Journal articles on the topic 'Stabilised layers method'
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Lisitano, Domenico, Elvio Bonisoli, and John E. Mottershead. "Experimental direct spatial damping identification by the Stabilised Layers Method." Journal of Sound and Vibration 437 (December 2018): 325–39. http://dx.doi.org/10.1016/j.jsv.2018.08.055.
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Sawka, Agata. "Chemical Vapour Deposition of Scandia-Stabilised Zirconia Layers on Tubular Substrates at Low Temperatures." Materials 15, no. 6 (March 14, 2022): 2120. http://dx.doi.org/10.3390/ma15062120.
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The paper presents results of investigation on synthesis of non-porous ZrO2-Sc2O2 layers on tubular substrates by MOCVD (metalorganic chemical vapor deposition) method using Sc(tmhd)3 (Tris(2,2,6,6-tetramethyl-3,5-heptanedionato)scandium(III), 99%) and Zr(tmhd)4 (Tetrakis(2,2,6,6-tetramethyl-3,5-heptanedionato)zirconium)(IV), 99.9+%) as basic reactants. The molar content of Sc(tmhd)3 in the gas mixture was as follows: 14, 28%. The synthesis temperature was in the range of 600–700 °C. The value of extended Grx/Rex2 expression (Gr-Grashof number, Re-Reynolds number and x-the distance from the gas inflow point) was less than 0.01. The layers were deposited under reduced pressure or close to atmospheric pressure. The layers obtained were tested using scanning electron microscope (SEM) with an energy dispersive X-ray spectroscope (EDS) microanalyzer, X-ray diffractometer and UV-Vis spectrophotometer. The layers deposited were non-porous, amorphous or nanocrystalline with controlled chemical composition. The layers synthesized at 700 °C were nanocrystalline. ZrO2-Sc2O3 layers with 14 mol.% Sc2O3 content had a rhombohedral structure.
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Zabielska-Adamska, Katarzyna, Mariola Wasil, and Patryk Dobrzycki. "Resilient Response of Cement-Treated Coarse Post-Glacial Soil to Cyclic Load." Materials 14, no. 21 (October 29, 2021): 6495. http://dx.doi.org/10.3390/ma14216495.
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Stabilisation with cement is an effective way to increase the stiffness of base and subbase layers and to improve the rutting of subgrade. The aim of the study is to investigate the effect of different percentages of cement additives (1.5%, 3.0%, 4.5% and 6.0%) on the resilient modulus of coarse-grained soil used on road foundations. The influence of the compaction method, the standard Proctor and the modified Proctor, as well as the sample curing time is analysed. The cement addition significantly increases the resilient modulus and reduces the resilient axial strain. Extending the curing time from 7 to 28 days also improves the resilient modulus. The change in the compaction energy from standard to modified does not increase the resilient modulus of the stabilised gravelly sand due to its compaction characteristics. The test results of the resilient modulus of the gravelly sand stabilised with cement indicate the possibility of using it as a material for the road base and subbase due to meeting the AASHTO requirements. However, the non-stabilised gravelly sand does not meet the above requirements. It has been sheared during cyclic tests at the first load sequence, regardless of the compaction method.
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Gołos, Michał, and Piotr Mazurowski. "Pavement Optimisation With Aggregate Base Or Asphalt Layers Stabilised With Hexagonal Geogrids." IOP Conference Series: Materials Science and Engineering 1202, no. 1 (November 1, 2021): 012024. http://dx.doi.org/10.1088/1757-899x/1202/1/012024.
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Abstract The use of hexagonal geogrids in pavement structures results in the increase of the life of designed structure. This offers the possibility to reduce the thickness of layers without reduction of pavement life, or to increase the traffic capacity of a pavement without the need to increase its thickness. This way of using geogrids in pavements design was introduced to the pavement industry by one producer of hexagonal geogrids as a Pavement Optimisation (PO) concept. It can be transformed into both economic and environmental benefits, and obviously results in savings of natural resources and reduction of carbon footprint of a project. PO with geogrids can be used both in the newly designed pavement structures, and in the asphalt overlays of the existing old pavements. Asphalt overlays enhancement with a geogrid either increases the fatigue life of overlays or allows the reduction of overlays thickness to achieve the same pavement life. In new pavements, stabilisation of aggregate base with geogrids increases the stiffness of aggregate, which increases the performance of a whole pavement. This paper presents several tests results, which confirm beneficial effects of using hexagonal geogrids in asphalt overlays and aggregate base layers, from laboratory to full scale accelerated pavement tests. Also, modifications of Mechanistic-Empirical pavement design method, which allow to implement the geogrid benefits into the design process, are discussed. Finally, case studies of pavements – newly designed and reconstructed – optimised with hexagonal geogrids are presented.
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Zikulnig, Johanna, Ali Roshanghias, Lukas Rauter, and Christina Hirschl. "Evaluation of the Sheet Resistance of Inkjet-Printed Ag-Layers on Flexible, Uncoated Paper Substrates Using Van-der-Pauw’s Method." Sensors 20, no. 8 (April 23, 2020): 2398. http://dx.doi.org/10.3390/s20082398.
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With the growing significance of printed sensors on the electronics market, new demands on quality and reproducibility have arisen. While most printing processes on standard substrates (e.g., Polyethylene terephthalate (PET)) are well-defined, the printing on substrates with rather porous, fibrous and rough surfaces (e.g., uncoated paper) contains new challenges. Especially in the case of inkjet-printing and other deposition techniques that require low-viscous nanoparticle inks the solvents and deposition materials might be absorbed, inhibiting the formation of homogeneous conductive layers. As part of this work, the sheet resistance of sintered inkjet-printed conductive silver (Ag-) nanoparticle cross structures on two different, commercially available, uncoated paper substrates using Van-der-Pauw’s method is evaluated. The results are compared to the conductivity of well-studied, white heat stabilised and treated PET foil. While the sheet resistance on PET substrate is highly reproducible and the variations are solely process-dependent, the sheet resistance on uncoated paper depends more on the substrate properties themselves. The results indicate that the achievable conductivity as well as the reproducibility decrease with increasing substrate porosity and fibrousness.
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Fukutomi, M., S. Kumagai, and H. Maeda. "Fabrication of YBa2Cu3Oy Thin Films on Textured Buffer Layers grown by Plasma Beam Assisted Deposition." Australian Journal of Physics 50, no. 2 (1997): 381. http://dx.doi.org/10.1071/p96055.
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A new technique named plasma beam assisted deposition (PBAD) is proposed to grow in-plane textured yttria-stabilised zirconia (YSZ) thin films on polycrystalline metallic substrates as a buffer layer for deposition of YBa2Cu3Oy (YBCO) films. The in-plane texturing of the YBCO films obtained is decisively governed by that of the YSZ buffer layer on which the YBCO grows. Because of a reduction of the weak links at high-angle grain boundaries, a marked increase in the critical current density Jc is observed with improved texturing of the YBCO films. So far, it has been demonstrated that YBCO films with Jc above 105 A cm-2 (77 K, 0 T) can be successfully deposited by a laser ablation technique. The PBAD process proposed here is found to be valuable technologically because it offers a very convenient method to grow textured films on long tape or large area substrates. An attempt was also made to grow textured films simultaneously on one side or both sides of various pieces of tape substrates. The results indicate that PBAD is one potential technique for future large scale application of YBCO films.
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Góral, Marek, Tadeusz Kubaszek, Marcin Kobylarz, Marcin Drajewicz, and Maciej Pytel. "Thermal Barrier Coating Deposited Using the PS-PVD Method on TiAl-Nb-Mo Intermetallic Alloy with Different Types of Bond Coats." Solid State Phenomena 320 (June 30, 2021): 60–65. http://dx.doi.org/10.4028/www.scientific.net/ssp.320.60.
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TiAl intermetallics can be considered an alternative for conventional nickel superalloys in the high-temperature application. A TBC (Thermal Barrier Coatings) with ceramic topcoat with columnar structure obtained using EB-PVD (electron beam physical vapour deposition) is currently used to protect TiAl intermetallics. This article presents the new concept and technology of TBC for TiAl intermetallic alloys. Bond coats produced using the slurry method were obtained. Si and Al nanopowders (70 nm) were used for water-based slurry preparation with different composition of solid fraction: 100 wt.% of Al, 50 wt.% Al + 50 wt.% Si and pure Si. Samples of TNM-B1 (TiAl-Nb-Mo) TiAl intermetallic alloy were used as a base material. The samples were immersed in slurries and dried. The samples were heat treated in Ar atmosphere at 1000 °C for 4 h. The outer ceramic layer was produced using the new plasma spray physical vapour deposition (PS-PVD) method. The approximately 110 μm thick outer ceramic layers contained yttria-stabilised zirconium oxide. It was characterised by a columnar structure. Differences in phase composition and structures were observed in bond coats. The coatings obtained from Al-contained slurry were approximately 30 μm thick and consisted of two zones: the outer contained the TiAl3 phase and the inner zone consisted of the TiAl2 phase. The second bond coat produced from 50 wt.% Al + 50 wt.% Si slurry was characterised by a similar thickness and contained the TiAl2 phase, as well as titanium silicides. The bond coat formed from pure-Si slurry had a thickness < 10 μm and contained up to 20 at % of Si. This suggests the formation of different types of titanium silicides and Ti-Al phases. The obtained results showed that PS-PVD method can be considered as an alternative to the EB-PVD method, which is currently applied for deposition a columnar structure ceramic layer. On the other hand, the use of nanopowder for slurry production is problematic due to the smaller thickness of the produced coating in comparison with conventional micro-sized slurries.
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Zhang, Fuhai, Lei Zhang, and Wangxi Hong. "Stabilization of Expansive Soil with Polyvinyl Alcohol and Potassium Carbonate." Advances in Civil Engineering 2019 (November 14, 2019): 1–11. http://dx.doi.org/10.1155/2019/7032087.
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Expansive soils have great volume change potentials with water content changes, which is problematic to facilities. Great efforts have been spent on finding proper methods to stabilize expansive soils, but these stabilizers all had limitations. The Polyvinyl alcohol (PVA) and K2CO3 combination was proposed in this paper. Free swell tests, oedometric tests, unconfined compression tests, and direct shear tests were performed to investigate the effectiveness of the PVA and K2CO3 combination to control the volume change and increase the soil strength. Microstructures of the natural expansive soil and the stabilized soil were also studied with SEM photos. SEM photos showed a homogenous and dense microstructure after stabilization. In addition, a laboratory soil column model was built to study the ability of this stabilizer combination to stabilize expansive soils by directly spraying the solution on the ground surface. All these test results show that the combination of PVA and K2CO3 is able to effectively stabilize the natural expansive soil and increase the shear strength. It is possible to directly spray the stabilizer solution on the soil surface to form a relatively thick layer of the stabilized expansive soil.
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Gromysz, Krzysztof, Łukasz Szoblik, Ewa Cyrulik, Agnieszka Tanistra-Różanowska, Zofia Drabczyk, and Szymon Jancia. "Analysis of stabilisation method of gable walls of a barrack located at the section BI of the former KL Auschwitz II-Birkenau." MATEC Web of Conferences 284 (2019): 08004. http://dx.doi.org/10.1051/matecconf/201928408004.
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The subject of the article is an analysis of the stabilisation method of the western gable walls of a barrack with the inventory number B-123, situated at the section BI of the former German Nazi concentration and extermination camp Auschwitz II-Birkenau. The barracks of the former Birkenau have a documentary and historical value and are subject to protective conservation. A barrack with inv. no. B-123 had been erected in the last months of 1941 as a residential barrack, then it was used as a hospital facility. The barrack walls are characterised by low stiffness, because with the building’s plan of 36.17 m 11.39 m, the walls are only 0.12 m thick. Gable walls have been greatly deformed, as a result they have detached from longitudinal walls and their deflection is up to 120 mm. The construction of the walls is at risk, because a bad-quality wall is loaded with horizontal and vertical forces transmitted from the roof, on the eccentricity reaching 120 mm. Deformations are progressing as a consequence of such forces and the walls must be stabilised. In case of the western wall, it was decided to stop its further deformation and to increase the local carrying capacity by stabilising with steel elements connected with ties anchored in the ground. Given the historical value of the plasters with paint coats layers covering the wall, it was decided not to remove the wall deformation mechanically. For the eastern wall, which is not covered with plaster and was partly reconstructed after the war, the removal of its deflection by rectification was designed.
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Mallick, Rajib B., Animesh Das, and S. Nazarian. "Fast Nondestructive Field Test Method to Determine Stiffness of Subsurface Layer in Thin Surface Hot-Mix Asphalt Pavement." Transportation Research Record: Journal of the Transportation Research Board 1905, no. 1 (January 2005): 82–89. http://dx.doi.org/10.1177/0361198105190500109.
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The determination of the moduli of subsurface stabilized layers in pavements with unknown and variable layers and thin asphalt layers is a challenging problem. Reliable estimation of moduli cannot be obtained from backcalculation of falling weight deflectometer data. In addition, for many stabilized layers, full-depth intact cores cannot be obtained from the field, and hence, laboratory determination of the moduli is not possible. Analysis of the seismic property of a pavement is a well-known method for estimation of the surface modulus of the pavement. This paper proposes a simple methodology on how seismic data acquired on the pavement surface can be effectively used to estimate the modulus of the surface layer as well as those of the subsequent subsurface layers of a flexible pavement. A research study was conducted on three hot-mix asphalt pavements with a foamed asphalt (FA) stabilized base in Maine. These three pavements were tested with both portable seismic and falling weight deflectometer equipment. Cores were taken from the same locations and tested in the laboratory for their resilient moduli. The modulus values obtained from different tests were compared, the effect of temperature on the modulus of the FA was evaluated, and the deflections computed from layered elastic analysis by use of the predicted modulus of the FA layer were compared with the observed deflections. It is concluded that the portable seismic equipment can be used to determine accurate moduli of subsurface stabilized layers. The practical advantages of using such equipment warrant further study for refinement of the method.
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Guenet, B., T. Eglin, N. Vasilyeva, P. Peylin, P. Ciais, and C. Chenu. "The relative importance of decomposition and transport mechanisms in accounting for soil organic carbon profiles." Biogeosciences 10, no. 4 (April 10, 2013): 2379–92. http://dx.doi.org/10.5194/bg-10-2379-2013.
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Abstract. Soil is the major terrestrial reservoir of carbon and a substantial part of this carbon is stored in deep layers, typically deeper than 50 cm below the surface. Several studies underlined the quantitative importance of this deep soil organic carbon (SOC) pool and models are needed to better understand this stock and its evolution under climate and land-uses changes. In this study, we tested and compared three simple theoretical models of vertical transport for SOC against SOC profiles measurements from a long-term bare fallow experiment carried out by the Central-Chernozem State Natural Biosphere Reserve in the Kursk Region of Russia. The transport schemes tested are diffusion, advection and both diffusion and advection. They are coupled to three different formulations of soil carbon decomposition kinetics. The first formulation is a first order kinetics widely used in global SOC decomposition models; the second one, so-called "priming" model, links SOC decomposition rate to the amount of fresh organic matter, representing the substrate interactions. The last one is also a first order kinetics, but SOC is split into two pools. Field data are from a set of three bare fallow plots where soil received no input during the past 20, 26 and 58 yr, respectively. Parameters of the models were optimised using a Bayesian method. The best results are obtained when SOC decomposition is assumed to be controlled by fresh organic matter (i.e., the priming model). In comparison to the first-order kinetic model, the priming model reduces the overestimation in the deep layers. We also observed that the transport scheme that improved the fit with the data depended on the soil carbon mineralisation formulation chosen. When soil carbon decomposition was modelled to depend on the fresh organic matter amount, the transport mechanism which improved best the fit to the SOC profile data was the model representing both advection and diffusion. Interestingly, the older the bare fallow is, the lesser the need for diffusion is, suggesting that stabilised carbon may not be transported within the profile by the same mechanisms than more labile carbon.
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Song, Guochenhao, Zhuang Mo, and J. Stuart Bolton. "A general stable approach to modeling and coupling multilayered systems with various types of layers." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 265, no. 6 (February 1, 2023): 1834–41. http://dx.doi.org/10.3397/in_2022_0259.
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In this article, a general method is proposed to model layered systems with two-by-two transfer matrices, and further, to solve for the acoustic absorption, reflection, and transmission coefficients. Since the proposed method uses the matrix representation of various layers and interfaces from the Transfer Matrix Method (TMM), the equation system can be established efficiently. However, the traditional TMM can lose stability when there is a large disparity between the magnitudes of the waves traveling in opposite directions within the layers (i.e., at higher frequencies, for a thick layer, or for extreme parameter values). In such cases, the contribution of the most attenuated wave can be masked by numerical errors and can induce instability when solving the system. Therefore, in the proposed method, to stabilize the calculated acoustic properties of the system, the principle is to ensure the accuracy of the wave attenuation terms by decomposing each layer's transfer matrix and reformulating the equation system. This method can couple different layer types in a general way and is easy to assemble and implement with numerical code. The predicated acoustic properties of layered systems calculated using the proposed method have been validated by comparison with those predicted by other existing methods.
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Qin, Yue, Yongjun Meng, Zubiao Lu, Qixiong Zhao, and Hongliu Rong. "Analysis of Loading Stress of Pavement Structure using One-Step Forming Cement-Stabilized Macadam Base." E3S Web of Conferences 136 (2019): 04042. http://dx.doi.org/10.1051/e3sconf/201913604042.
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Layered construction of large thickness cement-stabilized macadam base makes the base change from designed being forced by whole layer to being forced by two thin layers, the existence of interfacial friction between two thin layers reduces the pavement performance of the base, which finally cause the reduction of pavement performance of whole pavement structure. To analyze the load responses of large thickness cement-stabilized macadam base asphalt pavement under different working conditions, pavement surface deflection, maximum principal stresses of surface layer bottom and base layer bottom, minimum principal strain of soil base top and maximum shear stress of surface layer bottom under two different working conditions(layered construction and one-step forming) are taken as indexes and are obtained by finite element analysis method in this paper.
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Tereshchenko, Tatiana, and Serhii Illiash. "CLASSIFICATION AND APPLICATION OF SOILS STABILIZED WITH HYDRAULIC BINDER IN ACCORDANCE WITH EUROPEAN STANDARDS." Avtoshliakhovyk Ukrayiny, no. 1 (261)’2020 (March 20, 2020): 40–48. http://dx.doi.org/10.33868/0365-8392-2020-1-261-40-48.
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Soils being the most widely used materials for road building industry predominantly contribute the improvement of their mechanical and/or technological properties. Relating to the world-wide experience in road building industry, the most effective method for such improvement is treatment of soils with hydraulic binder under optimum water content. Those mixtures being properly compacted set and harden by hydraulic reaction and give stabilized soils. Requirements and classification of hydraulically stabilized soils established by European standards provide wide possibilities for soils application considering their performance in pavement layers. The elaboration of Ukrainian standards identical to the European standards relating hydraulically stabilized soils should permit the elongated life cycle of pavement and also decrease expenses on repairs of road pavements caused by deformation of sub-grade. This article reviews classification and application of hydraulically stabilized soils according to the requirements of European standards. In accordance with European standards, stabilized soils are classified as hydraulically bound mixtures which properties are covered by Specifications on Hydraulically Bound Mixtures (European Standard EN 14227, Part 15). To conform the standard requirements soils should be treated by standard hydraulic binder (or a combination thereof): cement, slag, fly ash, lime, or a standard hydraulic road binder should be applied. Composition and methods of manufacturing (compaction) of specimens of hydraulically stabilized soils give several strength classes of stabilized materials with the highest category characterized by the cubes compressive strength not less than 12 MPa. European standards establish also classification of hydraulically stabilized soils by tensile strength Rt in combination with elastic modulus E; according to that classification the stabilized materials are divided into five categories from T1 to T5. European standards establish also classification of fresh mixtures by immediate bearing index. This value determines the suitability of a compacted layer to support the immediate trafficking. Nevertheless, that requirement may not cover cement-stabilized mixtures for construction of layers which are not intended to be trafficked for 7 days. The in-situ manufacture of stabilized mixtures needs some measures to minimize the inadequacy of properties of a material, or geometry of a layer such as an increased proportion of a binder or an increased layer thickness. Keywords: hydraulically stabilized soils, classification, compressive strength, immediate bearing index, construction of a layer.
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Shin, Seung Ho, Jun-Sik Park, Hojae Lee, Seok-Won Kong, Junghum Park, Yoonjin Won, and Young-Beom Kim. "Fabrication of Scandia-Stabilized Zirconia Thin Films by Instant Flash Light Irradiation." Coatings 10, no. 1 (December 21, 2019): 9. http://dx.doi.org/10.3390/coatings10010009.
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In this study, scandia-stabilized zirconia (ScSZ) electrolyte thin-film layers were deposited via chemical solution deposition (CSD). We selected 10ScSZ (10% Sc 2 O 3 , 90% ZrO 2 molar ratio) as the target material, and the precursor solution was prepared by precise calculations. The 10ScSZ solution was deposited on Al2O3 substrate using a spin-coating method. Then, the substrate was sintered using two methods: flash light irradiation and thermal. The characteristics of the thin films were compared, including ionic conductivity, surface morphology, and chemical composition. Pulsed light sintering was applied in the sintering step under a variety of energy density conditions from 80 to 130 J/ cm 2 , irradiation on/off times of 10 ms and 10 ms/500 ms, number of pulses, and bottom heat from 300 to 600 °C. The ionic conductivity of the ScSZ electrolyte layers fabricated by thermal or flash light irradiation methods was tested and compared. The results show that the ScSZ electrolyte layer sintered by flash light irradiation within a few seconds of process time had similar ionic conductivity to the electrolyte layer that was thermal sintered for about 10 h including cooling process.
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Xu, Hailiang, Hehuan Ren, Jining Qin, and Xu Guo. "Experimental Study on Structural Mechanics of Asphalt Pavement by Digital Speckle Correlation Methods." Mathematical Problems in Engineering 2020 (November 5, 2020): 1–10. http://dx.doi.org/10.1155/2020/8857369.
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The experiments on the structural mechanics of asphalt pavement were carried out by the digital speckle correlation method (DSCM). The digital speckle correlation method is used to collect experimental data. The displacement and strain values of each layer of the asphalt pavement structure are analyzed. The research showed that (1) the digital speckle correlation methods could accurately observe the displacement value and the strain value of the pavement structure. (2) The stress state of the pavement structure was greatly influenced by the interlayer effect. The vertical displacement changed suddenly between layers. The concentration phenomenon of the tension-compression strain and the shear strain appeared between layers. (3) The overloading situation seriously worsened the overall stress state of the pavement structure, especially at the bottom of the asphalt top layer and lower layer and at the top of the cement-stabilized crushed stone. The research results are of great significance to the structural design of heavy-duty roads.
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Cao, Mingming, Wanqing Huang, Yiwen Zou, and Zhiyong Wu. "Equivalent Resilient Modulus Inversion and Calculation of Different Asphalt Pavement Structures." Advances in Civil Engineering 2021 (November 22, 2021): 1–9. http://dx.doi.org/10.1155/2021/2620559.
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Based on the modulus inversion theory and the equivalent principle of deflection basin, by analyzing the deflection basin data of each structure layer measured by the FWD, the obtained equivalent resilient moduli of different structural layers in three different structures (a semirigid type Asphalt pavement and two inverted asphalt pavements) were compared. At the same time, the calculated equivalent resilient modulus of the top surface of the structural layer based on the inversion method was used to modify the existing theory formula. The results show that, with the inversion method and the theoretical calculation method, the calculated equivalent resilient modulus of the top surface of the cushion layer has a small error, but the theoretical calculation method overestimates the equivalent resilient modulus of the top surface of the cement stabilized crushed stone layer and the top surface of the graded crushed stone transition layer, especially for the inverted asphalt pavement; by contrast, the corresponding result of the inversion method is closer to the value in actual engineering. While determining the equivalent resilient modulus of the cushion layer, the influence of the thickness of the cement stabilized crushed stone layer needs to be considered, and the inverted asphalt pavement structure should adopt a thicker asphalt layer to reduce the modulus deviation; at the same time, the more the structural layers and the larger the difference in the interlayer modulus ratio, the larger the deviation of equivalent resilient modulus of the top surface of the base layer; for the inverted asphalt pavement and semirigid asphalt pavement, the correction coefficients of the calculation formula of the equivalent resilient modulus of the top surface of cement stabilized gravel layer are 0.35∼0.55 and 0.65∼0.75, respectively. The inversion method can be used to determine the equivalent resilient modulus of each structural layer of the inverted asphalt pavement and semirigid asphalt pavement, and its results can provide a basis for the design of the structure reconstruction of asphalt pavement.
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Cao, Mingming, Wanqing Huang, Yiwen Zou, and Guomin Liu. "Modulus Inversion Layer by Layer of Different Asphalt Pavement Structures." Advances in Civil Engineering 2021 (September 2, 2021): 1–10. http://dx.doi.org/10.1155/2021/1928383.
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In order to improve the accuracy of modulus inversion of the pavement structure layer, a layer-by-layer inversion method was proposed to be compared with the traditional inversion method by inverting the modulus of each structural layer of the inverted asphalt pavement and semirigid asphalt pavement. The results show that the influence of cushion modulus on the modulus of inverted subgrade and modulus of cement-stabilized crushed stone is restricted by the cushion modulus and pavement structure characteristics, and the thicker cement-stabilized crushed stone layer is beneficial for improving inverted modulus of subgrade; besides, for the inverted asphalt pavement, the modulus of the graded crushed stone transition layer has a significant influence on the modulus inversion of cement-stabilized crushed stone. The modulus of the graded gravel transition layer inverted by these two methods is underestimated, the modulus of cement-stabilized gravel is overestimated using the traditional inversion method, and the inversion result of the inverted asphalt pavement is more significantly affected by the inversion method than the semirigid base asphalt pavement. Moreover, the modulus of the pavement structural layer is determined by the material and structural characteristics, and its recommended empirical value or the value in the indoor test does not conform to the actual value of the site; by contrast, the inversion modulus obtained using the layer-by-layer inversion method is closer to the actual value, which can be used in the design of similar pavement structures to accumulate data for determining the material modulus or the pavement structure adjustment coefficient in the pavement structure.
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Barstis, William F., and John Metcalf. "Practical Approach to Criteria for the Use of Lime–Fly Ash Stabilization in Base Courses." Transportation Research Record: Journal of the Transportation Research Board 1936, no. 1 (January 2005): 20–27. http://dx.doi.org/10.1177/0361198105193600103.
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In October 2000 the Mississippi Department of Transportation (MDOT) initiated a study to evaluate the long-term performance of lime–fly ash (LFA) stabilized soil as a base course material. This study entailed performing falling weight deflectometer (FWD) tests on both newer and older pavements and coring pavement at each FWD location to observe the condition of the layers, to obtain pavement thicknesses, and to perform unconfined compressive strength (UCS) testing. Visual observation, backcalculated modulus, and in situ structural layer coefficient values showed that MDOT LFA-stabilized soil base courses have highly variable material properties and thicknesses. Recommendations were made to increase the average LFA material property values and to reduce the spread in these values by increasing the required compaction of the LFA-stabilized soil base layer to 100% standard Proctor effort, setting the required in situ Proctor UCS at 400 psi, and reducing variability by either improving the current method of field-mixed-in-place stabilization or requiring plant-mixed material with placement of the blended material via a paver. It is further recommended to increase the typical LFA-stabilized soil base layer design thickness from 6 to 8 in. and to use a 6-in. chemically stabilized subgrade layer to provide additional support to the pavement structure.
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Góral, Marek, Tadeusz Kubaszek, Barbara Kościelniak, Marcin Drajewicz, and Mateusz Gajewski. "Microstructure and Oxidation Resistance of Thermal Barrier Coatings with Different Ceramic Layer." Solid State Phenomena 320 (June 30, 2021): 31–36. http://dx.doi.org/10.4028/www.scientific.net/ssp.320.31.
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Thermal barrier coatings are widely used for protection of gas turbine parts against high temperature oxidation and hot corrosion. In present work the microstructural assessment of TBCs produced by atmospheric plasma spray (APS) method was conducted. Three types of ceramic powders were used: magnesia- stabilized zirconia oxide (Metco 210), yttria stabilized zirconia oxide (YSZ -Metco 204) and fine-grained YSZ – Metco 6700. As a base material the Inconel 713 was used as well and CoNiCrAlY was plasma sprayed (APS) as a bond coat. The thickness of all ceramic layers was in range 80 – 110 μm. The elemental mapping of cross-section of magnesia-stabilized zirconia showed the presence of Mg, Zr and O in outer layer. In the YSZ ceramic layer the Y, Zr and O were observed during elemental mapping. The isothermal oxidation test was conducted at 1100 °C for 500 h in static laboratory air. On all samples the delamination and spallation of ceramic layers was observed. Chemical composition analysis of coatings showed the presence of two areas: the first one contained elements from bond coats: Ni, Cr, Al, Co and second area contained O, Cr Co and O that suggest the scale formation. The obtained results showed the total degradation of all ceramic layers as a result of internal stresses in bond-coat. Microscopic analysis showed the areas with complete degradation of bond coats and formation of thick oxides layer.
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HAUKE, GUILLERMO, GIANCARLO SANGALLI, and MOHAMED H. DOWEIDAR. "COMBINING ADJOINT STABILIZED METHODS FOR THE ADVECTION-DIFFUSION-REACTION PROBLEM." Mathematical Models and Methods in Applied Sciences 17, no. 02 (February 2007): 305–26. http://dx.doi.org/10.1142/s0218202507001929.
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Computational methods for the advection-diffusion-reaction transport equation are still a challenge. Although there exist globally stable methods, oscillations around sharp layers such as boundary, inner and outflow layers, are typical in multi-dimensional flows. In this paper a variational formulation that combines two types of stabilization integrals is proposed, namely an adjoint stabilization and a gradient adjoint stabilization. Two free parameters are chosen by imposing one-dimensional superconvergence. Then, when applied to multi-dimensional flows, the method presents better local stability than the present stabilized methods. Furthermore, in the advective-diffusive limit and for piecewise linear functional spaces, the method recovers the classical SUPG method.
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Aly, Abdelraheem M. "Natural convection of a nanofluid-filled circular enclosure partially saturated with a porous medium using ISPH method." International Journal of Numerical Methods for Heat & Fluid Flow 30, no. 11 (March 18, 2020): 4909–32. http://dx.doi.org/10.1108/hff-12-2019-0919.
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Purpose The purpose of this study is to simulate the natural convection of a heated square shape embedded in a circular enclosure filled with nanofluid using an incompressible smoothed particle hydrodynamics (ISPH) method. Design/methodology/approach In the ISPH method, the evaluated pressure was stabilized by using a modified source term in solving the pressure Poisson equation. The divergence of the velocity was corrected, and the dummy particles were used to treat the rigid boundary. Dummy wall particles were initially settled in outer layers of the circular enclosure for preventing particle penetration and reducing the error of truncated kernel. The circular enclosure was partially filled with a porous medium near to the outer region. The single-phase model was used for the nanofluid, and the Brinkman–Forchheimer-extended Darcy model was used for the porous medium. Dummy wall particles were initially settled in outer layers of circular enclosure for preventing particle penetration and reducing error from the truncated kernel on the boundary. Findings The length of the inner square shape plays an important role in enhancing the heat transfer and reducing the fluid flow inside a circular enclosure. The porous layer represents a resistance force for the fluid flow and heat transfer, and, consequently, the velocity field and temperature distributions are reduced at the outer region of the circular cylinder. Then, the radius of the inner square shape, Darcy parameter and radius of the porous layer were considered the main factors for controlling the fluid flow and heat transfer inside a circular enclosure. The average Nusselt number decreases as the inner square length, radius of the porous layer and solid volume fraction increase. Originality/value The stabilized ISPH method is corrected for simulating the natural convection from an inner hot square inside a nanofluid-filled circular enclosure saturated with a partial layer of a porous medium.
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Lin, Chun-Yi, and Wu-Sung Yao. "Analysis and Design Multiple Layer Adaptive Kalman Filter Applied to Electro-Optical Infrared Payload Vision System." Electronics 11, no. 5 (February 23, 2022): 677. http://dx.doi.org/10.3390/electronics11050677.
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This study designs a trigger to determine the number of layers of a multi-layer adaptive Kalman filter and applies it to optoelectronic infrared payload system vision. This feature reduces the number of mechanically stabilized motors, equipment weight, CPU resources, and power for an electro-optical infrared payload system. The goal is to reduce the traditional use of multiple gyroscopes to perform calibration measurements on different gimbal frames by this design. In this study, mathematical modeling was carried out for the three-axis, three-frame camera stabilizer system, and the system foundation without motor and gimbal frame was established to achieve aperture-type camera mode. The exposure of the drone’s payload structure outside the aircraft can be reduced. This study provides the adaptive Kalman filter with the offset parameters of the camera image Minimum Output Sum of Squared Error and the three-axis degrees of freedom vector and angle data on the gyroscope. By using the image processing unit, the offset was corrected at each frame per second. The experimental results show that under the same hardware, failure limit and camera field of view constraints. The processing time by this method was compared to the traditional frame correction and full image stabilization methods. The results show that the proposed method can shorten 6 microseconds under the traditional method and can be used to provide lower power consumption, lower image delay, and a larger viewing angle range.
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Araki, Koiti, Eisuke Mizuguchi, Hirofumi Tanaka, and Takuji Ogawa. "Preparation of Very Reactive Thiol-Protected Gold Nanoparticles: Revisiting the Brust-Schiffrin Method." Journal of Nanoscience and Nanotechnology 6, no. 3 (March 1, 2006): 708–12. http://dx.doi.org/10.1166/jnn.2006.079.
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The preparation and properties of tert-dodecanethiol protected gold nanoparticles amenable to very rapid surface functionalization by associative mechanism is described. The new material can be easily prepared by controlling the reaction time, because only a limited but enough number of tert-dodecanethiol to stabilize the gold clusters is bond to the surface until about an hour. Accordingly, it can be isolated as a solid and handled much like the highly stabilized Brust-Schiffrin analogues, but reacted very rapidly with any molecular species containing one or multiple functional groups such as thiol, disulfide, pyridine, etc., These characteristics are ideal for the preparation of a variety of new organic–inorganic hybrid nanomaterials by coordinative self-assembly. This possibility was illustrated using meso-tetra(4-pyridyl)porphyrin, which promptly bonded to the reactive protected gold nanoparticles generating a solid that can be grown as thin films with layer-by-layer control on a suitably modified surface.
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Račko, Vladimír, Ol’ga Mišíková, Jaroslava Štefková, and Igor Čunderlík. "A fast method to prepare microslides of wood in advanced stages of decay." IAWA Journal 39, no. 2 (June 13, 2018): 234–43. http://dx.doi.org/10.1163/22941932-20170196.
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ABSTRACTBiologically degraded wood in advanced stages of decay has a very soft and brittle structure that causes many problems during sectioning. Embedding wood specimens in different kinds of media ensures preparation of good quality microsections, but the preparation time is very long. The proposed method does not only have a reduced preparation time but also minimizes costs and consumption of chemicals while improving stabilization of the specimen and enhancing the quality of sections. The crux of the method is application of a reinforcing layer of transparent nail polish gel on a dry specimen that has been only stabilized (not embedded) with PEG 1500 medium. The gel is applied on a specimen in two layers just before sectioning. The first layer infiltrates the specimen sufficiently deep to fill the lumens and cell walls and allows preparation of thin sections from decayed wood. The second layer reinforces the section and allows better handling. Subsequently, the reinforcing and embedding layers are removed using pure acetone. This innovative method has so far been successfully tested on specimens that were degraded by the fungusPleurotus ostreatus(mass loss 55% and 83%) and the fungusPhaeolus schweinitzii(mass loss 45%), taken fromFagus sylvaticaandPinus sylvestrisspecies, a hardwood and softwood respectively with contrasting wide vessels and narrow tracheids.
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Li, Bo, Yong He Yue, and Zheng Wei Zhang. "Comparative Analysis on Stress-Strain Characteristics for Cement Stabilized Macadam Base in Different Layer Contact Conditions." Applied Mechanics and Materials 477-478 (December 2013): 547–52. http://dx.doi.org/10.4028/www.scientific.net/amm.477-478.547.
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In this paper, roads analysis software bisar 3.0 be used to build an elastic layered system analysis model for cement stabilized macadam base. Different construction methods and structures contact conditions between the layers were comprehensive considered based on the actual pavement structure, in order to analyze the internal stress-strain state of cement stabilized macadam. The results show that interlayer contact conditions is approximately smooth state when cement stabilized macadam base used the traditional two layered construction method, which may occur structural damage between cement stabilized macadam base caused by partial stress concentration. However, the interlayer contact conditions is approximately completely continuous state when used the overall construction methods, and the stress-strain state of cement stabilized macadam can significantly improve by changing interlayer contact conditions. Finally, by changing the construction methods for to change interlayer contact conditions, the stress-strain state of cement stabilized macadam can be effectively improved, and the road performance and service life also be significantly improved.
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Bhuvanesh, Thanga, Rainhard Machatschek, Yue Liu, Nan Ma, and Andreas Lendlein. "Self-stabilized fibronectin films at the air/water interface." MRS Advances 5, no. 12-13 (November 4, 2019): 609–20. http://dx.doi.org/10.1557/adv.2019.401.
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ABSTRACTFibronectin (FN) is a mediator molecule, which can connect cell receptors to the extracellular matrix (ECM) in tissues. This function is highly desirable for biomaterial surfaces in order to support cell adhesion. Controlling the fibronectin adsorption profile on substrates is challenging because of possible conformational changes after deposition, or due to displacement by secondary proteins from the culture medium. Here, we aim to develop a method to realize self-stabilized ECM glycoprotein layers with preserved native secondary structure on substrates. Our concept is the assembly of FN layers at the air-water (A-W) interface by spreading FN solution as droplets on the interface and transfer of the layer by the Langmuir-Schäfer (LS) method onto a substrate. It is hypothesized that 2D confinement and high local concentration at A-W interface supports FN self-interlinking to form cohesive films. Rising surface pressure with time, plateauing at 10.5 mN·m-1 (after 10 hrs), indicated that FN was self-assembling at the A-W interface. In situ polarization-modulation infrared reflection absorption spectroscopy of the layer revealed that FN maintained its native anti-parallel β-sheet structure after adsorption at the A-W interface. FN self-interlinking and elasticity was shown by the increase in elastic modulus and loss modulus with time using interfacial rheology. A network-like structure of FN films formed at the A-W interface was confirmed by atomic force microscopy after LS transfer onto Si-wafer. FN films consisted of native, globular FN molecules self-stabilized by intermolecular interactions at the A-W interface. Therefore, the facile FN self-stabilized network-like films with native anti-parallel β-sheet structure produced here, could serve as stable ECM protein coatings to enhance cell attachment on in vitro cell culture substrates and planar implant materials.
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Zhang, Zhaohui, Xinxin Zhou, Xiaobo Zhang, Lizhi Wang, and Pengwei Wang. "A Model Based on Convolutional Neural Network for Online Transaction Fraud Detection." Security and Communication Networks 2018 (August 6, 2018): 1–9. http://dx.doi.org/10.1155/2018/5680264.
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Using wireless mobile terminals has become the mainstream of Internet transactions, which can verify the identity of users by passwords, fingerprints, sounds, and images. However, once these identity data are stolen, traditional information security methods will not avoid online transaction fraud. The existing convolutional neural network model for fraud detection needs to generate many derivative features. This paper proposes a fraud detection model based on the convolutional neural network in the field of online transactions, which constructs an input feature sequencing layer that implements the reorganization of raw transaction features to form different convolutional patterns. Its significance is that different feature combinations entering the convolution kernel will produce different derivative features. The advantage of this model lies in taking low dimensional and nonderivative online transaction data as the input. The whole network consists of a feature sequencing layer, four convolutional layers and pooling layers, and a fully connected layer. Verifying with online transaction data from a commercial bank, the experimental results show that the model achieves excellent fraud detection performance without derivative features. And its precision can be stabilized at around 91% and recall can be stabilized at around 94%, which increased by 26% and 2%, respectively, comparing with the existing CNN for fraud detection.
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Dolgov, Nikolay, Kristine Carjova, Leonid Vinogradov, Olexandr Melnychenko, Janis Brunavs, Sintija Girgensone, Janis Baronins, and Lilit Zakoyan. "The Model for Estimating the Failure Mechanism of Tensioned Plasma-Sprayed Zirconia Ceramic Hard Coating." Coatings 12, no. 8 (August 14, 2022): 1175. http://dx.doi.org/10.3390/coatings12081175.
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Loading flat coated specimens with tensile forces is a universal method to determine the nature of fracture of hard coatings in maritime applications. Such an approach allows the determination of the shear strength at the interfaces between layers and the cohesive properties. Thus, the authors studied the fracturing processes of plasma-sprayed yttria-stabilized zirconia two-layer coatings under the action of tensile forces. The results revealed cracking characteristics in the outer ceramic layer and delamination of flat metal specimens. An analytical method led to normal stress determination in the coating. It also exhibited shear stresses at the bond coat-substrate interface and the top coat-bond coat interfaces. The results include normal and shear stress distributions before and after fragmentation of the ceramic top layer. Tested substrate, the metal bond coat, and the ceramic top coat exhibit a modulus of elasticity of 196, 142, and 47 GPa, respectively. Engineers could apply the proposed methodology and the mathematical analysis to study the causes of cracks and delamination between layers.
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Grygierek, Marcin, Piotr Kalisz, Krzysztof Pacześniowski, Andrzej Pytlik, and Magdalena Zięba. "Assessment of burned coal shale properties based on cyclic load." E3S Web of Conferences 36 (2018): 03001. http://dx.doi.org/10.1051/e3sconf/20183603001.
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Road surfaces that are subjected to cyclic loads generated by vehicle wheels must meet the requirements concerning the durability in the assumed period of use. The durability of the layered pavement construction systems depends on the value and frequency of the load as well as on the mechanical features of its individual layers. Layers of unbound, mechanically stabilized mixtures are a significant aspect of surfaces that are susceptible. Mixtures of this type can be applied both to the subgrade layers as well as to the bottom pavement layers, including the improved course. Considering the cyclic nature of the load on the surface of the entire system, mechanically stabilized layers are subject to continuous, but slow, densification during the period of use, which results in the formation of permanent deformations and so-called structural ruts. Post-mining waste is frequently used in road construction. which is the so-called burned shale that can be used for the bottom layers of the surface and layers of the improved subgrade (soil replacement). This material was the subject of the analysis. The evaluation was based mainly on the results of pilot studies covering cyclic loads of the layer/course made of the so-called red shale. The applied research method was aimed at preliminary assessment of its suitability for the assessment of the behaviour of the disintegrated medium under the conditions of test loads simulating the movement of vehicles.
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Sharipova, Altynai, Asem Issayeva, Saule Aidarova, Zhanar Ospanova, Akerke Bektursyn, and Alpamys Babayev. "Study of the kinetics of the release of lipophilic ingredients from capsules using synthetic and natural systems." Chemical Bulletin of Kazakh National University, no. 4 (October 22, 2021): 28–33. http://dx.doi.org/10.15328/cb1216.
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In the work, the kinetics of the release of vitamin E and polyphyte oil from capsules was studied using synthetic and natural systems. The release of active ingredients was monitored on a Cary 50 Cons UV spectrophotometer equipped with CaryWinUV software. The kinetics of the release of vitamin E from capsules stabilized with sodium caseinate and then coated with chitosan shows a sustained prolonged release of 20% of vitamin E within 1 h, within 5 h about 45% is released, within 48 h about 80%. It was found that the efficiency of capsulation of vitamin E is higher than that of polyphyte oil, the release of vitamin E is more delayed and prolonged in comparison with polyphyte oil. The release of vitamin E from capsules stabilized with a synthetic system polymer-surfactant / vitamin E) chitosan) polystyrene sulfonate PSS was also investigated. It was determined that the release of vitamin E from capsules stabilized by a synthetic system (polymer-surfactant and coated with two layers of oppositely charged polyelectrolyte by the Layer-by-Layer method) is prolonged, within 1 h – 23% of vitamin E is released, 70% – within 12 h and 100% – within 80 h.
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Zhang, Gao Wei, Guan Wei Zhang, and Qing Zhang. "Research on Spiral Drill Stabilizer Wear-Resisting Layer Repair Technology." Applied Mechanics and Materials 157-158 (February 2012): 373–76. http://dx.doi.org/10.4028/www.scientific.net/amm.157-158.373.
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This paper introduced the repair methods of wear-resistant layer of the drilling tool stabilizer, and proposed a simple fitting method for spiral drill stabilizer wear belt, fitting of spatial spiral surface is essence of the space spiral curve fitting, for a pitch fixed spiral can be expanded to two-dimensional line, and then using interpolation technique can control drill stabilizer and repair work head of joint motion, the synthesis of these two motions is the space spiral.
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Stachowicz, Katarzyna. "Physicochemical Principles of Adhesion Mechanisms in the Brain." International Journal of Molecular Sciences 24, no. 6 (March 7, 2023): 5070. http://dx.doi.org/10.3390/ijms24065070.
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The brain functions through neuronal circuits and networks that are synaptically connected. This type of connection can exist due to physical forces that interact to stabilize local contacts in the brain. Adhesion is a fundamental physical phenomenon that allows different layers, phases, and tissues to connect. Similarly, synaptic connections are stabilized by specialized adhesion proteins. This review discusses the basic physical and chemical properties of adhesion. Cell adhesion molecules (CAMs) such as cadherins, integrins, selectins, and immunoglobulin family of cell adhesion molecules (IgSF) will be discussed, and their role in physiological and pathological brain function. Finally, the role of CAMs at the synapse will be described. In addition, methods for studying adhesion in the brain will be presented.
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Ogunmakin, B., K. Zamara, J. Kawalec, and M. C. Todisco. "Geodynamic Modelling of Geogrid-Stabilised Aggregate on Soft Ground in High Speed Rail Environments Using Field-Derived Shear Wave Data." IOP Conference Series: Materials Science and Engineering 1260, no. 1 (October 1, 2022): 012013. http://dx.doi.org/10.1088/1757-899x/1260/1/012013.
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Abstract Geogrids have been used for many years to stabilise and enhance the performance of rail ballast and sub-ballast in terms of maintaining both vertical and lateral track alignment. However, the ability of geogrids to improve these properties within a high-speed rail environment at close-to-critical velocity remain uncertain. The potential for geogrid to improve the stiffness and the ability of a geogrid-stabilised aggregate layer to transmit ground waves such as Rayleigh waves has great potential for reducing dig out depth in soft ground in cuttings and reduce the need to use great thicknesses of engineered, high quality aggregate in embankments in order to mitigate the effects of such waves. New research has been conducted on a trial embankment comparing 4 geogrid-stabilised trial sections with a control section. This embankment has been subjected to low strain stiffness testing using geophysical methods to determine if the stabilised sections can offer an increase in ground wave velocity over the control and thereby offer the potential to reduce engineered construction thickness beneath the track on high-speed rail lines. Initial geodynamic modelling using the results of the on-site testing suggests that specific geogrids have a significant potential to reduce overall construction costs by reducing the need to dig-out-and-replace in soft ground in order to mitigate the effects of Rayleigh waves.
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Andertová, Jana, Jiří Havrda, and Radek Tláskal. "Functional Gradient Alumina Ceramics with Controlled Porosity." Key Engineering Materials 333 (March 2007): 223–26. http://dx.doi.org/10.4028/www.scientific.net/kem.333.223.
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The work deals with preparation of functional gradient alumina ceramics with controlled porosity by slip casting method of aqueous alumina suspension containing pore-generating agent. The sol-gel transition of AlO(OH) was employed to stabilize pore-generating agent in the suspension. The composite bodies with layers of variable porosity were prepared. Based on dilatometer measurement the admission difference of irreversible dilatation changes #αirr between compounded layers was determined in order to prepare defect free bi-layer bodies. The dependence of physical and mechanical properties of as fired composite bodies on the porosity value was expressed.
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Asim, Muhammad, Mahmood Ahmad, Muhammad Alam, Shahid Ullah, Muhammad Junaid Iqbal, and Shahid Ali. "Prediction of Rutting in Flexible Pavements using Finite Element Method." Civil Engineering Journal 7, no. 8 (August 1, 2021): 1310–26. http://dx.doi.org/10.28991/cej-2021-03091727.
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In this research study three dimensional (3D) finite element analysis are performed on a flexible pavement section for different material properties, temperature and loading conditions. The main objective of this study is to predict the rut depth under different conditions of temperature, loadings and material properties. Three dimensional finite element model of flexible pavement is developed using ABAQUS to predict rut depth. The pavement system is assumed to be an elastic multi-layers system with each layer being isotropic, homogeneous with specified Resilient Modulus (Mr) and Poisson ratio (µ). With the exception of the bottom subgrade layer, each layer is extending to an unlimited horizontal extent and has a finite thickness. The pavement system analyze in this study for a cyclic load of 10000 cycles taken as 0.01sec per cycle. Standard Axle Load (ESAL) of 18 kips (80 kN) loading on an axle with a dual set of tires, the wheel spacing is 13.78 in (350 mm) with a tire contact pressure of 100 psi (0.69 MPa) is used. After performing a series of analysis the results showed that rut depth increases with increase in temperature and loading and decreases by using base stabilizer. Doi: 10.28991/cej-2021-03091727 Full Text: PDF
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Boström, Mathias, Victoria Esteso, Johannes Fiedler, Iver Brevik, Stefan Yoshi Buhmann, Clas Persson, Sol Carretero-Palacios, Drew F. Parsons, and Robert W. Corkery. "Self-preserving ice layers on CO2 clathrate particles: Implications for Enceladus, Pluto, and similar ocean worlds." Astronomy & Astrophysics 650 (June 2021): A54. http://dx.doi.org/10.1051/0004-6361/202040181.
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Context. Gas hydrates can be stabilised outside their window of thermodynamic stability by the formation of an ice layer – a phenomenon termed self-preservation. This can lead to a positive buoyancy for clathrate particles containing CO2 that would otherwise sink in the oceans of Enceladus, Pluto, and similar oceanic worlds. Aims. Here we investigate the implications of Lifshitz forces and low occupancy surface regions on type I clathrate structures for their self-preservation through ice layer formation, presenting a plausible model based on multi-layer interactions through dispersion forces. Methods. We used optical data and theoretical models for the dielectric response for water, ice, and gas hydrates with a different occupancy. Taking this together with the thermodynamic Lifshitz free energy, we modelled the energy minima essential for the formation of ice layers at the interface between gas hydrate and liquid water. Results. We predict the growth of an ice layer between 0.01 and 0.2 μm thick on CO, CH4, and CO2 hydrate surfaces, depending on the presence of surface regions depleted in gas molecules. Effective hydrate particle density is estimated, delimiting a range of particle size and compositions that would be buoyant in different oceans. Over geological time, the deposition of floating hydrate particles could result in the accumulation of kilometre-thick gas hydrate layers above liquid water reservoirs and below the water ice crusts of their respective ocean worlds. On Enceladus, the destabilisation of near-surface hydrate deposits could lead to increased gas pressures that both drive plumes and entrain stabilised hydrate particles. Furthermore, on ocean worlds, such as Enceladus and particularly Pluto, the accumulation of thick CO2 or mixed gas hydrate deposits could insulate its ocean against freezing. In preventing freezing of liquid water reservoirs in ocean worlds, the presence of CO2-containing hydrate layers could enhance the habitability of ocean worlds in our Solar System and on the exoplanets and exomoons beyond.
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Cho, Haeran, Huryul Lee, Sun-Min Park, Byung-Hyun Choi, and Misook Kang. "Synthesis of Octahedral-Shaped NiO and Approaches to an Anode Material of Manufactured Solid Oxide Fuel Cells Using the Decalcomania Method." Journal of Nanomaterials 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/640146.
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Micrometer-sized and octahedral-shaped NiO particles were synthesized by microwave thermal treatment at 300 watt power for 15 min in a microwave chamber to be used as an anode material in solid oxide fuel cells. SEM image and particle size distribution revealed near-perfect octahedral NiO microparticle with sizes ranging from 4.0~11.0 μm. The anode functional layer (AFL, 60 wt% NiO synthesized: commercial 40 wt% YSZ), electrolyte (commercial Yttria-stabilized zirconia, YSZ), and cathode (commercial La0.8Sr0.2MnO3, LSM) layers were manufactured using the decalcomania method on a porous anode support, sequentially. The sintered electrolyte at 1450°C for 2 h using the decalcomania method was dense and had a thickness of about 10 μm. The cathode was sintered at 1250°C for 2 h, and it was porous. Using humidified hydrogen as a fuel, a coin cell with a 15 μm thick anode functional layer exhibited maximum power densities of 0.28, 0.38, and 0.65 W/cm2at 700, 750, and 800°C, respectively. Otherwise, when a commercial YSZ anode functional layer was used, the maximum power density was 0.55 W/cm2at 800°C.
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Cho, Byoung Hooi, Moon Won, and Boo Hyun Nam. "Layer Composition of Continuously Reinforced Concrete Pavement Optimized Using a Regression Analysis Method." Infrastructures 6, no. 4 (April 6, 2021): 56. http://dx.doi.org/10.3390/infrastructures6040056.
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A procedure for determining the optimized composition of layer properties for a continuously reinforced concrete pavement (CRCP) system was constructed using field tests, finite element (FE) analysis, and regression analysis methods. The field support characteristics of a rigid pavement system were investigated using a falling weight deflectometer (FWD), dynamic cone penetrometer (DCP), and a static plate load test. The subgrade layer exhibited a more uniform condition than the aggregate base, and the modulus of the subgrade reaction of the aggregate base and subgrade combination (effective k-value) was improved by about 1.5 times by introducing a 2 inch (50.8 mm) asphalt stabilized base (ASB) layer. Thereafter, FE support models describing the actual field conditions were studied. The effects of the thickness of the stabilized base layer, the elastic modulus of the stabilized base material, and the effective k-value on the composite k-value of the support system were identified using a regression analysis method, and the results showed that the variables had a similar effect when determining the composite k-value. Afterward, a procedure for selecting the layer properties for producing a suitable composite k-value was constructed, and we identified that the maximum stress in the concrete slab was induced at different levels, even with identical composite k-values. Lastly, regression relationships were derived to estimate the maximum stress in the concrete slab by considering both the support layer properties and the concrete slab. Subsequently, an algorithm for selecting an optimized layer composition of the CRCP structure was construction considering the economical aspect.
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Hu, Peng Cheng, Jiu Bin Tan, Qi Wang, and Pei Zhang. "Asymmetric Thermal Structure for Frequency Stabilized Two-Mode Lasers." Key Engineering Materials 437 (May 2010): 416–20. http://dx.doi.org/10.4028/www.scientific.net/kem.437.416.
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In order to improve the frequency stabilization and the anti-interference ability of two-mode power-balance lasers, the asymmetric thermal structure made up of several thermal transfer layers with different heat transfer coefficient is proposed. Through the heat isolation effect of the middle layer in the structure, the laser has asymmetric thermal responses to electric heater control and air interference. So the anti-interference ability of the system is improved by keeping a low speed in air disturbance while keeping a high speed in thermal stabilization. Several experiments were made with two-mode laser to prove the effectiveness of the proposed method. The experimental results indicate that, frequency stability of the two-mode power-balance laser based on asymmetric thermal structure can be locked in 4.1×10-10 in ordinary lab condition, while it becomes 1.9×10-9 where the air velocity is 1m/s.
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Niroumand, Bahman, and Hamed Niroumand. "Gravel impact compaction piers as a method of soil improvement." Revista de la construcción 21, no. 3 (2022): 539–54. http://dx.doi.org/10.7764/rdlc.21.3.539.
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The purpose of this study was to evaluate the performance of gravel impact compaction piers system (GICPs) in improving a 3.5m thick loose silty sand in a multilayer coastal soil system located in Bushehr, Iran. The liquefiable sandy soil layer was layered on clay layers with moderate to very stiff consistency and below the engineering embankment layer with a thickness of 1.8 m. Implementation of gravel impact compaction piers is a new generation of aggregate piers. Gravel impact compaction piers were used to improve the liquefiable soil layers and to increase the bearing capacity and reduce subgrade settlement to withstand surface infrastructures. The process of making gravel impact compaction piers in a triangular or square-patterned grid was created using three types of special mandrels and feeding and compacting the gravels in the cavity in several stages without removing the soil from the cavities. The experience gained in this case study showed that artificial liquefiable was created immediately after the construction of these piers in a limited area and the soil became unstable. After about 11-14 days, the soil stabilized rapidly. The results of the standard penetration test in the matrix soil around the piers showed that the amount of (N1)60 in compacted soils was in the range of 21-30 and on average 15 times the amount of (1-3) in the initial soil. Also, the relative density of the initial soil was increased from 25% to 75% after soil improvement. Accordingly, by relying merely on the compaction properties of the piers and without relying on other primary soil remediation factors, such as piers drainage and soil texture change, the safety factor of the improved soil is 1.7-1.95 times the minimum required according to the two risk levels in the design.
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Arora, Neha, M. Ibrahim Dar, Alexander Hinderhofer, Norman Pellet, Frank Schreiber, Shaik Mohammed Zakeeruddin, and Michael Grätzel. "Perovskite solar cells with CuSCN hole extraction layers yield stabilized efficiencies greater than 20%." Science 358, no. 6364 (September 28, 2017): 768–71. http://dx.doi.org/10.1126/science.aam5655.
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Perovskite solar cells (PSCs) with efficiencies greater than 20% have been realized only with expensive organic hole-transporting materials. We demonstrate PSCs that achieve stabilized efficiencies exceeding 20% with copper(I) thiocyanate (CuSCN) as the hole extraction layer. A fast solvent removal method enabled the creation of compact, highly conformal CuSCN layers that facilitate rapid carrier extraction and collection. The PSCs showed high thermal stability under long-term heating, although their operational stability was poor. This instability originated from potential-induced degradation of the CuSCN/Au contact. The addition of a conductive reduced graphene oxide spacer layer between CuSCN and gold allowed PSCs to retain >95% of their initial efficiency after aging at a maximum power point for 1000 hours under full solar intensity at 60°C. Under both continuous full-sun illumination and thermal stress, CuSCN-based devices surpassed the stability of spiro-OMeTAD–based PSCs.
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Matějíček, Jiří, Radek Mušálek, and Pavel Chráska. "Residual Stresses and Young's Moduli of Plasma Sprayed W+Cu Composites and FGMs Determined by In Situ Curvature Method." Key Engineering Materials 606 (March 2014): 151–54. http://dx.doi.org/10.4028/www.scientific.net/kem.606.151.
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In this work, application of the in-situ curvature method on plasma sprayed composite and graded coatings is presented. First, uniform composites of different W/Cu ratio, were sprayed by water stabilized plasma. By continuous monitoring of the curvature of a flat specimen during spraying, the stress evolution throughout the entire history of coating formation was traced. By a simultaneous monitoring of curvature and temperature during post-deposition cooling, Youngs moduli of the coatings were determined. Second, a 5-layer stepwise functionally graded material (FGM) was sprayed. With the knowledge of each layers properties, the complex evolution of deposition, thermal and residual stresses in the FGM could be determined. The ability to determine the stresses and mechanical properties with a spatial resolution comparable to the thickness of one spray pass is demonstrated.
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Shariffudin, Shafinaz Sobihana, Farliana Samat Farah, Sukreen Hana Herman, and Mohamad Rusop. "Optical and Electrical Characteristic of Layer-by-Layer Sol-Gel Spin Coated Nanoparticles ZnO Thin Films." Advanced Materials Research 364 (October 2011): 149–53. http://dx.doi.org/10.4028/www.scientific.net/amr.364.149.
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Transparent nanoparticles ZnO thin films have been deposited on glass substrates using sol-gel spin coating technique. 0.35M sol were prepared by dissolving zinc acetate dehydrate in 2-methoxyethanol with monoethanolamine as the stabilizer. In this paper, a novel method called layer-by-layer is introduced, where the thin film is not only dried after each layer is spin-coated, but also directly annealed at 500°C to improve the electrical and optical properties of the films. Samples without annealing were also prepared as the reference sample. ZnO thin films were characterized using current-voltage measurement, UV-Vis spectroscopy and photoluminescence spectroscopy. The results revealed that layer-by-layer ZnO thin films have lower resistivity compared to the reference samples with a maximum value of 0.77Ω.cm for ZnO films deposited with 2 layers. Transmittance spectra show that the films were transparent in the visible range above 400nm with range of 86%-98% for the layer-by-layer ZnO films. The optical band gaps were between 3.2 to 3.3eV for both layer-by-layer and the reference samples. PL spectra indicate that layer-by-layer method improves the crystallinity of the films.
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Wang, Jingan, Haifang Wen, and Balasingam Muhunthan. "Test Method Evaluation and Model Development for Erodibility Properties of Cementitiously Stabilized Layers." Geotechnical Testing Journal 42, no. 1 (August 16, 2018): 20170052. http://dx.doi.org/10.1520/gtj20170052.
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Guan, Xi, Yufei Wang, Shang Feng, Jidong Zhang, Qingqing Yang, Binyuan Liu, and Dashan Qin. "Improving the stabilities of organic solar cells via employing a mixed cathode buffer layer." European Physical Journal Applied Physics 95, no. 3 (September 2021): 30201. http://dx.doi.org/10.1051/epjap/2021210151.
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Organic solar cells (OSCs) have been fabricated using cathode buffer layers based on bathocuproine (BCP) and 4,4'-N,N'-dicarbazole-biphenyl (CBP). It is found that despite nearly same power conversion efficiencies, the bilayer of BCP/CBP shows increased thermal stability of device than the monolayer of BCP, mostly because upper CBP thin film stabilizes under BCP thin film. The mixed layer of BCP:CBP gives slightly decreased efficiency than BCP and BCP/CBP, mostly because the electron mobility of the OSC using BCP:CBP is decreased than those using BCP and BCP/CBP. However, the BCP:CBP increases thermal stability of device than BCP and BCP/CBP, ascribed to that the BCP and CBP effectively inhibit reciprocal tendencies of crystallizations in the mixed layer. Moreover, the BCP:CBP improves the light stability of device than the BCP and BCP/CBP, because the energy transfer from BCP to CBP in in the mixed layer effectively decelerates the photodegradation of BCP. We provide a facial method to improve the stabilities of cathode buffer layers against heat and light, beneficial to the commercial development of OSCs.
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Légaré, P., G. F. Cabeza, and N. J. Castellani. "Numerical Simulation of Pt Overlayers on Ni(111) and Co(0001)." Surface Review and Letters 05, no. 02 (April 1998): 581–88. http://dx.doi.org/10.1142/s0218625x98000967.
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The growth of pseudomorphic Pt layers (from one to four) on Ni(111) and Co(0001) has been investigated by the ECT–BFS method. The behaviors on the two substrates are very similar. The growth of the first layer appears to be highly favorable as the energy of the system is negative. Higher coverages could be stabilized with huge relaxations perpendicularly to the surface. The evolution of the plane-by-plane energies (separated in stress and chemical contributions) and relaxations during the growth is presented and discussed. The always-stabilizing chemical interaction at the interface makes it likely that interdiffusion of metals could be a competing mechanism.
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Pollock, Sara. "Stabilized and inexact adaptive methods for capturing internal layers in quasilinear PDE." Journal of Computational and Applied Mathematics 308 (December 2016): 243–62. http://dx.doi.org/10.1016/j.cam.2016.06.011.
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Sendur, Ali. "A Comparative Study on Stabilized Finite Element Methods for the Convection-Diffusion-Reaction Problems." Journal of Applied Mathematics 2018 (2018): 1–16. http://dx.doi.org/10.1155/2018/4259634.
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The disproportionality in the problem parameters of the convection-diffusion-reaction equation may lead to the formation of layer structures in some parts of the problem domain which are difficult to resolve by the standard numerical algorithms. Therefore the use of a stabilized numerical method is inevitable. In this work, we employ and compare three classical stabilized finite element formulations, namely, the Streamline-Upwind Petrov-Galerkin (SUPG), Galerkin/Least-Squares (GLS), and Subgrid Scale (SGS) methods, and a recent Link-Cutting Bubble (LCB) strategy proposed by Brezzi and his coworkers for the numerical solution of the convection-diffusion-reaction equation, especially in the case of small diffusion. On the other hand, we also consider the pseudo residual-free bubble (PRFB) method as another alternative that is based on enlarging the finite element space by a set of appropriate enriching functions. We compare the performances of these stabilized methods on several benchmark problems. Numerical experiments show that the proposed methods are comparable and display good performance, especially in the convection-dominated regime. However, as the problem turns into reaction-dominated case, the PRFB method is slightly better than the other well-known and extensively used stabilized finite element formulations as they start to exhibit oscillations.
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Hangleiter, R., and G. Lube. "Stabilized Galerkin methods and layer-adapted grids for elliptic problems." Computer Methods in Applied Mechanics and Engineering 166, no. 1-2 (November 1998): 165–82. http://dx.doi.org/10.1016/s0045-7825(98)00089-9.
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