534 research outputs found

    Automation potential of a new, rapid, microscopy based method for screening drug-polymer solubility

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    For the pharmaceutical industry, the preformulation screening of the compatibility of drug and polymeric excipients can often be time-consuming because of the use of trial-and-error approaches. This is also the case for selecting highly effective polymeric excipients for forming molecular dispersions in order to improve the dissolution and subsequent bio-availability of a poorly soluble drug. Previously, we developed a new thermal imaging-based rapid screening method, thermal analysis by structure characterization (TASC), which can rapidly detect the melting point depression of a crystalline drug in the presence of a polymeric material. In this study, we used melting point depression as an indicator of drug solubility in a polymer and further explored the potential of using the TASC method to rapidly screen and identify polymers in which a drug is likely to have high solubility. Here, we used a data bank of 5 model drugs and 10 different pharmaceutical grade polymers to validate the screening potential of TASC. The data indicated that TASC could provide significant improvement in the screening speed and reduce the materials used without compromising the sensitivity of detection. It should be highlighted that the current method is a screening method rather than a method that provides absolute measurement of the degree of solubility of a drug in a polymer. The results of this study confirmed that the TASC results of each drug-polymer pair could be used in data matrices to indicate the presence of significant interaction and solubility of the drug in the polymer. This forms the foundation for automating the screening process using artificial intelligence

    Evaluation of a Learning System to Teach GIS for Civil Engineering

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    An evaluation was conducted on a web-based e-learning system designed to facilitate integration of Geographical Information Systems (GIS) into the Civil Engineering curriculum. The principal goals of the evaluation were to determine the overall effectiveness of the system and to better understand underlying learning processes. Data were collected from 80 students who participated in a computer laboratory session involving a typical geotechnical exercise. Students rated their learning and motivation significantly higher than studying from the class text, and rated the labā€™s applicability to the ā€œreal worldā€ significantly higher than the class text or lecture. Furthermore, students rated their knowledge of GIS significantly higher after the lab session. Qualitative analysis indicated that students were motivated to use the system in order to develop a broad overview of GIS, to learn specific GIS functionality, and as a method for on-going review of GIS

    Towards 5G Zero Trusted Air Interface Architecture

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    5G is destined to be supporting large deployment of Industrial IoT (IIoT) with the characteristics of ultra-high densification and low latency. 5G utilizes a more intelligent architecture, with Radio Access Networks (RANs) no longer constrained by base station proximity or proprietary infrastructure. The 3rd Generation Partnership Project (3GPP) covers telecommunication technologies including RAN, core transport networks and service capabilities. Open RAN Alliance (O-RAN) aims to define implementation and deployment architectures, focusing on open-source interfaces and functional units to further reduce the cost and complexity. O-RAN based 5G networks could use components from different hardware and software vendors, promoting vendor diversity, interchangeability and 5G supply chain resiliency. Both 3GPP and O-RAN 5G have to manage the security and privacy challenges that arose from the deployment. Many existing research studies have addressed the threats and vulnerabilities within each system. 5G also has the overwhelming challenges in compliance with privacy regulations and requirements which mandate the user identifiable information need to be protected. In this paper, we look into the 3GPP and O-RAN 5G security and privacy designs and the identified threats and vulnerabilities. We also discuss how to extend the Zero Trust Model to provide advanced protection over 5G air interfaces and network components

    Impact of ESD Generator Parameters on Failure Level in Fast CMOS System

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    Electrostatic discharge (ESD) generators are used for testing the robustness of electronics towards ESD. Most generators are built in accordance with the IEC 61000-4-2 specifications. It is shown that the voltage induced in a small loop correlates with the failure level observed in an ESD failure test on the systems comprising fast CMOS devices, while rise time and current derivative of the discharge current did not correlate well. The electric parameters are compared for typical and modified ESD generators and the effect on the failure level of fast CMOS electronics is investigated. The consequences of aligning an ESD standard with the suggestions of this paper are discussed with respect to reproducibility and test severity

    All-Cellulose-Based Quasi-Solid-State Sodium-Ion Hybrid Capacitors Enabled by Structural Hierarchy

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    Na-ion hybrid capacitors consisting of battery-type anodes and capacitor-style cathodes are attracting increasing attention on account of the abundance of sodium-based resources as well as the potential to bridge the gap between batteries (high energy) and supercapacitors (high power). Herein, hierarchically structured carbon materials inspired by multiscale building units of cellulose from nature are assembled with cellulose-based gel electrolytes into Na-ion capacitors. Nonporous hard carbon anodes are obtained through the direct thermal pyrolysis of cellulose nanocrystals. Nitrogen-doped carbon cathodes with a coral-like hierarchically porous architecture are prepared via hydrothermal carbonization and activation of cellulose microfibrils. The reversible charge capacity of the anode is 256.9 mAh gāˆ’1 when operating at 0.1 A gāˆ’1 from 0 to 1.5 V versus Na+/Na, and the discharge capacitance of cathodes tested within 1.5 to 4.2 V versus Na+/Na is 212.4 F gāˆ’1 at 0.1 A gāˆ’1. Utilizing Na+ and ClO4āˆ’ as charge carriers, the energy density of the full Na-ion capacitor with two asymmetric carbon electrodes can reach 181 Wh kgāˆ’1 at 250 W kgāˆ’1, which is one of the highest energy devices reported until now. Combined with macrocellulose-based gel electrolytes, all-cellulose-based quasi-solid-state devices are demonstrated possessing additional advantages in terms of overall sustainability

    Characterization of heterogeneity and spatial distribution of phases in complex solid dispersions by thermal analysis by structural characterization and X-ray micro computed tomography

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    Purpose: This study investigated the effect of drug-excipient miscibility on the heterogeneity and spatial distribution of phase separation in pharmaceutical solid dispersions at a micron-scale using two novel and complementary characterization techniques, thermal analysis by structural characterization (TASC) and X-ray micro-computed tomography (XCT) in conjunction with conventional characterization methods. Method: Complex dispersions containing felodipine, TPGS, PEG and PEO were prepared using hot melt extrusion-injection moulding. The phase separation behavior of the samples was characterized using TASC and XCT in conjunction with conventional thermal, microscopic and spectroscopic techniques. The in vitro drug release study was performed to demonstrate the impact of phase separation on dissolution of the dispersions. Results: The conventional characterization results indicated the phase separating nature of the carrier materials in the patches and the presence of crystalline drug in the patches with the highest drug loading (30% w/w). TASC and XCT where used to provide insight into the spatial configuration of the separate phases. TASC enabled assessment of the increased heterogeneity of the dispersions with increasing the drug loading. XCT allowed the visualization of the accumulation of phase separated (crystalline) drug clusters at the interface of air pockets in the patches with highest drug loading which led to poor dissolution performance. Semi-quantitative assessment of the phase separated drug clusters in the patches were attempted using XCT. Conclusion: TASC and XĪ¼CT can provide unique information regarding the phase separation behavior of solid dispersions which can be closely associated with important product quality indicators such as heterogeneity and microstructure

    The First Provenance Challenge

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    The first Provenance Challenge was set up in order to provide a forum for the community to help understand the capabilities of different provenance systems and the expressiveness of their provenance representations. To this end, a Functional Magnetic Resonance Imaging workflow was defined, which participants had to either simulate or run in order to produce some provenance representation, from which a set of identified queries had to be implemented and executed. Sixteen teams responded to the challenge, and submitted their inputs. In this paper, we present the challenge workflow and queries, and summarise the participants contributions

    Clip-on Gadgets: Expanding Multi-touch Interaction Area with Unpowered Tactile Controls

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    ABSTRACT Virtual keyboards and controls, commonly used on mobile multi-touch devices, occlude content of interest and do not provide tactile feedback. Clip-on Gadgets solve these issues by extending the interaction area of multi-touch devices with physical controllers. Clip-on Gadgets use only conductive materials to map user input on the controllers to touch points on the edges of screens; therefore, it is batteryfree, lightweight, and low-cost. In addition, it can be used in combination with multi-touch gestures. We present several hardware designs and a software toolkit, which enable users to simply attach Clip-on Gadgets to an edge of a device and start interacting with it

    3D Heisenberg universality in the Van der Waals antiferromagnet NiPS3_3

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    Van der Waals (vdW) magnetic materials are comprised of layers of atomically thin sheets, making them ideal platforms for studying magnetism at the two-dimensional (2D) limit. These materials are at the center of a host of novel types of experiments, however, there are notably few pathways to directly probe their magnetic structure. We report the magnetic order within a single crystal of NiPS3_3 and show it can be accessed with resonant elastic X-ray diffraction along the edge of the vdW planes in a carefully grown crystal by detecting structurally forbidden resonant magnetic X-ray scattering. We find the magnetic order parameter has a critical exponent of Ī²āˆ¼0.36\beta\sim0.36, indicating that the magnetism of these vdW crystals is more adequately characterized by the three-dimensional (3D) Heisenberg universality class. We verify these findings with first-principle density functional theory, Monte-Carlo simulations, and density matrix renormalization group calculations

    Cross-National Differences in Victimization : Disentangling the Impact of Composition and Context

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    Varying rates of criminal victimization across countries are assumed to be the outcome of countrylevel structural constraints that determine the supply ofmotivated oĀ”enders, as well as the differential composition within countries of suitable targets and capable guardianship. However, previous empirical tests of these ā€˜compositionalā€™ and ā€˜contextualā€™ explanations of cross-national diĀ”erences have been performed upon macro-level crime data due to the unavailability of comparable individual-level data across countries. This limitation has had two important consequences for cross-national crime research. First, micro-/meso-level mechanisms underlying cross-national differences cannot be truly inferred from macro-level data. Secondly, the eĀ”ects of contextual measures (e.g. income inequality) on crime are uncontrolled for compositional heterogeneity. In this paper, these limitations are overcome by analysing individual-level victimization data across 18 countries from the International CrimeVictims Survey. Results from multi-level analyses on theft and violent victimization indicate that the national level of income inequality is positively related to risk, independent of compositional (i.e. micro- and meso-level) diĀ”erences. Furthermore, crossnational variation in victimization rates is not only shaped by diĀ”erences in national context, but also by varying composition. More speciĀ¢cally, countries had higher crime rates the more they consisted of urban residents and regions with lowaverage social cohesion.
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