bluuebunny/crossref_metadata_2025 huggingface dataset:
Profit Maximization with Imbalance Cost Improvement by Solar PV-Battery Hybrid System in Deregulated Power Market
Authors: Patil Ganesh Sampatrao , Mulla Anwar , Dawn Subhojit , Ustun Taha Selim
Published: July 2022

The changeable nature of renewable sources creates difficulties in system security and stability. Therefore, it is necessary to study system risk in several power system scenarios. In a wind-integrated deregulated power network, the wind farm needs to submit the bid for its power-generating quantities a minimum of one day ahead of the operation. The wind farm submits the data based on the expected wind speed (EWS). If any mismatch occurs between real wind speed (RWS) and expected wind speed, ISO enforces the penalty/rewards to the wind farm. In a single word, this is called the power market imbalance cost, which directly distresses the system profit. Here, solar PV and battery energy storage systems are used along by the wind farm to exploit system profit by grasping the negative outcome of imbalance cost. Along with system profit, the focus has also been on system risk. The system risk has been calculated using the risk assessment factors, i.e., Value-at-Risk (VaR) and Cumulative Value-at-risk (CVaR). The work is performed on a modified IEEE 14 and modified IEEE 30 bus test system. The solar PV-battery storage system can supply the demand locally first, and then the remaining power is given to the electrical grid. By using this concept, the system risk can be minimized by the incorporation of solar PV and battery storage systems, which have been studied in this work. A comparative study has been performed using three dissimilar optimization methods, i.e., Artificial Gorilla Troops Optimizer Algorithm (AGTO), Artificial Bee Colony Algorithm (ABC), and Sequential Quadratic Programming (SQP) to examine the consequence of the presented technique. The AGTO has been used for the first time in the risk assessment and alleviation problem, which is the distinctiveness of this work.
A Comparative Analysis on the Variability of Temperature Thresholds through Time for Wind Turbine Generators Using Normal Behaviour Modelling
Authors: Turnbull Alan , Carroll James , McDonald Alasdair
Published: July 2022

Data-driven normal behaviour models have gained traction over the last few years as a convenient way of modelling turbine operational health to detect anomalies. By leveraging high-dimensional operational relationships, temperature thresholds can be automatically calculated based on each individual turbine unique operating envelope, in theory minimising false alarms and providing more reliable diagnostics. The aim of this work is to provide further insight into practical uses and limitations of implementing normal behaviour temperature models in practice, to inform practitioners, as well as assist in improving wind turbine generator fault detection systems. Results suggest that, on average, as little as two months of data are adequate to produce stable temperature alarm thresholds, with the worst case example requiring approximately 200–290 days of data depending on the component and desired convergence criteria.
Power Electronic Circuits for Electric Drives and Renewable Energy Sources
Authors: Loncarski Jelena , Boström Cecilia , Mandrioli Riccardo
Published: July 2022

This Special Issue was intended to consolidate the most recent advances in the field of power electronics for renewable energy sources and electric drives [...]
An Empirical Energy Demand Flexibility Metric for Residential Properties
Authors: Crawley Jenny , Manouseli Despina , Mallaburn Peter , Elwell Cliff
Published: July 2022

Shifting from heating using fossil fuel combustion to electrified heating, dominated by heat pumps, is central to many countries’ decarbonisation strategy. The consequent increase in electricity demand, combined with that from electric vehicles, and the shift from non-renewable to renewable generation requires increased demand flexibility to support system operation. Demand side response through interrupting heating during peak demands has been widely proposed and simulation modelling has been used to determine the technical potential. This paper proposes an empirical approach to quantifying a building’s potential to operate flexibly, presenting a metric based on measured temperature drop in a dwelling under standard conditions after heating is switched off, using smart meter and internal temperature data. A result was derived for 96% of 193 homes within a test dataset, mean temperature drop of 1.5 °C in 3 h at 15 °C inside-outside temperature differential. An empirical flexibility metric may support decision making and decarbonisation. For households it may support the transition to heat pumps, enabling time of use costs and tariffs to be better understood and system to be specified by installers. Electricity system stakeholders, such as aggregators and DNOs may use it to identify the potential for demand response, managing local networks, infrastructure and aggregation.
Estimators for Structural Damage Detection Using Principal Component Analysis
Authors: Caselles Oriol , Martín Alejo , Vargas-Alzate Yeudy F. , Gonzalez-Drigo Ramon , Clapés Jaume
Published: July 2022

Structural damage detection is an important issue in conservation. In this research, principal component analysis (PCA) has been applied to the temporal variation of modal frequencies obtained from a dynamic test of a scaled steel structure subjected to different damages and different temperatures. PCA has been applied in order to reduce, as much as possible, the number of variables involved in the problem of structural damage detection. The aim of the PCA study is to determine the minimum number of principal components necessary to explain all the modal frequency variation. Three estimators have been studied: T2 (the square of the vector norm of the projection in the principal component plan), Q (the square of the norm of the residual vector), and the variance explained. In the study, the results related to the undamaged structure needed one principal component to explain the modal frequency variation. However, the high damage configurations need five principal components to explain the modal frequency. The T2 and Q estimators have been arranged in order of increasing damage for all the performed experimental tests. The results indicate that these estimators could be useful to detect damage and to distinguish among a range of intensities of structural damage.
Application of Parallel Reaction Monitoring to the Development and Validation of a Quantitative Assay for ST-246 in Human Plasma
Authors: Chernonosov Alexander A. , Oleinik Galina A. , Koval Vladimir V.
Published: July 2022

In this work, we developed and validated a robust and sensitive method of liquid chromatography with high-resolution mass spectrometry in parallel reaction monitoring (PRM) mode for ST-246 (tecovirimat) quantification in human blood plasma. The method was compared with the multiple reaction monitoring (MRM) technique and showed better selectivity and similar sensitivity in a wider concentration range (10–5000 ng/mL). Within this range, intra- and interday variability of precision and accuracy were within acceptable ranges in accordance with the European Medicines Agency guidelines, and recovery was 87.9–100.6%. Samples were stable at 4 °C within 48 h and at −20 °C up to 3 months. The recovery and matrix effects in the proposed HRMS method were about 5% higher than those reported for the MRM method, but the PRM method showed better accuracy with comparable precision. It was found that the ST-246 concentration shown by the PRM method is approximately 24% higher than the output of the MRM one. Nonetheless, the high selectivity with similar sensitivity, as compared with traditional MRM methods, makes the proposed approach attractive for research and clinical use.
Regulated Expression of lpxC Allows for Reduction of Endotoxicity in Bordetella pertussis
Authors: Pérez-Ortega Jesús , van Boxtel Ria , de Jonge Eline F. , Tommassen Jan
Published: July 2022

The Gram-negative bacterium Bordetella pertussis is the causative agent of a respiratory infection known as whooping cough. Previously developed whole-cell pertussis vaccines were effective, but appeared to be too reactogenic mainly due to the presence of lipopolysaccharide (LPS, also known as endotoxin) in the outer membrane (OM). Here, we investigated the possibility of reducing endotoxicity by modulating the LPS levels. The promoter of the lpxC gene, which encodes the first committed enzyme in LPS biosynthesis, was replaced by an isopropyl β-D-1-thiogalactopyranoside (IPTG)-inducible promoter. The IPTG was essential for growth, even when the construct was moved into a strain that should allow for the replacement of LPS in the outer leaflet of the OM with phospholipids by defective phospholipid transporter Mla and OM phospholipase A. LpxC depletion in the absence of IPTG resulted in morphological changes of the cells and in overproduction of outer-membrane vesicles (OMVs). The reduced amounts of LPS in whole-cell preparations and in isolated OMVs of LpxC-depleted cells resulted in lower activation of Toll-like receptor 4 in HEK-Blue reporter cells. We suggest that, besides lipid A engineering, also a reduction in LPS synthesis is an attractive strategy for the production of either whole-cell- or OMV-based vaccines, with reduced reactogenicity for B. pertussis and other Gram-negative bacteria.
Treatment of Mouse Sperm with a Non-Catalytic Mutant of PLA2G10 Reveals That PLA2G10 Improves In Vitro Fertilization through Both Its Enzymatic Activity and as Ligand of PLA2R1
Authors: Abi Nahed Roland , Dhellemmes Magali , Payré Christine , Le Blévec Emilie , Perrier Jean-Philippe , Hennebicq Sylviane , Escoffier Jessica , Ray Pierre F. , Loeuillet Corinne , Lambeau Gérard , Arnoult Christophe
Published: July 2022

The group X secreted phospholipase A2 (PLA2G10) is present at high levels in mouse sperm acrosome. The enzyme is secreted during capacitation and amplifies the acrosome reaction and its own secretion via an autocrine loop. PLA2G10 also improves the rate of fertilization. In in vitro fertilization (IVF) experiments, sperm from Pla2g10-deficient mice produces fewer two-cell embryos, and the absence of PLA2G10 is rescued by adding recombinant enzymes. Moreover, wild-type (WT) sperm treated with recombinant PLA2G10 produces more two-cell embryos. The effects of PLA2G10 on mouse fertility are inhibited by sPLA2 inhibitors and rescued by products of the enzymatic reaction such as free fatty acids, suggesting a role of catalytic activity. However, PLA2G10 also binds to mouse PLA2R1, which may play a role in fertility. To determine the relative contribution of enzymatic activity and PLA2R1 binding in the profertility effect of PLA2G10, we tested H48Q-PLA2G10, a catalytically-inactive mutant of PLA2G10 with low enzymatic activity but high binding properties to PLA2R1. Its effect was tested in various mouse strains, including Pla2r1-deficient mice. H48Q-PLA2G10 did not trigger the acrosome reaction but was as potent as WT-PLA2G10 to improve IVF in inbred C57Bl/6 mice; however, this was not the case in OF1 outbred mice. Using gametes from these mouse strains, the effect of H48Q-PLA2G10 appeared dependent on both spermatozoa and oocytes. Moreover, sperm from C57Bl/6 Pla2r1-deficient mice were less fertile and lowered the profertility effects of H48Q-PLA2G10, which were completely suppressed when sperm and oocytes were collected from Pla2r1-deficient mice. Conversely, the effect of WT-PLA2G10 was not or less sensitive to the absence of PLA2R1, suggesting that the effect of PLA2G10 is polymodal and complex, acting both as an enzyme and a ligand of PLA2R1. This study shows that the action of PLA2G10 on gametes is complex and can simultaneously activate the catalytic pathway and the PLA2R1-dependent receptor pathway. This work also shows for the first time that PLA2G10 binding to gametes’ PLA2R1 participates in fertilization optimization.
Preclinical Assessment of the Combination of PSMA-Targeting Radionuclide Therapy with PARP Inhibitors for Prostate Cancer Treatment
Authors: Ruigrok Eline , Verkaik Nicole , de Blois Erik , de Ridder Corrina , Stuurman Debra , Roobol Stefan , Van Gent Dik , de Jong Marion , Van Weerden Wytske , Nonnekens Julie
Published: July 2022

Prostate specific membrane antigen targeted radionuclide therapy (PSMA-TRT) is a promising novel treatment for prostate cancer (PCa) patients. However, PSMA-TRT cannot be used for curative intent yet, thus additional research on how to improve the therapeutic efficacy is warranted. A potential way of achieving this, is combining TRT with poly ADP-ribosylation inhibitors (PARPi), which has shown promising results for TRT of neuroendocrine tumor cells. Currently, several clinical trials have been initiated for this combination for PCa, however so far, no evidence of synergism is available for PCa. Therefore, we evaluated the combination of PSMA-TRT with three classes of PARPi in preclinical PCa models. In vitro viability and survival assays were performed using PSMA-expressing PCa cell lines PC3-PIP and LNCaP to assess the effect of increasing concentrations of PARPi veliparib, olaparib or talazoparib in combination with PSMA-TRT compared to single PARPi treatment. Next, DNA damage analyses were performed by quantifying the number of DNA breaks by immunofluorescent stainings. Lastly, the potential of the combination treatments was studied in vivo in mice bearing PC3-PIP xenografts. Our results show that combining PSMA-TRT with PARPi did not synergistically affect the in vitro clonogenic survival or cell viability. DNA-damage analysis revealed only a significant increase in DNA breaks when combining PSMA-TRT with veliparib and not in the other combination treatments. Moreover, PSMA-TRT with PARPi treatment did not improve tumor control compared to PSMA-TRT monotherapy. Overall, the data presented do not support the assumption that combining PSMA-TRT with PARPi leads to a synergistic antitumor effect in PCa. These results underline that extensive preclinical research using various PCa models is imperative to validate the applicability of the combination strategy for PCa, as it is for other cancer types.
Recent Advances in the Photoreactions Triggered by Porphyrin-Based Triplet–Triplet Annihilation Upconversion Systems: Molecular Innovations and Nanoarchitectonics
Authors: Yao Bin , Sun Hongfei , He Youzhou , Wang Song , Liu Xingyan
Published: July 2022

Triplet–triplet annihilation upconversion (TTA-UC) is a very promising technology that could be used to convert low-energy photons to high-energy ones and has been proven to be of great value in various areas. Porphyrins have the characteristics of high molar absorbance, can form a complex with different metal ions and a high proportion of triplet states as well as tunable structures, and thus they are important sensitizers for TTA-UC. Porphyrin-based TTA-UC plays a pivotal role in the TTA-UC systems and has been widely used in many fields such as solar cells, sensing and circularly polarized luminescence. In recent years, applications of porphyrin-based TTA-UC systems for photoinduced reactions have emerged, but have been paid little attention. As a consequence, this review paid close attention to the recent advances in the photoreactions triggered by porphyrin-based TTA-UC systems. First of all, the photochemistry of porphyrin-based TTA-UC for chemical transformations, such as photoisomerization, photocatalytic synthesis, photopolymerization, photodegradation and photochemical/photoelectrochemical water splitting, was discussed in detail, which revealed the different mechanisms of TTA-UC and methods with which to carry out reasonable molecular innovations and nanoarchitectonics to solve the existing problems in practical application. Subsequently, photoreactions driven by porphyrin-based TTA-UC for biomedical applications were demonstrated. Finally, the future developments of porphyrin-based TTA-UC systems for photoreactions were briefly discussed.
Exposure to Bisphenol A Caused Hepatoxicity and Intestinal Flora Disorder in Rats
Authors: Liu Ruijing , Liu Boping , Tian Lingmin , Jiang Xinwei , Li Xusheng , Cai Dongbao , Sun Jianxia , Bai Weibin , Jin Yulong
Published: July 2022

Bisphenol A (BPA) is a globally utilized industrial chemical and is commonly used as a monomer of polycarbonate plastics and epoxy resins. Recent research reveals that BPA could cause potential adverse biological effects and liver dysfunction. However, the underlying mechanisms of BPA-induced hepatoxicity and gut dysbiosis remain unclear and deserve further study. In this study, male Sprague Dawley rats were exposed to different doses (0, 30, 90, and 270 mg/kg bw) of BPA by gavage for 30 days. The results showed that the high dose of BPA decreased superoxide dismutase (SOD), glutathione (GSH), and increased malondialdehyde (MDA) levels. Moreover, a high dose of BPA caused a significant increase in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C), while high-density lipoprotein cholesterol (HDL-C) was significantly decreased in BPA-treated rats. The gene expression of PGC-1α and Nrf1 were decreased in the liver of high doses of BPA-administrated rats, as well as the protein levels of SIRT1, PGC-1α, Nrf2, and TFAM. However, the protein expression of IL-1β was significantly increased in BPA-treated rats. In addition, BPA weakened the mitochondrial function of hepatocytes and promoted cell apoptosis in the liver by up-regulating the protein levels of Bax, cleaved-Caspase3, and cleaved-PARP1 while down-regulating the Bcl-2 in the liver. More importantly, a high dose of BPA caused a dramatic change in microbiota structure, as characterized at the genus level by increasing the ratio of Firmicutes to Bacteroidetes (F/B), and the relative abundance of Proteobacteria in feces, while decreasing the relative abundance of Prevotella_9 and Ruminococcaceae_UCG-014, which is positively correlated with the content of short-chain fatty acids (SCFAs). In summary, our data indicated that BPA exposure caused hepatoxicity through apoptosis and the SIRT1/PGC-1α pathway. BPA-induced intestinal flora and SCFA changes may be associated with hepatic damage. The results of this study provide a new sight for the understanding of BPA-induced hepatoxicity.
Yohimbine, an α2-Adrenoceptor Antagonist, Suppresses PDGF-BB-Stimulated Vascular Smooth Muscle Cell Proliferation by Downregulating the PLCγ1 Signaling Pathway
Authors: Chiu Chih-Wei , Hsieh Cheng-Ying , Yang Chih-Hao , Tsai Jie-Heng , Huang Shih-Yi , Sheu Joen-Rong
Published: July 2022

Yohimbine (YOH) has antiproliferative effects against breast cancer and pancreatic cancer; however, its effects on vascular proliferative diseases such as atherosclerosis remain unknown. Accordingly, we investigated the inhibitory mechanisms of YOH in vascular smooth muscle cells (VSMCs) stimulated by platelet-derived growth factor (PDGF)-BB, a major mitogenic factor in vascular diseases. YOH (5–20 μM) suppressed PDGF-BB-stimulated a mouse VSMC line (MOVAS-1 cell) proliferation without inducing cytotoxicity. YOH also exhibited antimigratory effects and downregulated matrix metalloproteinase-2 and -9 expression in PDGF-BB-stimulated MOVAS-1 cells. It also promoted cell cycle arrest in the initial gap/first gap phase by upregulating p27Kip1 and p53 expression and reducing cyclin-dependent kinase 2 and proliferating cell nuclear antigen expression. We noted phospholipase C-γ1 (PLCγ1) but not ERK1/2, AKT, or p38 kinase phosphorylation attenuation in YOH-modulated PDGF-BB-propagated signaling pathways in the MOVAS-1 cells. Furthermore, YOH still inhibited PDGF-BB-induced cell proliferation and PLCγ1 phosphorylation in MOVAS-1 cells with α2B-adrenergic receptor knockdown. YOH (5 and 10 mg/kg) substantially suppressed neointimal hyperplasia in mice subjected to CCA ligation for 21 days. Overall, our results reveal that YOH attenuates PDGF-BB-stimulated VSMC proliferation and migration by downregulating a α2B-adrenergic receptor–independent PLCγ1 pathway and reduces neointimal formation in vivo. Therefore, YOH has potential for repurposing for treating atherosclerosis and other vascular proliferative diseases.
Adversity Quotient Promotes Teachers’ Professional Competence More Strongly Than Emotional Intelligence: Evidence from Indonesia
Authors: Widodo Widodo , Gustari Irvandi , Chandrawaty Chandrawaty
Published: July 2022

Teachers’ professional competence has become a popular issue since the COVID-19 pandemic. Therefore, this study investigates teachers’ professional competence, in terms of emotional intelligence (EI), adversity quotient (AQ), and organizational citizenship behavior (OCB), when teachers need to deal with abnormal situations, such as the COVID-19 pandemic. Moreover, this study also seeks to explore the relationship of EI and AQ with teachers’ professional competence mediated by OCB. The research data were collected through a questionnaire using a Likert scale from 589 participants: elementary school teachers in Indonesia were chosen through accidental sampling. The data analysis used structural equation modeling (SEM), complemented by common method bias, correlational, and descriptive analysis. The result shows that EI, AQ, and OCB have a significant relationship with teachers’ professional competence. However, AQ more strongly promotes teachers’ OCB and professional competence than EI does. In addition, OCB mediates the relationship between EI and AQ with teachers’ professional competence. Accordingly, a new model regarding the relationship of EI and AQ with teachers’ professional competence mediated by OCB was confirmed. Therefore, it is suggested that teachers’ professional competence can increase through EI, AQ, and OCB. Hence, the new empirical model deserves to be discussed, adapted, and even adopted by practitioners and researchers to develop the professional competence of teachers in the future.
Quaternary Glauconitization on Gulf of Guinea, Glauconite Factory: Overview of and New Data on Tropical Atlantic Continental Shelves and Deep Slopes
Authors: Giresse Pierre
Published: July 2022

For a long time, particular attention was paid to glauconitization in the surficial sediments lying on the outer continental shelves of present oceans. Subsequently, the processes observed and analyzed may have served as models for studies of glauconite in Cenozoic or even Mesozoic shelf deposits. Access to the sedimentary domains of deep oceans, particularly those of contouritic accumulation fields, has made it possible to discover unexpected processes of glauconitization. Thus, the long-term prevalence of control using fairly high-temperature water has become obsolete, and the prerequisite influence of continental flows has come to be considered on a new scale. Frequently, sediments from contouritic accumulation provide a condensed and undisturbed sedimentary record without periods of sediment erosion. Glauconitic grains could possibly integrate the signatures of bottom-water masses over prolonged periods of time, which, while preventing their use in high-resolution studies, would provide an effective means of yielding reliable average estimates on past εNd signatures of bottom-water masses. In this regard, glauconitic grains are probably better-suited to paleoceanographic reconstructions than foraminifera and leached Fe-oxyhydroxide fractions, which appear to be influenced by sediment redistribution and the presence of terrestrial continental Fe-oxides, respectively. Direct methodological access to the compositions of the semi-confined microenvironments of neoformation has largely renewed the information, chemical or crystallographic, that was previously, and for a long time, restricted to macromeasurements. The various granular supports (mudclasts, fecal pellets, and foraminifera infillings) include inherited 1:1 clays (or Te-Oc; i.e., clay minerals consisting of one tetrahedral sheet and one octahedral sheet, such as kaolinite) that are gradually replaced by 2:1 clays (Te-Oc-Te) dominated first by smectite, and then by glauconite. In small pores, the water’s activity is diminished; as a consequence, the precipitation of a great number of mineral species is thereby made easier, and their stability domains are changed. A specific methodological approach allows the study of the mineralogy and chemistry of the fine-scale mineral phases and to avoid the global aspect of the analytical methods previously used in the initial studies. Wide-field micrographs taken at a mean direct magnification of 100.000 show the intimate and characteristic organization of the main phases that occur in a single grain. One or several “fine” (about 10 nanometers in scale) microchemical analyses can be recorded, and directly coupled with each interesting and well-identified structure image observed in HRTEM.
Physiological Stress as Risk Factor for Hypersensitivity to Contrast Media: A Narrative Review of the Literature and a Proposal of Psychophysiological Tools for Its Detection
Authors: Pruneti Carlo , Guidotti Sara
Published: July 2022

The use of contrast media in clinical diagnostic practice has increased significantly in recent years, accompanied by an increase in adverse reactions. These are the fleeting symptoms most complained about by patients: Flushing of the face, feeling of nausea, and heat lasting a few seconds, considered side effects related to the drug. Hypersensitivity reactions are rarer but dangerous and are driven by the immune system. To ensure the optimal management of adverse reactions to iodinated contrast media, various types of health specialists, such as radiologists, are looking into how to deal with the problem. While there are many suggestions in the scientific literature on what to do in the case of important reactions during or after radiological examination, unfortunately, there are no studies on primary and secondary prevention and, in particular, on psychophysical and psychophysiological influences. Some inferences could be made by observing the studies about psychophysiological stress and immune-inflammatory processes of allergies. The few studies in the literature on the analysis of processes affecting both psychophysiological stress and allergic responses have been analyzed. Finally, stress measurement methods are proposed that can highlight “hypersensitive” people with physiological characteristics capable of exacerbating or accentuating an allergic reaction to contrast media.
Dir-MUSIC Algorithm for DOA Estimation of Partial Discharge Based on Signal Strength Represented by Antenna Gain Array Manifold
Authors: Xu Wencong , Chen Bingshu , Li Yandong , Hu Yue , Li Jianxun , Zeng Zijing
Published: July 2022

Inspection robots are widely used in the field of smart grid monitoring in substations, and partial discharge (PD) is an important sign of the insulation state of equipment. PD direction of arrival (DOA) algorithms using conventional beam forming and time difference of arrival (TDOA) require large-scale antenna arrays and high computational complexity, making them difficult to implement on inspection robots. To address this problem, a novel directional multiple signal classification (Dir-MUSIC) algorithm for PD direction finding based on signal strength is proposed, and a miniaturized directional spiral antenna circular array is designed in this paper. First, the Dir-MUSIC algorithm is derived based on the array manifold characteristics. This method uses strength intensity information rather than the TDOA information, which could reduce the computational difficulty and the requirement of array size. Second, the effects of signal-to-noise ratio (SNR) and array manifold error on the performance of the algorithm are discussed through simulations in detail. Then, according to the positioning requirements, the antenna array and its arrangement are developed and optimized. Simulation results suggested that the algorithm has reliable direction-finding performance in the form of six elements. Finally, the effectiveness of the algorithm is tested by using the designed spiral circular array in real scenarios. The experimental results show that the PD direction-finding error is 3.39°, which meets the need for partial discharge DOA estimation using inspection robots in substations.
An Underwater Positioning System for UUVs Based on LiDAR Camera and Inertial Measurement Unit
Authors: Yang Hongbo , Xu Zhizun , Jia Baozhu
Published: July 2022

Underwater positioning presents a challenging issue, because of the rapid attenuation of electronic magnetic waves, the disturbances and uncertainties in the environment. Conventional methods usually employed acoustic devices to localize Unmanned Underwater Vehicles (UUVs), which suffer from a slow refresh rate, low resolution, and are susceptible to the environmental noise. In addition, the complex terrain can also degrade the accuracy of the acoustic navigation systems. The applications of underwater positioning methods based on visual sensors are prevented by difficulties of acquiring the depth maps due to the sparse features, the changing illumination condition, and the scattering phenomenon. In the paper, a novel visual-based underwater positioning system is proposed based on a Light Detection and Ranging (LiDAR) camera and an inertial measurement unit. The LiDAR camera, benefiting from the laser scanning techniques, could simultaneously generate the associated depth maps. The inertial sensor would offer information about its altitudes. Through the fusion of the data from multiple sensors, the positions of the UUVs can be predicted. After that, the Bundle Adjustment (BA) method is used to recalculate the rotation matrix and the translation vector to improve the accuracy. The experiments are carried out in a tank to illustrate the effects and accuracy of the investigated method, in which the ultra-wideband (UWB) positioning system is used to provide reference trajectories. It is concluded that the developed positioning system is able to estimate the trajectory of UUVs accurately, whilst being stable and robust.
Design and Implementation of a Subnanometer Heterodyne Interference Signal Processing Algorithm with a Dynamic Filter
Authors: Zeng Qilin , Zhao Zhengyi , Xiong Xianming , Du Hao , Zhang Wentao , Zhang Zhicheng , Wang Peng , Lei Lihua
Published: July 2022

In this study, a subnanometer heterodyne interference signal processing algorithm with a dynamic filter is proposed. The algorithm can effectively reduce the measurement error caused by the noise introduced in the optical path and circuit. Because of the low signal−to−noise ratio of the measurement signal, a dynamic filter with variable coefficients is designed. The role of the bi−quadrature lock−in amplifier algorithm in the problem of different amplitudes among the measurement signal, reference signal, and uncertainty of the frequency difference of the dual−frequency laser is analyzed. With the aid of the heterodyne interferometry platform, the error in the solution results of the proposed algorithm and the conventional algorithm is compared. The results indicate that the maximum deviation of the phase increment of the algorithm does not exceed 6 mrad, the single−cycle phase difference can be subdivided by 1024, and the system resolution reaches 0.15 nm.
Crosstalk Defect Detection Method Based on Salient Color Channel Frequency Domain Filtering
Authors: Xie Wenqiang , Chen Huaixin , Wang Zhixi , Liu Xing , Liu Biyuan , Shuai Lingyu
Published: July 2022

Display crosstalk defect detection is an important link in the display quality inspection process. We propose a crosstalk defect detection method based on salient color channel frequency domain filtering. Firstly, the salient color channel in RGBY is selected by the maximum relative entropy criterion, and the color quaternion matrix of the displayed image is formed with the Lab color space. Secondly, the image color quaternion matrix is converted into the logarithmic spectrum in the frequency domain through the hyper-complex Fourier transform. Finally, Gaussian threshold band-pass filtering and hyper-complex inverse Fourier transform are used to separate the low-contrast defects and background of the display image. The experimental results show that the accuracy of the proposed algorithm reaches 96% for a variety of crosstalk defect detection. Compared with the current advanced defect detection algorithms, the effectiveness of the proposed method for low-contrast crosstalk defect detection is confirmed.
Identification of Bamboo Species Based on Extreme Gradient Boosting (XGBoost) Using Zhuhai-1 Orbita Hyperspectral Remote Sensing Imagery
Authors: Zhou Guoli , Ni Zhongyun , Zhao Yinbing , Luan Junwei
Published: July 2022

Mapping the distribution of bamboo species is vital for the sustainable management of bamboo and for assessing its ecological and socioeconomic value. However, the spectral similarity between bamboo species makes this work extremely challenging through remote sensing technology. Existing related studies rarely integrate multiple feature variables and consider how to quantify the main factors affecting classification. Therefore, feature variables, such as spectra, topography, texture, and vegetation indices, were used to construct the XGBoost model to identify bamboo species using the Zhuhai-1 Orbita hyperspectral (OHS) imagery in the Southern Sichuan Bamboo Sea and its surrounding areas in Sichuan Province, China. The random forest and Spearman’s rank correlation analysis were used to sort the main variables that affect classification accuracy and minimize the effects of multicollinearity among variables. The main findings were: (1) The XGBoost model achieved accurate and reliable classification results. The XGBoost model had a higher overall accuracy (80.6%), kappa coefficient (0.708), and mean F1-score (0.805) than the spectral angle mapper (SAM) method; (2) The optimal feature variables that were important and uncorrelated for classification accuracy included the blue band (B1, 464–468 nm), near-infrared band (B27, 861–871 nm), green band (B5, 534–539 nm), elevation, texture feature mean, green band (B4, 517–523 nm), and red edge band (B17, 711–720 nm); and (3) the XGBoost model based on the optimal feature variable selection showed good adaptability to land classification and had better classification performance. Moreover, the mean F1-score indicated that the model could well balance the user’s and producer’s accuracy. Additionally, our study demonstrated that OHS imagery has great potential for land cover classification and that combining multiple features to enhance classification is an approach worth exploring. Our study provides a methodological reference for the application of OHS images for plant species identification.
Environmental Sustainability Commitment and Access to Finance by Small and Medium Enterprises: The Role of Financial Performance and Corporate Governance
Authors: Dzomonda Obey
Published: July 2022

Small and Medium Enterprises in South Africa contribute critically to the economy, yet they face many challenges, such as lack of access to external finance. Thus, applying the stakeholder theory, this study tested the relationship between environmental sustainability commitment and access to finance and whether this relationship was mediated by financial performance. The study further examined the moderating role of corporate governance on the relationship between environmental sustainability commitment and access to finance. Owner/managers of 600 SMEs from three provinces in South Africa were randomly selected using a probability sampling method. Primary data were collected using self-administered questionnaires. The moderated mediation model was tested using PLS-SEM. The findings showed that environmental sustainability commitment significantly predicts access to finance both directly and indirectly through financial performance. Moreover, the results showed that corporate governance positively moderates the link between environmental sustainability commitment and access to finance. This study has several implications. Practically, small unlisted firms can adopt and apply the model developed in this study to enhance their environmental, social, and governance practices to unlock external funding. The novelty of this study is that it proposed and tested a moderated mediation model to understand SMEs’ determinants of access to finance. In addition, this study provides a nuanced understanding of responsible business through green behaviour in the context of SMEs, which has been lacking in the existing literature.
Research on the Impact of Technical Measures on Enterprise Export Participation
Authors: Wang Han-Lin , Zhao Wan-Wan
Published: July 2022

Technical Measures to Trade have the characteristics of strong concealment and imperceptibility, which makes some WTO members frequently use “technical barriers” to restrict China’s product exports. Based on the multi-period differences-in-differences method, we use micro-data at the level of Chinese companies from 2000 to 2013 to empirically test the impact of technical measures on the export participation of companies from the perspective of corporate heterogeneity. The study found that for the strength of the technical measures, the coefficients on the technical measures variables are all significantly positive. From the perspective of the types of Technical Measures to Trade, the increase of Technical Barriers to Trade and Pre-shipment Inspection has significantly improved enterprises, and the promotion effect of Sanitary and Phytosanitary Measures on the export participation degree of enterprises is not significant. According to the intermediary effect model, it can be concluded that there is an indirect transmission channel through which technical measures affect the participation of enterprises in export through export diversification.
Propuesta de modernización del sistema de control de temperatura de la Máquina Flejadora de la Empresa Mixta Compacto caribe S.A de Santiago de Cuba
Authors: Canjimbi Ngombe L. C. , Giralt Sánchez A. , Garbey Torres M. , Andrial Mora Y.
Published: July 2022

El presente trabajo tiene como objetivo modernizar el sistema de control de temperatura de la Máquina Flejadora de la Empresa Mixta Compacto Caribe S.A de Santiago de Cuba.  Esta propuesta es elaborada mediante un control lógico programable, se establece el control de temperatura ON/OFF con un rango de 270ºc a 300ºc. Se realizó la programación del PLC utilizando el software SoMachin Basic. Se explican los sistemas de control, la instrumentación, y un sistema de supervisión del proceso soportado sobre el Software SoMachine, Vijeo Designer.

 

Palabras claves— Flejadora, PLC.,
Diseño de un sistema de control automático para la alimentación de caña del tándem en el central “Argeo Martínez”
Authors: Bazan de los Santos M. , Giralt Sánchez A. , Garbey Torres M. , AndrialMora Y.
Published: July 2022

En ésta investigación se proyecta un sistema de control automático, que garantiza el flujo constante de caña al primer molino del tándem en el Central Argeo Martínez de la provincia de Guantánamo en Cuba; de forma que se garantiza la eficiencia de extracción de jugos durante el proceso de molienda. Para esto fue necesario caracterizar los sistemas de alimentación de caña, así como el análisis de la situación actual del proceso en dicho central. Se presenta además, la arquitectura del sistema de control propuesto, la selección de la estrategia de control, así como el modelado y cálculo de la potencia de los motores que demandada el proceso. Se caracterizaron los diferentes instrumentos que se usan en el proceso. Se describió el PLC de la marca Mitsubishi de la serie FX3U -32M.

 

Palabras claves— Regulador de frecuencia, micro-controladores PSoC, centrales hidroeléctricas.
INFLUENCIA DEL GASTO E INVERSION PUBLICA EN EL DESARROLLO DE VIAS NO CONSECIONADAS EN ZONAS RURALES
Authors: Vladimir Chimborazo Marco
Published: July 2022

En la última década mediante de la aplicación de certeros cambios en la matriz productiva, se ha evidenciado un cambio acelerado en la producción del país, lo cual como consecuencia ha inferido a restablecer la vialidad a nivel nacional y en muchos casos a incrementarla para satisfacer la creciente demanda a nivel nacional y en especial a nivel industrial, siendo este es el motivo el cual impulsó el desarrollar una investigación la cual analizó la gestión realizada por un ente Gubernamental encargado de la proyección y construcción vial en función del tiempo y determinar su cumplimiento en virtud de lo programado y lo ejecutado.
Prediction of Groundwater Level in Safwan-Zubair Area Using Artificial Neural Networks
Authors: Al-Aboodi Ali , Khudhair Kifah , Al-Aidani Ali
Published: July 2022

Safwan-Zubair area is regarded as one of theimportant agricultural areas in Basrah province, South of Iraq.The aim of this study is to predict groundwater level in this areausing ANNs model. The data required for building the ANNmodel are generated using MODFLOW model (V.5.3).MODFLOW model was calibrated based on field measurementsof groundwater level in13 monitoring wells during a period ofone year (Nov./2013 to Oct/2014). The neural network toolboxavailable in MATLAB version 7.1 (2010B) was used to developthe ANN models. Three layers feed-forward network with Log-sigmoid transfer function was used. The networks were trainedusing Levenberg-Marquardt back-propagation algorithm. TheANN modes are divided into two groups, each of four models.The input data of the first group include hydraulic heads, while,the input data of the second group include hydraulic heads andrecharge rates. Based on results of this study it was found that;the best ANN model for predicting groundwater levels in thestudy area is obtained when the input data includes hydraulicheads and recharge rates of two successive months preceding thetarget month, the best structure of ANN model is of three layersfeed-forward network type composes of two hidden layers, eachof ten nodes, and the including of recharge rates as input data,beside the hydraulic heads has improved slightly the results.
Sound Signal Analysis Using FIR Filters for Musical Fountain Operation
Authors: Jasim Ali , Mahmood Jawad , Ali Ramzy
Published: July 2022

In digital signal processing (DSP), FIR digital filter isvery important device to deal with particular frequencies of acertain signal to be appropriate for some applications such ascommunications, sound equalizers, etc. In this paper, FIRfilters are adapted to decompose the original sound signal intofour signals. Each one is created by one FIR filter and eachfilter represents a narrow band of frequencies. The filteroutput is used to drive a certain variable speed drive (VSD) tocontrol the speed of a water pump and light intensity of acolored lamp. This filter output signal is applied to the analogcontrol voltage terminals of the VSD unit to control thefrequency and magnitude of the voltage supplied to the lampand pump. Thus, the heads of the water jets and the lightintensity is controlled according to the analog control signalswhich are created by the FIR filters (The VSD is used to mapthe filter output into light intensity and water head bycontrolling the supplied voltage of them). The goal of this studyis to design and simulate four sound harmonics bandsproduced by FIR filters to drive four VSDs which aresimulated using V/F ratio constant method for musicalfountain operation.
IDENTIFIKASI PROFIL FITOKIMIA DAUN TORBANGUN (Coleus amboinicus) UNTUK MENINGKATKAN PRODUKSI ASI
Authors: Yulinda Dwi , Rahmawati Sholihah Nur
Published: July 2022

Coleus amboinicus merupakan tumbuhan yang memiliki metabolit sekunder yaitu saponin, alkaloid, flavonoid, polifenol dan minyak atsiri. Senyawa yang sangat berpengaruh terhadap peningkatan produksi ASI termasuk dalam polifenol. Beberapa bentuk pemanfaatan daun torbangun banyak digunakan untuk meningkatkan produksi ASI dalam bentuk tablet dan teh. Perlunya inovasi baru untuk lebih meningkatkan daya konsumsi adalah dengan membuat simplisia daun torbangun dalam bentuk effervescent. Perlu dilakukan penelitian untuk mengetahui kandungan metabolit sekunder daun torbangun. Penelitian ini bertujuan untuk mengetahui kandungan metabolit sekunder daun torbangun melalui uji fitokimia. Penelitian eksperimental dengan metode kualitatif untuk mengetahui kandungan fitokimia pada daun torbangun dilakukan di laboratorium farmasi. Dimulai dengan ekstraksi dan dilanjutkan dengan pengujian. Identifikasi profil fitokimia dapat dilihat dari perubahan warna dan karakteristik ekstraksi daun torbangun dengan menambahkan beberapa bahan kimia yang berfungsi untuk mengikat fitokimia. Karakteristik organoleptic bentuk serbuk kering, warna hijau kehitaman, bau langu, rasa pahit. Fitokimia yg teridentifikasi antara lain alkaloid, flavonoid, saponin, terpenoid dan steroid, serta tannin. Hasil pengembangan KLT akan dideteksi di bawah sinar tampak, UV 254, dan UV 366 untuk melihat pola kandungan senyawanya.

Coleus amboinicus is a plant that has secondary metabolites, namely saponins, alkaloids, flavonoids, polyphenols and essential oils. Compounds that are very influential on increasing breast milk production include polyphenols. Several forms of utilization of torbangun leaves are widely used to increase breast milk production in the form of tablets and tea. The need for new innovations to further increase consumption power is to make torbangun leaf simplicia in the form of effervescent. Research needs to be done to determine the content of secondary metabolites of torbangun leaves. This study aims to determine the content of secondary metabolites of torbangun leaves through phytochemical tests. Experimental research using qualitative methods to determine the phytochemical content of torbangun leaves was carried out in a pharmaceutical laboratory. Starting with extraction and continued with testing. Identification of the phytochemical profile can be seen from the color changes and the extraction characteristics of torbangun leaves by adding several chemicals that function to bind phytochemicals. Organoleptic characteristics of dry powder form, blackish green color, unpleasant odor, bitter taste. The identified phytochemicals include alkaloids, flavonoids, saponins, terpenoids and steroids, and tannins. The results of the TLC development will be detected under visible light, UV 254, and UV 366 to see the pattern of the compound content.