18 research outputs found

    Treatment of olive mill based wastewater by means of magnetic nanoparticles: Decolourization, dephenolization and COD removal

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    AbstractOlive mill wastewater (OMW) is an environmental concern that has been highlighted as a serious environmental problem in the Mediterranean basin countries because of its high organic load and phytotoxic and antibacterial phenolic compounds, which resist biological degradation. Consequently, this type of wastewater represents a huge challenge for the conventional wastewater treatment techniques as it can impact the lifetime of bacteria needed for the treatment. Iron-oxide nanoparticles are attractive for wastewater treatment for two important reasons. First, nanoparticles can remove pollutants from wastewater rapidly. Second, this magnetic type of nanoparticles could be separated easily using a magnet after finishing treatment process. In this study, we aimed at investigating the effectiveness of the magnetic iron oxide nanoparticles in the removal of large organic contaminants from OMW. Batch and continuous mode processes were applied on OMW treatment to determine the effect of contact time, solution pH, coexisting contaminants and the adsorption isotherm.The results showed that the adsorption was fast and the adsorption reached equilibrium within less than 30min. The adsorption equilibrium data fit very well to the Brunauer–Emmett–Teller (BET) Model, indicating multi-layers adsorption. The adsorption of major pollutants was associated to an efficient removal of coexisting contaminants such as heavy metals and free ions. The adsorption of OMW pollutants was dependent on pH of the solution. Finally, continuous-mode process was tested successfully using a packed bed column that combined sand filtration with magnetic nanoparticles to decolourize OMW effluent. This study will provide valuable insight on the effect of nanoparticles toward the treatment and recyclability of olive mill wastewater, which is crucial for the local olive mill industry. After seeing the successful achievement of integrating nanoparticles with fixed bed filtration, a preliminary process description and cost estimation of stand-alone plant (with a capacity of 4m3/h) for OMW treatment were considered in this study. Process capital and annual operating costs were estimated to be 12,306and12,306 and 476/year, respectively

    Xeno-free trans-differentiation of adipose tissue-derived mesenchymal stem cells into glial and neuronal cells.

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    Mesenchymal stem cells (MSCs) are undifferentiated cells that have the ability of self-renewal and trans-differentiation into other cell types. They hold out hope for finding a cure for many diseases. Nevertheless, there are still some obstacles that limit their clinical transplantation. One of these obstacles are the xenogeneic substances added in either proliferation or differentiation media with subsequent immunogenic and infectious transmission problems. In this study, we aimed to replace fetal bovine serum (FBS), the main nutrient source for MSC proliferation with xeno-free blood derivatives. We tested the effect of human activated pure platelet-rich plasma (P-PRP) and advanced platelet-rich fibrin (A-PRF) on the proliferation of human adipose derived-MSCs (AD-MSCs) at different concentrations. For the induction of MSC neural differentiation, we used human cerebrospinal fluid (CSF) at different concentrations in combination with P-PRP to effect xeno-free/species-specific neuronal/glial differentiation and we found that media with 10% CSF and 10% PRP promoted glial differentiation, while media with only 10% PRP induced a neuron-like phenotype

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Comparative Study of AVR Control Systems Considering a Novel Optimized PID-Based Model Reference Fractional Adaptive Controller

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    Voltage regulation is a crucial task for electrical grids in the presence of high penetration levels of renewable energies. The regulation of generator excitation improves the stability of the power system. An essential tool for controlling the excitation of generators is the automatic voltage regulator (AVR). It is advised to use a controller to increase the reliability of an AVR. A survey about different types of controllers is proposed in this paper. Then, a novel optimized PID-Based model reference fractional adaptive controller is proposed, with detailed mathematical modeling. The novel controller was compared to the controllers in the survey. The novel proposed controller proved its superiority over the other controllers through its fast response and low rising and settling times. Moreover, the proposed controller smoothly and instantaneously tracked dynamic reference changes

    Development of a Solid-Phase Extraction (SPE) Cartridge Based on Chitosan-Metal Oxide Nanoparticles (Ch-MO NPs) for Extraction of Pesticides from Water and Determination by HPLC

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    The present study aims to prepare two new types of chitosan-metal oxide nanoparticles (Ch-MO NPs), namely, chitosan-copper oxide nanoparticles (Ch-CuO NPs) and chitosan-zinc oxide nanoparticles (Ch-ZnO NPs), using sol-gel precipitation mechanism, and test them new as adsorbent materials for extraction and clean-up of different pesticides from water. The design of core-shell was implemented by metal oxide core with chitosan as a hard shell after crosslinking mechanism by glutaraldehyde and then epichlorohydrin. The characterizations of the prepared nanoparticles were investigated using Fourier transform infrared spectrometry (FT-IR), zeta potential, scanning electron microscopy (SEM), transmission electron microscope (TEM), and X-ray diffraction (XRD). FT-IR confirmed the interaction between chitosan, metal oxide, and crosslinking mechanism. SEM and TEM explained that the nanoparticles have a spherical morphology and nanosize of 93.74 and 97.95 nm for Ch-CuO NPs and Ch-ZnO NPs, respectively. Factorial experimental design was applied to study the effect of pH, concentration of pesticide, agitation time, and temperature on the efficiency of adsorption of pesticides from water samples. The results indicated that optimum conditions were pH of 7, temperature of 25°C, and agitation time of 25 min. The SPE cartridges were then packed with Ch-MO NPs, and seven pesticides of abamectin, diazinon, fenamiphos, imidacloprid, lambda-cyhalothrin, methomyl, and thiophanate-methyl were extracted from water samples and determined by HPLC. The extraction efficiency of Ch-ZnO NPs was higher than Ch-CuO NPs, but both removed a larger amount of most of tested pesticides than the standard ODS cartridge (C18). The results showed that this method achieves rapid and simple extraction in small quantities of adsorbents (Ch-MO NPs) and solvents. In addition, the method is highly sensitive to pesticides and has a high recovery rate

    An Optimized PV Control System Based on the Emperor Penguin Optimizer

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    During the day, photovoltaic (PV) systems are exposed to different sunlight conditions in addition to partial shading (PS). Accordingly, maximum power point tracking (MPPT) techniques have become essential for PV systems to secure harvesting the maximum possible power from the PV modules. In this paper, optimized control is performed through the application of relatively newly developed optimization algorithms to PV systems under Partial Shading (PS) conditions. The initial value of the duty cycle of the boost converter is optimized for maximizing the amount of power extracted from the PV arrays. The emperor penguin optimizer (EPO) is proposed not only to optimize the initial setting of duty cycle but to tune the gains of controllers used for the boost converter and the grid-connected inverter of the PV system. In addition, the performance of the proposed system based on the EPO algorithm is compared with another newly developed optimization technique based on the cuttlefish algorithm (CFA). Moreover, particle swarm optimization (PSO) algorithm is used as a reference algorithm to compare results with both EPO and CFA. PSO is chosen since it is an old, well-tested, and effective algorithm. For the evaluation of performance of the proposed PV system using the proposed algorithms under different PS conditions, results are recorded and introduced

    An Optimized PV Control System Based on the Emperor Penguin Optimizer

    No full text
    During the day, photovoltaic (PV) systems are exposed to different sunlight conditions in addition to partial shading (PS). Accordingly, maximum power point tracking (MPPT) techniques have become essential for PV systems to secure harvesting the maximum possible power from the PV modules. In this paper, optimized control is performed through the application of relatively newly developed optimization algorithms to PV systems under Partial Shading (PS) conditions. The initial value of the duty cycle of the boost converter is optimized for maximizing the amount of power extracted from the PV arrays. The emperor penguin optimizer (EPO) is proposed not only to optimize the initial setting of duty cycle but to tune the gains of controllers used for the boost converter and the grid-connected inverter of the PV system. In addition, the performance of the proposed system based on the EPO algorithm is compared with another newly developed optimization technique based on the cuttlefish algorithm (CFA). Moreover, particle swarm optimization (PSO) algorithm is used as a reference algorithm to compare results with both EPO and CFA. PSO is chosen since it is an old, well-tested, and effective algorithm. For the evaluation of performance of the proposed PV system using the proposed algorithms under different PS conditions, results are recorded and introduced

    Reducing the frequency of unnecessary rectal biopsies by combined interpretation of clinical and radiological findings in Egyptian children with suspected Hirschsprung’s disease

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    AbstractIntroductionHirschsprung’s disease (HD) should be considered in children with neonatal-onset constipation. Clinical differentiation between HD and idiopathic constipation (IC) is difficult in late presenting infants. Consequently, paediatric surgical centres receive numerous referrals for rectal biopsies, requiring admissions and GA, particularly if suction biopsy is unavailable, and in older children.MethodsForty-two cases referred for rectal biopsy, were studied for clinical features, single contrast enema, as compared to rectal biopsy findings, to determine the statistical reliability towards achieving a diagnosis.ResultsThe mean age at presentation was 106days in HD patients, and 172days in IC. Significant neonatal clinical features were present in 54%. Delayed passage of meconium was present in 86% of HD, compared to 14% of IC (p=0.001). Rectal examination found a tight segment in 90% of HD, and a distended anorectum in 64% of IC (p=0.005). The sensitivity of contrast enema was 86%, and the specificity was 90%. The histological analysis of strip rectal biopsy was sensitive in 93%, and inconclusive in 7%.ConclusionThis audit generated a checklist of 6 clinical and 3 radiological criteria, to differentiate HD from ID, including clinically (1) neonatal onset; (2) male sex; (3) congenital anomalies, dysmorphic features and/or family history of HD; (4) delayed meconium passage; (5) enterocolitis or significant bowel obstruction/impaction; (6) tight segment on rectal examination; and radiologically (7) funnelled transition zone or a reversed rectosigmoid index (<1); (8) delayed evacuation of contrast after 24h; and (9) absent distension of the anorectum with contrast, absent mucosal irregularities, and absent sigmoid looping
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