Impedance of cylindrical antennas in plasma - A review

Cylindrical antenna impedance in linear cold or warm plasma

Two-Dimensional FTIR as a Tool to Study the Chemical Interactions within Cellulose-Ionic Liquid Solutions

In this study two-dimensional FTIR analysis was applied to understand the temperature effects on processing cellulose solutions in imidazolium-based ionic liquids. Analysis of the imidazolium ion νC2–H peak revealed hydrogen bonding within cellulose solutions to be dynamic on heating and cooling. The extent of hydrogen bonding was stronger on heating, consistent with greater ion mobility at higher temperature when the ionic liquid network structure is broken. At ambient temperatures a blue shifted νC2–H peak was indicative of greater cation-anion interactions, consistent with the ionic liquid network structure. Both cellulose and water further impact the extent of hydrogen bonding in these solutions. The FTIR spectral changes appeared gradual with temperature and contrast shear induced rheology changes which were observed on heating above 70°C and cooling below 40°C. The influence of cellulose on solution viscosity was not distinguished on initial heating as the ionic liquid network structure dominates rheology behaviour. On cooling, the quantity of cellulose has a greater influence on solution rheology. Outcomes suggest processing cellulose in ionic liquids above 40°C and to reduce the impacts of cation-anion effects and enhance solubilisation, processing should be done at 70°C

Effects of fluoxetine on functional outcomes after acute stroke (FOCUS): a pragmatic, double-blind, randomised, controlled trial

Background Results of small trials indicate that fluoxetine might improve functional outcomes after stroke. The FOCUS trial aimed to provide a precise estimate of these effects. Methods FOCUS was a pragmatic, multicentre, parallel group, double-blind, randomised, placebo-controlled trial done at 103 hospitals in the UK. Patients were eligible if they were aged 18 years or older, had a clinical stroke diagnosis, were enrolled and randomly assigned between 2 days and 15 days after onset, and had focal neurological deficits. Patients were randomly allocated fluoxetine 20 mg or matching placebo orally once daily for 6 months via a web-based system by use of a minimisation algorithm. The primary outcome was functional status, measured with the modified Rankin Scale (mRS), at 6 months. Patients, carers, health-care staff, and the trial team were masked to treatment allocation. Functional status was assessed at 6 months and 12 months after randomisation. Patients were analysed according to their treatment allocation. This trial is registered with the ISRCTN registry, number ISRCTN83290762. Findings Between Sept 10, 2012, and March 31, 2017, 3127 patients were recruited. 1564 patients were allocated fluoxetine and 1563 allocated placebo. mRS data at 6 months were available for 1553 (99·3%) patients in each treatment group. The distribution across mRS categories at 6 months was similar in the fluoxetine and placebo groups (common odds ratio adjusted for minimisation variables 0·951 [95% CI 0·839–1·079]; p=0·439). Patients allocated fluoxetine were less likely than those allocated placebo to develop new depression by 6 months (210 [13·43%] patients vs 269 [17·21%]; difference 3·78% [95% CI 1·26–6·30]; p=0·0033), but they had more bone fractures (45 [2·88%] vs 23 [1·47%]; difference 1·41% [95% CI 0·38–2·43]; p=0·0070). There were no significant differences in any other event at 6 or 12 months. Interpretation Fluoxetine 20 mg given daily for 6 months after acute stroke does not seem to improve functional outcomes. Although the treatment reduced the occurrence of depression, it increased the frequency of bone fractures. These results do not support the routine use of fluoxetine either for the prevention of post-stroke depression or to promote recovery of function. Funding UK Stroke Association and NIHR Health Technology Assessment Programme

Generation of Spherical Cellulose Nanoparticles from Ionic Liquid Processing via Novel Nonsolvent Addition and Drying

A novel method to prepare spherical cellulose nanoparticles has been developed using imidazolium ionic liquid processing and regeneration from controlled acetonitrile nonsolvent addition and drying. Nanoparticles ranging from 100 to 400 nm have been prepared with high uniformity. Minimisation of moisture via solvent exchange drying led to discrete nanoparticles, whereas the presence of ambient moisture during regeneration contributed to aggregated morphologies. Chemical analyses of the spherical cellulose nanoparticles reveal a high-amorphous cellulose content. Furthermore, the range of particle sizes achieved with acetonitrile nonsolvent fractionation and solvent exchange drying suggest the size and uniformity of nanoparticle distributions reflect the fractionated cellulose weight fractions. This ionic liquid method is simple, energy efficient, and likely to have wide applicability across other biopolymers as well as potential to prepare surface functionalized spherical cellulose nanoparticles

Effect of mixing speed and time on some textural and physicochemical properties of wheat starch gels

The physicochemical and textural properties of wheat starch gels prepared at different mixing speeds, 15, 150 and 350 rpm and heating times, 10, 30, and 45 min at 95 °C were studied and compared. With increasing time and mixing speed most of the textural properties of starch gels obtained from texture profile analysis and residual modulus of Maxwell model obtained from stress relaxation data decreased. The samples prepared at 15 rpm and 10 min heating had the highest hardness, springiness, cohesiveness, chewiness and gumminess values whilst, the gels prepared at 350 rpm and 45 min had the lowest values for these textural properties. The images of starch gels taken by scanning electron microscopy indicated that with increasing the time and speed of mixing, honeycomb-like structure of the gels formed larger cells with thicker cell walls. Intrinsic viscosity of the samples decreased with increasing heating time and mixing speed indicating depolymerisation of starch biopolymers. Rapid Visco Analyzer data showed reduction in cold-water viscosity of starch gels with increasing time and mixing speed. Mixing speed and time during starch pasting are determining factors of final textural properties, therefore require through control to achieve final products of consistent characteristics. © 2014 Elsevier Ltd. All rights reserved