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1 – 10 of 217Sai Bharadwaj B. and Sumanth Kumar Chennupati
The purpose of this manuscript is to detect heart fault using Electrocardiogram. Mutually low and high frequency noises such as electromyography (EMG) and power line interference…
Abstract
Purpose
The purpose of this manuscript is to detect heart fault using Electrocardiogram. Mutually low and high frequency noises such as electromyography (EMG) and power line interference (PLI) degrades the performance of ECG signals.
Design/methodology/approach
The ECG record depicts the procedural electrical movement of the heart, which is non-invasive foot age obtained by placing surface electrodes on designated locations of the patient’s skin. The main concept of this manuscript is to present a novel filtering method to cancel the unwanted noises in ECG signal. Here, intrinsic time scale decomposition (ITD) is introduced to suppress the effect of PLI from ECG signals.
Findings
In the existing ITD, the gain control parameter is a constant value; however, in this paper it is an adaptive feature that varies according to certain constraints. Simulation outcomes show that the proposed method effectively reduces the effect of PLI and quantitatively express the effectiveness with different evaluation metrics.
Originality/value
The results found by the proposed method are compared with Fourier decomposition technique and eigen value decomposition methods (EDM) to validate the effectiveness of the proposed method.
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Keywords
Xiaodi Xu, Shanchao Sun, Yang Fei, Liubin Niu, Xinyu Tian, Zaitian Ke, Peng Dai and Zhiming Liang
This article aims to predict the rapid track geometry change in the short term with a higher detection frequency, and realize the monitoring and maintenance of the railway state.
Abstract
Purpose
This article aims to predict the rapid track geometry change in the short term with a higher detection frequency, and realize the monitoring and maintenance of the railway state.
Design/methodology/approach
Firstly, the ABA data needs to be filtered to remove the DC component to reduce the drift due to integration. Secondly, the quadratic integration in frequency domain for concern components of the vertical and lateral ABA needs to be done. Thirdly, the displacement in lateral of the wheelset to rail needs to be calculated. Then the track alignment irregularity needs to be calculated by the integration of lateral ABA and the lateral displacement of the wheelset to rail.
Findings
By comparing with a commercial track geometry measurement system, the high-speed railway application results in different conditions, after removal of the influence of LDWR, identified that the proposed method can produce a satisfactory result.
Originality/value
This article helps realize detection of track irregularity on operating vehicle, reduce equipment production, installation and maintenance costs and improve detection density.
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Keywords
Chao Li, Jin Gao, Qingqing Xu, Chao Li, Xuemei Yang, Kui Xiao and Xiangna Han
The color painting of ancient buildings has high historical and artistic value but is prone to aging due to long-term outdoor exposure. The purpose of this study is to develop a…
Abstract
Purpose
The color painting of ancient buildings has high historical and artistic value but is prone to aging due to long-term outdoor exposure. The purpose of this study is to develop a new type of sealing coating to mitigate the impact of ultraviolet (UV) light on color painting.
Design/methodology/approach
The new coating was subjected to a 500-h UV-aging test. Compared with the existing acrylic resin Primal AC33, the UV aging behavior of the new coating, such as color difference and gloss, was studied with aging time. The Fourier infrared spectra of the coatings were analyzed after the UV-aging test.
Findings
Compared with AC33, the antiaging performance of SF8 was substantially improved. SF8 has a lower color difference value and better light retention and hydrophobicity. The Fourier transform infrared spectroscopy results showed that the C-F bond and Si-O bonds in the resin of the optimized sealing coating protected the main chain C-C structure from degradation during the aging process; thus, the resin maintained good stability. The hindered amine light stabilizer TN292 added to the coating inhibited the antiaging process by trapping active free radicals.
Originality/value
To address the problem of UV aging of oil-decorated colored paintings, a new type of sealing coating with excellent antiaging properties was developed, laying the foundation for its demonstration application on the surface of ancient buildings.
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Kai Xu, Ying Xiao and Xudong Cheng
The purpose of this study is to investigate the effects of nanoadditive lubricants on the vibration and noise characteristics of helical gears compared with conventional…
Abstract
Purpose
The purpose of this study is to investigate the effects of nanoadditive lubricants on the vibration and noise characteristics of helical gears compared with conventional lubricants. The experiment aims to analyze whether nanoadditive lubricants can effectively reduce gear vibration and noise under different speeds and loads. It also analyzes the sensitivity of the vibration reduction to load and speed changes. In addition, it compares the axial and radial vibration reduction effects. The goal is to explore the application of nanolubricants for vibration damping and noise reduction in gear transmissions. The results provide a basis for further research on nanolubricant effects under high-speed conditions.
Design/methodology/approach
Helical gears of 20CrMnTi were lubricated with conventional oil and nanoadditive oils. An open helical gearbox with spray lubrication was tested under different speeds (200–500 rpm) and loads (20–100 N·m). Gear noise was measured by a sound level meter. Axial and radial vibrations were detected using an M+P VibRunner system and fast Fourier transform analysis. Vibration spectrums under conventional and nanolubrication were compared. Gear tooth surfaces were observed after testing. The experiment aimed to analyze the noise and vibration reduction effects of nanoadditive lubricants on helical gears and the sensitivity to load and speed.
Findings
The key findings are that nanoadditive lubricants significantly reduce the axial and radial vibrations of helical gears under low-speed conditions compared with conventional lubricants, with a more pronounced effect on axial vibrations. The vibration reduction is more sensitive to rotational speed than load. At the same load and speed, nanolubrication reduces noise by 2%–5% versus conventional lubrication. Nanoparticles change the friction from sliding to rolling and compensate for meshing errors, leading to smoother vibrations. The nanolubricants alter the gear tooth surfaces and optimize the microtopography. The results provide a basis for exploring nanolubricant effects under high speeds.
Originality/value
The originality and value of this work is the experimental analysis of the effects of nanoadditive lubricants on the vibration and noise characteristics of hard tooth surface helical gears, which has rarely been studied before. The comparative results under different speeds and loads provide new insights into the vibration damping capabilities of nanolubricants in gear transmissions. The findings reveal the higher sensitivity to rotational speed versus load and the differences in axial and radial vibration reduction. The exploration of nanolubricant effects on gear tribological performance and surface interactions provides a valuable reference for further research, especially under higher speed conditions closer to real applications.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2023-0220/
Nader L. Labib, Fouad Zahran, Mohamed Adel Youssef, Azza M. Mazrouaa and Manal Gamal Mohamed
This study aims to extend the pot life without altering the qualities and performance of the coating, which is important to increase when manufacturing polyurethane coatings.
Abstract
Purpose
This study aims to extend the pot life without altering the qualities and performance of the coating, which is important to increase when manufacturing polyurethane coatings.
Design/methodology/approach
An acrylic polyol from a mixture of different monomers of hydroxypropyl methacrylate, methacrylic acid, 2-ethylhexyl acrylate, methyl methacrylate and n-butyl methacrylate was prepared with different ratios of 2,4-pentanedione as a pot life extender. The reaction takes place in presence of di-tert-butyl peroxide as initiator with samples (T1–T7). The physical properties of prepared acrylic polyol were characterized. Then, coating polyurethane varnish was prepared from the prepared acrylic polyol with an aliphatic polyisocyanate in a 1:1 equivalent ratio of OH:NCO at room temperature, in presence of paint thinner (diluents/solvent) and dibutyltin dilaurate as a catalyst to give samples (T1C–T7C). This coating was evaluated via Fourier-transform infrared spectroscopy, drying time, hardness and gloss, distinctness of image and reflected image quality.
Findings
The coating has a prolonged pot life while still maintaining the other qualities, thanks to the greater 2,4-pentanedione content.
Originality/value
It is desired to have a paint which has a satisfactory pot life, short curing time and reduces many drawbacks such as inefficient working and deterioration of the paint before application.
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Manikandan R. and Raja Singh R.
The purpose of this paper is to prevent the destruction of other parts of a wind energy conversion system because of faults, the diagnosis of insulated-gate bipolar transistor…
Abstract
Purpose
The purpose of this paper is to prevent the destruction of other parts of a wind energy conversion system because of faults, the diagnosis of insulated-gate bipolar transistor (IGBT) faults has become an essential topic of study. Demand for sustainable energy sources has been prompted by rising environmental pollution and energy requirements. Renewable energy has been identified as a viable substitute for conventional fossil fuel energy generation. Because of its rapid installation time and adaptable expenditure for construction scale, wind energy has emerged as a great energy resource. Power converter failure is particularly significant for the reliable operation of wind power conversion systems because it not only has a high yearly fault rate but also a prolonged downtime. The power converters will continue to operate even after the failure, especially the open-circuit fault, endangering their other parts and impairing their functionality.
Design/methodology/approach
The most widely used signal processing methods for locating open-switch faults in power devices are the short-time Fourier transform and wavelet transform (WT) – based on time–frequency analysis. To increase their effectiveness, these methods necessitate the intensive use of computational resources. This study suggests a fault detection technique using empirical mode decomposition (EMD) that examines the phase currents from a power inverter. Furthermore, the intrinsic mode function’s relative energy entropy (REE) and simple logical operations are used to locate IGBT open switch failures.
Findings
The presented scheme successfully locates and detects 21 various classes of IGBT faults that could arise in a two-level three-phase voltage source inverter (VSI). To verify the efficacy of the proposed fault diagnosis (FD) scheme, the test is performed under various operating conditions of the power converter and induction motor load. The proposed method outperforms existing FD schemes in the literature in terms of fault coverage and robustness.
Originality/value
This study introduces an EMD–IMF–REE-based FD method for VSIs in wind turbine systems, which enhances the effectiveness and robustness of the FD method.
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Walid Shaaban Abdelrasoul Mohamed
This paper aims to find a suitable solution to treat the solidification paper by using hydroxypropyl cellulose (HPC) to improve the mechanical, physical and chemical properties of…
Abstract
Purpose
This paper aims to find a suitable solution to treat the solidification paper by using hydroxypropyl cellulose (HPC) to improve the mechanical, physical and chemical properties of paper.
Design/methodology/approach
The samples have gone several stages, starting with the manufacture of paper from the linen pulp and the same components of the hardened manuscript papers. It was subjected to artificial aging to reach an age comparable to the manuscript age, then it was subjected to natural aging by inoculation it with A. niger. Mechanical cleaning of the leaves was done with soft brushes. The samples have been consolidated by HPC 2%. Digital microscopy, scanning electron microscopy, mechanical properties measurement, color change, Fourier transform infrared and pH measurements were used to assess the effect of HPC on the qualities of leaves.
Findings
HPC succussed in strengthening and restoring the natural, chemical and mechanical properties for the solidified leaves.
Originality/value
The solidified papers phenomenon constitutes severe suffering for manuscripts and books conservators. The paper consolidation initial stage is one of the most important conservation stages because paper has lost many natural, mechanical and chemical properties. The most important feature of this study is providing a solution to the hardened leaves strengthening problem and restoring their chemical, natural and mechanical properties.
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Hung Ngoc Phan and Satoko Okubayashi
Dehydrated bacterial cellulose’s (BC) intrinsic rigidity constrains applicability across textiles, leather, health care and other sectors. This study aims to yield a novel BC…
Abstract
Purpose
Dehydrated bacterial cellulose’s (BC) intrinsic rigidity constrains applicability across textiles, leather, health care and other sectors. This study aims to yield a novel BC modification method using glycerol and succinic acid with catalyst and heat, applied via an industrially scalable padding method to tackle BC’s stiffness drawbacks and enhance BC properties.
Design/methodology/approach
Fabric-like BC is generated via mechanical dehydration and then finished by using padding method with glycerol, succinic acid, catalyst and heat. Comprehensive material characterizations, including international testing standards for stiffness, bending properties (cantilever method), tensile properties, moisture vapor transmission rate, moisture content and regain, washing, thermal gravimetric analysis, derivative thermogravimetry, Fourier-transform infrared spectroscopy and colorimetric measurement, are used.
Findings
The combination of BC/glycerol/succinic acid dramatically enhanced porous structure, elongation (27.40 ± 6.39%), flexibility (flexural rigidity of 21.46 ± 4.01 µN m; bending modulus of 97.45 ± 18.20 MPa) and moisture management (moisture vapor transmission rate of 961.07 ± 86.16 g/m2/24 h; moisture content of 27.43 ± 2.50%; and moisture regain of 37.94 ± 4.73%). This softening process modified the thermal stability of BC. Besides, this study alleviated the drawbacks for washing (five cycles) of BC and glycerol caused by the ineffective affinity between glycerol and cellulose by adding succinic acid with catalyst and heat.
Originality/value
The study yields an effective padding process for BC softening and a unique modified BC to contribute added value to textile and leather industries as a sustainable alternative to existing materials and a premise for future research on BC functionalization by using doable technologies in mass production as padding.
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Sümeyye Üstüntağ and Nazim Paşayev
This study aims to comparatively reveal the physical, thermal and mechanical properties of horse tail and mane hairs, which have the potential to be used in many areas.
Abstract
Purpose
This study aims to comparatively reveal the physical, thermal and mechanical properties of horse tail and mane hairs, which have the potential to be used in many areas.
Design/methodology/approach
Physical properties of horsehairs such as diameter, density, moisture and water absorption were measured. Fourier transform infrared, field emission scanning electron microscopy and amino acid analyzes were applied to the hairs. Thermal stability of horsehair was investigated by thermogravimetric analysis and differential scanning calorimetry analysis. In addition, breaking strength and elongation values of mane and tail hairs were measured.
Findings
As a result of morphological analysis of horsehair, it was observed that there are usually gaps in the internal structure of horsehair, but the size and continuity of these gaps vary. It has been determined that there is a significant difference between the tenacity values of tail and mane hairs as well as geometric characteristics. In addition, amino acid analysis has shown that the amino acid contents of horse tail and mane hairs are similar and not much different from sheep’s wool.
Originality/value
Horsehair has been used for various purposes such as clothing, accessories, brushes, upholstery and reinforcement material. To use horsehair in accordance with its application area and performance characteristics, it is necessary to know its physical, thermal and mechanical properties. It is considerable to reveal the similar and different aspects of tail and mane hairs to determine whether they are alternatives to each other. Therefore, revealing the characteristics of tail and mane hairs comparatively constitutes the originality of this study.
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Khaled Mostafa, Mohamed Ramadan and Azza El-Sanabary
The purpose of this study is to investigate the authors' previously prepared and fully characterized poly (methacrylamide)-chitosan nanoparticles (CNPs) graft copolymer having…
Abstract
Purpose
The purpose of this study is to investigate the authors' previously prepared and fully characterized poly (methacrylamide)-chitosan nanoparticles (CNPs) graft copolymer having 50.2% graft yield with respect to flocculation efficiency for ferric laurate aqueous dispersions. This was done to compare the ability of the latter cheap, biodegradable and ecofriendly hybrid natural-synthetic polymeric substrate as a flocculant in comparison with higher cost, nonbiodegradable and harmful polyacrylamide as a well-known synthetic flocculant counterpart.
Design/methodology/approach
The graft copolymerization process was carried out at 450°Cfor 120 min using (1.0 g) CNPs, methacrylamide (1.5 g), 100 mmol/l potassium chromate and 80 mmol/l mandelic acid. Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis and specific viscosity were used to characterize and analyze the resultant copolymer. The flocculation efficiency was conferred in terms of transmittance % and weight removal %. The main factors influencing the flocculation process, such as flocculent dose, flocculation medium pH, stirring speed, flocculation temperature and grafting extent, were comprehensively discussed.
Findings
The flocculation efficiency of the prepared copolymers revealed the following findings: increased by increasing the flocculant dose, pH, temperature and stirring speed to a maximum values denoted at 30 ppm, 6.0, 30°C and 50 r/min, respectively, then decreased thereafter; increased by increasing the extent of grafting within the range studied; showed a comparable flocculation efficiency in comparison with polyacrylamide as a synthetic polymeric flocculent; and, finally, a preliminary bridging mechanism representing the attraction between the anionic suspended particles ferric laurate and cationic poly (MAam)-CNPs graft copolymer has been projected.
Originality/value
The advancement addressed here is undertaken with using the authors’ poly (MAam)-CNPs graft copolymers having different extent of grafting (a point which is not cited in the literature especially for the authors’ prepared copolymer) as a hybrid natural-synthetic polymeric substrate as a flocculant for ferric laurate aqueous dispersions in comparison with the high cost and nondegradable polyacrylamide synthetic flocculant.
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