Articles de revues : « Layered Sample »

1

Du, H., J. W. Fang et J. J. Zheng. « Photoacoustic phase spectrum of a layered sample ». Applied Physics A : Materials Science & ; Processing 60, n^o 4 (1 mars 1995) : 419–23. http://dx.doi.org/10.1007/s003390050122.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

2

Du, H., J. W. Fang et J. J. Zheng. « Photoacoustic phase spectrum of a layered sample ». Applied Physics A Materials Science & ; Processing 60, n^o 4 (avril 1995) : 419–23. http://dx.doi.org/10.1007/bf01538344.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

3

Jia, Hailiang, Biwen Dong, Di Wu, Qingmin Shi et Yao Wei. « Capillary Imbibition in Layered Sandstone ». Water 15, n^o 4 (13 février 2023) : 737. http://dx.doi.org/10.3390/w15040737.

Texte intégral

Résumé :

Spontaneous capillary imbibition in rocks is fundamental to numerous geomorphological processes and has caused numerous engineering problems. Sedimentary rocks are widely distributed across the Earth’s surface and usually bear layer structures that make the pore structure anisotropic. Understanding the effects of the anisotropic pore structure on capillary imbibition in sedimentary rocks is crucially important but remains inadequate, especially on larger scales than a single tube. In this study, the capillary imbibition process in sandstone was monitored by measuring the water absorption mass, height of the water absorption front, NMR (nuclear magnetic resonance) T2 spectra, and stratified moisture distribution. The results demonstrate that (1) the layer structure had a significant effect on the capillary imbibition process by altering water absorption rate and water redistribution mode, as the time of the water front reaching the top of Sample A1 lagged behind Sample A2 by 500 min; (2) vapor diffusion and condensation occurred ahead of the water-absorption front, which was more obvious in samples with well-developed beddings; (3) in sandstone samples with bedding planes perpendicular to the height (Per samples), internal water migration lagged behind superficial water migration and was longer in sandstones with well-developed beddings, such as the case of Sample A2, for which the time lag was as large as 280min. Based on a combination of observations of the sandstone structure at pore scale and layer scale with results calculated from the Lucas–Washburn equation, we propose the concept of the representative pore-structure element (RPE). Based on analysis on water migration in RPEs, we suggest that the effects of the layer structure on capillary imbibition in sandstone are embedded in the different water migration modes in Par (samples with bedding planes parallel to the height) and Per samples. The water migration mode in Par samples can be simplified as primary upward intra-layer migration followed by intra-layer horizontal migration, while that in Per samples is primary intra-layer horizontal migration followed by intra-layer upward migration.

Styles APA, Harvard, Vancouver, ISO, etc.

4

Aref'eva L. P., Duka V. V. et Zabiyaka I. Y. « Relationship between the Structural-Phase Composition and the Fracture Mechanism of High-Strength Contruction Steel ». Technical Physics Letters 48, n^o 4 (2022) : 73. http://dx.doi.org/10.21883/tpl.2022.04.53490.19093.

Texte intégral

Résumé :

In this work, the fracture surface of a 1.0481 steel sample having a layered ferrite-martensitic structure after special heat treatment was studied by optical and scanning electron microscopy. The samples were subjected to a shock-bending test at negative temperature. A sample made of the same steel with a homogeneous martensitic structure was used for comparative analysis. The features of the destruction mechanisms of the studied samples are described. Keywords: construction steel, layered structure, fracture surface, visco-brittle mechanism, impact strength.

Styles APA, Harvard, Vancouver, ISO, etc.

5

Liu, Guangjin, Yaxiong Peng, Qingjun Zuo, Ying Su et Li Wu. « Dynamic Mechanics and Energy Dissipation of Saturated Layered Phyllite ». Minerals 12, n^o 10 (29 septembre 2022) : 1246. http://dx.doi.org/10.3390/min12101246.

Texte intégral

Résumé :

This paper is a study of the dynamic mechanics and energy dissipation of saturated layered phyllite. Using the Split-Hopkinson pressure bar system, the mechanical properties and energy dissipation law of the sample during dynamic loading in the test were analyzed. The results show that the weakening effect of water on the phyllite rock body will have a great impact on its mechanical properties, strain rate sensitivity damage mode, and fracture energy dissipation. The values of mechanical parameters such as the modulus of elasticity and compressive strength of the specimens in the test varied with the dip angle of the layer with 0° > 90° > 30° > 60°, and the mechanical parameters of the specimens in the saturated state were smaller than those of the dry specimens. The damage of the sample is mainly in the form of crushing damage at 0° dip angle, shear damage along the laminar surface at 30° and 60°, and destabilization damage of the compression bar at 90° dip angle, with higher fragmentation of the sample in the saturated state. The energy dissipation densities of different inclination samples in the saturated state of schist are greater than those in the dry state, with the highest energy dissipation density in the 0° inclination sample and the lowest in the 90° inclination sample. Both the mean strain rate and compressive strength of the samples showed a multiplicative power relationship with the crushing energy dissipation density of the samples, showing a strong strain rate correlation. These results indicate that the use of rock crushing energy dissipation density can better reflect the strength characteristics of phyllite samples under dynamic loading.

Styles APA, Harvard, Vancouver, ISO, etc.

6

Yu, Tao, Hang Guo, Xiangyu Wang, Baojun Li et Xianji Guo. « Preparation and Photocatalytic Performance of Iron Oxide-Pillared Layered Tantalum–Tungsten Acid ». International Journal of Nanoscience 19, n^o 05 (21 février 2020) : 1950037. http://dx.doi.org/10.1142/s0219581x19500376.

Texte intégral

Résumé :

Using trirutile-structure layered tantalum–tungsten acid as the layered host, [Formula: see text]-propylamin as the pre-swelling agent and aqueous solution of [Fe3(CH3COO)7(OH)(H2O)]NO3 as the pillaring solution, oligomeric polyhydroxyacetato-Fe(III) species-intercalated layered HTaWO6 was synthesized by a stepwise ion-exchange way at room temperature. Upon calcining at 673[Formula: see text]K in air atmosphere, iron oxide-pillared layered HTaWO6with nanoscale interlayer distance (denoted as Fe2O3-HTaWO[Formula: see text] was obtained. A series of Fe2O3-HTaWO6 samples with various Fe contents were prepared by using different volume of Fe(III)-pillaring solution. The layered intermediates obtained at each stage of the ions-exchange process and the final layered products were characterized by powder XRD, FT-IR, DR UV-Vis and SEM techniques. The photocatalytic performance of the Fe2O3-pillared layered HTaWO6 samples for degradation of rhodamine B was investigated. Compared with un-pillared layered HTaWO6, the Fe2O3-pillared layered HTaWO6 exhibited a significantly-improved photo-absorption performance and an enhanced photocatalytic activity. The Fe2O3-HTaWO6 sample with 5.8% (wt) iron showed the best catalytic performance in the photodegradation reaction of rhodamine B.

Styles APA, Harvard, Vancouver, ISO, etc.

7

Hane, Kazuhiro, et Shuzo Hattori. « Photothermal bending of a layered sample in plate form ». Applied Optics 29, n^o 1 (1 janvier 1990) : 145. http://dx.doi.org/10.1364/ao.29.000145.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

8

Thumwong, Arkarapol, Jitsuna Darachai et Kiadtisak Saenboonruang. « Comparative X-ray Shielding Properties of Single-Layered and Multi-Layered Bi2O3/NR Composites : Simulation and Numerical Studies ». Polymers 14, n^o 9 (27 avril 2022) : 1788. http://dx.doi.org/10.3390/polym14091788.

Texte intégral

Résumé :

This work theoretically compared the X-ray attenuation capabilities in natural rubber (NR) composites containing bismuth oxide (Bi2O3) by determining the effects of multi-layered structures on the shielding properties of the composites using two different software packages (XCOM and PHITS). The shielding properties of the single-layered and multi-layered Bi2O3/NR composites investigated consisted of the transmission factor (I/I0), effective linear attenuation coefficient (µeff), effective mass attenuation coefficient (µm,eff), and effective half-value layer (HVLeff). The results, with good agreement between those obtained from XCOM and PHITS (with less than 5% differences), indicated that the three-layered NR composites (sample#4), with the layer arrangement of pristine NR (layer#1)-Bi2O3/NR (layer#2)-pristine NR (layer#3), had relatively higher X-ray shielding properties than either a single-layer or the other multi-layered structures for all X-ray energies investigated (50, 100, 150, and 200 keV) due to its relatively larger effective percentage by weight of Bi2O3 in the composites. Furthermore, by varying the Bi2O3 contents in the middle layer (layer#2) of sample#4 from 10 to 90 wt.%, the results revealed that the overall X-ray shielding properties of the NR composites were further enhanced with additional filler, as evidenced by the highest values of µeff and µm,eff and the lowest values of I/I0 and HVLeff observed in the 90 wt.% Bi2O3/NR composites. In addition, the recommended Bi2O3 contents for the actual production of three-layered Bi2O3/NR composites (the same layer structure as sample#4) were determined by finding the least Bi2O3 content that enabled the sample to attenuate incident X-rays with equal efficiency to that of a 0.5-mm lead sheet (with an effective lead equivalence of 0.5 mmPb). The results suggested that the recommended Bi2O3 contents in layer#2 were 82, 72, and 64 wt.% for the combined 6 mm, 9 mm, and 12 mm samples, respectively.

Styles APA, Harvard, Vancouver, ISO, etc.

9

Huang, Jow-Lay, Feng-Chi Chou et Horng-Hwa Lu. « Investigation of Si3N4–TiN/Si3N4–Si3N4 trilayer composites with residual surface compression ». Journal of Materials Research 12, n^o 9 (septembre 1997) : 2357–65. http://dx.doi.org/10.1557/jmr.1997.0312.

Texte intégral

Résumé :

The present study involved the fabrication of three-layered composites consisting of outer layers that contained Si3N4 and an inner layer that contained TiN in a Si3N4 matrix. Surface compressive stresses were developed upon cooling due to the relatively higher thermal expansion coefficient (CTE) in the inner layer. The flexural strength of layered Si3N4 composites was substantially greater than that of monolithic Si3N4. This was attributed to the surface compressive stress. The effects of TiN composition and inner layer thickness on the mechanical properties were investigated. Layered samples containing 20 vol.% TiN had lower flexural strength than Si3N4–10% TiN/Si3N4–Si3N4 due to the formation of microcracks in the inner layer. Crack behaviors in layered samples were affected by the residual stress, interface, and free sample surface. Both theoretical and experimental results indicated that the strength and toughness of layered composites were substantially greater than those of monolithic materials. The determination of fracture toughness in three-layered materials by the surface indentation technique should be done carefully due to the influence of residual stress.

Styles APA, Harvard, Vancouver, ISO, etc.

10

Kim, Jae Won, Seong Hwan Park, Yeon Gil Jung et Hee Soo Lee. « Evaluation and Control of Crack Propagation in Dense Porcelain/ Porous Alumina Layered Structures for Dental Material Applications ». Key Engineering Materials 317-318 (août 2006) : 457–60. http://dx.doi.org/10.4028/www.scientific.net/kem.317-318.457.

Texte intégral

Résumé :

Layered structures of dense porcelain/porous alumina and dense porcelain/porcelainalumina/ porous alumina are designed and their crack propagation behaviors are investigated. As a substrate, the porous alumina, which is prepared by a gel-casting process using the binary slip of alumina powder and PMMA spherical micro-bead, is dried at room temperature for 24 h and then sintered at 1600 for 2 h. Porcelain is coated on the porous alumina substrate and then re-sintered at 987. Bi- and tri-layered structures are produced by the different dwell times (2 min, 10 min) at re-sintering temperature. There is no delaminating or cracks observed after re-sintering the layered samples. The crack propagation behaviors in the bi- and tri-layered structures are evaluated by micro-indentation. The indentation cracks do not propagate into the porous alumina through interface (porosity; 36~62%) except for another one (porosity; 70%) in the bi-layered samples. In the case of the high porosity bi-layered sample (porosity; 70%), cracks are scattered along the 3-D open-pore channels. However, cracks do not propagate through the interface in the tri-layered samples with a porcelain-alumina buffer layer, because the porcelain-alumina buffer layer plays an important part such as a barrier layer in crack propagation.

Styles APA, Harvard, Vancouver, ISO, etc.

11

York, Warren L., Dong Ding, Hanping Ding et Joshua D. Sugar. « TEM Sample Preparation of Buried Interfaces in Porous Layered Materials ». Microscopy and Microanalysis 27, S1 (30 juillet 2021) : 3466–67. http://dx.doi.org/10.1017/s1431927621012186.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

12

Vignesh, S., J. T. Winowlin Jappes, Khan M. Adam et Temal Varol. « Mechanical Loading and Tribological Studies on Boron Carbide (B4C) and Lead (Pb) Particles Dispersed Epoxy-Based Multilayered Composites ». Advances in Materials Science and Engineering 2022 (16 avril 2022) : 1–8. http://dx.doi.org/10.1155/2022/4029882.

Texte intégral

Résumé :

The study aims in the development of functionally graded epoxy-based layered composites dispersed with B4C and lead particles. The development route adopted for the composites is a novel route called layered molding and curing. Various compositions of single and trilayered composites were prepared through the abovementioned route. The samples prepared were subjected to mechanical and tribological studies, and the results were reported in this article. It is found that the mechanical properties of the single-layered composites consisting of 20% lead and 20% B4C show superior characteristics than those of the samples with increased addition of lead. However, the trilayered samples with lead core showcased excellent mechanical properties. On the other hand, the wear rate and mass loss of the trilayered samples with B4C cladding show minimum wear rate than the samples with lead cladding. Furthermore, the coefficient of friction of the samples also showcases the better performance of single-layered samples with 20% lead. The worn surface analysis done through scanning electron microscopy and stereo zoom microscopy reveals the reason for the low specific wear rate of 20% lead sample as the self-hindrance of wear debris evolved during the wear study.

Styles APA, Harvard, Vancouver, ISO, etc.

13

Emura, Satoshi, Xin Ji, Xiaohua Min et Koichi Tsuchiya. « Effects of Mo segregation on Charpy absorbed energy in Ti-12Mo alloys ». MATEC Web of Conferences 321 (2020) : 11050. http://dx.doi.org/10.1051/matecconf/202032111050.

Texte intégral

Résumé :

Beta phase stabilizing elements such as Mo have strong tendency to segregate. We have introduced swirly type segregation of Mo in Ti-12Mo (mass %) alloy through groove bar rolling. After solution treatment and low temperature aging, hard omega phase was precipitated heterogeneously, which improved the room temperature tensile elongation values without sacrificing tensile strength. In this study, the effect of Mo segregation and heterogeneous distribution of omega phase on Charpy absorbed energy was investigated in Ti-12Mo alloy. Samples with two types of segregation were prepared; namely, swirly segregation in bar rolled sample and layered segregation in plate rolled sample. For comparison, we have also prepared Ti-12Mo bar samples with lesser Mo segregation, through high temperature thermomechanical treatment. Charpy impact tests were carried out at room temperature, 373 K and 473 K, respectively, using the samples after aging to introduce isothermal omega-phase. The samples with the segregation exhibited higher Charpy absorbed energy, especially at higher temperature of 473 K, while the sample with the swirly segregation showed higher Charpy absorbed energy than that with the layered segregation. The sample with lesser Mo segregation exhibited brittle intergranular fracture surface after Charpy testing. On the contrary, samples with Mo segregation exhibited ductile transgranular fracture surfaces.

Styles APA, Harvard, Vancouver, ISO, etc.

14

Zong, Yun, et Di Kang. « Study on Influence of Ca²⁺ Ions Doping at a Site on Magnetic Properties and Magnetocaloric Effect of Nominal Compositions La_1.4Sr_1.6-xCa_xMn₂O₇ ». Advanced Materials Research 1120-1121 (juillet 2015) : 406–13. http://dx.doi.org/10.4028/www.scientific.net/amr.1120-1121.406.

Texte intégral

Résumé :

Polycrystalline layered perovskite manganese oxides La1.4Sr1.6-xCaxMn2O7 (x=0,0.2,0.4,0.8,1.0,1.4,1.6) samples is prepared using solid state reaction.The XRD analysis shows that La1.4Sr1.6-xCaxMn2O7 (0 ≤ x ≤ 0.8) samples are Sr3Ti2O7-type tetragonal structure with space group I4/mmm and forms a layered perovskite structure; for the 1.0≤ x ≤1.6 series of samples the main phase is ABO3 type orthorhombic structure with space group Pbnm.For small amount of Ca2+ ion-doped sample (x= 0.2,0.4), induce serious Jahn-Teller(J-T) distortion of MnO6 octahedral.For a large number of doping (1.0≤ x ≤1.6) samples, ferromagnetic - paramagnetic transition occurs near the Curie temperature (Tc) from low to high temperatures.With increasing doping amount, the magnetization reached maximum at x=1.4 samples.Maximum magnetic entropy change of the three samples(x=1.0,1.4,1.6) reaches 0.84, 1.20 and 2.28 J kg-1 K-1 at 320,268 and 215K near the Curie temperature, respectively. The large magnetic entropy change effect under low magnetic field of the sample makes it an optimal candidate of room temperature magnetic refrigeration materials.

Styles APA, Harvard, Vancouver, ISO, etc.

15

Арефьева, Л. П., В. В. Дука et И. Ю. Забияка. « Взаимосвязь структурно-фазового состава с механизмом разрушения высокопрочной строительной стали ». Письма в журнал технической физики 48, n^o 8 (2022) : 39. http://dx.doi.org/10.21883/pjtf.2022.08.52366.19093.

Texte intégral

Résumé :

In this work, the fracture surface of a 1.0481 steel sample having a layered ferrite-martensitic structure after special heat treatment was studied by optical and scanning electron microscopy. The samples were subjected to a shock-bending test at negative temperature. A sample made of the same steel with a homogeneous martensitic structure was used for comparative analysis. The features of the destruction mechanisms of the studied samples are described.

Styles APA, Harvard, Vancouver, ISO, etc.

16

Badaut, D., A. Decarreau et G. Besson. « Ferripyrophyllite and related Fe3+-rich 2:1 clays in Recent deposits of Atlantis II Deep, Red Sea ». Clay Minerals 27, n^o 2 (juin 1992) : 227–44. http://dx.doi.org/10.1180/claymin.1992.027.2.07.

Texte intégral

Résumé :

AbstractIron-rich dioctahedral 2:1 clays were sampled in metalliferous sediments from Atlantis II Deep (Red Sea), and studied by XRD, TEM, FTIR and Mössbauer spectroscopy. One sample with the structural formula (Si3·94Fe3+0·06)(Fe3+1·90Mg0·10)K0·1(Mg, Ca)0·03 is closer to the theoretical end-member ferripyrophyllite Si4Fe3+2O10(OH)2 than any other Fe-rich clay previously described. Other samples appear as mixed-layered clays: ferripyrophyllite-hydroferripyrophyllite or hydroferripyrophyllite-celadonite.

Styles APA, Harvard, Vancouver, ISO, etc.

17

Rattanadecho, P., K. Aoki and et M. Akahori. « Experimental Validation of a Combined Electromagnetic and Thermal Model for a Microwave Heating of Multi-Layered Materials Using a Rectangular Wave Guide ». Journal of Heat Transfer 124, n^o 5 (11 septembre 2002) : 992–96. http://dx.doi.org/10.1115/1.1495521.

Texte intégral

Résumé :

The heating of multi-layered materials by microwave heating with rectangular wave guide has been investigated numerically and experimentally. The multi-layered materials, which consist of the layer of higher dielectric material (antireflection layer) and lower dielectric material (sample), have the convergent effect of the incident microwave in sample, and it can change the heating pattern in the sample with ease. In this study, the effect of an antireflection layer thickness on the heating process is clarified in detail, considering the interference between incidents and reflected waves in the dielectric materials. Based on a model combining the Maxwell and heat transport equations, the results showed that when a layer of lower dielectric material is attached in front of sample, the microwave energy absorbed and distribution of temperature within the sample are enhanced. The predicted results are in agreement with experimental results for microwave heating of multi-layered materials using a rectangular wave guide.

Styles APA, Harvard, Vancouver, ISO, etc.

18

Soo, S. P., M. S. Idris, Rozana A. M. Osman et A. Rahmat. « The Effect of Synthesis Temperature on Interlayer Mixing in Layered Rock Salt Cathode Materials LiNi_0.7Mn_0.1Co_0.2O₂ for Li-Ion Batteries Application ». Materials Science Forum 819 (juin 2015) : 155–60. http://dx.doi.org/10.4028/www.scientific.net/msf.819.155.

Texte intégral

Résumé :

The interlayer mixing of layered rock salt cathode materials LiNi0.7Mn0.1Co0.2O2 that prepared by mixed hydroxide method at various temperatures (750-950°C) has been studied. X-ray Diffraction (XRD) was used to determine a suitable temperature range to obtain the fully reacted sample. Phase of pure sample was obtained at high temperature above 850°C. The results of XRD show that the LiNi0.7Mn0.1Co0.2O2 samples are iso-structural with α-NaFeO2 with space group of R-3m.The sample that heated at 900°C exhibits a well-ordered and lower cation mixed layered structure than others. Rietveld refinement using XRD data was used to determine the amount of interlayer mixing vary as a function of temperature. Refinements data showed that the interlayer mixing varies depend upon the synthesis temperature and the optimum temperature to prepare LiNi0.7Mn0.1Co0.2O2 with the lowest amount of interlayer mixing was 900°C.

Styles APA, Harvard, Vancouver, ISO, etc.

19

del Arco, Margarita, Daniel Carriazo, Cristina Martín, Amalia M. Pérez Grueso et Vicente Rives. « Characterization of Chromate-Intercalated Layered Double Hydroxides ». Materials Science Forum 514-516 (mai 2006) : 1541–45. http://dx.doi.org/10.4028/www.scientific.net/msf.514-516.1541.

Texte intégral

Résumé :

PXRD (powder x-ray diffraction), FT-IR (Fourier Transform infrared), N2 adsorption at - 196 °C and TG/DTA (thermogravimetric and differential thermal analyses) techniques have been used for characterisation of MgAl- and ZnAl-CrO4 LDHs, which had been prepared by the ion exchange method from the corresponding chloride LDH (layered double hydroxides) precursors. The results indicates that the oxometalate intercalation in both systems produces interlayer microporosity and a basal spacing of 8.7 Å; This gallery height decreases when the samples are calcined in the temperature range 100-300 °C, due to a grafting process. A larger thermal stability is detected for MgAl-CrO4 sample than for the zinc-containing one.

Styles APA, Harvard, Vancouver, ISO, etc.

20

Zhang, Hetong, Yue Guo, Xiang Zhang, Xinqian Wang, Hang Wang, Chunsheng Shi et Fang He. « Enhanced Shielding Performance of Layered Carbon Fiber Composites Filled with Carbonyl Iron and Carbon Nanotubes in the Koch Curve Fractal Method ». Molecules 25, n^o 4 (21 février 2020) : 969. http://dx.doi.org/10.3390/molecules25040969.

Texte intégral

Résumé :

Layered carbon fiber composites (CFC) with enhanced shielding effectiveness (SE) were prepared with mixed fillers of carbon nanotubes (CNTs) and carbonyl iron powders (CIPs) in the form of a Koch curve fractal. In the layered composite structure, glass fiber (GF) cloth was used in the wave–transmissive layer (WTL), and the carbon fiber (CF) cloth was used in the supporting layer (SL). Between WTL and SL, CNTs and CIPs were distributed in epoxy resin in the form of a Koch curve fractal to act as an absorbing layer (AL), and copper foil was used as a reflective layer (RL) and bonded at the bottom of the whole composites. The layered structure design and excellent interlayer interface integration obviously improved the SE performance of the CFC. The SE of different samples was investigated, and the results show that, with the increase in the number (n) of Koch curve fractals, the SE of the samples enhanced in the low frequency scope (1–5 GHz). The sample with n = 2 has the highest SE value of 73.8 dB at 2.3 GHz. The shielding performance of the fractal sample filled by CNTs and CIPs simultaneously has a comprehensive improvement in the whole scope of 1–18 GHz, especially for the sample with n = 2. The cumulative bandwidth value of the SE exceeding 55 dB is about 14.3 GHz, accounting for 85% of the whole frequency scope, indicating the composite fabricated in this paper is an electromagnetic shielding material with great prospect.

Styles APA, Harvard, Vancouver, ISO, etc.

21

Abad, Sara, Alicia Prados, Marco Maicas, Neven Biskup, Maria Varela et Rocio Ranchal. « Electrodeposition of Hybrid Magnetostrictive/Magnetoelectric Layered Systems ». Materials 14, n^o 21 (22 octobre 2021) : 6304. http://dx.doi.org/10.3390/ma14216304.

Texte intégral

Résumé :

The potential use of electrodeposition to synthesize a hybrid magnetostrictive/magnetoelectric layered system is shown in this paper. By appropriately adjusting pH, growth potential, and electrolyte composition, it is possible to achieve thin films in which magnetoelectric oxide GaFeO3 (GFO) is formed in close contact with magnetostrictive metallic FeGa alloy. X-ray diffractometry shows the formation of FeGa as well as GFO and Fe oxides. Electron microscopy observations reveal that GFO mainly segregates in grain boundaries. Samples are ferromagnetic with an isotropic magnetic behavior in the sample plane. Magnetic stripes are observed by magnetic force microscopy and are correlated to Fe3O4. When its segregation is minimal, the absence of stripes can be used to monitor Fe oxide segregation.

Styles APA, Harvard, Vancouver, ISO, etc.

22

Siyar, Muhammad, Maroosha Farid, Haad Khan, Malik Adeel Umar, Waqas Hassan Tanveer et Amna Safdar. « Controlled Morphology and Its Effects on the Thermoelectric Properties of SnSe2 Thin Films ». Crystals 11, n^o 8 (13 août 2021) : 942. http://dx.doi.org/10.3390/cryst11080942.

Texte intégral

Résumé :

In the last few years, the thermoelectric properties of tin selenide (SnSe) have been explored in much detail due to its high efficiency and green nature, being free of Te and Pb. In the same chalcogenide family, SnSe2 is also a layered structured material, but its thermoelectric potential has not been widely explored experimentally. Since SnSe2 has the layered structure, its electrical transport properties may strongly be affected by its microstructure and morphology. Here, we report the effect of reaction time on the structure, phase, and morphology of the SnSe2 during solvothermal synthesis process. We have studied four SnSe2 samples with different reaction times. The sample obtained after 16 h of reaction time was named as M1, for 20 h M2, similarly for 24 h was M3 and for 48 hours’ time, the sample was named as M4. We investigated its thermoelectric properties and found that phase purity and morphology can affect the thermoelectric performance of the synthesized samples. The peak power factor (PF) value along the ab plane was (0.69 μWcm−1K−2) for the M4 sample at 575 K, which was the highest among all the measured samples. The comparatively larger PF value of sample M4 can be related to the increase in its electrical conductivity due to increase in phase purity and band gap reduction.

Styles APA, Harvard, Vancouver, ISO, etc.

23

Zhang, Xiao, Linchi Zou, Junfeng Chen, Pinqiang Dai et Jian Pan. « Design and Preparation of CNTs/Mg Layered Composites ». Materials 15, n^o 3 (23 janvier 2022) : 864. http://dx.doi.org/10.3390/ma15030864.

Texte intégral

Résumé :

In order to effectively solve the problem of strength and ductility mismatch of magnesium (Mg) matrix composites, carbon nanotubes (CNTs) are added as reinforcement. However, it is difficult to uniformly disperse CNTs in a metal matrix to form composites. In this paper, electrophoretic deposition (EPD) was used to obtain layered units, and then the CNTs/Mg layered units were sintered by spark plasma sintering to synthesize layered CNTs/Mg composites. The deposition morphology of the layered units obtained by EPD and the microstructure, damping properties, and mechanical properties of the composite material were analyzed. The results show that the strength and ductility of the composite sample sintered at 590 °C were improved compared with the layered pure Mg and the composite sample sintered at 600 °C. Compared with pure Mg, the composites rolled by 40% had a much higher strength but no significant decrease in ductility. The damping properties of the CNTs/Mg composites were tested. The damping–test-temperature curve (tanδ~T) rose gradually with increasing temperature in the range of room temperature to 350 °C, and two internal friction peaks appeared. The damping properties of the tested composites at room temperature decreased with increasing frequency. The layered structure of the CNTs/Mg had ultra-high strengthening efficiency and maintained its ductility. The layered units prepared by EPD can uniformly disperse the CNTs in the composites.

Styles APA, Harvard, Vancouver, ISO, etc.

24

S. Abbas Al-Khafaji, Raghad. « Synthesis and some Features of Three-Phases Polymer/Metal/Ceramic Multilayers Nanocomposite ». Ibn AL- Haitham Journal For Pure and Applied Sciences 33, n^o 4 (20 octobre 2020) : 10. http://dx.doi.org/10.30526/33.4.2521.

Texte intégral

Résumé :

Layer by layer development two features of pulsed laser deposition PLD, with a high kinetic energy and sharp instantaneous deposition rating. Layered films of polymer/metal/ceramic nanocomposites consisting of polystyrene PS(as substrate) , tin Sn and cadmium oxide CdO were deposited by PLD. Structure for layered samples were measured by XRD X ray diffraction, there were appearance of peaks which reflected to formation of new compounds result of reaction between layers. Particles size was calculated using two methods and it give nanoscale. Microstrain was also calculated and exhibited high value (0.01) for sample p/m.

Styles APA, Harvard, Vancouver, ISO, etc.

25

Novak, Ondrej, Petr Kulhavy, Tomas Martinec, Michal Petru et Pavel Srb. « Development of fire shutters based on numerical optimizations ». EPJ Web of Conferences 180 (2018) : 02076. http://dx.doi.org/10.1051/epjconf/201818002076.

Texte intégral

Résumé :

This article deals with a prototype concept, real experiment and numerical simulation of a layered industrial fire shutter, based on some new insulating composite materials. The real fire shutter has been developed and optimized in laboratory and subsequently tested in the certified test room. A simulation of whole concept has been carried out as the non-premixed combustion process in the commercial final volume sw Pyrosim. Model of the combustion based on a stoichiometric defined mixture of gas and the tested layered samples showed good conformity with experimental results – i.e. thermal distribution inside and heat release rate that has gone through the sample.

Styles APA, Harvard, Vancouver, ISO, etc.

26

Xia, Y. P., H. Wu, K. S. Miao, L. Geng, G. H. Fan, T. Yu et D. Juul Jensen. « Effects of alloying, microstructure and texture on the strength–ductility trade-off in layered aluminum ». IOP Conference Series : Materials Science and Engineering 1249, n^o 1 (1 juillet 2022) : 012037. http://dx.doi.org/10.1088/1757-899x/1249/1/012037.

Texte intégral

Résumé :

Abstract Tailoring constituent layers can lead to improved mechanical properties of layered metals. In this work, we designed and fabricated two samples of layered Al. One sample with AA3003 and AA1060 layers and the other with only AA1060 layers. The effects of these designs on the deformation behaviors are revealed by in-situ monitoring of the local strain evolution. It was found that larger microstructural and textural variations can lead to a larger difference in transverse compressive strain between constituent layers under uniaxial tension, which indicates more significant defomation incompatibility and thus a larger strain gradient caused by the constraint effect. The effects of the texture on the transverse compressive strain levels was analysed by the Lankford values calculated by the visco-plastic self-consistent method. Furthermore, the fracture behaviors of the two samples are compared and discussed based on the cross-sectional fracture morphologies. This work illustrates the potential of tailoring layered metals for a superior strength–ductility combination.

Styles APA, Harvard, Vancouver, ISO, etc.

27

Basheer, Mohammed Abdul, Vagmare Gangadhar, Guduru Prasad, Gobburu Subramanya Kumar et Nandi Venkata Prasad. « Electrical and Raman Spectroscopic Studies on Aurivillius Layered-Pervoskite Ceramics ». Advanced Materials Research 1154 (juin 2019) : 80–90. http://dx.doi.org/10.4028/www.scientific.net/amr.1154.80.

Texte intégral

Résumé :

Double rare-earth (La; Sm/Gd) substituted Aurivillius family of Bismuth Layered Structured Ferroelectrics (BLSF) namely Bi2.6Sm0.2La0.2TiNbO9 (BSLT; sample-A), Bi2.6Gd0.2La0.2TiNbO9 (BGLT; sample-B), single phase ceramics were prepared by solid state route. In addition, intergrowth (x BSLT - (1-x) BGLT, where x=0.49; sample-C) and solid solution (BSLTx - BGLTy; where x + y=0.4; sample-D) materials were prepared. Dielectric, ferroelectric and Raman spectroscopic properties were studied on the said above materials. The X-ray diffraction analysis and Raman spectra revealed well-formation of stable structure. Though, the sample-C and sample-D have lower coercive field, compared to the sample-A and sample-B, but they exhibited sharp hysterisis loop. Therefore the instrinsic defects of sample-D inhabits more sensitivity towards the ferroelectric behaviour. The results were corroborated to the impedance and dielectrical data. The results were consistent with the SEM micrographs and complex impedance plots. An attempt is made to understand the effect of rare-earth ions on A-site of layered-pervoskite structure, defined as: (Bi2O2)2+(An-1BnO3n+1)2-.The term n represents number of pervoskite blocks interleaved with the bismuth oxide layers.

Styles APA, Harvard, Vancouver, ISO, etc.

28

Reddy, Y. S. « Electrical transport and magnetoresistance of double layered CMR manganites R1.2Sr1.8Mn2O7(R = La, Pr, Sm) ». Materials Science-Poland 35, n^o 2 (26 juillet 2017) : 440–46. http://dx.doi.org/10.1515/msp-2017-0048.

Texte intégral

Résumé :

Abstract Polycrystalline bulk samples of double layered (DL) colossal magnetoresistive (CMR) manganites R1.2Sr1.8Mn2O7 (R = La, Pr, Sm) were prepared by sol-gel method to study the effect of size of lanthanide ion on their magnetotransport properties. The electrical resistivity of the samples was investigated in the temperature range of 70 K to 300 K at different magnetic fields. The samples LSMO and PSMO show insulator-to-metal transition (IMT) behavior, while SSMO sample exhibits insulating behavior in the entire temperature range with a very large value of resistivity. The insulator-to-metal transition temperature (TIM) decreases from 123 K (LSMO) to 90 K (PSMO) and disappears in SSMO sample. To explain the electrical transport above TIM, the temperature dependent resistivity data (T > TIM) of all the samples were fitted to the equations of different conduction models. The results indicate that the conduction at T > TIM is due to Mott variable range hopping (VRH) mechanism in the LSMO and PSMO samples, while Efros-Shkloskii (ES) type of VRH model dominates the conduction process in the SSMO sample. All the three samples show increasing magnetoresistance (MR) even below TIM and the maximum MR is shown by LSMO (39 % at 75 K, 3 T).

Styles APA, Harvard, Vancouver, ISO, etc.

29

Hopen, Thomas J., Richard S. Brown, R. Keith Wheeles et Wilfried Stocklein. « Cathodoluminescence Microscopy of Architectural Paint Samples ». Microscopy and Microanalysis 4, S2 (juillet 1998) : 488–89. http://dx.doi.org/10.1017/s143192760002256x.

Texte intégral

Résumé :

The layer sequence of multi-layered white and off-white paint chips usually encountered by the forensic scientist in cases involving structural and/or maintenance paint is sometimes difficult to discern when utilizing commonly employed microscopical methods. This layer sequence information becomes vitally important when comparing a questioned paint sample to a paint sample of known origin. Techniques such as reflected light microscopy, fluorescence microscopy, and scanning electron microscopy (SEM) coupled with energy dispersive x-ray spectroscopy (EDS) may not provide the needed discrimination. Also, binder information may not be available for comparison since the thinness of the layers the difficulty in detecting individual layers, and the abundance of the extender pigments may preclude analysis by infrared microspectrophotometry.Cathodoluminescence microscopy (CLM) may provide the needed layer sequence information and discrimination when analyzing and comparing multi-layered white and off-white paint samples. Cathodoluminescence (CL) is the emission of radiation from the sample in the visible light region and neighboring wavelengths during excitation by electrons generated from a cathode electron gun.

Styles APA, Harvard, Vancouver, ISO, etc.

30

Baldenegro-Perez, Leo A., Wardia Debray-Mechtaly, E. Fuentes-Fernandez, M. A. Quevedo-López, Husam N. Alshareef, Pradeep Shah et B. E. Gnade. « Study on the Microstructure and Electrical Properties of Pb(Zr_0.53 Ti_0.47)O₃ Thin-Films ». Materials Science Forum 644 (mars 2010) : 97–100. http://dx.doi.org/10.4028/www.scientific.net/msf.644.97.

Texte intégral

Résumé :

In the present study a complete analysis of the morphological and electrical properties of PZT layers with composition 53Zr-47Ti is presented. Three different samples composed of 3, 6, and 9 PZT layers were analyzed on a substrate consisting of ZrO2-SiO2-Si structures. The PZT and ZrO2 layers were deposited via Sol-Gel, whereas the SiO2 layer, on every sample, was deposited via PECVD. SEM results showed morphology of very small granules on the 3 layered thin-film samples (12 nm), on the 6 layered thin-film samples a mixture of small and large size (100-300 nm) granule formation was observed, with the 9 layered thin-film samples exhibiting very large granule sizes (bigger than 300 nm). XRD results showed that increasing the number of deposited layers caused an incremental increase on the detected peak intensities, aided in the promotion of the perovskite phase, and diminished the presence of the pyrochlore phase. It was also observed, during electrical measurements, that increasing the number deposited layers directly increased the overall capacitance of the thin-film structure. This effect was attributed primarily to the large amount of perovskite and large size of grains presented on thick samples.

Styles APA, Harvard, Vancouver, ISO, etc.

31

Zhuang, Li, Sun Yeom, Inhwan Yeo et Kyungsuk Cho. « Characterization of Microstructure in Glass Wool Insulation Using Micro X-ray CT ». Journal of the Korean Society of Hazard Mitigation 22, n^o 6 (31 décembre 2022) : 133–39. http://dx.doi.org/10.9798/kosham.2022.22.6.133.

Texte intégral

Résumé :

We investigate microstructures of three insulation samples made of glass wool fiber with low to high density through X-ray Computed Tomography. Analysis results indicate that the volume fraction of fibers increases linearly with increasing bulk density, and thermal conductivity decreases nonlinearly with increasing volume fraction of fibers. In addition, the insulation samples have nonuniform structures, particularly for the low-density sample, showing that the average local volume fraction of fibers in one layer varies up to two times. The sample with the highest density exhibits a more distinct layered structure than the other two relatively low-density samples.

Styles APA, Harvard, Vancouver, ISO, etc.

32

Yu, Zhi Yong, et Han Xing Liu. « Effect of Synthesis Conditions on the Structure and Electrochemical Properties of LiNi_1/2Mn_1/2O₂ by Sol Gel Method ». Advanced Materials Research 399-401 (novembre 2011) : 1447–50. http://dx.doi.org/10.4028/www.scientific.net/amr.399-401.1447.

Texte intégral

Résumé :

The layered LiNi1/2Mn1/2O2 cathode materials were synthesized by a sol gel method. The effects of calcination temperature and time on the structural and electrochemical properties of the LiNi1/2Mn1/2O2 were investigated. The prepared samples were characterized by X-ray diffraction (XRD) and electrochemical analysis. The results revealed that the layered LiNi1/2Mn1/2O2 material could be optimal synthesized at temperature of 900°C for 10h. The sample prepared under the above conditions has the highest initial discharge capacity of 151 mAh/g and showed no dramatic capacity fading during 20 cycles between 2.5-4.5V at a current rate of 20mA/g.

Styles APA, Harvard, Vancouver, ISO, etc.

33

Xu, Guo Feng. « Optimized Lithium-Indium Chloride Solid Electrolyte for High Energy All-Solid-State Batteries ». Nano Hybrids and Composites 34 (23 février 2022) : 3–8. http://dx.doi.org/10.4028/p-xk5392.

Texte intégral

Résumé :

All-solid-state battery is a promising next-generation energy storage and conversion device and the development of solid electrolyte is very important as the core of all solid-state batteries. Herein lithium-indium chloride solid electrolyte is successfully prepared and the ionic conductivity is increased from 1.07 to 1.41 mS/cm by optimizing the vacuum parameter in the process of preparation. The samples have typical C2/m space group of cubic crystal system, and the vacuum optimized sample has more regular ion arrangement, better crystallinity and fewer lattice defects. The prepared sample is used as the electrolyte layer and the electrolyte part of the composite cathode, and the layered oxide LiNi0.6Co0.2Mn0.2O2 without surface modification was used as the active material. After assembling the cell, the initial discharge specific capacity of the cell was tested to be 157.5mAh/g. In addition, the phase transition of the composite cathode is analyzed under different charge and discharge state. It is found that the use of the lithium-indium chloride solid electrolyte in composite electrode does not affect the REDOX reaction of LiNi0.6Co0.2Mn0.2O2 layered oxide, indicating that the electrolyte material is stable and compatible with layered cathode material, showing its excellent application prospect.

Styles APA, Harvard, Vancouver, ISO, etc.

34

Bailey, James A., R. Brian Dyer, Darla K. Graff et Jon R. Schoonover. « High Spatial Resolution for IR Imaging Using an IR Diode Laser ». Applied Spectroscopy 54, n^o 2 (février 2000) : 159–63. http://dx.doi.org/10.1366/0003702001949122.

Texte intégral

Résumé :

By coupling an infrared diode laser to a conventional infrared microscope, one achieves resolution approaching the diffraction limit while enabling rapid data collection. This technique is demonstrated with the use of a layered polymer sample that has been contaminated by migration of a volatile additive from an exogenous source. The distribution of this additive in the layered structure is shown to correlate with specific layers and reveals a concentration gradient suggesting a diffusive mechanism of additive migration parallel to the layered structure.

Styles APA, Harvard, Vancouver, ISO, etc.

35

Zeng, Zhao Tian, Hai Bo Lu, Jin Jin Zhang et Yan Lin Zhao. « Effects of Sample Preparation Methods on Tensile Strength of Red Clay ». Applied Mechanics and Materials 204-208 (octobre 2012) : 3847–51. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.3847.

Texte intégral

Résumé :

Effects of two sample preparation methods on tensile strength of red clay are studied. The first method adopts standard layered-bumping to make sample whose layer interfaces are vertical to tensile force. The second method uses compaction apparatus to prepare big sample and the big sample is cut to prepare triaxial sample whose layer interface is parallel to tensile force. Test results indicate that the layer interfaces of soil sample have large influence on the single axle tension test, because the results of the sample prepared by 1st method have large dispersion and low strength, while the results of the sample prepared by 2nd method are just the opposite.Moreover,the layer interfaces of soil sample have little influence on the unconfined compressive strength test, and the results of the tensile test and unconfined compressive strength test of the samples prepared by 2nd method meet with the Griffith Criterion, so the samples of uniaxial tension test should be prepared by 2nd method.

Styles APA, Harvard, Vancouver, ISO, etc.

36

Butt, Ghorabian, Mohaghegh et Shirvani. « Finite Element Modeling and Mechanical Testing of Metal Composites Made by Composite Metal Foil Manufacturing ». Journal of Manufacturing and Materials Processing 3, n^o 3 (6 septembre 2019) : 81. http://dx.doi.org/10.3390/jmmp3030081.

Texte intégral

Résumé :

Foils of aluminum 1050 H14 ½ hard temper and 99.9% copper with 500-micron thickness have been used to manufacture similar and dissimilar composites by composite metal foil manufacturing (CMFM). The metal foils are bonded to each other using a special 80% zinc and 20% aluminum by weight brazing paste. A 3D finite element model has been developed to numerically analyze the time required to heat the metal foils so that a strong bond can be developed by the paste. The numerical simulations run in ANSYS 19.1 have been validated through experiments and rectangular layered composite products have been developed for flexural testing. The flexural test results for layered Al and Al/Cu composites are compared with solid samples of Al 1050 and 99.9% pure copper made by subtractive method. The results show that the layered Al composite is 5.2% stronger whereas the Al/Cu sample is 11.5% stronger in resisting bending loads compared to a solid Al 1050 sample. A higher bend load indicates the presence of a strong intermetallic bond created by the brazing paste between the metal foils. Corrosion testing was also carried out on the composite samples to assess the effect of corrosion on flexural strength. The tests revealed that the composites made by CMFM are not affected by galvanic corrosion after 7 days of testing and the flexural loads remained consistent with composites that were not immersed in a solution of distilled water and NaCl.

Styles APA, Harvard, Vancouver, ISO, etc.

37

Aljaafari, Abdullah, et Sobhy S. Ibrahim. « Electromagnetic interference shielding and mechanical properties of multi-layered polyvinyl chloride/multiwall carbon nanotubes nanocomposite ». Materials Express 9, n^o 8 (1 novembre 2019) : 872–81. http://dx.doi.org/10.1166/mex.2019.1568.

Texte intégral

Résumé :

Electromagnetic shielding is one of the promising research areas that attract the interest of many researchers, especially researchers interested in polymer nanocomposite. In this work, the shielding efficiency and dynamic mechanical analysis for multi-layered samples are reviewed and analyzed. The multi-layered samples were prepared using two sheets of polyvinyl chloride (PVC) polymer loaded with multiwall carbon nanotubes over the electrical percolation threshold, and a MWCNTs buckypaper (MWCNTs BP) sheet between them. The three sheets were collected together by hot-press technique to form a multi-layered nanocomposite sample. The shielding efficiency of single and double layers of PVC/MWCNTs sheets loaded by 5 wt.% MWCNTs, was very weak. The new structured (3 layered/multilayered) nanocomposite samples were prepared with different weight percent of MWCNTs BP sheet (0, 1, 2, 3 and 4 wt.%). The SE values over all the frequency range (450 MHz to about 2.0 GHz) are strongly depends on the weight percent of the MWCNTs BP. Shielding efficiency increased as the MWCNTs BP weight percent increased. Decreases the elastic modulus, storage modulus and the coefficient of complex viscosity were found for a new set of samples contains 0.14, 0.27, 0.28 and 0.44 wt.% MWCNTs BP layers. This is due to the diffused MWCNTs from the mesh to polymer layers making the composite more brittle. The glass transition temperature determined from tanδ(f) increased as MWCNTs BP content increases.

Styles APA, Harvard, Vancouver, ISO, etc.

38

Cai, Y. H., X. A. Mei, Min Chen, K. L. Su, W. K. An et J. Liu. « Electrical Characteristics and Microstructures of (Gd, Dy)-Doped Bi₄Ti₃O₁₂ Ceramics ». Key Engineering Materials 368-372 (février 2008) : 88–90. http://dx.doi.org/10.4028/www.scientific.net/kem.368-372.88.

Texte intégral

Résumé :

The electrical properties of Bi3.25Dy0.75Ti3O12 (BDT) and Bi3.25Gd0.75Ti3O12 (BGT) ceramics were investigated. The current-voltage curve of the BGT sample exhibits a negative differential resistance behavior, whereas that of the BDT sample exhibits a simple ohmic behavior. The impedance spectrum of the BDT and BGT samples indicate that both consist of semiconducting grain and moderately insulating grain boundary regions. XRD, SEM and EPMA analyses reveal crystalline phase characterized by a Bi-layered perovskite structure of Bi4Ti3O12 and the distribution of every element is uniform. Both BDT and BGT samples exhibit randomly oriented and plate-like morphology.

Styles APA, Harvard, Vancouver, ISO, etc.

39

Nestroinaia, Olga, et Oksana Ponomarenko. « Synthesis of hybrid materials based on layered double hydroxides ». Chemical Bulletin of Kazakh National University, n^o 2 (29 juin 2019) : 4–10. http://dx.doi.org/10.15328/cb1025.

Texte intégral

Résumé :

The use of pesticides adversely affects not only the environment, but also human health. A promising direction in solving this problem is to obtain hybrid materials capable of controlled release of pesticides. Layered double hydroxides (LDHs) can act as a matrix. Layered double hydroxides with intercalated glyphosate anions (MgAl-Gly-LDH) were synthesized by different methods: coprecipitation at constant pH (MgAl-Gly-LDH-c), synthesis under hydrothermal conditions (MgAl-Gly-LDH-ht), microwave method (MgAl-Gly-LDH-mw) and rehydration method (MgAl-Gly-LDH-re). All the synthesized samples were analyzed by X-ray phase analysis (XRD), energy dispersive X-ray spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. It is shown that the methods of co-precipitation and synthesis under hydrothermal conditions are most suitable for the synthesis of hybrid materials. Samples of MgAl-Gly-LDH-ht and MgAl-Gly-LDH-c have a well-crystallized structure, unlike the sample of MgAl-Gly-LDH-re, in which the LDH phase is practically absent.

Styles APA, Harvard, Vancouver, ISO, etc.

40

Guo, Cun Biao, Li Han, Qin Wang, Jian Feng Wang, Yu Zhong Zhan, Shi Ling Guo, Yi Liang Chen et Rui Zhang. « Synthesis of Layered AlPO₄-5 in Polyacrylamide Hydrogels ». Applied Mechanics and Materials 189 (juillet 2012) : 172–75. http://dx.doi.org/10.4028/www.scientific.net/amm.189.172.

Texte intégral

Résumé :

Layered AlPO4-5 molecular sieve was synthesized in polyacrylamide (PAM) hydrogels. The sample was produced using synthesis gel with weight composition of 1.0Al2O3 : 1.8P2O5 : 1.2 triethylamine (TEA) : 18.0H2O : 2.2 acrylamide (AM). The synthesized layered AlPO4-5 molecular sieve had an average thickness of 2.5 μm, and each layer was approximate circle with an average diameter of 5 μm.

Styles APA, Harvard, Vancouver, ISO, etc.

41

NAKAGAWA, KEIZO, TOSHIMASA OGATA, KEN-ICHIRO SOTOWA, SHIGERU SUGIYAMA et MOTONARI ADACHI. « CONTROL OF MORPHOLOGY AND SURFACE PROPERTIES OF FLAKY LAYERED TITANATE NANOSHEETS USING SURFACTANT IN HYDROTHERMAL SOLUTION ». International Journal of Modern Physics B 24, n^o 15n16 (30 juin 2010) : 3248–52. http://dx.doi.org/10.1142/s0217979210066409.

Texte intégral

Résumé :

Layered titanate nanosheets were synthesized by hydrolyzing titanium tetraisopropoxide (TIPT) in hydrothermal solution using triethanolamine (TEOA), and dodecanediamine (DDA) as surfactant. The effects of synthesis conditions on the formation of layered titanate nanosheets were investigated. A layered structure of the titanate was produced under basic (pH12.8) conditions using NaOH or NH4OH aqueous solution. The flaky forms were observed only in reaction mixtures that included DDA, and the flaky forms had multilayer structure comprising several monolayer sheets. In addition, TEOA and DDA promote control of the crystalline structure of layered titanate. The surface acidity of layered titanate nanosheets was studied by coloration with color indicator reagents. The acidity of the sample corresponds to that of dilute hydrochloric acid. It is assumed that acid sites can be formed on the surface of titanate nanosheets by elimination of NH4+ caused by calcination in air.

Styles APA, Harvard, Vancouver, ISO, etc.

42

Xu, Huichen, Yong Zhang, Chengwei Zhao, Chengyu Miao et Xiaoming Sun. « Creep Structure Effect of Layered Rock Mass Based on Acoustic Emission Characteristics ». Shock and Vibration 2021 (14 septembre 2021) : 1–14. http://dx.doi.org/10.1155/2021/7419741.

Texte intégral

Résumé :

Investigating the creep structural effect of layered rock mass is of great practical and theoretical significance. In this paper, taking the Muzhailing tunnel as an example, structure effect of layered rock mass based on acoustic emission characteristics has been analyzed. The study shows that creep parameters of layered rock mass are significantly influenced by structural effects, and the overall creep variable is small. The creep deformation of layered rock mass includes transient creep and steady-state creep at a low stress level. At a higher stress level, when the long-term strength of the rock sample is reached, the deformation increases rapidly, and the accelerated creep occurs in a very short period of time. The creep equation of the structural effects of layered rock mass was established based on the experimental results. Acoustic emission characteristics are analyzed during creep experiment; the study shows that the energy released at the time of initial loading and destruction accounted for most of the total energy. The initial energy release increased first and then decreased with the increase in inclination angle; as the inclination angle increased, the cumulative energy when the rock sample was damaged first decreased and then increased. The structural effect on the main frequency value at the time of failure mainly reflected in the trend that the main frequency value first increased and then decreased as the inclination angle increased. Based on the above analysis, we can recognize the structural effects of layered rock mass and provide the necessary parameters for on-site support.

Styles APA, Harvard, Vancouver, ISO, etc.

43

Vignesh, S., J. T. Winowlin Jappes, S. Nagaveena, R. Krishna Sharma, M. Adam Khan, Chaitali V. More, N. Rajini et Temel Varol. « Development of Lightweight Polymer Laminates for Radiation Shielding and Electronics Applications ». International Journal of Polymer Science 2022 (8 octobre 2022) : 1–13. http://dx.doi.org/10.1155/2022/5252528.

Texte intégral

Résumé :

The present study portrays the development of lightweight epoxy laminates filled with boron carbide (B4C) and lead (Pb) particles through a novel layered molding and curing route. Six different laminates of single and tri-layers were prepared with varying compositions and were subjected to thermal, radiation shielding, and dielectric studies. Radiation shielding test were done using a narrow beam setup with six different sources such as Cobalt-57 (Co57-122 keV), Barium-133 (Ba133-356 keV), Sodium-22 (Na22-511 and 1275 keV), Cesium-137 (Cs137-662 keV), Manganese-54 (Mn54-840 keV), and Cobalt-60 (Co60-1170 and 1330 keV). The dielectric studies were done to understand the dielectric constant, dielectric loss factor, and AC conductivity at different temperature and frequency ranges. From the characterizations, it was found that the thermal stability of the single-layered sample increased with respect to the addition of B4C and Pb particles, which may be due to the thermally stable nature of the particles. The radiation shielding study of the samples witnessed the superior characteristics and radiation shielding ability of sample D (40% Pb) and sample E with Pb cladding at incident gamma radiation energy of 662 keV. The dielectric constant of the samples increased significantly at higher temperatures and the dielectric loss factor increased with an increase in temperature and decreased with an increase in frequency. The AC conductivity of the samples increased with respect to an increase in temperature and frequency.

Styles APA, Harvard, Vancouver, ISO, etc.

44

Nestroinaia, Olga V., Irina G. Ryltsova et Olga E. Lebedeva. « Effect of Synthesis Method on Properties of Layered Double Hydroxides Containing Ni(III) ». Crystals 11, n^o 11 (21 novembre 2021) : 1429. http://dx.doi.org/10.3390/cryst11111429.

Texte intégral

Résumé :

Unstable oxidation state +3 of nickel can be stabilized in the structure of layered double hydroxides, the resulting crystallinity and properties being dependent on the synthesis method. Three different wet chemical methods (co-precipitation at variable pH, co-precipitation followed by hydrothermal treatment, co-precipitation with microwave treatment) were used to synthesize Mg/Ni–Al layered double hydroxides containing triply charged nickel cations. Lattice parameters of the samples synthesized by various methods were found to differ from each other by about 1.5%. The most crystallized sample was obtained by hydrothermal synthesis. The oxidation state of nickel in the LDH samples was confirmed by XPS. TEM mapping gave evidence of the uniform distribution of nickel in all the samples. The LDHs’ reduction with hydrogen and thermal transformations of the phase composition and morphology of LDHs were studied in detail. The properties of the samples synthesized by the different methods were shown to be quite similar.

Styles APA, Harvard, Vancouver, ISO, etc.

45

Hu, Zhao Hui, Yi Li, Li Ma et Hong Jun Liu. « Tensile Behavior and Fractography of Ti-TiAl Multi-Layered Foil Prepared by Electron Beam Physical Vapor Deposition Technology ». Applied Mechanics and Materials 55-57 (mai 2011) : 183–87. http://dx.doi.org/10.4028/www.scientific.net/amm.55-57.183.

Texte intégral

Résumé :

Ti-TiAl multi-layered materials have been prepared by electron beam physical vapor deposition technique. The tensile behavior of samples at room temperature and high temperature was tested, and then the deformation mechanism at different temperature was analyzed according to the fracture surface. The results show that the tensile curves hot-pressed samples have a broad step during the plastic deformation process, and the breaking strain of the sample has been increased for a wide-range. The presence of Ti layers have led to the cracks stagger along the inter-laminar interface or the layer due to which micro laminate expresses a good characteristic of delayed fracture. With the increase of temperature, the bulk modulus and yield strength of multi-layered Ti-TiAl have been increased abnormally due to the anomalous yield strengthening behavior of TiAl intermetallic.

Styles APA, Harvard, Vancouver, ISO, etc.

46

Li, Qiaoyi, Guangqing Yang, He Wang et Zhijie Yue. « The Direct and Oblique Shear Bond Strength of Geogrid-Reinforced Asphalt ». Coatings 12, n^o 4 (11 avril 2022) : 514. http://dx.doi.org/10.3390/coatings12040514.

Texte intégral

Résumé :

The interlayer bonding strength is an essential property of geogrid-reinforced asphalt. To study the interlayer bonding characteristics of geogrid-reinforced asphalt, direct shear and oblique shear tests were carried out in the laboratory. The direct interlaminar shear strength of geogrid-reinforced asphalt was lower than that of unreinforced asphalt. The oblique shear strength of the carbon–carbon geogrid-reinforced sample was the highest, the unreinforced sample was second, and the carbon–glass geogrid-reinforced sample was the lowest. The stiffness of the geogrid affects the oblique shear strength. The interlayer direct shear strengths of AC-20C asphalt samples were higher than AC-13C asphalt samples. The oblique shear strengths of AC-20C asphalt samples were almost the same as the AC-13C asphalt samples. Normal stress made the double-layered sample tend to behave as a homogeneous granular material. The direct shear strength vs. shear displacement curves showed an area of oscillation, but the oblique shear curves were smooth throughout the process.

Styles APA, Harvard, Vancouver, ISO, etc.

47

Kundu, T. « Transient Response of an Interface-Crack in a Layered Plate ». Journal of Applied Mechanics 53, n^o 3 (1 septembre 1986) : 579–86. http://dx.doi.org/10.1115/1.3171814.

Texte intégral

Résumé :

In this paper, the transient response of an interface crack, in a two layered plate subjected to an antiplane stress field, is analytically computed. The problem is formulated in terms of semi-infinite integrals following the technique developed by Neerhoff (1979). It has been shown that the major steps of Neerhoff’s technique, which was originally developed for layered half-spaces, can also be applied to layered plate problems. An improved method for manipulation of semi-infinite singular integrals is also presented here. Finally, the new method is coded in FORTRAN program and numerical results for a sample problem are presented.

Styles APA, Harvard, Vancouver, ISO, etc.

48

Liu, Zong-Huai, Liping Kang, Mingzhu Zhao et Kenta Ooi. « Preparation, ion-exchange, and electrochemical behavior of Cs-type manganese oxides with a novel hexagonal-like morphology ». Journal of Materials Research 22, n^o 9 (septembre 2007) : 2437–47. http://dx.doi.org/10.1557/jmr.2007.0302.

Texte intégral

Résumé :

Cs-type layered manganese oxide with a novel hexagonal-like morphology (Cs–BirMO) was prepared by a solid-state reaction procedure. The Cs+ extraction and alkali–metal ion insertion reactions were investigated by chemical analyses, x-ray analyses, scanning electron microscopy observation, Fourier transform-infrared spectroscopy, thermogravimetric differential thermal analyses, pH titration, and distribution coefficient (Kd) measurements. A considerable percentage (88%) of Cs+ ions in the interlayer sites were topotactically extracted by acid treatment, accompanied by a slight change of the lattice parameters. Alkali–metal ions could be inserted into the interlayer of the acid-treated sample (H–BirMO), mainly by an ion-exchange mechanism. The pH titration curve of the H–BirMO sample showed a simple monobasic acid toward Li+, Rb+, and Cs+ ions, and dibasic acid behavior toward Na+ and K+ ions. The order of the apparent capacity was K+ > Li+ ≈ Na+ ≈ Rb+ ≈ Cs+ at pH < 6. The Kd study showed the selectivity sequence of K+ > Rb+ > Na+ > Li+ for alkali–metal ions at the range of pH <5; H–BirMO sample showed markedly high selectivity for the adsorption of K+ ions. Preliminary investigations of the electrochemical properties of the Li+-inserted sample Li–BirMO(1M, 6d) showed that the obtained samples had a relatively high discharge capacity of 115 mAh g−1 and excellent layered stability.

Styles APA, Harvard, Vancouver, ISO, etc.

49

Michalski, Krzysztof A. « SPECTRAL DOMAIN ANALYSIS OF A CIRCULAR NANO-APERTURE ILLUMINATING A PLANAR LAYERED SAMPLE ». Progress In Electromagnetics Research B 28 (2011) : 307–23. http://dx.doi.org/10.2528/pierb11011010.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

50

Png, Gretel M., Bernd M. Fischer, Dominique Appadoo, Ruth Plathe et Derek Abbott. « Double-layered nitrocellulose membrane sample holding technique for THz and FIR spectroscopic measurements ». Optics Express 23, n^o 4 (18 février 2015) : 4997. http://dx.doi.org/10.1364/oe.23.004997.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Articles de revues sur le sujet « Layered Sample »

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres