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1
Zhang, Tao. "Influence factors and adjusting method of refractive indices of solid media." Modern Physics Letters B 32, no. 32 (November 20, 2018): 1850391. http://dx.doi.org/10.1142/s0217984918503918.
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It is of great significance to explore changing behavior and adjustment method of the refractive index. Expression of the refractive index, which was derived from the electron-cloud conductor model, contains the equivalent volume V of the electron clouds and the molecular density [Formula: see text]. The expression shows that the refractive index increases with V and [Formula: see text]. Based on this expression, main factors influencing the refractive index of solid medium are analyzed and summarized: the Nephelauxetic Effect, number of bonding electrons in the molecule, chemical bond property, number of nonbonding electrons in outermost layer of the molecule, and molecular density of the medium (electromagnetic wave factor is not considered). The relationship between the refractive index and the Nephelauxetic Effect is established. The calculations show that the Nephelauxetic Effect helps to increase the refractive index. Some viewpoints related to the Nephelauxetic Effect are supplemented. Characteristics of the solid medium that has a high refractive index are proposed: (1) Covalent bond component is high, and number of covalent bonds in one molecule is large. (2) Periodic number is as large as possible without increasing the ionic bond component. (3) Molecular density is high. According to these characteristics, method of adjusting the refractive index is discussed, and the results are consistent with the real situations.
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Kucherov, Olexandr. "Direct Visualization of Si and Ge Atoms by Shifting Electron Picoscopy." Applied Functional Materials 2, no. 4 (December 30, 2022): 10–16. http://dx.doi.org/10.35745/afm2022v02.04.0002.
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The picoscopy images of the Si/Ge(100) system were analyzed, and electron cloud densitometry of silicon is presented in this study. The picoscopy is used to distinguish Ge, Si, and other chemical elements because different atoms have different densities of electron clouds. This result is in full accordance with Kucherov's law which states that the current passed through an electron cloud is proportional to the density of the cloud. The picoscopy image has shown Si crystals, Si/Ge solid solution, and their interface as the single crystal without defects. Local deformations in crystals were investigated using methods of direct visualization of individual atoms and measuring the distance of the center of atoms from the node of the crystal lattice. Visual сrystallography becomes a new way to study applied functional materials. This is the first publication on the real structure of a silicon atom.
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Sotome, M., M. Nakamura, J. Fujioka, M. Ogino, Y. Kaneko, T. Morimoto, Y. Zhang, et al. "Spectral dynamics of shift current in ferroelectric semiconductor SbSI." Proceedings of the National Academy of Sciences 116, no. 6 (January 22, 2019): 1929–33. http://dx.doi.org/10.1073/pnas.1802427116.
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Photoexcitation in solids brings about transitions of electrons/holes between different electronic bands. If the solid lacks an inversion symmetry, these electronic transitions support spontaneous photocurrent due to the geometric phase of the constituting electronic bands: the Berry connection. This photocurrent, termed shift current, is expected to emerge on the timescale of primary photoexcitation process. We observe ultrafast evolution of the shift current in a prototypical ferroelectric semiconductor antimony sulfur iodide (SbSI) by detecting emitted terahertz electromagnetic waves. By sweeping the excitation photon energy across the bandgap, ultrafast electron dynamics as a source of terahertz emission abruptly changes its nature, reflecting a contribution of Berry connection on interband optical transition. The shift excitation carries a net charge flow and is followed by a swing over of the electron cloud on a subpicosecond timescale. Understanding these substantive characters of the shift current with the help of first-principles calculation will pave the way for its application to ultrafast sensors and solar cells.
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Sauvaud, J. A., P. Koperski, T. Beutier, H. Barthe, C. Aoustin, J. J. Thocaven, J. Rouzaud, E. Penou, O. Vaisberg, and N. Borodkova. "The INTERBALL-Tail ELECTRON experiment: initial results on the low-latitude boundary layer of the dawn magnetosphere." Annales Geophysicae 15, no. 5 (May 31, 1997): 587–95. http://dx.doi.org/10.1007/s00585-997-0587-z.
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Abstract. The Toulouse electron spectrometer flown on the Russian project INTERBALL-Tail performs electron measurements from 10 to 26 000 eV over a 4<pi> solid angle in a satellite rotation period. The INTERBALL-Tail probe was launched on 3 August 1995 together with a subsatellite into a 65° inclination orbit with an apogee of about 30 RE. The INTERBALL mission also includes a polar spacecraft launched in August 1996 for correlated studies of the outer magnetosphere and of the auroral regions. We present new observations concerning the low-latitude boundary layers (LLBL) of the magnetosphere obtained near the dawn magnetic meridian. LLBL are encountered at the interface between two plasma regimes, the magnetosheath and the dayside extension of the plasma sheet. Unexpectedly, the radial extent of the region where LLBL electrons can be sporadically detected as plasma clouds can reach up to 5 RE inside the magnetopause. The LLBL core electrons have an average energy of the order of 100 eV and are systematically field-aligned and counterstreaming. As a trend, the temperature of the LLBL electrons increases with decreasing distance to Earth. Along the satellite orbit, the apparent time of occurrence of LLBL electrons can vary from about 5 to 20 min from one pass to another. An initial first comparison between electron- and magnetic-field measurements indicates that the LLBL clouds coincide with a strong increase in the magnetic field (by up to a factor of 2). The resulting strong magnetic field gradient can explain why the plasma-sheet electron flux in the keV range is strongly depressed in LLBL occurrence regions (up to a factor of \\sim10). We also show that LLBL electron encounters are related to field-aligned current structures and that wide LLBL correspond to northward interplanetary magnetic field. Evidence for LLBL/plasma-sheet electron leakage into the magnetosheath during southward IMF is also presented.
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Kouchi, Akira, Masashi Tsuge, Tetsuya Hama, Hiromasa Niinomi, Naoki Nakatani, Takashi Shimonishi, Yasuhiro Oba, et al. "Formation of chiral CO polyhedral crystals on icy interstellar grains." Monthly Notices of the Royal Astronomical Society 505, no. 1 (April 27, 2021): 1530–42. http://dx.doi.org/10.1093/mnras/stab1173.
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ABSTRACT The crystallinity and morphology of solid carbon monoxide (CO) on icy interstellar grains were examined by observing the deposition, crystallization, and UV and electrons irradiation of solid CO using transmission electron microscopy. Herein, we found that solid CO deposited in molecular clouds was crystalline, and that even if amorphous CO was deposited, amorphous CO crystallized within 103 yr at 10 K. Conversely, crystalline CO was not amorphized by UV rays or electron beam at 10 K. These results indicated the occurrence of chiral crystalline CO instead of amorphous CO in space. Furthermore, the large surface diffusion coefficients of CO on eamorphous H2O and crystalline CO at 10 K facilitated the morphological equilibration of crystalline CO. Bad wetting of crystalline CO with amorphous H2O proved that the morphology of the ice grains was not spherical with an onion-like structure, as hitherto assumed, but rather it was a polyhedral crystalline CO attached to amorphous H2O. This has important implications for phenomena associated with the collision and subsequent sticking between ice grains, surface chemical reactions, non-thermal desorption of molecules and the origin of homochirality in interstellar biomolecules.
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Celebonovic, Vladan, and W. Dappen. "The plasma-solid transition: some implications in astrophysics." Serbian Astronomical Journal, no. 165 (2002): 23–26. http://dx.doi.org/10.2298/saj0265023c.
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Using a criterion proposed by Salpeter and standard solid-state physics, we have determined the Debye temperature of a solid in equilibrium with the electron gas surrounding it. The results obtained can have astrophysical applications in the determination of parameters of interstellar and interplanetary clouds.
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Slaughter, J. M., W. Weber, Gernot Güntherodt, and Charles M. Falco. "Quantitative Auger and XPS Analysis of Thin Films." MRS Bulletin 17, no. 12 (December 1992): 39–45. http://dx.doi.org/10.1557/s0883769400046947.
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In 1925, P. Auger first observed the so-called Auger electrons in a Wilson cloud chamber. He explained this occurrence as being due to a radiationless transition in atoms excited by a primary x-ray photon source. In 1953, Lander first pointed out that Auger electrons arising from solid samples can be detected in the energy distribution curve of secondary electrons from surfaces subjected to electron bombardment. Moreover, low-energy Auger electrons (∼1 keV kinetic energy) can escape from only the first several atomic layers of a surface since they are strongly absorbed by even a monolayer of atoms. Thus Auger electron spectroscopy (AES) possesses high surface sensitivity. This is one characteristic that makes AES very useful for the study of thin films. For such applications, an important development in AES occurred when Harris showed that the sensitivity of the detection of Auger electrons can be improved by differentiating the electron energy distribution curve with respect to the energy. Furthermore, Weber and Johnson demonstrated that, provided the Auger line profile does not change, the peak-to-peak height in the differentiated energy distribution curves is proportional to the Auger current in the peak. Therefore, in addition to its surface sensitivity, AES also can be used for quantitative studies of thin films.Like AES, x-ray photoelectron spectroscopy (XPS) is a surface-sensitive technique that uses the energy distribution of electrons ejected from a thin film for quantitative analysis. However, in many ways the information provided by AES and XPS is complementary.
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Liu, Fei, Shan Cong, and Long Hao. "First principle study of occupancy, bonding characteristics and alloying effect of Zr, Nb, V in bulk γ-Fe(C)." E3S Web of Conferences 213 (2020): 01019. http://dx.doi.org/10.1051/e3sconf/202021301019.
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The total energy, binding characteristics, density of states, charge distribution and differential charge density of γ-Fe(C)-M crystal cells formed by solid solution of Zr, Nb and V in γ-Fe(C) were calculated by using the first-principles method. Thus, the mechanism of Zr, Nb, and V with γ-Fe(C) was investigated in this paper. The results show that Zr, Nb and V all preferentially replaced the Fe atoms which are at the top angle in γ-Fe(C). Crystal cell reaches its highest stability after V solid solution. Nb reaches after it, and Zr is relatively weak. In the γ-Fe(C)-Zr cell, Fe-Zr covalent bond and Zr-C ionic bond are the main chemical bonds. In the γ-Fe(C)-Nb and γ-Fe(C)-V cells, Fe-Nb and Fe-V covalent bonds are the main chemical bonds with a number of Nb-C and V-C ionic bonds. After solid solution, the electron cloud density around C atom changed little, while Fe atom changed obviously. The orbital electrons around Fe atoms in γFe(C)-V has maximal distribution, which means that the electrons delocalized most and most of the electrons are bonding. It is the main factor for the increase in the binding energy of crystal cell. The effects of Zr, Nb, V solution on austenitic stability are investigated by studying the influence of alloy element on γFe(C) electronic structure.
9
Zhang, Tao. "Relationship between band gap and equivalent volume of electron cloud." Modern Physics Letters B 34, no. 35 (August 25, 2020): 2050400. http://dx.doi.org/10.1142/s021798492050400x.
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The characteristic parameter [Formula: see text] related to bandgap [Formula: see text] is proposed ([Formula: see text] is the equivalent volume of the outermost electron cloud of molecule). [Formula: see text] values of dozens of solid media are calculated. The results show that [Formula: see text] decreases as [Formula: see text] increases. Furthermore, change behavior of [Formula: see text] with composition is studied by using [Formula: see text], and the composition characteristics of high-[Formula: see text] solid media are summarized. According to this result, [Formula: see text] can be regulated to a certain extent by adjusting the composition. Importantly, connection among refractive index [Formula: see text], [Formula: see text] and [Formula: see text] is revealed: [Formula: see text] has both a major contribution to [Formula: see text] and a decisive effect on [Formula: see text]. These results help to promote the development of new semiconductor materials.
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Yuan, Xiaoping, Chengxia Shi, and Zhihong Wang. "The Optimization of Hospital Financial Management Based on Cloud Technology and Wireless Network Technology in the Context of Artificial Intelligence." Wireless Communications and Mobile Computing 2022 (May 18, 2022): 1–11. http://dx.doi.org/10.1155/2022/9998311.
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In the reign of Internet technology, cloud technology has emerged as one of the powerful tools in computing with many advantages in the bag. Cloud technology is defined as online access to all types of computing applications. The applications range from access to data, servers, software, databases to storage and retrieval of data. The data can be accessed from anywhere, anytime. The user does not need to own the hardware in this case. Clouds have multiple data centers located at various places. On-demand data service is the best part of cloud technology. This technology is made use in many industries. In this research, we will study how cloud technology and wireless networking technology are applied to optimize hospital financial management. The healthcare industry faces various challenges in financial management such as budgeting, growth planning, and cost-effectiveness. Considering this scenario, it is evident that there is a solid need to optimize its financial management. The cloud computing technology driven by artificial intelligence (AI) is deployed in carrying out repetitive tasks and automation, resulting in increased productivity. In this research, the proposed system uses wireless networking systems and cloud technology to optimize hospital financial management. The model works with the implementation of a hybrid of fuzzy neural networks. The proposed model is analyzed with the existing fuzzy logic and neural network models, and it is found that the proposed model has obtained an accuracy of 97.56% with minimum resources for successful financial management at hospitals.
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Zhang, Xiaogang, Shengnan Zhang, Duo Pan, Peipei Chen, Xiaobo Xue, Wei Zhuang, and Jingbiao Chen. "Hanle Detection for Optical Clocks." Scientific World Journal 2015 (2015): 1–6. http://dx.doi.org/10.1155/2015/614737.
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Considering the strong inhomogeneous spatial polarization and intensity distribution of spontaneous decay fluorescence due to the Hanle effect, we propose and demonstrate a universe Hanle detection configuration of electron-shelving method for optical clocks. Experimental results from Ca atomic beam optical frequency standard with electron-shelving method show that a designed Hanle detection geometry with optimized magnetic field direction, detection laser beam propagation and polarization direction, and detector position can improve the fluorescence collection rate by more than one order of magnitude comparing with that of inefficient geometry. With the fixed 423 nm fluorescence, the improved 657 nm optical frequency standard signal intensity is presented. The potential application of the Hanle detection geometry designed for facilitating the fluorescence collection for optical lattice clock with a limited solid angle of the fluorescence collection has been discussed. The Hanle detection geometry is also effective for ion detection in ion optical clock and quantum information experiments. Besides, a cylinder fluorescence collection structure is designed to increase the solid angle of the fluorescence collection in Ca atomic beam optical frequency standard.
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Zou, Zheng Guang, Yi Wu, Fei Long, Wen Wu Xu, and Dong Ye Yao. "Effects of Mo(Ni) on Valence Electron Structures of TiC/Fe Cermets." Key Engineering Materials 368-372 (February 2008): 1119–22. http://dx.doi.org/10.4028/www.scientific.net/kem.368-372.1119.
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Based on the empirical electron theory (EET) of solids and molecules, the valence electron structures (VESs) of TiC-Mo(Ni)-Fe system were calculated by building proper structure model. The results indicate that additives of Mo and Ni improve the interface conjunction factors of the cermets in different ways. By adding Mo, the VESs of the ceramic phase are improved for the formation of the rim phase (Ti1-xMox)C, which leads to the enhancement of the interface conjunction, while the improvement of the VESs on metal phase by adding Ni is due to the formation of the Fe100-yNiy. Mo and Ni additives increase the interface electron density of cermets, that is, the adding of the Mo and Ni enhance the overlapping grade of the electron cloud on interface and increase the binding energy of the interface, which is propitious to the wettability. The best wettability was found at x=0.5 or y=30.
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Magee, Nathan, Katie Boaggio, Samantha Staskiewicz, Aaron Lynn, Xuanyi Zhao, Nicholas Tusay, Terance Schuh, et al. "Captured cirrus ice particles in high definition." Atmospheric Chemistry and Physics 21, no. 9 (May 11, 2021): 7171–85. http://dx.doi.org/10.5194/acp-21-7171-2021.
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Abstract. Cirrus clouds composed of small ice crystals are often the first solid matter encountered by sunlight as it streams into Earth's atmosphere. A broad array of recent research has emphasized that photon particle scattering calculations are very sensitive to ice particle morphology, complexity, and surface roughness. Uncertain variations in these parameters have major implications for successfully parameterizing the radiative ramifications of cirrus clouds in climate models. To date, characterization of the microscale details of cirrus particle morphology has been limited by the particles' inaccessibility and technical difficulty in capturing imagery with sufficient resolution. Results from a new experimental system achieve much higher-resolution images of cirrus ice particles than existing airborne-particle imaging systems. The novel system (Ice Cryo-Encapsulation by Balloon, ICE-Ball) employs a balloon-borne payload with environmental sensors and hermetically sealed cryo-encapsulation cells. The payload captures ice particles from cirrus clouds, seals them, and returns them via parachute for vapor-locked transfer onto a cryo-scanning electron microscopy stage (cryo-SEM). From 2015–2019, the ICE-Ball system has successfully yielded high-resolution particle images on nine cirrus-penetrating flights. On several flights, including one highlighted here in detail, thousands of cirrus particles were retrieved and imaged, revealing unanticipated particle morphologies, extensive habit heterogeneity, multiple scales of mesoscopic roughening, a wide array of embedded aerosol particles, and even greater complexity than expected.
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Kareiva, Simonas, Algirdas Selskis, Feliksas Ivanauskas, and Simas Sakirzanovas. "Stereophotography and spatial surface reconstruction using scanning electron microscopy images." Pure and Applied Chemistry 87, no. 3 (March 1, 2015): 283–92. http://dx.doi.org/10.1515/pac-2014-0808.
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Abstract Three-dimensional reconstruction technique to fully characterize structural performance of solid materials is suggested. The three-dimensional sample data out of the SEM images taken from different angles were extrapolated, measured and interpreted. In stereometry, the technique of three dimensional SEM imaging is fairly straightforward. Selected specimen area is photographed using SEM imaging tools from two different angles. Tilting is performed using standard SEM manipulation tools. In some cases, the specimen must be rotated to such a position, in which the tilting is done on visual ordinate axis. The resulting images are combined in pairs using any three-dimensional anaglyph software available to produce an anaglyph image, which, in turn, can be analyzed using standard 3D glasses. To achieve finer results, extrapolation of spatial data was done from three or more sample images using visual reconstruction software applications. This technique for recovering spatial data from the SEM pictures (structure-from-motion) is the VisualSFM software, which is an application for spatial reconstruction using structure from sample motion. Using VisualSFM, the images are analyzed for matching points and the camera angle is guessed for each image. Any number of additional viewports can be added to VisualSFM software. Based on this input, a surface is reconstructed where the matching points intersect and a colour value is assigned. The software produces a cloud of points, which has to be processed externally. Freely available software, such as MeshLab can be used to join the point cloud to a mesh and, as a second step of reconstruction, apply surface properties to the mesh polygons. The gold particles were selected as model material for the spatial 3D surface reconstruction.
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Lalousis, P., I. B. Földes, and H. Hora. "Ultrahigh acceleration of plasma by picosecond terawatt laser pulses for fast ignition of fusion." Laser and Particle Beams 30, no. 2 (March 9, 2012): 233–42. http://dx.doi.org/10.1017/s0263034611000875.
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AbstractA fundamental different mechanism dominates laser interaction with picosecond-terawatt pulses in contrast to the thermal-pressure processes with ns pulses. At ps-interaction, the thermal effects are mostly diminished and the nonlinear (ponderomotive) forces convert laser energy instantly with nearly 100% efficiency into the space charge neutral electron cloud, whose motion is determined by the inertia of the attached ion cloud. These facts were realized only by steps in the past and are expressed by the ultrahigh plasma acceleration, which is more than few thousand times higher than observed by any thermokinetic mechanism. The subsequent application for side-on ignition of uncompressed fusion fuel by the ultrahigh accelerated plasma blocks is studied for the first time by using the genuine two-fluid hydrodynamics. Details of the shock-like flame propagation can be evaluated for the transition to ignition conditions at velocities near 2000 km/s for solid deuterium-tritium.
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Sileo, Monica, Domenico Daniele Bloisi, and Francesco Pierri. "Grasping of Solid Industrial Objects Using 3D Registration." Machines 11, no. 3 (March 17, 2023): 396. http://dx.doi.org/10.3390/machines11030396.
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Robots allow industrial manufacturers to speed up production and to increase the product’s quality. This paper deals with the grasping of partially known industrial objects in an unstructured environment. The proposed approach consists of two main steps: (1) the generation of an object model, using multiple point clouds acquired by a depth camera from different points of view; (2) the alignment of the generated model with the current view of the object in order to detect the grasping pose. More specifically, the model is obtained by merging different point clouds with a registration procedure based on the iterative closest point (ICP) algorithm. Then, a grasping pose is placed on the model. Such a procedure only needs to be executed once, and it works even in the presence of objects only partially known or when a CAD model is not available. Finally, the current object view is aligned to the model and the final grasping pose is estimated. Quantitative experiments using a robot manipulator and three different real-world industrial objects were conducted to demonstrate the effectiveness of the proposed approach.
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Han, Jaehyun, Guangyu Zhu, Sangmook Lee, and Yongseok Son. "An Empirical Performance Evaluation of Multiple Intel Optane Solid-State Drives." Electronics 10, no. 11 (May 31, 2021): 1325. http://dx.doi.org/10.3390/electronics10111325.
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Cloud computing as a service-on-demand architecture has grown in importance over the last few years. The storage subsystem in cloud computing has undergone enormous innovation to provide high-quality cloud services. Emerging Non-Volatile Memory Express (NVMe) technology has attracted considerable attention in cloud computing by delivering high I/O performance in latency and bandwidth. Specifically, multiple NVMe solid-state drives (SSDs) can provide higher performance, fault tolerance, and storage capacity in the cloud computing environment. In this paper, we performed an empirical evaluation study of performance on recent NVMe SSDs (i.e., Intel Optane SSDs) with different redundant array of independent disks (RAID) environments. We analyzed multiple NVMe SSDs with RAID in terms of different performance metrics via synthesis and database benchmarks. We anticipate that our experimental results and performance analysis will have implications for various storage systems. Experimental results showed that the software stack overhead reduced the performance by up to 75%, 52%, 76%, 91%, and 92% in RAID 0, 1, 10, 5, and 6, respectively, compared with theoretical and expected performance.
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Thurgate, S. M. "Auger Spectroscopy and Surface Analysis." Australian Journal of Physics 50, no. 4 (1997): 745. http://dx.doi.org/10.1071/p96075.
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Abstract In 1925 Pierre Auger reported on his observations of low energy electrons associated with core-ionised atoms in cloud chamber experiments. He was able to correctly identify the mechanism for their production, and such electrons are now known as Auger electrons. Typically Auger electrons have energies in the range 10 eV to 2 keV. The short distance that such low energy electrons travel in solids ensures that Auger electrons come from the surface layers. The data generated by the AES technique are complex. There are at least three electrons involved in the process, and there are many possible configurations for the atom. These possibilities led to spectra that are not readily interpreted in detail. Theory lags behind experiment in this area. In principle, it should be possible to find information about the chemical environment of atoms from Auger spectra. While there are clear changes in spectral lineshapes, there is no simple way to go from the spectra to an understanding of the chemical bonding of the atom. There are a number of experiments currently underway which aim to improve our understanding of the Auger process. Synchrotron experiments with tunable energy x-rays are providing new insight. Experiments that use positrons to excite Auger emission have also produced further recent understanding. Coincidence experiments between photoelectrons and Auger electrons have also made recent advances. Auger photoelectron coincidence spectroscopy reduces the complexity of Auger spectra by only counting those electrons that occur as a consequence of selected ionisations. The effect is to reduce the complexity of the spectra, and to isolate processes that are often clouded by the simultaneous occurrence of other effects.
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Ilisca, Ernest, Loïc Houssais, and Filippo Ghiglieno. "Symmetry Breakings in the interactions of Molecular Hydrogen with Solids." EPJ Web of Conferences 263 (2022): 01013. http://dx.doi.org/10.1051/epjconf/202226301013.
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The following conference report considers hydrogen gases with odd and even rotational quantum number as two separate gases, the ortho and para varieties which do not interconvert in absence of a catalyst. The physical catalysis of hydrogen is interpreted in terms of symmetry breakings introduced by the solid to pass round the peculiar selection rules of the molecular hydrogen assigned by the Pauli Principle. The catalytic effect presents the striking effect of reducing drastically the interconversion time, longer than the age of the universe for isolated molecules, to a few seconds or minutes when an hydrogen sample (gaseous or liquid) is brought into contact with an efficient catalyst. In the present report, the variety of new optical and electronic devices, measurements and interpretations that have been reported since the turning of the new century are reviewed. New experiments on non-magnetic catalysts measuring hydrogen conversion on the time scales of one-ten minutes turned upside down the previous theory, established in 1933, of the absolute necessity of a magnetic catalyst to break the Pauli Principle. The o-p catalyzed reaction is discussed for hydrogen molecules adsorbed on electric surfaces, or in confining porous structures or inside nanocages. New concepts and new electromagnetic conversion channels that interpret these experimental renewals are described in terms of how the hydrogen nuclei feel the solid-molecule electron cloud complex. The described channels differentiate one another owing to the catalyst and owing to the electronic path followed in the configuration space by the o-p reaction.
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Tembhare, Yash, Lokesh Kachhi, and Amber Agey. "Cloud Computing –Security Issues and Threats." Journal of Cyber Security, Privacy Issues and Challenges 2, no. 2 (June 1, 2023): 1–9. http://dx.doi.org/10.46610/jcspic.2023.v02i02.001.
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One of the most exciting topics in the IT business nowadays is cloud computing. The cloud computing resource paradigm has changed the geography of computing. Computing's promises of cost reductions, enormous scalability, lower dependency on third parties, and increased trust have attracted both businesses and individuals. This increases the power of information technology. Cloud computing has grown significantly recently in the field of information technology. Concerns over information security are growing as more and more people and businesses store information in the cloud. Many companies, including Microsoft, which is considered a software development powerhouse, are working on developing cloud services. Customers are reluctant to change their business practices ignoring the excitement around it, to the cloud. Protection is one of them. All three aspects are covered by a comprehensive cloud security plan to ensure the foundation is solid. Each can be viewed through a different lens or perspective on cloud security. For your company to use the cloud to grow securely, a solid plan must decrease risk (security controls), defend against threats (secure coding and deployment), and overcome obstacles (adopt cultural and technical solutions).
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Niranjanamurthy, M., M. P. Amulya, N. M. Niveditha, and P. Dayananda. "Creating a Custom Virtual Private Cloud and Launch an Elastic Compute Cloud (EC2) Instance in Your Virtual Private Cloud." Journal of Computational and Theoretical Nanoscience 17, no. 9 (July 1, 2020): 4509–14. http://dx.doi.org/10.1166/jctn.2020.9106.
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Cloud Computing is regarded to as putting away and getting to data over the web. The hard disk of your PC doesn’t hold this data. In Cloud computing, you can get to information from a remote server. Amazon Web Services (AWS) enables adaptable, solid, versatile, simple to-utilize and practical Cloud computing arrangements. AWS is an extensive, simple to utilize processing stage offered Amazon. A virtual private cloud (VPC) is devoted to the AWS account which is in the AWS cloud that acts coherently detached with different virtual systems. Amazon EC2 is a secure web administration which allows register with the modifiable limit in the cloud .In this work, we are giving route subtleties of Creating a custom VPC and dispatch an EC2 Instance in your VPC.
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Li, Xueqin, Junyou Shi, Zhiwei Wang, Xixin Duan, Gaofeng Chen, Qian Guan, Xiangyu Li, and Tingzhou Lei. "Preparation of carbon-based magnetic solid acid catalyst from various carbon sources and characterization of its catalytic performance." BioResources 12, no. 4 (August 28, 2017): 7525–38. http://dx.doi.org/10.15376/biores.12.4.7525-7538.
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Four kinds of carbon-based magnetic solid acid catalysts (CBMSACs) were prepared from rice husk, wood chips, peanut shells, and corn straw. The structure was investigated via x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), elemental Analysis (EA), scanning/transmission electron microscope (SEM/TEM), and BET analyses. The catalysts were used to hydrolyze cellulose, and the hydrolysis efficiencies were determined. The catalysts were all comprised of a disordered carbon structure with random polycyclic aromatic hydrocarbons similar to graphite layers. This structure had a large number of -SO3H groups and the alkyl side chain, which increased the electron cloud density of the carbon carrier, relative to the other catalysts; this was advantageous to the adhesion of the -SO3H group to increase the activity of catalysts. The product also contained a large number of magnetic particles, making it easy to separate the catalysts from the reaction residue. The properties of the catalyst derived from corn straw as the carbon source appeared to be the best. Although it could be further recycled many times, the catalyst activity decreased due to the loss of -SO3H groups. At the same time, the catalyst had a high specific surface area of 755 m2/g.
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Rahman, Mohammad Akhlaquer. "Spray-dried nanoemulsion for improved oral delivery of silymarin against hepatic cancer cells." Journal of Drug Delivery and Therapeutics 12, no. 3-S (June 15, 2022): 7–14. http://dx.doi.org/10.22270/jddt.v12i3-s.5479.
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Silymarin recognized for numerous activities, but the use is limited due to poor aqueous solubility, inefficient intestinal permeability, and low-erratic bioavailability. The aim of the current research was formulation of spray-dried nanoemulsion to enhance the solubility of silymarin. The nanoemulsion was prepared by aqueous titration method, spray died and characterized for thermal analysis by diffraction scanning calorimetry, crystallography analysis by x-ray diffraction, surface morphology by scanning electron microscopy. The reconstitution properties were determining for droplet size, polydispersity index and microscopic structure. Optimized nanoemulsion composed of 15% v/v of oil, 33% v/v of Smix and 52% v/v of distilled water demonstrated lowest droplet size (52.4 ± 1.63 nm) and polydispersity index (0.112), optimum viscosity (23.37 ± 2.36 cps), maximum % transmittance (94.55), optimum cloud point (88°C) and cumulative % drug release (98.43%). The microscopic structure of spray-dried nanoemulsion after reconstitution in distilled water revealed spherical shape free from any aggregation. Spray-dried nanoemulsion demonstrated amorphous sate of silymarin after fabrication into solid state. The cumulative % release of silymarin was significantly higher than marketed conventional suspension (Limarin). The developed spray-dried nanoemulsion was robust and stable for a period of 3 months that could be recommended for oral administration of silymarin after further study. Solids are preferred over liquid dosage form; the formulation may offer better patient compliance over liquid nanoemulsion. In addition, the in-vitro cytotoxicity study revealed more cytotoxicity of SD-NE than plain silymarin against HepG2 cell line after 48 h of incubation. Moreover, the HepG2 cellular uptake silymarin was found to be substantially higher from NE when compared to the plain silymarin. Further, silymarin loaded SD-NE could be potential approach against hepatic cancer.
Keywords: Silymarin, spray-dried nanoemulsion, dextran, phase diagram, solubility, stability
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Moreno, Hugo, Constantino Valero, José María Bengochea-Guevara, Ángela Ribeiro, Miguel Garrido-Izard, and Dionisio Andújar. "On-Ground Vineyard Reconstruction Using a LiDAR-Based Automated System." Sensors 20, no. 4 (February 18, 2020): 1102. http://dx.doi.org/10.3390/s20041102.
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Crop 3D modeling allows site-specific management at different crop stages. In recent years, light detection and ranging (LiDAR) sensors have been widely used for gathering information about plant architecture to extract biophysical parameters for decision-making programs. The study reconstructed vineyard crops using light detection and ranging (LiDAR) technology. Its accuracy and performance were assessed for vineyard crop characterization using distance measurements, aiming to obtain a 3D reconstruction. A LiDAR sensor was installed on-board a mobile platform equipped with an RTK-GNSS receiver for crop 2D scanning. The LiDAR system consisted of a 2D time-of-flight sensor, a gimbal connecting the device to the structure, and an RTK-GPS to record the sensor data position. The LiDAR sensor was facing downwards installed on-board an electric platform. It scans in planes perpendicular to the travel direction. Measurements of distance between the LiDAR and the vineyards had a high spatial resolution, providing high-density 3D point clouds. The 3D point cloud was obtained containing all the points where the laser beam impacted. The fusion of LiDAR impacts and the positions of each associated to the RTK-GPS allowed the creation of the 3D structure. Although point clouds were already filtered, discarding points out of the study area, the branch volume cannot be directly calculated, since it turns into a 3D solid cluster that encloses a volume. To obtain the 3D object surface, and therefore to be able to calculate the volume enclosed by this surface, a suitable alpha shape was generated as an outline that envelops the outer points of the point cloud. The 3D scenes were obtained during the winter season when only branches were present and defoliated. The models were used to extract information related to height and branch volume. These models might be used for automatic pruning or relating this parameter to evaluate the future yield at each location. The 3D map was correlated with ground truth, which was manually determined, pruning the remaining weight. The number of scans by LiDAR influenced the relationship with the actual biomass measurements and had a significant effect on the treatments. A positive linear fit was obtained for the comparison between actual dry biomass and LiDAR volume. The influence of individual treatments was of low significance. The results showed strong correlations with actual values of biomass and volume with R2 = 0.75, and when comparing LiDAR scans with weight, the R2 rose up to 0.85. The obtained values show that this LiDAR technique is also valid for branch reconstruction with great advantages over other types of non-contact ranging sensors, regarding a high sampling resolution and high sampling rates. Even narrow branches were properly detected, which demonstrates the accuracy of the system working on difficult scenarios such as defoliated crops.
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Li, T., Y. Wang, W. J. Li, J. M. Chen, T. Wang, and W. X. Wang. "Concentrations and solubility of trace elements in fine particles at a mountain site, southern China: regional sources and cloud processing." Atmospheric Chemistry and Physics 15, no. 15 (August 13, 2015): 8987–9002. http://dx.doi.org/10.5194/acp-15-8987-2015.
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Abstract. The concentrations and solubility of twelve trace elements in PM2.5 at Mt. Lushan, southern China, were investigated during the summer of 2011 and the spring of 2012. The average PM2.5 mass was 55.2 ± 20.1 μg m−3 during the observation period. Temporal variations of all trace elements including total and water-soluble fractions with several dust storm spikes in total fractions of Al and Fe were observed. The enrichment factor (EF) values were 1 order of magnitude higher for the water-soluble fractions versus the total fractions of trace elements. Four major emission sources, namely nonferrous metal mining and smelting (for Cr, As, Ba and parts of Zn), coal combustion (for Pb, Zn, Se, Cu and Mn), crustal materials (for Al and Fe) and municipal solid waste incineration (for Cd and Mo), were classified by principal component analysis (PCA). Trajectory cluster analysis and the potential source contribution function (PSCF) consistently identified the Yangtze River delta (YRD), the Pearl River delta (PRD), and the neighbouring provinces of Mt. Lushan as the major source regions and transport pathways for anthropogenic elements. Northern China was identified as a major source region for crustal elements. It should be noted that apart from the YRD, the area around Mt. Lushan has become the most significant contributor to the solubility of most trace elements. Element solubility can be partially determined by emission sources. However, enhanced solubility of trace elements corresponding to increased concentrations of sulfate after the occurrence of cloud events indicated significant effects of cloud processing on aerosol element dissolution. Metal particles mixed with sulfate in cloud droplet residues were further investigated through transmission electron microscopy (TEM) analysis. Irreversible alteration of particle morphology by cloud processing was confirmed to be highly responsible for the enhancement of trace element solubility. The findings from this study imply an important role of regional anthropogenic pollution and cloud processing in the evolution of aerosol trace element solubility during transport in the troposphere.
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Tahir, Adnan, Fei Chen, Habib Ullah Khan, Zhong Ming, Arshad Ahmad, Shah Nazir, and Muhammad Shafiq. "A Systematic Review on Cloud Storage Mechanisms Concerning e-Healthcare Systems." Sensors 20, no. 18 (September 21, 2020): 5392. http://dx.doi.org/10.3390/s20185392.
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As the expenses of medical care administrations rise and medical services experts are becoming rare, it is up to medical services organizations and institutes to consider the implementation of medical Health Information Technology (HIT) innovation frameworks. HIT permits health associations to smooth out their considerable cycles and offer types of assistance in a more productive and financially savvy way. With the rise of Cloud Storage Computing (CSC), an enormous number of associations and undertakings have moved their healthcare data sources to distributed storage. As the information can be mentioned whenever universally, the accessibility of information becomes an urgent need. Nonetheless, outages in cloud storage essentially influence the accessibility level. Like the other basic variables of cloud storage (e.g., reliability quality, performance, security, and protection), availability also directly impacts the data in cloud storage for e-Healthcare systems. In this paper, we systematically review cloud storage mechanisms concerning the healthcare environment. Additionally, in this paper, the state-of-the-art cloud storage mechanisms are critically reviewed for e-Healthcare systems based on their characteristics. In short, this paper summarizes existing literature based on cloud storage and its impact on healthcare, and it likewise helps researchers, medical specialists, and organizations with a solid foundation for future studies in the healthcare environment.
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Huang, Jian Yu, Li Zhong, Chong Min Wang, John P. Sullivan, Wu Xu, Li Qiang Zhang, Scott X. Mao, et al. "In Situ Observation of the Electrochemical Lithiation of a Single SnO2 Nanowire Electrode." Science 330, no. 6010 (December 9, 2010): 1515–20. http://dx.doi.org/10.1126/science.1195628.
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We report the creation of a nanoscale electrochemical device inside a transmission electron microscope—consisting of a single tin dioxide (SnO2) nanowire anode, an ionic liquid electrolyte, and a bulk lithium cobalt dioxide (LiCoO2) cathode—and the in situ observation of the lithiation of the SnO2 nanowire during electrochemical charging. Upon charging, a reaction front propagated progressively along the nanowire, causing the nanowire to swell, elongate, and spiral. The reaction front is a “Medusa zone” containing a high density of mobile dislocations, which are continuously nucleated and absorbed at the moving front. This dislocation cloud indicates large in-plane misfit stresses and is a structural precursor to electrochemically driven solid-state amorphization. Because lithiation-induced volume expansion, plasticity, and pulverization of electrode materials are the major mechanical effects that plague the performance and lifetime of high-capacity anodes in lithium-ion batteries, our observations provide important mechanistic insight for the design of advanced batteries.
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Li, T., Y. Wang, W. J. Li, J. M. Chen, T. Wang, and W. X. Wang. "Concentrations and solubility of trace elements in fine particles at a mountain site, southern China: regional sources and cloud processing." Atmospheric Chemistry and Physics Discussions 15, no. 9 (May 5, 2015): 13001–42. http://dx.doi.org/10.5194/acpd-15-13001-2015.
Full textAbstract:
Abstract. The concentrations and solubility of twelve trace elements in PM2.5 at Mt. Lushan, southern China, were investigated during the summer of 2011 and the spring of 2012. The average PM2.5 mass was 55.2 ± 20.1 μg m-3 during the observation period. Temporal variations of all trace elements including total and water-soluble fractions with several dust storm spikes for total fraction Al and Fe were observed. The enrichment factor (EF) values were one order of magnitude higher for the water-soluble fractions vs. the total fractions of trace elements. Four major emission sources were classified by principal component analysis (PCA), namely nonferrous metal mining and smelting (for Cr, As, Ba and parts of Zn), coal combustion (for Pb, Zn, Se, Cu and Mn), crustal materials (for Al and Fe) and municipal solid waste incineration (for Cd and Mo). Trajectory cluster analysis and the potential source contribution function (PSCF) consistently identified the Yangtze River Delta (YRD), the Pearl River Delta (PRD) and parts of Hunan and Jiangxi as the major source regions and pathways for anthropogenic elements, while northern China was identified for crustal elements. In contrast, the local Jiangxi area has become the most significant contributor to the solubility of most trace elements, apart from the YRD with severe air pollution. In addition, the solubility alteration of trace elements in cloud events was investigated and transmission electron microscopy (TEM) analysis indicated that the irreversible alteration of particle morphology by cloud processing was highly responsible for the enhancement of element solubility. Our work implies an important role of regional anthropogenic pollution and cloud processing in the evolution of trace element solubility during transport.
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Honório, Leonardo M., Milena F. Pinto, Maicon J. Hillesheim, Francisco C. de Araújo, Alexandre B. Santos, and Delfim Soares. "Photogrammetric Process to Monitor Stress Fields Inside Structural Systems." Sensors 21, no. 12 (June 10, 2021): 4023. http://dx.doi.org/10.3390/s21124023.
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This research employs displacement fields photogrammetrically captured on the surface of a solid or structure to estimate real-time stress distributions it undergoes during a given loading period. The displacement fields are determined based on a series of images taken from the solid surface while it experiences deformation. Image displacements are used to estimate the deformations in the plane of the beam surface, and Poisson’s Method is subsequently applied to reconstruct these surfaces, at a given time, by extracting triangular meshes from the corresponding points clouds. With the aid of the measured displacement fields, the Boundary Element Method (BEM) is considered to evaluate stress values throughout the solid. Herein, the unknown boundary forces must be additionally calculated. As the photogrammetrically reconstructed deformed surfaces may be defined by several million points, the boundary displacement values of boundary-element models having a convenient number of nodes are determined based on an optimized displacement surface that best fits the real measured data. The results showed the effectiveness and potential application of the proposed methodology in several tasks to determine real-time stress distributions in structures.
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Lubenchenko, Alexander V., and Olga I. Lubenchenko. "Solving the Boundary Problem of a Non-Stationary Equation Transfer of Radiation and Particles for a Semi-Infinite Medium." Light & Engineering, no. 04-2022 (August 2022): 31–41. http://dx.doi.org/10.33383/2022-019.
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The boundary problem of non-stationary radiative and particle transfer equation for a semi-infinite medium with an arbitrary single scattering law is considered. This problem comes to finding of a path length distribution function for particles in a turbid medium. A non-linear integro-differential equation for path length distribution function in the case of non-stationary multiple scattering in a semi-infinite medium with an anisotropic scattering law is found by means of invariant embedding. With the help of the discrete ordinates method, matrix non-linear differential equations are deduced that are solved by formulae of backward differentiation and matrix methods for solution of the Lyapunov equation. The computing results are verified by the Monte Carlo method for the path length distribution function for photons backscattered from a drop WC1 cloud and elastically scattered electrons backscattered from a solid semi-infinite target.
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Sun, Xinyu, Lisheng Jin, Yang He, Huanhuan Wang, Zhen Huo, and Yewei Shi. "SimoSet: A 3D Object Detection Dataset Collected from Vehicle Hybrid Solid-State LiDAR." Electronics 12, no. 11 (May 26, 2023): 2424. http://dx.doi.org/10.3390/electronics12112424.
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Three-dimensional (3D) object detection based on point cloud data plays a critical role in the perception system of autonomous driving. However, this task presents a significant challenge in terms of its practical implementation due to the absence of point cloud data from automotive-grade hybrid solid-state LiDAR, as well as the limitations regarding the generalization ability of data-driven deep learning methods. In this paper, we introduce SimoSet, the first vehicle view 3D object detection dataset composed of automotive-grade hybrid solid-state LiDAR data. The dataset was collected from a university campus, contains 52 scenes, each of which are 8 s long, and provides three types of labels for typical traffic participants. We analyze the impact of the installation height and angle of the LiDAR on scanning effect and provide a reference process for the collection, annotation, and format conversion of LiDAR data. Finally, we provide baselines for LiDAR-only 3D object detection.
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Vargas Rivero, Jose Roberto, Thiemo Gerbich, Boris Buschardt, and Jia Chen. "Data Augmentation of Automotive LIDAR Point Clouds under Adverse Weather Situations." Sensors 21, no. 13 (June 30, 2021): 4503. http://dx.doi.org/10.3390/s21134503.
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In contrast to previous works on data augmentation using LIDAR (Light Detection and Ranging), which mostly consider point clouds under good weather conditions, this paper uses point clouds which are affected by spray. Spray water can be a cause of phantom braking and understanding how to handle the extra detections caused by it is an important step in the development of ADAS (Advanced Driver Assistance Systems)/AV (Autonomous Vehicles) functions. The extra detections caused by spray cannot be safely removed without considering cases in which real solid objects may be present in the same region in which the detections caused by spray take place. As collecting real examples would be extremely difficult, the use of synthetic data is proposed. Real scenes are reconstructed virtually with an added extra object in the spray region, in a way that the detections caused by this obstacle match the characteristics a real object in the same position would have regarding intensity, echo number and occlusion. The detections generated by the obstacle are then used to augment the real data, obtaining, after occlusion effects are added, a good approximation of the desired training data. This data is used to train a classifier achieving an average F-Score of 92. The performance of the classifier is analyzed in detail based on the characteristics of the synthetic object: size, position, reflection, duration. The proposed method can be easily expanded to different kinds of obstacles and classifier types.
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Mayer, C., W. Kerschbaumer, M. Mancini, and R. Weber. "Time dependent simulations of dispersion of a cloud of solid particles." Journal of the Energy Institute 80, no. 3 (September 1, 2007): 181–83. http://dx.doi.org/10.1179/174602207x223752.
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Byun, Siwoo. "Reused Shadow Recovery Scheme for Flash-based Edge Gateway Servers." International Journal of Circuits, Systems and Signal Processing 15 (December 6, 2021): 1695–701. http://dx.doi.org/10.46300/9106.2021.15.183.
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Edge computing refers to decentralized computing technology to reduce cloud computing's overload or security problems that redirect local data to a central data center. Edge computing is emerging as a technology that complements cloud computing in an IoT environment where huge amounts of data are generated in real time. Recently, solid state drives using flash memory have recently been recognized as a suitable storage for massive IoT data services. In this study, we propose a new data recovery scheme based on shadow paging using flash memory for effective and safe data services in IoT edge gateways. The proposed scheme recycles invalidated old data blocks that are discarded when new data is stored. Thus, The proposed scheme minimizes the burden of additional storage space required to traditional shadow paging schemes, and reduces I/O performance degradation. Simulation results show that the space gain of the proposed scheme reaches even to 29%.
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Layssac, Y., A. Gutiérrez-Quintanilla, T. Chiavassa, and F. Duvernay. "Detection of glyceraldehyde and glycerol in VUV processed interstellar ice analogues containing formaldehyde: a general formation route for sugars and polyols." Monthly Notices of the Royal Astronomical Society 496, no. 4 (July 2, 2020): 5292–307. http://dx.doi.org/10.1093/mnras/staa1875.
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ABSTRACT Complex organic molecules (COMs) have been identified toward high- and low-mass protostars as well as molecular clouds. Among them, sugar-like and polyol two carbon-bearing molecules such as glycolaldehyde (GA) and ethylene glycol (EG) are of special interest. Recent laboratory experiments have shown that they can efficiently be formed via atom addition reactions between accreting H-atoms and CO molecules or via energetic processes (UV, electrons) on ice analogues containing methanol or formaldehyde. In this study, we report new laboratory experiments on the low-temperature solid state formation of complex organic molecules – the first sugar glyceraldehyde and its saturated derivative glycerol – through VUV photolysis performed at three different temperatures (15, 50, and 90 K) of astrochemically relevant ices composed of water and formaldehyde. We get evidence that the species production depends on the ice temperature during photolysis. The results presented here indicate that a general scheme of aldose and polyol formation is plausible and that heavier COMs than GA and EG could exist in interstellar environments. We propose a general pathway involving radical-formaldehyde reactions as common initiation step for aldose and polyol formation. Future telescope observations may give additional clues on their presence in star-forming regions as observations are currently limited because of the detection thresholds.
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Suhaimi Sulaiman, Mohd, Mohamad Faizal Abd Rahman, and Aileen Farida Mohd Adam. "Variance of total dissolved solids and electrical conductivity for water quality in Sabak Bernam." International Journal of Electrical and Computer Engineering (IJECE) 13, no. 2 (April 1, 2023): 2259. http://dx.doi.org/10.11591/ijece.v13i2.pp2259-2269.
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<span lang="EN-US">Water pollution is one of the most serious environmental problems in Malaysia. The most notable occurrence of pollution happened in Selangor. Currently, there are various water quality monitoring (WQM) methods to observe the quality of water. One of the methods used is the internet of things (IoT) for wireless sensor network technology to obtain real-time data measurement. In this study, the developed WQM system is equipped with a sensor that can measure total dissolved solid (TDS) and electrical conductivity (EC). Arduino UNO was used in this system as a microcontroller to interact with the sensor. The Wi-Fi module, ESP8266, was used to transfer the collected data to ThingSpeak, which acts as a cloud to store all the data. The results showed that both sample populations can be discriminated since the p-value is greater than 0.05 in the normality test, while in the paired sample t-test, the p-value is less than 0.05. In conclusion, this research provides an easier way to monitor water quality by taking up less time at less cost, as well as being reliable in giving real-time data reading.</span>
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Kostka, Joel E., Dava D. Dalton, Hayley Skelton, Sherry Dollhopf, and Joseph W. Stucki. "Growth of Iron(III)-Reducing Bacteria on Clay Minerals as the Sole Electron Acceptor and Comparison of Growth Yields on a Variety of Oxidized Iron Forms." Applied and Environmental Microbiology 68, no. 12 (December 2002): 6256–62. http://dx.doi.org/10.1128/aem.68.12.6256-6262.2002.
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ABSTRACT Smectite clay minerals are abundant in soils and sediments worldwide and are typically rich in Fe. While recent investigations have shown that the structural Fe(III) bound in clay minerals is reduced by microorganisms, previous studies have not tested growth with clay minerals as the sole electron acceptor. Here we have demonstrated that a pure culture of Shewanella oneidensis strain MR-1 as well as enrichment cultures of Fe(III)-reducing bacteria from rice paddy soil and subsurface sediments are capable of conserving energy for growth with the structural Fe(III) bound in smectite clay as the sole electron acceptor. Pure cultures of S. oneidensis were used for more detailed growth rate and yield experiments on various solid- and soluble-phase electron acceptors [smectite, Fe(III) oxyhydroxide FeOOH, Fe(III) citrate, and oxygen] in the same minimal medium. Growth was assessed as direct cell counts or as an increase in cell carbon (measured as particulate organic carbon). Cell counts showed that similar growth of S. oneidensis (108 cells ml−1) occurred with smectitic Fe(III) and on other Fe forms [amorphous Fe(III) oxyhydroxide, and Fe citrate] or oxygen as the electron acceptor. In contrast, cell yields of S. oneidensis measured as the increase in cell carbon were similar on all Fe forms tested while yields on oxygen were five times higher, in agreement with thermodynamic predictions. Over a range of particle loadings (0.5 to 4 g liter−1), the increase in cell number was highly correlated to the amount of structural Fe in smectite reduced. From phylogenetic analysis of the complete 16S rRNA gene sequences, a predominance of clones retrieved from the clay mineral-reducing enrichment cultures were most closely related to the low-G+C gram-positive members of the Bacteria (Clostridium and Desulfitobacterium) and the δ-Proteobacteria (members of the Geobacteraceae). Results indicate that growth with smectitic Fe(III) is similar in magnitude to that with Fe(III) oxide minerals and is dependent upon the mineral surface area available. Iron(III) bound in clay minerals should be considered an important electron acceptor supporting the growth of bacteria in soils or sedimentary environments.
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Wang, Junfeng, Yansong Zhang, Huifeng Su, Jinshe Chen, Bo Liu, and Yuyuan Zhang. "Explosion Characteristics and Flame Propagation Behavior of Mixed Dust Cloud of Coal Dust and Oil Shale Dust." Energies 12, no. 20 (October 9, 2019): 3807. http://dx.doi.org/10.3390/en12203807.
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Coal and oil shale are often mined and utilized together, and mixed dust is easily formed in these processes. In order to ensure safe production in these processes, the explosion characteristics of mixed dust were studied. Using a Godbert-Greenwold (G-G) Furnace experimental device, Hartmann tube experimental device, and 20 L explosion vessel, the oil shale and coal mixed dust ignition sensitivity experiment, flame propagation experiment, and explosion characteristics experiment were carried out. The minimum ignition temperature (MIT), minimum ignition energy (MIE), maximum explosion pressure (Pmax), maximum rate of pressure rise ((dp/dt)max), and explosibility index (KSt) parameters and the flame propagation behavior of the mixed dust were analyzed in detail. A scanning electron microscope (SEM) analysis of the coal and oil shale dust before and after the explosion was carried out to study the changes in the microscopic morphology of the dust particles. The results show that due to the oil shale having a high volatile content and low moisture content, in the mixture, the greater the percentage of oil shale, the more likely the dust cloud is to be ignited and the faster the explosion flame is propagated; the greater the percentage of oil shale, the greater the (dP/dt)max and KSt will be and, under a high dust concentration, a greater Pmax will be produced. During explosion, coal dust will experience particle pyrolysis and the gas phase combustion of the volatile matter, followed by solid phase combustion of coal char, whereas oil shale dust will only experience particle pyrolysis and the gas phase combustion of the volatile matter.
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Pasha, M. Jahir, K. Sreenivasulu, B. Roja Ramani, M. Jaya Sunitha, K. Swetha, and K. Samunnisa. "Solid Waste Supervision System based on Heuristic Algorithmic approach and Internet of Things." International Journal on Recent and Innovation Trends in Computing and Communication 11, no. 1s (January 18, 2023): 64–70. http://dx.doi.org/10.17762/ijritcc.v11i1s.6000.
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This research article emphasises on use of algorithmic approach to activate sensors to optimize waste disposal and internet of things technology to notify the trash collectors when it is time to clean the trash cans. Here, a heuristic algorithmic approach will serve as the universal alarm and an SMS will be sent to the cleaners' registered mobile numbers as the local alert. The registered higher officials will receive an SMS alert if cleaners don't finish cleaning by the deadline. The top and bottom of a trashcan are where the ultrasonic sensors will be placed as part of the research goals. Every second, the value of the sensed ultrasonic sensor will be stored in the cloud. If the trash can is full, the lid will automatically close as a local warning. There will be a global alert sent via SMS to the authorised cleaners and higher officials. The research objectives include placing the ultrasonic at top and bottom of a dustbin. The sensed ultrasonic sensor value will store in a cloud at every second. As a local alert the lid of the garbage will be closed automatically if the dustbin is full. Global alert as a SMS will send to the authorized cleaners and higher officials. To know where the trash can is, attach a GPS sensor there. The existing intelligent dustbin is equipped with a voice controller that is used to classify the garbage but is not connected to the internet. In the existing system, an IoT platform was used with the assistance of a computer terminal, an infrared sensor, and continuous monitoring of the root plan to empty the dustbin. The lead of a dustbin is closed and opened by a vibration switch in smart homes. Whether the trash is full or not, the intelligent trash can will only locally but not worldwide transmit an alarm. The smart waste tank will communicate with smart phones by sending local dustbin values but was not stored in the cloud for every second. In this garbage narrow band IoT module was used but not internet. Accordingly the IoT enabled dustbin by placing the ultrasonic sensors, GPS sensor it is capable to know whether the dustbin is full or empty and the status will be indicated as local alert and global alert. The local alert will be the automatic lid closing of a dustbin and the global alert will be a SMS with the location of a dustbin and the status as full.
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Niessen, Benedikt, Eugen Schumacher, Jörn Lueg-Althoff, Jörg Bellmann, Marcus Böhme, Stefan Böhm, A. Erman Tekkaya, et al. "Interface Formation during Collision Welding of Aluminum." Metals 10, no. 9 (September 8, 2020): 1202. http://dx.doi.org/10.3390/met10091202.
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Collision welding is a high-speed joining technology based on the plastic deformation of at least one of the joining partners. During the process, several phenomena like the formation of a so-called jet and a cloud of particles occur and enable bond formation. However, the interaction of these phenomena and how they are influenced by the amount of kinetic energy is still unclear. In this paper, the results of three series of experiments with two different setups to determine the influence of the process parameters on the fundamental phenomena and relevant mechanisms of bond formation are presented. The welding processes are monitored by different methods, like high-speed imaging, photonic Doppler velocimetry and light emission measurements. The weld interfaces are analyzed by ultrasonic investigations, metallographic analyses by optical and scanning electron microscopy, and characterized by tensile shear tests. The results provide detailed information on the influence of the different process parameters on the classical welding window and allow a prediction of the different bond mechanisms. They show that during a single magnetic pulse welding process aluminum both fusion-like and solid-state welding can occur. Furthermore, the findings allow predicting the formation of the weld interface with respect to location and shape as well as its mechanical strength.
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Zhu, Ling Ling, Zu Ming Hu, Jun Rong Yu, Guo Ping Tang, Lei Chen, and Jing Zhu. "Preparation of Ultra-High Molecular Weight Polyethylene Microporous Membranes via Thermally Induced Phase Separation." Advanced Materials Research 476-478 (February 2012): 2363–67. http://dx.doi.org/10.4028/www.scientific.net/amr.476-478.2363.
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Ultra-high molecular weight polyethylene (UHMWPE) microporous membranes were fabricated via thermally induced phase separation (TIPS). Thermogravimetric analyzer was used to obtain the true concentration of films. To characterize the permeation property, the testing of water flux was carried out and it was found that with the increase of thickness, concentration and molecular weight, a decrease in water flux occurred. However, the water flux changed slightly when the thickness turned into 150μm and the molecular weight reached 4,000,000. Moreover, the pore structure investigated by Field emission scanning electron microscopy (FESEM) was consistent with the above phenomena. It is known that the pore size is affected by two factors: crystallization rate and the diffusion rate of diluent. The curves of the relative crystallinity (Xt) with time for the various films under the cooling rate of 10°C/min showed that the difference between crystallization rate of various membranes was small. So it was considered that the viscosity of system did greater influence on diffusion rate of diluent. In addition, the disparity between cloud points (Tcd) and crystallization temperature (T0) was not obvious, indicating that only solid-liquid phase separation could be observed in the range of cooling rates during the non-isothermal process.
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Arie, Ady, Eric K. Gustafson, and Robert L. Byer. "Frequency-Stabilized Diode-Laser-Pumped Solid State Lasers: Optical Clocks of the Future." Optics and Photonics News 3, no. 12 (December 1, 1992): 43. http://dx.doi.org/10.1364/opn.3.12.000043.
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Doležel, Ivo, Václav Kotlan, Roman Hamar, and David Pánek. "Numerical modeling of hybrid laser welding taking into account phase change of material." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 36, no. 2 (March 6, 2017): 417–26. http://dx.doi.org/10.1108/compel-05-2016-0225.
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Purpose This paper aims to present a three-dimensional (3D) model of hybrid laser welding of a steel plate. Before welding, the plate is pre- and/or post-heated by induction to avoid mechanical stresses in material due to high gradients of temperature. Welding itself is realized by laser beam without welding rod. The model takes into account existence of both solid and liquid phases in the weld. Design/methodology/approach Presented is the complete mathematical model of the above heat treatment process, taking into account all relevant nonlinearities (saturation curve of the processed steel material and temperature dependences of its physical parameters). Its numerical solution is realized by the finite element method. Some important results are compared with experimental data. Findings In comparison with the former model developed by the authors that did not take into account the phase change, the results are more realistic and exhibit a better accordance with measurements. On the other hand, they strongly depend on sufficiently accurate knowledge of material parameters in both solid and liquid levels (that represent the input data). Research limitations/implications The quality of calculated results strongly depends on the material properties and their temperature dependencies. In case of alloys (whose chemical composition may vary in some range), such data are often unavailable and must be estimated on the basis of experiments. Another quantity that has to be calibrated is the time dependence of power delivered by the laser beam, which is due to the production of a plasma cloud above the exposed spot. Practical implications The presented model and methodology of its solution may represent a basis for design of the complete technology of laser welding with induction pre-heating and/or post-heating. Originality/value Fully 3D model of hybrid laser welding (supplemented with pre- and/or post-heating by magnetic induction) taking into account both solid and liquid phases of welded metal and influence of the plasma cloud is presented.
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Khan, Shams Tabrez, Yoko Horiba, Masamitsu Yamamoto, and Akira Hiraishi. "Members of the Family Comamonadaceae as Primary Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate)-Degrading Denitrifiers in Activated Sludge as Revealed by a Polyphasic Approach." Applied and Environmental Microbiology 68, no. 7 (July 2002): 3206–14. http://dx.doi.org/10.1128/aem.68.7.3206-3214.2002.
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ABSTRACT The distribution and phylogenetic affiliations of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)-degrading denitrifying bacteria in activated sludge were studied by a polyphasic approach including culture-independent biomarker and molecular analyses as well as cultivation methods. A total of 23 strains of PHBV-degrading denitrifiers were isolated from activated sludges from different sewage treatment plants. 16S ribosomal DNA (rDNA) sequence comparisons showed that 20 of the isolates were identified as members of the family Comamonadaceae, a major group of β-Proteobacteria. When the sludges from different plants were acclimated with PHBV under denitrifying conditions in laboratory scale reactors, the nitrate removal rate increased linearly during the first 4 weeks and reached 20 mg NO3 −-N h−1 g of dry sludge−1 at the steady state. The bacterial-community change in the laboratory scale sludges during the acclimation was monitored by rRNA-targeted fluorescence in situ hybridization and quinone profiling. Both approaches showed that the population of β-Proteobacteria in the laboratory sludges increased sharply during acclimation regardless of their origins. 16S rDNA clone libraries were constructed from two different acclimated sludges, and a total of 37 clones from the libraries were phylogenetically analyzed. Most of the 16S rDNA clones were grouped with members of the family Comamonadaceae. The results of our polyphasic approach indicate that β-Proteobacteria, especially members of the family Comamonadaceae, are primary PHBV-degrading denitrifiers in activated sludge. Our data provide useful information for the development of a new nitrogen removal system with solid biopolymer as an electron donor.
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Ginige, Maneesha P., Philip Hugenholtz, Holger Daims, Michael Wagner, Jürg Keller, and Linda L. Blackall. "Use of Stable-Isotope Probing, Full-Cycle rRNA Analysis, and Fluorescence In Situ Hybridization-Microautoradiography To Study a Methanol-Fed Denitrifying Microbial Community." Applied and Environmental Microbiology 70, no. 1 (January 2004): 588–96. http://dx.doi.org/10.1128/aem.70.1.588-596.2004.
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ABSTRACT A denitrifying microbial consortium was enriched in an anoxically operated, methanol-fed sequencing batch reactor (SBR) fed with a mineral salts medium containing methanol as the sole carbon source and nitrate as the electron acceptor. The SBR was inoculated with sludge from a biological nutrient removal activated sludge plant exhibiting good denitrification. The SBR denitrification rate improved from less than 0.02 mg of NO3 −-N mg of mixed-liquor volatile suspended solids (MLVSS)−1 h−1 to a steady-state value of 0.06 mg of NO3 −-N mg of MLVSS−1 h−1 over a 7-month operational period. At this time, the enriched microbial community was subjected to stable-isotope probing (SIP) with [13C]methanol to biomark the DNA of the denitrifiers. The extracted [13C]DNA and [12C]DNA from the SIP experiment were separately subjected to full-cycle rRNA analysis. The dominant 16S rRNA gene phylotype (group A clones) in the [13C]DNA clone library was closely related to those of the obligate methylotrophs Methylobacillus and Methylophilus in the order Methylophilales of the Betaproteobacteria (96 to 97% sequence identities), while the most abundant clone groups in the [12C]DNA clone library mostly belonged to the family Saprospiraceae in the Bacteroidetes phylum. Oligonucleotide probes for use in fluorescence in situ hybridization (FISH) were designed to specifically target the group A clones and Methylophilales (probes DEN67 and MET1216, respectively) and the Saprospiraceae clones (probe SAP553). Application of these probes to the SBR biomass over the enrichment period demonstrated a strong correlation between the level of SBR denitrification and relative abundance of DEN67-targeted bacteria in the SBR community. By contrast, there was no correlation between the denitrification rate and the relative abundances of the well-known denitrifying genera Hyphomicrobium and Paracoccus or the Saprospiraceae clones visualized by FISH in the SBR biomass. FISH combined with microautoradiography independently confirmed that the DEN67-targeted cells were the dominant bacterial group capable of anoxic [14C]methanol uptake in the enriched biomass. The well-known denitrification lag period in the methanol-fed SBR was shown to coincide with a lag phase in growth of the DEN67-targeted denitrifying population. We conclude that Methylophilales bacteria are the dominant denitrifiers in our SBR system and likely are important denitrifiers in full-scale methanol-fed denitrifying sludges.
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Guo, Jing, Lin Gui, Wei Hou, Liwei Sun, Yang Liu, and Junye Li. "Quality Study and Numerical Simulation Analysis of Solid–Liquid Two-Phase Magnetic Fluid Polishing Seven-Order Variable-Diameter Pipe." Micromachines 13, no. 4 (March 23, 2022): 500. http://dx.doi.org/10.3390/mi13040500.
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Variable-diameter pipe parts have been widely used in the automobile industry, aerospace industry, and other fields. To enhance the surface quality of variable-diameter pipe and explore the effect of solid–liquid two-phase magnetic fluid (SLTPMF) on polishing, in this paper, the seven-order variable-diameter pipe with symmetrical structure is taken as the research object to carry out experimental research and numerical simulation. The experimental research shows that the best surface roughness is reduced by an order of magnitude to Ra 0.054 μm. The solid–liquid two-phase magnetic fluid polishing (SLTPMFP) technology has reliability and superiority in improving the roughness of variable-diameter pipe parts. The simulation results show that the wall shear stress of solid–liquid two-phase magnetic fluid on the wall surface of the workpiece affects the improvement of roughness. The greater the wall shear force, the better the surface roughness can be obtained. The velocity and dynamic pressure cloud diagram show that the velocity and dynamic pressure on the center axis of the workpiece first increase and then decrease with the flow of the magnetic fluid. The velocity and dynamic pressure on the near wall surface are reduced due to the shear collision with the workpiece. This work can provide technical and theoretical support for the actual production of SLTPMF precision polishing.
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Wang, Minzhen, Cheng Li, Xinheng Wang, Zheyong Piao, Yongsheng Yang, Wentao Dai, and Qi Zhang. "Research on Comprehensive Evaluation and Early Warning of Transmission Lines’ Operation Status Based on Dynamic Cloud Computing." Sensors 23, no. 3 (January 28, 2023): 1469. http://dx.doi.org/10.3390/s23031469.
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The current methods for evaluating the operating condition of electricity transmission lines (ETLs) and providing early warning have several problems, such as the low correlation of data, ignoring the influence of seasonal factors, and strong subjectivity. This paper analyses the sensitive factors that influence dynamic key evaluation indices such as grounding resistance, sag, and wire corrosion, establishes the evaluation criteria of the ETL operation state, and proposes five ETL status levels and seven principles for selecting evaluation indices. Nine grade I evaluation indices and twenty-nine grade II evaluation indices, including passageway and meteorological environments, are determined. The cloud model theory is embedded and used to propose a warning technology for the operation state of ETLs based on inspection defect parameters and the cloud model. Combined with the inspection defect parameters of a line in the Baicheng district of Jilin Province and the critical evaluation index data such as grounding resistance, sag, and wire corrosion, which are used to calculate the timeliness of the data, the solid line is evaluated. The research shows that the dynamic evaluation model is correct and that the ETL status evaluation and early warning method have reasonable practicability.
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Nalajala, Anusha, T. Ragunathan, Ranesh Naha, and Sudheer Kumar Battula. "HRFP: Highly Relevant Frequent Patterns-Based Prefetching and Caching Algorithms for Distributed File Systems." Electronics 12, no. 5 (March 1, 2023): 1183. http://dx.doi.org/10.3390/electronics12051183.
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Data-intensive applications are generating massive amounts of data which is stored on cloud computing platforms where distributed file systems are utilized for storage at the back end. Most users of those applications deployed on cloud computing systems read data more often than they write. Hence, enhancing the performance of read operations is an important research issue. Prefetching and caching are used as important techniques in the context of distributed file systems to improve the performance of read operations. In this research, we introduced a novel highly relevant frequent patterns (HRFP)-based algorithm that prefetches content from the distributed file system environment and stores it in the client-side caches that are present in the same environment. We have also introduced a new replacement policy and an efficient migration technique for moving the patterns from the main memory caches to the caches present in the solid-state devices based on a new metric namely the relevancy of the patterns. According to the simulation results, the proposed approach outperformed other algorithms that have been suggested in the literature by a minimum of 15% and a maximum of 53%.
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Arun Kumar, S., and M. S. Anbarasi. "Noble Authentication Protocol with Privacy Preservation Policy for Public Auditing on Shared Data." Journal of Computational and Theoretical Nanoscience 16, no. 8 (August 1, 2019): 3252–58. http://dx.doi.org/10.1166/jctn.2019.8172.
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The cloud based services today offers a large amount of services irrespective of the geographical location to individuals or a group. This opens the way to new security dangers to the protection and also the integrity of the information put away. Public Key Infrastructure mechanism, advanced endorsements, computerized marks are existing techniques to accomplish numerous security prerequisite sites, however late dangers make them powerless against genuine assaults when utilized without earlier trust-point establishments. At the time of open reviewing of the information by Third Party Auditor, it is quite possible that it might trade off in protecting client’s privacy. This outcome in two separate issues which represents the dangers of authentication and additionally the trustworthiness of the information that is being shared. In this paper, we propose a Noble Authentication Protocol with privacy preservation policy cloud that gives solid common verification framework utilizing the Pedersen Commitment scheme alongside using ring signature algorithm calculations that will authenticate the TPA and just give the essential data to checking the trustworthiness of the mutual information with keeping the privacy of the clients covered up. The proposed technique helps in staying away from conceivable hash crashes, approving the chain of trust to certificate authorities and different denial records.
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Adachi, Kouji, Naga Oshima, Sho Ohata, Atsushi Yoshida, Nobuhiro Moteki, and Makoto Koike. "Compositions and mixing states of aerosol particles by aircraft observations in the Arctic springtime, 2018." Atmospheric Chemistry and Physics 21, no. 5 (March 9, 2021): 3607–26. http://dx.doi.org/10.5194/acp-21-3607-2021.
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Abstract. Aerosol particles were collected at various altitudes in the Arctic during the Polar Airborne Measurements and Arctic Regional Climate Model Simulation Project 2018 (PAMARCMiP 2018) conducted in the early spring of 2018. The composition, size, number fraction, and mixing state of individual aerosol particles were analyzed using transmission electron microscopy (TEM), and their sources and transport were evaluated by numerical model simulations. We found that sulfate, sea-salt, mineral-dust, K-bearing, and carbonaceous particles were the major aerosol constituents. Many particles were composed of two or more compositions that had coagulated and were coated with sulfate, organic materials, or both. The number fraction of mineral-dust and sea-salt particles decreased with increasing altitude. The K-bearing particles increased within a biomass burning (BB) plume at altitudes > 3900 m, which originated from Siberia. Chlorine in sea-salt particles was replaced with sulfate at high altitudes. These results suggest that the sources, transport, and aging of Arctic aerosols largely vary depending on the altitude and air-mass history. We also provide the occurrences of solid-particle inclusions (soot, fly-ash, and Fe-aggregate particles), some of which are light-absorbing particles. They were mainly emitted from anthropogenic and biomass burning sources and were embedded within other relatively large host particles. Our TEM measurements revealed the detailed mixing state of individual particles at various altitudes in the Arctic. This information facilitates the accurate evaluation of the aerosol influences on Arctic haze, radiation balance, cloud formation, and snow/ice albedo when deposited.