Magnetic nanowires (MNWs) were explored as potential magnetic tags for cell detection with giant magneto-resistance (GMR) biosensors based on a handheld system. Due to size, shape anisotropy and higher moment material...
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Magnetic nanowires (MNWs) were explored as potential magnetic tags for cell detection with giant magneto-resistance (GMR) biosensors based on a handheld system. Due to size, shape anisotropy and higher moment materials, the signal detected from a single MNW was 2500 times larger than that from a single magnetic iron oxide nanobead, which is important for ultra-low concentration cell detection. A model was used to determine how the MNW orientation with respect to the GMR sensor impacts detection performance, and the results aligned well with the experimental results. As a proof of concept OSCA-8 cells tagged with Ni MNWs were also detected using the same handheld system. The limit of detection (LOD) in aqueous solution appeared to be 133 cells, and single-cell detection can be realized if the cell is in direct contact with the sensor surface. Since MNWs are already employed in magnetic separation of cells, directly using MNWs as tags in cell detection eliminates the need of additional functionalization with other labels. This largely simplifies the detection process and reduces the risk of contamination during sample preparation.
Digital government services differ from different countries due to different cultures, bureaucracies, financial strength, available infrastructure, literacy levels, among other things. All nations globally, both devel...
ISBN:
(数字)9789380544380
ISBN:
(纸本)9781728129587
Digital government services differ from different countries due to different cultures, bureaucracies, financial strength, available infrastructure, literacy levels, among other things. All nations globally, both developed and developing states are looking for new ways to adopt and integrate digital technology in offering government services to its citizens. Although developing countries like Saudi Arabia face a myriad of challenges in the implementation of digital government services, notable progress has been made. This paper presents a comparative study of digital government services in developed countries and Saudi Arabia. To make this comparison, a citizen satisfaction survey (CSS), service maturity (SM), and citizen service delivery experience (CSDE) results will be presented. For this paper, a comparative study on digital government services in developed countries like the United kingdom, the United States and Norway, and Saudi Arabia has been presented.
The development of narrow-bandgap (Eg ~ 1.2 eV) mixed tin-lead (Sn-Pb) halide perovskites enables all-perovskite tandem solar cells. Whereas pure-lead halide perovskite solar cells (PSCs) have advanced simultaneously ...
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ISBN:
(数字)9781728161150
ISBN:
(纸本)9781728161167
The development of narrow-bandgap (Eg ~ 1.2 eV) mixed tin-lead (Sn-Pb) halide perovskites enables all-perovskite tandem solar cells. Whereas pure-lead halide perovskite solar cells (PSCs) have advanced simultaneously in efficiency and stability, achieving this crucial combination remains a challenge in Sn-Pb PSCs. Here Sn-Pb perovskite grains are anchored with ultra-thin layered perovskites to overcome the efficiency-stability tradeoff. Defect passivation is achieved both on the perovskite film surface and at grain boundaries, an approach implemented by directly introducing phenethylammonium ligands in the antisolvent. This improves device operational stability and also avoids the excess formation of layered perovskites that would otherwise hinder charge transport. Sn-Pb PSCs with fill factors of 79% and a certified PCE of 18.95% are reported - among the highest for Sn-Pb PSCs. Using this approach, a 200-fold enhancement in device operating lifetime is achieved relative to the non-passivated Sn-Pb PSCs under full AM1.5G illumination, and a 200-hour diurnal operating time without efficiency drop is achieved under filtered AM1.5G illumination.
At the core of plasmonic-enhanced applications lies photon energy harvesting and conversion over plasmonic/non-plasmonic multicomponent hybrid materials. The direct excitation of local interfacial electronic states th...
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At the core of plasmonic-enhanced applications lies photon energy harvesting and conversion over plasmonic/non-plasmonic multicomponent hybrid materials. The direct excitation of local interfacial electronic states that arise from the chemical bonding between plasmonic metal and attached functional entity opens up an exceptionally efficient energy transfer channel. However, there is a lack of a general strategy to manipulate these states and insights into the impact of such electronic modulations on light -driven functionalities. We demonstrate in a plasmonic-metal/molecule hybrid system that by precisely manipulating microfacets of nanostructures, it is possible to engineer metal -adsorbate -hybridized interfacial states in terms of both energy gap opening and permissible electronic excitations. Low -index microfacets feature much more efficient interfacial electronic transitions than high -index ones, retarding plasmonic relaxation and entailing enhanced photocatalytic activity toward molecular coupling reactions. This study contributes to pushing forward frontiers of plasmonic research from geometric control to nanostructure engineering and enlightens new strategies for plasmonic-enhanced applications.
Metal-organic frameworks (MOFs) with their tunable topology, functionality and coordination environment have been considered as potential materials for various applications including electrocatalysis. Herein, we have ...
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Metal-organic frameworks (MOFs) with their tunable topology, functionality and coordination environment have been considered as potential materials for various applications including electrocatalysis. Herein, we have synthesised a water coordinated nickel based 2D metal-organic framework (Ni-MOF) and a coordination complex (Ni-C) and investigated their electrocatalytic OER activity. The Ni-MOF showed a 2D sheet structure with one water coordination whereas a four water molecule coordinated charged complex was formed in the Ni-C. Thermogravimetric analysis (TGA) confirmed their water coordination and good thermal stability. Interestingly, electrocatalytic OER studies showed strongly enhanced activity for the Ni-MOF and that it required a low overpotential (194 mV) to produce a geometric current density of 10 mA cm(-2). The Ni-C required 225 mV to produce 10 mA cm(-2). The post-catalytic analysis suggested that the Ni-MOF and Ni-C are converted to nickel hydroxides/oxyhydroxides during electrocatalysis and acted as the catalytic centre. The low Tafel slope and charge transfer resistance further supported the higher activity of Ni-MOF based nickel hydroxides/oxyhydroxides. Chronoamperometric studies revealed the excellent stability of the Ni-MOF based catalyst over 72 h. The present study revealed the potential of developing highly active electrocatalysts based on Ni-MOFs by optimizing the topology and coordination environment.
Compressive strain engineering improves perovskite stability. Twodimensional compressive strain along the in -plane direction can be applied to perovskites through the substrate;however, this in -plane strain results ...
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Compressive strain engineering improves perovskite stability. Twodimensional compressive strain along the in -plane direction can be applied to perovskites through the substrate;however, this in -plane strain results in an offsetting tensile strain perpendicular to the substrate, linked to the positive Poisson ratio of perovskites. Substrateinduced strain engineering has not yet resulted in state-of-the-art operational stability. Here, we seek instead to implement hydrostatic strain in perovskites by embedding lattice -mismatched perovskite quantum dots (QDs) into a perovskite matrix. QD-in-matrix perovskites show a homogeneously strained lattice as evidenced by grazing -incidence X-ray diffraction. We fabricate mixed -halide wide -band -gap (E-g;1.77 eV) QD-in-matrix perovskite solar cells that maintain >90% of their initial power conversion efficiency (PCE) after 200 h of one -sun operation at the maximum power point (MPP), a significant improvement relative to matrix -only devices, which lose 10% (relative) of their initial PCE after 5 h of MPP tracking.
In recent years, many cases of suffocation in school buses among pupils and students have been reported due to poor safety measures. To overcome this critical issue, this project aims to provide a well-designed, safet...
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The hip joint is unique anatomically and physiologically, so a lot of problems may appear through its structure lead to damage. In this study, a 2D/3D model of the hip joint was implemented using a Software platform (...
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ISBN:
(纸本)9781728191119;9781728191126
The hip joint is unique anatomically and physiologically, so a lot of problems may appear through its structure lead to damage. In this study, a 2D/3D model of the hip joint was implemented using a Software platform (SolidWorks program) to study the behavior of the most common compatible materials that may use to design a hip joint (Ti-6-Al4V, Al2O3, and Cr-Co-Mo alloys) under specific load applied (261.6 N) to compare the behavior of the materials based on stress, strain, and displacement response. The stability of the model was observed and verified by static test and the materials have been applied one by one, the results showed that the use of Al2O3 as a material of femoral head presents higher stress values compared to use Cr-Co-Mo or Ti-6-Al4V alloy, according to strain and displacement, Al2O3 gave the lowest values compared to the rest of the alloys.
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