Archive of

Advanced Engineering Science

Gongcheng Kexue Yu Jishu/Advanced Engineering Science
Journal ID : AES-17-05-2022-190

Abstract : Kaolin is an aluminosilicate mineral with low adsorption and degradation ability for organic dye molecules. Herein, to improve its adsorption properties, kaolin was composited with goethite, which is known to absorb and degrade dye molecules. The kaolin/goethite composites were synthesized via a simple low-temperature method. Specifically, a ferric ion solution and sodium hydroxide were consecutively added to commercial kaolin, and the mixture was aged at 40 °C for seven days. The synthesized composites were characterized by means of XRD and SEM, and their use in the adsorption and degradation of methylene blue dye was investigated. The ability of the composites to degrade organic matter was evaluated using the advanced oxidation process method. A mineralogical and morphological analysis of the synthetic products showed that goethite and the composites were synthesized on the surface of kaolin. However, the presence of amorphous iron material was detected in both types of products. The adsorption capacity of goethite, kaolin, and the kaolin/goethite composites for methylene blue was 54.64, 14.68, and 50.76 mg/g, respectively. The adsorption process fitted the Langmuir isotherm model with a correlation efficiency higher than 0.999. Goethite and the composites degraded effectively methylene blue upon addition of hydrogen peroxide. Although the composites exhibited lower adsorption and degradation ability than goethite, their structure was more stable, which was confirmed by the more efficient readsorption of methylene blue after the degradation process compared with kaolin and goethite. This study demonstrates that the adsorption and catalytic ability of kaolin can be modified by compositing with goethite..
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Gongcheng Kexue Yu Jishu/Advanced Engineering Science
Journal ID : AES-13-05-2022-187

Abstract : This research describes a low-profile frequency reconfigurable monopole antenna working in the microwave frequency range. The suggested structure is printed on a flame retardant-4 epoxy (FR4-epoxy) substrate with a permittivity of 4.4 and tangent loss of 0.002. Three-pin diode switches are fitted between radiating patches to alter the different operating modes of an antenna. The proposed antenna operates in four modes, covering eight different bands by operating at single bands of 4.43 GHz in Mode 1, and dual bands (i.e., 3.5 and 5.66 GHz, 3.1 and 5.5 GHz) in Mode 2 and 3, and triple bands in Mode 4 (i.e., 2.9, 5.2, and 5.7 GHz). The voltage standing wave ratio (VSWR) of the provided antenna is less than 1.4 for all the working bands. The efficiency of the developed antenna is 73 to 93 percent, and the gain varies from 1.39 to 2.57 dBi, respectively, at matching resonance frequencies. The obtained bandwidths at corresponding frequencies varied from 6.5 to 24.15 percent. The suggested structure is modeled in the Computer Simulation Technology microwave studio (CST MWS), and the simulated findings are experimentally confirmed. Due to its fairly modest size and compatibility with numerous wireless protocols, the suggested antenna may be employed in contemporary portable fifth generation (5G) devices as well as Internet of Things (IoT) enabled systems in smart cities..
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Gongcheng Kexue Yu Jishu/Advanced Engineering Science
Journal ID : AES-13-05-2022-186

Abstract : Concrete made with geopolymer technology is thought to be both pro-ecological and minimal cost-effective. Geopolymer concrete manufacture aids in the conversion of industrial by-product materials into reusable products. Geopolymer concrete outperforms OPC concrete in terms of strength. The ternary blended high-molarity [12M] geopolymer concrete used in this experiment was made of red mud (RM), fly ash (FA), and Ground granulated blast furnace slag (GGBFS). The current study intended to establish the best ratio of RM - FA - GGBFS -based ternary geopolymer concrete. The compressive strength, split tensile strength, and flexural strength tests were performed to determine the strength properties and water absorption, permeability, and sorptivity tests determined the durability characteristics. The results showes that the proportions of RM-based ternary GPC with RM: FA:GGBFS in 45:35:20 ratio resulted in a significant increase in the synthesis. This resulting in improved mechanical and microstructural properties than the other proportions. Higher results were also seen at the aforementioned ratio in the chemical analysis performed on the ternary-based geopolymer paste to determine the maximum pH value. The study's findings are encouraging sustainable and cost-effective routes for dealing with the industrial by-products that are presently produced in multiple regions..
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Gongcheng Kexue Yu Jishu/Advanced Engineering Science
Journal ID : AES-13-05-2022-185

Abstract : A documentary review was carried out on the production and publication of research papers on the study of the variable Economic Shock during the Covid-19 pandemic. The purpose of the bibliometric analysis proposed in this document is to know the main characteristics of the volume of publications registered in Scopus database during the period 2020-2021 in Latin American countries and to measure the impact that has been generated in the different economic sectors of Chile. A total of 46 publications were identified and the information provided by this platform was organized by means of tables and figures, categorizing the information by Year of Publication, Country of Origin, Area of Knowledge and Type of Publication. Once these characteristics were described, a qualitative analysis was used to refer to the position of different authors on the proposed topic..
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Gongcheng Kexue Yu Jishu/Advanced Engineering Science
Journal ID : AES-09-05-2022-181

Abstract : It is planned to develop a more compact ultra-wideband (UWB) patch antenna employing meta-materials. The total size is reduced, and the simulated impedance bandwidth operates from 3.4 to 9.1 GHz for a single-slot antenna, with the bandwidth improved (3.04 to 14.35 GHz) with an S-parameter of less than -10 dB by etching another slot in the patch and using CSRR instead of wire in the back of the ground plane. These two antennas have a bandwidth of 5.7GHz and 11.33GHz, respectively. Both substantial horizontal radiation and practical properties have been observed. As a result, these antennas could have some specific applications in the future for UWB wireless communications..
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