Search

Porous silicon has generated interest in scientific community after its photoluminescence discovery and thereafter, research was focused on to the chemical functionalization of silicon and subsequent anchoring of nanoparticles onto silicon surface. In the present work, the porous silicon has been effectively modified with magnetic nanoparticles which were prepared through metallorganic approach. The as-fabricated magnetic-porous silicon composites were characterised using FTIR and Raman spectroscopies, Scanning Electron Microscopy (SEM) as well as magnetic measurements.

Porous silicon has generated interest in scientific community after its photoluminescence discovery and thereafter, research was focused on to the chemical functionalization of silicon and subsequent anchoring of nanoparticles onto silicon surface. In the present work, the porous silicon has been effectively modified with magnetic nanoparticles which were prepared through metallorganic approach. The as-fabricated magnetic-porous silicon composites were characterised using FTIR and Raman spectroscopies, Scanning Electron Microscopy (SEM) as well as magnetic measurements.

Porous silicon has generated interest in scientific community after its photoluminescence discovery and thereafter, research was focused on to the chemical functionalization of silicon and subsequent anchoring of nanoparticles onto silicon surface. In the present work, the porous silicon has been effectively modified with magnetic nanoparticles which were prepared through metallorganic approach. The as-fabricated magnetic-porous silicon composites were characterised using FTIR and Raman spectroscopies, Scanning Electron Microscopy (SEM) as well as magnetic measurements.

Porous silicon has generated interest in scientific community after its photoluminescence discovery and thereafter, research was focused on to the chemical functionalization of silicon and subsequent anchoring of nanoparticles onto silicon surface. In the present work, the porous silicon has been effectively modified with magnetic nanoparticles which were prepared through metallorganic approach. The as-fabricated magnetic-porous silicon composites were characterised using FTIR and Raman spectroscopies, Scanning Electron Microscopy (SEM) as well as magnetic measurements.

Lubricin (LUB, aka PRG4), a mucin-like glycoprotein, is best known for the significant role it plays in the boundary lubrication, wear protection, and adhesion control systems in human joints. However, LUB exhibits a number of diverse and useful properties, including a remarkable ability to self-assemble into a telechelic brush structure onto virtually any substrate. This self-assembly behavior has spawned the emergence of numerous nontraditional applications of LUB coatings in numerous areas such as microfluidics, electrochemical sensors, contact lenses, antifouling surfaces, and bionic neural interfaces. Although LUB will readily self-assemble on most substrates, it has become apparent that the substrate has a significant influence on the LUB layer's demonstrated lubrication, antiadhesion, electrokinetic, and size-selective transport properties; however, investigations into LUB-substrate interactions and how they influence the self-assembled LUB layer structure remain a neglected aspect of LUB research. This study utilizes AFM force spectroscopy to directly assess the adhesion energy of LUB molecules adsorbed to a wide variety of different substrates which include inorganic, polymeric, and metallic materials. An analysis of the steric repulsive forces measured on approach provides a qualitative assessment of the LUB layer's mechanical modulus, related to the chain packing density, across substrates. These modulus measurements, combined with characteristic features and the dwell time dependence of the LUB adhesion forces provide insight into the organization and uniformity of the LUB brush structure. The results of these measurements indicate that LUB interactions with different substrates are highly variable and substrate-specific, resulting in a surprisingly broad spectrum of adhesion energies and layer properties (i.e., chain density, uniformity, etc.) which are not, themselves, correlated or easily predicted by substrate properties. In addition, this study find

Lubricin (LUB, aka PRG4), a mucin-like glycoprotein, is best known for the significant role it plays in the boundary lubrication, wear protection, and adhesion control systems in human joints. However, LUB exhibits a number of diverse and useful properties, including a remarkable ability to self-assemble into a telechelic brush structure onto virtually any substrate. This self-assembly behavior has spawned the emergence of numerous nontraditional applications of LUB coatings in numerous areas such as microfluidics, electrochemical sensors, contact lenses, antifouling surfaces, and bionic neural interfaces. Although LUB will readily self-assemble on most substrates, it has become apparent that the substrate has a significant influence on the LUB layer's demonstrated lubrication, antiadhesion, electrokinetic, and size-selective transport properties; however, investigations into LUB-substrate interactions and how they influence the self-assembled LUB layer structure remain a neglected aspect of LUB research. This study utilizes AFM force spectroscopy to directly assess the adhesion energy of LUB molecules adsorbed to a wide variety of different substrates which include inorganic, polymeric, and metallic materials. An analysis of the steric repulsive forces measured on approach provides a qualitative assessment of the LUB layer's mechanical modulus, related to the chain packing density, across substrates. These modulus measurements, combined with characteristic features and the dwell time dependence of the LUB adhesion forces provide insight into the organization and uniformity of the LUB brush structure. The results of these measurements indicate that LUB interactions with different substrates are highly variable and substrate-specific, resulting in a surprisingly broad spectrum of adhesion energies and layer properties (i.e., chain density, uniformity, etc.) which are not, themselves, correlated or easily predicted by substrate properties. In addition, this study find

Lubricin (LUB, aka PRG4), a mucin-like glycoprotein, is best known for the significant role it plays in the boundary lubrication, wear protection, and adhesion control systems in human joints. However, LUB exhibits a number of diverse and useful properties, including a remarkable ability to self-assemble into a telechelic brush structure onto virtually any substrate. This self-assembly behavior has spawned the emergence of numerous nontraditional applications of LUB coatings in numerous areas such as microfluidics, electrochemical sensors, contact lenses, antifouling surfaces, and bionic neural interfaces. Although LUB will readily self-assemble on most substrates, it has become apparent that the substrate has a significant influence on the LUB layer's demonstrated lubrication, antiadhesion, electrokinetic, and size-selective transport properties; however, investigations into LUB-substrate interactions and how they influence the self-assembled LUB layer structure remain a neglected aspect of LUB research. This study utilizes AFM force spectroscopy to directly assess the adhesion energy of LUB molecules adsorbed to a wide variety of different substrates which include inorganic, polymeric, and metallic materials. An analysis of the steric repulsive forces measured on approach provides a qualitative assessment of the LUB layer's mechanical modulus, related to the chain packing density, across substrates. These modulus measurements, combined with characteristic features and the dwell time dependence of the LUB adhesion forces provide insight into the organization and uniformity of the LUB brush structure. The results of these measurements indicate that LUB interactions with different substrates are highly variable and substrate-specific, resulting in a surprisingly broad spectrum of adhesion energies and layer properties (i.e., chain density, uniformity, etc.) which are not, themselves, correlated or easily predicted by substrate properties. In addition, this study find

Lubricin (LUB, aka PRG4), a mucin-like glycoprotein, is best known for the significant role it plays in the boundary lubrication, wear protection, and adhesion control systems in human joints. However, LUB exhibits a number of diverse and useful properties, including a remarkable ability to self-assemble into a telechelic brush structure onto virtually any substrate. This self-assembly behavior has spawned the emergence of numerous nontraditional applications of LUB coatings in numerous areas such as microfluidics, electrochemical sensors, contact lenses, antifouling surfaces, and bionic neural interfaces. Although LUB will readily self-assemble on most substrates, it has become apparent that the substrate has a significant influence on the LUB layer's demonstrated lubrication, antiadhesion, electrokinetic, and size-selective transport properties; however, investigations into LUB-substrate interactions and how they influence the self-assembled LUB layer structure remain a neglected aspect of LUB research. This study utilizes AFM force spectroscopy to directly assess the adhesion energy of LUB molecules adsorbed to a wide variety of different substrates which include inorganic, polymeric, and metallic materials. An analysis of the steric repulsive forces measured on approach provides a qualitative assessment of the LUB layer's mechanical modulus, related to the chain packing density, across substrates. These modulus measurements, combined with characteristic features and the dwell time dependence of the LUB adhesion forces provide insight into the organization and uniformity of the LUB brush structure. The results of these measurements indicate that LUB interactions with different substrates are highly variable and substrate-specific, resulting in a surprisingly broad spectrum of adhesion energies and layer properties (i.e., chain density, uniformity, etc.) which are not, themselves, correlated or easily predicted by substrate properties. In addition, this study find

Lubricin (LUB, aka PRG4), a mucin-like glycoprotein, is best known for the significant role it plays in the boundary lubrication, wear protection, and adhesion control systems in human joints. However, LUB exhibits a number of diverse and useful properties, including a remarkable ability to self-assemble into a telechelic brush structure onto virtually any substrate. This self-assembly behavior has spawned the emergence of numerous nontraditional applications of LUB coatings in numerous areas such as microfluidics, electrochemical sensors, contact lenses, antifouling surfaces, and bionic neural interfaces. Although LUB will readily self-assemble on most substrates, it has become apparent that the substrate has a significant influence on the LUB layer's demonstrated lubrication, antiadhesion, electrokinetic, and size-selective transport properties; however, investigations into LUB-substrate interactions and how they influence the self-assembled LUB layer structure remain a neglected aspect of LUB research. This study utilizes AFM force spectroscopy to directly assess the adhesion energy of LUB molecules adsorbed to a wide variety of different substrates which include inorganic, polymeric, and metallic materials. An analysis of the steric repulsive forces measured on approach provides a qualitative assessment of the LUB layer's mechanical modulus, related to the chain packing density, across substrates. These modulus measurements, combined with characteristic features and the dwell time dependence of the LUB adhesion forces provide insight into the organization and uniformity of the LUB brush structure. The results of these measurements indicate that LUB interactions with different substrates are highly variable and substrate-specific, resulting in a surprisingly broad spectrum of adhesion energies and layer properties (i.e., chain density, uniformity, etc.) which are not, themselves, correlated or easily predicted by substrate properties. In addition, this study find

The fabrication of high efficiency perovskite solar cells at larger scales will rely on the optimized deposition conditions of every layer using scalable methodologies. Most current perovskite devices that employ the archetypal TiO2 hole blocking layer utilise a simple air-brush approach. This approach is not scalable as it results in significant layer inhomogeneity across larger devices areas. To overcome this inherent limitation, in this work we use ultrasonic spray deposition as an alternative approach for the TiO2 deposition. Focusing on identical reaction chemistries as for air-brush, namely bis(isopropoxide)-bis(acetylacetonate) titanium (IV) based solutions, we find that under optimized conditions smooth TiO2 layers can be readily deposited over scalable areas on fluorine doped tin oxide. Using these layers at electron transport layers within diodes and perovskite solar cell devices, we develop effective benchmarks that predict the effectiveness of the underlying charge transport layer. This enables for the standardisation of the electron transport properties within any batch of solar cells, thus providing a readily accessible pathway towards enhancing reproducibility of fabricated devices. Under these optimized conditions, methylammonium lead halide photovoltaic devices readily possessing efficiencies of >16% are achieved. Importantly, the mean batch efficiency of devices fabricated using the ultrasonic spray deposition method is significantly improved and the standard deviation is drastically narrowed. The deposition of an additional meso-porous layer is found to lead to further improvements for both of these parameters.

The fabrication of high efficiency perovskite solar cells at larger scales will rely on the optimized deposition conditions of every layer using scalable methodologies. Most current perovskite devices that employ the archetypal TiO2 hole blocking layer utilise a simple air-brush approach. This approach is not scalable as it results in significant layer inhomogeneity across larger devices areas. To overcome this inherent limitation, in this work we use ultrasonic spray deposition as an alternative approach for the TiO2 deposition. Focusing on identical reaction chemistries as for air-brush, namely bis(isopropoxide)-bis(acetylacetonate) titanium (IV) based solutions, we find that under optimized conditions smooth TiO2 layers can be readily deposited over scalable areas on fluorine doped tin oxide. Using these layers at electron transport layers within diodes and perovskite solar cell devices, we develop effective benchmarks that predict the effectiveness of the underlying charge transport layer. This enables for the standardisation of the electron transport properties within any batch of solar cells, thus providing a readily accessible pathway towards enhancing reproducibility of fabricated devices. Under these optimized conditions, methylammonium lead halide photovoltaic devices readily possessing efficiencies of >16% are achieved. Importantly, the mean batch efficiency of devices fabricated using the ultrasonic spray deposition method is significantly improved and the standard deviation is drastically narrowed. The deposition of an additional meso-porous layer is found to lead to further improvements for both of these parameters.

The fabrication of high efficiency perovskite solar cells at larger scales will rely on the optimized deposition conditions of every layer using scalable methodologies. Most current perovskite devices that employ the archetypal TiO2 hole blocking layer utilise a simple air-brush approach. This approach is not scalable as it results in significant layer inhomogeneity across larger devices areas. To overcome this inherent limitation, in this work we use ultrasonic spray deposition as an alternative approach for the TiO2 deposition. Focusing on identical reaction chemistries as for air-brush, namely bis(isopropoxide)-bis(acetylacetonate) titanium (IV) based solutions, we find that under optimized conditions smooth TiO2 layers can be readily deposited over scalable areas on fluorine doped tin oxide. Using these layers at electron transport layers within diodes and perovskite solar cell devices, we develop effective benchmarks that predict the effectiveness of the underlying charge transport layer. This enables for the standardisation of the electron transport properties within any batch of solar cells, thus providing a readily accessible pathway towards enhancing reproducibility of fabricated devices. Under these optimized conditions, methylammonium lead halide photovoltaic devices readily possessing efficiencies of >16% are achieved. Importantly, the mean batch efficiency of devices fabricated using the ultrasonic spray deposition method is significantly improved and the standard deviation is drastically narrowed. The deposition of an additional meso-porous layer is found to lead to further improvements for both of these parameters.

A novel wallboard with double layers shape-stabilized phase change materials (SSPCMs) for year round energy management was proposed. Its energy saving potential in five typical climate regions of China was studied. One office room integrated with double layers SSPCMs wallboard was used for simulation platform. The other normal office room with the same envelope and just without double layers SSPCMs wallboard was used as reference room. Studies were conducted to investigate the energy saving potential of double layers SSPCMs wallboard in five cities representing five typical climate regions of China, including severe cold region, cold region, hot summer and cold winter region, hot summer and warm winter region, mild region. The optimal melting temperature and corresponding thickness of SSPCMs wallboard in five representative cities were given when the energy saving potential reached maximal value. It concluded that the optimal melting temperature of internal SSPCM layer was effected by indoor air temperature and the optimal melting temperature of external SSPCM layer was effected by outdoor solar air temperature. The regularity of optimal values in the five representative cities were given for reference in this scope.

Hexagonal boron nitride nanosheets (h-BNNS) have been proposed as an ideal substrate for graphene-based electronic devices, but the synthesis of large and homogeneous h-BNNS is still challenging. In this contribution, we report a facile synthesis of few-layer h-BNNS on melted copper via an atmospheric pressure chemical vapor deposition process. Comparative studies confirm the advantage of using melted copper over solid copper as a catalyst substrate. The former leads to the formation of single crystalline h-BNNS that is several microns in size and mostly in mono- and bi-layer forms, in contrast to the polycrystalline and mixed multiple layers (1-10) yielded by the latter. This difference is likely to be due to the significantly reduced and uniformly distributed nucleation sites on the smooth melted surface, in contrast to the large amounts of unevenly distributed nucleation sites that are associated with grain boundaries and other defects on the solid surface. This synthesis is expected to contribute to the development of large-scale manufacturing of h-BNNS/graphene-based electronics.

Hexagonal boron nitride nanosheets (h-BNNS) have been proposed as an ideal substrate for graphene-based electronic devices, but the synthesis of large and homogeneous h-BNNS is still challenging. In this contribution, we report a facile synthesis of few-layer h-BNNS on melted copper via an atmospheric pressure chemical vapor deposition process. Comparative studies confirm the advantage of using melted copper over solid copper as a catalyst substrate. The former leads to the formation of single crystalline h-BNNS that is several microns in size and mostly in mono- and bi-layer forms, in contrast to the polycrystalline and mixed multiple layers (1-10) yielded by the latter. This difference is likely to be due to the significantly reduced and uniformly distributed nucleation sites on the smooth melted surface, in contrast to the large amounts of unevenly distributed nucleation sites that are associated with grain boundaries and other defects on the solid surface. This synthesis is expected to contribute to the development of large-scale manufacturing of h-BNNS/graphene-based electronics.

Fe/Fe3O4/N-carbon composite consisting of a porous carbon matrix containing a highly conductive N-doped graphene-like network and Fe/Fe3O4 nanoparticles was prepared. The porous carbon has a hierarchical structure which is inherited from rice husk and the N-doped graphene-like network formed in situ. When used as an anode material for lithium batteries, the composite delivered a reversible capacity of approximately 610 mA h g(-1) at a current density of 200 mA g(-1) even after 100 cycles, due to the synergism between the unique hierarchical porous structures, highly electrically conductive N-doped graphene- like networks and nanosized particles of Fe/Fe3O4. This work provides a simple approach to prepare N-doped porous carbon activated nanoparticle composites which could be used to improve the electrochemical performance of lithium ion batteries.

Electron backscatter diffraction (EBSD) analysis has been presented to investigate the microstructure and microtexture evolutions of deformed oxide scale formed on a microalloyed steel during hot rolling and accelerated cooling. Magnetite and wustite in oxide layers share a strong {0. 0. 1}and a weak {1. 1. 0} fibres texture parallel to the oxide growth. Trigonal hematite develops the {0. 0. 0. 1} basal fibre parallel to the crystallographic plane {1. 1. 1} in magnetite. Taylor factor estimates have been conducted to elucidate the microtexture evolution. The fine-grained magnetite seam adjacent to the substrate is governed by stress relief and ions vacancy diffusion mechanism.

Hexagonal boron nitride nanosheets (h-BNNS) have been proposed as an ideal substrate for graphene-based electronic devices, but the synthesis of large and homogeneous h-BNNS is still challenging. In this contribution, we report a facile synthesis of few-layer h-BNNS on melted copper via an atmospheric pressure chemical vapor deposition process. Comparative studies confirm the advantage of using melted copper over solid copper as a catalyst substrate. The former leads to the formation of single crystalline h-BNNS that is several microns in size and mostly in mono- and bi-layer forms, in contrast to the polycrystalline and mixed multiple layers (1-10) yielded by the latter. This difference is likely to be due to the significantly reduced and uniformly distributed nucleation sites on the smooth melted surface, in contrast to the large amounts of unevenly distributed nucleation sites that are associated with grain boundaries and other defects on the solid surface. This synthesis is expected to contribute to the development of large-scale manufacturing of h-BNNS/graphene-based electronics.

Hexagonal boron nitride nanosheets (h-BNNS) have been proposed as an ideal substrate for graphene-based electronic devices, but the synthesis of large and homogeneous h-BNNS is still challenging. In this contribution, we report a facile synthesis of few-layer h-BNNS on melted copper via an atmospheric pressure chemical vapor deposition process. Comparative studies confirm the advantage of using melted copper over solid copper as a catalyst substrate. The former leads to the formation of single crystalline h-BNNS that is several microns in size and mostly in mono- and bi-layer forms, in contrast to the polycrystalline and mixed multiple layers (1-10) yielded by the latter. This difference is likely to be due to the significantly reduced and uniformly distributed nucleation sites on the smooth melted surface, in contrast to the large amounts of unevenly distributed nucleation sites that are associated with grain boundaries and other defects on the solid surface. This synthesis is expected to contribute to the development of large-scale manufacturing of h-BNNS/graphene-based electronics.

Hexagonal boron nitride nanosheets (h-BNNS) have been proposed as an ideal substrate for graphene-based electronic devices, but the synthesis of large and homogeneous h-BNNS is still challenging. In this contribution, we report a facile synthesis of few-layer h-BNNS on melted copper via an atmospheric pressure chemical vapor deposition process. Comparative studies confirm the advantage of using melted copper over solid copper as a catalyst substrate. The former leads to the formation of single crystalline h-BNNS that is several microns in size and mostly in mono- and bi-layer forms, in contrast to the polycrystalline and mixed multiple layers (1-10) yielded by the latter. This difference is likely to be due to the significantly reduced and uniformly distributed nucleation sites on the smooth melted surface, in contrast to the large amounts of unevenly distributed nucleation sites that are associated with grain boundaries and other defects on the solid surface. This synthesis is expected to contribute to the development of large-scale manufacturing of h-BNNS/graphene-based electronics.

Aligned CoF2 nanochannel layers have been formed by self-ordering electrochemical anodization. In voltammograms these layers provide multiple oxidation states, an almost ideal rectangular pseudocapacitive behavior, a high specific capacitance and good capacitance retention. These layers may thus be promising for supercapacitor applications. the Partner Organisations 2014.

Aligned CoF2 nanochannel layers have been formed by self-ordering electrochemical anodization. In voltammograms these layers provide multiple oxidation states, an almost ideal rectangular pseudocapacitive behavior, a high specific capacitance and good capacitance retention. These layers may thus be promising for supercapacitor applications. the Partner Organisations 2014.

Aligned CoF2 nanochannel layers have been formed by self-ordering electrochemical anodization. In voltammograms these layers provide multiple oxidation states, an almost ideal rectangular pseudocapacitive behavior, a high specific capacitance and good capacitance retention. These layers may thus be promising for supercapacitor applications. the Partner Organisations 2014.

Aligned CoF2 nanochannel layers have been formed by self-ordering electrochemical anodization. In voltammograms these layers provide multiple oxidation states, an almost ideal rectangular pseudocapacitive behavior, a high specific capacitance and good capacitance retention. These layers may thus be promising for supercapacitor applications. the Partner Organisations 2014.

Oxide layer on the surface of a high speed steel (HSS) hot work roll can act as a protective layer and affects the wear and friction between the strip and the roll. In the numerical design of a work roll, it is necessary to understand the mechanical properties of these oxide layers. This paper describes a combined FE simulations and nanoindentation experiments to obtain the depth dependent mechanical properties of oxide layers on HSS. The mechanical properties of this layer, including the elastic modulus, yield strength, Poisson's ratio and porosity, are inferred from the input parameters to the FE simulations after the simulated load-displacement curves match the experimental curves to within a specified tolerance. The results showed that the outer layer has a higher modulus and higher hardness than the inner layer. The interaction between the mechanical properties and nanoindentation parameters such as the maximum load and unloading slope of the load-displacement curves were established via multiple regression analysis. The maximum load and slope of the load-displacement were strongly correlated with the elastic modulus and yield strength whilst the relationship between porosity and Poisson's ratio is relatively weak. This paper describes a combined FE simulations and nanoindentation experiments to obtain the depth dependent mechanical properties of oxide layers on high speed steels (HSS). The interaction between the mechanical properties and nanoindentation parameters such as the maximum load and unloading slope of the load-displacement curves are established via multiple regression analysis.

We are developing two-layered Yttrium Barium Copper Oxide (YBCO) thin film structures for energy efficient data links for superconducting electronics and present the results of their property measurements. High temperature superconductors (HTS) are advantageous for the implementation of energy-efficient cables interconnecting low temperature superconductor-based circuits and other cryogenic electronics circuits at higher temperature stages. The advantages of the HTS cables come from their low loss and low dispersion properties, allowing ballistic transfer of low power signals with very high bandwidth, low heat conduction and negligible inter-line crosstalk. The microstrip line cable geometry for typical materials is a two-layered film, in which the two superconducting layers are separated by an insulation layer with a minimized permittivity. We have made a proof of concept design of two YBCO films grown by pulsed laser deposition and then assembled into a sandwich with uniform insulating interlayer of tens of micrometers thick. We report on results obtained from such systems assembled in different ways. Structural and electromagnetic properties have been examined on individual films and on the corresponding sandwich composite.

This paper presents a series of new single-grain optically stimulated luminescence (OSL) ages for the Still Bay at Blombos Cave, South Africa, and compares them to previously published OSL, thermoluminescence (TL) and electron-spin resonance (ESR) ages for this site. Details are provided about the measurement and analytical procedures, including a discussion of the characteristics of the OSL signals of individual quartz grains. This forms the basis for further investigations into the sensitivity of the equivalent dose (De) estimates to a range of different analytical approaches, including changes in the size of the test dose, the choice of signal integration interval, the subtraction of an appropriate background, and isolation of the most light-sensitive ('fast') component of quartz OSL. We also report the results of an inter-operator test of De determination using seven new samples from Blombos Cave, and demonstrate the reproducibility of results obtained for two samples that had been dated previously at another laboratory and were measured and analysed again in this study. Together, these tests validate the robustness of the Blombos Cave single-grain OSL age estimates to a variety of alternative OSL dating procedures. We have incorporated, for the first time, these ages for Blombos Cave into a data set of all single-grain OSL ages for Still Bay and Howieson's Poort sites across southern Africa, and have used a statistical model to re-evaluate the timing and duration of the Still Bay industry. We calculate the most plausible start and end dates of the Still Bay as 72.2 ka and 71.3 ka, respectively - amounting to a duration of 0.9 ka - and estimate (with conventional 95% confidence) that this industry began no earlier than 75.5 ka, ended no later than 67.8 ka and lasted no longer than 6.6 ka.

This paper presents a series of new single-grain optically stimulated luminescence (OSL) ages for the Still Bay at Blombos Cave, South Africa, and compares them to previously published OSL, thermoluminescence (TL) and electron-spin resonance (ESR) ages for this site. Details are provided about the measurement and analytical procedures, including a discussion of the characteristics of the OSL signals of individual quartz grains. This forms the basis for further investigations into the sensitivity of the equivalent dose (De) estimates to a range of different analytical approaches, including changes in the size of the test dose, the choice of signal integration interval, the subtraction of an appropriate background, and isolation of the most light-sensitive ('fast') component of quartz OSL. We also report the results of an inter-operator test of De determination using seven new samples from Blombos Cave, and demonstrate the reproducibility of results obtained for two samples that had been dated previously at another laboratory and were measured and analysed again in this study. Together, these tests validate the robustness of the Blombos Cave single-grain OSL age estimates to a variety of alternative OSL dating procedures. We have incorporated, for the first time, these ages for Blombos Cave into a data set of all single-grain OSL ages for Still Bay and Howieson's Poort sites across southern Africa, and have used a statistical model to re-evaluate the timing and duration of the Still Bay industry. We calculate the most plausible start and end dates of the Still Bay as 72.2 ka and 71.3 ka, respectively - amounting to a duration of 0.9 ka - and estimate (with conventional 95% confidence) that this industry began no earlier than 75.5 ka, ended no later than 67.8 ka and lasted no longer than 6.6 ka.

This paper presents a series of new single-grain optically stimulated luminescence (OSL) ages for the Still Bay at Blombos Cave, South Africa, and compares them to previously published OSL, thermoluminescence (TL) and electron-spin resonance (ESR) ages for this site. Details are provided about the measurement and analytical procedures, including a discussion of the characteristics of the OSL signals of individual quartz grains. This forms the basis for further investigations into the sensitivity of the equivalent dose (De) estimates to a range of different analytical approaches, including changes in the size of the test dose, the choice of signal integration interval, the subtraction of an appropriate background, and isolation of the most light-sensitive ('fast') component of quartz OSL. We also report the results of an inter-operator test of De determination using seven new samples from Blombos Cave, and demonstrate the reproducibility of results obtained for two samples that had been dated previously at another laboratory and were measured and analysed again in this study. Together, these tests validate the robustness of the Blombos Cave single-grain OSL age estimates to a variety of alternative OSL dating procedures. We have incorporated, for the first time, these ages for Blombos Cave into a data set of all single-grain OSL ages for Still Bay and Howieson's Poort sites across southern Africa, and have used a statistical model to re-evaluate the timing and duration of the Still Bay industry. We calculate the most plausible start and end dates of the Still Bay as 72.2 ka and 71.3 ka, respectively - amounting to a duration of 0.9 ka - and estimate (with conventional 95% confidence) that this industry began no earlier than 75.5 ka, ended no later than 67.8 ka and lasted no longer than 6.6 ka.

This paper presents a series of new single-grain optically stimulated luminescence (OSL) ages for the Still Bay at Blombos Cave, South Africa, and compares them to previously published OSL, thermoluminescence (TL) and electron-spin resonance (ESR) ages for this site. Details are provided about the measurement and analytical procedures, including a discussion of the characteristics of the OSL signals of individual quartz grains. This forms the basis for further investigations into the sensitivity of the equivalent dose (De) estimates to a range of different analytical approaches, including changes in the size of the test dose, the choice of signal integration interval, the subtraction of an appropriate background, and isolation of the most light-sensitive ('fast') component of quartz OSL. We also report the results of an inter-operator test of De determination using seven new samples from Blombos Cave, and demonstrate the reproducibility of results obtained for two samples that had been dated previously at another laboratory and were measured and analysed again in this study. Together, these tests validate the robustness of the Blombos Cave single-grain OSL age estimates to a variety of alternative OSL dating procedures. We have incorporated, for the first time, these ages for Blombos Cave into a data set of all single-grain OSL ages for Still Bay and Howieson's Poort sites across southern Africa, and have used a statistical model to re-evaluate the timing and duration of the Still Bay industry. We calculate the most plausible start and end dates of the Still Bay as 72.2 ka and 71.3 ka, respectively - amounting to a duration of 0.9 ka - and estimate (with conventional 95% confidence) that this industry began no earlier than 75.5 ka, ended no later than 67.8 ka and lasted no longer than 6.6 ka.

The present work reports the enhancement of the photoelectrochemical water splitting performance of in-situ silicon (Si)-doped nanotubular/nanoporous (NT/NP) layers. These layers were grown by self-organizing anodizationon Fe-Si alloys of various Sicontent. The incorporation of Si is found to retard the layer growth rates, leadsto a more pronounced nanotubular morphology, and most importantly, an improved photoelectrochemical behavior. By increasing Si content from1, 2 to 5 at.% in the iron oxide NT/NP photoanodes, the photocurrent onset potential shifts favorably to lower values. At 1.3 V vs. RHE, hematite layer with 5 at.% Si shows a 5-fold increase of the photocurrent, i.e. 0.5 mA cm -2 in comparison to 0.1 mA cm-2 for the undoped samples. The study also reveals that a suitable layer thickness is essential to achieve a beneficial effect of the Si doping. 2013 Elsevier B.V. All rights reserved.

Nanoporous materials: High-aspect-ratio, ordered porous Co 3O4 layers were formed by self-organizing anodization of a cobalt substrate and subsequent annealing. The key for successful formation of such layers is to sufficiently suppress competing oxygen evolution during anodization. The aligned Co3O4 channel layers behave as a highly efficient water oxidation catalyst (see picture). Copyright 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

We are developing two-layered Yttrium Barium Copper Oxide (YBCO) thin film structures for energy efficient data links for superconducting electronics and present the results of their property measurements. High temperature superconductors (HTS) are advantageous for the implementation of energy-efficient cables interconnecting low temperature superconductor-based circuits and other cryogenic electronics circuits at higher temperature stages. The advantages of the HTS cables come from their low loss and low dispersion properties, allowing ballistic transfer of low power signals with very high bandwidth, low heat conduction and negligible inter-line crosstalk. The microstrip line cable geometry for typical materials is a two-layered film, in which the two superconducting layers are separated by an insulation layer with a minimized permittivity. We have made a proof of concept design of two YBCO films grown by pulsed laser deposition and then assembled into a sandwich with uniform insulating interlayer of tens of micrometers thick. We report on results obtained from such systems assembled in different ways. Structural and electromagnetic properties have been examined on individual films and on the corresponding sandwich composite.

Oxide layer on the surface of a high speed steel (HSS) hot work roll can act as a protective layer and affects the wear and friction between the strip and the roll. In the numerical design of a work roll, it is necessary to understand the mechanical properties of these oxide layers. This paper describes a combined FE simulations and nanoindentation experiments to obtain the depth dependent mechanical properties of oxide layers on HSS. The mechanical properties of this layer, including the elastic modulus, yield strength, Poisson's ratio and porosity, are inferred from the input parameters to the FE simulations after the simulated load-displacement curves match the experimental curves to within a specified tolerance. The results showed that the outer layer has a higher modulus and higher hardness than the inner layer. The interaction between the mechanical properties and nanoindentation parameters such as the maximum load and unloading slope of the load-displacement curves were established via multiple regression analysis. The maximum load and slope of the load-displacement were strongly correlated with the elastic modulus and yield strength whilst the relationship between porosity and Poisson's ratio is relatively weak. This paper describes a combined FE simulations and nanoindentation experiments to obtain the depth dependent mechanical properties of oxide layers on high speed steels (HSS). The interaction between the mechanical properties and nanoindentation parameters such as the maximum load and unloading slope of the load-displacement curves are established via multiple regression analysis.

The present work reports the enhancement of the photoelectrochemical water splitting performance of in-situ silicon (Si)-doped nanotubular/nanoporous (NT/NP) layers. These layers were grown by self-organizing anodizationon Fe-Si alloys of various Sicontent. The incorporation of Si is found to retard the layer growth rates, leadsto a more pronounced nanotubular morphology, and most importantly, an improved photoelectrochemical behavior. By increasing Si content from1, 2 to 5 at.% in the iron oxide NT/NP photoanodes, the photocurrent onset potential shifts favorably to lower values. At 1.3 V vs. RHE, hematite layer with 5 at.% Si shows a 5-fold increase of the photocurrent, i.e. 0.5 mA cm -2 in comparison to 0.1 mA cm-2 for the undoped samples. The study also reveals that a suitable layer thickness is essential to achieve a beneficial effect of the Si doping. 2013 Elsevier B.V. All rights reserved.

Nanoporous materials: High-aspect-ratio, ordered porous Co 3O4 layers were formed by self-organizing anodization of a cobalt substrate and subsequent annealing. The key for successful formation of such layers is to sufficiently suppress competing oxygen evolution during anodization. The aligned Co3O4 channel layers behave as a highly efficient water oxidation catalyst (see picture). Copyright 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

We are developing two-layered Yttrium Barium Copper Oxide (YBCO) thin film structures for energy efficient data links for superconducting electronics and present the results of their property measurements. High temperature superconductors (HTS) are advantageous for the implementation of energy-efficient cables interconnecting low temperature superconductor-based circuits and other cryogenic electronics circuits at higher temperature stages. The advantages of the HTS cables come from their low loss and low dispersion properties, allowing ballistic transfer of low power signals with very high bandwidth, low heat conduction and negligible inter-line crosstalk. The microstrip line cable geometry for typical materials is a two-layered film, in which the two superconducting layers are separated by an insulation layer with a minimized permittivity. We have made a proof of concept design of two YBCO films grown by pulsed laser deposition and then assembled into a sandwich with uniform insulating interlayer of tens of micrometers thick. We report on results obtained from such systems assembled in different ways. Structural and electromagnetic properties have been examined on individual films and on the corresponding sandwich composite.

In this paper, we use a continuum approach together with the Lennard-Jones potential to determine the potential energy for an atom and a C60 fullerene interacting with a single-layer graphene sheet. We also consider the interactions involving double-layer graphene structures. In order to explore the possibility of using double-layer graphene structures as a nano-carrier for targeted drug delivery, we investigate the molecular insertion of a carbon atom and a C60 molecule into the space between the graphene layers. We find that an atom and the outer surface of the fullerene prefer to be approximately 3.4 and 2.95 ˚A away from a single-layer graphene, which is consistent with the literature. Further, we find that the minimum distances between the two layers of the graphene structure for an atom and a C60 molecule to be accepted into the interspace are 6.2 and 12.2 ˚A, respectively. However, we find that when the distances between the layers equal to 6.8 and 13 ˚A for the atom and the C60 molecule, respectively, the total interaction energy is minimum and therefore the system is most stable. When the inter-layer distance is greater than 6.8 and 13 ˚A for the atom and the fullerene C60, even though the atom and the fullerene C60 will be accepted into the inter-layer spacing, the system is not stable as the energy is higher. Knowledge of the size of the inter-layer spacing may be particularly useful for the design of the double-layer graphene structures for drug delivery applications.

The characterization of a polyelectrolyte complex material comprised of two biopolymers, a chitosan upper layer and a gellan gum under layer, is reported. It is shown that the upper layer of chitosan with incorporated levofloxacin displays an antibacterial activity, while the under layer of a gellan gum/TiO2 composite supports the growth of fibroblastic cells.

The characterization of a polyelectrolyte complex material comprised of two biopolymers, a chitosan upper layer and a gellan gum under layer, is reported. It is shown that the upper layer of chitosan with incorporated levofloxacin displays an antibacterial activity, while the under layer of a gellan gum/TiO2 composite supports the growth of fibroblastic cells.

The characterization of a polyelectrolyte complex material comprised of two biopolymers, a chitosan upper layer and a gellan gum under layer, is reported. It is shown that the upper layer of chitosan with incorporated levofloxacin displays an antibacterial activity, while the under layer of a gellan gum/TiO2 composite supports the growth of fibroblastic cells.

The characterization of a polyelectrolyte complex material comprised of two biopolymers, a chitosan upper layer and a gellan gum under layer, is reported. It is shown that the upper layer of chitosan with incorporated levofloxacin displays an antibacterial activity, while the under layer of a gellan gum/TiO2 composite supports the growth of fibroblastic cells.

In this paper, we use a continuum approach together with the Lennard-Jones potential to determine the potential energy for an atom and a C60 fullerene interacting with a single-layer graphene sheet. We also consider the interactions involving double-layer graphene structures. In order to explore the possibility of using double-layer graphene structures as a nano-carrier for targeted drug delivery, we investigate the molecular insertion of a carbon atom and a C60 molecule into the space between the graphene layers. We find that an atom and the outer surface of the fullerene prefer to be approximately 3.4 and 2.95 ˚A away from a single-layer graphene, which is consistent with the literature. Further, we find that the minimum distances between the two layers of the graphene structure for an atom and a C60 molecule to be accepted into the interspace are 6.2 and 12.2 ˚A, respectively. However, we find that when the distances between the layers equal to 6.8 and 13 ˚A for the atom and the C60 molecule, respectively, the total interaction energy is minimum and therefore the system is most stable. When the inter-layer distance is greater than 6.8 and 13 ˚A for the atom and the fullerene C60, even though the atom and the fullerene C60 will be accepted into the inter-layer spacing, the system is not stable as the energy is higher. Knowledge of the size of the inter-layer spacing may be particularly useful for the design of the double-layer graphene structures for drug delivery applications.

"A high-performance anode material was prepared from a hierarchically structured activated carbon which contains in situ graphene and nano-graphite. The activated carbon was immersed in a solution of SnCl(2)center dot 2H(2)O and subjected to ultrasound. As a result, nanoparticles of SnO(2) were uniformly deposited on the surface of the activated carbon. The composite material was then coated with a thin layer of carbon by soaking it in a sucrose solution, followed by carbonization of the adsorbed sucrose at 500 degrees C. The resulting composite showed an outstanding high-rate cycling performance that can deliver an initial discharge capacity of 1417 mAh g(-1) and maintain a discharge capacity of more than 400 mAh g(-1) after 100 cycles at a high current density of 1000 mA g(-1). This outstanding electrochemical performance is likely to be related to a unique combination of the excellent electrical conductivity of the activated carbon with graphite layers formed inside, its hierarchical pore structure which enhances lithium-ion transportation, and the carbon coating which alleviates the effects of volume changes, shortens the distance for Li(+) diffusion, facilitates the transmission of electrons, and keeps the structure stable."

Our research examines how the organisational structure facilitates knowledge sharing within the group. This case study examines a Victorian regional sustainable group using interviews and social network analysis to identify the group's organisational structure and its effect on knowledge sharing between the members. Our findings indicate that while the mixed membership, lack of hierarchy and layered structure are complex, these elements work together to provide members with a rich body of knowledge. The diversity and differences in membership are complimentary and combined can provide a more in-depth understanding of the regional sustainable development issues.

Our research examines how the organisational structure facilitates knowledge sharing within the group. This case study examines a Victorian regional sustainable group using interviews and social network analysis to identify the group's organisational structure and its effect on knowledge sharing between the members. Our findings indicate that while the mixed membership, lack of hierarchy and layered structure are complex, these elements work together to provide members with a rich body of knowledge. The diversity and differences in membership are complimentary and combined can provide a more in-depth understanding of the regional sustainable development issues.

Our research examines how the organisational structure facilitates knowledge sharing within the group. This case study examines a Victorian regional sustainable group using interviews and social network analysis to identify the group's organisational structure and its effect on knowledge sharing between the members. Our findings indicate that while the mixed membership, lack of hierarchy and layered structure are complex, these elements work together to provide members with a rich body of knowledge. The diversity and differences in membership are complimentary and combined can provide a more in-depth understanding of the regional sustainable development issues.

Our research examines how the organisational structure facilitates knowledge sharing within the group. This case study examines a Victorian regional sustainable group using interviews and social network analysis to identify the group's organisational structure and its effect on knowledge sharing between the members. Our findings indicate that while the mixed membership, lack of hierarchy and layered structure are complex, these elements work together to provide members with a rich body of knowledge. The diversity and differences in membership are complimentary and combined can provide a more in-depth understanding of the regional sustainable development issues.

The electrochemical and photophysical properties of a luminescent metal center, [Os(bpy)3]2+, are significantly modified by encapsulation within a conducting polymer composite film. Cyclic voltammetry reveals that the encapsulation in an inherently conducting polymer, polyaniline (Pani) or polypyrrole (PPy), can dramatically influence the charge-transfer rates between the metal centers. The increased electron transport, most likely mediated through the conducting polymer backbone, significantly enhances the electrochemiluminescence (ECL) efficiency. The increased communication between adjacent metal centers can also result in other interesting properties, such as photoinduced electron-transfer processes. In situ electron spin resonance (ESR) spectroscopy has been used to probe the photo-oxidation of an osmium metal center encapsulated in a PPy composite film. The irradiation of PPy in the presence of the osmium metal center resulted in the photo-oxidation of the Os2+ to Os3+ state and the consequent reduction of the PPy polyelectrolyte. The degree of communication between luminescent metal centers allows the composite properties to be tuned for various applications including ECL sensor devices and light-switching and light-harvesting systems.

We report on Ag and Cu doping in MgB2 thick films using amorphous Ag- and Cu-impurity layers with various thicknesses, 4, 8, 16, and 32 nm. Firstly, Ag- and Cu-impurity layers were deposited on Al2O3(0 0 0 1) substrates at room temperature by using pulsed laser deposition system. Subsequently MgB2 films were grown on the top of Ag or Cu/Al2O3 substrates at 560 and 600 °C by using hybrid physical–chemical vapor deposition. The effect of Ag and Cu doping as well as growth temperature on the microstructure and critical current density (Jc) of MgB2 films were investigated. It was found that both of Ag/Cu doping and low growth temperature can significantly enhance Jc without suppression of Tc. The increase in Jc results from improved grain connectivity and strong flux pinning by high density of grain boundaries and other types of defects introduced by Ag- or Cu-impurity layers.