Ethanol and Water Adsorption in Conventional and Hierarchical All-Silica MFI Zeolites.

Hierarchical zeolites containing both micro- (<2 nm) and mesopores (2-50 nm) have gained increasing attention in recent years because they combine the intrinsic properties of conventional zeolites with enhanced mass transport rates due to the presence of mesopores. The structure of the hierarchical self-pillared pentasil (SPP) zeolite is of interest because all-silica SPP consists of orthogonally intergrown single-unit-cell MFI nanosheets and contains hydrophilic surface silanol groups on the mesopore surface while its micropores are nominally hydrophobic. Therefore, the distribution of adsorbed polar molecules, like water and ethanol, in the meso- and micropores is of fundamental interest.

Ogilvie Syndrome in a Refractory Germ Cell Tumor Treated with Vinblastine, Ifosfamide and Cisplatin Regimen.

Ogilvie syndrome or intestinal pseudo-obstruction is a clinical syndrome characterized by autonomic imbalance affecting peristalsis of colon leading to obstructive signs and symptoms. The etiologies commonly implicated are drugs affecting the cholinergic system, narcotics, electrolyte imbalance, severe sepsis, cancer, major surgery, and renal and cardiac failure. Ogilvie syndrome secondary to chemotherapy is a very rare phenomenon with very few reports in the literature.

First principles Monte Carlo simulations of unary and binary adsorption: CO, N, and HO in Mg-MOF-74.

Dative bonding of adsorbate molecules onto coordinatively-unsaturated metal sites in metal-organic frameworks can lead to unique adsorption selectivities. However, the distortion of the electron density during dative bonding poses a challenge for force-field-based simulations. Here, we report first principles Monte Carlo simulations with the PBE-D3 functional for the adsorption of CO2, N2, and H2O in Mg-MOF-74, and obtain accurate predictions of the unary isotherms without any of the adjustments or fitting often required for systems with strong adsorption sites.

Understanding the Reactive Adsorption of H S and CO in Sodium-Exchanged Zeolites.

Purifying sour natural gas streams containing hydrogen sulfide and carbon dioxide has been a long-standing environmental and economic challenge. In the presence of cation-exchanged zeolites, these two acid gases can react to form carbonyl sulfide and water (H S+CO ⇌H O+COS), but this reaction is rarely accounted for. In this work, we carry out reactive first-principles Monte Carlo (RxFPMC) simulations for mixtures of H S and CO in all-silica and Na-exchanged forms of zeolite beta to understand the governing principles driving the enhanced conversion.

Hydrogen Sulfide Capture: From Absorption in Polar Liquids to Oxide, Zeolite, and Metal-Organic Framework Adsorbents and Membranes.

Hydrogen sulfide removal is a long-standing economic and environmental challenge faced by the oil and gas industries. HS separation processes using reactive and non-reactive absorption and adsorption, membranes, and cryogenic distillation are reviewed. A detailed discussion is presented on new developments in adsorbents, such as ionic liquids, metal oxides, metals, metal-organic frameworks, zeolites, carbon-based materials, and composite materials; and membrane technologies for HS removal.

Identifying Optimal Zeolitic Sorbents for Sweetening of Highly Sour Natural Gas.

Raw natural gas is a complex mixture comprising methane, ethane, other hydrocarbons, hydrogen sulfide, carbon dioxide, nitrogen, and water. For sour gas fields, selective and energy-efficient removal of H2 S is one of the crucial challenges facing the natural-gas industry. Separation using nanoporous materials, such as zeolites, can be an alternative to energy-intensive amine-based absorption processes.

Monte Carlo Simulations Probing the Adsorptive Separation of Hydrogen Sulfide/Methane Mixtures Using All-Silica Zeolites.

Selective removal of hydrogen sulfide (H2S) from sour natural gas mixtures is one of the key challenges facing the natural gas industry. Adsorption and pervaporation processes utilizing nanoporous materials, such as zeolites, can be alternatives to highly energy-intensive amine-based absorption processes. In this work, the adsorption behavior of binary mixtures containing H2S and methane (CH4) in seven different all-silica zeolite frameworks (CHA, DDR, FER, IFR, MFI, MOR, and MWW) is investigated using Gibbs ensemble Monte Carlo simulations at two temperatures (298 and 343 K) and pressures ranging from 1 to 50 bar.

Development of the Transferable Potentials for Phase Equilibria Model for Hydrogen Sulfide.

The transferable potentials for phase equilibria force field is extended to hydrogen sulfide. The pure-component and binary vapor-liquid equilibria with methane and carbon dioxide and the liquid-phase relative permittivity are used for the parametrization of the Lennard-Jones (LJ) and Coulomb interactions, and models with three and four interaction sites are considered. For the three-site models, partial point charges are placed on the sites representing the three atoms, while the negative partial charge is moved to an off-atom site for the four-site models.

Effects of tobacco smoke condensate on estrogen receptor-alpha gene expression and activity.

Metallo-estrogens are a new class of potent environmental estrogens. This study investigates whether tobacco smoke condensate (TSC), which contains metals and metalloids, elicits estrogen-like effects at environmentally relevant doses. Treatment of human breast cancer cells, MCF-7, with 40 microg/ml TSC resulted in a 2.

Substance use among a sample of foreign- and U.S.-born southeast Asians in an urban setting.

Asian Americans (AA) are thought to have the lowest rates of substance use. This study examined substance use prevalence among 494 urban-dwelling Southeast Asians using snowball techniques. Prevalence estimates were age-adjusted proportionate to the U.