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Nanomagnetic Actuation: Controlling Cell Behavior with Magnetic Nanoparticles
Published in Jeffrey N. Anker, O. Thompson Mefford, Biomedical Applications of Magnetic Particles, 2020
Particles range in size from a few tens of nanometers to several microns. Generally, smaller particles (10–300 nm) are used in studies that focus on targeting specific ion channels and for tissue engineering applications, while larger particles are used for investigations of cellular and cytoskeletal mechanical properties due to the larger forces that can be generated. In the case of magnetic twisting cytometry, the particles must be magnetically blocked in order to maintain their magnetization following the initial magnetizing pulse. For magnetite/maghemite, this equates to a diameter of roughly 30 nm or greater (however, micron-sized particles are generally used). Below this threshold, the particles behave as superparamagnets and do not preserve a stable remanent magnetization or experience a torque in the twisting field.
Environmental Ergonomics
Published in Robert W. Proctor, Van Zandt Trisha, Human Factors in Simple and Complex Systems, 2018
Robert W. Proctor, Van Zandt Trisha
We can improve air quality by one of two methods. We can use devices like high-energy particulate absorbing (HEPA) filters in air purifiers. These filters remove over 99% of particles of 0.3 micrometers (microns) diameter, and larger and smaller particles are filtered even better. (For reference, the HIV virus is 0.1 micron in diameter). Alternatively, the contaminated air can be diluted with outdoor air by increasing ventilation rates (Cunningham, 1990), assuming that the outdoor air is not also polluted. All ventilation systems work by bringing outdoor air inside the building, but different buildings will require higher or lower rates of air circulation. In the U.S., state building codes will state the amount of outdoor air required for specific applications, such as the combustion of wood, dry cleaning, painting, hospitals, and so forth.
Terms and Definitions
Published in Rick Houghton, William Bennett, Emergency Characterization of Unknown Materials, 2020
Rick Houghton, William Bennett
These small particles are measured in the scale of microns (one-millionth of a meter). A human hair can range from about 20 to 180 microns in diameter. Unaided visual resolution of 1–5 microns might be possible, but don’t count on it, even if lighting and contrast conditions are ideal. Particles of one micron or less are easily inhaled deep into the alveoli of the lungs, where they are barely divided from the bloodstream. Particles of approximately 10 microns lodge in the bronchioles, which can stimulate asthmatic symptoms. Sometimes a liquid is adsorbed onto a small particle to change its intended application, such as a liquid pesticide in powder form.
A novel asymmetric CDI device for targeted removal of cation in water desalination
Published in Environmental Technology, 2023
Chang Liu, Xiaoying Ma, Lan Ma, Yongyi Xu, Feng Wang, Luyue Huang, Shuangchen Ma
Figure 3(a) shows the SEM image of activated carbon, it can be found that the activated carbon is composed of irregular particles and varies greatly in structure. The particle size ranges from a few microns to several tens of microns. The morphology has a lamellar scale structure and the high specific surface area of activated carbon is attributed to the concave and convex structure of the surface [36]. Figure 3(b) shows the SEM image of the surface of the electrode material, it can be seen that many spherical particles have been added, which are formed by the addition of carbon black and PVDF and heated at high temperature. It increases the specific surface area whilst enhancing the electrical conductivity. After the surface analyser test, the BET surface area of the material is measured as 321.14 m²/g, the micropore volume is 0.097 cm³/g and the average pore size is 1.2 nm; the parameters are shown in Table 1. This pore structure may lead to electric double layer overlap during the electro-sorption process [37].
Investigation of suspended particle size effects on clogging of soil filters under laminar flow
Published in European Journal of Environmental and Civil Engineering, 2022
Sahar Banihashem, Mohsen Karrabi
Diffusion is the transference resulted by random Brownian motion due to the collisions of water molecules and particles. This mechanism is important for particles smaller than 1 micron (particle size is close to the size of water molecules). The deposition mechanism is caused by the gravity and relates to particle sedimentation rate that leads to passing the particle through stream lines and reaching the Collector. Particle density plays an important role in this mechanism and for particles larger than 1 micron. Interception occurs when the particles move along the stream lines close enough to the Collector to attach it. The mechanism of hydrodynamic process is caused by particle rotation and its movement across the stream lines and highly depends on particle form and its interaction with fluid. Inertia is also a mechanism for air filtration and is negligible for water filtration (Amirtharajah, 1988; Ives, 1982).
CFD simulations of single-phase flow in settling tanks: comparison of turbulence models
Published in Indian Chemical Engineer, 2020
Amol V. Ganjare, Ashwin W. Patwardhan
The single-phase steady-state simulations are performed using the SIMPLE algorithm. The SIMPLE algorithm is well developed for a single-phase flow [36]. The secondary phase in the settling tanks is the suspended particles. The loading of the suspended particles is usually low (1–5%). The size of the particles is usually in the range of 10–100 microns. Particles with low loading and small particle size do not affect the primary phase in the settling tanks. Therefore, single-phase simulations can be performed.