bluuebunny/crossref_metadata_2025 huggingface dataset:
Δ0 (1232) production in n+12C collisions at 4.2GeV/c
Authors: Olimov Kosim , Khudaiberdyev Gulmurod U. , Olimov Alisher K. , Bekmirzaev Rakhmatulla N. , Kurbanov Anvar R. , Gulamov Kadyr G. , Aliyev Mirza , Shodmonov Maratbek Z. , Yuldashev Bekhzod S. , Olimov Khusniddin K.
Published: October 2021

For the first time, the production of [Formula: see text] (1232) resonances has been analyzed in minimum bias [Formula: see text]C collisions at 4.2[Formula: see text]GeV/[Formula: see text]. The value of the mass and width of the [Formula: see text] resonances as well as the fraction of the negative pions coming from [Formula: see text] decay obtained in this work in [Formula: see text]C collisions coincide within the uncertainties with those extracted earlier in [Formula: see text]C collisions at 4.2[Formula: see text]GeV/[Formula: see text] per nucleon. The inclusive cross-section for production of [Formula: see text] (1232) resonances in [Formula: see text]C collisions at 4.2[Formula: see text]GeV/[Formula: see text] is estimated to be [Formula: see text][Formula: see text]mb. Production of [Formula: see text] resonances in [Formula: see text]C collisions at 4.2[Formula: see text]GeV/[Formula: see text] has been investigated separately in regions of fragmentation of the target and projectile. The mass of the [Formula: see text] (1232) proved to be the same within the statistical errors in the target and projectile fragmentation regions. The width of the invariant mass spectrum of [Formula: see text] excited in the projectile region proved to be considerably larger than that in the target fragmentation region, coinciding within statistical errors with that obtained in collisions of free nucleons. The results of the previous experiments, in which production of [Formula: see text] resonances is investigated in the whole phase space (without separating the target and projectile fragmentation regions), can be approximately regarded as the mean values of [Formula: see text] parameters, averaged over those in the target and projectile fragmentation regions.
Symmetric polynomials in the free metabelian Poisson algebras
Authors: Dushimirimana Andre , Fındık Şehmus , Şahi̇n Öğüşlü Nazar
Published: October 2021

Let K be a field of characteristic zero and [Formula: see text] be a finite set of variables. Consider the free metabelian Poisson algebra [Formula: see text] of rank n generated by [Formula: see text] over K. An element in [Formula: see text] is called symmetric if it is preserved under any change of variables, i.e. under the action of each permutation in [Formula: see text]. In this study, we determine the algebra [Formula: see text] of symmetric polynomials of [Formula: see text].
Invariant bilinear operators and the second 𝔰𝔩(2)-relative cohomology of the Lie algebra of vector fields on ℝ
Authors: Abdaoui Meher
Published: October 2021

Let [Formula: see text] be the Lie algebra of smooth vector fields on [Formula: see text] and [Formula: see text] be the space of bilinear differential operators acting on weighted densities. In this paper, we classify [Formula: see text]-invariant skew-symmetric binary differential operators from [Formula: see text] to [Formula: see text] vanishing on [Formula: see text]. This result allows us to compute the second differential [Formula: see text]-relative cohomology of [Formula: see text] with coefficients in [Formula: see text].
An Improved Fuzzy TOPSIS Method with a New Ranking Index
Authors: Sadabadi S. A. , Hadi-Vencheh A. , Jamshidi A. , Jalali M.
Published: October 2021

Owing to vague concepts frequently represented in decision data, the crisp values are inadequate to model real-life situations. In this paper, the rating of each alternative and the weight of each criterion is described by linguistic terms which can be expressed in triangular fuzzy numbers. Next, we focus on fuzzy TOPSIS (FTOPSIS) method. We show that, however, the conventional FTOPSIS is interesting, but it suffers from some flaws. The shortcomings of classical FTOPSIS are shown and some solutions are given. Further, a new similarity index is proposed and then is illustrated using numerical examples. By treating the separations of an alternative from the fuzzy positive ideal solution (FPIS) and the fuzzy negative ideal solution (FNIS) as “cost” criterion and “benefit” criterion, respectively, we reduce the original fuzzy multiple criteria decision making (FMCDM) problem to a new one with two criteria. Illustrative examples are given to show the advantages of the proposed approach.
A Comparison Between Organic and Inorganic Nanoparticles: Prime Nanoparticles for Tumor Curation
Authors: Bukhari Bakhtawar , Naveed Muhammad , Makhdoom Syeda Izma , Jabeen Khizra , Asif Muhammad Farrukh , Batool Hira , Ahmed Naveed , Chan Yean Yean
Published: October 2021

In the modern era, nanotechnology is one of the rapidly growing fields in many biomedical applications especially in delivering therapeutics for the curation of tumor cells. Cancer is a lethal disease that grows silently in the human body, caused by mutations in the genetic material of cells. The presence of a high number of physiologically active chemicals on the cancer cell surface does not particularly lead to tumor cell targeting. The lack of effective targeting of tumor cells by conventionally administered chemotherapeutic drugs demands the use of nanomedicine. Conventional medicines have immense cytotoxic effects, i.e., they do not kill tumor cells only but also destroy normal body cells. Nanoparticles (NPs) have an advantage over conventional therapeutic methods due to their small size, large surface area, and especially for targeting tumor cells without harming normal body cells. Based on durability and molecular weight, NPs are classified as organic and inorganic nanoparticles. Common organic and inorganic nanoparticles are highly effective against cancer curation and have high efficacy values along with their mechanism of action.
IMPROVING THE NORTH AMERICAN MULTI-MODEL ENSEMBLE (NMME) PRECIPITATION FORECASTS AT SEASONAL SCALE OVER THE HIMALAYAN REGION USING MACHINE LEARNING
Authors: SHRIVASTAVA SOURABH , AVTAR RAM , BAL PRASANTA KUMAR
Published: October 2021

The coarse horizontal resolution global climate models (GCMs) have limitations in producing large biases over the mountainous region. Also, single model output or simple multi-model ensemble (SMME) outputs are associated with large biases. While predicting the rainfall extreme events, this study attempts to use an alternative modeling approach by using five different machine learning (ML) algorithms to improve the skill of North American Multi-Model Ensemble (NMME) GCMs during Indian summer monsoon rainfall from 1982 to 2009 by reducing the model biases. Random forest (RF), AdaBoost (Ada), gradient (Grad) boosting, bagging (Bag) and extra (Extra) trees regression models are used and the results from each models are compared against the observations. In simple MME (SMME), a wet bias of 20[Formula: see text]mm/day and an RMSE up to 15[Formula: see text]mm/day are found over the Himalayan region. However, all the ML models can bring down the mean bias up to [Formula: see text][Formula: see text]mm/day and RMSE up to 2[Formula: see text]mm/day. The interannual variability in ML outputs is closer to observation than the SMME. Also, a high correlation from 0.5 to 0.8 is found between in all ML models and then in SMME. Moreover, representation of RF and Grad is found to be best out of all five ML models that represent a high correlation over the Himalayan region. In conclusion, by taking full advantage of different models, the proposed ML-based multi-model ensemble method is shown to be accurate and effective.
The Pentecostal Gender Paradox: Pentecostalism and Intimate Partner Violence in Ghana
Authors: Gundersen Sara
Published: October 2021

Pentecostalism is large, influential, and growing quickly in Ghana. This growth has been argued to benefit women due to the religion’s teachings on individualism and use of female leaders. However, the religion’s focus on female submissiveness may also present a challenge to women. Whilst this theoretical paradox has been largely untested, Gundersen (Gundersen, S (2018). Will god make me rich? An investigation into the relationship between membership in Charismatic churches, wealth, and women’s empowerment in Ghana. Religions, 9(6), 195) finds that women who identify as Pentecostal exhibit less decision-making power than other Christians when it comes to big household purchases and their own health care. Using the 2008 and 2014 Demographic Health Surveys, this study examines the relationship between Pentecostalism and intimate partner violence in Ghana. Women who identify as Pentecostal are more likely to have experienced physical violence than other women, but this effect may disappear for women in the highest wealth quintiles. Higher wealth Pentecostal women are also less likely to believe a husband is justified in hitting his wife. Thus, it seems wealth may have a protective effect for Pentecostal women in Ghana.
An Investigation Into Religious Peer Effects
Authors: Ooi Daniel Boon Yann
Published: October 2021

The communal nature of religion suggests peer effects exist in religiosity, potentially through positive spillovers in religious participation and social formation of religious beliefs. Using seven measures of religiosity, we estimate positive and negative peer effects in each case using peer group composition. We use a simultaneous equation model to account for self-selection into religious peer groups, and while we find positive peer effects are insignificant, there are significant negative peer effects operating through non-religious friends. This suggests peers affect social formation of religious beliefs, rather than through positive spillovers in religious participation.
Thin Film Skyrmionics
Authors: Dohi Takaaki , Reeve Robert M. , Kläui Mathias
Published: October 2021

In condensed matter physics, magnetic skyrmions, topologically stabilized magnetic solitons, have been discovered in various materials systems, which has intrigued the community in terms of not only fundamental physics but also with respect to engineering applications. In particular, skyrmions in thin films are easily manipulable by electrical means even at room temperature. Concomitantly, a variety of possible applications have been proposed and proof-of-concept devices have been demonstrated. Recently, the field of skyrmion-based electronics has been referred to as skyrmionics and this field has been rapidly growing and extended in multiple directions. This review provides recent progress for skyrmion research in thin film systems and we discuss promising new directions, which will further invigorate the field.
The Basis of Navigation Across Species
Authors: Freas Cody A. , Cheng Ken
Published: October 2021

Animals navigate a wide range of distances, from a few millimeters to globe-spanning journeys of thousands of kilometers. Despite this array of navigational challenges, similar principles underlie these behaviors across species. Here, we focus on the navigational strategies and supporting mechanisms in four well-known systems: the large-scale migratory behaviors of sea turtles and lepidopterans as well as navigation on a smaller scale by rats and solitarily foraging ants. In lepidopterans, rats, and ants we also discuss the current understanding of the neural architecture which supports navigation. The orientation and navigational behaviors of these animals are defined in terms of behavioral error-reduction strategies reliant on multiple goal-directed servomechanisms. We conclude by proposing to incorporate an additional component into this system: the observation that servomechanisms operate on oscillatory systems of cycling behavior. These oscillators and servomechanisms comprise the basis for directed orientation and navigational behaviors.
Evaluation of Wisconsin and CaPTHUS Indices Usefulness for Predicting Monoglandular and Multiglandular Disease in Patients with Primary Hyperparathyroidism through the Analysis of a Single-Center Experience
Authors: De Pasquale Loredana , Lori Eleonora , Bulfamante Antonio Mario , Felisati Giovanni , Castellani Luca , Saibene Alberto Maria
Published: October 2021

Background. The main challenge for treating primary hyperparathyroidism (PHPT) is to understand if it is caused by a single adenoma (80–85% of the cases) or by a multiglandular disease (15–20%), both preoperatively and intraoperatively. For this reason, some preoperative scores were proposed in the literature, to perform focused parathyroidectomy, avoiding intraoperative parathormone assay (ioPTH). The most known are the CaPTHUS test and the Wisconsin index. We applied them to our experience. Methods. A retrospective cohort study on 462 patients referred for parathyroidectomy to Thyroid and Parathyroid Unit at Santi Paolo e Carlo Hospital, Milan, Italy, from 2011 to 2021. Only patients affected with benign PHPT and neck ultrasound performed at our institution were included. Both patients for whom preoperative imaging agreed with the localization of a single diseased parathyroid and those with only ultrasound or scintigraphy positive for parathyroid localization underwent Mini-Invasive Video-assisted parathyroidectomy. In all cases, ioPTH assay was performed. The conversion to bilateral neck exploration was decided based on the drop in ioPTH. CaPTHUS score and the Wisconsin index (Win) were applied to the series. CaPTHUS score ≥3 and Win index >1600, according to the original studies of the literature, were considered at high probability of monoglandular disease. Outcomes in these two groups were examined. Results. 236 patients were eligible for the study. The pathology resulted in multiglandular disease in 24 patients (10.2%). Among these, 18 (75.0%) obtained a CaPTHUS score ≥3, and 20 (83.3%) had a Win index>1600. Intraoperative PTH allowed to identify multiglandular disease in 16 of 18 cases with CaPTHUS ≥3 and in 18 of 20 cases with win >1600, who could have been lost, based only on the results of these 2 tests. Conclusion. Based on our experience, CaPTHUS test and Wisconsin index were not so useful in predicting multiglandular disease as ioPTH.
Research on Influencing Factors of Technological Independent Innovation of Equipment Manufacturing Enterprises from the Perspective of Iceberg Theory
Authors: Liu Tie , Yang Xu , Guo Yu
Published: October 2021

Technological independent innovation is not only the internal need for equipment manufacturing enterprises to improve their core competitiveness but also the urgent requirement to promote economic and social development. Based on the development status of technological independent innovation of equipment manufacturing enterprises, this study analyzes the explicit and implicit influencing factors of technological independent innovation using iceberg theory and obtains the multilevel hierarchical structure model of explicit and implicit influencing factors and its key influencing factors using the integrated DEMATEL‐ISM method. The three aspects of enterprises give suggestions and countermeasures for the existing problems, put forward correct and effective guidance for the technological independent innovation of equipment manufacturing enterprises, and lay a solid foundation for China’s industrial revitalization and economic development.
Computer‐Aided Teaching System Based on Data Mining
Authors: Tang Yonghua , Fan Qiang , Liu Peng
Published: October 2021

The traditional teaching model cannot adapt to the teaching needs of the era of smart teaching. Based on this, this paper combines data mining technology to carry out teaching reforms, constructs a computer‐aided system based on data mining, and constructs teaching system functions based on actual conditions. The constructed system can carry out multisubject teaching. Moreover, this paper uses a data mining system to mine teaching resources and uses spectral clustering methods to integrate multiple teaching resources to improve the practicability of data mining algorithms. In addition, this paper combines digital technology to deal with teaching resources. Finally, after building the system, this paper designs experiments to verify the performance of the system. From the research results, it can be seen that the system constructed in this paper has certain teaching and practical effects, and it can be applied to a larger teaching scope in subsequent research.
Rare Case of 6 cm Right Atrial Myxoma in Patient with Synchronous Endometrial Adenocarcinoma
Authors: Altujjar Mohammad , Zaiem Feras , Sheehan Erin , Gan Willy , Mhanna Mohammed , Khokher Waleed , Ullah Ikram , Mujtaba Mohammad Tokir
Published: October 2021

Primary cardiac tumors are extremely rare. Cardiac myxomas most frequently appear in the left atrium. In this article, we present a case of an asymptomatic 6 cm right atrial mass in a patient undergoing staging for endometrial cancer. The mass was resected, and final pathology was consistent with cardiac myxoma.
Chromobacterium violaceum: A Rare Cause of Urinary Tract Infection
Authors: Laghu Ujjwal , Yanagawa Manami , Morimoto Konosuke , Dhoubhadel Bhim Gopal
Published: October 2021

A 41-year-old man with a neurogenic bladder due to spinal cord injury (SCI) attended the outpatient department with chief complaints of fever, pain in the lower abdomen, and persistent hematuria for 10 days. From the urine culture and the microbiological and biochemical tests, the causative organism was identified as Chromobacterium violaceum. The isolate was resistant to cephalosporins, while it was sensitive to ofloxacin, gentamicin, and imipenem. Clinicians should be aware of this rare cause of urinary tract infection (UTI), the choice of antibiotic, length of treatment, and necessity of prompt treatment in SCI patients.
The Potential use of a Curcumin-Piperine Combination as an Antimalarial Agent: A Systematic Review
Authors: Khairani Shafia , Fauziah Nisa , Wiraswati Hesti Lina , Panigoro Ramdan , Setyowati Endang Yuni , Berbudi Afiat
Published: October 2021

Malaria remains a significant global health problem, but the development of effective antimalarial drugs is challenging due to the parasite’s complex life cycle and lack of knowledge about the critical specific stages. Medicinal plants have been investigated as adjuvant therapy for malaria, so this systematic review summarizes 46 primary articles published until December 2020 that discuss curcumin and piperine as antimalarial agents. The selected articles discussed their antioxidant, anti-inflammatory, and antiapoptosis properties, as well as their mechanism of action against Plasmodium species. Curcumin is a potent antioxidant, damages parasite DNA, and may promote an immune response against Plasmodium by increasing reactive oxygen species (ROS), while piperine is also a potent antioxidant that potentiates the effects of curcumin. Hence, combining these compounds is likely to have the same effect as chloroquine, that is, attenuate and restrict parasite development, thereby reducing parasitemia and increasing host survival. This systematic review presents new information regarding the development of a curcumin-piperine combination for future malaria therapy.
Recent Advances in Three-Dimensional Stem Cell Culture Systems and Applications
Authors: Wu Xiaowen , Su Junxiang , Wei Jizhen , Jiang Nan , Ge Xuejun
Published: October 2021

Cell culture is one of the most core and fundamental techniques employed in the fields of biology and medicine. At present, although the two-dimensional cell culture method is commonly used in vitro, it is quite different from the cell growth microenvironment in vivo. In recent years, the limitations of two-dimensional culture and the advantages of three-dimensional culture have increasingly attracted more and more attentions. Compared to two-dimensional culture, three-dimensional culture system is better to realistically simulate the local microenvironment of cells, promote the exchange of information among cells and the extracellular matrix (ECM), and retain the original biological characteristics of stem cells. In this review, we first present three-dimensional cell culture methods from two aspects: a scaffold-free culture system and a scaffold-based culture system. The culture method and cell characterizations will be summarized. Then the application of three-dimensional cell culture system is further explored, such as in the fields of drug screening, organoids and assembloids. Finally, the directions for future research of three-dimensional cell culture are stated briefly.
Influence of Early-Onset Peritonitis on Mortality and Clinical Outcomes in ESRD Patients with Diabetes Mellitus on Peritoneal Dialysis: A Retrospective Multicenter Study
Authors: Guo Qiaoyan , Chen Yangyang , Yang Liming , Zhu Xueyan , Zhang Xiaoxuan , Zhao Qiao , Zhuang Xiaohua , Wu Yanfeng , Luo Ping , Cui Wenpeng
Published: October 2021

Introduction: The impact of early-onset peritonitis (EOP) on patients with diabetes undergoing peritoneal dialysis (PD) has not been adequately addressed. We therefore sought to investigate the effects of EOP on the therapeutic response to management and long-term prognostic outcomes in patients with diabetes undergoing PD. Methods: For this retrospective cohort study, we analyzed the data for patients with end-stage renal disease, who were also suffering from diabetes mellitus and had undergone PD between January 1, 2013, and December 31, 2018. EOP was defined as the first episode of peritoneal dialysis-related peritonitis (PDAP) occurring within 12 months of PD initiation. All patients were divided into an EOP group and a later-onset peritonitis (LOP) group. Clinical data, treatment results, and outcomes were compared between groups. Results: Ultimately, 202 patients were enrolled for the analysis. Compared to the EOP group, the LOP group had more Streptococcus (p = 0.033) and Pseudomonas (p = 0.048). Patients with diabetes in the EOP group were less likely to have PDAP-related death (OR 0.13, CI: 0.02–0.82, p = 0.030). Patients with diabetes in the EOP group were more likely to have multiple episodes of PDAP and had higher rates of technical failure and poorer patient survival than those in the LOP group, as indicated by Kaplan-Meier analysis (p = 0.019, p = 0.004, and p < 0.001). In the multivariate Cox proportional hazards model, EOP was a significant predictor for multiple PDAP (HR 4.20, CI: 1.48–11.96, p = 0.007), technical failure (HR 6.37, CI: 2.21–18.38, p = 0.001), and poorer patient survival (HR 3.09, CI: 1.45–6.58, p = 0.003). Conclusions: The occurrence of EOP is significantly associated with lower rates of PDAP-related death and poorer clinical outcomes in patients with diabetes undergoing PD.
Clinical Analysis of Pyocele of Tunica Vaginalis in 56 Newborns
Authors: He Tian-Qu , Zhu Li-Hui , Li Chuang-Ye , Peng Qian-Long , Zu Jian-Cheng , Liu Yu , Zhao Yao-Wang
Published: October 2021

Objective: This study aimed to explore the clinical characteristics, treatment methods, and prognosis of neonatal pyocele of tunica vaginalis and to provide a reference for the clinical treatment. Methods: A total of 56 newborns with pyocele of tunica vaginalis were admitted to our hospital due to the scrotal emergency from January 2015 to January 2020. Our study retrospectively analyzed these 56 cases. Of the 56 cases, including 32 full-term infants and 24 premature infants, age ranged from 1 to 27 days. Initially, conservative treatment (intravenous antibiotic treatment) was applied to 42 cases, and surgery to 14 cases. Then, 7 underwent surgical exploration during the conservative treatment, and 2 cases with initial surgical treatment experienced orchiectomy because of complete necrosis. For 56 cases, the average follow-up time was 18 months. Results: The clinical recovery time of cases with conservative treatment ranged from 8 to 17 days, with an average of 11.02 ± 2.31 days. The clinical recovery time of cases with surgery ranged from 6 to 15 days, with an average of 9.28 ± 2.78 days. During the follow-up, for 56 cases, except for the 2 cases with orchiectomy, the testicular position and Doppler flow both went back to normal, of the 42 cases with initial conservative treatment, 1 case experienced testicular retardation, of the 14 cases with initial surgical treatment, 2 cases experienced testicular retardation, and hydrocele of 42 cases were self-healed. Conclusions: Neonatal pyocele of tunica vaginalis is mostly secondary to intra-abdominal infection. Color Doppler ultrasound is helpful for the diagnosis. The percutaneous aspiration is a way of collecting pathogenic bacteria during the conservative treatment. If the color Doppler suggests testicular involvement, surgical exploration should be performed.
Performance enhancement of BLDC motor using PID controller
Authors: Usha S. , Dubey Pranjul Mani , Ramya R. , Suganyadevi M. V.
Published: October 2021

Mainly the DC motors are employed in most of the application. The main objective is to Regulate the DC motor system. A motor which displays the appearances of a DC motor but there is no commutator and brushes is called as brushless DC motor. These motors are widespread to their compensations than other motors in relationships of dependability, sound, efficiency, preliminary torque and longevity. To achieve the operation more reliable and less noisy, brushless dc motors are employed. In the proposed work, dissimilar methods of speed control are analysed. In real time submission of speed control of BLDC motor, numerous strategies are executed for the speed control singularity. The modified approaches are the employment of PI controller, use of PID controller and proposed current controller.
Implementation of speed control of sensorless brushless DC motor drive using H-infinity controller with optimized weight filters
Authors: Vinida K. , Chacko Mariamma
Published: October 2021

The hardware implementation of sensorless brushless direct current motor drive incorporating H-infinity control strategy with optimized weights by particle swarm optimization in the speed control is carried out in this work. The methodology involved in the design of brushless direct current (BLDC) motor control with sensorless position detection technique, the design of H-infinity speed controller, steps involved in particle swarm optimization for optimizing coefficients of its weights and the hardware implementation is discussed in detail in this paper. Texas Instruments microcontroller board C2000 Delfino Launchpad LAUNCHXL F28377S and driver BOOSTXL DRV8301 are used for realization of the speed controller. The code is developed using C2000 hardware support package in MATLAB/SIMULINK platform. A comprehensive performance analysis is accomplished during starting of the motor and during the fast application and removal of load. This strategy is found to be robust resulting in faster load disturbance rejection and better reference speed tracking. The experimental results of the proposed strategy are compared with that of conventional proportional-integral (PI) controller. The time domain parameters are also compared. It is found that the proposed strategy exhibits better performance characteristics during transients and sudden disturbances in load.
A New Optimal DTC Switching Strategy for Open-End Windings Induction Machine using Dual Inverter
Authors: Aisyah Nabilah , Azri Maaspaliza , Jidin Auzani , Aihsan M. Z. , Talib MHN
Published: October 2021

Since the early 1980s, fast torque dynamic control has been a subject of research in AC drives. To achieve superior torque dynamic control, two major techniques are used, namely Field Oriented Control (FOC) and Direct Torque Control (DTC), spurred on by rapid advances in embedded computing systems. Both approaches employ the space vector modulation (SVM) technique to perform the voltage source inverter into over modulation region for producing the fastest torque dynamic response. However, the motor current tends to increase beyond its limit (which can damage the power switches) during the torque dynamic condition, due to inappropriate flux level (i.e. at rated stator flux). Moreover, the torque dynamic response will be slower, particularly at high speed operations since the increase of stator flux will produce negative torque slopes more often. The proposed research aims to formulate an optimal switching modulator and produce the fastest torque dynamic response. In formulating the optimal switching modulator, the effects of selecting different voltage vectors on torque dynamic responses will be investigated. With greater number of voltage vectors offered in dual inverters, the identification of the most optimal voltage vectors for producing the fastest torque dynamic responses will be carried out based on the investigation. The main benefit of the proposed strategy is that it provides superior fast torque dynamic response which is the main requirements for many AC drive applications, e.g. traction drives, electric transportations and vehicles.
Vision based solar tracking system for efficient energy harvesting
Authors: Kumar Kanhaiya , Varshney Lokesh , Ambikapathy A. , Ali Inayat , Rajput Ashish , Bhatnagar Anant , Omar Sajal
Published: October 2021

Electricity is a major source of energy for fast growing population and the use of nonrenewable source is harmful for our environment. This reason belongs to devastating of environment, so it is required to take immediate action to solve these problems which result the solar energy development. Production of a solar energy can be maximizing if we use solar follower. The major part of solar panels is microcontroller with arrangement of LDR sensor is used to follow the sun, where the sensors is less efficient to track the sun because of the low sensitivity of LDR. We are proposing a method to track sun more effetely with the help of both LDR sensors and image processing. This type of mechanism can track sun with the help of image processing software which combines both result of sensors and processed sun image to control the solar panel. The combination of both software and hardware can control thousands of solar panels in solar power plants.
Performance improvement of decentralized control for bidirectional converters in a DC micro-grid
Authors: Abbasi Seyed Mojtaba , Nafar Mehdi , Simab Mohsen
Published: October 2021

In this paper, using a neural controller and a genetic optimization algorithm to control the voltage as well as, control the frequency of the grid along with the management of the reactive power of the micro-grid to control the output power during islanding using Simultaneous bilateral power converters with voltage/frequency droop strategy and optimization of PI coefficients of parallel power converters by genetic-neural micro-grid algorithm to suppress AC side-current flow that increases stability and improvement of conditions frequency and voltage are discussed. Given the performance of the micro-grid in two simulation scenarios, namely transition from on-grid to off-grid, the occurrence of a step change in load in island mode as well as return to working mode is connected. The ability to detect the robust performance and proper performance of two-level neural controller. The controller performance time was also very good, indicating the appropriate features of the method used to design the controller, namely two-level neural, genetics. The main advantage of this method is its simplicity of design. The method used is also efficient and resistant to changes in the system, which results from the simulations.
A comprehensive review of distributed power system architecture for telecom and datacenter applications
Authors: Darla Ramesh B. , A Chitra
Published: October 2021

With the dominating utility of the internet, it becomes critical to manage the efficiency and reliability of telecom and datacenter, as the power consumption of the involved equipment also increases. Much power being wasted through the power conversion stages by converting AC voltage to DC voltage and then stepping down to lower voltages to connect to information and communication technology (ICT) equipment. 48/12 VDC is the standard DC bus architecture to serve the end utility equipment. This voltage level is further processed to multiple lower voltages to power up the internal auxiliary circuits. Power losses are involved when it is converted from higher voltage to lower voltages. Therefore, the efficiency of power conversion is lower. There is a need to increase the efficiency by minimizing the power losses which occur due to the conversion stages. Different methods are available to increase the efficiency of a system by optimizing the converter topologies, semiconductor materials and control methods. There is another possibility of increasing the efficiency by changing the architecture of a system by increasing the DC bus voltage to higher voltages to optimize the losses. This paper presents a review of available high voltage options for telecom power distribution and developments, implementations and challenges across the world.
Newly fault-tolerant indirect vector control for traction inverter
Authors: Zerdani Sara , Elhafyani Mohamed Larbi , Fadil Hicham , Zouggar Smail
Published: October 2021

The traction inverter is a crucial power device in the electric vehicle’s powertrain, and its failure is intolerable as it would considerably compromise the system’s safety. For more reliable driving, installing a traction inverter that is sufficiently resistant to electrical failure is inherent. Due to its compact size and the small number of switches incorporated in three-phase four-switch inverter, this modular topology was used to compensate for the open switch’s failure. However, it is known to have manifold weaknesses mainly distinguished in the low-frequency region. This paper introduces a new fault-tolerant indirect control that handles the IGBT’s failure constituting the traction inverter. The fault compensator is designed first based on the Proportional Integral regulator combined with the notch filter to mitigate the current imbalance and restore the DC voltage equilibrium.Furthermore, to conceive a comprehensive fault-tolerant control, there must therefore contain an accurate fault detector. In this regard, an uncomplicated fault diagnosis method based on the current spectral analysis has been performed. The effectiveness of the submitted controller was validated by simulation using Matlab.
Two-level inverter and three-level neutral point diode clamped inverter for traction applications: a comparative analysis study
Authors: Abdelsalam Asmaa A. , Esmaeel Mohamed Adel , Zaid Salama Abo
Published: October 2021

This paper presents an analytical comparison between two-level inverter and three-level neutral point diode clamped inverters for electric vehicle traction purposes. The main objective of the research is to declare the main differences in the performance of the two inverter schemes in terms of the switching and conduction losses over an entire domain of the modulation index and the phase angle distribution, steady-state operation, transient operation at a wide range of speed variation, and the total harmonic distortion THD% of the line voltage output waveform. It also declares the analysis of the three-level neutral point diode clamped inverter (NPCI) obstacle and the unbalance of the DC-link capacitor voltages. The introduced scheme presents an Induction Motor (IM) drive for electric vehicle (EV) applications. Considering the dynamic operation of the EV, the speed of the three-phase induction motor is controlled using a scalar V/Hz control for the full range of the IM power factor (PF). A comprehensive MATLAB/Simulink model for the proposed scheme is established.
Using Y-source network as a connector between turbine and network in the structure of variable speed wind turbine
Authors: Zadehbagheri Mahmoud , Sutikno Tole , Ildarabadi Rahim
Published: October 2021

Environmental factors such as air pollution and increase in global warming by using polluting fuels are the most important reasons of using renewable and clean energy that runs in global community. Wind energy is one of the most suitable and widely used kind of renewable energy which had been in consideration so well. This paper introduces an electric power generation
system of wind based on Y-source and improved Y-source inverter to deliver optimal electrical power to the network. This new converter is from impedance source converters family. This presented converter has more degrees of freedom to adjust voltage gain and modulation. Also, by limiting the range of simultaneous control (shooting through) while it maintains the
highest power of maximizer, it can operate in higher modulation range. This causes the reduce of stress in switching and thus it will improve the quality of output. Recommended system had been simulated in MATLAB/Simulink and shown results indicate accurate functionality.
Improved 25-level inverter topology with reduced part count for PV grid-tie applications
Authors: Majdoul Radouane , Touati Abelwahed , Ouchatti Abderrahmane , Taouni Abderrahim , Abdelmounim Elhassane
Published: October 2021

A new bidirectional multilevel inverter topology with a high number of voltage levels with a very reduced number of power components is proposed in this paper. Only TEN power switches and four asymmetric DC voltage sources are used to generate 25 voltage levels in this new topology. The proposed multilevel converter is more suitable for e-mobility and photovoltaic applications where the overall energy source can be composed of a few units/associations of several basic source modules. Several benefits are provided by this new topology: Highly sinusoidal current and voltage waveforms, low Total Harmonic Distortion, very low switching losses, and minimum cost and size of the device. For optimum control of this 25-level voltage inverter, a special Modified Hybrid Modulation technique is performed. The proposed 25-level inverter is compared to various topologies published recently in terms of cost, the number of active power switches, clamped diodes, flying capacitors, DC floating capacitors, and the number of DC voltage sources. This comparison clearly shows that the proposed topology is cost-effective, compact, and very efficient. The effectiveness and the good performance of the proposed multilevel power converter (with and without PWM control) are verified and checked by computational simulations.
New bidirectional step-up DC-DC converter derived from buck- boost DC-DC converter
Authors: Aditama Ridha D. N. , Ramadhani Naqita , Furqani Jihad , Rizqiawan Arwindra , Dahono Pekik Argo
Published: October 2021

This paper proposes a new bidirectional step-up DC-DC converter, namely modified buck-boost DC-DC converter. The proposed DC-DC converter was derived from the conventional buck-boost DC-DC converter. Output voltage expression of the proposed converter was derived by considering the voltage drops across inductors and switching devices. The results have shown that with the same parameter of input LC filter, proposed DC-DC converter has lower conduction losses. Moreover, the proposed DC-DC converter has lower rated voltage of filter capacitor than the conventional boost DC-DC converter which lead to cost efficiency. Finally, a scaled-down prototype of laboratory experiment was used to verify its theoretical analysis.
Comparison of electronic load using linear regulator and boost converter
Authors: Ayop Razman , Md Ayob Shahrin , Tan Chee Wei , Sutikno Tole , Abdul Aziz Mohd Junaidi
Published: October 2021

Direct current (DC) electronic load is a useful equipment for testing the electrical system. It can emulate various load at a high rating. The electronic load requires a power converter to operate and a linear regulator is a common option. Nonetheless, it is hard to control due to the temperature variation. This paper proposed a DC electronic load using the boost converter. The proposed electronic load operates in the continuous current mode and control using the integral controller. The electronic load using the boost converter is compared with the electronic load using the linear regulator. The results show that the boost converter able to operate as an electronic load with an error lower than 0.5% and response time lower than 13 ms.
A modified bridge-type nonsuperconducting fault current limiter for distribution network application
Authors: Fokui Willy Stephen Tounsi , Saulo Michael , Ngoo Livingstone
Published: October 2021

The electrical distribution network is undergoing tremendous modifications with the introduction of distributed generation technologies which have led to an increase in fault current levels in the distribution network. Fault current limiters have been developed as a promising technology to limit fault current levels in power systems. Though, quite a number of fault current limiters have been developed; the most common are the superconducting fault current limiters, solid-state fault current limiters, and saturated core fault current limiters. These fault current limiters present potential fault current limiting solutions in power systems. Nevertheless, they encounter various challenges hindering their deployment and commercialization. This research aimed at designing a bridge-type nonsuperconducting fault current limiter with a novel topology for distribution network applications. The proposed bridge-type nonsuperconducting fault current limiter was designed and simulated using PSCAD/EMTDC. Simulation results showed the effectiveness of the proposed design in fault current limiting, voltage sag compensation during fault conditions, and its ability not to affect the load voltage and current during normal conditions as well as in suppressing the source powers during fault conditions. Simulation results also showed very minimal power loss by the fault current limiter during normal conditions.
Short and open circuit faults study in the PV system inverter
Authors: Bouzidi Mohammed , Harrouz Abdelkader , Mohammed Tadj , Mansouri Smail
Published: October 2021

The inverter is the principal part of the photovoltaic (PV) systems that assures the direct current/alternating current (DC/AC) conversion (PV array is connected directly to an inverter that converts the DC energy produced by the PV array into AC energy that is directly connected to the electric utility). In this paper, we present a simple method for detecting faults that occurred during the operation of the inverter. These types of faults or faults affect the efficiency and cost-effectiveness of the photovoltaic system, especially the inverter, which is the main component responsible for the conversion. Hence, we have shown first the faults obtained in the case of the short circuit. Second, the open circuit failure is studied. The results demonstrate the efficacy of the proposed method. Good monitoring and detection of faults in the inverter can increase the system's reliability and decrease the undesirable faults that appeared in the PV system. The system behavior is tested under variable parameters and conditions using MATLAB/Simulink.
Primary frequency control of large-scale PV-connected multi-machine power system using battery energy storage system
Authors: Rahman S. M. Imrat , Hazari Md. Rifat , Hani Sumaiya Umme , Pathik Bishwajit Banik , Mannan Mohammad Abdul , Mahfuz Asif , Alam Mohammad Khurshed , Hassan Md. Kamrul
Published: October 2021

Large-scale grid-tied photovoltaic (PV) station are increasing rapidly. However, this large penetration of PV system creates frequency fluctuation in the grid due to the intermittency of solar irradiance. Therefore, in this paper, a robust droop control mechanism of the battery energy storage system (BESS) is developed in order to damp the frequency fluctuation of the multi-machine grid system due to variable active power injected from the PV panel. The proposed droop control strategy incorporates frequency error signal and dead-band for effective minimization of frequency fluctuation. The BESS system is used to consume/inject an effective amount of active power based upon the frequency oscillation of the grid system. The simulation analysis is carried out using PSCAD/EMTDC software to prove the effectiveness of the proposed droop control-based BESS system. The simulation result implies that the proposed scheme can efficiently curtail the frequency oscillation.  
Comparison of roughness index for Kitka and Koznica wind farms
Authors: Hoxha Bukurije , Dragusha Bedri
Published: October 2021

Kosovo has limited renewable energy resources and its power generation sector is based on fossil fuels. Such a situation emphasizes the importance of active research and efficient use of renewable energy potential. According to the analysis of meteorological data for Kosovo, it can be concluded that among the most attractive potential wind power sites are the locations known as Kitka (42° 29' 41" N and 21° 36' 45" E) and Koznica (42° 39′ 32″ N, 21° 22′30″E). The two terrains in which the analysis was carried out are mountain areas, with altitudes of 1142 m (Kitka) and 1230 m (Koznica). the same measuring height, about 84 m above the ground, is obtained for these average wind speeds: Kitka 6,667 m/s and Koznica 6,16 m/s. Since the difference in wind speed is quite large versus a difference in altitude that is not being very large, analyses are made regarding the terrain characteristics including the terrain relief features. In this paper it will be studied how much the roughness of the terrain influences the output energy. Also, that the assumption to be taken the same as to how much they will affect the annual energy produced.
Soft computing and IoT based solar tracker
Authors: Kumar Kanhaiya , Varshney Lokesh , Ambikapathy A. , Mittal Vrinda , Prakash Sachin , Chandra Prashant , Khan Namya
Published: October 2021

The significance of the solar energy is to intensify the effectiveness of the Solar Panel with the use of a primordial solar tracking system. Here we propounded a solar positioning system with the use of the global positioning system (GPS) , artificial neural network (ANN) and image processing (IP) . The azimuth angle of the sun is evaluated using GPS which provide latitude, date, longitude and time. The image processing used to find sun image through which centroid of sun is calculated and finally by comparing the centroid of sun with GPS quadrate to achieve optimum tracking point. Weather conditions and situation observed through AI decision making with the help of IP algorithms. The presented advance adaptation is analyzed and established via experimental effects which might be made available on the memory of the cloud carrier for systematization. The proposed system improve power gain by 59.21% and 10.32% compare to stable system (SS) and two-axis solar following system (TASF) respectively. The reduced tracking error of IoT based Two-axis solar following system (IoT-TASF) reduces their azimuth angle error by 0.20 degree.
Integration of artificial neural networks for multi-source energy management in a smart grid
Authors: Jarmouni Eziitouni , Mouhsen Ahmed , Lamhammedi Mohammed , Ouldzira Hicham
Published: October 2021

Among the most widespread renewable energy sources is solar energy; Solar panels offer a green, clean, and environmentally friendly source of energy. In the presence of several advantages of the use of photovoltaic systems, the random operation of the photovoltaic generator presents a great challenge, in the presence of a critical load. Among the most used solutions to overcome this problem is the combination of solar panels with generators or with the public grid or both. In this paper, an energy management strategy is proposed with a safety aspect by using artificial neural networks (ANNs), in order to ensure a continuous supply of electricity to consumers with a maximum solicitation of renewable energy.