Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 6 de 6
Filter
Add more filters










Database
Language
Publication year range
1.
Article in English | MEDLINE | ID: mdl-37987975

ABSTRACT

This research presents an in-depth examination that utilizes a hybrid technique consisting of response surface methodology (RSM) for experimental design, analysis of variance (ANOVA) for model development, and the artificial bee colony (ABC) algorithm for multi-objective optimization. The study aims to enhance engine performance and reduce emissions through the integration of global maxima for brake thermal efficiency (BTE) and global minima for brake-specific fuel consumption (BSFC), hydrocarbon (HC), nitrogen oxides (NOx), and carbon monoxide (CO) emissions into a composite objective function. The relative importance of each objective was determined using weighted combinations. The ABC algorithm effectively explored the parameter space, determining the optimum values for brake mean effective pressure (BMEP) and 1-decanol% in the fuel mix. The results showed that the optimized solution, with a BMEP of 4.91 and a 1-decanol % of 9.82, improved engine performance and cut emissions significantly. Notably, the BSFC was reduced to 0.29 kg/kWh, demonstrating energy efficiency. CO emissions were lowered to 0.598 vol.%, NOx emissions to 1509.91 ppm, and HC emissions to 29.52 vol.%. Furthermore, the optimizing procedure produced an astounding brake thermal efficiency (BTE) of 28.78%, indicating better thermal energy efficiency within the engine. The ABC algorithm enhanced engine performance and lowered emissions overall, highlighting the advantageous trade-offs made by a weighted mix of objectives. The study's findings contribute to more sustainable combustion engine practises by providing crucial insights for upgrading engines with higher efficiency and fewer emissions, thus furthering renewable energy aspirations.

2.
Materials (Basel) ; 15(23)2022 Nov 22.
Article in English | MEDLINE | ID: mdl-36499794

ABSTRACT

This research investigates the machinability of Inconel 718 under conventional machining speeds using three different tool coatings in comparison with uncoated tool during milling operation. Cutting speed, feed rate and depth of cut were selected as variable machining parameters to analyze output responses including surface roughness, burr formation and tool wear. It was found that uncoated and AlTiN coated tools resulted in lower tool wear than nACo and TiSiN coated tools. On the other hand, TiSiN coated tools resulted in highest surface roughness and burr formation. Among the three machining parameters, feed was identified as the most influential parameter affecting burr formation. Grey relational analysis identified the most optimal experimental run with a speed of 14 m/min, feed of 1 µm/tooth, and depth of cut of 70 µm using an AlTiN coated tool. ANOVA of the regression model identified the tool coating parameter as most effective, with a contribution ratio of 41.64%, whereas cutting speed and depth of cut were found to have contribution ratios of 18.82% and 8.10%, respectively. Experimental run at response surface optimized conditions resulted in reduced surface roughness and tool wear by 18% and 20%, respectively.

3.
Polymers (Basel) ; 14(11)2022 May 25.
Article in English | MEDLINE | ID: mdl-35683821

ABSTRACT

This study is very promising for providing a renewable enrgy (H2 gas fuel) under the elctrochemical splitting of the wastwater (sewage water). This study has double benefits: hydrogen generation and contaminations removel. This study is carried out on sewage water, third stage treated, from Beni-Suef city, Egypt. Antimony tin oxide (ATO)/polyaniline (PANI)/PbI2 photoelectrode is prepared through the in situ oxidative polymerization of PANI on ATO, then PANI is used as an assistant for PbI2 deposition using the ionic adsorption deposition method. The chemical structural, morphological, electrical, and optical properties of the composite are confirmed using different analytical tools such as X-ray diffreaction (XRD), scanning electron microscope (SEM), transmision electron microscope (TEM), Fourier-transform infrared spectroscopy (FTIR), and UV-Vis spectroscopy. The prepared PbI2 inside the composite has a crystal size of 33 nm (according to the peak at 12.8°) through the XRD analyses device. SEM and TEM confirm the hexagonal PbI2 sheets embedded on the PANI nanopores surface. Moreover, the bandgap values are enhanced very much after the composite formation, in which the bandgap values for PANI and PANI/PbI2 are 3 and 2.51 eV, respectively. The application of ATO/PANI/PbI2 nanocomposite electrode for sewage splitting and H2 generation is carried out through a three-electrode cell. The measurements carreid out using the electrocehical worksattion under th Xenon lamp (100 mW.cm-2). The produced current density (Jph) is 0.095 mA.cm-2 at 100 mW.cm-2 light illumination. The photoelectrode has high reproducibility and stability, in which and the number of H2 moles is 6 µmole.h-1.cm-1. The photoelectrode response to different monochromatic light, in which the produced Jph decreases from 0.077 to 0.072 mA.cm-2 with decreasing of the wavelengths from 390 to 636 nm, respectively. These values confirms the high response of the ATO/PANI/PbI2 nanocomposite electrode for the light illuminaton and hydrogen genration under broad light region. The thermodynamic parameters: activation energy (Ea), enthalpy (ΔH*), and entropy (ΔS*) values are 7.33 kJ/mol, -4.7 kJ/mol, and 203.3 J/mol.K, respectively. The small values of ΔS* relted to the high sesnivity of the prepared elctrode for the water splitting and then the hydrogen gneration. Finally, a theoretical study was mentioned for calculation geometry, electrochemical, and thermochemistry properties of the polyaniline/PbI2 nanocomposite as compared with that for the polyaniline.

4.
Chemosphere ; 305: 135378, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35738408

ABSTRACT

Marine pollution has a deleterious impact, both on the conditions of the ecosystem and the biodiversity of the ocean. Researchers in the field of marine chemistry have been putting effort into the creation of efficient catalysts for the purification of seawater. There has been extensive research done on membrane technology for the activation of peroxymonosulfate, which is an extremely effective therapy for saltwater. The sediment of QX03, which was obtained from the western coast of Bohai, is located very close to the modern coastline. The uppermost 15 m of this sector were thoroughly analyzed in sedimentary petrology, grain size, shell, and sediment chroma dating to reconstruct the sedimentary environment and relative sea-level during the time period of 44.80 ka cal BP. This indicates that a sea-retreating and retreating process has taken place; VI (5.2-0 m), Terrestrial deposition, is separated into swamp wetlands (VI-1) and flood plain (VI-2). The changes in sedimentary levels had a fairly strong correlation with the changes in sea level. Within the scope of this study, we conducted an in-depth investigation of the innovative membrane technology for the treatment of seawater by means of aqueous phase advanced oxidation close to the Bohai. The results of this study present a prospective technique that could make it possible to use membrane technology in the process of environmental restoration in marine settings.


Subject(s)
Ecosystem , Geologic Sediments , Environmental Monitoring , Prospective Studies , Seawater , Wetlands
5.
Chemosphere ; 304: 135337, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35714953

ABSTRACT

In recent years, the environmental pollution of microplastics has attracted much attention. To date, there have been a lot of researches on microplastics and a series of studies published. In this study, by bibliometric analysis method to evaluated the development and evolution on microplastics research trends and hot spots. A total of 2872 literature information was collected from the Web of Science (2004-2020), which was used for bibliometric visual analysis by CiteSpace. It was possible to see the contributing countries, institutions, authors, keywords, and future study directions in the microplastics sectors by looking at the visual representation of the results. (1) Since 2004, scientific advancements in this sector have advanced significantly, with a significant increase in speed since 2012. (2) China and the United States are the world's leading researchers in microplastics. (3) The study of microplastics was multidisciplinary, comprising researchers from the fields of ecology, chemistry, molecular biology, environmental science, and oceanography. (4) In recent years, researchers have concentrated their attention on the distribution and toxicity of microplastics in the environment, as well as their coupled pollution with heavy metal contaminants. In conclusion microplastics study in environmental science has become increasingly popular in recent years. Topics include dispersion, toxicity, and coupled pollution with heavy metal pollutants. Researchers in a wide range of fields are involved in microplastics research. Furthermore, policies and regulations about microplastics in global were summarized, and membrane technology has potential to remove microplastics from water. The above findings help to clearly grasp the content and development trend of microplastics research, point out the future research direction for scholars, and promote microplastics research and pollution prevention and control.


Subject(s)
Metals, Heavy , Water Pollutants, Chemical , Environmental Pollution , Microplastics/toxicity , Plastics , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/toxicity
6.
Micromachines (Basel) ; 14(1)2022 Dec 21.
Article in English | MEDLINE | ID: mdl-36677073

ABSTRACT

Super alloys offer excellent mechanical and chemical properties at elevated temperatures that make them an attractive choice for aerospace, automotive and chemical processing, and marine applications. These alloys are, however, difficult to machine due to their high strength at elevated temperatures, low thermal conductivity and work hardening. In this study, micro milling of Inconel 600 super alloy has been carried out and the effects of the key input parameters (cutting speed, feed rate, depth of cut) on response parameters (burr formation, surface roughness and tool wear), under various cooling conditions (dry, wet and cryogenic), have been analyzed. High speed micro milling (range up to 80,000 RPM) was carried out, while keeping the feed rate values below and above the cutting edge radius. The Taguchi design of experiments was used during this study. The results have been analyzed using SEM and 3D optical microscopy. Analysis of Variance (ANOVA) revealed that the best surface roughness values can be achieved under cryogenic machining condition with an overall contribution ratio of 28.69%. It was also revealed that cryogenic cooling resulted in the highest tool life with the contribution ratio of cooling conditions at 26.52%.

SELECTION OF CITATIONS
SEARCH DETAIL
...