bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk and Protective Factors of Generalized Anxiety Disorder of Elite Collegiate Athletes: A Cross-Sectional Study
Authors: Li Chunxiao , Fan Rong , Sun Jian , Li Guoxing
Published: February 2021

The aim of this study was to examine the prevalence of Generalized Anxiety Disorder (GAD) and its risk and protective factors in elite collegiate athletes. A cross-sectional survey was conducted during the 2019 in-season. A sample of elite collegiate athletes (n = 285) from China completed a self-report form assessing GAD and potential predictors including age, gender, sport type, sport achievement, sport injury, attention deficit hyperactivity disorder (ADHD), fear of failure, mental toughness, and satisfaction in sport. The overall prevalence of GAD symptoms was 22%. The results of zero-order correlation showed that age, gender, sport type, and sport achievement were not significantly related to GAD. However, athletes with a history of sport injury, a high risk of ADHD, and a high level of fear of failure had a significant and positive association with GAD (r = 0.14–0.54). Meanwhile, high levels of mental toughness and satisfaction in sport were significantly and negatively related to GAD (r = −0.22 to −0.24). The results of multiple regression analysis indicated that sport injury, ADHD, and fear of failure were significant risk factors of GAD (β = 0.10–0.40). These findings suggest the necessity to understand the GAD symptoms in elite collegiate athletes. Further research is needed to better understand and support the mental health of this target group.
Diagnosis of Patellofemoral Pain Syndrome Based on a Multi-Input Convolutional Neural Network With Data Augmentation
Authors: Shi Wuxiang , Li Yurong , Xiong Baoping , Du Min
Published: February 2021

Patellofemoral pain syndrome (PFPS) is a common disease of the knee. Despite its high incidence rate, its specific cause remains unclear. The artificial neural network model can be used for computer-aided diagnosis. Traditional diagnostic methods usually only consider a single factor. However, PFPS involves different biomechanical characteristics of the lower limbs. Thus, multiple biomechanical characteristics must be considered in the neural network model. The data distribution between different characteristic dimensions is different. Thus, preprocessing is necessary to make the different characteristic dimensions comparable. However, a general rule to follow in the selection of biomechanical data preprocessing methods is lacking, and different preprocessing methods have their own advantages and disadvantages. Therefore, this paper proposes a multi-input convolutional neural network (MI-CNN) method that uses two input channels to mine the information of lower limb biomechanical data from two mainstream data preprocessing methods (standardization and normalization) to diagnose PFPS. Data were augmented by horizontally flipping the multi-dimensional time-series signal to prevent network overfitting and improve model accuracy. The proposed method was tested on the walking and running datasets of 41 subjects (26 patients with PFPS and 15 pain-free controls). Three joint angles of the lower limbs and surface electromyography signals of seven muscles around the knee joint were used as input. MI-CNN was used to automatically extract features to classify patients with PFPS and pain-free controls. Compared with the traditional single-input convolutional neural network (SI-CNN) model and previous methods, the proposed MI-CNN method achieved a higher detection sensitivity of 97.6%, a specificity of 76.0%, and an accuracy of 89.0% on the running dataset. The accuracy of SI-CNN in the running dataset was about 82.5%. The results prove that combining the appropriate neural network model and biomechanical analysis can establish an accurate, convenient, and real-time auxiliary diagnosis system for PFPS to prevent misdiagnosis.
Populism and Protest
Authors: Hirschmann Nancy J.
Published: February 2021

The essay considers populism in the present moment in relation to Black Lives Matter as a popular protest movement. Popular protest movements demand that government change; populism in the present moment seeks to act extra-governmentally, and to this end relies on violence in the face of peace protest movement. This violence demonstrates the white patriarchalism of contemporary populism. I argue that peaceful, popular protest is an important tool to resist white patriarchal populist authoritarianism.
Pain During a Marathon Run: Prevalence and Correlates in a Cross-Sectional Study of 1,251 Recreational Runners in 251 Marathons
Authors: O'Connor Patrick J.
Published: February 2021

This cross-sectional study aimed to obtain fundamental knowledge about pain during a marathon run. During the first seven months of 2007, announcements on websites of interest to marathon runners were used to recruit participants. A total of 1,251 runners (550 female runners) completed a 41-question online survey about the location and intensity of their primary pain during their last marathon and potentially related variables [perception of effort during the marathon, number of prior marathons run, typical pain intensity during training runs, percentage of training days with run-induced pain, highest intensity pain ever experienced]. Pain location was selected from a list of 27 specified body sites covering the entire body. Kilometer at which pain first occurred indexed pain threshold. Pain intensity at the primary location of pain was measured with a standardized, well-validated 0–10 pain intensity scale. Pearson correlations and multiple regression quantified the associations between average pain intensity and other variables. Sex-related differences in pain were tested using independent t-tests. Effort ratings (6–20) were added as a covariate in an ANCOVA to test if perceived effort accounted for possible sex-related differences in pain. Based on the available research, it was hypothesized that: (i) most runners would report moderate intensity pain, (ii) pain would be associated with both exercise intensity during the marathon and pain during training, and (iii) after adjusting for expected sex-related differences in perceived effort, females would experience pain earlier and rate the pain intensity as higher. All but two runners (99.8%) reported pain during a marathon, and most frequently in the anterior/medial thigh (17.1%), hamstring (10%), and calf (9.3%) locations. Pain threshold occurred at 25.3 ± 9.8 km (15.7 ± 6.1 miles) and the overall pain intensity of the run was 5.26 ± 2.45. No sex-related pain differences were found. Overall pain intensity during a marathon was significantly associated with: pain intensity during training runs (r = 0.39), percentage of training days with run-induced pain (r = 0.23), highest intensity pain ever experienced (r = 0.23), number of prior marathons (r = −0.18), and intensity of effort (r = 0.11) (all P < 0.001). Most runners experience moderate to very strong intensity pain during a marathon; the pain was independent of biological sex, and the pain is weakly associated with marathon race experience, pain during training, race effort, and the highest intensity of pain ever experienced.
Possible Antiviral Activity of 5-Aminolevulinic Acid in Feline Infectious Peritonitis Virus (Feline Coronavirus) Infection
Authors: Takano Tomomi , Satoh Kumi , Doki Tomoyoshi
Published: February 2021

Feline infectious peritonitis (FIP) is a life-threatening infectious disease of cats caused by virulent feline coronavirus (FIP virus: FIPV). For the treatment of FIP, several effective antivirals were recently reported, but many of these are not available for practical use. 5-amino levulinic acid (5-ALA) is a low-molecular-weight amino acid synthesized in plant and animal cells. 5-ALA can be synthesized in a large amount, and it is widely applied in the medical and agricultural fields. We hypothesized that 5-ALA inhibits FIPV infection. Therefore, we evaluated its antiviral activity against FIPV in felis catus whole fetus-4 cells and feline primary macrophages. FIPV infection was significantly inhibited by 250 μM 5-ALA. Our study suggested that 5-ALA is applicable for the treatment and prevention of FIPV infection.
Requirements for Sustainable Irrigated Agriculture
Authors: Loiskandl Willibald , Nolz Reinhard
Published: February 2021

The aim of this review is to present a holistic view on irrigation with respect to local environmental and social conditions. Future irrigation development is addressed with a focus on sustainable development. However, technical irrigation aspects are included and references are provided for further reading and completeness. An irrigation intervention is always a combination of feasible technical, social and environmental aspects. This review provides an overview of the various fields of expertise involved in irrigation interventions and contributes to cross-discipline discussions and understanding. The selected cases demonstrate the bias of human developments and they serve to raise awareness of the impact of human interventions. The practical examples refer mainly to the authors’ project experiences and were selected so as to support pathways for sustainable irrigation development. Placing modern irrigation in relation to sustainable development goals needs a sophisticated holistic approach.
Ceftobiprole Perspective: Current and Potential Future Indications
Authors: Lupia Tommaso , Pallotto Carlo , Corcione Silvia , Boglione Lucio , De Rosa Francesco Giuseppe
Published: February 2021

Ceftobiprole combines an excellent spectrum for community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP) pathogens, with a low/medium MDR risk, and the β-lactams’ safety in frail patients admitted to the hospital in internal medicine wards which may be at high risk of adverse events by anti-MRSA coverage as oxazolidinones or glycopeptides. We aimed to report the available evidence regarding ceftobiprole use in pneumonia and invasive bacterial infections, shedding light on ceftobiprole stewardship. The clinical application and real-life experiences of using ceftobiprole for bloodstream infections, including infective endocarditis, are limited but nevertheless promising. In addition, extended-spectrum ceftobiprole activity, including Enterococcus faecalis, Enterobacteriaceae, and Pseudomonas aeruginosa, has theoretical advantages for use as empirical therapy in bacteremia potentially caused by a broad spectrum of microorganisms, such as catheter-related bacteremia. In the future, the desirable approach to sepsis and severe infections will be administered to patients according to their clinical situation, the intrinsic host characteristics, the susceptibility profile, and local epidemiology, while the “universal antibiotic strategy” will no longer be adequate.
Energy Efficient Secure Communication Model against Cooperative Eavesdropper
Authors: Rajaram Akashkumar , Jayakody Dushnatha Nalin K. , Dinis Rui , Beko Marko
Published: February 2021

In a wiretap channel system model, the jammer node adopts the energy-harvesting signal as artificial noise (jamming signal) against the cooperative eavesdroppers. There are two eavesdroppers in the wiretap channel: eavesdropper E1 is located near the transmitter and eavesdropper E2 is located near the jammer. The eavesdroppers are equipped with multiple antennas and employ the iterative block decision feedback equalization decoder to estimate the received signal, i.e., information signal at E1 and jamming signal at E2. It is assumed that E1 has the channel state information (CSI) of the channel between transmitter and E1, and similarly, E2 has the CSI of channel between jammer and E2. The eavesdroppers establish communication link between them and cooperate with each other to reduce the information signal interference at E2 and jamming signal interference at E1. The performance of decoders depends on the signal to interference plus noise ratio (SINR) of the received signal. The power of information signal is fixed and the power of the jamming signal is adjusted to improve the SINR of the received signal. This research work is solely focused on optimizing the jamming signal power to degrade the performance of cooperative eavesdroppers. The jamming signal power is optimized for the given operating SINR with the support of simulated results. The jamming signal power optimization leads to better energy conservation and degrades the performance of eavesdroppers.
A Study on Deep Learning Application of Vibration Data and Visualization of Defects for Predictive Maintenance of Gravity Acceleration Equipment
Authors: Lee SeonWoo , Yu HyeonTak , Yang HoJun , Song InSeo , Choi JungMu , Yang JaeHeung , Lim GangMin , Kim Kyu-Sung , Choi ByeongKeun , Kwon JangWoo
Published: February 2021

Hypergravity accelerators are a type of large machinery used for gravity training or medical research. A failure of such large equipment can be a serious problem in terms of safety or costs. This paper proposes a prediction model that can proactively prevent failures that may occur in a hypergravity accelerator. An experiment was conducted to evaluate the performance of the method proposed in this paper. A 4-channel accelerometer was attached to the bearing housing, which is a rotor, and time-amplitude data were obtained from the measured values by sampling. The method proposed in this paper was trained with transfer learning, a deep learning model that replaced the VGG19 model with a Fully Connected Layer (FCL) and Global Average Pooling (GAP) by converting the vibration signal into a short-time Fourier transform (STFT) or Mel-Frequency Cepstral Coefficients (MFCC) spectrogram and converting the input into a 2D image. As a result, the model proposed in this paper has seven times decreased trainable parameters of VGG19, and it is possible to quantify the severity while looking at the defect areas that cannot be seen with 1D.
Phosphogypsum Recycling: A Review of Environmental Issues, Current Trends, and Prospects
Authors: Chernysh Yelizaveta , Yakhnenko Olena , Chubur Viktoriia , Roubík Hynek
Published: February 2021

The problem of recycling and storage of phosphogypsum is topical for many countries around the world, as it is associated with environmental problems of pollution of water bodies, land, and atmosphere. Therefore, this paper analyzes the directions of phosphogypsum recycling and possible alternatives to its use. The main disadvantages of the existing methods of phosphogypsum processing were identified and trends in this waste management were also considered. Through the VOSviewer programme, a visualization of cluster interconnections was carried out in research publications of various fields of phosphogypsum utilization. Five clusters were formed: a red cluster—phosphogypsum recycling in the construction industry; green cluster—radiation pollution problem of phosphogypsum and phosphate fertilizers; yellow cluster—monitoring migration of phosphogypsum components in the ecosystem, with the mobile forms of heavy metals and their inflow into aquifers from phosphogypsum dumps; blue cluster—use of phosphogypsum in agriculture as an ameliorant and a component of fertilizer; and a purple cluster—the impact of phosphogypsum on microorganisms, particularly in bioremediation processes. Under the proposed integrated biochemical approach, the use of various bioprocesses of phosphogypsum recovery from waste dumps and implementation of new biotechnological solutions for processing phosphorus raw materials are presented.
A Molecularly Imprinted Polymer for Selective Extraction of Phenolic Acids from Human Urine
Authors: Mora-Granados Marco , González-Gómez David , Jeong Jin Su , Gallego-Picó Alejandrina
Published: February 2021

Studies for monitoring the bioavailability of dietary flavonoid compounds generate great interest. Among them, low-molecular-weight phenolic acids, secondary metabolites present in colonic catabolism and urinary excretion, have been proposed as biomarkers of polyphenol intake. Using 4-hydroxyphenylacetic acid as a template, a molecularly imprinted polymer (MIP) was synthesized for selective extraction of these hydroxylated metabolites from human urine samples and posterior analysis in an HPLC-DAD-MS system. Polymers were characterized by Scanning electron microscopy (SEM), Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), Brunauer-Emmett-Teller (BET) method, and binding experiments. MIP presents specific recognition ability for template and analogues molecules. This capacity of recognition and the pH dependence of the binding strength was also studied. The method was validated over a concentration range of 0.25–40 mg/L, r2 > 0.995. In the optimized conditions, the recovery value was 94% with RSD 1.2%. The Limit of Detection (LOD) and Limit of Quantification (LOQ) were 1.22 and 3.69 mg/L, respectively. In our knowledge, it is the first time that this methodology is applied to analyze urinary catabolites of the polyphenol compound and to provide a specific method and simple analysis alternative. The selective extraction of these metabolites improves the application and results obtained by other less sensitive analysis methods than the validation method. It also facilitates the development of new screening methods.
Crucial Role of Juvenile Hormone Receptor Components Methoprene-Tolerant and Taiman in Sexual Maturation of Adult Male Desert Locusts
Authors: Holtof Michiel , Van Lommel Joachim , Gijbels Marijke , Dekempeneer Elfie , Nicolai Bart , Vanden Broeck Jozef , Marchal Elisabeth
Published: February 2021

Currently (2020), Africa and Asia are experiencing the worst desert locust (Schistocerca gregaria) plague in decades. Exceptionally high rainfall in different regions caused favorable environmental conditions for very successful reproduction and population growth. To better understand the molecular mechanisms responsible for this remarkable reproductive capacity, as well as to fill existing knowledge gaps regarding the regulation of male reproductive physiology, we investigated the role of methoprene-tolerant (Scg-Met) and Taiman (Scg-Tai), responsible for transducing the juvenile hormone (JH) signal, in adult male locusts. We demonstrated that knockdown of these components by RNA interference strongly inhibits male sexual maturation, severely disrupting reproduction. This was evidenced by the inability to show mating behavior, the absence of a yellow-colored cuticle, the reduction of relative testes weight, and the drastically reduced phenylacetonitrile (PAN) pheromone levels of the treated males. We also observed a reduced relative weight, as well as relative protein content, of the male accessory glands in Scg-Met knockdown locusts. Interestingly, in these animals the size of the corpora allata (CA), the endocrine glands where JH is synthesized, was significantly increased, as well as the transcript level of JH acid methyltransferase (JHAMT), a rate-limiting enzyme in the JH biosynthesis pathway. Moreover, other endocrine pathways appeared to be affected by the knockdown, as evidenced by changes in the expression levels of the insulin-related peptide and two neuroparsins in the fat body. Our results demonstrate that JH signaling pathway components play a crucial role in male reproductive physiology, illustrating their potential as molecular targets for pest control.
Dysregulation of PGC-1α-Dependent Transcriptional Programs in Neurological and Developmental Disorders: Therapeutic Challenges and Opportunities
Authors: McMeekin Laura J. , Fox Stephanie N. , Boas Stephanie M. , Cowell Rita M.
Published: February 2021

Substantial evidence indicates that mitochondrial impairment contributes to neuronal dysfunction and vulnerability in disease states, leading investigators to propose that the enhancement of mitochondrial function should be considered a strategy for neuroprotection. However, multiple attempts to improve mitochondrial function have failed to impact disease progression, suggesting that the biology underlying the normal regulation of mitochondrial pathways in neurons, and its dysfunction in disease, is more complex than initially thought. Here, we present the proteins and associated pathways involved in the transcriptional regulation of nuclear-encoded genes for mitochondrial function, with a focus on the transcriptional coactivator peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1α). We highlight PGC-1α’s roles in neuronal and non-neuronal cell types and discuss evidence for the dysregulation of PGC-1α-dependent pathways in Huntington’s Disease, Parkinson’s Disease, and developmental disorders, emphasizing the relationship between disease-specific cellular vulnerability and cell-type-specific patterns of PGC-1α expression. Finally, we discuss the challenges inherent to therapeutic targeting of PGC-1α-related transcriptional programs, considering the roles for neuron-enriched transcriptional coactivators in co-regulating mitochondrial and synaptic genes. This information will provide novel insights into the unique aspects of transcriptional regulation of mitochondrial function in neurons and the opportunities for therapeutic targeting of transcriptional pathways for neuroprotection.
The Metabolic Stability of the Nicotinic Acetylcholine Receptor at the Neuromuscular Junction
Authors: Martinez-Pena y Valenzuela Isabel , Akaaboune Mohammed
Published: February 2021

The clustering and maintenance of nicotinic acetylcholine receptors (AChRs) at high density in the postsynaptic membrane is a hallmark of the mammalian neuromuscular junction (NMJ). The regulation of receptor density/turnover rate at synapses is one of the main thrusts of neurobiology because it plays an important role in synaptic development and synaptic plasticity. The state-of-the-art imaging revealed that AChRs are highly dynamic despite the overall structural stability of the NMJ over the lifetime of the animal. This review highlights the work on the metabolic stability of AChRs at developing and mature NMJs and discusses the role of synaptic activity and the regulatory signaling pathways involved in the dynamics of AChRs.
Graphite Studded with Facile-Synthesized Cu2O Nanoparticle-Based Cubes as a Novel Electrochemical Sensor for Highly Sensitive Voltametric Determination of Mebeverine Hydrochloride
Authors: Naggar Ahmed H. , Kotb Ahmed , Gahlan Ahmed A. , Mahross Mahmoud H. , El-Sayed Abd El-Aziz Y. , Abdelwahab Adel A.
Published: February 2021

Herein, a feasible chemical reduction method followed by intensive mixing was applied for the preparation of an attractive material based on graphite studded with cuprous oxide nanoparticle-based cubes (Cu2ONPs–C@G). Transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD) and cyclic voltammetry (CV) were utilized for characterization. Cuprous oxide nanoparticles (Cu2ONPs), with a diameter range mainly distributed from 4 to 20 nm, aggregate to form microcubes (Cu2ONPs–C) with an average diameter of about 367 nm. Paste electrode was prepared using Cu2ONPs–C@G (Cu2ONPs–C@G/PE) for voltametric quantification of the musculotropic antispasmodic drug: mebeverine hydrochloride (MEB). The electrochemical behavior of MEB was studied using CV, and the optimum analytical parameters were investigated using square wave adsorptive anodic stripping voltammetry (SWAdASV). Moreover, density functional theory (DFT) was used to emphasize the ability of MEB to form a complex with Cu2+, confirming the suggested electrochemical behavior of MEB at Cu2ONPs–C@G/PE. With good stability and high reproducibility, SWAdASV of Cu2ONPs–C@G/PE shows successful quantification of MEB over the concentration range of 5.00 × 10−11–1.10 × 10−9 M with lower limit of detection (LOD) and lower limit of quantification (LOQ) values of 2.41 × 10−11 M and 8.05 × 10−11 M, respectively. Finally, accurate quantification of MEB in dosage forms (tablets) and biological fluids (spiked human urine and plasma samples) was achieved using Cu2ONPs-C@G/PE.
Factors Affecting the Quality of Sleep in Children
Authors: Fadzil Ahmad
Published: February 2021

Sleep quality is one of the domains of sleep. Having adequate quality sleep is defined as one’s “feeling fresh” after waking-up. Inadequate sleep quality results in sleep insufficiency producing a variety of symptoms and signs. The central nervous system is affected the most in children, although other system too may be involved. Several factors affect sleep quality in children including genetics, sleep habits, medical problems, parents/caregiver factors, screen time and the child’s environment. These factors are inter-related and dynamic. The outcome of sleep insufficiency is many involving neurocognitive and neurobehavior, mood and emotional issues and specific conditions, like pulmonary hypertension, cor pulmonale and obesity. Management should start with proper history taking to identify the multifaceted nature of the condition. Treatment is planned cognizant of the age of the patient and the associated etiological factors, and should involve both the children and their parents.
Long-Term Changes of Aquatic Invasive Plants and Implications for Future Distribution: A Case Study Using a Tank Cascade System in Sri Lanka
Authors: Kariyawasam Champika S. , Kumar Lalit , Kogo Benjamin Kipkemboi , Ratnayake Sujith S.
Published: February 2021

Climate variability can influence the dynamics of aquatic invasive alien plants (AIAPs) that exert tremendous pressure on aquatic systems, leading to loss of biodiversity, agricultural wealth, and ecosystem services. However, the magnitude of these impacts remains poorly known. The current study aims to analyse the long-term changes in the spatio-temporal distribution of AIAPs under the influence of climate variability in a heavily infested tank cascade system (TCS) in Sri Lanka. The changes in coverage of various features in the TCS were analysed using the supervised maximum likelihood classification of ten Landsat images over a 27-year period, from 1992 to 2019 using ENVI remote sensing software. The non-parametric Mann–Kendall trend test and Sen’s slope estimate were used to analyse the trend of annual rainfall and temperature. We observed a positive trend of temperature that was statistically significant (p value < 0.05) and a positive trend of rainfall that was not statistically significant (p values > 0.05) over the time period. Our results showed fluctuations in the distribution of AIAPs in the short term; however, the coverage of AIAPs showed an increasing trend in the study area over the longer term. Thus, this study suggests that the AIAPs are likely to increase under climate variability in the study area.
Caputo Fractional Derivative and Quantum-Like Coherence
Authors: Culbreth Garland , Bologna Mauro , West Bruce J. , Grigolini Paolo
Published: February 2021

We study two forms of anomalous diffusion, one equivalent to replacing the ordinary time derivative of the standard diffusion equation with the Caputo fractional derivative, and the other equivalent to replacing the time independent diffusion coefficient of the standard diffusion equation with a monotonic time dependence. We discuss the joint use of these prescriptions, with a phenomenological method and a theoretical projection method, leading to two apparently different diffusion equations. We prove that the two diffusion equations are equivalent and design a time series that corresponds to the anomalous diffusion equation proposed. We discuss these results in the framework of the growing interest in fractional derivatives and the emergence of cognition in nature. We conclude that the Caputo fractional derivative is a signature of the connection between cognition and self-organization, a form of cognition emergence different from the other source of anomalous diffusion, which is closely related to quantum coherence. We propose a criterion to detect the action of self-organization even in the presence of significant quantum coherence. We argue that statistical analysis of data using diffusion entropy should help the analysis of physiological processes hosting both forms of deviation from ordinary scaling.
A Single-Amplifier Dual-Residue Pipelined-SAR ADC
Authors: Seo Min-Jae
Published: February 2021

This work presents a 12 bit 200 MS/s dual-residue pipelined successive approximation registers (SAR) analog-to-digital converter (ADC) with a single open-loop residue amplifier (RA). By using the inherent characteristics of the SAR conversion scheme, the proposed ADC sequentially generates two residue levels from the single RA, which eliminates the need for inter-stage gain-matching calibration. To convert the sequentially generated the two residues, a capacitive interpolating SAR ADC (I-SAR ADC) is also proposed. The I-SAR ADC is very compact because it consists of the one comparator, a CDAC, and control logic like a conventional SAR ADC. In addition, the I-SAR ADC needs no static power dissipation for the residue interpolation. A prototype ADC fabricated in a 40 nm CMOS technology occupies an active area of 0.026 mm2. At a 200 MS/s sampling-rate with the Nyquist input, the ADC achieves an SNDR (Signal-to-Noise distortion ratio) of 62.1 dB and 67.1 dB SFDR (Spurious-Free Dynamic Range), respectively. The total power consumed is 3.9 mW under a 0.9 V supply. Without any inter-stage mismatch calibration, the ADC achieve Walden Figure-of-Merit (FoM) of 19.0 fJ/conversion-step.
Three-Output Flyback Converter with Synchronous Rectification for Improving Cross-Regulation and Efficiency
Authors: Leng Chung-Ming , Chiu Huang-Jen
Published: February 2021

This paper proposes a single stage alternating current/direct current (AC/DC) flyback converter which contains three output windings with synchronous rectification (SR) function to achieve better cross-regulation and efficiency. Because the three output windings are stacked in a series structure and use synchronous rectification instead of diode rectification, the forward conduction loss of the diode can be eliminated, and the current of each winding can flow bilaterally. Therefore, the energy of leakage inductance can be dissipated through heavy load winding without transient overvoltage in light load winding. Compared with existing methods in the literature, the proposed converter can be realized by simple analog IC with fewer winding turns. Finally, under the extreme load imbalance condition, the cross-regulation is still within ±2.26%. The maximum efficiency of the proposed converter reaches 87%, which is about 3% higher than the conventional Schottky diode solution’s efficiency. The circuit structure and operation principle are described. A practical prototype and experiment results are implemented to verify the feasibility of the proposed converter.
Research Progress and Prospects of Multi-Stage Centrifugal Pump Capability for Handling Gas–Liquid Multiphase Flow: Comparison and Empirical Model Validation
Authors: Ali Asad , Yuan Jianping , Deng Fanjie , Wang Biaobiao , Liu Liangliang , Si Qiaorui , Buttar Noman Ali
Published: February 2021

The working capability of multi-stage pumps, such as electrical submersible pumps (ESPs) handling multiphase flow, has always been a big challenge for petroleum industries. The major problem is associated with the agglomeration of gas bubbles inside ESP-impellers, causing pump performance degradation ranging from mild to severe deterioration (surging/gas pockets). Previous literature showed that the two-phase performance of ESPs is greatly affected by gas involvement, rotational speed, bubble size, and fluid viscosity. Thus, it is necessary to understand which parameter is actually accountable for performance degradation and different flow patterns in ESP, and how it can be controlled. The present study is mainly focused on (1) the main parameters that impede two-phase performance of different ESPs; (2) comparison of existing empirical models (established for two-phase performance prediction and surging initiation) with our single-stage centrifugal pump results to determine their validity and working-range; (3) gas-handling techniques applied to enhance the multiphase performance of ESPs. Firstly, it aims at understanding the internal flow mechanism in different ESP designs, followed by test studies based on empirical models, visualization techniques, bubble-size measurements, and viscosity analysis. The CFD-based (computational fluid dynamics) numerical analysis concerning multiphase flow is described as well. Furthermore, gas-handling design methods are discussed that are helpful in developing the petroleum industry by enhancing the multiphase performance of ESPs.
GIS Application for the Estimation of Bioenergy Potential from Agriculture Residues: An Overview
Authors: Bharti Avinash , Paritosh Kunwar , Mandla Venkata Ravibabu , Chawade Aakash , Vivekanand Vivekanand
Published: February 2021

Agriculture residue is a promising resource of energy. It can be seen as a source of power production. In India, there is a huge amount of biomass available, but it cannot be used in proper ways, and with the help of GIS it can be customised. In the present paper, it is estimated that biomass reserves are available for power generation. The biomass produced by the surplus agricultural crops is reflected as a source of fuel for electricity generation. The data taken by satellite are useful for assessment of the areas with the help of satellite images taken in high resolution, which increases the preciseness of estimation. An agriculture cropland map with agricultural statistics has been analyzed in GIS to discover the agricultural straw potential for bioenergy generation. Due to unawareness about the benefits and uses of GIS, the modern farming sector bears a loss of huge bioenergy potential every year. To overcome the above mentioned challenges, the agricultural system needs a major shift from conventional farming to smart farming practices with the help of GIS. Agricultural waste is the best source for bioenergy production, and it can be used as biomass for meeting renewable energy goals in the country.
Breaking-Down and Parameterising Wave Energy Converter Costs Using the CapEx and Similitude Methods
Authors: Choupin Ophelie , Henriksen Michael , Etemad-Shahidi Amir , Tomlinson Rodger
Published: February 2021

Wave energy converters (WECs) can play a significant role in the transition towards a more renewable-based energy mix as stable and unlimited energy resources. Financial analysis of these projects requires WECs cost and WEC capital expenditure (CapEx) information. However, (i) cost information is often limited due to confidentiality and (ii) the wave energy field lacks flexible methods for cost breakdown and parameterisation, whereas they are needed for rapid and optimised WEC configuration and worldwide site pairing. This study takes advantage of the information provided by Wavepiston to compare different costing methods. The work assesses the Froude-Law-similarities-based “Similitude method” for cost-scaling and introduces the more flexible and generic “CapEx method” divided into three steps: (1) distinguishing WEC’s elements from the wave energy farm (WEF)’s; (2) defining the parameters characterising the WECs, WEFs, and site locations; and (3) estimating elements that affect WEC and WEF elements’ cost and translate them into factors using the parameters defined in step (2). After validation from Wavepiston manual estimations, the CapEx method showed that the factors could represent up to 30% of the cost. The Similitude method provided slight cost-overestimations compared to the CapEx method for low WEC up-scaling, increasing exponentially with the scaling.
Influence of the Share of Renewable Energy Sources on the Level of Energy Security in EECCA Countries
Authors: Trifonov Ivan , Trukhan Dmitry , Koshlich Yury , Prasolov Valeriy , Ślusarczyk Beata
Published: February 2021

In this study we aimed to determine the extent to which changes in the share of renewable energy sources, their structural complex, and the level of energy security in Eastern Europe, Caucasus and Central Asia (EECCA) countries in the medium- and long-term are interconnected. The study was performed through modeling and determination of the structural characteristics of energy security in the countries. The methodology of the approach to modeling was based on solving the problem of nonlinear optimization by selecting a certain scenario. For the study, the data of EECCA countries were used. The ability of EECCA countries to benefit from long-term indirect and induced advantages of the transformation period depends on the extent to which their domestic supply chains facilitate the deployment of energy transformation and induced economic activity. This study provides an opportunity to assess the degree of influence of renewable energy sources on the level of energy security of countries in the context of energy resource diversification. The high degree of influence of renewable energy sources on energy security in the EECCA countries has been proven in the implementation of the developed scenarios for its increase. Energy security is growing. At the same time, its level depends not only on an increase in the share of renewable sources but also on the structure of energy resources complex of countries, and the development of various renewable energy sources. Therefore, today the EECCA countries are forced not only to increase the share of renewable energy sources but also to attach strategic importance to the structural content of their energy complex.
Estimation of Infiltration Rate (ACH Natural) Using Blower Door Test and Simulation
Authors: Mun Junghyon , Lee Jongik , Kim Minsung
Published: February 2021

One of the primary factors for generating heating and cooling loads in apartment houses is infiltration. However, the evaluation method for infiltration rates has not been well established for the apartment houses in Korea. The existing method measures air change per hour of a house at 50 Pa (ACH50) and divides it by the leakage–infiltration ratio, N = 20, as suggested by the Lawrence Berkeley National Laboratory (LBL). In this study, a method to evaluate the average infiltration rate of an apartment house using blower door tests and simulations is suggested. Six sets of blower door tests were conducted, and the measurement data were used to estimate the flow coefficients and pressure exponents of all infiltration routes. The values were used as the input data for EnergyPlus to calculate the natural air change per hour values (ACHn) of two households. The calculated ACHn values were compared to the ACHn values calculated using the LBL method, which is commonly used in Korea. Through this process, the limitations of applying the LBL method to calculate the ACHn values in Korea were investigated. The results show that investigating the proper leakage–infiltration ratio is required for Korea. The method suggested in this study can be used to determine the proper leakage–infiltration ratio for apartment houses.
Hybrid-Excited PM Motor for Electric Vehicle
Authors: Cinti Luca , Bianchi Nicola
Published: February 2021

This paper deals with the potentials of a Hybrid-Excitation Permanent-Magnet (HEPM) machine. The HEPM machine is characterized by a rotor including both permanent magnets (PMs) and excitation coils. The PMs produce a constant flux at the air gap of the machine, while an excitation current is supplied so as to regulate such a flux. A flux increase could be necessary during transient overload operations, while a flux decrease is useful during Flux-Weakening (FW) actions to operate at speeds higher than the nominal speed. Torque, power, efficiency, flux density and losses of an interior permanent magnet (IPM) motor and an HEPM motor are analyzed in detail. It is shown that this excitation winding produces a great advantage in terms of torque and power performance during the operations at speeds higher than the nominal speed. Despite the additional rotor losses, it is shown that there is a higher efficiency.
Influence of Biochar Derived Nitrogen on Cadmium Removal by Ryegrass in a Contaminated Soil
Authors: Antonangelo João , Zhang Hailin
Published: February 2021

Little is known about the effect of nitrogen (N) application via biochar on the removal of trace elements by crops, and the effects with chemical fertilizers are inconsistent. We determined, from a previous study, the influence of increased N addition via biochars produced from switchgrass (SGB) and poultry litter (PLB) on cadmium (Cd) removal by ryegrass. The biochar rates of 0, 0.5, 1, 2, and 4% w/w were applied to a Cd-contaminated soil before seeding in a potting experiment with a complete randomized block design (CRBD). Ryegrass yield and N and Cd removed by harvest were strongly related (p < 0.05). The ryegrass yields increased up to 1% of PLB, and Cd removal was also the highest at 1% of PLB. The biomass of ryegrass roots increased with Cd accumulation (p < 0.05). Overall, the Cd transfer factor (TF) from ryegrass roots to shoots increased when up to 206 ± 38 kg N ha−1 was removed in ryegrass shoots (p < 0.0001). The application of PLB up to 1% might be a viable option since it is a practical rate for handling operations requiring less volume of material than SGB. Additionally, the Cd concentration in the aboveground forage remained acceptable for grazing cattle. Future studies are encouraged to evaluate different sources of N fertilizers affecting Cd uptake on cash crops.
Preharvest Application of Chitosan Improves the Postharvest Life of ‘Garmrok’ Kiwifruit through the Modulation of Genes Related to Ethylene Biosynthesis, Cell Wall Modification and Lignin Metabolism
Authors: Kumarihami H. M. Prathibhani C. , Kim Jin Gook , Kim Yun-Hee , Lee Mockhee , Lee Young-Suk , Kwack Yong-Bum , Kim Joonyup
Published: February 2021

The influence of the preharvest application of chitosan on physicochemical properties and changes in gene expression of ‘Garmrok’ kiwifruit during postharvest cold storage (0 °C; RH 90–95%; 90 days) was investigated. Preharvest treatment of chitosan increased the fruit weight but had no significant effect on fruit size. The chitosan treatment suppressed the ethylene production and respiration rate of kiwifruit during the cold storage. The reduction of ethylene production of chitosan-treated kiwifruit was accompanied with the suppressed expression of ethylene biosynthesis genes. Moreover, preharvest application of chitosan diminished weight loss and delayed the changes in physicochemical properties that include firmness, soluble solids content, titratable acidity, total sugars, total acids, total phenols, and total lignin. As a result, the preharvest application of chitosan delayed the maturation and ripening of fruit. Expression of genes related to cell wall modification was down-regulated during the early maturation (ripening) period, while those related to gene expression for lignin metabolism were up-regulated at the later stages of ripening. These results demonstrate that the preharvest application of chitosan maintained the fruit quality and extends the postharvest life of ‘Garmrok’ kiwifruit, possibly through the modulation of genes related to ethylene biosynthesis, cell wall modification, and lignin metabolism.
The Effect of Virtual Reality Exercise Program on Sitting Balance Ability of Spinal Cord Injury Patients
Authors: Lee Min-Jae , Lee Sun-Min
Published: February 2021

(1) Background: Virtual reality (VR) is a useful device for rehabilitation therapy. The purpose of this study was to examine the effect of virtual reality exercise program on sitting balance with spinal cord injury; (2) Methods: 20 subjects who selected on the basis of the screening criteria were divided into the experimental group (n = 10) who underwent the virtual reality exercise program and rehabilitation therapy and the control group (n = 10) who underwent a regular sitting balance training program and a regular rehabilitation therapy. Each intervention consisted of a 30-min session a day, three times a week, for eight weeks. In order to measure functions of the sitting balance, FSA (force sensitive application) and LOS (limit of stability) were used before and after the treatment intervention; (3) Results: We found significant differences for the FSA, LOS between pre-test and post-test in the 2 groups; (4) Conclusions: The findings of this study suggest that virtual reality exercise program can be applied as a useful approach for spinal cord injury patients.
Impact of Nutrition Care Process Documentation in Obese Children and Adolescents with Metabolic Syndrome and/or Non-Alcoholic Fatty Liver Disease
Authors: Mujlli Gadah , Aldisi Dara , Aljuraiban Ghadeer S. , Abulmeaty Mahmoud M. A.
Published: February 2021

This study evaluated the Nutrition Care Process documentation used by dietitians for obese pediatric patients diagnosed with metabolic syndrome (MetS) and/or non-alcoholic fatty liver disease (NAFLD) and its impact on the achievement of nutritional goals. This retrospective cohort study utilized data retrieved from three tertiary care hospitals in Riyadh. A total of 142 obese pediatric patients aged 8–18 years diagnosed with NAFLD and/or MetS were evaluated. Data on weight, height, blood pressure (BP), lipid profile, and liver enzymes were collected. A validated audit was used to assess the documentation quality. Twenty-seven (46.6%) dietitian notes received a high score, 21 (36.2%) received a medium score, and 10 (17.2%) received a low score. There was no significant effect of dietitian audit scores on nutritional outcomes, however, the change in body mass index from 6 to 12 months follow-up period was inversely correlated with the audit score (r = −0.761, p = 0.007), and alkaline phosphatase was inversely correlated with the audit score (r = −0.819, p = 0.013). In conclusion, there was a clear variation in the quality of dietitians’ documentation and the impact of documentation scores on nutritional outcomes.
Per- and Polyfluoroalkyl Substances in Human Serum Samples of Selected Populations from Ghana
Authors: Dartey Emmanuel , Ellingsen Dag G. , Berlinger Balazs , Thomassen Yngvar , Odland Jon Ø. , Brox Jan , Nartey Vincent K. , Yeboah Francis A. , Huber Sandra
Published: February 2021

The aims of this study were to assess serum concentrations of per- and polyfluoroalkyl substances (PFASs) in selected populations from Ghana, including workers engaged in the repair of electronic equipment (ERWs), and to elucidate PFAS concentrations in relation to blood mercury concentrations (B-Hg) as a biomarker of seafood consumption. In all, 219 participants were recruited into the study, of which 26 were women and 64 were ERWs. Overall, the PFAS concentrations were low. The most abundant components were perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonic acid (PFHxS). Women had generally lower PFAS concentration than men. The ERWs had statistically significantly higher concentrations of perfluorooctanoate (PFOA), which was associated with the concentration of tin in urine. This could indicate exposure during soldering. The concentration of B-Hg was associated with several of the PFASs such as PFOA, PFOS and perfluoroheptane sulfonate (PFHpS). Additionally, the concentrations of perfluorodecanoic acid (PFDA) and perfluoroundecanoate (PFUnDA) were highly associated with the concentrations of B-Hg. It is noteworthy that the linear isomer of PFHxS was strongly associated with B-Hg while the branched isomers of PFHxS were not. In conclusion, the PFAS concentrations observed in the present study are low compared to other populations previously investigated, which also reflects a lower PFAS exposure within the Ghanaian cohorts. ERWs had significantly higher PFOA concentrations than the other participants. Several PFASs were associated with B-Hg, indicating that seafood consumption may be a source of PFAS exposure.