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Showing 1 to 20 of 25 for “"ultrafine particles"”.
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Hydrophobic-Hydrophilic Separation Process for the Recovery of Ultrafine Particles
… REEs in the U.S. However, the valuable mineral particles in these resources are ultrafine in size, which poses considerable challenges to the most widely used fine particle beneficiation technique, i.e., froth flotation. A novel technology called the Hydrophobic-Hydrophilic Separation (HHS) …
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Precipitation of ultrafine particles using liquid antisolvent with concentric ultrasonic nozzle and subcritical CO2
… using subcritical CO_2 have been used to produce ultrafine particles of this drug. In liquid antisolvent precipitation, a combination of ultrasound, polymer and surfactant is used to precipitate ultrafine particles. Ultrasound is used to increase the nucleation rate by enhancing the micro mixing …
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Responses of respiratory system cells in vitro and in vivo to petrochemical combustion-derived ultrafine particles
Environmental contamination with airborne particles has been a human health concern for many years. Epidemiologic studies in urban communities have linked ambient particle exposure to various health effects, including chronic obstructive pulmonary disease, lung cancer, and several cardiovascular …
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Particle-chemical interactions and environmental chemodynamics of fine and ultrafine particles in a natural disaster scenario
The interactions of fine and ultrafine particles with chemicals play a dominant role in determining the mobility and availability of pollutants in the environment. Fine particles in sediments can sequester chemicals from the water column, and release volatile and semi-volatile organic compounds to …
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Design and Implementation of Mode Localised Resonant MEMS Oscillators for Gravimetric Sensing
… which is of the order of 10^(26) m, airborne ultrafine particles have a diameter of less than 100nm. The adverse impact of these ultrafine airborne particles on human health has been the focus of numerous clinical studies, including respiratory and cardiovascular diseases. Empirical results of …
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Miniaturization of Electrical Ultrafine Particle Sizers
<p>Nanoparticles, or ultrafine particles, have potential risks for human health, and the adverse health effects caused by ultrafine particles have been proven to be size related. To meet the increasing demanding for personal exposure monitoring and spatial distribution measurements of ultrafine …
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Advancement of the Hydrophobic-Hydrophilic Separation Process
… regarded as the best available technology for ultrafine particles separation. However, froth flotation has extreme deficiencies for recovering ultrafine particles that are less than 30-50 μm in size for coal and 10-20 μm for minerals. Furthermore, dewatering of flotation products is difficult …
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Development and implementation of a microresonator impactor for atmospheric particulate sensing
… to consistently size and count individual particles. OPCs have limitations, however, in their inability to detect ultrafine particles (considered the most influential to human health) or to measure particle mass directly (the standard metric for air quality). The growing field of …
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Measurement of particulate matter size, concentration and mass emissions from in-use heavy duty vehicles
… a subsequent reduction in particle size. These ultrafine particles are able to better penetrate the alveolar region where they can cause serious lung disorders. Alternative fuels such as compressed and liquefied natural gas (CNG and LNG) and the synthetic diesel fuel Mossgas are attractive in …
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The influence of land use on the quality of seston in southern Appalachian stream ecosystems
Seston is the complex of organic and inorganic particles suspended in the water column in stream ecosystems. This detrital pool is a significant vector of energy and nutrients from headwaters to the ocean. Many of the processes involved in seston generation in streams involve the terrestrial …
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Evaluation of Methods for Improving Classifying Cyclone Performance
… separation efficiency decreases dramatically for particles smaller than approximately 150 μm. In addition, classifiers commonly suffer from bypass, which occurs when a portion of the ultrafine particles (slimes) are misplaced by hydraulic carryover into the oversize product. The unwanted …
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The Production of Low Ash Coals Using the Hydrophobic-Hydrophilic Separation Process with Novel Developments
… as particle size is reduced. Because of this ultrafine particles are often discarded prior to froth flotation, and contributes to a substantial amount of coal waste in impoundments. An impoundment is a dam built using coarse reject to hold fine reject in slurry. Because of the land-use and …
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Development Of A Unified Approach (An Index) To Study The Particulate, Carbon Monoxide Emissions And The Combustion Efficiency Using Field And Laboratory Investigations
… that they didn’t use the surface area of the particles emitted from the cookstoves. As it has been established in the previous studies, the ultrafine particles have more surface area and therefore they interact with a large area of the human lungs. Therefore, surface area monitor was used to …
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Processing of Low Rank Coal and Ultrafine Particle Processing by Hydrophobic-Hydrophilic Separation (HHS)
… pertains to the processing of ultra-fine mineral particles and low rank coal using the hydrophobic--hydrophilic separation (HHS) method. Several explorative experimental tests have been carried out to study the effect of the various physical and chemical parameters on the HHS process. In this …
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The effect of flotation reagents on the coagulation and dewatering of flotation tailings
… collector or depressant only systems retained particles under 200 μm, whereas flocculant and coagulant systems had broader distributions (up to 1100 μm), which corresponded with effective sedimentation. To improve polymer adsorption performance, tailored reagent optimisation exploited optimal …
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Effects of combustion derived air pollution on vascular and fibrinolytic function in man
… diesel exhaust and concentrated ambient fine and ultrafine particles on vascular endothelial, endogenous fibrinolytic and myocardial function in healthy volunteers and patients with stable coronary artery disease. In total, forty-two healthy men and thirty-two patients with stable coronary artery …
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Measuring Aerosol Nanoparticles By Ultraviolet Photoionisation
… health. Mechanistic studies have indicated that ultrafine aerosol nanoparticles, those under 100 nm in diameter, may have significant health impacts due to their relatively high number concentration, surface area and potential for deep penetration into the human lung. However, epidemiological …
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Bubble Size Effects in Coal Flotation and Phosphate Reverse Flotation using a Pico-nano Bubble Generator
… recognized that the low-flotation efficiency of ultrafine particles is mainly due to the low probability of bubble-particle collision while the main reason for poor flotation recovery of coarse particles is the high probability of detachment of particles from the bubble surface.;Pico-nano bubbles …
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Development and Testing of a Mobile Pilot Plant for the Advancement and Scale-up of the Hydrophobic-Hydrophilic Separation Process
… and adaptable; however, it is inefficient for particles less than 20 microns. Owing to this limitation, some mining sectors, such as coal, opt to discard the ultrafine particles to waste impoundments as the costs to recover and dewater these materials are prohibitive. The Hydrophilic …
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Variability, origin and physical characteristics of dust aerosol in Iceland
… source consists of extreme numbers of close-to-ultrafine particles with a similar numbers as reported during the active eruptions. However, giant Icelandic particles (50 – 100 µm), can travel long distances. Suspended grains > 2 mm were captured during the severe dust storm after the …
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