This research connects the mechanical and dielectric responses of three samples of hybrid polymer films composed of iron oxide nanoparticles and polyvinyl butyral (PVB) matrices with different ...average molecular weight. The mechanical responses were analyzed by dynamic mechanical analysis and the electrical responses by dynamic dielectric analysis, and they were interpreted by two fractional models, the Mechanical and the Dielectric Fractional Model. Correlation between mechanical and dielectric responses was determined for hybrid films. The comparison between fractional model parameters reveals that PVB matrix, with different average molecular weight, combined with the same nominal concentration of Fe-ions precursor, produces higher molecular mobility when average molecular weight is higher, and for the three samples, studied molecular mobility is higher for the dielectric manifestation of
α
-relaxation than the mechanic response. These results contribute in an important way to a better understanding of the molecular mobility of these materials where the possible applications require a certain compromise between the mechanical and electrical properties.
1. Very few studies to date have evaluated experimentally the effects of blood parasites on physiological variables and breeding performance in wild birds. In this study, blood parasitaemias of ...female Blue Tits Cyanistes caeruleus L. were experimentally manipulated to assess subsequent changes in immunoglobulin level and parental effort during reproduction. 2. At the beginning of the nestling period, female Blue Tits were medicated with a high dose (HD) or a low dose (LD) of the antimalarial Primaquine, or with saline solution (control). Treatment with Primaquine causes a reduction in blood parasitaemias in the study population. 3. Immunoglobulin levels decreased in females from the HD group during the experimental period (10 days), while the levels increased in control females. 4. Only females in the HD group increased significantly their provisioning rates from the early to the late nestling stage. Total (male and female) provisioning rates increased significantly for the HD and LD groups, but not for the control group. 5. Nestlings reared by control females suffered a higher infestation by the ectoparasitic blowfly Protocalliphora azurea (Fallén). 6. Medication and the associated decrease in immunoglobulin levels allow females to allocate more resources towards parental effort. In addition, there is a potential link of medication with the health of the nestlings. 7. This study gives indirect support to the trade-off between reproductive effort and immune defence in avian hosts, and sheds light on the evolutionary significance of the link between parasitism, immunity, life-history decisions and fitness.
In this paper, we report results on the processing of cadmium zinc sulfide (CdxZn1-xS) ternary compound starting from the deposition of cadmium sulfide (CdS)/zinc sulfide (ZnS) bi-layers buffer ...configuration and a subsequent thermal annealing for its application to thin film solar cells. The impact of different CdS/ZnS bi-layers buffer configurations as effective alternative to the single CdS buffer layer, as well as the physical and chemical properties of the equivalent CdxZn1-xS ternary compound are presented and discussed. Results on physical properties optimization of CdxZn1-xS ternary compound for future applications to thin film solar cells are presented.
•Synthesis of cadmium zinc sulfide compound starting from bilayers deposition•A varied range of ternary composition can be obtained in a more controlled way.•The impact of different layer thickness on physical properties is studied.•Zinc sulfide thickness lower than 20 nm allows optimal physical properties.
In this work the high velocity impact of ice spheres is analysed. An experimental methodology has been developed in order to launch, at high velocity, ice spheres of different diameters against a ...load cell to measure the force induced during the impact. An analysis of the influence of the ice mass on the impact force is accomplished using the contact force which was calculated by means of an inverse problem technique. Finally a study of the impact phenomenon has been performed using the videos obtained with a high speed camera.
Impacts on composites produce interlaminar failure (delamination) which is difficult to detect in common maintenance tasks, and affects the structural integrity. Therefore it is critical, for safety, ...to improve prediction tools in order to perform tolerant damage designs. The numerical modeling of impacts of deformable objects (such as ice) on composite panels is still a challenge. Not only the modeling of the laminate should be appropriate to reproduce its behavior and failures, but also the modeling of the deformable projectile should be capable to induce the corresponding response and damages. In this work a two-step numerical methodology is proposed for the study of ice impact. First, the deformable impactor is analyzed, studying the impact process on a rigid target (a steel plate attached to a load cell). Once the deformable projectile behavior is fully captured, the ice impact on a deformable target (a carbon/epoxy laminate) is studied. The composite material model takes into account intralaminar and interlaminar failure in order to reproduce the laminate behavior. Different ice sphere diameters (30,40 and 50mm) and impact velocities (50−250m/s) are considered in this study. All the results from the numerical simulations have been compared with the experimental results.
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•Ice material model widely validated for impacts onto different kinds of structures•Development of a numerical methodology for soft body impactors•Simplified composite model capable to reproduce the overall effects of ice sphere impacts
Summary
Background
Older subjects with type 2 diabetes mellitus (T2DM) have differential characteristics compared with middle‐aged or younger populations, and require tailored management of the ...disease.
Aims
To evaluate how clinical characteristics, degree of control of glycaemia and cardiovascular risk factors, presence of chronic complications and treatments differ between older T2DM patients and younger adults.
Methods
Cross‐sectional study using data from a population‐based electronic database. We retrieved data from 318,020 patients ≥ 30 years diagnosed with T2DM, attended during 2011 in primary care centres in Catalonia, Spain. We performed descriptive and comparative analyses stratified by gender and age subgroups: ≤ 65, 66–75, 76–85 and >85 years.
Results
Both men and women across older age subgroups (> 65 years) had longer diabetes duration than younger adults (8.0 vs. 5.6 in men and 8.4 vs. 6.9 years in women; p < 0.001), but better glycaemic control (mean glycated haemoglobin 7.1 vs. 7.7 in men and 7.1 vs. 7.4 in women; p < 0.001), and better combined control of different cardiovascular risk factors (p < 0.001). Moreover, older patients were more likely to achieve glycaemic targets irrespective of having cardiovascular disease. The use of oral antidiabetics decreased with increasing age, and insulin in monotherapy was more frequently prescribed among patients in the older age subgroups. Diabetes‐related complications were more frequent in men of all group ages. In the older age subgroups, patients of both sexes had a longer duration of T2DM but better glycaemic control. In this context, the prevalence of diabetic retinopathy decreased unexpectedly with increasing age.
Conclusion
Control of glycaemia and cardiovascular risk factors was better among older T2DM patients. There is a need for prospective studies to quantify the weight of risk factors in each complication to adapt the therapeutic and care approaches in elderly people.
In this work a numerical methodology to predict the behavior of composite unidirectional laminates under high velocity impact is developed. In order to validate the model, experimental results of ...high velocity impacts of steel sphere against laminate coupons, were accomplished. The residual velocity in case of penetration and the damaged area in the panel are the variables chosen to validate the results obtained in the numerical methodology proposed. Finally an analysis of the influence of the projectile geometry is accomplished.
An analytical model to study the impact process of a spherical projectile penetrating at high velocity into a carbon/epoxy plain woven laminate is developed in this work. The model is based on an ...energy balance, where the kinetic energy of the projectile is absorbed by the laminate by three different mechanisms: laminate crushing, linear momentum transfer and tensile fiber failure. A non-homogeneous differential equation is obtained. A subsequent simplification using regular perturbation analysis gives a closed-form solution that allows the approximative calculation of the residual velocity and hence the ballistic limit. The model is validated with the results of experimental tests in which the residual velocity is measured by means of high speed cameras.
In this work, the process of impact that takes place in a partially filled tank is analyzed, performing a numerical simulation, in order to understand the response of the composite laminated ...structure. The commercial finite-element code LS-DYNA v.R7 has been used to simulate an Hydrodynamic RAM event created by a steel spherical projectile impacting a partially water-filled woven CFRP square tube using two different approaches (MM-ALE and SPH). The intralaminar and interlaminar damage have been taken into account implementing an user subroutine and by means of a cohesive interaction, respectively. Once the numerical model is validated using available experimental data, the effect of the filling level in the failure of the tank is analyzed in detail taking advantage of the information provided by the numerical model.
Non-alcoholic fatty liver disease (NAFLD) is currently a growing epidemic disease that can lead to cirrhosis and hepatic cancer when it evolves into non-alcoholic steatohepatitis (NASH), a gap not ...well understood. To characterize this disease, pigs, considered to be one of the most similar to human experimental animal models, were used. To date, all swine-based settings have been carried out using rare predisposed breeds or long-term experiments. Herein, we fully describe a new experimental swine model for initial and reversible NASH using cross-bred animals fed on a high saturated fat, fructose, cholesterol, cholate, choline and methionine-deficient diet. To gain insight into the hepatic transcriptome that undergoes steatosis and steatohepatitis, we used RNA sequencing. This process significantly up-regulated 976 and down-regulated 209 genes mainly involved in cellular processes. Gene expression changes of 22 selected transcripts were verified by RT-qPCR. Lipid droplet area was positively associated with CD68, GPNMB, LGALS3, SLC51B and SPP1, and negatively with SQLE expressions. When these genes were tested in a second experiment of NASH reversion, LGALS3, SLC51B and SPP1 significantly decreased their expression. However, only LGALS3 was associated with lipid droplet areas. Our results suggest a role for LGALS3 in the transition of NAFLD to NASH.
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