Papers by Keyword: Physical Properties

Abstract: Water is one of the most important factors affecting the mechanical properties of soil.Research on the intrinsic mechanism of soil by water effect is significant. In this paper, the mechanical properties of loess in Shanxi under different water content is studied from the experimental angle. The result shows that the stress of intact loess increases with the water content decreasing. Pressure failure stress increases with water content decreasing under the same confining, and amplitude reduction increases.Keywords: moisture content; physical properties; intact soil; confining pressure

Abstract: In a society with a high growth rate and increased standards of comfort arises the need to minimize the currently high energy consumption by taking advantage of renewable energy sources. The mortars with incorporation of phase change materials (PCM) have the ability to regulate the temperature inside buildings, contributing to the thermal comfort and reduction of the use of heating and cooling equipment, using only the energy supplied by the sun. However, the incorporation of phase change materials in mortars modifies its characteristics. The main purpose of this study was the production and characterization in the fresh and hardened state of mortars with incorporation of different contents of PCM in mortars based in different binders. The binders studied were aerial lime, hydraulic lime, gypsum and cement. For each type of binder, different mortars were developed with different content of PCM. The proportion of PCM studied was 0%, 20%, 40% and 60% of the mass of the sand. It was possible to observe that the incorporation of PCM in mortars caused differences in properties such as workability, microstructure, compressive strength, flexural strength and adhesion.

Abstract: The use of agricultural residues for particleboard manufacturing increases their value-add and help meet the growing demand of raw materials for the panel industry. Accordingly, the aim of this study was to assess the quality of particleboards produced only with sugarcane bagasse or along with Pinus and Eucalyptus wood. The experimental design consisted of 5 treatments: T1) Eucalyptus panels, T2) Pinus panels, T3) sugarcane bagasse panels, T4) 50% Eucalyptus and 50% sugarcane bagasse panels, and T5) 50% Pinus and 50% of sugarcane bagasse panels. For each treatment, three panels were produced using 8% urea-formaldehyde adhesive, with 0.65 g/cm3 apparent density, 160°C pressing temperature, 4 MPa pressure, and 8 min of pressing time. The analyses revealed that use of sugarcane bagasse for particleboard manufacturing resulted in improved water absorption and thickness swelling properties after 2 h of immersion in water. In addition, the panels produced with bagasse only showed significant reductions in the mechanical properties. However, the use of sugarcane bagasse along with Pinus or Eucalyptus wood allowed the manufactured panels to meet all the conditions required by the CS 236-66 [1], ANSI A208.1 [2], and EN 312 [3] standards.

Abstract: Physical and chemical properties were measured to study quality of 5 strawberry cultivars, which were fruit weight, firmness, vitamin C, total sugar, total anthocyanin, total phenols, pH, total soluble solid, titratable acid, crude protein and juice yield. The result showed that PC1 explained 54.519% of the total variance in the data set, PC2 explained 28.184% and PC3 explained 9.252%. Accumulative variance contribution of these three main compositions extracted by principal component analysis was 91.954%. Eleven properties could reduce to three main components, and five strawberry cultivars were distinguished based on PC scores.

Abstract: To avoid unpredictable time to float due to variable pH of the gastric fluid in each subject, sublimation technique is the new interesting approach to prepare non-effervescent floating drug delivery system (FDDS). In this study, a floating matrix tablet using borneol as sublimable agent was developed. The system consists of drug, matrix-forming polymer and sublimable agent. The highly porous and low-density floating matrix tablet was obtained when borneol was sublimated. The floating matrix tablets immediately floated and maintained buoyancy over 8 h. The sublimation of borneol increased with increasing sublimation temperature and incubation time. Increasing amount of sublimable agent exhibited lower density of the floating tablet because of higher porous structure. The results demonstrated that boneol was one of good candidates to be used as sublimable agent for non-effervescent floating tablets. However, physical properties of the matrix floating tablets were needed to be concerned.

Abstract: A deep understanding of the mould flux effect on the wear mechanisms of Al₂O₃-C nozzles (AG) is relevant to avoid premature damage and to decrease the cost of black refractories in the industry. In this paper, a post mortem study on a nozzle was carried out to identify the causes of the wear mechanisms during the continuous casting of billets. Physical properties such as viscosity and surface tension of the mould fluxes were determined at operation temperature (1550oC), in order to correlate with microstructural results obtained by light and scanning electron microscopy (SEM). Also dihedral angle φ measurements were carried out at high magnification by SEM. Applying EDS analysis the infiltrated mould flux chemical composition was determined. The study was completed by EBSD. The EBSD technique contributed to increase the knowledge on wear mechanisms because of the possibility of identifying and localizing phases together with crystalline condition. The phases, the grain orientations and the properties of grain boundaries, have a large influence on the corrosion behaviour. Therefore, it is essential to have a characterization technique that can provide information such as: grain size, orientation, misorientation angle and the present phases. In this context, EBSD can provide relevant information on crystallographic and structural analysis of AG nozzle including the insert of ZrO₂-C.

Abstract: The purpose of this study was to establish a relationship between the physical properties of powder and its behavior during high shear granulation. Andrographis extract was utilized as a model drug and microcrystalline cellulose (MCC) and soluble starch were selected as excipients. The extract was mixed with different excipient with the ratio 1:0.5, 1:1, 1:2 by weigh, respectively. The granules were prepared by using high shear granulation. The result of HSG was evaluated by monitoring such responses as granule yield, the ratio of Lumps and Fine. The effect of physical properties on granulation behavior was analyzed through stepwise regression. The results showed that angle of repose, moisture content, pore volume, and density were the main factors linked to the granulation. The main physical properties of extract powder were the important factors for high shear granulation, and statistical analysis identified the trends that interpreted in light of physical models of high shear granulation.

Abstract: The aim of this work is to determine the main mechanical properties, related to timber structures design, of the Brazilian tropical wood specie: Dipteryx odorata (Aublet) Willd. Tests were conducted according to the guidelines of the Brazilian Code ABNT NBR 7190: 1997 "Design of Timber Structures". Specimens were obtained from a so-called homogeneous clear wood lot, with moisture content around 12% . Mean values ​​of strength and stiffness properties confirmed Dipteryx odorata (Aublet) Willd as a good alternative for structural uses.

Abstract: In this study, the principal component analysis (PCA) was used to analyze and classify the electric arc furnace oxidizing slag based on physical properties. The results indicated that about 91.44 % information could be explained using the previous four PC. The Los Angeles abrasion test (LAAT) and loss of sodium sulfate soundness test (LSSST) mainly contributed to the first PC, meanwhile the saturated surface-dry specific gravity (SSDSG) contributed mainly to the second PC. The significant physical properties of EAF slag including LAAT, LSSST, and SSDSG could be identified according to PCA. According to the two dimension classification using PC1 and PC2, the 60 samples could be approximately classified into two groups. They could be also classified into two groups in three dimension classification.

Abstract: In this study, exact radial basis function neural network (ERBFNN) was used to predict the concrete compressive strength based on physical properties of electric arc furnace oxidizing slag. The mean absolute percentage error (MAPE) was used to evaluate the predicting performance. The results indicated the minimum MAPE of 0.08 % and 5.28 % could be achieved when training and predicting, respectively. According to the results, it revealed that ERBFNN was an efficiently tool for providing information.