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Published By Trans Tech Publications

1662-9752
Updated Friday, 22 October 2021

2021 ◽  
Vol 1047 ◽  
pp. 20-24
Author(s):  
Rafail Apakashev ◽  
Mark Khazin ◽  
Sergey Krasikov

A method of synthesizing dispersion-strengthened aluminum matrix composites using a powder metallurgical technique and an in situ method was considered. Methods combination was aimed at ensuring energy efficiency, avoiding vacuum treatment of the reaction medium, and using inert gasses to protect from oxidation. Reinforcement phase precursors are capable of ensuring good wettability of dispersed particles by the molten matrix metal. The options of the methods’ practical implementation are presented by the example of producing aluminum matrix composites filled with various functional particles.


2021 ◽  
Vol 1047 ◽  
pp. 220-226
Author(s):  
Md Nasir Uddin ◽  
Ling Zhi Li ◽  
Raja Khurram Mahmood Khan ◽  
Farhan Shahriar ◽  
Landry Wilfried Tim Sob

The estimation of the ultimate capacity of rectangular or circular shaped steel tubular members filled with concrete, such as columns, beams, and beam-column connections, requires a detailed structural study to be carried out. Therefore, identify the concrete strength the member subjected to axial-load only. Using the Levenberg-Marquardt artificial neural network, this paper investigates the concrete-filled steel tubular (CFT) members axial strength. 201 experimental specimens were collected from the literature to obtain the best results, and a wide range of geometric and material properties of CFT members were included. The proposed design and specimens illustrate the practicality and effectiveness of the chosen CFT column approach to classify real structural results.


2021 ◽  
Vol 1047 ◽  
pp. 3-8
Author(s):  
Zheng Lu Ma ◽  
Jui Chin Chen ◽  
Chi Hui Tsou ◽  
Yan Mei Wang ◽  
Xin Yuan Tian ◽  
...  

High-density polyethylene (HDPE) is used as the matrix and attapulgite (ATT) is used as the reinforcing phase. HDPE/ATT nanocomposites are prepared by melt blending. The effect of ATT content on the mechanical properties, water absorption and morphology of HDPE/ATT composites was studied. The results show that adding a small amount of ATT can improve the mechanical properties of HDPE, but excessive addition will reduce the mechanical properties of HDPE. The water absorption and contact angle test results show that as the ATT content increases, the composite material becomes more and more hydrophilic. After joining ATT, the performance of HDPE / ATT composite material has a significant improvement effect, and it is believed that it will have broad application prospects in the future.


2021 ◽  
Vol 1047 ◽  
pp. 202-206
Author(s):  
Wei Ting Hsu ◽  
Kun Ze Ho ◽  
Yu Xin Liu ◽  
Shu Ti Chung

Double-symmetry I-beams are the most common beam cross-sections in structural building. Because that is simpler to design and analyze steel profiles than single-symmetry I-beams. However, with the advancement of economy, the improvement of the quality of life and the cultural standards, large-scale emergence of various large span bridges, special bridge-type landscapes and viaducts. Single symmetrical I-section is better than Double-symmetry I-section to fairly in line with demand characteristics and material economy. This study chooses different Iyc/Iy ratio sections, 0.229, 0.23, 0.3 and 0.5. Iyc/Iy =0.23 is the change point of the sudden drop of the strength of the compressed airfoil. In study, the section is divided into three sections of plasticity, inelasticity and elasticity for analysis and comparison. Considering the different section sizes. If the value of Lb for a small non-elastic interval is too large, the section with a smaller cross-section will reach the elastic interval. Taking all section conditions Lb into consideration, taking 1.4m as a section will reach the non-elastic interval, if the value of the longer Lb is too small, the section with the larger section does not reach the elastic interval. In study, 10m is taken as the section to reach the elastic interval, orientation the AISC ( 2017 ) specification is used to analyze the I-beam. Symmetrical wing plate cross-sections were increased and reduced. The strength of the cross-sections between the compressed side and the tensioned side was discussed, and a single-symmetric I-section with the best cross-sectional efficiency was proposed.


2021 ◽  
Vol 1047 ◽  
pp. 143-150
Author(s):  
Jeanmpierre Castro ◽  
Zenner Chávez ◽  
Chaviguri Pool ◽  
Aarón Amarillo ◽  
Mario Chauca

The Plastic especially that used for beverage containers generates large tons of daily waste, currently being the first waste material that accumulates the most in our cities. A problem that increases when one takes into account that it is a material that takes around 500 years to fully degrade. In recent years, the development of ideas in the use and recycling of PET bottles has increased worldwide due to the level of the ecological problem it poses. There are processes that reuse waste beverage containers for the elaboration of construction elements another of its magnificent advantages is the simplicity in its production process. They do not require firing and, unlike the conventional brick manufacturing process that joins cement and sand, for the manufacture of a PET brick the sand is replaced by particles of PET plastic from twenty waste bottles, with which we obtain a much more alternative ecological sustainable,


2021 ◽  
Vol 1047 ◽  
pp. 62-67
Author(s):  
Shen Wang ◽  
Le Tong ◽  
Guang Jun Chen ◽  
Mao Xun Wang ◽  
Bin Dai ◽  
...  

7075 aluminum alloy is widely used due to its great performance, especially in aerospace area. In this paper, ultrasonic-assisted grinding technology is used to process 7075 aluminum alloy. The data is obtained through experiments, and the surface roughness and morphology of ultrasonic assisted grinding and conventional grinding under different spindle speeds, feed rates, and amplitudes are analyzed. Research has found that the increase in spindle speed and amplitude will improve the quality of the machined surface and reduce the surface roughness by 82.1% and 36%. However, with the increase of feed rate, the surface quality decreased significantly, and the surface roughness increased by 55.6%. The surface micro-morphology of the machined workpiece is observed, and the effects of different processing parameters on the surface micro-morphology are obtained.


2021 ◽  
Vol 1047 ◽  
pp. 179-185
Author(s):  
Siti Zubaidah Mohd Asri ◽  
Faridah Hanim Khairuddin ◽  
Choy Peng Ng ◽  
Noor Aina Misnon ◽  
Nur Izzi Md Yusoff ◽  
...  

Pavement failures such as fatigue, rutting, cracking, bleeding, and stripping are typical pavement deterioration. Researchers have been experimenting with pavement modification to overcome these problems. This study determines the optimum binder content (OBC) for modifying an asphalt mixture with a partial replacement of coarse aggregate (5mm-14mm sieve size) with palm kernel shell (PKS). A 60/70 penetration grade bitumen was mixed with 10, 20 and 30% PKS at selected aggregate gradation following the Public Work Department of Malaysia (JKR/SPJ/2008-S4) specification. The preparation of 60 samples of unmodified and modified asphalt mixture employed the Marshall Method compacted with 75 blows. The OBC was determined based on five volumetric properties of asphalt mixture namely stability, flow, bulk density, void filled with asphalt, and void in total mix. The OBC and volumetric properties of the modified PKS asphalt mixture samples were compared with unmodified asphalt mixture samples in accordance to the specification. Results showed that the OBC sample with 30% aggregate replacement produced the highest OBC value of 5.53% relative to the control sample with 5.40% OBC. The trend for OBC with PKS replacement begins with 10% PKS with 5.30% OBC, 20% PKS with 5.32% OBC and 30% PKS. All volumetric properties of the PKS samples are within the specification limit. Thus, PKS has a promising potential as a coarse aggregate replacement in asphalt mixture.


2021 ◽  
Vol 1047 ◽  
pp. 111-119
Author(s):  
Zhao Liu ◽  
Shu Sen Cheng ◽  
Liang Wang

A 300-metric ton converter in a steel plant in China was studied. The influence of factors such as slag composition and temperature in the smelting process on the dephosphorization effect was statistically analyzed. The dephosphorization ability of slag increased firstly and then decreased with the increase of temperature, basicity and FeO content. Low-temperature, high-basicity and high-oxidizing slag are thermodynamically beneficial to promote the dephosphorization reaction, but the basicity is higher than 4.0, and the temperature is higher than 1640 °C are not conducive to the slag to obtain better fluidity. At the same time, too high FeO content will increase the activity coefficient of P2O5, thereby increasing its activity, which is not conducive to the progress of the dephosphorization reaction. As the end point content of carbon decreases, the oxygen content increases and the phosphorus content decreases. A very low carbon content is not conducive to metal yield and temperature control.


2021 ◽  
Vol 1047 ◽  
pp. 120-127
Author(s):  
Reylina Garcia Tayactac ◽  
Edward B.O. Ang

Geothermal is known as renewable energy and a clean energy source but inherent properties make this energy clean. Minerals and deposits in geothermal reservoirs create a scale that is persistent in its corrosive nature. In addition, heat extremes and pressure variations present challenges to the integrity of the wellhead components and the downhole casing. Such challenges need to be mitigated to achieve maximum output from these aging or even newly commissioned wells. The geothermal power industry has reported a wide range of corrosion problems. Given the highly corrosive conditions to be treated in the geothermal sector and the benefits of reduced unplanned downtime, operating cost savings would be expected if more CRAs clad products were used. In many cases, only the material's surface requires corrosion resistance and carbon or alloy steel can be clad with a more corrosion-resistant alloy. Up to 80% of the cost of using solid alloy can be saved by cladding. Carbon or low-alloy steel cladding can be carried out by overlay welding. This paper reviews available literature on corrosion in the geothermal environment and presents the successful use of clad products in other industries to support the rising demand for Philippine geothermal applications.


2021 ◽  
Vol 1047 ◽  
pp. 97-102
Author(s):  
Nattanicha Khamsao ◽  
Kornkamon Waengwan ◽  
Sunisorn Konchai ◽  
Poonnapat Patthong ◽  
Bpantamars Phadungchob ◽  
...  

Seedling bags are low cost and light weight containers used by farmers to germinate and sprout seeds into seedlings before transplanting into the ground. However, cutting and removing seedling bags before the transplantation can damage the plant roots and cause losses in their productivity. In addition, plastics used in conventional seedling bags contribute to more plastic waste during this process. This study offers a solution to these problems with alternative biodegradable materials; i.e. modified papers made from an invasive alien aquatic plant species—water hyacinth—and enhanced with Chitosan solution coating. Papers were made from water hyacinth and dipped or sprayed with Chitosan solution in acetic acid at concentrations of 1% wt., 1.5% wt., and 2% wt. The dipping method showed better water barrier properties than the spraying method in every concentration, with 2% wt. concentration having the best barrier properties. The 2% wt. concentration of Chitosan coating by dipping method changed the water contact angle of the water hyacinth paper from a hydrophilic to a hydrophobic surface. This enhancement in water resistance was confirmed by water absorption time, which reached over 1.5 hours—3 times longer than the spraying method.


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