181 research outputs found
Sustainability assessment of electrokinetic bioremediation compared with alternative remediation options for a petroleum release site
Sustainable management practices can be applied to the remediation of contaminated land to maximise
the economic, environmental and social benefits of the process. The Sustainable Remediation Forum UK
(SuRF-UK) have developed a framework to support the implementation of sustainable practices within
contaminated land management and decision making. This study applies the framework, including
qualitative (Tier 1) and semi-quantitative (Tier 2) sustainability assessments, to a complex site where the
principal contaminant source is unleaded gasoline, giving rise to a dissolved phase BTEX and MTBE
plume. The pathway is groundwater migration through a chalk aquifer and the receptor is a water supply
borehole. A hydraulic containment system (HCS) has been installed to manage the MTBE plume
migration. The options considered to remediate the MTBE source include monitored natural attenuation
(MNA), air sparging/soil vapour extraction (AS/SVE), pump and treat (PT) and electrokinetic-enhanced
bioremediation (EK-BIO). A sustainability indictor set from the SuRF-UK framework, including priority
indicator categories selected during a stakeholder engagement workshop, was used to frame the assessments.
At Tier 1 the options are ranked based on qualitative supporting information, whereas in Tier
2 a multi-criteria analysis is applied. Furthermore, the multi-criteria analysis was refined for scenarios
where photovoltaics (PVs) are included and amendments are excluded from the EK-BIO option. Overall,
the analysis identified AS/SVE and EK-BIO as more sustainable remediation options at this site than either
PT or MNA. The wider implications of this study include: (1) an appraisal of the management decision
from each Tier of the assessment with the aim to highlight areas for time and cost savings for similar
assessments in the future; (2) the observation that EK-BIO performed well against key indicator categories
compared to the other intensive treatments; and (3) introducing methods to improve the sustainability
of the EK-BIO treatment design (such as PVs) did not have a significant effect in this instance
Update of the Search for the Neutrinoless Decay
We present an update of the search for the lepton family number violating
decay using a complete CLEO II data sample of 12.6 million
pairs. No evidence of a signal has been found and the
corresponding upper limit is \BR(\tau \to \mu\gamma) < 1.0 \times 10^{-6}
at 90% CL, significantly smaller than previous limits. All quoted results are
preliminary.Comment: 9 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
Low-lying octupole isovector excitation in Nd-144
International audienceThe nature of low-lying 3− levels in Nd144 was investigated in the Nd143(n,γγ) cold neutron-capture reaction. The combination of the high neutron flux from the research reactor at the Institut Laue-Langevin and the high γ-ray detection efficiency of the EXILL setup allowed the recording of γγ coincidences. From the coincidence data precise branching ratios were extracted. Furthermore, the octagonal symmetry of the setup allowed angular-distribution measurements to determine multipole-mixing ratios. Additionally, in a second measurement the ultra-high resolution spectrometer GAMS6 was employed to conduct lifetime measurements using the gamma-ray induced Doppler-shift technique (GRID). The confirmed strong M1 component in the 33−→31− decay strongly supports the assignment of the 33− level at 2779keV as low-lying isovector octupole excitation. Microscopic calculations within the quasiparticle phonon model confirm an isovector component in the wave function of the 33− level, firmly establishing this fundamental mode of nuclear excitation in near-spherical nuclei
SARS-CoV-2 Spike triggers barrier dysfunction and vascular leak via integrins and TGF-β signaling
Severe COVID-19 is associated with epithelial and endothelial barrier dysfunction within the lung as well as in distal organs. While it is appreciated that an exaggerated inflammatory response is associated with barrier dysfunction, the triggers of vascular leak are unclear. Here, we report that cell-intrinsic interactions between the Spike (S) glycoprotein of SARS-CoV-2 and epithelial/endothelial cells are sufficient to induce barrier dysfunction in vitro and vascular leak in vivo, independently of viral replication and the ACE2 receptor. We identify an S-triggered transcriptional response associated with extracellular matrix reorganization and TGF-β signaling. Using genetic knockouts and specific inhibitors, we demonstrate that glycosaminoglycans, integrins, and the TGF-β signaling axis are required for S-mediated barrier dysfunction. Notably, we show that SARS-CoV-2 infection caused leak in vivo, which was reduced by inhibiting integrins. Our findings offer mechanistic insight into SARS-CoV-2-triggered vascular leak, providing a starting point for development of therapies targeting COVID-19
Determination of the Form Factors for the Decay B0 --> D*-l+nu_l and of the CKM Matrix Element |Vcb|
We present a combined measurement of the Cabibbo-Kobayashi-Maskawa matrix element and of the parameters , , and , which fully characterize the form factors of the decay in the framework of HQET, based on a sample of about 52,800 decays recorded by the BABAR detector. The kinematical information of the fully reconstructed decay is used to extract the following values for the parameters (where the first errors are statistical and the second systematic): , , , . By combining these measurements with the previous BABAR measurements of the form factors which employs a different technique on a partial sample of the data, we improve the statistical accuracy of the measurement, obtaining: and Using the lattice calculations for the axial form factor , we extract , where the third error is due to the uncertainty in
Study of the Exclusive Initial-State Radiation Production of the System
A study of exclusive production of the system through initial-state r adiation is performed in a search for charmonium states, where or . The mesons are reconstructed in the , , and decay modes. The is reconstructed through the decay mode. The analysis makes use of an integrated luminosity of 288.5 fb collected by the BaBar experiment. The mass spectrum shows a clear signal. Further structures appear in the 3.9 and 4.1 GeV/ regions. No evidence is found for Y(4260) decays to , implying an up per limit \frac{\BR(Y(4260)\to D \bar D)}{\BR(Y(4260)\to J/\psi \pi^+ \pi^-)} < 7.6 (95 % confidence level)
Measurement of CP observables in B± → D(⁎)K± and B± → D(⁎)π± decays
Measurements of CP observables in B ± →D (⁎) K ± and B ± →D (⁎) π ± decays are presented, where D (⁎) indicates a neutral D or D ⁎ meson that is an admixture of D (⁎)0 and D¯ (⁎)0 states. Decays of the D ⁎ meson to the Dπ 0 and Dγ final states are partially reconstructed without inclusion of the neutral pion or photon, resulting in distinctive shapes in the B candidate invariant mass distribution. Decays of the D meson are fully reconstructed in the K ± π ∓ , K + K − and π + π − final states. The analysis uses a sample of charged B mesons produced in pp collisions collected by the LHCb experiment, corresponding to an integrated luminosity of 2.0, 1.0 and 2.0 fb −1 taken at centre-of-mass energies of s=7, 8 and 13 TeV, respectively. The study of B ± →D ⁎ K ± and B ± →D ⁎ π ± decays using a partial reconstruction method is the first of its kind, while the measurement of B ± →DK ± and B ± →Dπ ± decays is an update of previous LHCb measurements. The B ± →DK ± results are the most precise to date
A search for the decay
We search for the rare flavor-changing neutral-current decay in a data sample of 82 fb collected with the {\sl BABAR}
detector at the PEP-II B-factory. Signal events are selected by examining the
properties of the system recoiling against either a reconstructed hadronic or
semileptonic charged-B decay. Using these two independent samples we obtain a
combined limit of
at the 90% confidence level. In addition, by selecting for pions rather than
kaons, we obtain a limit of using only the hadronic B reconstruction method.Comment: 7 pages, 8 postscript figures, submitted to Phys. Rev. Let
High-reflectivity broadband distributed Bragg reflector lattice matched to ZnTe
We report on the realization of a high quality distributed Bragg reflector
with both high and low refractive index layers lattice matched to ZnTe. Our
structure is grown by molecular beam epitaxy and is based on binary compounds
only. The high refractive index layer is made of ZnTe, while the low index
material is made of a short period triple superlattice containing MgSe, MgTe,
and ZnTe. The high refractive index step of Delta_n=0.5 in the structure
results in a broad stopband and the reflectivity coefficient exceeding 99% for
only 15 Bragg pairs.Comment: 4 pages, 3 figure
EuFeAs under high pressure: an antiferromagnetic bulk superconductor
We report the ac magnetic susceptibility and resistivity
measurements of EuFeAs under high pressure . By observing nearly
100% superconducting shielding and zero resistivity at = 28 kbar, we
establish that -induced superconductivity occurs at ~30 K in
EuFeAs. shows an anomalous nearly linear temperature dependence
from room temperature down to at the same . indicates that
an antiferromagnetic order of Eu moments with ~20 K persists
in the superconducting phase. The temperature dependence of the upper critical
field is also determined.Comment: To appear in J. Phys. Soc. Jpn., Vol. 78 No.
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