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Pre-treatment, Concentration, and Enrichment of Precious Metals from Urban Mine Resources
Published in Sadia Ilyas, Hyunjung Kim, Rajiv Ranjan Srivastava, Sustainable Urban Mining of Precious Metals, 2021
Hyunjung Kim, Sadia Ilyas, Rajiv Ranjan Srivastava
When the two materials are placed in contact and then separated, negatively charged electrons are transferred from the surface of one material to the surface of the other. Which material loses electrons and which gains them will depend on the nature of the two materials. The material that loses electrons becomes positively charged, while the material that gains electrons is negatively charged. This imbalance of electrons produces an electric field that can be measured and that can influence other objects at a distance. Electrostatic discharge is defined as the transfer of charge between bodies at different electrical potentials. When two materials contact and separate, the polarity and magnitude of the charge are indicated by the materials’ positions in the triboelectric series. The triboelectric simply lists materials according to their relative triboelectric charging characteristics. When two materials contact and separate, the one nearer the top of the series takes on a positive charge and the other a negative charge. Materials further apart on the table typically generate a higher charge than ones closer together (Knoll et al., 1988; Bendimerad et al., 2009; Miloudi et al., 2011; Inculet et al., 1994; Higashiyama et al., 1997).
Field Applications
Published in Ahmad Shahid Khan, Saurabh Kumar Mukerji, Electromagnetic Fields, 2020
Ahmad Shahid Khan, Saurabh Kumar Mukerji
An electric (including electrostatic) field is a force field that acts upon material bodies by virtue of their property of charge. It is analogous to a gravitational field, which is also a force field that acts upon material bodies by virtue of their property of mass. The electrostatic (or static electric) fields may result due to the presence of stationary (or quasi-stationary) point charges, cluster of discrete charges, line charge, surface charge, or volume charge distribution. This field exerts a force on other (moving or stationary) charges. Although this electrostatically induced force appears to be weak, the magnitude of this force in a hydrogen atom between an electron and a proton is nearly 36 times (Ref: https://en.wikipedia.org/.../Electrostatics) stronger than the gravitational force acting between them. This category of field dwells around electric field intensity, electric flux density, electric potential, etc. As long as the field remains electrostatic in nature, these quantities have no relation with those involved in other categories, viz. magnetostatic and electromagnetic fields.
Nanoparticles for Nanorobotic Agents Dedicated to Cancer Therapy
Published in Nguyễn T. K. Thanh, Clinical Applications of Magnetic Nanoparticles, 2018
Mahmood Mohammadi, Charles Tremblay, Ning Li, Kévin Gagné, Maxime Latulippe, Maryam S. Tabatabaei, Sylvain Martel
Many techniques have been investigated and applied as encapsulation approaches, including mainly electrostatic spray, air jet, and microfluidic channel.44 The electrostatic spray has significant merits such as the possibility of sterile operation, small size particles, and ease of manipulation. Electrostatic force, also known as the Coulomb interaction or Coulomb force, is defined as the attraction or repulsion between two charged objects. Figure 17.3 shows a simple encapsulation setup by using the electrostatic force. When a high voltage is applied, the charge can be distributed on the meniscus surface of a liquid during droplets forming, which enables them to drop down from a needle tip with the help of electrostatic force.45 Therefore, the size of droplets can be decreased. A higher voltage means a higher electrostatic force and a smaller particle size. Using this method, the diameter of the particles can be scaled down to 200 μm. However, the liquid droplets can easily become a continuous flow jet if the surface tension is close to 0.46 In such a case, the droplets may break into small and uniform drops. As such, the voltage needs to be maintained at a proper scale depending on the distance of the needle tip and the liquid surface below.
Stability and interfacial rheology of oil-based foam with polydimethylsiloxane and natural rubber
Published in Journal of Dispersion Science and Technology, 2022
Huanxin Wang, Zhidong Chang, Wenli Luo, Bin Dong, Xinyuan Zou, Wenjun Liu, Sihang Ma, Hui Dang
The three directions of the simulation box were all periodic, and the COMPASS force field was selected. The system was geometrically optimized using the Smart algorithm and the maximum number of iterations was 20,000 steps. Both the electrostatic force and van der Waals force were atom based. The optimized system was simulated under the NVT ensemble (atomic number (N), volume (V) and temperature (T) unchanged). The initial velocity was set to random, the time step was 1fs, and the temperature control method was controlled at 298 K by the Nose method. The van der Waals interaction was calculated by an atom-based method with a cutoff radius of 12.5 Å, and the electrostatic interaction was calculated by the Ewald method. Save the complete trajectory and output one frame every 1ps until the system reached a fully balanced state. The total simulation time for each system was 1 ns.
On controlling of gas film shape in electrochemical discharge machining process for fabrication of elliptical holes
Published in Materials and Manufacturing Processes, 2021
Botcha Appalanaidu, Akshay Dvivedi
From Eq. (13), a relationship can be noticed between the electrostatic force, and IEG (h), Cd, and q. The amount of Cd and q is dependent on applied electrical energy. Hence, generated electrostatic force is a function of IEG and applied electrical energy. This implies that as the IEG decreases or electrical energy increases, the electrostatic force (FES) acting on the bubble increases and vice versa. During the ECDM process, this electrostatic force (FES) pulls the hydrogen bubble from the tool surface toward the counter electrode position. On the other hand, the surface tension force (Fsy) tries to hold the hydrogen bubble on the tool electrode surface. As the IEG decreases and electrical energy increases, the hydrogen bubble comes into the range of sphere of influence region of counter electrode charge. This increases the magnitude of electrostatic force acting on the hydrogen bubble. This phenomenon leads to the deformation of the bubble shape in the direction of the counter electrode or sometimes depart the hydrogen bubble from the tool electrode surface. The same effect is applied to all the bubbles, which are actively participating in gas film formation. This results in a deviation of the gas film in the same direction.
Building memory devices from biocomposite electronic materials
Published in Science and Technology of Advanced Materials, 2020
Xuechao Xing, Meng Chen, Yue Gong, Ziyu Lv, Su-Ting Han, Ye Zhou
In 2015, Wan et al. prepared an independent artificial synapse based on oxygen crystals on the chitosan membrane (Figure 8(a)) [109]. Under repeated high pulsed voltage, proton-related electrochemical doping occurred in the indium zinc oxide (IZO) channel layer, which caused the transition from short-term memory to long-term memory. When a positive synapse was applied on the gate, protons were driven laterally and accumulated at the chitosan/IZO channel interface. Owing to proton/electron electrostatic coupling, electrons accumulated and leakage current increased. When a pre-synaptic potential (0.1 V, 10 ms) was applied to the gate, and a voltage of 70 mV was applied between the source and drain for excitatory postsynaptic current (EPSC) measurement, EPSC reached a peak of 5.6 nA and gradually decayed to the initial value of 1.9 nA (Figure 8(b)). This EPSC behavior was very similar to the EPSC process in biological excitatory synapses. Interestingly, they also made pulse logic operations by this artificial synapse. When pulses were applied to one or two pre-synaptic inputs, post-synaptic current could be measured, and the positive and negative pulses on the control gate were used to adjust the logic function ‘OR’ or ‘AND’ (Figure 8(c,d)) [109].