bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasmacytoma Variant Translocation 1 (PVT1) Gene as a Potential Novel Target for the Treatment of Diabetic Nephropathy
Authors: Mok Helen , Al-Jumaily Ahmed , Lu Jun
Published: October 2022

Introduction: Diabetic nephropathy (DN), a severe microvascular complication in patients with diabetes, is clinically characterized by progressive decline in glomerular filtration rate (GFR). DN is the most common cause of end-stage renal disease (ESRD), and has a consistently high mortality rate. Despite the fact that the prevalence of DN is increasing worldwide, the molecular mechanism underlying the pathogenesis of DN is not fully understood. Previous studies indicated PVT1 as a key determinant of ESRD as well as a mediator of extracellular matrix (ECM) accumulation in vitro. More investigations into the role of PVT1 in DN development are needed. Objectives: To study the effect of PVT1 silencing on progression of DN in diabetic male C57BL/6 mice at early, intermediate and relatively advanced ages. Methods: Diabetic mice were treated with either scramble-siRNA (DM + siRNA (scramble)) or PVT1-siRNA (DM + siRNA (PVT1)), whereas the control mice were normal mice without siRNA injection (Control). Blood, urine and kidney were collected at the age of 9 (young), 16 (middle-aged) or 24 (old) weeks old. Kidney function, histology and molecular gene expression were evaluated. Results: Our findings showed that silencing of PVT1 reduced kidney hypertrophy, proteinuria (UAE, UACR, UPE, UPCR), serum creatinine, serum TGF-β1, serum insulin decline, glomerular and mesangial areas, and increased creatinine clearance in diabetic mice to levels closer to the age-matched controls. Also, silencing of PVT1 markedly suppressed the upregulation of PAI-1, TGF-β1, FN1, COL4A1, and downregulation of BMP7. Conclusion: Silencing of PVT1 ameliorates DN in terms of kidney function and histology in diabetic mice. The renoprotection is attributed to the reduction in ECM accumulation, TGF-β1 elevation and insulin decline. PVT1 is suggested to play an important role in ECM accumulation which makes it a possible target for the treatment of DN.
Structural and Heat Transfer Model Analysis of Wall-Mounted Solar Chimney Inlets and Outlets in Single-Story Buildings
Authors: Fang Zhicheng , Wang Wanjiang , Chen Yanhui , Song Junkang
Published: October 2022

Wall-mounted solar chimneys use solar radiation to heat the air inside the chimney cavity and use thermal pressure to create natural convection. Applying this principle allows for the indoor ventilation of a building without energy consumption. However, in wall-mounted solar chimney designs, different air inlet and outlet design dimensions can have varying degrees of impact on the effectiveness of wall-mounted solar chimney ventilation. In order to analyze the internal airflow state and airflow temperature field distribution of wall-mounted solar chimneys, physical models of wall-mounted solar chimneys with six different air outlet-to-inlet cross-sectional area ratios were developed in this research work. Before numerical simulation analysis, heat transfer analysis of the wall-mounted solar chimney’s structural components and airflow channels was carried out, and corresponding mathematical heat transfer models were established. The internal flow state and temperature distribution characteristics of a wall-mounted solar chimney were analyzed by steady-state simulations using the computational fluid dynamics software, Ansys Fluent. Finally, transient simulation calculation analysis was conducted under six different S-value models to investigate the variation in the natural ventilation of a single-story building’s wall-mounted solar chimney for a whole day. The study showed that under the same simulation conditions, 80% ≤ S < 100% effectively avoided the formation of vortices in the internal airflow of the wall-mounted solar chimneys and kept the ventilation effect of wall-mounted solar chimneys at a high level. The results of this study provide a reference for the optimization of research on the design of the air inlet and outlet structures of wall-mounted solar chimneys for single-story buildings.
Zinc Finger Proteins: Functions and Mechanisms in Colon Cancer
Authors: Liu Shujie , Sima Xiaonan , Liu Xingzhu , Chen Hongping
Published: October 2022

According to the global cancer burden data for 2020 issued by the World Health Organization (WHO), colorectal cancer has risen to be the third-most frequent cancer globally after breast and lung cancer. Despite advances in surgical treatment and chemoradiotherapy for colon cancer, individuals with extensive liver metastases still have depressing prognoses. Numerous studies suggest ZFPs are crucial to the development of colon cancer. The ZFP family is encoded by more than 2% of the human genome sequence and is the largest transcriptional family, all with finger-like structural domains that could combine with Zn2+. In this review, we summarize the functions, molecular mechanisms and recent advances of ZFPs in colon cancer. We also discuss how these proteins control the development and progression of colon cancer by regulating cell proliferation, EMT, invasion and metastasis, inflammation, apoptosis, the cell cycle, drug resistance, cancer stem cells and DNA methylation. Additionally, several investigations have demonstrated that Myeloid zinc finger 1 (MZF1) has dual functions in colon cancer, which may both promote cancer proliferation and inhibit cancer progression through apoptosis. Generally, a comprehensive understanding of the action mechanisms of ZFPs in colon cancer will not only shed light on the discovery of new diagnostic and prognosis indicators but will also facilitate the design of novel targeted therapies.
A Negative Body Image among Adolescent and Young Adult (AYA) Cancer Survivors: Results from the Population-Based SURVAYA Study
Authors: Saris Laura M. H. , Vlooswijk Carla , Kaal Suzanne E. J. , Nuver Janine , Bijlsma Rhodé M. , van der Hulle Tom , Kouwenhoven Mathilde C. M. , Tromp Jacqueline M. , Lalisang Roy I. , Bos Monique E. M. M. , van der Graaf Winette T. A. , Husson Olga
Published: October 2022

Adolescent and young adult (AYA) cancer survivors (18–39 years at diagnosis) often experience negative body changes such as scars, amputation, and disfigurement. Understanding which factors influence body image among AYA survivors can improve age-specific care in the future. Therefore, we aim to examine the prevalence, and association of a negative body image with sociodemographic, clinical, and psychosocial factors, among AYA cancer survivors (5–20 years after diagnosis). A population-based cross-sectional cohort study was conducted among AYA survivors (5–20 years after diagnosis) registered within the Netherlands Cancer Registry (NCR) (SURVAYA-study). Body image was examined via the EORTC QLQ-C30 and QLQ-SURV100. Multivariable logistic regression models were used. Among 3735 AYA survivors who responded, 14.5% (range: 2.6–44.2%), experienced a negative body image. Specifically, AYAs who are female, have a higher Body Mass Index (BMI) or tumor stage, diagnosed with breast cancer, cancer of the female genitalia, or germ cell tumors, treated with chemotherapy, using more maladaptive coping strategies, feeling sexually unattractive, and having lower scores of health-related Quality of Life (HRQoL), were more likely to experience a negative body image. Raising awareness and integrating supportive care for those who experience a negative body image into standard AYA survivorship care is warranted. Future research could help to identify when and how this support for AYA survivors can be best utilized.
Polygodial, a Sesquiterpene Dialdehyde, Activates Apoptotic Signaling in Castration-Resistant Prostate Cancer Cell Lines by Inducing Oxidative Stress
Authors: Venkatesan Reshmii , Hussein Mohamed Ali , Moses Leah , Liu Jennifer S. , Khetani Salman R. , Kornienko Alexander , Munirathinam Gnanasekar
Published: October 2022

Prostate cancer (PCa) is the second leading cause of cancer death among men in the United States. Surgery, radiation therapy, chemotherapy, and androgen deprivation therapy are currently the standard treatment options for PCa. These have poor outcomes and result in the development of castration-resistant prostate cancer (CRPC), which is the foremost underlying cause of mortality associated with PCa. Taxanes, diterpene compounds approved to treat hormonal refractory PCa, show poor outcomes in CRPC. Polygodial (PG) is a natural sesquiterpene isolated from water pepper (Persicaria hydropiper), Dorrigo pepper (Tasmannia stipitata), and mountain pepper (Tasmannia lanceolata). Previous reports show that PG has an anticancer effect. Our results show that PG robustly inhibits the cell viability, colony formation, and migration of taxane-resistant CRPC cell lines and induces cell cycle arrest at the G0 phase. A toxicity investigation shows that PG is not toxic to primary human hepatocytes, 3T3-J2 fibroblast co-cultures, and non-cancerous BPH-1 cells, implicating that PG is innocuous to healthy cells. In addition, PG induces oxidative stress and activates apoptosis in drug-resistant PCa cell lines. Our mechanistic evaluation by a proteome profiler–human apoptotic array in PC3-TXR cells shows that PG induces upregulation of cytochrome c and caspase-3 and downregulation of antiapoptotic markers. Western blot analysis reveals that PG activates apoptotic and DNA damage markers in PCa cells. Our results suggest that PG exhibits its anticancer effect by promoting reactive oxygen species generation and induction of apoptosis in CRPC cells.
Deep Learning Approaches in Histopathology
Authors: Ahmed Alhassan Ali , Abouzid Mohamed , Kaczmarek Elżbieta
Published: October 2022

The revolution of artificial intelligence and its impacts on our daily life has led to tremendous interest in the field and its related subtypes: machine learning and deep learning. Scientists and developers have designed machine learning- and deep learning-based algorithms to perform various tasks related to tumor pathologies, such as tumor detection, classification, grading with variant stages, diagnostic forecasting, recognition of pathological attributes, pathogenesis, and genomic mutations. Pathologists are interested in artificial intelligence to improve the diagnosis precision impartiality and to minimize the workload combined with the time consumed, which affects the accuracy of the decision taken. Regrettably, there are already certain obstacles to overcome connected to artificial intelligence deployments, such as the applicability and validation of algorithms and computational technologies, in addition to the ability to train pathologists and doctors to use these machines and their willingness to accept the results. This review paper provides a survey of how machine learning and deep learning methods could be implemented into health care providers’ routine tasks and the obstacles and opportunities for artificial intelligence application in tumor morphology.
Upregulation of Nav1.6 Mediated by the p38 MAPK Pathway in the Dorsal Root Ganglia Contributes to Cancer-Induced Bone Pain in Rats
Authors: Lin Mingxue , Chen Xiaohui , Wu Shuyan , Chen Pinzhong , Wan Haiyang , Ma Simeng , Lin Na , Liao Yanling , Zheng Ting , Jiang Jundan , Zheng Xiaochun
Published: October 2022

Cancer-induced bone pain (CIBP) occurs frequently among advanced cancer patients. Voltage-gated sodium channels (VGSCs) have been associated with chronic pain, but how VGSCs function in CIBP is poorly understood. Here, we aimed to investigate the specific role of VGSCs in the dorsal root ganglia (DRGs) in CIBP. A CIBP rat model was generated by the intratibial inoculation of MRMT-1 breast carcinoma cells. Transcriptome sequencing was conducted to assess the gene expression profiles. The expression levels of key genes and differentiated genes related to activated pathways were measured by Western blotting and qPCR. We implanted a catheter intrathecally for the administration of lentivirus and drugs. Then, the changes in the mechanical withdrawal threshold (MWT) were measured. We identified 149 differentially expressed mRNAs (DEmRNAs) in the DRGs of CIBP model rats. The expression of Nav1.6, which was among these DEmRNAs, was significantly upregulated. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of the DEmRNAs showed that they were mainly enriched in the mitogen-activated protein kinase (MAPK) pathway. The decrease in MWT induced by bone cancer was attenuated by Nav1.6 knockdown. Western blot analysis revealed that a p38 inhibitor decreased the expression of Nav1.6 and attenuated pain behavior. Our study shows that the upregulation of Nav1.6 expression by p38 MAPK in the DRGs of rats contributes to CIBP.
Engineering Raspberry-like Plasmonic Nanoclusters as Tags in Surface-Enhanced Raman Scattering-Based Immunoassays
Authors: Xu Jingwen , Huang Shizhen , Gao Zhida , Song Yanyan
Published: October 2022

Surface-enhanced Raman scattering (SERS) is highly attractive with the advantages of non-destructive performance, high specificity, and ultra-sensitivity. However, it is still a great challenge to design SERS tags with strong and undisturbed SERS signals via a simple method for an SERS-based immunoassay. Herein, a simple one-pot method was developed for the fabrication of SERS nanotags with interior reporters located at the nanogaps between plasmonic structures. Benefiting from the reducibility and easy-to-polymerize properties of aniline, Au3+ ions were reduced and grew into small-sized Au nanoparticles with a thin layer of polyaniline (PANI) by using aniline as the reductant. Following the continuous polymerization and the reduction reactions, PANI-coated Au nanoparticles were assembled into a nanocluster with sub 5 nm gaps, and PANI located at these gaps were used as interior reporters in SERS tags. As proof-of-concept, a histidine-tagged antigen was used as the model analyte for the SERS-based immunoassay. The proposed sensing platform showed the response to the histidine-tagged antigen ranging from 0.1 to 1000 ng mL−1 with a detection limit of 0.01 ng mL−1. The remarkable and undisturbed SERS signals make the proposed SERS tags feasible for detections of biomarkers with a low concentration in complex biological samples.
Building a Sensor Benchmark for E-Nose Based Lung Cancer Detection: Methodological Considerations
Authors: Martin Justin D. M. , Romain Anne-Claude
Published: October 2022

Lung cancer is one of the deadliest form of cancer in Europe, characterized by a lack of obvious symptoms until the terminal stages of the illness. Electronic noses are a rising screening technology to detect early-stage lung cancer directly in the homes of people at risk. Electronic noses need to be tested using samples from patients. However, obtaining numerous samples from cancer patient turns out to be a difficult task in practice. Therefore, the development of a sensor benchmark able to evaluate the performance of sensors without direct breath sampling is of high interest. This paper focuses on the methodology for developing such a benchmark, in the case of a breath sampling electronic nose. The setup used is introduced and general recommendations based on literature and undergoing experiments is detailed. The benchmark can be used for a variety of sensors and a variety of target illnesses. It is also possible to apply it to other types of medical gaseous samples or environmental VOC monitoring. The benchmark is currently still undergoing tests, and results will be published in a following article.
Piperazine Derivative Stabilizes Actin Filaments in Primary Fibroblasts and Binds G-Actin In Silico
Authors: Zernov Nikita , Ghamaryan Viktor , Makichyan Ani , Melenteva Daria , Hunanyan Lernik , Popugaeva Elena
Published: October 2022

Alzheimer’s disease (AD) is characterized by synaptic dysfunction, which is expressed through the loss of dendritic spines and changes in their morphology. Pharmacological compounds that are able to protect spines in the AD brain are suggested to be novel drugs that would be able to slow down the disease progression. We have recently shown that a positive modulator of transient receptor potential cation channel subfamily C member 6 (TRPC6), the compound N-(2-chlorophenyl)-2-(4-phenylpiperazine-1-yl) acetamide (51164), causes the upregulation of postsynaptic neuronal store-operated calcium entry, maintains mushroom spine percentage, and recovers synaptic plasticity in amyloidogenic mouse models of Alzheimer’s disease. Here, using confocal microscopy and calcium imaging methods, we present the experimental data indicating that 51164 possesses an alternative mechanism of action. We demonstrated that 51164 can increase the mushroom spine percentage in neurons with the downregulated activity of TRPC6-dependent neuronal store-operated calcium entry. Moreover, we report the binding of 51164 to G-actin in silico. We observed that 51164 interacts with Lys 336, Asp157, and Ser14 of G-actin, amino acids involved in the stabilization/polymerization of the G-actin structure. We showed that interactions of 51164 with G-actin are much stronger in comparison to the well-characterized F-actin stabilizing and polymerizing drug, jasplakinolide. The obtained results suggest an alternative protective mechanism of 51164 that is related to the preservation of actin filaments in vitro.
Impact of Regulatory Approval Status on CADTH Reimbursement of Oncology Drugs and Role of Real-World Evidence on Conditional Approvals from 2019 to 2021
Authors: Lau Catherine , Dranitsaris George
Published: October 2022

Real-world evidence (RWE) is health and outcomes data generated from a patient’s journey through the health care system or disease process (i.e., real-world data). RWE is now having an increasingly important role in regulatory/reimbursement decisions. This article examines reimbursement recommendations by the Canadian Agency for Drugs and Technology in Health (CADTH) on oncology drugs approved between 2019 and 2021. Oncology drugs with a Summary Basis of Decision (SBD) for original marketing approvals were used to generate a corresponding list of CADTH final clinical recommendations for review. Of the 45 oncology drugs approved by Health Canada, CADTH granted positive funding recommendations to all 11 drugs that had priority review approvals. Two of the 17 drugs with standard reviews did not file to CADTH and 3 received a negative recommendation. Of the 17 drugs with Notice of Compliance with Conditions (NOCc) status, three were not filed to CADTH and four were under active reviews. Of the ten completed NOCc reviews, all contained RWE from sponsors and six received a negative decision on their first review. No significant differences in review times were found between the three approval statuses. Regulatory approval status appeared to influence reimbursement outcomes in Canada and evaluation of 10 NOCc approvals provided little insight regarding robustness of RWE required for more favorable considerations.
Distribution and Diversity of Diaptomid Copepods in Freshwater Habitats of Cambodia (Crustacea: Copepoda: Calanoida: Diaptomidae)
Authors: Chaicharoen Rachada , Sanoamuang Laorsri
Published: October 2022

Freshwater diaptomid copepods in Cambodia are poorly studied, and only seven taxa were known previously. From February to October 2007, 255 samples were collected from 237 freshwater sites in nine provinces representing four regions (northwest, Cardamom and Elephant Mountains, Mekong Lowlands, and east) of Cambodia. Diversity, seasonal occurrence, geographical distribution of each species, and a checklist of diaptomid copepods are documented. In this case, 24 species were recorded, including two undescribed species belonging to the genera Phyllodiaptomus and Tropodiaptomus. In this case, 14 species are recorded for the first time in Cambodia, and Mongolodiaptomus formosanus has been recorded for the first time in Southeast Asia. One species appears to be endemic to Cambodia and nine to the lower Mekong River Basin. Mongolodiaptomus malaindosinensis was the most common, frequently recorded throughout the four regions (40.5% of the sampled sites), followed by Vietodiaptomus blachei (39.2%), Eodiaptomus phuvongi (38.8%), Mongolodiaptomus formosanus (31.2%), and Eodiaptomus draconisignivomi (27.4%). Very rare species such as Eodiaptomus sanoamuangae, Tropodiaptomus vicinus, Mongolodiaptomus calcarus, and Tropodiaptomus sp. were only recorded at 0.4% to 0.8% of the sampled sites. The species diversity of Cambodia is most similar to that of Thailand, where 22 species (91.6%) occur both in Cambodia and Thailand, and 12 (50%) of the species have been recorded in both Cambodia and Vietnam.
Discovery of a New Species Provides a Deeper Insight into Taxonomic Grouping of the Deep-Sea Genus Acanthephyra (Crustacea: Decapoda)
Authors: Vereshchaka Alexander , Kulagin Dmitry , Lunina Anastasiia
Published: October 2022

We describe and diagnose a new species of Acanthephyra (Acanthephyridae: Caridea: Decapoda) and provide an amended key to all species of the genus. In order to assess the taxonomic position of the new species, we examined and coded 55 characters in available specimens of Acanthephyra and ran morphological phylogenetic analyses. We also used a COI gene marker for molecular analyses of the new species and other available specimens of Acanthephyra. Both analyses retrieved an unexpected grouping of species that contradicted a recently accepted morphological grouping. We tested a new, quantitative, set of characters and found that three of them may explain the molecular grouping of the genus. These characters are linked to: (1) proportions of the 6th pleonic somite, (2) length of the same against carapace length, and (3) length of the same against length of two preceding somites. We suggest that these characters mirror evolutionary traits in Acanthephyra and discuss their possible adaptive sense.
The Use of Open Educational Resources during the COVID-19 Pandemic: A Qualitative Study of Primary School Mathematics Teachers in Hong Kong
Authors: Lo Chung-Kwan , Tlili Ahmed , Huang Xiaowei
Published: October 2022

During the COVID-19 pandemic, teaching and learning activities had to be conducted fully online. To sustain quality education, teachers could use open educational resources (OERs) available in the public domain to make online mathematics teaching more effective and interactive. However, we currently know little about the use of OERs in primary school settings. Therefore, this study seeks to understand their school policies and guidelines on and teachers’ experience of using OERs during the pandemic. Our overarching goal is to provide recommendations on the future development and use of OERs in the context of primary school mathematics education. We employed a qualitative approach and interviewed 13 mathematics teachers from different primary schools. Our findings suggest that teachers tended to rely on OERs more during the pandemic than before. They used OERs to introduce mathematics and to facilitate class interactions in online lessons. However, not all schools had policies and guidelines on the use of OERs in place. Some teachers also encountered challenges when using OERs, such as finding that the resources were unsuitable for school contexts and lower primary school students. Based on the findings, we discuss some possible strategies for the improvement, such as ensuring the suitability of OERs, through developer–teacher collaborations.
Multisensory Interactive Digital Text for English Phonics Instruction with Bilingual Beginning Readers
Authors: O’Brien Beth A. , Seward Reneé , Zhang Dongbo
Published: October 2022

We investigated a technology-based tool for teaching English letter-sound correspondences with bilingual children learning phonologically and typologically distant languages: English and Chinese. We expect that learning about print at the phoneme level may be particularly challenging, given children’s experience with the morphosyllabic language of Chinese. This randomized-controlled study with 90 kindergarteners examined the effects of an iPad-based supplementary reading program compared with a control condition. The See Word Reading® program utilized picture-embedded cues for teaching phonics within lessons directed at the letter, word, and text levels. Measures of decoding, word reading, and spelling were taken at the pretest, posttest, and follow-up for both groups. Results showed better gains in word reading for the reading group, indicating the positive impact of this supplementary reading tool. Further, data collected online from the app showed that different types of letter-sound pairings were more challenging to learn, including pairings that are inconsistent and with phonemes that are specific to English.
Reflecting on Ethical Processes and Dilemmas in Doctoral Research
Authors: Quickfall Aimee
Published: October 2022

This paper discusses ethical dilemmas from an early-career researcher perspective, drawing upon doctoral research experiences—my own. The doctoral study involved life-history interviews with five primary-school-teacher mothers. During the study, ethical dilemmas arose that were not considered by me or in the official university ethical processes. This left me feeling vulnerable in the data-collection period and overwhelmed with concerns for the well-being of participants and for myself as researcher. This paper draws on my journal entries and reflections; detailed reflections of the pre-, during and post-fieldwork stages were collected (totalling over 600 entries). The paper utilizes critical incidents analysis to explore two ethical dilemmas from the data collection phase. Findings include personal reflections on experiences of university processes and the mismatch between the metaphor of ethics as a ‘hurdle’ on a smooth track to completion, and the real-life incidents and dilemmas that followed ethical approval. Recommendations are made for a consideration of doctoral ethical dilemma support and the limitations of formal ethics processes in UK universities.
Semi-Supervised Segmentation of Echocardiography Videos Using Graph Signal Processing
Authors: El rai Marwa Chendeb , Darweesh Muna , Al-Saad Mina
Published: October 2022

Machine learning and computer vision algorithms can provide a precise and automated interpretation of medical videos. The segmentation of the left ventricle of echocardiography videos plays an essential role in cardiology for carrying out clinical cardiac diagnosis and monitoring the patient’s condition. Most of the developed deep learning algorithms for video segmentation require an enormous amount of labeled data to generate accurate results. Thus, there is a need to develop new semi-supervised segmentation methods due to the scarcity and costly labeled data. In recent research, semi-supervised learning approaches based on graph signal processing emerged in computer vision due to their ability to avail the geometrical structure of data. Video object segmentation can be considered as a node classification problem. In this paper, we propose a new approach called GraphECV based on the use of graph signal processing for semi-supervised learning of video object segmentation applied for the segmentation of the left ventricle in echordiography videos. GraphECV includes instance segmentation, extraction of temporal, texture and statistical features to represent the nodes, construction of a graph using K-nearest neighbors, graph sampling to embed the graph with small amount of labeled nodes or graph signals, and finally a semi-supervised learning approach based on the minimization of the Sobolov norm of graph signals. The new algorithm is evaluated using two publicly available echocardiography videos, EchoNet-Dynamic and CAMUS datasets. The proposed approach outperforms other state-of-the-art methods under challenging background conditions.
Image Large Rotation and Scale Estimation Using the Gabor Filter
Authors: Tang Wei , Jia  Fangxiu , Wang Xiaoming
Published: October 2022

This paper proposes a novel image large rotation and scale estimation method based on the Gabor filter and pulse-coupled neural network (PCNN). First, the Gabor features of the template image and its rotated one are extracted by performing the Gabor filter. Second, we present a modified PCNN model to measure the similarity between the Gabor features of the image and its rotated one. Finally, the rotation angle is calculated by searching the global minimum of the correlation coefficients. Besides rotation estimation, we also propose a scale estimation method based on the max-projection strategy. The Gabor feature image is projected along the estimated rotation angle, and the scale is calculated by searching the peak of this projection result. Moreover, experiments illustrate that the proposed method has high accuracy on rotation and scale estimation and is robust to noise. Compared with the state-of-the-art methods, the proposed approach has a more stable performance.
Calculating Available Charge and Energy of Lithium-Ion Cells Based on OCV and Internal Resistance
Authors: Steger Fabian , Krogh Jonathan , Meegahapola Lasantha , Schweiger Hans-Georg
Published: October 2022

The design and operation of performant and safe electric vehicles depend on precise knowledge of the behavior of their electrochemical energy storage systems. The performance of the battery management systems often relies on the discrete-time battery models, which can correctly emulate the battery characteristics. Among the available methods, electric circuit-based equations have shown to be especially useful in describing the electrical characteristics of batteries. To overcome the existing drawbacks, such as discrete-time simulations for parameter estimation and the usage of look-up tables, a set of equations has been developed in this study that solely relies on the open-circuit voltage and the internal resistance of a battery. The parameters can be obtained from typical cell datasheets or can be easily extracted via standard measurements. The proposed equations allow for the direct analytical determination of available discharge capacity and the available energy content depending on the discharge current, as well as the Peukert exponent. The fidelity of the proposed system was validated experimentally using 18650 NMC and LFP lithium-ion cells, and the results are in close agreement with the datasheet.
Investigation of the Effect of Albedo in Photovoltaic Systems for Urban Applications: Case Study for Spain
Authors: Barbón Arsenio , Bayón Luis , Díaz Guzmán , Silva Carlos A.
Published: October 2022

Rooftop photovoltaic generation can help cities become key players in the transition to clean energy. The optimal solar photovoltaic production on rooftops depends on two angles: tilt angle and azimuth angle. It is accepted in all studies that the ideal orientation of photovoltaic modules is toward the south (north) in the northern hemisphere (south). In contrast, the determination of the optimum tilt angle is more complex, and there are different equations for its calculation. Most of these equations do not take albedo into account. In this work, 47 Spanish province capitals representing the most populated cities have been studied with different equations for the calculation of the optimum annual tilt angle (Technical report by the Spanish Institute for the Diversification and Saving of Energy (IDAE), Lorenzo’s and Jacobson’s equation) and different types of albedo. Accounting for the geographical and the meteorological conditions of the cities, we analyzed the optimum tilt angle through a Mathematica© optimization code. The influence that different variables have on optimum tilt angle has been quantified by means of the term relative energy harvested. The use of the equations as a function of latitude increases the annual relative energy harvested by increasing the albedo. When the albedo is 0.2, the annual relative energy harvested is very similar in all equations. Comparing to the method that maximizes the total irradiation incident on a tilted surface, the minimum and maximum value of the percentage of relative energy harvested per year were 0.01 and 2.50% for the IDAE guideline, 0.00 and 2.38% for Lorenzo’s equation, 0.00 and 2.46% for Jacobson’s equation. A simplified polynomial regression model to estimate optimum tilt angle as a function of latitude, altitude and albedo has been proposed as well.
Energy Performance Evaluation of a Solar PVT Thermal Energy Storage System Based on Small Size Borefield
Authors: Sakellariou Evangelos I. , Axaopoulos Petros J. , Bot Bill Vaneck , Sarris Ioannis E.
Published: October 2022

In this study, a PVT-based solar-assisted ground source heat pump (SAGSHP) system with a small size borefield as the long-term heat storage component was energetically evaluated. The mathematical model of the system was formulated in TRNSYS and three cities with distinctive climates were chosen: Athens (Greece); Melbourne (Australia); and Ottawa (Canada). The parametric analyses were carried out for 10 years by varying the number of the PVT collectors and the size of the earth energy bank (EEB). The evaluation of the systems was made via two energy indicators, and the heat flow across the EEB was analyzed. The under-consideration system was found capable of establishing self-sufficiency as regards the energy consumption (renewable power fraction RPF > 1) for all locations. Namely, for Athens, any system with more than four PVT collectors, and for Melbourne, any system with more than eight PVTs was found with an RPF higher than 1, regardless of the EEB size. For Ottawa, self-sufficiency can be achieved with PVT arrays larger than 12 collectors for small EEBs, and with eight collectors for larger EEBs. The storage capacity was found to be an important parameter for the energy performance of the system. In particular, it was determined that, as the storage capacity enlarges the RPF and the seasonal performance factor (SPF) of the system improves, mainly due to the reduction of the electricity consumed by the heat pump and the auxiliary heating. Moreover, a larger storage capacity facilitates solar heat production by enlarging the available heat storage volume and by maintaining the EEB at relatively low temperatures.
Effects of Water and Cyclic Loading on Ultrasonic and Mechanical Properties of Sandstone: An Experimental Study
Authors: Chen Yan , Zhang Guolong , Bai Erhu , Guo Baohua , Dou Rong
Published: October 2022

In this study, the water absorption, mechanical properties, and energy evolution characteristics of sandstone were examined through experimental and theoretical analysis. The P-wave velocity was found to initially decrease, then increased with immersion time and water content. The water absorption rates of three sandstone specimens decreased with immersion time and water content. The post-peak deformation of the sandstone changed from brittle failure to strain softening. With the increase in water content, the peak strength and loading Young’s modulus per cycle decreased. The loading Young’s modulus showed that the unloading stress and increment of unloading stress nonlinearly increased with the number of cycles and decreased before peak strength. With the increase in the number of cycles, residual strains of the sandstone specimens decreased slightly initially and then increased, while the elastic strains increased before peak strength and then decreased at the post-peak stage. With the increase in unloading stress, the energy densities nonlinearly increased. At the same unloading stress, an increase in water content led to an increase in the input energy density and energy ratios of the sandstone specimens.
Power Quality Analysis of a Hybrid Microgrid-Based SVM Inverter-Fed Induction Motor Drive with Modulation Index Diversification
Authors: Vasantharaj Subramanian , Indragandhi Vairavasundaram , Bharathidasan Mohan , Aljafari Belqasem
Published: October 2022

The effects of varying modulation indices on the current and voltage harmonics of an induction motor (IM) powered by a three-phase space vector pulse-width modulation (SVM) inverter are presented in this research. The effects were examined using simulation and an experimental setup. IMs can be governed by an SVM inverter drive or a phase-angle control drive for applications that require varying speeds. The analysis of THD content in this study used the modulation index (MI), whose modification affects the harmonic content, and voltage-oriented control (VOC) with SVM in three-phase pulse-width modulation (PWM) inverters with fixed switching frequencies. The control technique relies on two cascaded feedback loops, one controlling the grid current and the other regulating the dc-link voltage to maintain the required level of dc-bus voltage. The control strategy was developed to transform between stationary (α–β) and synchronously rotating (d–q) coordinate systems. To test the viability of the suggested control technique, a 1-hp/3-phase/415-V experimental prototype system built on the DSPACE DS1104 platform was created, and the outcomes were evaluated with sinusoidal pulse-width modulation (SPWM).
Falling-Film Absorption Model Considering Surface Wave and Vibration Effects Based on Lattice Boltzmann Method
Authors: Zhang Huayu , Gao Hongtao , Gao Xiangcheng , Yan Yuying
Published: October 2022

As one of the effective solutions to recover waste heat, absorption refrigeration systems are used in various industrial or refrigeration places. Flat-plate falling-film absorption is one of the newer types, and the lattice Boltzmann method (LBM) has certain advantages compared with the traditional numerical simulation method. In this work, an LBM is used to analyze flat-plate falling-film absorption. Using the additional calculation of the pressure by the pseudo-force model, a lithium bromide–water working fluid–heat and mass transfer model driven by steam partial pressure is realized. The results show that the turbulence generated in the surface wave has a favorable effect on the absorption process; the degree of turbulence gradually decreases with the increase in the Reynolds number, which weakens the increasing effect of the surface wave on the absorption. When the Reynolds number is moderate, the solitary wave flows forward relative to the front thin liquid film, which promotes concentration and temperature diffusion inside the liquid film and inside the solitary wave. The model of falling-film flow under vibration environment is realized by using the characteristic of imposing inertial force in the model by pseudo-force method. The results show that vibration has a favorable effect on liquid film absorption, increasing the amplitude can increase the gas–liquid contact area and obtain a lower average film thickness, while increasing the vibration frequency can promote the internal diffusion of the solution.
Identification of the Dynamic Properties of the Coal Flotation Process as a Control Object with the Use of the Kalman Filter
Authors: Joostberens Jarosław , Rybak Aurelia , Rybak Aleksandra
Published: October 2022

For various sorts of hard coal, enrichment by flotation is used for feed consisting of grains smaller than 0.5 mm. Regarding process automation, coal flotation is a multidimensional, dynamic nonlinear object of control, for which the main control signal is the flow rate of the flotation agent. Typically, in Polish coal-processing facilities the monitoring and control systems of the flotation process can only measure the parameter of the waste quality (content of ash in flotation tailings). This naturally becomes an output signal, enabling an indirect assessment of the ongoing process. Therefore, knowledge of the dynamic properties of the flotation process, analysed as an object with one control input (the flow rate of the flotation agent) and with one output for measuring (content of ash in flotation tailings) may be material in designing automatic control systems for this operation. It is important to use an appropriate identification method when developing a model of the dynamics of the flotation process, especially if the model parameters are to be determined on an ongoing basis. This article discusses the research method and presents the results of applying the method of identifying the dynamic properties of the coal flotation process with the use of the Kalman filter. We carried out a comparative analysis of the results obtained by this method based on the Kalman algorithm and the method of least squares, taken as the reference method. The presented parameters of the dynamic models were calculated based on actual data obtained from industrial tests conducted at the coal-processing plant at one of the Polish mines. It was demonstrated that, for control purposes, the Kalman algorithm can be successfully applied in identification of the coal flotation process. This is due to the fact that it gives satisfactory results in relation to the adopted reference method despite the fact that it is a recursive algorithm.
New Trends in the Control of Grid-Connected Photovoltaic Systems for the Provision of Ancillary Services
Authors: Riquelme-Dominguez Jose Miguel , Riquelme Jesús , Martinez Sergio
Published: October 2022

The gradual displacement of conventional generation from the energy mix to give way to renewable energy sources represents a paradigm shift in the operation of future power systems: on the one hand, renewable technologies are, in general, volatile and difficult to predict; and on the other hand, they are usually connected to the grid through electronic power converters. This decoupling due to power converters means that renewable generators lack the natural response that conventional generation has to the imbalances between demand and generation that occur during the regular operation of power systems. Renewable generators must, therefore, provide a series of complementary services for the correct operation of power systems in addition to producing the necessary amount of energy. This paper presents an overview of existing methods in the literature that allow photovoltaic generators to participate in the provision of ancillary services, focusing on solutions based on power curtailment by modifying the traditional maximum power point tracking algorithm.
Design of a Hydrogen Production System Considering Energy Consumption, Water Consumption, CO2 Emissions and Cost
Authors: González Palencia Juan , Itoi Yuta , Araki Mikiya
Published: October 2022

CO2 emissions associated with hydrogen production can be reduced replacing steam methane reforming with electrolysis using renewable electricity with a trade-off of increasing energy consumption, water consumption and cost. In this research, a linear programming optimization model of a hydrogen production system that considers simultaneously energy consumption, water consumption, CO2 emissions and cost on a cradle-to-gate basis was developed. The model was used to evaluate the impact of CO2 intensity on the optimum design of a hydrogen production system for Japan considering different stakeholders’ priorities. Hydrogen is produced using steam methane reforming and electrolysis. Electricity sources include grid, wind, solar photovoltaic, geothermal and hydro. Independent of the stakeholders’ priorities, steam methane reforming dominates hydrogen production for cradle-to-gate CO2 intensities larger than 9 kg CO2/kg H2, while electrolysis using renewable electricity dominates for lower cradle-to-gate CO2 intensities. Reducing the cradle-to-gate CO2 intensity increases energy consumption, water consumption and specific cost of hydrogen production. For a cradle-to-gate CO2 intensity of 0 kg CO2/kg H2, the specific cost of hydrogen production varies between 8.81 and 13.6 USD/kg H2; higher than the specific cost of hydrogen production targeted by the Japanese government in 2030 of 30 JPY/Nm3, 3.19 USD/kg H2.
Artificial Neural Networks: Multilayer Perceptron and Radial Basis to Obtain Post-Contingency Loading Margin in Electrical Power Systems
Authors: Bonini Neto Alfredo , Alves Dilson Amancio , Minussi Carlos Roberto
Published: October 2022

This paper presents the ANN (Artificial Neural Networks) approach to obtaining complete P-V curves of electrical power systems subjected to contingency. Two networks were presented: the MLP (multilayer perceptron) and the RBF (radial basis function) networks. The differential of our methodology consisted in the speed of obtaining all the P-V curves of the system. The great advantage of using ANN models is that they can capture the nonlinear characteristics of the studied system to avoid iterative procedures. The applicability and effectiveness of the proposed methodology have been investigated on IEEE test systems (14 buses) and compared with the continuation power flow, which obtains the post-contingency loading margin starting from the base case solution. From the results, the ANN performed well, with a mean squared error (MSE) in training below the specified value. The network was able to estimate 98.4% of the voltage magnitude values within the established range, with residues around 10−4 and a percentage of success between the desired and obtained output of approximately 98%, with better result for the RBF (radial basis function) network compared to MLP (multilayer perceptron).
Robust Suppression Strategy for Photovoltaic Grid-Connected Inverter Cluster Resonance Based on Kalman Filter Improved Disturbance Observer
Authors: He Guofeng , Yan Cheng , Zhou Zichun , Lin Junfang , Li Guojiao
Published: October 2022

In response to the key engineering problems of photovoltaic grid-connected inverter cluster resonance suppression affected by grid-connected inverter impedance, in this paper, a control strategy based on a disturbance observer is proposed to dynamically compensate for the damping coefficient of the controlled system and improve the robustness of the system. First, an engineering mathematical model of a 200 MW photovoltaic inverter cluster is established, and the mechanism of the active damping of the cluster inverter influenced by the disturbance is analyzed. Secondly, the capacitor current feedback is utilized to constitute the virtual damping, and the inverter output impedance is reshaped to suppress the resonance peak. Then, a Kalman filter is used to improve the traditional disturbance observer to accurately detect disturbance of the system during the dynamic process of the cluster inverter so as to better adapt to changes in grid impedance and dynamically compensate for the virtual damping of the cluster resonant system. Finally, the proposed control strategy is verified with respect to a practical PV power station. The experimental results demonstrate the feasibility of the proposed control method.