The presence of phenolic compounds in the aquatic environment has posed severe risks due to their toxicity. Among the phenolic families, nitro- and alkyl-phenolic compounds have been categorized as ...precedence contaminants by the United States Environmental Protection Agency (US EPA). Therefore, efficient treatment methods for wastewater containing nitro- and alkyl-phenolic compounds are urgently needed. Due to the advantages of creating reactive species and generating efficient degradation of hazardous contaminants in wastewater, advanced oxidation processes (AOPs) are well-known in the field of treating toxic contaminants. In this review paper, the recent directions in AOPs, catalysts, mechanisms, and kinetics of AOPs are comprehensively reviewed. Furthermore, the conclusion summarizes the research findings, future prospects, and opportunities for this study. The main direction of AOPs lies on the optimization of catalyst and operating parameters, with industrial applications remain as the main challenge. This review article is expected to present a summary and in-depth understanding of AOPs development; and thus, inspiring scientists to accelerate the evolution of AOPs in industrial applications.
•Recent advances in AOPs for the treatment of nitro- and alkyl-phenolic compounds are reviewed.•Development of AOPs technologies, process improvement, and catalysts are comprehensively reviewed.•Reaction kinetics and mechanism are comprehensively gathered.•Future prospects, opportunities, and conclusions are comprehensively discussed.
•NiO-CMD catalyst has shown potential bi-functional deoxygenation catalyst due to high capacity in removing oxygen compound to produce high quality of green fuel.•Synergistic effects of bi-functional ...NiO-CaO/MgO (acid-base) properties favored deoxyegnation pathways.•NiO doped Malaysian Dolomite restricted coke formation and improved product selectivity.•NiO-CMD catalyst had catalyzed simultaneous cracking- deoxygenation reaction.
This study investigates the multi-objective optimization of reaction parameters with response surface methodology (RSM) with central composite design (CCD) for the deoxygenation of waste cooking oil (WCO) over low cost-modified local carbonate mineral catalyst (NiO-Malaysian dolomite) into green fuel in the range of gasoline, kerosene and diesel. RSM was performed to study the effect of four operating parameters: temperature (390–430 °C), time (30–120 min), catalyst loading (1–10 wt%) and nitrogen flow rate (50–300 cm3/min). The results indicate that for maximum WCO conversion, deoxygenated oil and product yield, the optimum parameters of the deoxygenation reaction were at 410 °C, 60 min, 5.50 wt% of catalyst loading, and 175 cm3/min of N2. The green fuel properties testing (density, kinematic viscosity, flash point, cloud point, pour point, sulfur, carbon residue, cetane index, oxidation stability, acid value, iodine value and calorific value) and GC–MS analysis show that the product oil meets almost all the requirements of green diesel fuel and hydrocarbon biofuel standards for fuel application while the quadratic model proposed agreed with the experimental data (95% confidence) which indicates that the RSM can adequately predict the reaction products.
Understanding the behavior of lead-free solder alloys within a high humidity environment is a serious topic in the deployment of products in various electronics applications. The work reported herein ...investigates this specific impact on Sn–1.0Ag–0.5Cu–0.5Fe solder alloy. Specimens were treated with 5% NaCl salt spray. All specimens showed strong resistance to corrosion. Microstructural deformations after the test were analyzed using Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy (SEM/EDX). Concerns were at the localized corroded area, as this would cause significant degradation at the solder joints. The mechanisms leading to these disadvantageous results as well as the microstructural evolution and correlation with the intrinsic properties of the solder alloy are discussed.
In machining, heat concentration is generated at the surface contact between the tool and workpiece. This is the effect of hard frictions at the shear cutting plane to remove hard and brittle ...materials. The highly adhesive behavior of aluminum alloy 6061-T6 is more severe in higher cutting temperature, which may affect tool failures such as flank wear, tool chip and built-up edge, particularly on the edge of cutting inserts during the process. As a result, this may lead to the rough surface and low-dimensional accuracy of the machined parts. Realizing that metal-cutting industry players are demanding high-quality products with better surface finish and dimensional accuracy led to this study. Aluminum alloy 6061-T6 is a standard alloy used in automotive, aerospace and food packaging due to good hardness, high strength-to-weight ratio, resistance to corrosion and weldability. In order to address this problem, a newly developed metal working fluid which is SiO
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-Al
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O
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-ZrO
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tri-hybrid nanofluid is applied in the cutting zone to achieve a good surface finish of the machined parts and lowering the cutting temperature. This study is the first attempt to enhance machining performance, particularly at high-speed machining, by employing a combination of tri-hybrid nanofluids and a minimum quantity lubricant technique. Industrial standards include uncoated tungsten carbide and CVD TiCN-Al
2
O
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carbide used during machining of aluminum alloy 6061-T6. The minimum quantity lubricant method is an alternative in supplying the lubricant into the machining zone due to flood machining and conventional fluid possess safety, health, economic and environmental effects. In this study, the experimental data were analyzed statistically using analysis of variance and response surface methodology. The responses studied were reduced significantly when tri-hybrid nanoparticles present at the cutting interface with higher MQL flow rate and concentration. There are two-factor interactions which are significant to the responses studied. Therefore, the combinations of MQL and excellent tri-hybrid nanofluids characteristics have enhanced between 16 and 76% of surface roughness and the cutting temperature, respectively, which is very promising in the future.
A lateral flow rapid diagnostic test (RDT) enables detection of measles specific immunoglobulin M (IgM) antibody in serum, capillary blood, and oral fluid with accuracy consistent with enzyme ...immunoassay (EIA). The objectives of the study were: 1) to assess measles RDT inter-reader agreement between two clinic staff; 2) to assess the sensitivity and specificity of the measles RDT relative to standard surveillance testing in a low transmission setting; 3) to evaluate the knowledge, attitudes, and practices of staff in clinics using the RDT; and 4) to assess the impact of RDT testing on the measles public health response in Malaysia.
The clinic-based prospective evaluation included all suspected measles cases captured by routine measles surveillance at 34 purposely selected clinics in 15 health districts in Malaysia between September 2019 and June 2020, following day-long regional trainings on RDT use. Following informed consent, four specimens were collected from each suspected case, including those routinely collected for standard surveillance serum for EIA and throat swabs for quantitative reverse transcriptase polymerase chain reaction (RT-qPCR) together with capillary blood and oral fluid tested with RDTs during the study. RDT impact was evaluated by comparing the rapidity of measles public health response between the pre-RDT implementation (December 2018 to August 2019) and RDT implementation periods (September 2019 to June 2020). To assess knowledge, attitudes, and practices of RDT use, staff involved in the public health management of measles at the selected sites were surveyed.
Among the 436 suspect cases, agreement of direct visual readings of measles RDT devices between two health clinic staff was 99% for capillary blood (k = 0.94) and 97% for oral fluid (k = 0.90) specimens. Of the total, 45 (10%) were positive by measles IgM EIA (n = 44, including five also positive by RT-qPCR) or RT-qPCR only (n = 1), and 38 were positive by RDT (using either capillary blood or oral fluid). Using measles IgM EIA or RT-qPCR as reference, RDT sensitivity using capillary blood was 43% (95% CI: 30%-58%) and specificity was 98% (95% CI: 96%-99%); using oral fluid, sensitivity (26%, 95% CI: 15%-40%) and specificity (97%, 95% CI: 94%-98%) were lower. Nine months after training, RDT knowledge was high among staff involved with the public health management of measles (average quiz score of 80%) and was highest among those who received formal training (88%), followed by those trained during supervisory visits (83%). During the RDT implementation period, the number of days from case confirmation until initiation of public response decreased by about 5 days.
The measles IgM RDT shows >95% inter-reader agreement, high retention of RDT knowledge, and a more rapid public health response. However, despite ≥95% RDT specificity using capillary blood or oral fluid, RDT sensitivity was <45%. Higher-powered studies using highly specific IgM assays and systematic RT-qPCR for case confirmation are needed to establish the role of RDT in measles elimination settings.
In this paper, we investigate the flow of magnetohydrodynamic Casson fluid over a linear stretching surface in porous medium with slip condition. The governing partial differential equations are ...reduced to non-linear ordinary differential equations with the aid of similarity transformation. The transformed equations and boundary conditions are then solved by using exact analytical method. The flow field is affected by the presence of physical parameters, such as Casson fluid parameter, magnetohydrodynamic parameter, velocity slip parameter, porosity parameter, and suction/injection, whereas the temperature field is additionally affected by magnetohydrodynamic, thermal radiation, Prandtl and Eckert numbers. The effects of the pertinent physical parameters on the velocity and temperature fields are presented through graphs and discussed. Skin friction and heat transfer coefficients are tabulated and analyzed.
The effect of slip on stagnation point flow and heat transfer over an exponentially stretching/shrinking sheet filled with Copper-Alumina/water nanofluids is investigated numerically in this paper. ...The governing boundary layer equations are transformed into a set of ordinary differential equations using a similarity transformation and then solved numerically using the bvp4c function in Matlab. The effects of nanoparticle volume fraction, slip parameter and stretching/shrinking parameter on the flow pattern and heat transfer have been studied. It is found that dual solutions exist for hybrid nanofluid in the case of shrinking sheet. Furthermore, slip parameter and Copper nanoparticle acts in widening the range of solution. Hybrid nanofluids have the higher heat transfer rate compared to nanofluid and viscous fluid. A stability analysis showed that the first solution is linearly stable and physically realizable.
The problem of the steady magnetohydrodynamic （MHD） stagnation-point flow of an incompressible viscous fluid over a stretching sheet is studied. The effect of an induced magnetic field is taken into ...account. The nonlinear partial differential equations are transformed into ordinary differential equations via the similarity transformation. The transformed boundary layer equations are solved numerically using the shooting method. Numerical results are obtained for various magnetic parameters and Prandtl numbers. The effects of the induced magnetic field on the skin friction coefficient, the local Nusselt number, the velocity, and the temperature profiles are presented graphically and discussed in detail.
Diabetes Mellitus (DM) is a non-communicable disease and is a severe chronic illness. Early detection of DM is one way to detect the possibility of someone getting DM. This application was made to ...determine the accuracy of the diagnosis of DM using backpropagation ANN. There are 11 risk factors used, namely gender, smoker or not, heredity, systolic blood pressure, diastolic blood pressure, total cholesterol levels, HDL (High-Density Lipoprotein) levels, LDL (Low-Density Lipoprotein) levels, triglyceride levels, BMI (Body Mass Index), and HBA1c levels (Hemoglobin A1c). Risk factors are taken based on medical records of DM patients and data on healthy people. The training and testing of artificial neural networks showed promising results for the suitability of network output and desired targets with a correlation coefficient of 0.98043. The results of testing showed promising results for network output and target match desired with a correlation coefficient of 0.97894.
This paper presents the analyst the number of layers and the number of neurons in the hidden layer of the Artificial Neural Network. In this study, case studies were taken in the recognition of ...alphabet patterns and shape patterns. First, the number of layers is varied to get the best number of layers. Furthermore, the number of neurons is varied to get the best number of neurons. The results showed that the best number of layers was 1-5 layers in the hidden layer, with validation values from the recognition system 96-100%. While the best number of neurons is obtained with 19 neurons, with an average accuracy percentage of 81%.
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