Chlamydomonas reinhardtii NCBI:txid See: PubMed. Daphnia magna NCBI:txid Jones, Nathalie Dom, Julian L. Saccharomyces cerevisiae NCBI:txid Source: yeast. Escherichia coli NCBI:txid Homo sapiens NCBI:txid See: DOI. Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website.
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It is mandatory to procure user consent prior to running these cookies on your website. Tweet Share Share. This website uses cookies to enhance your user experience. The coated material can also permit control of the availability of nitrogen to the plant. Suplhur is an interesting coating material as it is water impervious, is used as a micronutrient with an important role in the development of many plants, is cheap and an is abundant industrial residue.
The objective of this work is to develop a process of coating urea with sulphur in a two-dimensional spouted bed and analyse the quality of the coated particles related to the process variables: temperature of the spout air and the mass flowrates of sulphur and atomized air. The surface of the coated particle was also analysed using an electronic microscope.
Rindt et al. They studied several cost-fertilizer combinations, but only the urea coated with sulphur showed the possibility of large-cale marketing. The first process for coating urea with sulphur was developed by TVA. This process consisted of five stages: the pre heating of urea, the coating of the urea particles in a rotary drum, where liquid sulphur was atomized on the particles, a second coating stage with wax to cover imperfections on the sulphur coating, which presented some holes through which the urea could be leached, the cooling of the coated product and the adequate conditioning of the product to avoid particle agglomeration.
The TVA process is mechanically complex and the investment and maintenance costs are high. Meisen and Mathur verified the possibility of using the spouted bed for coating urea with sulphur. A batch-operated pilot plant was developed and the particles were coated in a cone-cylindrical spouted bed. The authors concluded that product quality is a function of air temperature and that the product obtained was comparable to that of the TVA process for some fixed process conditions.
Weiss and Meisen modified the basic equipment used by Meisen and Mathur and related product quality to the operational conditions. Elementary sulphur was used as the coating material. Some of its physical properties are shown in Table 1 Sander, In this temperature range the melted sulphur is yellow. This behavior of the viscosity of sulphur in relation to temperature is explained by the modification of its molecular structure. The Sauter mean diameter was obtained by granulometric analysis in a standard sieve series and is 1.
A particle density of With these values and the density of the air, we could verify in Geldart's diagram that urea particles are classified as a group D powder, which justifies the choice of the spouted bed as the proper gas-solids contact.
The two-dimensional spouted bed was constructed of Plexi glass to allow the observation of particle movement. Bed dimensions followed the relations proposed by Kalwar et al. Figure 1 shows the two-dimensional spouted bed used in this work. The double-fluid atomizer was set at the bed base. The complete experimental assembly developed and constructed is shown in Figure 2.
Asked 5 years, 2 months ago. Active 8 months ago. Viewed 52k times. First, I found the total atomic weights of each element in this compound to find the percent composition: N: Improve this question. From the molecular formula there should be as many oxygen atoms as carbon atoms. There should be 4 times as many hydrogen atoms as carbon atoms.
There should be twice as many nitrogen atoms as carbon atoms. The only incorrect answer was for Nitrogen and only the exponent was wrong. Add a comment. Active Oldest Votes. Improve this answer. KeatonB KeatonB 3 3 silver badges 13 13 bronze badges. Vidyanshu Mishra Vidyanshu Mishra 1, 1 1 gold badge 13 13 silver badges 34 34 bronze badges. Oscar Lanzi Oscar Lanzi
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