5,907 research outputs found

    Electronic Tuning of Zinc Oxide by Direct Fabrication of Chromium (Cr) incorporated photoanodes for Visible-light driven Water Splitting Applications

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    This is the final version. Available on open access from Nature Research via the DOI in this recordHerein, we report the synthesis of Cr incorporated ZnO sheets arrays microstructures and construction of photoelectrode through a direct aerosol assisted chemical vapour deposition (AACVD) method. The as-prepared Cr incorporated ZnO microstructures were characterized by transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, powdered X-ray spectroscopy, X-ray photoelectron spectroscopy and UV-Vis diffused reflectance spectroscopy. The Cr incorporation in ZnO red shifted the optical band gap of as-prepared photoanodes. The 15% Cr incorporation in ZnO has shown enhanced PEC performance. The AACVD method provides an efficient in situ incorporation approach for the manipulation of morphological aspects, phase purity, and band structure of photoelectrodes for an enhanced PEC performance.Higher Education Commission of PakistanUniversity of Mancheste

    Balanced Tripartite Entanglement, the Alternating Group A4 and the Lie Algebra sl(3,C)u(1)sl(3,C) \oplus u(1)

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    We discuss three important classes of three-qubit entangled states and their encoding into quantum gates, finite groups and Lie algebras. States of the GHZ and W-type correspond to pure tripartite and bipartite entanglement, respectively. We introduce another generic class B of three-qubit states, that have balanced entanglement over two and three parties. We show how to realize the largest cristallographic group W(E8)W(E_8) in terms of three-qubit gates (with real entries) encoding states of type GHZ or W [M. Planat, {\it Clifford group dipoles and the enactment of Weyl/Coxeter group W(E8)W(E_8) by entangling gates}, Preprint 0904.3691 (quant-ph)]. Then, we describe a peculiar "condensation" of W(E8)W(E_8) into the four-letter alternating group A4A_4, obtained from a chain of maximal subgroups. Group A4A_4 is realized from two B-type generators and found to correspond to the Lie algebra sl(3,C)u(1)sl(3,\mathbb{C})\oplus u(1). Possible applications of our findings to particle physics and the structure of genetic code are also mentioned.Comment: 14 page

    Superior visible-light assisted water splitting performance by Fe incorporated ZnO photoanodes

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordTransition metal ion incorporation has been emerged as an effective stratagem to enhance the performance of metal oxide photoanodes. In the present work, we design and fabricate the plain ZnO and (2, 5, 10 and 15%) Fe incorporated ZnO photoanodes by aerosol assisted chemical vapor deposition (AACVD) method. The 15% Fe incorporated ZnO photoanode displayed excellent photocurrent density of 4.6 mA/cm2 at 0.7 VAg/AgCl with photo conversion efficiency of 2.4%, which is 159 times higher than pure ZnO photoanode (0.028 mA/cm2). The obtained results are remarkably superior to the previous results. Furthermore, the Fe incorporated photoelectrodes have also shown good stability. The excellent photoelectrochemical performance of Fe incorporated ZnO showed red shift in band edge with relative decrease in the band gap energy compared to pure ZnO. The demonstration of this simple method for the deposition of Fe incorporated ZnO to fabricate highly efficient photoanode for the PEC water splitting can easily be applied to other similar systems.Higher Education Commission of Pakista

    Security Implications of Running Windows Software on a Linux System Using Wine

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    Linux is considered to be less prone to malware compared to other operating systems, and as a result Linux users rarely run anti-malware. However, many popular software applications released on other platforms cannot run natively on Linux. Wine is a popular compatibility layer for running Windows programs on Linux. The level of security risk that Wine poses to Linux users is largely undocumented. This project was conducted to assess the security implications of using Wine, and to determine if any specific types of malware or malware behavior have a significant effect on the malware being successful in Wine. Dynamic analysis (both automated and manual) was applied to 30 malware samples both in a Windows environment and Linux environment running Wine. Behavior analyzed included file system, registry, and network access, and the spawning of processes, and services. The behavior was compared to determine malware success in Wine. The study results provide evidence that Wine can pose serious security implications when used to run Windows software in a Linux environment. Five samples of Windows malware were run successfully through Wine on a Linux system. No significant relationships were discovered between the success of the malware and its high-level behavior or malware type. However, certain API calls could not be recreated in a Linux environment, and led to failure of malware to execute via Wine. This suggests that particular malware samples that utilize these API calls will never run completely successfully in a Linux environment. As a consequence, the success of some samples can be determined from observing the API calls when run within a Windows environment

    Chip-based Brillouin processing for carrier recovery in coherent optical communications

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    Modern fiber-optic coherent communications employ advanced spectrally-efficient modulation formats that require sophisticated narrow linewidth local oscillators (LOs) and complex digital signal processing (DSP). Here, we establish a novel approach to carrier recovery harnessing large-gain stimulated Brillouin scattering (SBS) on a photonic chip for up to 116.82 Gbit/sec self-coherent optical signals, eliminating the need for a separate LO. In contrast to SBS processing on-fiber, our solution provides phase and polarization stability while the narrow SBS linewidth allows for a record-breaking small guardband of ~265 MHz, resulting in higher spectral-efficiency than benchmark self-coherent schemes. This approach reveals comparable performance to state-of-the-art coherent optical receivers without requiring advanced DSP. Our demonstration develops a low-noise and frequency-preserving filter that synchronously regenerates a low-power narrowband optical tone that could relax the requirements on very-high-order modulation signaling and be useful in long-baseline interferometry for precision optical timing or reconstructing a reference tone for quantum-state measurements.Comment: Part of this work has been presented as a postdealine paper at CLEO Pacific-Rim'2017 and OSA Optic

    Author Correction to: The VAR2CSA malaria protein efficiently retrieves circulating tumor cells in an EpCAM-independent manner (Nature Communications, (2018), 9, 1, (3279), 10.1038/s41467-018-05793-2)

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    This Article contained an error in the consent of some of the patients used in Figure 4. Following an institute-led investigation within BARTS Cancer Institute post-publication, no documentation of informed consent from the nine lung cancer patients whose blood samples were used in this research project could be recovered and therefore, this data have been removed from the published article.The patients and their families were informed of the original error and apologies were made.The following changes have been made to the paper to remove all mention of the lung cancer samples and the data associated with them.In the abstract, the sentence ‘We show that rVAR2 efficiently captures CTCs from hepatic, lung, pancreatic, and prostate carcinomapatients with minimal contamination of peripheral blood mononuclear cells.’ has been changed to read ‘We show that rVAR2 efficiently captures CTCs from hepatic, pancreatic, and prostate carcinoma patients with minimal contamination of peripheral blood mononuclear cells

    Laboratory scale optimization of alkali pretreatment for improvingenzymatic hydrolysis of sweet sorghum bagasse

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    Sweet sorghum has been identified as a promising feedstock for biological conversion to fuels as wellas other chemicals. The lignocellulosic stalk of sweet sorghum, called sweet sorghum bagasse (SSB) isa potential source of lignocellulosic biofuel. The primary goal of this study was to determine optimalalkali (lime: Ca(OH)2and lye: NaOH) pretreatment conditions to obtain higher yield of total reducingsugar while reducing the lignin content for biofuel production from SSB. Biomass conversion and ligninremoval were simultaneously optimized through four quadratic models analyzed by response surfacemethodology (RSM). The optimal conditions for lime pretreatment was 1.7% (w/v) lime concentration,6.0% (w/v) SSB loading, 2.4 h pretreatment time with predicted yields of 85.6 total biomass conversionand 35.5% lignin reduction. For lye pretreatment, 2% (w/v) alkali, 6.8% SSB loading and 2.3 h durationwere the optimal levels with predicted biomass conversion and lignin reduction of 92.9% and 50.0%,respectively. More intensive pretreatment conditions removed higher amounts of hemicelluloses andcellulose. Fourier transform infrared spectroscopy (FTIR) spectrum and scanning electron microscope(SEM) image revealed compositional and microstructural changes caused by the alkali pretreatment

    The Tetrodotoxin Receptor of Voltage-Gated Sodium Channels—Perspectives from Interactions with μ-Conotoxins

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    Neurotoxin receptor site 1, in the outer vestibule of the conducting pore of voltage-gated sodium channels (VGSCs), was first functionally defined by its ability to bind the guanidinium-containing agents, tetrodotoxin (TTX) and saxitoxin (STX). Subsequent studies showed that peptide μ-conotoxins competed for binding at site 1. All of these natural inhibitors block single sodium channels in an all-or-none manner on binding. With the discovery of an increasing variety of μ-conotoxins, and the synthesis of numerous derivatives, observed interactions between the channel and these different ligands have become more complex. Certain μ-conotoxin derivatives block single-channel currents partially, rather than completely, thus enabling the demonstration of interactions between the bound toxin and the channel’s voltage sensor. Most recently, the relatively small μ-conotoxin KIIIA (16 amino acids) and its variants have been shown to bind simultaneously with TTX and exhibit both synergistic and antagonistic interactions with TTX. These interactions raise new pharmacological possibilities and place new constraints on the possible structures of the bound complexes of VGSCs with these toxins

    A meta-analysis of long-term effects of conservation agriculture on maize grain yield under rain-fed conditions

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    Conservation agriculture involves reduced tillage, permanent soil cover and crop rotations to enhance soil fertility and to supply food from a dwindling land resource. Recently, conservation agriculture has been promoted in Southern Africa, mainly for maize-based farming systems. However, maize yields under rain-fed conditions are often variable. There is therefore a need to identify factors that influence crop yield under conservation agriculture and rain-fed conditions. Here, we studied maize grain yield data from experiments lasting 5 years and more under rain-fed conditions. We assessed the effect of long-term tillage and residue retention on maize grain yield under contrasting soil textures, nitrogen input and climate. Yield variability was measured by stability analysis. Our results show an increase in maize yield over time with conservation agriculture practices that include rotation and high input use in low rainfall areas. But we observed no difference in system stability under those conditions. We observed a strong relationship between maize grain yield and annual rainfall. Our meta-analysis gave the following findings: (1) 92% of the data show that mulch cover in high rainfall areas leads to lower yields due to waterlogging; (2) 85% of data show that soil texture is important in the temporal development of conservation agriculture effects, improved yields are likely on well-drained soils; (3) 73% of the data show that conservation agriculture practices require high inputs especially N for improved yield; (4) 63% of data show that increased yields are obtained with rotation but calculations often do not include the variations in rainfall within and between seasons; (5) 56% of the data show that reduced tillage with no mulch cover leads to lower yields in semi-arid areas; and (6) when adequate fertiliser is available, rainfall is the most important determinant of yield in southern Africa. It is clear from our results that conservation agriculture needs to be targeted and adapted to specific biophysical conditions for improved impact
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