Oil Recovery in Low Temperature and Salinity Reservoir Rock Using Anionic and Anionic/Cationic Surfactant Formulations

As oil reserves are being depleted in the United States, there is an increasing need to recover the trapped oil in the reservoir rock which accounts for up to 60% of the total oil available. This oil may be recovered using chemical enhanced oil recovery (EOR) techniques. In our case study, we investigated viable EOR surfactant/polymer formulations for conditions conducive to high efficiency oil recovery in ultra-low salinity, low temperature, and high hardness reservoirs. Formulations were screened for Winsor Phase I (microemulsions) or Winsor Phase III (bicontinuous emulsions),: both of which are conducive to high efficiency oil recovery. Strong emulsion phase behavior at low salinities was observed in binary surfactant mixtures of anionic alkyl-alkoxy sulfates (at \u3e 16,000 ppm). Using a novel anionic/cationic formulation, emulsion phase behavior was observed at the ultra-low reservoir salinity of 10,000 ppm. These formulations demonstrate industrially viable surfactant/polymer formulations that can used for high efficiency EOR in low temperature-salinity and high hardness reservoirs within the continental United States and abroad

Dietary Strategies to Optimize Wound Healing after Periodontal and Dental Implant Surgery: An Evidence-Based Review

Methods to optimize healing through dietary strategies present an attractive option for patients, such that healing from delicate oral surgeries occurs as optimally as possible with minimal patient-meditated complications through improper food choices. This review discusses findings from studies that have investigated the role of diet, either whole foods or individual dietary components, on periodontal health and their potential role in wound healing after periodontal surgery. To date, research in this area has largely focused on foods or individual dietary components that may attenuate inflammation or oxidant stress, or foster de novo bone formation. These studies suggest that a wide variety of dietary components, including macronutrients and micronutrients, are integral for optimal periodontal health and have the potential to accelerate oral wound healing after periodontal procedures. Moreover, this review provides guidance regarding dietary considerations that may help a patient achieve the best possible outcome after a periodontal procedure

Optimal Surfactant Selection for Chemical Enhanced Oil Recovery in Low Temperature, Low Salinity, High Hardness Reservoirs

Based on the environmental properties of a crude oil reservoir, only 20-30 % of oil product can be recovered using primary and secondary extraction methods. The remaining stranded oil can only be recovered via various enhanced oil recovery methods. Chemical enhanced oil recovery (EOR) uses specialty chemicals to extract trapped oil in rock layers by generating in-situ microemulsion in the presence of reservoir brine and oil. In this case study, phase behavior tests are conducted for microemulsion formation between the surfactant solution and the oil. The phase behavior tests model reservoirs with low temperature and low salinity. In order to narrow the selection of surfactants for testing, phase behavior tests and interfacial tension experiments were used to determine the equivalent alkane carbon number (EACN) of the oil in this reservoir. Along with phase testing, extensive interfacial tension measurements were carried out with the model oil and the reservoir fluid at various salinities. The reservoir sample oil was determined to have an EACN of around 12, which effectively models the hydrocarbon part of the multicomponent crude oil similar to a dodecane system. These results facilitate in method development for EACN determination and in the selection of the surfactants that will create optimum emulsion for high efficiency oil recovery in low temperature and low salinity reservoirs typical to the Illinois basin in the United States

Contending cultures of counterterrorism: transatlantic divergence or convergence?

Terrorist attacks on the United States, Spain and the United Kingdom have underlined the differing responses of Europe and the United States to the 'new terrorism'. This article analyses these responses through the prism of historically determined strategic cultures. For the last four years the United States has directed the full resources of a 'national security' approach towards this threat and has emphasized unilateralism. Europe, based on its own past experience of terrorism, has adopted a regulatory approach pursued through multilateralism. These divergences in transatlantic approaches, with potentially major implications for the future of the relationship, have appeared to be mitigated by a revised American strategy of counterterrorism that has emerged during 2005. However, this article contends that while strategic doctrines may change, the more immutable nature of strategic culture will make convergence difficult. This problem will be compounded by the fact that neither Europe nor America have yet addressed the deeper connections between terrorism and the process of globalization

Are Supershells Powered by Multiple Supernovae? Modeling the Radio Pulsar Population Produced by OB Associations

Traditional searches for radio pulsars have targeted individual small regions such as supernova remnants or globular clusters, or have covered large contiguous regions of the sky. None of these searches has been specifically directed towards giant supershells, some of which are likely to have been produced by multiple supernova (SN) explosions from an OB association. Here we perform a Montecarlo simulation of the pulsar population associated with supershells powered by multiple SNe. We predict that several tens of radio pulsars could be detected with current instruments associated with the largest Galactic supershells (with kinetic energies >~ 10^{53} ergs), and a few pulsars with the smaller ones. We test these predictions for some of the supershells which lie in regions covered by past pulsar surveys. For the smaller supershells, our results are consistent with the few detected pulsars per bubble. For the giant supershell GSH 242-03+37, we find the multiple SN hypothesis inconsistent with current data at the 95% level. We stress the importance of undertaking deep pulsar surveys in correlation with supershells. Failure to detect any pulsar enhancement in the largest of them would put serious constraints on the multiple SN origin for them. Conversely, the discovery of the pulsar population associated with a supershell would allow a different/independent approach to the study of pulsar properties.Comment: accepted to ApJ; 17 pages, 2 figures, 1 tabl

Unravelling the Structure of Magnus' Pink Salt

A combination of multinuclear ultra-wideline solid-state NMR, powder X-ray diffraction (pXRD), X-ray absorption fine structure experiments, and first principles calculations of platinum magnetic shielding tensors has been employed to reveal the previously unknown crystal structure of Magnus’ pink salt (MPS), [Pt(NH3)4][PtCl4], study the isomeric Magnus’ green salt (MGS), [Pt(NH3)4][PtCl4], and examine their synthetic precursors K2PtCl4 and Pt(NH3)4Cl2·H2O. A simple synthesis of MPS is detailed which produces relatively pure product in good yield. Broad 195Pt, 14N, and 35Cl SSNMR powder patterns have been acquired using the WURST-CPMG and BRAIN-CP/WURST-CPMG pulse sequences. Experimentally measured and theoretically calculated platinum magnetic shielding tensors are shown to be very sensitive to the types and arrangements of coordinating ligands as well as intermolecular Pt–Pt metallophilic interactions. High-resolution 195Pt NMR spectra of select regions of the broad 195Pt powder patterns, in conjunction with an array of 14N and 35Cl spectra, reveal clear structural differences between all compounds. Rietveld refinements of synchrotron pXRD patterns, guided by first principles geometry optimization calculations, yield the space group, unit cell parameters, and atomic positions of MPS. The crystal structure has P-1 symmetry and resides in a pseudotetragonal unit cell with a distance of >5.5 Å between Pt sites in the square-planar Pt units. The long Pt–Pt distances and nonparallel orientation of Pt square planes prohibit metallophilic interactions within MPS. The combination of ultra-wideline NMR, pXRD, and computational methods offers much promise for future investigation and characterization of Pt-containing systems

Optical Spectroscopy Results for the Self-Magnetic Pinch Electron Beam Diode on the ITS-6 Accelerator.

Experiments have been conducted at Sandia National Laboratories' RITS-6 accelerator facility [1] (operating at 7.5 MV and 180 kA) investigating plasma formation and propagation in relativistic electron beam diodes used for flash x-ray radiography. High resolution, visible and ultraviolet spectra were collected in the anode-cathode (A-K) vacuum gap of the Self-Magnetic Pinch (SMP) diode [2-4]. Time and space resolved spectra are compared with time-dependent, collisional-radiative (CR) calculations [5-7] and Lsp, hybrid particle-in-cell code simulations [8,9]. Results indicate the presence of a dense (>1x1017cm-3), low temperature (few eV), on-axis plasma, composed of hydrocarbon and metal ion species, which expands at a rate of several cm/s from the anode to the cathode. In addition, cathode plasmas are observed which extend several millimeters into the A-K gap [10]. It is believed that the interaction of these electrode plasmas cause premature impedance collapse of the diode and subsequent reduction in the total radiation output. Diagnostics include high speed imaging and spectroscopy using nanosecond gated ICCD cameras, streak cameras, and photodiode arrays