139 research outputs found

    A secured data transform-and-transfer algorithm for energy internet-of-things applications

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    Digital transformation (DT) is one of the key technologies with effective impacts on many traditional processes towards a digital world. DT influences the way other digital services behave. Hence, there is a need to consider DT-related processes carefully specifically while designing phase. DT contributes to many services. It can, for example, contribute to implement security tasks applied to digital contents and therefore can be applied to change contents being secured. One of the transformation ways applied in security is to consider the way those digital contents are being stored or transferred. This paper proposes a DT algorithm (DTA) for energy internet-of-things (EIOT) contents. DTA consists of two steps, to convert original contents to another digital form and to transfer that form utilizing IOT. This paper utilizes DT in term of security. EIOT contents are converted to increase security. It is aimed to transfer EIOT contents to destination safely and efficiently. Thus, EIOT contents are transformed first to hide original contents. To make sure that the transferring process is done safely, DTA is evaluated in terms of efficiency, accuracy, and robustness. Results confirm that DTA is efficient, accurate, and robust against loss of bits caused by transferring

    Size-dependent Auger spectra and two-hole Coulomb interaction of small supported Cu-clusters

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    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Auger (L3M4,5M4,5) and X-ray photoionization spectra (2p, 3d) of mass-selected CuN-clusters supported by a thin natural silica layer are presented in the size range N = 8–55 atoms per cluster. The Auger spectra of all clusters are shifted to a lower kinetic energy with respect to the spectrum of the bulk. Furthermore the Auger energy decreases systematically with decreasing cluster size. The binding energies of the 2p and 3d valence states are higher than the corresponding bulk values. Using the energy of the Auger main line, the corresponding core hole peak and the centroid of the self-convoluted 3d valence band the on-site Coulomb interaction energy Udd of the two-hole final state as a function of cluster size has been determined

    Operando and High-throughput multicscale-tomography

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    We report about multiscale tomography with high throughput at the Diamond beamline I13L. The beamline has the purpose of multi-scale and operando imaging and consists of two independent branchlines operating in real and reciprocal space. The imaging branch -called Diamond-Manchester branchline- hosts micro-tomography, grating interferometry and a full-field microscope. For rapid recording a broad spectrum of the undulator radiation is used either with band-passing the light with a combination of a filter and a deflecting mirror or using a multilayer monochromator. For all the methods similar recording times can be achieved, with typical scanning times of some minutes and covering the resolution range from microns to the 100nm range. Most recently a robot arm has been installed to increase the throughput to 300 samples per day. The system is now implemented for user operation in remote operation mode for the micro-tomography setup and can be expanded to the two other experiments. The instrumental capabilities are applied on various topics such as the study of biodiversity of insects or the structural variations of electrode materials in batteries. Fast recording with dedicated sample environments (not using the sample changing robot) enables operando studies in many areas, the charging/discharging cycles on batteries, the degradation of teeth enamel under various conditions or loading brine sandstone mixtures with CO2, to name some examples. For imaging with highest spatial resolution we managed to improve significantly the recording speed of ptycho-tomography, which is now in the order of hours and will be reduced further. We demonstrated in the past 2-D recording with 10kHz and expand the instrumental capability with specific hardware dependent triggering and scanning schemes. We expand the research program for multi-scale imaging across both branchlines (imaging and coherence branchlines) with first studies such as batteries, brain research, concrete

    Pixel intensity-based contrast algorithm (PICA) for image edges extraction (IEE)

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    In this paper, images' pixels are exploited to extract objects' edges. This paper has proposed a Pixel Intensity based Contrast Algorithm (PICA) for Image Edges Extraction (IEE). This paper highlights three contributions. Firstly, IEE process is fast and PICA has less computation time when processing different images' sizes. Secondly, IEE is simple and uses a 2×42\times 4 mask which is different from other masks where it doesn't require while-loop(s) during processing images. Instead, it has adopted an if-conditional procedure to reduce the code complexity and enhance computation time. That is, the reason why this design is faster than other designs and how it contributes to IEE will be explained. Thirdly, design and codes of IEE and its mask are available, made an open source, and in-detail presented and supported by an interactive file; it is simulated in a video motion design. One of the PICA's features and contributions is that PICA has adopted to use less while-loop(s) than traditional methods and that has contributed to the computation time and code complexity. Experiments have tested 526 samples with different images' conditions e.g., inclined, blurry, and complex-background images to evaluate PICA's performance in terms of computation time, enhancement rate for processing a single image, accuracy, and code complexity. By comparing PICA to other research works, PICA consumes 5.7 mS to process a single image which is faster and has less code complexity by u×uu\times u. Results have shown that PICA can accurately detect edges under different images' conditions. Results have shown that PICA has enhanced computation time rate for processing a single image by 92.1% compared to other works. PICA has confirmed it is accurate and robust under different images' conditions. PICA can be used with several types of images e.g., medical images and useful for real-time applications

    A review on preparation and characterization of silver/nickel oxide nanostructures and their applications

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    Nickel oxide and silver oxide nanoparticles have wonderful properties that could be employed in numerous applications. Thus, synthesis of nickel silver oxide nanostructures with different characteristics is of great interest. In this review, many synthesis methods were reported such as: electrodeposition, electrochemical method, simple immersion process and subsequent RFsputtering deposition, chemical oxidative polymerization, followed by acidic sol–gel process, flame-based process, liquidphase reduction technique, sol–gel, hydrothermal method, co-precipitation method, simple precipitation method, thermal decomposition, chemical wet synthesis, low and high-temperature reduction, high-pressure autoclave, thermal treatment method, and laser-liquid–solid interaction technique. Reporting all methods employed for the fabrication of NiO and Ag2O nanostructures is useful to produce and develop novel nanomaterials with enhanced properties and applications. Studying the factors that tuned their properties: particle size, shape, and capping agents as well as solution pH is highly recommended in future works. Also, further research studies should be conducted for finding another/other facile and effective synthesis method/methods

    Nanofabrication of (Cr2O3)x (NiO)1-x and the impact of precursor concentrations on nanoparticles conduct

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    This study aims to synthesize the (Cr2O3)x (NiO)1-x nanoparticles at lower and higher precursor values using the calcination method. There is a lack in regard to investigating the lower and higher precursor values on structural and optical properties of the (Cr2O3)x (NiO)1-x nanoparticles. To synthesize the (Cr2O3)x (NiO)1-x nanoparticles, Cr (III) acetate hydrate and Ni (II) acetate tetrahydrate were reacted with poly (vinyl alcohol). Several techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR), have been employed to characterize the synthesized sample. The XRD pattern analysis indicated that, following calcination, nanoparticle formation occurred, indicating hexagonal crystalline structures (HCP) and face-centred cubic (FCC) of (Cr2O3)x (NiO)1-x nanoparticles. FT-IR verified the existence of Ni-O and Cr-O as the original compounds of ready (Cr2O3)x (NiO)1-x nanoparticle samples. In term of average particle size, this varied from 5 to 16 nm when the precursor concentration rised from x = 0.20 to x = 0.80, as reflected in the TEM results. X-ray photoelectron spectroscopy (XPS) was employed to measure the valence state and surface composition of the prepared product nanoparticles. To identify the optical band gap using the Kubelka-Munk equation, diffuse UV-visible reflectance spectra were employed, which revealed that the energy band gap fell with a rise in the value of x. In addition, photoluminescence (PL) spectra indicated that the photoluminescence intensity was related to a directly proportional way to particle size. Hence, the results can be employed with a broad range of applications in solar cell energy applications at higher x values and antibacterial activity at lower x values

    Binary nickel and silver oxides by thermal route: preparation and characterization

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    Many studies have concentrated on exploring behaviors of nickel silver oxide nanoparticles using various routes of fabrication. Thermal treatment technique has never been utilized to fabricate nickel oxide silver oxide nanoparticles. In this research, binary (NiO)0.4 (Ag2O)0.6 nanoparticles were synthesized using the thermal treatment method due to its attractive advantages such as low cost, eco-friendly, and purity of nanoparticles. The structural, morphological, and optical behaviors of these nanoparticles were investigated at different calcined temperatures. X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible spectroscopy (UV–Vis), and photoluminescence (PL) were the techniques used to characterize the synthesized nanoparticles. XRD was conducted at different calcined temperatures. The crystallite size was increased from 25.4 nm to 37.0 nm as the calcined temperature increased from 500 °C to 800 °C. Also, TEM results verified that the mean particle size was enlarged as the calcined temperatures increased. Two band gaps were found for each temperature, which were decreased from (3.05, 2.45) to (2.70, 1.95) eV as the temperature varied from 500 to 800 °C, respectively. Broadbands were observed by PL spectra, and the intensity of two emission peaks was also increased at higher temperatures. The results approved the successful formation of binary (NiO)0.4 (Ag2O)0.6 nanoparticles by a novel facile synthesis route. These nanoparticles are likely to have various applications, especially optical applications due to the formation of two band gaps

    The effect of PVP concentration on particle size, morphological and optical properties of cassiterite nanoparticles

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    Different concentrations of polyvinylpyrrolidone (PVP) have been successfully employed to prepare high purity tetragonal cassiterite nanoparticles, and control the growth of particle size. The effect of PVP on the structural, morphological, size, composition, and optical properties of the prepared cassiterite nanoparticles has been investigated. It has been found that various characteristics of tetragonal cassiterite nanoparticles could be optimized by simply changing the values of PVP. The pure tetragonal cassiterite nanoparticles have been produced at the optimum calcination temperature. The XRD and SEM results indicated the structural and morphological properties of the tetragonal cassiterite nanoparticles, respectively. The particles' size and their distribution have been displayed by TEM images. The composition phase and the surface composition of the prepared samples have been evaluated via FTIR and XPS, respectively. The optical properties of the prepared tetragonal cassiterite nanoparticles have been studied using UV-vis and PL spectroscopy. Outcomes cassiterite nanoparticles are useful for antibacterial activity and application of solar energy

    Host-Guest Chemistry Meets Electrocatalysis: Cucurbit[6]uril on a Au Surface as a Hybrid System in CO2 Reduction.

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    The rational control of forming and stabilizing reaction intermediates to guide specific reaction pathways remains to be a major challenge in electrocatalysis. In this work, we report a surface active-site engineering approach for modulating electrocatalytic CO2 reduction using the macrocycle cucurbit[6]uril (CB[6]). A pristine gold surface functionalized with CB[6] nanocavities was studied as a hybrid organic-inorganic model system that utilizes host-guest chemistry to influence the heterogeneous electrocatalytic reaction. The combination of surface-enhanced infrared absorption (SEIRA) spectroscopy and electrocatalytic experiments in conjunction with theoretical calculations supports capture and reduction of CO2 inside the hydrophobic cavity of CB[6] on the gold surface in aqueous KHCO3 at negative potentials. SEIRA spectroscopic experiments show that the decoration of gold with the supramolecular host CB[6] leads to an increased local CO2 concentration close to the metal interface. Electrocatalytic CO2 reduction on a CB[6]-coated gold electrode indicates differences in the specific interactions between CO2 reduction intermediates within and outside the CB[6] molecular cavity, illustrated by a decrease in current density from CO generation, but almost invariant H2 production compared to unfunctionalized gold. The presented methodology and mechanistic insight can guide future design of molecularly engineered catalytic environments through interfacial host-guest chemistry

    The effect of precursor concentration on the particle size, crystal size, and optical energy gap of CexSn1â’xO2 nanofabrication

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    In the present work, a thermal treatment technique is applied for the synthesis of CexSn1−xO2 nanoparticles. Using this method has developed understanding of how lower and higher precursor values affect the morphology, structure, and optical properties of CexSn1−xO2 nanoparticles. CexSn1−xO2 nanoparticle synthesis involves a reaction between cerium and tin sources, namely, cerium nitrate hexahydrate and tin (II) chloride dihydrate, respectively, and the capping agent, polyvinylpyrrolidone (PVP). The findings indicate that lower x values yield smaller particle size with a higher energy band gap, while higher x values yield a larger particle size with a smaller energy band gap. Thus, products with lower x values may be suitable for antibacterial activity applications as smaller particles can diffuse through the cell wall faster, while products with higher x values may be suitable for solar cell energy applications as more electrons can be generated at larger particle sizes. The synthesized samples were profiled via a number of methods, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). As revealed by the XRD pattern analysis, the CexSn1−xO2 nanoparticles formed after calcination reflect the cubic fluorite structure and cassiterite-type tetragonal structure of CexSn1−xO2 nanoparticles. Meanwhile, using FT-IR analysis, Ce-O and Sn-O were confirmed as the primary bonds of ready CexSn1−xO2 nanoparticle samples, whilst TEM analysis highlighted that the average particle size was in the range 6−21 nm as the precursor concentration (Ce(NO3)3·6H2O) increased from 0.00 to 1.00. Moreover, the diffuse UV-visible reflectance spectra used to determine the optical band gap based on the Kubelka–Munk equation showed that an increase in x value has caused a decrease in the energy band gap and vice versa
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