bluuebunny/crossref_metadata_2025 huggingface dataset:
Seed germination requirements of Hypericum scruglii, an endangered medicinal plant species of Sardinia (Italy)
Authors: Porceddu Marco , Sanna Martina , Serra Sara , Manconi Maria , Bacchetta Gianluigi
Published: June 2020

Hypericum scruglii Bacch., Brullo & Salmeri is an endangered endemic plant of Sardinia, and the phloroglucinol compounds identified in this species have been reported to inhibit the activity of the Human Immunodeficiency Virus. Seed banks are a genetic repository that effectively preserve taxa of conservation interest, and they hold knowledge about the biology and germination ecophysiology of the taxa they preserve. The main goals of this study were to investigate the germination requirements for H. scruglii, to evaluate the seed viability after eight years of long-term conservation and to suggest an efficient protocol for germination. Seeds stored at –25 °C in the seed bank were tested at temperatures from 5 to 30 °C and 25/10 °C. Base temperature (Tb) and thermal time (θ50) for germination were estimated. Seeds of H. scruglii germinated over a wide range of temperatures, responding positively to high temperatures and 25/10 °C. Tb was estimated at 4.92 °C, and θ50 was estimated at 198.27 degree days. The high viability detected in seeds of H. scruglii allows us to suggest the use of seeds stored in a seed bank when fresh material for plant propagation is scarce. Our results provide new and useful baseline information for implementing conservation and multiplication strategies for this endangered medicinal plant.
A phenomenological analysis of the nonperturbative QCD contributions for the photon wave function
Authors: Gonçalves V. P. , Moreira B. D.
Published: June 2020

The photon – induced interactions, present in ep, eA, pp, pA, AA and $$e^+ e^-$$e+e- collisions, are expressed within the color dipole approach in terms of the photon wave function, which describes the transition of the photon into a quark – antiquark color dipole. Such quantity is usually calculated using perturbation theory assuming that long distance corrections associated to strong interactions can be neglected. In this paper we investigate the impact of these nonperturbative QCD (npQCD) corrections to the description of the photon wave function for dipoles of large size in several observables measured at HERA, LEP and LHC. We assume a phenomenological ansatz for the treatment of these npQCD corrections and constrain the free parameters of our model using the experimental data for the photoproduction cross section. The predictions for the $$\gamma \gamma $$γγ cross section, exclusive $$\rho $$ρ production in ep collisions and the rapidity distribution for the $$\rho $$ρ production in PbPb collisions are compared with the data. We demonstrate that the inclusion of the nonperturbative QCD corrections improves the description of processes that are dominated by large dipoles.
Trentino Porphyry, Italy
Authors: Primavori P. , Angheben A.
Published: June 2020

Trentino Porphyry is an igneous rock composed of rhyolitic–rhyodacitic ignimbrites. It belongs to the Athesian Volcanic Group, a widespread calc-alkaline magmatic association of Lower Permian age (280–270 Ma) occurring in the Trentino-Alto Adige region, north Italy. Extraction and processing are currently carried out in Trento Province, particularly in the region of Cembra Valley and its surroundings. Initially introduced for road setts throughout Trentino and Südtirol, Trentino Porphyry has progressively become one of the most important materials for paving and facing in Europe and all over the world, where it is appreciated and renowned for its durability. It has successively acquired an unquestionable versatility of application, thanks to a rare mix of mineralogy and textural and structural features, combined with excellent technical properties. Given the role played by this stone in almost any aspect of the area – cultural, architectural, production and social – it is proposed for candidacy as a Global Heritage Stone Resource.
Design of Adiabatic Logic-Based Energy-Efficient and Reliable PUF for IoT Devices
Authors: Kumar S. Dinesh , Thapliyal Himanshu
Published: June 2020

Internet of Things (IoT) devices have stringent constraints on power and energy consumption. Adiabatic logic has been proposed as a novel computing platform to design energy-efficient IoT devices. Physically Unclonable Functions (PUFs) is a promising paradigm to solve security concerns such as Integrated Circuit (IC) piracy, IC counterfeiting, and the like. PUFs have shown great promise for generating the secret bits that can be used in the secure systems in an inexpensive way. However, designing a reliable PUF along with energy-efficiency is a big challenge. Therefore, for energy-efficient and reliable PUFs, we are proposing a novel energy-efficient adiabatic logic-based PUF structure. The proposed adiabatic PUF uses energy recovery concept to achieve high energy efficiency and uses the time ramp voltage to exhibit the reliable start-up behavior. The channel length of the transistors play a major role in controlling manufacturing variations. So, in this article, the circuit simulations are performed with 180nm and 45nm Complementary metal-oxide-semiconductor (CMOS) technology in a Cadence Spectre simulator to analyze the impact of channel length variations. The proposed adiabatic PUF has worst-case reliability of 96.84% and 99.6% with temperature variations at 180nm and 45nm CMOS technology, respectively. Further, the proposed adiabatic PUF consumes 1.071fJ/bit-per cycle at 180nm CMOS technology and 0.08fJ/bit-per cycle at 45nm CMOS technology.
Systematic review and meta-analysis as a structured platform for teaching principles of experimentation
Authors: Land Stephen C. , Booth David
Published: June 2020

Access to knowledge has never been easier in the internet age, and so it is important that students develop skills to discriminate undependable information from reliably investigated research. We have created an exercise that teaches good research practice by exploring the history, ethics, and design of clinical trials. Students apply their understanding of these principles through an assessed systematic review and meta-analysis (SRMA) exercise. Here, a clinically themed hypothesis is tested using a structured literature search in conjunction with an eligibility matrix to map study design, ethics, subject selection, randomization and blinding, methodological standards, study power, and other potential sources of interstudy heterogeneity. Data extracted from selected studies are used to produce a forest plot with an aggregated effect size, confidence range, and measure of interstudy heterogeneity. A funnel plot is then used in conjunction with the eligibility matrix to evaluate study bias tendency, and, in this way, students reflect on the factors that promote disparate conclusion-making among studies with a common research focus. This exercise produced a normally distributed grade-profile across three academic-year cohorts, and comparison of individual exercise grade with year-long aggregated average suggested students who performed less well on conventional assignments engaged successfully with the systematic nature of this assessment. Those opting to use this format for their final-year capstone project also performed above their grade point average from the preceding year. We suggest that SRMA offers a readily applied method for students to quantitatively explore how differences in experimental research practices influence study dependability.
Student response to a cooperative learning element within a large physiology class setting: lessons learned
Authors: Essop M. Faadiel , Beselaar Leandrie
Published: June 2020

Physiology students grapple with large amounts of subject content and hence memorize facts to pass examinations. In parallel, students display limited critical-thinking and creative skills, integration abilities, and/or a deeper engagement with subject content. This study aimed to assess the feasibility of introducing active learning methods (cooperative learning) in a relatively large class to final-year undergraduate physiology students (Bachelor of Science stream) at Stellenbosch University in South Africa. An assignment designed to enhance active and engaged learning was made available to the students ( n = 225) during the second week of a 5-wk cardiovascular physiology series of lectures. Students were instructed to freely form working groups ( n = 3/group) and the assignment was due by the end of the module. Student groups were expected and encouraged to continuously work on the assignment (outside class time). Three cooperative learning slots were also created during class time, with the lecturer and postgraduate students acting as guides. After the module, students anonymously completed an electronic questionnaire. This study revealed three major findings in terms of implementing cooperative learning in large classes within a South African context, i.e., 1) relatively good reception by students with some indication of group work; 2) it is logistically feasible in relatively large classes, although adequate support is crucial; and 3) additional measures need to be adopted to ensure its success.
Contribution of Amaranthus cruentus and Solanum macrocarpon Leaves Flour to Nutrient Intake and Effect on Nutritional Status of Rural School Children in Volta Region, Ghana
Authors: Egbi Godfred , Glover-Amengor Mary , Tohouenou Margaret M. , Zotor Francis
Published: June 2020

Background. Plant-based foods are staple diets and main micronutrient sources of most rural Ghanaian households. The objective of this study was to determine the effect of Amaranthus cruentus and Solanum macrocarpon leafy vegetable flour on micronutrient intake and nutritional status of rural Ghanaian school children. Method. This study was a randomized controlled trial that consisted of baseline data collection and a three-month nutrition intervention feeding program. Two groups of 53 children, age 4–9 years, involved in the Ghana School Feeding Program took part in the study. An experimental group consumed Amaranthus cruentus and Solanum macrocarpon leaves flour (ACSMLVF) stews and soup. The control group consumed stews and soup without ACSMLVF. Haemoglobin and serum vitamin A concentrations were determined. Dietary and anthropometric data were collected and analysed. Participants were screened for malaria parasitaemia and hookworm. Results. Anaemia was present in 41.5% and 37.3%, respectively, of the intervention and control groups at baseline. It was present in 28.3% and 53.3%, respectively, at the end of the study. This was significantly different (p=0.024). There was a low vitamin A concentration in 66.0% and 64.7% at baseline and 20.8% and 23.4% at the end of the study in the intervention and control groups, respectively. The mean iron, zinc, and provitamin A (beta-carotene) intakes of the intervention group were 14.2 ± 7.1 mg, 5.7 ± 2.1 mg, and 214.5 ± 22.6 μg, respectively, at baseline. Those of the control were 13.7 ± 6.1 mg, 5.4 ± 2.1 mg, and 210.6 ± 20.1 μg, respectively. At the end of the study, the mean intake of iron, zinc, and beta-carotene for the intervention group was 24.1 ± 10.9 mg, 13.8 ± 8.2 mg, and 694.2 ± 33.1 μg, respectively. The intake of these micronutrients for the control at the end of the study was 14.8 ± 6.2 mg, 5.9 ± 2.3 mg, and 418.4 ± 34.7 μg, respectively. Conclusion. Consumption of ACSMLVF stews and soup increased iron, zinc, and beta-carotene intakes. Anaemia prevalence was lower in the intervention group at the end of the study.
A Comparative Study on Flight Delay Networks of the USA and China
Authors: Wang Yanjun , Zheng Hongfeng , Wu Fan , Chen Jun , Hansen Mark
Published: June 2020

Recent studies have characterized the structures of air transport network in different countries and regions using complex network metrics. These studies coincided with the trend of increasingly available large empirical flight datasets that enable researchers to investigate the dynamics of the system, such as the propagation of flight delay. However, linking network structure with network dynamics remains a challenging task. In this paper, we proposed a method to construct flight delay networks from operational data. We provided a detailed comparison of the key structural properties of the flight delay networks in the United States and China. The comparisons of betweenness centrality of delay networks and flight networks show the advantage of the proposed method. We further found that airports in similar geographical locations do exhibit similar delay patterns in both countries. To explore the underlying mechanisms, the Multifractal Detrended Fluctuation Analysis (MF-DFA) is applied to the flights’ delay time series at both the airport level and network level. Singularity spectra analyses reveal the fundamental characteristics of the airport systems and air transportation system. Our findings contribute to the understanding of structure and dynamics of air transportation systems.
Numerical Simulation of Static Stress‐Strain Relationship and Failure Mode for Freeze‐Thaw Concrete
Authors: Yang Xiaolin , Wang Genhui , Li Hongzhao , Fan Jiang
Published: June 2020

To analyze the causes of failure of cubic concrete test specimens under quasistatic axial compression, microtests and finite element numerical simulation of C40 cubic concrete test specimens were conducted without the freeze‐thaw cycle and with 50 freeze‐thaw cycles. Based on the analysis of the microstructure of concrete, the variation law of the full curve of stress and strain was analyzed by the uniaxial compression test and the splitting tensile test of concrete. The results show that freeze‐thaw damage is mainly caused by the cyclic reciprocating stress of the micropore structure inside the concrete. The peak stress of concrete uniaxial compression and splitting tensile strength gradually decrease with the number of freeze‐thaw cycles; the full stress‐strain curve tends to shift downward and to the right. Finite element analysis shows that under the quasistatic uniaxial compression loading condition, the stress and strain fields in the test specimens are symmetrically distributed but nonuniform. The plastic deformation of the concrete weakens the nonuniformity of the stress distribution and is closer to the experimental failure morphology.
MicroRNA-7 as a Potential Biomarker for Prognosis in Pancreatic Cancer
Authors: Ye Zhi-qiang , Zou Chang-lin , Chen Han-bin , Jiang Ming-jie , Mei Zhu , Gu Dian-na
Published: June 2020

MicroRNAs play critical roles in tumor progression. Our recent study has indicated that microRNA-7 (miR-7) impairs autophagy-derived pools of glucose to suppress the glycolysis in pancreatic cancer progression. However, the roles of miR-7 in clinical significance and chemoresistance of pancreatic cancer remain unexplored. The aim of this study was to assess the expression of miR-7 in patients with pancreatic cancer and to evaluate the possibility of its usage as a prognostic molecular biomarker. MicroRNA array-based quantification analysis of 372 miRNAs was compared in serum between pancreatic cancer and healthy individuals, gemcitabine-sensitive and gemcitabine-resistance patients. We identified miR-7 showed the potential predictive power for gemcitabine-sensitive patients with pancreatic cancer. Then, the results were validated in pancreatic tissue microarray and The Cancer Genome Atlas (TCGA) dataset, demonstrating that lower miR-7 expression was correlated with more advanced tumor stages and worse prognosis in pancreatic cancer. The Cox proportional-hazards model analysis identified miR-7 to be an independent variable for prediction of the survival. Furthermore, the mechanistic exploration suggested the clinical significance of miR-7 involved its interference effect on autophagy and glycolysis in pancreatic cancer using pancreatic cancer tissue microarrays and TCGA data. Therefore, the results of the present study provide evidences that low microRNA-7 expression may contribute to tumor progression and poor prognosis in pancreatic cancer.
Microbiological Quality, Physicochemical Properties, and Antioxidant Capacity of Honey Samples Commercialized in the Moroccan Errachidia Region
Authors: El Menyiy Nawal , Akdad Mourad , Elamine Youssef , Lyoussi Badiaa
Published: June 2020

An examination of possible effect of hot desert climate on microbiological safety and physicochemical and antioxidant properties of honey marketed in the province of Errachidia in Morocco was made. The assessment of microbiological properties showed no alarming sign of microbiological contamination or quality deterioration. This can be seen by the low moisture content in all analysed samples, which was below 20% (the maximum allowed in honey), and acid pH which was raging from 3.32 ± 0.05 to 4.37 ± 0.12. The ash content values ranged between 0.02 ± 0.01% and 0.23 ± 0.001%, and the electrical conductivity ranged between 87.4 ± 0.42 and 1148.06 ± 2.16 mS/cm. Considering the mineral content, the potassium was the most abundant species in all the analysed samples. The phenol content values varied from 17.35 ± 2.15 mg GAE/100 g in H7 to 219.026 ± 2.26 mg GAE/100 g in H9. Similarly, the same behavior was seen in the case of the other bioactive subfamilies of phenolic compound flavonoid content. Hence, the highest value of flavonoids, flavones, and flavanols was detected in H9, and the minimum value was observed in sample H7. A negative correlation was found between the bioactive fraction of honey samples and free radical scavenging activity assessed as IC50, the concentration of honey that scavenges 50% of the used free radicals. The bioactive fraction, the antioxidant assays, and their correlation values showed the same profile in comparison to the honey samples of other Moroccan regions.
Squamous Cell Papilloma of the Esophagus: A Case Series Highlighting Endoscopic and Histologic Features
Authors: Uhlenhopp Dustin J. , Olson Kristin M. , Sunkara Tagore
Published: June 2020

Esophageal squamous papillomas are rare epithelial lesions typically discovered incidentally during EGD. Their prevalence is estimated to be less than 0.01% in the general population. We present three cases of esophageal squamous papillomas identified histologically. It may be possible to identify these lesions macroscopically. One study provided a positive predictive value of 88% for squamous papilloma utilizing the triad of exophytic growth, wart-like projections, and surface vessel crossing seen on narrow band imaging during endoscopy. The etiology is unclear. Chronic mucosal irritation from GERD or esophagitis is the prevailing theory of pathogenesis, but HPV has been detected in some lesions. The malignant potential of these lesions is considered controversial. There are documented cases demonstrating complications with squamous cell carcinoma, so we recommend removal of all esophageal squamous papillomas; however, the small absolute number of cases documented in the literature makes drawing any associations or conclusions between esophageal squamous papillomas and squamous cell carcinoma difficult. Further research is needed regarding treatment and surveillance. This case series helps contribute to the small but growing literature of this rare finding.
Surface Albedo Assimilation and Its Impact on Surface Radiation Budget in Beijing
Authors: Meng Chunlei
Published: June 2020

Surface albedo is a crucial parameter in land surface radiation budget. As bias exists between the model simulated and observed surface albedo, data assimilation is an important method to improve the simulation results. Moreover, surface albedo is associated with the wavelength of the sunlight. So, solar radiation partitioning is important to parameterize the surface albedo. In this paper, the moderate resolution imaging spectroradiometer- (MODIS-) retrieved direct visible, direct near-infrared, diffuse visible, and diffuse near-infrared surface albedos were assimilated into the integrated urban land model (IUM). The solar radiation partitioning method was introduced to parameterize the surface albedo. Based on the albedo data from MODIS and the solar radiation partitioning method, the surface albedo data set for the Beijing municipal area was generated. Based on the surface albedo data set and the IUM, the impacts of the surface albedo on the surface radiation budget were discussed quantitatively. Surface albedo is inversely proportional to the net radiation. For urban areas, after assimilation, the annual average net radiation decreases about 5.6%. For cropland, grassland, and forest areas, after assimilation, the annual average net radiations increase about 20.2%, 24.3%, and 18.7%, respectively.
Simulation of the Final Size of the Evolution Curve of Coronavirus Epidemic in Morocco using the SIR Model
Authors: Ifguis Ousama , El Ghozlani Mohamed , Ammou Fouzia , Moutcine Abdelaziz , Abdellah Zeroual
Published: June 2020

Since the epidemic of COVID-19 was declared in Wuhan, Hubei Province of China, and other parts of the world, several studies have been carried out over several regions to observe the development of the epidemic, to predict its duration, and to estimate its final size, using complex models such as the SEIR model or the simpler ones such as the SIR model. These studies showed that the SIR model is much more efficient than the SEIR model; therefore, we are applying this model in the Kingdom of Morocco since the appearance of the first case on 2 March 2020, with the objective of predicting the final size of the epidemic.
Efficacy of a Newly Modified Short Hydration Method for Gemcitabine and Cisplatin Combination Chemotherapy in Patients with Urothelial Carcinoma
Authors: Naiki Taku , Sugiyama Yosuke , Tasaki Yoshihiko , Iida Keitaro , Etani Toshiki , Hamamoto Shuzo , Nagai Takashi , Nozaki Satoshi , Ando Ryosuke , Kawai Noriyasu , Yasui Takahiro
Published: June 2020

Introduction: Conventional first-line chemotherapy for patients with metastatic urothelial carcinoma (UC) is gemcitabine and cisplatin (GC). However, cisplatin can cause renal failure, necessitating abundant fluid replacement and hospitalization during treatment. Recent evidence exists for short hydration methods in cisplatin-based chemotherapy. Objective: This study aims to analyze the efficacy of newly established modified short hydration GC (m-shGC) therapy in patients with UC. Methods: From May 2017 to March 2019, 48 patients with UC who received m-shGC therapy were treated with 1,000 mg/m2 gemcitabine on days 1, 8, and 15, and 70 mg/m2 cisplatin and 2,000 mL fluid replacement on day 1, in each 28-day cycle. We retrospectively evaluated renal function, serum electrolyte abnormalities, and adverse events (AEs) following treatment, and retrospectively compared patients under m-shGC therapy with those under conventional GC (c-GC) therapy from 2015 to 2017. In addition, from April 2019 to August 2019 in a prospective analysis, 15 patients were newly enrolled, and AE profiles and physical activity during m-shGC therapy were quantified using a wearable tracker. Results: In a retrospective analysis of 101 patients (53 c-GC and 48 m-shGC), patient characteristics were not statistically significant between the two groups. Myelosuppression, including predominant neutropenia and decreased platelets, fatigue, nausea, and constipation were the main common AEs. However, renal function and serum sodium levels in the m-shGC group remained unchanged. Grade 3–4 AEs were not more severe in the m-shGC compared with the c-GC group. Furthermore, in a prospective analysis using a wearable tracker, the amount of walking by patients on day 1 significantly declined. However, immediate recovery occurred reflecting the short hydration. Conclusion: Our m-shGC therapy has an acceptable AE profile compared with conventional therapy, with UC patients showing good physical activity.
An International Survey of Mediastinal Staging Practices amongst Interventional Bronchoscopists
Authors: Guinde Julien , Roy Pascalin , Dutau Hervé , Musani Ali , Quadrelli Silvia , Stratakos Grigoris , Vergnon Jean-Michel , Tremblay Alain , Fortin Marc
Published: June 2020

Introduction: In potentially curable non-small-cell lung cancer, different practice guidelines recommend invasive me­diastinal staging in tumors larger than 3 cm, central, or hy­permetabolic N1 lymph nodes. There is no consensus concerning the use of an endosonographic procedure or a mediastinoscopy in the first line in patients with a radiologically normal mediastinum, while in case of a mediastinal involvement, the latest European guidelines recommend the combination of endobronchial ultrasound (EBUS) and endoscopic ultrasound/endoscopic ultrasound with EBUS endoscope (EUS/EUS-B), using a systematic endosonographic procedure. This international survey was conducted to describe current medical practices in endoscopic mediastinal staging amongst interventional bronchoscopists. Methods: A survey was developed and sent to all members of different interventional pulmonology societies, with the purpose to describe who, when and how an endoscopic mediastinal staging was performed. Results: One hundred and fifty-three bronchoscopists responded to the survey. Most of them practiced in Europe (n = 84, 55%) and North America (n = 52, 34%). In the first line, EBUS alone was the most widely used endoscopic procedure for mediastinal staging. Half of the responders performed a systematic endoscopic staging procedure, including a systematic examination of all accessible nodal stations and a sampling of all lymph nodes >5 mm in the short axis at each station. A higher proportion of bronchoscopists who have completed a dedicated fellowship program performed systematic endoscopic mediastinal staging. Few endoscopists routinely perform combined EBUS/EUS(-B) for mediastinal staging and use the combination only in selected cases. Conclusion: There are several areas of divergence between published guidelines and current practices reported by interventional bronchoscopists. EBUS alone is the most widely used endoscopic procedure for mediastinal staging in lung cancer, and a combined endoscopic approach is frequently omitted by the responders. A fellowship program appears to be associated with a higher rate of systematic endoscopic staging procedures.
Photovoltaic emulator of different solar array configurations under partial shading conditions using damping injection controller
Authors: Alaoui Mustapha , Maker Hattab , Mouhsen Azeddine , Hihi Hicham
Published: June 2020

In the last decades, researchers and scientists have been trending towards photovoltaic (PV) solar energy research as one of the noteworthy renewable energies. As a matter of fact, the need for a laboratory system devoted to performing measurements and experimentation on PV systems is being increased. The PV array emulator is designed to accomplish this task by reproducing accurately the electrical behavior of real PV sources. The present paper proposes thus a new control and design of PV array emulators. It is based essentially on a hybrid Damping Injection controller. The proposed control strategy circumvents obviously the existing PV emulator's limitations in terms of accuracy, speed and partial shading emulation. Several results are given and discussed to show the efficiency of the proposed system to emulate PV modules and different PV array configurations under uniform solar irradiance and partial shading conditions.
An improved control for MPPT based on FL-PSo to minimize oscillation in photovoltaic system
Authors: Firdaus Aji Akbar , Yunardi Riky Tri , Agustin Eva Inaiyah , Nahdliyah Sisca D. N. , Nugroho Teguh Aryo
Published: June 2020

Photovoltaic (PV) is a source of electrical energy derived from solar energy and has a poor level of efficiency. This efficiency is influenced by PV condition, weather, and equipments like Maximum Power Point Tracking (MPPT). MPPT control is widely used to improve PV efficiency because MPPT can produce optimal power in various weather conditions. In this paper, MPPT control is performed using the Fuzzy Logic-Particle Swarm Optimization (FL-PSO) method. This FL-PSO is used to get the Maximum Power Point (MPP) and minimize the output power oscillation from PV. From the simulation results using FL-PSO, the values of voltage, and output power from the boost converter are 183.6 V, and 637.7 W, respectively. The ripple of output power from PV with FL-PSO is 69.5 W. Then, the time required by FL-PSO reaches MPP is 0.354 s. Compared with MPPT control based on the PSO method, the MPPT technique using FL-PSO indicates better performance and faster than the PSO.
Active cell balancing for electric vehicle battery management system
Authors: Duraisamy Thiruvonasundari , Kaliyaperumal Deepa
Published: June 2020

The shrink in accessibility of petroleum products and increment in asset request are eventual outcomes for Electrical Vehicles (EVs). The battery has an impact on the performance of electrical vehicles, the driving range. Lithium ion (Li-ion) chemistry is extremely sensitive to overcharge and deep discharge, which can harm the battery, shortening its period of time, and even inflicting risky things. The Battery Management System (BMS) comprises of the consequent parts: management, equalization and protection. Of the three components, equalization is that the most crucial with respect to the durability of the battery framework. The ability of the full pack diminishes rapidly amid the procedure which leads to degradation of the full battery framework. This condition is extreme once the battery incorporates a more number of cells in series and frequent charging is conveyed through the battery string. The cell imbalance during charging, discharging is a major issue in battery systems used in EVs. To circumvent the cell imbalance, cell balancing is used. Cell balancing enhances battery safety and extends battery life. This paper discusses about different active balancing method to increase the life span of the battery module. Based on the comparison, the inductor based balancing method for 60V battery system is implemented in the MATLAB/Simscape environment and the results are discussed.
Design and analysis of controllers for high voltage gain DC-DC converter for PV panel
Authors: Nagaraj S. , Ranihemamalini R. , Rajaji L.
Published: June 2020

Bidirectional high gain DC-DC buck boost converter is a virtual interface among PV source and inverter fed motor drive. In this article, a PV panel integrating a non-isolated bidirectional DC/DC converter that has high voltage gain voltage and a 3 phase three level DC/AC inverter is projected. It highlights the comparison between proportional integral controller (PIC), fractional order proportional integral derivative Controller (FOPIDC) and fuzzy logic controller (FLC) based Bidirectional DC/DC Power Converter System (BDDPCS). The design, model and simulation using SIMULINK of open loop BDDPCS and closed loop PIC, FOPIDC and FLC based BDDPCS are done and the results are discussed. The findings indicate higher performance for FLC based control of BDDPCS. The proposed BDDPCS has merits such as bidirectional power transferability, lesser hardware count with enhanced dynamic response. The hardware of BDDPCS is tested and the experiment result is compared in association with simulation results.
New DTC strategy of multi-machines single-inverter systems for electric vehicle traction applications
Authors: Ahmed Taibi , Kada Hartani , Ahmed Allali
Published: June 2020

In high power traction system applications two or more machines are fed by one converter. This topology results in a light, more compact and less costly system. These systems are called multi-machines single-converter systems. The problems posed by different electrical and mechanical couplings in these systems (MMS) affect various stages of the systems and require control strategy to reduce adverse effects. Control of multi-machines single-converter systems is the subject of this paper. The studied MMS is an electric vehicle with four in-wheel PMS motors. A three-leg inverter supplies two permanent magnet synchronous machines which are connected to the front right and rear right wheels, and another inverter supplies the left side. Several methods have been proposed for the control of multi-machines single-inverter systems, the master-slave control structure seems best adapted for our traction system. In this paper, a new control structure based on DTC method is used for the control of bi-machine traction system of an EV. This new control has been implanted in simulation to analyze its robustness in the presence of the various load cases involved in our electric vehicle traction chain. Simulation results indicated that this structure control allowed the stability of the traction system.
Feasibility analysis of standalone PV powered battery using SEN for Smart Grid
Authors: Islam Syed Zahurul , Othman Mohammad Lutfi , Mariun Norman , Hizam Hashim , Ayuni Nur
Published: June 2020

In Smart Grid (SG) communication network, sensors integrated communication radios namely ZigBee, Wi-Fi, and Bluetooth are becoming urgent and crucial part of SG wireless communication. Sensor nodes are generally battery powered. With the enhancement and huge utilization of sensor technologies, batteries have not been improved significantly at the same pace. However, batteries are essential to power the sensor nodes and there is no alternative of this energy bank. Therefore, to provide seamless power to the nodes is a challenge when the nodes are meant for integrating distributed renewable generations for years. Necessitate of the battery replacement is not often cost effective when the batteries are drained out. This paper presents a feasibility study of standalone Photovoltaic (PV) powered battery using Sensors-radios integrated Embedded Node (SEN) for SG application. In this study, we have analyzed charging characteristics of a lead-acid battery that can be recharged during day time by a PV module. The aim of this research is to testify the two simultaneous jobs- (i) the battery is sufficient to power Sensors-ZigBee integrated Arduino (SZA) for at least one day operation, (ii) scrutiny the optimal size of PV for recharging the battery considering three different day variations- average, cloudy, and full rainy day. The result from real data analysis reveals that the module is sufficient to recharge the battery on an average day; however, it is not sufficient for full cloudy or full rainy day. Finally, a mathematical model is obtained from regression analysis that shows battery internal resistance is exponential to voltage on both full cloudy and rainy day, but it is linear on average day.
DG integration to distribution system with active power injection control
Authors: Satyanarayana P. V. V , Rao P. V. Ramana
Published: June 2020

Conventional methodology for electrical power generation is vulnerable due to environmental limitations and the availability of fuel. Distributed generation, offering virtuous benefits to the market partakers, is trending in electrical power system in modern era. This paper presents the distributed generation integration to grid with active power injection control. Distributed generation source delivers DC power which is processed through square wave inverter. Inverter circuit is controlled using a simple control technique to match grid code. Fixing the current reference and varying the same, analysis is carried out for grid integration scheme of distributed generation injecting active power to grid. Simulation work is carried out and results are shown using MATLAB/SIMULINK software.
Fault detection and location of power transmission lines using intelligent distance relay
Authors: Al Kazzaz Sa’ad Ahmed S. , Ismaeel Ibrahim , Mohammed Karam Khairullah
Published: June 2020

The aim of this paper is to design a three-phase distance relay using an adaptive neuro-fuzzy inference system algorithm (ANFIS). The proposed relay is used to protect the power transmission lines where they are subjected to faults continuously. These faults may produce a high electric current which leads to high damage in power system equipment. The relay is used to detect the transmission line faults by measuring the voltage and current values for each phase. The line impedance is then calculated to detect the faults and issue instantaneous trip signal to circuit breaker, to separate the fault zone of the transmission line without affecting the work of other relays. To isolate the faulty line without affecting the other lines within the network the relays were trained using adaptive neuro-fuzzy inference system (ANFIS). The obtained results through this work show that the designated distance relay with (ANFIS) algorithm has the ability to detect the faults occurrence, recognize it from the cases of the disturbance and to isolate only the fault zone without affecting the work of other relays in system.
Design and implementation of variable and constant load for induction motor
Authors: Shneen Salam Waley , Dakheel Hashmia Sh. , Abdulla Zainab B.
Published: June 2020

To design and implementation of variable and constant with no load for induction motor (IM) that is the goal in this work. This paper was including three parts, first the simulation model with no load for IM, Second the simulation model with constant load for IM, Third the simulation model with variable load for IM. In addition, this work includes comparative between two different controllers (PI and fuzzy logic control (FLC). The simulation results clearly the implementation of variable and constant with no load for IM. The simulation response of the system achieves better results when choosing to use type fuzzy-PI controller technique comparison with conventional PI controller and improve the performance of the system at different operation conditions.
Modeling and simulation of DC to DC boost converter using single phase matrix converter topology
Authors: Kadir Fajariah , Noor S.Z. Mohammad , A.H. Faranadia , Muhammad K.S.
Published: June 2020

The main objective of this work is to model and simulate DC to DC Boost Converter using Single Phase Matrix Converter (SPMC) topology using MATLAB/Simulink (MLS). The output voltage is controlled by using Pulse Width Modulation (PWM) technique. Four pairs of Insulated Gate Bipolar Transistor (IGBT) is used as the switching device where for each pair, it is located in parallel and opposite direction. Safe commutation technique is performed in preventing voltage spike at the output. Through the simulation, at switching frequency of 25kHz, the model is able to step up its input voltage about two times larger and all of the results achieved a good agreement with the principle of four quadrant operation. It is also realized that without the implementation of safe commutation technique, spikes were generated and the model is unable to boost its input voltage. All of the selected results from the analysis which includes variation of quadrant, switching frequency, duty cycle and resistive load are presented in this paper.
Stability analysis of photovoltaic system under grid faults
Authors: Pati Nivedita , Panda Babita , Panda Bhagabat
Published: June 2020

This work includes the establishment of a Photovoltaic system connected to the grid by means of an inverter. The fundamental goal of the work is to incorporate an advanced active power flow management scheme in order to adopt load at any weather condition along with the advantage of maximum active power flow and zero harmonics from PV inverter to the grid. The outcome of analysis and control design of grid connected PV inverter using a Proportional-Integral (PI) control technique is based on synchronous dq rotating reference frame so as to achieve maximum output voltage and record the active power. It has been observed that the model provides a better rate of stability as compared to the existing topology.
Control of PMSG based variable speed wind energy conversion system connected to the grid with PI and ADRC approach
Authors: Barradi Youssef , Zazi Khalida , Zazi Malika , Khaldi Naoufel
Published: June 2020

This paper presents the modeling and simulation of wind energy Conversion System using the Permanent Magnet Synchronous Generator (PMSG).
 The objectives are: to extract the maximum power of the wind speed by controlling the electromagnetic torque of the PMSG, to maintain constant the DC-link voltage despite the wind speed variations and to attain the unity power factor. In order to ensure a regulation with high performance and a good robustness against the internal and the external disturbances, a new control strategy called the Active Disturbance Rejection Control (ADRC) is used. Therefore, the Analysis and simulation of the ADRC and PI controllers are developed with MATLAB/Simulink software. The performance of these controllers is compared in term of references tracking, robustness
 and grid faults.
Contribution of DGs in the stability and voltage drop reduction for future MV network in desert regions
Authors: Abdelkader Bouafia , Djamel Labed
Published: June 2020

Day by day, the integration of decentralized generation in medium voltage networks becomes more important during the last years and even in the near future. This increase causes, at the same time, several negative effects and rarely positive impacts on the stability of the network. Therefore, this work aims at analyzing the impact of ambient temperature on radial distribution network parameters’ e.g.: voltage drop and stability voltage level (index). Based on MATLAB program, different analyses of distributed generation (DG) insertion influence’s on voltage drop in the radial distribution feeder, as well as the influence of climatic conditions such as ambient temperature on network parameters. The Integration of Photovoltaic DGs in MV networks can play an important role in reducing the global warming effect (in voltage drop, and voltage stability index) especially in radial distribution feeder. Furthermore, it protects network’s parameters if its location and power are well selected.
Three-phase five-level CHB inverter fed induction motor for renewable applications
Authors: Nagaraju G. V. V. , Rao G. Sambasiva
Published: June 2020

This paper presents the three-phase CHB inverter fed induction motor suitable for renewable energy source applications. Normally, all present existing multilevel inverters produce multilevel output, but the number of components required is more, bulk in size, more in cost. Which are more burdens to small capacity renewable sources. These challenges are eliminated in CHB inverter. This CHB mainly consisting of one DC source, one capacitor and eight switches in each phase. To generate a five-level output in phase to ground voltage, it is required to maintain the capacitor voltage (V2) at fifty percent of the DC source voltage (V1). This capacitor voltage is regulated by a sensor less voltage regulating technique. The sensor less voltage regulation works without any sensor devices. We can implement this technique with very less cost compared to other techniques. The sensor less voltage regulation is realized by level-shifted sinusoidal pulse width modulation. The simulation results show a very good dynamic performance. Controller maintains the capacitor voltage at fifty percent of the source voltage irrespective of main source voltage changes and load changes. Inverter generates a five-level wave at the output from line to ground and seven-level wave from line to line with fewer Harmonic. It is implemented in matlab/simulink and showing good dynamic performance.
Field oriented control based on a 24-sector vector space decomposition for dual three-phase PMSM applied on electric ship propulsion
Authors: Hasoun Mhammed , El Afia Aziz , Khafallah Mohamed , Benkirane Karim
Published: June 2020

A Field Oriented Control (FOC) strategy based on a 24-Sector Vector  Space Decomposition (24SVSD) technique used to control a Dual Three-Phase Permanent Magnet Synchronous Motor (DTP-PMSM) applied on electric ship propulsion prototype is presented in this paper. This machine is supplied by Dual Three-Phase Voltage Source Inverter (DTP-VSI). This study carried out on these multiphase machines has revealed that the large zero sequence harmonic current components on (z1, z2) subspace, constitutes major drawbacks; despite their advantages. The machine’s dynamic model is accomplished in three two-dimensional and orthogonal subspaces. In order to reduce more extra stator harmonic currents that produces losses, the current work is also concering of to consider the three different approaches for the sake of boosting the machine’s efficiency. Thus, the principle selection of the reference voltage vector and the time calculation method are presented in details. The proposed strategy effectiveness is validated by simulation results.
Effect analysis of residual magnetism availability level on the success of voltage generation processes in self-excited induction generators
Authors: Nazir Refdinal , Syafii Syafii , Pawawoi Andi , Akbar Fajril , Arfan Yudi
Published: June 2020

The voltage generation process is a very crucial initial stage for the successful operation of the self-excited induction generator (SEIG). The availability of residual magnetism and the adequacy of excitation capacitor value are factors that determine the success of the voltage generation process on the SEIG. This paper analyzes the effect of the availability of residual magnetism on the rotor's magnetic core. With a simple approach, the terminal voltage on the SEIG can be solved through the intersection between the magnetization curve (Xm) and the excitation curve (Xce). The shape and equation of the magnetization curve will be affected by the availability of residual magnetism. The change in residual magnetism availability will cause a change in the intersection point between the magnetization curve (Xm) and the excitation curve (Xce), which will determine the value of voltage generated by the generator. In this study, Newton Rhapson's method with numerical iteration approach has been used to analyze the effect of changes in the availability of residual magnetism on the success of voltage generation on the SEIG. The analysis results have been shown that the availability of residual magnetism with residual voltage values below 1.04 Volt will cause the failure of the SEIG to generate the terminal voltage at its nominal value. Meanwhile, the availability of residual magnetism in SEIG with residual voltage values above 1.04 Volt, will succeed in generating terminal voltage at its nominal value. For SEIG used as the object of this study, the value of Eres = 1.04 Volt is a critical value of the availability of residual magnetism.