bluuebunny/crossref_metadata_2025 huggingface dataset:
Track the maximum power of a photovoltaic to control a cascade five-level inverter a single-phase grid-connected with a fuzzy logic control
Authors: Chaithanakulwat Arckarakit
Published: December 2019

This research presents tracking the maximum power of a photovoltaic to control a five-level inverter, a cascade type connecting a single-phase grid-connected system with a fuzzy logic control model. Maximum power tracking control In this research, the principle of controlling the maximum current amplitude of the photovoltaic multiplied by the sine signal per unit that used as a reference current compared to the grid current. Signal comparison with the PID controller allows the creation of five levels of PWM of cascade control of five-level inverter connects single-phase grids. The results of the simulation test using the program MATLAB/Simulink to compare with the generated prototype found that the fuzzy logic principle was used to control the maximum power tracking conditions of the P&O method, when the amount of radiation light intensity decreases suddenly, making it possible to track the maximum power of the photovoltaic. Also, when the inverter connected to the grid by controlling the power angle to compare results between the simulation and the prototype — found that the current flowing into the grid increases according to the power angle control. Resulting in a nearby waveform, sine wave and an out of phase angle to the grid voltage because the system is in the inverter mode, and the harmonic spectrum of the grid currently has total harmonic distortion (THD) is reduced as an indication of the proposed system can be developed and applications.
Performance analysis of LMS based control algorithm for power quality improvement in three phase grid connected system for linear/non-linear load
Authors: Ahmad Mohmmad , Kirmani Sheeraz
Published: December 2019

This paper presents the adaptive filtering based least mean square control
algorithm for distribution static compensator (DSTATCOM) in three-phase
grid tied system for linear/non-linear load, to solve the power quality
problems caused by solid-state equipment and devices. This is shown that the
active component weights obtained from the load currents in the LMS
adaptive filter are used to produce the reference currents and subsequently
produces the switching pulses for VSC of the compensator. The complete
circuit along with the adaptive technique and diode bridge rectifier type nonlinear load is simulated in Matlab/Simulink software. Initially the circuit was
simulated for a three phase linear inductive load. Later it was simulated for a
rectifier load connected at PCC with a disconnection of the load of any phase
for a short duration of time. It is concluded that the harmonics are found
within the limit. The harmonics and power results for both types of loads are
compared in a tabular form. Hence this three phase system with
DSTATCOM improves the power quality in the three-phase distribution
network therefore, serves to provide harmonics reduction, load balancing and
regulating the terminal voltage at the point of common coupling (PCC).
DC-DC converter based power management for go green applications
Authors: W Abitha Memala , Bhuvaneswari C. , Shyni S.M. , Sheeba G. Merlin , Mahendra Modi Surya , Jaishree V
Published: December 2019

A non-isolated tri-port converter is a fully compact and functional system by the integration of basic converters. This can be used for renewable energy applications. This converter is capable of achieving different switching patterns of power flow between the source and load, interfaced sources of various voltage and current levels with the dc grid. This tri-port converter has to be used for continuous power distribution of rechargeable battery, photovoltaic panels and load. Due to the implementation of this dc-dc converter some operations like buck, boost and buck-boost operations became easy. Use of this converter helps in easy implementation of the system. The solar PV panel implementation boosts the system to a high level and bidirectional flow became easy from source to load and vice versa
Robust power control methods for wind turbines using DFIG-generator
Authors: El Karaoui Imane , Maaroufi Mohammed , Bossoufi Badre
Published: December 2019

The purpose of this work is to present the advantages of the power control (active and reactive) of a wind energy system in order to improve the quality of the energy produced to the grid by presenting two control strategies applied to the conversion system of wind energy equipped with an asynchronous generator with dual power supply. Both techniques are studied and developed and consist of a field control (FOC) and a sliding mode control. They find their strongest justifications for the problem of using a nonlinear control law that is robust to the uncertainties of the model. The goal is to apply these two commands to independently control the active and reactive powers generated by the decoupled asynchronous machine by flow orientation. Thus, a study of these commands will be detailed and validated in the Matlab / Simulink environment with the simultaneous use of the "Pitch Control" and "Maximum Power Point Tracking (MPPT)" techniques. The results of numerical simulations obtained show the increasing interest of the two controls in the electrical systems. They also attest that the quality of the active and reactive powers and voltages of the wind system is  considerably improved.
Performance comparison of artificial intelligence techniques in short term current forecasting for photovoltaic system
Authors: Othman Muhammad Murtadha , Fazil Mohammad Fazrul Ashraf Mohd , Harun Mohd Hafez Hilmi , Musirin Ismail , Sulaiman Shahril Irwan
Published: December 2019

This paper presents artificial intelligence approach of artificial neural network (ANN) and random forest (RF) that used to perform short-term photovoltaic (PV) output current forecasting (STPCF) for the next 24-hours. The input data for ANN and RF is consists of multiple time lags of hourly solar irradiance, temperature, hour, power and current to determine the movement pattern of data that have been denoised by using wavelet decomposition. The Levenberg-Marquardt optimization technique is used as a back-propagation algorithm for ANN and the bagging based bootstrapping technique is used in the RF to improve the results of forecasting. The information of PV output current is obtained from Green Energy Research (GERC) University Technology Mara Shah Alam, Malaysia and is used as the case study in estimation of PV output current for the next 24-hours. The results have shown that both proposed techniques are able to perform forecasting of future hourly PV output current with less error.
Mini review on the design of axial type eddy current braking technology
Authors: Waloyo H.T. , Ubaidillah Ubaidillah , Tjahjana D.D.D.P. , Nizam M. , Koga T.
Published: December 2019

Eddy Current Brake (ECB) is a type of electric braking that uses eddy current to produce braking forces. This article delivers a solid review of the design of Axial ECB, which is very promising for an alternative braking system. Several types of axial ECB are classified and named as a single disk, double disk, and unipolar model. The classification of axial ECB is based on the design of coil placement, which induces axial area of the disk as well as the electromagnet source. A potential issue for the development of axial ECB is also discussed to explore the braking performance improvement of the axial type ECB. It was highlighted that research on how to change the direction of magnetic field vectors by changing the shape of the pole-shoe on the electromagnetic ECB in axial type has not been widely studied. Therefore, this issue would be interesting for future investigation.
D-STATCON model for voltage sag mitigation
Authors: Masdi Hendri , Hasanah Rini Nur , Suyono Hadi , Musirin Ismail Bin , Taufik Taufik
Published: December 2019

Development of a FACTS device model for mitigating voltage sag is presented. It deals with a static synchronous condenser (STATCON) to be used in the AC distribution networks. Simulation with the help of a commercial software Matlab/Simulink was explored to investigate its characteristics and performance during the voltage sag occurrence. The considered main cause of voltage sag was the starting of high capacity asynchronous motor. A voltage source inverter based on the phase-controlled thyristor components was implemented in this application to compensate the change in reactive power of the system. The concerns have been put on the influence of initial operation point and DC capacitance. The study results show the capability of D-STATCON model to reduce the consequence of voltage sag following the starting of high-power asynchronous motor in the distribution network. A fast response of the condenser work confirmed the desired performance.
Design and Analysis of In-Wheel Double Stator Slotted Rotor BLDC Motor for Electric Bicycle Application
Authors: Farina S. , Firdaus R.N. , Azhar F. , Azri M. , Ahmad M. S. , Suhairi R. , Jidin A. , Sutikno Tole
Published: December 2019

This paper discusses about design and analysis of double stator slotted rotor (DSSR) BLDC motor for electric bicycle application. Usually single stator (SS) BLDC motor is used in an electric bicycle. This type of motor has low performance and need to be charged regularly. The objective of this research is to design and analysis DSSR motor that have high torque. At starts, design specification for the electric bicycle is calculated. Next, design process for DSSR is carried out by using the desired parameter. Lastly, analysis for double stator slotted rotor is simulated using FEM. Result  for average back emf, average inductance, inner stator flux density, outer stator flux density, average torque and estimate torque constant is obtained. Result for average torque from FEM archieve the requirement of motor torque for DSSR design where the maximum average torque is 16.2 Nm. This research will give benefit to mankind and society in term of environment protection and energy consumption.
Maximum Power Point Tracking of Wind Turbine Conversion Chain Variable Speed Based on DFIG
Authors: Becheri H. , Bousarhanne I. K. , Harrouz A. , Glaoui H. , Belbekri T.
Published: December 2019

Wind energy has many advantages, it does not pollute and it is an inexhaustible source. However, the cost of this energy is still too high to compete with traditional fossil sources. The yield of a wind turbine depends on three parameters: the power of the wind, the turbine power curve and the ability of the generator to respond to fluctuations in the wind. This article presented the MPPT of a wind turbine system equipped with an asynchronous generator has dual power under MatlabSimulink program, in the first time we simulated all the conversion chain with complete model of DFIG and vector control in second stepthen applied the extracted maximum power MPPT strategists, this command is effective and has several advantages it offered to kept the maximum power delivered to network despite all the parameter is change.
Enhanced Three-Phase Inverter Faults Detection And Diagnosis Approach - Design And Experimental Evaluation
Authors: Fadil Hicham , Elhafyani Mohamed Larbi , Zouggar Smail
Published: December 2019

Efficiency, reliability, high power quality and continuous operation are important aspects in electric vehicle attraction system. Therefore, quick fault detection, isolation and enhanced fault-tolerant control for open-switches faults in inverter driving systems become more and more required in this filed. However, fault detection and localization algorithms have been known to have many performance limitations due to speed variations such as wrong decision making of fault occurrence. Those weaknesses are investigated and solved in this paper using currents magnitudes fault indices, current direct component fault indices and a decision system. A simulation model and experimental setup are utilized to validate the proposed concept. Many simulation and experimental results are carried out to show the effectiveness of the proposed fault detection approach.
Extended Kalman Filter for Sensorless Fault Tolerant Control of PMSM with Stator Resistance Estimation
Authors: Moujahed Mongi , Touaiti Bilel , Benazza Hechmi , Jemli Mohamed , Boussak Mohamed
Published: December 2019

This paper aims to provide a high performance sensorless control based on an Extended Kalman Filter (EKF) applied to fault-tolerant PMSM drive system with stator-resistance estimation. It proposes a fast method of fault switches detection in the power converters. The considered drive is composed of three phases PMSM and a four leg three phase’s inverter when the fourth is the redundant leg. After a short-switch fault occurrence, the redundant leg replaces the faulty leg. The simulation results verify that the proposed control method and the fault tolerant inverter ensure the high reliability and continuously operation of the sensorless vector control PMSM system under inverter fault.
A Novel Line Current Control Strategy to Control the Real Power Flow at PCC using H-bridge Inverter
Authors: Salem Qusay , Xie Jian
Published: December 2019

This paper presents the power flow control between the main grid and the microgrid in low-voltage distribution network using H-bridge inverter. Controlling the real power flow in the line using the H-bridge inverter is investigated by implementing the line current control strategy. The feasibility of the proposed H-bridge inverter and its control strategy is validated by varying the line current reference. Hence, the H-bridge inverter will operate in its inductive or capacitive operation mode depending on the reference current value and the output of the PI controller in the control unit. The control strategy of the microgrid distributed generators has also been investigated in which P/V droop characteristics is applied to the power control of each DG in the microgrid. The effectiveness of the proposed approaches is validated through simulations. 
Predictive Approach for Power Quality Improvement Based Direct Power Control
Authors: Medouce Houssam Eddine , Benalla Hocine
Published: December 2019

The extensive use of non-linear loads in industry becomes increasingly a serious problem that affects the quality of energy delivered to customers. Therefore, the shunt active power filter (SAPF) has emerged as an important industrial tool to eliminate induced harmonic currents   and compensating of reactive power. This paper proposes an improved control configuration for SAPF based on a modern technique called predictive direct power control (Predictive-DPC). The principle of this control is based on the direct regulation of the instantaneous active and reactive powers to guarantee a good energy quality on the grid side. For this purpose the appropriate average voltage vector which cancels power tracking errors is calculated by a simple predictive model at the bigining of each control period. This type of control includes various features such as the lack of look up table (LUTs) and closed current loops and the constant switching frequency is achieved through the use of PWM modulation.  The results of the simulation process show a high performance in the steady and transient state function for predictive-DPC control that might be a reasonable alternative to conventional DPC in the field of active power filtering.
Pulse Density Modulation Based Series Resonant Inverter Fed Induction Heater System
Authors: Rubavathy S. Jaanaa , Murugesan P.
Published: December 2019

This paper deals with implementation of a multi-output Series Resonant Inverter(SRI) for induction heating applications, which uses pulse density modulation(PDM) control for full bridge Series resonant inverters for output voltage and power control. It ensures better efficiency performances than conventional control strategies. The proposed converter can be considered as a two output extension of a full bridge inverter. This full bridge inverter can control the two outputs, simultaneously and independently, up to their rated powers, which reduces the usage of number of components as compared with conventional method. It also ensures higher utilization of switches used for its operation. A two output full bridge series resonant inverter is simulated and implemented. The Experimental results are compared with the simulation results.
Implementation of NN controlled DVR for Enhancing The Power Quality By Mitigating Harmonics
Authors: Periaswamy Abirami , Lizbeth George Merin
Published: December 2019

Now a days there is a widespread use of  semiconductor devices, which are mostly implemented as the power switches for converters and inverters. These converters and inverters play a vital role in power systems both in transmission and distribution systems. This provides a way for the introduction of harmonics in the power system which leads to poor power quality. To overcome this many solutions have been suggested by the research community but each solution holds its own merits and demerits. Of all these suggested solutions, the Dynamic Voltage Restorer is one of the most cost effective systems for various power quality issues. In this paper the DVR is considered for enhancing the power quality by reducing the harmonics generated because of sensitive loads. Here the power quality is enhanced by controlling the DVR using Neural Network Controller which is trained by Levenberg Marquardt algorithm. In this paper the THD analysis of the voltage quantity is analysed by introducing an unbalanced three phase fault in the system. The simulation is done by using MATLAB/Simulink. From the results, it is verified that the harmonics are reduced by the NN controlled DVR unit. Also the simulation results are verified with the hardware results. 
Optimal Power System Planning with Renewable DGs with Reactive Power Consideration
Authors: T. Hanumesh , Reddy H.R Sudarshana
Published: December 2019

This paper analyses the optimal power system planning with DGs used as real and reactive power compensator. Recently planning of DG placement reactive power compensation are the major problems in distribution system. As the requirement in the power is more the DG placement becomes important. When planned to make the DG placement, cost analysis becomes as a major concern. And if the DGs operate as reactive power compensator it is most helpful in power quality maintenance. So, this paper deals with the optimal power system planning with renewable DGs which can be used as a reactive power compensators. The problem is formulated and solved using popular meta-heuristic techniques called cuckoo search algorithm (CSA) and particle swarm optimization (PSO). the comparative results are presented.
Modeling and Nonlinear Control of a Wind Turbine System Based on a Permanent Magnet Synchronous Generator Connected to the Three-phase Network
Authors: Boussairi Yasser , Abouloifa Abdelmajid , Lachkar Ibtissam , Hamdoun Abdellatif , Aouadi Chaouqi
Published: December 2019

This article presents nonlinear control of wind conversion chain connected to the grid based on a permanent magnet synchronous generator. The control objectives are threefold; i) forcing the generator speed to track a varying reference signal in order to extract the maximum power at different wind speed (MPPT); ii) regulating the rectifier output capacitor voltage; iii) reducing the harmonic and reactive currents injected in the grid. This means that the inverter output current must be sinusoidal and in phase with the AC supply voltage (PFC). To this end, a nonlinear state-feedback control is developed, based on the average nonlinear model of the whole controlled system. This control strategy involves backstepping approach, Lyapunov stability and other tools from theory of linear systems. The proposed state-feedback control strategy is tested by numerical simulation which shows that the developed controller reaches its objectives
MPPT Control for Wind Energy Conversion System Based on a T-S Fuzzy
Authors: Benkada Abdennasser , Chaikhy H. , Monkade M.
Published: December 2019

In this paper, we focus on the modeling and control of a wind power system based on a Permanent Magnet Synchronous Generator (PMSG). We proposed a technique of control strategies to have the maximum power from wind turbine (WT). This study deals with the problem of Maximum Power Point Tracking (MPPT) based on Takagi Sugeno fuzzy model. The stability analysis is achieved. The gains of the designed controller are calculated by solving Linear Matrix Inequality (LMI). Finally, simulation results are provided to demonstrate the validity and the effectiveness of the proposed method.  
Modelling and Parameters Identification of a Quadrotor Using a Custom Test Rig
Authors: Mohammad Ashraf Mohammad Shafiq , Zainal Abidin Mohamad Shukri , Azimi Mahmud Mohd Saiful , Abd Rahman Muhammad Khairie Idham , Nasser Saleh Motea Zakarya Mohammed
Published: December 2019

Quadrotor by nature is a very unstable system and flying it without any feedback control algorithm is deemed impossible. However, before designing the control system, system identification need to be conducted as the accuracy of the control system depends highly on the accuracy of the model. Therefore, this paper explained the design of the quadrotor model with an “X” configuration using the Euler-Newton model. Two types of test rig were designed to measure the thrust coefficient, torque coefficient and throttle command relation parameter needed in the model. Other parameter such as moment of inertia was also being measured by separating the quad rotor model into several sections: Motors, Electronics Speed Controllers (ESC) and Central Hub. All parameters needed in the designed quad rotor model has been successfully identified by measuring the parameters using the custom-built quad rotor and test rigs. The parameters found in this paper will be used in designing the control system for the quadrotor.
Women & the Vote
Authors: Teele Dawn Langan
Published: December 2019

There are four contexts in which women have won voting rights: as part of a universal reform for all citizens (15 percent of countries that granted women suffrage); imposed by a conqueror or colonial metropole (28 percent); gradually, after some men had been enfranchised (44 percent); or a hybrid category, often in the wake of re-democratization (14 percent). This essay outlines the global patterns of these reforms and argues that in a plurality of cases, where women's suffrage was gradual, enfranchisement depended on an electoral logic. Politicians subject to competition who believed women would, on average, support their party, supported reform. The suffrage movement provided information, and a potential mobilization apparatus, for politicians to draw on after the vote was extended. Together, both activism and electoral incentives were imperative for reform, providing important lessons for feminist mobilization today.
Gender Lens to the Future of Work
Authors: Jivani Anita I.
Published: December 2019

Acquiring new skills will be foundational to surviving in and leading in the workplace of the future. Organizations must make concerted efforts in upskilling women to maintain high levels of productivity and growth. This acquisition of new skills will help women make the transition into new jobs that will be necessary due to automation and today's workplace realities. Without it, the workplace could become even more unbalanced than it is today. Further, today's gaps need to be filled in a holistic manner to ensure that not only are tomorrow's technologies created by a diverse group of people, but also that they are implemented in a human-centered manner that aligns with the original intention. The private sector has a vital role to play in preparing the workforce that it will need and should prototype holistic solutions to help respond to this critical need.
Equality
Authors: MacKinnon Catharine A.
Published: December 2019

The distinction between formal and substantive equality is theorized then illustrated by sexual harassment law in the United States and in international legal developments. The convergence of sexual harassment concepts with prostitution, hence of sex discrimination law with the Nordic/Equality Model, is explained and explored.
Good Fellows: Men's Role & Reason in the Fight for Gender Equality
Authors: Spar Debora L.
Published: December 2019

This essay attempts to make the case for including – even embracing – men in the fight for gender equality. I do not mean to argue that men should supplant women in this struggle, or that enlisting men implies dismissing or diminishing women. My aim instead is to make this fight less isolated and more practical, and to attack the so-called women's problem with a broader, blunter tool. If men believe in equality, then expanding that belief to explicitly include women is not a leap of logic or act of charity. It is instead a basic extension of a truth already deemed self-evident, and a channel through which men can begin to redefine their own identities and interests. Men have been an obstacle to women's equality for a very long time. Perhaps the moment has come to make them part of the solution as well.
Development of Pumping Equipment for Oil and Gas Production in Complicated Conditions
Authors: Mokhov M. A. , Sazonov Yu. A. , Mulenko V. V. , Frankov M. A. , Tumanyan Kh. A. , Timoshenko V. G. , Kruglov S. V.
Published: December 2019

The research is aimed at the development of new scientific principles for the creation of special pumping equipment for the extraction of oil and gas in complicated conditions. In many cases, the complicated operating conditions of the pump are determined by the high gas content and
high content of mechanical impurities in the multiphase flow. In the course of scientific research, new methods of designing hydraulic machines were tested, including the use of additive technologies. In the study of labyrinth pumps, the issues were considered concerning the features of the
operating process with increased rotor speed. New design of the rotor manufactured using additive technologies was discussed. It is shown that the rotor screw in a labyrinth pump can be replaced by a set of impellers, for example, by a set of centrifugal wheels or a set of axial wheels. New
results concerning labyrinth pumps can give impetus to the development of research on hydraulic and gas turbines, as well as on heat engines. Some results of the works performed can be used to create robotics.
Functional and Elemental Composition of Humic Acids of Sapropels of the River Ob’s Left Bank of Khmao-Yugra
Authors: Osnitsky Evgeny M. , Gurova Olga A. , Boroduy Davyd V. , Litvinenko Natalia V. , Grekhova Iraida V.
Published: December 2019

This article describes qualitative and quantitative characteristics of chemical elements and acidbase functional groups of humic acids (HA) in five lakes of the left bank of the Ob of Khanty-Mansi Autonomous Okrug-Yugra. The data on their elemental composition (CNHO), atomic ratios
(H/C, O/C) carboxyl (COOH) and phenolic (OH) functional groups have been presented. The relationship between the elemental and functional composition of HA has been traced. It is found that with increasing hydrogen content, the percentage of carboxyl groups in the macromolecule of HA increases,
the proportion of aromatic moieties reduces, and with increasing oxygen content the number of phenolic hydroxyls increases. According to the chart of atomic ratios describing the content of aromatic and aliphatic parts, HA are placed in the sequence, characterizing the maximum proportion of
aromatic structures. Clearly there is a group of HA of lake Shchuchye sapropel, which is characterized by a maximum degree of aromaticity, followed by in decreasing order according to the contents of the Carom humic acids of sapropels of lakes Srednesatyginskiy Tuman, Nyartur,
Medvezhye and Satyginskiy Tuman. The highest content of the Carom is typical for the more formed, “mature” HA.
A Hybrid of Cognitive Entrepreneurial Training and Education and Their Impact on Business Opportunity Recognition in Thailand: Moderating Role of Entrepreneurial Passion
Authors: Suteerachai Boonsri , Suksod Pornkul , Somjai Sudawan
Published: December 2019

Aim of the study: The aim of this paper was to analyze the impact of cognitive entrepreneurial training and education and their impact on business opportunity recognition in Thailand with the moderating role of entrepreneurial passion. This study has four main objectives such
as to study the impact of cognitive entrepreneurial training on business opportunity recognition accuracy, to study the impact of entrepreneurial education on business opportunity recognition accuracy, to analyze the role of entrepreneurial passion between cognitive entrepreneurial training
and business opportunity recognition accuracy and to analyze the role of entrepreneurial passion between entrepreneurial education and business opportunity recognition accuracy. In the era of rapid development and growth, entrepreneurial education is extremely vital for students. Entrepreneurial
passion as well as play an important role in recognizing business opportunities. The process of experiential education facilitates potential business-persons to learn how to identify business opportunities, through developing and building their framework of (Cognitive Opportunity Identification),
and through improving their entrepreneurship skills through entrepreneurial learning and education. Methods: Quantitative method and cross sectional time horizon have been used by the researcher in this paper. The researcher gathered data from Thai students. Findings: The study
findings suggest that hypothesis 1, 2, 3 and 4, all are accepted. Implications: The programs of entrepreneurial education should provide theoretical understandings to students, facilitating them to make better sense of their pertinent experiences and to transmute them into understanding
and knowledge.
Template Protection Using Multi Biometric Web Modulo Graph
Authors: Kumaran P. , Ashoka Rajan R. , Veeramani T. , Thilagavathy R.
Published: December 2019

To develop a complete biometric authentication system, security is highly needed. Even though there are several methods for storing fingerprint templates, they are compromised by the attacker leaving it as an unprotected system. In this paper, a novel method is proposed for protecting
biometrics through an user defined graph named Web Modulo Graph. Feature vectors are extracted from the Left Fingerprint, Right Fingerprint and Palm Print during the enrollment process. The captured information from the biometrics are combined and stored in Web Modulo Graph where the insertion
and traversal of feature vectors are unknown to the attacker. So even if the database or the graph structure is stolen by the attacker the correct sequence cannot be obtained. In this case, guessing the correct sequence is not almost possible as user defined graph is used and the system can
achieve this with an Equal Error Rate (EER) of 4.8%. After various analyses, the proposed system is found to have high computational hardness.
Transformation and Upwelling of Bottom Water in Fracture Zone Valleys
Authors: Thurnherr A. M. , Clément L. , St. Laurent L. , Ferrari R. , Ijichi T.
Published: December 2019

Closing the overturning circulation of bottom water requires abyssal transformation to lighter densities and upwelling. Where and how buoyancy is gained and water is transported upward remain topics of debate, not least because the available observations generally show downward-increasing turbulence levels in the abyss, apparently implying mean vertical turbulent buoyancy-flux divergence (densification). Here, we synthesize available observations indicating that bottom water is made less dense and upwelled in fracture zone valleys on the flanks of slow-spreading midocean ridges, which cover more than one-half of the seafloor area in some regions. The fracture zones are filled almost completely with water flowing up-valley and gaining buoyancy. Locally, valley water is transformed to lighter densities both in thin boundary layers that are in contact with the seafloor, where the buoyancy flux must vanish to match the no-flux boundary condition, and in thicker layers associated with downward-decreasing turbulence levels below interior maxima associated with hydraulic overflows and critical-layer interactions. Integrated across the valley, the turbulent buoyancy fluxes show maxima near the sidewall crests, consistent with net convergence below, with little sensitivity of this pattern to the vertical structure of the turbulence profiles, which implies that buoyancy flux convergence in the layers with downward-decreasing turbulence levels dominates over the divergence elsewhere, accounting for the net transformation to lighter densities in fracture zone valleys. We conclude that fracture zone topography likely exerts a controlling influence on the transformation and upwelling of bottom water in many areas of the global ocean.
Prosodic Prominence and Focus: Expectation Affects Interpretation in Samoan and English
Authors: Calhoun Sasha , Wollum Emma , Kruse Va’ai Emma
Published: December 2019

This paper looks at the perception of prosodic prominence and the interpretation of focus position in the unrelated languages, Samoan and English. In many languages, prosodic prominence is a key marker of focus, so it is expected that prosodic prominence would affect judgments of focus position. However, it is shown that focus position, in turn, influences the perception of prosodic prominence according to language-specific expectations about the alignment between focus position and nuclear accent placement. Two sets of parallel perception experiments in Samoan and English are reported. In the first, participants judged the most prosodically prominent word in sentences which varied in syntactic construction (cleft/canonical) and intended stress position (subject/object). In both languages, participants were more likely to choose the intended stressed word if it was in the focus position. However, this effect was much larger in Samoan, which fits with its relatively lower functionality of prosodic prominence. In the second experiment, participants were asked to choose which question had been asked, consistent with subject or object focus. It was found that in both languages, participants weighted syntactic and prosodic cues to focus in line with expectations from their language. These findings have implications for how we conceive the role of prosodic prominence in speech processing across languages.
The prediction of quality characteristics of cotton/elastane core yarn using artificial neural networks and support vector machines
Authors: Doran Enver Can , Sahin Cenk
Published: December 2019

Core yarn is a type of yarn that has a filament fiber in the center with a different fiber wrapped around it. This type of yarn is of growing importance in the textile industry. It is important to predict the quality characteristics of a core yarn before production to prevent the faulty production of fabrics. Therefore, the development of predictive models is a necessity in the textile industry. In this study, artificial neural network (ANN) and support vector machine (SVM) models are proposed to predict the quality characteristics of cotton/elastane core yarn, using fiber quality and spinning parameters. Principal component analysis and analysis of variance techniques are also used to reduce input dimensions, since high dimensional data may reduce a model’s potential for success in prediction. The prediction models are trained and tested using the data obtained from a textile production plant. The results of all the models are compared with each other on test data. Mean absolute percentage error (MAPE), mean absolute error (MAE) and correlation coefficient (R) are used to assess the prediction power of the models. Although on most of the tests SVM models fared slightly better than ANN models, both models provide accurate predictions for most of the yarn quality characteristics. The results show that the best models have over 90% success rate in MAPE and R. In particular, the Coefficient of Variance of mass (CVm) along the yarn, hairiness and Reisskilometer quality characteristics of the cotton/elastane core yarn are predicted with 91%, 93% and 95% accuracy, respectively.
The Effect of School-Wide Positive Behavior Interventions and Supports on Disciplinary Exclusions: A Conceptual Replication
Authors: Gage Nicholas A. , Grasley-Boy Nicolette , Lombardo Michael , Anderson Lucas
Published: December 2019

Disciplinary exclusions, particularly out-of-school suspension and expulsions, are a pressing concern for schools, as research demonstrates that they are associated with myriad deleterious outcomes such as increased risk for poor academic achievement, school dropout, and contact with juvenile justice. Research suggests that School-Wide Positive Behavior Interventions and Supports (SWPBIS), a prevention and intervention framework for addressing school-based problem behavior, can have a significant and meaningful impact on reducing the likelihood of student suspensions and expulsions. In this study, we conceptually replicated a series of previous studies conducted in other states and examined the effect of universal SWPBIS on disciplinary exclusions in California. Using propensity score matching, we examine differences in suspension and expulsion rates for 98 schools implementing universal SWPBIS with fidelity and 98 comparison schools not implementing SWPBIS. Results suggest that schools implementing SWPBIS with fidelity have significantly fewer suspensions. No effects were found for expulsions. Implications and recommendations for future research are discussed.
Effect of rational-emotive adult education intervention on burnout symptoms among primary school teachers in Southeast Nigeria
Authors: Nwabuko Linus Okechukwu , Eze Georgina Chinagorom , Eneh Eberechukwu Charity , Okechukwu Ann Ebere , Udom Inwang Etim
Published: December 2019

Objective

To determine the effect of a rational-emotive adult education intervention (REAEI) on burnout symptoms among primary school teachers in Southeast Nigeria.

Methods

Primary school teachers with burnout symptoms were randomised to treatment or control condition. Treatment was a 16-week REAEI programme delivered in 32 group therapeutic sessions. The Teachers’ Burnout Inventory (TBI) score was recorded before and after therapy and at a three-month follow-up.

Results

Overall, 27% (86/320) of the sample of primary school teachers had burnout symptoms. TBI scores were statistically significantly lower in the treatment group compared with the control group both after therapy and at the three- month follow up.

Conclusion

In this sample of primary school teachers, burnout symptoms were alleviated by use of a REAEI program.
Trends in chronic hepatitis B treatment-related research from 1973 to 2018: a bibliometric and visual analysis
Authors: Li Guiyu , Lin Jiyong , Jiang Cen , Feng Quansheng , Wen Li
Published: December 2019

Objective

Chronic hepatitis B (CHB) is a worldwide disease and the most common cause of liver cancer. This study aimed to identify specific areas of research activity concerning CHB treatment between 1973 and 2018 and to aid in identifying new areas for future development.

Methods

The literature was searched from the GoPubMed and Web of Science databases using terms related to CHB treatment, analyzed with bibliometric methods and visualized using VOSviewer.

Results

A total of 9486 and 5883 papers were collected from PubMed and Web of science, respectively. The studies focused on two clusters of topics: antiviral therapy for CHB and progressive diseases, and drug resistance. Studies related to antiviral drugs concentrated on lamivudine (n = 788), entecavir (n = 390), and adefovir dipivoxil (n = 376). Studies addressing conditions developing from CHB highlighted hepatocellular carcinoma (n = 403) and cirrhosis (n = 223). China (n = 1978) contributed the most publications. The 10 most quantitatively prolific organizations were in France. All 20 of the most cited papers investigated antiviral treatments for CHB or CHB-associated cirrhosis.

Conclusions

Research on CHB treatment over the past 45 years has concentrated on antiviral therapy, CHB-associated progressive conditions, drug resistance and immunization. Although work on CHB treatment has made considerable progress, new approaches must be explored.
Application of bedside real-time tracheal ultrasonography for confirmation of emergency endotracheal intubation in patients in the intensive care unit
Authors: Chen Weiting , Chen Junbo , Wang Hehao , Chen Yingzi
Published: December 2019

Objective

Critically ill patients often require emergency endotracheal intubation and mechanical ventilation. When esophageal intubation is not confirmed early, treatment may be delayed, even for life-threatening conditions. We examined the accuracy of bedside real-time airway ultrasonography in confirming the endotracheal tube (ETT) position during emergency endotracheal intubation in patients in the intensive care unit (ICU).

Methods

This single-center prospective observational study included 118 patients who underwent urgent endotracheal intubation in the ICU of Taizhou Hospital of Integrated Traditional Chinese and Western Medicine. Tracheal ultrasonography was used to confirm the ETT position during endotracheal intubation, after which fiberoptic bronchoscopy was performed. The accuracy of bedside real-time tracheal ultrasonography in determining the ETT position was examined.

Results

Twelve (10.2%) patients underwent endotracheal intubation. The kappa value was 0.844, indicating perfect consistency between tracheal ultrasonography and fiberoptic bronchoscopy in identifying esophageal intubation. The sensitivity, specificity, and positive and negative predictive values of tracheal ultrasonography in determining the ETT position were 75.0%, 100%, 100%, and 97.2%, respectively.

Conclusions

Bedside real-time tracheal ultrasonography accurately assesses the ETT position in the ICU and can identify the ETT position during intubation. These findings have important clinical applications and are of great significance for treatment of ICU patients.
Outcomes of coronary rotational atherectomy in patients with reduced left ventricular ejection fraction
Authors: Zhang Hui-Ping , Zhao Ying , Ai Hu , Li Hui , Tang Guo-Dong , Zheng Nai-Xin , Sun Fu-Cheng
Published: December 2019

Objective

We evaluated the safety and efficacy of rotational atherectomy (RA) in patients with a reduced left ventricular ejection fraction (LVEF).

Methods

In total, 140 consecutive patients with severe coronary artery calcification (CAC) who underwent RA were retrospectively enrolled. Patients were grouped based on LVEF: ≤35% (n = 10), 36% to 50% (n = 11), and >50% (n = 119). We assessed procedural success and periprocedural complication rates as well as the incidences of in-hospital and 2-year major adverse cardiac events (MACEs), defined as hospitalization for myocardial infarction and worsening heart failure, target vessel revascularization, and cardiac death.

Results

Procedural success was achieved in nearly all patients in each group. Most periprocedural complications were minor, and major complications were uncommon. The 2-year MACE rate was significantly higher in the LVEF ≤35% than LVEF >50% group (40.0% vs. 6.7%, respectively). Multivariable regression analysis revealed that the LVEF was the only independent predictor of 2-year MACEs in patients who underwent RA.

Conclusions

Patients with a reduced LVEF who underwent RA had procedural success rates similar to those of patients with preserved left ventricular systolic function. The LVEF might be an independent predictor of 2-year MACEs in patients with severe CAC after percutaneous coronary intervention following RA.
Productive Activities and Risk of Cognitive Impairment and Depression: Does the Association Vary by Gender?
Authors: Lee Haena , Ang Shannon
Published: December 2019

We examine how labor together with social participation protects against cognitive impairment and depression, with a focus on gender differences. Data are drawn from four waves of the Korean Longitudinal Study of Aging (2006–2012). Both paid work and unpaid work are considered labor participation. Social participation includes the frequency of participation in formal social institutions, religious groups, grandparenting, and interactions with family and friends. Using growth curve models, we find that social and labor participation are independently associated with outcomes and effects vary by gender. Religious group activity was beneficial only for women, whereas inability to work was detrimental for men only. Informal social gatherings and labor participation, paid or unpaid, were beneficial for both genders. Findings on gender differences highlight how social identities can shape social roles and confine activity space, and productive engagement, affecting outcomes for mental health in later life.
Book review: Bhaswati Mukherjee, India and EU: An Insider’s View
Authors: Sachdeva Gulshan
Published: December 2019

Bhaswati Mukherjee, India and EU: An Insider’s View. New Delhi: ICWA and Vij Books, 2018, pp. +336, ₹995.
Large in-plane elastic deformations of bi-pantographic fabrics: asymptotic homogenization and experimental validation
Authors: Barchiesi Emilio , Eugster Simon R , dell’Isola Francesco , Hild François
Published: December 2019

Bi-pantographic fabrics are composed of two families of pantographic beams and correspond to a class of architectured materials that are described in plane as second-gradient 2D continua. On a discrete level, a pantographic beam is a periodic arrangement of cells and looks like an expanding barrier. The materialization of a bi-pantographic fabric made from polyamide was achieved by additive manufacturing techniques. Starting from a discrete spring system, the deformation energy of the corresponding continuum is derived for large strains by asymptotic homogenization. The obtained energy depends on the second gradient of the deformation through the rate of change in orientation and stretch of material lines directed along the pantographic beams. Displacement-controlled bias extension tests were performed on rectangular prototypes for total elastic extension up to 25%. Force–displacement measurements complemented by local digital image correlation analyses were used to fit the continuum model achieving excellent agreement.
The effect of freedom on international tourism demand: Empirical evidence from the top eight most visited countries
Authors: Bulut Umit , Kocak Emrah , Suess Courtney
Published: December 2019

The present study investigates the impact of freedom (i.e. the effects of political rights and civil liberties) on tourist arrivals for the eight countries with the highest tourist arrivals in 2016 (France, the United States, Spain, China, Italy, the United Kingdom, Germany, and Mexico), using annual data from 1998 to 2016, through advanced panel data methods. Notably, the key strengths of this study are as follows: (i) it examines the impact of institutional quality on international tourism demand for the most visited countries and (ii) it employs advanced panel data techniques, which have been suggested in recent years. We first constituted a freedom index using political rights and civil liberties data. Second, we performed cross-sectional dependence (CD) tests to examine whether there existed CD in the panel data set. After detecting the presence of CD, we used panel unit root and cointegration tests, which are robust to CD to avoid problems from spurious regression. Finally, we estimated long-run parameters of the empirical model through a panel data estimator that is capable of presenting efficient and unbiased output in the presence of CD. Our empirical findings show that the level of freedom may play a role in explaining the volume of international tourist arrivals. Theoretical and policy implications are discussed in the study, particularly with respect to the importance of rights and freedom in the context of international inbound tourist arrivals.