Calculation of Cost-Effectiveness of Molds Made of Aluminum, MDF (Medium Density Fiberboard) and Steel

We implemented the process of producing a new Rib in three different ways, and we selected the process that was the most affordable and required the least labor, and we did it. This paper also considers the influence of the cost of the form from MDF, Alumina and Steel on the quality of the product.

Prediction of the position of coal particles in an air dense medium fluidized bed system

An air dense medium fluidized bed separator(ADMFBS) is used for dry beneficiation of coal using ultrafine magnetite particles as a pseudo-fluid medium. In this process, the coal particle gains additional weight due to coating on its surface and deposition at dead zone area by fine magnetite particles.Hence, the effective density of coal particle increases and the position of coal particle changes accordingly. In this work, an attempt was made to predict the position of coal particle in non-bubbling condition dense medium fluidized bed system. Coal particles of different shape such as cubical, rectangular prism,spherical and triangular prism with different projected area and density were used. The results show that the position of coal particle in air dense medium fluidized bed follows descending order with respect to the increase of density, projected area of coal particle and different shapes(i.e., triangular prism, cubical,rectangular prism and spherical). Empirical mathematical correlations were developed to predict the position of coal particle.

A multiple criteria analysis of factors affecting markets of engineered wood products with respect to customer preferences: a case study of particleboard and MDF

Of considerable importance and a principal goal in business is the creation of customer satisfaction. Evalu- ation of end user preferences for producers of particleboard and medium density fiberboard （MDF） requires indices for the assessment of markets and modification of product quality. However, only sporadic research has been carried out in this field. Therefore, the goal of this survey was to identify indices with respect to the points of view of： 1） consumers in order to select particleboard and MDF, 2） suppliers in order to consider production strategies, improve product quality, improve competitive ability of domestic producers in the market and help industry to be more customer oriented. This survey consisted of two stages. In the first stage, factors affecting customer preferences in the selection of particleboard and MDF were determined using a Delphi method, with the help of experts and a group of principal users of these prod- ucts. Then these factors were categorized in three groups： qualitative, technical and technological and marketing factors. Furthermore, questionnaires were prepared and distributed among consumers and responses evaluated and weighted by using an analytic hierarchy process （AHP） using expert choice software. Our results show that at both stages, the consistency ratio was less than 0.1, indicating that all results and judgments were stable and acceptable. The results obtained from questionnaires about particleboard rank the priorities for factors in the selection by consumers as follows： nail and screw holding ability, homogeneity in structure, edge strength of panel, durability and bending strength. The most important factors for MDF were machinability of panels, homogeneity in structure, nail and screw holding ability, edge strength of panel, durability and bending strength.

A thermodynamic model on predicting density of medium-Mn steels with experimental verification

A new model on predicting the density of hot-rolled multi-phased medium-Mn steel has been presen ted on the basis of thermodynamic calculations. This is an integrated model, which includes one for calculating the retained austenite （RA） fraction and the other for volume expansion during the aus tenite-to martensite transformation, because both of them are key parameters for calculating the den- sity of steel at ambient temperature. The existing empirical equations for calculating Mx temperature and lattice constants of both martensite and austenite have been all rcassessed by the XRD measure ments on the microstructures of seven hot-rolled medium-Mn steels. Finally, the densities ot seven steels were calculated merely from compositions and compared with the measured ones. The differ ence between them is no more than 1 %, suggesting that the presented model should be of good value in designing the low density steels.

Oil Palm Particleboard: Properties and Fungi Susceptibility

The utilization of oil palm biomass in the production of high-value products has increased substantially.Due to the presence of sugars and starches in their tissues,oil palms have an exceptionally low natural resistance to fungi,making them susceptible to contamination.In this study,the properties of particleboard made from oil palmfibers,namely empty fruit bunches(EFB),oil palm trunks(OPT),and oil palm fronds(OPF)fibers and its poten-tial for fungal attack were evaluated.The chemical composition,spectroscopic characterization,morphological features,and elemental analysis of oil palm biomassfibers were identified and thoroughly examined.The mechan-ical properties and dimensional stability of the boards were assessed based on Japanese Industrial Standards(JIS)and American National Standards Institute(ANSI)guidelines.The density,strength,and moisture resistance of particleboard made from OPTfibers may vary from those made from OPF and EFB due to inherent changes in chemical composition andfiber structure.These differences have an impact on the overall performance of the particleboard.Based on the ANOVA and Tukey’s test results,significant differences in elasticity properties were observed mainly between OPT and otherfibers,while bending strength revealed notable differences between various pairs of particleboards.The evaluation also highlighted variations in dimensional stability and water absorption capabilities.However,bending strength properties did not demonstrate any significant deviations.For the fungi test,fungal activity on the boards was observed over a two-week period in a controlled environment.The study revealed that oil palm-based particleboard exhibited susceptibility to fungal attacks,particularly from Aspergillus sp.,Trichoderma sp.,and Paecilomyces variotii.Thesefindings highlight the necessity for additional treatments to control or prevent fungal growth,thereby enhancing the commercial value of the particleboards.

Utilizing agro-industrial wastes panels in developing cost-efficient thermally insulating wall claddings for residential energy retrofitting in Egypt

Local agro-industrial wastes-based particleboards and fiberboards in Egypt are manufactured mainly from sugarcane-bagasse and flax shives.These panels are used in decorations and interior claddings.This paper aimed to broaden their market to be utilized in local low-cost and simple building envelope retrofitting packages in-stead of conventional packages that depend on imported expanded polystyrene and wet-rendered gypsum boards.Thermal conductivities of various existing sugarcane-bagasse and flax-shives-based panels were measured to be used in developing multilayered interior claddings with adequate thermal insulating performance to increase the thermal mass of a validated non-insulated case-study residential building as recommended by the Egyptian Code for Energy Efficiency of Residential Buildings.Models retrofitted using the developed cladding assemblies were simulated using Design Builder to determine their achieved annual energy savings and predict their profitability.Thermal conductivities of sugarcane-bagasse and flax-shives-based particleboards were lower than wood-based cladding panels,with the range of 0.05-0.1166 W/mK.Moreover,the thermal conductivities of sugarcane-bagasse fiberboard had the range of 0.0926-01,111 W/mK which is significantly lower than wood-based fiberboards.Simulation results showed that both models retrofitted,sugarcane bagasse-based and flax shives-based,achieved better energy savings,5.07%and 5.04%,than the conventionally retrofitted model,3.73%.Furthermore,the flax-shives-based model showed higher profitability,with positive income achieved in the 15th year,than a con-ventionally retrofitted model,achieved in the 20th year,and the sugarcane-bagasse-based model,achieved in the 19th year.Thus,it was recommended that although flax-shives-based wall claddings were usually 14-20%thicker than sugarcane-bagasse-based claddings,they provided similarly high annual energy savings with lower initial costs and higher profitability.

Application of the finite element method for evaluating the stress distribution in buried damaged polyethylene gas pipes

During the loading process,buried gas pipes can experience severe stresses due to soil-structure interaction,the presence of traffic load,the soil’s column weight,daily and/or seasonal temperature changes and uniform internal pressure.In this research,the finite element method is employed to evaluate the behavior of buried Medium Density Polyethylene(MDPE)pipes which have been subjected to damage at the pipe crown.The modeled pipe damage ranges from a very small circular hole to a large circular hole and elliptic holes with various minor to major diameter ratios,a/b,to simulate circular to crack-shaped defects.The computer simulation and stress analyses were performed using the ANSYS software finite element package.The stress distribution around the defect was determined under the aforementioned mechanical and thermal loading conditions.Then,the maximum values of Von Mises stresses in the damaged buried PE pipes,which were evaluated by finite element solution,were compared with their corresponding reduced strength for safe operation with a life expectancy of fifty years.Based on the results,the maximum Von Mises stress values in the defective buried polyethylene gas pipeline are significantly above the pipe strength limit at 35℃.The previously mentioned stress values increase with the following factors:temperature increase,increase in circular hole diameter and decrease in elliptic hole diameter ratio(a/b).The maximum stress in the damaged PE pipe is due to the simultaneous loading effects of soil column weight,internal pressure,vehicle wheel load and pipe temperature increase.Additionally,the novel finite element models and stress plots for the buried damaged pipe and the pipe material allowable strength will be used to investigate the correct repair method for the damaged gas pipeline and to choose the best patch arrangement which will assure a safe repair.