bluuebunny/crossref_metadata_2025 huggingface dataset:
[Retracted] Machine Learning Algorithms Are Applied in Nanomaterial Properties for Nanosecurity
Authors: Prasad K. R. K. V. , Srinivasa Rao V. , Harini P. , Mukiri Ratna Raju , Ravindra K. , Vijaya Kumar D. , Kasirajan Ramachandran
Published: July 2022

Large and complicated datasets may now be generated utilising device reading machine learning approaches, which can subsequently be used to model and study substances in a variety of ways, along with people who require robotics and automation. For data analysis, there was a delay in implementing device learning methodologies since nanomaterials have not yet achieved the overall benefits of automation. There has been an explosion in the number of tools available for learning about nanomaterials, but there are still significant roadblocks in the way of actually putting those tools to use in a practical way. The homes of nanoparticles can be examined and anticipated with the help of system learning algorithms, and this painting shows how classic and deep system mastery techniques may be done to preserve nanomaterials. Among the topics covered are the history of nanoprotection, as well as a forecast for the future of artificial intelligence’s (AI) role in the field in the near future.
A Comprehensive Review of Mathematical Modeling for Drying Processes of Fruits and Vegetables
Authors: Akter Ferdusee , Muhury Ripa , Sultana Afroza , Deb Ujjwal Kumar
Published: July 2022

Drying fruits and vegetables is a procedure of food preservation with simultaneous heat, mass, and momentum transfer, which increases the shelf life of the food product. The aim of this review was to provide an overview of the researches on mathematical modeling for drying of fruits and vegetables with the special emphasis on the computational approach. Various heat-mass transport models, their applications, and modern drying technologies to the food industry have been reported in this study. Computational fluid dynamics, a new approach for solving heat and mass transfer problems, increases the accuracy of the predicted values. To investigate the parameters of drying needs a significant amount of time as well as costly laboratory and experimental efforts. Therefore, computational modeling could be an effective alternative to experimental approaches. This review will be beneficial for future studies in drying processes, especially for modeling, analysis, design, and optimization of food science and food engineering.
[Retracted] University Network and New Media Advertising Teaching Design Features and Influence: Environmental Perspective Analysis in Campus Humanistic Governance
Authors: Zhang Jing
Published: July 2022

Under the background of network development in the new era, the integration of multimedia technology and information technology promotes the development of teaching environment. Based on the influence of humanistic governance environment, the university network environment and the advertising teaching environment are constantly integrating new elements with the development of the times, becoming the key point to guarantee the teaching quality. In the research, the relevant data and information were collected and analyzed by the methods of inference and induction analysis. According to the sensory parameters of students’ cognitive emotions (n = 64, a > 0.847), the standard deviation was 0.810/0.695 and the action was 0.927/0.655. How to construct the university network and advertising teaching environment were explored. And, in view of the design of the environment characteristics as well as the impact on students, the purpose was to ensure that students had a good learning environment, which could improve the learning efficiency.
Efficacy and Safety of Vitamin D Adjuvant Therapy for Ulcerative Colitis: A Meta-Analysis
Authors: Guo Xinyi , Liu Changxing , Huang Yahui
Published: July 2022

Objective. To examine the clinical efficacy and safety of Vitamin D in the treatment of ulcerative colitis in a systematic manner. Methods. RCT studies on Vitamin D in the treatment of ulcerative colitis were searched from CNKI, Wanfang Data, PubMed, Cochrane Library, and Web of Science databases. RevMan 5.4 software was used for analysis. Results. 10 articles were included, including 1077 patients. Meta-analysis results showed that when clinical efficacy was used as the outcome index, the clinical efficacy of the oral vitamin group was higher than that of the conventional treatment group (

OR
=
4.07

, 95% CI 2.64-6.27), and the difference was statistically significant (

Z
=
6.38

,

P
<
0.00001

). When the Mayo risk score was used as the outcome index, the difference was statistically significant, indicating that oral Vitamin D significantly reduced the Mayo risk score (MD: -0.41,

CI
=

−
0.47

,

−

0.34

,

Z
=
13.09

,

P
<
0.00001

). Using the intestinal mucosal barrier as the outcome index, the results showed that (1) the MDA group (

MD
=
−
0.75

, 95% CI (-0.96~-0.53),

P
<
0.00001

), (2) the DAO group (

MD
=
−
1.17

, 95% CI (-1.39-0.95),

P
<
0.00001

), and the Vitamin D group could effectively improve intestinal mucosal barrier function after sensitivity analysis (

MD
=
−
1.00

, 95% CI (-1.08-0.92),

P
<
0.00001

). When inflammatory factors were used as outcome indicators, IL-6, TNF-α, and CRP groups had statistical significance (

MD
=
−
4.50

, 95% CI (-5.13-3.87),

P
<
0.00001

);

MD
=
−
7.27

, 95% CI (18.96-5.58),

P
<
0.00001

; and

MD
=
−
1.49

, 95% CI (-1.76~-1.23),

P
<
0.00001

, respectively). When the incidence of adverse reactions was used as the outcome indicator (

OR
=
0.73

, 95% CI (0.34-1.32),

P
=
0.23

), there was no significant difference between the two groups. Conclusion. Vitamin D combined with mesalazine is effective in the treatment of ulcerative colitis, by improving the Mayo score and intestinal barrier function, and reducing inflammatory factors, with no significant safety difference. However, due to the quality of the included researches, more RCT researches needed to provide sufficient evidence to support clinical application. This study is registered with INPLASY 202250044.
Laticifer Identification, Rubber Characterization, Phenolic Content, and Antioxidant Activity of Pergularia tomentosa Latex Extract
Authors: Lahmar Imen , Ben Nasri-Ayachi Mouhiba , Belghith Karima
Published: July 2022

Pergularia tomentosa is a perennial twining herb widely spread out arid and semiarid Tunisian regions. It is searched for its richness in enzymes, secondary metabolites, antifungal activity, and milk‐clotting activity. Traditional use implies the fresh latex in wounding heals. The present study was aimed at identifying laticifer distribution in Pergularia tomentosa stems, leaves, and petioles. In the present study, the identification of latex extract’s components and its valorisation by estimation of phenolic content, flavonoids, and antioxidant activity are conducted. Anatomical structures proved the presence of laticifers in the aerial parts of Pergularia tomentosa. They are particularly observed along the pith and cortical parenchyma in stem, in leaf mesophyll, and in petiole phloem. Identified laticifers were characterized as nonarticulated. FTIR spectroscopy proves the presence of several functional groups in the latex and mainly the cis-1‐4‐isoprene monomer. Results suggested that Pergularia tomentosa latex contributes significantly as a source of phenol content (62.3 mg Eq GAE/g) and flavonoids (24.8 mg Eq QE/g). Scavenging free radicals of DPPH exhibited IC50 value of 12 μg/ml. In conclusion, latex extracted from Pergularia tomentosa can be implied in industry as a natural rubber. It can be used, also, in medicine as a therapeutic agent.
One Hidden Semantic Model Based on Intergroup Effects for E-Commerce
Authors: Li Yanli , Zhang Wensong
Published: July 2022

E-commerce systems often collect data that clearly express user preferences without considering the remaining negative cases, which gives rise to the hidden semantic problem. In this paper, we improve the original hidden semantic model and propose an intergroup effect model that incorporates users’ historical browsing behavior, user type, and browsing content; by adopting the weighting and add weighting factors, we can predict users’ preferences for different products more accurately and match the candidate products with users’ current behaviors, so as to give more reasonable and effective product recommendation results; by adding the group effect model of user group and product group, we can achieve more accurate prediction of user preferences and make the recommendation more reasonable and effective. The research shows that the hidden semantic method based on intergroup effects information is better than other basic methods at a certain identified evaluation stage. In practice, users’ purchasing preferences change with time, and using a hidden semantic method based on intergroup effects recommendation can effectively improve the recommendation quality of e-commerce recommendation systems.
A Modified Seven-Level Inverter with Inverted Sine Wave Carrier for PWM Control
Authors: Vijayakumar Arun , Alexander Stonier Albert , Peter Geno , Kumaresan Praghash , Reyes Elenor M.
Published: July 2022

The conventional multilevel inverter necessitates more active switching devices and high dc-link voltages. To minimalize the employment of switching devices and dc-link voltages, a novel topology has been proposed. In this paper, a novel minimum switch multilevel inverter is established using six switches and two dc-link voltages in the proportion of 1 : 2. In addition, the proposed topology is proficient in making seven-level voltages by appropriate gate signals. The PWM signals were produced using several inverted sine carriers and a single trapezoidal reference. When compared to other existing inverters, this configuration needs fewer components, as well as fewer gate drives. Furthermore, this module can generate a negative level without the use of a supplementary circuit such as an H-Bridge. As a result, overall cost and complexity are greatly reduced. The proposed minimum switch multilevel inverter operation is validated through simulations followed by experimental results of a prototype.
Salvianolic Acid A Protects against Lipopolysaccharide-Induced Acute Lung Injury by Inhibiting Neutrophil NETosis
Authors: Liu Qiang , Zhu Cheng-long , Li Hui-ru , Xie Jian , Guo Yu , Li Peng , Zhao Zhen-zhen , Wang Jia-feng , Deng Xiao-ming
Published: July 2022

Salvianolic acid A (SAA) is one of bioactive polyphenol extracted from a Salvia miltiorrhiza (Danshen), which was widely used to treat cardiovascular disease in traditional Chinese medicine. SAA has been reported to be protective in cardiovascular disease and ischemia injury, with anti-inflammatory and antioxidative effect, but its role in acute lung injury (ALI) is still unknown. In this study, we sought to investigate the therapeutic effects of SAA in a murine model of lipopolysaccharide- (LPS-) induced ALI. The optimal dose of SAA was determined by comparing the attenuation of lung injury score after administration of SAA at three different doses (low, 5 mg/kg; medium, 10 mg/kg; and, high 15 mg/kg). Dexamethasone (DEX) was used as a positive control for SAA. Here, we showed that the therapeutic effect of SAA (10 mg/kg) against LPS-induced pathologic injury in the lungs was comparable to DEX. SAA and DEX attenuated the increased W/D ratio and the protein level, counts of total cells and neutrophils, and cytokine levels in the BALF of ALI mice similarly. The oxidative stress was also relieved by SAA and DEX according to the superoxide dismutase and malondialdehyde. NET level in the lungs was elevated in the injured lung while SAA and DEX reduced it significantly. LPS induced phosphorylation of Src, Raf, MEK, and ERK in the lungs, which was inhibited by SAA and DEX. NET level and phosphorylation level of Src/Raf/MEK/ERK pathway in the neutrophils from acute respiratory distress syndrome (ARDS) patients were also inhibited by SAA and DEX in vitro, but the YEEI peptide reversed the protective effect of SAA completely. The inhibition of NET release by SAA was also reversed by YEEI peptide in LPS-challenged neutrophils from healthy volunteers. Our data demonstrated that SAA ameliorated ALI via attenuating inflammation, oxidative stress, and neutrophil NETosis. The mechanism of such protective effect might involve the inhibition of Src activation.
Effect of Perioperative Dexmedetomidine Anesthesia on Prognosis of Elderly Patients with Gastrointestinal Tumor Surgery
Authors: Guo Lijia , Liu Yufei , Wang Meitan
Published: July 2022

It was to investigate the influence of perioperative dexmedetomidine (DEX) anesthesia on the prognosis of elderly patients with gastrointestinal tumor (GIT) surgery. 90 patients who underwent laparoscopic radical gastrectomy for GIT were included. They were randomly divided into the experimental group (45 cases) with DEX+general anesthesia, and the control group (45 cases) with epidural anesthesia+general anesthesia. The indicators after surgery were compared between the two groups. The mean arterial pressure (MAP) was

74.8
±
3.5

 mmHg and the heart rate (HR) was

52.7
±
8.2

beats/min-1 in the experimental group, significantly lower than those of the control group (

P
<
0.05

). The Visual Analog Scale (VAS) scores of both groups decreased greatly associated to those before surgery (

P
<
0.05

). The levels of cortisol (COR) and immune adhesion inhibitor (FEIR) in the experimental group were significantly dissimilar from those in the control group (

P
<
0.05

). The tumor necrosis factor-alpha (TNF-α) was

96.4
±
21.8

 ng/L in the experimental group, observably lower than that in the control group (

P
<
0.05

). The postoperative diamine oxidase (DAO) and D-lactate (D-lac) were

62.4
±
9.3

 μmol/mL and

33.8
±
7.2

 ng/L, respectively, in the experimental group, much lower than those in the control group (

P
<
0.05

). There were also significant differences in the initial recovery of bowel sounds, defecation, and total length of hospital stay (LOHS) between the groups (

P
<
0.05

). DEX anesthesia had ideal sedative and analgesic effects, improving the prognosis of patients during surgery, and shortening the LOHS. Thus, it deserved a clinical application value.
Utilization of 3D Laser Scanning for Stability Evaluation and Deformation Monitoring of Landslides
Authors: Guo Yanwei , Li Xiongwei , Ju Shangwei , Lyu Qifeng , Liu Tao
Published: July 2022

Three‐dimensional laser scanning technology can comprehensively and accurately monitor slope deformation. To conduct deformation monitoring and stability evaluation of the Changzhou Shunguoshan landslide, in this paper, the causes of the Changzhou Shunguoshan landslide were analyzed. Consequently, 3D laser scanning technology and the traditional monitoring methods such as data from the total station were compared. The point cloud data provides big data support for landslide deformation monitoring and landslide stability early warning. Meanwhile, the landslide stability was evaluated by analogy with existing studies on slope deformation monitoring data. Results show that the three‐dimensional laser scanning monitoring data is similar to the total station monitoring data. The overall deformation of the Shunguoshan landslide is no more than ± 0.0015 m; the deformation of the Liyang slope is less than ±0.09 m, which is far less than the analog slope deformation monitoring data. The slope construction and monitoring process are in a stable state.
Construction and Application of a Cloud Platform for English Teaching Supported by Computer Network Technology
Authors: Zhang Congying
Published: July 2022

With the rapid development of network technology, network users have higher and higher requirements for understanding and using the network. At present, the wide application of cloud technology provides the best solution for people. Network is the main carrier of information exchange and interpersonal communication and a new way for human beings to obtain information. The education community, like other industries, is increasingly recognizing the importance of cloud computing and constantly using these new capabilities in education and instruction. Cloud service group and WeChat group are the new mobile applications. This article introduces cloud computing technology into college English classroom, aiming to explore new methods of college English by using the new Internet technology. At the same time, it also discusses some problems existing in the current college English classroom, providing new ideas for the reform of college English classroom. This paper adopts J2EE technology in college English classroom teaching cloud platform application. Based on B/S model, a cloud university English teaching platform is established. The cloud platform English classroom teaching system covers three modules of English listening, English reading, and English writing, covering various fields of education and management. It has laid a solid foundation for the development of education informatization and network.
Comparison of Outcomes between Two Surgical Techniques for Patients with Intestinal Neuronal Dysplasia
Authors: Lin Yu , Wu Dianming , Shen Yong , He Yuanbin , Ye Jianxin
Published: July 2022

Objective. Hirschsprung disease (HSCR) is a serious congenital intestinal disease with a prevalence of 1/5000. HSCR remains one of the most severe congenital malformations of the abdominal organs in children that require complex reconstructive surgery. This study is aimed at investigating the clinical analysis of ileal Santulli stoma and ileal double-lumen stoma in children diagnosed with intestinal neuronal dysplasia (IND). Methods. Retrospective analysis was performed on the children who were admitted to our hospital for intestinal obstruction from January 2014 to January 2019, underwent fistula operation and fistula closure operation, and were diagnosed with IND. According to the different modes of fistula, the children were divided into ileal Santulli stoma group and ileal double-lumen stoma group. The body weight of the children in the two groups during the second stage of fistula closure operation was compared. The number of hospitalizations due to enteritis and dehydration during the two operations was compared. Results. A total of 23 cases (12 males and 11 females) were included in this study, including 10 cases in the Santulli group and 13 cases in the ileal double-lumen stoma group. There were no significant differences in baseline data and fistula location between the two groups. Compared with the ileal double-lumen stoma group, the Santulli stoma group had significantly higher weight of fistula precursor (

P
<
0.05

), the interval between two operations was shorter (

P
<
0.05

), there is less hospitalization for enteritis and dehydration during the two operations (

P
<
0.05

), and there is less economic cost after fistula (

P
<
0.05

). Conclusion. The clinical effect of ileum Santulli fistula is significantly better than double-lumen ileum fistula, which is not only beneficial to the growth and development of children after the first fistula but also can shorten the time of fistula closure, reduce the incidence of dehydration, and reduce the economic burden of family members. Therefore, it is worthy of clinical promotion and application.
Diverse Clinical Manifestations of Cardiofaciocutaneous Syndrome Type 3 in Two Patients from South East Asia
Authors: Tzen Elyn Y.-L. , Lim Jiin Yin , Cheah Sue Mei , Choo Jonathan T.L. , Kam Sylvia , Ng Zhi Min , Thomas Biju , Jamuar Saumya , Koh Ai Ling , Tan Ene-Choo
Published: July 2022

Background: Cardiofaciocutaneous syndrome (CFCS) is a rare genetic condition caused by mutations in BRAF, KRAS, MAP2K1, or MAP2K2. It is characterized by ectodermal abnormalities, cardiac defects, intellectual disability, and distinct craniofacial features. CFCS falls under a group of conditions caused by mutations in the RAS/MAPK pathway called RASopathies which share many features. In particular, CFCS has significant phenotypic overlaps with Costello syndrome (CS) and Noonan syndrome (NS). Objective: The aim of this study was to assess the patients’ phenotypic features for syndromic disorders and evaluate the use of molecular testing to clarify the clinical diagnosis. Method: The patients were recruited for genetic testing with written informed consent. Genomic DNA from venous blood was sequenced and potential variants were identified via targeted next-generation sequencing. Their phenotypic features were compared with other CFCS cases carrying pathogenic variants in the same gene. Results and Discussion: One patient had a de novo variant (c.370C>T; p.P124S) in MAP2K1 and presented with mild and typical features which do not significantly affect her quality of life. The second patient presented with severe features, including failure to thrive, feeding difficulties, epileptic spasms, septal hypertrophy, and global developmental delay, and developed chronic lung disease and sequelae from multiple infections. She had a severe disease course and severe global developmental delay. The discovery of a de novo variant (c.371C>A; p.P124Q) in MAP2K1, which had been reported in another patient with a similar phenotype, clarifies her clinical diagnosis. Her presentations add to existing reports that support expanding the CFCS phenotype to include features previously thought to be more suggestive of CS. Conclusion: The genetic findings for the 2 patients affirm the use of identified gene mutations to confirm the clinical diagnosis of syndromic disorders and add to the phenotypic spectrum of CFCS.
Development of Neuronal Excitability of the Bushy Cells in Anteroventral Cochlear Nucleus of Rats
Authors: Feng Yufei , Zhang Qiaodan , Lu Xiang , Li Xuyan , Liu Wenxin
Published: July 2022

The ultrafast and precise single-onset action potential (AP) of the bushy cells (BCs) in the anteroventral cochlear nucleus (AVCN) plays an important role in precise processing of temporal auditory information for localizing sound sources and communication cues. The specialized properties of high conductance of the low-voltage-activated potassium (K+LVA) channel contribute to generate ultrafast and precise single-onset APs in BCs. However, the developmental changes of K+LVA distribution and their contributions to shape neuronal excitability of BCs remain unclear. Therefore, we investigated the developmental changes in neuronal excitability of BCs and K+LVA distribution at different developmental periods. Using electrophysiological recording, we first characterized the firing pattern of BCs in response to a sequence of current injections at different developmental periods. The expression of the K+LVA subunit Kv1.1 in AVCN was examined with Western blot. The results indicated that BCs showed single-onset AP firing patterns and paused multiple APs firing patterns at the postnatal time of day 7 (P7) and were then refined into single-onset firing patterns at P14 and P21. With development, the active membrane properties, including latency and half-width of AP, and passive membrane properties, including capacitance, input resistance, and time constant, were significantly decreased. Furthermore, the refinement of firing patterns in BCs was correlated with the upregulation of the Kv1.1 channel in AVCN. In summary, the present study indicated that BCs optimize precise and single-onset firing with development, possibly driven by the changes in membrane properties and upregulation of Kv1.1 in AVCN.
Empirical studies on the effect of electromagnetic radiation from multiple sources in Dhaka
Authors: Quamruzzaman Mohammad , Hossain Shohag , Rahaman S. M. Sahidur , Haque Munima
Published: July 2022

Just after the invention of electricity by Michael Faraday, there has been a revolution in the communication technology, which lead to the invention of radio, television, radar, satellite, and mobile. While these machines transformed our life high quality, safer and simpler, they have been associated with alarming probable health hazards owing to their electromagnetic radiation (EMR) emission. Couple of cases it has been reported by personals regarding various health related issues relating to exposure on electromagnetic field (EMF) and EMR. Although couple of persons showed light symptoms and respond by avoiding the electrical field (EF) and EMR fields as much as possible, some others are so much affected that they have changed their entire lifestyle. In this paper, empirical survey study has been carried out in the laboratories of Daffodil International University (DIU) main and permanent campus. It was found that some of the instrument had higher EMFs. The findings from this survey may be helpful for the students to take precautionary measurement who work for long duration in the various laboratories for their practical classes and for the users of the domestic appliances as well as office equipment and industrial instruments.
Restaurant food ordering method using NFC technology
Authors: Sangulagi Prashant , Kalyane Sangamesh J , Bhavikatti Arvind M , Sharad Shivpuje Pooja
Published: July 2022

Mobile apps of various kinds continue to emerge as smartphones become more popular and mobile telecommunication matures. NFC is the most common wireless technology used in smartphones presently. It is used in mobile devices having built-in NFC to allow consumers to input payments, receive messages, and do nearer device recognition, among other things. The paper proposes the NFC technology-based food ordering system for all the customers who want to have food at their residence only. The results show that the application works properly in finding the nearby restaurants and completing the food order without any hustle.
Dynamic modeling of an open cathode PEM fuel cell for automotive energy management applications
Authors: Rifai Nada , Sabor Jalal , Alaoui Chakib , Petrone Raffaele , Gualous Hamid
Published: July 2022

Among the different clean energy conversion devices, fuel cells systems are largely employed due to their high-power densities and efficiencies. Several models are available in literature to characterize their functioning, both for stationary and dynamic behaviors. Vehicular application of a fuel cell requires a model that is accurate enough, and simple enough for quick computations for real-time reporting. To meet these constraints, the model of the different sources must be simple and efficient as they are used in the energy management strategy block to estimate the power references to be requested from the sources. The objective of this paper is then to develop a fuel cell model that is both efficient at representing the dynamic and static behavior of the fuel cell, and low consuming in terms of storage space and computation time. The aim is to have a suitable model for use in online simulations for vehicle energy management applications. The proposed model is compared to a representative dynamic model, and the results approve the performance of the model. An experimental test bench is performed to evaluate and validate the proposed model. The model shows good agreement with the experimental data.
Universal phase shifter regulator system modeling with robust GPC using neural networks for compensation power in transmission line
Authors: Abdelkrim Bouanane , Madani Nerziou , Merzoug Yahiaoui , Driss Raouti
Published: July 2022

Electricity consumption is increasing gradually and this trend will continue in the future. In addition, rapid network control systems using the resources offered by power electronics and control microelectronics have been recently studied and developed, and are currently in normal application for some, for others, in pilot applications or as prototypes. This paper attempts to show that these systems are referred to by the general acronym flexible alternative current transmission systems (FACTS) similarly dethroned the traditional systems while offering better solutions and solving the energy quality problem such as the hybrid system (unified power flow controller (UPFC), or universal phase shifter regulator (UPSR)) which opens up new perspectives for more efficient operation of networks by continuous and rapid action on the various parameters of the network (voltage, phase shift, and impedance); thus, the power transits will be better controlled and the voltages better held, which will make it possible to increase the stability margins or tend towards the thermal limits of the lines. In this work, we used a classic control (PI-decoupled) and others while offering more flexibility of control thanks to the development of strategies identification/control based on generalized predictive control (GPC) with neural network to ensure robust control with advanced algorithms.
A novel overvoltage protection scheme for power electronics switching under differential surge conditions
Authors: Kuan Teik Hua , Chew Kuew Wai , Chua Kein Huat
Published: July 2022

The proposed scheme is employed for the efficient operation of a DC-DC-based buck converter. This protection scheme shows the optimal placement of a varistor in the power electronics converter side under different surge conditions. Advanced varistors have excellent electrical material properties and electrothermal behavior for the enhancement of power absorption capability. Varistors have been examined widely in the last four decades that are employed for surge protection applications. The advantage of power surge protection using varistor-based power devices is vital due to the great sensitivity of the equipment integrated into the grid and emerging power electronics-based DC systems with low and high voltage ratings. In this research, a varistor can be placed to protect the switching devices such as MOSFETs in power electronic-based buck converter side due to uncertain overvoltage under differential surge. The proposed MATLAB simulation study shows the peak voltage stress on the grid due to the surge and its enhancement scheme.
Performance analysis of capacitor voltage balancing in modular multilevel converter by sorting algorithm
Authors: Al-Khayyat Ali Salam , Ridha Amel Ahmad , Fadel Haider
Published: July 2022

Due to the modularity of modular multilevel converter (MMC), therefore it has been considered as a substitute for the diode-clamp multilevel inverter in applications of high-voltage high-power. Where it can obtain any level of voltage without imposing complexity on the control system. This study analyses in detail the operation principle and balances the capacitor voltage of sub-module (SM) in modular multilevel converter by sorting algorithm. The output voltage control and capacitor voltage balancing technique are confirmed by MATLAB/Simulink and the obtained result has been discussed, where the capacitor voltage of the sub-module has controlled within the acceptable deviation limit, which is 5-10%. In addition, the circulating current has been controlled and reduced.
Modeling and simulation of a stand-alone wind turbine supplying an inductive load through a long cable
Authors: Al-Omari Zakaria , Emar Walid
Published: July 2022

This paper considers the principles of modeling, control, and simulation of variable speed wind turbines (VSWTs), based on a stand-alone doubly fed induction generator (DFIG). The DFIG is used to feed a three-phase highly inductive load through a long cable via a three-phase multi-level frequency converter (MLFC). The proposed MLFC increases the number of voltage levels with less power electronic components as compared to the conventional back-to-back AC/DC/AC converter. The length of the cable (transmission line TL) influences a mismatch between the load and TL impedances; therefore, a reflected signal will occur. If the "incident signal" is a "continuous AC waveform", these waveforms will mix with another oncoming "incident waveform", creating stationery waveforms called "standing waves". The simulation process shows that the value of the transient’s over-voltage that appears either on the windings of the DFIG or across the load reaches twice the DC-link voltage periodically, which may cause premature failure of the DFIG windings and cable insulations. Usually, this is produced by generating high harmonics within the loads. Therefore, the main benefit of using the MLFC is the significant reduction of the total harmonic distortion and enhancement of the load voltage waveforms. This was verified, primarily by using the "MATLAB/Simulink, Simplorer 7" simulation software.
Wind energy management of a standalone system operating at maximum power point
Authors: Albalawi Hani , Zaid Sherif A. , Buswig Yonis M. , El-Rab Hassan Wedaa , Lakhouit Abderrahim , Arshad Muhammed Ayas
Published: July 2022

In this paper, the management and control of a standalone wind energy system versus variations of wind speed and load are investigated. The system includes a wind turbine coupled to a variable-speed permanent magnet synchronous generator (PMSG), rectifier, boost converter, power inverter, and an energy storage system (ESS). The ESS is a very important part to achieve system stability and support the maximum power point tracking (MPPT) operation. A simple off-line MPPT algorithm is introduced that can be accomplished using the boost converter. The system dynamic model is derived then the control and energy management algorithms are introduced to improve the system performance. The MATLAB platform has been utilized to simulate the proposed system under different disturbances in the load power and wind speed. The results show perfect management of the system energy, good performance of the DC link voltage, stable load voltage, and load frequency.
New improved MPPT based on artificial neural network and PI controller for photovoltaic applications
Authors: Idrissi Yassine El Aidi , Assalaou Khalid , Elmahni Lahoussine , Aitiaz Elmostafa
Published: July 2022

This paper details an maximum power point tracking (MPPT) approach based on artificial neural network (ANN) to track the maximum power produced by a PV panel. This approach is rapid and accurate for following the maximum power point (MPP) during changes in weather conditions such as solar irradiation and temperature. A PV system structure including an MPPT controller is studied, designed, and simulated in this work. The aim of this paper is to use the artificial neural network (ANN) technique to develop a MPPT controller for PV applications. To increase the performance of the ANN-MPPT controller, a proportional integral (PI) controller is also included. In addition, the performance of an ANN-based MPPT controller is also compared to the conventional perturb and observe (P&O) method. To analyze the results, simulations are performed by using MATLAB software.
Fault-tolerant control with high-order sliding mode for manipulator robot
Authors: Omali Khaoula Oulidi , Kabbaj Mohammed Nabil , Benbrahim Mohammed
Published: July 2022

The safety of manipulators systems is receiving a lot of attention these days. Faults have the ability to carry out harmful activities that harm equipment, the environment, or persons. As a result, it is critical to detect and diagnose problems as soon as possible, as well as to incorporate fault tolerance to avoid performance deterioration and harmful circumstances. Robust sensor fault detection and isolation (FDI) as well as fault-tolerant control (FTC) for a robotic system are discussed in this work. The goal of this research is to create an FDI method that uses a super-twisting third-order sliding mode (STW-TOSM) observer to estimate residual signals. A suggested system based on a higher-order sliding mode (HOSM) observer/controller approaches is used to accomplish this. In comparison to an active FTC technique, the test results demonstrate high level of performance. Finally, simulation results illustrate the efficacy of the presented techniques.
Design of a photovoltaic mppt charge controller using DC-DC zeta converter with a modified three-stage charging method
Authors: Semeskandeh Sina , Hojjat Mehrdad , Abardeh Mohamad Hosseini
Published: July 2022

Nowadays, one of the primary kinds of renewable energies is photovoltaic (PV) systems. In standalone PV systems, the battery charge controller plays an important role in the system efficiency. In the maximum power point tracking (MPPT) charge controller, due to adjusting the voltage level and tracking the maximum power, DC-DC converter and MPPT algorithm are used. ZETA converter, as a DC-DC converter, offers a low output ripple. In the proposed MPPT charge controller, a DC-DC ZETA converter accompanied by a P&O (perturb and observe) algorithm will be used for tracking maximum power. Furthermore, over-charging and gassing are phenomena that may reduce the battery life by increasing the battery's temperature. To overcome this obstacle, the proposed three-stage charging method, which is the battery charging voltage levels (bulk, absorption, and float) are based on the battery temperature. The proposed MPPT charge controller is used for providing lower temperature for the battery when being charged. By comparing the proposed MPPT charge controller with the conventional method, the simulation results can ensure the desired performance of the proposed charge controller.
Development and optimization of specially designed air ventilation system combined with thermoelectric and composite desiccant unit
Authors: Tongdee Dararat , Maneewan Somchai , Chirarattananon Surapong , Punlek Chantana
Published: July 2022

This research focused on the enhancement of a conventional air ventilation system by using monitoring control. A specially designed system was developed to optimize the current systems in order to improve the air quality and thermal comfort in buildings. Indoor parameters, such as temperature, humidity, and air pollution (CO2), were monitored and controlled. Researchers accumulated data and implemented performance analysis as a tool for assessing specially designed air ventilation systems. These practices were designed based on a concept that is dedicated outdoor air systems that were comprised of a composite desiccant unit in addition to a thermoelectric module to address tremendous latent and sensible loads of air inlet. The results of the experiment indicated that the 12 V of electrical supply to thermoelectric provided the highest COP of the system, and the temperature and humidity in the comfort zone was approximately 27 ๐C and 55%, respectively, due to this newly developed system. Furthermore, the CO2 levels were lower than 1000 ppm during this research study, which were in accordance with established standards of indoor air quality.
Load current balancing for 4-wire systems using harmonic treated TCR based SVCs
Authors: Obais Abdulkareem Mokif , Mukheef Ali Abdulkareem
Published: July 2022

In this paper, a harmonic-treated thyristor-controlled reactor TCR is presented as a linearized harmonic-free compensating susceptance controllable in inductive and capacitive modes. The harmonic-treated TCR is a traditional TCR conditioned in such a manner that it can respond continuously and linearly to capacitive and inductive reactive current demands without noticeable harmonic association or active power contribution. The conditioned configuration is produced by equipping the TCR with self-harmonic suppressing and filtering circuitries, which guarantee harmonic cancellation with minimal no load operating losses. The harmonic treated TCR avoids the need to high power harmonic filters required to treat the harmonics of the traditional TCR. The devised susceptances are used to build a load current balancing system for grounded loads in a 380-V, 50Hz power distribution system. Both the compensating susceptances and the load current balancing system were designed and tested on PSpice. The simulation results have demonstrated the linearity, control continuity, and harmonic cancellation of the proposed harmonic-treated TCR as a fast response compensating susceptance reliable for load current balancing purposes. The proposed load current balancing system revealed superior treatment to various unbalance conditions, thus it is deservedly promoted to have the feasibility of supporting grids having fast varying loads.
PLCβ2 Promotes VEGF-Induced Vascular Permeability
Authors: Phoenix Kathryn N. , Yue Zhichao , Yue Lixia , Cronin Chunxia G. , Liang Bruce T. , Hoeppner Luke H. , Claffey Kevin P.
Published: July 2022

Background:

Regulation of vascular permeability is critical to maintaining tissue metabolic homeostasis. VEGF (vascular endothelial growth factor) is a key stimulus of vascular permeability in acute and chronic diseases including ischemia reperfusion injury, sepsis, and cancer. Identification of novel regulators of vascular permeability would allow for the development of effective targeted therapeutics for patients with unmet medical need.

Methods:

In vitro and in vivo models of VEGFA-induced vascular permeability, pathological permeability, quantitation of intracellular calcium release and cell entry, and phosphatidylinositol 4,5-bisphosphate levels were evaluated with and without modulation of PLC (phospholipase C) β2.

Results:

Global knock-out of
PLCβ2
in mice resulted in blockade of VEGFA-induced vascular permeability in vivo and transendothelial permeability in primary lung endothelial cells. Further work in an immortalized human microvascular cell line modulated with stable knockdown of PLCβ2 recapitulated the observations in the mouse model and primary cell assays. Additionally, loss of PLCβ2 limited both intracellular release and extracellular entry of calcium following VEGF stimulation as well as reduced basal and VEGFA-stimulated levels of phosphatidylinositol 4,5-bisphosphate compared to control cells. Finally, loss of PLCβ2 in both a hyperoxia-induced lung permeability model and a cardiac ischemia:reperfusion model resulted in improved animal outcomes when compared with wild-type controls.

Conclusions:

The results implicate PLCβ2 as a key positive regulator of VEGF-induced vascular permeability through regulation of both calcium flux and phosphatidylinositol 4,5-bisphosphate levels at the cellular level. Targeting of PLCβ2 in a therapeutic setting may provide a novel approach to regulating vascular permeability in patients.
Glaciogenic Seeding of Cold-Season Orographic Clouds to Enhance Precipitation: Status and Prospects
Authors: Geerts Bart , Rauber Robert M.
Published: July 2022

This essay is intended to provide stakeholders and news outlets with a plain-language summary of orographic cloud seeding research, new capabilities, and prospects. Specifically, we address the question of whether a widely practiced type of weather modification, glaciogenic seeding of orographic clouds throughout the cold season, can produce an economically useful increase in precipitation over a catchment-scale area. Our objective is to clarify current scientific understanding of how cloud seeding may affect precipitation, in terms that are more accessible than in the peer-reviewed literature. Public confidence that cloud seeding “works” is generally high in regions with operational seeding, notwithstanding decades of scientific reports indicating that the changes in precipitation are uncertain. Randomized seeding experiments have a solid statistical foundation and focus on the outcome, but, in light of the small seeding signal and the naturally noisy nature of precipitation, they generally require too many cases to be affordable, and therefore are discouraged. A complementary method, physical evaluation, examines changes in cloud and precipitation processes when seeding material is injected and yields insights into the most suitable ambient conditions. Recent physical evaluations have established a robust, well-documented scientific basis for glaciogenic seeding of cold-season orographic clouds to enhance precipitation. The challenge of seeding impact assessment remains, but evidence is provided that, thanks to recent significant progress in observational and computational capabilities, the research community is finally on track to be able to provide stakeholders with guidance on the likely quantitative precipitation impact of cloud seeding in their region. We recommend further process-level evaluations combined with highly resolved, well-constrained numerical simulations of seasonal cloud seeding.
Environmental Analysis of Warm-Season First Cloud-To-Ground Lightning Events over the Western Florida Peninsula
Authors: Chavez Ivan , Milrad Shawn M. , Halperin Daniel J. , Mroczka Bryan , Tyle Kevin R.
Published: July 2022

Florida annually leads the United States in lightning-caused fatalities. While many studies have examined the lightning frequency maximum near Cape Canaveral, relatively little attention has been paid to the western Florida peninsula, which features a similar warm-season lightning event density. Of particular concern are first cloud-to-ground (FCG) lightning events in developing thunderstorms, which are difficult to predict with sufficient lead time and can catch people off guard. This study performs an environmental analysis of warm-season (May–September) FCG events (2014–21) across the western Florida peninsula using high-resolution model analysis data, including a comparison to null (No CG) days. FCG events and No CG days are first identified from ground-based lightning data and partitioned into nine synoptic-scale flow regimes. Next, spatiotemporal distributions of FCG events are elucidated for the western Florida peninsula. An ingredients-based analysis shows that the convective environment one hour before FCG events during strong south-southeast flow features the largest amounts of moisture, but the smallest instability values and weak midtropospheric lapse rates, primarily due to warm advection and moisture transport from the Atlantic Ocean. Environments one hour before FCG events in all nine flow regimes feature markedly greater instability values, larger relative humidity values, and steeper midtropospheric lapse rates than do No CG days. Results emphasize that instability and moisture are the key ingredients for warm-season FCG events in the region. Convective parameter statistical distributions and composite soundings populate an online dashboard that can be used by regional forecasters to better predict FCG events and increase alert lead times.

Significance Statement

Florida annually leads the United States in lightning fatalities. Of particular concern are first cloud-to-ground (FCG) lightning events, which are difficult to forecast and can catch people off guard especially during outdoor recreational activities and labor. We investigate the environmental characteristics of warm-season FCG events across the western Florida peninsula. Among nine regional flow patterns, some are associated with a less moist and more unstable atmosphere one hour before an FCG event, while other regimes exhibit a more moist and less unstable atmosphere. However, regardless of flow pattern, FCG events consistently feature substantially greater instability and moisture than do null events. Key findings are displayed on an online dashboard, to better inform regional forecasters.