检索结果-南通市图书馆

Very Short-Term Probabilistic Prediction Method for Wind Speed Based on ALASSO-Nonlinear Quantile Regression and Integrated Criterion

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2023年第6期9卷 2121-2129页

作者： Yan Zhou Yonghui Sun Sen Wang Linquan Bai Dongchen Hou Rabea Jamil mahfoud Peng Wang the College of Energy and Electrical Engineering Hohai UniversityNanjing 210098China Department of Systems Engineering and Engineering Management the University of North CarolinaCharlotte NC 28223USA

To enhance the performance of the prediction intervals (PIs), a novel very short-term probabilistic prediction method for wind speed via nonlinear quantile regression (NQR) based on adaptive least absolute shrinkage and selection operator (ALASSO) and integrated criterion (IC) is proposed. The ALASSO method is studied for shrinkage of output weights and selection of variables. Furthermore, for the better performance of PIs, composite weighted linear programming (CWLP) is proposed to modify the conventional linear programming cost function of quantile regression (QR), by combining it with Bayesian information criterion (BIC) as an IC to optimize the coefficients of PIs. Then, the multiple fold cross model (MFCM) is utilized to improve the PIs performance. Multistep probabilistic prediction of 15-minute wind speed is performed based on the real wind farm data from the northeast of China. The effectiveness of the proposed approach is validated through the performances' comparisons with conventional methods.

关键词： Composite weighted linear programming least absolute shrinkage and selection operator integrated criterion wind speed

Small scale biodiesel synthesis from waste frying oil and crude methanol in Morocco

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2016年第9期24卷 1178-1185页

作者： Fatiha Ouanji Marouane Nachid Mohamed Kacimi Leonarda F.Liotta Fabtizio Puleo mahfoud Ziyad Universite Mohammed V Faculte des SciencesDepartement de ChimieLaboratoire de Physico-chimie des Materiaux et Catalyse(URAC26)Avenue lbn BattoutaBP.1014RabatMorocco Hassan 11 Academy of Sdence and Technology RabatMorocco lstituto per lo Studio dei Materiali Nanostrutturati(ISMN)-CNR via Ugo La Malfa15390146 PalermoItaly

Biodiesel was produced at small scale by transesterification of used frying oil（UFO） recovered from Moroccan pastry shops and fish frying restaurants. Biodiesel was first synthesised at laboratory scale in order to optimize the transesterification parameters. The cost of the final product was also optimized using low-cost raw *** UFO and the produced biodiesel were characterized with several techniques including gas chromatography,1H NMR,13 C NMR, FTIR, and TGA–TDA techniques.1H NMR gas chromatographic analyses of the final product confirmed that the transesterification in the chosen experimental conditions was completed. These results were confirmed by TGA–TDA analysis used as new techniques to monitoring triglyceride conversion. The biodiesel did not contain any trace of glycerol, and it did meet the international standards. The transesterification at low cost in small scale conditions was performed at 60 ℃ using 1.2% of KOH and a methanol/oil molar ratio of 6：1. A yield of 80.8% was achieved. The properties of the produced biodiesel were found to be as good as those of biodiesels obeying to European standards. The biodiesel production was also performed at small-scale for individual utilisation. Thus, the product was tested in a kerosene stove for heating and non-modified commercial diesel engine producing electricity.

关键词： Biodiesel Transesterification Small-scale Thermogravimetry

Low-voltage ride-through capability improvement of Type-3 wind turbine through active disturbance rejection feedback control-based dynamic voltage restorer

在线全文

学校读者我要写书评

暂无评论

Clean Energy 2023年第5期7卷 1091-1109页

作者： El mahfoud Boulaoutaq Asma Aziz Abdelmounime El Magri Ahmed Abbou Mohamed Ajaamoum Azeddine Rachdy Ibn Zohr University Higher School of Technology Agadir School of Engineering Edith Cowan UniversityJoondalupWAaustralia Hassan II University of Casablanca National School of Technical Education Mohammed V University of Rabat Mohammadia School of Engineering

Disconnections due to voltage drops in the grid cannot be permitted if wind turbines(WTs)contribute significantly to electricity pro-duction,as this increases the risk of production loss and destabilizes the *** mitigate the negative effects of these occurrences,WTs must be able to ride through the low-voltage conditions and inject reactive current to provide dynamic voltage *** paper investigates the low-voltage ride-through(LVRT)capability enhancement of a Type-3 WT utilizing a dynamic voltage restorer(DVR).During the grid voltage drop,the DVR quickly injects a compensating voltage to keep the stator voltage *** paper proposes an active disturbance rejection control(ADRC)scheme to control the rotor-side,grid-side and DVR-side converters in a wind–DVR integrated *** performance of the Type-3 WT with DVR topology is evaluated under various test conditions using MATLAB®/Simulink®.These simulation results are also compared with the experimental results for the LVRT capability performed on a WT emulator equipped with a crowbar and direct current(DC)*** simulation results demonstrate a favourable transient and steady-state response of the Type-3 wind turbine quantities defined by the LVRT codes,as well as improved reactive power support under balanced fault *** the most severe voltage drop of 95%,the stator currents,rotor currents and DC bus voltage are 1.25 pu,1.40 pu and 1.09 UDC,respectively,conforming to the values of the LVRT *** controlled by the ADRC technique significantly increases the LVRT capabilities of a Type-3 doubly-fed induction generator-based WT under symmetrical voltage dip *** setting up ADRC controllers might be challenging,the proposed method has been shown to be extremely effective in reducing all kinds of internal and external disturbances.

关键词： active disturbance rejection controller(ADRC) dynamic voltage restorer(DVR) low-voltage ride-through(LVRT) Type-3 wind turbines(WTs) doubly-fed induction generator(DFIG)

Performance Improvement of Very Short-term Prediction Intervals for Regional Wind Power Based on Composite Conditional Nonlinear Quantile Regression

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2022年第1期10卷 60-70页

作者： Yan Zhou Yonghui Sun Sen Wang Rabea Jamil mahfoud Hassan Haes Alhelou Nikos Hatziargyriou Pierluigi Siano College of Energy and Electrical Engineering Hohai UniversityNanjing 210098China Department of Electrical Engineering Tishreen UniversityLatakia 2230Syria National Technical University of Athens Athens 15773Greece Department of Management&Innovation Systems University of SalernoSalerno 84084Italy

Accurate regional wind power prediction plays an important role in the security and reliability of power *** the performance improvement of very short-term prediction intervals(PIs),a novel probabilistic prediction method based on composite conditional nonlinear quantile regression(CCNQR)is ***,the hierarchical clustering method based on weighted multivariate time series motifs(WMTSM)is studied to consider the static difference,dynamic difference,and meteorological difference of wind power time ***,the correlations are used as sample weights for the conditional linear programming(CLP)of *** optimize the performance of PIs,a composite evaluation including the accuracy of PI coverage probability(PICP),the average width(AW),and the offsets of points outside PIs(OPOPI)is used to quantify the appropriate upper and lower ***,the adaptive boundary quantiles(ABQs)are quantified for the optimal performance of ***,based on the real wind farm data,the superiority of the proposed method is verified by adequate comparisons with the conventional methods.

关键词： Regional wind power probabilistic prediction nonlinear quantile regression composite evaluation adaptive boundary quantiles

Dimensional(premenstrual symptoms screening tool)vs categorical(mini diagnostic interview,module U)for assessment of premenstrual disorders

在线全文

学校读者我要写书评

暂无评论

World Journal of Psychiatry 2022年第4期12卷 603-614页

作者： Rifka Chamali Rana Emam Ziyad R mahfoud Hassen Al-Amin Department of Research Weill Cornell Medicine-QatarDoha 00974Qatar Department of Psychiatry Hamad Medical CorporationDoha 00974Qatar Department of Medical Education Weill Cornell Medicine-QatarDoha 00974Qatar Division of Epidemiology Department of Population of Health SciencesWeill Cornell MedicineNew York 10065NYUnited States Department of Psychiatry Weill Cornell Medicine-QatarDoha 00974Qatar

BACKGROUND Premenstrual syndrome(PMS)is the constellation of physical and psychological symptoms before *** dysphoric disorder(PMDD)is a severe form of PMS with more depressive and anxiety *** Mini international neuropsychiatric interview,module U(MINI-U),assesses the diagnostic criteria for probable *** Premenstrual Symptoms screening tool(PSST)measures the severity of these *** To compare the PSST ordinal scores with the corresponding dichotomous MINI-U *** Arab women(n=194)residing in Doha,Qatar,received the MINI-U and *** Operating Characteristics(ROC)analyses provided the cut-off scores on the PSST using MINI-U as a gold *** All PSST ratings were higher in participants with positive responses on *** addition,ROC analyses showed that all areas under the curves were significant with the cutoff scores on *** This study confirms that the severity measures from PSST can recognize patients with moderate/severe PMS and PMDD who would benefit from immediate treatment.

关键词： Premenstrual symptoms screening tool Premenstrual dysphoric disorder Arabs Categorical vs dimensional classification

Nonparametric Probabilistic Prediction of Regional PV Outputs Based on Granule-based Clustering and Direct Optimization Programming

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2023年第5期11卷 1450-1461页

作者： Yonghui Sun Yan Zhou Sen Wang Rabea Jamil mahfoud Hassan Haes Alhelou George Sideratos Nikos Hatziargyriou Pierluigi Siano College of Energy and Electrical Engineering Hohai UniversityNanjing 210098China College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China IEEE Department of Electrical Engineering Tishreen UniversityLatakia 2230Syria National Technical University of Athens Athens 15773Greece Department of Management&Innovation Systems University of SalernoSalerno 84084Italy

Regional photovoltaic(PV) power prediction plays an important role in power system planning and operation. To effectively improve the performance of prediction intervals(PIs) for very short-term regional PV outputs, an efficient nonparametric probabilistic prediction method based on granulebased clustering(GC) and direct optimization programming(DOP) is proposed. First, GC is proposed to formulate and cluster the sample granules consisting of numerical weather prediction(NWP) and historical regional output data, for the enhanced hierarchical clustering performance. Then, to improve the accuracy of samples' utilization, an unbalanced extension is used to reconstruct the training samples consisting of power time series. After that, DOP is applied to quantify the output weights based on the optimal overall performance. Meanwhile, a balance coefficient is studied for the enhanced reliability of PIs. Finally, the proposed method is validated through multistep PIs based on the numerical comparison of real PV generation data.

关键词： Regional photovoltaic output prediction intervals granule-based clustering direct optimization programming nonparametric probabilistic prediction

Potential antioxidant properties and hepatoprotective effects of Juniperus phoenicea berries against CCl4 induced hepatic damage in rats

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2017年第3期10卷 249-255页

作者： Amel Laouar Fahima Klibet Ezzeddine Bourogaa Amel Benamara Amel Boumendjel Azzedine Chefrour Messarah mahfoud Laboratory of Biochemistry and Environmental Toxicology Faculty of SciencesUniversity of Badji MokhtarAnnaba 23000Algeria Department of Biochemistry and Biological Cellular and Molecular Faculty of SciencesUniversity of MentouriBP 25000 ConstantineAlgeria Laboratoryof Animal Ecophysiology Faculty of SciencesSfaxSoukra road-Km 3.5BP 8023018 SfaxTunisia Department of Applied Biology Faculty of Natural Sciences and LifeUniversity of Larbi TebessiTebessa 12000Algeria Laboratory of pharmaceutical preparations for hospital use Department of PharmacyFaculty of MedicineUniversity of Badji Mokhtar-Annaba 23000Algeria Department of Biology Faculty of Natural Sciences and LifeUiversity of Mohamed Cherif MesaadiaSouk Ahras 41000Algeria

Objective:To investigate the antioxidant and hepatoprotective properties of Juniperus phoenicea(***)berries against CCl_4-induced oxidative damage in ***:Hepatotoxicity was induced in albino Wistar rats by single dose of CCl_4 dissolved in olive oil(1 mL/kg BW,1/1 in olive oil,ip).Aqueous extract of *** berries(AEJP)was administered at the dose of 250 mg/kg/day by gavage for 12 ***:Obtained results revealed that administration of CCl_4 caused a significant increase in plasma ASAT,ALAT,ALP and LDH activities and total bilirubin concentration,compared to the control ***,albumin and total protein concentration were significantly ***,a significant decrease in the level of hepatic GSH,GPx and GST activities associated with a significant increase of MDA content in CCl_4 group than those of the ***,the treatment of experimental rats with AEJP prevented these alterations and maintained the antioxidant *** histopathological observations supported the biochemical evidences of ***:The results of the present investigation indicate that *** possesses hepatoprotective activity and this effect was may be due to its antioxidant proprerties.

关键词： Juniperus phoenicea Oxydative stress Antioxydant Lipid peroxidation Hepatoprotective Biochemical parameters

氮掺杂碳纳米管负载的Ru和Pd催化剂上异丙醇的转化(英文)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

催化学报 2014年第6期35卷 970-978页

作者： Anas Benyounes Mohamed Kacimi mahfoud Ziyad Philippe Serp Laboratory of Coordination Chemistry UPR CNRS 8241 ENSIACET Group Toulouse University 4 allée Emile Monso - CS 44362 Toulouse Cedex 4 France Laboratory of Physical Chemistry of Materials Catalysis and Environment (URAC26) Department of Chemistry Faculty of Science University of Mohammed V-Agdal BP1014 Rabat Morocco Hassan II Academy of Science and Technology Rabat Morocco

Ru and Pd (2 wt%) loaded on pure and on Ndoped carbon nanotubes (NCNTs) were prepared and tested using the isopropyl alcohol decomposition reaction as probe reaction. The presence of nitrogen functionalities (pyridinic, pyrrolic, and quaternary nitrogen) on the nitrogen doped support induced a higher metal dispersion: Pd/NCNT (1.8 nm) < Pd/CNT (4.9 nm), and Ru/NCNT (2.4 nm) < Ru/CNT (3.0 nm). The catalytic activity of the supports was determined first. Isopropyl alcohol conversion produces acetone on CNTs while on NCNTs it led to both dehydration and dehydrogenation products. At 210 °C and in the presence of air, the isopropyl alcohol conversion was higher on the NCNTs (25%) than on the CNTs (11%). The Pd loaded catalysts were more active and more selective than the Ru ones. At 115 °C, the Pd catalysts were 100% selective towards acetone for a conversion of 100%, whereas the Ru catalysts led to dehydration and dehydrogenation products. The nitrogen doping induced the appearance of redox properties when oxygen is present in the reaction mixture.

关键词：碳纳米管氮掺杂异丙醇 Ru Pd 氧化还原性质钯催化剂加载

Disruption of biofilms from sewage pipes under physical and chemical conditioning

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2009年第1期21卷 120-126页

作者： Charbel mahfoud Antoine El Samrani Rita Mouawad Walid Hleihel Rim El Khatib Bruno S. Lartiges Nam Ouani Holy Spirit University of Kaslik(USEK) Faculty of Sciences and Computer Engineering Department of Chemistry and Life SciencesWater and Environment Laboratory. P.B. 446JouniehLebanon Nancy University LEM-ENSG/INPL-CNRSPole de l'Eau15Avenue du CharmoisBP 40-F-54501 Vandoeuvre CedexFrance

Biofilms grown inside two sewage collecting pipes located in industrial and residential areas are studied. Bacterial biomass inside three layers of biofilms was evaluated. Biofilm cohesion under different mixing rate and ionic strength was also investigated. Effects of physical and chemical parameters in the biofilms were evaluated by monitoring turbidity, chemical and biochemical oxygen demands. Extracted organic matter from biofilms was partitioned to polar, aromatic and saturated fractions using activated silica column chromatography. Results revealed that bacterial biomass growth depending on biofilm thickness and stratification. The most loaded stratum in bacteria/biomass was the sewage-biofilm interface stratum that represented 51% of the total bacteria/biomass. Stirring rate and ionic strength of mono- and bivalent salts showed a major influence in biofilm disruption. The stirring time enhanced the exchange dynamic and matter capture between biofilm fragments at the critical stirring rate 90 r/min. Sodium chloride showed the dispersing effect on biofilms in suspension, and decreased the BOD5 （biochemical oxygen demand） beyond the physiological salt concentration.

关键词： biofilms, biochemical oxygen demand (BODs) chemical oxygen demand (COD) biomass ionic strength