ALBERT

Beschreibung: Fluorescence microscopy allows us to observe fluorescently labeled molecules in diverse biological processes and organelle structures within living cells. However, the diffraction limit restricts its spatial resolution to about half of its wavelength, limiting the capability of biological observation at the molecular level. Structured-illumination microscopy (SIM), a type of super-resolution microscopy, doubles the spatial resolution in all three dimensions by illuminating the sample with a patterned excitation light, followed by computer reconstruction. SIM uses a relatively low illumination power compared with other methods of super-resolution microscopy and is easily available for multicolor imaging. SIM has great potential for meeting the requirements of live-cell imaging. Recent developments in diverse types of SIM have achieved higher spatial (~50 nm lateral) and temporal (~100 Hz) resolutions. Here, we review recent advancements in SIM and discuss its application in noninvasive live-cell imaging.

Beschreibung: One of the most popular super-resolution microscopies that breaks the diffraction barrier is stimulated emission depletion (STED) microscopy. As the optical set-up of STED microscopy is based on a laser scanning microscopy (LSM) system, it potentially has several merits of LSM like confocal or two-photon excitation LSM. In this article, we first describe the principles of STED microscopy and then describe the features of our newly developed two-photon excitation STED microscopy. On the basis of our recent results and those of other researchers, we conclude by discussing future research and new technologies in this field.

Beschreibung: The electrically automated ultrathin sectioning apparatus, which has been developed in recent years, can produce consecutive ultrathin sections with a diamond knife and a gallium ion beam. These newly developed apparatuses, however, have several shortcomings, such as the limited block cutting area, thermal damage to the sample by the focused ion beam and a sample electronic charge. To overcome these faults and for easier scanning electron microscopy three-dimensional fine structural reconstruction, we have developed a new cutting method using a deep ultraviolet laser, which we have named the ‘LANTome (Light Ablation Nanotome)’. Using this method, we confirmed the widening of sectioning areas, shortening of the sectioning time, automatic smoothing of rough surfaces, no sample electronic charge and minimal heat effects on the sample tissue, such as thermal denaturation.

Beschreibung: Recent advances in nanoscopy, which breaks the diffraction barrier and can visualize structures smaller than the diffraction limit in cells, have encouraged biologists to investigate cellular processes at molecular resolution. Since nanoscopy depends not only on special optics but also on ‘smart’ photophysical properties of photocontrollable fluorescent probes, including photoactivatability, photoswitchability and repeated blinking, it is important for biologists to understand the advantages and disadvantages of fluorescent probes and to choose appropriate ones for their specific requirements. Here, we summarize the characteristics of currently available fluorescent probes based on both proteins and synthetic compounds applicable to nanoscopy and provide a guideline for selecting optimal probes for specific applications.

Beschreibung: As one of the most powerful tools in the biological investigation of cellular structures and dynamic processes, fluorescence microscopy has undergone extraordinary developments in the past decades. The advent of super-resolution techniques has enabled fluorescence microscopy – or rather nanoscopy – to achieve nanoscale resolution in living specimens and unravelled the interior of cells with unprecedented detail. The methods employed in this expanding field of microscopy, however, are especially prone to the detrimental effects of optical aberrations. In this review, we discuss how super-resolution microscopy techniques based upon single-molecule switching, stimulated emission depletion and structured illumination each suffer from aberrations in different ways that are dependent upon intrinsic technical aspects. We discuss the use of adaptive optics as an effective means to overcome this problem.

Beschreibung: The acrosome is a Golgi-derived sperm cell organelle enclosed by a continuous acrosomal membrane. The acrosomal membrane complexes with surrounding matrices containing molecules necessary for fertilization; however, the complex of acrosomal membrane and associating matrices (CAMAM) has not been visualized in detail under living conditions. Here, we analyzed the CAMAM at the nanometer level using super-resolution stimulated emission depletion (STED) fluorescence microscopy and equatorin-enhanced green fluorescent protein transgenic mice. The STED images were compared with the corresponding images taken by immunoelectron microscopy. Consequently, the substructure of CAMAM could be differentiated at nanometer-scale resolution by STED microscopy without the need for sectioning. The information obtained in this study will be beneficial not only for understanding the molecular mechanism of fertilization but also for cell imaging under living conditions.

Beschreibung: Ptychographic iterative engine (PIE), a form of coherent diffractive imaging in which the phase of both low-angle and high-angle diffraction data is used to form an image without a lens, can in principle deliver wavelength-limited resolution. Working at low accelerating voltages (30 keV) reduces specimen knock-on damage, increases high-resolution contrast and allows a scanning electron microscope to be used as a transmission electron microscopy. However, electrons are very strongly scattered at low energy. To that end, the effect of dynamical scattering on PIE at low accelerating voltages is calculated to illustrate the possibility of generating high-resolution images with low energy electrons.

Beschreibung: The application of multispectral imaging to discriminate myelinated and demyelinated areas of neural tissue is herein presented. The method is applied through a custom-made, multispectral imaging monochromator, coupled to a commercially available microscope. In the present work, a series of spinal cord sections were analysed derived from mice with experimental autoimmune encephalomyelitis (EAE), an experimental model widely used to study multiple sclerosis (MS). The multispectral microscope allows imaging of local areas with loss of myelin without the need of tissue labelling. Imaging with the aforementioned method and system is compared in a parallel way with conventional methods (wide-field and confocal fluorescence microscopies). The diagnostic sensitivity of our method is 90.4% relative to the ‘gold standard’ method of immunofluorescence microscopy. The presented method offers a new platform for the possible future development of an in vivo , real-time, non-invasive, rapid imaging diagnostic tool of spinal cord myelin loss-derived pathologies.

Beschreibung: Advancement of microscopic technologies established significant progress in our understanding of the brain. In the recent effort to elucidate the complete wiring map of the brain circuitry termed ‘connectome’, the different modalities of imaging technology, including those of light and electron microscopy, have started providing essential contribution in multiple organisms. The contribution would be impossible without the recent innovation in both acquisition and analyses of the big connectomic data. The current data demonstrated complicated networks with unidirectional and reciprocal connections of the cerebral circuits at the macroscopic and light microscopic (‘mesoscopic’) levels, and the unimaginable complexity of synaptic connections between axons and dendrites at the electron microscopic (‘microscopic’) level. At the same time, the data highlighted the necessity to make substantial advancement in methodology of the connectomic studies, including efficient handling and automated analyses of the acquired dataset. Further understanding about structural and functional connectome seems to be facilitated by combinations of the different imaging modalities. Such multidisciplinary approaches will give us the clues to address whether the complete connectome can elucidate fundamental mechanisms processing the basic and higher functions of human brains.

Beschreibung: The occupation sites and the occupancies of trace dopants in La/Co co-doped Sr-M-type ferrite, SrFe 12 O 19 , were quantitatively and precisely determined by beam-rocking energy-dispersive X-ray spectroscopy (EDXS) on the basis of electron-channeling effects. Because the Co atoms, in particular, should be partially substituted for the five crystallographically inequivalent sites, which could be key parameters in improving the magneto-crystalline anisotropy, it is difficult yet intriguing to discover their occupation sites and occupancies without using the methods of large-scale facilities, such as neutron diffraction and synchrotron radiation. In the present study, we tackled this problem by applying an extended statistical atom location by channeling enhanced microanalysis method, using conventional transmission electron microscopy, EDXS and dynamical electron elastic/inelastic scattering theories. The results show that the key occupation sites of Co were the 2a, 4f 1 and 12k sites. The quantified occupancies of Co were consistent with those of the previous study, which involved a combination of neutron diffraction and extended X-ray absorption fine structure analysis, as well as energetics considerations based on by first-principles calculations.

Beschreibung: Needle-shaped precipitates in an aged Al–0.62Mg–0.93Si (mass%) alloy were identified using a compositional threshold method, an isoconcentration surface, in atom probe tomography (APT). The influence of thresholds on the morphological and compositional characteristics of the precipitates was investigated. Utilizing optimum parameters for the concentration space, a reliable number density of the precipitates is obtained without dependence on the elemental concentration threshold in comparison with evaluation by transmission electron microscopy (TEM). It is suggested that careful selection of the concentration space in APT can lead to a reasonable average Mg/Si ratio for the precipitates. It was found that the maximum length and maximum diameter of the precipitates are affected by the elemental concentration threshold. Adjustment of the concentration threshold gives better agreement with the precipitate dimensions measured by TEM.

Beschreibung: Acetazolamide (AZA) reduces the water permeability of aquaporin-4, the predominant water channel in the brain. We determined the structure of aquaporin-4 in the presence of AZA using electron crystallography. Most of the features of the 5-Å density map were consistent with those of the previously determined atomic model. The map showed a protruding density from near the extracellular pore entrance, which most likely represents the bound AZA. Molecular docking simulations supported the location of the protrusion as the likely AZA-binding site. These findings suggest that AZA reduces water conduction by obstructing the pathway at the extracellular entrance without inducing a large conformational change in the protein.

Beschreibung: To understand the bainitic transformation behavior in Cu–17Al–11Mn (at.%) alloys, dynamic in situ observation during heating was carried out in a scanning electron microscope (SEM). In this study, after optimizing the sample preparation method and observation conditions, we successfully observed the transformation process with sufficient resolution and contrast. From the observation results, bainite is first formed preferentially at the grain boundaries of the parent phase. Bainite is also formed inside the grains to relax the elastic strain generated by the initial bainite. Regarding the growth mode, in the early stage of the transformation, bainite grows along the longitudinal direction, and in the late stage, it grows along the lateral direction. The growth rate of the bainite was also evaluated by continuous observation of the same plate. Dynamic in situ observation of a martensitic transformation in the same alloy was also performed to compare the growth mode with that of bainite, and it was found that the behavior is considerably different between bainitic and the martensitic transformations.

Beschreibung: Although many studies of the Golgi apparatus structure have been performed by light and electron microscopy, the full shape of the Golgi apparatus remained unclear due to the technical limitations of the previously applied microscopy techniques. In this study, we used serial section scanning electron microscopy (SEM) for the morphological study of the Golgi apparatus. This method is useful for three-dimensional (3D) reconstruction of cellular structures without requiring specialized instruments, unlike focused ion beam SEM (FIB-SEM) and serial block face SEM (SBF-SEM). Using the serial section SEM method developed by our laboratory, we investigate the 3D shape of the osmium-impregnated Golgi apparatus in rat epididymal cells, pancreatic acinar cells and gonadotropes. The combination of serial section SEM and a 3D reconstruction technique enabled us to elucidate the entire shape of the Golgi apparatus in these cells. The full shape of the Golgi apparatus in epididymal cells formed a basket-like structure with oval-shaped cisterns, while the Golgi apparatus in an acinar cell from the pancreas was composed of elongated ribbon-like structures that were connected to each other, making a coarse network. The overall image of the Golgi apparatus cisterns from a gonadotrope looked like a spherical cage. This study has clearly shown that entire 3D shape of the Golgi apparatus varies depending on the cell type and that the Golgi cisterns network appears as a single mass located in the large region of the cytoplasm.

Beschreibung: The initial determination of left–right asymmetry is an essential process in embryonic development. In mouse embryo, cilia in the node play an important role generating the nodal flow that subsequently triggers left–right determination in the embryo. Although nodal cilia have historically been thought to have a 9 + 0 axonemal configuration, the existence of 9 + 2 cilia has been reported so far. Because the distribution of those two types of cilia within the node has not yet been reported, we assessed the arrangement of 9 + 0 and 9 + 2 cilia in the node. In this study, we concluded that most of the nodal cilia were 9 + 0 in structure and there were much fewer 9 + 2 cilia than 9 + 0 cilia. Furthermore, the two types of cilia were randomly distributed in the node with no regularity. In addition, we studied the embryonic origin of the crown cells surrounding the node to better understand their identity.

Beschreibung: The ultrastructure of melanin granules in human hair was studied using 1,000 kV high-voltage scanning transmission electron microscopy to successfully reconstruct three-dimensional images of the whole melanin granule. It was revealed that the melanin granule was composed of a membrane-like outer structure that included many spherical vesicles, and an inner matrix containing a sheet-like structure in the elongated direction of the melanin granule and a sheet-like arrays structure in the cross direction. The outer structure of the melanin granule was maintained even after exposure to hair-bleaching agents to decompose the melanin granule, suggesting that the outer structure was a highly robust structure and composition compared with the inner matrix .

Beschreibung: The dependence of the microstructure of Ge 2 Sb 2 Te 5 (GST) on Ti diffusion into GST by annealing in GST/Ti/TiN phase-change random access memory stack was studied by various transmission electron microscopy (TEM) techniques. The microstructure and crystal structure of GST were identified with high-resolution TEM (HRTEM) and image simulation technique, and the Ti diffusion into GST was revealed by scanning transmission electron microscope-energy-dispersive X-ray spectroscopy analysis. It was observed that Ti atoms of Ti/TiN thin layers were incorporated into GST cell through several thermal annealing steps and they could retard the phase transition from face-centered cubic (FCC) phase into hexagonal close-packed (HCP) phase partially and restrain the increase in grain size. Thus, it is concluded that Ti diffusion can affect the microstructure of GST including the type of the crystal phase and grain size of GST. It was shown that the insertion of diffusion barrier between TiN and GST could block Ti diffusion into GST and make it possible for FCC phase to completely transform into HCP phase.

Beschreibung: In this study, we introduce scanning electron microscopy (SEM) of semithin resin sections. In this technique, semithin sections were adhered on glass slides, stained with both uranyl acetate and lead citrate, and observed with a backscattered electron detector at a low accelerating voltage. As the specimens are stained in the same manner as conventional transmission electron microscopy (TEM), the contrast of SEM images of semithin sections was similar to TEM images of ultrathin sections. Using this technique, wide areas of semithin sections were also observed by SEM, without the obstruction of grids, which was inevitable for traditional TEM. This study also applied semithin section SEM to correlative light and electron microscopy. Correlative immunofluorescence microscopy and immune-SEM were performed in semithin sections of LR white resin-embedded specimens using a FluoroNanogold-labeled secondary antibody. Because LR white resin is hydrophilic and electron stable, this resin is suitable for immunostaining and SEM observation. Using correlative microscopy, the precise localization of the primary antibody was demonstrated by fluorescence microscopy and SEM. This method has great potential for studies examining the precise localization of molecules, including Golgi- and ER-associated proteins, in correlation with LM and SEM.

Beschreibung: All-solid-state Li-ion batteries (LIBs) with solid electrolytes are expected to be the next generation devices to overcome serious issues facing conventional LIBs with liquid electrolytes. However, the large Li-ion transfer resistance at the electrode/solid-electrolyte interfaces causes low power density and prevents practical use. In-situ -formed negative electrodes prepared by decomposing the solid electrolyte Li 1+ x +3 z Al x (Ti,Ge) 2– x Si 3 z P 3– z O 12 (LASGTP) with an excess Li-ion insertion reaction are effective electrodes providing low Li-ion transfer resistance at the interfaces. Prior to our work, however, it had still been unclear how the negative electrodes were formed in the parent solid electrolytes. Here, we succeeded in dynamically visualizing the formation by in situ spatially resolved electron energy-loss spectroscopy in a transmission electron microscope mode (SR-TEM-EELS). The Li-ions were gradually inserted into the solid electrolyte region around 400 nm from the negative current-collector/solid-electrolyte interface in the charge process. Some of the ions were then extracted in the discharge process, and the rest were diffused such that the distribution was almost flat, resulting in the negative electrodes. The redox reaction of Ti 4+ /Ti 3+ in the solid electrolyte was also observed in situ during the Li insertion/extraction processes. The in situ SR-TEM-EELS revealed the mechanism of the electrochemical reaction in solid-state batteries.

Beschreibung: We have investigated how accurately atomic-resolution annular dark-field (ADF) images match between experiments and simulations to conduct more reliable crystal structure analyses. Quantitative ADF imaging, in which the ADF intensity at each pixel represents the fraction of the incident probe current, allows us to perform direct comparisons with simulations without the use of fitting parameters. Although the conventional comparison suffers from experimental uncertainties such as an amorphous surface layer and specimen thickness, in this study we eliminated such uncertainties by using a single-layer graphene as a specimen. Furthermore, to reduce image distortion and shot noises in experimental images, multiple acquisitions with drift correction were performed, and the atomic ADF contrast was quantitatively acquired. To reproduce the experimental ADF contrast, we used three distribution functions as the effective source distribution in simulations. The optimum distribution function and its full-width at half-maximum were evaluated by measuring the residuals between the experimental and simulated images. It was found that the experimental images could be explained well by a linear combination of a Gaussian function and a Lorentzian function with a longer tail than the Gaussian function.

Beschreibung: Mechanical properties of complex steels are affected by their multi-phase structure. Scanning electron microscopy (SEM) is routinely used for characterizing dual-phase (DP) steels, although the identification of steel constituents is not straightforward. In fact, there are several ways of enabling the ferrite–martensite segmentation by SEM, and a wide range of electron energies can be utilized. This study demonstrates the phase identification of DP steels at high, low and extremely low landing energies of the primary electrons from tens of keV to tens of eV. Visualization of the specimen surface at very low landing energies has been achieved by inserting an earthed detector between the pole piece and the negatively biased specimen. This ‘cathode lens mode’ enables the use of the full energy range up to the primary electron energies. It has been found that extremely slow electrons (〈100 eV) are exceptionally suitable for separation of the martensite from the ferrite matrix due to high surface sensitivity, enabling visualization of very fine features. Moreover, the channelling contrast is significantly suppressed at the landing energy of tens of eV of the primary electrons, which enables separation of the phases clearly even in the images acquired at low magnification. The contrast between the phases at tens of eV can be explained by the different thickness of native oxide covering the martensite and the ferrite phase.

Beschreibung: ‘Tubular aggregates’ are morphologically distinct cytoplasmic structures that have been linked to a variety of pathological conditions. This report documents the presence of tubular aggregates in an insect cell line (C6/36 cells derived from Aedes albopictus ) following inoculation of the cells with material derived from cell culture passaged homogenized Culex australicus mosquitoes. The tubular aggregates were detected in ~2% of treated cells and had three morphological forms that were termed primary, secondary and tertiary, with progressively greater levels of structural complexity. The findings indicate that tubular aggregates can be induced in an insect cell culture system by an unidentified agent present in some mosquitoes.

Beschreibung: In this article, we propose a smart image-analysis method suitable for extracting target features with hierarchical dimension from original data. The method was applied to three-dimensional volume data of an all-solid lithium-ion battery obtained by the automated sequential sample milling and imaging process using a focused ion beam/scanning electron microscope to investigate the spatial configuration of voids inside the battery. To automatically fully extract the shape and location of the voids, three types of filters were consecutively applied: a median blur filter to extract relatively larger voids, a morphological opening operation filter for small dot-shaped voids and a morphological closing operation filter for small voids with concave contrasts. Three data cubes separately processed by the above-mentioned filters were integrated by a union operation to the final unified volume data, which confirmed the correct extraction of the voids over the entire dimension contained in the original data.

Beschreibung: Polyelectrolyte brushes are polyelectrolyte polymers with one end fixed to a substrate. In this study, direct nano-scale visualization of polyelectrolyte brushes was carried out under ‘aqueous conditions’ by atmospheric scanning electron microscopy. The thickness of the polyelectrolyte brush layer was measured under both dry and aqueous conditions, experimentally confirming the swollen state of the brushes. These experimental findings qualitatively agreed with the results from previous neutron reflectivity experiments using similar polyelectrolyte brushes. Such direct visualization of polymer brushes in real space opens up a new route for better understanding their surface properties, such as friction, adhesion and wettability.

Beschreibung: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Ultramicroscopy, Volume 206〈/p〉 〈p〉Author(s): P. Kükelhan, T. Hepp, S. Firoozabadi, A. Beyer, K. Volz〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Quantitative scanning transmission electron microscopy (STEM) is a powerful tool for the characterization of nano-materials. Absolute composition determination for ternary III–V semiconductors by direct comparison of experiment and simulation is well established. Here, we show a method to determine the composition of quaternary III–V semiconductors with two elements on each sub lattice from the intensities of one STEM image. As an example, this is applied to (GaIn)(AsBi). The feasibility of the method is shown in a simulation study that also explores the influence of detector angles and specimen thickness. Additionally, the method is applied to an experimental STEM image of a (GaIn)(AsBi) quantum well grown by metal organic vapour phase epitaxy. The obtained concentrations are in good agreement with X-ray diffraction and photoluminescence results.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: Available online 5 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Radiation Measurements〈/p〉 〈p〉Author(s): Hui-Yu Tsai, Hsin-Yu Chen, Ming-Wei Lee, Ze Wang, Sheng-Pin Tseng, Ji-Hong Hong, Meei-Ling Jan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Prompt-gamma Compton imaging (PGCI) has been presented as a promising 〈em〉in-vivo〈/em〉 method for proton range verification. An accurate estimation of the Bragg-peak position can potentially be achieved by imaging high-energy prompt-gamma rays (in the range of several MeV). Therefore, scintillation detectors with thick and high Z crystals are mostly used as Compton absorbers for high-energy gamma-ray detection. However, an absorber using thick crystals degrades the angular resolution unless the absorber can provide continuous depth-of-interaction (DOI) measurement. The study investigated various detector configurations using thick crystals for developing a Compton absorber with DOI resolving capability without compromising energy performance. Two groups of lutetium yttrium oxyorthosilicate (LYSO) with dimensions of 1.8 × 1.8 × 50 mm〈sup〉3〈/sup〉 and 1.8 × 1.8 × 20 mm〈sup〉3〈/sup〉 LYSO arrays, and each with four different surface treatments (combining crystal surface finishing and type of reflector coverage), were constructed for the study. The DOI detector utilized the dual-ended readout of pixelated scintillator arrays for depth encoding. The results revealed that the influences of type of the reflector coverage and crystal surface roughness on the performance of the DOI detectors for the 50- and 20-mm-thick LYSO differed greatly. Moreover, the combined use of the proposed partial inter-crystal reflector coverage and the unpolished surface finishing on the 50-mm-thick crystals were shown to improve the DOI resolution without compromising the energy performance but degraded the flood map quality. These results provide useful guidance for selecting an applicable Compton DOI absorber design for developing a high-performance PGCI system.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 AEU - International Journal of Electronics and Communications, Volume 108〈/p〉 〈p〉Author(s): Hongbo Cao, Faqiang Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, a new current-controlled memristor is proposed and its characteristics are analyzed. Based on this new memristor, a new four-dimensional chaotic circuit is proposed. The complex dynamics of the proposed chaotic circuit are investigated. From the results of the theoretical analysis and the numerical simulations, it is found that the memristor-based chaotic circuit can generate different types of attractors including single-scroll, double-scroll, and periodic attractors for varying circuit parameters. By taking symmetrical initial conditions, symmetric steady coexisting attractors are obtained under the same set of circuit parameters. For certain initial conditions, striking transient coexisting attractors with different timescales can be obtained. In particular, there are two transient changes occurring successively at different time scales respect to the same initial conditions for the proposed chaotic circuit, which is a novel dynamic property. Finally, a practical circuit platform that describes the proposed chaotic circuit on Field Programmable Gate Arrays (FPGA) is designed, and some experimental results are presented for confirmation.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 AEU - International Journal of Electronics and Communications, Volume 109〈/p〉 〈p〉Author(s): Negar Daryanavardan, Mostafa Derakhtian, Mohammad Neinavaie, Saeed Gazor〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper presents a new low complexity sphere decoding (SD) for the generalized spatial modulation (GSM). We introduce a pre-processing stage using the lattice reduction (LR) aided minimum mean squared error (MMSE) equalization in the GSM systems. This stage speeds up the search in the decoding tree and provides a lattice dependent (LD) initial choice of the radius. Moreover, we derive a lattice independent (LI) initial radius that guarantees the optimal performance at a high signal-to-noise ratio (SNR). We also propose an iterative method to increase the radius in order to achieve the maximum likelihood (ML) performance at all SNRs. We show that the proposed algorithm achieves the ML performance while requiring prominently less computational complexity (CC) than an exhaustive search. In addition, we analyze the CC of the resulting algorithm at high SNRs and we derive an analytical expression for the complexity. The simulation results demonstrate a noticeable decrease in the CC of the proposed sphere decoding algorithm in comparison with its counterparts, particularly at low SNRs.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 AEU - International Journal of Electronics and Communications, Volume 109〈/p〉 〈p〉Author(s): Nazir Hatami, Javad Nourinia, Changiz Ghobadi, Maryam Majidzadeh, Burhan Azarm〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A multiple-input-multiple-output (MIMO) wireless local area network (WLAN) band-notched antenna with high inter-element isolation is proposed. The proposed MIMO system is composed of two monopole antennas, each composed of a slotted radiating patch and a stepped ground plane. The embedded slots and the ground plane steps are wisely located to achieve the desired wide band functionality as well as WLAN band-notched realization. The overall size of the MIMO antenna is 20 × 34 mm〈sup〉2〈/sup〉 printed on 1.6 mm FR4 substrate. Moreover, to reduce the coupling between the constituent monopole antennas and enhance the isolation, a parasitic element is embedded between the antennas on the substrate backside. By wise tuning of the position and dimensions of the parasitic element, high isolation is achieved which is necessary for MIMO communication systems. Both simulation and measured results confirm a 10-dB impedance bandwidth of 2.6–11.2 GHz excluding the rejected band for |S〈sub〉11〈/sub〉| ≤ −10 dB, and |S〈sub〉21〈/sub〉| ≤ −20 dB. Wide bandwidth, small size, and band-notched feature are some of the merits of the proposed MIMO antenna. Detailed analysis on the antenna performance are released in detail throughout the paper.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 297〈/p〉 〈p〉Author(s): Nohora Caicedo, Renaud Leturcq, Jean-Pierre Raskin, Denis Flandre, Damien Lenoble〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Metal-oxide nanowires are showing a great interest in the domain of gas sensing due to their large response even at a low temperature, enabling low-power gas sensors. However their response is still not fully understood, and mainly restricted to the linear response regime, which limits the design of appropriate sensors for specific applications. Here we analyse the non-linear response of a sensor based on ZnO nanowires network, both as a function of the device geometry and as a response to oxygen exposure. Using an appropriate model, we disentangle the contribution of the nanowire resistance and of the junctions between nanowires in the network. The applied model shows a very good consistency with the experimental data, allowing us to demonstrate that the response to oxygen at room temperature is dominated by the barrier potential at low bias voltage, and that the nanowire resistance starts to play a role at higher bias voltage. This analysis allows us to find the appropriate device geometry and working point in order to optimize the sensitivity. Such analysis is important for providing design rules, not only for sensing devices, but also for applications in electronics and opto-electronics using nanostructures networks with different materials and geometries.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 297〈/p〉 〈p〉Author(s): Gang Xu, Chen Cheng, Wei Yuan, Zhaoyang Liu, Lihang Zhu, Xintong Li, Yanli Lu, Zetao Chen, Jinglong Liu, Zheng Cui, Jingjing Liu, Hong Men, Qingjun Liu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Last decade has seen a growing trend toward smartphone-based biochemical sensing systems. Meanwhile, flexible electrochemical sensing devices like wristbands, patches, and tattoos have been widely developed for 〈em〉in situ〈/em〉 detections of analytes in accessible biofluids. For these devices, the connectivity with smartphone and the flexibility of the whole device are hard to achieve at the same time, due to the need for rigid batteries or wired connections. Here, a smartphone-based battery-free and flexible electrochemical patch is developed for real-time calcium and chloride ions detections in various biofluids. The patch is integrated with near field communication (NFC) module, on-site signal processing circuitry, and an all-printed stretchable electrode array which can maintain stable conductivity during stretching, without the need for serpentine designs. The device enables wireless power harvesting, on-site signal processing, and wireless data transmission capabilities. NFC-enabled smartphones can wirelessly power the patch and get the detection results through inductive coupling between antennas. The calcium and chloride sensors showed good sensitivity, repeatability, selectivity, and stability in quantitative detections of target ions. 〈em〉Ex situ〈/em〉 measurements in serum, urine, tear, and sweat demonstrated good consistency with specialized instrument. Real-time on-body sweat analysis with the patch was also performed, which further indicated the usability and stability of the device in wearable applications. This platform provides a battery-free, wireless, and flexible solution for smartphone-based electrochemical sensing systems, which can be applied to rapid analysis of various biofluids.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092540051930944X-ga1.jpg" width="354" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 297〈/p〉 〈p〉Author(s): Shuangming Wang, Jing Cao, Wen Cui, Longlong Fan, Xifei Li, Dejun Li, Tong Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉One dimensional porous Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 rectangular microrods (MR) are designed and successfully prepared by a distinctive electrospun precursor-hydrothermal regulation-annealing treatment strategy while Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 nanofibers (NF) are also synthesized for comparison by directly calcining precursors without hydrothermal treatment. The hydrothermal treatment before annealing process results in morphology and structure transition of Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 products from compact solid nanofibers to porous rods. When applied as a gas sensing material, Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 porous rods based sensors exhibit enhanced gas sensing properties in terms of rapid response time (3 s), recovery time (5 s), good selectivity and stability towards 100 ppm acetone gas at a relatively low working temperature of 200 °C. Meanwhile, the response of Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 porous rods toward 100 ppm acetone reaches approximately 5 times higher than that of solid Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 nanofibers. The enhanced acetone gas sensing properties of Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 rectangular porous rods are believed to originate from its porous structure and large surface area, facilitating gas adsorption and surface reaction and causing significant change in the thickness of holes accumulation layer (HAL). Feasible morphology-adjusting strategy and enhanced acetone gas sensing performances further highlight the advantage of as-prepared Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 porous rods in future acetone real-time monitoring.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 297〈/p〉 〈p〉Author(s): Xiuyu Wang, Heng Li, Xuantong Zhu, Mengzhen Xia, Tao Tao, Binxin Leng, Wen Xu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A kind of ZnSn(OH)〈sub〉6〈/sub〉 crystalline precursor composed of micro- and nano-sized particles with two different morphologies was synthesized by co-precipitation method with the presence of triethanolamine (TEOA) as functional reagent. Zn〈sub〉1-〈/sub〉〈em〉〈sub〉x〈/sub〉〈/em〉Mg〈em〉〈sub〉x〈/sub〉〈/em〉Sn(OH)〈sub〉6〈/sub〉 samples (0≤〈em〉x〈/em〉≤0.5) were prepared by doping Mg〈sup〉2+〈/sup〉 ions in the synthesis process of ZnSn(OH)〈sub〉6〈/sub〉 precursor. Experimental results reveal that both the morphology and size of ZnSn(OH)〈sub〉6〈/sub〉 particles can be changed by TEOA and Mg〈sup〉2+〈/sup〉 ions, but not changed by dehydration at high temperature with the formation of Zn〈sub〉1-〈/sub〉〈em〉〈sub〉x〈/sub〉〈/em〉Mg〈em〉〈sub〉x〈/sub〉〈/em〉SnO〈sub〉3〈/sub〉 samples. When 〈em〉x〈/em〉 is 0.1, the effect of Mg〈sup〉2+〈/sup〉 ions on the morphology and size of ZnSn(OH)〈sub〉6〈/sub〉 particles is not remarkable, but the ethanol sensitivity of the resulting ZnSnO〈sub〉3〈/sub〉 sample at a low temperature of 80 °C is significantly improved by Mg〈sup〉2+〈/sup〉 ions at the conditions of nano-TiO〈sub〉2〈/sub〉 decoration and UV radiation. The ethanol response of the composite sample (ZM〈sub〉0.1〈/sub〉SO–T〈sub〉10〈/sub〉) is as high as ca. 149 at 500 ppm concentration, and its corresponding response and recovery time is about 4 s and 80 s, respectively. Furthermore, the sensor with ZM〈sub〉0.1〈/sub〉SO–T〈sub〉10〈/sub〉 also shows a good selectivity and long-term stability. Possible reasons for the superior ethanol sensitivity at low temperature were discussed.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉*Here ZnSnO〈sub〉3〈/sub〉 without Mg doping and Zn〈sub〉0.9〈/sub〉Mg〈sub〉0.1〈/sub〉SnO〈sub〉3〈/sub〉 with10% TiO〈sub〉2〈/sub〉 decoration samples prepared by this study are denoted as ZM〈sub〉0〈/sub〉SO and ZM0.1SO, respectively.〈/p〉 〈p〉In this study ZnSn(OH)〈sub〉6〈/sub〉 crystalline precursor composed of micro- and nano-sized particles with two different morphologies in (a) was synthesized by the control of the amount of triethanolamine (TEOA) as functional additive based on co-precipitation method. The −OH groups in TEOA can make ZnSn(OH)〈sub〉6〈/sub〉 cubic crystal nuclei adsorbed and connected together, resulting in the formation of a micro-sized cluster with cubic corners exposed (a). Usually, the cubic corners are corroded in the etching process [46], but those cubic corners of the micro-sized clusters in (a) are not corroded when nano-sized particles exist with them. However, Mg〈sup〉2+〈/sup〉 ions used for substitute for Zn〈sup〉2+〈/sup〉 ions by doping can counteract the role of TEOA in the synthesis of ZnSn(OH)〈sub〉6〈/sub〉 precursor. The cubic corners of the micro-sized clusters in (a) begin to be corroded when ZnSn(OH)〈sub〉6〈/sub〉 precursor is synthesized with the presence of a small number of Mg2+ ions (b), and no micro-sized clusters are formed if there are more Mg2+ ions in the synthesizing process. After dehydration of Zn〈sub〉1-〈/sub〉〈em〉〈sub〉x〈/sub〉〈/em〉Mg〈em〉〈sub〉x〈/sub〉〈/em〉Sn(OH)〈sub〉6〈/sub〉 precursor at high temperature, Zn〈sub〉1-〈/sub〉〈em〉〈sub〉x〈/sub〉〈/em〉Mg〈em〉〈sub〉x〈/sub〉〈/em〉SnO〈sub〉3〈/sub〉 was formed.〈/p〉 〈p〉Gas-sensing test reveals the following results: (1) The ZnSnO〈sub〉3〈/sub〉 (ZM〈sub〉0〈/sub〉SO) and Zn〈sub〉0.9〈/sub〉Mg〈sub〉0.1〈/sub〉SnO3 (ZM〈sub〉0.1〈/sub〉SO) samples, originating from the dehydration of samples in (a) and (b), respectively, have a high response to ethanol at a high temperature of 220 °C. The gas-sensing activity of ZnSnO〈sub〉3〈/sub〉 is greatly enhanced by Mg〈sup〉2+〈/sup〉 doping, as can be inferred from the gas response value of the two samples. (2) When nano-TiO〈sub〉2〈/sub〉 was used to decorate ZM〈sub〉0.1〈/sub〉SO, the resulting sensor under UV irradiation has a low operating temperature at a maximum gas response of 149, which is far more than that of our previous study [46].〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925400519309463-ga1.jpg" width="126" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 297〈/p〉 〈p〉Author(s): Peng Lei, Ying Zhou, Ruiqi Zhu, Yang Liu, Chuan Dong, Shaomin Shuang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Iron phthalocyanine (FePc) functionalized nitrogen, boron–doped reduced graphene oxide (N,B–rGO) nanocomposite (FePc/N,B–rGO) was facilely fabricated for the first time as a electrochemical platform for sensitive detection of glutathione (GSH). FePc was immobilized on N,B–rGO substrate through π–π interaction, and N,B–rGO provided FePc with a large specific surface area to improve electron transfer and maintain its electrocatalytic activity. Cyclic voltammetric measurements showed that FePc and N,B–rGO triggered the synergistic effect and exhibited a satisfactory electrocatalytic activity. By integration of FePc and N,B–rGO, the FePc/N,B–rGO/GCE sensor displayed a wide linear dynamic range from 5.0 × 10〈sup〉–8〈/sup〉 M to 1.6 × 10〈sup〉–3〈/sup〉 M with a low detection limit of 7.1 × 10〈sup〉–9〈/sup〉 M. Besides, the electrochemical sensor presented satisfiable reproducibility, excellent anti–interference performance and long–term stability. The method was further expanded to determinate GSH in human serum sample with the recoveries between 95.0–109.0%.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925400519309578-ga1.jpg" width="378" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 435〈/p〉 〈p〉Author(s): Soner Çakar〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, a novel 1–10 phenanthroline and 1–10 phenanthroline 5,6 diol based metal complex sensitizers for dyes sensitized solar cells applications is investigated. The 1–10 phenanthroline 5,6 diol structure is formed by the addition of two –OH groups to 1–10 phenanthroline, which has higher cell yields due to binding sites of TiO〈sub〉2〈/sub〉. The 1–10 phenanthroline 5,6 diol metal complexes are prepared with Cu and Fe at different pH values. Additionally, these metal complexes are mixed at different ratio to prepare cocktail dyes. The maximum cell efficiency value of dyes sensitized solar cells based on 1–10 phenanthroline 5,6 diol prepared with Cu:Fe 2:1 ratio cocktail dyes is 3.70%. The phen-ol based DSSC containing Cu-complex dye exhibits 2.80% conversion efficiency value, which shows an 25% lower than cocktail phen-ol based dyes sensitized solar cells. The solar cell efficiency values are demonstrated decrement by increasing of Fe-complex ratio. However, the Fe-complexes exhibit more stable complex structures than Cu-complexes. This phenomenon also gives a new way to the use of the environmentally friendly metal complex-based dyes sensitized solar cells. Additionally, these transition metal-based sensitizers will be an alternative to synthetic organic dyes and noble metal-based solar cells.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 297〈/p〉 〈p〉Author(s): Bradley Ledden, Joe Bruton〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We developed a ring electrode sensor for down-stream electrochemical sensing of microfluidic ELISA assay. The sensor is designed to easily integrate into the flow environment. Noble metal inks on Low Temperature Co-fired Ceramic provide straight forward fabrication at the mesoscale yielding robust sensors with very low sensing volumes. Two different sensor geometries were modeled. The best design was fabricated and tested in both static and flowing solutions. The sensor exhibits both macroelectrode and microelectrode behavior depending on fluid flow rate. Sensors of this type may be ideal for applications where electrochemical detection is desired in a flowing solution since the ring electrode has low propensity for bubble trapping.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 297〈/p〉 〈p〉Author(s): Nada F. Atta, Ahmed Galal, Yousef M. Ahmed, Ekram H. El-Ads〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cardiovascular disease is a class of diseases that involves the heart or blood vessels. It includes coronary artery diseases such as angina and myocardial infarction. In addition, hypertension is quantitatively the most important risk factor for premature cardiovascular disease. Dobutamine (DB) and amlodipine (AM) are medications commonly used for treating these diseases. Therefore, simultaneous determination of these drugs in presence of interfering compounds in biological fluids; paracetamol (PA), and ascorbic acid (AA) is essential for patients under medical treatment by these drugs. An innovative strategy is introduced for fabrication of a novel layered composite based on layer-by-layer modification of a glassy carbon electrode surface (GC) with multi-walled carbon nanotubes (CNT), ionic liquid crystal (ILC), graphene (RGO) and 18-Crown-6 (CW); (GC/CNT/ILC/RGO/CW). The layered sensor exhibited excellent electro-catalytic activity for determination of AA in the drugs mixture and simultaneous determination of DB, PA, and AM in human serum in linear dynamic ranges; 0.4 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"〉〈mo〉→〈/mo〉〈/math〉 40 μM, 0.02 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"〉〈mo〉→〈/mo〉〈/math〉 40 μM, 0.001 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"〉〈mo〉→〈/mo〉〈/math〉 20 μM and 0.008 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mtext〉 〈/mtext〉〈mo〉→〈/mo〉〈/math〉 30 μM with low detection limit values; 9.24 nM, 0.497 nM, 0.0906 nM and 0.139 nM, respectively and low quantification limit values; 30.8 nM, 1.66 nM, 0.302 nM and 0.463 nM, respectively. Further practical application was performed for quantitative analysis of AA, DB, PA and AM in their pharmaceutical formulations.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925400519308482-ga1.jpg" width="392" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 435〈/p〉 〈p〉Author(s): Weiping Diao, Saurabh Saxena, Michael Pecht〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Accelerated cycle life testing of lithium-ion batteries is conducted as a means to assess whether a battery will meet its life cycle requirements. This paper presents a study to identify optimal accelerated cycle testing conditions for LiCoO〈sub〉2〈/sub〉-graphite cells. A full factorial design of experiment with three stress factors—ambient temperature (10 °C, 25 °C, 45 °C, 60 °C), discharge current rate (C-rate, 0.7C, 1C, 2C), and charge cut-off C-rate (C/5, C/40)—is used to study the effects of these stress factors on battery capacity fade and to obtain the data necessary for decision making. An empirical accelerated degradation model is then developed to capture the characteristics of the two-stage capacity degradation process, along with an accelerated test planning approach.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 435〈/p〉 〈p〉Author(s): Linna Dai, Qing Sun, Jianguang Guo, Jun Cheng, Xiaoyan Xu, Huanhuan Guo, Deping Li, Long Chen, Pengchao Si, Jun Lou, Lijie Ci〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Li-O〈sub〉2〈/sub〉 batteries are considered as one of the future candidates for electrochemical power sources due to their high theoretical energy density. As the dominating component affects the performance of Li-O〈sub〉2〈/sub〉 batteries, O〈sub〉2〈/sub〉-cathode catalyst with high efficiency, low price, facile preparation is important. Herein, polyhedral and porous Mn〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 rods are fabricated for cathode catalysts in Li-O〈sub〉2〈/sub〉 batteries via electrospinning method followed by calcination. The Mn〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 catalyst possesses a three-dimensional porous structure, which can offer good catalytic activity, expose plenty of active sites and improve the diffusion of electrolyte and O〈sub〉2〈/sub〉. When employed as the cathode catalyst, the Li-O〈sub〉2〈/sub〉 batteries show enhanced initial discharge capacity of 9701 mA h g〈sup〉−1〈/sup〉 at a current density of 200 mA g〈sup〉−1〈/sup〉, superior rate capacity and good cycling stability within 160 cycles at the capacity of 500 mA h g〈sup〉−1〈/sup〉. These enhanced performances demonstrate a facile method to fabricate Mn〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 with unique structure as a promising catalytic material for Li-O〈sub〉2〈/sub〉 batteries.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 435〈/p〉 〈p〉Author(s): Yong Zhang, Guangwu Wen, Shan Fan, Yuanyuan Chu, Shuhua Li, Baoyun Xu, Jing Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, three-dimensional phenolic hydroxyl functionalized partially reduced graphene oxides with high hydroxyl content and significantly enhanced electrochemical performance have been successfully prepared by a one-pot hydrothermal method from graphene oxide dispersions. A very small amount of 4-aminophenol is employed as reducing and N-doping agent, structure modifier and the phenolic hydroxyl source, at the same time. The electrochemical test results show that as binder-free electrode, the as-synthesized sample with high hydroxyl content (6.15 at%) exhibits an ultrahigh specific capacitance of 284.1 F g〈sup〉−1〈/sup〉 at current density of 0.3 A g〈sup〉−1〈/sup〉 in 6 M KOH electrolyte, and retains for 80.4% even at a current density of 10 A g〈sup〉−1〈/sup〉. Above all, the as-assembled symmetric supercapacitor shows superior energy density of 9.9 Wh kg〈sup〉−1〈/sup〉 at a power density of 75.0 W kg〈sup〉−1〈/sup〉. The significantly enhanced electrochemical performance can be ascribed to the high hydroxyl content and other oxygen functional groups, N-doping, modified porous framework and the high specific surface area of the graphene. Those special characteristics suggest that the as-synthesized graphene materials may have potential applications in high performance supercapacitors.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319307840-fx1.jpg" width="330" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 435〈/p〉 〈p〉Author(s): Anna Slesarenko, Igor K. Yakuschenko, Vahid Ramezankhani, Visweshwar Sivasankaran, Olga Romanyuk, Alexander V. Mumyatov, Ivan Zhidkov, Sergey Tsarev, Ernst Z. Kurmaev, Alexander F. Shestakov, Olga V. Yarmolenko, Keith J. Stevenson, Pavel A. Troshin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report a facile synthesis of octahydroxytetraazapentacene (OHTAP) and the application of this redox-active material as a cathode for lithium- and potassium-ion batteries. While testing in lithium half-cells, OHTAP was used in the form of lithium salt and delivered the specific discharge capacity of 〉400 mAh g〈sup〉−1〈/sup〉 and the energy density of ~700 Wh kg〈sup〉−1〈/sup〉, which are impressive values achieved for organic electrode materials and can also be favorably compared with the characteristics of the current commercial benchmark cathodes based on LiFePO〈sub〉4〈/sub〉 (~155 mAh g〈sup〉−1〈/sup〉 and 543 Wh kg〈sup〉−1〈/sup〉). The potassium half-cells fabricated using pristine OHTAP depending on the electrode deposition technique showed specific capacities of 120–220 mAh g〈sup〉−1〈/sup〉, which are among the record values reported so far for this type of batteries. Quantum chemical DFT modelling provided insights in the mechanistic aspects of metallation of OHTAP and revealed that lithium- and potassium-ion storage might involve both the hydroquinone-quione chemistry as well as the redox transformations of pyrazine rings.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319306950-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 435〈/p〉 〈p〉Author(s): Meetu Bharti, Ajay Singh, Gajender Saini, Sudeshna Saha, Anil Bohra, Yuki Kaneko, A.K. Debnath, K.P. Muthe, Kazuhiro Marumoto, D.K. Aswal, S.C. Gadkari〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We demonstrate that introduction of p-type Bi〈sub〉0.5〈/sub〉Sb〈sub〉1.5〈/sub〉Te〈sub〉3〈/sub〉 nanostructures into the polymer matrix not only causes highly adherent drop-casted films of PEDOT:PSS (on Kapton sheets) to attain a free-standing nature but also brings a significant improvement in their thermoelectric properties. Hall and ESR measurements of these hybrid films clearly show that both the carrier concentration and mobility can be varied with Bi〈sub〉0.5〈/sub〉Sb〈sub〉1.5〈/sub〉Te〈sub〉3〈/sub〉 content. Whereas, results of X-ray diffraction, Raman and X-ray photoelectron spectroscopy confirm the enhancement in chain alignment and better connectivity among PEDOT:PSS and Bi〈sub〉0.5〈/sub〉Sb〈sub〉1.5〈/sub〉Te〈sub〉3〈/sub〉 nanosheets; leading to remarkable enhancement of electrical conductivity. These hybrid films, due to energy filtering of charge carriers at the organic/inorganic interface, exhibit improvement in the Seebeck coefficient also. In fact, such a synergetic combination of improved electrical conductivity and Seebeck coefficient expertly tailors the power factor (from order of ~10〈sup〉−4〈/sup〉 to 8.3 μW/mK〈sup〉2〈/sup〉) over a vast range. The optimized films are tested for their power conversion ability and a single thermoelement based device exhibits an open circuit voltage ~536 μV and current ~134 μA for a temperature difference of 53 °C. Such an evolution of organic-inorganic hybrid films in a flexible, free-standing motif with enhanced thermoelectric properties exhibit good potential for recovering heat from the curved hot surfaces.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319307293-fx1.jpg" width="252" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 435〈/p〉 〈p〉Author(s): Mohammed Srout, Karima Lasri, Mouad Dahbi, Abdelkader Kara, Laurene Tetard, Ismael Saadoune〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Being considered as a high Li-ion mobility material, Nasicon structured Li〈sub〉1.5〈/sub〉Fe〈sub〉0.5〈/sub〉Ti〈sub〉1.5〈/sub〉(PO〈sub〉4〈/sub〉)〈sub〉3〈/sub〉 phosphate material was synthesized via sol-gel route and electrochemically tested as electrode material for lithium-ion batteries. The material was tested in half-lithium electrochemical cells, within two voltage windows, 1.5–3.0 V and 0.5–3.0 V, and delivered first discharge capacities of 129 mAh/g and 567 mAh/g, respectively. Raman spectroscopy was used to confirm the material's structure before and during cycling. In addition, a comparative study of the electrochemical performance by the use of two different binders (PVDF and CMC), was conducted and showed a significant change in the electrochemical performance due to the change of the binder. Electrochemical impedance spectroscopy was used to evidence the electrodes' interface changes during cycling.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 435〈/p〉 〈p〉Author(s): Kingo Ariyoshi, Satoshi Mizutani, Yusuke Yamada〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Electrochemical impedance analysis was performed for Li[Li〈sub〉0.1〈/sub〉Al〈sub〉0.1〈/sub〉Mn〈sub〉1.8〈/sub〉]O〈sub〉4〈/sub〉 (LAMO) used as a lithium-insertion electrode by the diluted electrode method to identify the origin of resistance. Utilization of diluted electrodes, in which some portion of active material, LAMO, was systematically replaced with the same amounts of spectator Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 material to maintain the original structure of the LAMO electrode, is a promising method to discriminate between the resistance attributed to the lithium-insertion reaction in LAMO (charge-transfer resistance) and that accompanied by conduction of electron and/or ion in the porous electrodes. Electrochemical impedance spectra of the diluted electrodes consisted of two semicircles. The radius of a semicircle in the lower frequency region depends on the LAMO content in a diluted electrode, indicating that the semicircle is associated with charge-transfer resistance. On the other hand, the radius of the other semicircle in the higher frequency region is independent of the LAMO contents, suggesting that the semicircle is mainly related to the resistance accompanied by the porous structure of electrodes. Thus, the structure of lithium-insertion electrode should be carefully considered in designing high-energy and high-power lithium-ion batteries that employ thick electrodes.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 435〈/p〉 〈p〉Author(s): Rajesh Thomas, Shashikant P. Patole, Pedro M.F.J. Costa〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The electrochemical storage of aluminum in graphitic electrodes is a topic of much interest in the search for alternative battery systems. Here, we show that an Al-based battery can be realized using a cathode assembled with graphene flakes obtained from processed expandable graphite. When compared to pristine graphite (in this work, with 45 mAh/g at a current density of 214 mA/g), the capacity and cycle life performance are notably increased by the use of the graphene flakes (172 mAh/g, at 214 mA/g, after 100 cycles). The location and persistence of the charged choloraluminate species in the carbon materials was experimentally analyzed and complemented with computational modelling. Accordingly, and besides intercalation, grafting of the Al-species onto the graphene layers was identified as a possible mechanism that enhanced the performance of the processed expandable graphite cathodes. Such a phenomena would make the electrode more conductive and introduce a path for charge storage on its surface (akin to faradaic supercapacitors).〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319307517-fx1.jpg" width="443" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 435〈/p〉 〈p〉Author(s): Elizabeth Whiddon, Haihui Zhu, Xiuping Zhu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Salinity gradient (SG) energy is a renewable and clean energy resource that exists worldwide from the change in Gibbs free energy when two solutions with different salinities are mixed. More recently, concentration flow cells (CFCs) have been introduced as a new technology for SG energy recovery with the highest reported power density output to date as a result of the utilization of both the electrode potential and Donnan potential. In this study, multiple CFCs are connected to form a consecutive number of stacks, and systematic analysis is conducted to investigate the influence of both parallel and series electrical wire connections on the overall performance. For both wire connections, an effective increase in the overall power output with an increase in stack size is observed. The power densities normalized to the membrane area are however lower (3.7 W m〈sup〉−2〈/sup〉 in series and 5.8 W m〈sup〉−2〈/sup〉 in parallel, for 5-stacks) than that of the individual cell unit (8.9 W m〈sup〉−2〈/sup〉) because the back of the stack experiences cumulative mixing. Additionally, as a result of an ionic cross-conduction causing a parasitic current in the series cell, the parallel wire configuration is demonstrated to be more successful in the CFC stack than the series.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 435〈/p〉 〈p〉Author(s): Martin Miller, Norman T.M. Baltes, Peter M. Rabenecker, Markus W. Hagen, Jens Tübke〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Supercapacitors are usually used as energy storage devices that work at a high current rate. This operating mode is often accompanied by the production of large amounts of heat inside the cell. Therefore, health monitoring of supercapacitors is still needed to avoid overheating and subsequent destruction. This paper presents a new method to determine the heat generation and the resulting temperature development of an aqueous hybrid capacitor based on extensive measurement data. We concentrate not only on the Ohmic power loss but also on heat phenomenon originating from side and overcharge reactions as well as entropy effects. The bearing of the final state of charge and the charging current on the temperature development is demonstrated. Finally, the temperature parameters of air and water cooled capacitors are simulated. The temperature distribution within the cell as a function of time is presented and discussed. The great advantage of the developed evaluation method is that it is an inexpensive method which can be realised in most test laboratories and that the measurements and simulations consider all crucial origins of power loss. The results obtained can be used to evaluate appropriate cooling systems. The method can be applied to capacitors and batteries.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 435〈/p〉 〈p〉Author(s): Dipali S. Patil, Sachin A. Pawar, Jae Cheol Shin, Hyo Jin Kim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, we report a simple one pot all hydrothermal synthesis route to grow nano structure of zinc-cobalt (Zn-Co) @ nickel-cobalt (Ni-Co) layered double hydroxides through oriented attachment growth with ultrathin nanosheets on 3D graphene foam using no additives or oxidants. The pseudocapacitor electrode based on Zn-Co@Ni-Co layered double hydroxides display an enhanced areal capacitance (7485 mFcm〈sup〉−2〈/sup〉, at 5 mVs〈sup〉−1〈/sup〉) and energy density (1202 mWhcm〈sup〉−2〈/sup〉, at 15 mAcm〈sup〉−2〈/sup〉) compared to pristine Zn-Co layered double hydroxides, with a greater cycling stability of 108% after 5000 charging-discharging cycles. We fabricate an all solid state symmetrical supercapacitor device with G-Zn-Co@Ni-Co//G-Zn-Co@Ni-Co layered double hydroxides that exhibits an areal capacitance of 1278 mFcm〈sup〉−2〈/sup〉, at 10 mVs〈sup〉−1〈/sup〉 and energy density of 171 mWhcm〈sup〉−2〈/sup〉, at 2.5 mAcm〈sup〉−2〈/sup〉. The credit of superior performance of these pseudocapacitor electrodes is to the easy access of electrolyte to the nanosheets, the conductivity enhancement by 3D graphene foam scaffold and the synergistic effect due to the composite structure of the Zn-Co@Ni-Co layered double hydroxides.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉A facile and low cost, hydrothermal technique was used to form a ZnCo@NiCo layered double hydroxide nanostructure composite electrode on graphene coated nickel foam for electrochemical supercapacitor.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319307979-fx1.jpg" width="424" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 435〈/p〉 〈p〉Author(s): Yachao Jin, Fuyi Chen, Jiali Wang, Longfei Guo, Tao Jin, Huazhen Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hydrogen oxidation and evolution reactions (HOR and HER) in alkaline media are very kinetically sluggish, which becomes one of major barriers for the breakthrough of anion exchange membrane fuel cells. Thus, developing highly active and economically competitive HOR/HER electrocatalysts for alkaline electrolytes is of critical importance to realize future hydrogen economy. Herein, we for the first time report a new class of platinum-rhodium nanoalloy aerogel (PtRh NAA) via a facile and controllable strategy as exceptional HOR/HER electrocatalysts in alkaline environment. The as-synthesized PtRh NAA features unique lamellar architecture, hierarchical pores system and abundant low-coordinated sites. Benefiting from the combined structural and electronic effects as well as bifunctional synergetic effects, the lamellar PtRh NAA delivers an excellent HOR specific activity of 1.25 mA cm〈sup〉−2〈/sup〉〈sub〉Pt+Rh〈/sub〉, which is 5.5 times higher than that of the commercial Pt/C (0.225 mA cm〈sup〉−2〈/sup〉〈sub〉Pt〈/sub〉). Meanwhile, its HER overpotential at −10 mA cm〈sup〉−2〈/sup〉 can be lowered to −55 mV, representing one of the highest HER activity so far. Moreover, no obvious deactivations are observed even after 5000 potential cycles for both HOR and HER, exhibiting excellent operation stability. These findings open a new field to design more advanced aerogels with high electrocatalytic performance.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319307839-fx1.jpg" width="449" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 30 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 435〈/p〉 〈p〉Author(s): Akos Kriston, Ibtissam Adanouj, Vanesa Ruiz, Andreas Pfrang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Differential Scanning Calorimetry (DSC) and Thermal Gravimetry (TGA) combined with gas analysis are used to identify the main decomposition processes and to develop reaction kinetic models for thermal runaway modelling of Graphite – Lithium Nickel–Manganese–Cobalt-Oxide (NMC 111) cells. Heating rates of 5, 10 and 15 °C min〈sup〉−1〈/sup〉 with multiple replications are performed to determine the frequency factor, activation energy and the heat of reaction of the different sub-processes. It is found that both the anode and cathode decompose in multiple parallel and consecutive reactions between 5 °C and 600 °C. A double breakdown mechanism of the protecting Solid Electrolyte Interface (SEI) is suggested to describe the anode decomposition reactions. For the cathode, decomposition and evaporation of ethylene carbonate (EC), decomposition of NMC with the liberation of oxygen, combustion of EC with the liberated oxygen, decomposition of binder, decomposition of EC and combustion of carbon additive reactions are identified and modelled. The proposed model can be used to simulate thermal runaway initiation methods in a realistic way.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319307451-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: Available online 29 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical〈/p〉 〈p〉Author(s): Xiangmei Li, Xinze Wu, Jin Wang, Qicheng Hua, Jinxiao Wu, Xing Shen, Yuanming Sun, Hongtao Lei〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, colloidal gold (CG), latex microspheres (LM), and time-resolved fluorescent microsphere (TrFM), were utilized as the antibody labeled tracers in three kinds of lateral flow immunochromatographic assays (LFIAs), which were established to detect tylosin (TYL) and tilmicosin (TIM) residues in milk and pork. The cut-off values of the CG-LFIA, LM-LFIA, and TrFM-LFIA for TYL in milk were 8, 4, and 2 ng/mL, respectively, and that for pork were 15, 8, and 4 μg/kg, respectively. The sample preparation of the three LFIAs is simple and fast, and the results can be acquired within 5-8 min. The three LFIAs have a strong cross-reaction to TIM and can be applied to simultaneously detect TIM. Forty milk samples were analyzed by both the three LFIAs and LC-MS/MS, the results showed a good correlation between the four methods, and no false positive or false negative results were found, indicating that the developed three assays could provide rapid, reliable, and multi-selective technical support for the on-site determination of macrolide antibiotics or other pollutants residues in a considerable amount of samples.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925400519312584-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: Available online 29 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical〈/p〉 〈p〉Author(s): Mohammad Khavani, Mohammad Izadyar, Mohammad Reza Housaindokht〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Different sensors composed of aptasensor have been largely designed for detection of many analytes recently due to the ease of detection, high sensitivity, and potential for high-throughput analysis. In this article, a joint theoretical and experimental study was performed to design new gold nanoparticle based colorimetric aptasensor. At the first step, by employing molecular dynamic (MD) simulations, twenty new RNA aptamers for detection of neomycin B (NB) were theoretically designed. The sensing ability and their binding affinity of these aptamers toward NB were investigated from the theoretical viewpoint and the predicted behaviors were compared with that of the wild type aptamer (AP-W). Theoretical results indicated that two aptamers of AP-M18 and AP-M20 have a greater affinity toward NB in comparison with AP-W. At the next step, AP-M18, AP-M20 and AP-W were synthesized and their affinity and selectivity toward NB were investigated by gold nanoparticles (AuNPs) based colorimetric method. On the basis of experimental results, the calculated limit of detection (LOD) values of AP-M18 and AP-M20 are 27 and 360 nM, respectively, which are lower than that of AP-W (470 nM). Moreover, quantum chemistry calculations indicated that van der Waals and electrostatic interactions may be the driving force of the NB complexation. A greater affinity of AP-M18 against NB can be explained by the possible stronger donor-acceptor interactions. A good agreement between different predicted properties with the experimental results suggests the ability of the theoretical methods to design new aptamers for detection of various targets.〈/p〉〈/div〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925400519311463-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈p〉Experimental investigation indicates that the theoretical methods have an interesting ability for designing new aptasensors for detection of different targets.〈/p〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 29 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical〈/p〉 〈p〉Author(s): Xiaohui Lu, Jin Wang, Guodong Lu, Bo Lin, Meizhuo Chang, Wei He〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉China grows and consumes numerous types of tea, which have diverse processing techniques. West Lake Longjing Tea is one of the most famous and popular varieties of tea in China. It is difficult for consumers to assess the quality of Longjing green tea, as it usually requires well-trained experts to make the judgement based on colour, aroma, and taste. To this end, we propose a quality identification system consisting of a self-developed electronic nose and a data analysis algorithm to assess the quality of West Lake Longjing Tea based on its aroma. The equipment was tested extensively in experiments conducted on real-world data. The results show that the proposed system is capable of distinguishing the tea grades accurately. Furthermore, we studied the quality specifications of Longjing tea sold by different brands and found that standard certified brands have more accurate quality identification criteria than non-standard certified brands. Our findings will assist customers and tea factories in evaluating the quality of Longjing Tea and guide the optimisation of quality standards.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 300〈/p〉 〈p〉Author(s): Hao Guo, Kun Qian, Anjiang Cai, Jun Tang, Jun Liu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We demonstrate a method for fabricating nanoparticles in a line at the top of silver wrinkled structures by tilting the substrate. The center of gravity of the colloidal droplets was moved backward, resulting in a small volume of droplets at the front of the colloidal droplet. The droplet rapidly evaporated, and the nanoparticles that remained formed lines of highly ordered nanoparticles. The distance between the nanoparticles changed after stretching the PDMS substrate due to the Poisson effect. An optimal plasma effect was achieved by controlling the distance between the nanoparticles. Finally, the Surface-Enhanced Raman Scattering (SERS) effects of CV and R6G molecules in water were determined, and the detection limit was 10〈sup〉−20〈/sup〉 M. This method provides an extremely high sensitivity SERS substrate for the detection of biomolecules.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 297〈/p〉 〈p〉Author(s): Jin Her, Hunho Jo, Changill Ban〈/p〉

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 436〈/p〉 〈p〉Author(s): Wentao Fu, Ruijie Xu, Xiaoqing Zhang, Ziqin Tian, Henghui Huang, Jiayi Xie, Caihong Lei〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The hydroxyl groups in inorganic-organic hybrid poly (cyclotriphosphazene-co-4,4-sulfonyldiphenol) (PZS) exhibits some reactivity toward lithium ions. In this work, the core-shell structured silica-poly (cyclotriphosphazene-co-4,4′-sulfonyldiphenol) nanoparticles (SiO〈sub〉2〈/sub〉-PZS) are synthesized and the composite separator is prepared by coating on both sides of polyethylene (PE) microporous membrane. Compared to pure SiO〈sub〉2〈/sub〉 coated separator and PE membrane, the PE-SiO〈sub〉2〈/sub〉@PZS separator shows higher ionic conductivity. The corresponding discharge capacity at 8C rate reaches a value of 115 mA h g〈sup〉−1〈/sup〉, compared to 105 mA h g〈sup〉−1〈/sup〉 for PE membrane and 106 mA h g〈sup〉−1〈/sup〉 for PE-SiO〈sub〉2〈/sub〉 separator. The hydroxyl group and N、O atoms on the surface of PZS can coordinate with lithium ions to enhance the dissociation of lithium salt (LiPF〈sub〉6〈/sub〉), thus improving the ionic conductivity and discharge capacity. Meanwhile the lower interfacial impedance resistance for PE-SiO〈sub〉2〈/sub〉@PZS separator indicates intimate adhesion between electrode and separator. In a word, the SiO〈sub〉2〈/sub〉-PZS nanoparticles are a promising filler for enhancing the wettability and electrochemical performance of Lithium-ion battery separator.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 436〈/p〉 〈p〉Author(s): Fangfang Zheng, Huilong Dong, Yujin Ji, Youyong Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The development of high-performance cathode electrocatalysts in nonaqueous lithium-oxygen (Li–O〈sub〉2〈/sub〉) battery is mainly restricted by high charge/discharge overpotentials. Based on first-principles calculations, we theoretically explore the application potential of BC〈sub〉3〈/sub〉 and NC〈sub〉3〈/sub〉 nanosheets as the suitable cathode electrocatalysts. By analyzing the stable adsorption configurations of Li〈sub〉x〈/sub〉O〈sub〉2y〈/sub〉 (x = 0–4, y = 0–2) intermediates on BC〈sub〉3〈/sub〉/NC〈sub〉3〈/sub〉, it is confirmed that oxygen reduction reaction (ORR) on BC〈sub〉3〈/sub〉 follows four-electron pathway with (Li〈sub〉2〈/sub〉O)〈sub〉2〈/sub〉 as the discharge product, while for ORR on NC〈sub〉3〈/sub〉, (Li〈sub〉2〈/sub〉O〈sub〉2〈/sub〉)〈sub〉2〈/sub〉 is the discharge product following two-electron pathway. We then plot the corresponding free energy diagrams of charge/discharge processes and calculate the theoretical discharge and charge overpotentials (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi〉η〈/mi〉〈/mrow〉〈mrow〉〈mi〉O〈/mi〉〈mi〉R〈/mi〉〈mi〉R〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 and 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi〉η〈/mi〉〈/mrow〉〈mrow〉〈mi〉O〈/mi〉〈mi〉E〈/mi〉〈mi〉R〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉) along the optimal reaction pathways. Our results show that both the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi〉η〈/mi〉〈/mrow〉〈mrow〉〈mi〉O〈/mi〉〈mi〉R〈/mi〉〈mi〉R〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 and 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi〉η〈/mi〉〈/mrow〉〈mrow〉〈mi〉O〈/mi〉〈mi〉E〈/mi〉〈mi〉R〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 on BC〈sub〉3〈/sub〉 are considerably low (0.21 V and 0.36 V), indicating that BC〈sub〉3〈/sub〉 can serve as a high-performance cathode electrocatalyst. Meanwhile, the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi〉η〈/mi〉〈/mrow〉〈mrow〉〈mi〉O〈/mi〉〈mi〉R〈/mi〉〈mi〉R〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 and 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi〉η〈/mi〉〈/mrow〉〈mrow〉〈mi〉O〈/mi〉〈mi〉E〈/mi〉〈mi〉R〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 on NC〈sub〉3〈/sub〉 (0.37 V and 0.95 V) are comparable to previously reported materials following two-electron pathway (such as N-doped graphene), exhibiting practical values. Both the BC〈sub〉3〈/sub〉 and NC〈sub〉3〈/sub〉 nanosheets are stable enough for application in Li–O〈sub〉2〈/sub〉 battery, and dimethyl sulfoxide (DMSO) isn't recommended as an organic electrolyte when BC〈sub〉3〈/sub〉 works as the cathode catalyst.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319308389-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 436〈/p〉 〈p〉Author(s): Yoon-Sok Kang, Dong Young Kim, Jaegu Yoon, JoungWon Park, Gyusung Kim, Yongnam Ham, Insun Park, Meiten Koh, Kwangjin Park〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A new synthetic method using biotemplating for fabrication of LiCoO〈sub〉2〈/sub〉 (LCO) for batteries of mobile products is developed. The LCO can be manufactured in various forms, and rapidly charged and discharged, even when using a thick electrode. Among three types of candidate biotemplates wood, cotton, and grass pollen, cotton was selected as the biotemplate considering its performance and potential for commercialization. Both the size of the primary particle and the shape of the secondary particle are controllable by using cotton. When using a thin electrode, the difference in capacitance between the LCO fabricated by the general method (solid-LCO) and the LCO made by using cotton (cotton-LCO) is within 3%, regardless of current density. On the other hand, the capacity difference in the case of a thick electrode between two samples is approximately 1.5 times higher than that observed for solid-LCO at very high current density (6C). The capacity retention values are 1.4% and 75.1% at 6C after the 100th cycle for solid-LCO and cotton-LCO, respectively. The superior performance at high current density for the cotton-LCO likely arises from decreasing the distance that the Li〈sup〉+〈/sup〉 ion must diffuse in the solid-state by connected nanoparticles.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 438〈/p〉 〈p〉Author(s): Yunhe Zhao, Hongxing Dong, Xinyi He, Jing Yu, Rongrong Chen, Qi Liu, Jingyuan Liu, Hongsen Zhang, Rumin Li, Jun Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Electrode materials with a large internal surface area, tunable pore size, efficient transport of electrons and high ion-accessibility are highly desired in the development of advanced flexible supercapacitors. Recently, transition metal sulfides with rationally designed nanostructures have attracted considerable attention as electrode materials for supercapacitors. In this study, we report the synthesis of Zn〈sub〉0.76〈/sub〉Co〈sub〉0.24〈/sub〉S/NiCo〈sub〉2〈/sub〉S〈sub〉4〈/sub〉 nanosheets grown on carbon cloth using a two-dimensional bimetallic Zn/Co zeolitic imidazolate framework (named as Zn/Co-ZIF-L) as a precursor through a simple and cost-effective chemical solution process. The ZIF-derived Zn〈sub〉0.76〈/sub〉Co〈sub〉0.24〈/sub〉S/NiCo〈sub〉2〈/sub〉S〈sub〉4〈/sub〉 electrode nanosheets deliver an ultrahigh specific capacitance of 2674 F g〈sup〉−1〈/sup〉 at 1 A g〈sup〉−1〈/sup〉, a superior ratio performance and cycle stability. Furthermore, the as-fabricated Zn〈sub〉0.76〈/sub〉Co〈sub〉0.24〈/sub〉S/NiCo〈sub〉2〈/sub〉S〈sub〉4〈/sub〉//AC all-solid-state asymmetric supercapacitor (ASC) achieves a maximum energy density of 48.1 Wh kg〈sup〉−1〈/sup〉 as well as a power density of 837 W kg〈sup〉−1〈/sup〉, and a superior cycling performance of 91% retention after 5000 cycles. The detailed electrochemical kinetic analysis demonstrates that the total capacitance of Zn〈sub〉0.76〈/sub〉Co〈sub〉0.24〈/sub〉S/NiCo〈sub〉2〈/sub〉S〈sub〉4〈/sub〉 is derived from its capacitive-effective charge storage mechanism. This ZIF-derived strategy provides a reasonable and simple way to synthesize transition metal sulfides as potential active materials for next-generation flexible supercapacitors.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S037877531931050X-fx1.jpg" width="252" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 31 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 438〈/p〉 〈p〉Author(s): Hao-Jen You, Hsu-Shen Chu, Wen-Jin Li, Wen-Li Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The thermoelectric effect is a promising source of renewable energy that can be used to interconvert thermal and electrical energy based on the Seebeck effect and Peltier effect. Conventional thermoelectric modules (CTEMs) cannot be bent to cover irregular surfaces such as the human body. Further, they are fragile and have expensive ceramic substrates. Hence, it is difficult to apply them, particularly in wearable devices. We demonstrate low-cost flexible thermoelectric modules (FTEMs) using flexible copper clad lamination as a substrate. The weight of an FTEM is only 0.43 g/cm〈sup〉2〈/sup〉, which is approximately 2.5 times lower than that of a CTEM (1.06 g/cm〈sup〉2〈/sup〉), even though the two devices use the same thermoelectric materials (n-type Bi〈sub〉2〈/sub〉Se〈sub〉0.3〈/sub〉Te〈sub〉2.7〈/sub〉 and p-type Bi〈sub〉0.5〈/sub〉Sb〈sub〉1.5〈/sub〉Te〈sub〉3〈/sub〉) fabricated using the same process. In addition, the output density of the FTEM is several tens of times higher than that of the CTEM with a temperature difference of 15 K. The FTEM also exhibits a cooler performance of 13.76%. This is particularly important for cases where the power density per unit area and weight are important, such as the applications of a thermoelectric module on human skin, automobiles, and spaceships. These results can be applied to improve the applications of thermoelectric modules.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319310481-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 299〈/p〉 〈p〉Author(s): Gao-Chao Fan, Zimeng Li, Yanwei Lu, Linzheng Ma, Huan Zhao, Xiliang Luo〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Resulting from nonspecific adsorption or obvious biofouling, target detection in real biological media is a potential challenge for most of the biosensors. Herein, we first report an antifouling photoelectrochemical (PEC) cytosensor by using zwitterionic peptide. The typical cervical carcinoma Henrietta Lacks (HeLa) cell was chosen as a target model and the aptamer AS1411 was used as its recognition element. TiO〈sub〉2〈/sub〉 nanoparticles (NPs) and ZnIn〈sub〉2〈/sub〉S〈sub〉4〈/sub〉 nanocrystals (NCs) were modified in order on a bare indium–tin oxide (ITO), forming ITO/TiO〈sub〉2〈/sub〉/ZnIn〈sub〉2〈/sub〉S〈sub〉4〈/sub〉 electrode as the PEC matrix to immobilize aptamer AS1411 and zwitterionic peptide. The fabricated PEC cytosensor exhibited a high sensitivity toward HeLa cell detection, with the detection limit of 34 cells/mL. Besides, owning to excellent antifouling property of the zwitterionic peptide, evidently reduced nonspecific adsorption of the cytosensor was realized in the biological media.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉An efficient but general strategy for antifouling photoelectrochemical cytosensor was proposed by introducing zwitterionic peptide. The cytosensor demonstrated the distinct merits of high sensitivity and low fouling in the biological media.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925400519311955-ga1.jpg" width="283" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Beschreibung: 〈p〉Publication date: Available online 20 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Solid-State Electronics〈/p〉 〈p〉Author(s): Paul Clifton, Andreas Goebel, Robert Mulfinger, Amy Child, Sherry Straub, Ryan Sporer, Rick Carter, Jon Kluth, Jamie Schaeffer, Bich-Yen Nguyen, Guillaume Chabanne, Nicolas Daval, Walter Schwarzenbach, Manish Hemkar, Schubert Chu, Steve Moffatt〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report for the first time the implementation of SiGe buried stressors in the context of research and development of an advanced foundry FDSOI process and the observation of improved transconductance and current drive performance of n-channel FDSOI MOSFETs. Epitaxial SiGe stressors grown by CVD at Applied Materials were incorporated under the buried oxide of 300 mm FDSOI wafers by Soitec using lower temperature SOI bonding, splitting and thinning processes and the wafers were subsequently processed through an FDSOI development line at GLOBALFOUNDRIES. The use of FDSOI with buried stressor under the BOX eliminates the risk of extended defects in the epitaxial SiGe layer penetrating up into the SOI channel and also provides an opportunity to obtain a high level of strain in any semiconductor on insulator. A 70 nm thick SiGe buried stressor with 20% Ge is shown to provide a 10% improvement in I〈sub〉dsat〈/sub〉 at a fixed I〈sub〉off〈/sub〉 for n-FETs with 20 nm gate length and transconductance, gm is correspondingly improved by 15%.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 299〈/p〉 〈p〉Author(s): Xiang Tao, Tan Dai Nguyen, Hao Jin, Ran Tao, Jingting Luo, Xin Yang, Hamdi Torun, Jian Zhou, Shuyi Huang, Lin Shi, Des Gibson, Michael Cooke, Hejun Du, Shurong Dong, Jikui Luo, YongQing Fu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Manipulating biological cells or microparticles in three dimensions (3D) is invaluable for many biomedical applications, and recently effective and rapid manipulations of microparticles in 2D and 3D within microchannels or chambers using surface acoustic waves (SAWs) with bulk piezoelectric materials have been reported. However, these are generally expensive, or brittle and cannot be easily integrated into a single lab-on-chip. In this paper, we realized microparticle/cell patterning and 3D manipulation of yeast cells inside a chamber with a height of 1 mm using thin film ZnO/Si SAW devices. Effects of SAW frequency, channel width and thickness on alignment of microparticles were firstly investigated, and positions of the microparticles in the direction of SAW propagation can be controlled precisely by changing the phase angle of the acoustic waves from the ZnO/Si SAW device. A numerical model has been developed to investigate the SAW acoustic field and the resulted 3D motions of microparticles under the acoustic radiation forces within the microchamber. Finally, we realized and observed the 3D patterning of yeast cells within the microchannel. Our work shows a great potential for acoustofluidic, neural network research and biomedical applications using the ZnO/Si SAW devices.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: Available online 20 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Radiation Measurements〈/p〉 〈p〉Author(s): I.S. Peracchi, J. Vohradsky, S. Guatelli, D. Bolst, L.T. Tran, D.A. Prokopovich, A.B. Rosenfeld〈/p〉 〈div xml:lang="en"〉 〈h5〉〈span〉Abstract〈/span〉〈/h5〉 〈div〉 〈p〉Astronauts are exposed to high-energy cosmic radiation which may have harmful health effects. At the altitude of the International Space Station (ISS), the main radiation sources are Galactic Cosmic Rays (GCRs), Solar Particle Events (SPEs) and trapped protons of the Van Allen Belts. The radiation field mainly consists of protons, helium nuclei and heavy ions with energies up to hundreds of GeV/n. A powerful approach to determine the effect of space radiation on astronauts is microdosimetry. The Centre for Medical Radiation Physics is active in the development of Silicon-On-Insulator (SOI) microdosimeters, as an alternative to Tissue Equivalent Proportional Counters (TEPCs) for radiation protection purposes. SOI microdosimeters are portable and do not require a high-voltage power supply. They consist of a matrix of silicon Sensitive Volumes (SV), which mimic the dimensions of biological cells.〈/p〉 〈p〉In this study, we investigated for the first time the response of the 3D “Mushroom” microdosimeter, a type of SOI microdosimeter in the Columbus module of the ISS. Tissue-equivalent microdosimetric spectra of GCRs, SPEs, and trapped protons were obtained to estimate the dose equivalent delivered to the astronauts. Results demonstrate a non-negligible production of secondary particles due to the propagation of space radiation through the wall of the Columbus and the microdosimeter. A number of heavy ions were detected with high lineal energies, these events pose a significant hazard in terms of radiation protection.〈/p〉 〈p〉Moreover, the dose evaluation shows a good agreement with experimental data found in the literature, confirming the suitability of our Geant4 model and the feasibility of using the SOI microdosimeter for ISS astronauts’ personal dosimetry.〈/p〉 〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 299〈/p〉 〈p〉Author(s): Oleg Lupan, Vasile Postica, Thierry Pauporté, Bruno Viana, Maik-Ivo Terasa, Rainer Adelung〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, we investigated performances of individual and multiple networked Au nanoparticles (NPs)-functionalized ZnO nanowires (NWs) integrated into nanosensor devices using dual beam focused ion beam/scanning electron microscopy (FIB/SEM) and tested them as gas sensors at room temperature. Such important parameters as diameter and relative humidity (RH) on the gas sensing properties were investigated in detail. The presented results demonstrate that thin Au/ZnO NWs (radius of 60 nm) have a gas response of 〈em〉I〈sub〉gas〈/sub〉/I〈sub〉air〈/sub〉〈/em〉 of about 7.5–100 ppm of H〈sub〉2〈/sub〉 gas which is higher compared to 〈em〉I〈sub〉gas〈/sub〉/I〈sub〉air〈/sub〉〈/em〉 of about 1.2 for NWs with a radius of 140 nm. They have a low dependence of electrical parameters on water vapors presence in environment, which is very important for practical and real time applications in ambient atmosphere. Also, the devices based on multiple networked Au/ZnO NWs demonstrated a higher gas response of 〈em〉I〈sub〉gas〈/sub〉/I〈sub〉air〈/sub〉〈/em〉 about 40 and a lower theoretical detection limit below 1 ppm compared to devices based on an individual NW due to the presence of multiple potential barriers between the NWs. The corresponding gas sensing mechanisms are tentatively proposed. The proposed concept and models of nanosensors are essential for further understanding the role of noble metal nanoclusters on semiconducting oxide nanowires and contribute for a design of new room-temperature gas sensors.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925400519311761-ga1.jpg" width="265" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: Available online 9 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources〈/p〉 〈p〉Author(s): A.J. Paleo, P. Staiti, A.M. Rocha, G. Squadrito, F. Lufrano〈/p〉

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 436〈/p〉 〈p〉Author(s): Rahul B. Pujari, Swati J. Patil, Jongsung Park, Arunkumar Shanmugasundaram, Dong-Weon Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Present work focuses on hydrothermal preparation of FeOOH@MnO〈sub〉2〈/sub〉 core shell as a vertically aligned 1-D nanostructure and improvement in electrochemical charge storage by utilizing MnO〈sub〉2〈/sub〉 nanostructure as an active electrode material and vertically aligned FeOOH nanorods for one dimensional electron transfer paths. A FeOOH@MnO〈sub〉2〈/sub〉 core shell thin film electrode gives maximum capacitance of 0.252 Fcm〈sup〉−2〈/sup〉 for the applied current density of 1 mAcm〈sup〉−2〈/sup〉 and maintains 99.5% capacitance retention for 2000 charge discharge cycles at 5 mAcm〈sup〉−2〈/sup〉 that attributes to better capacitive charge storage in the material. Assembled solid state symmetric electrochemical capacitor of FeOOH@MnO〈sub〉2〈/sub〉 electrode yields maximum of 0.05 mWhcm〈sup〉−2〈/sup〉 energy density with power delivery of 1.5 mWcm〈sup〉−2〈/sup〉.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319308195-fx1.jpg" width="498" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 436〈/p〉 〈p〉Author(s): Isao Shitanda, Kotaro Takamatsu, Ayumu Niiyama, Tsutomu Mikawa, Yoshinao Hoshi, Masayuki Itagaki, Seiya Tsujimura〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As lactate is a useful biomarker for evaluating conditions of the body and also has a high theoretical energy density as a fuel, enzymatic biofuel cells (BFCs) that utilize lactate as a fuel have received considerable attention. In this study, we have developed a high-power lactate/O〈sub〉2〈/sub〉 BFC that comprises composite electrodes made from carbon cloth as a current collector and MgO-templated porous carbon as an electroenzymatic reaction field and enzyme support. The bioanode contains lactate oxidase as an enzyme and 1-methoxy-5-methylphenazinium methylsulfate as a redox mediator. The biocathode contains bilirubin oxidase as an oxygen reduction electrocatalyst and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) as a mediator. To obtain an efficient gas diffusion biocathode, the hydrophobicity of the carbon cloth is modulated by modification with PTFE. The lactate/O〈sub〉2〈/sub〉 BFC shows a maximum power density of 4.3 mW cm〈sup〉−2〈/sup〉 at a lactate concentration of 300 mM. This high performance is promising for the development of BFCs for wearable applications.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319308377-fx1.jpg" width="315" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 436〈/p〉 〈p〉Author(s): Puritut Nakhanivej, Sul Ki Park, Kang Ho Shin, Sol Yun, Ho Seok Park〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Vanadium pentoxide is considered as a candidate of cathode material for lithium-ion batteries owing to its high specific capacity, large potential window, and short diffusion pathway. However, vanadium pentoxide has its own limitations such as insufficient electronic conductivity, sluggish ion diffusion, and volume expansion. In order to resolve these problems, we demonstrate spray frozen assembly into hierarchically structured open-porous vanadium pentoxide/reduced graphene oxide composite microballs for high performance lithium-ion battery cathodes. The uniform distribution of vanadium pentoxide particles immobilized onto the open-porous surface of reduced graphene oxide microballs is associated with the short ion diffusion pathway, the percolated electronic conduction, and the buffering space. Accordingly, vanadium pentoxide/reduced graphene oxide composite microballs achieve the initial discharge capacity of 273 mAh g〈sup〉−1〈/sup〉 at 100 mA g〈sup〉−1〈/sup〉 which is higher than those of reduced graphene oxide (78 mAh g〈sup〉−1〈/sup〉) and vanadium pentoxide (214 mAh g〈sup〉−1〈/sup〉). When the current density increases from 100 to 1000 mA g〈sup〉−1〈/sup〉, the capacity retention of vanadium pentoxide/reduced graphene oxide composite microballs is 51.3%, much greater than 36.4% of vanadium pentoxide particles. The capacity retention of 80.4% with the Coulombic efficiency of 97.1% over 200 cycles is twice greater than that of V〈sub〉2〈/sub〉O〈sub〉5〈/sub〉 particles, indicating improved cyclic stability.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S037877531930847X-fx1.jpg" width="492" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 436〈/p〉 〈p〉Author(s): Michail-Antisthenis Tsompanas, Jiseon You, Lauren Wallis, John Greenman, Ioannis Ieropoulos〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Microbial fuel cells (MFCs) are gaining interest due to higher power production achieved by deep analysis of their characteristics and their effect on the overall efficiency. To date, investigations on MFC efficiency, can only be based on laboratory experiments or mathematical modelling. However, there is only a handful of rule-based mathematical modelling due to the difficulties imposed by the high sensitivity of the MFC system to environmental parameters and the highly complex bacterial consortia that dictate its behavior. Thus, an application of an artificial neural network (ANN) is proposed to simulate the polarisation of cylindrical MFCs with different materials as the separation membranes. ANNs are ideal candidates for investigating these systems, as there is no need for explicit knowledge of the detailed rules that govern the system. The ANN developed here is a feed-forward back-propagation network with a topology of 4-10-1 neurons that approximates the voltage of each MFC at a given state. Two different membrane materials with two different electrode configurations were assembled and utilized in laboratory experiments to produce the data set on which the ANN was trained upon. For the whole data set the correlation coefficient (〈em〉R〈/em〉) between real values and outputs of the network was 0.99662.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 436〈/p〉 〈p〉Author(s): J. Sturm, S. Ludwig, J. Zwirner, C. Ramirez-Garcia, B. Heinrich, M.F. Horsche, A. Jossen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Local inhomogeneous electrode utilization in recent lithium-ion batteries tends to increase due to larger sizes and/or higher densification, which poses a challenge for accurate, model-based monitoring. Pseudo-two dimensional (p2D) physicochemical models (PCM) can offer such locality via calculating local potentials and concentrations through the thickness of the electrode stack and are numerically reduced for implementation in a microcontroller in this work. Finite difference method combined with solid-diffusion approximations and orthogonal collocation reformulation are applied to generate three MATLAB- and three microcontroller-suitable 〈em〉C〈/em〉-code p2D-PCMs, which are experimentally validated towards constant current charge/discharge and driving cycle loads on a high-energy NMC-811/SiC-18650 lithium-ion battery. Benchmarking to an equivalent circuit model reveals similar mean cell voltage errors below 20 mV for the driving cycle. Reducing spatial elements reveals errors below 1% for local (〈em〉i.e.〈/em〉 concentrations/potentials) and global states (〈em〉i.e.〈/em〉 cell voltage/temperature) and is applied to speed-up the 〈em〉C〈/em〉-code p2D-PCMs in the microcontroller (max. 168 MHz with 192 kB RAM) to calculate at least 37% faster than real-time. Real-time computability is investigated via varying processor frequencies and using hardware acceleration schemes. The memory allocation to solve and store the p2D-PCMs on the microcontroller require 115 kB and 213 kB at a maximum, respectively.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319308274-fx1.jpg" width="441" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 31 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 438〈/p〉 〈p〉Author(s): Asia Rafique, Rizwan Raza, Amjad Ali, Muhammad Ashfaq Ahmad, Mikael Syväjärvi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper describes the fabrication of Ni〈sub〉0.6〈/sub〉Zn〈sub〉0.4〈/sub〉-Gd〈sub〉0.2〈/sub〉Ce〈sub〉0.8〈/sub〉O〈sub〉2-δ〈/sub〉 (NiZn-GDC) via a two-step wet chemical synthesis technique. This composite was found to be more thermally stable and carbon resistive under the intense reducing environment of biogas. This was confirmed by different characterization techniques. The maximum power density P〈sub〉max〈/sub〉, was achieved at 600 °C as 820 mW/cm〈sup〉2〈/sup〉 and 548 mW/cm〈sup〉2〈/sup〉 with hydrogen and biogas, respectively. Different characterization techniques have been performed, such as X-ray diffractometry (XRD), scanning electron microscopy (SEM/EDX), UV–visible spectroscopy, and Raman spectroscopy. The XRD pattern by Rietveld refinement showed two-phase structures of the anode composite with an average crystallite size of 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mrow〉〈mn〉25〈/mn〉〈mo linebreak="goodbreak" linebreakstyle="after"〉−〈/mo〉〈mn〉35〈/mn〉〈mspace width="0.25em"〉〈/mspace〉〈mtext〉nm〈/mtext〉〈/mrow〉〈/math〉 before and after reduction with methane. The optical band gap (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.svg"〉〈mrow〉〈msubsup〉〈mrow〉〈mi〉E〈/mi〉〈/mrow〉〈mrow〉〈mi〉g〈/mi〉〈/mrow〉〈mrow〉〈mi〉o〈/mi〉〈mi〉p〈/mi〉〈mi〉t〈/mi〉〈/mrow〉〈/msubsup〉〈/mrow〉〈/math〉) of NiZn-GDC was calculated to be 2.24eV from the Tauc plot using absorbance data. The Nyquist plot was also drawn to study the AC electrochemical impedance spectra (EIS) of the nanocomposite anode from 450 °C to 600 °C in air. The maximum DC conductivity of 1.37 S/cm was observed at a temperature of 600 °C using the four-probe DC technique.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 299〈/p〉 〈p〉Author(s): Ye Liu, Fei Zhou, Hongcheng Wang, Xiaoyuan Huang, Dongxiong Ling〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Coffee-ring structures, which are easy to prepare, have many hotspots for surface-enhanced Raman scattering (SERS). However, the inhomogeneous distribution of hotspots causes very poor SERS detection reproducibility, which strongly restricts their practical applications. In this paper, by combining a coffee-ring structure with the waveguide effect of optical fibers, we propose novel micro-coffee-ring-patterned fiber SERS probes fabricated by a laboratory-developed laser-induced dynamic dip-coating method. The mechanisms of micro-coffee-ring formation on fiber facet are analyzed in detail. With the help of a programmable dip-coater, micro-coffee-ring-patterned fiber SERS probes can be automatically and reproducibly fabricated, and they simultaneously show high sensitivity and good reproducibility in SERS detections. A detection limit lower than 10〈sup〉−8〈/sup〉 M in aqueous solvent for thiram and methyl parathion (MP) is achieved, and the relative standard deviation (RSD) of the SERS peaks is less than 6%. In addition, benefiting from numerous hotspots provided by micro-coffee rings, this micro-coffee-ring-patterned fiber SERS probe presents superior performance in 〈em〉in-situ〈/em〉 trace detection of target molecules in complex liquid environments. Detection sensitivities of 10〈sup〉−7〈/sup〉 M for thiram in lake water and in orange juice and 10〈sup〉−6〈/sup〉 M for melamine and tetracycline in liquid milk are achieved.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 299〈/p〉 〈p〉Author(s): Xiaofang Qiao, Zhiming Ma, Lihui Si, Wei Ding, Guangmeng Xu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, a lanthanide cation, Eu(III), was firstly coordinated with a series of organic antenna ligands and then doped into bio-MOF-1 via cation exchange for O〈sub〉2〈/sub〉 optical sensing. These organic ligands were supposed to increase dynamic collision probability between O〈sub〉2〈/sub〉 molecules and excited probe molecules, so that sensitivity could be increased and response time could be decreased. These composite samples were firstly identified using SEM, XRD, N〈sub〉2〈/sub〉 adsorption/desorption and ICP measurement to confirm their microstructure. Then their absorption spectra, emission spectra and emission lifetimes were discussed. It was found that these composite samples showed long emission lifetime up to 595 μs, which ensured enough time for O〈sub〉2〈/sub〉 collision. Their O〈sub〉2〈/sub〉 sensing performance was discussed via their emission spectra under increasing O〈sub〉2〈/sub〉 concentrations. Linear sensing curves were observed for all samples. It was found that a large conjugation plane improved sensitivity and decreased response time since this large conjugation plane increased dynamic collision probability. The sensing mechanism was confirmed as the O〈sub〉2〈/sub〉 quenching on long-range energy roll-back from ligand triplet state to bio-MOF-1. The highest sensitivity and the shortest response time were obtained as 6.96, three times higher than literature values, and 12 s, respectively.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925400519311773-ga1.jpg" width="276" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 298〈/p〉 〈p〉Author(s): Naveen Kumar Sompalli, Akhila Maheswari Mohan, C.V.S. Brahmananda Rao, Sivaraman Nagarajan, Prabhakaran Deivasigamani〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We present a facile approach towards the fabrication of solid state optical sensors for the naked-eye sensing of carcinogenic Cr〈sup〉6+〈/sup〉 ions, using porous polymer and silica monoliths, as probe anchoring templates. The monoliths proffer superior structural properties of high surface area and capacious pore size for the uniform and voluminous probe anchoring. The surface morphology and structural features of the monoliths are analyzed using various surface and structural characterization techniques. The solid-state optical sensors are concocted by the transmogrification of monoliths through impregnation of an amphipathic chromoionophore 〈em〉i.e.〈/em〉, 〈em〉1,5〈/em〉-bis-(〈em〉4〈/em〉-butylphenyl)carbazone (BBPC), as the ion-sensing probe. The sensors offer long-term stability and rapid response kinetics (〈 10 min) with superior ion-selectivity for ultra-trace Cr〈sup〉6+〈/sup〉 ions. The ascendancy of physicochemical parameters with reference to solution pH, probe concentration, response kinetics, medium temperature, sensor capacity, linear signal response, selectivity, and sensitivity has been optimized. The sensors exhibit a linear signal response for Cr〈sup〉6+〈/sup〉 ions in the concentration range of 5–125 ppb and 3–150 ppb, for silica and polymer sensors, respectively. The solid-state sensor systems exhibit excellent data reliability and reproducibility (RSD ≤ 2.85%), with an L〈sub〉D〈/sub〉 of 1.87 and 0.41 ppb, and an L〈sub〉Q〈/sub〉 of 6.23 and 1.36 ppb, for silica and polymer sensors, respectively.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925400519310950-ga1.jpg" width="461" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 31 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 438〈/p〉 〈p〉Author(s): Qi Feng, Lin Zeng, Jiaoyan Xu, Zhen Zhang, Zhiliang zhao, Yajun Wang, Xiao-Zi Yuan, Hui Li, Haijiang Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Molybdenum phosphide (MoP) is a prospective non-precious catalyst for hydrogen evolution reaction (HER), though its HER elctrocatalytic performance need to be further enhanced. We first report a facile, easy-scalable and low-cost approach for fabricating porous lamellar MoP/C hybrids by simply mixing the common ingredients of ammonium molybdate, ammonium dihydrogen phosphate, dicyandiamide and sodium chloride (NaCl), followed by freeze-drying, annealing and water-washing. Here, NaCl is used as pore-forming and template-directing agent during the high-temperature annealing and “cooling recrystallization” process. Highly crystalline and ultrafine MoP nanoparticles are intimately wrapped by lamellar carbon nanosheets. The lamellar conductive architecture with ultrathin and porous carbon nanosheets provides multiple attractive properties for HER, such as impeding the growth of nanoparticles, offering an expressway for boosting mass/charge transfer, and delivering large specific surface area with numerous exposed eletrocatalytic sites. Consequently, the MoP/C (NaCl) electrocatalyst presents a low HER overpotential of 118 mV at 10 mA cm〈sup〉−2〈/sup〉 with a small Tafel slope of 50.7 mV dec〈sup〉−1〈/sup〉 in 0.5 M H〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉, as well as robust stability. Moreover, a home-made electrolyzer using MoP/C (NaCl) as cathode achieves 0.71 A cm〈sup〉−2〈/sup〉 at 2 V〈sub〉cell〈/sub〉 at 80 °C, and is operated stably for more than 3300 min at 150 mA cm〈sup〉−2〈/sup〉.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319310419-fx1.jpg" width="425" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 31 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 438〈/p〉 〈p〉Author(s): Jiaming Sun, Wei Li, Lei E, Zhou Xu, Chunhui Ma, Zhenwei Wu, Shouxin Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Optimizing the structure of electrodes to decrease electrolyte transport resistance is essential for high electrochemical performance in supercapacitors. Here, we prepare ultralight carbon aerogels containing tubular structures and N-containing sandwich-like walls based on the natural structure of kapok fibers, by in-situ polymerization of pyrrole and carbonization. The resulting carbon aerogels are composed of microtubes with a diameter of 10 μm, an ultralow density of 6 mg cm〈sup〉−3〈/sup〉, and also N-containing sandwich-like walls composed of pyridinic nitrogen, pyrrolic/pyridine nitrogen, and quaternary nitrogen/oxidized nitrogen. The unique tubular structure promotes transport of electrolyte, yielding higher electrochemical performance. Consequently, the tubular structure produces a 72 F g〈sup〉−1〈/sup〉 increase in the capacitance compared with that of a cattail carbon aerogel without a tubular structure. The N-containing sandwich-like walls provide more active sites, greater pseudocapacitance, and increase the thickness of the microtube to protect the tubular structures from damage during carbonization. Specifically, the optimal sample has a specific capacitance of 274 F g〈sup〉−1〈/sup〉 at a current density of 1 A g〈sup〉−1〈/sup〉 with an energy density of 8.51 Wh kg〈sup〉−1〈/sup〉, a superior rate capability, and excellent cycling stability with a capacitance retention of 97.7% after 4000 cycles.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 438〈/p〉 〈p〉Author(s): Jinhua Zhou, Shuchi Xu, Lu Ni, Ningna Chen, Xiaoge Li, Chunliang Lu, Xizhang Wang, Luming Peng, Xuefeng Guo, Weiping Ding, Wenhua Hou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A new strategy is proposed for the preparation of Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 encapsulated in N-doped carbon (denoted as Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@NC) through a self-assembly of the colloidal FeOOH with polyaniline (PANI) and then a subsequent pyrolysis. Benefiting from the well-designed heterostructure, the resultant Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@NC shows an ultra-high gravimetric capacitance of 313 F g〈sup〉−1〈/sup〉 at 1 A g〈sup〉−1〈/sup〉 and still delivers 193 F g〈sup〉−1〈/sup〉 at a high current density of 15 A g〈sup〉−1〈/sup〉, demonstrating an excellent rate performance. In addition, it has an outstanding volumetric capacitance of 20.25 F cm〈sup〉−3〈/sup〉 at 1 A g〈sup〉−1〈/sup〉. The asymmetric supercapacitors (ASCs) are constructed by using Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@NC as anode and layered double hydroxides (LDHs) as cathode, respectively. Due to the enlarged voltage window and matched capacity and kinetics, the obtained CoMn-LDH//Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@NC ASC device shows a remarkable electrochemical performance with a large energy density up to 35 Wh·kg〈sup〉−1〈/sup〉 at a power density of 900 W kg〈sup〉−1〈/sup〉 and a high energy density of 24 Wh·kg〈sup〉−1〈/sup〉 at a power density of 13.5 kW kg〈sup〉−1〈/sup〉 as well as an excellent rate capability and a good cycling stability. The present work may provide an insight into the design of novel anode materials for high-performance ASCs.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319310407-fx1.jpg" width="285" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 297〈/p〉 〈p〉Author(s): Xiaowei Li, Chaohan Han, Dongxiao Lu, Changlu Shao, Xinghua Li, Yichun Liu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The size of sensing materials matters a lot to the performance of gas sensors. Herein, size-controlled three-component ZnO/ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/Au nanomeshes were elaborately prepared by combining electrospinning, atomic layer deposition and room-temperature solution reaction methods. The as-prepared ZnO/ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/Au is characterized by uniform ZnO nanotube skeletons (˜50 nm), ultrathin ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 nanosheets (˜10 nm) and well-dispersed Au nanoparticles. To demonstrate the superiority of such ultrafine ZnO/ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/Au nanomeshes, a comparison of sensing performance between the gas sensors fabricated by pristine ZnO, ZnO/ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 and ZnO/ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/Au was carried out. Results of the measurement evidence that the sensor based on ZnO/ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/Au nanomeshes exhibited the highest sensing response, significantly enhanced selectivity, and faster response/recover speed compared with the other two reference counterparts. The response of ZnO/ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/Au towards acetone was improved about 3-fold versus the ZnO/ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 composites and 5.5-fold versus pristine ZnO. The enhanced gas sensing performance was found to be closely related to the highly electron-depleted layer derived from the small material size and the interfacial heterojunctions as well as the sensitization effect endowed by the Au nanoparticles. This study shows the great potential of ZnO/ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/Au nanomeshes on acetone detection and provides a promising mean for the rational design of high-performance gas sensor.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 297〈/p〉 〈p〉Author(s): Mingquan Pi, Chuantao Zheng, Ran Bi, Huan Zhao, Lei Liang, Yu Zhang, Yiding Wang, Frank K. Tittel〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The reported chalcogenide (ChG) waveguide sensor mainly focuses on rectangular waveguide with a small evanescent field for light-gas interaction. In order to improve the sensing performance in the mid-infrared spectral range and ease wavguide fabrication, a suspended ChG/silica-on-silicon slot-waveguide gas sensor was proposed, where ChG was used as the core layer, silica was adopted as the lower buffer as well as a support layer with the silica under the waveguide core removed. The new sensor structure resulted in an increased light-gas interaction, a decreased waveguide loss in the mid-infrared and a small depth-to-width ratio for feasible slot fabrication. The optimized suspended slot waveguide reveals a large power confinement factor (PCF) of 85.77% at 3291 nm. CH〈sub〉4〈/sub〉 was adopted as the target gas for performance evaluation of the ChG/silica-on-silicon slot-waveguide sensor at the absorption line of 3038.5 cm〈sup〉−1〈/sup〉. An optimal waveguide length of 1.45 cm was determined with a waveguide loss of 3 dB/cm for maximizing the sensitivity. The response time is as short as 〈3 μs due to the exposure of the waveguide sensing area to the atmosphere. The limit of detection (LoD) was decided to be 1.70 parts-per-million (ppm) for a minimum detectable signal-to-noise ratio of 10. Effects of ambient temperature/pressure change and fabrication error on the sensor performance were discussed. The proposed suspended ChG/silica-on-silicon slot-waveguide sensor possesses a ∼ 10 times larger PCF than other reported ChG rectangular waveguide sensors in the mid-infrared and reveals an improved performance for potential environmental monitoring and wearable gas sensing applications.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 31 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 438〈/p〉 〈p〉Author(s): Nripendra K. Patel, Robert G. Utter, Diganta Das, Michael Pecht〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Solid oxide fuel cells (SOFCs) are chemical-to-electrical energy conversion devices that consist of ceramic and metallic materials. The electrodes of SOFCs function as sites for electrochemical reactions, and as electronic conductors to transfer charge. The strontium-based perovskite electrode has been considered because it offers ionic and electronic conductivity, and tolerance to reduction-oxidation cycling. However, as shown in this work, exposure to humidity greater than 40% relative humidity, that may be present during non-operation conditions, including storage, can result in changes in the electrode surface composition with resulting degradation of electrical performance. This study investigates the physical-chemical and electrical characteristics of electrode surfaces when subjected to various humidity and temperature conditions, using scanning electron microscopy, energy dispersive spectroscopy, X-ray fluorescence spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction techniques. Electrode phase decomposition, along with strontium-based degradation mechanisms, were found at humidity levels greater than 40% relative humidity.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 31 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 438〈/p〉 〈p〉Author(s): Guodong Zhao, Xianlin Xu, Youbo Di, Hang Wang, Bowen Cheng, Lei Shi, Yan Zhu, Xupin Zhuang, Yan Yin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Inspired by the structure of amino acid residues chain in transmembrane proteins, amino acid molecules are immobilized onto cellulose nanofibers to form clusters as quasi-one dimensional proton-conducting pathways for nanofiber hybrid proton exchange membranes. The structure of conducting clusters and properties of the hybrid proton exchange membranes are examined. The results show that the amino acid clusters enhance the proton conductivity, and the proton exchange membrane with Ser-clusters shows the highest proton conductivity of 0.264 S/cm at 80 °C under 100% humidity and temperature. Diffusion coefficients and mean square displacements of hydronium ion are then calculated using Density-Functional Tight-Binding method to better understand the proton-conducting mechanism of amino acid clusters, and the results of molecular dynamics simulation are in good agreement with the experiments. Besides, the structure of three-dimensional hydrophilic network of nanofibers exhibits significant effect on the performance of water uptake, dimensional stability, methanol permeability and thermal stability of the hybrid proton exchange membranes. Fuel cell performance test confirms that these membranes are suitable for direct methanol fuel cells.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319310286-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: Available online 22 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 AEU - International Journal of Electronics and Communications〈/p〉 〈p〉Author(s): Renata I.S. Pereira, Marcelo M. Camboim, Andrea W.R. Villarim, Cleonilson P. Souza, Sandro C.S. Jucá, Paulo C.M. Carvalho〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In Brazil, photovoltaic (PV) plants have been increasing their importance in the country’s electricity matrix mainly because its annual irradiation can achieve up to 2,400 kWh/m2. On the other hand, the high temperature levels along the PV modules impose a negative effect on the electrical efficiency. For instance, in a PV plant in the Brazilian Northeast region, the PV modules temperature can reach 70°C in a sunny day while the ambient temperature is around 30°C. This difference can be used to generate heat as a residual thermal energy, but, in general, it is wasted to the surrounding environment. In other context, currently, there is an increasing development of Renewable Energy Monitoring Systems (REMS) for monitoring PV plants. In this paper, we present an experimental study on the potential of harvesting PV-module residual thermal energy using thermoelectric generators (TEGs) for powering low-power wireless sensor for REMS to monitor the whole PV plant itself. From the experimental results, 3.3 V is achieved from stepping up about 220 mV harvested from monthly average temperature difference of 15 °C. In addition, it is shown that 528 mW can be harvested every burst of 30 ms, which is enough to power low-power devices.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1434841119308829-ga1.jpg" width="361" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Ultramicroscopy, Volume 207〈/p〉 〈p〉Author(s): Abhishek Tripathi, Stefan Zaefferer〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We measured the 〈em〉physical〈/em〉 lateral resolution of the electron backscatter diffraction (EBSD) technique for the case of pure magnesium and tungsten and compared these data with other values from literature. Spatial resolution, among other parameters, depends significantly on the accelerating voltage and the atomic number of the material. For the case of lighter metals, it is supposed to be lower than in the case of heavier metals for a given accelerating voltage. In the present work, lateral resolution was measured in dependence of accelerating voltage on a straight high angle grain boundary which was positioned parallel (horizontal boundary) and perpendicular (vertical boundary) to the tilt axis of the specimen. For magnesium the best lateral resolution of 240 nm was obtained at an accelerating voltage of 5 kV. The resolution dramatically worsened to values as high as 3500 nm as the voltage was increased from 15 kV to 30 kV. The aspect ratio of horizontal and vertical lateral resolution tended to 1.0 at the accelerating voltage of 5 kV and to 2.5 at the accelerating voltage of 30 kV. These values as function of accelerating voltages were compared with those obtained on the high atomic number metal tungsten. Here resolution at 5 kV was about a quarter of that of magnesium. With increasing voltage, the value almost didn't change. For all voltages the resolution aspect ratio stayed close to 1.0.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304399119301901-fx1.jpg" width="301" alt="Image, graphical abstract" title="Image, graphical abstract"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 299〈/p〉 〈p〉Author(s): Thitarat Prathumsuwan, Panichakorn Jaiyong, Insik In, Peerasak Paoprasert〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, we reported a simple strategy for the synthesis of highly fluorescent carbon-based nanomaterials from one of the world’s most invasive aquatic plants and investigated their uses as practical, low-cost borax sensors, which have not been reported elsewhere to date. The carbon dots (CDs) were synthesized through acid-treatment-assisted pyrolysis with water hyacinth leaves as a precursor. Quasi-spherical CDs in solution were shown to produce blue emission, at a relatively high quantum yield of 27%. Their use as a borax probe was demonstrated with a detection limit of 1.5 μM. The selectivity and sensitivity of CDs toward borax in the presence of interferences confirmed their unique and selective sensing properties. A portable paper-based device was fabricated for use in on-site borax detection and was shown to have a detection limit 11.85 μM. Real fish ball samples were tested, and the CDs exhibited excellent borax recovery, in the range 98.8–101.8%. Our computational findings based upon density functional theory (DFT) and time-dependent density functional theory (TD-DFT) suggested that selective fluorescence quenching arose from charge transfer between the CDs and borax 〈em〉via〈/em〉 their favorable lowest unoccupied molecular orbitals. Both experimental and computational findings therefore confirmed the novel sensing properties of the CDs.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925400519311359-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 31 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 438〈/p〉 〈p〉Author(s): Pan Yang, Jun Long, Sensen Xuan, Yanlin Wang, Yaping Zhang, Jinchao Li, Hongping Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The trade-off between high proton conductivity and low vanadium ion permeability needs to be overcome urgently for membrane in vanadium redox flow battery (VRFB). A series of fluorine-containing branched sulfonated polyimide membranes with ionic cross-linking (c-FbSPI) and different degrees of sulfonation (40–70%) are prepared through polycondensation by introducing –CF〈sub〉3〈/sub〉 group, branched structure and ionic cross-linking. The c-FbSPI membranes have much lower vanadium ion permeabilities (0.36–3.87 ✕ 10〈sup〉−7〈/sup〉 cm〈sup〉2〈/sup〉 min〈sup〉−1〈/sup〉) and higher proton selectivities (0.89–4.20 ✕ 10〈sup〉5〈/sup〉 S min cm〈sup〉−3〈/sup〉) comparing with Nafion 115 membrane, respectively. Besides, c-FbSPI membranes have outstanding chemical stabilities when immersing in strong acidic and oxidizing solution for 38 days. The VRFB with selected c-FbSPI-60 membrane shows lower self-discharge speed and higher charge-discharge capacity and energy comparing to those with Nafion 115 membrane. During 300-time cyclical charge-discharge measurement, the VRFB assembled with c-FbSPI-60 membrane shows higher coulombic efficiency (97–99.5%), energy efficiency (68.2–75.1%) and capacity retention (50.5–55.1%) compared with the VRFB using Nafion 115 membrane at 80–60 mA cm〈sup〉−2〈/sup〉. This work provides a new approach for preparing high cost-performance aromatic polymer membrane, which is significant for accelerating the industrialization process of VRFB.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319309863-fx1.jpg" width="329" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 31 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 438〈/p〉 〈p〉Author(s): Meng Xu, Rui Wang, Peng Zhao, Xia Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Enabling fast charging of lithium-ion batteries may accelerate the commercial application of electric vehicles (EVs). The fast charging, however, could lead to capacity fade, lithium plating, and thermal runaway. This paper develops an optimal multi-stage charging protocol for lithium-ion batteries to minimize capacity fade due to the solid-electrolyte interphase (SEI) increase, to maximize the SEI potential to decrease the lithium plating, and to reduce the temperature rise to avoid a thermal runaway situation. An electrochemical-thermal-capacity fade coupled model is developed to monitor the battery internal state. The dynamic programming (DP) optimization algorithm is employed to search for the suboptimal charging current profiles. The optimization results illustrate that the optimized charging current profile varies with the state of charge (SOC) and the cycle number. As compared to the constant current charging protocol, each optimized charging strategy can reduce the capacity fade ratio by 4.6%, increase the SEI potential by 57%, and reduce the temperature rise by 16.3% for over 3300 charging-discharging cycles, respectively.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 297〈/p〉 〈p〉Author(s): XinXin He, Shwu Jen Chang, Kalpana Settu, Ching-Jung Chen, Jen-Tsai Liu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As the number of diabetic patients increases year by year, the demand for a self-monitoring blood glucose test also increases. Additionally, more in-depth studies of blood glucose biosensors have led to increasing accuracy requirements. However, at present, most enzyme glucose sensors have difficulty solving issues related to hematocrit (HCT) interference. Most studies on anti-HCT interference in blood glucose sensing have mainly focused on correction factors, such as glucose correction, and electrical impedance or resistivity characteristics to correct the impact of HCT. In this work, we developed an anti-HCT-interference blood glucose sensor based on a fiber paper-based screen-printed carbon electrode with a mediator (potassium ferricyanide) and glucose oxidase (GOD), which were fixed through inkjet printing. When testing whole blood samples with HCT levels of 20%–70% and a fluid dropping method, the results of a consensus error grid analysis showed that 91% of the data points lied within zones A and B. The glucose sensor was exclusively designed with a 16 μL chamber in the working area of the sensor. When the testing fluid was taken in by capillary sucking, the effect of HCT was further reduced, and 95% of the data points lied within zones A and B in the consensus error grid.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 297〈/p〉 〈p〉Author(s): Hongye Yan, Lei Jiao, Hengjia Wang, Weiqing Xu, Yu Wu, Wenling Gu, Dan Du, Yuehe Lin, Chengzhou Zhu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Enzyme-linked immunosorbent assay (ELISA) has been widely used in the area of biological analysis, while there are still some challenges getting in the way to ensure both excellent sensitivity and reliable accuracy. To overcome these obstacles, we simulated the “smart” sense-and-treat carriers in a drug delivery system to fabricate an improved ELISA, employing zeolitic imidazolate framework-8 (ZIF-8) as the carrier to deliver the tracer agent carbon dots (CDs) and the “drug” thymolphthalein (TP), which was referred to as a “sense-and-treat” ELISA. In the “sense” part, the strong fluorescence intensity of CDs could be observed directly to achieve the sensitive detection of the target. In the “treat” part, after stimulation of alkaline solution, TP was released from ZIF-8 carriers and generated a color change with an obvious absorption, which was beneficial for increasing the sensitivity of this ELISA due to the high loading of the TP. Finally, we took carcinoembryonic antigen (CEA) as a model and performed dual-modal detection using this improved “sense-and-treat” ELISA to accomplish quantitative determinations sensitively and accurately. In addition, the results indicated by the two parts kept good concordance, which could demonstrate the reliable accuracy of this ELISA.〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 297〈/p〉 〈p〉Author(s): Priyan Weerappuli, Taisuke Kojima, Shuichi Takayama, Amar Basu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The use of monolithic normally-closed (NC) valves within microfluidic systems is currently limited by the poor scalability of mitigation strategies developed to prevent the formation of a permanent bond between the valve ‘seat’ and elastomeric membrane during fabrication. Herein we report the highly-scalable design and characterization of a slightly-open doormat (SOD) valve that exhibits properties traditionally associated with NC valves including operability at low actuation pressures, and the capacity to produce a complete seal. In addition, these valves are comparable in their scalability and in responsiveness, and exhibit a capacity to eliminate resting channel resistance that is absent in their NC counterparts. We demonstrate the utility of this novel valve design through the design and operation of a gas-on-gas multiplexer containing 32 device valves controlled by a multiplexer containing 160 SOD valves using only 10 external solenoid valves and a single common pressure source.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925400519309761-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 297〈/p〉 〈p〉Author(s): Yueying Zhang, Ce Ma, Xinyu Yang, Yang Song, Xishuang Liang, Xu Zhao, Yilin Wang, Yuan Gao, Fengmin Liu, Fangmeng Liu, Peng Sun, Geyu Lu〈/p〉

Beschreibung: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Sensors and Actuators B: Chemical, Volume 299〈/p〉 〈p〉Author(s): Daiki Kawasaki, Kenichi Maeno, Hirotaka Yamada, Kenji Sueyoshi, Hideaki Hisamoto, Tatsuro Endo〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Metal nanostructures have great potential for optical label-free biosensors based on localized surface plasmon resonance (LSPR). The sensitivity of a metal nanostructure-based label-free biosensor (i.e., plasmonic sensor) depends on its plasmonic properties, which suffer a decrease in sensitivity by energy losses in the metal material. Here, we demonstrate an approach to improve the plasmonic properties of metal nanostructures by controlling the carrier density in the base polymer material using titanium nitride (TiN). It is expected that the light energy absorbed by TiN is converted into excitons, and it will assist LSPs in the metal nanostructure; thus, the losses of the metal material are compensated by the excitons excited in TiN. We designed a TiN-contained polymer-metal/core-shell structured nanocone array (NCA), comprising TiN nanoparticles (NPs) in a polymer core and metal shell (Au or Ag), and realized improvement of the refractive index (RI) sensitivity of a label-free biosensor by optimizing the TiN-contained polymer composition. As a result, the TiN-contained polymer-metal NCA, with a TiN NP concentration of 10 wt% in the polymer core, had a 1.5-fold higher RI sensitivity than that of the same NCA without TiN NPs. The results of the resistance measurement of the metal surface with the TiN NP-contained polymer (10 wt%) under light exposure suggest the conversion of exposed light into LSPs of metal via TiN. It is suggested that plasmonic properties and sensor performances can be improved by the presented approach. Moreover, in DNA hybridization detection, an extremely low limit of detection of 117.5 fM was achieved.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925400519311311-ga1.jpg" width="436" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: Available online 9 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Radiation Measurements〈/p〉 〈p〉Author(s): David Strebler, Svenja Riedesel, Georgina King, Dominik Brill, Helmut Brückner〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉During the last decades, luminescence dating has entered a phase of diversification. This evolution is strongly linked to a series of technical advances, including but not limited to the improvement of EMCCD cameras and the use of violet and yellow LEDs. New measurement techniques have been developed, such as post infra-red infra-red stimulated luminescence (postIR-IRSL) measurement protocols and thermally-transferred OSL (TT-OSL), and the luminescence properties of new materials, such as gypsum and apatite, have been reinvestigated.〈/p〉〈/div〉 〈/div〉

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 436〈/p〉 〈p〉Author(s): Ting Feng, Haining Wang, Yiyang Liu, Jin Zhang, Yan Xiang, Shanfu Lu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉An electrolyte solution that includes redox couples is an essential component of a redox flow battery (RFB), and it directly affects the efficiency, power density, and cycle stability of the device. In this work, 12-phosphotungstic acid (PTA), a keggin type heteropolyacid, is evaluated as a redox active material in negative electrolyte. PTA has high redox reversibility and electrochemical activity with a kinetic constant of 0.015 cm s〈sup〉−1〈/sup〉 and a low permeability of 6.17 × 10〈sup〉−10〈/sup〉 cm〈sup〉2〈/sup〉 min〈sup〉−1〈/sup〉 through a Nafion〈sup〉®〈/sup〉211 membrane. A single RFB is assembled with PTA and HI as the negative and positive redox active materials, respectively. The cell has a specific capacity of 12.8 Ah·L〈sup〉−1〈/sup〉 at 100 mA cm〈sup〉−2〈/sup〉; however, it exhibits poor cycle stability because of the osmotic pressure imbalance between the electrolyte solutions, the permeation of I〈sup〉−〈/sup〉, and the serious hydrogen evolution side reaction. Using a mixed solution of PTA and HI as electrolytes on both sides of the cell and by adjusting the charge cutoff voltage, the cycle stability improved significantly. During 700 charge/discharge cycles at 100 mA cm〈sup〉−2〈/sup〉, the battery has high coulombic efficiency of 99.6%, energy efficiency around 80.1%, and capacity retention of 99.99% per hour.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319308249-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 436〈/p〉 〈p〉Author(s): Kazuaki Kisu, Sangryun Kim, Hiroyuki Oguchi, Naoki Toyama, Shin-ichi Orimo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉LiBH〈sub〉4〈/sub〉-based complex hydrides have attracted much attention as solid electrolytes that are highly compatible with Li metal anode, because of their reducing character and deformable nature. However, the compatibility of LiBH〈sub〉4〈/sub〉-based complex hydrides following the formation of a stable interface with Li metal has not yet been fully verified. In this study, electrochemical and mechanical stabilities of LiBH〈sub〉4〈/sub〉 and Li〈sub〉4〈/sub〉(BH〈sub〉4〈/sub〉)〈sub〉3〈/sub〉I complex hydride solid electrolytes against Li metal were investigated. Li plating/stripping test performed for 100 cycles and cyclic voltammetry indicated their favorable electrochemical stabilities. Scanning electron microscopy and fast charge–discharge tests revealed the formation of a mechanically tight and durable interface between these solid electrolytes and the Li metal anode. To demonstrate the adequacy of the LiBH〈sub〉4〈/sub〉-based complex hydride solid electrolyte for all-solid-state batteries with Li metal anode, an all-solid-state Li–S battery with a Li〈sub〉4〈/sub〉(BH〈sub〉4〈/sub〉)〈sub〉3〈/sub〉I solid electrolyte was assembled and electrochemically tested. The battery showed reversible discharge and charge abilities. This study provides useful insights into a strategy that can be applied to develop complex hydride solid electrolytes.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0378775319308146-fx1.jpg" width="386" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Beschreibung: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Power Sources, Volume 436〈/p〉 〈p〉Author(s): Naiguang Wang, Wenping Li, Yixiang Huang, Gang Wu, Mingchang Hu, Guanzhou Li, Zhicong Shi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Wrought Mg-Al-Pb-RE strips of different thicknesses are synthesized via extrusion and used as the anodes in Mg-air batteries. We find that, compared to other Mg-Al-Pb-RE samples, the 5 mm-thick strip exhibits greater stability and higher discharge voltage plateaus for long time (10 h). Its anodic efficiency at 10 mA cm〈sup〉−2〈/sup〉 reaches 64.1%, which is even higher than pure magnesium and AZ31 magnesium alloy. The outstanding performance of the 5 mm-thick Mg-Al-Pb-RE anode strip is attributed to its unique microstructure favourable for anodic dissolution. Furthermore, the correlations between microstructure features and electrochemical performance for the wrought Mg-Al-Pb-RE strips are also systematically defined.〈/p〉〈/div〉 〈/div〉