bluuebunny/crossref_metadata_2025 huggingface dataset:
Surgical Management for Transposed Ovarian Recurrence of Cervical Cancer: A Systematic Review with Our Experience
Authors: Maeda Michihide , Hisa Tsuyoshi , Kurahashi Hiroki , Hayashida Harue , Lee Misooja , Kakubari Reisa , Matsuzaki Shinya , Mabuchi Seiji , Kamiura Shoji
Published: September 2022

In early-stage cervical cancer, ovarian metastasis is relatively rare, and ovarian transposition is often performed during surgery. Although rare, the diagnosis and surgical approach for recurrence at transposed ovaries are challenging. This study focused on the diagnosis and surgical management of transposed ovarian recurrence in cervical cancer patients. A 45-year-old premenopausal woman underwent radical hysterectomy, bilateral salpingectomy, and pelvic lymphadenectomy following postoperative concurrent chemoradiotherapy for stage IB1 cervical cancer. During the initial surgery, the ovary was transposed to the paracolic gutter, and no postoperative complications were observed. Ovarian recurrence was diagnosed using positron emission tomography–computed tomography, and a laparoscopic bilateral oophorectomy was performed. A systematic review identified nine women with transposed ovarian recurrence with no other metastases of cervical cancer, and no studies have discussed the optimal surveillance of transposed ovaries. Of those (n = 9), four women had died of the disease within 2 years of the second surgery, and the prognosis of transposed ovarian cervical cancer seemed poor. Nevertheless, three women underwent laparoscopic oophorectomies, none of whom experienced recurrence after the second surgery. Few studies have examined the surgical management of transposed ovarian recurrence. The optimal surgical approach for transposed ovarian recurrence of cervical cancer requires further investigation.
Variation in Fish Abundance, Diversity and Assemblage Structure in Seagrass Meadows across the Atlanto-Mediterranean Province
Authors: Máñez-Crespo Julia , Tomas Fiona , Fernández-Torquemada Yolanda , Royo Laura , Espino Fernando , Antich Laura , Bosch Néstor E. , Castejón Inés , Hernan Gema , Marco-Méndez Candela , Mateo-Ramírez Ángel , Pereda-Briones Laura , Del Pilar-Ruso Yoana , Terrados Jorge , Tuya Fernando
Published: September 2022

Seagrasses worldwide provide key habitats for fish assemblages. Biogeographical disparities in ocean climate conditions and seasonal regimes are well-known drivers of the spatial and temporal variation in seagrass structure, with potential effects on associated fish assemblages. Whether taxonomically disparate fish assemblages support a similar range of ecological functions remains poorly tested in seagrass ecosystems. In this study, we examined variation in the abundance, diversity (from a taxonomic and functional perspective), and assemblage structure of fish community inhabiting nine meadows of the seagrass Cymodocea nodosa across three regions in the Mediterranean (Mallorca and Alicante) and the adjacent Atlantic (Gran Canaria), and identified which attributes typifying the structure of meadows, and large-scale variability in ocean climate, contributed most to explaining such ecological variation. Despite a similar total number of species between Mallorca and Gran Canaria, the latter region had more taxonomically and functionally diverse fish assemblages relative to the western Mediterranean regions, which translated into differences in multivariate assemblage structure. While variation in the abundance of the most conspicuous fish species was largely explained by variation in seagrass structural descriptors, most variation in diversity was accounted for by a descriptor of ocean climate (mean seasonal SST), operating at regional scales. Variation in fish assemblage structure was, to a lesser extent, also explained by local variability in seagrass structure. Beyond climatic drivers, our results suggest that lower temporal variability in the canopy structure of C. nodosa meadows in Gran Canaria provides a more consistent source of food and protection for associated fish assemblages, which likely enhances the more abundant and diverse fish assemblages there.
An Overview of Gracillariidae Leaf Mining Moths in Slovenia with New Records for the Country
Authors: Gomboc Stanislav , Kirichenko Natalia I.
Published: September 2022

Gracillariidae is one of the richest families of leaf mining moths, known by its ornamental and orchard plant pests expanding their primary ranges. We here provide a revised checklist of Gracillariidae (Lepidoptera) of Slovenia that presently accounts for 123 species. Among them, four species, Dialectica imperialella (Zeller, 1847), Phyllonorycter abrasella (Duponchel, 1843), Ph. trifoliella (Gerasimov, 1933), and Phyllocnistis valentinensis M. Hering, 1936, are new records for the country. The distribution of the other three species in Slovenia, Caloptilia honoratella (Rebel, 1914), Dialectica scalariella (Zeller, 1850), and Ph. messaniella (Zeller, 1846), is clarified. For the above seven species, short synopses of the bionomics, a current range, and images of biotopes, adult moths and their genitalia are provided. For P. valentinensis sampled at a larval stage, the DNA barcode was obtained to confirm the species identification. Given the known distribution of some of the newly recorded moths in Europe, we believe that these species do not represent a new invasion but rather are discoveries of native species, except for the newly documented Ph. trifoliella in Slovenia, which is likely to be an alien species for the country.
Contributing Factors for Mutagenic DNA Lesion Bypass by DNA Polymerase Eta (polη)
Authors: Jung Hunmin
Published: September 2022

The integrity of DNA replication is under constant threat from various exogenous and endogenous factors along with some epigenetic factors. When there is damage to the genome, cells respond to the damage in two major ways, DNA damage repair and DNA damage tolerance. One of the major mechanisms for DNA damage tolerance is DNA lesion bypass, which is performed by specific DNA polymerases called Y-family DNA polymerases including DNA polymerase eta (polη). Ever since the discovery of polη’s unique role in bypassing cyclobutane pyrimidine dimer (CPD), a wide range of DNA lesions have been experimentally shown to be bypassed by polη. The structural study of polη was greatly boosted by the first elucidation of the N-terminal catalytic domain of polη by X-ray crystallography in 2010. Ever since, a lot of polη catalytic domain crystal structures have been published, which were complexed with an incoming nucleotide and a lesion containing DNA including pyrimidine dimers, cisplatin GpG adduct, 8-oxoguanine (oxoG), 8-oxoadenine (oxoA), N7-methylguanine (N7mG), O6-methylguanine (O6mG), hypoxanthine (HX), and many others. Though polη’s active site is known to be rigid with few conformational changes, there are several contributing factors that could facilitate the lesion bypass such as catalytic metals, syn–anti conformational equilibrium, tautomerization, and specific residues of polη. Each of these components are discussed in detail in this review.
Contextuality, Complementarity, Signaling, and Bell Tests
Authors: Khrennikov Andrei
Published: September 2022

This is a review devoted to the complementarity–contextuality interplay with connection to the Bell inequalities. Starting the discussion with complementarity, I point to contextuality as its seed. Bohr contextuality is the dependence of an observable’s outcome on the experimental context; on the system–apparatus interaction. Probabilistically, complementarity means that the joint probability distribution (JPD) does not exist. Instead of the JPD, one has to operate with contextual probabilities. The Bell inequalities are interpreted as the statistical tests of contextuality, and hence, incompatibility. For context-dependent probabilities, these inequalities may be violated. I stress that contextuality tested by the Bell inequalities is the so-called joint measurement contextuality (JMC), the special case of Bohr’s contextuality. Then, I examine the role of signaling (marginal inconsistency). In QM, signaling can be considered as an experimental artifact. However, often, experimental data have signaling patterns. I discuss possible sources of signaling—for example, dependence of the state preparation on measurement settings. In principle, one can extract the measure of “pure contextuality” from data shadowed by signaling. This theory is known as contextuality by default (CbD). It leads to inequalities with an additional term quantifying signaling: Bell–Dzhafarov–Kujala inequalities.
Learned Practical Guidelines for Evaluating Conditional Entropy and Mutual Information in Discovering Major Factors of Response-vs.-Covariate Dynamics
Authors: Chen Ting-Li , Fushing Hsieh , Chou Elizabeth P.
Published: September 2022

We reformulate and reframe a series of increasingly complex parametric statistical topics into a framework of response-vs.-covariate (Re-Co) dynamics that is described without any explicit functional structures. Then we resolve these topics’ data analysis tasks by discovering major factors underlying such Re-Co dynamics by only making use of data’s categorical nature. The major factor selection protocol at the heart of Categorical Exploratory Data Analysis (CEDA) paradigm is illustrated and carried out by employing Shannon’s conditional entropy (CE) and mutual information (I[Re;Co]) as the two key Information Theoretical measurements. Through the process of evaluating these two entropy-based measurements and resolving statistical tasks, we acquire several computational guidelines for carrying out the major factor selection protocol in a do-and-learn fashion. Specifically, practical guidelines are established for evaluating CE and I[Re;Co] in accordance with the criterion called [C1:confirmable]. Following the [C1:confirmable] criterion, we make no attempts on acquiring consistent estimations of these theoretical information measurements. All evaluations are carried out on a contingency table platform, upon which the practical guidelines also provide ways of lessening the effects of the curse of dimensionality. We explicitly carry out six examples of Re-Co dynamics, within each of which, several widely extended scenarios are also explored and discussed.
Is There a Fourth Law for Non-Ergodic Systems That Do Work to Construct Their Expanding Phase Space?
Authors: Kauffman Stuart
Published: September 2022

Substantial grounds exist to doubt the universal validity of the Newtonian Paradigm that requires a pre-stated, fixed phase space. Therefore, the Second Law of Thermodynamics, stated only for fixed phase spaces, is also in doubt. The validity of the Newtonian Paradigm may stop at the onset of evolving life. Living cells and organisms are Kantian Wholes that achieve constraint closure, so do thermodynamic work to construct themselves. Evolution constructs an ever-expanding phase space. Thus, we can ask the free energy cost per added degree of freedom. That cost is roughly linear or sublinear in the mass constructed. However, the resulting expansion of the phase space is exponential or even hyperbolic. Thus, the evolving biosphere does thermodynamic work to construct itself into an ever-smaller sub-domain of its ever-expanding phase space at ever less free energy cost per added degree of freedom. The universe is not correspondingly disordered. Entropy, remarkably, really does decrease. A testable implication of this, termed here the Fourth Law of Thermodynamics, is that at constant energy input, the biosphere will construct itself into an ever more localized subregion of its ever-expanding phase space. This is confirmed. The energy input from the sun has been roughly constant for the 4 billion years since life started to evolve. The localization of our current biosphere in its protein phase space is at least 10–2540. The localization of our biosphere with respect to all possible molecules of CHNOPS comprised of up to 350,000 atoms is also extremely high. The universe has not been correspondingly disordered. Entropy has decreased. The universality of the Second Law fails.
Spike Timing-Dependent Plasticity with Enhanced Long-Term Depression Leads to an Increase of Statistical Complexity
Authors: Pallares Di Nunzio Monserrat , Montani Fernando
Published: September 2022

Synaptic plasticity is characterized by remodeling of existing synapses caused by strengthening and/or weakening of connections. This is represented by long-term potentiation (LTP) and long-term depression (LTD). The occurrence of a presynaptic spike (or action potential) followed by a temporally nearby postsynaptic spike induces LTP; conversely, if the postsynaptic spike precedes the presynaptic spike, it induces LTD. This form of synaptic plasticity induction depends on the order and timing of the pre- and postsynaptic action potential, and has been termed spike time-dependent plasticity (STDP). After an epileptic seizure, LTD plays an important role as a depressor of synapses, which may lead to their complete disappearance together with that of their neighboring connections until days after the event. Added to the fact that after an epileptic seizure the network seeks to regulate the excess activity through two key mechanisms: depressed connections and neuronal death (eliminating excitatory neurons from the network), LTD becomes of great interest in our study. To investigate this phenomenon, we develop a biologically plausible model that privileges LTD at the triplet level while maintaining the pairwise structure in the STPD and study how network dynamics are affected as neuronal damage increases. We find that the statistical complexity is significantly higher for the network where LTD presented both types of interactions. While in the case where the STPD is defined with purely pairwise interactions an increase is observed as damage becomes higher for both Shannon Entropy and Fisher information.
Coupled Electromagnetic-Dynamic Modeling and Bearing Fault Characteristics of Induction Motors considering Unbalanced Magnetic Pull
Authors: Huang Liangyuan , Shen Guoji , Hu Niaoqing , Chen Ling , Yang Yi
Published: September 2022

Induction motors are complex energy conversion systems across the domains of dynamics, electricity, and magnetism. Most existing models mainly consider unidirectional coupling, such as the effect of dynamics on electromagnetic properties, or the effect of unbalanced magnetic pull on dynamics, while in practice it should be a bidirectional coupling effect. The bidirectionally coupled electromagnetic-dynamics model is beneficial to the analysis of induction motor fault mechanisms and characteristics. This paper proposes a coupled electromagnetic-dynamic modeling method that introduces unbalanced magnetic pull. By using the rotor velocity, air gap length, and unbalanced magnetic pull as the coupling parameters, the coupled simulation of the dynamic and electromagnetic models can be effectively realized. Simulation results for bearing faults show that the introduction of magnetic pull induces a more complex dynamic behavior of the rotor, which in turn leads to modulation in the vibration spectrum. The fault characteristics can be found in the frequency domain of the vibration and current signals. Through the comparison between simulation and experimental results, the effectiveness of the coupled modeling approach and the frequency domain characteristics caused by the unbalanced magnetic pull are verified. The proposed model can help to obtain a variety of information that is difficult to measure in reality and can also serve as a technical basis for further research on nonlinear characteristics and chaos in induction motors.
A Framework for Developing Educational Industry 4.0 Activities and Study Materials
Authors: Christiansen Lasse , Hvidsten Tommy Edvardsen , Kristensen Jesper Hemdrup , Gebhardt Jonas , Mahmood Kashif , Otto Tauno , Lassen Astrid Heidemann , Brunoe Thomas Ditlev , Schou Casper , Laursen Esben Skov
Published: September 2022

The advent of Industry 4.0 is changing the role of human labour towards a more supportive function in the production system, requiring new digital-, technical-, interdisciplinary-, collaborative- and communicative competencies. This challenges educational institutions to develop new teaching activities and materials to address ever emerging needs. To address this, this paper presents an Educational Framework to support educators in developing new teaching activities and study material for Industry 4.0. The model distinguishes itself from other educational design models by combining an iterative approach toward problem-solving, with the concept of authentic task design, as the core elements. Based on 14 pilot cases, it is concluded that educational framework have increased the educational activities in the areas in focus.
Music Recommendation Based on “User-Points-Music” Cascade Model and Time Attenuation Analysis
Authors: Wang Tuntun , Li Junke , Zhou Jincheng , Li Mingjiang , Guo Yong
Published: September 2022

Music has an increasing impact on people’s daily lives, and a sterling music recommendation algorithm can help users find their habitual music accurately. Recent research on music recommendation directly recommends the same type of music according to the specific music in the user’s historical favorite list. However, users’ behavior towards a certain cannot reflect the preference for this type of music and possibly provides music the listener dislikes. A recommendation model, MCTA, based on “User-Point-Music” structure is proposed. By clustering users’ historical behavior, different interest points are obtained to further recommend high-quality music under interest points. Furthermore, users’ interest points will decay over time. Combined with the number of music corresponding to each interest point and the liking degree of each music, a multi-interest point attenuation model is constructed. Based on the real data after desensitization and encoding, including 100,000 users and 12,028 pieces of music, a series of experimental results show that the effect of the proposed MCTA model has improved by seven percentage points in terms of accuracy compared with existing works. It came to the conclusion that the multi-interest point attenuation model can more accurately simulate the actual music consumption behavior of users and recommend music better.
Microwave-Assisted Annealing Method for Low-Temperature Fabrication of Amorphous Indium-Gallium-Zinc Oxide Thin-Film Transistors
Authors: Kim Jong-Woo , Park Seong-Geon , Yang Min Kyu , Ju Byeong-Kwon
Published: September 2022

Compared with conventional silicon-based semiconductors, amorphous oxide semiconductors present several advantages, including the possibility of room-temperature fabrication, excellent uniformity, high transmittance, and high electron mobility. Notably, the application of oxide semiconductors to flexible electronic devices requires a low-temperature fabrication process. However, for the realization of semiconductor characteristics and stable products, the fabrication process requires annealing at temperatures of 300 °C or higher. To address this, a low-temperature microwave annealing method, which improves the electrical characteristics of a transistor and reduces the production time compared with the conventional annealing method, is presented herein. Microwave annealing is a well-known method of annealing that minimizes the heat energy transferred to a substrate via instantaneous heat transfer through the vibrations of the lattice in the material during microwave irradiation and is suitable as a low-temperature annealing method. In this study, we evaluate the electrical characteristics of devices subjected to conventional annealing at 200 °C and 300 °C for 1 h and microwave annealing at 200 °C for 10 min. For the device subjected to microwave annealing at 200 °C for 10 min, the threshold voltage, current on/off ratio, subthreshold swing, and saturation mobility are 13.9 V, 1.14 × 105, 3.05 V/dec, and 4.23 cm2/V·s, respectively. These characteristic results are far superior to the characteristic results of the device subjected to conventional annealing at 200 °C for 1 h and are equivalent to those of the device treated at 300 °C for 1 h. Thus, this study develops a more effective annealing method, which facilitates low-temperature fabrication in a reduced period.
An Unmanned Underwater Vehicle Torpedoes Attack Behavior Autonomous Decision-Making Method Based on Model Fusion
Authors: Guo Liqiang , Ma Liang , Zhang Hui , Yang Jing , Cheng Zhuo , Jiang Wenmin
Published: September 2022

The autonomous technology of unmanned platforms is the most dynamic frontier among fields of technology and, inevitably, is trending towards future development. Aiming at the dual requirements of reliable and real-time autonomous decision-making of unmanned underwater vehicles in complex and unfamiliar environments, this article proposes an intelligent decision-making method of attack behavior based on model fusion. The experimental dataset is generated through simulation modeling, and an appropriate amount of noise is added to simulate the observation error in a real situation. The threshold of weapon-hit probability is set according to the requirements of combat missions, and the decision-making of attack behavior is transformed into the problem of imbalanced sample classification with noisy data. Through theoretical analysis and experimental testing, the classification effects of algorithms such as Logistic Regression (LR), K-nearest neighbor (KNN), support vector machine (SVM), multilayer perceptron (MLP), decision tree (DT), and ensemble learning are compared. On this basis, the intelligent decision model is constructed by using synthetic minority oversampling technique resampling and three model fusion methods of voting, stacking, and blending. The experimental results show that compared with traditional simulation decision-making and common classification algorithms, the proposed method has higher accuracy, recall rate, area-under-the-curve value, and model generalization ability. It can not only effectively identify the impact of noise data on attack-behavior decision-making, but also ensures the decision-making speed through offline training, and provides references for the research in the field of equipment development and intelligent decision-making in the future.
Design and Analysis of Omnidirectional Receiver with Multi-Coil for Wireless Power Transmission
Authors: An Huilin , Yuan Jian , Li Jun , Cao Liqiang
Published: September 2022

In order to solve the misalignment problem of wireless power transmission, this paper designed and analyzed the omnidirectional receiver with multi-coil. The circuit models and transmission characteristics of the wireless power transfer system (WPTS) containing multi-coil were established. Besides, an accurate mutual inductance modelling method of the circular coil under different horizontal offset and angular deflection was presented. Based on the circuit models and the mutual inductance model, the relationship between transmission characteristics and the coil parameters were studied. Simultaneously, the design method which can synthetically and quantificationally consider the radius of the coil and the number of turns was proposed. Finally, an omnidirectional receiver with multi-coil using the quantificational model and transmission characteristics in different horizontal offset and angular deflection was designed.The transmission efficiency of three-coils-receiver system was up 12.3% higher than that of one-coil-receiver system and 4% higher than that of two-coils-receiver system when horizontal offset was between 0 cm and 30 cm. Similarly, when angular deflection was between 0 and π/2, the efficiency of three-coils-receiver system was up 73.25% higher than that of one-coil-receiver system and 1.6% higher than that of two-coils-receiver system.
EE-MPTCP: An Energy-Efficient Multipath TCP Scheduler for IoT-Based Power Grid Monitoring Systems
Authors: Dong Zihang , Cao Yunming , Xiong Naixue , Dong Pingping
Published: September 2022

The Internet-of-Things (IoT) based monitoring system has significantly promoted the intelligence and automation of power grids. The inspection robots and wireless sensors used in the monitoring system usually have multiple network interfaces to achieve high throughput and reliability transmission. The concurrent usage of these available interfaces with Multipath TCP (MPTCP) can enhance the quality of service of the communications. However, traditional MPTCP scheduling algorithms may bring about data disorder and even buffer blocking, which severely affects the transmission performance of MPTCP. And the common MPTCP improvement mechanisms for IoT lack sufficient attention to energy consumption, which is important for the battery-limited wireless sensors. With the aim to promote conservative energy without loss of throughput, this paper develops an integrated multipath scheduler for energy consumption optimization named energy-efficient MPTCP (EE-MPTCP). EE-MPTCP first constructs a target optimization function which considers both network throughput and energy consumption. Then, based on the proposed MPTCP transmission model and existing energy efficiency model, the network throughput and energy consumption of each path can be estimated. Finally, a heuristic scheduling algorithm is proposed to find a suitable set of paths for each application. As confirmed by experiments based on Linux testbed as well as the NS3 simulation platform, the proposed scheduler can shorten the average completion time and reduce the energy consumption by up to 79.9% and 79.2%, respectively.
Complete Transitions of Hybrid Wind-Diesel Systems with Clutch and Flywheel-Based Energy Storage
Authors: Monroy-Morales José , Peña-Alzola Rafael , Campos-Gaona David , Anaya-Lara Olimpo
Published: September 2022

A Wind Diesel Hybrid System (WDHS) is an isolated power system that combines Diesel Generators (DGs) and Wind Turbines (WTGs). The WDHS has three operation modes: Diesel Only (DO), Wind Diesel (WD) and Wind Only (WO). The latter mode is the only one resulting in substantial savings, as the DG consumes fuel even with no load. Moreover, adding an energy storage system (ESS) can significantly reduce the start/stop cycles in the DG. The FESS is robust, immune to deep discharges and its state of charge (SOC) is simple to monitor. The WDHS considered in this article uses a friction clutch to disengage the diesel engine (DE) from the synchronous generator (SG) in WO mode. The AVR regulates the voltage amplitude and the frequency regulation results from balancing the power produced by the DG and WT with the power consumed by the load and dump load along with the FESS utilisation. The control algorithms of the different elements present in the WHDS are explained, as well as the general control. The FESS always has priority over the DL for the maximum harnessing of the wind power. Simulations assess the proposed solutions for the different operation modes in the WDHS.
ULP Super Regenerative Transmitter with Digital Quenching Signal Controller
Authors: Kayed Somaya , Saleh Sherif , Shawkey Heba
Published: September 2022

This paper demonstrates an on–off keying (OOK) super-regenerative quenching transmitter operating in 402–405 MHz MICs band applications. To reduce power consumption, the transmitter is controlled by a novel digital quenching signal controller that generates a digital control signal to start transmitter operation when a baseband signal is input to the transmitter. The digital signal controller consists of an envelope detector, a comparator, and a quench timer designed using a state machine to synchronize the operation between the digital controller and the input baseband signal. The transmitter consists of a Colpitts oscillator operating in double operating frequency followed by a frequency divider by 2; this configuration reduces system area and improves phase noise and signal spectrum. The proposed transmitter is implemented using UMC 130 nm CMOS technology and a 1.2 V supply. Simulation shows that the proposed transmitter can meet MICS band mask specifications with data rates up to 1 Mbps and total power dissipation of 537 uW.
Innovative Solar Concentration Systems and Its Potential Application in Angola
Authors: Constantino Erany D. G. , Teixeira Senhorinha F. C. F. , Teixeira José C. F. , Barbosa Flavia V.
Published: September 2022

Energy demands have been increasing worldwide, endangering the future supply–demand energy balance. To provide a sustainable solution for future generations and to comply with the international goal to achieve Carbon Neutrality by 2050, renewable energies have been at the top of the international discussions, actively contributing to the energy transition and climatic policies. To achieve the international goal, Angola proposed a long-term strategy that promotes a fair and sustainable development of the national territory by means of improving the electric sector. Among all the renewable resources, solar energy is found to be the most promising solution since it has the second major renewable energy potential in Angola. However, the main problem related to solar energy is the efficiency of the solar systems and the electrical and thermal energy storage. As part of the solution, Concentration Solar Power (CSP) can make a sounder contribution to the transformation of the Angolan energy sector since it enables a significant increase in energy intensity through the concentration of solar energy. Moreover, the large applicability of this technology can contribute to the development of the rural regions which still struggle for energy equity. By considering the potential of CSP, this work presents the status of the Angolan energy sector, and focus is provided on the solar potential of the country. The advantages of the CSP technologies with emphasis on the parabolic dish systems are presented, and the contribution and innovative solutions for the enhancement of thermal efficiency are presented.
High Entropy Alloys for Energy Conversion and Storage: A Review of Grain Boundary Wetting Phenomena
Authors: Straumal Boris , Korneva Anna , Kuzmin Alexei , Klinger Leonid , Lopez Gabriel A. , Vershinin Nikolai , Straumal Alexander , Gornakova Alena
Published: September 2022

The multicomponent alloys with nearly equal concentration of components, also known as high entropy alloys (HEAs), were first proposed 22 years ago. The HEAs quickly became very important in materials science due to their unique properties. Nowadays, the HEAs are frequently used in energy conversion and storage applications. HEAs can consist of five, six or more components. Plasma cladding permits coating of the large surfaces of cheap substrates with (often expensive) HEAs and to enlarge, in such a way, their application area. The large-area coatings deposited by plasma cladding possess multiple advantages such as low thermal distortion, very high energy density, as well as low dilution of the substrate material. Plasma cladding ensures good metallurgical bonding between coating and substrate. The costs of operation and equipment are also very attractive. During plasma cladding, the mixed powders are blown by carrier gas into a plasma torch or are positioned on a substrate. This powder mixture is then melted in or under the plasma torch. The plasma torch, in turn, sequentially scans the substrate. After finalizing the crystallization process, the solid polycrystal appears which contains few residual melts. This remaining melt can completely or incompletely wet the grain boundaries (GBs) in solid phase of the polycrystal. These completely or incompletely wetted GBs can strongly influence the microstructure of HEA coatings and their morphology. In this review we analyze the GB wetting HEAs containing one phase in HEAs with two, three and more phases, as well as in HEAs reinforced with particles of carbides, nitrides, borides, or oxides. We also analyze the microstructure of the rather thick coatings after plasma cladding after additional laser remelting and observe how GB wetting changes over their thickness.
Study on CO2–Water Co-Injection Miscible Characteristics in Low-Permeability Near-Critical Volatile Oil Reservoir
Authors: Hou Dali , Li Jinghui , Tang Hongming , Guo Jianchun , Xiang Xueni
Published: September 2022

Low-permeability near-critical volatile reservoirs are characterized by light oil, complex fluid phase, and strong reservoir inhomogeneity, etc. Purely injecting CO2 will create a series of problems, such as serious gas channeling, low sweep efficiency, and low oil recovery. Therefore, in this paper, through a combination of experiments and simulations and in the process of studying the problem from simple to complex, we carried out phase equilibrium experiments for CO2-near-critical volatile oil and CO2-near-critical volatile oil-formation water, as well as experiments for minimum miscible pressure of slim-tube with pure CO2 and CO2–water co-injection to the comparative study of the miscible characteristics and displacement oil efficiency between pure CO2 injection and CO2–water co-injection. It provides an important reference for improving oil recovery by CO2–water co-injection in low-permeability near-critical volatile reservoir. The results of CO2-near-critical volatile oil/CO2-near-critical volatile oil-formation water phase equilibrium experiments show that the saturation pressure, density, and gas–oil ratio of the system increase, and the viscosity decreases with the increase in CO2 injection. In the three-phase system of CO2-near-critical volatile oil-formation water, the CO2 content in the flash gas of crude oil, gas–oil ratio, and gas–water ratio are negatively correlated with the water saturation. The results of slim-tube experiments and simulations on the miscible characteristics and displacement oil efficiency of pure CO2 injection and CO2–water co-injection show that the recovery degree of crude oil under CO2–water co-injection is higher than that of pure CO2 injection, and the CO2 dissolved transition section in oil and gas is shorter and the gas breakthrough time is later under CO2–water co-injection, which effectively increases the sweep efficiency and improves the degree recovery of crude oil. When CO2–water co-injection, the ratio of water is higher, the later the gas–oil ratio rises, the later the CO2 breakthrough, and the higher the degree of crude oil recovery. It indicates that when CO2–water co-injection, the ratio of water is higher, the more CO2 is dissolved in water, which effectively inhibits the occurrence of gas channeling and increases the sweep area, thus improving the degree recovery of crude oil. The research results of this paper provide an experimental basis and theoretical foundation for CO2–water co-injection for enhanced crude oil recovery in low-permeability near-critical volatile reservoirs.
Taguchi Techniques as an Effective Simulation-Based Strategy in the Design of Numerical Simulations to Assess Contact Stress in Gerotor Pumps
Authors: Gamez-Montero Pedro Javier , Bernat-Maso Ernest
Published: September 2022

The contact problem of a trochoidal gear is a drawback and a well-known performance indicator of a gerotor pump. Although numerical simulations aid in the evaluation of contact stress, the difficult task of determining geometrical parameters, operating conditions, and the number of simulations to run falls to the designer. This paper presents the Taguchi techniques as an effective simulation-based strategy to narrow down the geometrical parameter combinations, reducing the solution space and optimizing the number of simulations. The work is first focused on the validation of the proposed numerical model by means of published contact stress results of recognized researchers in the field, as well as the unification of nomenclature and notation. Then, the Taguchi approach is based on a sequence of four experiments, ranging from the screening case with two levels and seven parameters to multiple levels and four parameters with three software input operating conditions (temperature, torque, and friction coefficient) emulating noise effects. The contact stresses of 128 gear sets, having common volumetric capacity and dimensional constraints to detach mechanical performance from flow rate and casing, were analyzed. Results prove the feasibility of the proposed methodology by identifying the most suitable gear set configuration and predicting the quantifiable performances of a real-working gerotor pump.
Quantitative Evaluation of Gypsum-Salt Caprock Sealing Capacity Based on Analytic Hierarchy Process—A Case Study from the Cambrian in the Tarim Basin, Western China
Authors: Zhao Shan , Liu Hua , Zhu Yongfeng , Wang Shen , Yang Xianzhang
Published: September 2022

Gypsum-salt caprock is one of the most important caprocks in petroliferous basins around the world. Its sealing capacity extremely affects hydrocarbon accumulation and distribution. However, there are numerous variables that affect caprock sealing performance, making a quantitative evaluation challenging. The analytic hierarchy process (AHP), which has the advantage of turning several influencing factors into multi-level single objectives, can be utilized in this context to quantify the weight of each element impacting caprock sealing capacity. As a result, using the Tarim Basin’s Cambrian as an example, this article quantitatively assessed the gypsum-salt caprock sealing capacity using AHP. The results show that factors affecting the sealing capacity of Cambrian gypsum-salt caprock in the Tarim Basin can be summarized into three major categories and nine sub-categories, including the lithology (rock assemblage type and lithology zoning), the thickness (total thickness of thick single layer, maximum thickness of thick single layer, total thickness, and ratio of caprock to stratum), and the mechanical properties (internal friction coefficient, compressive strength, peak strength). The sealing ability evaluation index (C) was created by applying AHP to quantify a number of different characteristics. The capacity of the caprock to seal is inversely correlated with the C-value. The value of C in the plane climbs consistently from Tabei to Tazhong and subsequently to the Bachu region, indicating a steady improvement in caprock sealing ability. Additionally, the evaluation’s findings are in line with how hydrocarbon accumulations are currently distributed. Furthermore, hydrocarbons are mostly distributed in subsalt and subsalt-dominated layers when C is greater than 2. On the contrary, hydrocarbons are mainly distributed in post-salt layers when C is less than 2. Furthermore, in areas affected by faults, hydrocarbons are favorably distributed in subsalt layers when C reaches 2, and fault activity is poor or strong in the early period and weak in the late period.
Analysis of Employees’ Competencies in the Context of Industry 4.0
Authors: Kowal Barbara , Włodarz Daria , Brzychczy Edyta , Klepka Andrzej
Published: September 2022

The implementation of Industry 4.0 technology and meeting the expectations of employers, the labour market, and, in fact, sustainable development are new challenges for industry employees, especially for their knowledge and skills. The changes introduced during industrial revolutions have always affected the job market and employees’ required competencies. The same can be said for the latest industrial revolution, Industry 4.0, in which the human factor plays an important role, mainly because new challenges are posed by human beings’ role in digitised reality. Our research aimed to identify the employee competencies that are required in the context of Industry 4.0. We investigated two groups of respondents (employees and students). These groups were subjected to a comparative analysis of their digital, technical, social and personal competencies. As a result of the analysis, we identified the highest-ranked competencies in defined groups. Our results show that technical and soft skills are equally important in this highly technically based industrial revolution.
Stable Carbon Isotopic Composition of Selected Alkylnaphthalenes and Alkylphenanthrenes from the Tarim Oilfields, NW China
Authors: Konan N’Guessan Francois De Sales , Li Meijun , Shi Shengbao , Kojo Amoako , Toyin Abdulkareem , Boakye Nancy Pearl Osei , Li Tiantian
Published: September 2022

The present study aimed firstly to use a set of crude oil samples and a dataset to provide new evidence for source input contribution in selected aromatic isomers for discrimination of oils from three oilfields from Tarim Basin and identify the key factor (s) controlling the isotope composition. Thus, the present research showed that the δ13C values of alkylnaphthalenes and alkylphenanthrenes plotted against P/DBT and Ga/C30H ratios is a reliable and convenient tool for discrimination of organic matter variations in different oilfields. More importantly, molecular ratios and different diagram plots revealed that the selected oil samples would be derived from a mixing of indigenous organic matter from the terrestrial (in Kuqa area) and marine (in the cratonic area) depositional environments prior the apparition of the Yakela Faulted Uplift. Thus, Daolaoba, Yakela, and Tahe oils were made up of organic materials from both marine and terrestrial sources. Furthermore, marine organic matter input dominates oils from the Tahe and Yakela, with a minor input from terrestrial sources. The oils from Daolaoba were assigned to be from a mixing of marine and terrestrial material inputs. The controlling factors assessment revealed that biodegradation has an insignificant effect on the set of oils; however, the source input and the thermal maturity together control the isotopic compositions of individual aromatic isomers from these three oilfields.
Failure Patterns of Transmission Tower-Line System Caused by Landslide Events
Authors: Yu Hong , Li Hao , Zhang Zhi-Qiang , Zhang Gui-Feng , Wang Da-Hai , Zheng Hua-Dong
Published: September 2022

A transmission tower-line system consists of many towers and cables, which is a long-span structure. Due to topographical restrictions, the structure inevitably passes through wide areas prone to landslide hazards. The landslide causes the failure of the tower foundation and threatens the safety of the power transmission system. Therefore, the aim of this study was to investigate the collapse patterns of a transmission tower-line structure under landslides. The explicit analysis method was used to deal with the nonlinear dynamic response equations of the structure. To prove the effect of the landslides on the collapse patterns of the transmission tower-line structure, two foundation failure cases (Case 1 and Case 2) under landslides were considered. For each case, the displacement responses at tower tops and the progressive collapse behavior were analyzed, which illustrate that the failure patterns of the tower-line structure under landslides are dominated by two factors, i.e., the failure mode of the tower foundation and the pulling effect of cables. The overall tilting and hinge formation in the middle of the tower body are the main collapse patterns of the structure under Case 1 and Case 2, respectively. In addition, because of the pulling of cables, the collapse of one tower induced by the landslides always triggers the local failure of neighboring tower heads.
Study on Physicochemical Properties and Rock-Cracking Mechanism of High-Energy Expansion Agent
Authors: Zhang Yansong , Cai Li , Shi Jing , Wei Xiangrui
Published: September 2022

Aiming at the shortcomings of the current rock-breaking technology, a new type of high-energy expansion agent for energetic materials based on combustion-to-detonation was developed. By characterizing the basic physical and chemical properties of the high-energy expansion agent (HEEA) such as morphology, particle size distribution, and pyrolysis characteristics, the work performance of different types of high-energy expansion agents was analyzed in combination with the energy characteristics. The results showed that the relationship between the expansion work done by the gas to the outside world was WHEEA-I > WHEEA-II > WHEEA-III under the same quality of HEEA combustion. The damage effect of high-temperature and high-pressure gas cracking specimens generated by deflagration of HEEA was obvious, having the rule that the disturbance damage of rock caused by low heat and high gas specific volume was smaller, and the damage degree of rock caused by high heat and low gas specific volume was larger. The mechanism of HEEA combustion and detonation in confined space is revealed, which provides a theoretical basis for the application of HEEA-cracked rock.
Optimal Planning of Future District Heating Systems—A Review
Authors: Jiang Mengting , Rindt Camilo , Smeulders David M. J.
Published: September 2022

This article provides the state-of-the-art on the optimal planning and design of future district heating (DH) systems. The purpose is to provide practical information of first-step actions for countries with a low DH market share for heating and cooling supply. Previous research showed that for those countries, establishing a heat atlas with accurate geographical data is an essential prerequisite to promote the development of DH systems. In this review, essential techniques for building a high-quality heat atlas are elaborated. This includes a review of methodologies for district thermal energy demand prediction and the status of the integration of sustainable resources in DH systems. In the meanwhile, technical barriers for the implementation of various sustainable heat sources are identified. Furthermore, technologies for the optimal planning of DH systems are discussed. This includes the review of current approaches for the optimal planning of DH systems, discussions on various novel configurations which have been actively investigated recently, and common upgrading measures for existing DH systems.
Development of a Flashover Voltage Prediction Model with the Pollution and Conductivity as Factors Using the Response Surface Methodology
Authors: Ghermoul Oussama , Benguesmia Hani , Benyettou Loutfi
Published: September 2022

In this paper, the response surface methodology (RSM) is used to predict the flashover voltage of a cap and pin 1512L insulator used by SONELGAZ Algerian Power Company (SPE). The pollution and conductivity are studied using a two-level central composite design. MINITAB 19 software is used to perform the regression analysis and analysis of variance (ANOVA) of the data, from which the full quadratic model is developed. The results show that both the pollution and conductivity have a significant effect on the response. The model validation shows the good agreement between the experiment’s obtained results and the predicted results. Therefore, the model could be used to predict the flashover voltage.