Some thermophysical property measurements of porous ceramic ''Glassrock''

Thermophysical properties of porous ceramic material - thermal conductivity, specific heat, density, and porosity measurement

Optimizing end-labeled free-solution electrophoresis by increasing the hydrodynamic friction of the drag-tag

We study the electrophoretic separation of polyelectrolytes of varying lengths by means of end-labeled free-solution electrophoresis (ELFSE). A coarse-grained molecular dynamics simulation model, using full electrostatic interactions and a mesoscopic Lattice Boltzmann fluid to account for hydrodynamic interactions, is used to characterize the drag coefficients of different label types: linear and branched polymeric labels, as well as transiently bound micelles. It is specifically shown that the label's drag coefficient is determined by its hydrodynamic size, and that the drag per label monomer is largest for linear labels. However, the addition of side chains to a linear label offers the possibility to increase the hydrodynamic size, and therefore the label efficiency, without having to increase the linear length of the label, thereby simplifying synthesis. The third class of labels investigated, transiently bound micelles, seems very promising for the usage in ELFSE, as they provide a significant higher hydrodynamic drag than the other label types. The results are compared to theoretical predictions, and we investigate how the efficiency of the ELFSE method can be improved by using smartly designed drag-tags.Comment: 32 pages, 11 figures, submitted to Macromolecule

Two-neutron knockout from neutron-deficient 34^{34}Ar, 30^{30}S, and 26^{26}Si

Two-neutron knockout reactions from nuclei in the proximity of the proton dripline have been studied using intermediate-energy beams of neutron-deficient $^{34}$Ar, $^{30}$S, and $^{26}$Si. The inclusive cross sections, and also the partial cross sections for the population of individual bound final states of the $^{32}$Ar, $^{28}$S and $^{24}$Si knockout residues, have been determined using the combination of particle and $\gamma$-ray spectroscopy. Similar to the two-proton knockout mechanism on the neutron-rich side of the nuclear chart, these two-neutron removal reactions from already neutron-deficient nuclei are also shown to be consistent with a direct reaction mechanism.Comment: Phys. Rev. C, rapid communication, in pres

Population of bound excited states in intermediate-energy fragmentation reactions

Fragmentation reactions with intermediate-energy heavy-ion beams exhibit a wide range of reaction mechanisms, ranging from direct reactions to statistical processes. We examine this transition by measuring the relative population of excited states in several sd-shell nuclei produced by fragmentation with the number of removed nucleons ranging from two to sixteen. The two-nucleon removal is consistent with a non-dissipative process whereas the removal of more than five nucleons appears to be mainly statistical.Comment: 5 pages, 6 figure

Linking the oceans to public health : current efforts and future directions

© 2008 Author et al. This is an open access article distributed under the terms of the Creative Commons Attribution License The definitive version was published in Environmental Health 7 (2008): S6, doi:10.1186/1476-069X-7-S2-S6.We review the major linkages between the oceans and public health, focusing on exposures and potential health effects due to anthropogenic and natural factors including: harmful algal blooms, microbes, and chemical pollutants in the oceans; consumption of seafood; and flooding events. We summarize briefly the current state of knowledge about public health effects and their economic consequences; and we discuss priorities for future research. We find that: • There are numerous connections between the oceans, human activities, and human health that result in both positive and negative exposures and health effects (risks and benefits); and the study of these connections comprises a new interdisciplinary area, "oceans and human health." • The state of present knowledge about the linkages between oceans and public health varies. Some risks, such as the acute health effects caused by toxins associated with shellfish poisoning and red tide, are relatively well understood. Other risks, such as those posed by chronic exposure to many anthropogenic chemicals, pathogens, and naturally occurring toxins in coastal waters, are less well quantified. Even where there is a good understanding of the mechanism for health effects, good epidemiological data are often lacking. Solid data on economic and social consequences of these linkages are also lacking in most cases. • The design of management measures to address these risks must take into account the complexities of human response to warnings and other guidance, and the economic tradeoffs among different risks and benefits. Future research in oceans and human health to address public health risks associated with marine pathogens and toxins, and with marine dimensions of global change, should include epidemiological, behavioral, and economic components to ensure that resulting management measures incorporate effective economic and risk/benefit tradeoffs.Funding was provided in part by the NSF-NIEHS Oceans Centers at Woods Hole, University of Hawaii, University of Miami, and University of Washington, and the NOAA Oceans and Human Health Initiative Centers of Excellent in Charleston, Seattle and Milwaukee, the National Center for Environmental Health (NCEH) of the Centers for Disease Control and Prevention (CDC), and the WHOI Marine Policy Center. Grant numbers are: NIEHS P50 ES012742 and NSF OCE-043072 (HLKP, RJG, PH); NSF OCE 0432368 and NIEHS P50 ES12736 (LEF); NIEHS P50 ES012762 and NSF OCE-0434087 (EMF, AT, LRY); NSF OCE04-32479 and NIEHS P50 ES012740 (BAW

Determination of the Axial-Vector Weak Coupling Constant with Ultracold Neutrons

A precise measurement of the neutron decay $\beta$-asymmetry $A_0$ has been carried out using polarized ultracold neutrons (UCN) from the pulsed spallation UCN source at the Los Alamos Neutron Science Center (LANSCE). Combining data obtained in 2008 and 2009, we report $A_0 = -0.11966 \pm 0.00089_{-0.00140}^{+0.00123}$, from which we determine the ratio of the axial-vector to vector weak coupling of the nucleon $g_A/g_V = -1.27590_{-0.00445}^{+0.00409}$.Comment: 5 pages, 2 figure

First direct constraints on Fierz interference in free neutron β\beta decay

Precision measurements of free neutron $\beta$-decay have been used to precisely constrain our understanding of the weak interaction. However the neutron Fierz interference term $b_n$, which is particularly sensitive to Beyond-Standard-Model tensor currents at the TeV scale, has thus far eluded measurement. Here we report the first direct constraints on this term, finding $b_n = 0.067 \pm 0.005_{\text{stat}} {}^{+0.090}_{- 0.061}{}_{\text{sys}}$, consistent with the Standard Model. The uncertainty is dominated by absolute energy reconstruction and the linearity of the beta spectrometer energy response

Effi cacy of a Russian-backbone live attenuated infl uenza vaccine among children in Senegal: a randomised, double-blind, placebo-controlled trial

Background Live attenuated infl uenza vaccines have been shown to signifi cantly reduce infl uenza in diverse populations of children, but no effi cacy studies have been done in resource-poor tropical settings. In Senegal, we assessed the effi cacy and safety of a live attenuated infl uenza vaccine based on Russian-derived master donor viruses and licensed as a single dose. Methods In this double-blind, placebo-controlled, parallel group, single-centre trial done near Niakhar, Senegal, generally healthy children aged 2–5 years were randomly allocated (2:1) to receive a single intranasal dose of masked trivalent live attenuated infl uenza vaccine or placebo. The allocation sequence was computer-generated by PATH with block sizes of three. The manufacturer provided vaccine and placebo in coded vials to preserve blinding. Participants were monitored through the predictable infl uenza season in Senegal for adverse events and signs and symptoms of infl uenza using weekly home visits and surveillance in clinics. The primary outcome was symptomatic laboratoryconfi rmed infl uenza caused by any strain and occurring from 15 days post-vaccination to the end of the study. The primary analysis was per protocol. This study is registered with ClinicalTrials.gov, number NCT01854632. Findings Between May 23, and July 1, 2013, 1761 children were randomly assigned, 1174 to receive live attenuated infl uenza vaccine and 587 to receive placebo. The per-protocol set included 1173 vaccinees and 584 placebo recipients followed up to Dec 20, 2013. Symptomatic infl uenza was laboratory-confi rmed in 210 (18%) of 1173 recipients of live attenuated infl uenza vaccine and 105 (18%) of placebo recipients, giving a vaccine effi cacy of 0·0% (95% CI –26·4 to 20·9). Adverse events were balanced between the study groups. Two girls who had received live attenuated infl uenza vaccine died, one due to anasarca 12 days postvaccination and one due to malnutrition 70 days postvaccination. Interpretation Live attenuated infl uenza vaccine was well tolerated in young children in Senegal, but did not provide protection against infl uenza. Further study in such populations, which might experience extended periods of infl uenza circulation, is warranted