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Underground hard rock (metal/non-metal) mining
Published in A.J.S. (Sam) Spearing, Liqiang Ma, Cong-An Ma, Mine Design, Planning and Sustainable Exploitation in the Digital Age, 2023
A.J.S. (Sam) Spearing, Liqiang Ma, Cong-An Ma
Examples of oxidizers are ammonium nitrate, calcium nitrate, sodium nitrate and black powder. Oxidizers are compounds which are capable of reacting with and oxidizing other materials. They “give” oxygen molecules to other materials, such as fuels, in which they burn and create gases and pressure.
Corrosion Induced Cracking of Reinforcing Steel
Published in J. Mietz, B. Elsener, R. Polder, Corrosion of Reinforcement in Concrete — Monitoring, Prevention and Rehabilitation, 2020
Nitrates in concrete result from storage of fertilisers and the presence of nitric oxides in the surrounding area of the construction. In cattle stables calcium nitrate (Ca(NO3)2) is produced by bacterial processes of components of liquid manure. Nitrates in the dissolved condition penetrate into the pore system of the concrete. During alternating wetting (absorption) more nitrates may penetrate into the interior of concrete than during immersion (diffusion) (Fig. 3).
Water Management
Published in L.B. (Bert) McCarty, Golf Turf Management, 2018
Gypsum applications. Gypsum is a by-product of phosphorus mining. Pure gypsum contains 26% Ca and 21% S; however, little of this is sold. Most commercial sources contain 50% to 90% CaSO4 with approximately 23% Ca. If gypsum contains impurities or is wet, it will contain less Ca and/or S and larger quantities will be necessary. For comparison, dolomitic limestone contains 21% to 30% Ca, calcitic limestone, 32% Ca, and calcium nitrate, 19% Ca.
A review on the synthesis and properties of hydroxyapatite for biomedical applications
Published in Journal of Biomaterials Science, Polymer Edition, 2022
V. G. DileepKumar, Mysore Santosh Sridhar, Pornanong Aramwit, Valentina K. Krut’ko, Olga N. Musskaya, Ilya E. Glazov, Narendra Reddy
Microwave synthesis has been found to be favourable for obtaining HAp with better yields, lesser reaction times and higher purity. Microwave synthesis of nano HAp has been particularly suitable for developing biomaterials and bioceramics as bone substitutes [46]. Various approaches and considerably different conditions have been used for the microwave synthesis of HAp (Figures 2 and 3) [46]. The chemical approach used and the conditions during the microwave synthesis substantially affect the structure and properties of the HAp obtained as seen from Tables 5 and 6. Simulated body fluid (SBF) was used to produce HAp from different sources of calcium using microwaves. SBF prepared with different ion concentrations was combined with calcium chloride, calcium nitrate tetra hydrate or calcium hydroxide and di-ammonium hydrogen phosphate as the phosporous source. pH of the solution was adjusted to 7.4 and treated in a microwave at 800 W for 15 min. Products formed were washed with water, precipitated and dried. Later, the material was heated at a temperature of 950 °C for 1 h at 5 °C/min. Schematic of the process used is shown in Figure 3 [59].
Designing of porous PMMA/diopside bone cement for non-load bearing applications
Published in Journal of Asian Ceramic Societies, 2020
Rajan Choudhary, Senthil Kumar Venkatraman, Inna Bulygina, Fedor Senatov, Sergey Kaloshkin, Sasikumar Swamiappan
Eggshell-derived calcium nitrate solution was utilized as a calcium source for the preparation of diopside. Eggshells were collected from VIT mess and washed under the running tap water to clean their surfaces. The bacterial contamination and unnecessary protein coatings were eliminated by boiling at 120°C for 3 hours with continuous stirring on a magnetic stirrer. The boiled eggshells were transferred to a sheet of tissue paper to absorb water droplets from the surface. Later, the eggshells were dried in a hot air oven at 150°C for a day. The dried eggshells were crushed and grinded manually to fine powders by using agate mortar and pestle. The powdered eggshell was further utilized to prepare a 1 M calcium nitrate solution by adding 37.5 ml of concentrated nitric acid to 25 gm eggshell powder. A sudden brisk effervescence giving foam-like appearance was noticed due to the liberation of carbon dioxide (CO2) and water (H2O). The foamy mixture was kept undisturbed for about 12 hours to facilitate the completion of the reaction. The unreacted content of the solution was separated by filtering through Whatman 41 filter paper. The resultant filtrate was collected in a standard flask and made up to 250 ml by using deionized water. The concentration of calcium ion in the stock solution was estimated by ethylenediaminetetraacetic acid (EDTA) titration by following the procedure mentioned elsewhere [24]. The estimated calcium ion concentration in the eggshell stock solution was observed to be 0.99 molar.
Effects of the nitrogen form ratios on photosynthetic productivity of poplar under condition of phenolic acids
Published in International Journal of Phytoremediation, 2023
Degang Fu, Liudong Zhang, Hui Li, Feng Li, Zongjie Yue, Yaobin Li, Qicheng Cai
The nitrogen treatments were based on the Hoagland’s nutrient solution. In Hoagland’s solution, the original ratio of NH4+:NO3− is 1:14 and the total nitrogen concentration is 15,000 μmol L−1. Then, the amount of nitrogen compounds (calcium nitrate tetrahydrate, potassium nitrate, and ammonium nitrate) were modified to adjust the Hoagland’s nutrient solutions to NH4+:NO3− ratios of 1:7 and 1:3. Thereafter, the three different phenolic acid solutions were combined with the three different nutrient solutions, resulting in nine different treatments (Table 2). These treatments were applied to the seedlings once per day (1,600 mL each time) form to 1st May to 30th July.