China 
Africa 
Explore chapters and articles related to this topic
C
Published in Splinter Robert, Illustrated Encyclopedia of Applied and Engineering Physics, 2017
[astronomy/astrophysics, atomic] Radiation consisting of both electromagnetic energy as well as particles emerging from outer space as well as from the Sun. Cosmic rays consist of gamma rays, protons, alpha particles, neutrinos, and electrons next to a minor contribution from isotopes of heavy nuclei. The interaction of cosmic rays with atoms in the upper atmosphere of Earth generate excitation and decay effects next to scattering, which all result in (cascade of; depending on the incident energy) secondary radiation. The stream of particles and electromagnetic radiation reaching Earth from the Sun, the stars in our milky way as well as emission from other galaxies. The particles range in energy from 106 eV to in excess of 1022 eV and are composed of protons (~86%), helium nuclei (alpha particles; 12.7%), heavy nuclei (1.3%) as well as electrons (~1%) and a trace of electromagnetic radiation (depending on the interpretation). At the lower end of the scale, gamma rays released in the production of π0 eV mesons have an energy of approximately 105 eV, higher energies are in electrons and positrons, increasing to alpha particles (He2+). Additionally, neutrinos and a mixture of nuclei are also detected using methods including bubble–chamber. At the highest range the energetic content is dominated by protons at increasing velocity. The particle flux (“j”) for particle in excess of a specific threshold energy (E) is expressed as j(>E)=KcosmicE−δ, where Kcosmic and δ are positive constants in the energy regime described by the power lawE≥10GeV/nucleon.
A Review on Floc-Flotation of Fine Particles: Technological Aspects, Mechanisms, and Future Perspectives
Published in Mineral Processing and Extractive Metallurgy Review, 2023
Kaveh Asgari, Hamid Khoshdast, Fardis Nakhaei, Mohammad Reza Garmsiri, Qingqing Huang, Ahmad Hassanzadeh
The BAF device benefits from similar aspects to the ASH device. In this technique, the aeroflocs are generated in a bubble chamber called a liquid cyclone particle positioner (LCPP) (Figure 9) before they reach the tank. Since the pressurized air and flocculants are simultaneously introduced to the head of the LCPP, the produced aeroflocs have a very porous structure. Hence, the BAF chamber acts as an ancillary separator for the flocs and makes the possibility of the hydraulic flows with higher rates through the flotation cell (Colic et al. 2001). Compared to the ASH procedure, the BAF system can enhance the formation of final large flocs using a mixture of low-molecular-weight coagulants at relatively high energy and high-molecular-weight flocculants at relatively medium and low mixing energy. This improvement has led to an effective removal of particulate pollutants, smaller footprints, sludge with lower moisture content, more durability, higher flocs strength, rapid response, and a process without any recycling characteristics (Colic et al. 2001; Colic, Gotovac, and Lechter 2014).
Analysis of parallel flow type internally cooled membrane based liquid desiccant dehumidifier using neural networks approach
Published in Science and Technology for the Built Environment, 2022
Jaimon Dennis Quadros, S. A. Khan, Prashanth T.
Figure 3 depicts the IMLDD experimental setup. Prior to entering the IMLDD, the humidified air from the bubble chamber is combined with dry air. By modifying the blend ratio of the two air streams, the air humidity is controlled. The air is dehumidified using the desiccant solution from the solution tank, which then becomes ineffective. Concurrently, heat from the desiccant solution is removed by cooling water through absorption of water vapor from air. The experiments used a semi permeable membrane that consisted of two layers; ePTFE micro-porous hydrophobic layer and a PTE support layer. The ePTFE microporous layer inhibits the permeation of desiccant solution yet, enables the passage of water vapor. PTE nonwoven fibers tend to enhance the composite membrane's mechanical efficiency. Table 1 shows the functional and design specifications of the IMLDD.
Support vector regression-based modeling of cumulative infiltration of sandy soil
Published in ISH Journal of Hydraulic Engineering, 2020
Parveen Sihag, N. K. Tiwari, Subodh Ranjan
In the study, infiltration characteristics of soil are measured using a tension infiltrometer termed as mini disk infiltrometer (Decagon devices inc., 2014). As depicted in Figure 1, the mini disk infiltrometer having a total length of 32.7 cm, consists of upper and lower chambers separated by an air-tight chamber barrier. Both these chambers are filled with ordinary tap water manually. The 21.2-cm-long lower chamber is the water reservoir that contains the volume of water infiltrating into the soil. The upper chamber is the bubble chamber that provides the required suction head (0.50–7.0 cm) to the infiltrating water. The movable suction control tube (10.2-cm long) attached to the upper chamber can slide up and down to adjust the required tension. The mariotte tube which is 28-cm long transfers the suction head from the bubble chamber to the sintered steel disk. Sintered stainless steel disk is 4.5 cm in diameter and 3 mm in thickness, and acts as the interface through which water infiltrate into the sandy soil at a predetermined suction head. Having prepared the mini disk infiltrometer for experimentation, it is placed on the sandy soil surface for measuring infiltration characteristics. The time was considered zero and the time interval required for infiltrating a certain quantity of water was measured. The depth of water infiltering into the sandy soil (in cm) was obtained as volume of infiltrated water divided by the area of disk and the cumulative infiltration (cm) was works out.