Topic Review
Abrasive Wear of Cermets
Abrasive wear occurs when hard particles or sometimes hard protuberances on a counterface are forced against and are moved along the surface. The amount of material removed depends on the normal load pressing particles against the surface and the sliding distance. A distinction is usually made between the two-body and the three-body abrasive wear and between low-stress (abrasive particles remain unbroken during abrasion) and high-stress (abrasive particles are broken during the wear process) abrasion. WC-based hardmetals (cemented carbides) are employed widely as wear-resistant ceramic-metal composites for tools and wear parts. Raw materials supply, environmental concerns and some limitations of hardmetals have directed efforts toward development of alternative wear-resistant composites-cermets. Cermets consist primarily of ceramic particles such as titanium carbonitride (Ti(C,N)), titanium carbide (TiC), and chromium carbide (Cr3C2) bonded with alloys of Ni, Co or Fe. Cermets as resistant to abrasive wear materials demonstrate their potential mainly in environmentally severe wear conditions – at elevated temperatures and corrosive envronments.
  • 722
  • 10 Jan 2022
Topic Review
Accuracy Improvement in Double-Sided Incremental Forming Process
Low geometric accuracy is one of the main limitations in double-sided incremental forming (DSIF) with a rough surface finish, long forming time, and excessive sheet thinning. The lost contact between the support tool and the sheet is considered the main reason for the geometric error. Toolpath compensations strategies improve geometric precision without adding extra tooling to the setup. It relies on formulas, simulation, and algorithm-based studies to enhance the part accuracy. Toolpath adaptation improves the part accuracy by adding additional equipment such as pneumatically or spring-loaded support tools or changing the conventional toolpath sequence such as accumulative-DSIF (ADSIF) and its variants. It also includes forming multi-region parts with various arrangements. Toolpath adaptation mostly requires experimental trial-and-error experiments to adjust parameters to obtain the desired shape with precision. Material redistribution strategies are effective for high-wall-angle parts.
  • 705
  • 05 May 2022
Topic Review
Acer Aspire Laptops
Acer Aspire (stylized as Λspire or ΛSPIRE) is a series of personal computers by Acer Inc. aimed at the casual household user or for small business use. The Aspire series covers both desktop computers and laptops. Acer developed the series in order to cover from essentials to high performances. Many of the Aspire laptops, such as model 8920G, have built in Blu-ray drives, 5.1 audio outputs and transflective displays. Acer was the first to include these drives in laptops. Most Aspire laptops have water-resistant screens, such as the 1410 and the 5741 Z. In 2007, Acer introduced the Gemstone series that marked a milestone in the Acer Aspire line. As with many Windows laptops, different models may have different specification in different parts of the world.
  • 2.5K
  • 20 Oct 2022
Topic Review
Acer Predator
Predator Gaming is a gamer-focused brand and line of computer hardware owned by Acer. In 2008, Acer introduced itself in the gaming computer market with a line of desktop computers: the Acer Aspire Predator series, later renamed as Acer Predator. The series is characterized by the futuristic computer chassis and high performance. In 2016, a complete range of Predator desktops, gaming laptops, tablets and accessories exists. The range competes with Lenovo's Legion, Dell's G series and Alienware subsidiary, HP's Omen and Asus ROG series.
  • 1.4K
  • 20 Oct 2022
Topic Review
Achieving Sustainability in Solar Energy Firms in Turkey
Lean principles and sustainability are considered important terms in business. Solar firms are witnessing great competition to fulfill energy requirements, suffering from a huge amount of waste, negatively affecting the sustainability dimensions. Thus, the aim of the study is to build a framework for solar energy firms to achieve sustainability through adopting lean principles, which will help to fix many problems as waste and costs. The method included reviewing the literature to explore the founding of the relation between the two terms, and using a questionnaire that was directed to the responsible people in Turkish solar energy firms. The results of the survey were analyzed to: (1) Find out what the responsible people think about the two terms lean and sustainability; (2) Measure the probable relationship between lean principles and sustainability dimensions by applying a linear regression test; (3) Use the results of point number two to build the framework. The result showed there was a high level of relative importance about the two terms from the point of view of managers and experts in solar firms. In addition, the study found a relationship between adopting pull and flow principles of lean, and achieving economic and social dimensions of sustainability, this finding is represented in a framework. 
  • 482
  • 19 Jan 2022
Topic Review
Acid-Resistant Thin-Film Composite Nanofiltration Membrane
Membrane filtration technology has attracted extensive attention in academia and industry due to its advantages of eco-friendliness related to environmental protection and high efficiency. Polyamide thin-film composite nanofiltration (PA TFC NF) membranes have been widely used due to their high separation performance. Non-acid-resistant PA TFC NF membranes face tremendous challenges in an acidic environment. Novel and relatively acid-resistant polysulfonamide-based and triazine-based TFC NF membranes have been developed, but these have a serious trade-off in terms of permeability and selectivity. Hence, how to improve acid resistance of TFC NF membranes and their separation performance in acidic environments is a pivotal issue for the design and preparation of these membranes.
  • 578
  • 12 Jan 2023
Topic Review
Acoustic Emissions in Crack Detection
Acoustic emissions (AE) are becoming an important tool for hydraulic turbine failure detection and troubleshooting. In particular, artificial intelligence is a promising signal analysis research hotspot, and it has a great potential in the condition monitoring of hydraulic turbines using acoustic emissions as a key factor in the digitalisation process. 
  • 141
  • 01 Mar 2024
Topic Review
Acoustic Extinguishing
In the fire-extinguishing process, in principle, one of the components in the fire tetrahedron must be removed. For example, a natural gas fire occurring on a stovetop burner can be extinguished in various ways: Eliminating the fuel source by shutting off the gas supply may be the first option. Another option is to completely cover the flame to block any oxidizer that is present, such as oxygen in the air, during combustion.
  • 3.4K
  • 25 Mar 2022
Topic Review
Acoustic Metamaterials for Architectural and Urban Noise Mitigations
Owing to a steep rise in urban population, there has been a continuous growth in construction of buildings, public or private transport like cars, motorbikes, trains, and planes at a global level. Hence, urban noise has become a major issue affecting the health and quality of human life. In the current environmental scenario, architectural acoustics has been directed towards controlling and manipulating sound waves at a desired level. Structural engineers and designers are moving towards green technologies, which may help improve the overall comfort level of residents. A variety of conventional sound absorbing materials are being used to reduce noise, but attenuation of low-frequency noise still remains a challenge. Recently, acoustic metamaterials that enable low-frequency sound manipulation, mitigation, and control have been widely used for architectural acoustics and traffic noise mitigation. 
  • 1.5K
  • 28 Mar 2022
Topic Review
Acoustic Metamaterials in Aeronautics
Metamaterials, man-made composites that are scaled smaller than the wavelength, have demonstrated a huge potential for application in acoustics, allowing the production of sub-wavelength acoustic absorbers, acoustic invisibility, perfect acoustic mirrors and acoustic lenses for hyper focusing, and acoustic illusions and enabling new degrees of freedom in the control of the acoustic field. The zero, or even negative, refractive sound index of metamaterials offers possibilities for the control of acoustic patterns and sound at sub-wavelength scales. The potential of metamaterial-based technologies has recently caught the interest of the aeronautics community. Their effect in the presence of realistic flows in the surrounding domains, with boundary layer, turbulence, is currently a hot research topic. The interaction with flow requires a careful design of the metamaterial to avoid detrimental effects and enabling the device maximum capabilities in aeronautics.
  • 1.1K
  • 25 Jun 2021
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