Core-shell Structured Composite Silica Micro- and Nanoparticles with Ability Release a De fined Quantity „on Demand“

The aim of this work was the preparation of biocompatible micro- and nanoparticles with a hollow in-terrior. The particles must be able to encapsulate and store a chemical payload for a certain time, followed by the release on demand of this payload. In our previous work [13] we have prepared silica microparticles with a hollow core and found that the diffusion across the mesoporous silica shell was strongly dependent on temperature. In this work, we used this dependence and attached iron oxide nanoparticles on the sur-face of the silica shell to create composite iron oxide/silica particles. The iron oxide nanoparticles were able to heat up in the presence of an alternating magnetic field. This property allowed us to use magnetic field as a tool for remote control of diffusion across the particle shell. To avoid spontaneous leakage of encapsu-lated payload in time, we have modified the surface of the composite micropaticles with a layer of palm oil. Palm oil is a phase change material which is solid under 37 °C. We showed that the resultant composite particles are able to store a payload for several months and release a defined quantity on demand by the application of a magnetic field. The particles were characterised in shape, size, heating ability and their mass transport properties. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3557

What Limits the Rate Capability of Li-S Batteries during Discharge: Charge Transfer or Mass Transfer?

Li-S batteries exhibit poor rate capability under lean electrolyte conditions required for achieving high practical energy densities. In this contribution, we argue that the rate capability of commercially-viable Li-S batteries is mainly limited by mass transfer rather than charge transfer during discharge. We first present experimental evidence showing that the charge-transfer resistance of Li-S batteries and hence the cathode surface covered by Li2S are proportional to the state-of-charge (SoC) and not to the current, directly contradicting previous theories. We further demonstrate that the observed Li-S behaviors for different discharge rates are qualitatively captured by a zero-dimensional Li-S model with transport-limited reaction currents. This is the first Li-S model to also reproduce the characteristic overshoot in voltage at the beginning of charge, suggesting its cause is the increase in charge transfer resistance brought by Li2S precipitation

Factors Limiting Microbial Activity in Volcanic Tuff at Yucca Mountain

Samples of tuff aseptically collected from 10 locations in the Exploratory Shaft Facility at the site of the proposed high-level nuclear waste repository at Yucca Mountain, Nevada Test Site were analyzed for microbiological populations, activities, and factors limiting microbial activity. Radiotracer assays ({sup 14}C-labeled organic substrate mineralization), direct microscopic counts, and plate counts were used. Radiolabeled substrates were glucose, acetate, and glutamate. Radiotracer experiments were carried out with and without moisture and inorganic nutrient amendments to determine factors limiting to microbial activities. Nearly all samples showed the presence of microorganisms with the potential to mineralize organic substrates. Addition of inorganic nutrients stimulated activities in a small number of samples. The presence of viable microbial communities within the tuff has implications for transport of contaminants

Rotation-induced 3D vorticity in 4He superfluid films adsorbed on a porous glass

Detailed study of torsional oscillator experiments under steady rotation up to 6.28 rad/sec is reported for a 4He superfluid monolayer film formed in 1 micrometer-pore diameter porous glass. We found a new dissipation peak with the height being in proportion to the rotation speed, which is located to the lower temperature than the vortex pair unbinding peak observed in the static state. We propose that 3D coreless vortices ("pore vortices") appear under rotation to explain this new peak. That is, the new peak originates from dissipation close to the pore vortex lines, where large superfluid velocity shifts the vortex pair unbinding dissipation to lower temperature. This explanation is confirmed by observation of nonlinear effects at high oscillation amplitudes.Comment: 4pages, 5figure

The effect of current inhomogeneity on the performance and degradation of Li-S batteries

The effect of thermal gradients on the performance and cycle life of Li-S batteries is studied using bespoke single-layer Li-S cells, with isothermal boundary conditions maintained by Peltier elements. A temperature difference is shown to cause significant current imbalance between parallel connected single-layer cells, causing the hotter cell to provide more charge and discharge capacities during cycling. During charge, significant shuttle is induced in the hotter Li-S cell, causing accelerated degradation of it. A bespoke multi-tab cell in which the inner layers are electrically connected to different tabs versus the outer layers, is used to demonstrate that noticeable current inhomogeneity occurs during the operation of practical multilayer Li-S pouch cells, which is expected to affect their performance and degradation. The observed thermal and current inhomogeneity should have a direct consequence on battery pack and thermal management system design for real world Li-S battery packs

The Influence of Different Fertilization Strategies on the Grain Yield of Field Peas (Pisum sativum L.) under Conventional and Conservation Tillage

Weather, tillage, and fertilization are the major factors affecting the grain yield of field peas (Pisum sativum L.). However, the impact of tillage and fertilization on yield is not well understood. Therefore, this experiment was initiated in 1999. In this manuscript, we report the data recorded during the period of 2011-2015 to quantify the impacts on yield. Field peas were planted in seedbeds prepared through conventional tillage (CT)-moldboard ploughing to the depth of 0.22 m; and minimum tillage (MT)-disking to the depth of 0.12 m. The crop received three fertilization treatments, including zero fertilization (control); nitrogen, phosphorus and potassium (NPK) mineral fertilization treatment; and NPK mineral fertilization plus the incorporation of pre-crop biomass. Five years' average data indicated the highest yield on fertilized treatments (2.85-2.98 t ha(-1) vs. 2.66 t ha(-1)) regardless of the tillage. When comparing the yield of fertilized treatments, the yield under CT (2.98 t ha(-1)) was significantly higher than that of MT (2.85 t ha(-1)). However, on non-fertilized treatments (less fertile plots), a higher yield was recorded under MT (2.71 t ha(-1)) compared with CT (2.40 t ha(-1)). Overall, the results of this study suggest that fertilizer application together with incorporation of the above-ground biomass of the previous crop may help sustain pea grain yield

Thrombolysis in Stroke With Unknown Onset Based on Non-Contrast Computerized Tomography (TRUST CT).

Background Intravenous thrombolysis (IVT) in wake-up stroke (WUS) or stroke with unknown onset (SUO) has been recently proven to be safe and effective using advanced neuroimaging (magnetic resonance imaging or computerized tomography-perfusion) for patient selection. However, in most of the thrombolyzing centers advanced neuroimaging is not instantly available. We hypothesize that pragmatic non-contrast computed tomography-based IVT in WUS/SUO may be feasible and safe. Methods and Results TRUST-CT (Thrombolysis in Stroke With Unknown Onset Based on Non-Contrast Computerized Tomography) is an international multicenter registry-based study. WUS/SUO patients undergoing non-contrast computed tomography-based IVT with National Institute of Health Stroke Scale ≥4 and initial Alberta Stroke Program Early Computerized Tomography score ≥7 were included and compared with propensity score matched non-thrombolyzed WUS/SUO controls. Primary end point was the incidence of symptomatic intracranial hemorrhage; secondary end points included 24-hour National Institute of Health Stroke Scale improvement of ≥4 and modified Rankin Scale at 90 days. One hundred and seventeen WUS/SUO patients treated with non-contrast computed tomography-based IVT were included. As compared with 112 controls, the median admission National Institute of Health Stroke Scale was 10 and the median Alberta Stroke Program Early Computerized Tomography score was 10 in both groups. Four (3.4%) IVT patients and one control patient (0.9%) suffered symptomatic intracranial hemorrhage (adjusted odds ratio 7.9, 95% CI 0.65-96, P=0.1). A decrease of ≥4 National Institute of Health Stroke Scale points was observed in 67 (57.3%) of IVT patients as compared with 25 (22.3%) in controls (adjusted odds ratio 5.8, CI 3.0-11.2, P<0.001). A months, 39 (33.3%) IVT patients reached a modified Rankin Scale score of 0 or 1 versus 23 (20.5%) controls (adjusted odds ratio 1.94, CI 1.0-3.76, P=0.05). Conclusions Non-contrast computed tomography-based thrombolysis in WUS/SUO seems feasible and safe and may be effective. Randomized prospective comparisons are warranted. Clinical Trial Registration URL: https://www.clinicaltrials.gov/. Unique identifier: NCT03634748