Low-Pressure Phase Equilibria of Heavy Aromatic Compounds.

Phase equilibrium diagrams for systems containing compounds found in coal liquids and heavy crude oil are useful in designing separation processes and also in testing and developing of thermodynamic models. Solid-liquid equilibrium (SLE) data are easy to obtain compared with vapor-liquid equilibrium (VLE) data for systems that are solid near room temperature, because the solids melt to liquids and have relatively high boiling points. It may be possible to extrapolate activity coefficients derived from SLE data to higher temperatures and thus predict vapor-liquid equilibrium. This dissertation presents new SLE and VLE data for compounds related to coal liquids. The problem of obtaining VLE data from SLE data is investigated. Vapor-liquid equilibrium data were measured at 170 and 190\sp\circC for 15 binary and 8 ternary systems containing polynuclear aromatic compounds. Binary VLE data were correlated using five different activity coefficient models and regular solution theory to determine the non-ideality of the liquid mixtures. Ternary vapor-liquid equilibrium data were predicted using the interaction parameters obtained from regression of binary data for the UNIQUAC, Wilson, and regular solution theory models. Solid-liquid equilibrium data were also measured for five systems containing the same compounds. These solid solubility data along with one vapor-liquid point were used to predict the vapor-liquid equilibrium curve for each binary system. SLE and VLE data were also combined to determine global parameters valid from 298 to 463 K. Finally, experimental studies and predictions of the solid-liquid phase diagram of ternary systems containing two solutes were also carried out. The study of such phase diagrams is an important tool in analyzing various chemical engineering processes such as crystallization and extraction

Functional Analysis of \u3cem\u3eSquamosa-Promoter\u3c/em\u3e Binding \u3cem\u3eProtein Like 13\u3c/em\u3e in Controlling Flowering Time, Plant Architecture, Grain Size, and Grain Number in Wheat

Higher and stable yield is always a major objective of wheat genetic improvement programs. The SQUAMOSA-promoter binding protein-like (SPL) genes constitute a small family of plant-specific transcription factors with diverse functions in plant development and growth and have great potential in improving yield and other major agronomic traits. However, the functional characterization of the SPL gene family in wheat is far behind other cereal crops such as rice. Using phylogenetic analysis, we identified 56 wheat orthologues of rice SPL genes belonging to 19 homoeologous groups. Among these 19 orthologous TaSPL genes, nine harbor the micro RNA 156 recognition element (MRE) in their last exon except for one gene, TaSPL13, which harbors the MRE in 3’-untranslated region (UTR). We edited the MRE of TaSPL13 using CRISPR-Ca9 and generated 11 mutations in three homoeologous genes. CRISPR mutations of 10- and 25-bp deletions in MRE increased the expression of TaSPL13-A by ~1.7 and 1.9-fold, respectively, and two 1-bp insertion mutations in MRE upregulated the expression of TaSPL13-B by 2.25-fold compared to wildtype (WT). Phenotypic evaluation showed that the 1-bp insertion mutations in TaSPL13-B has the highest impact on decreasing days to flowering, tiller number, and plant height, and has positive effects on grain size and grain number. In terms of flowering time, the expression of wheat Vernalization 1 gene, which is orthologous to flowering gene APETALA 1 of Arabidopsis, was upregulated by 2.3-fold in the double mutant TaSPL13-ab, which combined the 5-bp deletion in TaSPL13-A and the 1-bp insertion in TaSPL13-B. Our results demonstrate the pleiotropic effects of TaSPL13 mutants in wheat and functional conservation among the orthologous SPL gene between wheat and the model plants Arabidopsis and rice. The TaSPL13 holds great potential in improving wheat yield by simultaneously increasing grain size and number. The novel mutations generated in the homeologs can be utilized in wheat breeding programs to improve these agronomic traits. While working with the CRISPR-Cas9 technique we developed a new and simple protocol for cost-effective genotyping of CRISPR mutations. Simultaneously, we discuss the advantages and pitfalls of various genotyping platforms such as mismatch cleavage assay, restriction enzyme assay, ribonucleoprotein assay, and Sanger sequencing. The case study-based approach provides details about the methods and can act as a guide to screen CRISPR mutations in wheat

Gas Convective and Overall Heat Transfer Coefficient for a Vertical Tube Immersed in a Gas - Solid Fluidized Bed

Experimental data were obtained for the average gas convective and overall heat transfer coefficients for a vertical tube immersed in a fluidized bed containing four narrowly distributed particle size mixtures. Silica sand of weight-mean diameters ranging from 0.237 to 1.350 mm was used as the bed material. The static bed height was maintained at about 21 cm. The gas convective heat transfer coefficient was determined by measuring the amount of naphthalene sublimated from a vertical naphthalene tube of 0.0262 m in diameter and using an analogy between heat and mass transfer. The data were obtained at a bed temperature of about 333 K and superficial gas velocities of 0.1 to 1.1 m/s. The overall heat transfer coefficient was measured by placing a vertical heater ( D = 0.0262 m, L = 0.1012 m ) t h in the fluidized bed of average temperature 333 K and having fluidizing velocity of 0.1 to 1.1 m/s. The experimental data were examined using existing correlations. The gas convective heat transfer coefficient calculated using the correlation proposed by Xavier and Davidson (13) predicted the data within 25 percent. The overall heat transfer coefficients were compared with many existing correlations and models. The Martin (Z2) and Xavier and Davidson (13 ) models, and Wender and Cooper (^8) correlation predicted the data within 35 percent. However, for maximum overall heat transfer coefficient all of the four correlations (25^, 3j3, £0, ^1) are found to be reliable within 35 percent. The gas convective and overall heat transfer coefficients were also obtained for widely distributed particle size mixtures. Two base particle sizes were selected (d = 0.896 and 1.350 mm). Mixtures containing 5, P 10, and 23 percent by weight of fines (0.237 mm) were prepared using 0.896 mm particles, and 10 and 34 percent of 0.545 mm sand were mixed with 1.350 mm particles. The average bed temperature was maintained at 333 K and the fluidizing velocity was varied from 0.45 to 0.95 m/s. The value of gas convective and overall heat transfer coefficients from the data were compared with the existing correlations. The correlations proposed by Xavier and Davidson (JU3) and Baskakov and Suprun (21) were found to predict the data well within 27 percent for the gas convective heat transfer. For the overall heat transfer coefficient, the Xavier and Davidson (^3) and Martin (22 ) model and Wender and Cooper (J3J3) correlation were recommended to predict the data within 32 percent. However, for maximum heat transfer coefficient all of the four correlations (2 5 3_9, 40^, _41) were good within 30 percent. Finally, using the experimental data for narrowly and widely distributed particle size mixtures, the contribution of the gas convective heat transfer coefficient to the overall heat transfer coefficient was determined. It was observed that this contribution becomes significant at high gas velocities and velocities close to minimum fluidization