Iodine-Rich Biocidal Reactive Materials

2013 ◽  
Vol 1521 ◽  
Author(s):  
Curtis E. Johnson ◽  
Kelvin T. Higa
Keyword(s):  
Average Particle Size ◽  
Amorphous Structure ◽  
Average Particle ◽  
Acid Solutions ◽  
Nitric Acid Solutions ◽  
Reactive Materials ◽  
Biocidal Products ◽  
Addition Rate ◽  
Mixed Material ◽  
Rapid Reaction

ABSTRACTThe objectives of this work are to prepare and characterize iodine-rich thermites and reactive materials for potential application in bio-agent defeat. Iodine-rich compositions were prepared using metal iodate oxidizers in combination with aluminum fuel. Higher iodine contents were achieved using iodine-rich additives, tetraiodoethylene and tin tetraiodide. Reactivity during rapid combustion was evaluated for both nanoscale and micron-scale materials. The nanoscale materials were evaluated directly using a spark-initiated pan dent test. The micron-scale materials were mixed with 50% of nano Al/MoO3 and also evaluated with the pan dent test. The results for the mixed material were shown to fit well to a linear combination of the expected dent for each component, based on a rapid reaction. Results of the pan dent test were used to down-select micron thermites for further testing. Bismuth iodate was synthesized by precipitation from nitric acid solutions. The average particle size was controlled by the addition rate, and sizes included 95 nm (amorphous structure), and 330 nm and 3 micron (both crystalline). Additional sizes were produced by ball milling the 3 micron material, giving 1 micron and 350 nm sizes. Fluoropolymers were included in some compositions to provide additional biocidal products, namely HF, that could be produced from reaction of AlF3 product with water.

Characterization of Industrial Wastes, Glass and Ceramic Wool

2012 ◽  
Vol 727-728 ◽  
pp. 1585-1590
Author(s):  
Neuza Evangelista ◽  
Jorge Alberto Soares Tenório ◽  
José Roberto Oliveira ◽  
Paulo R. Borges ◽  
Taiany Coura M. Ferreira
Keyword(s):  
Average Particle Size ◽  
Amorphous Structure ◽  
Glass Wool ◽  
Industrial Wastes ◽  
Average Particle ◽  
X Rays ◽  
Ceramic Fibers ◽  
High Concentrations ◽  
Reduction Of Energy Consumption ◽  
Superior Corrosion Resistance

Ceramic fibers are characterized by their light weight, high degree of purity, low heat storage, low thermal conductivity, thermal shock resistance and superior corrosion resistance in high-temperature environments. In addition, they can be produced extensively in substitution to all materials used in the coating of almost all heating equipment as well as contributing to the reduction of energy consumption. Such characteristics make them ideal in the coating of distributors, mufflers, heating ovens, among others, as highly demanded by the mining and metallurgical industries, among others. After use in the process of industrial production, generated waste will lose their insulation capacity and thus require safe disposal. The present work focuses specifically on ceramic and glass wools aiming at an evaluation of their recycling prospect of incorporation into cement mortars and concrete. This residues were pulverized and displayed ~30µm average particle size. The scan electronic microscopy (SEM) presented elongated, thin and straight particles, which is very different than flocular structure of cement. The X-rays diffraction revealed amorphous structure for glass wool and crystalline structure for ceramics wool. The chemical analysis showed high concentrations of Al2O3 and silica in both residues, with higher percentage of calcium oxide in glass wool.

The Method of Obtaining Amorphous Nanosized Silicon Dioxide from Rice Production Waste

2019 ◽  
Vol 23 (4) ◽  
pp. 30-35
Author(s):  
Ngo Hong Nghia ◽  
L.A. Zenitova ◽  
Le Quang Dien ◽  
Dao Ngoc Truyen
Keyword(s):  
Silicon Dioxide ◽  
Rice Husk ◽  
Black Liquor ◽  
Average Particle Size ◽  
Amorphous Structure ◽  
Rice Production ◽  
Raw Material ◽  
Production Waste ◽  
Average Particle ◽  
Naoh Solution

The method of using rice husk, which is a rice production waste, as a raw material for the production of silicon dioxide as an alternative to synthetic silicon dioxide – aerosil is considered. A low-energy process for extracting silicon dioxide and cellulose from the husk by alkaline digestion in an NaOH solution was proposed, followed by treating the black liquor with an acid solution and calcining the precipitate at 575 °C during 5 hours. The yield of inorganic products from rice husk is determined based on the ash content of the pulp. It was shown that the product obtained mainly consists of silicon dioxide (SiO2) of amorphous structure, has an average particle size of less than 100 nm, which makes it possible to characterize it as nanosilica. At the same time, silicon dioxide consists of 51.7 % silicon and 48.3% oxygen against theoretical amounts of 30.4 % silicon and 69.6 % oxygen, respectively. The output of silicon dioxide is 8.8 % by weight of rice husk. At the same time, the process allows to obtain another valuable nanocellulose product.

Uranium Metal Oxidation, Grinding, and Encapsulation in BoroBond®: TRU Waste Management

2011 ◽  
Author(s):  
Kevin S. Cook ◽  
Larry A. Addington ◽  
Beth Utley
Keyword(s):  
Hydrogen Generation ◽  
Average Particle Size ◽  
Average Particle ◽  
Fenton’S Reagent ◽  
Metal Oxidation ◽  
Standard Samples ◽  
Fenton's Reagent ◽  
Uranium Metal ◽  
Wear Rates ◽  
Addition Rate

Hydrogen generation mitigation for K Basin sludge was examined by encapsulation of uranium metal in BoroBond®, pre-oxidation of uranium metal with Fenton’s reagent and grinding of Densalloy SD170, an irradiated uranium metal surrogate. Encapsulation in BoroBond® resulted in pressure increase rates at 60 °C ranging from 0.116 torr/h to 0.186 torr/h compared to 0.240 torr/h for a uranium metal in water standard. Samples cast with higher water content led to increased rates. A Fenton’s reagent system consisting of a simple reagent mix of FeSO4·7H2O, H2O2 and HCl effectively oxidized 1/4″ cubes of uranium metal in under four days at room temperature. Increased peroxide addition rate, increased FeSO4·7H2O concentration and low pH all increase the corrosion rate. Densalloy SD170 with an average particle size of 581 μm with 7.63% of particles less than 90 μm was milled so that over 90% of the Densalloy mass measured less than 90 μm in 6 hours of milling. Acceptable wear rates were seen on wear components that were from standard materials (Nitronic SS and 440SS).

Application of Amorphous Nanoparticle Fe-B Magnetic Fluid in Wastewater Treatment

NANO ◽  
2019 ◽  
Vol 14 (09) ◽  
pp. 1950119 ◽  
Author(s):  
Chuncheng Yang ◽  
Mengchun Yu ◽  
Xiuling Cao ◽  
Xiufang Bian
Keyword(s):  
Wastewater Treatment ◽  
Magnetic Fluid ◽  
Magnetic Particles ◽  
High Efficiency ◽  
Removal Rate ◽  
Average Particle Size ◽  
Oxygen Demand ◽  
Amorphous Structure ◽  
Average Particle ◽  
High Concentration

Amorphous magnetic particles demonstrate excellent comprehensive properties and outstanding characteristics for numerous applications. In this report, magnetic crystalline Fe3O4 and amorphous Fe-B nanoparticles were successfully synthesized and introduced to prepare water-based magnetic fluids. The Fe3O4 and Fe-B particles are homogeneous nanoparticles with an average particle size of [Formula: see text][Formula: see text]nm. The shape of Fe-B amorphous nanoparticles is regular. The saturation magnetizations of Fe-B and Fe3O4 particles are 74 emu/g and 69 emu/g. The use of crystalline Fe3O4 magnetic fluid and amorphous Fe-B magnetic fluid in advanced treatment of high concentration organic wastewater was presented. The removal rate of chemical oxygen demand by using the amorphous Fe-B magnetic fluid reached 96%, about 16% higher than that by using the Fe3O4 magnetic fluid. Moreover, compared with Fe3O4 magnetic fluid, the treatment results demonstrate that the decolorizing effect by using the amorphous Fe-B magnetic fluid was 20% higher. It has been found that the nano-size Fe-B particles in magnetic fluid with amorphous structure led to high efficiency of wastewater treatment due to the catalytic activity.

Enhanced catalytic activity of low-Pt content nanocatalysts supported on hollow carbon spheres for the ORR in alkaline media

MRS Advances ◽  
2020 ◽  
Vol 5 (57-58) ◽  
pp. 2961-2972
Author(s):  
P.C. Meléndez-González ◽  
E. Garza-Duran ◽  
J.C. Martínez-Loyola ◽  
P. Quintana-Owen ◽  
I.L. Alonso-Lemus ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Anion Exchange ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Alkaline Media ◽  
High Catalytic Activity ◽  
Average Particle ◽  
Carbon Spheres ◽  
Hollow Carbon ◽  
Hollow Carbon Spheres

In this work, low-Pt content nanocatalysts (≈ 5 wt. %) supported on Hollow Carbon Spheres (HCS) were synthesized by two routes: i) colloidal conventional polyol, and ii) surfactant-free Bromide Anion Exchange (BAE). The nanocatalysts were labelled as Pt/HCS-P and Pt/HCS-B for polyol and BAE, respectively. The physicochemical characterization of the nanocatalysts showed that by following both methods, a good control of chemical composition was achieved, obtaining in addition well dispersed nanoparticles of less than 3 nm TEM average particle size (d) on the HCS. Pt/HCS-B contained more Pt0 species than Pt/HCS-P, an effect of the synthesis method. In addition, the structure of the HCS remains more ordered after BAE synthesis, compared to polyol. Regarding the catalytic activity for the Oxygen Reduction Reaction (ORR) in 0.5 M KOH, Pt/HCS-P and Pt/HCS-B showed a similar performance in terms of current density (j) at 0.9 V vs. RHE than the benchmark commercial 20 wt. % Pt/C. However, Pt/HCS-P and Pt/HCS-B demonstrated a 6 and 5-fold increase in mass catalytic activity compared to Pt/C, respectively. A positive effect of the high specific surface area of the HCS and its interactions with metal nanoparticles and electrolyte, which promoted the mass transfer, increased the performance of Pt/HCS-P and Pt/HCS-B. The high catalytic activity showed by Pt/HCS-B and Pt/HCS-P for the ORR, even with a low-Pt content, make them promising cathode nanocatalysts for Anion Exchange Membrane Fuel Cells (AEMFC).

A New Method for Direct Determination of the Recoilless Fraction with Application to Magnetic Nanoparticles

2002 ◽  
Vol 721 ◽  
Author(s):  
Monica Sorescu
Keyword(s):  
Room Temperature ◽  
Average Particle Size ◽  
Direct Determination ◽  
Average Particle ◽  
Lattice Method ◽  
Recoilless Fraction ◽  
Single Room ◽  
Magnetite Particles ◽  
Physical Mixtures

AbstractWe propose a two-lattice method for direct determination of the recoilless fraction using a single room-temperature transmission Mössbauer measurement. The method is first demonstrated for the case of iron and metallic glass two-foil system and is next generalized for the case of physical mixtures of two powders. We further apply this method to determine the recoilless fraction of hematite and magnetite particles. Finally, we provide direct measurement of the recoilless fraction in nanohematite and nanomagnetite with an average particle size of 19 nm.

Determination of grinding parameters of fenugreek seed

1970 ◽  
Vol 26 (1) ◽  
pp. 16 ◽  
Author(s):  
S Balasubramanian ◽  
Rajkumar Rajkumar ◽  
K K Singh
Keyword(s):  
Particle Size ◽  
Energy Consumption ◽  
Moisture Content ◽  
Specific Energy ◽  
Feed Rate ◽  
Average Particle Size ◽  
Specific Energy Consumption ◽  
Average Particle ◽  
Fenugreek Seeds ◽  
Fenugreek Seed

Experiment to identify ambient grinding conditions and energy consumed was conducted for fenugreek. Fenugreek seeds at three moisture content (5.1%, 11.5% and 17.3%, d.b.) were ground using a micro pulverizer hammer mill with different grinding screen openings (0.5, 1.0 and 1.5 mm) and feed rate (8, 16 and 24 kg h-1) at 3000 rpm. Physical properties of fenugreek seeds were also determined. Specific energy consumptions were found to decrease from 204.67 to 23.09 kJ kg-1 for increasing levels of feed rate and grinder screen openings. On the other hand specific energy consumption increased with increasing moisture content. The highest specific energy consumption was recorded for 17.3% moisture content and 8 kg h-1 feed rate with 0.5 mm screen opening. Average particle size decreased from 1.06 to 0.39 mm with increase of moisture content and grinder screen opening. It has been observed that the average particle size was minimum at 0.5 mm screen opening and 8 kg h-1 feed rate at lower moisture content. Bond’s work index and Kick’s constant were found to increase from 8.97 to 950.92 kWh kg-1 and 0.932 to 78.851 kWh kg-1 with the increase of moisture content, feed rate and grinder screen opening, respectively. Size reduction ratio and grinding effectiveness of fenugreek seed were found to decrease from 4.11 to 1.61 and 0.0118 to 0.0018 with the increase of moisture content, feed rate and grinder screen opening, respectively. The loose and compact bulk densities varied from 219.2 to 719.4 kg m-3 and 137.3 to 736.2 kg m-3, respectively.  

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