775 research outputs found

    Optimal Parameter Estimation of Solar PV Panel Based on Hybrid Particle Swarm and Grey Wolf Optimization Algorithms

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    The performance of a solar photovoltaic (PV) panel is examined through determining its internal parameters based on single and double diode models. The environmental conditions such as temperature and the level of radiation also influence the output characteristics of solar panel. In this research work, the parameters of solar PV panel are identified for the first time, as far as the authors know, using hybrid particle swarm optimization (PSO) and grey wolf optimizer (WGO) based on experimental datasets of I-V curves. The main advantage of hybrid PSOGWO is combining the exploitation ability of the PSO with the exploration ability of the GWO. During the optimization process, the main target is minimizing the root mean square error (RMSE) between the original experimental data and the estimated data. Three different solar PV modules are considered to prove the superiority of the proposed strategy. Three different solar PV panels are used during the evaluation of the proposed strategy. A comparison of PSOGWO with other state-of-the-art methods is made. The obtained results confirmed that the least RMSE values are achieved using PSOGWO for all case studies compared with PSO and GWO optimizers. Almost a perfect agreement between the estimated data and experimental data set is achieved by PSOGWO

    Modification of bacterial cell membrane to accelerate decolorization of textile wastewater effluent using microbial fuel cells: role of gamma radiation

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    The aim of the present work was to increase bacterial adhesion on anode via inducing membrane modifications to enhance textile wastewater treatment in Microbial Fuel Cell (MFC). Real textile wastewater was used in mediator-less MFCs for bacterial enrichment. The enriched bacteria were pre-treated by exposure to 1 KGy gamma radiation and were tested in MFC setup. Bacterial cell membrane permeability and cell membrane charges were measured using noninvasive dielectric spectroscopy measurements. The results show that pre-treatment using gamma radiation resulted in biofilm formation and increased cell permeability and exopolysaccharide production; this was reflected in both MFC performance (average voltage 554.67 mV) and decolorization (96.42%) as compared to 392.77 mV and 60.76% decolorization for non-treated cells. At the end of MFC operation, cytotoxicity test was performed for treated wastewater using a dermal cell line, the results obtained show a decrease in toxicity from 24.8 to 0 (v/v%) when cells were exposed to gamma radiation. Fourier-transform infrared (FTIR) spectroscopy showed an increase in exopolysaccharides in bacterial consortium exposed to increasing doses of gamma radiation suggesting that gamma radiation increased exopolysaccharide production, providing transient media for electron transfer and contributing to accelerating MFC performance. Modification of bacterial membrane prior to MFC operation can be considered highly effective as a pre-treatment tool that accelerates MFC performance

    Isothermal Modelling Based Experimental Study of Dissolved Hydrogen Sulfide Adsorption from Waste Water using Eggshell Based Activated Carbon

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    This paper reports on the experimental work using batch process conducted to determine the adsorption capacity of dissolved hydrogen sulfide in the synthetic wastewater onto the activated carbon which is derived from the eggshell. Fourier Transform Infrared Spectroscopy (FTIR), Energy-Dispersive X-ray Spectroscopy (EDX), Scanning Electron Microscopy (SEM), and particle size distribution have been used to characterize the prepared material. The raw materials of chicken eggshell are adopted to retrieve the carbon content which is then activated using KOH as the activation agent. The examined concentration of dissolved hydrogen sulfide is ranging from 100 to 500 ppm. The maximum adsorption capacity of the dissolved H2S onto the activated carbon is 289.3 mg/g and the equilibrium time is 6 hours. The examined pH value in this study is ranging from 4.5 to 5.5. The two well-known equilibrium adsorption isotherm models, i.e. the Langmuir and the Freundlich models, are employed. It is found that the adsorption isotherm capacity agrees very well to the Freundlich isotherm model. This paper attempts to show the difficulties of converting CaCO 3 to carbon due to the fact that the raw material contains higher calcium (Ca) content instead of carbon. It is concluded that the carbon derived from the chickens’ eggshells is very beneficial for treatment of dissolved H2S in waste water

    Toward establishing model organisms for marine protists : Successful transfection protocols for Parabodo caudatus (Kinetoplastida: Excavata)

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    Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Environmental Microbiology 19 (2017): 3487-3499, doi:10.1111/1462-2920.13830.We developed protocols for, and demonstrated successful transfection of, the free-living kinetoplastid flagellate Parabodo caudatus with three plasmids carrying a fluorescence reporter gene (pEF-GFP with the EF1 alpha promoter, pUB-GFP with Ubiquitin C promoter, and pEYFP37 Mitotrap with CMV promoter). We evaluated three electroporation approaches: 1) a square-wave electroporator designed for eukaryotes, 2) a novel microfluidic transfection system employing hydrodynamically-controlled electric field waveforms, and 3) a traditional exponential decay electroporator. We found the microfluidic device provides a simple and efficient platform to quickly test a wide range of electric field parameters to find the optimal set of conditions for electroporation of target species. It also allows for processing large sample volumes (> 10 ml) within minutes, increasing throughput 100 times over cuvettes. Fluorescence signal from the reporter gene was detected a few hours after transfection and persisted for 3 days in cells transformed by pEF-GFP and pUB-GFP plasmids and for at least 5 days post-transfection for cells transformed with pEYFP-Mitotrap. Expression of the reporter genes (GFP and YFP) was also confirmed using reverse transcription-PCR (RT-PCR). This work opens the door for further efforts with this taxon and close relatives toward establishing model systems for genome editing.This project was funded by the Gordon and Betty Moore Foundation through Grant GBMF4963 to V. Edgcomb, P. Girguis, and C. Buie

    Forecasting the Climate Change through the Distributions of Solar Radiation and Maximum Temperature

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    The climate change crisis is negatively affecting the world and is the focus of many researchers attention for its life-threatening economic and climate impact on Earth. Therefore, this study aims to estimate the joint distribution function (EFXY) of both daily solar radiation (S) and daily maximum temperature (T) along with the Markov property. In this study, three-parameter distributions have been utilized with S and T, which are generalized extreme value (GEV) and Weibull (W-3P), respectively. Each of these parameters and the joint distribution function ((, )) have been estimated. Four real data of S and T in Queensland, Australia during two consecutive years are applied. The method of maximum likelihood estimation (MLE) is applied on the proposed distributions of S and T to estimate their parameters, which was validated using Goodness-of-Fit tests. In addition, the logarithmic (LFXY) model and the multi-regression model (MFXY) for (, ) are obtained. The results have been compared and the EFXY and LFXY are found to be non-equivalently, while the EFXY and MFXY are equivalent and homogeneous, confirming the validity of the joint distribution function estimate with the least error. Thus, the climate change probabilities are more accurately predictable by knowing both X and Y or by knowing both () and () with minimal error

    Fast phonetic similarity search over large repositories

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    Analysis of unstructured data may be inefficient in the presence of spelling errors. Existing approaches use string similarity methods to search for valid words within a text, with a supporting dictionary. However, they are not rich enough to encode phonetic information to assist the search. In this paper, we present a novel approach for efficiently perform phonetic similarity search over large data sources, that uses a data structure called PhoneticMap to encode language-specific phonetic information. We validate our approach through an experiment over a data set using a Portuguese variant of a well-known repository, to automatically correct words with spelling errors

    A Retrospective Study of Acute Poisoning in Children under 5 Years Old Admitted to Alexandria Poison Center in Egypt

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    Abstract Childhood poisoning represents a major public health preventable problem worldwide. It has been identified that unintentional poisoning is the most common circumstances of poisoning in young children. Various drugs and chemical compounds have been implicated such as kerosene being the most common household agent. Aim: The current study aimed to retrospectively study acute poisoning in children less than 5 years old admitted to Alexandria Poison Center (APC) at Alexandria Main University hospital as regards; pattern of childhood poisoning (incidence and prevalence), risk factors related to poisoning accidents and the outcome. Subjects and Methods: All patients aged less than 5 years with acute poisoning admitted to Alexandria Poison Center at Alexandria Main University Hospital, Alexandria, Egypt, during the period of 8 months started from 1st January to 31st August 2012 were included in the study. Results: This retrospective study involved 620 intoxicated children which represented 20.7% of total poisoning cases admitted to APC at that period of time. The incidence of poisoning was found to be highest in children aged between 3 to 5 years old and constituted 49.1% and 39.6% of males and females respectively. The mode of poisoning was found to be accidental with no reported cases of neither homicidal nor suicidal poisonings. The most common agent of toxicity in children was found to be kerosene, followed by chlorine and cholinesterase inhibitor insecticide. The outcome of most of cases (84.5%) was recovery and discharge, with 10.5% being admitted to (Intensive Care Unit) ICU and 5% mortality rate. Conclusion: Risk factors for unintentional poisoning in children involve accessibility to hazardous chemicals and medicines caused by unsafe storage, aggressive child's behavior, unsafe storage of kerosene oil and petrol, low socioeconomic status as well as low educational level of the mother
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