Effect of sintering atmosphere on the pore-structure stability of cerium-doped nanostructured alumina

Pore-structure stability of pure and Ce-doped alumina in air and argon atmospheres was studied using DTA, TGA, N2 ads./des. and XRD with a view to understand the importance of the ionic size of the dopant cation on the pore-structure stability of alumina. The ionic size effect was studied by heat treating the Ce-alumina system in both oxidizing and reducing atmospheres to have Ce4+ (87 pm) and Ce3+ (106 pm) respectively. No compound formation between Ce and alumina was observed. In the case of pure alumina there is a drastic reduction in porosity during the transformation to α-alumina. Ce-doped alumina has a higher DSC transformation temperature corresponding to the α-alumina transformation compared to pure alumina. Ce-doped alumina showed higher pore-structure stability compared with pure alumina and the stability was relatively higher in reducing atmosphere (higher Ce3+/Ce4+ ratio, higher effective ionic size) compared with oxidizing conditions (lower Ce3+/Ce4+ ratio, lower effective ionic size)

Relationship between cortisol and physical performance in older persons

Objective: Hypercortisolism is associated with muscle weakness. This study examines the relationship between cortisol and physical performance in older persons. Design/patients: The study was conducted within the Longitudinal Aging Study Amsterdam (LASA), an ongoing cohort study in a population-based sample of healthy older persons in the Netherlands. Data from the second (1995/1996) and fourth (2001/2002) cycle were used pertaining to 1172 (65-88 years) and 884 (65-94 years) men and women, respectively. Measurements: Physical performance was measured by adding up scores on the chair stands, tandem stand and walk test (range 0-12). In the second cycle serum total and calculated free cortisol were assessed; in the fourth cycle evening salivary cortisol was assessed. Regression analysis (stratified for sex, adjusted for age, body mass index, alcohol use, physical activity and region) was performed to examine the cross-sectional relationship between cortisol and physical performance. Results: Women with higher calculated free cortisol scored less well on physical performance (b = -0.28 per SD higher cortisol, P = 0.016), which was mainly explained by poorer performance on the tandem stand (OR = 1.32 for a lower score per SD higher cortisol, P = 0.003). Men with higher salivary cortisol scored less well on physical performance (b = -0.90 in the highest vs. the lowest quartile, P = 0.008), which was mainly explained by poorer performance on the chair stands and walk test (OR = 1.88, P = 0.020 and OR = 1.81, P = 0.027, respectively, in the highest vs. the lowest quartile). Conclusion: Physical performance is negatively associated with high cortisol levels in older persons. © 2007 The Authors

Combined sensitivity to the neutrino mass ordering with JUNO, the IceCube Upgrade, and PINGU

The ordering of the neutrino mass eigenstates is one of the fundamental open questions in neutrino physics. While current-generation neutrino oscillation experiments are able to produce moderate indications on this ordering, upcoming experiments of the next generation aim to provide conclusive evidence. In this paper we study the combined performance of the two future multi-purpose neutrino oscillation experiments JUNO and the IceCube Upgrade, which employ two very distinct and complementary routes toward the neutrino mass ordering. The approach pursued by the 20 kt medium-baseline reactor neutrino experiment JUNO consists of a careful investigation of the energy spectrum of oscillated νe produced by ten nuclear reactor cores. The IceCube Upgrade, on the other hand, which consists of seven additional densely instrumented strings deployed in the center of IceCube DeepCore, will observe large numbers of atmospheric neutrinos that have undergone oscillations affected by Earth matter. In a joint fit with both approaches, tension occurs between their preferred mass-squared differences Δm312=m32-m12 within the wrong mass ordering. In the case of JUNO and the IceCube Upgrade, this allows to exclude the wrong ordering at >5σ on a timescale of 3-7 years - even under circumstances that are unfavorable to the experiments' individual sensitivities. For PINGU, a 26-string detector array designed as a potential low-energy extension to IceCube, the inverted ordering could be excluded within 1.5 years (3 years for the normal ordering) in a joint analysis

Design and performance of the first IceAct demonstrator at the South Pole

In this paper we describe the first results of IceAct, a compact imaging air-Cherenkov telescope operating in coincidence with the IceCube Neutrino Observatory (IceCube) at the geographic South Pole. An array of IceAct telescopes (referred to as the IceAct project) is under consideration as part of the IceCube-Gen2 extension to IceCube. Surface detectors in general will be a powerful tool in IceCube-Gen2 for distinguishing astrophysical neutrinos from the dominant backgrounds of cosmic-ray induced atmospheric muons and neutrinos: the IceTop array is already in place as part of IceCube, but has a high energy threshold. Although the duty cycle will be lower for the IceAct telescopes than the present IceTop tanks, the IceAct telescopes may prove to be more effective at lowering the detection threshold for air showers. Additionally, small imaging air-Cherenkov telescopes in combination with IceTop, the deep IceCube detector or other future detector systems might improve measurements of the composition of the cosmic ray energy spectrum. In this paper we present measurements of a first 7-pixel imaging air Cherenkov telescope demonstrator, proving the capability of this technology to measure air showers at the South Pole in coincidence with IceTop and the deep IceCube detector

Time-Integrated Neutrino Source Searches with 10 Years of IceCube Data.

This Letter presents the results from pointlike neutrino source searches using ten years of IceCube data collected between April 6, 2008 and July 10, 2018. We evaluate the significance of an astrophysical signal from a pointlike source looking for an excess of clustered neutrino events with energies typically above ∼1  TeV among the background of atmospheric muons and neutrinos. We perform a full-sky scan, a search within a selected source catalog, a catalog population study, and three stacked Galactic catalog searches. The most significant point in the northern hemisphere from scanning the sky is coincident with the Seyfert II galaxy NGC 1068, which was included in the source catalog search. The excess at the coordinates of NGC 1068 is inconsistent with background expectations at the level of 2.9σ after accounting for statistical trials from the entire catalog. The combination of this result along with excesses observed at the coordinates of three other sources, including TXS 0506+056, suggests that, collectively, correlations with sources in the northern catalog are inconsistent with background at 3.3σ significance. The southern catalog is consistent with background. These results, all based on searches for a cumulative neutrino signal integrated over the 10 years of available data, motivate further study of these and similar sources, including time-dependent analyses, multimessenger correlations, and the possibility of stronger evidence with coming upgrades to the detector

Amine impregnated porous silica gel sorbents synthesized from water-glass precursors for CO2 capturing

In this work, porous silica gel-solid beads have been made from economically affordable water-glass precursors via sol-gel nano casting technique. A stable nanometric silica sol was prepared first from water glass and studied for surface potential and sol to gel transition. A free-flow, injectable gel was obtained upon aging the sol which was then assembled into spherical silica beads in a chemical bath. A surface area of 304.7m2g-1 was obtained for water glass derived silica gel beads. These gel beads were impregnated with 3-aminopropyltrimethoxysilane (APTMS) and polyethylenimine (PEI) active functional groups at different percentages for turning the gel beads as sorbents for CO2 gas adsorption. The effect of amine loading on the thermal stability, morphology as well as porosity was studied and was correlated with CO2 adsorption values. Depending upon the amount of amine loaded in the gel support CO2 uptake was found varied. These amine modified silica gel porous adsorbents showed CO2 adsorption capacity at temperatures as low as 100°C; samples modified with 15wt% PEI had CO2 adsorption capacity of 1.16mmolg-1 at 50°C. © 2015 Elsevier B.V

Cluster randomised controlled trial of a peer-led lifestyle intervention program: study protocol for the Kerala diabetes prevention program.

BACKGROUND: India currently has more than 60 million people with Type 2 Diabetes Mellitus (T2DM) and this is predicted to increase by nearly two-thirds by 2030. While management of those with T2DM is important, preventing or delaying the onset of the disease, especially in those individuals at 'high risk' of developing T2DM, is urgently needed, particularly in resource-constrained settings. This paper describes the protocol for a cluster randomised controlled trial of a peer-led lifestyle intervention program to prevent diabetes in Kerala, India. METHODS/DESIGN: A total of 60 polling booths are randomised to the intervention arm or control arm in rural Kerala, India. Data collection is conducted in two steps. Step 1 (Home screening): Participants aged 30-60 years are administered a screening questionnaire. Those having no history of T2DM and other chronic illnesses with an Indian Diabetes Risk Score value of ≥60 are invited to attend a mobile clinic (Step 2). At the mobile clinic, participants complete questionnaires, undergo physical measurements, and provide blood samples for biochemical analysis. Participants identified with T2DM at Step 2 are excluded from further study participation. Participants in the control arm are provided with a health education booklet containing information on symptoms, complications, and risk factors of T2DM with the recommended levels for primary prevention. Participants in the intervention arm receive: (1) eleven peer-led small group sessions to motivate, guide and support in planning, initiation and maintenance of lifestyle changes; (2) two diabetes prevention education sessions led by experts to raise awareness on T2DM risk factors, prevention and management; (3) a participant handbook containing information primarily on peer support and its role in assisting with lifestyle modification; (4) a participant workbook to guide self-monitoring of lifestyle behaviours, goal setting and goal review; (5) the health education booklet that is given to the control arm. Follow-up assessments are conducted at 12 and 24 months. The primary outcome is incidence of T2DM. Secondary outcomes include behavioural, psychosocial, clinical, and biochemical measures. An economic evaluation is planned. DISCUSSION: Results from this trial will contribute to improved policy and practice regarding lifestyle intervention programs to prevent diabetes in India and other resource-constrained settings. TRIAL REGISTRATION: Australia and New Zealand Clinical Trials Registry: ACTRN12611000262909

A rare case of pediatric enteroplueural fistula, which presented as lung abscess

We report a case of a 14-year-old male patient referred to us as a case of right-sided lung abscess. The patient was treated for the entericperforation elsewhere, following which he developed productive cough, which progressively worsened. The preoperative diagnosis ofentero-pleural fistula was made with the help of thoraco abdominal computed tomography scan after 4 months of antitubercular andantibiotic treatment. Enteric perforation leading to entero-pleural fistula is very rare. The patient did well after laparotomy and completeexcision of the fistula

Studies on Bracing Member End Connections for Cold Formed Steel Sections

This paper is concentrated mainly on the behaviour of bracing end connections for cold formed steel lipped angle and lipped channel sections. For bracing members, only one flange is possible to connect with tower leg member or supporting member, which causes uneven distribution of stresses in the end section popularly known as shear lag effect. Tension tests have been carried out to simulate the bracing end connections. Special test rig has been assembled and end fittings fabricated such that the load will be applied as concentric load at the pulling end and on the other end load is transferred through the connected flange only. All the specimens have been instrumented with dial gauges, to study the deformations and one specimen is instrumented with strain gauges to study the strain variation. The failure load for tested joints has been calculated by using various International Standards and compared with the test results

Enhanced CO2 absorption kinetics in lithium silicate platelets synthesized by a sol–gel approach

Platelet-shaped lithium orthosilicate particles synthesized by a sol–gel approach employing the precursors lithium nitrate and colloidal silica displayed enhanced absorption kinetics for CO2 compared to the powders prepared by a solid-state reaction process involving Li2CO3 and silica. The sol–gel samples showed a CO2 absorption capacity of 350 mg g-1 at an absorption rate of 22.5 mg g-1 min-1, a value 70% higher than the rate of 13.2 mg g-1 min-1 measured with the solid-state samples under similar conditions. The higher sorption kinetics of CO2 by the sol–gel derived lithium orthosilicate could be attributed to the unique platelet morphology of the particles, which have a very small thickness. A porous carbon mesh coated with the sol–gel based particles exhibited CO2 absorption capacity of 150 mg g-1 at an absorption rate of 37.5 mg g-1 min-1. This supported absorbent also showed stable absorption and desorption performance for the 8 cycles examined in this study. The excellent absorption characteristics of the sol–gel prepared powders, more specifically the coated strips, provide a successful pathway for the commercialisation of these materials