Characterisation of porous solids using small-angle scattering and NMR cryoporometry

The characteristics of several porous systems have been studied by the use of small-angle neutron scattering [SANS] and nuclear magnetic resonance [NMR] techniques. The measurements reveal different characteristics for sol-gel silicas, activated carbons and ordered mesoporous silicas of the MCM and SBA type. Good agreement is obtained between gas adsorption measurements and the NMR and SANS results for pore sizes above 10 nm. Recent measurements of the water/ice phase transformation in SBA silicas by neutron diffraction are also presented and indicate a complex relationship that will require more detailed treatment in terms of the possible effects of microporosity in the silica substrate. The complementarity of the different methods is emphasised and there is brief discussion of issues related to possible future developments

Activities of the RTG Radiation Test Laboratory Progress report, 1 Jul. - 31 Dec. 1969

Safety, gamma ray spectrum, and data analysis of SNAP fuel capsule

Freezing Out Early Dark Energy

A phenomenological model of dark energy that tracks the baryonic and cold dark matter at early times but resembles a cosmological constant at late times is explored. In the transition between these two regimes, the dark energy density drops rapidly as if it were a relic species that freezes out, during which time the equation of state peaks at +1. Such an adjustment in the dark energy density, as it shifts from scaling to potential-domination, could be the signature of a trigger mechanism that helps explain the late-time cosmic acceleration. We show that the non-negligible dark energy density at early times, and the subsequent peak in the equation of state at the transition, leave an imprint on the cosmic microwave background anisotropy pattern and the rate of growth of large scale structure. The model introduces two new parameters, consisting of the present-day equation of state and the redshift of the freeze-out transition. A Monte Carlo Markov Chain analysis of a ten-dimensional parameter space is performed to compare the model with pre-Planck cosmic microwave background, large scale structure and supernova data and measurements of the Hubble constant. We find that the transition described by this model could have taken place as late as a redshift z~400. We explore the capability of future cosmic microwave background and weak lensing experiments to put tighter constraints on this model. The viability of this model may suggest new directions in dark-energy model building that address the coincidence problem.Comment: 11 pages, 15 figure

Resonance raman characterization of the forms of ground-state 8-substituted 7-hydroxyquinoline caged acetate compounds in aqueous solutions

Monday Poster Session: Resonance Raman in Biological and Chemical Systems (MP22) - Poster Number: 0978-substituted 7-hydroxyquinolines, like 8-chloro-7-hydroxyquinoline (CHQ) and 8-cyano-7-hydroxyquinoline (CyHQ), are able to be useful for 1PE and 2PE and their acetate acids CHQ−OAc and CyHQ−OAc were also able to undergo photolysis reactions in neutral aqueous buffer solutions. To examine the substituent effect on the relative populations of the forms of the ground state species of 8-substituted 7-hydroxyquinolines, ultraviolet absorption and resonance Raman spectroscopy experiments were done for CHQ–OAc and CyHQ–OAc in differnt solutions.postprintThe 22nd International Conference on Raman Spectroscopy (ICORS 2010), Boston, MA., 8-13 August 2010

Importation of generic hepatitis C therapies: Bridging the price - access gap in high-income countries

The global burden of hepatitis C infection and the emergence of effective therapies An estimated 80-150 million people are infected with hepatitis C infection (HCV) worldwide, with the highest prevalence rates in low- and medium-income countries of Africa and Asia. HCV-related liver disease mortality is estimated to be half a million per annum.1,2 Chronic HCV treatment was interferon-based for two decades, with the addition of ribavirin (RBV),3 pegylated-interferon (PEG-IFN)4 and initial protease inhibitor direct acting antiviral (DAA) therapies (telaprevir, boceprevir)5,6 subsequently providing stepwise improvements in the rate of sustained virological response (SVR). Despite these improvements, interferon-containing HCV therapy uptake remained low in most countries, ranging from <1% to a maximum of 5% of people with chronic HCV initiating therapy each year.7 Fortunately, recent years have seen a revolution in HCV therapeutic development, with the advent of interferon-free DAA therapies, which disrupt replication through inhibition of HCV protease, polymerase and NS5A function.8 Simple (single daily dosing oral regimens), highly tolerable, short-duration (8-24 weeks) regimens with extremely high efficacy (cure rates above 95%) have been developed and registered internationally. Used in various combinations depending on HCV genotypes and previous treatment exposure, these include: sofosbuvir/ledipasvir ,9-11 paritaprevir/ritonavir/ombitasvir/dasabavir/+/-ribavirin ,12-14 sofosbuvir/daclatasvir,15,16 elbasvir/grazoprevir,17,18 and sofosbuvir/velpatasvir. There is clear evidence that HCV cure impacts HCV-related liver disease and hepatocellular carcinoma (HCC) risk.19 Early treatment may have greater benefit. Furthermore, as a result of the high efficacy and tolerance, and ease of delivery of these medications, HCV treatment as prevention is being explored in some countries, particularly treating high prevalence populations, such as people who inject drugs and incarcerated populations.20 The broad implementation of these therapeutic regimens has the potential to dramatically impact HCV-related disease burden globally. Indeed, new HCV treatments have been deemed so important that some (sofosbuvir, daclatasvir) were added to the 2015 WHO Essential Medicines List along with a number of their combinations.NHMRC project grant, App 108067

Confinement effects on glass forming liquids probed by DMA

Many molecular glass forming liquids show a shift of the glass transition T-g to lower temperatures when the liquid is confined into mesoporous host matrices. Two contrary explanations for this effect are given in literature: First, confinement induced acceleration of the dynamics of the molecules leads to an effective downshift of T-g increasing with decreasing pore size. Second, due to thermal mismatch between the liquid and the surrounding host matrix, negative pressure develops inside the pores with decreasing temperature, which also shifts T-g to lower temperatures. Here we present dynamic mechanical analysis measurements of the glass forming liquid salol in Vycor and Gelsil with pore sizes of d=2.6, 5.0 and 7.5 nm. The dynamic complex elastic susceptibility data can be consistently described with the assumption of two relaxation processes inside the pores: A surface induced slowed down relaxation due to interaction with rough pore interfaces and a second relaxation within the core of the pores. This core relaxation time is reduced with decreasing pore size d, leading to a downshift of T-g proportional to 1/d in perfect agreement with recent differential scanning calorimetry (DSC) measurements. Thermal expansion measurements of empty and salol filled mesoporous samples revealed that the contribution of negative pressure to the downshift of T-g is small (<30%) and the main effect is due to the suppression of dynamically correlated regions of size xi when the pore size xi approaches

Multi-gap superconductivity in a BaFe1.84Co0.16As2 film from optical measurements at terahertz frequencies

We measured the THz reflectance properties of a high quality epitaxial thin film of the Fe-based superconductor BaFe$_{1.84}$Co$_{0.16}$As$_2$ with T$_c$=22.5 K. The film was grown by pulsed laser deposition on a DyScO$_3$ substrate with an epitaxial SrTiO$_3$ intermediate layer. The measured $R_S/R_N$ spectrum, i.e. the reflectivity ratio between the superconducting and normal state reflectance, provides clear evidence of a superconducting gap $\Delta_A$ close to 15 cm$^{-1}$. A detailed data analysis shows that a two-band, two-gap model is absolutely necessary to obtain a good description of the measured $R_S/R_N$ spectrum. The low-energy $\Delta_A$ gap results to be well determined ($\Delta_A$=15.5$\pm$0.5 cm$^{-1}$), while the value of the high-energy gap $\Delta_B$ is more uncertain ($\Delta_B$=55$\pm$7 cm$^{-1}$). Our results provide evidence of a nodeless isotropic double-gap scenario, with the presence of two optical gaps corresponding to 2$\Delta/kT_c$ values close to 2 and 7.Comment: Published Versio

Fish Health Unit Report of Activities Undertaken in 2018 and 2019

This report summarises the activities undertaken by the Fish Health Unit (FHU) of the Marine Institute (MI) in 2018 and 2019. The services of the FHU, undertaken on behalf of the State, are largely driven by European and national legislation on aquatic animal health. European Council Directive 2006/88/EC on animal health requirements for aquaculture animals lays down rules for the control of aquatic animal health within the EU. The directive is enacted in Irish Law by Statutory Instrument (SI) 261 of 2008. The MI is the Competent Authority (CA) responsible for implementation of aquatic animal health regulation in Ireland as described in these statutes. Aquatic animal health regulations in SI 261 of 2008 apply to finfish farms, shellfish farms, and put and take fisheries, and require that such aquaculture production businesses (APBs) obtain a Fish Health Authorisation (FHA) from the CA prior to operation

A comparison of word analysis ability and spelling achievement of 562 sixth grade children

Thesis (M.A.)--Boston Universit