CHEMISTRY OF THE ADSORPTION OF CARBON DIOXIDE BY ARGONNE PREMIUM COALS AND A MODEL TO SIMULATE CO2 SEQUESTRATION IN COAL SEAMS

The interactions of CO2 with coal were investigated under a set of conditions to determine the effects of the nature of the coal and the sequestration environment including parameters such as rank and moisture content of the coal, the temperature, pressure, and pH. A mathematical model was also developed to simulate the coal bed methane production and the CO2 sequestration processes. The excess adsorption and desorption isotherms of CO2 on eight Argonne Premium coal samples were measured using the volumetric method. The isotherms were found to be rectilinear and fit to the conventional adsorption model equations poorly due to the coal swelling. An adsorption isotherm equation was derived to account for the volumetric changes and significantly better fits were obtained. Upon drying, the volume of coals was determined to shrink, which was about 2% to 5% for medium and high rank coals, and up to 40% for the low rank coals. The swelling of coals during adsorption isotherm measurements in CO2 was estimated to be about the same as the shrinkage that occurred during the moisture loss. If the swelling was not included in the adsorption isotherm equation, the reported adsorption capacities and surface areas of the coals were overestimated by about 15%. The adsorption capacities of moisture-free Argonne coals were found to be about 2.2 ± 0.8 mmole/g-coal, daf basis and to be lower in wet coals. The isosteric heat of adsorption for CO2 on Argonne coals was estimated to be about 25±2 kJ/mole, regardless of the coal rank. The adsorption capacity of CO2 on the weak solutions of acid leached coals was higher than both the base leached and untreated coals, possibly due to the removal of ash content of the coals. The modeling results developed to simulate the CO2 injection process suggest that the CO2 can be injected at a rate of about 10*103 standard m3 per day. The injected CO2 will reach the production well, which is separated from the injection well by 826 m, in about 30 years. During this period, about 160*106 Sm3 of CO2 can be stored within a 2.14 (km)2 coal seam

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

Relations between Post-traumatic Stress Disorder, Dissociation and Attention-Deficit/Hyperactivity Disorder among Earthquake Survivors

Дипломний проект викладено на 108 сторінках пояснювальної записки та містить 74 таблиці, 3 рисунка, 3 додатки, 46 інформаційних джерел. Графічний матеріал 4 аркуша. Розроблено рецептуру та технологію безглютенового супу-пюре з використанням амарантового борошна. Визначена структурно-технологічна схема підприємства, розроблена виробнича програма ресторану. На основі розрахунків визначені технологічне обладнання, склад та площі приміщень. Розроблено організаційну структуру та об’ємно-планувальне рішення підприємства, інженерно-будівельні рішення, заходи щодо охорони праці та безпеки в надзвичайних ситуаціях. Об’єкт дослідження: ресторан. Предмет дослідження: технологічні розрахунки; архітектурно-будівельні рішення; заходи щодо охорони праці

Contributory roles of concentration and pH in CaCO3 growth inhibition by additive Ca2+ ions

CaCO3 particles grow excessively upon chemical precipitation in the absence of impurities or growth inhibitors. Additive Ca2+ ions have been shown to preferentially adsorb on CaCO3 precipitates, effectively inhibiting their growth and promoting the crystallization of pure calcite without an observable intermediate phase. This phenomenon can be adapted towards the synthesis of small calcite particles from a conventional chemical precipitation method. Complementing such effort, this study discusses the influence of additive Ca2+ ions concentration and solution pH on the extent of CaCO3 growth inhibition. Equal volumes of equimolar CaCl2 and Na2CO3 solutions were mixed in a tubular reactor at a constant flowrate. The precipitates were continuously dispersed in Ca(OH)2 solution, where Ca2+ ions irreversibly adsorb on their surfaces. Compared to conditions where additive Ca2+ ions are absent, this method can produce more than 90% decrease in particle size. The results show the degree of growth inhibition increases as the concentration of additive Ca2+ ions increase. However, it is limited by increasing volume of precipitates. This study also reveals an unusual role of media pH. Here, growth inhibition that leads to the synthesis of monodisperse submicron CaCO3 particles is only observed in high alkaline pH conditions. This is due to the hydration of additive Ca2+ ions in low pH conditions. While additive Ca2+ ions adsorb on CaCO3 precipitates in pH conditions above the isoelectric point (pH ≈ 9), their ability to limit CaCO3 growth diminishes when pH < 12