Topic Review
Supercritical Fluid Applications in Novel Antimicrobial Materials
The extraordinary properties of supercritical fluids such as high density, near-zero surface tension, and high diffusivities enable the uniqueness and numerous advantages of the materials obtained.  The application of supercritical fluids is a powerful tool in the development of novel materials with antimicrobial activity desperately needed in the time of increasing bacterial resistance to antibiotics and the dramatic appearance and spread of not only multidrug-resistant (MDR) but also pandrug-resistant (PDR) bacterial strains. MDR is defined as the resistance to at least one antibiotic from at least three different categories, while PDR is defined as non-susceptibility to all drugs in all antimicrobial categories.
  • 462
  • 06 Dec 2021
Topic Review
Supercritical CO2 Extraction
Supercritical CO2 extraction is a green method that combines economic and environmental benefits. Microalgae, on the other hand, is a biomass in abundance, capable of providing a vast variety of valuable compounds, finding applications in the food industry, cosmetics, pharmaceuticals and biofuels.
  • 410
  • 21 Feb 2023
Topic Review
Supercritical CO2 Power Technology
In the late 1960s, a handful of inspired researchers predicted the great potential of supercritical CO2 (“sCO2”) cycles for the production of electricity and highlighted the prospects for dramatic reductions in component sizes and efficiency increases. Since then, considerable development programs have been deployed around the world to “tame” this new technology. 
  • 179
  • 08 Mar 2024
Topic Review
Supercritical Carbon Dioxide(s-CO2) Power Cycle
Supercritical CO2 power cycles have been deeply investigated in recent years. However, their potential in waste heat recovery is still largely unexplored. This paper presents a critical review of engineering background, technical challenges, and current advances of the s-CO2 cycle for waste heat recovery. Firstly, common barriers for the further promotion of waste heat recovery technology are discussed. Afterwards, the technical advantages of the s-CO2 cycle in solving the abovementioned problems are outlined by comparing several state-of-the-art thermodynamic cycles. On this basis, current research results in this field are reviewed for three main applications, namely the fuel cell, internal combustion engine, and gas turbine. For low temperature applications, the transcritical CO2 cycles can compete with other existing technologies, while supercritical CO2 cycles are more attractive for medium- and high temperature sources to replace steam Rankine cycles. Moreover, simple and regenerative configurations are more suitable for transcritical cycles, whereas various complex configurations have advantages for medium- and high temperature heat sources to form cogeneration system. Finally, from the viewpoints of in-depth research and engineering applications, several future development directions are put forward. This review hopes to promote the development of s-CO2 cycles for waste heat recovery.
  • 1.5K
  • 25 Nov 2020
Topic Review
Supercritical Carbon Dioxide Flow and Heat Transfer Characteristics
Supercritical carbon dioxide (SCO2) is widely used in many fields of energy and power engineering, such as nuclear reactors, solar thermal power generation systems, and refrigeration systems. In practical applications, SCO2 undergoes a cooling process significantly when it is cooled near the pseudo–critical point.
  • 1.1K
  • 08 Dec 2022
Topic Review
Supercritical Antisolvent Technique for the Preparation of Nanocatalysts
In an era where sustainability is becoming the main driving force for research and development, supercritical fluids-based techniques are presented as a very efficient alternative technology to conventional extraction, purification, and recrystallization processes. Supercritical antisolvent (SAS) precipitation is a novel technique that can replace liquid antisolvent precipitation techniques. Additionally, through the optimization of precipitation operating conditions, morphology, particle size, and particle size distribution of nanoparticles can be controlled. As an antisolvent, supercritical carbon dioxide (scCO2) is far more sustainable than its conventional liquid counterparts; not only does it have a critical point (304 K and 73.8 bar) on its phase diagram that allows for the precipitation processes to be developed so close to room temperature, but also its recovery and, consequently, the precipitated solute purification stage is considerably simpler. This technique can be used efficiently for preparing nanocatalysts to be used in biodiesel production processes.
  • 1.1K
  • 21 Dec 2022
Topic Review
Superconductivity and Hydrogen Economy
Hydrogen as an energy carrier is a promising alternative to fossil fuels, and it becomes more and more popular in developed countries as a carbon-free fuel. The low boiling temperature of hydrogen (20 K or −253.15 °C) provides a unique opportunity to implement superconductors with a critical temperature above 20 K such as MgB2 or high-temperature superconductors. Superconductors increase efficiency and reduce the loss of energy, which could compensate for the high price of LH2 to some extent. Norway is one of the pioneer countries with adequate infrastructure for using liquid hydrogen in the industry, especially in marine technology where a superconducting propulsion system can make a remarkable impact on its economy. Using superconductors in the motor of a propulsion system can increase its efficiency from 95% to 98% when the motor operates at full power. The difference in efficiency is even greater when the motor does not work at full power.
  • 708
  • 19 Oct 2022
Topic Review
Supercapacitors
Supercapacitors are a category of energy-storage devices based on high-speed electrostatic or Faradaic electrochemical processes. The charge is mainly stored at the electrode−electrolyte interface of the active materials, such as high surface porous carbons, metal oxides, or conducting polymers. They consist of one positive electrode and one negative electrode soaked in an electrolyte and separated by an ion-permeable, electronically insulating separator.Compared with batteries, supercapacitors can supply much faster charge and discharge rates within seconds or minutes time scales but lower specific energy. Besides the high power densities, supercapacitors also have some other advantages over batteries, such as high operating safety, long cycling life, high efficiency, and high performance stability.
  • 678
  • 19 Feb 2021
Topic Review
Supercapacitor Applications and Developments
The storage of enormous energies is a significant challenge for electrical generation. Researchers have studied energy storage methods and increased efficiency for many years. In recent years, researchers have been exploring new materials and techniques to store more significant amounts of energy more efficiently. In particular, renewable energy sources and electric vehicle technologies are triggering these scientific studies. Scientists and manufacturers recently proposed the supercapacitor (SC) as an alternating or hybrid storage device.
  • 7.3K
  • 28 Mar 2022
Topic Review
Super Duplex Stainless Steel
In this present study, the influence of isothermal aging temperature and duration on microstructural and mechanical properties of a hot-deformed UNS S32750 Super Duplex Stainless Steel (SDSS) alloy was investigated by SEM-EBSD (Scanning Electron Microscopy-Electron Backscatter Diffraction) and tensile testing techniques. An isothermal aging treatment, at temperatures between (400 - 600)°C and treatment duration between (3 - 120)h, was applied to a commercial UNS S32750 SDSS alloy. Microstructural characteristics of all thermo-mechanical (TM) processed states, such as distribution and morphology of constituent phases, grain’s modal orientation (MO) and, obtained mechanical properties were analysed correlated with the TM processing conditions. Obtained experimental results show that the constituent phases, in all TM processed states, are represented by delta- and gamma-phases. SEM-EBSD analysis revealed microstructural modifications induced by TM processing, showing elongated gamma-phase grains within delta-phase matrix. Within the delta-phase matrix, dynamically recrystallized grains were identified as a result of applying hot deformation and isothermal aging treatments. Also, it was observed that aging treatment parameters can significantly influence the mechanical behaviour exhibited by the UNS S32750 SDSS alloy, in terms of elongation to fracture and absorbed energy during impact testing.
  • 1.8K
  • 29 Oct 2020
  • Page
  • of
  • 677
Video Production Service