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1
Konvalina, Ivo, Filip Mika, Stanislav Krátký, Eliška Materna Mikmeková, and Ilona Müllerová. "In-Lens Band-Pass Filter for Secondary Electrons in Ultrahigh Resolution SEM." Materials 12, no. 14 (July 19, 2019): 2307. http://dx.doi.org/10.3390/ma12142307.
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Scanning electron microscopes come equipped with different types of detectors for the collection of signal electrons emitted from samples. In-lens detection systems mostly consist of several auxiliary electrodes that help electrons to travel in a direction towards the detector. This paper aims to show that a through-the-lens detector in a commercial electron microscope Magellan 400 FEG can, under specific conditions, work as an energy band-pass filter of secondary electrons that are excited by the primary beam electrons. The band-pass filter properties verify extensive simulations of secondary and backscattered electrons in a precision 3D model of a microscope. A unique test sample demonstrates the effects of the band-pass filter on final image and contrast with chromium and silver stripes on a silicon substrate, manufactured by a combination of e-beam lithography, wet etching, and lift-off technique. The ray tracing of signal electrons in a detector model predicate that the through-the-lens detector works as a band-pass filter of the secondary electrons with an energy window of about 3 eV. By moving the energy window along the secondary electron energy spectrum curve of the analyzed material, we select the energy of the secondary electrons to be detected. Energy filtration brings a change in contrast in the image as well as displaying details that are not otherwise visible.
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Merli, P. G., and V. Morandi. "Low-Energy STEM of Multilayers and Dopant Profiles." Microscopy and Microanalysis 11, no. 1 (January 28, 2005): 97–104. http://dx.doi.org/10.1017/s1431927605050063.
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A conventional scanning electron microscope equipped with a LaB6 source has been modified to operate in a scanning transmission mode. Two detection strategies have been considered, one based on the direct collection of transmitted electrons, the other on the collection of secondary electrons resulting from the conversion of the transmitted ones. Two types of specimens have been mainly investigated: semiconductor multilayers and dopant profiles in As-implanted Si. The results show that the contrast obeys the rules of mass–thickness contrast whereas the resolution is always defined by the probe size independently of specimen thickness and beam broadening. The detection strategy may affect the bright field (light regions look brighter) or dark field (heavy regions look brighter) appearance of the image. Using a direct collection of the transmitted electrons, the contrast can be deduced from the angular distribution of transmitted electrons and their collection angles. When collecting the secondary electrons to explain the image contrast, it is also necessary to take into account the secondary yield dependence on the incidence angle of the transmitted electrons.
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Nengsih, Erlinda, Aried Eriadi, and Anzharni Fajrina. "Review: Antioxidant Activity Test of Various Types of Mangroves." International Journal of Pharmaceutical Sciences and Medicine 6, no. 8 (August 30, 2021): 32–41. http://dx.doi.org/10.47760/ijpsm.2021.v06i08.003.
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Free radicals are reactive oxygen that have unpaired electrons looking for partners by binding to electron molecules in the vicinity. Free radicals can cause several degenerative diseases such as diabetes, atherosclerosis, Parkinson's disease, Alzheimer's disease. The content of secondary metabolites in mangroves has the potential to prevent various diseases. Several methods commonly used to estimate the presence of antioxidants in plants include DPPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (ferrous reducing antioxidant power), and ABTS (2,2-azinobis-3-ethylbenzothiazole-6-sulfonic acid). The results of recent studies showed that some mangrove plants have antioxidant activity including: Rhyzophora mucronata, Nypa fruticans, Avicennia marina, Sonneratia alba, Acanthus ilicifolius L, Acrostichum aureum dan Scaevola taccada. Mangrove plants that have the highest IC50 value were found in leaves (methanol extract). The antioxidant activity of mangrove plants is caused by the presence of secondary metabolites contained in the extract such as flavonoids, phenolics, saponins, and tannins.
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Savic, Marija, and Marija Radmilovic-Radjenovic. "Gas discharges modeling by Monte Carlo technique." Chemical Industry 64, no. 3 (2010): 171–75. http://dx.doi.org/10.2298/hemind091221022s.
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The basic assumption of the Townsend theory - that ions produce secondary electrons - is valid only in a very narrow range of the reduced electric field E/N. In accordance with the revised Townsend theory that was suggested by Phelps and Petrovic, secondary electrons are produced in collisions of ions, fast neutrals, metastable atoms or photons with the cathode, or in gas phase ionizations by fast neutrals. In this paper we tried to build up a Monte Carlo code that can be used to calculate secondary electron yields for different types of particles. The obtained results are in good agreement with the analytical results of Phelps and. Petrovic [Plasma Sourc. Sci. Technol. 8 (1999) R1].
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Postek, M. T. "Electron detection modes and their relation to linewidth measurement in the Scanning Electron Microscope." Proceedings, annual meeting, Electron Microscopy Society of America 44 (August 1986): 646–49. http://dx.doi.org/10.1017/s0424820100144668.
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The basic premise underlying the use of the scanning electron microscope (SEM) for linewidth measurement for semiconductor research and production applications is that the video image acquired, displayed, and ultimately measured reflects accurately the structure of interest. It should be understood that not all the secondary electrons detected originate at the point of impact with the primary electron beam. Those that do are referred to as Type I electrons. Some of the signal is contributed by re-emergent backscattered electrons creating secondary electrons at the surface of the sample (Type II electrons) and at the final lens polepiece (Type III electrons). Other signal contributions include line-of-sight backscattered electrons and other sources particular to each instrument (Type IV electrons). The effects of these four types of contributions to the actual image or linewidth measurement have not been fully evaluated. In measurement applications, error due to the actual location of signal origination will not affect pitch measurements as the errors cancel. However, in linewidth measurement, the errors are additive and thus give twice the edge detection error to the measured width. The basic intent of this work is to demonstrate the magnitude of these errors relative to the mode of signal detection at a variety of beam acceleration voltages.
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Kohashi, Teruo. "Magnetization Analysis by Spin-Polarized Scanning Electron Microscopy." Scanning 2018 (2018): 1–6. http://dx.doi.org/10.1155/2018/2420747.
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Spin-polarized scanning electron microscopy (spin SEM) is a method for observing magnetic-domain structures by detecting the spin polarization of secondary electrons. It has several unique abilities such as detection of full magnetization orientation and high-spatial-resolution measurement. Several spin-SEM experiments have demonstrated that it is a promising method for studying various types of magnetic materials and devices. This review paper presents several spin-SEM observations to demonstrate the capability and potential of spin SEM.
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Basko, M. M. "Preheating of heavy-ion-beam targets by secondary particles." Laser and Particle Beams 10, no. 1 (March 1992): 189–200. http://dx.doi.org/10.1017/s0263034600004316.
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The contribution of different sorts of secondary particles to the preheating of thermonuclear targets driven by heavy-ion beams is analyzed. Two types of illumination geometry are considered: side-on and face-on locations of the fuel with respect to the ion beam. It is shown that a substantial preheating can be expected from (1) nuclear fission fragments for the face-on fuel position and (2) δ-electrons and low-Z nuclear fragments for the side-on fuel location. All the X-ray and gamma photons of various origin are shown to produce a negligible fuel heating.
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KWEON, MINJUNG. "FIRST LOOK AT BEAUTY AND BEAUTY-JET TAGGING VIA SECONDARY VERTEXING WITH ALICE IN p+p COLLISIONS AT $\sqrt{S} = 7\,\, \rm{TeV}$." International Journal of Modern Physics E 20, no. 07 (July 2011): 1629–34. http://dx.doi.org/10.1142/s0218301311019994.
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The heavy flavour single electron data from RHIC indicate strong coupling of heavy quarks to the medium. The LHC extends greatly the kinematic range to high transverse momentum which enables new tests of heavy quark jet dynamics. Jets containing beauty hadrons have distinctive properties from other types of jets, which enhance their clear identification. We first introduce a method to preferentially select electrons from beauty hadron decay by reconstructing secondary vertices and show the results of this approach on simulated data. A preliminary look at the heavy flavour electron analysis and the beauty analysis in p + p collisions at [Formula: see text] is also presented.
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Joy, David C. "Image modelling for SEM-based metrology." Proceedings, annual meeting, Electron Microscopy Society of America 44 (August 1986): 650–51. http://dx.doi.org/10.1017/s042482010014467x.
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Much of the success of the scanning electron microscope (SEM) can be attributed to the fact that the images that it produces appear similar to those seen by our eyes. Consequently the interpretation of SEM micrographs is perceived as a straightforward process. Although this casual approach works well enough for many qualitative purposes, when the SEM is to be used to make precise dimensional measurements of micron-sized features, such as resist strips or conductor pads, then more care must be paid to the details of image formation.Two types of electron signal, backscattered (BS) and secondary (SE), are usually available in an SEM. In many respects quantitative image interpretation is more straightforward for backscattered than for secondary electrons because Monte Carlo trajectory tracing techniques can be employed to compute the expected variation of signal with beam position.
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Steck, M. "Magnetic micro structure evaluation by means of electron beam measuring techniques." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 4 (August 1990): 762–63. http://dx.doi.org/10.1017/s0424820100176940.
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The trend to micro miniaturization of magnetic devices with structure dimensions in the sub micrometer range at present necessitates more and more test techniques with a high spatial resolution. The electron beam techniques have been proved to be particularly suitable even ensuring high quality and reliability of these devices.In principle, two different types of measurement can be distinguished. In the sample-hitting type, the e-beam hits the sample and interacts with certain magnetic properties of the specimen. Two categories can be divided: reflection mode and transmission mode. In reflection mode, secondary electrons (SE) and back scattered electrons (BSE) are created by the primary beam. These SE change their trajectories due to the magnetic micro field at the specimen’s surface yielding to different signals at the detector. This contrast is very well known as magnetic contrast type 1. Magnetic contrast type 2 uses the change in the BSE-generation volume due the internal magnetization of the sample. A very new and promising technique is secondary electron microscopy with polarization analysis (SEMPA). SEMPA analyses the SE-spin which depends on the direction of magnetization in the magnetic domains. In reflection mode, SEMPA offers the best spatial resolution (sub-0.1 μm) up to now.
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CAZAUX, J. "About the role of the various types of secondary electrons (SE1; SE2; SE3) on the performance of LVSEM." Journal of Microscopy 214, no. 3 (June 2004): 341–47. http://dx.doi.org/10.1111/j.0022-2720.2004.01326.x.
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Shimizu, Ryuichi, and Hideki Yoshikawa. "Monte Carlo Simulation of Background in electron spectroscopies." Proceedings, annual meeting, Electron Microscopy Society of America 50, no. 2 (August 1992): 1664–65. http://dx.doi.org/10.1017/s0424820100132959.
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Recent progress in getting precise knowledge on inelastic scattering, particularly, on dielectric functions for various types of material has been enabling the electron spectroscopic spectra obtained by Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and reflection electron energy loss spectroscopy (REELS) to be reproduced theoretically with considerable success. For this Monte Carlo simulation is probably most powerful tool, leading to more comprehensive understanding of not only the signal generation but also the background formation.In this paper we present a Monte Carlo simulation approach based on the uses of Mott-scattering cross section and appropriate dielectric function for describing elastic scattering and inelastic scatterings, respectively. With respect to the dielectric function one can use, to good approximation in general, the optical dielectric constants from the data base provided by synchrotron radiation facilities.As typical examples of the Monte Carlo simulation the applications to the AES, XPS, and REELS are shown in Figs. 1, 2, and 3, respectively. The N(E)-spectrum in Fig.l demonstrates how the Monte Carlo simulation describes the energy loss spectrum due to plasmon excitation near at primary energy, general shape of energy distributions of backscattered electrons and secondary electrons.
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Chen, Ya, and David Wokosin. "Chromium Coating for High Resolution SEM." Microscopy and Microanalysis 3, S2 (August 1997): 1233–34. http://dx.doi.org/10.1017/s1431927600013052.
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High quality imaging of the macromolecular structure of biological samples can be obtained when combining high resolution SEM with advanced thin metal film coating techniques. A thin layer of fine grain metal film is often necessary to enrich the secondary electron (SE) signal generation and to enhance the contrast of features of interest, because the yield of SE signal from biological samples is low. Secondary electron signals, types SE-I and SE-II, are generated by primary beam at the impact point or by backscattered electrons (BSE) dislocated from the impact point, respectively (Peters, 1982; Joy, 1984). The SE-II signal yield depends on the amount of BSE signal and the collection ratio of SE-I/SE-II components regulates the surface topographic contrast. Therefore, the low atomic number metals with low backscattering coefficients should be considered for high resolution SEM coating. Chromium, which has both the features of low atomic number (Z=24) and sufficient SE signal yield, is an appropriate choice and was first used by Peters (1982) for high resolution SEM imaging.
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Zhang, Yanmei, Gang Xiao, Zhongyang Luo, Mingjiang Ni, Tianfeng Yang, and Weiping Xu. "Comparison of different types of secondary mirrors for solar application." Optik 125, no. 3 (February 2014): 1106–12. http://dx.doi.org/10.1016/j.ijleo.2013.07.113.
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Sarazin, Craig L. "Diffuse radio sources in clusters of galaxies: models and long-wavelength radio observations." Proceedings of the International Astronomical Union 2, no. 14 (August 2006): 369–71. http://dx.doi.org/10.1017/s1743921307011039.
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AbstractClusters of galaxies contain several types of diffuse radio sources with very steep radio spectra which are associated with the cluster environment, including central radio bubbles, cluster radio relics, and cluster radio halos. Radio halos and relics are found only in merging clusters. Cluster radio relics may be produced by particle acceleration in merger shocks, while radio halos, may result from electron re-acceleration by turbulence produced by mergers. Secondary production of electrons and positrons by hadronic interactions also plays a role. If cluster radio halos and relics are related to mergers, then deep low frequency radio surveys could detect 1000's of clusters. Long-wavelength radio observations have a great potential to help us understand clusters and large scale structure, and can provide a diagnostic of cluster mergers, which affect the use of clusters in cosmological and dark energy studies.
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Dieckmann, M. E. "The formation of relativistic plasma structures and their potential role in the generation of cosmic ray electrons." Nonlinear Processes in Geophysics 15, no. 6 (November 3, 2008): 831–46. http://dx.doi.org/10.5194/npg-15-831-2008.
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Abstract. Recent particle-in-cell (PIC) simulation studies have addressed particle acceleration and magnetic field generation in relativistic astrophysical flows by plasma phase space structures. We discuss the astrophysical environments such as the jets of compact objects, and we give an overview of the global PIC simulations of shocks. These reveal several types of phase space structures, which are relevant for the energy dissipation. These structures are typically coupled in shocks, but we choose to consider them here in an isolated form. Three structures are reviewed. (1) Simulations of interpenetrating or colliding plasma clouds can trigger filamentation instabilities, while simulations of thermally anisotropic plasmas observe the Weibel instability. Both transform a spatially uniform plasma into current filaments. These filament structures cause the growth of the magnetic fields. (2) The development of a modified two-stream instability is discussed. It saturates first by the formation of electron phase space holes. The relativistic electron clouds modulate the ion beam and a secondary, spatially localized electrostatic instability grows, which saturates by forming a relativistic ion phase space hole. It accelerates electrons to ultra-relativistic speeds. (3) A simulation is also revised, in which two clouds of an electron-ion plasma collide at the speed 0.9c. The inequal densities of both clouds and a magnetic field that is oblique to the collision velocity vector result in waves with a mixed electrostatic and electromagnetic polarity. The waves give rise to growing corkscrew distributions in the electrons and ions that establish an equipartition between the electron, the ion and the magnetic energy. The filament-, phase space hole- and corkscrew structures are discussed with respect to electron acceleration and magnetic field generation.
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Naderi, Peyman, Malihe Heidary, and Mahdis Vahedi. "Performance analysis of ladder-secondary-linear induction motor with two different secondary types using Magnetic Equivalent Circuit." ISA Transactions 103 (August 2020): 355–65. http://dx.doi.org/10.1016/j.isatra.2020.03.013.
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Chernyi, S. A. "Secondary Resources of Rare Еarth Мetals." Ecology and Industry of Russia 24, no. 9 (September 1, 2020): 44–50. http://dx.doi.org/10.18412/1816-0395-2020-9-44-50.
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The article provides an overview of the main existing methods for recycling rare earth metals from various types of waste. It was noted that the demand for rare-earth metals is increasing annually due to the growth of advanced technologies, mainly in the sectors of electronics, power engineering and photonics. It has been established that in countries producing final products of high processing, the chemical-technological processes of processing goods that have worked out their life cycle, and, first of all, fluorescent lamps, NdFeB magnets from electronic devices, and nickel-metal hydride (NiMeH) batteries containing rare earths are most quickly created. The most profitable and recycling option is the reuse of products containing rare-earth metals, however, such technologies are applicable for a narrow range of waste. Another important area of REM recycling is the processing of industrial waste. For countries with developed mining and chemical industries, mining processing technologies are attractive. It is shown that for Russia, more appropriate are schemes for the disposal of industrial waste, primarily waste from the production of apatite concentrate. The main problems of the development of REM recycling are identified: low content and dispersion of rare earths in waste; the presence of impurities that impede the extraction of valuable components and the toxicity of the used recycling schemes.
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Russ, John C. "Measurements in 3D images." Proceedings, annual meeting, Electron Microscopy Society of America 49 (August 1991): 408–9. http://dx.doi.org/10.1017/s0424820100086349.
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Three-dimensional (3D) images consisting of arrays of voxels can now be routinely obtained from several different types of microscopes. These include both the transmission and emission modes of the confocal scanning laser microscope (but not its most common reflection mode), the secondary ion mass spectrometer, and computed tomography using electrons, X-rays or other signals. Compared to the traditional use of serial sectioning (which includes sequential polishing of hard materials), these newer techniques eliminate difficulties of alignment of slices, and maintain uniform resolution in the depth direction. However, the resolution in the z-direction may be different from that within each image plane, which makes the voxels non-cubic and creates some difficulties for subsequent analysis.
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Harland, Duane, Joy Woods, James Vernon, Richard Walls, David Scobie, Jeff Plowman, Charisa Cornellison, et al. "Like Follicle, like Fibre? Diameter and not Follicle Type Correlates with Fibre Ultrastructure." Key Engineering Materials 671 (November 2015): 88–94. http://dx.doi.org/10.4028/www.scientific.net/kem.671.88.
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The hair follicles of most mammals are of two types, primary and secondary. Primary follicles develop earlier and have a prominent arrectorpili muscle. Secondary follicles have less prominent muscles and are often clumped, sharing a common opening from which fibres emerge. It is not entirely clear what types of follicles occur in human scalps. Partly this is because human hairs have a uniform appearance, unlike many mammals in which robust primary hairs differ markedly from narrow secondary fibres. Some sheep breeds are an exception because like humans, wool fibres have a similar macro-scale appearance irrespective of follicle type. How deep does this similarity go? Using electron microscopy, we examined wool primary fibres from different breeds and contrasted them to secondary fibres. For fibres of similar diameter, there was no significant difference in the ultrastructure or proportion and distribution of cortex cell types in primary and secondary fibres. We conclude that fibre diameter is the most important fibre parameter with respect to structural differences between fibres, not whether the fibres originate from primary or secondary follicles.
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Xu, Shun, Mingyu Gong, Yanyao Jiang, Christophe Schuman, Jean-Sébastien Lecomte, and Jian Wang. "Secondary twin variant selection in four types of double twins in titanium." Acta Materialia 152 (June 2018): 58–76. http://dx.doi.org/10.1016/j.actamat.2018.03.068.
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Jung, Donghwan, Jiyoung Song, Jeasoo Kim, and Jaehyuk Lee. "Comparative Experimental Investigation on Optimal Parametric Array Types." Sensors 21, no. 15 (July 27, 2021): 5085. http://dx.doi.org/10.3390/s21155085.
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As a sound transmitting device that relies on the nonlinearity of a medium, a parametric array (PA) can generate high-directivity low-frequency signals using a small aperture transducer and high-frequency signals. Despite their relatively low source level, the PA is frequently used to measure the acoustic properties of materials in low-frequency regions owing to their high directivity in confined acoustic water tanks. Therefore, methods for improving the source level of secondary signals are of interest. Currently, there are two driving methods for PA: the dual-frequency PA and the broadband PA with amplitude modulation. In this study, we share the results of an elaborate and comparative experimental investigation of these two driving methods. Comparisons are made and discussed in terms of the intensity of the generated secondary signal and its characteristics in the frequency domain. Based on these factors, we confirmed that the broadband PA was more suitable as the sound source of the low-frequency characteristic measurement system of acoustic materials.
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Klemettinen, Lassi, Katri Avarmaa, Hugh O’Brien, Pekka Taskinen, and Ari Jokilaakso. "Behavior of Tin and Antimony in Secondary Copper Smelting Process." Minerals 9, no. 1 (January 12, 2019): 39. http://dx.doi.org/10.3390/min9010039.
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Different types of metal-bearing wastes, such as WEEE (Waste Electrical and Electronic Equipment), are important urban minerals in modern society, and the efficient recycling and reuse of their metal values is of key interest. Pyrometallurgical copper smelting is one of the most prominent ways of treating WEEE, however, more accurate experimental data is needed regarding the behavior of different elements during each process stage. This article investigates the behavior of tin and antimony, both commonly present as trace elements in electrical and electronic waste, in secondary (i.e., sulfur-free) copper smelting conditions. The experiments were conducted in oxygen partial pressure range of 10−10–10−5 atm, covering the different process steps in copper smelting. The basis of the equilibrium system was metallic copper–iron silicate slag, with the addition of alumina and potassium oxide to account for the presence of these compounds in the actual industrial process. The results showed that the distribution coefficients of both trace metals, LCu/slag = [wt % Me]copper/(wt % Me)slag, increased significantly as a function of decreasing oxygen pressure, and the addition of basic potassium oxide also had an increasing effect on the distribution coefficient. A brief comparison between EPMA and LA-ICP-MS (electron probe microanalysis and laser ablation–inductively coupled plasma–mass spectrometry), the two in situ analytical techniques used, was also presented and discussed.
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Dal, H. A. "The flare cumulative frequencies of UV Ceti stars from different spectral types." Monthly Notices of the Royal Astronomical Society 495, no. 4 (June 3, 2020): 4529–41. http://dx.doi.org/10.1093/mnras/staa1484.
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ABSTRACT In this study, as a result of the photometric observations continued on nine UV Ceti type stars, examining the parameters obtained from the models of distributions of the flare equivalent durations in the logarithmic scale versus flare total durations, it is found that the highest flare equivalent durations occurring on the stars (Plateau values) are varying with the B − V colour indexes of those stars in agreement with the variations of both the magnetic field strength (B) of the magnetic loop and especially the electron density of its plasma (ne). The distributions of flare cumulative frequencies were derived by using the flare equivalent durations, instead of the flare energy. The main result of this study is a secondary variation, which can be just modelled with the damping sine waves, behind the main exponential variation of the flare cumulative frequency. The models indicate that this secondary variation in the flare cumulative frequency distributions is in the same shape with the periodic or quasi-periodic oscillations detected in the light curves of the stellar and solar flares. This caused to ask new questions about the flare mechanism working on stellar atmospheres.
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Hauska, G. "Phylloquinone in photosystem I: are quinones the secondary electron acceptors in all types of photosynthetic reaction centers?" Trends in Biochemical Sciences 13, no. 11 (November 1988): 415–16. http://dx.doi.org/10.1016/0968-0004(88)90206-x.
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Hutchinson, W. Bevis. "Origin of Goss Texture during Secondary Recrystallisation in Silicon-Steel." Materials Science Forum 715-716 (April 2012): 73–80. http://dx.doi.org/10.4028/www.scientific.net/msf.715-716.73.
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Primary recrystallised sheets of 3% silicon steel from two different industrial processing routes have been examined after laboratory annealing to initiate secondary recrystallisation. Metallography included etching to reveal individual dislocations and sub-boundaries as well as EBSD in scanning electron microscopy. Residual low angle boundaries are not normally observed inside the secondary grains. The growth of secondaries appears to occur in a jerky manner, associated with local intrusions into the primary matrix that destabilise the interface. The frequency of occurrence of special low energy grain boundaries such as 9 and 5 is believed to dictate the selectivity of the Goss orientation in both types of steel sheet.
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Fukatsu, Takema, Naruo Nikoh, Rena Kawai, and Ryuichi Koga. "The Secondary Endosymbiotic Bacterium of the Pea Aphid Acyrthosiphon pisum (Insecta: Homoptera)." Applied and Environmental Microbiology 66, no. 7 (July 1, 2000): 2748–58. http://dx.doi.org/10.1128/aem.66.7.2748-2758.2000.
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ABSTRACT The secondary intracellular symbiotic bacterium (S-symbiont) of the pea aphid Acyrthosiphon pisum was investigated to determine its prevalence among strains, its phylogenetic position, its localization in the host insect, its ultrastructure, and the cytology of the endosymbiotic system. A total of 14 aphid strains were examined, and the S-symbiont was detected in 4 Japanese strains by diagnostic PCR. Two types of eubacterial 16S ribosomal DNA sequences were identified in disymbiotic strains; one of these types was obtained from the primary symbiont Buchnera sp., and the other was obtained from the S-symbiont. In situ hybridization and electron microscopy revealed that the S-symbiont was localized not only in the sheath cells but also in a novel type of cells, the secondary mycetocytes (S-mycetocytes), which have not been found previously inA. pisum. The size and shape of the S-symbiont cells were different when we compared the symbionts in the sheath cells and the symbionts in the S-mycetocytes, indicating that the S-symbiont is pleomorphic under different endosymbiotic conditions. Light microscopy, electron microscopy, and diagnostic PCR revealed unequivocally that the hemocoel is also a normal location for the S-symbiont. Occasional disordered localization of S-symbionts was also observed in adult aphids, suggesting that there has been imperfect host-symbiont coadaptation over the short history of coevolution of these organisms.
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Ohtani, Jun. "Sem Observations on Trabeculae in Abies Sachalinensis." IAWA Journal 6, no. 1 (1985): 43–51. http://dx.doi.org/10.1163/22941932-90000909.
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The morphology of normal and abnormal trabeculae were observed in the secondary xylem of Abies sachalinensis using scanning electron microscopy. Both the usual types of trabeculae and the various abnormalities observed are described and illustrated.
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Bondarenko, G. G., M. R. Fisher, V. I. Kristya, and P. Żukowski. "Modeling of an Impact of Thin Insulating Film on the Electrode Surface on Discharge Ignition in Mercury Illuminating Lamps at Low Ambient Temperatures." Devices and Methods of Measurements 10, no. 1 (March 15, 2019): 7–13. http://dx.doi.org/10.21122/2220-9506-2019-10-1-7-13.
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The mixture of argon and mercury vapor with temperature-dependent composition is used as the background gas in different types of gas discharge illuminating lamps. The aim of this work was to develop a model of the low-current discharge in an argon-mercury mixture at presence of a thin insulating film on the cathode and to investigate the influence of film on the discharge ignition voltage at low ambient temperatures. When discharge modeling, we used the obtained earlier expression which describes dependence of the mixture ionization coefficient on temperature. When there was a thin insulating film on the cathode the model took into account that positive charges are accumulated on its surface during the discharge. They generate an electric field in the film sufficient for the field emission of electrons from the metal substrate of the electrode into the insulator and some of them can overcome the potential barrier at the film outer boundary and go out in the discharge volume improving emission characteristics of the cathode.Calculations showed that at a temperature decrease the electric field strengthes in the discharge gap and the voltage in it are increased due to reduction of the saturated mercury vapor density in the mixture followed by the decrease of its ionization coefficient. Existence of a thin insulating film on the cathode surface results in an increase of the cathode effective secondary electron emission yield which compensates the reduction of the mixture ionization coefficient value.The results of discharge characteristics modeling demonstrate that in case of the cathode with an insulating film the discharge ignition becomes possible at a lower inter-electrode voltage. This ensures outdoor mercury lamp turning on at a reduced supply voltage and increases its reliability under low ambient temperatures.
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Kurochkin, V. D., and O. M. Romanenko. "GDMS Analysis Of Calcium Carbonate Naturaly Doped By REE, Phospates And Other Impurities." Methods and Objects of Chemical Analysis 14, no. 2 (2019): 91–101. http://dx.doi.org/10.17721/moca.2019.91-101.
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A mathematical model was developed for calculation of types and intensities of molecular interferences and simulation of mass-spectra at GDMS analysis of non-conducting samples with the use of a secondary cathode. An improved design of the cell with Ta-secondary cathode were suggested enhancing the matrix to tantalum ion current ratio and sensitivity of the analysis in ca. 1.5 orders of magnitude. The model have been used for interpretation of complicate mass-spectra of calcium carbonate naturally doped with REE, phosphates and other impurities. Comparison calculated and experimental mass-spectra of VG9000 instrument demonstrates good agreement and allows select the most suitable isotopes and rejecting wrong molecular peaks. It have been shown that electrons in glow discharge plasma have different temperatures in different zones that reveals itself as separate Boltzmann populations of ionization levels for molecules, metal atoms and argon atoms/ions. Calcium carbonate is widely used for many application including as precursor for nano-hydroxyapatite synthesis. Calcium carbonate was precipitated from natural mine waters and was used as model object having high number of various impurities allowing to investigate the impact of complicate molecular ions, determine necessary resolving power of the GD-instruments to meet required detection limit.
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Chaus, Alexander S., and F. I. Rudnickii. "Diffusion and Secondary Carbide Precipitation in High-Speed Steels." Defect and Diffusion Forum 297-301 (April 2010): 1071–76. http://dx.doi.org/10.4028/www.scientific.net/ddf.297-301.1071.
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Besides primary carbides, so-called secondary carbides are usually observed in high-speed steel (HSS) microstructure, which precipitate from the oversaturated solid solution upon its cooling. Some of the secondary carbides precipitate from an oversaturated austenite at cooling during solidification or quenching, in both cases, in the form of the relatively big particles in the bulk of a matrix. Considerably finer secondary carbides precipitate in martensitic condition during tempering inducing secondary hardening in HSSs. In general, secondary carbides of both types have obvious effect on the fracture mode of HSSs. The precipitation of secondary carbides in HSSs in solidified and heat-treated conditions has been investigated. The microstructures of HSSs have been examined using light and electron microscopy (both scanning and transmission), X-ray diffraction analysis, and energy dispersive X-ray spectrometry. Results indicate that diffusion of both carbon and alloying elements plays an important role in the secondary carbide precipitation in HSSs.
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Buck, E. C., N. L. Dietz, and J. K. Bates. "Analysis of reacted nuclear-waste glass using electron beams." Proceedings, annual meeting, Electron Microscopy Society of America 52 (1994): 656–57. http://dx.doi.org/10.1017/s0424820100171018.
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When waste glass reacts with water, secondary phases may form, which will effect the distribution of radionuclides formally contained within the glass. In order to determine the long term behavior of waste glass, the secondary phases formed need to be identified. Analytical electron microscopy (AEM) is being used to characterize the secondary phases. Glasses have been reacted in test vessels at different surface areas to leachate volumes (S/V) and for periods in excess of 700 days. Increasing the S/V permits one to accelerate the reaction. Samples of the reacted waste forms are embedded in epoxy and thin sectioned by ultramicrotomy for observation in the transmission electron microscopy (TEM). Examinations were performed in a JEOL 2000FXII TEM operated at 200 kV. This abstract describes two types of glass tests, a high level waste sludge based glass and a low level waste glassy slag. Many hundreds of glass tests have been performed and examined by TEM to determine layer thickness, morphology of the leach layer, and identification of secondary phases.
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Kim, Yang-Soo, and Soon-Ki Jeong. "Atomic Force Microscopy for Understanding Solvent Cointercalation into Graphite Electrode in Lithium Secondary Batteries." Journal of Spectroscopy 2015 (2015): 1–6. http://dx.doi.org/10.1155/2015/462140.
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The electrochemical processes occurring at the surface of a highly ordered pyrolytic graphite (HOPG) electrode were investigated byin situatomic force microscopy (AFM) to understand the solvent cointercalation involved in the formation of a surface film. AFM images were recorded under the conditions that AFM probe does not affect the electrode reaction. The AFM images show the morphological changes occurring at the electrode surface, indicating that two different types of reactions occurred in the film formation at the surface of the electrode. The formation of a blister structure was observed on the graphite surface, because of the decomposition of solvated lithium ions produced in the electrolyte solution and intercalation between the graphite layer and particulate materials. The solvent cointercalation reaction leading to the blister structure was more pronounced for the HOPG electrode with a higher value of mosaic spread.
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Chen, Guo Min, Quan Wen Liu, Min Quan Xia, and Xiang Sheng Bao. "Reservoir Physical Property and Controlling Factors for the Lower Youshashan Formation in Youshashan-Dawusi Area, Southwestern Qaidam Basin." Applied Mechanics and Materials 675-677 (October 2014): 1363–67. http://dx.doi.org/10.4028/www.scientific.net/amm.675-677.1363.
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The core data, casting thin sections and scanning electron microscopy are used to study the clastic reservoir characteristics and controlling factors of reservoir growth. It indicated that the main reservoir rock types are lithic arkose, Feld spathic sandstone, and a small amount of feldspar lithic sandstone, and with compositional maturity and low to middle structural maturity. Moreover, the primary reservoir space types are mainly intergranular pores, secondary are secondary pores, and reservoir types belong to the medium-high porosity and permeability, and the average porosity and permeability of lower Youshashan formation are 17.70% and 112.5×10-3μm2 separately. Furthermore, the reservoir body is mainly sand body result from deposits of distributary channel and mouth bar of which belong to the braided delta front, and the planar physical property tends to be better reservoir to worse reservoir from northwest to southeast. Finally, mainly factors to control the distribution of reservoir physical property, are the sedimentary environment and lithology, were worked out.
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Wang, Pei, Katarzyna Kulp, and Michael Bron. "Hierarchically structured 3D carbon nanotube electrodes for electrocatalytic applications." Beilstein Journal of Nanotechnology 10 (July 24, 2019): 1475–87. http://dx.doi.org/10.3762/bjnano.10.146.
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Hierarchically structured 3-dimensional electrodes based on branched carbon nanotubes (CNTs) are prepared on a glassy carbon (GC) substrate in a sequence of electrodeposition and chemical vapor deposition (CVD) steps as follows: Primary CNTs are grown over electrodeposited iron by CVD followed by a second Fe deposition and finally the CVD growth of secondary CNTs. The prepared 3-dimensional CNT structures (CNT/CNT/GC) exhibit enhanced double-layer capacitance and thus larger surface area compared to CNT/GC. Pt electrodeposition onto both types of electrodes yields a uniform and homogeneous Pt nanoparticle distribution. Each preparation step is followed by scanning electron microscopy, while the CNTs were additionally characterized by Raman spectroscopy. In this way it is demonstrated that by varying the parameters during the electrodeposition and CVD steps, a tuning of the structural parameters of the hierarchical electrodes is possible. The suitability of the hierarchical electrodes for electrocatalytic applications is demonstrated using the methanol electro-oxidation as a test reaction. The Pt mass specific activity towards methanol oxidation of Pt-CNT/CNT/GC is approximately 2.5 times higher than that of Pt-CNT/GC, and the hierarchical electrode exhibits a more negative onset potential. Both structures demonstrate an exceptionally high poisoning tolerance.
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Yorukoglu, Sinan, Fuad Nasibov, Mehmet Mungan, and Mustafa Bagriyanik. "The Effect of the Types of Network Topologies on Nontechnical Losses in Secondary Electricity Distribution Systems." IEEE Transactions on Industry Applications 52, no. 5 (September 2016): 3631–43. http://dx.doi.org/10.1109/tia.2016.2582820.
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Takesaki, Naomi Andreia, Marcelo Conrado dos Reis, Maria Luisa Ferreira de Miranda, and Emílio Carlos Elias Baracat. "Hemorrhagic shock secondary to button battery ingestion." Sao Paulo Medical Journal 132, no. 3 (2014): 184–88. http://dx.doi.org/10.1590/1516-3180.2014.1323697.
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CONTEXT:Button battery ingestion is a frequent pediatric complaint. The serious complications resulting from accidental ingestion have increased significantly over the last two decades due to easy access to gadgets and electronic toys. Over recent years, the increasing use of lithium batteries of diameter 20 mm has brought new challenges, because these are more detrimental to the mucosa, compared with other types, with high morbidity and mortality. The clinical complaints, which are often nonspecific, may lead to delayed diagnosis, thereby increasing the risk of severe complications.CASE REPORT:A five-year-old boy who had been complaining of abdominal pain for ten days, was brought to the emergency service with a clinical condition of hematemesis that started two hours earlier. On admission, he presented pallor, tachycardia and hypotension. A plain abdominal x-ray produced an image suggestive of a button battery. Digestive endoscopy showed a deep ulcerated lesion in the esophagus without active bleeding. After this procedure, the patient presented profuse hematemesis and severe hypotension, followed by cardiorespiratory arrest, which was reversed. He then underwent emergency exploratory laparotomy and presented a new episode of cardiorespiratory arrest, which he did not survive. The battery was removed through rectal exploration.CONCLUSION:This case describes a fatal evolution of button battery ingestion with late diagnosis and severe associated injury of the digestive mucosa. A high level of clinical suspicion is essential for preventing this evolution. Preventive strategies are required, as well as health education, with warnings to parents, caregivers and healthcare professionals.
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Koutsoukis, T., Abdelkrim Redjaïmia, and G. Fourlaris. "Characterization of Precipitation Sequences in Superaustenitic Stainless Steels." Solid State Phenomena 172-174 (June 2011): 493–98. http://dx.doi.org/10.4028/www.scientific.net/ssp.172-174.493.
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Superaustenitic stainless steels exhibit excellent corrosion resistance, at a wide variety of exposure temperatures, especially in chloride containing environments, coupled with desirable mechanical properties. Previous studies have shown that these steels are prone to precipitation of secondary phases, such as sigma phase (σ), chi phase (χ), Laves-phase, carbides, nitrides or secondary austenite, when exposed at elevated temperatures, directly affecting their mechanical properties and corrosion behaviour. A detailed study of the effect of isothermal ageing on the microstructure of S32654 (Fe-24Cr-21Ni-7Mo-0.5N-0.013C) and S31254 (Fe-20Cr-18Ni-6Mo-0.2N-0.012C) superaustenitic stainless steels was carried out. Samples were aged within the temperature range of 650οC to 950οC for times up to 3000 h. Following ageing, precipitation of secondary phases was clearly observed with precipitates varying in volume fraction, size, shape and spatial distribution. Several secondary phases were identified via transmission electron microscopy (TEM) and electron diffraction (ED). The orientation relationships between the austenitic matrix and the secondary phases were identified. Interaction and also phase transformation among different types of precipitates, such as between precipitates and the austenitic matrix were observed and an attempt of understanding these phase transformations was carried out.
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Běhalová, Hana, Bohuslava Tremlová, Ludmila Kalčáková, Matej Pospiech, and Dani Dordevic. "Assessment of the Effect of Secondary Fixation on the Structure of Meat Products Prepared for Scanning Electron Microscopy." Foods 9, no. 4 (April 13, 2020): 487. http://dx.doi.org/10.3390/foods9040487.
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The aim of the research was to verify the necessity of secondary fixation with osmium tetroxide in various types of meat products and evaluation of structural changes of products using different fixation procedures. The material for the study consisted of 11 types of meat products that were analyzed using a scanning electron microscope (SEM) with two different methods of chemical fixation. The first method included the usual processing of biological samples: glutaraldehyde primary fixation, the use of a buffer, secondary fixation by osmium tetroxide (OsO4), buffer, and dehydration using ethanol of increasing concentrations. The second method comprised the glutaraldehyde primary fixation and dehydration using the ethanol of increasing concentrations only. The results unambiguously suggest that the main difference between these methods is in fixation and visibility of fat. Our analysis principally suggests that fixation of the product with OsO4 allows the tracking of all components (fat droplets, muscle fibers, connective tissue) in meat products. At the same time, our results also support the possibility that the secondary fixation can be skipped during the analysis, where the main objection is an observation of lipid-free structures of the meat products (e.g., connection between muscle and starches or spices) or meat products with an insignificant amount of fat.
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Son, Jiyoung, Edgar C. Buck, Shawn L. Riechers, and Xiao-Ying Yu. "Stamping Nanoparticles onto the Electrode for Rapid Electrochemical Analysis in Microfluidics." Micromachines 12, no. 1 (January 6, 2021): 60. http://dx.doi.org/10.3390/mi12010060.
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Electrochemical analysis is an efficient way to study various materials. However, nanoparticles are challenging due to the difficulty in fabricating a uniform electrode containing nanoparticles. We developed novel approaches to incorporate nanoparticles as a working electrode (WE) in a three-electrode microfluidic electrochemical cell. Specifically, conductive epoxy was used as a medium for direct application of nanoparticles onto the electrode surface. Three approaches in this work were illustrated, including sequence stamping, mix stamping, and droplet stamping. Shadow masking was used to form the conductive structure in the WE surface on a thin silicon nitride (SiN) membrane. Two types of nanomaterials, namely cerium oxide (CeO2) and graphite, were chosen as representative nanoparticles. The as-fabricated electrodes with attached particles were characterized using atomic force microscopy (AFM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Electrochemical analysis was performed to verify the feasibility of these nanoparticles as electrodes. Nanomaterials can be quickly assessed for their electrochemical properties using these new electrode fabrication methods in a microfluidic cell, offering a passport for rapid nanomaterial electrochemical analysis in the future.
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Hassan, Mennaallah, Masao Nakayama, Mohammed Salah, Hiroaki Akasaka, Hikaru Kubota, Makiko Nakahana, Tatsuichiro Tagawa, et al. "A Comparative Assessment of Mechanisms and Effectiveness of Radiosensitization by Titanium Peroxide and Gold Nanoparticles." Nanomaterials 10, no. 6 (June 7, 2020): 1125. http://dx.doi.org/10.3390/nano10061125.
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The development of potentially safe radiosensitizing agents is essential to enhance the treatment outcomes of radioresistant cancers. The titanium peroxide nanoparticle (TiOxNP) was originally produced using the titanium dioxide nanoparticle, and it showed excellent reactive oxygen species (ROS) generation in response to ionizing radiation. Surface coating the TiOxNPs with polyacrylic acid (PAA) showed low toxicity to the living body and excellent radiosensitizing effect on cancer cells. Herein, we evaluated the mechanism of radiosensitization by PAA-TiOxNPs in comparison with gold nanoparticles (AuNPs) which represent high-atomic-number nanoparticles that show a radiosensitizing effect through the emission of secondary electrons. The anticancer effects of both nanoparticles were compared by induction of apoptosis, colony-forming assay, and the inhibition of tumor growth. PAA-TiOxNPs showed a significantly more radiosensitizing effect than that of AuNPs. A comparison of the types and amounts of ROS generated showed that hydrogen peroxide generation by PAA-TiOxNPs was the major factor that contributed to the nanoparticle radiosensitization. Importantly, PAA-TiOxNPs were generally nontoxic to healthy mice and caused no histological abnormalities in the liver, kidney, lung, and heart tissues.
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Hunniford, C. Adam, Robert W. McCullough, R. Jeremy H. Davies, and David J. Timson. "DNA damage by low-energy ions." Biochemical Society Transactions 37, no. 4 (July 22, 2009): 893–96. http://dx.doi.org/10.1042/bst0370893.
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Ion-beam irradiation provides a promising treatment for some types of cancer. This promise is due mainly to the selective deposition of energy into a relatively small volume (the Bragg peak), thus reducing damage to healthy tissue. Recent observations that electrons with energies below the ionization potential of DNA can cause covalent damage to the bases and backbone have led to investigations into the ability of low-energy (<1 keV·Da−1) ion beams to damage double-stranded DNA. It has been clearly demonstrated that these low-energy ions induce a mixture of single- and double-strand breaks to dried DNA in vacuo. These effects depend upon the number of ions incident upon the DNA, the kinetic energy of the ions and on their charge state. This DNA damage may be important, as all radiotherapies will result in the production of low-energy secondary ions as radiation passes through tissues. Currently, their effects are neglected in treatment planning, and thus more work is required to quantify and understand DNA damage by low-energy ions.
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Wang, M., Y. Lu, B. Pang, Z. T. Kloenne, H. L. Fraser, Y. L. Chiu, and M. H. Loretto. "Origins and importance of fine secondary α in slowly cooled Ti6Al4V." MATEC Web of Conferences 321 (2020): 12042. http://dx.doi.org/10.1051/matecconf/202032112042.
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It has been known for sometime that slowly cooled Ti6Al4V (Ti64) contains only about 10vol% of β and that this β takes three different forms. Firstly, there are thin volumes of interfacial β, between the grains of α, which are clearly the remains of the β present at high temperatures left when α replaces the β present at high temperatures, by diffusion and boundary migration. Secondly, there are regions of roughly equiaxed β at triple points, but some of this β contains very fine secondary α, whereas the other grains are retained β. Analytical transmission electron microscopy has been used in an attempt to understand the origin of these two different types of equiaxed β grains. It has been found that grains, which are retained β contain about 20wt%V, but the β grains that contain secondary α originate from parent β grains that have only about 14wt%V. The origin and the significance of these observations will be discussed in the presentation.
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Murovec, Jana, Kazimir Drašlar, and Borut Bohanec. "Detailed analysis of Cucurbita pepo seed coat types and structures with scanning electron microscopy." Botany 90, no. 11 (November 2012): 1161–69. http://dx.doi.org/10.1139/b2012-088.
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Discovery of a mutant thin-coated seed phenotype at the end of the 19th century facilitated pumpkin (Cucurbita pepo L.) seed oil production and increased botanic interest in seed coat types and their structures. The main seed coat characteristics were usually analyzed by light and fluorescent microscopy, and more recently, seed coat traits have also been mapped on a C. pepo gene map. The aim of our research was to collect and describe various pumpkin seed types and to analyze, using scanning electron microscopy (SEM), the detailed structure of their seed coats. Seeds of 29 cultivars and landraces were collected and visually evaluated based on seed coat characteristics. Seed samples belonging to different seed types discovered in our collection were transversely sectioned and analyzed by SEM. Twelve seed types were determined, and SEM analysis revealed high variability in their seed coat structures. Using SEM, tissue and cell structures were clearly visible, and novel details of cell and tissue topography were documented. Hypodermal and aerenchyma cells in wild-type seed coats showed fibrous or reticulate secondary cell wall thickening, respectively. In mutant seed types, an absence of different seed coat layers was clearly noted, while the remaining layers were distinctly pronounced. A new completely hull-less seed type was described for the first time. Description of the variability of seed coats in pumpkin was complemented by novel seed coat types, and their structures were analyzed in detail the first time by SEM.
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Schmidt, Marek E., Shinichi Ogawa, and Hiroshi Mizuta. "Contrast Differences Between Nitrogen and Helium Ion Induced Secondary Electron Images Beyond Instrument Effects." MRS Advances 3, no. 10 (2018): 505–10. http://dx.doi.org/10.1557/adv.2018.33.
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ABSTRACTThe gas field ion source (GFIS) is able to generate tightly focused ion beams, which can be used to image or modify a specimen. Among the beam species, helium offers extremely high resolution, however, low sputter yield and sub-surface bubble formation are limiting factors in some applications. Therefore, heavier ions such as neon or nitrogen are used as well. In addition to being a suitable choice for lithographic mask editing, secondary electron (SE) generation by nitrogen beams has been recently shown to be affected by certain types of samples, providing additional contrast compared to helium ions. Here, we report our progress on the study of SE imaging differences between the nitrogen ion microscopy (N2IM) and helium ion microscopy (HIM). SE images of two nano-patterned samples comprising insulator, metal and carbon regions have been imaged by nitrogen and helium ions in two fundamentally different GFIS microscopes. The results corroborate previous reports of significant contrast differences in certain samples caused by the different ion species.
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Marin, Marija, Lia Ascensao, and Branislava Lakusic. "Trichomes of Satureja horvatii Silic (Lamiaceae): Micromorphology and histochemistry." Archives of Biological Sciences 64, no. 3 (2012): 995–1000. http://dx.doi.org/10.2298/abs1203995m.
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Considering the importance of Satureja horvatii Silic as an endemic plant, and due to the essential oils produced in its glandular trichomes, we have done a comprehensive study of the micromorphology and a histochemical analysis of the plant?s glandular trichomes. This investigation was carried out using light microscopy and scanning electron microscopy. Non-glandular unbranched and three types of glandular trichomes on the leaf surface - peltate, capitate and digitiform - were investigated. The results of histochemical tests showed a positive reaction to polysaccharides, proteins, pectins, lipids and to some secondary compounds such as terpenes, tannins and phenols in different types of glandular trichomes.
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Park, Go Eun, Ki Woo Kim, Don Koo Lee, and Jung Oh Hyun. "Adaptive Phenotypic Plasticity of Siberian Elm in Response to Drought Stress: Increased Stomatal Pore Depth." Microscopy and Microanalysis 19, S5 (August 2013): 178–81. http://dx.doi.org/10.1017/s1431927613012610.
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AbstractLeaf stomatal characteristics of Siberian elm (Ulmus pumila) were investigated by electron microscopy and white light scanning interferometry. On the basis of average annual precipitations, two types of tree specimens were collected from Korea, China, and Mongolia: (1) trees under normal environmental conditions and (2) trees under arid conditions. Field emission scanning electron microscopy revealed oval-shaped stomata on the lower surface, and they were ca. 20 μm in width. In-lens secondary electron imaging showed differences in electron density and stomatal pore depth between the two types. According to the line profile analysis by white light scanning interferometry, stomata under arid conditions appeared to have higher levels of the stomatal pore depth than ones under normal conditions. Focused ion beam–field emission electron microscopy supported the increased stomatal pore depth with the increasing drought stress gradient. These results suggest that complementary microscopy can be employed to unravel the adaptive phenotypic plasticity of Siberian elm in response to drought stress.
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Cristian, Roxana E., Israa J. Mohammad, Maria Mernea, Beatrice G. Sbarcea, Bogdan Trica, Miruna S. Stan, and Anca Dinischiotu. "Analyzing the Interaction between Two Different Types of Nanoparticles and Serum Albumin." Materials 12, no. 19 (September 28, 2019): 3183. http://dx.doi.org/10.3390/ma12193183.
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Two different types of nanoparticles (silicon dioxide and titanium dioxide) were selected within this study in order to analyze the interaction with bovine and human serum albumin. These particles were characterized by transmission and scanning electron microscopy (TEM and SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDXS). In addition, the hydrodynamic size and the zeta potential were measured for all these nanoparticles. The serum proteins were incubated with the nanoparticles for up to one hour, and the albumin adsorption on the particle surface was investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The effect induced on the secondary structure of proteins was analyzed by Fourier transform infrared spectroscopy (FTIR). The results showed that albumin adsorbed on the surface of both types of nanoparticles, but in different quantities. In addition, we noticed different changes in the structure of albumin depending on the physicochemical properties of each type of particle tested. In conclusion, our study provides a comparative analysis between the different characteristics of nanoparticles and the protein corona formed on the particle surface and effects induced on protein structure in order to direct the development of “safe-by-design” nanoparticles, as their demands for research and applications continue to increase.
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Tobin-Schnittger, Patrick, Jane O’Doherty, Ray O’Connor, and Andrew O’Regan. "Improving quality of referral letters from primary to secondary care: a literature review and discussion paper." Primary Health Care Research & Development 19, no. 03 (December 7, 2017): 211–22. http://dx.doi.org/10.1017/s1463423617000755.
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BackgroundReferral letters sent from primary to secondary or tertiary care are a crucial element in the continuity of patient information transfer. Internationally, the need for improvement in this area has been recognised. This aim of this study is to review the current literature pertaining to interventions that are designed to improve referral letter quality.MethodsA search strategy designed following a Problem, Intervention, Comparator, Outcome model was used to explore the PubMed and EMBASE databases for relevant literature. Inclusion and exclusion criteria were established and bibliographies were screened for relevant resources.ResultsA total of 18 publications were included in this study. Four types of interventions were described: electronic referrals were shown to have several advantages over paper referrals but were also found to impose new barriers; peer feedback increases letter quality and can decrease ‘inappropriate referrals’ by up to 50%; templates increase documentation and awareness of risk factors; mixed interventions combining different intervention types provide tangible improvements in content and appropriateness.ConclusionSeveral methodological considerations were identified in the studies reviewed but our analysis demonstrates that a combination of interventions, introduced as part of a joint package and involving peer feedback can improve.
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Gauvin, Raynald. "What Remains to Be Done to Allow Quantitative X-Ray Microanalysis Performed with EDS to Become a True Characterization Technique?" Microscopy and Microanalysis 18, no. 5 (October 2012): 915–40. http://dx.doi.org/10.1017/s1431927612001468.
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AbstractThis article reviews different methods used to perform quantitative X-ray microanalysis in the electron microscope and also demonstrates the urgency of measuring the fundamental parameters of X-ray generation for the development of accurate standardless quantitative methods. Using ratios of characteristic lines acquired on the same X-ray spectrum, it is shown that the Cliff and LorimerKA-Bfactor can be used in a general correction method that is appropriate for all types of specimens and electron microscopes, providing that appropriate corrections are made for X-ray absorption, fluorescence, and indirect generation. Since the fundamental parameters appear in theKA-Bfactor, only the ratio of the ionization cross sections needs to be known, not their absolute values. In this regard, the measurement of ratios of theKA-Bfactor (or intensities at different beam energies of the same material with no change of beam spreading in the material) permits the validation for the best models to compute the ratio of ionization cross sections. It is shown, using this method, that the nonrelativistic Bethe equation, to compute ionization cross section, is very close to the equation of E. Casnati et al. (J Phys B15, 155–167, 1982) and also to the equations proposed by D. Bote and F. Salvat (Phys Rev A77, 042701, 2008) for the computation of the ratio of ionization cross sections. The method is extended to show that it could be used to determine the values of the Coster-Kronig transitions factors, an important fundamental parameter for the generation of L and M lines that is mostly known with poor accuracy. The detector efficiency can be measured with specimens where their intensities were measured with an energy dispersive spectrometer detector, the efficiency of which has been measured in an X-ray synchrotron (M. Alvisi et al.,Microsc Microanal12, 406–415, 2006). The spatial resolution should always be computed when performing quantitative X-ray microanalysis and the equations of R. Gauvin (Microsc Microanal13(5), 354–357, 2007) for bulk materials and the one presented in this article for thin films should be used. The effects of X-rays generated by fast secondary electrons and by Auger electrons are reviewed, and their effect can be detrimental for the spatial resolution of materials involving low-energy X-ray lines, in certain specific conditions. Finally, quantitative X-ray microanalysis of heterogeneous materials is briefly reviewed.