bluuebunny/crossref_metadata_2025 huggingface dataset:
Fréchet Binomial Distribution: Statistical Properties, Acceptance Sampling Plan, Statistical Inference and Applications to Lifetime Data
Authors: Alyami Salem A. , Elgarhy Mohammed , Elbatal Ibrahim , Almetwally Ehab M. , Alotaibi Naif , El-Saeed Ahmed R.
Published: August 2022

A new class of distribution called the Fréchet binomial (FB) distribution is proposed. The new suggested model is very flexible because its probability density function can be unimodal, decreasing and skewed to the right. Furthermore, the hazard rate function can be increasing, decreasing, up-side-down and reversed-J form. Important mixture representations of the probability density function (pdf) and cumulative distribution function (cdf) are computed. Numerous sub-models of the FB distribution are explored. Numerous statistical and mathematical features of the FB distribution such as the quantile function (QUNF); moments (MO); incomplete MO (IMO); conditional MO (CMO); MO generating function (MOGF); probability weighted MO (PWMO); order statistics; and entropy are computed. When the life test is shortened at a certain time, acceptance sampling (ACS) plans for the new proposed distribution, FB distribution, are produced. The truncation time is supposed to be the median lifetime of the FB distribution multiplied by a set of parameters. The smallest sample size required ensures that the specified life test is obtained at a particular consumer’s risk. The numerical results for a particular consumer’s risk, FB distribution parameters and truncation time are generated. We discuss the method of maximum likelihood to estimate the model parameters. A simulation study was performed to assess the behavior of the estimates. Three real datasets are used to illustrate the importance and flexibility of the proposed model.
Emergent Role of IFITM1/3 towards Splicing Factor (SRSF1) and Antigen-Presenting Molecule (HLA-B) in Cervical Cancer
Authors: Gómez-Herranz Maria , Faktor Jakub , Yébenes Mayordomo Marcos , Pilch Magdalena , Nekulova Marta , Hernychova Lenka , Ball Kathryn L. , Vojtesek Borivoj , Hupp Ted R. , Kote Sachin
Published: August 2022

The IFITM restriction factors play a role in cancer cell progression through undefined mechanisms. We investigate new protein–protein interactions for IFITM1/3 in the context of cancer that would shed some light on how IFITM1/3 attenuate the expression of targeted proteins such as HLA-B. SBP-tagged IFITM1 protein was used to identify an association of IFITM1 protein with the SRSF1 splicing factor and transporter of mRNA to the ribosome. Using in situ proximity ligation assays, we confirmed a predominant cytosolic protein–protein association for SRSF1 and IFITM1/3. Accordingly, IFITM1/3 interacted with HLA-B mRNA in response to IFNγ stimulation using RNA–protein proximity ligation assays. In addition, RT-qPCR assays in IFITM1/IFITM3 null cells and wt-SiHa cells indicated that HLA-B gene expression at the mRNA level does not account for lowered HLA-B protein synthesis in response to IFNγ. Complementary, shotgun RNA sequencing did not show major transcript differences between IFITM1/IFITM3 null cells and wt-SiHa cells. Furthermore, ribosome profiling using sucrose gradient sedimentation identified a reduction in 80S ribosomal fraction an IFITM1/IFITM3 null cells compared to wild type. It was partially reverted by IFITM1/3 complementation. Our data link IFITM1/3 proteins to HLA-B mRNA and SRSF1 and, all together, our results begin to elucidate how IFITM1/3 catalyze the synthesis of target proteins. IFITMs are widely studied for their role in inhibiting viruses, and multiple studies have associated IFITMs with cancer progression. Our study has identified new proteins associated with IFITMs which support their role in mediating protein expression; a pivotal function that is highly relevant for viral infection and cancer progression. Our results suggest that IFITM1/3 affect the expression of targeted proteins; among them, we identified HLA-B. Changes in HLA-B expression could impact the presentation and recognition of oncogenic antigens on the cell surface by cytotoxic T cells and, ultimately, limit tumor cell eradication. In addition, the role of IFITMs in mediating protein abundance is relevant, as it has the potential for regulating the expression of viral and oncogenic proteins.
RNA Modifications in Gastrointestinal Cancer: Current Status and Future Perspectives
Authors: Zhang Xiaoting , Su Hao , Chen Hongyan , Li Qing , Liu Xiaodong , Zhang Lin , Wu William Ka Kei , Chan Matthew Tak Vai , Chen Huarong
Published: August 2022

Gastrointestinal (GI) cancer, referring to cancers of the digestive system such as colorectal cancer (CRC), gastric cancer (GC), and liver cancer, is a major cause of cancer-related deaths in the world. A series of genetic, epigenetic, and epitranscriptomic changes occur during the development of GI cancer. The identification of these molecular events provides potential diagnostic, prognostic, and therapeutic targets for cancer patients. RNA modification is required in the posttranscriptional regulation of RNA metabolism, including splicing, intracellular transport, degradation, and translation. RNA modifications such as N6-methyladenosine (m6A) and N1-methyladenosine (m1A) are dynamically regulated by three different types of regulators named methyltransferases (writers), RNA binding proteins (readers), and demethylases (erasers). Recent studies have pointed out that abnormal RNA modification contributes to GI tumorigenesis and progression. In this review, we summarize the latest findings on the functional significance of RNA modification in GI cancer and discuss the therapeutic potential of epitranscriptomic inhibitors for cancer treatment.
Improving Design Quality by Contractor Involvement: An Empirical Study on Effects
Authors: Lappalainen Eelon , Uusitalo Petteri , Pikas Ergo , Seppänen Olli , Peltokorpi Antti , Uusitalo Petri , Reinbold Ana , Menzhinskii Nikolai
Published: August 2022

It is generally acknowledged that good-quality design is a prerequisite for good quality and productive construction work. One proposed measure to improve the quality of construction has been contractors’ involvement in the design phase, and this phenomenon has been studied by several researchers. However, such approaches have not adequately addressed how this involvement affects the quality of the design. In this study, the aim was to study the effects of the early involvement of contactors on design quality based on evaluating the design quality factors. A case study was used to collect data and content analysis to analyze structural drawings and design meeting minutes of a large-scale infrastructure project. Particularly, the focus was on gathering information on the quality of the design and how it was addressed in the design coordination. We combined this quantitative data with qualitative open-ended thematic interviews, including respondents who led and coordinated the design on both the client and contractor sides. Our findings suggest that despite the vast amount of design changes, contractors’ involvement and development work in the detailed design phase improved design quality and constructability. Our findings also suggest that the contractor’s involvement during the schematic design phase had a design-enhancing effect in the detailed design phase. This study contributes to our understanding of contractors’ valuable role in design quality.
Rheometry for Concrete 3D Printing: A Review and an Experimental Comparison
Authors: Jayathilakage Roshan , Rajeev Pathmanathan , Sanjayan Jay
Published: August 2022

The rapid advancement of 3D concrete printing (3DCP) and the development of relevant cementitious material compositions can be seen in the last few decades. The commonly used 3DCP method is to build the structure layer by layer after extruding the material through a nozzle. Initially, the pumping and extrusion of the material should be done with considerable fluidity and workability. The extruded layers should retain their shape immediately after extruding and depositing. While constructing the structure in a layerwise manner, the bottom layers should have enough early age strength to support the layers at the top. Therefore, at different processes in 3DCP, the rheological requirement is contradictory. As the rheology of the material is the deterministic factor which decides the fluidity or workability of the mix, proper rheological characterization should be completed accurately. In some instances, due to the higher stiffness, and higher time and rate-dependent material behavior (thixotropic behavior) compared to the conventional concrete, standard rheology measurement techniques have many limitations when used for 3DCP material. Therefore, non-conventional and novel techniques can be implemented with suitable material models to characterize the rheology of 3DCP material. In this study, a comprehensive review was conducted on conventional and non-conventional methods used for characterizing the rheological parameters for 3DCP material. The previously conducted studies were highlighted with the targeted 3DCP processes in the study (if applicable), and rheological parameters achieved from the test (i.e., yield stress, viscosity, and thixotropy). In addition, some experimental studies were conducted to compare several selected testing methods. The rheological parameters achieved from different test methods were compared to identify the similarities, dissimilarities, pros, and cons between the test methods. Furthermore, the extrudability and buildability studies were conducted for the mixes to demonstrate the usage of the mixes in 3DCP applications and to correlate the achieved rheological parameters with these processes.
Modeling of 1,2-Dibromoethane Biodegradation in Constant Electric Field
Authors: Popova-Krumova Petya , Beschkov Venko , Vasileva Evgenia , Parvanova-Mancheva Tsvetomila
Published: August 2022

This study proposes a mathematical modeling approach for evaluating the effect of applying a permanent electric field on the biodegradation of 1,2-dibromoethane by bacterial cells of Bradyrhizobium japonicum 273. Two models for inhibited microbial growth including product inhibition were composed—one using the Monod–Yerusalimsky approach and another one—the Levenspiel kinetic equation. The models were used to process own experimental data obtained without an electric field and ones obtained at the application of an electric field. The experiments were carried out at an optimum anode potential of 0.8 V vs. the standard hydrogen electrode (SHE). Three initial concentrations of substrate were tested: 0.05, 0.1, and 0.15 g dm−3. The modeling takes into account the product inhibition on microbial growth assuming 2-bromoethanol as the first biodegradation product. It was found that the positive effect of the electric field is the enhancement of microbial growth, expressed by the increase in the maximum specific growth rate and the increase in the inhibition constant when the model of Monod–Yerusalimsky is applied. The main effect of the electric field is in the increase in the rate constant of 2-bromoethanol removal by electrochemical oxidation, enabling the enhancement the microbial growth and substrate conversion to the product. The obtained results show that the application of a permanent electric field leads to a higher electrochemical oxidation rate (with a rate constant up to 60% higher than for the control experiments) and complete substrate and 2-bromoethanol biodegradation. The model of Levenspiel is not so sensitive to the effects of the electric field on product inhibition.
Graphene-Based Surface-Enhanced Raman Scattering (SERS) Sensing: Bibliometrics Based Analysis and Review
Authors: Zhou Qingwei , Jin Meiqing , Wu Weihong , Fu Li , Yin Chengliang , Karimi-Maleh Hassan
Published: August 2022

Surface-enhanced Raman scattering (SERS) has received increasing attention from researchers since it was first discovered on rough silver electrode surfaces in 1974 and has promising applications in life sciences, food safety, and environmental monitoring. The discovery of graphene has stirred considerable waves in the scientific community, attracting widespread attention in theoretical research and applications. Graphene exhibits the properties of a semi-metallic material and has also been found to have Raman enhancement effects such as in metals. At the same time, it quenches the fluorescence background and improves the ratio of a Raman signal to a fluorescence signal. However, graphene single-component substrates exhibit only limited SERS effects and are difficult to use for trace detection applications. The common SERS substrates based on noble metals such as Au and Ag can produce strong electromagnetic enhancement, which results in strong SERS signals from molecules adsorbed on the surface. However, these substrates are less stable and face the challenge of long-term use. The combination of noble metals and graphene to obtain composite structures was an effective solution to the problem of poor stability and sensitivity of SERS substrates. Therefore, graphene-based SERS has been a popular topic within the last decade. This review presents a statistically based analysis of graphene-based SERS using bibliometrics. Journal and category analysis were used to understand the historical progress of the topic. Geographical distribution was used to understand the contribution of different countries and institutions to the topic. In addition, this review describes the different directions under this topic based on keyword analysis and keyword co-occurrence. The studies on this topic do not show a significant divergence. The researchers’ attention has gradually shifted from investigating materials science and chemistry to practical sensing applications. At the end of the review, we summarize the main contents of this topic. In addition, several perspectives are presented based on bibliometric analysis.
Microwave Interferometric Cytometry for Signal Analysis of Single Yeast Cells
Authors: Zhang Meng , Huo Guangxin , Bao Juncheng , Markovic Tomislav , Van Dijck Patrick , Nauwelaers Bart
Published: August 2022

Microwave dielectric sensing offers a rapid, label-free, and non-invasive way of characterization and sensing of biological materials at the microfluidic scale. In this work, a dielectric sensing is achieved with a microwave interferometric setup that is applied to cytometric applications. A fast way to analyze and design an interferometric system at microwave frequencies in software tools is proposed together with a novel manufacturing and assembly process, which enables a short recovery time and avoids extensive microwave-microfluidic chip fabrication. The simulation and measurement results of the interferometric setup are in agreement with an excellent match at levels below S21 = −60 dB. The sensitive microwave setup is evaluated on measurements of 3 µm polystyrene spheres and finally applied for characterization of a widely used laboratory Saccharomyces cerevisiae strain, the S288C, in a frequency range from 4 to 18 GHz.
High-Efficiency Generation, Drug and Radiosensitivity Test of Multicellular Tumor Spheroids by a Novel Microdevice
Authors: Ding Siwei , Lu Chunyang , Sun Xiaoyi , Li Tiancheng , Zhao Ye , Yang Gen
Published: August 2022

Compared with traditional two-dimensional culture, a three-dimensional (3D) culture platform can not only provide more reliable prediction results, but also provide a simple, inexpensive and less time-consuming method compared with animal models. A direct in vitro model of the patient’s tumor can help to achieve individualized and precise treatment. However, the existing 3D culture system based on microwell arrays has disadvantages, such as poor controllability, an uneven spheroid size, a long spheroid formation time, low-throughput and complicated operation, resulting in the need for considerable labor, etc. Here, we developed a new type of microdevice based on a 384-well plate/96-well plate microarray design. With our design, cells can quickly aggregate into clusters to form cell spheroids with better roundness. This design has the advantage of high throughput; the throughput is 33 times that of a 384-well plate. This novel microdevice is simple to process and convenient to detect without transferring the cell spheroid. The results show that the new microdevice can aggregate cells into spheroids within 24 h and can support drug and radiation sensitivity analyses in situ in approximately one week. In summary, our microdevices are fast, efficient, high-throughput, simple to process and easy to detect, providing a feasible tool for the clinical validation of individualized drug/radiation responses in patients.
Determining the Factors That Influence Stunting during Pandemic in Rural Indonesia: A Mixed Method
Authors: Yunitasari Esti , Lee Bih O. , Krisnana Ilya , Lugina Rayi , Solikhah Fitriana Kurniasari , Aditya Ronal Surya
Published: August 2022

Objective: Pandemic causes an increase in the poverty rate. The consequences will be many, including the birth of stunting babies. The COVID-19 pandemic has had an impact on stunting. Analyzing the factors that cause stunting during a pandemic will provide suggestions for effective stunting prevention strategies at the national, regional, community, and household levels. This study aims to determine the factors that influence stunting during the pandemic. Method: We use mixed methods. The respondents of this study were 152 mothers of the Maternal and Child Nutrition Security project, and the sampling technique is Cluster Sampling. Quantitatively using a baseline survey whose analysis uses multiple logistic regression to determine the unadjusted and adjusted odds ratio. The qualitative data used focus group discussions which were analyzed using Nvivo 12 with a questionnaire, and anthropometric measurements of children from surveyed households. Results: This study summarizes the multivariate analysis of stunting determinants in the pandemic era, revealing statistically significant interactions between household sanitation facilities and household water treatment. Significant risk factors for severe stunting during the pandemic were male gender, older child age, coming from a low socioeconomic quintile, not participating in prenatal care at a health facility, and mother’s involvement in choices about what to prepare for Community House. The FGDs identified misinformation about childcare and consumption of sweetened condensed milk as significant contributors to child malnutrition. Conclusions: Lack of sanitation facilities and untreated water are contributing factors. Water, sanitation, and hygiene initiatives must be included into Indonesian policies and programs to combat child stunting during a pandemic. The need for further research related to government assistance for improving toddler nutrition, as well as the relationship between WASH and linear development in early infancy should be explored.
Floating Photovoltaics: A Review
Authors: Essak Laura , Ghosh Aritra
Published: August 2022

The world is transitioning towards a net zero emissions future and solar energy is at the forefront of the transition. The land use requirements to install solar farms present a barrier for the industry as population density increases and land prices rise. Floating photovoltaics (FPV) addresses this issue by installing solar photovoltaics (PV) on bodies of water. Globally, installed FPV is increasing and becoming a viable option for many countries. A 1% coverage of global reservoirs with FPV would have a potential capacity of 404GWp benign power production. There are numerous advantages to FPV compared to ground mounted PV (GPV), which are discussed in this review. The major gap in research is the impact FPV has on water quality and living organisms in the bodies of water. This review paper examines the most recent research around FPV, analyzing the benefits, downfalls, and future. The review provides more insight into FPV in terms of varying water bodies that can be used, system efficiency, global potential, and potential for coupling FPV with other technologies.
Special Issue: The Diagnosis and Management of OSA
Authors: Izci Balserak Bilgay
Published: August 2022

Obstructive sleep apnea (OSA) is the most common form of sleep-disordered breathing (SDB) and is demonstrating an increasing prevalence worldwide [...]
Mixed-Up-Ness or Entropy?
Authors: Seitz W. , Kirwan A. D.
Published: August 2022

Mixed-up-ness can be traced to unpublished notes by Josiah Gibbs. Subsequently, the concept was developed independently, and under somewhat different names, by other investigators. The central idea of mixed-up-ness is that systems states can be organized in a hierarchy by their degree of mixed-up-ness. In its purest form, the organizing principle is independent of thermodynamic and statistical mechanics principles, nor does it imply irreversibility. Yet, Gibbs and subsequent investigators kept entropy as the essential concept in determining system evolution, thus retaining the notion that systems evolve from states of perfect “order” to states of total “disorder”. Nevertheless, increasing mixed-up-ness is consistent with increasing entropy; however, there is no unique one-to-one connection between the two. We illustrate the notion of mixed-up-ness with an application to the permutation function of integer partitions and then formalize the notion of mixed-up-ness as a fundamental hierarchal principle, the law of mixed-up-ness (LOM), for non-thermodynamic systems.
Systematic Literature Review of Models Used in the Epidemiological Analysis of Bovine Infectious Diseases
Authors: Ballesteros-Ricaurte Javier Antonio , Fabregat Ramon , Carrillo-Ramos Angela , Parra Carlos , Pulido-Medellín Martin Orlando
Published: August 2022

There are different bovine infectious diseases that show economic losses and social problems in various sectors of the economy. Most of the studies are focused on some diseases (for example, tuberculosis, salmonellosis, and brucellosis), but there are few studies on other diseases which are not officially controlled but also have an impact on the economy. This work is a systematic literature review on models (as a theoretical scheme, generally in mathematical form) used in the epidemiological analysis of bovine infectious diseases in the dairy farming sector. In this systematic literature review, criteria were defined for cattle, models, and infectious diseases to select articles on Scopus, IEEE, Xplorer, and ACM databases. The relations between the found models (model type, function and the proposed objective in each work) and the bovine infectious diseases, and the different techniques used and the works over infectious disease in humans, are presented. The outcomes obtained in this systematic literature review provide the state-of-the-art inputs for research on models for the epidemiological analysis of infectious bovine diseases. As a consequence of these outcomes, this work also presents an approach of EiBeLec, which is an adaptive and predictive system for the bovine ecosystem, combining a prediction model that uses machine-learning techniques and an adaptive model that adapts the information presented to end users.
Deadline-Aware Dynamic Task Scheduling in Edge–Cloud Collaborative Computing
Authors: Zhang Yu , Tang Bing , Luo Jincheng , Zhang Jiaming
Published: August 2022

In recent years, modern industry has been exploring the transition to cyber physical system (CPS)-based smart factories. As intelligent industrial detection and control technology grows in popularity, massive amounts of time-sensitive applications are generated. A cutting-edge computing paradigm called edge-cloud collaborative computing was developed to satisfy the need of time-sensitive tasks such as smart vehicles and automatic mechanical remote control, which require substantially low latency. In edge-cloud collaborative computing, it is extremely challenging to improve task scheduling while taking into account both the dynamic changes of user requirements and the limited available resources. The current task scheduling system applies a round-robin policy to cyclically select the next server from the list of available servers, but it may not choose the best-suited server for the task. To satisfy the real-time task flow of industrial production in terms of task scheduling based on deadline and time sensitivity, we propose a hierarchical architecture for edge-cloud collaborative environments in the Industrial Internet of Things (IoT) and then simplify and mathematically formulate the time consumption of edge-cloud collaborative computing to reduce latency. Based on the above hierarchical model, we present a dynamic time-sensitive scheduling algorithm (DSOTS). After the optimization of DSOTS, the dynamic time-sensitive scheduling algorithm with greedy strategy (TSGS) that ranks server capability and job size in a hybrid and hierarchical scenario is proposed. What cannot be ignored is that we propose to employ comprehensive execution capability (CEC) to measure the performance of a server for the first time and perform effective server load balancing while satisfying the user’s requirement for tasks. In this paper, we simulate an edge-cloud collaborative computing environment to evaluate the performance of our algorithm in terms of processing time, SLA violation rate, and cost by extending the CloudSimPlus toolkit, and the experimental results are very promising. Aiming to choose a more suitable server to handle dynamically incoming tasks, our algorithm decreases the average processing time and cost by 30% and 45%, respectively, as well as the average SLA violation by 25%, when compared to existing state-of-the-art solutions.
A Fully Polarity-Aware Double-Node-Upset-Resilient Latch Design
Authors: Park Jung-Jin , Kang Young-Min , Kim Geon-Hak , Chang Ik-Joon , Kim Jinsang
Published: August 2022

Due to aggressive scaling down, multiple-node-upset hardened design has become a major concern regarding radiation hardening. The proposed latch overcomes the architecture and performance limitations of state-of-the-art double-node-upset (DNU)-resilient latches. A novel stacked latch element is developed with multiple thresholds, regular architecture, increased number of single-event upset (SEU)-insensitive nodes, low power dissipation, and high robustness. The radiation-aware layout considering layout-level issues is also proposed. Compared with state-of-the-art DNU-resilient latches, simulation results show that the proposed latch exhibits up to 92% delay and 80% power reduction in data activity ratio (DAR) of 100%. The radiation simulation using the dual-double exponential current source model shows that the proposed latch has the strongest radiation-hardening capability among the other DNU-resilient latches.
Face-Based CNN on Triangular Mesh with Arbitrary Connectivity
Authors: Wang Hui , Guo Yu , Wang Zhengyou
Published: August 2022

Applying convolutional neural networks (CNNs) to triangular meshes has always been a challenging task. Because of the complex structure of the meshes, most of the existing methods apply CNNs indirectly to them, and require complex preprocessing or transformation of the meshes. In this paper, we propose a novel face-based CNN, which can be directly applied to triangular meshes with arbitrary connectivity by defining face convolution and pooling. The proposed approach takes each face of the meshes as the basic element, similar to CNNs with pixels of 2D images. First, the intrinsic features of the faces are used as the input features of the network. Second, a sort convolution operation with adjustable convolution kernel sizes is constructed to extract the face features. Third, we design an approximately uniform pooling operation by learnable face collapse, which can be applied to the meshes with arbitrary connectivity, and we directly use its inverse operation as unpooling. Extensive experiments show that the proposed approach is comparable to, or can even outperform, state-of-the-art methods in mesh classification and mesh segmentation.
Experimental Study of Thermal and Pressure Performance of Porous Heat Sink Subjected to Al2O3-H2O Nanofluid
Authors: OZBALCI Oguzhan , DOGAN Ayla , ASILTURK Meltem
Published: August 2022

With the developing technology, the dimensions of electronic systems are becoming smaller, and their performance and the amount of energy they need increases. This situation causes the electronic components to heat up more and the existing cooling systems to become inadequate. In this study, instead of the fins used in existing systems, 10 PPI and 40 PPI PHS were placed inside a water block, and the Al2O3-H2O nanofluid at a mass fraction of 0.1% was used as the cooling fluid. Experiments were carried out under constant heat flux of 454.54 W/m2 and 1818.18 W/m2, with volumetric flow rates varying between 100 mL/min and 800 mL/min. The heat transfer results were compared with the results obtained from the base fluid and the empty surface. The results showed that the nanofluid reduced the surface temperatures compared to the base fluid. Especially when PHSs were used together with the nanofluid, a significant increase in heat transfer occurred compared to the empty surface. The highest heat transfer was observed when both the nanofluid and 40 PPI PHS were used together. In addition, the highest thermal performance value was determined as 1.25 times compared to the empty surface when the nanofluid and 10 PPI PHS were used together.
Non-Linear Inductor Models Comparison for Switched-Mode Power Supplies Applications
Authors: Scirè Daniele , Lullo Giuseppe , Vitale Gianpaolo
Published: August 2022

The use of non-linear power inductors, intended as devices exploited up to a current at which the inductance is halved, is of great interest in switched-mode power supplies (SMPSs). Indeed, it allows the use of lighter and cheaper inductors improving the power density. On the other hand, the analysis of SMPSs equipped with non-linear inductors requires appropriate modeling of the inductor reproducing the inductance versus current. This paper compares two main analytical models proposed in the literature: the former is based on a polynomial, and the latter exploits the arctangent function to reproduce the non-linearity of the inductance. Performance is compared by considering the effort of retrieving the model’s parameters, evaluating a current profile by the characteristic equation of the inductor, and exploiting the two models to simulate a switched-mode power supply. Results are given both in terms of computation time and accuracy with reference to experimental values, highlighting the pros and cons of each model.
DC-DC High-Step-Up Quasi-Resonant Converter to Drive Acoustic Transmitters
Authors: Roshandel Emad , Mahmoudi Amin , Kahourzade Solmaz , Davazdah-Emami Hamid
Published: August 2022

This paper proposes a quasi-resonant step-up DC-DC converter to provide the DC-link voltage for piezoelectric transmitters (PZETs). The resonance not only provides a soft-switching condition for the converter switches, but also helps to decrease the converter element sizes for marine applications. Operation modes of the proposed converter are discussed. The current and voltage of the converter components are derived analytically, and hence the converter gain is obtained. The performance of the proposed high-step-up, high-power density converter is examined through a comprehensive simulation study. The simulation results demonstrate the soft-switching operation and short transient time required for the converter to reach the reference output voltage. The converter output voltage remains unchanged when an inverter with a passive filter is placed at its output while supplying the PZET. The proposed DC-DC converter is prototyped to validate the converter gain and soft-switching operation experimentally. The converter gain and soft-switching results in simulation are well matched with those of the experimental tests. The converter efficiency in three different switching frequencies is obtained experimentally. The power density of the proposed topology is determined via the designing of a printed circuit board. The experimental results demonstrate the appropriate gain and efficiency of the converter in the tested power range.
Volume-of-Fluid Based Finite-Volume Computational Simulations of Three-Phase Nanoparticle-Liquid-Gas Boiling Problems in Vertical Rectangular Channels
Authors: Mavi Anele , Chinyoka Tiri
Published: August 2022

This study develops robust numerical algorithms for the simulation of three-phase (solid-liquid-gas) boiling and bubble formation problems in rectangular channels. The numerical algorithms are based on the Finite Volume Methods (FVM) and implement both the volume-of-fluid (VOF) methods for liquid-gas interface tracking as well as the volume-fraction methods to account for the concentration of embedded solid nano-particles in the liquid phase. Water is used as the base-liquid and the solid phase is modelled via metallic nano-particles (both aluminium oxide and titanium oxide nano-particles are considered) that are homogeneously mixed within the liquid phase. The gas phase is considered as a vapour arising from the bolling processes of the liquid-phase. The finite volume methodology is implemented on the OpenFOAM software platform, specifically by careful modification and manipulation of existing OpenFOAM solvers. The governing fluid dynamical equations, for the three-phase boiling problem, take into account the thermal conductivity effects of the solid (nano-particle), the momentum and energy equations for both the liquid-phase and the gas-phase, and finally the decoupled mass conservation equations for the liquid- and gas- phases. The decoupled mass conservation equations are specifically used to model the phase change between the liquid- and gas- phases. In addition to the FVM and VOF numerical methodologies for the discretization of the governing equations, the pressure-velocity coupling is resolved via the PIMPLE algorithm, a combination of the Pressure Implicit with Splitting of Operator (PISO) and the Semi-Implicit Method for Pressure-Linked Equations (SIMPLE) algorithms. The computational results are presented graphically with respect to variations in time as well as in the nano-particle volume fractions. The simulations and results accurately capture the formation of vapour bubbles in the two-phase (particle-free) liquid-gas flow and additionally the computational algorithms are similarly demonstrated to accurately illustrate and capture simulated boiling processes. The presence of the nano-particles is demonstrated to enhance the heat-transfer, boiling, and bubble formation processes.
Intelligent Action Planning for Well Construction Operations Demonstrated for Hole Cleaning Optimization and Automation
Authors: Saini Gurtej Singh , Pournazari Parham , Ashok Pradeepkumar , van Oort Eric
Published: August 2022

Reactive and biased human decision-making during well construction operations can result in problems ranging from minor inefficiencies to events that can have far-reaching negative consequences for safety, environmental compliance and cost. A system that can automatically generate an optimal action sequence from any given state to meet an operation’s objectives is therefore highly desirable. Moreover, an intelligent agent capable of self-learning can offset the computation and memory costs associated with evaluating the action space, which is often vast. This paper details the development of such action planning systems by utilizing reinforcement learning techniques. The concept of self-play used by game AI engines (such as AlphaGo and AlphaZero in Google’s DeepMind group) is adapted here for well construction tasks, wherein a drilling agent learns and improves from scenario simulations performed using digital twins. The first step in building such a system necessitates formulating the given well construction task as a Markov Decision Process (MDP). Planning is then accomplished using Monte Carlo tree search (MCTS), a simulation-based search technique. Simulations, based on the MCTS’s tree and rollout policies, are performed in an episodic manner using a digital twin of the underlying task(s). The results of these episodic simulations are then used for policy improvement. Domain-specific heuristics are included for further policy enhancement, considered factors such as trade-offs between safety and performance, the distance to the goal state, and the feasibility of taking specific actions from specific states. We demonstrate our proposed action planning system for hole cleaning, a task which to date has proven difficult to optimize and automate. Comparing the action sequences generated by our system to real field data, it is shown that it would have resulted in significantly improved hole cleaning performance compared to the action taken in the field, as quantified by the final state reached and the long-term reward. Such intelligent sequential decision-making systems, which use heuristics and exploration–exploitation trade-offs for optimum results, are novel applications in well construction and may pave the way for the automation of tasks that until now have been exclusively controlled by humans.
Implementation and Design of FREEDM System Differential Protection Method Based on Internet of Things
Authors: Hatata Ahmed Y. , Essa Mohamed A. , Sedhom Bishoy E.
Published: August 2022

This paper introduces an enhancement of the protection and operation of the Future Renewable Electric Energy Delivery and Management (FREEDM) system. It uses the solid-state transformers to connect the residential A.C. and D.C. microgrids to the distribution system and fault isolation devices for faulty line isolation. In this paper, a current differential protection scheme has been proposed to detect faults in the FREEDM-based microgrid network. This method is based on the current measurement at the two-line terminals using phasor measurement units to ensure data synchronization and minimize the measuring error. Also, a communication scheme that is based on the Internet of things technology and Wi-Fi is constructed for data monitoring and interlinking between the relays, transducers, and the fault isolation devices in the two-terminals lines. A hypothetical FREEDM system has been used for the verification and testing of the proposed method. Different fault types at different locations and fault resistances have been applied to prove the effectiveness of the proposed protection method in detecting the fault condition. The performance of the proposed method is investigated using the security, dependability, and accuracy indices. A prototype of the FREEDM system is designed, implemented, and tested using the Proteus software simulator and in the laboratory. The results prove the efficiency of the proposed protection method in detecting and isolating the fault conditions in a fast, reliable, and accurate manner. Moreover, the protection scheme achieved high accuracy for all faults, equal to 98.825%.
Study of Blockage Effects of Metro Train on Critical Velocity in Sloping Subway Tunnel Fires with Longitudinal Ventilation
Authors: Wang Haitao , Gao Huanhuan
Published: August 2022

Critical velocity is very important for smoke control in longitudinally ventilated subway tunnel fires. Numerical investigations are conducted in this paper to study the impacts of metro train blockages on critical velocity in sloping subway tunnel fires by using fire dynamics simulator (FDS) tunnel models validated with the field-experiment data. Moreover, a global model of critical velocity is presented for the blocked zone of a metro train in subway tunnel fires including influencing factors of the blockage ratio and tunnel slope. The results show that the reduction ratio of critical velocity in the blocked zone is less than the metro-train blockage ratio. The correction factor between the critical velocity reduction ratio and metro-train blockage ratio is 0.545. The aerodynamic shadow zone downstream of a subway train blockage has important impacts on the critical velocity. The critical velocity in the unblocked zone of a metro train is higher than that in the blocked zone of a metro train blockage. The reason is that smoke flow is hindered by the metro train blockage in subway tunnel fires. With an increase in the blockage–fire source distance, the critical velocity first decreases and then tends to be constant. The global model presented can accurately predict the critical velocity in a sloping subway tunnel with a train blockage. The results may provide beneficial suggestions for designing ventilation systems for subway tunnels.
The Quality of Goodwill Disclosures and Impairment in the Financial Statements of Energy, Mining, and Fuel Sector Groups during the Pandemic Period—Evidence from Poland
Authors: Gierusz Maciej , Hońko Stanisław , Strojek-Filus Marzena , Świetla Katarzyna
Published: August 2022

The COVID-19 pandemic has strongly affected the economic situation of many countries, which is worth considering not only globally but also in the context of specific industries. An asset that is particularly sensitive to negative economic changes is goodwill. The aim of this study is to assess the impact of the pandemic on the quality of financial disclosures concerning goodwill in consolidated financial statements of groups of chosen strategic sectors in Poland. We investigated the implications of the pandemic on the frequency and scale of goodwill impairment in relation to 23 companies listed on the Warsaw Stock Exchange from the Energy, Mining, and Fuel Index. We identified the research gap in this area. For the purposes of this study, two research hypotheses were formulated: (H1) during the COVID-19 pandemic, there has been a slight improvement in the quality of goodwill disclosures in the consolidated financial statements of groups in the energy, fuel, and mining sectors; (H2) The COVID-19 pandemic caused a decrease in goodwill due to impairment losses in the consolidated financial statements of groups in the energy, fuel, and mining sectors. The hypotheses were verified on the basis of the above research sample. In order to verify the first hypothesis, we tested 81 consolidated financial statements for the years 2018–2021 based on a self-developed index of the quality of disclosed information. To verify the second hypothesis, we analyzed the frequency and scale of the estimated loss of goodwill during the COVID-19 pandemic and its impact on the deterioration of the financial condition of the same research sample. The conducted research shows that the quality of disclosures regarding the goodwill in the examined sample has changed slightly. Contrary to our expectations, the pandemic did not materially reduce the value of goodwill. This means that the first hypothesis was verified positively, while the second hypothesis had to be rejected.
Effects of Total Dissolved Solids, Extraction Yield, Grinding, and Method of Preparation on Antioxidant Activity in Fermented Specialty Coffee
Authors: Várady Matúš , Tauchen Jan , Klouček Pavel , Popelka Peter
Published: August 2022

The aim of this study was to determine the effect of total dissolved solids (TDS), extraction yield (EY), and grinding on total polyphenols (TP), total flavonoids (TF), and total antioxidant capacity (TAC) in a fermented specialty coffee prepared using different methods of filtration (Hario V60, Aeropress, and the French press). The concentrations of antioxidant compounds differed between the TDS treatments and the methods of preparation. The TP and TF with Hario V60 were the highest at a TDS of 1.84%. The TP with Aeropress was at its highest at a TDS of 1.82%. TAC with the French press was at its highest at a TDS of 1.58%. EY was at its highest with fine grinding (Hario V60 > French press > Aeropress at 25.91%, 21.69%, and 20.67%, respectively). French press coffees had the highest TP (p = 0.045). Hario V60 coffee had the highest TF, but the TAC of the coffees remained comparable for all methods. EY and TDS influenced TP, TF, and TAC in the coffee beverages using the finest grinding size for all methods of preparation. The finer the grind, the higher the antioxidant activity of the beverages. Measuring coffee extractions should be one of the most important processes in fermented coffee preparation.
Molecular Characterization and Nutrition Regulation of the Glutamine Synthetase Gene in Triploid Crucian Carp
Authors: Zhou Xiaomei , Zhao Dafang , Chen Yuan , Xiao Yangbo , Mao Zhuangwen , Cao Shenping , Qu Fufa , Li Yutong , Jin Junyan , Liu Zhen , Li Jianzhong , He Zhimin
Published: August 2022

Glutamine synthetase (GS) is a key enzyme that catalyzes the synthesis of glutamine from glutamate, which plays a role in the promotion of muscle cell growth and in improving the flavor of meats. In this study, a GS gene encoding 371 amino acids was cloned from triploid crucian carp and showed the highest level of similarity with the GS gene found in Cyprinus carpio. Meanwhile, GS was differentially expressed in different tissues, and its day–night expression changes showed obvious oscillation. Additionally, the effects of glutamate and glutamine on GS expression in muscle cells were investigated in vitro and in vivo. We found that its expression was obviously increased due to high levels of glutamate (2 mg/mL) but decreased by glutamine in vitro. However, it was significantly promoted by glutamate and glutamine in vivo, with an optimal concentration of 2%. Furthermore, the use of lysine–glutamate dipeptides as feed additives also had a positive influence on GS expression (the optimal concentration is 0.8%). Finally, we explored the effects of different protein levels and sources on the expression of GS, and the results demonstrated that GS had the highest expression at the 35% protein level, but no significant differences were observed in the different protein sources between the fish meal diet (FM) and the mixed diet comprising soybean meal and rapeseed meal (SM). This study sheds new light on the regulation of GS in teleost fish and provides new perceptions and strategies for the formulation of high-quality feed for triploid crucian carp.
Integrative Physiological and Transcriptome Analysis Reveals the Mechanism for the Repair of Sub-Lethally Injured Escherichia coli O157:H7 Induced by High Hydrostatic Pressure
Authors: Hao Jing-Yi , Lei Yu-Qing , Shi Jun-Yan , Zhao Wan-Bin , Gan Zhi-Lin , Hu Xin , Sun Ai-Dong
Published: August 2022

The application of high hydrostatic pressure (HHP) technology in the food industry has generated potential safety hazards due to sub-lethally injured (SI) pathogenic bacteria in food products. To address these problems, this study explored the repair mechanisms of HHP-induced SI Escherichia coli O157:H7. First, the repair state of SI E. coli O157:H7 (400 MPa for 5 min) was identified, which was cultured for 2 h (37 °C) in a tryptose soya broth culture medium. We found that the intracellular protein content, adenosine triphosphate (ATP) content, and enzyme activities (superoxide dismutase, catalase, and ATPase) increased, and the morphology was repaired. The transcriptome was analyzed to investigate the molecular mechanisms of SI repair. Using cluster analysis, we identified 437 genes enriched in profile 1 (first down-regulated and then tending to be stable) and 731 genes in profile 2 (up-regulated after an initial down-regulation). KEGG analysis revealed that genes involved in cell membrane biosynthesis, oxidative phosphorylation, ribosome, and aminoacyl-tRNA biosynthesis pathways were enriched in profile 2, whereas cell-wall biosynthesis was enriched in profile 1. These findings provide insights into the repair process of SI E. coli O157:H7 induced by HHP.