22 research outputs found
Characterization of Swirling Fluidized Bed
This dissertation is intended to conclude and summarize the overall milestone of Final Year Project, Characterization of Swirling Fluidized Bed. In recent years, the Swirling Fluidized Bed has been regarded as one of the novel designs in fluidization technology. This new technique features an annular-blade distributor which injects the fluidizing gas through a certain inclination, is capable of fluidizing the bed and at the same time causes swirling motion of particles in a circular trajectory. In the present work, the fluidization characteristics and hydrodynamics of a swirling bed are studied using experimental approach. The behavior of gas-particle interaction in a swirling bed in terms of operation regimes, trends of pressure drop across particle bed and hysteresis effects of bed pressure drop with increasing superficial velocity of gas, are explored by varying bed configurations. Three different sizes of spherical Polyvinyl chloride particle, two sizes in irregular shape and two sizes in cylindrical form, are used as bed material by considering four bed weights from 500 g to 2000 g, with increment of 500 g in each step, three blade overlap angles of 9°, 15° and 18°, for air superficial velocities up to approximately 3.5 m/s and two blade inclination of 10° and 15°. In this report, a well-structured review of the literature is constructed to compile the critical and substantive discoveries in the past researches. Furthermore, detailed research methodology and detailed analysis of experiment results are illustrated and expounded. The findings explicitly show that the solid particle size, shape, and bed weight are the major variables that give significant impact on the fluidized bed characteristics, while the blade dimension has relatively smaller effect on the bed behavior. This project has, hopefully, revealed how everything responds in SFB and this correlated relationship could be a precious benchmark in designing a reactor bed. As a conclusion, the research is intended to demonstrate the superiority of SFB over conventional bed. Through this exploration, the author sincerely hopes that this project will become an achievable reference volume for every practitioner in this field, spanning the boundary of various disciplines especially for fluidization engineering
Transient hydraulics and multiphase kick tolerance study to improve design of narrow margin well
Hydraulic and well control studies are the essential parts of well construction planning, especially for drilling of complex and challenging wells with narrow drilling margins. However, the complete applications of dynamic hydraulic analysis and multiphase kick tolerance studies in well design are scanty, which result in ineffective mud pressure management and extra cost spent on unnecessary casing strings, due to excessive emphasis on previous practices (steady-state model) with liberal sprinkling of safety factors. This research project was set out clearly to improve the well design for narrow margin field, in terms of hydraulics and well control. A deductive quantitative method constitutes major part of the research methodology, in which simulation of real case studies and interpretation were conducted. The dynamic hydraulics simulated equivalent circulating density (ECD) was compared with steadystate results in terms of accuracy and extensiveness in providing a good well design. In addition, the single bubble kick tolerance results which are commonly used by the industry in spreadsheet format were compared with the multiphase model results. Sensitivity studies were performed to understand the effect of each of the operational or well design parameters towards primary and secondary well control. As compared to steady-state hydraulics, transient model covers important parameters like pressure and temperature dependent fluid properties, thermophysical properties, detailed geometry description and operational effects, thus it is more representative to the operational ECD. Meanwhile, multiphase kick model is proven to be more effective for the evaluation of kick tolerance as it is able to provide the information of pressure development during a well control operation, from initial influx and shut-in until influx is circulated out of the well at the surface. This includes all phase transitions including dissolving of a gas kick in oil based mud and breakout of free gas when the gas contaminated mud reaches the bubble point at shallower depth in the well. The flow model is much more accurate and reliable than the over-conservative traditional single bubble theory
The genetic architecture of type 2 diabetes
The genetic architecture of common traits, including the number, frequency, and effect sizes of inherited variants that contribute to individual risk, has been long debated. Genome-wide association studies have identified scores of common variants associated with type 2 diabetes, but in aggregate, these explain only a fraction of heritability. To test the hypothesis that lower-frequency variants explain much of the remainder, the GoT2D and T2D-GENES consortia performed whole genome sequencing in 2,657 Europeans with and without diabetes, and exome sequencing in a total of 12,940 subjects from five ancestral groups. To increase statistical power, we expanded sample size via genotyping and imputation in a further 111,548 subjects. Variants associated with type 2 diabetes after sequencing were overwhelmingly common and most fell within regions previously identified by genome-wide association studies. Comprehensive enumeration of sequence variation is necessary to identify functional alleles that provide important clues to disease pathophysiology, but large-scale sequencing does not support a major role for lower-frequency variants in predisposition to type 2 diabetes
Jasper Heywood's translation of Seneca's Thyestes, with particular reference to the latter's sixteenth-century reception and the themes of tyranny, kingship and revenge
SIGLEAvailable from British Library Document Supply Centre-DSC:DXN023889 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Analysis of 6,515 exomes reveals the recent origin of most human protein-coding variants
Identification and Functional Characterization of G6PC2 Coding Variants Influencing Glycemic Traits Define an Effector Transcript at the G6PC2-ABCB11 Locus
Whole genome sequencing identifies structural variants contributing to hematologic traits in the NHLBI TOPMed program
Genome-wide association studies have identified thousands of single nucleotide variants and small indels that contribute to variation in hematologic traits. While structural variants are known to cause rare blood or hematopoietic disorders, the genome-wide contribution of structural variants to quantitative blood cell trait variation is unknown. Here we utilized whole genome sequencing data in ancestrally diverse participants of the NHLBI Trans Omics for Precision Medicine program (N = 50,675) to detect structural variants associated with hematologic traits. Using single variant tests, we assessed the association of common and rare structural variants with red cell-, white cell-, and platelet-related quantitative traits and observed 21 independent signals (12 common and 9 rare) reaching genome-wide significance. The majority of these associations (N = 18) replicated in independent datasets. In genome-editing experiments, we provide evidence that a deletion associated with lower monocyte counts leads to disruption of an S1PR3 monocyte enhancer and decreased S1PR3 expression