bluuebunny/crossref_metadata_2025 huggingface dataset:
Machine Learning in Tribology—More than Buzzwords?
Authors: Tremmel Stephan , Marian Max
Published: April 2022

Tribology has been and continues to be one of the most relevant fields, being present in almost all aspects of our lives [...]
Advances in the Application of Vegetable-Oil-Based Cutting Fluids to Sustainable Machining Operations—A Review
Authors: Kazeem Rasaq A. , Fadare David A. , Ikumapayi Omolayo M. , Adediran Adeolu A. , Aliyu Samuel J. , Akinlabi Stephen A. , Jen Tien-Chien , Akinlabi Esther T.
Published: April 2022

Scientists and tribologists are currently exploring sustainable and inexhaustible lubricants as a result of increased awareness of environmental and health-related issues. Vegetable oils are being investigated as a potential form of environmentally friendly cutting fluids due to their excellent renewability, biodegradability, and lubricating performance. This report provides an overview of different vegetable oils used as cutting fluids in the machining of engineering materials. The effects of virgin vegetable oils, emulsified vegetable-based oils, and vegetable-oil-based nano-cutting fluids on the cutting force, the surface finish of machined parts, the tool wear, and the temperature of the cutting area were surveyed critically. Compared to mineral-oil-based cutting fluids, studies have demonstrated that vegetable-oil-based cutting fluids meet cleaner manufacturing standards with good or better efficiency.
Current Status and Future Prospects of Biolubricants: Properties and Applications
Authors: Narayana Sarma Rakesh , Vinu Ravikrishnan
Published: April 2022

Biolubricants generated from biomass and other wastes can reduce the carbon footprint of manufacturing processes and power generation. In this paper, the properties and uses of biolubricants have been compared thoroughly with conventional mineral-based lubricants. The biolubricants, which are currently based on vegetable oils, are discussed in terms of their physicochemical and thermophysical properties, stability, and biodegradability. This mini-review points out the main features of the existing biolubricants, and puts forward the case of using sustainable biolubricants, which can be generated from agro-residues via thermochemical processes. The properties, applications, and limitations of non-edible oils and waste-derived oils, such as bio-oil from pyrolysis and bio-crude from hydrothermal liquefaction, are discussed in the context of biolubricants. While the existing studies on biolubricants have mostly focused on the use of vegetable oils and some non-edible oils, there is a need to shift to waste-derived oils, which is highlighted in this paper. This perspective compares the key properties of conventional oils with different oils derived from renewable resources and wastes. In the authors’ opinion, the use of waste-derived oils is a potential future option to address the problem of the waste management and supply of biolubricant for various applications including machining, milling applications, biological applications, engine oils, and compressor oils. In order to achieve this, significant research needs to be conducted to evaluate salient properties such as viscosity, flash point, biodegradability, thermo-oxidative and storage stability of the oils, technoeconomics, and sustainability, which are highlighted in this review.
Accelerated Wear Test Design Based on Dissipation Wear Model Entropy Analysis under Mixed Lubrication
Authors: Li Hongju , Liu Ying , Liao Haoran , Liang Zhurong
Published: April 2022

Theoretical life prediction of tribo-pairs such as seals, bearings and gears with the failure form of wear under mixed lubrication depends on quantitative analysis of wear. Correspondingly, the wear life test depends on an accelerated wear test method to save the time and financial costs. Therefore, the theoretical basis of accelerated test design is a wear model providing a quantitative relationship between equivalents and accelerated test duration. In this paper, an accelerated wear test design method based on dissipation wear model entropy analysis under mixed lubrication is proposed. Firstly, the dissipation wear model under mixed lubrication is verified by standard experiments as a theoretical basis. Then, an accelerated wear test design method is proposed, taking the entropy increase in the dissipation wear model as an equivalent. The verification test shows that 20 times acceleration could be reached by adjustment of the entropy increase rate. The effect of entropy increase rate gradient of duty parameters is also discussed, revealing the fastest acceleration direction. Finally, the advantages and disadvantages of the proposed method are discussed. The results in this paper are expected to contribute to long life predictions of tribo-pairs.
End-of-Life Management of Biodegradable Plastic Dog Poop Bags through Composting of Green Waste
Authors: Dróżdż Danuta , Malińska Krystyna , Postawa Przemysław , Stachowiak Tomasz , Nowak Dorota
Published: April 2022

Plastic waste derived from plastic dog poop bags (DPBs) could be considered a negligible source of plastic waste. However, it is estimated that this kind of waste contributes to 0.6% of the total plastic waste generated worldwide, and it is expected to increase in the following years. Plastic dog poop bags can be replaced with biodegradable and bio-based alternatives. These alternatives can biodegrade in various environments such as composting, soil, or water and thus allow for end-of-life management without the risk of contaminating the environment with microplastics. However, not all biodegradable bags are always compostable. In this study, we tested composting as the end-of-life management of selected biodegradable dog poop bags (i.e., prototypes of bags and commercially available bags). We analyzed the biodegradation of selected biodegradable plastic dog poop bags during the composting of green waste in laboratory composting reactors after 4 weeks and 90 days of composting. All the investigated DPBs decomposed 100% after 90 days of composting. However, the fresh compost obtained after the 90-day composting of green waste mixed with the investigated bags containing dog poop did not demonstrate high quality.
The Thermographic Analysis of the Agglomeration Process in the Roller Press of Pillow-Shaped Briquettes
Authors: Uhryński Andrzej , Bembenek Michał
Published: April 2022

When the briquetting process of fine-grained material takes place in the roller press unit, the pressure reached is over a hundred megapascals. This parameter is a result, among other factors, of the geometry of a compaction unit and also the properties of the consolidated material. The pressure of the unit is not constant and the changes in value depend on a given place on the molding surface. By the process of generating different types of pressure on the surface of briquettes, their compaction is different as well. The distribution of temperature on the surface of the briquettes may determine the pressure used locally on them. Nevertheless, the distribution of stress in the briquetting material is still a subject of scientific study. However, it is known that the pressure exerted on the briquette is different for different compaction systems. The article includes authors’ further thermography studies on the classical pillow-shaped briquetting process (instead of the saddle-shaped ones that were previously conducted) of four materials (calcium hydroxide and water mixture, mill scale, charcoal fines and starch mixture, as well as a mixture of EAFD, scale, fine coke breeze, molasses, and calcium hydroxide). Immediately after the briquettes left the compaction zone, thermal images were taken of them, as well as forming rollers. Thermograms that were obtained and the variability of temperature at characteristic points of the surface of pillow-shaped briquettes were analyzed. They showed differences in temperature on the surface of briquettes. In all four cases, the highest briquette temperatures were recorded in their upper part, which proves their better densification in this part. The temperature differences between the lower and upper part of the briquettes ranged from 1.8 to 9.7 °C, depending on the mixture.
A Pragmatic Transfer Learning Approach for Oxygen Vacancy Formation Energies in Oxidic Ceramics
Authors: Yin Xiaoyan , Spatschek Robert , Menzler Norbert H. , Hüter Claas
Published: April 2022

Lower oxygen vacancy formation energy is one of the requirements for air electrode materials in solid oxide cells applications. We introduce a transfer learning approach for oxygen vacancy formation energy prediction for some ABO3 perovskites from a two-species-doped system to four-species-doped system. For that, an artificial neural network is used. Considering a two-species-doping training data set, predictive models are trained for the determination of the oxygen vacancy formation energy. To predict the oxygen vacancy formation energy of four-species-doped perovskites, a formally similar feature space is defined. The transferability of predictive models between physically similar but distinct data sets, i.e., training and testing data sets, is validated by further statistical analysis on residual distributions. The proposed approach is a valuable supporting tool for the search for novel energy materials.
Colloidal Processing of Complex-Shaped ZrB2-Based Ultra-High-Temperature Ceramics: Progress and Prospects
Authors: Liu Guoqian , Yan Changhai , Jin Hua
Published: April 2022

Ultra-high-temperature ceramics (UHTCs), such as ZrB2-based ceramics, are the most promising candidates for ultra-high-temperature applications. Due to their strong covalent bonding and low self-diffusion, ZrB2-based UHTCs are always hot-pressed at temperatures above 1800 °C. However, the hot-pressing technique typically produces disks or cylindrical objects limiting to relatively simple geometrical and moderate sizes. Fabrication of complex-shaped ZrB2-based UHTC components requires colloidal techniques. This study reviews the suspension dispersion and colloidal processing of ZrB2-based UHTCs. The most important issues during the colloidal processing of ZrB2-based UHTCs are summarized, and an evaluation of colloidal processing methods of the ZrB2-based UHTCs is provided. Gel-casting, a net or near-net colloidal processing technique, is believed to exhibit a great potential for the large-scale industrialization of ZrB2-based UHTCs. In addition, additive manufacturing, also known as 3D printing, which has been drawing great attention recently, has a great potential in the manufacturing of ZrB2-based UHTC components in the future.
Seismic Performance and Cost Analysis of UHPC Tall Buildings in UAE with Ductile Coupled Shear Walls
Authors: AlHamaydeh Mohammad , Elkafrawy Mohamed , Banu Shaziya
Published: April 2022

The superior mechanical characteristics of ultra-high-performance concrete (UHPC) have attracted the interest of many researchers worldwide. Researchers have attempted to perform comparative analyses on the behavior of UHPC versus conventional and high-strength concrete, with their aim being to gain more insights into the difference between different types of concrete. However, the current state-of-the-art revealed no direct comprehensive comparisons between their behaviors in ductile coupled shear walls under seismic loading. This paper explores a comprehensive side-by-side comparison in terms of seismic behavior and cost analysis for four 60-story archetype buildings. The reference building was designed using high-strength concrete with a strength of 60 MPa. The other three archetype variations incorporated three different UHPC grades: 150 MPa, 185 MPa, and 220 MPa. The plan configuration and the lateral force-resisting system (LFRS) were chosen according to the most common practice in the UAE. The main objective is to report the effect of UHPC on the LFRS (ductile coupled shear walls). Moreover, a simplified initial cost analysis (materials and labor) design was performed. The findings of this paper indicate that the use of UHPC is capable of improving the seismic performance behavior of the lateral system as well as reducing the total initial costs.
Prediction of Exchange-Correlation Energy of Graphene Sheets from Reverse Degree-Based Molecular Descriptors with Applications
Authors: Albadrani Mohammed , Ali Parvez , El-Garaihy Waleed H. , Abd El-Hafez Hassan
Published: April 2022

Over the past few years, the popularity of graphene as a potential 2D material has increased since graphene-based materials have applications in a variety of fields, including medicine, engineering, energy, and the environment. A large number of graphene sheets as well as an understanding of graphene’s structural hierarchy are critical to the development of graphene-based materials. For a variety of purposes, it is essential to understand the fundamental structural properties of graphene. Molecular descriptors were used in this study to investigate graphene sheets’ structural behaviour. Based on our findings, reverse degree-based molecular descriptors can significantly affect the exchange-correlation energy prediction. For the exchange-correlation energy of graphene sheets, a linear regression analysis was conducted using the reverse general inverse sum indeg descriptor, RGISI(p,q). From RGISI(p,q), a set of reverse topological descriptors can be obtained all at once as a special case, resulting in a model with a high correlation coefficient (R between 0.896 and 0.998). Used together, these reverse descriptors are graphed in relation to their response to graphene. Based on this study’s findings, it is possible to predict the exchange correlation energy as well as the geometric structures of graphene sheets with very little computational cost.
Tensile Test Coupled with an EBSD Study of a GH4169 Ring Rolled Product
Authors: Wang Hao , Niu Haoyi , Wu Hao , Li Rengeng , Fan Guohua
Published: April 2022

An in situ tensile test of the ring-rolled GH4169 alloy is performed to investigate the plastic deformation behavior at the micro level. Slip system activations are identified by slip traces captured by a scanning electron microscope and lattice orientation data acquired by electron backscattered diffraction. Our results demonstrated that the fraction of low-angle grain boundaries gradually increased upon tensile deformation, and the misorientation evolution in the grain interior was severely inhomogeneous. The Schmid factors at the grains of interest are calculated for comparison with the actual activated slip systems. Most of the slip system activation coincides with the Schmid law, as opposed to the initiation of other potential slip systems at some grains.
Expired EBT3 Films’ Sensitivity for the Measurement of X-ray and UV Radiation: An Optical Analysis
Authors: Abu Mhanna Hamad Yahia , Omar Ahmad Fairuz , Radzi Yasmin Md , Akhdar Hanan Fawaz , Al Ewaidat Haytham
Published: April 2022

The aim of this study is to compare the optical responses of external beam therapy 3 (EBT3) films exposed to X-rays and solar ultraviolet rays (SUV-rays), as a dose control technique in the clinical sector for various radiation types, energies, and absorbed doses up to 4 Gy. In this study, EBT3 films with three different expiry dates were prepared and cut into pieces of size 2 by 2 cm2. The first group was exposed to 90 kVp X-rays, while the second group was exposed to the SUV-rays at noon. The analysis was performed using a visible Jaz spectrometer and an EPSON Perfection V370 Photo scanner to obtain the absorbance, the net reflective optical density (ROD) and the red-green-blue (RGB) values of the samples. The results have shown that spectroscopic measurements of the exposed expired EBT3 films with these radiation sources are able to produce primary peaks and secondary peaks at λ = 641.74 nm and λ = 585.98 nm for X-rays, and at λ = 637.93 nm and λ = 584.45 nm for SUV-rays, respectively. According to these findings, compared to 2021 films that expired shortly before the trial start date; 2018 films responded better to the absorbed dose than 2016 films when exposed to both X-ray and SUV-rays. In terms of energy dependence, the expired EBT3 2018 had the largest net ROD value. Using L*a*b* indices extracted from the RGB data, and despite that EBT3 films have expiry dates according to the manufacturer; all the films exhibited a substantial colour change, indicating that these films are still usable for clinical and research purposes.
Microstructure, Crystallographic Texture, and Mechanical Properties of Friction Stir Welded Mild Steel for Shipbuilding Applications
Authors: Ahmed Mohamed M. Z. , El-Sayed Seleman Mohamed M. , Touileb Kamel , Albaijan Ibrahim , Habba Mohamed I. A.
Published: April 2022

In the current work, mild steel used in shipbuilding applications was friction-stir-welded (FSWed) with the aim of investigating the microstructure and mechanical properties of the FSWed joints. Mild steel of 5 mm thickness was friction-stir-welded at a constant tool rotation rate of 500 rpm and two different welding speeds of 20 mm/min and 50 mm/min and 3° tool tilt angle. The microstructure of the joints was investigated using optical and scanning electron microscopes. Additionally, the grain structure and crystallographic texture of the nugget (NG) zone of the FSWed joints was investigated using electron backscattering diffraction (EBSD). Furthermore, the mechanical properties were investigated using both tensile testing and hardness testing. The microstructure of the low-welding-speed joint was found to consist of fine-grain ferrite and bainite (acicular ferrite) with an average grain size of 3 µm, which indicates that the temperature experienced above A1, where a ferrite and austenite mixture is formed, and upon cooling, the austenite transformed into bainite. The joint produced using high welding speed resulted in a microstructure consisting mainly of polygonal ferrite and pearlite. This could be due to the temperature far below A1 experienced during FSW. In terms of joint efficiency expressed in terms of relative ultimate tensile, the stress of the joint to the base material was found to be around 92% for the low-speed joint and 83% for the high-welding-speed joint. A reduction in welding was attributed to the microstructure, as well as the microtunnel defect formed near the advancing side of the joint. The tensile strain was preserved at 18% for low welding speed and increased to 24% for the high welding speed. This can be attributed to the NG zone microstructural constituents. In terms of crystallographic texture, it is dominated by a simple shear texture, with increased intensity achieved by increasing the welding speed. In both joints, the hardness was found to be significantly increased in the NG zone of the joints, with a greater increase in the case of the low-welding-speed joint. This hardness increase is mainly attributed to the fine-grained structure formed after FSW.
3D Printing Application in Wood Furniture Components Assembling
Authors: Nicolau Antoniu , Pop Mihai Alin , Coșereanu Camelia
Published: April 2022

Additive manufacturing (AM) is used in many fields and is a method used to replace wood components or wood-jointed furniture components in the furniture industry. Replacing wood joints by 3D printed connectors would be an advantage, considering the fact that during the process of assembling furniture, the execution technology of the joints is difficult, time-consuming, and labor-intensive. Advanced technology of AM applied in furniture manufacturing helps the designers to create new concepts of product design, with no limits of shape, number of joints, color, or size. The diversity of 3D printers and AM technologies provides the selection of materials in relation with the applicability of the 3D printed object. In this respect, the objective of the present research is to design a 3D printed connector to be used for jointing three chair components, namely the leg and two stretchers made from larch (Larix decidua Mill.) wood, and to use reinforced polylactic acid (PLA) fiberglass (20 wt. %) filament for 3D printing this connector using AM with fused filament fabrication (FFF) technology. The design of the connector, the possibility of using this type of material, and the deposition method of filament were investigated in this research. For this purpose, several evaluation methods were applied: microscopic investigation with 50×, 100×, and 200× magnifications, both of the filament and of the 3D printed connector; mechanical testing of corner joint formed with the help of connector between chair leg and the two stretchers; and a microscopic investigation of the connectors’ defects that occurred after applying the compression and tensile loads on the diagonal direction of the L-type joint. The microscopic investigation of the composite filament revealed the agglomerations of glass fibers into the core matrix and areas where the distribution of the reinforcements was poor. The heterogeneous structure of the filament and the defects highlighted in the 3D printed connectors by the microscopic investigation contributed to the mechanical behavior of L-type connecting joints. The bending moments resulting from compression and tensile tests of the 3D printed connectors were compared to the results recorded after testing, under the same conditions, the normal mortise–tenon joint used to assemble the abovementioned chair components. The larch wood strength influenced the mechanical results and the conclusions of the microscopic investigations, as well as the analysis of the broken connectors after testing recommended the change of connector design and filament deposition direction.
Analysis of the Mechanical Properties and Damage Mechanism of Carbon Fiber/Epoxy Composites under UV Aging
Authors: Shi Zhongmeng , Zou Chao , Zhou Feiyu , Zhao Jianping
Published: April 2022

The UV durability of carbon fiber composites has been a concern. In this work, UV irradiation on carbon fiber-reinforced polymer (CFRP) materials was performed using an artificial accelerated UV aging chamber to investigate the effect of UV exposure on carbon fiber composites. UV aging caused some of the macromolecular chains on the surface resin to break, resulting in the loss of small molecules and loss of mass. After 80 days of UV irradiation exposure, a significant decline in the macroscopic mechanical properties occurred in the longitudinal direction, with the largest decrease of 23% in longitudinal compressive strength and a decreasing trend in the transverse mechanical properties at the later stage of aging. The microscopic mechanical properties of the CFRP specimens were characterized using nanoindentation, and it was found that UV aging had an embrittlement effect on the matrix, and its hardness/modulus values were higher than the initial values with UV exposure. The fibers were less affected by UV irradiation.
Study of the Course of Cement Hydration in the Presence of Waste Metal Particles and Pozzolanic Additives
Authors: Pundienė Ina , Pranckevičienė Jolanta , Kligys Modestas , Girskas Giedrius
Published: April 2022

As the construction of hydrotechnical and energy facilities grows worldwide, so does the need for special heavyweight concrete. This study presents the analysis of the influence of waste-metal particle filler (WMP) on Portland cement (PC) paste and mortars with pozzolanic (microsilica and metakaolin) additives in terms of the hydration process, structure development, and physical–mechanical properties during 28 days of hardening. Results have shown that waste-metal particle fillers prolong the course of PC hydration. The addition of pozzolanic additives by 37% increased the total heat value and the ultrasound propagation velocity (UPV) in WMP-containing paste by 16%; however, in the paste with only WMP, the UPV is 4% lower than in the WMP-free paste. The density of waste-metal particle fillers in the free mortar was about two times lower than waste-metal particle fillers containing mortar. Due to the lower water absorption, the compressive strength of WMP-free mortar after 28 days of hardening achieved 42.1 MPa, which is about 14% higher than in mortar with waste-metal particle filler. The addition of pozzolanic additives decreased water absorption and increased the compressive strength of waste-metal particle filler containing mortar by 22%, compared to pozzolanic additive-free waste-metal particle fillers containing mortar. The pozzolanic additives facilitated a less porous matrix and improved the contact zone between the cement matrix and waste-metal particle fillers. The results of the study showed that pozzolanic additives can solve difficulties in local waste-metal particle fillers application in heavyweight concrete. The successful development of heavyweight concrete with waste-metal particle fillers and pozzolanic additives can significantly expand the possibility of creating special concrete using different local waste. The heavyweight concrete developed by using waste-metal particle fillers is suitable for being used in load balancing and in hydrotechnical foundations.
Assessment of the Destruction of a Fibre Cement Board Subjected to Fire in a Large-Scale Study
Authors: Schabowicz Krzysztof , Sulik Paweł , Gorzelańczyk Tomasz , Zawiślak Łukasz
Published: April 2022

This article presents the results of a study involving the assessment of the structural destruction of fibre cement boards taken from a large-scale model subjected to fire. These were subjected to a three-point bending test using the acoustic emission method. The analysis of the obtained results took into account the course of bending stresses σm, the modulus of rupture (MOR), the number of acoustic emission events Nzd and the sum of EA events ∑Nzd. The conducted tests showed that the samples subjected to fire exhibited a clear decrease, up to 72%, in the recorded sum of EA events compared to a reference board (not subjected to fire). The analysis of the obtained modulus of rupture (MOR) values showed a similar trend—the reduction of the modulus of rupture for the degraded samples was in the range of 66–96%. In order to illustrate the changes taking place in the structure of the tested plates more precisely, analyses were carried out using the optical method and a digital microscope. This method may be sufficient for the final evaluation of degraded samples.
Improved DCNN Based on Multi-Source Signals for Motor Compound Fault Diagnosis
Authors: Gong Xiaoyun , Zhi Zeheng , Feng Kunpeng , Du Wenliao , Wang Tao
Published: April 2022

Induction motors, the key equipment for rotating machinery, are prone to compound faults, such as a broken rotor bars and bearing defects. It is difficult to extract fault features and identify faults from a single signal because multiple fault features overlap and interfere with each other in a compound fault. Since current signals and vibration signals have different sensitivities to broken rotor and bearing faults, a multi-channel deep convolutional neural network (MC-DCNN) fault diagnosis model based on multi-source signals is proposed in this paper, which integrates the original signals of vibration and current of the motor. Dynamic attenuation learning rate and SELU activation function were used to improve the network hyperparameters of MC-DCNN. The dynamic attenuated learning rate can improve the stability of model training and avoid model collapse effectively. The SELU activation function can avoid the problems of gradient disappearance and gradient explosion during model iteration due to its function configuration, thereby avoiding the model falling into local optima. Experiments showed that the proposed model can effectively solve the problem of motor compound fault identification, and three comparative experiments verified that the improved method can improve the stability of model training and the accuracy of fault identification.
A Fast Method for Protecting Users’ Privacy in Image Hash Retrieval System
Authors: Huang Liang , Zhan Yu , Hu Chao , Shi Ronghua
Published: April 2022

Effective search engines based on deep neural networks (DNNs) can be used to search for many images, as is the case with the Google Images search engine. However, the illegal use of search engines can lead to serious compromises of privacy. Affected by various factors such as economic interests and service providers, hackers and other malicious parties can steal and tamper with the image data uploaded by users, causing privacy leakage issues in image hash retrieval. Previous work has exploited the adversarial attack to protect the user’s privacy with an approximation strategy in the white-box setting, although this method leads to slow convergence. In this study, we utilized the penalty norm, which sets a strict constraint to quantify the feature of a query image into binary code via the non-convex optimization process. Moreover, we exploited the forward–backward strategy to solve the vanishing gradient caused by the quantization function. We evaluated our method on two widely used datasets and show an attractive performance with high convergence speed. Moreover, compared with other image privacy protection methods, our method shows the best performance in terms of privacy protection and image quality.
Rapid Calculation and Optimization of Vibration and Noise of Permanent-Magnet Synchronous Motors for EVs Based on Equivalent Structural Network
Authors: Song Tengfei , Liu Huijuan , Bu Binbin , Zhang Zhenyang
Published: April 2022

Optimizing electromagnetic performance and vibration noise performance simultaneously is important when designing the drive motor for electric vehicles (EVs). This has not been fully explored, and there are only a few relevant studies. To achieve simultaneous optimization, this paper proposes an equivalent structural network (ESN) of stator assembly to calculate the modal distribution and harmonic response transfer functions. Based on the ESN model, the motor’s electromagnetic vibration noise harmonic response, such as acceleration and equivalent radiated power level (ERPL), can be quickly calculated. The feasibility of the established ESN model is verified by structural-field finite-element method (FEM) and modal hammer tests. Based on the modern optimization algorithm and the ESN model, an improved multi-physics and multi-objective optimization design approach is proposed for an optimized design of a 30 kW interior permanent-magnet synchronous machine (IPMSM). The motor’s maximum output torque and ERPL were selected as optimization objectives, and then the ERPL and acceleration were recalculated using structural-field FEM to validate the accuracy of the optimal design. Finally, vibration acceleration tests were carried out on a manufactured prototype motor to verify the feasibility and validity of the proposed optimization design method.
A Lightweight Model for Bearing Fault Diagnosis Based on Gramian Angular Field and Coordinate Attention
Authors: Cui Jialiang , Zhong Qianwen , Zheng Shubin , Peng Lele , Wen Jing
Published: April 2022

The key to ensuring rotating machinery’s safe and reliable operation is efficient and accurate faults diagnosis. Intelligent fault diagnosis technology based on deep learning (DL) has gained increasing attention. A critical challenge is how to embed the characteristics of time series into DL to obtain stable features that correlate with equipment conditions. This study proposes a lightweight rolling bearing fault diagnosis method based on Gramian angular field (GAF) and coordinated attention (CA) to improve rolling bearing recognition performance and diagnosis efficiency. Firstly, the time domain signal is encoded into GAF images after downsampling and segmentation. This method retains the temporal relation of the time series and provides valuable features for DL. Secondly, a lightweight convolution neural network (CNN) model is constructed through depthwise separable convolution, inverse residual block, and linear bottleneck layer to learn advanced features. After that, CA is employed to capture the long-range dependencies and identify the precise position information of the GAF images with nearly no additional computational overhead. The proposed method is tested and evaluated by CWRU bearing dataset and experimental dataset. The results demonstrate that the CNN based on GAF and CA (GAF-CA-CNN) model can effectively reduce the calculation overhead of the model and achieve high diagnostic accuracy.
Enhanced Coercivity of Low-Density Barium Hexaferrite Magnets from Paste-Injection Molding
Authors: Thongsamrit Wannisa , Jantaratana Pongsakorn , Charoensuk Thanida , Sirisathitkul Chitnarong
Published: April 2022

Ceramic–polymer paste-injection molding is demonstrated as a facile fabrication route for barium hexaferrite magnets. Interestingly, these low-density (1.90–2.35 g/cm3) magnets exhibit substantial coercivity of 3868–4002 Oe. When ceramic paste without polymeric additives is used, reduced coercivity and slightly increased magnetizations are obtained from a magnet with the density of 2.55 g/cm3. Their magnetizations are also higher than those obtained from compactions of sol–gel-derived powders. For compact magnets (3.46–3.77 g/cm3), the DI water addition results in a slightly higher magnetization but lower coercivity than dry-pressed magnets. Compactions into disk and bar magnets give rise to comparable magnetic properties. The morphological characterizations reveal smaller barium hexaferrite particles leading to larger coercivity, and the density and shape of magnets have a less pronounced effect.
A Survey on the Distribution of Ovothiol and ovoA Gene Expression in Different Tissues and Cells: A Comparative Analysis in Sea Urchins and Mussels
Authors: Murano Carola , Zuccarotto Annalisa , Leone Serena , Sollitto Marco , Gerdol Marco , Castellano Immacolata , Palumbo Anna
Published: April 2022

Ovothiols are histidine-derived thiols produced by a variety of marine invertebrates, protists and bacteria. These compounds, which are among the strongest natural antioxidants, are involved in controlling the cellular redox balance due to their redox exchange with glutathione. Although ovothiols were initially reported as protective agents against environmental stressors, new evidence suggests that they can also act as pheromones and participate in fundamental biological processes such as embryogenesis. To get further insight into the biological roles of ovothiols, we compared ovothiol biosynthesis in the sea urchin Paracentrotus lividus and in the mussel Mytilus galloprovincialis, the two species that represent the richest sources of these compounds among marine invertebrates. Ovothiol content was measured in different tissues and in the immune cells from both species and the expression levels of ovoA, the gene responsible for ovothiol biosynthesis, was inferred from publicly available transcriptomes. A comparative analysis of ovothiol biosynthesis in the two species allowed the identification of the tissues and cells synthesizing the metabolite and highlighted analogies and differences between sea urchins and mussels. By improving our knowledge on the biological roles of ovothiols and pointing out the existence of sustainable natural sources for their isolation, this study provides the basis for future biotechnological investigations on these valuable compounds.
Climate Uncertainties: A Personal View
Authors: McIntyre Michael Edgeworth
Published: April 2022

This essay takes a brief personal look at aspects of the climate problem. The emphasis will be on some of the greatest scientific uncertainties, as suggested by what is known about past as well as present climates, including tipping points that likely occurred in the past and might occur in the near future. In the current state of knowledge and understanding, there is massive uncertainty about such tipping points. For one thing, there might or might not be a domino-like succession, or cascade, of tipping points that ultimately sends the climate system into an Eocene-like state, after an uncertain number of centuries. Sea levels would then be about 70 m higher than today, and surface storminess would likely reach extremes well outside human experience. Such worst-case scenarios are highly speculative. However, there is no way to rule them out with complete confidence. Credible assessments are outside the scope of current climate prediction models. So there has never in human history been a stronger case for applying the precautionary principle. Today there is no room for doubt—even from a purely financial perspective—about the need to reduce greenhouse gas emissions urgently and drastically, far more than is possible through so-called “offsetting”.
Prospeksi dan Masalah Lingkungan Akibat Penambangan Timah di Pulau Karimun
Authors: Irzon Ronaldo
Published: April 2022

ABSTRAK Penambangan timah di Asia Tenggara yang kaitannya dengan sabuk timah telah dimulai sejak abad ke-19. Eksploitasi tersebut tentu telah meninggalkan beberapa lokasi pembuangan limbah timah yang dapat membahayakan lingkungan. Namun demikian, limbah pertambangan juga memungkinan masih mengandung bahan-bahan yang bernilai ekonomis. Penelitian ini bertujuan untuk mempelajari komposisi bahan sisa dari beberapa lokasi pembuangan tailing timah di Pulau Karimun agar dapat mengetahui potensi maupun dampaknya terhadap lingkungan. Hasil analisis XRF dan ICP-MS menunjukkan bahwa kandungan Al2 O3 dan Ce pada beberapa lokasi cukup prospektif. Kedua oksida tersebut menarik untuk dipisahkan karena merupakan bahan buangan, berada tidak jauh dari permukaan, lunak, dan memiliki luas permukaan yang besar. Limbah penambangan timah di Karimun terbukti telah menyebabkan polusi aluminium, magnesium, dan potasium pada tingkat beragam. Program reboisasi, penggunaan bakteri pengurai, dan penambahan beberapa bahan kimia sesuai dosis dapat diadaptasi dalam perbaikan kondisi lingkungan pasca penambangan timah.Kata kunci: geokimia, Karimun, limbah timah, prospeksi, polusiABSTRACT Tin mining in Southeast Asia, which is closely associated with the tin belt, was initiated in the 19th century. The exploitation certainly created tin waste disposal locations which may endanger the environment. On the other hand, mining waste might also contain valuable materials. This study aims to analyse the composition of the residual materials from several tin tailings disposal sites on Karimun Island for any potential prospects and environmental impacts The results of XRF and ICP-MS measurements show that Al2 O3 and Ce in some sites are prospective and interesting to be beneficiated on behalf of their condition as waste material, located near the surface, soft, and a large surface area. On the other hand, the tin mining wastes of Karimun lead to aluminium, magnesium and potassium pollutants at various degrees. The revegetation program, the use of decomposing bacteria, and the addition of several environmentally friendly chemicals with certain dosage could be adapted to improve environmental conditions after tin mining.Keywords: geochemistry, Karimun, pollution, prospecting, tin tailings
Potensi Bahaya Gempa Bumi Berdasarkan Kondisi Tapak Lokal di Daerah Amlapura, Karangasem, Bali
Authors: Robiana Rahayu , Cipta Athanasius
Published: April 2022

ABSTRAK Bahaya gempa bumi dapat dievaluasi setidaknya dari dua sudut pandang, yaitu sumber dan area yang berpotensi terdampak. Dari sudut pandang area berpotensi terdampak, kondisi geologi lokal memegang peranan penting dalam memperbesar dampak kerusakan akibat guncangan gempa bumi. Kecepatan gelombang geser merupakan parameter penting untuk mengevaluasi perilaku dinamis tanah di bawah permukaan. Pemodelan profil kecepatan menggambarkan kedalaman batuan sedimen dan batuan dasar di Amlapura yang menunjukkan ketebalan sedimen lunak yang bervariasi mulai dari 50 m hingga 150 m. Indeks kerentanan terhadap gempa bumi yang dihitung berdasarkan parameter faktor amplifikasi, frekuensi dominan, serta percepatan tanah puncak (pga) pada batuan dasar digunakan untuk menilai potensi dampak guncangan gempa bumi seperti likuefaksi/ gerakan tanah/ kerusakan berat pada bangunan di Amlapura, sehingga diketahui pada pga 0,3 g atau lebih besar, potensi longsor, bangunan runtuh dan likuefaksi meluas terutama di bagian timur kota Amlapura dimana morfologi pedataran bertemu morfologi pebukitan bergelombang.Kata kunci: Amlapura, bahaya gempa bumi, kecepatan gelombang geser, kondisi tapak lokal, percepatan tanah puncakABSTRACT Earthquake hazard can be evaluated at least from two point of views, the source and area which potentialy affected. From the perspective of the potential affected area, local geological conditions play an important role in magnifying the impact of damage due to earthquake shocks. Shear wave velocity is an important parameter for evaluating the dynamic behavior of subsurface soils. Shear wave profile modelling illustrates the depth of sedimentary rocks and bedrock in Amlapura which shows the thickness of soft sediments that vary from 50 m to 150 m. An earthquake susceptibility index calculated based on parameters of amplification factors, dominant frequency, and peak soil acceleration (pga) on bedrock is used to assess potential impacts of earthquake shocks such as liquefaction / ground motion / heavy damage to buildings in Amlapura, so that it is known at the pga 0.3 g and 0.4 g potential for landslides, buildings collapse and liquefaction extends mainly in the eastern part of the city of Amlapura where the flat meets the the surging hills morphology.Keywords: Amlapura, earthquake hazard, shear-wave velocity, site class, peak ground acceleration
Features of Treatment of Children with Tonsils Hypertrophy
Authors: Якимцова А.В. , Песоцкая М.В. , Куницкий В.С.
Published: April 2022

Гипертрофия небных миндалин (ГНМ) представляет собой актуальную проблему детской оториноларингологии в связи с широкой распространенностью данной патологии у детей и ее последствиями. Увеличение небных миндалин существенно ухудшает качество жизни, так как сопровождается затруднением носового дыхания, синдромом обструктивного апноэ сна, кашлем, голосо-речевыми нарушениями, ринолалией, повышенным рвотным рефлексом, воспалительными изменениями со стороны верхних дыхательных путей. Многообразие хирургических методов, предложенных для лечения данной патологии, не исключает риска развития интра- и послеоперационных осложнений, вплоть до летального исхода. Таким образом, поиск новых методов хирургического лечения пациентов с гипертрофией небных миндалин IIIII степени, позволяющих достичь запланированного клинического результата с минимальным риском осложнений, является важной практической задачей современной оториноларингологии. В статье рассмотрены вопросы эпидемиологии и этиология развития гипертрофии небных миндалин, существующие хирургические методы лечения и представлены результаты использования метода лазерной фотокоагуляции небных миндалин при их гипертрофии у детей, проходивших лечение в оториноларингологическом отделении УЗ ВОДКЦ за период с 01.01.2017 по 01.07.2019 г.

Hypertrophy of palatine tonsils is an urgent problem of pediatric otorhinolaryngology due to both the widespread prevalence of this pathology and its consequences. An increase in palatine tonsils significantly worsens the quality of life, as it is accompanied by difficulty in nasal breathing, obstructive sleep apnea syndrome, coughing, impaired speech and diction, nasal voices, and an increased gag reflex. The variety of surgical methods proposed for the treatment of this pathology does not exclude postoperative complications, including death. Thus, the search for new methods of surgical treatment of patients with hypertrophy of palatine tonsils II-III degree, allowing to achieve the planned clinical result with minimal risk of complications, is an important task of modern otorhinolaryngology. The article discusses the epidemiology and etiology of hypertrophy of palatine tonsils, the existing surgical methods of treatment, and presents the results of using laser photocoagulation of palatine tonsils with their hypertrophy in children undergoing treatment at the Vitebsk Regional Childrens Clinical Center for the period from 01.01.2017 to 01.07.2019.
The Role of Laryngeal Ultrasound in the Assessment and Treatment of Functional Dysphonia
Authors: Криштопова М.А. , Петрова Л.Г. , Гирса В.Н.
Published: April 2022

Цель исследования: повышение эффективности диагностики и объективизации эффекта комплексного лечения пациентов с функциональными дисфониями с помощью УЗИ гортани. Материалы и методы: исследование гортани с помощью УЗИ проводилось здоровым лицам без дисфонии (n10) и пациентам с функциональной дисфонией/афонией (n20). Основными видами лечения пациентов были комплексное медикаментозное лечение и фонопедия (G1, n10) или фонопедия с ультразвуковой биологической обратной связью (G2, n10). Результаты: УЗИ гортани в B-режиме и в режиме доплерографии с фонаторными пробами позволяет визуализировать нарушение координации работы мышц гортани в виде напряжения вестибулярного отдела гортани, ограничения подвижности, наличия неполного смыкания и отсутствие вибрации голосовых складок при фонации. Более быстрое и стойкое восстановление голоса наблюдалось в группе пациентов, получавших комплексное медикаментозное лечение и фонопедию с ультразвуковой биологической обратной связью, по сравнению с группой пациентов, получавших комплексное медикаментозное лечение и фонопедию без ультразвуковой биологической обратной связи (p0,005). Заключение: УЗИ гортани в B-режиме и режиме доплерографии с фонаторными пробами позволяет глубже понять патофизиологические процессы функциональной дисфонии. Фонопедическое лечение с биологической обратной связью является эффективным методом лечения функциональной дисфонии.

The purpose of the study is to improve diagnosis and treatment of patients with functional dysphonia by using ultrasound of the larynx. Materials and methods. Larynx ultrasonography was performed to healthy people without dysphonia (n10) and patients with functional dysphonia/aphonia (n20). Complex medication therapy and oropharyngeal muscle exercise therapy without ultrasound biofeedback (G1, n10) or oropharyngeal muscle exercise therapy with ultrasound biofeedback (G2, n10) were used. Results. Larynx ultrasonography is a minimally invasive, easily reproducible, and inexpensive method of laryngeal examining. It may become a perfect tool for functional dysphonia identification with its later monitoring. The group of patients receiving complex medication therapy and oropharyngeal muscle exercise therapy with ultrasound biofeedback compared to the group of patients without ultrasound biological feedback had significantly higher functional results (p0.005). Conclusion. Larynx ultrasonography is a perfect tool for understanding the pathophysiology of functional dysphonia. Oropharyngeal muscle exercise therapy with ultrasound biofeedback is an effective treatment tool for functional dysphonia.
Pengaruh Kompetensi dan Karakteristik Individu Terhadap Kinerja Karyawan CV. Bumi Kencana Jaya
Authors: Lumanauw Meiske Kristin
Published: April 2022

Tujuan penelitian ini untuk mengetahui dan menganalisis pengaruh kompetensi terhadap kinerja karyawan di CV. Bumi Kencana Jaya; pengaruh karakteristik individu terhadap kinerja karyawan di CV. Bumi Kencana Jaya; dan pengaruh kompetensi dan karakteristik individu secara simultan terhadap kinerja karyawan di CV. Bumi Kencana Jaya. Metode penelitian yang digunakan merupakan metode penelitian kuantitatif. Populasi dalam penelitian ini adalah seluruh karyawan CV. Bumi Kencana Jaya yang berjumlah 33 orang. Mengingat jumlah populasi relatif kecil, yaitu di bawah 100, maka seluruh anggota populasi diambil semua sebagai sampel penelitian, sehingga penelitiannya disebut sebagai penelitian populasi atau penelitian sensus. Data yang didapatkan dari penyebaran kuesioner dianalisis dengan analisis regresi berganda untuk pengujian hipotesisnya. Hasil penelitian menunjukkan Kompetensi berpengaruh positif adan signifikan terhadap kinerja karyawan di CV. Bumi Kencana Jaya; Karakteristik individu tidak berpengaruh terhadap kinerja karyawan di CV. Bumi Kencana Jaya. Kompetensi dan karakteristik individu secara simultan berpengaruh signifikan terhadap kinerja karyawan di CV. Bumi Kencana Jaya.