Separation science and technology

The focus of this project is the demonstration and advancement of membrane-based separation and destruction technologies. The authors are exploring development of membrane systems for gas separations, selective metal ion recovery, and for separation or destruction of hazardous organics. They evaluated existing polymers and polymer formulations for recovery of toxic oxyanionic metals such as chromate and arsenate from selected waste streams and developed second-generation water-soluble polymeric systems for highly selective oxyanion removal and recovery. They optimized the simultaneous removal of radioactive strontium and cesium from aqueous solutions using the new nonhazardous separations agents, and developed recyclable, redox-active extractants that permitted recovery of the radioactive ions into a minimal waste volume. They produced hollow fibers and fabricated prototype hollow-fiber membrane modules for applications to gas separations and the liquid-liquid extraction and recovery of actinides and nuclear materials from process streams. They developed and fabricated cyclodextrin-based microporous materials that selectively absorb organic compounds in an aqueous environment; the resultant products gave pure water with organics at less than 0.05 parts per billion. They developed new, more efficient, membrane-based electrochemical reactors for use in organic destruction in process waste treatment. They addressed the need for advanced oxidation technologies based on molecular-level materials designs that selectively remove or destroy target species. They prepared and characterized surface-modified TiO{sub 2} thin films using different linking approaches to attach ruthenium photosensitizers, and they started the measurement of the photo-degradation products generated using surface modified TiO{sub 2} films in reaction with chlorophenol

Perspectives on metaphyseal conservative stems

Total hip replacement is showing, during the last decades, a progressive evolution toward principles of reduced bone and soft tissue aggression. These principles have become the basis of a new philosophy, tissue sparing surgery. Regarding hip implants, new conservative components have been proposed and developed as an alternative to conventional stems. Technical and biomechanical characteristics of metaphyseal bone-stock-preserving stems are analyzed on the basis of the available literature and our personal experience. Mayo, Nanos and Metha stems represent, under certain aspects, a design evolution starting from shared concepts: reduced femoral violation, non-anatomic geometry, proximal calcar loading and lateral alignment. However, consistent differences are level of neck preservation, cross-sectional geometry and surface finishing. The Mayo component is the most time-tested component and, in our hands, it showed an excellent survivorship at the mid-term follow-up, with an extremely reduced incidence of aseptic loosening (partially reduced by the association with last generation acetabular couplings). For 160 implants followed for a mean of 4.7 years, survivorship was 97.5% with 4 failed implants: one fracture with unstable stem, 1 septic loosening and 2 aseptic mobilizations. DEXA analysis, performed on 15 cases, showed a good calcar loading and stimulation, but there was significant lateral load transfer to R3–R4 zones, giving to the distal part of the stem a function not simply limited to alignment. Metaphyseal conservative stems demonstrated a wide applicability with an essential surgical technique. Moreover, they offer the options of a “conservative revision” with a conventional primary component in case of failure and a “conservative revision” for failed resurfacing implants

Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at s=8 TeV

Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7  fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale

Searches for electroweak neutralino and chargino production in channels with Higgs, Z, and W bosons in pp collisions at 8 TeV

Searches for supersymmetry (SUSY) are presented based on the electroweak pair production of neutralinos and charginos, leading to decay channels with Higgs, Z, and W bosons and undetected lightest SUSY particles (LSPs). The data sample corresponds to an integrated luminosity of about 19.5 fb(-1) of proton-proton collisions at a center-of-mass energy of 8 TeV collected in 2012 with the CMS detector at the LHC. The main emphasis is neutralino pair production in which each neutralino decays either to a Higgs boson (h) and an LSP or to a Z boson and an LSP, leading to hh, hZ, and ZZ states with missing transverse energy (E-T(miss)). A second aspect is chargino-neutralino pair production, leading to hW states with E-T(miss). The decays of a Higgs boson to a bottom-quark pair, to a photon pair, and to final states with leptons are considered in conjunction with hadronic and leptonic decay modes of the Z and W bosons. No evidence is found for supersymmetric particles, and 95% confidence level upper limits are evaluated for the respective pair production cross sections and for neutralino and chargino mass values

Pushing the volcanic explosivity index to its limit and beyond: constraints from exceptionally weak explosive eruptions at Kīlauea in 2008

Estimating the mass, volume, and dispersal of the deposits of very small and/or extremely weak explosive eruptions is difficult, unless they can be sampled on eruption. During explosive eruptions of Halema'uma'u Crater (Kīlauea, Hawaii) in 2008, we constrained for the first time deposits of bulk volumes as small as 9–300 m³ (1 × 10⁴ to 8 × 10⁵ kg) and can demonstrate that they show simple exponential thinning with distance from the vent. There is no simple fit for such products within classifications such as the Volcanic Explosivity Index (VEI). The VEI is being increasingly used as the measure of magnitude of explosive eruptions, and as an input for both hazard modeling and forecasting of atmospheric dispersal of tephra. The 2008 deposits demonstrate a problem for the use of the VEI, as originally defined, which classifies small, yet ballistic-producing, explosive eruptions at Kīlauea and other basaltic volcanoes as nonexplosive. We suggest a simple change to extend the scale in a fashion inclusive of such very small deposits, and to make the VEI more consistent with other magnitude scales such as the Richter scale for earthquakes. Eruptions of this magnitude constitute a significant risk at Kīlauea and elsewhere because of their high frequency and the growing number of "volcano tourists" visiting basaltic volcanoes

Magma mixing and high fountaining during the 1959 Kīlauea Iki eruption, Hawai‘i

The 1959 Kīlauea Iki eruption provides a unique opportunity to investigate the process of shallow magma mixing, its impact on the magmatic volatile budget and its role in triggering and driving episodes of Hawaiian fountaining. Melt inclusions hosted by olivine record a continuous decrease in H2O concentration through the 17 episodes of the eruption, while CO2 concentrations correlate with the degree of post-entrapment crystallization of olivine on the inclusion walls. Geochemical data, when combined with the magma budget and with contemporaneous eruption observations, show complex mixing between episodes involving hot, geochemically heterogeneous melts from depth, likely carrying exsolved vapor, and melts which had erupted at the surface, degassed and drained-back into the vent. The drained-back melts acted as a coolant, inducing rapid cooling of the more primitive melts and their olivines at shallow depths and inducing crystallization and vesiculation and triggering renewed fountaining. A consequence of the mixing is that the melts became vapor-undersaturated, so equilibration pressures cannot be inferred from them using saturation models. After the melt inclusions were trapped, continued growth of vapor bubbles, caused by enhanced post-entrapment crystallization, sequestered a large fraction of CO2 from the melt within the inclusions. This study, while cautioning against accepting melt inclusion CO2 concentrations “as measured” in mixed magmas, also illustrates that careful analysis and interpretation of post-entrapment modifications can turn this apparent challenge into a way to yield novel useful insights into the geochemical controls on eruption intensity

Association of neighborhood characteristics with incidence of out-of-hospital cardiac arrest and rates of bystander-initiated CPR: Implications for community-based education intervention

Objective A 10-fold regional variation in survival after out-of-hospital cardiac arrest (OHCA) has been reported in the United States, which partly relates to variability in bystander cardiopulmonary resuscitation (CPR) rates. In order for resources to be focused on areas of greatest need, we conducted a geospatial analysis of variation of CPR rates. Methods Using 2010–2011 data from Durham, Mecklenburg, and Wake counties in North Carolina participating in the Cardiac Arrest Registry to Enhance Survival (CARES) program, we included all patients with OHCA for whom resuscitation was attempted. Geocoded data and logistic regression modeling were used to assess incidence of OHCA and patterns of bystander CPR according to census tracts and factors associated herewith. Results In total, 1466 patients were included (median age, 65 years [interquartile range 25]; 63.4% men). Bystander CPR by a layperson was initiated in 37.9% of these patients. High-incidence OHCA areas were characterized partly by higher population densities and higher percentages of black race as well as lower levels of education and income. Low rates of bystander CPR were associated with population composition (percent black: OR, 3.73; 95% CI, 2.00–6.97 per 1% increment in black patients; percent elderly: 3.25; 1.41–7.48 per 1% increment in elderly patients; percent living in poverty: 1.77, 1.16–2.71 per 1% increase in patients living in poverty). Conclusions In 3 counties in North Carolina, areas with low rates of bystander CPR can be identified using geospatial data, and education efforts can be targeted to improve recognition of cardiac arrest and to augment bystander CPR rates