Journal articles: 'Ledge mechanism'

1

Huang, Yunhao, Jincheng Wang, Zhijun Wang, and Junjie Li. "One-dimensional ledges and migration mechanism of incoherent interphase boundaries." Journal of Applied Crystallography 54, no. 1 (February 1, 2021): 211–16. http://dx.doi.org/10.1107/s1600576720015587.

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Since the edge-to-edge matching relationship of close-packed planes on an incoherent interphase boundary was found, the one-dimensional ledge migration mechanism has been put forward. However, owing to the lack of direct experimental evidence, the existence of the one-dimensional ledge is still questioned and it is thus usually treated as just an assumption. In this study, focusing on the existence of one-dimensional ledges and the migration mechanism of incoherent interphase boundaries, an atomic scale investigation on the migration of incoherent interphase boundaries in a body- to face-centered cubic transformation has been carried out using the phase-field crystal model. Simulation results demonstrated the presence of one-dimensional ledges on incoherent interphase boundaries, but only on those boundaries with high atomic densities. The simulation results further showed that the interphase boundaries with one-dimensional ledges migrate as a result of the nucleation and extension of the one-dimensional ledge, similar to the mechanism for two-dimensional ledges; meanwhile the interphase boundaries without one-dimensional ledges migrate according to a continuous mechanism by random atomic jumping. Because it is difficult for one-dimensional ledges to nucleate under low driving forces, interphase boundary migration based on the one-dimensional ledge mechanism is slower than that based on the continuous mechanism. This study reveals the structures and mechanisms of complex transitions of incoherent interphase boundaries and can aid a deeper understanding of solid phase transformations.

2

Whiting, M. J., and P. Tsakiropoulos. "The ledge mechanism of pearlite growth." Scripta Metallurgica et Materialia 32, no. 12 (June 1995): 1965–66. http://dx.doi.org/10.1016/0956-716x(95)00096-e.

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3

Zhang, J. X., and H. Q. Ye. "Deformation-induced α2 ↔ γ phase transformation in a Ti–48Al–2Cr alloy." Journal of Materials Research 15, no. 10 (October 2000): 2145–50. http://dx.doi.org/10.1557/jmr.2000.0309.

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The structure of γ–α2 interfaces in deformed Ti–48Al–2Cr alloy was analyzed by high-resolution transmission electron microscopy (HREM) and image simulations. Growth of γ–TiAl plate in α2–Ti3Al phase was found to be a result of a ledge mechanism consisting of Shockley partial dislocations on alternate (0001)α2 planes. The height of the ledges was always a multiple of two (0001)α2 planes. The γ → α2 phase transformation was also an interface-related process. Large ledges of six close packed planes (111)γ high were often observed at the γ–α2 interface. Every large ledge consisted of six Shockley partial dislocations that originated from the γ–a2 interfacial lattice misfit. The movement of these partial dislocations accomplished the transformation of γ → α2 phase. Comparing the experimental and simulated HREM image, it was found that atomic reordering appears during the deformation-induced γ↔α2 transformation.

4

Huang, Yunhao, Jincheng Wang, Zhijun Wang, and Junjie Li. "Atomic structures and migration mechanisms of interphase boundaries during body- to face-centered cubic phase transformations." Journal of Applied Crystallography 52, no. 5 (October 1, 2019): 1176–88. http://dx.doi.org/10.1107/s1600576719011889.

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Atomic structures and migration mechanisms of interphase boundaries have been of scientific interest for many years owing to their significance in the field of phase transformations. Though the interphase boundary structures can be deduced from crystallographic investigations, the detailed atomic structures and migration mechanisms of interphase boundaries during phase transformations are still poorly understood. In this study, a systematic study on atomic structures and migration mechanisms of interphase boundaries in a body-centered cubic (b.c.c.) to face-centered cubic (f.c.c.) massive transformation was carried out using the phase-field crystal model. Simulation results show that the f.c.c./b.c.c. interphase boundaries can be classified into faceted interphase boundaries and side surfaces. The faceted interphase boundaries are semi-coherent with a group of dislocations, leading to a ledge migration mechanism, while the side surfaces are incoherent and thus migrate in a continuous way. After a careful analysis of the simulated migration process of interphase boundaries at atomic scales, a detailed description of the ledge mechanism based on the motion and nucleation of interphase boundary dislocations is presented. The ledge-forming process is accompanied by the nucleation of new heterogeneous dislocations and motions of original dislocations, and thus the barrier of ledge formation comes from the hindrance of these two dislocation behaviors. Once the ledge is formed, the original dislocations continue to advance until the ledge height reaches 1/|Δg|, where Δg represents the difference in reciprocal lattice vectors between two phases. The new heterogeneous dislocation moves along the radial direction of the interphase boundary, resulting in ledge extension. The interface dislocation behaviors greatly affect the migration of the interphase boundary, leading to different migration kinetics of faceted interphase boundaries under the Kurdjumov–Sachs and the Nishiyama–Wasserman orientation relationships. This study revealed the mechanisms and kinetics of complex structure transition during a b.c.c.–f.c.c. massive phase transformation and can shed some light on the process of solid phase transformations.

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Zhu, Yuanmin, Pingping Liu, Rong Yu, Ying-Hui Hsieh, Dan Ke, Ying-Hao Chu, and Qian Zhan. "Orientation-tuning in self-assembled heterostructures induced by a buffer layer." Nanoscale 6, no. 10 (2014): 5126–31. http://dx.doi.org/10.1039/c3nr06664a.

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Whiting, M. J., and P. Tsakiropoulos. "Ledge mechanism of pearlite growth: growth velocity of ferrous pearlite." Materials Science and Technology 11, no. 10 (October 1995): 977–84. http://dx.doi.org/10.1179/mst.1995.11.10.977.

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Hoyt, J. J. "The velocity of plate precipitates growing by the ledge mechanism." Acta Materialia 61, no. 13 (August 2013): 4953–60. http://dx.doi.org/10.1016/j.actamat.2013.04.051.

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Whiting, M. J., and P. Tsakiropoulos. "On the ledge mechanism of pearlite growth: The Cu-Al lamellar eutectoid." Scripta Metallurgica et Materialia 29, no. 3 (August 1993): 401–6. http://dx.doi.org/10.1016/0956-716x(93)90520-3.

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9

Aikin, R. M., S. Elangovan, T. G. Zocco, and M. R. Plichta. "Kinetic equations for concurrent size and shape coarsening by the ledge mechanism." Metallurgical Transactions A 22, no. 6 (June 1991): 1381–90. http://dx.doi.org/10.1007/bf02660670.

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Baev, A. R., A. L. Mayorov, M. V. Asadchaya, G. E. Konovalov, and O. S. Sergeeva. "TRANSFORMATION AND SCATTERING OF SURFACE WAVES ON THE ACOUSTIC LOAD TO ULTRASONIC EVALUATION AND MEASUREMENTS. Part 2. The object to study – solid with ledge." Devices and Methods of Measurements 9, no. 2 (June 15, 2018): 142–54. http://dx.doi.org/10.21122/2220-9506-2018-9-2-142-154.

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The lack of information about the features of processes of the surface wave's transformation into volume waves and its scattering in metal objects with ledge, slots, grooves and the others is one of the obstacles to improve of the acoustical testing reliability and widening of technical application. The aim of this work was to study of mechanism of acoustical mode's transformation and determination the laws of the fields forming of scatted volume edge wave's in solids with ledge of different geometry and to suggest direction of the study application in area of acoustical testing and measurements.The features of transformation of surface waves into edge transverse and longitudinal wave modes scatted and their fields forming in the volume of the object with ledge vs. its angle of the slope front surface side (0–135°) and a dimensionless transition radius (0–10,2) varied were studied. Theoretical analysis and experimental data shown that in general case the field of the edge transverse waves in the volume of ledge can be imagined as a superposition of the field of edge waves (scatted on ledge) and accompany waves too, radiated simultaneously with the surface waves to radiate. If dimensionless size of the ledge's transition radius lesser than 1 the resulting field of the edge transverse waves is the summary field of two sources. One of them (with small aperture) is localized in the vicinity of the place of intersection of contact surface with ledge's front side surface. As it was found, the second source of the edge transverse waves – the edge head longitudinal waves to appear in the results of transformation of surface waves on the ledge′s radius transition. The structure of the edge acoustic fields including their extremes vs. ledge's angle and its radius transition, position of the surface wave's probe were experimentally studied and theoretically analyzed.Some directions of the results of researches using are the next: а) ultrasonic testing of hard-to-make technological objects in which defects have low sound reflection; b) ultrasonic structure diagnostics of solid (specimens) set far from the ultrasonic by using edge volume transverse and longitudinal modes; c) creation of new ultrasonic arrangements to sound and to receive transverse waves of different polarization.

11

Spanos, G., R. A. Masumura, R. A. Vandermeer, and M. Enomoto. "The evolution and growth kinetics of precipitate plates growing by the ledge mechanism." Acta Metallurgica et Materialia 42, no. 12 (December 1994): 4165–76. http://dx.doi.org/10.1016/0956-7151(94)90193-7.

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Liu, Zhen-qing, Zhi-gang Yang, Zhao-dong Li, and Chi Zhang. "Transformation character of ferrite formation by a ledge mechanism under a mixed-control model." International Journal of Minerals, Metallurgy, and Materials 19, no. 5 (April 30, 2012): 428–33. http://dx.doi.org/10.1007/s12613-012-0574-6.

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13

Enomoto, Masato. "Computer simulation of morphological changes of grain boundary precipitates growing by the ledge mechanism." Metallurgical Transactions A 22, no. 6 (June 1991): 1235–45. http://dx.doi.org/10.1007/bf02660655.

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14

Mendebaev, Toktamys, Nurlan Smashov, and Zhania Kambarbek. "Scientific and technological foundations of groundwater deposits development with forced self-discharge." Sustainable Development of Mountain Territories 16, no. 1 (March 30, 2024): 322–35. http://dx.doi.org/10.21177/1998-4502-2024-16-1-322-335.

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Introduction. A two-well borehole system is proposed, providing for the extraction of groundwater by forced self-discharge. The essence is to create conditions for the emergence of a down hole energy source in the form of hydraulic shocks, alternating hydraulic impulses affecting aquifers and ensuring the rise of water to a height. Materials and methods of research. A block diagram of a two-well circulation system of wells consisting of an above-ground tank, an injection well with a ledge, a water-lifting well connected by an intermediate trunk. The objects of the study are the shape of the above–ground tank, its connection with the injection well, the location of the ledge and the conditions for conducting a water circulation channel from the ledge to the above-ground tank. Methods – calculation of the energy characteristics of a two-well system, experiments to study the mechanism of the origin of incomplete hydraulic shock, boundary values of the modes of water movement in the system and the coefficient of injection of rocks. They were carried out on the installation with the possibility of visual observation of the processes taking place in the system. Results. When an incomplete hydraulic shock occurs on the ledge of the injection well, the flow is divided into core and lateral components. The water flow from the tank into the well was in the range of 20–60 l/min. The origin of incomplete hydraulic shock occurred at a water flow rate of 20 l/min, with an increase in pressure up to 7.0 atmospheres. The boundary values of the laminar flow mode of water flow are 60 l/min. The height of the water rise (H) mainly depends on the depth of origin of incomplete hydraulic shock (H1). The ejection coefficient of rocks decreases with increasing flow rate of the working flow. Discussion. The results of the study are due to the design features of the elements of the two-well circulation system of wells. The operating conditions of the system are the type of communication ground tank – injection well – aquifer, the location of the ledge, the execution of the water circulation channel from the ledge to the entrance to the ground tank with one diameter, the preservation of the laminar flow regime of water, the exclusion of pressure loss and water leakage in the intermediate trunk. Conclusions. The conditions for the origin of a down hole energy source in the form of renewable hydraulic shocks, which have a hydro impulsive effect on aquifers, have been established. A block diagram of the injection and circulation system of wells for the extraction of groundwater by forced self-discharge has been formed. Resume. The validity of the idea of injection-forced self-discharge of groundwater is proved by the results of research. The results are applicable in the development of groundwater with low-pressure and non-pressure aquifers. The objects of future research are the optimal ratios of the diameter of the injection well and the passage section of the ledge, the expansion of the boundary values of the flow transition from laminar to turbulent motion, and an increase in the ejection coefficient.

15

Hall, M. G., and H. I. Aaronson. "Formation of invariant plane-strain and tent-shaped surface reliefs by the diffusional ledge mechanism." Metallurgical and Materials Transactions A 25, no. 9 (September 1994): 1923–31. http://dx.doi.org/10.1007/bf02649040.

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16

Whiting, M. J., and P. Tsakiropoulos. "The ledge mechanism of pearlite growth: Some thoughts on the solution to the kinetic problem." Scripta Metallurgica et Materialia 30, no. 8 (April 1994): 1031–36. http://dx.doi.org/10.1016/0956-716x(94)90550-9.

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17

Chu, Kuei-Yi, Shiou-Ying Cheng, Tzu-Pin Chen, Ching-Wen Hung, Li-Yang Chen, Tsung-Han Tsai, Wen-Chau Liu, and Lu-An Chen. "Influence of emitter-ledge thickness on the surface- recombination mechanism of InGaP/GaAs heterojunction bipolar transistor." Superlattices and Microstructures 43, no. 4 (April 2008): 368–74. http://dx.doi.org/10.1016/j.spmi.2008.01.018.

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18

Zhang, Jin Hua, Si Xiong, Chang Ming Ke, Hong Dan Wu, and Xin Rong Lei. "Synthesis and Reaction Mechanism of Ti₃SiC₂ by Molten Salt Method from Ti-Si-Fe Alloy." Key Engineering Materials 768 (April 2018): 159–66. http://dx.doi.org/10.4028/www.scientific.net/kem.768.159.

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Titanium silicon carbide (Ti3SiC2) were obtained by molten salt synthesis method using the Ti-Si-Fe alloy extracted from high titania blast furnace slag and natural graphite as the raw materials. The phase composition, microscopic structure of the products were characterized by powder X-ray diffraction, scanning electron microscope and transmission electron microscope. The influence of firing temperature and chloride salts species on the phase and morphology of the products were investigated. The results indicated that the synthetic temperature of Ti3SiC2 by molten salt synthesis method was about 100 °C, which was lower than that without molten salts. The “dissolution-precipitation” mechanism governed the overall molten salt synthesis process. The lamellar Ti3(Si,Al)C2 crystal growth obeyed by a two-dimensional ledge growth mechanism.

19

Ganot, G. S., P. C. van der Wilt, H. K. Effron, B. A. Turk, U. J. Chung, A. M. Chitu, A. B. Limanov, and James S. Im. "Mechanism of Twin Formation in Excimer-laser-induced Lateral Solidification of Si Films." MRS Proceedings 1426 (2012): 389–94. http://dx.doi.org/10.1557/opl.2012.1179.

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ABSTRACTIn this paper, we present experimental findings pertaining to the formation of twins in isolated single-crystal islands obtained via the dot-SLS method. Systematic characterization of the islands using EBSD reveals that Σ = 3 CSL twins constitute the predominant extended defect. Given this, the surface orientation of the seed and twinned regions are shown to be related by a 180° rotation about a <111> axis, and the orientation of the twinned area is apparently manifested in the inverse pole figure as a reflection across the {112} zone. By considering (1) the overall pattern of the twin boundaries within the islands, (2) that solidification proceeds via a facetted mode of growth and, (3) that intragrain-defect-free regions were obtained when the dot-SLS process was performed on a {100} surface-oriented seed, we suggest that these twins are most likely generated heterogeneously at the Si/SiO2interface during the ledge nucleation stage of rapid lateral solidification of the films.

20

Lukens, Jennifer M., Gregory W. Reich, and Brian Sanders. "Wing Mechanization Design and Wind Tunnel Testing for a Perching Micro Air Vehicle." Advances in Science and Technology 56 (September 2008): 589–94. http://dx.doi.org/10.4028/www.scientific.net/ast.56.589.

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This paper describes the development of a mechanized wing concept for a perching micro air vehicle. The wings are capable of rotating in pitch at two spanwise joints to simulate the motion of a bird’s wings during a perching maneuver. This project focuses on the wing mechanization design and analysis as well as the structure/mechanism integration. The advantage of a perching type of landing is that it allows the vehicle to land with approximately zero vertical and horizontal velocity on a tree branch, power line, or ledge. The requirements to perform this maneuver were investigated, the structural design was developed, and the mechanization integration to achieve this motion was determined. A model was designed and manufactured to demonstrate the kinematic mechanism making this wing motion possible. Wind tunnel testing and analytical simulation were also completed to further develop the model.

21

Sinclair, Robert, and Toyohiko J. Konno. "In situ HREM of interface interactions." Proceedings, annual meeting, Electron Microscopy Society of America 51 (August 1, 1993): 830–31. http://dx.doi.org/10.1017/s0424820100149982.

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We have applied in situ high-resolution electron microscopy (HREM) to the study of interface reactions, particularly in metal-semiconductor systems. There is contrasting behavior whether or not the manufactured interface undergoes a chemical reaction. The in situ technique allows determination of the reaction mechanisms on an atomic scale.Reactive interfaces are characterized by systems in which new chemical compounds are formed (e.g., silicides for metal-silicon interfaces, metal gallides and arsenides for GaAs, etc.). We found that the equilibrium phase formation is often preceded by a solid-state amorphization reaction. In situ observations allow very precise measurement of the reaction rate in a sufficient temperature range to confirm that this process is diffusion controlled. Crystallization of the amorphous material can be followed as well as the development of any crystallographic orientation relationships. A ledge growth mechanism can easily be distinguished from a random process.It might be expected that non-reactive interfaces are stable upon heating.

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Howe, J. M., M. M. Tsai, and A. A. Csontos. "In SituHigh-Resolution Electron Spectroscopic Imaging and Real-Time Image Simulation of Precipitate Growth Mechanisms." Microscopy and Microanalysis 3, S2 (August 1997): 627–28. http://dx.doi.org/10.1017/s1431927600010023.

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Precipitate interfaces are ideal for studying the relationship between atomic bonding, structure and composition at internal interfaces and the mechanisms and kinetics of their motion as a function of temperature or driving force for reaction. The crystallography between coherent and semicoherent precipitates and the matrix is well-defined and the precipitate interfaces are often planar and grow by a terrace-ledge-kink mechanism, making them well-suited for study by conventional and high-resolution transmission electron microscopy (HRTEM).Motion of precipitate interfaces, or more generally, interphase boundaries, involves a change in lattice, composition or both. In order to understand the mechansims of interfacial motion, it is necessary to determine the structural and compositional changes that occur at the highest possible resolution, i.e., as close to the atomic level as possible, and also, to determine the corresponding kinetics of interface motion. HRTEM is an excellent technique for determining the atomic structure of transformation interfaces and in situhot-stage HRTEM is deal for determining interface dynamics at the atomic level, provided the transformation mechanisms are not altered by the thinness of the TEM foil.

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Kimura, Yoshisato, Ko Kato, and Yaw Wang Chai. "Effects of Si on Phase Stability and Precipitation Behavior of C14 Laves Phase (Fe,Cr)2(Nb,Mo) in High Cr αFe-base Alloys." MRS Advances 4, no. 25-26 (2019): 1477–83. http://dx.doi.org/10.1557/adv.2019.112.

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ABSTRACTThe growth mechanism of C14 Laves phase in the bcc αFe matrix was determined as the ledge mechanism on the (110)α//(0001)C14 habit plane in Fe-20Cr-0.5Nb-1Mo (at%) alloys annealed at 1073 K for 24 hours, using conventional and scanning transmission electron microscopy. Terrace planes are the basal plane of hcp-based C14 structure. Precipitation particles tend to grow in plate shape depending on the anisotropic difference of lattice mismatch. The addition of Si with Mo remarkably enhances C14 Laves phase precipitation. The area fraction of Laves phase increases from 5.9% to 12.1% by the 2Si addition on Fe-20Cr-0.5Nb-2Mo alloys. Contrary to this, the addition of Si is not effective to increase Laves phase precipitation. It is indicated that Si improves the phase stability of C14 Laves phase while the partitioning of Mo into C14 Laves phase would be promoted due to the attractive interaction between Mo and Si.

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Qin, Gao-Wu, Shiming Hao, and Xudong Sun. "Ledge mechanism of primary α2/γ lamellae growing in the supersaturated α2 matrix for γ-TiAl-based (γα2) alloy." Scripta Materialia 39, no. 3 (July 1998): 289–93. http://dx.doi.org/10.1016/s1359-6462(98)00153-5.

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25

Lee, Chia-Hung, Erh-Ju Lin, Jyun-Yang Wang, Yi-Xuan Lin, Chen-Yu Wu, Chung-Yu Chiu, Ching-Yu Yeh, Bo-Rong Huang, Kuan-Lin Fu, and Cheng-Yi Liu. "Effect of De-Twinning on Tensile Strength of Nano-Twinned Cu Films." Nanomaterials 11, no. 7 (June 22, 2021): 1630. http://dx.doi.org/10.3390/nano11071630.

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Tensile tests were carried on the electroplated Cu films with various densities of twin grain boundary. With TEM images and a selected area diffraction pattern, nano-twinned structure can be observed and defined in the electroplated Cu films. The density of the nano-twin grain structure can be manipulated with the concentration of gelatin in the Cu-sulfate electrolyte solution. We found that the strength of the Cu films is highly related to the twin-boundary density. The Cu film with a greater twin-boundary density has a larger fracture strength than the Cu film with a lesser twin-boundary density. After tensile tests, necking phenomenon (about 20 μm) occurred in the fractured Cu films. Moreover, by focused ion beam (FIB) cross-sectional analysis, the de-twinning can be observed in the region where necking begins. Thus, we believe that the de-twinning of the nano-twinned structure initiates the plastic deformation of the nano-twinned Cu films. Furthermore, with the analysis of the TEM images on the nano-twinned structure in the necking region of the fractured Cu films, the de-twinning mechanism attributes to two processes: (1) the ledge formation by the engagement of the dislocations with the twin boundaries and (2) the collapse of the ledges with the opposite twin-boundaries. In conclusion, the plastic deformation of nano-twinned Cu films is governed by the de-twinning of the nano-twinned structure. Moreover, the fracture strength of the nano-twinned Cu films is proportional to the twin-boundaries density.

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Klimenko, M. V., B. Zhao, A. T. Karpachev, and V. V. Klimenko. "Stratification of the Low-Latitude and Near-EquatorialF2Layer, Topside Ionization Ledge, andF3Layer: What We Know about This? A Review." International Journal of Geophysics 2012 (2012): 1–22. http://dx.doi.org/10.1155/2012/938057.

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A large number of researches have been devoted to the formation of additional layers in theFregion of the equatorial ionosphere, first of which has been published in 1940s. Originally the occurrence of such layer was named “stratification of equatorialF2layer.” The additional layer was later named as theF3layer. The theoretical researches have shown that theF3layer is formed by zonal component of electric field with assistance of meridional component of thermospheric wind and field-aligned plasma diffusion. The physical mechanism of theF3layer formation is clearly formulated for the morning-noon period, although theF3layer is also observed at other hours. This paper presents a brief review into the history of the additional layer researches, describes the current progress of these researches, and identifies the most important problems in this field of the ionospheric physics.

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Yang, Fan, Hao-ru Zhao, and Chao Liu. "Improvement of the Efficiency of the Axial-Flow Pump at Part Loads due to Installing Outlet Guide Vanes Mechanism." Mathematical Problems in Engineering 2016 (February 4, 2016): 1–10. http://dx.doi.org/10.1155/2016/6375314.

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In order to investigate the influence of adjustable outlet guide vane on the hydraulic performance of axial-flow pump at part loads, the axial-flow pump with 7 different outlet guide vane adjustable angles was simulated based on the RNG k-ε turbulent model and Reynolds time-averaged equations. The Vector graphs of airfoil flow were analyzed in the different operating conditions for different adjustable angles of guide vane. BP-ANN prediction model was established about the effect of adjustable outlet guide vane on the hydraulic performance of axial-flow pump based on the numerical results. The effectiveness of prediction model was verified by theoretical analysis and numerical simulation. The results show that, with the adjustable angle of guide vane increasing along clockwise, the high efficiency area moves to the large flow rate direction; otherwise, that moves to the small flow rate direction. The internal flow field of guide vane is improved by adjusting angle, and the flow separation of tail and guide vane inlet ledge are decreased or eliminated, so that the hydraulic efficiency of pumping system will be improved. The prediction accuracy of BP-ANN model is 1%, which can meet the requirement of practical engineering.

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Yamaguchi, Toshihito, and Yoshikazu Ikuta. "CLIMBER'S FINGER." Hand Surgery 12, no. 02 (January 2007): 59–65. http://dx.doi.org/10.1142/s0218810407003420.

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Introduction: Climbers sometimes support their body with one finger hooked on a rocky ledge. This peculiar manoeuvre may cause a characteristic injury of the flexor tendon sheath, named "climber's finger". Symptoms: (1) A sharp pain when grasping, and a sudden "snap" sound and snapping phenomenon in the concerned fingers and (2) a tender palpable mass proximal to the PIP joint. Mechanism of occurrence: When a finger forms a hook, the highest stress point of the flexor tendon sheath is between the first cruciform pulley and the second annular pulley. When the full body weight is held mainly with the weak first cruciform pulley, it sometimes ruptures. Therapy: Conservative therapy to prevent bowstringing was applied for eight cases. Six patients recovered after three months; the other two cases underwent operations. Conclusion: If conservative therapy is found to be ineffective after three months, suturing of the tendon sheath should be indicated for climber's finger.

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Enomoto, M., and H. I. Aaronson. "Influence of the ledge mechanism of diffusivities back-calculated from the migration kinetics of planar interphase boundaries in two-phase diffusion couples." Scripta Metallurgica 23, no. 1 (January 1989): 55–58. http://dx.doi.org/10.1016/0036-9748(89)90092-6.

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30

Ramesh, R., A. Inam, D. M. Hwang, T. S. Ravi, T. Sands, X. X. Xi, X. D. Wu, Q. Li, T. Venkatesan, and R. Kilaas. "The atomic structure of growth interfaces in Y–Ba–Cu–O thin films." Journal of Materials Research 6, no. 11 (November 1991): 2264–71. http://dx.doi.org/10.1557/jmr.1991.2264.

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We have examined the atomic structure of growth interfaces in thin films of Y–Ba–Cu–O grown on [001] perovskite or cubic substrates. At substrate heater temperatures in the range of 780–820 °C c-axis oriented growth is observed on these substrates. On SrTiO3, the first layer appears to be either a BaO or a CuO2 plane while on LaAlO3 the first layer appears to be a CuO chain layer. The mismatch on the a-b plane is accommodated by the formation of interface dislocations. Defects on the substrate surface propagate as defects in the film. These defects are primarily translational boundaries and in some cases second phases. At lower substrate heater temperatures, i.e., 650–700 °C, a, b-axis growth dominates. Defects and steps on the substrate surface are more detrimental in the growth of a, b-axis oriented films, since they tend to favor the nucleation of c-axis oriented domains. This is ascribed to the ledge mechanism of c-axis film growth, for which the surface steps are good nucleation sites.

31

Yee, Andrew L., H. C. Ong, L. M. Stewart, and R. P. H. Chang. "Development of flat, smooth (100) faceted diamond thin films using microwave plasma chemical vapor deposition." Journal of Materials Research 12, no. 7 (July 1997): 1796–805. http://dx.doi.org/10.1557/jmr.1997.0248.

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A novel approach has been used to develop (100) faceted diamond films with flat, smooth surfaces. A morphological study of the early stages of growth behavior of (100) homoepitaxial films versus process temperature and methane percentage was carried out using atomic force microscopy. The results showed that spiral growth features and penetration twin density were dominant for growth conditions not well suited for (100) growth. Optimized process parameters were found to proceed via a step mechanism consistent with ledge growth on (2 × 1) reconstructed (100) diamond surfaces. These optimized conditions were then applied to growth of polycrystalline diamond on pretreated silicon substrates. A unique octahedral faceted film resulted, indicating strong preference for growth in the 〈100〉 direction. Scanning electron microscopy, x-ray diffraction, and Raman spectroscopy were used to assess film morphology, internal fiber texture, and carbon phase, respectively. A second stage growth step was used to flatten the surface topography to achieve the desired (100) flat tile-like morphology. This smooth (100) surface exhibited enhanced tribological performance compared to a typical randomly textured diamond film.

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Valiev, Sherali, Alexander Kamenskikh, and Andrey Kochetkov. "Features of application of sprayed waterproofing of bridge structures at low temperatures." Smart composite in construction 4, no. 2 (June 23, 2023): 64–76. http://dx.doi.org/10.52957/2782-1919-2024-4-2-64-76.

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The paper concerns the mechanism of bugholes formation (breach) in the waterproofing layer on the slope of the macro-roughness protrusion associated with the temperature and flow rate of the sprayed mixture, cooling time, width, and height of the macro-roughness protrusion. The point bugholes formation occurs on the slopes of areas with maximum irregularities (the greatest depth of the depression relative to the adjacent ledge). Taking into account the results of the production experiment, the research recommends ones to increase the temperature of the sprayed mixture to 70-80 °C to ensure the polymerization rate of the mixture up to 1-2 minutes. Meanwhile, the bubble of the vapor-air mixture does not have time to reach the surface of the sprayed layer and burst with the formation of a bugholes (a defect in the integrity of the waterproofing layer of the bridge structure). The paper shows the prospects of mass application of sprayed polymer three layer waterproofing of bridge structures and the accumulation of new theoretical knowledge in the construction and repairing of bridges.

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Alve, Elisabeth, and Susan T. Goldstein. "Resting stage in benthic foraminiferal propagules: a key feature for dispersal? Evidence from two shallow-water species." Journal of Micropalaeontology 21, no. 1 (May 1, 2002): 95–96. http://dx.doi.org/10.1144/jm.21.1.95.

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Abstract. Understanding dispersal mechanisms in benthic formainifera has wide implications for explaining their geological and biological distribution in space and time, including evolutionary and genetic trends. Because they lack a planktonic larval stage (although a few have a meroplanktonic life stage), their mode of dispersal in the marine environment has been subject to much speculation, and a range of alternative mechanisms have been suggested (for a review, see Alve (1999) and further discussion in Hayward et al. (1999)).In the present note, we suggest a mechanism which is more efficient and probably more widespread than most of those previously proposed. We hypothesize that many species produce ‘propagules’ (small juveniles, perhaps just the proloculus) released in large numbers following reproduction that may enter a resting stage. Propagules can be widely dispersed by normal physical processes (currents, sediment transport) and ultimately settle over a range of habitats and conditions. Growth and reproduction commence only in those individuals and species that reach a suitable environment. We have two lines of evidence from completely different shallow-water environments (Norwegian fjord and the Florida Keys, USA) that strongly support our hypothesis.ObservationsSurface sediments from a box core were collected at 60 m water depth in the inner part of Oslofjord 10 September 1999. Some of the sediment was processed immediately after collection, and the remaining bulk sample was transferred to a transparent container with ambient seawater, sealed, and placed on a window ledge until 30 March 2000. Those sub-samples processed immediately after collection contained no live . . .

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Stern, Ana L., Emmanuel Burgos, Laurent Salmon, and Juan J. Cazzulo. "Ribose 5-phosphate isomerase type B from Trypanosoma cruzi: kinetic properties and site-directed mutagenesis reveal information about the reaction mechanism." Biochemical Journal 401, no. 1 (December 11, 2006): 279–85. http://dx.doi.org/10.1042/bj20061049.

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Trypanosoma cruzi, the human parasite that causes Chagas disease, contains a functional pentose phosphate pathway, probably essential for protection against oxidative stress and also for R5P (ribose 5-phosphate) production for nucleotide synthesis. The haploid genome of the CL Brener clone of the parasite contains one gene coding for a Type B Rpi (ribose 5-phosphate isomerase), but genes encoding Type A Rpis, most frequent in eukaryotes, seem to be absent. The RpiB enzyme was expressed in Escherichia coli as a poly-His tagged active dimeric protein, which catalyses the reversible isomerization of R5P to Ru5P (ribulose 5-phos-phate) with Km values of 4 mM (R5P) and 1.4 mM (Ru5P).4-Phospho-D-erythronohydroxamic acid, an analogue to the reaction intermediate when the Rpi acts via a mechanism involving the formation of a 1,2-cis-enediol, inhibited the enzyme competi-tively, with an IC50 value of 0.7 mM and a Ki of 1.2 mM. Site-directed mutagenesis allowed the demonstration of a role for His102, but not for His138, in the opening of the ribose furanosic ring. A major role in catalysis was confirmed for Cys69, since the C69A mutant was inactive in both forward and reverse directions of the reaction. The present paper contributes to the know-ledge of the mechanism of the Rpi reaction; in addition, the absence of RpiBs in the genomes of higher animals makes this enzyme a possible target for chemotherapy of Chagas disease.

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Miyamoto, Goro, Poorganji Behrang, and Tadashi Furuhara. "Interphase Boundary Precipitation of VC Accompanying Ferrite and Pearlite Transformation in Medium Carbon Steels." Solid State Phenomena 172-174 (June 2011): 420–25. http://dx.doi.org/10.4028/www.scientific.net/ssp.172-174.420.

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Demands for medium carbon steels with high strength used for forging parts in automobile have been increasing. V addition to such steels leads to interphase boundary precipitation (IBP) of VC and thus an increase of strength. However, mechanism and strengthening effect of IBP have not been clarified in detail. In this study, precipitation of VC accompanying ferrite and pearlite transformations and its effect on hardness have been examined in medium carbon steels microalloyed with 0.3%V. Specimens transformed in a temperature range between 873 and 973K consist of pearlite and small amount of proeutectoid ferrite. Hardness increase by the V addition becomes larger by lowering transformation temperature at these temperatures. Meanwhile the alloying effect of V on the hardness remarkably decreases at 823K where bainite transformation takes place partly. TEM characterization has revealed that VC are precipitated in both of proeutectoid and pearlitic ferrites in the manner of fine rows parallel to the austenite / ferrite interphase boundary. The size of VC decreases and its number density increases by lowering transformation temperature, corresponding to the larger hardness increase. Orientation relationship analyses between ferrite and austenite in the V-added specimen based of EBSD measurements reveals that proeutectoid ferrite grows preferentially towards an austenite grain with which ferrite does not hold a specific orientation relationship, indicating that classical ledge mechanism does not play a role for interphase boundary precipitation of VC in this alloy.

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Häusler, Ines, Reza Kamachali, Walid Hetaba, and Birgit Skrotzki. "Thickening of T1 Precipitates during Aging of a High Purity Al–4Cu–1Li–0.25Mn Alloy." Materials 12, no. 1 (December 21, 2018): 30. http://dx.doi.org/10.3390/ma12010030.

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The age hardening response of a high-purity Al–4Cu–1Li–0.25Mn alloy (wt. %) during isothermal aging without and with an applied external load was investigated. Plate shaped nanometer size T1 (Al2CuLi) and θ′ (Al2Cu) hardening phases were formed. The precipitates were analyzed with respect to the development of their structure, size, number density, volume fraction and associated transformation strains by conducting transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) studies in combination with geometrical phase analysis (GPA). Special attention was paid to the thickening of T1 phase. Two elementary types of single-layer T1 precipitate, one with a Li-rich (Type 1) and another with an Al-rich (Defect Type 1) central layer, were identified. The results show that the Defect Type 1 structure can act as a precursor for the Type 1 structure. The thickening of T1 precipitates occurs by alternative stacking of these two elementary structures. The thickening mechanism was analyzed based on the magnitude of strain associated with the precipitation transformation normal to its habit plane. Long-term aging and aging under load resulted in thicker and structurally defected T1 precipitates. Several types of defected precipitates were characterized and discussed. For θ′ precipitates, a ledge mechanism of thickening was observed. Compared to the normal aging, an external load applied to the peak aged state leads to small variations in the average sizes and volume fractions of the precipitates.

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Zhou, S. J., and Robb Thomson. "Dislocation emission at ledges on cracks." Journal of Materials Research 6, no. 3 (March 1991): 639–53. http://dx.doi.org/10.1557/jmr.1991.0639.

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In this paper, we propose that, depending on their height, ledges on cracks can be efficient sources of dislocations at loadings well below the critical loading for homogeneous emission. Detailed 3-D elastic calculations are presented supporting this proposition. There are two configurations for emission: one which blunts the crack, and one we call a jogging configuration. By our calculations, the blunting configuration should be the more efficient source; however, jogging dislocations are more frequently observed, experimentally. We find that the ledge is only a finite source of dislocations, in the sense that the ledge height decreases as the dislocations are emitted. The atomic configuration at the ledge is composed of finite lengths of real dislocations, which is the reason why such dislocations can be emitted easier than homogeneously produced dislocations. The stresses at the ledge tip produce a cloud of bound dislocations near the ledge, pinned at the ledge ends, so that the ledge crack configuration becomes delocalized. Delocalization of the pileup dislocations in the jogging direction may explain why the jogging dislocations are more frequently seen. Implications for dislocation free zones and ductile transitions are discussed.

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Kabbara, Hiba, Jaafar Ghanbaja, Abdelkrim Redjaïmia, and Thierry Belmonte. "Crystal structure, morphology and formation mechanism of a novel polymorph of lead dioxide, γ-PbO2." Journal of Applied Crystallography 52, no. 2 (March 5, 2019): 304–11. http://dx.doi.org/10.1107/s1600576719001079.

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Nanosecond-pulsed spark discharge between two lead electrodes in liquid nitrogen has been used to synthesize hexagonal lead nanosheets. These original nanostructures are collected on a substrate located under the electrodes. After the full evaporation of the liquid nitrogen, the nanosheets are oxidized in air and transform into a lead dioxide. The resulting hexagonal sheets have typical widths of around 1 µm and typical thicknesses of around 10 nm. Investigations by energy dispersive spectroscopy microanalysis, transmission electron microscopy, high-angle annular dark-field scanning transmission electron microscopy and electron microdiffraction were performed in order to identify the crystal structure in which these hexagonal nanosheets crystallize. An analysis of the chemical composition pointed to a stoichiometric lead dioxide, PbO2. This PbO2 lead dioxide crystallizes in the hexagonal system (a = 0.912 nm and c = 1.265 nm) and belongs to the space group P6/m2/m2/m. On the basis of group theory (symmetry analysis), the nanosheets develop a hexagonal-prismatic shape in liquid nitrogen, assumed to be an isotropic medium. From the energetic point of view, this shape, dictated by the 6/m2/m2/m point group, corresponds to an absolute extremum, an indicator of the stability of this lead dioxide. A mechanism similar to that of the ledge mechanism explaining the formation of thin plates in a metallic matrix has been adapted and proposed for the formation of the lead nanosheets in the liquid nitrogen. When the liquid nitrogen is removed, the lead nanosheet is oxidized, leading to a lead dioxide, inheriting the nanosheet morphology. As far as the authors are aware, this is the first time that such a lead dioxide has been synthesized by spark discharge in liquid nitrogen followed by oxidation in air. The crystallographic structure is determined and the morphology is explained. A mechanism for the development of the lead nanosheets and their oxidation is proposed. This hexagonal phase, designated γ-PbO2, is thought to be the third polymorph after the α-PbO2 and β-PbO2 phases of lead dioxide, the former being orthorhombic and the latter being tetragonal.

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Yang, Jer Ren, H. W. Yen, C. Y. Chen, and C. Y. Huang. "The Development of Interphase Precipitated Nanometre-Sized Carbides in the Advanced Low-Alloy Steels." Materials Science Forum 762 (July 2013): 95–103. http://dx.doi.org/10.4028/www.scientific.net/msf.762.95.

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In this work, the investigation of transmission electron microscopy has elucidated the morphologies of the interphase precipitated carbides in an experimental Ti-Mo-bearing steel into three types: (1) planar interphase precipitation with regular sheet spacing (designated as PIP), (2) curved interphase precipitation with regular sheet spacing (designated as Regular CIP), and (3) curved interphase precipitation with irregular sheet spacing (designated as Irregular CIP). The planar sheets of carbides have also been analyzed and found to be oriented close to ferrite planes {211}, {210} and {111}; the results of transmission electron microscopy provide strong evidence to suggest that the development of interphase-precipitated carbides can be associated with the growth of incoherent ferrite/austenite interface by the ledge mechanism. The sheet spacing and inter-carbide spacing in the sheet have been measured and estimated in this work. The sheet spacing is found to be finer than the inter-carbide spacing in the sheet for all samples investigated. The result reflects that the distribution of interphase-precipitated carbides is anisotropic and cannot be considered random distribution. The relevance of the Orowan mechanism to the non-random distribution of interphase-precipitated carbides has been considered. The contribution of the dispersion of interphase-precipitated carbides to the yield strength of the steel studied has been estimated. It is revealed that an optimum component about 400 MPa contributed by interphase-precipitated carbides can be achieved, and the finding is consistent with the hardness data. Other examples of the different alloy steels are also addressed.

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Watanabe, Chihiro, and Ryoichi Monzen. "Precipitation Process in a Cu-Ni-Be Alloy." Solid State Phenomena 172-174 (June 2011): 432–36. http://dx.doi.org/10.4028/www.scientific.net/ssp.172-174.432.

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The precipitation process in an aged Cu-1.9wt%Ni-0.3wt%Be alloy has been examined by high-resolution transmission electron microscopy. The precipitation sequence found is: Guinier- Preston (G.P.) zones → γ'' → γ' → stable γ. The disk-shaped G.P. zones and the disk-shaped γ'', γ' and γ precipitated phases are composed of monolayers of Be atoms on {100}αof the Cu matrix and alternative Be and Ni matrix layers parallel to {100}α. The γ'' phases consisting of two to eight Be-layers has a body-centered tetragonal (bct) lattice witha=b=0.24 nm andc=0.28 nm. The γ' or γ phase is bct witha=b=0.24 nm andc=0.26 nm ora=b=0.26 nm andc=0.27 nm. The γ'', γ' or γ phase aligns with the matrix according to the Bain orientation relationship. The growth kinetics of disk-shaped γ precipitates on aging at 500°C has been also investigated. The {001}αhabit planes of the γ precipitates migrate by a ledge mechanism. The average thickness of the γ disks increases with aging timetast1/2. An analysis of experimental data using a kinetic model yields the diffusivity of solute in the Cu matrix, which is in agreement with the reported diffusivity of Ni in Cu.

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Wightman, Catherine S., and Mark R. Fuller. "Influence of Habitat Heterogeneity on Distribution, Occupancy Patterns, and Productivity of Breeding Peregrine Falcons in Central West Greenland." Condor 108, no. 2 (May 1, 2006): 270–81. http://dx.doi.org/10.1093/condor/108.2.270.

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Abstract We used occupancy and productivity data collected at 67 cliffs used for nesting from 1972 to 1999 to assess patterns of distribution and nest-site selection in an increasing population of Peregrine Falcons (Falco peregrinus) in central West Greenland. Peregrine Falcons breeding at traditionally occupied cliffs used for nesting had significantly lower variation in productivity and thus these cliffs were better quality sites. This indicates that Peregrine Falcons occupied cliffs according to a pattern of despotic distribution. Falcons breeding at cliffs that were consistently occupied during the breeding season had higher average productivity and lower variation in productivity than falcons at inconsistently occupied cliffs, and thus consistent occupancy also was indicative of cliff quality. Features of high quality habitat included tall cliffs, greater change in elevation from the lowest point within 3 km of the cliff to the cliff top (elevation gain), and protection from weather on the eyrie ledge. Spacing of suitable and occupied cliffs also was an important feature, and the best cliffs generally were more isolated. Increased spacing was likely a mechanism for reducing intraspecific competition. Our results suggest that Peregrine Falcons use a resource defense strategy to compete for better quality habitats and may use spacing and physical features of a nest site to identify good quality breeding habitat.

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Andrade, J. E., H. B. Aquiar, and F. Cunha. "Silver Nanoparticles Self Assembled on HOPG: Unusual Behavior as Probed by Scanning Tunneling Microscopy." Microscopy and Microanalysis 11, S03 (December 2005): 158–61. http://dx.doi.org/10.1017/s1431927605051135.

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The controlled construction of nanostructures on solid surfaces for technological applications depends primarily on a deep understanding of the physical chemistry of the interface. Several methods have been devised to grow metallic nanostructures on solid surfaces, notably physical vapor deposition and electrodeposition. The electrochemical method led to the creation of a very promising technology called Electrochemical Step Edge Decoration (ESED) by the Penner group in Irvine, Ca. In this method, metallic nano and mesowires are built through electrochemical deposition on the step edges of the basal plane of Highly Oriented Pyrolytic Graphite (HOPG) [1]. The proposed growth mechanism is based on the Terrace-Ledge-Kink (TLK) model [2], in which the foreign adatoms nucleate the electrochemically induced growth of nanoparticles in the lower plane of step edges. White and collaborators [3], while studying the stability of gold nanoparticles electrodeposited on HOPG, noticed the preferential nucleation on the upper plane of step edges in stark opposition to the TLK model. They proposed that this preferential deposition is associated with a slippage of the atomic layer near the edge. This proposition indicates that the surface in the upper plane near the edge will present a decrease in the atomic distance in the plane, disrupting the registry with the underlying plane. To further assess this proposition we have devised another experimental approach where, instead of electrodepositing foreign adatoms for nucleation and growth, we deposited fully formed silver nanoparticles on HOPG through a Self Assembly mechanism and studied its spatial distribution. Through this approach, we intend to study the surface mobility of nanoparticles, as opposed to atomic species as studied in electrochemical deposition.

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Lux, Vanda, Tine Brouns, Kateřina Čermáková, Pavel Srb, Milan Fábry, Marcela Mádlíková, Magdalena Hořejší, et al. "Molecular Mechanism of LEDGF/p75 Dimerization." Structure 28, no. 12 (December 2020): 1288–99. http://dx.doi.org/10.1016/j.str.2020.08.012.

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ZHUKEVYCH, Svitlana, and Vіktoriia ROZHELIUK. "FINANCIAL STABILITY OF THE ENTERPRISE IN THE CONTEXT OF SUSTAINABLE DEVELOPMENT OF UKRAINE." WORLD OF FINANCE, no. 4(57) (2018): 75–85. http://dx.doi.org/10.35774/sf2018.04.075.

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Introduction. The modernization of the financial mechanism, the main purpose of which is to increase the efficiency of the use of financial resources at different levels of management and optimize management of budget funds is an important element of implementing the concept of sustainable development in Ukraine. At the same time, today the most urgent issue is the development of such a financial mechanism of the state, business entities that will stimulate the formation favorable conditions for meeting the needs of present and future generations. The purposeof the article is to highlight the issues related to the impact of financial sustainability on the sustainable development of enterprises in the framework of the implementation of the state strategy, which determines its relevance. Methods. The basis is based on scientific methods based on dialectical know ledge and objective laws of the economy. Results. Sustainable development of an enterprise is a gradual change or maintenance of the appropriate level of all indicators of enterprise sustainability, capable of resisting negative environmental factors, using internal potential, while preserving the integrity and basic properties. That is, it can be argued that sustainable development of the enterprise is provided on the basis of taking into account the influence of the external environment and improving the strategic management within the enterprise in order to increase its efficiency and continuous development. For the enterprises sustainable development means adopting business strategies and endorsing activities that meet market needs and stakeholders at the same time protecting, sustaining and strengthening the human and natural resources that will be needed in the future. The development of an effective management structure for the sustainable development of the business entity requires the integration of all functional components - business planning, organization, accounting, analysis, control. The calculation of permissible and economically justified rates of growth of an enterprise is an important stage in the diagnosis of the financial component of a sustainable development of an enterprise. Conclusions. The financial and economic stability is the condition of life and the basis of stability of an enterprise in a market economy. It is determined, that only a systematic approach that considers an enterprise as a social and economic system functioning in the external environment will prevent the negative trends of the present. The growth factors are the indicators in the management of sustainable growth: the coefficient of internal growth, which shows the ability of enterprises to increase the negotiable and non-current assets at the expense of domestic sources of funding and the coefficient of sustainable growth, which characterizes the growthof equity capital of the enterprise.

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Ivanova, A. M., P. A. Arkhipov, A. V. Rudenko, O. Y. Tkacheva, and Yu P. Zaikov. "Formation of Side Ledge and Bottom Ledge in an Aluminum Electrolyzer." Russian Journal of Non-Ferrous Metals 60, no. 6 (November 2019): 624–31. http://dx.doi.org/10.3103/s1067821219060075.

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Luther, William J., and Sean Stein Smith. "Is Bitcoin a decentralized payment mechanism?" Journal of Institutional Economics 16, no. 4 (March 20, 2020): 433–44. http://dx.doi.org/10.1017/s1744137420000107.

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AbstractWe make a distinction between centralized, decentralized, and distributed payment mechanisms. A centralized payment mechanism processes a transaction using a trusted third party. A decentralized payment mechanism processes a transaction between the parties to the transaction. A distributed payment mechanism relies on the network of users to process a transaction on a shared ledger. We maintain that bitcoin is neither a centralized nor a decentralized payment mechanism. It is, instead, a distributed payment mechanism. We then consider decentralized and centralized aspects of the broader bitcoin payment space.

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Idrobo, Juan Carlos. "Leaning on a ledge." Nature Materials 19, no. 12 (November 18, 2020): 1260–61. http://dx.doi.org/10.1038/s41563-020-00846-8.

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Franca Peri Giglio. "Modelo Educativo sustentado en Valores Espirituales para la vida, la autorrealización y trascendencia." GACETA DE PEDAGOGÍA, no. 48 (January 23, 2024): 17–30. http://dx.doi.org/10.56219/rgp.vi48.2438.

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La espiritualidad es la cualidad propia de la naturaleza trascendente del ser humano que define su sentido y propósito de vida. La educación juega un rol fundamental en este mecanismo de autoco-nocimiento y autorrealización ya que su finalidad no es sólo educare -instruir, entrenar- sino también educere -sacar a la luz, hacer salir-. Al respecto, la presente investigación desarrolló un modelo que operacionaliza lo espiritual a través de valores centrados en el autoconocimiento y la emancipación del Ser, e incorpora a los actores del hecho educativo como participantes activos del proceso en el marco de la educación permanente. El diseño se nutrió de referencias exitosas en el mundo donde las prácticas pedagógicas desarrollan cualidades que promue-ven la integridad y autonomía. Se concluyó que esta propuesta podrá validarse en tanto evidencie transformación interna y externa de los involucrados, en las instituciones y espacios de la sociedad de la cual forman parte. ABSTRACT Spirituality is the quality proper to the transcendent nature of human beings that defines their meaning and purpose in life. Education plays a fundamental role in this mechanism of self-know-ledge and self-realization since its purpose is not only educare -to instruct, to train- but also educere -to bring to light, to bring out-. In this regard, the present research developed a model that operationalizes the spiritual through values centered on self-know-ledge and emancipation of the Self, and incorporates the actors of the educational process as active participants in the process within the framework of lifelong education. The design was nourished by successful references in the world where pedagogical practices develop qualities that promote integrity and autonomy. It was concluded that this proposal can be validated as long as it evidences internal and external transformation of those involved, in the institutions and spaces of the society of which they are part. Key words: Self-realization, Self-knowledge, Spiritual Values, Educational Models, Pedagogy of Being, Continuing Education RESUMO A espiritualidade é a qualidade da natureza transcendente dos seres humanos que define seu significado e propósito na vida. A educação dessempenha um papel fundamental nesse mecanismo de autoconhecimento e autorrealização, uma vez que seu propósito não é apenas educare - instruir, treinar - mas também educere - trazer à luz, trazer à tona. A esse respeito, a presente pesquisa desenvolveu um modelo que operacionaliza o espiritual por meio de valores centrados no autoconhecimento e na emancipação do eu, e incorpora os atores do processo educacional como participantes ativos do processo dentro da estrutura da aprendizagem ao longo da vida. O projeto foi alimentado por referências bem-sucedidas no mundo em que as práticas pedagógicas desenvolvem qualidades que promovem a integridade e a auto-nomia. Concluiu-se que essa proposta pode ser validada desde que evidencie a transformação interna e externa dos emvolvidos, nas instituições e nos espaços da socie-dade da qual fazem parte. Palavras-chave: Autorrealização, Autoconhecimento, Valores Espirituais, Modelos Educacionais, Pedagogia do Eu, Educação ao Longo da Vida RÉSUMÉ La spiritualité est la qualité de la nature transcendante des êtres humains qui définit le sens et le but de leur vie. L'éducation joue un rôle fondamental dans ce mécanisme de conna-issance et de réalisation de soi, puisque son but n'est pas seulement educare - instruire, former - mais aussi educere - mettre en lumière, faire ressortir. À cet égard, la présente recherche a développé un modèle qui opérationnalise la spiritualité à travers des valeurs centrées sur la connaissance de soi et l'émancipation du moi, et qui intègre les acteurs du processus éducatif en tant que participants actifs au processus dans le cadre de l'apprentissage tout au long de la vie. La com-ception a été nourrie par des références réussies dans le monde où les pratiques pédagogiques développent des qualités qui promeuvent l'intégrité et l'autonomie. Il a été conclu que cette pro-position peut être validée tant qu'elle témoigne d'une transformation interne et externe des personnes impliquées, dans les institutions et les espaces de la société dont elles font partie. Mots-clés: Réalisation de soi, connaissance de soi, valeurs spirituelles, modèles éducatifs, pédagogie du soi, éducation tout au long de la vie.

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Berg, Chris. "What Diplomacy in the Ancient Near East Can Tell Us About Blockchain Technology." Ledger 2 (December 18, 2017): 55–64. http://dx.doi.org/10.5195/ledger.2017.104.

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A blockchain is an institutional technology—a protocol—that allows for economic coordination between agents separated by boundaries of possible mistrust. Blockchains are not the only technology in history to have these characteristics. The paper looks at the role of the diplomatic protocol at the very beginning of human civilisation in the ancient near east. These two protocols—diplomatic and blockchain—have significant similarities. They were created to address to similar economic problems using similar mechanisms: a permanent record of past dealings, public and ritualistic verification of transactions, and game-theoretic mechanisms of reciprocity. The development of the diplomatic protocol allowed for the creation of the first international community and facilitated patterns of peaceful trade and exchange. Some questions about a generalised ‘protocol economics’ are drawn.

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Peng, Jiawei, Yijun Wu, and Kunfeng Yuan. "A research on the consensus mechanisms." Applied and Computational Engineering 16, no. 1 (October 23, 2023): 127–37. http://dx.doi.org/10.54254/2755-2721/16/20230853.

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A distributed and decentralized ledger widely used in the computer science and financial fields called blockchain has provided safe and fast transactions for multiple parties. Also, check the transaction by each node on the blockchain. The consensus mechanism is the core of the blockchain. It lets all the nodes reach an agreement for those transactions, which ensures security and accuracy and make Bitcoin valuable and popular. Two of the most mainstream Consensus mechanisms are Proof of Work (PoW) and Proof of Stake (PoS), and Proof of Authority (PoA) is the new one that will apply in the future. Many discourses talk about consensus mechanisms, most of which are review papers. Those papers mainly show a specific aspect of a consensus mechanism or introduce the primary notion, but they rarely explain the corresponding relationship between theories and cryptocurrency. So, the purpose is to give a clear structure, connect the consensus mechanism to its application and simplify the reader's understanding. This paper aims to provide an overview of the consensus mechanism, including its general definition, concepts of different mechanism variants, and advantages and disadvantages. For the structure below, the essay introduces the notion of consensus mechanism and how PoW, PoS, and PoA work. Then summarize the papers based on these three consensus mechanisms, describing the theories of many consensus mechanisms and comparing the advantages and disadvantages. The essay also creates a comparison table about these three consensus mechanisms to embody the content above the stem better.

Journal articles on the topic 'Ledge mechanism'

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