Controlled adsorption of metallic nanoparticles on polymeric microcapsules with a view to growing secondary continuous metal films

Small, volatile actives cannot be micro-encapsulated efficiently over the lifetime of a product using current encapsulation techniques. This is due to the inherent porosity of the polymeric membranes which are used as the capsule shell material. We have developed a method for preventing undesired loss of encapsulated actives which prevents loss of the core into ethanol over 90 days +. Oil core microcapsules are produced using oil-in-water emulsification followed by co-solvent extraction to precipitate a polymeric shell around the oil core. Metallic catalytic nanoparticles are then physically adsorbed onto the microcapsules and used to catalyse the growth of a continuous secondary metallic film via electroless deposition. It is important to have good control over the primary nanoparticle adsorption density which requires a good control over and understanding of the original nanoparticle (NP) synthesis. In this work we use Quartz crystal microbalance (QCM) and transmission electron microscopy (TEM) to demonstrate the ability to control NP adsorption densities by varying several parameters such as concentration of polymeric stabiliser used in the original NP dispersion synthesis and NP dispersion concentration. We show that NP films form in seconds and demonstrate good adsorption energies. We also discuss/explain the semi regular hexagonal packing of the NP cores we observe under TEM. Please click Additional Files below to see the full abstract

Hurricane Florence Flooding in Georgetown County: A Qualitative Explanation of the Interactions of Estuary and Tidal River

This paper examines data from 18 USGS gauges in the lower Pee Dee Basin in an effort to explain the behavior of the flooding following Hurricane Florence (2018) in Georgetown County, South Carolina. Despite record or near-record flooding in all the tributaries to the Winyah Bay estuary, water levels near the city of Georgetown were well below predicted heights. Floodplain storage in the lower Great Pee Dee, Lynches, and Little Pee Dee River valleys stored over 1.2 million acre-feet of floodwaters, delaying peak stage near Bucksport for five days and reducing peak flow into the Winyah Bay tidal river/estuary system by nearly 50%. An unknown amount of flow from the Winyah Bay tidal river/estuary system flowed through the Atlantic Intracoastal Water Way to Little River rather than through Winyah Bay. The resulting freshwater flow to Winyah Bay only moved the point of tidal stagnation (where upstream tidal flow balances downstream freshwater flow) to near Georgetown. Since the city of Georgetown was near the point of stagnation, water level there was driven by ocean tidal height rather than river flood stage. The lack of discharge data from the tidal rivers in Georgetown County prevents evaluation of the importance of each of these factors and will limit efforts to make quantitative predictions of future flooding in the county

Dissecting pathways to thrombocytopenia in a mouse model of visceral leishmaniasis

Visceral leishmaniasis is an important yet neglected parasitic disease caused by infection with Leishmania donovani or L infantum. Disease manifestations include fever, weight loss, hepatosplenomegaly, immune dysregulation, and extensive hematological complications. Thrombocytopenia is a dominant hematological feature seen in both humans and experimental models, but the mechanisms behind this infection-driven thrombocytopenia remain poorly understood. Using a murine model of experimental visceral leishmaniasis (EVL), we demonstrated a progressive decrease in platelets from day 14 after infection, culminating in severe thrombocytopenia by day 28. Plasma thrombopoietin (TPO) levels were reduced in infected mice, at least in part because of the alterations in the liver microenvironment associated with granulomatous inflammation. Bone marrow (BM) megakaryocyte cytoplasmic maturation was significantly reduced. In addition to a production deficit, we identified significant increases in platelet clearance. L donovani–infected splenectomized mice were protected from thrombocytopenia compared with sham operated infected mice and had a greater response to exogenous TPO. Furthermore, infection led to higher levels of platelet opsonization and desialylation, both associated with platelet clearance in spleen and liver, respectively. Critically, these changes could be reversed rapidly by drug treatment to reduce parasite load or by administration of TPO agonists. In summary, our findings demonstrate that the mechanisms underpinning thrombocytopenia in EVL are multifactorial and reversible, with no obvious residual damage to the BM microenvironment

Experimental detection of entanglement via witness operators and local measurements

In this paper we address the problem of detection of entanglement using only few local measurements when some knowledge about the state is given. The idea is based on an optimized decomposition of witness operators into local operators. We discuss two possible ways of optimizing this local decomposition. We present several analytical results and estimates for optimized detection strategies for NPT states of 2x2 and NxM systems, entangled states in 3 qubit systems, and bound entangled states in 3x3 and 2x4 systems.Comment: 24 pages, 2 figures. Contribution to the proceedings of the International Conference on Quantum Information in Oviedo, Spain (July 13-18, 2002). Error in W_W1-witness Eq. (35) corrected as well as minor typos. Reference adde

It\u27s a Small World: Enhancing Human Cognition through Virtual Dioramas

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Regio

Low-Energy Electron-Track Imaging for a Liquid Argon Time-Projection-Chamber Telescope Concept using Probabilistic Deep Learning

The GammaTPC is an MeV-scale single-phase liquid argon time-projection-chamber gamma-ray telescope concept with a novel dual-scale pixel-based charge-readout system. It promises to enable a significant improvement in sensitivity to MeV-scale gamma-rays over previous telescopes. The novel pixel-based charge readout allows for imaging of the tracks of electrons scattered by Compton interactions of incident gamma-rays. The two primary contributors to the accuracy of a Compton telescope in reconstructing an incident gamma-ray's original direction are its energy and position resolution. In this work, we focus on using deep learning to optimize the reconstruction of the initial position and direction of electrons scattered in Compton interactions, including using probabilistic models to estimate predictive uncertainty. We show that the deep learning models are able to predict locations of Compton scatters of MeV-scale gamma-rays from simulated pixel-based data to better than 0.6 mm RMS error, and are sensitive to the initial direction of the scattered electron. We compare and contrast different deep learning uncertainty estimation algorithms for reconstruction applications. Additionally, we show that event-by-event estimates of the uncertainty of the locations of the Compton scatters can be used to select those events that were reconstructed most accurately, leading to improvement in locating the origin of gamma-ray sources on the sky

Nickel partitioning in biogenic and abiogenic ferrihydrite: the influence of silica and implications for ancient environments

Fe(III) (oxyhydr)oxides are ubiquitous in modern soils and sediments, and their large surface area leads to scavenging of trace elements. Experimental trace element partitioning between Fe(III) (oxyhydr)oxides and aqueous solutions have been used to elucidate the geochemical composition of the Precambrian oceans based on the trace element concentrations in Precambrian banded iron formations (BIFs). However, previous partitioning experiments did not consider the potential influence of microbially-derived organic material, even though it is widely believed that bacterial phytoplankton was involved in Fe(II) oxidation and the deposition of BIF primary minerals. Therefore, the present study focuses on sorption of Ni to, and co-precipitation of Ni with, both biogenic ferrihydrite (Fe(OH)3) precipitated by the freshwater photoferrotroph Rhodobacter ferrooxidans SW2 and the marine photoferrotroph Rhodovulum iodosum, as well as chemically synthesized ferrihydrite. We considered the influence of cellular organic material, medium composition and the availability of dissolved silica. Our results show a preferential association of Ni with ferrihydrite, and not with the microbial cells or extracellular organic substances. We found that the addition of silica (2 mM) did not influence Ni partitioning but led to the encrustation of some cells with ferrihydrite and amorphous silica. The two- to threefold lower Ni/Fe ratio in biogenic as compared to abiogenic ferrihydrite is probably due to a competition between Ni and organic matter for sorption sites on the mineral surface. Additionally, the competition of ions present at high concentrations in marine medium for sorption sites led to decreased Ni sorption or co-precipitation. Based on our data we conclude that, if the Fe(III) minerals deposited in BIFs were – at least to some extent – biological, then the Ni concentrations in the early ocean would have been higher than previously suggested. This study shows the importance of considering the presence of microbial biomass and seawater ions in paleomarine reconstructions

Hypermatrix factors for string and membrane junctions

The adjoint representations of the Lie algebras of the classical groups SU(n), SO(n), and Sp(n) are, respectively, tensor, antisymmetric, and symmetric products of two vector spaces, and hence are matrix representations. We consider the analogous products of three vector spaces and study when they appear as summands in Lie algebra decompositions. The Z3-grading of the exceptional Lie algebras provide such summands and provides representations of classical groups on hypermatrices. The main natural application is a formal study of three-junctions of strings and membranes. Generalizations are also considered.Comment: 25 pages, 4 figures, presentation improved, minor correction

Strain Relaxation Mechanisms and Local Structural Changes in Si_{1-x}$Ge_{x} Alloys

In this work, we address issues pertinent to the understanding of the structural and electronic properties of Si_{1-x} Ge_{x}alloys, namely, (i) how does the lattice constant mismatch between bulk Si and bulk Ge manifests itself in the alloy system? and (ii) what are the relevant strain release mechanisms? To provide answers to these questions, we have carried out an in-depth study of the changes in the local geometric and electronic structures arising from the strain relaxation in Si_{1-x} Ge_{x} alloys using an ab initio molecular dynamics scheme. The optimized lattice constant, while exhibiting a general trend of linear dependence on the composition (Vegard's law), shows a negative deviation from Vegard's law in the vicinity of x=0.5. We delineate the mechanisms responsible for each one of the above features. We show that the radial-strain relaxation through bond stretching is responsible for the overall trend of linear dependence of the lattice constant on the composition. On the other hand, the negative deviation from Vegard's law is shown to arise from the angular-strain relaxation.Comment: 21 pages, 7 figure