Struvite precipitation has been widely applied for the removal of ammonium-nitrogen (NH4–N) from wastewater. Due to the high cost of phosphorus (P) reagents, the current research trend was directed ...to find alternative sources of P, in order to maintain a sustainable NH4–N removal process. The current study investigated waste bones ashes as alternative sources of P. Different types of bones' ashes were characterized, in which the ash produced from waste fish bones was the highest in P content (17%wt.). The optimization of the factors affecting P extraction from ash by acidic leaching showed that applying 2M H2SO4 and 1.25 kg H2SO4/kg ash achieved the highest P recovery (95%). Thereafter, the recovered P was successfully used in struvite precipitation, which achieved more than 90% NH4–N removal and high purity struvite.
•Fish bone ash contains higher amount of phosphorus than chicken and cow bone ashes.•Phosphorus was extracted from ash by acidic leaching using sulfuric acid.•Mg–P solution improved the reactivity of MgO.•Applying Mg–P solution for NH4–N recovery resulted with high-purity struvite.
Nanocomposites, consisting of a polymeric matrix and nanosized elements as reinforcement, have attracted significant scientific attention because of their high mechanical performance. A large variety ...of nanocomposites have been prepared using bio-based materials as a matrix and nanoreinforcement, so that it can reduce the dependence on nondegradable products and move to a sustainable materials basis. The objective of this study was to isolate nanocellulose from empty fruit bunch (EFB) fiber and their reinforcing effect on polyvinyl alcohol (PVA)/starch blend films. A series of PVA/starch films with different content of nanocellulose were prepared by solution casting method. Nanocellulose fiber with diameters ranging from 4 to 15 nm has been successfully prepared. On the other hand, PVA/starch films reinforced with nanocellulose fiber possess significantly improved properties compared to unreinforced film. From the results, PVA/starch films with the addition of 5% (v/v) of nanocellulose exhibited best combination of properties. This nanocomposite was found to have tensile strength at about 5.694 MPa and elongation at break was 481.85%. In addition to good mechanical properties, this nanocomposite has good water resistance and biodegradability.
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•Thermodynamic comparative analysis of steam and dry reforming is evaluated.•Hydrogen formation from methane-ethane-glycerol steam and dry reforming is analysed.•Comparatively, ...methane-ethane-glycerol steam reforming produces more hydrogen.•Optimum hydrogen production at WMEG 3:1 and CMEG 1:1 at 1273 K.•Steam reforming reactions inhibits the carbon deposition thermodynamically.
Glycerol is produced as a by-product waste during the biodiesel manufacturing process. In recent researches, glycerol has been extensively studied for its potential to be converted into higher value-added compounds because it is renewable and bioavailable compound to reduce the high biodiesel production cost. As a result, various methods and technologies, such as steam reforming and dry reforming, were utilized to convert glycerol to higher value added products. The straightforward route of dry and steam reforming techniques uses carbon dioxide and other greenhouse gases to create added-value products like syngas, which may be considered renewable alternatives to fossil fuels as global CO2 emission issues get higher and near-uncontrollable. Therefore, this article presents a novel thermodynamic equilibrium analysis of steam and dry reforming with methane-ethane-glycerol mixture based on the total Gibbs free energy minimization method for hydrogen generation. Equilibrium product compositions were determined as a function of molar ratio between H2O/methane-ethane-glycerol (WMEG) from 1:1 to 12:1 and CO2/methane-ethane-glycerol (CMEG) from 1:1 to 12:1 for steam and dry reforming respectively, where the molar basis of the methane-ethane-glycerol mixture is 1:1:1. The reforming temperatures are ranged from 573 K to 1273 K at atmospheric pressure of 1 bar. The production trends of H2, CO, CO2, CH4 and C were compared between both reforming of glycerol. From to the result of the study, the optimal operating parameter for the highest hydrogen production was under steam reforming with WMEG of 3:1 at 1273 K and zero carbon deposition is achieved. In comparison with CO and CO2 production, dry reforming produced higher yields than steam reforming. Furthermore, a significant increment of hydrogen production was not observed at higher ratios of WMEG and CMEG. Steam reforming inhibited the carbon formation thermodynamically better than dry reforming.
•Transesterification of vegetable palm oil (VPO) to biodiesel was performed over CaO-TiO2 under UV light.•Effects of reaction time, VPO:methanol ratio and catalyst dosage on biodiesel yield was ...studied.•The catalyst was reusable up to four cycles at optimized conditions with >80% biodiesel yield.•The fatty methyl ester (FAME) in the biodiesel was analyzed using GC-MS.•The biodiesel produced meets the ASTM D6751 specifications.
This study examines the production of biodiesel from vegetable palm oil (VPO) via transesterification catalyzed by calcium oxide modified with titanium dioxide (CaO-TiO2) under UV light. Response surface methodology (RSM) with central composite design (CCD) was used to optimize the biodiesel yield. The optimized conditions for transesterification were 2.52wt.% for catalyst dosage, 3:4 for volumetric ratio of VPO to methanol, 65°C for reaction temperature, and 145.51min for reaction time. VPO transesterification under optimum conditions produced 96.67% biodiesel yield. In addition, regeneration of CaO-TiO2 catalyst was studied under optimum conditions. This catalyst can be reused for four times with biodiesel yields beyond 80%. GC-MS analysis revealed the main methyl ester components in the biodiesel product including 9-octadecenoic acid, methyl ester (E)-(oleic acid) and hexadecanoic acid methyl ester (palmitic acid). Kinetic viscosity and higher heating value of the biodiesel were found to be in agreement with the ASTM D 6751 standard. This study demonstrated a practical method to produce biodiesel from VPO with less corrosion, less toxicity, and less environmental problems using an effective, stable and economic heterogeneous basic catalyst, CaO-TiO2.
Breast cancer is the most common cancer among women and it is one of the main causes of death for women worldwide. To attain an optimum medical treatment for breast cancer, an early breast cancer ...detection is crucial. This paper proposes a multi- stage feature selection method that extracts statistically significant features for breast cancer size detection using proposed data normalization techniques. Ultra-wideband (UWB) signals, controlled using microcontroller are transmitted via an antenna from one end of the breast phantom and are received on the other end. These ultra-wideband analogue signals are represented in both time and frequency domain. The preprocessed digital data is passed to the proposed multi- stage feature selection algorithm. This algorithm has four selection stages. It comprises of data normalization methods, feature extraction, data dimensional reduction and feature fusion. The output data is fused together to form the proposed datasets, namely, 8-HybridFeature, 9-HybridFeature and 10-HybridFeature datasets. The classification performance of these datasets is tested using the Support Vector Machine, Probabilistic Neural Network and Naïve Bayes classifiers for breast cancer size classification. The research findings indicate that the 8-HybridFeature dataset performs better in comparison to the other two datasets. For the 8-HybridFeature dataset, the Naïve Bayes classifier (91.98%) outperformed the Support Vector Machine (90.44%) and Probabilistic Neural Network (80.05%) classifiers in terms of classification accuracy. The finalized method is tested and visualized in the MATLAB based 2D and 3D environment.
Abstract
In this paper, a photovoltaic (PV) system based on modified duty cycle sweeping (MDCS) has been proposed to achieve the maximum power point tracking (MPPT). The disadvantages of perturb and ...observe (P&O), such as diverging tracking directions and the inability to detect the global peak during partial shading (PS), are intended to be overcome by this method (PS). An intelligent double identification and tracking method consistently tracks the global peak under partial shading and the MPP under rapid irradiance fluctuations. Strict dynamic irradiance and partial shading tests are imposed in MATLAB/Simulink
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and simulated to validate the suggested concept. Additionally, a laboratory prototype MPPT standalone PV system supported by Texas Instruments’ Code Composer Studio is operated by a SEPIC converter in conjunction with the C2000 real-time microcontroller in order to conduct an experimental validation study. The effectiveness of the method is compared with the other well-known MPPT techniques, conventional P&O. The suggested method successfully follows the global peak under various patterns of partial shading as compared to the conventional algorithms. The algorithm’s efficiency has been preserved at around 95-100%.
ABSTRACT
Previous studies have reported that coronal mass ejections (CMEs) and solar flares lead to the development of huge storms and high-speed streams. Our aim in this paper is to investigate the ...response of the geomagnetic index SYM/H to the solar wind parameters, such as solar wind speed V, dynamic pressure P, input energy IE and the interplanetary magnetic field (IMF) Bz component, associated with solar flares and CME events. The response of the ground geomagnetic field (H-component) to the solar wind parameters and the IMF Bz component at three low-latitude stations has also been analysed. Our findings show that the delay of the solar wind changes in the Earth’s magnetosphere in response to the weak geomagnetic storm (SYM/H = −30 nT) at the beginning of 2014 December 21. A weak storm of SYM/H = −30 nT in the middle of 2014 November 5 is suggested by a low magnetic reconnection process in the magnetosphere. In addition, the strong southward IMF Bz component and high solar wind changes in the magnetosphere system, which were a result of the X2.0 solar flare event and the CMEs on 2014 October 27, responded to the moderate storm (SYM/H = −60 nT) at the beginning of 2014 October 28. This dynamic physical process in the magnetosphere caused by solar wind variation is seen to excite the Earth’s H-component through ultra low frequency at the ground-based magnetometers at the BCL (Vietnam), TIR (India) and SCN (Indonesia) stations during the geomagnetic storm. This study relates to seismic investigations and geomagnetic-induced current on the ground.
Multicriteria decision making (MCDM) is one of the methods that popularly has been used in solving personnel selection problem. Alternatives, criteria, and weights are some of the fundamental aspects ...in MCDM that need to be defined clearly in order to achieve a good result. Apart from these aspects, fuzzy data has to take into consideration that it may arise from unobtainable and incomplete information. In this paper, we propose a new approach for personnel selection problem. The proposed approach is based on Hamming distance method with subjective and objective weights (HDMSOW’s). In case of vagueness situation, fuzzy set theory is then incorporated onto the HDMSOW’s. To determine the objective weight for each attribute, the fuzzy Shannon’s entropy is considered. While for the subjective weight, it is aggregated into a comparable scale. A numerical example is presented to illustrate the HDMSOW’s.
With an approach towards generating a wearable skin hydration detecting system, simple, cheap, and flexible skin hydration sensing strategy was demonstrated here using an interdigitated electrode ...(IDE) coated with polydimethylsiloxane (PDMS) matrix. Aluminium IDE with a 400 µm gap and 250 µm electrode sizes were fabricated using a photolithography method. Morphological characterizations were performed using a high power microscope, 3D-profilometer, and scanning electron microscope. The dimensions of electrodes and gaps measured through electron microscopic analysis affirmed the exactness of IDE and the fabrication process. After coated with PDMS polymer, the IDE/PDMS surface was examined under a high power microscope and 3D-profilometer. The optical characterization revealed the polymer was coated on IDE through the color-shade changes and smooth surface observed under an optical microscope and the respective 3D-visualization. IDE/PDMS was also analyzed by an atomic force microscope, revealing the smoothness of the IDE surface. Electrical characterizations were performed using different pH and urea solutions and the sweat to investigate the influence of real-time and artificial sweat on IDE/PDMS. As the device showed appropriate results with real-time sweat and no effect with artificial interferences, it is highly encouraged and recommended for detecting skin hydration and the related illnesses with the point-of-care concept.
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