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Modern improvement techniques of direct torque control for induction motor drives - a review

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Protection and Control of Modern Power Systems 2019年第1期4卷 138-149页

作者： Najib El Ouanjli Aziz Derouich Abdelaziz El Ghzizal Saad Motahhir ali Chebabhi Youness El Mourabit Mohammed Taoussi Laboratory of Production Engineering Energy and Sustainable DevelopmentHigher School of TechnologySidi Mohamed Ben Abdellah UniversityFezMorocco Faculty of Sciences and Technology University of Bordj Bou ArreridjBordj Bou ArreridjAlgeria Laboratory of Systems Integration and Advanced Technologies Faculty of Sciences Dhar El MahrazSidi Mohamed Ben Abdellah UniversityFezMorocco

Conventional direct torque control (DTC) is one of the excellent control strategies available to control the torque of the induction machine (im). However, the low switching frequency of the DTC causes high ripples in the flux and torque that leads to an acoustic noise which degrades the control performances, especially at low speeds. Many direct torque control techniques were appeared to remedy these problems by focusing specifically on the torque and flux. In this paper, a state of the art review of various modern techniques for improving the performance of DTC control is presented. The objective is to make a critical analysis of these methods in terms of ripples reduction, tracking speed, switching loss, algorithm complexity and parameter sensitivity. Further, it is envisaged that the information presented in this review paper will be a valuable gathering of information for academic and industrial researchers.

关键词： Induction machine Direct torque Control(DTC) Fuzzy logic(FL) Neural network(NN) Sliding mode(SG) Genetic algorithm(GA)

Pd/silicalite-1: An highly active catalyst for the oxidative removal of toluene

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Journal of Environmental Sciences 2022年第6期34卷 209-219页

作者： Linke Wu Jiguang Deng Yuxi Liu Lin Jing Xiaohui Yu Xing Zhang Ruyi Gao Wenbo Pei Xiuqing Hao ali Rastegarpanah Hongxing Dai Beijing Key Laboratory for Green Catalysis and Separation Key Laboratory of Beijing on Regional Air Pollution ControlKey Laboratory of Advanced Functional MaterialsEducation Ministry of ChinaLaboratory of Catalysis Chemistry and NanoscienceDepartment of Environmental Chemical EngineeringSchool of Environmental and Chemical EngineeringFaculty of Environment and LifeBeijing University of TechnologyBeijing 100124China

Catalytic combustion is thought as an efficient and economic pathway to remove volatile organic compounds, and its critical issue is the development of high-performance catalytic materials. In this work, we used the in situ synthesis method to prepare the silicalite-1(S-1)-supported Pd nanoparticles(NPs). It is found that the as-prepared catalysts displayed a hexagonal prism morphology and a surface area of 390-440 m^(2)/g. The sample(0.28Pd/S-1-H)derived after reduction at 500°C in 10 vol% H_(2)showed the best catalytic activity for toluene combustion(T50%= 180℃ and T90%= 189℃ at a space velocity of 40,000 m L/(g·hr), turnover frequency(TOFPd) at 160℃ = 3.46 × 10^(-3)sec^(-1), and specific reaction rate at 160℃ = 63.8μmol/(gPd·sec)), with the apparent activation energy(41 k J/mol) obtained over the bestperforming 0.28Pd/S-1-H sample being much lower than those(51-70 k J/mol) obtained over the other samples(0.28Pd/S-1-A derived from calcination at 500℃ in air, 0.26Pd/S-1-im derived from the impregnation route, and 0.27Pd/ZSM-5-H prepared after reduction at 500℃ in 10 vol% H_(2)). Furthermore, the 0.28Pd/S-1-H sample possessed good thermal stability and its partial deactivation due to CO_(2) or H_(2)O introduction was reversible, but SO_(2) addition resulted in an irreversible deactivation. The possible pathways of toluene oxidation over 0.28Pd/S-1-H was toluene → p-methylbenzoquinone → maleic anhydride, benzoic acid, benzaldehyde → carbon dioxide and water. We conclude that the good dispersion of Pd NPs, high adsorption oxygen species concentration, large toluene adsorption capacity, strong acidity,and more Pd~0 species were responsible for the good catalytic performance of 0.28Pd/S-1-H.

关键词： Silicalite-1 Hexagonal prism shape Supported palladium catalyst Volatile organic compound Toluene combustion

Novel power capture optimization based sensorless maximum power point tracking strategy and internal model controller for wind turbines systems driven SCIG

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Frontiers in Energy 2019年第4期13卷 742-756页

作者： ali EL YAAKOUBI Kamal ATTARI Adel ASSELMAN Abdelouahed DJEBLI Optic and Photonic Tcam Faculty of SciencesAbdelmalek Essaaidi UniversityTetouan 93002Morocco Energetics Fluid Mechanics and Materials LaboratoryAbdelmalek Essaadi UniversityTetouan 93002Morocco

Under the trends to using renewable energy sources as alternatives to the traditional ones,it is important to contribute to the fast growing development of these sources by using powerful soft computing *** this context,this paper introduces a novel structure to optimize and control the energy produced from a variable speed wind turbine which is based on a squirrel cage induction generator(SCIG)and connected to the *** optimization strategy of the harvested power from the wind is realized by a maximum power point tracking(MPPT)algorithm based on fuzzy logic,and the control strategy of the generator is implemented by means of an internal model(im)*** im controllers are incorporated in the vector control technique,as an alternative to the proportional integral(PI)controller,to implement the proposed optimization *** MPPT in conjunction with the im controller is proposed as an alternative to the traditional tip speed ratio(TSR)technique,to avoid any disturbance such as wind speed measurement and wind turbine(WT)characteristic *** on the simulation results of a six KW-WECS model in Matlab/Simulink,the presented control system topology is reliable and keeps the system operation around the desired response.

关键词： power optimization wind energy conversion system maximum power point tracking(MPPT) fuzzy logic internal model(im)controller

Incidence of T3151 mutation in BCR/ABL-positive CML and ALL patients

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Frontiers in Biology 2016年第5期11卷 404-411页

作者： Fatemeh Norozi Javad Mohammadi-asl Tina Vosoughi Mohammad ali Jalali Far Areal Saki Malehi Najmaldin Saki Health Research Institute Thalassemia and Hemoglobinopathy Research Center Ahvaz Jundishapur University of Medical Sciences Ahvaz Iran Department of Medical Genetics Ahvaz Jundishapur University of Medical Sciences Ahvaz Iran

OBJECTIVES： Targeted therapy of Philadelphia-positive ALL and CML patients using imatinib （im） has caused significant changes in treatment course and has increased the survival of patients. A small group of patients show resistance to im. Acquired mutations in tyrosine kinase domain of BCR-ABL protein are a mechanism for development of resistance. T315I is one of the most common acquired mutations in this domain, which occurs in ATP binding site and inhibits the formation of hydrogen bond with im. The aim of this study was to evaluate the prevalence of this mutation in BCR/ABL-positive CML and ALL patients. METHODS： To conduct this study, 60 BCR-ABL-positive patients （including 50 CML and 10 ALL patients） who were subject to treatment with im were selected. After taking the samples, presence of T315I mutation was assessed using ARMS- PCR on cDNA and its polymorphism was evaluated by sequencing. RESULTS： The results showed that among 60 patients, only three patients had T315I mutation, which was detected using ARMS technique. The three patients bearing mutation were afflicted with CML and no significant association was found between blood parameters with duration of treatment in presence of mutation. CONCLUSIONS： The mutation was found in three CML patients, which indicated lower likelihood and diagnostic value of this mutation in ALL patients. Given the negative direct sequencing results in T3151 patients, it can be concluded that ARMS- PCR is a more sensitive technique when the number of cancer cells is low in patients during treatment.

关键词： BCR-ABL T315I mutation imatinib CML ALL

Plasticity of wheat seedling responses to K^(+) deficiency highlighted by integrated phenotyping of roots and root hairs over the whole root system

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Stress Biology 2023年第1期3卷 69-83页

作者： Ikram Madani Jean-Benoit Peltier Martin Boeglin Hervé Sentenac Anne-aliénor Véry Institut des Sciences des Plantes de Montpellier UMR 5004 CNRS-386 INRAE-Université Montpellier-Institut AgroCampus SupAgro-INRAE Bat 7Place VialaMontpellier 34060 Cedex 2France

The availability in the soil of potassium(K^(+)),a poorly mobile macronutrient required in large quantities for plant growth,is generally suboptimal for crop production in the absence of fertilization,making improvement of the ability of crops to adapt to K^(+)deficiency stress a major *** the uptake capacity of the root system is among the main strategies to achieve this ***,we report an integrative approach to examine the effect of K^(+)deficiency on the development of young plant entire root system,including root hairs which are known to provide a significant contribution to the uptake of poorly mobile nutrients such as K^(+),in two genetically distant wheat varieties.A rhizobox-type methodology was developed to obtain highly-resolved images of root and root hairs,allowing to describe global root and root hair traits over the whole root system via image analysis *** two wheat varieties responded differently to the K^(+)shortage:Escandia,a wheat ancestor,reduced shoot biomass in condition of K^(+)shortage and substantially increased the surface area of its root system,specifically by increasing the total root hair *** Zenati,a landrace,conversely appeared unresponsive to the K^(+)shortage but was shown to constitutively express,independently of the external K^(+)availability,favorable traits to cope with reduced K^(+)availability,among which a high total root hair ***,valuable information on root system adaptation to K^(+)deficiency was provided by global analyses including root hairs,which should also be relevant for other nutrient stresses.

关键词： K^(+)deficiency Root hair Root system Phenotyping Wheat Rhizobox Root plasticity

Cost Effective Scheme for OLT in Next Generation Passive Optical Access Network Based on Noise Free Optical Multi Carrier

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China Communications 2016年第6期13卷 76-87页

作者： Rahat Ullah Bo Liu Qi Zhang Qinghua Tian Amjad ali Yousaf Khan Feng Tian M.Azam Zia Haseeb Ahmad Lijia Zhang Xiangjun Xin State Key Laboratory of Information Photonics and Optical Communications.Beijing University of Posts and Telecommunications No.10 Xitucheng RoadBeijingChina100876 School of Electronic Engineering Beijing University of Posts and TelecommunicationsNo.10 Xitucheng RoadBeijingChina100876 Sarhad University of Science and Information technology PeshawarPakistan. Electrical Engineering Department Iqra University PeshawarPakistan. State Key laboratory of Network and Switching Technology Beijing University of Posts and TelecommunicationsNo.10 Xitucheng RoadBeijing100876China

We propos e a cos t-effective multi-carrier generation technique which minimizes the passive optical access network(PON) costs. In this study replacement of laser array with multi-carrier source at optical line terminal(OLT) side in PON is addressed. With 25-GHz frequency spacing, the generated optical multi-carriers exhibit good tone to noise ratio(TNR) i. e. above 20 d B, and least amplitude difference i. e. 1.5d B. At the OLT, multi-carriers signal based multiplexed differential phase shift keying(DPSK) data from all the channels each having 10 Gbps for downlink is transmitted through 25 km single mode fiber. While the transmitted information is retrieved at optical network unit(ONU), part of the downlink signal is re-modulated using intensity modulated(im) on-off keying(OOK) for upstream transmission at 10-Gbps. Simulation results are in good agreement with the theoretical analysis, showing error free transmission in downlink and uplink with 10 Gbps symmetric data rate at each channel. The receivedpower, both for uplink and downlink transmission, is adequate for all channels at BER of 10-9 with minimum power penalties. Power budget is calculated for different splitting ratios showing excellent system margins for any unseen losses. The proposed setup provides a cost-effective way minimizing transmission losses, and providing greater system's margin in PON architecture.

关键词： differential phase shift keying intensity modulated on-off-keying optical frequency comb generation optical access network

A Comprehensive Survey of Candidate Waveforms for 5G, beyond 5G and 6G Wireless Communication Systems

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Open Journal of Applied Sciences 2023年第1期13卷 136-161页

作者： Bakhit Amine Adoum Kalsouabe Zoukalne Mahamat Saleh Idriss ali Mahmoud ali Amir Moungache Mahamoud Youssouf Khayal Ecole Nationale Superieure des Technologies de l’Information et de la Communication (ENASTIC) N’Djamena Tchad Institute of Sciences and Techniques of Abeche (INSTA) Abeche Tchad Université de N’Djamena N’Djamena Tchad Virtual University of Chad N’djamena Tchad Centre National de Recherche pour le Developpement (CNRD) N’djamena Tchad

The evolution of global mobile data over the past decades in broadcasting, Internet of Things (IoT), education, healthcare, commerce, and energy has put strong pressure on 3G/4G mobile networks to improve their service offerings. These generations of mobile networks were initially invented to meet the requirements of the above-mentioned applications. However, as the requirements in these applications continue to increase, new mobile technologies such as 5G (fifth generation), 5G and beyond (B5G, beyond fifth generation), and 6G (sixth generation) are still progressing and being experimented. These networks are very heterogeneous generations of mobile networks that will have to offer very high throughput per user, good energy efficiency, better traffic capacity per area, improved spectral efficiency, very low latency, and high mobility. To meet these requirements, the radio interface of future mobile networks will have to be flexible and rationalized the available frequency resources. Therefore, new modulation methods, access techniques and waveforms capable of supporting these technological changes are proposed. This review presents brief descriptions of the types of 5G, B5G, and 6G waveforms. The 5G consists of OFDM including its transmission techniques: generalized frequency division multiplexing (GFDM), filter bank based multi-carrier (FBMC), universal filtered multi-carrier (UFMC), and index modulation (im). Meanwhile, the 6G covers orthogonal time frequency space (OTFS), orthogonal chirp division multiplexing (OCDM) and orthogonal time sequence multiplexing (OTSM). The networks’ potentialities, advantages, disadvantages, and future directions are outlined.

关键词： Modulation 5G B5G 6G Waveforms

Feasibility of allogeneic mesenchymal stem cells in pediatric hypoxic-ischemic encephalopathy: Phase I study

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World Journal of Stem Cells 2021年第5期13卷 470-484页

作者： Serdar Kabatas Erdinç Civelek Eyüp Can Savrunlu Necati Kaplan Osman Boyalı Furkan Diren Halil Can ali Genç Tunç Akkoç Erdal Karaöz Department of Neurosurgery University of Health SciencesGaziosmanpaşa Training and Research HospitalIstanbul 34255Turkey Pediatric Allergy-immunology Marmara UniversityInstitute of Health SciencesIstanbul 34854Turkey Center for Stem Cell&Gene Therapy Research and Practice University of Health SciencesIstanbul 34255Turkey Department of Neurosurgery Istanbul Rumeli UniversityÇorlu Reyap HospitalTekirdağ59860Turkey Department of Neurosurgery Istanbul Biruni UniversityFaculty of MedicineIstanbul 34010Turkey Department of Neurosurgery Istanbul Medicine HospitalIstanbul 34203Turkey Department of Neurosurgery Istanbul Asya HospitalIstanbul 34250Turkey Pediatric Allergy-immunology Marmara UniversityIstanbul 34899Turkey Center for Regenerative Medicine and Stem Cell Research&Manufacturing(LivMedCell) Liv HospitalIstanbul 34340Turkey Department of Histology and Embryology Istinye UniversityFaculty of MedicineIstanbul 34010Turkey Center for Stem Cell and Tissue Engineering Research and Practice Istinye UniversityIstanbul 34340Turkey

BACKGROUND Hypoxic-ischemic encephalopathy(HIE)is one of the leading causes of death and long-term neurological impairment in the pediatric *** a limited number of treatments to cure HIE,stem cell therapies appear to be a potential treatment option for brain injury resulting from *** To investigate the efficacy and safety of stem cell-based therapies in pediatric patients with *** The study inclusion criteria were determined as the presence of substantial deficit and disability caused by ***’s jelly-derived mesenchymal stem cells(WJ-MSCs)were intrathecally(IT),intramuscularly(im),and intravenously administered to participants at a dose of 1×10^(6)/kg for each administration route twice monthly for 2 *** different follow-up durations,the effect of WJ-MSCs administration on HIE,the quality of life,prognosis of patients,and side effects were investigated,and patients were evaluated for neurological,cognitive functions,and spasticity using the Wee Functional Independence Measure(Wee Fim)Scale and Modified Ashworth(MA)*** For all participants(n=6),the mean duration of exposure to hypoxia was 39.17+18.82 min,the mean time interval after HIE was 21.83±26.60 mo,the mean baseline Wee Fim scale score was 13.5±0.55,and the mean baseline MA scale score was 35±*** patients developed only early complications such as low-grade fever,mild headache associated with IT injection,and muscle pain associated with im injection,all of which were transient and disappeared within 24 *** treatment was evaluated to be safe and effective as demonstrated by magnetic resonance imaging examinations,electroencephalographies,laboratory tests,and neurological and functional scores of *** exhibited significant improvements in all neurological functions through a 12-mo *** mean Wee Fim scale score of participants increased from 13.5±0.55 to 15.17±1.6 points(mean±SD)at 1 mo(z=-1.826,P=0.068)and to 23.5±3.39 points at 12 mo(z

关键词： Hypoxic-ischemic encephalopathy Pediatric Stem cell Wharton jelly

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外商直接投资对阿富汗经济增长的影响

外商直接投资对阿富汗经济增长的影响

作者： Kazemi Safar ali 江西财经大学

学位级别：硕士

本研究的目的是评估和研究外国直接投资对阿富汗经济发展的影响,并将自变量与外国直接投资因变量联系起来。因此,选取的时间轴是从1987年到2017年。采用普遍最小二乘回归模型定量法。选择OLS模型是因为它是许多先前研究人员常用的研究模... 详细信息

本研究的目的是评估和研究外国直接投资对阿富汗经济发展的影响,并将自变量与外国直接投资因变量联系起来。因此,选取的时间轴是从1987年到2017年。采用普遍最小二乘回归模型定量法。选择OLS模型是因为它是许多先前研究人员常用的研究模型,并且由于其能够使本研究的偏差最小化,而完全符合主题。从1987年至2017年期间,本研究引用了之前的数据,数据来源于世界银行的世界发展指标。收集的数据包括国内生产总值(GDP)数据,在这种情况下用作因变量,用于衡量阿富汗的经济增长。其他收集的信息包括自变量数据,包括外国直接投资(FDI),出口(EX),进口(im),政府支出(GE)和国民收入(NI)。本文分析了1987-2017年期间外国直接投资流入对阿富汗经济增长的影响,因此回归是本文的重要组成部分,可以凭经验得出可接受的结论性结果。用于此分析的OLS模型,它是帮助我们进行回归分析的基本模型。该研究还采用了线性回归的基本生产函数。在模型中,GDP作为因变量,而作为外国直接投资的其他变量,出口,进口,政府支出和国民收入是自变量。在我们的研究结果中,我们发现外国直接投资对阿富汗的经济增长有积极影响。进口数据也很重要,与外国直接投资呈正相关。政府支出对外国直接投资流入具有负面的影响,而进口数据与外国直接投资呈负相关。另一方面,国民收入与外国直接投资的关系不大。研究建议,政府应该在其正式机构上做出更多的努力,以确保形成问责制和保证透明度,从而吸引更多的外企投资,这可能有利于经济的增长。政府应投资于道路和电信服务等基础设施,使投资者的流动性和协调性增强。该研究还建议建立有效的税收制度,对投资者征税,这可能会吸引更多的投资者,从而增加GDP。尽管本文已经做了一些足够的经验分析外国直接投资对经济增长的影响,但作为自变量的衡量可能无法完全解释外国直接投资对阿富汗经济的影响,因此本文建议使用未来的其他变量,如外汇,通货膨胀和劳动力。

关键词： FDI 经济增长 GDP 影响经济阿富汗