We discuss the effects of medium polarization on nuclear pairing in the context of the relativistic Hartree–Fock–Bogoliubov (HFB) approximation in the
σ
–
ω
model. The medium polarization effects on ...the scalar and vector meson masses, and on the pairing gap are shown for several values of the coupling constants scaled by a parameter
x. We find that the medium polarization increases the magnitude of the pairing gap at low density while the vacuum polarization decreases its magnitude at higher density.
The possibility of whether tRNAs with and without a highly modified base in their anticodon loop may influence the level of retroviral ribosomal frameshifting was examined. Rabbit reticulocyte ...lysates were programmed with mRNA encoding UUU or AAC at the frameshift site and the corresponding Phe tRNA with or without the highly modified wyebutoxine (Y) base on the 3′ side of its anticodon or Asn tRNA with or without the highly modified queuine (Q) base in the wobble position of its anticodon added. Phe and Asn tRNAs without the Y or Q base, respectively, stimulated the level of frameshifting, suggesting that the frameshift event is influenced by tRNA modification status. In addition, when AAU occurred immediately upstream of UUU as the penultimate frameshift site codon, addition of tRNAAsnwithout the Q base reduced the stimulatory effect of tRNAPhewithout the Y base, whereas addition of tRNAAsnwith the Q base did not alter the stimulatory effect. The addition of tRNAAsnwithout the Q base and tRNAPhewith the Y base inhibited frameshifting. The latter studies suggest an interplay between the tRNAs decoded at the penulimate frameshift and frameshift site codons that is also influenced by tRNA modification status. These data may be intrepreted as indicating that a hypomodified isoacceptor modulates frameshifting in an upward manner when utilized at the frameshift site codon, but modulates frameshifting in a downward manner when utilized at the penultimate frameshift site codon.
The Twomey effect is an increase of the cloud albedo with increasing concentration of tropospheric aerosols serving as cloud condensation nuclei (CCN). Confirmation and quantification of this effect ...on a global basis requires accurate satellite retrievals of CCN concentrations. We present a theoretical study of the ability of passive satellite remote sensing techniques to provide reliable estimates of tropospheric aerosol column densities over the ocean. We show that a retrieval algorithm based on single‐channel single‐viewing‐angle radiance measurements is incapable of accurately determining CCN column densities and that an algorithm based on multiangle radiance measurements provides much better retrievals. However, even for the latter algorithm the errors in the retrieved CCN column densities can exceed a factor of 5. The poor performance of single‐channel radiance‐only algorithms is explained by the strong dependence of the extinction cross section and weak dependence of the phase function on aerosol effective radius. In contrast, high‐precision multiangle polarization measurements, which are much more sensitive to aerosol microphysics, are capable of constraining CCN column densities to within a few tens of percent.
The depletion of the world oil resource based upon the logistic function has been updated and fitted to the recent history of oil production. The analysis uses data through the year 2009 and further ...introduces the asymmetric Gompertz function in order to account for additional oil resources. Results of these calculations depict a range of production rates under different resource limits. The characteristic curvature coefficients and the peak years of production are fitted to United States Geological Survey estimates of ultimately recoverable resource (URR) limits between 2.5 and 4.5 terabarrels (TB). The logistic fittings yield peak productions from 30.4 to 38.6 gigabarrels per year (GB/yr) for URRs from 2.5 to 3.0 TB in years 2008 through 2016. The lower probability of occurrence URRs (from 4.0 to 4.5 TB) inclusive of forms of oils yet to be introduced yield peak productions from 30.9 to 33.5 GB/yr during the years 2018 through 2023. The Gompertz function is used as the model for the lower probability URR production.
Comprehensive calculations of cross sections of photon induced reactions on \(^{233-238}\)U targets for incident photon energies from 3 up to 30 MeV are undertaken with the statistical model code ...EMPIRE-3.2 Malta. Results are compared with the experimental data from EXFOR and with the current evaluations. The differences and the similarities between the models and parameters used in calculations of photon- and neutron-induced reactions on the same nuclei are discussed with focus on fission. The role of the extended optical model for fission in improving the description of the measured data and in determining consistent sets of barrier parameters is pointed out.
The ability to charge battery electric vehicles (BEVs) on a time scale that is on par with the time to fuel an internal combustion engine vehicle (ICEV) would remove a significant barrier to the ...adoption of BEVs. However, for viability, fast charging at this time scale needs to also occur at a price that is acceptable to consumers. Therefore, the cost drivers for both BEV owners and charging station providers are analyzed. In addition, key infrastructure considerations are examined, including grid stability and delivery of power, the design of fast charging stations and the design and use of electric vehicle service equipment. Each of these aspects have technical barriers that need to be addressed, and are directly linked to economic impacts to use and implementation. This discussion focuses on both the economic and infrastructure issues which exist and need to be addressed for the effective implementation of fast charging at 400 kW and above. In so doing, it has been found that there is a distinct need to effectively manage the intermittent, high power demand of fast charging, strategically plan infrastructure corridors, and to further understand the cost of operation of charging infrastructure and BEVs.
•Management of intermittent, high power demand is crucial.•Planning is needed for XFC including siting future corridors.•Planning needs to include cost of charging equipment, operation and installation.•Increased coordination needs to occur between governing authorities.•Safety, cyber physical security, interoperability and compatibility will impact use.
Increasing numbers of women are found in the military, and they are now performing roles very similar to those of male service members. More returning servicewomen and veterans have been exposed to ...stressful and traumatic experiences, such as combat and difficult living circumstances, and military sexual trauma is common. These experiences have been found to be associated with adverse mental health outcomes, posttraumatic stress disorder, depression, and substance abuse in particular. Comorbidity rates are also high. In addition, more veterans are returning with injuries, including traumatic brain injuries. Although more women veterans of Operation Enduring Freedom and Operation Iraqi Freedom are seeking health services at Veterans Administration facilities, many are not. Thus, community-based social workers need to be familiar with the needs of this growing population to serve them effectively. Use of empirically supported assessment instruments and screening for military sexual trauma are recommended. Recommended interventions include the use of evidence-supported practices, such as cognitive—behavioral treatment, and offering assistance to enhance social support among women veterans.
Systematic examination of fusion for \(^{39,41,45,47}\)K + \(^{28}\)Si and \(^{36,44}\)Ar + \(^{28}\)Si provides insight into the impact of neutron and proton exchange on fusion for nuclei at and ...near the N=20 and N=28 shells. Comparison of the reduced excitation functions reveals a marked difference between the behavior of open-shell and closed-shell systems. While coupled channels calculations provide a good description for the closed-shell nuclei they significantly under-predict the fusion cross-section for open-shell nuclei. The observed trends are examined in the context of a potential energy surface, including shell effects, and multi-nucleon exchange with consideration of Pauli-blocking.
PDF
