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We present in this work how to use the dura palm kernel shell powders as loads for the elaboration by extrusion of PVC tubes. The transformation of dura palm kernel shells into micronized shell powder as well as its characterizati...
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We present in this work how to use the dura palm kernel shell powders as loads for the elaboration by extrusion of PVC tubes. The transformation of dura palm kernel shells into micronized shell powder as well as its characterization was the subject of recent work. We carried out, the formulations by using the industrial scales of precision, the mixtures of the instrants with an industrial machine of mark HENSHLLE N˚ 2 MAIN 570762, the routine tests by ATG/DSC then by IRTF, the extrusion of the tubes with an extruder twin-screw with 9 rooms of transformation finally the tests of conformity by the observations and the analyses. We obtained for the formulations the dosage of 0%, 4.01%, 12.54%, 23.03%, 32.01%, 38.01%, 51.02% representing the percentage of hull powder in the mixture, the machine mixing gave perfectly homogeneous powders, the routine tests showed that the hull powder keeps all its properties until the end of the shaping whatever the percentage of hulls contained in the PVC, the extrusion gave tubes for each formulation and the conformity tests gave perfectly round tubes of diameter 90 × 82 mm, a coloration going from white grey at 0% to dark black at 51.02% showing the influence of the carbon black and the color of the shell powder according to its proportion. The infrared of the tubes obtained shows for each formulation a variation of the CH_(2) and CH bonds and a decrease of the −OH bonds. The thermogravimetric analyses and the differential calorimetric analyses of the tubes of each formulation, show each time that the quantity of shell powders in the mixture influences the PVC tubes obtained. Thus, we obtain a variation of the phase temperatures according to the dosage, giving from 108.72 ˚ C to 76.56 ˚ C for the glass transition temperature and from 494.71 ˚ C to 414.56 ˚ C for the melting temperature, at the DSC and a progressive decrease of the mass following the heat absorption with each time 4 phases instead of 5 for the unloaded PVC tubes at the ATG according to the dosage.
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The present work deals with reducing greenhouse gas emissions through im proving the life span of wooden power electric poles of Eucalyptus saligna . Indeed, in Sub-Saharan African countries , Cameroon in particular, most of the ...
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The present work deals with reducing greenhouse gas emissions through im proving the life span of wooden power electric poles of Eucalyptus saligna . Indeed, in Sub-Saharan African countries , Cameroon in particular, most of the power line networks are made of wooden supports and according to the Cameroon energy distribution company, wooden poles represent 32% of the causes of death linked to the state of the network. The company ’ s 2019 annual report indicates that 40,000 wooden poles were in critical condition and should be replaced. A significant number of mechanical failures affecting these sup ports have been observed. For example, on the HVA/LV power line “ D17 Nko - abang ” in Yaoundé in Cameroon, less than three years old, 10 (ten) cases of poles falling and/or breaking, due to their mechanical loading, were observed over a period of fewer than nine months, causing an average service stoppage for more than 11 hours and affecting an average of 3280 customers. These incidents lead to question s about how the supports are dimensioned and what load capacities they are designed to support. The aim of this work is , there fore , to suggest a method of dimensioning wooden poles hence reducing green - house gas emissions due to the deforestation by reducing the number of woo - den poles at risk to be replaced on Cameroon ’ s electricity distribution net work. And more specifically , to reduce the number of mechanical failures affecting the wooden supports observed by analyzing the current wooden supports with their loads and to make proposals for improving the actual dimensioning me - thods. From the study carried out, it appears that 449 out of 845 supports, i.e ., 53% needed to be replaced or monitored because they support the nominal forces ranging from 85% to 150% of their admissible limit and proposals have been made to improve their dimensioning.
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The management of information flow for production improvement has always been a target in the research. In this paper, the focus is on the analysis model of the characteristics of information flow in shop floor operations based on...
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The management of information flow for production improvement has always been a target in the research. In this paper, the focus is on the analysis model of the characteristics of information flow in shop floor operations based on the influence that dimension (support or medium), direction and the quality information flow have on the value of information flow using machine learning classification algorithms. The obtained results of classification algorithms used to analyze the value of information flow are Decision Trees (DT) and Random Forest (RF) with a score of 0.99% and the mean absolute error of 0.005. The results also show that the management of information flow using DT or RF shows that, the dimension of information such as digital information has the greatest value of information flow in shop floor operations when the shop floor is totally digitalized. Direction of information flow does not have any great influence on shop floor operations processes when the operations processes are digitalized or done by operators as machines.
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This work presents the physical and thermal characterization of the dura palm kernel powder of Cameroon for their use as fillers for polymers composites. The powders of palm kernel were obtained using a percussion grinder mill wit...
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This work presents the physical and thermal characterization of the dura palm kernel powder of Cameroon for their use as fillers for polymers composites. The powders of palm kernel were obtained using a percussion grinder mill with an industrial microniser which allowed obtaining a powder less than 50 μm with an apparent density between 0,505 ≤ ρ ≤ 0,680 g/cm~(3) at 1.56 of relative humidity. The infrared of the powder of palm kernel shows the presence of phenols groups with a large band around 3341 cm~(-1), -C-H at 2917.02 cm~(-1 )and -C-O at 1040 cm~(-1) as the main peaks. The polyvinyl chloride of infrared obtained shows the presence of -C-Cl, -CH_(2) and CH as the mains peaks. The infrared of 12.5% of palm kernel powder with polyvinyl chloride shows an increase of the CH_(2) and CH bonds and a decrease of the -OH bonds. Thermogravimetric analysis and differential scanning calorimetric analysis of powders, polyvinyl chloride and mixture showed that the mixing powders are intermediate between the polyvinyl chloride and palm kernel powder. The powder decreased the phase temperatures of the mixture from 98.58 ℃ to 95 ℃ for the glass transition temperature and from 515℃ to 459 ℃ for the crystallization temperature. The thermogravimetric curves of palm kernel powder and polyvinyl chloride have showed that these materials lose their different masses in three different phases, and the one of composite (mixture of polyvinyl chloride with 12.5% of palm kernel powder) in two different phases.
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Materials characterization is the part of materials science that allows engineers and researchers to value a material. Considering the quantity of materials and the number of existing property results, in order to make them access...
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Materials characterization is the part of materials science that allows engineers and researchers to value a material. Considering the quantity of materials and the number of existing property results, in order to make them accessible to solve the problem of material selection, it is important to find an easy way that should allow engineers to consult the data without needing enough sentences. Nowadays, the computer has become a reassuring library. Therefore, the work presented here consists in designing an industrial abacus model and a computer interface that should allow engineers and standardization teams, contractors and hardware dealers to calculate and save the thermal properties of PVC loaded with micronized palm kernel shell powder, although the dosage is known. The industrial elaboration of the loaded PVCs, its thermal characterization, the graphs representing the influence of the shell powder on the thermal properties of the PVCs as well as the mathematical models for the calculation of these properties according to the dosage with this shell powder have been the object of studies in the previous works. From the obtained results, we used a simple graphic method to design the industrial abacus and then the mathematical models of the previous works coupled with the Java programming language, NetBeans IDE 8.0.2 and Lauch4j, to design and implement an adequate computer interface. The results gave us for the abacus that it is simple and practical for workers in production plants and for the computer interface that it is easy to use, requiring neither special skills nor computer training. Practical examples have shown that the use of computer interfaces to calculate thermal properties gives a remarkable speed and accuracy allowing the engineers of construction sites and design offices to use it with confidence, unlike the abacus. These applications have made it possible to obtain that, the valorization of this model of calculation and conservation of the data will allow the researchers and the engineers to use this principle to safeguard the data in the future.
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In the Littoral and East regions of Cameroon, the proliferation of the water hyacinth threatens the conservation of biodiversity. Indeed, its rapid multiplication asphyxiates fish and promotes malaria. Integrated pest management a...
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In the Littoral and East regions of Cameroon, the proliferation of the water hyacinth threatens the conservation of biodiversity. Indeed, its rapid multiplication asphyxiates fish and promotes malaria. Integrated pest management and many other methods have been used to eliminate this plant, but it persists, endangering the eco-systemic balance of marine environments. The efficient management of this plant remains a challenge. The aim of this study is to contribute to the implementation of a water hyacinth management protocol. The idea was to use this plant not only for natural fertilizer for soil improvement but also as energy production (biogas). The tests were carried out at the HIMA application farm in the Abong-Mbang area. Experiments were conducted using 60-Liters batch digesters. In all three sets of experiments, combinations of water hyacinth, cow dung and chicken droppings were used. For water hyacinth alone, an average production of 70 L of biogas was recorded. The best yield was obtained for the mixture of water hyacinth (5 kg), cow dung (1.5 kg) and chicken droppings (1 kg) at 1/4 dilution, i.e. 179 L/kg of substrate. The results obtained are encouraging and are being effectively used. This technology can therefore be applied in areas infested by Eichhornia crassipes for the production of energy, compost and control of water hyacinth proliferation.
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Ce papier est dédié à l’implantation d’une loi de comportement mécanique dans le logiciel éléments finis Cast3M à l’aide d’un générateur de code open source nommé Mfront. Pour ce faire, un modèle de comportement él...
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Ce papier est dédié à l’implantation d’une loi de comportement mécanique dans le logiciel éléments finis Cast3M à l’aide d’un générateur de code open source nommé Mfront. Pour ce faire, un modèle de comportement élasto-plastique a été choisi à partir des lois existantes dans la littérature. Suivant une discrétisation implicite, une bibliothèque matérielle correspondant au modèle de CHABOCHE à écrouissage isotrope et cinématique non linéaire est générée grace à Mfront. L’interface informatique UMAT est utilisée pour construire la bibliothèque dans Cast3M. Une validation de l’approche a été menée en comparant les résultats numériques obtenus entre la bibliothèque matérielle générée et la bibliothèque équivalente préexistante dans Cast3M. Les simulations dans le cas d’une barre en traction et une plaque trouée montrent des résultats quasi identiques.
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