distribution of nodules. Chemical analysis and mechanical resistance tests were performed. The 25 mm thick specimen showed the best behavior among the three thicknesses evaluated, presenting the formation of many small nodules and a small amount of larger nodules in the center.

scholarly journals Effects of the Variety and Content of Natural Pozzolan Coarse Aggregate on the Thermo-Mechanical Properties of Concrete

2021 ◽  
Vol 12 (4) ◽  
pp. 5405-5415
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
The Other ◽  
Natural Pozzolan ◽  
Coarse Aggregates ◽  
Natural Aggregate ◽  
Middle Atlas

The present study investigated the effects of the variety and content of three natural pozzolan coarse aggregates on concrete. Natural pozzolan aggregates have been obtained from three volcanoes (Boutagrouine, Timahdite, and Jbel Hebri) located in the Middle Atlas region in Morocco. The three pozzolans studied were characterized, and then a comparison was made by replacing the natural aggregate with the pozzolan aggregate in the concrete in different percentages, namely 25, 50, and 100 % in volume. The results showed that the variety and content of pozzolan aggregate have a significant impact on the properties of concrete, primarily caused by the characterization of pozzolan aggregate. The density of concrete decreases with the addition of pozzolan aggregate, which decreases depending on the type of pozzolan aggregate used. The highest compressive strength was measured in the concrete specimens prepared with aggregate BP while the lowest compressive strength was noted in the concrete specimens prepared with aggregate RP. On the other hand, the substitution of NA at 100% by BP, GP, and RP aggregates leads to a decrease in the thermal conductivity of about 67%, 62%, and 55% respectively.

Product characterization of a traditional sausage aiming at geographical indication certification and entrepreneurship prospects: an empirical study of Goan “choris”

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Solomon Rajkumar ◽  
Renuka Nayar ◽  
Kavitha Rajagopal ◽  
Namratha Valsalan ◽  
Sudharsan Chinnasamy ◽  
...  
Keyword(s):  
Room Temperature ◽  
Fatty Acid Content ◽  
Storage Period ◽  
Geographical Indication ◽  
Content Type ◽  
Pork Sausage ◽  
Product Characterization ◽  
Physico Chemical ◽  
The Mean

PurposeThe purpose of this paper is the physico-chemical, microbiological, colorimetric, sensorial characterization of choris, a traditional smoked pork sausage produced in the state of Goa (India), including its storage stability (0–180 days) at room temperature, aiming at the geographical indication certification and entrepreneurship prospects.Design/methodology/approachA total of 48 samples of “choris” were collected from 24 villages of Goa and were analyzed at different intervals (0–180 days) for physico-chemical, proximate, microbiological, colorimetric and sensory attributes during the storage at room temperature.FindingsThe mean pH of 4.45 and water activity (aw) of 0.78 were recorded. The pH, tyrosine value, fat percentage and free fatty acid content registered a significant increase, whereas moisture content, aw and moisture–protein ratio reduced as storage progresses. The colorimetric values lightness (L*), hue angle (H*) and redness index values reduced significantly during storage. The mean total viable count, yeast and mold, and lactic acid bacteria count were found to proliferate significantly as storage advanced. Nevertheless, the hedonic scores not reaching an unacceptable level (= 4) at the end of the storage period.Originality/valueIn accordance with the various parameters adopted during the study, choris could be characterized as “naturally fermented dry smoked” sausages, which were shelf-stable at room temperature for 180 days. The product characterization of choris is essential to guarantee the genuineness, safety and consumer's acceptability. This study will also rebound in an augmented uniformity of the product, which will favor the geographical indication certification and the entrepreneurship prospects of this traditional product.

Thermal Insulation Particleboards Made with Wastes from Wood and Tire Rubber

2015 ◽  
Vol 668 ◽  
pp. 263-269 ◽  
Author(s):  
Marilia da Silva Bertolini ◽  
André Luis Christoforo ◽  
Francisco Antonio Rocco Lahr
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Environmental Problem ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Superior Performance ◽  
Tire Rubber ◽  
Polyurethane Resin

The concept of sustainable buildings addresses the environmentally efficiency, with respect to energy consumption, by adopting products that offer thermal insulation. Moreover, use of wastes from different materials also contributes to obtain products for this application. The volume of wastes from timber industry and those from tires are an environmental problem. This study aimed to production and characterization of particleboards using wastes from wood and tire rubber with castor-oil polyurethane resin. Panels were produced containing only wood and also with addition of tire rubber. The properties determined were density, modulus of rupture (MOR) and modulus of elasticity (MOE) in bending, according to Brazilian Code NBR 14810-3 (2006), and thermal conductivity. Statistical analysis was conducted in physical and mechanical properties. Panels containing wood were classified as low density (0.55 g/cm³), while those with wood and tire rubber resulted in medium density (0.78 g/cm³). For mechanical properties, the addition of rubber resulted in increased of MOR and reduction for MOE. Superior performance for thermal conductivity was achieved for panels produced only with wood. However, samples with a mixture of wood and tire rubber also showed consistent thermal conductivity with similar products. Considering the results obtained, panels containing wood and tire rubber addition have potential for application as thermal insulation.

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