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2. Impact of Sodium Tripolyphosphate on the Rheological Properties of Dams Sediments and Friction Factor during Hydraulic Dredging of Dams
- Author
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Lakhache, Brahim, Hammadi, Larbi, and Gaidi, Laouni
- Abstract
The transporting of sediments across watershed systems and their placement in reservoirs causes expensive issues for the operators of dams in many different nations throughout the world. In addition to the reservoir's functional capacity steadily decreasing as sediment settles in it, silt removal is a sensitive and challenging process that frequently necessitates taking the reservoir out of service, which is practically unachievable in dry and semi-arid regions. De-silting by hydraulic dredging has recently become a necessity to increase their longevity. But during this operation there are load loss exists so it is necessary to find solutions to reduce it. The present paper revealed that use the Sodium Tripolyphosphate as a reducing agent of the friction factor during the hydraulic dredging of dams. To carry out this study, a rheumatic characterization of dams sediments and dams sediments -sodium tripolyphosphate mixtures was carried out using a torque controlled rheometer (Discovery Hybrid Rheometer DHR2 from TA instrument). The flow curves as a function of dose of sodium tripolyphosphate added to dam sediments were analysed by the modified Cross model. It is clearly shown, in this work, when the quantity of sodium tripolyphosphate is less than of 0.4 % causes a decrease in the yield stress, the zero shear rate viscosity (lower Newtonian plateau) and the infinite shear rate viscosity (upper Newtonian plateau). However, when dose of sodium tripolyphosphate is greater than the critical dose, the the yield stress, the zero shear rate viscosity (lower Newtonian plateau) and the infinite shear rate viscosity (upper Newtonian plateau) are increased. As a result, this study find that the increase on thixotropic behavior of dams sediments is occurred by the addition of sodium tripolyphosphate in a concentration ranging between 0.2 wt% and 0.8 wt% to 40 wt% and 45 wt% of dams sediments. The study also demonstrated that adding of 0.4 wt% of sodium tripolyphosphate to 40 wt% and 45 wt% dam sediments decreased the friction factor by 96% and 25% respectively.
- Published
- 2023
- Full Text
- View/download PDF
3. Zinc Sulphide Quantum Dots’ Applications in Antibacterial as well as Estimation of E.Coli Concentration by Fabricating Mem-Mode Devices
- Author
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Duwarah, Himadri, Devi, Jutika, Sharma, Neelotpal, Saikia, Kandarpa Kumar, and Datta, Pranayee
- Abstract
This paper reports the synthesis of ZnS Quantum Dots (QDs) embedded in PVA by aqueous precipitation method and its application in antibacterial as well as to find or estimation of Escherichia coli (E.coli) concentration by using ZnS/PVA QD based mem-mode nanodevices. The as-synthesized ZnS/PVA samples are characterized by UV-Vis spectroscopy (UV), Photo luminescence (PL), X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). Antibacterial property of ZnS/PVA QDs against gram positive (S.aureus) as well as gram negative (E.coli) are tested. The antibacterial property is found to be more in S.aureus in comparision to E.coli. Mem-behaviour of the as-fabricated devices is observed through electrical characterization. COMSOL MP Software is used for simulating I-V characteristics. The voltage gap is found to be a promising parameter for estimating E.coli concentration with ZnS/PVA QDs as active material and an electrical circuit is presented
- Published
- 2023
- Full Text
- View/download PDF
4. Zinc Sulphide Quantum Dots’ Applications in Antibacterial as well as Estimation of E.Coli Concentration by Fabricating Mem-Mode Devices
- Author
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Himadri Duwarah, Jutika Devi, Neelotpal Sharma, Kandarpa Kumar Saikia, and Pranayee Datta
- Subjects
General Engineering - Abstract
This paper reports the synthesis of ZnS Quantum Dots (QDs) embedded in PVA by aqueous precipitation method and its application in antibacterial as well as to find or estimation of Escherichia coli (E.coli) concentration by using ZnS/PVA QD based mem-mode nanodevices. The as-synthesized ZnS/PVA samples are characterized by UV-Vis spectroscopy (UV), Photo luminescence (PL), X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). Antibacterial property of ZnS/PVA QDs against gram positive (S.aureus) as well as gram negative (E.coli) are tested. The antibacterial property is found to be more in S.aureus in comparision to E.coli. Mem-behaviour of the as-fabricated devices is observed through electrical characterization. COMSOL MP Software is used for simulating I-V characteristics. The voltage gap is found to be a promising parameter for estimating E.coli concentration with ZnS/PVA QDs as active material and an electrical circuit is presented
- Published
- 2023
5. Principles of Logic Design with Nanoscale Thin Film Memristive Systems for High Performance Digital Circuit Applications
- Author
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Chakraverty, Mayank and Ramakrishnan, V.N.
- Abstract
The characteristic pinched hysteresis behavior of memristors has been reported by stacks of a variety of materials. This paper aims to examine the principles of logic design using such two terminal memristive systems for high performance digital circuit applications. As against logic design with standard CMOS, the benefits of logic design with memristors have been stated. The realization and operation of memristor based AND and OR hybrid logic gates obtained by integrating memristors with standard CMOS logic have been discussed. The IMPLY and MAGIC logic families have been demonstrated by covering MAGIC NOR and NAND logic gate implementation with MAGIC NOR in detail. A qualitative comparison has been drawn towards the end of the paper to conclude on the suitability and application space for each of the logic families studied in this paper. This work also describes the hybrid CMOS-memristive logic family known as MRL (Memristor Ratioed Logic). With the addition of CMOS inverters, this logic family's OR and AND logic gates, which are based on memristive components, are given a full logic structure and signal restoration. The MRL family, in contrast to earlier memristor-based logic families, is compatible with conventional CMOS logic.
- Published
- 2023
- Full Text
- View/download PDF
6. Principles of Logic Design with Nanoscale Thin Film Memristive Systems for High Performance Digital Circuit Applications
- Author
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Mayank Chakraverty and V.N. Ramakrishnan
- Subjects
General Engineering - Abstract
The characteristic pinched hysteresis behavior of memristors has been reported by stacks of a variety of materials. This paper aims to examine the principles of logic design using such two terminal memristive systems for high performance digital circuit applications. As against logic design with standard CMOS, the benefits of logic design with memristors have been stated. The realization and operation of memristor based AND and OR hybrid logic gates obtained by integrating memristors with standard CMOS logic have been discussed. The IMPLY and MAGIC logic families have been demonstrated by covering MAGIC NOR and NAND logic gate implementation with MAGIC NOR in detail. A qualitative comparison has been drawn towards the end of the paper to conclude on the suitability and application space for each of the logic families studied in this paper. This work also describes the hybrid CMOS-memristive logic family known as MRL (Memristor Ratioed Logic). With the addition of CMOS inverters, this logic family's OR and AND logic gates, which are based on memristive components, are given a full logic structure and signal restoration. The MRL family, in contrast to earlier memristor-based logic families, is compatible with conventional CMOS logic.
- Published
- 2023
7. Light Induced Synthesis of Ag Nanorods for Potential Application as Optical Filter Tailored to Visible Domain
- Author
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Arnab Kumar Sarkar, Himanshu Rajbongshi, Sunandan Baruah, and Pranayee Datta
- Subjects
General Engineering - Abstract
Monodispersed Ag nanorods were synthesized using a one-pot synthesis method. These Ag nanorods normally manifest dual surface plasmon resonance (SPR) peaks. This work presents a study of the variation of SPR peaks with variation in the shape of Ag nanorods. Shape variation was achieved through the degradation of a shape-controlling agent (PVP in this work) under white light irradiance with silica passivation to halt further shape variations. This paper also reports the growth & characterization of thin films of the synthesized rod-shaped silver nanoparticles on glass slides along with studies on band pass filter characteristics of the as-synthesized nanoparticles.
- Published
- 2023
8. Light Induced Synthesis of Ag Nanorods for Potential Application as Optical Filter Tailored to Visible Domain
- Author
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Sarkar, Arnab Kumar, Rajbongshi, Himanshu, Baruah, Sunandan, and Datta, Pranayee
- Abstract
Monodispersed Ag nanorods were synthesized using a one-pot synthesis method. These Ag nanorods normally manifest dual surface plasmon resonance (SPR) peaks. This work presents a study of the variation of SPR peaks with variation in the shape of Ag nanorods. Shape variation was achieved through the degradation of a shape-controlling agent (PVP in this work) under white light irradiance with silica passivation to halt further shape variations. This paper also reports the growth & characterization of thin films of the synthesized rod-shaped silver nanoparticles on glass slides along with studies on band pass filter characteristics of the as-synthesized nanoparticles.
- Published
- 2023
- Full Text
- View/download PDF
9. Transition from Reflective to Energy-Storing Self-Illumination in Road Markings: A Review
- Author
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Fu Jie Li, Xin Ye Cao, Shuai Heng Liu, and Lei Lei He
- Subjects
General Engineering - Abstract
Road markings regulate and direct traffic by conveying specific information. It is of great significance to develop new road marking materials and improve the visibility of marking materials for improving traffic efficiency and ensuring traffic safety. This paper summarized the development status of various reflective road markings at home and abroad. In addition, the energy storage luminescent fluorescent/phosphor marking lines in road marking was emphatically generalized to evaluate the advantages and disadvantages of different improvement methods. Overall, strontium aluminate doped with Eu2+ co-doped with Dy3+ (SrAl2O4:Eu2+, Dy3+) phosphors and self-luminous pavement for energy storage had great prospects in improving road safety and reducing energy consumption.
- Published
- 2023
10. Transition from Reflective to Energy-Storing Self-Illumination in Road Markings: A Review
- Author
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Li, Fu Jie, Cao, Xin Ye, Liu, Shuai Heng, and He, Lei Lei
- Abstract
Road markings regulate and direct traffic by conveying specific information. It is of great significance to develop new road marking materials and improve the visibility of marking materials for improving traffic efficiency and ensuring traffic safety. This paper summarized the development status of various reflective road markings at home and abroad. In addition, the energy storage luminescent fluorescent/phosphor marking lines in road marking was emphatically generalized to evaluate the advantages and disadvantages of different improvement methods. Overall, strontium aluminate doped with Eu
2+ co-doped with Dy3+ (SrAl2 O4 :Eu2+ , Dy3+ ) phosphors and self-luminous pavement for energy storage had great prospects in improving road safety and reducing energy consumption.- Published
- 2023
- Full Text
- View/download PDF
11. Structural, Thermal, and Magnetic Characterization Analysis of Synthesized Fe3O4-Spinel Ferrite Nanoparticles
- Author
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Bandana Gogoi and Upamanyu Das
- Subjects
General Engineering - Abstract
Spinel ferrite nanoparticles are potential candidates for multiple biomedical applications. Spinel ferrite nanoparticles have been studied extensively for understanding physical, chemical, electro-optical as well as magnetic properties which are fascinating due to cationic distributions corresponding to tetrahedral sites and octahedral sites in a cubic phase. Biocompatibility and large magnetic moment are basic requirements in spinel ferrite nanoparticles for efficient functioning in specific application purpose. Fe3O4 (magnetite) is an important member of spinel ferrite group with high chemical stability and ferrimagetic material property at nanodimension. Superparamagnetic state and biocompatibility of magnetite (Fe3O4) spinel ferrite nanoparticle has already been proven. Spinel ferrite magnetite nanoparticles have been developed based on precipitation of iron oxide using ferric and ferrous ions at the ratio 2:1 in alkaline media at and above 100°C. The experimental parameters have been set to synthesize pure and uniformly sized magnetite nanoparticles. No other phases of iron oxides were detected other than magnetite spinel phase in the XRD result. The average crystal size has been determined from XRD peak broadening. Absorption spectra were investigated using UV-Vis Spectrometer and FTIR. Thermal and magnetic measurements were carried out Digital Scanning Calorimeter and SQUID Magnetometer. One sample of the prepared nanoparticles with polymer coating of polyvinyl alcohol has been studied for superparamagnetic nature. Superparamagnetic particles show saturation value of magnetization 51.26 emu/g at 100 K. ZFC-FC curves for two samples with polymer coating of polyvinyl alcohol and hydroxy-propyl methyl cellulose have also been studied. Keywords: Spinel Ferrite, Magnetite, Ferrimagnetism, Transition metal oxide, Superparamagnetism. Statements and declarations Competing Interests: The authors declare that there is no competing financial interest that are related directly or indirectly to the reported work in this paper. Conflict of interest: There is no conflict of interest. Acknowledgements The Authors are grateful to IISER Bhopal, CRF facility for providing instrumentation facility to characterize magnetic properties. We acknowledge thanks to Lovely Professional University for providing us necessary characterization technique for the XRD analysis and thermal analysis.
- Published
- 2023
12. Structural, Thermal, and Magnetic Characterization Analysis of Synthesized Fe3O4-Spinel Ferrite Nanoparticles
- Author
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Gogoi, Bandana and Das, Upamanyu
- Abstract
Spinel ferrite nanoparticles are potential candidates for multiple biomedical applications. Spinel ferrite nanoparticles have been studied extensively for understanding physical, chemical, electro-optical as well as magnetic properties which are fascinating due to cationic distributions corresponding to tetrahedral sites and octahedral sites in a cubic phase. Biocompatibility and large magnetic moment are basic requirements in spinel ferrite nanoparticles for efficient functioning in specific application purpose. Fe
3 O4 (magnetite) is an important member of spinel ferrite group with high chemical stability and ferrimagetic material property at nanodimension. Superparamagnetic state and biocompatibility of magnetite (Fe3 O4 ) spinel ferrite nanoparticle has already been proven. Spinel ferrite magnetite nanoparticles have been developed based on precipitation of iron oxide using ferric and ferrous ions at the ratio 2:1 in alkaline media at and above 100°C. The experimental parameters have been set to synthesize pure and uniformly sized magnetite nanoparticles. No other phases of iron oxides were detected other than magnetite spinel phase in the XRD result. The average crystal size has been determined from XRD peak broadening. Absorption spectra were investigated using UV-Vis Spectrometer and FTIR. Thermal and magnetic measurements were carried out Digital Scanning Calorimeter and SQUID Magnetometer. One sample of the prepared nanoparticles with polymer coating of polyvinyl alcohol has been studied for superparamagnetic nature. Superparamagnetic particles show saturation value of magnetization 51.26 emu/g at 100 K. ZFC-FC curves for two samples with polymer coating of polyvinyl alcohol and hydroxy-propyl methyl cellulose have also been studied. Keywords: Spinel Ferrite, Magnetite, Ferrimagnetism, Transition metal oxide, Superparamagnetism. Statements and declarations Competing Interests: The authors declare that there is no competing financial interest that are related directly or indirectly to the reported work in this paper. Conflict of interest: There is no conflict of interest. Acknowledgements The Authors are grateful to IISER Bhopal, CRF facility for providing instrumentation facility to characterize magnetic properties. We acknowledge thanks to Lovely Professional University for providing us necessary characterization technique for the XRD analysis and thermal analysis.- Published
- 2023
- Full Text
- View/download PDF
13. Possibilities of Artificial Muscles Using Dielectric Elastomers and their Applications
- Author
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Chiba, Seiki A., Waki, Mikio, Takeshita, Makoto, and Ohyama, Kazuhiro
- Abstract
The recent developments in dielectric elastomers (DE) are spectacular. Currently, a DE as an actuator, 0.15 g of acrylic sandwiching SWCNT electrodes, is capable of lifting a weight of 8 kg by more than 1 mm at a speed of 88 msec. In the near future, DE motors could be used to drive electric vehicles. Moreover, the DE can be used as a high-efficiency sensor with the same structure. With a diameter of 20 mm and a thickness of 0.5 mm, it can accurately measure pressure from several kg to 150 kg. In addition, reversing this DE actuator (DEA) movement also enables high-efficiency power generation. In other words, when the DEA is stretched or pushed, it generates electric power. Single wall nanotubes (SWCNTs) were used as an electrode, and an acrylic DE power generation cartridge with a diameter of 80 mm was used. When the center of the DE power generation cartridge is pushed by about 15 mm, a power of 33.6 mJ is generated. Using these two DE cartridges, it was possible to charge a secondary battery through a DC converter. In addition to this power generator, practical research and development of power generation using wave power, wind power, waste heat, and fluids (ocean currents, water currents, etc.) is progressing. In this paper, we have described state-of-the-art DEAs, DE generators (including the case that the power generated locally by microgenerators are consumed locally), and DE sensors and explained their usefulness.
- Published
- 2023
- Full Text
- View/download PDF
14. Possibilities of Artificial Muscles Using Dielectric Elastomers and their Applications
- Author
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Seiki A. Chiba, Mikio Waki, Makoto Takeshita, and Kazuhiro Ohyama
- Subjects
General Engineering - Abstract
The recent developments in dielectric elastomers (DE) are spectacular. Currently, a DE as an actuator, 0.15 g of acrylic sandwiching SWCNT electrodes, is capable of lifting a weight of 8 kg by more than 1 mm at a speed of 88 msec. In the near future, DE motors could be used to drive electric vehicles. Moreover, the DE can be used as a high-efficiency sensor with the same structure. With a diameter of 20 mm and a thickness of 0.5 mm, it can accurately measure pressure from several kg to 150 kg. In addition, reversing this DE actuator (DEA) movement also enables high-efficiency power generation. In other words, when the DEA is stretched or pushed, it generates electric power. Single wall nanotubes (SWCNTs) were used as an electrode, and an acrylic DE power generation cartridge with a diameter of 80 mm was used. When the center of the DE power generation cartridge is pushed by about 15 mm, a power of 33.6 mJ is generated. Using these two DE cartridges, it was possible to charge a secondary battery through a DC converter. In addition to this power generator, practical research and development of power generation using wave power, wind power, waste heat, and fluids (ocean currents, water currents, etc.) is progressing. In this paper, we have described state-of-the-art DEAs, DE generators (including the case that the power generated locally by microgenerators are consumed locally), and DE sensors and explained their usefulness.
- Published
- 2023
15. Analysis of a Vacuum-Infused Carbon Fiber/Epoxy Composite Beam under 3-Point Bending
- Author
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Eduardo Fischer Kerche, Maikson Luiz Passaia Tonatto, Laís Vasconcelos da Silva, and Sandro Campos Amico
- Subjects
General Engineering - Abstract
In this paper, a hollow square cross-section carbon fiber/epoxy composite beam was designed and manufactured. Evaluation of the beam behavior considered orientation and stacking sequence, aiming to reduce the number of layers and weight. Finite element method (FEM) was used to simulate the performance of the composite beam under 3-point bending and using three failure criteria, Tsai-Hill, Tsai-Wu and maximum stress. In order to identify the input parameters for the model, flat composites were tested under tension and compression. It was concluded that a minimum of 12 layers of unidirectional carbon fiber were required to reach the required load (44.5 kN). The prototype was successfully fabricated by vacuum-infusion process and subjected to 3-point bending test. The experimental failure load was within the predicted range by the Tsai-Hill failure criteria and maximum stress.
- Published
- 2023
16. Analysis of a Vacuum-Infused Carbon Fiber/Epoxy Composite Beam under 3-Point Bending
- Author
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Kerche, Eduardo Fischer, Tonatto, Maikson Luiz Passaia, da Silva, Laís Vasconcelos, and Amico, Sandro Campos
- Abstract
In this paper, a hollow square cross-section carbon fiber/epoxy composite beam was designed and manufactured. Evaluation of the beam behavior considered orientation and stacking sequence, aiming to reduce the number of layers and weight. Finite element method (FEM) was used to simulate the performance of the composite beam under 3-point bending and using three failure criteria, Tsai-Hill, Tsai-Wu and maximum stress. In order to identify the input parameters for the model, flat composites were tested under tension and compression. It was concluded that a minimum of 12 layers of unidirectional carbon fiber were required to reach the required load (44.5 kN). The prototype was successfully fabricated by vacuum-infusion process and subjected to 3-point bending test. The experimental failure load was within the predicted range by the Tsai-Hill failure criteria and maximum stress.
- Published
- 2023
- Full Text
- View/download PDF
17. Mechanochemical Synthesis of Dendrimers as Nanocarriers: A Review
- Author
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Alrbaihat, Mohammad
- Abstract
The process of mechanically activating chemical bonds usually involves applying external force. Since mechanical chemistry can be performed without solvents or with minimal amounts of solvent (catalytic quantities), it has become an imperative synthetic tool in multiple fields (e.g., physics, chemistry, and materials science) and is an attractive greener method for preparing diverse molecules. Catalysis, organic synthesis, solid-state medicinal preparation, metal complex synthesis, and many other chemistry fields have benefited from sustainable methods. The purpose of this paper is to shed light on the benefits of using mechanochemical methods to produce a pharmaceutical crystal that is composed of dendrimer nanocrystals. Consequently, we describe and examine the importance of mechanical procedures in forming dendrimers and pharmaceutical crystals in this review.
- Published
- 2023
- Full Text
- View/download PDF
18. Negative Thermal Expansion of Sulphur-Doped Graphene Oxide
- Author
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Figarova, Sophia, Aliyev, Elvin, Abaszade, Reshad, and Figarov, Vagif R.
- Abstract
The sulfur content present in graphene oxide prepared by Hummers' method has only been addressed by few papers so far. By modified Hammers method we synthesized thermally stable in ambient environment multilayer sulphur-doped graphene oxide. The samples were heat treated in an electrical furnace setup at different ambient temperatures and their crystallite size and linear coefficient of thermal expansion were extracted from Raman band intensity peak ratio as a function of temperature. We found unusually large (in comparison with graphene oxide) contraction on heating of multilayer two weight percent sulphur-doped graphene oxide with carbon to oxygen ratio of 2.3 in a narrow temperature range (308-318 K) with the lowest value of the linear thermal expansion coefficient of -18 ppm 1/K. Based upon an examination of the synthesized sulphur-doped graphene diffractograms, it is suggested that negative thermal expansion stems from the phonon backscattering by the sulphur impurity sites and the edges of the layers. The obtained experimental results have potential practical applications for fabrication of solar cells, sensors, lubricators, thermal actuators and also wavelike (second sound) thermal transport structures.
- Published
- 2023
- Full Text
- View/download PDF
19. Negative Thermal Expansion of Sulphur-Doped Graphene Oxide
- Author
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Sophia Figarova, Elvin Aliyev, Reshad Abaszade, and Vagif R. Figarov
- Subjects
General Engineering - Abstract
The sulfur content present in graphene oxide prepared by Hummers' method has only been addressed by few papers so far. By modified Hammers method we synthesized thermally stable in ambient environment multilayer sulphur-doped graphene oxide. The samples were heat treated in an electrical furnace setup at different ambient temperatures and their crystallite size and linear coefficient of thermal expansion were extracted from Raman band intensity peak ratio as a function of temperature. We found unusually large (in comparison with graphene oxide) contraction on heating of multilayer two weight percent sulphur-doped graphene oxide with carbon to oxygen ratio of 2.3 in a narrow temperature range (308-318 K) with the lowest value of the linear thermal expansion coefficient of -18 ppm 1/K. Based upon an examination of the synthesized sulphur-doped graphene diffractograms, it is suggested that negative thermal expansion stems from the phonon backscattering by the sulphur impurity sites and the edges of the layers. The obtained experimental results have potential practical applications for fabrication of solar cells, sensors, lubricators, thermal actuators and also wavelike (second sound) thermal transport structures.
- Published
- 2023
20. A Review on the Effect of Minimum Quantity Lubrication on Different Machining Parameters Emphasizing Vegetable Oil-Based Lubricants for Sustainable Manufacturing
- Author
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Chandrakant, Sheth Pushpak and Patel, Bhaveshkumar K.
- Abstract
The cutting fluid plays a significant role in minimizing heat generation and chip removal process during the machining of materials, hence improving tool life and surface finish of the workpiece. Many researchers have focused on minimum quantity lubrication (MQL) among the existing methods on the application of the coolant as it reduces the usage of coolant by spurting a mixture of compressed air and cutting fluid in an improved way instead of flood cooling. The MQL method has demonstrated to be appropriate as it fulfills the necessities of ‘green’ machining. Additionally, considering current environmental issues and provisions for safe healthy working conditions at the workplace, it is important to divert machining processes towards an eco-friendly path. Hence, the focus of research has been shifted to MQL using eco-friendly lubricants for green and sustainable manufacturing processes. In this review paper, the effect of different vegetable oil-based biodegradable coolants like castor oil, coconut oil, palm oil, etc. for different machining process parameters like cutting force, cutting temperature, surface finish, tool wear, etc. has been reviewed. It is observed that proper selection of cutting parameters along with lubricant through MQL can provide enhanced machinability to get desired outputs.
- Published
- 2023
- Full Text
- View/download PDF
21. A Review on the Effect of Minimum Quantity Lubrication on Different Machining Parameters Emphasizing Vegetable Oil-Based Lubricants for Sustainable Manufacturing
- Author
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Sheth Pushpak Chandrakant and Bhaveshkumar K. Patel
- Subjects
General Engineering - Abstract
The cutting fluid plays a significant role in minimizing heat generation and chip removal process during the machining of materials, hence improving tool life and surface finish of the workpiece. Many researchers have focused on minimum quantity lubrication (MQL) among the existing methods on the application of the coolant as it reduces the usage of coolant by spurting a mixture of compressed air and cutting fluid in an improved way instead of flood cooling. The MQL method has demonstrated to be appropriate as it fulfills the necessities of ‘green’ machining. Additionally, considering current environmental issues and provisions for safe healthy working conditions at the workplace, it is important to divert machining processes towards an eco-friendly path. Hence, the focus of research has been shifted to MQL using eco-friendly lubricants for green and sustainable manufacturing processes. In this review paper, the effect of different vegetable oil-based biodegradable coolants like castor oil, coconut oil, palm oil, etc. for different machining process parameters like cutting force, cutting temperature, surface finish, tool wear, etc. has been reviewed. It is observed that proper selection of cutting parameters along with lubricant through MQL can provide enhanced machinability to get desired outputs.
- Published
- 2023
22. Investigation of Forging Tools on the Basis of Subjective Assessment of Tool Life
- Author
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Abdulkerim Karaman, Rainer Labs, and Michael Marré
- Subjects
General Engineering - Abstract
Forging tools must be able to withstand very strong mechanical, thermal, tribological, and chemical stresses. The extent to which a tool can withstand these stresses depends on the material used and its pre-treatment as well as the heat and surface treatment, i.e. the load capacity. The ratio of stress to load capacity determines how high the tool life of a forging tool is. This paper deals with the variations in the tool life of forging tools using the example of a specific industrial stage sequence and production conditions. Due to a large number of influencing variables that have an effect on the tool during the entire tool life history, the focus of this work is placed on influencing variables of the forming process. Based on real production parameters of a forging company, which are recorded during a period for the investigation, the process data are analyzed about an influence on the tool life. The investigation focuses on four influencing variables, namely the subjective assessment of the end of the tool life, the interaction between the forming stages, production interruptions, and the cooling and lubrication of the forming tools. For the parameters that are not yet recorded during the trials, promising available measurement methods are identified and tested under laboratory conditions. One example of this is the recording of the actual spray quantities that are sprayed onto the tool surface before the forming process. The results of the investigations show that the tool life fluctuations can be reduced by about 16% and as a consequence, the average tool life can be increased by about 13%.
- Published
- 2023
23. Investigation of Forging Tools on the Basis of Subjective Assessment of Tool Life
- Author
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Karaman, Abdulkerim, Labs, Rainer, and Marré, Michael
- Abstract
Forging tools must be able to withstand very strong mechanical, thermal, tribological, and chemical stresses. The extent to which a tool can withstand these stresses depends on the material used and its pre-treatment as well as the heat and surface treatment, i.e. the load capacity. The ratio of stress to load capacity determines how high the tool life of a forging tool is. This paper deals with the variations in the tool life of forging tools using the example of a specific industrial stage sequence and production conditions. Due to a large number of influencing variables that have an effect on the tool during the entire tool life history, the focus of this work is placed on influencing variables of the forming process. Based on real production parameters of a forging company, which are recorded during a period for the investigation, the process data are analyzed about an influence on the tool life. The investigation focuses on four influencing variables, namely the subjective assessment of the end of the tool life, the interaction between the forming stages, production interruptions, and the cooling and lubrication of the forming tools. For the parameters that are not yet recorded during the trials, promising available measurement methods are identified and tested under laboratory conditions. One example of this is the recording of the actual spray quantities that are sprayed onto the tool surface before the forming process. The results of the investigations show that the tool life fluctuations can be reduced by about 16% and as a consequence, the average tool life can be increased by about 13%.
- Published
- 2023
- Full Text
- View/download PDF
24. The Design of the BP Neural Network Character Recognition in Matlab Environment
- Author
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Wen Jie Li, Ke Lun Tian, Hai Yan Sun, and Jie Zhang
- Subjects
Identification (information) ,Character (mathematics) ,Artificial neural network ,Computer science ,Time delay neural network ,Speech recognition ,General Engineering ,MATLAB ,computer ,Character recognition ,computer.programming_language - Abstract
This paper is based on the BP neural network, the identification method of character and the specific implementation steps were designed. Moreover, the method through the test form has been proved. The accuracy of character recognition is higher.
- Published
- 2014
25. Ultimate Elastic Wall Stress (UEWS) Test under Biaxial Loading for Glass-Fibre Reinforced Epoxy (GRE) Pipes
- Author
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Lutfeya A. Almagguz and Tarak A. Assaleh
- Subjects
Materials science ,business.industry ,education ,Glass fiber ,Composite number ,General Engineering ,Epoxy ,Structural engineering ,Wall stress ,visual_art ,visual_art.visual_art_medium ,Cylinder stress ,Composite material ,business ,Failure mode and effects analysis ,Leakage (electronics) - Abstract
This paper presents the results of an experimental investigation into the Ultimate Elastic Wall Stress (UEWS) of ±55° filament wound composite pipes. The UEWS test appears to provide an attractive alternative to the current method, and has proved to be one of the most effective in term of accuracy and speed. Moreover, it has been found to be sensitive to changes in key manufacturing and raw material parameters. The pipes were subjected to biaxial loading, which was achieved by combinations of hoop and axial stress. Loads were applied as groups of cycles which, were gradually increased until the UEWS had been determined. Various ratios of hoop to axial stress were applied to the pipes, ranging from pure axial to pure hoop loading at room temperature and at 65°C. These ratios were investigated by applying different pressures in both the main and small chambers built inside the pipe, and therefore it was unnecessary to add any external loads to the pipe wall. Tests were also conducted to observe leakage through the pipe wall. The main failure mode observed was weepage through the pipe wall, which was due to intensive matrix microcracking. The results from the UEWS tests are presented in the form of failure envelopes showing the effects of testing at an elevated temperature. Finally, degradation in the elastic properties of the pipe wall is also discussed and plotted against wall stress.
- Published
- 2014
26. The Effect of Ultraviolet Light Stabilizers on Color Stability, Melt Properties and Tensile Properties of Mixed Waste Plastics Blends
- Author
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Hyvärinen, Marko, Lagern, Viktor, and Kärki, Timo
- Abstract
Plastic waste disposal is among the most challenging problems of the current era. Therefore, new methods and applications for the utilization of waste plastics are increasingly needed. To find them, it is essential to research and develop the material properties of recycled plastics. The effect of different ultraviolet light (UV) stabilizers on the color stability, melt properties and tensile properties of mixed waste plastics blends was studied in this paper. The mixed waste plastics collected from two different waste sources were prepared as specimens by injection molding, and studied with two different types and loading amounts of UV stabilizers. UV absorbers (UVAs) and hindered amine light stabilizers (HALS) were used as UV stabilizers. A specimen produced without the addition of a UV stabilizer was used as a reference specimen of both the blends. After the accelerated weathering, the addition of a UVA provided an improved, smaller change in color than the addition of HALS. Among the tensile properties, the addition of UV stabilizers clearly improved the tensile strength and tensile modulus for almost all the studied specimens. Additionally, the melt properties of both the studied plastic blends were found to be increased by the addition of UV stabilizers.
- Published
- 2022
- Full Text
- View/download PDF
27. The Effect of Ultraviolet Light Stabilizers on Color Stability, Melt Properties and Tensile Properties of Mixed Waste Plastics Blends
- Author
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Marko Hyvärinen, Viktor Lagern, Timo Kärki, Lappeenrannan-Lahden teknillinen yliopisto LUT, Lappeenranta-Lahti University of Technology LUT, and fi=School of Energy Systems|en=School of Energy Systems
- Subjects
General Engineering - Abstract
Plastic waste disposal is among the most challenging problems of the current era. Therefore, new methods and applications for the utilization of waste plastics are increasingly needed. To find them, it is essential to research and develop the material properties of recycled plastics. The effect of different ultraviolet light (UV) stabilizers on the color stability, melt properties and tensile properties of mixed waste plastics blends was studied in this paper. The mixed waste plastics collected from two different waste sources were prepared as specimens by injection molding, and studied with two different types and loading amounts of UV stabilizers. UV absorbers (UVAs) and hindered amine light stabilizers (HALS) were used as UV stabilizers. A specimen produced without the addition of a UV stabilizer was used as a reference specimen of both the blends. After the accelerated weathering, the addition of a UVA provided an improved, smaller change in color than the addition of HALS. Among the tensile properties, the addition of UV stabilizers clearly improved the tensile strength and tensile modulus for almost all the studied specimens. Additionally, the melt properties of both the studied plastic blends were found to be increased by the addition of UV stabilizers. Post-print / Final draft
- Published
- 2022
28. Effect of Process Parameters on Properties of Titanium Alloy during Thermal Simulation Deformation
- Author
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Jin Jun Tang, Cui Liang, Chen Guang Xu, and Ji Qiang Li
- Subjects
General Engineering - Abstract
In this paper, aiming at the heat resistance and thermal deformation process of titanium matrix composites 0 vol.%, 2.5.vol.%, 5.vol.%. Thermal simulation experiment of titanium matrix composites with different (TiB+TiC) strengthening phase content. The measurement accuracy of material displacement is 0.01 mm. The compression is 70%, and the strain rate is 0.1 mm/s and 0.01 mm/s respectively. Compression tests at different strain rates and temperatures were carried out. The experimental results show that when the (TiB+TiC) 5vol% titanium composite is deformed at 0.01mm/s low strain rate, the peak stresses corresponding to 25°C, 250°C,350 °C and 500°C are increased to 1096MPa, 835MPa, 646MPa and 416MPa respectively. Under the condition of high strain rate of 0.1mm/s, the peak stresses corresponding to 25 °C, 250 °C, 350 °C and 500 °C are increased to 1230 MPa, 896 MPa, 723 MPa and 471 MPa respectively. The deformation law of stress rheological curve is roughly the same, and the high temperature zone has good plastic deformation ability. The titanium matrix composite has high compression rheological mechanical properties and good high-temperature plastic deformation ability. It is the preferred material component for the preparation of titanium matrix composite and powder forging.
- Published
- 2022
29. Effect of Process Parameters on Properties of Titanium Alloy during Thermal Simulation Deformation
- Author
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Tang, Jin Jun, Liang, Cui, Xu, Chen Guang, and Li, Ji Qiang
- Abstract
In this paper, aiming at the heat resistance and thermal deformation process of titanium matrix composites 0 vol.%, 2.5.vol.%, 5.vol.%. Thermal simulation experiment of titanium matrix composites with different (TiB+TiC) strengthening phase content. The measurement accuracy of material displacement is 0.01 mm. The compression is 70%, and the strain rate is 0.1 mm/s and 0.01 mm/s respectively. Compression tests at different strain rates and temperatures were carried out. The experimental results show that when the (TiB+TiC) 5vol% titanium composite is deformed at 0.01mm/s low strain rate, the peak stresses corresponding to 25°C, 250°C,350 °C and 500°C are increased to 1096MPa, 835MPa, 646MPa and 416MPa respectively. Under the condition of high strain rate of 0.1mm/s, the peak stresses corresponding to 25 °C, 250 °C, 350 °C and 500 °C are increased to 1230 MPa, 896 MPa, 723 MPa and 471 MPa respectively. The deformation law of stress rheological curve is roughly the same, and the high temperature zone has good plastic deformation ability. The titanium matrix composite has high compression rheological mechanical properties and good high-temperature plastic deformation ability. It is the preferred material component for the preparation of titanium matrix composite and powder forging.
- Published
- 2022
- Full Text
- View/download PDF
30. Effect of Alloying Elements on Strengthening Phase and Solidification Structure of Ti-Al-Mo-Zr Titanium Alloy
- Author
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Jin Jun Tang, Cui Liang, Chen Guang Xu, and Ji Qiang Li
- Subjects
General Engineering - Abstract
This paper mainly studies the composition of strengthening phase, characteristic precipitation temperature and composition range of strengthening phase in Ti-Al-Mo-Zr-Si medical titanium alloy, and the influence of element changes on the content and microstructure of strengthening phase. Promote the formulation of thermodynamic process of titanium alloy powder metallurgy, as well as the formulation of alloy hot working and solid solution aging process. In this paper, Panda thermodynamic software is used to calculate the multicomponent alloy thermodynamics and multicomponent phase diagram of titanium alloy materials. The effects of Al, Mo, Zr, Si and other elements on the precipitation of strengthening phase and the phase transformation content of solidification structure were obtained. It is found that the content of Mo is more than 2 wt.% β phase transition precipitation angle. Meanwhile, in order to avoid the excess of precipitates such as Mo5Si3 and M3Si, the content of Mo should be less than 4.6 wt.%. The content of Zr can be maintained at about 1.5 wt.%. If the aging precipitation of the material is considered, it can be controlled to be less than 2 wt.%. The content of this paper is the basis and improvement of titanium powder metallurgy technology and rapid prototyping technology.
- Published
- 2022
31. Effect of Alloying Elements on Strengthening Phase and Solidification Structure of Ti-Al-Mo-Zr Titanium Alloy
- Author
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Tang, Jin Jun, Liang, Cui, Xu, Chen Guang, and Li, Ji Qiang
- Abstract
This paper mainly studies the composition of strengthening phase, characteristic precipitation temperature and composition range of strengthening phase in Ti-Al-Mo-Zr-Si medical titanium alloy, and the influence of element changes on the content and microstructure of strengthening phase. Promote the formulation of thermodynamic process of titanium alloy powder metallurgy, as well as the formulation of alloy hot working and solid solution aging process. In this paper, Panda thermodynamic software is used to calculate the multicomponent alloy thermodynamics and multicomponent phase diagram of titanium alloy materials. The effects of Al, Mo, Zr, Si and other elements on the precipitation of strengthening phase and the phase transformation content of solidification structure were obtained. It is found that the content of Mo is more than 2 wt.% β phase transition precipitation angle. Meanwhile, in order to avoid the excess of precipitates such as Mo5Si3 and M3Si, the content of Mo should be less than 4.6 wt.%. The content of Zr can be maintained at about 1.5 wt.%. If the aging precipitation of the material is considered, it can be controlled to be less than 2 wt.%. The content of this paper is the basis and improvement of titanium powder metallurgy technology and rapid prototyping technology.
- Published
- 2022
- Full Text
- View/download PDF
32. Field Investigation of the Small House with the Ventilated Roof Tiles
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Withaya Puangsombut, Jongjit Hirunlabh, and Onvalee Amornleetrakul
- Subjects
Cement ,Materials science ,business.industry ,General Engineering ,Natural ventilation ,Structural engineering ,Attic ,Solar gain ,visual_art ,Thermal ,Air flow rate ,visual_art.visual_art_medium ,Tile ,Composite material ,business ,Roof - Abstract
This paper investigates the thermal performances and heat gain reduction of a new roof tile design referred as Ventilated Roof Tile (VRT) compared with an ordinary corrugated concrete roof tiles (CCR). The outside dimension of each small house was 1.70 x 1.70 x 2.85 m3 (W x L x H) and inside dimension was 1.50 x 1.50 x 2.20 m3. The volume of each room was 4.95 m3. The gable roofs slope were 25o and surface area of VRT was 2.58 m2 per each side facing north and south. The VRT tile composed of upper cement plate 40 × 40 cm2 and lower cement plate 30 x 40 cm2. Between plates was 3 cm thickness air gap. The experimental results showed that the top surface of VRT was lower than CCR about 2.10°C for average temperature (from 6:00 18:00) and made VRT room temperature lower than CCR about 1.41°C for average temperature. VRT could reduce heat gain with air flow rate through the roof tiles gaps varied following the solar radiation, during time 8:00-17:00 the natural ventilation varied from 0.003-0.014 m3/s (10.6-50.0 m3/hr.). Observed that, during 17:00-18:00, the air flow rate is about 0.003 m3/s (10.8 m3/hr.) due to heat accumulated in the attic space and roof tiles.
- Published
- 2014
33. New Results Regarding the Cavitation Destruction Behavior of Heat-Treated CuZn39Pb3 Brass with Different Parameters
- Author
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Cristian Ghera, Iosif Lazăr, Daniela Alexa, Ilare Bordeaşu, Nicușor-Alin Sîrbu, Daniel Ostoia, Mihai Hluscu, Cornelia Laura Salcianu, Daniel Catalin Stroita, Dumitru Viorel Bazavan, Marcela Sava, and Lavinia Madalina Micu
- Subjects
General Engineering - Abstract
Among other parts made of brass there are also the blades and the rotors of the hydraulic machines, respectively ship propellers, which during operation are degraded by cavitation erosion. As a result, most of the researches, including the most recent ones, are focused on the morphological analysis of structures eroded under the impact of micro-jets and shock waves, produced by cavitation hydrodynamics. The goal is to create new materials, but also to use new treatment technologies to increase cavitation resistance. As the literature is quite poor in studies related to the materials resistance to cavitation erosion, respectively treatments and technological procedures of it’s improvement, this paper presents the research results on the behavior of vibration cavitation erosion, carried out on three sets of CuZn39Pb3 brass samples, subjected to volumetric heat treatments of hardening for putting in solution at 800°C, followed by tempering at 250°C, 400°C and 600°C. The characterization of the behavior and the cavitation resistance of the structures resulting from the applied heat treatments is performed based on macroscopic images, taken at different representative periods, SEM images at the end of the test duration and values of specific parameters recommended by ASTM G32-2016. The analysis highlights the differences caused by the change in structure by varying the temperature, but also the hardness of the surface exposed to the cavity. Thus, of the three treatments, it is found that the best resistance to cavitation is conferred by the structure resulting from hardening at 800°C, with tempering at 250°C.
- Published
- 2022
34. New Results Regarding the Cavitation Destruction Behavior of Heat-Treated CuZn39Pb3 Brass with Different Parameters
- Author
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Ghera, Cristian, Lazăr, Iosif, Alexa, Daniela, Bordeaşu, Ilare, Sîrbu, Nicușor-Alin, Ostoia, Daniel, Hluscu, Mihai, Salcianu, Cornelia Laura, Stroita, Daniel Catalin, Bazavan, Dumitru Viorel, Sava, Marcela, and Micu, Lavinia Madalina
- Abstract
Among other parts made of brass there are also the blades and the rotors of the hydraulic machines, respectively ship propellers, which during operation are degraded by cavitation erosion. As a result, most of the researches, including the most recent ones, are focused on the morphological analysis of structures eroded under the impact of micro-jets and shock waves, produced by cavitation hydrodynamics. The goal is to create new materials, but also to use new treatment technologies to increase cavitation resistance. As the literature is quite poor in studies related to the materials resistance to cavitation erosion, respectively treatments and technological procedures of it’s improvement, this paper presents the research results on the behavior of vibration cavitation erosion, carried out on three sets of CuZn39Pb3 brass samples, subjected to volumetric heat treatments of hardening for putting in solution at 800°C, followed by tempering at 250°C, 400°C and 600°C. The characterization of the behavior and the cavitation resistance of the structures resulting from the applied heat treatments is performed based on macroscopic images, taken at different representative periods, SEM images at the end of the test duration and values of specific parameters recommended by ASTM G32-2016. The analysis highlights the differences caused by the change in structure by varying the temperature, but also the hardness of the surface exposed to the cavity. Thus, of the three treatments, it is found that the best resistance to cavitation is conferred by the structure resulting from hardening at 800°C, with tempering at 250°C.
- Published
- 2022
- Full Text
- View/download PDF
35. New Results Regarding the Cavitation Destruction Behavior of Heat-Treated CuSn12-C Bronze with Different Parameters
- Author
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Cornelia Laura Salcianu, Cristian Ghera, Sebastian Titus Duma, Daniela Alexa, Ilare Bordeaşu, Nicușor-Alin Sîrbu, Corneliu Eusebiu Podoleanu, Liviu Daniel Pîrvulescu, Dumitru Viorel Bazavan, Anton Hadar, Gabriel Mălaimare, and Lavinia Madalina Micu
- Subjects
General Engineering - Abstract
The present paper analyzes the differences in behavior and resistance to erosion through vibrating cavitation, between the bronze structures CuSn-12C resulting from two volumetric thermal treatments of hardening and tempering. The analysis was performed on the basis of macro and microscopic images, as well as on the basis of the histogram in which the values of the reference parameters used in the laboratory custom and prescribed by the international norms ASTM G32-2016 are compared. This shows the dependence of the degree of erosion as a function of the temperature of tempering heat treatment, after hardening, as a result of microstructural changes and the hardness of the surface attacked by cavitation. The experimental research is performed on the standard vibrating device within the Cavitation Erosion Research Laboratory of the Politehnica University of Timișoara.
- Published
- 2022
36. New Results Regarding the Cavitation Destruction Behavior of Heat-Treated CuSn12-C Bronze with Different Parameters
- Author
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Salcianu, Cornelia Laura, Ghera, Cristian, Duma, Sebastian Titus, Alexa, Daniela, Bordeaşu, Ilare, Sîrbu, Nicușor-Alin, Podoleanu, Corneliu Eusebiu, Pîrvulescu, Liviu Daniel, Bazavan, Dumitru Viorel, Hadar, Anton, Mălaimare, Gabriel, and Micu, Lavinia Madalina
- Abstract
The present paper analyzes the differences in behavior and resistance to erosion through vibrating cavitation, between the bronze structures CuSn-12C resulting from two volumetric thermal treatments of hardening and tempering. The analysis was performed on the basis of macro and microscopic images, as well as on the basis of the histogram in which the values of the reference parameters used in the laboratory custom and prescribed by the international norms ASTM G32-2016 are compared. This shows the dependence of the degree of erosion as a function of the temperature of tempering heat treatment, after hardening, as a result of microstructural changes and the hardness of the surface attacked by cavitation. The experimental research is performed on the standard vibrating device within the Cavitation Erosion Research Laboratory of the Politehnica University of Timișoara.
- Published
- 2022
- Full Text
- View/download PDF
37. Aspects Regarding the Operating Behavior of FSW Welding Tools
- Author
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Ion Aurel Perianu, Lia Nicoleta Boțilă, and Radu Cojocaru
- Subjects
General Engineering - Abstract
Welding tools are a determining factor in obtaining welded joints with desired characteristics. The international community pays great attention to research aimed at establishing the optimal characteristics of friction stir welding (FSW) tools. With the development of the FSW welding process with its own contributions, ISIM Timisoara has developed complex research resulting in the conception and design of (innovative) FSW welding tool solutions. A very important factor especially when welding high hardness materials is the durability / lifespan of FSW welding tools. The paper presents general considerations regarding the qualities that FSW welding tools must meet in general, but also ISIM achievements in the field of design and operation of welding tools. Studies regarding operating behavior of welding tools made of sintered tungsten carbide P20S, in terms of service life (wear), both in the case of applying the classical FSW welding process and the method of friction stir welding in inert gas environment (FSW-IG), when joining steels with wide industrial use (304L stainless steel, respectively DD13 steel), are also presented. Concrete data is presented with values of the degree of wear of the tools in the unit of time, in their critical areas: tools made of X38CrMoV5 steel alloy used for welding aluminum alloys with different characteristics, respectively tools made of sintered tungsten carbide P20S used for welding S 235 JR + N steel and 304L stainless steels.
- Published
- 2022
38. Aspects Regarding the Operating Behavior of FSW Welding Tools
- Author
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Perianu, Ion Aurel, Boțilă, Lia Nicoleta, and Cojocaru, Radu
- Abstract
Welding tools are a determining factor in obtaining welded joints with desired characteristics. The international community pays great attention to research aimed at establishing the optimal characteristics of friction stir welding (FSW) tools. With the development of the FSW welding process with its own contributions, ISIM Timisoara has developed complex research resulting in the conception and design of (innovative) FSW welding tool solutions. A very important factor especially when welding high hardness materials is the durability / lifespan of FSW welding tools. The paper presents general considerations regarding the qualities that FSW welding tools must meet in general, but also ISIM achievements in the field of design and operation of welding tools. Studies regarding operating behavior of welding tools made of sintered tungsten carbide P20S, in terms of service life (wear), both in the case of applying the classical FSW welding process and the method of friction stir welding in inert gas environment (FSW-IG), when joining steels with wide industrial use (304L stainless steel, respectively DD13 steel), are also presented. Concrete data is presented with values of the degree of wear of the tools in the unit of time, in their critical areas: tools made of X38CrMoV5 steel alloy used for welding aluminum alloys with different characteristics, respectively tools made of sintered tungsten carbide P20S used for welding S 235 JR + N steel and 304L stainless steels.
- Published
- 2022
- Full Text
- View/download PDF
39. Aspects Regarding Welding of DD13 Steel by Applying the FSW Process and some Processes Derived from it
- Author
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Boțilă, Lia Nicoleta, Cojocaru, Radu, and Perianu, Ion Aurel
- Abstract
Due to its characteristics, DD13 steel is recommended for various applications in the automotive field (including in the manufacture of components for car bodies). The paper presents solutions proposed by ISIM Timisoara for welding of DD13 steel, as alternative solutions to conventional welding processes. One solution that has proven to be viable for joining DD13 steel is the friction stir welding process (FSW). In terms of the quality of the welded joints obtained by applying the classic FSW welding process, these welds were excellent. In an attempt to obtain other benefits, mainly related to the efficiency of the welding process, ISIM Timisoara has developed research programs for the study and application of other methods based on the FSW process principle, namely: - hybrid friction stir welding ultrasonic assisted FSW-US; - friction stir welding in inert gas environment FSW – IG. The important effects due to the application of these methods are: improving (as appropriate) the degree of plasticization of the materials to be joined and increasing the degree of mixing of the materials as result of ultrasonic assistance of the FSW welding process; improvement of the welding process by reducing the pressing forces of the tool during welding, with an effect on increasing the service life of welding tool; respectively improving the aspect of the weld and some mechanical characteristics of the welded joints (at tensile tests, respectively static bending test). The obtained results showed that the two methods derived from the classical FSW welding process, can be used in industrial applications, with important benefits.
- Published
- 2022
- Full Text
- View/download PDF
40. Aspects Regarding Welding of DD13 Steel by Applying the FSW Process and some Processes Derived from it
- Author
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Lia Nicoleta Boțilă, Radu Cojocaru, and Ion Aurel Perianu
- Subjects
General Engineering - Abstract
Due to its characteristics, DD13 steel is recommended for various applications in the automotive field (including in the manufacture of components for car bodies). The paper presents solutions proposed by ISIM Timisoara for welding of DD13 steel, as alternative solutions to conventional welding processes. One solution that has proven to be viable for joining DD13 steel is the friction stir welding process (FSW). In terms of the quality of the welded joints obtained by applying the classic FSW welding process, these welds were excellent. In an attempt to obtain other benefits, mainly related to the efficiency of the welding process, ISIM Timisoara has developed research programs for the study and application of other methods based on the FSW process principle, namely: - hybrid friction stir welding ultrasonic assisted FSW-US; - friction stir welding in inert gas environment FSW – IG. The important effects due to the application of these methods are: improving (as appropriate) the degree of plasticization of the materials to be joined and increasing the degree of mixing of the materials as result of ultrasonic assistance of the FSW welding process; improvement of the welding process by reducing the pressing forces of the tool during welding, with an effect on increasing the service life of welding tool; respectively improving the aspect of the weld and some mechanical characteristics of the welded joints (at tensile tests, respectively static bending test). The obtained results showed that the two methods derived from the classical FSW welding process, can be used in industrial applications, with important benefits.
- Published
- 2022
41. Review: Advantages of Repairing Machine Parts in Order to Restore their Functionality
- Author
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Drakče Tanasković, Mihajlo Aranđelović, Branislav Đorđević, and Simon A. Sedmak
- Subjects
General Engineering - Abstract
This paper covers the literature review of the work by author, who have been involved in the subject of machine element repairing from the techno-economical point of view. Positive aspects of repairing, as opposed to purchasing new parts are shown and discussed. All of the examples given as part of the literature review are related to real, practical problems. It was concluded in all cases, that the repairing of damaged parts was the better option, since not only did it cost significantly less, it also noticeably decreased the equipment downtime, as there was no need to wait for the new part to be delivered.
- Published
- 2022
42. Review: Advantages of Repairing Machine Parts in Order to Restore their Functionality
- Author
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Tanasković, Drakče, Aranđelović, Mihajlo, Đorđević, Branislav, and Sedmak, Simon A.
- Abstract
This paper covers the literature review of the work by author, who have been involved in the subject of machine element repairing from the techno-economical point of view. Positive aspects of repairing, as opposed to purchasing new parts are shown and discussed. All of the examples given as part of the literature review are related to real, practical problems. It was concluded in all cases, that the repairing of damaged parts was the better option, since not only did it cost significantly less, it also noticeably decreased the equipment downtime, as there was no need to wait for the new part to be delivered.
- Published
- 2022
- Full Text
- View/download PDF
43. Simulation of Thermal Field in Eutectic Microwave Bonding for Electrical Connection of Photovoltaic Cells
- Author
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Cristian Daniel Ghelsingher, Robert Cristian Marin, Iulian Ştefan, Nicușor-Alin Sîrbu, Ionel Dănuț Savu, Andrej David, Sorin Vasile Savu, and Adrian Bebe Olei
- Subjects
General Engineering - Abstract
Sustainable development requires green energy and low carbon footprint in manufacturing sector of photovoltaic systems. The electrical connections of photovoltaic cells need to have low electrical resistance in order to reduce the electrical losses and therefore to improve the performance of the photovoltaic panels. This paper aims to present researches related to bonding of wires that connect solar cells by using microwave technology. The microwave bonding has the main advantage that offers fast bonding but, in the same time, this technology does not offer stability of the thermal heating. Two different unwanted phenomena like thermal runaway and plasma arc discharge often lead to the damaging of copper and aluminum wires used in electrical connection. The study presented in this paper is focused on simulation of the thermal field developed in copper wires in order to optimize the bonding process and increase the quality of products. The simulation of the thermal field has been done using Fourier equations for conducting heating in copper materials and eutectic alloys. The simulation model has been validated through experimental heating using a 6 kW water-cooled microwave generator controlled by a matching load auto-tuner for best transfer of the power from generator to copper wires. The temperature has been measured in real time using an infrared pyrometer for metals with 2.3 μm spectral range and measurement range between 0o C and 7000 C. The study is finalized with elaboration of mathematical model for microwave-injected power as function for temperature developed in copper wires that can be applied with success in further microwave bonding applications of copper wires. In addition, the electrical resistance of bonded wires was measured in order to collect feedback for improving the microwave bonding process.
- Published
- 2022
44. Simulation of Thermal Field in Eutectic Microwave Bonding for Electrical Connection of Photovoltaic Cells
- Author
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Ghelsingher, Cristian Daniel, Marin, Robert Cristian, Ştefan, Iulian, Sîrbu, Nicușor-Alin, Savu, Ionel Dănuț, David, Andrej, Savu, Sorin Vasile, and Olei, Adrian Bebe
- Abstract
Sustainable development requires green energy and low carbon footprint in manufacturing sector of photovoltaic systems. The electrical connections of photovoltaic cells need to have low electrical resistance in order to reduce the electrical losses and therefore to improve the performance of the photovoltaic panels. This paper aims to present researches related to bonding of wires that connect solar cells by using microwave technology. The microwave bonding has the main advantage that offers fast bonding but, in the same time, this technology does not offer stability of the thermal heating. Two different unwanted phenomena like thermal runaway and plasma arc discharge often lead to the damaging of copper and aluminum wires used in electrical connection. The study presented in this paper is focused on simulation of the thermal field developed in copper wires in order to optimize the bonding process and increase the quality of products. The simulation of the thermal field has been done using Fourier equations for conducting heating in copper materials and eutectic alloys. The simulation model has been validated through experimental heating using a 6 kW water-cooled microwave generator controlled by a matching load auto-tuner for best transfer of the power from generator to copper wires. The temperature has been measured in real time using an infrared pyrometer for metals with 2.3 μm spectral range and measurement range between 0o C and 7000 C. The study is finalized with elaboration of mathematical model for microwave-injected power as function for temperature developed in copper wires that can be applied with success in further microwave bonding applications of copper wires. In addition, the electrical resistance of bonded wires was measured in order to collect feedback for improving the microwave bonding process.
- Published
- 2022
- Full Text
- View/download PDF
45. Joining Photovoltaic Cell Connection Strips Using Ultra-Acoustic Wave - Resistive Hybrid Heating System
- Author
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Traian Țunescu, Andreea Filipciuc, Iulian Ştefan, Nicușor-Alin Sîrbu, Ionel Dănuț Savu, Andrej David, Sorin Vasile Savu, and Adrian Bebe Olei
- Subjects
General Engineering - Abstract
The manufacture of photovoltaic panels for the production of sustainable energy also involves the stage of electrical connection of the cells in the panel structure. This electrical connection is made by soldering of copper strips on the negative electrode of the cell. During the bonding process, due to the temperature of approximately 220-240°C at which the connecting strip is continuously heated, cracking processes of the upper layer of glass from the cell surface were identified. For this reason, it is necessary either to heat to lower temperatures, a solution that is not viable due to the melting temperature of the solder alloy which usually exceeds 210°C, or a different dosing of the heat flux. The solution proposed in the paper is to create a variable heat flux that allows the melting of the solder alloy, but at the same time to reduce the thermal load of the glass support layer. Through the proposed variant, the energy dosing is done with the help of a heating system consisting of two sources, an ultra-acoustic energy source and a classical resistive source. The resistive source provides an amount of energy to ensure a temperature in the range of 60-140°C, the difference to the melting point of the solder alloy being transferred locally by ultrasonic pulses. Research has highlighted the need to limit the range of values of the pressure of the circular sonotrode, which positively influences the mechanical stress of the photovoltaic cell, but also leads to a reduction in the joining speed. The dosing of the two components of the total energy, the one coming from the resistive source and the one coming from the ultra-acoustic vibration source is decisive for the efficiency of the joining process and for the quality of the soldered joint. Microscopic analyses revealed micro-cracks of the glass surface layer at forces higher than 100 N. Areas with lack of soldering for resistive heating at temperatures lower than 130oC were highlighted, the difference of 90-110°C being achieved by the contribution of ultra-acoustic energy.
- Published
- 2022
46. Joining Photovoltaic Cell Connection Strips Using Ultra-Acoustic Wave - Resistive Hybrid Heating System
- Author
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Țunescu, Traian, Filipciuc, Andreea, Ştefan, Iulian, Sîrbu, Nicușor-Alin, Savu, Ionel Dănuț, David, Andrej, Savu, Sorin Vasile, and Olei, Adrian Bebe
- Abstract
The manufacture of photovoltaic panels for the production of sustainable energy also involves the stage of electrical connection of the cells in the panel structure. This electrical connection is made by soldering of copper strips on the negative electrode of the cell. During the bonding process, due to the temperature of approximately 220-240°C at which the connecting strip is continuously heated, cracking processes of the upper layer of glass from the cell surface were identified. For this reason, it is necessary either to heat to lower temperatures, a solution that is not viable due to the melting temperature of the solder alloy which usually exceeds 210°C, or a different dosing of the heat flux. The solution proposed in the paper is to create a variable heat flux that allows the melting of the solder alloy, but at the same time to reduce the thermal load of the glass support layer. Through the proposed variant, the energy dosing is done with the help of a heating system consisting of two sources, an ultra-acoustic energy source and a classical resistive source. The resistive source provides an amount of energy to ensure a temperature in the range of 60-140°C, the difference to the melting point of the solder alloy being transferred locally by ultrasonic pulses. Research has highlighted the need to limit the range of values of the pressure of the circular sonotrode, which positively influences the mechanical stress of the photovoltaic cell, but also leads to a reduction in the joining speed. The dosing of the two components of the total energy, the one coming from the resistive source and the one coming from the ultra-acoustic vibration source is decisive for the efficiency of the joining process and for the quality of the soldered joint. Microscopic analyses revealed micro-cracks of the glass surface layer at forces higher than 100 N. Areas with lack of soldering for resistive heating at temperatures lower than 130oC were highlighted, the difference of 90-110°C being achieved by the contribution of ultra-acoustic energy.
- Published
- 2022
- Full Text
- View/download PDF
47. Effect of Varying Doping Level on Structural, Electrical and Optical Properties of Al Doped ZnO Spin Coated Films
- Author
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Basu, Sangita Rani and Mou, Sinthia Shabnam
- Abstract
The synthesis and characterization of spin-coated Al-doped ZnO (AZO) thin films with varying Al concentrations (0%, 5%, 10%, 15% and 20%) onto glass substrates have been demonstrated in this paper. The structural, electrical and optical properties of the spin-coated thin films have been investigated by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX) analysis, Van Der Pauw method and UV-visible spectroscopy. The EDX study shows well-defined peaks which confirm the presence of only Zn, O and Al and no other impurities in the films. The increase of Al and decrease of Zn weight percentages with increasing doping level confirms the effective substitution of Zn by Al. SEM of the surfaces of the films shows that undoped ZnO films contain particle agglomeration which is reduced with Al doping and the surfaces of the films gradually became more uniform. The thickness of the AZO films varied from 86 to 699 nm with increasing Al doping concentration. The electrical conductivity of the films increased up to ~ 7 × 10
-2 (Ω.cm)-1 due to doping with 5% Al concentration. The optical transmittance highly increased above 95% in the visible range with the introduction of Al dopant and it kept rising with the increase of Al concentration. The optical energy band gap of undoped ZnO increased from 3.275eV to 3.342 eV with 5% Al doping.- Published
- 2022
- Full Text
- View/download PDF
48. Effect of Varying Doping Level on Structural, Electrical and Optical Properties of Al Doped ZnO Spin Coated Films
- Author
-
Sangita Rani Basu and Sinthia Shabnam Mou
- Subjects
General Engineering - Abstract
The synthesis and characterization of spin-coated Al-doped ZnO (AZO) thin films with varying Al concentrations (0%, 5%, 10%, 15% and 20%) onto glass substrates have been demonstrated in this paper. The structural, electrical and optical properties of the spin-coated thin films have been investigated by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX) analysis, Van Der Pauw method and UV-visible spectroscopy. The EDX study shows well-defined peaks which confirm the presence of only Zn, O and Al and no other impurities in the films. The increase of Al and decrease of Zn weight percentages with increasing doping level confirms the effective substitution of Zn by Al. SEM of the surfaces of the films shows that undoped ZnO films contain particle agglomeration which is reduced with Al doping and the surfaces of the films gradually became more uniform. The thickness of the AZO films varied from 86 to 699 nm with increasing Al doping concentration. The electrical conductivity of the films increased up to ~ 7 × 10-2 (Ω.cm)-1 due to doping with 5% Al concentration. The optical transmittance highly increased above 95% in the visible range with the introduction of Al dopant and it kept rising with the increase of Al concentration. The optical energy band gap of undoped ZnO increased from 3.275eV to 3.342 eV with 5% Al doping.
- Published
- 2022
49. Electrochemical Properties of Layered LiMoO2 as Cathode for Li-Ion Batteries
- Author
-
Ai Fang Liu, Xiao Dong Wu, and Yu Lan Niu
- Subjects
General Engineering - Abstract
With the development of new energy vehicles, it is necessary to develope new fast charging cathode materials for lithium ion batteries. This paper reports a simple carbon thermal reduction routine to synthesize layered LiMoO2 cathode for Li-ion batteries. Impurity-free micro-crystalline powders were synthesized by one-step method with a thermal treatment at 800°C for 5 hrs under N2 atmosphere. The structural, morphological and electrochemical properties of LiMoO2 were characterized by using X-ray diffraction pattern (XRD), scanning electronic microscopy (SEM), charge/discharge cycling and electrochemical impedance spectroscopy (EIS). The diffraction results indicate that the prepared sample has a layered hexagonal structure related to α-NaFeO2. The secondary particles are in order of 2.0 μm length on average with homogeneous distribution. The initial discharge capacity of LiMoO2 is 110.9 mAh·g-1 at 0.1 C, and the capacity can still remain 92.8 mAh·g-1 after 100 cycles. The good cycling performance and high rate discharge performance are attributed to the smaller charge-transfer resistance revealed by EIS results.
- Published
- 2022
50. Electrochemical Properties of Layered LiMoO2 as Cathode for Li-Ion Batteries
- Author
-
Liu, Ai Fang, Wu, Xiao Dong, and Niu, Yu Lan
- Abstract
With the development of new energy vehicles, it is necessary to develope new fast charging cathode materials for lithium ion batteries. This paper reports a simple carbon thermal reduction routine to synthesize layered LiMoO
2 cathode for Li-ion batteries. Impurity-free micro-crystalline powders were synthesized by one-step method with a thermal treatment at 800° C for 5 hrs under N2 atmosphere. The structural, morphological and electrochemical properties of LiMoO2 were characterized by using X-ray diffraction pattern (XRD), scanning electronic microscopy (SEM), charge/discharge cycling and electrochemical impedance spectroscopy (EIS). The diffraction results indicate that the prepared sample has a layered hexagonal structure related to α-NaFeO2 . The secondary particles are in order of 2.0 μm length on average with homogeneous distribution. The initial discharge capacity of LiMoO2 is 110.9 mAh·g-1 at 0.1 C, and the capacity can still remain 92.8 mAh·g-1 after 100 cycles. The good cycling performance and high rate discharge performance are attributed to the smaller charge-transfer resistance revealed by EIS results.- Published
- 2022
- Full Text
- View/download PDF
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