To see the other types of publications on this topic, follow the link: Volume (Cubic content).
Journal articles on the topic 'Volume (Cubic content)'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Volume (Cubic content).'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Chan, Walker R., Veronika Stelmakh, Michael Ghebrebrhan, Marin Soljačić, John D. Joannopoulos, and Ivan Čelanović. "Enabling efficient heat-to-electricity generation at the mesoscale." Energy & Environmental Science 10, no. 6 (2017): 1367–71. http://dx.doi.org/10.1039/c7ee00366h.
Full text
2
Zhang, Pan, Yan Kun Zhang, Xiao Hu Li, and Zhen Lei Guo. "Experiment Research on Compressive Strength of Specified Density Steel Fiber Concrete." Advanced Materials Research 374-377 (October 2011): 1606–9. http://dx.doi.org/10.4028/www.scientific.net/amr.374-377.1606.
Full textAbstract:
Based on the experimental research, the prism compressive strength and cubic compressive strength of specified density steel fiber concrete are studied. Through regression analysis, the influence of type of steel fiber, volume content of the fiber and substitution ratio of lightweight aggregate is studied. According to the test results, the formula of prism compressive strength and cubic compressive strength is given.
3
Jiang, J. Z., F. W. Poulsen, and S. Mørup. "Structure and Thermal Stability of Nanostructured Iron-doped Zirconia Prepared by High-energy Ball Milling." Journal of Materials Research 14, no. 4 (April 1999): 1343–52. http://dx.doi.org/10.1557/jmr.1999.0183.
Full textAbstract:
Fully stabilized cubic zirconia doped with iron oxide has been synthesized by high-energy ball milling from powder mixtures of monoclinic zirconia and hematite. It is found that the iron ions dissolved in cubic ZrO2 are in substitutional positions with a maximum solubility of approximately 18.5 mol% α–Fe2O3. The unit-cell volume of the cubic ZrO2 phase decreases with increasing iron content. During heating the cubic-to-tetragonal transition occurs at approximately 827 °C and the tetragonal-to-monoclinic transition seems to be absent at temperatures below 950 °C. During cooling the tetragonal-to-monoclinic transition occurs at 900–1100 °C.
4
Li, Qing, and Xiao Xiang Yang. "Numerical Simulation for Mechanical Behavior of Carbon Black Filled Rubber Composites Based on Cubic Representative Volume Element." Key Engineering Materials 627 (September 2014): 285–88. http://dx.doi.org/10.4028/www.scientific.net/kem.627.285.
Full textAbstract:
Based on the connection between macroscopic and microscopic characteristics of carbon black filled rubber composites, Representative Volume Element (RVE) containing one single particle has been proposed, and three dimensional cubic RVE has been established to study and analyze the macroscopic mechanical properties of the carbon black filled rubber composites by the micromechanical finite element method. The research shows that the stiffness of the composite is increased with the increase of the volume fraction of carbon black filler particles. By comparison, it is shown that the results of the predictions on the stress-strain behavior of the rubber composite made with the cubic RVE numerical models containing one spherical particle are in good agreement with the experimental results for seven and fifteen percent carbon black filler content, but there is some discrepancy between them for twenty-five percent carbon black filler content. The results of the predictions on the stress-strain behavior of the rubber composite made with the cubic RVE numerical models containing one cubical particle are higher than the experimental results, and the higher the carbon black filler content, the greater is the discrepancy between them.
5
Solovev, S. A., O. V. Soloveva, I. G. Akhmetova, Y. V. Vankov, and R. Z. Shakurova. "Numerical investigation of the thermal conductivity of a composite heat-insulating material with microgranules." Power engineering: research, equipment, technology 24, no. 1 (May 24, 2022): 86–98. http://dx.doi.org/10.30724/1998-9903-2022-24-1-86-98.
Full textAbstract:
THE PURPOSE. To consider the problems that arise when creating a composite heatinsulating material, including a layer of microspherical granules. Numerical modeling of a composite material with different volume content of microspheres and different options for the formation of voids. Determination of the influence of the presence of zones not occupied by microgranules on the insulating properties of the composite material. Determination of the influence of the volume content of microspherical granules on the heat flux through the composite material.METHODS. Numerical simulation was carried out by creating models of elementary cubic cells of a composite with a package of 27 microspheres in the ANSYS Fluent 19.2 software package. The evaluation of the insulating properties was carried out by measuring the thermal conductivity coefficient.RESULTS. The article investigates the influence of the presence of zones not occupied by microspherical granules on the thermal insulation properties of a composite material. Models of elementary cubic cells with different volume content of microgranules are constructed. Models of elementary cells are built with various options for the formation of voids, such as the removal of a vertical or horizontal row of granules and the compaction of granules vertically or horizontally.CONCLUSION. The removal of microgranules has a significant effect on the insulating properties of the composite. The lowest thermal conductivity coefficient was obtained for a simple cubic cell with a volume content of microgranules φ = 40%. The presence of voids in the material contributes to large heat losses, and in the case of a vertical through channel, the heat losses are greater than for a horizontal through channel. In the case of densification of spheres, heat losses in the zone not occupied by microgranules are compensated by a decrease in the heat flux in the area with densification of spheres.
6
Максимов, В. И., Е. Н. Максимова, and Т. П. Суркова. "Вариативность результирующего поля микродеформаций в кристаллах Zn-=SUB=-1-x-=/SUB=-V-=SUB=-x-=/SUB=-Se (0.01≤ x≤0.10)." Физика твердого тела 60, no. 1 (2018): 50. http://dx.doi.org/10.21883/ftt.2018.01.45287.004.
Full textAbstract:
AbstractA detailed neutronographic study of the bulk ZnSe crystals doped with vanadium up to the content commensurate with the solubility limit in a semiconductor matrix has been carried out for the first time at room temperature. The data that characterize nonuniformly-deformed states based on the cubic structural modification of the II–VI compounds are obtained. A simplified analysis of the broadening patterns of the diffraction profiles of main Bragg reflexes of the studied crystals shows that the resulting deformation covers macroscopic volumes, and the distribution of vanadium ions in the given cases may significantly deviate from the uniform distribution over volume. Relative to the initial cubic lattice, dominating trends towards symmetry changes preceding the phase stratification in the ZnSe crystals heavily doped with vanadium are revealed.
7
Vavrukh, Valentyna. "Effects of the yttria content and sintering temperature on the phase evolution in yttria-stabilized zirconia." Ukrainian Journal of Mechanical Engineering and Materials Science 8, no. 1 (2022): 12–19. http://dx.doi.org/10.23939/ujmems2022.01.012.
Full textAbstract:
The microstructure of YSZ ceramics stabilized by the various amount of yttria, namely 3 mol % Y 2 O 3 (3YSZ), 4 mol% Y 2 O 3 (4YSZ) and 5 mol % Y 2 O 3 (5YSZ) has been studied. Three sintering temperatures, namely 1450 °C, 1500 °C and 1550 °C were used for each series of samples (3YSZ, 4YSZ, 5YSZ). The total area of the monoclinic and cubic zirconia phases in the microstructure of ceramics and the regularities of distribution of these phases were determined by ImageJ. Peculiarities of changes in volume percentage of the monoclinic and cubic phases with an increase in sintering temperature of ceramics were found. Quantitative analysis of these phases was carried out. The total distribution of the monoclinic and cubic phases by ranges of their areas was presented. Correlations between the yttria content, the sintering temperature and changes in the microstructure and phase balance of the studied ceramics were found.
8
Rao, Ya Xian, Chao Feng Liang, and Ying Xia. "Experimental Research on Physical and Mechanical Properties of EPS Recycled Concrete." Applied Mechanics and Materials 204-208 (October 2012): 4022–25. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.4022.
Full textAbstract:
In order to develop a new building material by recycling wasted concrete and expanded polystyrene (EPS), the EPS recycled concretes of different density were designed, and their basic physical and mechanical properties were studied. The results show that the EPS recycled concrete’s fluidity and saturated bibulous rate increase with the increase of EPS volume content. However, the dry apparent density, compressive strength, split tensile strength and thermal conductivity of EPS recycled concrete decrease linearly with increased EPS volume content. When the EPS volume content is 60%, the EPS recycled concrete’s cubic compressive strength is 4.0MPa and its thermal conductivity is 0.27W/m•K. Therefore, EPS recycled concrete can be widely applied to the non load-bearing lightweight insulation masonry.
9
Zhang, Peng, Xu Han, Yuanxun Zheng, Jinyi Wan, and David Hui. "Effect of PVA fiber on mechanical properties of fly ash-based geopolymer concrete." REVIEWS ON ADVANCED MATERIALS SCIENCE 60, no. 1 (January 1, 2021): 418–37. http://dx.doi.org/10.1515/rams-2021-0039.
Full textAbstract:
Abstract The effects of polyvinyl alcohol (PVA) fiber content on mechanical and fracture properties of geopolymer concrete (GPC) were investigated in the present study. Mechanical properties include cubic compressive, prism compressive, tensile and flexural strengths, and elastic modulus. The evaluation indices in fracture properties were measured by using the three-point bending test. Geopolymer was prepared by fly ash, metakaolin, and alkali activator, which was obtained by mixing sodium hydroxide and sodium silicate solutions. The volume fractions of PVA fiber (length 12 mm and diameter 40 μm) were 0, 0.2, 0.4, 0.6, 0.8, and 1.0%. The results indicate that the effects of the PVA fiber on the cubic and prism compressive strengths and elastic modulus are similar. A tendency of first increasing and then decreasing with the increase in the PVA fiber content was observed in these properties. They all reached a maximum at 0.2% PVA fiber content. There was also a similar tendency of first increase and then decrease for tensile and flexural strengths, peak load, critical effective crack lengths, fracture toughness, and fracture energy of GPC, which were significantly improved by the PVA fiber. They reached a maximum at 0.8% PVA fiber content, except the tensile strength whose maximum was at 1.0% PVA fiber volume fraction. Considering the parameters analyzed, it seems that the 0.8% PVA fiber content provides optimal reinforcement of the mechanical properties of GPC.
10
Cheng, Qi You, Jian Ping Huang, Ai Min Ling, and Zhi Zhuang Feng. "Investigation on the Effect of Resin Content on Buckling of Laminated Composite Plates." Advanced Materials Research 1035 (October 2014): 212–18. http://dx.doi.org/10.4028/www.scientific.net/amr.1035.212.
Full textAbstract:
Aerospace applications of composites involve components that are relatively thin plate or shell like structures, thus requiring the consideration of buckling as one of the many possible failure modes. To study the effect of the resin volume fraction on stability of composites, a finite element method based on micromechanics and classical lamination theory has been established to compute buckling loads of simply supported symmetric laminated composite plates subjected to the load of in-plane axial compress and shear load, respectively. The analysis procedure includes a Micromechanical finite element analysis that predicts the elastic modulus of lamina and a finite element linear buckling analysis that predicts buckling load of the composite plates. Three kinds of resin volume fraction that are equal to 44 percent, 47 percent, and 50 percent respectively are considered. The results show that the resin volume fraction has obvious influence on the stability of composite plate. The plate exhibits a relatively large increase in buckling load, about 12 percent, when the resin volume fraction increases by 3 percent. It is finds that the bending stiffness that has an obvious influence on the stability is an incremental function of elastic modulus and cubic thickness. The elastic modulus will be decreased slightly with the increase of resin volume fraction. However, the thickness of the plates is proportional to resin volume fraction.
11
Chou, Ruihua, Ying Sun, Huiqing Lu, and Guang-Hong Lu. "Structure, magnetic properties and thermal expansion of Mn3PtNx (0 ≤ x ≤ 1.0) compounds." International Journal of Modern Physics B 32, no. 28 (November 7, 2018): 1850314. http://dx.doi.org/10.1142/s0217979218503149.
Full textAbstract:
In this work, Mn3PtN[Formula: see text] (x = 0, 0.25, 0.5, 0.75 and 1.0) compounds were prepared by solid state reaction method. The structure, magnetic properties and thermal expansion behaviors of Mn3PtN[Formula: see text] compounds with different nitrogen content were systematically investigated. Mn3PtN has typical antiperovskite cubic structure with space group Pm-3m (221). With decreasing nitrogen content, the crystal structure changes to hexagonal with space group P63/mmc when the value of x decreases to x = 0.25, and then back to cubic with Fm3m at x = 0. All of the obtained Mn3PtN[Formula: see text] compound exhibit the magnetic transition from antiferromagnetic (AFM) to paramagnetic (PM). Moreover, another transition from AFM1 to AFM2 at lower temperature was also observed in Mn3Pt. The experimental results indicate that the magnetic transition induced abnormal thermal expansion behavior in Mn3PtN[Formula: see text]. Especially, a typical giant thermal expansion behavior of about [Formula: see text]8‰ volume change arising from the magneto-volume effect at 411 K is observed in Mn3Pt compound. The obtained results imply that this kind of compounds is a strong lattice–spin correlation system.
12
Wang, Li, Donghui Cheng, and Xiaoting Wang. "Experimental Research on Mechanical Properties of Carbon Fiber-Reinforced Reactive Powder Concrete after Exposure to Cryogenic Temperatures." Materials 15, no. 12 (June 15, 2022): 4240. http://dx.doi.org/10.3390/ma15124240.
Full textAbstract:
This study aims to evaluate the mechanical properties of carbon fiber-reinforced reactive powder concrete (CFRPC) after exposure to cryogenic temperature. The mechanical properties of plain RPC and CFRPC with carbon fiber volume contents of 0, 0.5%, 1.0%, and 1.5% were examined after exposure to 20 °C, −5 °C, −15 °C, and −25 °C for 72 h. The effect of fiber contents and exposure temperatures on the cubic and axial compressive strength, splitting tensile strength, elastic modulus, and peak strain were systematically reported and analyzed. The results showed adding carbon fiber to RPC could significantly enhance the strength and slightly improve ductility performance. Additionally, CFRPC with 1.0% fiber content showed the best mechanical properties. The maximum increases in cubic and axial compressive strength and tensile strength were 26.0%, 25.7%, and 21.8%, the elastic modulus was 13.2%, and the peak strain was 13.0% over the plain RPC. Additionally, all mechanical properties continued to degrade with decreasing temperature. After exposure to −25 °C, the cubic, axial compressive strength, and tensile strength of CFRPC degraded to 82.2–84.9%, 80.7–87.5%, and 72.7–73.7% of the normal temperature strength, respectively. In addition, the linear relationship equation between the discount factor of each mechanical property and the temperature was established. Finally, the equation for the stress–strain ascending curve of CFRPC described by a quadratic polynomial was proposed, which fitted well with the experimental results.
13
Adar, Ram M., and Samuel A. Safran. "Active volume regulation in adhered cells." Proceedings of the National Academy of Sciences 117, no. 11 (March 4, 2020): 5604–9. http://dx.doi.org/10.1073/pnas.1918203117.
Full textAbstract:
Recent experiments reveal that the volume of adhered cells is reduced as their basal area is increased. During spreading, the cell volume decreases by several thousand cubic micrometers, corresponding to large pressure changes of the order of megapascals. We show theoretically that the volume regulation of adhered cells is determined by two concurrent conditions: mechanical equilibrium with the extracellular environment and a generalization of Donnan (electrostatic) equilibrium that accounts for active ion transport. Spreading affects the structure and hence activity of ion channels and pumps, and indirectly changes the ionic content in the cell. We predict that more ions are released from the cell with increasing basal area, resulting in the observed volume–area dependence. Our theory is based on a minimal model and describes the experimental findings in terms of measurable, mesoscale quantities. We demonstrate that two independent experiments on adhered cells of different types fall on the same master volume–area curve. Our theory also captures the measured osmotic pressure of adhered cells, which is shown to depend on the number of proteins confined to the cell, their charge, and their volume, as well as the ionic content. This result can be used to predict the osmotic pressure of cells in suspension.
14
Huang, Xinfang, Zhiwen Xie, Kangsen Li, Qiang Chen, Yongjun Chen, and Feng Gong. "Thermal Stability of CrWN Glass Molding Coatings after Vacuum Annealing." Coatings 10, no. 3 (February 25, 2020): 198. http://dx.doi.org/10.3390/coatings10030198.
Full textAbstract:
CrWN glass molding coatings were deposited by plasma enhanced magnetron sputtering (PEMS). The microstructure and thermal stability of these coatings were investigated by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope, transmission electron microscope, atomic force microscope and nanoindentation tests. The as-deposited coating exhibited an aggravated lattice expansion resulting in a constant hardness enhancement. The vacuum annealing induced surface coarsening and the spinodal decomposition of the coating accompanied by the formation of nm-sized c-CrN, c-W2N, and h-WN domains. The annealed coating with low W content had mainly a face-centered cubic (f.c.c) matrix, strain fields caused by lattice mismatch caused hardness enhancement. Following an increase in W content, the annealed coating showed a mixed face-centered cubic (f.c.c) and hexagonal close-packed (h.c.p) matrix. The large volume fraction of h-WN phases seriously weakened the coating strengthening effect and caused an obvious drop in hardness.
15
Ledbetter, H. M., and S. A. Kim. "Molybdenum effect on Fe–Cr–Ni-alloy elastic constants." Journal of Materials Research 3, no. 1 (February 1988): 40–44. http://dx.doi.org/10.1557/jmr.1988.0040.
Full textAbstract:
This study involved the ultrasonic measurement of the polycrystalline elastic constants of six face-centered-cubic Fe–Cr–Ni alloys, nominally Fe–19Cr–12Ni (at. %). In these alloys, Mo content ranged up to 2.4 at. %. Molybdenum lowers the Young and shear moduli, and it raises the Poisson ratio. Against expectation (because it increases volume), Mo raises the bulk modulus. Qualitatively, the results show that Ni raises the bulk modulus and Poisson ratio; but Ni lowers the Young and shear moduli. (Nickel decreases the alloy's atomic volume.) The discussion includes existing models based on 3d-electron theory.
16
Verbovytskyy, Yuriy, Yuriy Kosarchyn, and Ihor Zavaliy. "Solid gas and electrochemical hydrogenation properties of the selected R,R’MgNi4-xMx (R,R’ = La, Pr, Nd; M = Fe, Mn; x = 0.5, 1) alloys." French-Ukrainian Journal of Chemistry 8, no. 2 (2020): 126–39. http://dx.doi.org/10.17721/fujcv8i2p126-139.
Full textAbstract:
New R,R’MgNi4-xMx (R,R’ = La, Pr, Nd; M = Fe, Mn; x = 0.5, 1) phases with cubic structure have been synthesized by powder sintering method. By the hydrogenation of the parent alloys seven hydrides with cubic (LaMgNi3.5Fe0.5H6.0, PrMgNi3.5Mn0.5H~6 and NdMgNi3.5Mn0.5H~5) and orthorhombic (PrMgNi3.5Fe0.5H4.5, NdMgNi3.5Fe0.5H4.3, La0.5Pr0.5MgNi3.5Fe0.5H4.6 and La0.5Nd0.5MgNi3.5Fe0.5H4.4) structures were obtained. The relationship between the structure, hydrogen content and the relative increase of the lattice volume of the new and early known hydrides is shown. Electrochemical parameters of the electrodes based on new materials are compared with already known ones. Highest discharge capacity is observed for PrMgNi3.5Mn0.5 (271 mAh/g) and NdMgNi3.5Mn0.5 (263 mAh/g). The best cyclic stability was seen for the electrode based on NdMgNi3.5Fe0.5 (S50 = 74%).
17
Pan, Li Yun, Hao Yuan, and Shun Bo Zhao. "Experimental Study on Mechanical Properties of Hybrid Fiber Reinforced Full Lightweight Aggregate Concrete." Advanced Materials Research 197-198 (February 2011): 911–14. http://dx.doi.org/10.4028/www.scientific.net/amr.197-198.911.
Full textAbstract:
Tests were carried out to study mechanical properties of hybrid fiber reinforced full lightweight aggregate concrete (HFRFLAC), the hybrid fiber was composed by steel fiber and polypropylene fiber, the expanded-shale and lightweight sand were used as coarse and fine aggregates. The apparent density and strengths in cubic compressive, splitting tensile and flexural tensile states of HFRFLAC were obtained. The results show that the average dry apparent density increases with the increasing cement content, which is much more affected by fraction of steel fiber by volume than mass content of polypropylene fiber; the tensile strengths increase somewhat with the increasing mass content of polypropylene fiber; all of the strengths increase with the increasing fraction of steel fiber by volume, and obvious are the enhancement of tensile strengths; there are somewhat relevance between the effects of polypropylene fiber and steel fiber on mechanical properties of HFRFLAC.
18
Diao, Guijiang, Mingyu Wu, Anqiang He, Zhen Xu, Seyed Elias Mousavi, and Dongyang Li. "Manipulate A2/B2 Structures in AlCrFexNi Alloys for Improved Mechanical Properties and Wear Resistance." Lubricants 11, no. 9 (September 12, 2023): 392. http://dx.doi.org/10.3390/lubricants11090392.
Full textAbstract:
Precipitation strengthening of body-center cubic (A2) alloys via ordered B2 nanoprecipitates is expected to achieve a desirable combination of strength and ductility. In this work, the A2/B2 configuration is manipulated by adjusting Fe content in medium-entropy AlCrFexNi (x = 0, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0) alloys fabricated via arc-melting for improved mechanical properties and wear resistance. As Fe content increases, the fraction of A2 phase increases, and A2 nanoprecipitates in the B2 matrix change to a weave-like A2/B2 structure. Continuously increasing Fe content leads to a mixture of BMAP (B2 matrix with A2 precipitates) and AMBP (A2 matrix with B2 precipitates), and finally to a complete AMBP structure. The yield strength decreases and fracture strain increases with increasing Fe content except x = 0. The alloy of x = 0 displays slightly higher hardness because of its relatively brittle B2 matrix. Cracks tend to propagate along A2/B2 interfaces. AMBP structure exhibits greater toughness than the BMAP structure. The alloy of x = 0 displays the second-greatest wear volume loss due to its relatively brittle B2 matrix. When Fe is added, the wear volume loss decreases considerably but shows a trend of an upward parabola with respect to the Fe content. After achieving the highest volume loss at x = 1.5 with a mixture of AMBP and BMAP, the volume loss decreases again. A completely uniform AMBP structure at x = 3.0 shows the least volume loss.
19
Ellner, M., and I. Park. "Unit cell volumes of the silicon- and germanium-containing solid solutions based on the 3d bcc transition metals." International Journal of Materials Research 93, no. 11 (November 1, 2002): 1168–71. http://dx.doi.org/10.1515/ijmr-2002-0200.
Full textAbstract:
Abstract The unit cell parameters and the unit cell volumes were investigated for Si- and Ge-containing solid solutions based on the 3d body-centred cubic transition metals. Excepting the high-temperature solid solution δ-Mn(Si), the solubility of Si increases with increasing number of 3d electrons. In contradiction to the large atomic volume of Si, which is substantially larger than that of the 3d transition metals, the unit cell volume of the terminal solid solutions decreases with increasing Si content. For solid solutions showing a large homogeneity range – α-Fe(Si) and α-Fe(Ge) –, the partial atomic volumes of Si and Ge were evaluated. Comparing the quasihomological Al- and Si-containing solid solutions α-Fe(Al) and α-Fe(Si), the higher bond energy occurs between atoms of Si and Fe than between Al and Fe atoms. Taking into consideration the homology of metalloids in the solid solutions α-Fe(Si) and α-Fe(Ge), the higher bond energy can also be expected between Si and Fe than between Ge and Fe atoms.
20
Максимов, В. И., Е. Н. Максимова, Т. П. Суркова, and В. Д. Пархоменко. "Характеристика микродеформационных полей в кристаллах разбавленных магнитных полупроводников ZnSe : Co по данным нейтронной дифракции." Физика твердого тела 63, no. 8 (2021): 1068. http://dx.doi.org/10.21883/ftt.2021.08.51155.092.
Full textAbstract:
The real structure of Zn1-хCoхSe (x=0.01; 0.15) volume cubic crystals was characterized by thermal neutrons scattering method. Characteristics of resulting micro strain fields formed by atomic displacements were obtained from analyses of tangential and radial profile scans of the structure peaks measured on investigated crystals. Indications of initial lattice destabilizations revealed in both crystals demonstrate that the character of the structure distortions is quality changed by increasing of Co-impurity content from extreme small amount to close to solubility limit level. In particular, growing probability of substructure crystallites appeared from reaching of high-level doping is accompanied by strain-tensions emerged on the whole volume of crystal.
21
Zhang, Peng, Jia Wang, Qingfu Li, Jinyi Wan, and Yifeng Ling. "Mechanical and fracture properties of steel fiber-reinforced geopolymer concrete." Science and Engineering of Composite Materials 28, no. 1 (January 1, 2021): 299–313. http://dx.doi.org/10.1515/secm-2021-0030.
Full textAbstract:
Abstract In this study, the effects of steel fibers on the mechanical properties of the geopolymer concrete – compressive, splitting tensile, and flexural strength; compressive elastic modulus; and fracture properties – were evaluated. Milling steel fibers were incorporated into the geopolymer concrete, and the volume fraction of the steel fibers was varied from 0 to 2.5%. Fly ash and metakaolin were chosen as the geopolymer precursors. Fracture parameters – critical effective crack length, initial fracture toughness, and unstable fracture toughness – were measured by a three-point bending test. The results indicated that all the mechanical properties of the geopolymer concrete are remarkably improved by the steel fibers with the optimum dosage. When the steel fiber content was under 2%, the cubic and axial compressive strength and the compressive elastic modulus increased. The inclusion of 2% steel fibers enhanced the cubic and axial compressive strength and the compressive elastic modulus by 27.6, 23.7, and 47.7%, respectively. When the steel fiber content exceeded 2%, the cubic and axial compressive strength and the compressive elastic modulus decreased, having values still higher than those of the geopolymer concrete without steel fibers. The splitting tensile strength and flexural strength of the concrete were enhanced with increasing steel fiber content. When the steel fiber content was 2.5%, the increment of the splitting tensile strength was 39.8%, whereas that of the flexural strength was 134.6%. The addition of steel fibers effectively improved the fracture toughness of the geopolymer concrete. With 2.5% steel fibers, the initial fracture toughness had an increase of 27.8%, and the unstable fracture toughness increased by 12.74 times compared to that of the geopolymer concrete without the steel fibers.
22
Fominykh, O. V., S. A. Leontiev, and V. N. Moroz. "Determining the gas volume dissolving in produced water during the oil field development." Oil and Gas Studies, no. 5 (December 4, 2022): 108–20. http://dx.doi.org/10.31660/0445-0108-2022-5-108-120.
Full textAbstract:
It is necessary to know the value of the gas factor in order to perform technological calculations when designing systems for the rational use of associated petroleum gas. The value of the gas factor is determined by the results of a study of deep oil samples. As a rule, the well production of oil fields is waterlogged, and its value increases with time. Many researchers have proven the fact of the dissolution of hydrocarbon gases in reservoir water; for example, according to some results, up to one cubic meter of gas can be dissolved in one cubic meter of water. This fact has a significant impact on the technological modes of operation of well production preparation units, since in their design only the value of the gas factor of the produced oil is taken into account. It is necessary to develop a reliable method for calculating the limiting gas content of reservoir water and the amount of gas releasing during pressure reduction in order to correctly account for the volume of gas dissolving in produced water. The article presents the results of studies on the calculation of the gas factor of reservoir water using various methods; the obtained results are compared with laboratory data.
23
Sarin, V. A., and A. A. Bush. "Neutron-diffraction study of the cubic-tetragonal phase structural transition in the single crystals of the solid solutions of zirconium and yttrium oxides." Fine Chemical Technologies 16, no. 1 (March 18, 2021): 55–66. http://dx.doi.org/10.32362/2410-6593-2021-16-1-55-66.
Full textAbstract:
Objectives. The determination of the phase relations, crystallographic characteristics, microstructure features, and atomic crystal structure of zirconium oxide crystals that are partially and completely stabilized by yttrium oxide additives, and the identification of the crystallographic and crystal-chemical correlations with the physicochemical properties of single crystals.Methods. The neutron structure of the crystals was studied using the neutron time-of-flight and constant wavelength methods using a high-resolution Fourier diffractometer on the IBR-2 pulsed fast reactor and a four-circle neutron diffractometer “Syntex.” Single crystals were grown by directed crystallization from the melts of mixtures (1 − х)ZrO2 ∙хY2O3 , х = 0.03 and х = 0.12 with different growth rates (10 and 40 mm/h).Results. It was observed that when growing single crystals with x = 0.03–0.05, the crystal was stratified into cubic and tetragonal phases, and the ratio between the phases depended on the growth rate. At a growth rate of 40 mm/h, the content of the cubic phase was insignificant. In the crystals of partially stabilized zirconium dioxide (ZrO2) with the additions of 3 mol % Y2O3, the coherent coexistence of cubic and tetragonal phases was established, and the twin law for a tetragonal component (rotation of unit cell axis by 90° around the a (b) axis) that was observed during the phase transition from high-temperature cubic phase to tetragonal phase was determined. For the fully stabilized zirconium oxide of the cubic symmetry (with 12 mol % Y2O3), the 0.3 Å displacements of oxygen atoms from their partial structural positions in the directions [100] and [111] were determined. These displacements correlated with the directions of the ion transport.Conclusions. Previous studies have shown that the ratio between the cubic and tetragonal phases of the single crystals of the ZrO2 –Y2O3 system depends on the growth rate of the single crystals. The content of Y2O3 in the cubic and tetragonal phases of a single crystal was determined using the non-destructive neutronography method on the same volume sample of a solid solution of this system. Moreover, the displacements of oxygen atoms from the main position of the crystal were determined.
24
Coble, Dean W., and Keith Hilpp. "Compatible Cubic-Foot Stem Volume and Upper-Stem Diameter Equations for Semi-intensive Plantation Grown Loblolly Pine Trees in East Texas." Southern Journal of Applied Forestry 30, no. 3 (August 1, 2006): 132–41. http://dx.doi.org/10.1093/sjaf/30.3.132.
Full textAbstract:
Abstract The Max-Burkhart taper equation was used to develop compatible taper and volume equations for semi-intensive plantation grown loblolly pine (Pinus taeda L.) trees in East Texas. Semi-intensive plantations in East Texas are characterized by some form of mechanical site preparation,a burn, possibly chemical weed control, improved seedlings if planted after 1985, and, possibly, a midrotation thinning and/or fertilization. The equations in this study were compared with those of Lenhart et al. [Lenhart, J.D., T.L. Hackett, C.J. Laman, T.J. Wiswell, and J.A. Blackard.1987. Tree content and taper functions for loblolly and slash pine trees planted on non-old field in east Texas. South J. Appl. For. 10(2)109–112.] and Baldwin and Feduccia [Baldwin, V.C. Jr., and D.P. Feduccia. 1991. Compatible tree-volume and upper-stem diameter equationsfor loblolly and slash pines in the West Gulf Region. South. J. Appl. For. 10(2)109–112.] using independent data. The new equations ranked first (sum of ranks = 9) in terms of percent bias and percent SEE for inside-bark predictions of upper-stem diameters and cubic-footvolumes, while the Lenhart et al. [Lenhart, J.D., T.L. Hackett, C.J. Laman, T.J. Wiswell, and J.A. Blackard. 1987. Tree content and taper functions for loblolly and slash pine trees planted on non-old field in east Texas. South J. Appl. For. 10(2)109–112.] ranked second (sumof ranks = 17) and Baldwin and Feduccia [Baldwin, V.C. Jr., and D.P. Feduccia. 1991. Compatible tree-volume and upper-stem diameter equations for loblolly and slash pines in the West Gulf Region. South. J. Appl. For. 10(2)109–112.] ranked third (sum of ranks =22). For outside-bark predictions of volumes and diameters, Baldwin and Feduccia [Baldwin, V.C. Jr., and D.P. Feduccia. 1991. Compatible tree-volume and upper-stem diameter equations for loblolly and slash pines in the West Gulf Region. South. J. Appl. For. 10(2)109–112.] rankedfirst (sum of ranks = 12), while the new equations ranked a close second (sum of ranks = 13) and Lenhart et al. [Lenhart, J.D., T.L. Hackett, C.J. Laman, T.J. Wiswell, and J.A. Blackard. 1987. Tree content and taper functions for loblolly and slash pine trees planted onnon-old field in east Texas. South J. Appl. For. 10(2)109–112.] ranked third (sum of ranks = 20). We recommend using the new equations for loblolly pine trees up to a 16-in. dbh and provide examples to illustrate their use. South. J. Appl.For. 30(3):142–146.
25
Baggio, Eugene Yudhistira, Toni Hartono Bagio, and Julistyana Tistogondo. "Mix design programming for normal concrete using cubic equation." astonjadro 12, no. 1 (January 3, 2023): 77. http://dx.doi.org/10.32832/astonjadro.v12i1.7143.
Full textAbstract:
<p>A computer programming requires inputs and processes to produce output, good data processing requires a formula, in programming when using tables is very inefficient, so an approach is needed in this case the existing table tables are converted into formulas, making it easier to process programming. Mix Design for normal concrete, in general, always use tables that have SNI (ACI), the tables are modified with Polynomial Regression to be equations, tables in SNI (ACI) that are transformed into equations. The equation produced, using polynomial regression, with a value of R² ≈ 1. The equation to find weight of mixing water (Ww) = y1j, y2j, with main variable aggregate maximum, additional variables are slump, the second equation is volume air content (VAC) = y3i, additional variables are exposures, water cement ratio (WCR) = y4i, with aggregate maximum variables, while additional variables are air requirements in concrete (non-air entrained/air entrained),weight of coarse aggregate (WCA) = y5i, with two variables aggregate maximum and FM (Finest Modulus), and initial estimates of fresh concrete weight (WFC) = y6i</p>
26
Aksenova, Tatiana V., Darya K. Mysik, and Vladimir A. Cherepanov. "Crystal Structure and Properties of Gd1-xSrxCo1-yFeyO3-δ Oxides as Promising Materials for Catalytic and SOFC Application." Catalysts 12, no. 11 (November 2, 2022): 1344. http://dx.doi.org/10.3390/catal12111344.
Full textAbstract:
A series of samples with the overall composition Gd1-xSrxCo1-yFeyO3-δ (x = 0.8; 0.9 and 0.1 ≤ y ≤ 0.9), which are promising materials for catalytic and SOFC application, was prepared by a glycerol nitrate technique. X-ray diffraction analysis allowed to describe Gd0.2Sr0.8Co1-yFeyO3-δ with 0.1 ≤ y ≤ 0.5 in a tetragonal 2ap × 2ap × 4ap superstructure (SG I4/mmm), while oxides with 0.6 ≤ y ≤ 0.9 exhibit cubic disordered perovskite structure (SG Pm-3m). All Gd0.1Sr0.9Fe1-yCoyO3-δ oxides within the composition range 0.1 ≤ y ≤ 0.9 possess the cubic perovskite structure (SG Pm-3m). The structural parameters were refined using the Rietveld full-profile method. The changes of oxygen content in Gd1-xSrxCo1-yFeyO3-δ versus temperature were determined by thermogravimetric analysis. The introduction of iron into the cobalt sublattice leads to a gradual increase in the unit cell parameters and unit cell volume, accompanied with increasing oxygen content. The temperature dependency of conductivity for Gd0.2Sr0.8Co0.3Fe0.7O3-δ exhibits a maximum (284 S/cm) at ≈600 K in air. The positive value of the Seebeck coefficient indicates predominant p-type conductivity in the Gd0.2Sr0.8Co0.3Fe0.7O3-δ complex oxide.
27
Mizuuchi, Kiyoshi, Kanryu Inoue, Yasuyuki Agari, Motohiro Tanaka, Takashi Takeuchi, Jun Ichi Tani, Masakazu Kawahara, Yukio Makino, and Mikio Ito. "Thermal Conductivity of Cubic Boron Nitride (cBN) Particle Dispersed Al Matrix Composites Fabricated by SPS." Materials Science Forum 879 (November 2016): 2413–18. http://dx.doi.org/10.4028/www.scientific.net/msf.879.2413.
Full textAbstract:
Cubic boron nitride (cBN) particle-dispersed-aluminum (Al) matrix composites were fabricated from the powder mixture composed of cBN, pure Al and Al-5mass% Si alloy in liquid and solid co-existent state by spark plasma sintering (SPS) process. Al/cBN composites were well consolidated by heating at a temperature range between 798 K and 876 K for 1.56 ks by SPS. Microstructures of the composites produced were examined by scanning electron microscopy and the reaction between the cBN particle and the Al matrix was not detected. The relative packing density of the Al/cBN composite was higher than 99 % in a volume fraction range of cBN up to 45 %. The thermal conductivity of the composite increased with increasing the cBN content in the composite in a volume fraction range of cBN between 35 and 45 vol. %. The highest thermal conductivity of 305 W/mK was obtained for Al matrix composite containing 45 vol.% cBN particles.
28
Xu, Anye, Xuding Song, Min Ye, Yipin Wan, and Chunguo Zhang. "Microhardness Variation with Indentation Depth for Body-Centered Cubic Steels Pertinent to Grain Size and Ferrite Content." Materials 17, no. 10 (May 15, 2024): 2371. http://dx.doi.org/10.3390/ma17102371.
Full textAbstract:
For a micro-indentation hardness test with non-destructivity, the Nix–Gao model is widely used to describe tested hardness or microhardness variation with an indentation depth induced by indentation size effect, in which tested hardness approaches the macrohardness when the indentation depth is large enough. Based on an analysis of hardness measurements on 10 body-centered cubic steels with diverse microstructure, this paper proposes an analytical relation between microhardness to macrohardness ratio and the indentation depth by explicitly linking characteristic indentation depth (a data-fitting parameter) to grain size and ferrite volume fraction using two different methods. In addition, the normal distribution theory is incorporated to consider the inevitable scatter of identical measurements resulting from material heterogeneity and machining/testing errors. Results show that the proposed model, with 96% reliability, can effectively predict microhardness variation with the indentation depth and its scatter.
29
Hamidi, Nurkholis, and Nasrul Ilminnafik. "Inert Effects on Flammability Limits and Flame Propagation of LPG by CO2." Applied Mechanics and Materials 664 (October 2014): 226–30. http://dx.doi.org/10.4028/www.scientific.net/amm.664.226.
Full textAbstract:
In this study, the inert effects of CO2 on the flammability limit and flame propagation of LPG has been investigated experimentally. The observation was done using cubic combustion bomb with the dimension of 500 mm x 200 mm x 10 mm. The results showed that the lower flammability limit (LFL) of LPG-Air mixtures is found to be 2.7% (by volume) and upper flammability limit (UFL) is 8.6% (by volume) with upward propagation of flame. The CO2 dilution effects on the flammability limits have been explored, the limits of flammability was narrowed by adding CO2 and propagation flame was reduced accordingly. The results indicated that to formulate an inflammable refrigerant mixture, using CO2, with substantial hydrocarbon content is not possible.
30
Miguel-Díez, Felipe de, Eduardo Tolosana-Esteban, and Tobias Cremer. "3D-Simulation of Wood Stacks to Analyze the Influence of Log Properties on Stack Volume." Environmental Sciences Proceedings 3, no. 1 (November 13, 2020): 76. http://dx.doi.org/10.3390/iecf2020-08063.
Full textAbstract:
The quantification of the solid wood content in a wood stack has been an object of investigation since the 18th century. Particularly, the log parameters exert a considerable influence on the volume of the stack, such as (1) the log midpoint diameter, (2) average bark thickness, (3) crookedness, and (4) log taper. Although many of these parameters have already been studied and some are already considered in many countries when measuring wood stacks, their influence has not been analyzed individually so far since a broad statistical database is needed and the data collection is very costly. Consequently, a 3D-simulation model was developed based on a cross-platform game engine. This model generates virtual wood stacks based on a data set of logs which are defined by the user. The simulation of a stack can be done in a few seconds only and each stack generated can be visualized once all iterations are done. The simulation results are the stacked cubic volume, solid wood cubic volume, and the respective conversion factors. The model, fed with both real data and user-defined data, allows for a detailed analysis of the effect of each parameter on the results, as the user can vary their values discretionary. To obtain the first results from real data, 1000 logs of Scots pine (Pinus sylvestris L.) were measured. The first simulations based on these data show reliable results and it is possible to quantify the influence of the proportion of crooked wood in a pile on the stack volume and the conversion factor. In addition, the results are highly in line with the real trials that have already been performed in parallel. A further scientific evaluation and statistical analysis will be done in a second study phase. However, the model already provides a reasonable tool that is easy to apply for the forest and wood industry in order to make the most accurate estimate possible of the solid wood content in a wood pile.
31
Bi, Qiao Wei, Qing Xiang Wang, and Hui Wang. "Study on Bond Properties of BFRP Bars to Basalt Fiber Reinforced Concrete." Advanced Materials Research 163-167 (December 2010): 1251–56. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.1251.
Full textAbstract:
In order to study the bonding characteristic of the BFRP(Basalt Fiber Reinforced Plastics for short) bars and the basalt fiber reinforced concrete, the BFRP was embedded into the cubic concrete specimen which mixed the basalt fiber sized the edge length 150 mm. By changing the diameter of the BFRP, the bonding length of the BFRP and the basalt fiber volume content of the basalt fiber reinforced concrete, the experimental results indicate that the average bonding strength decreased while the bonding length increased and it become weaker while the diameter of the BFRP was bigger, and it shows the best effect of the bonding strength when its fiber content was 0.1% comparing with three kinds of fiber content. The bond-slip constitutive model of BFRP bar and the basalt fiber concrete corresponded to the continuous curve model.
32
Wu, Changjun, Ya Sun, Ya Liu, and Hao Tu. "Effect of Long-Time Annealing at 1000 °C on Phase Constituent and Microhardness of the 20Co-Cr-Fe-Ni Alloys." Materials 12, no. 10 (May 25, 2019): 1700. http://dx.doi.org/10.3390/ma12101700.
Full textAbstract:
The phase constituent and microhardness of the arc-melted 20Co-Cr-Fe-Ni alloys, in both as-cast state and after annealing at 1000 °C for 30 days, were experimentally investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Experiment results indicated that a uniform, stable, single Face-Center Cubic (FCC) phase can be obtained in as-cast 20 Co-Cr-Fe-Ni alloys with less than 30 at.% Cr. Annealing at 1000 °C has no effect on their phase composition and microhardness. When the Cr content is above 40 at.%, the σ phase forms and its volume fraction increases with the Cr content, which leads to an increase in microhardness. Annealing at 1000 °C for 30 days can slightly decrease the volume fraction of the σ phase and slightly decrease the alloy microhardness. Except for the Fe-rich alloys, the alloy microhardness increases with the Cr content when the Co and Ni or the Co and Fe contents were fixed. Moreover, comparing with the thermodynamically calculated phase diagram based on the TCFE database, it has been proved that the calculation can predict the phase stability of the FCC phase and the 1000 °C isothermal section. However, it fails to predict the stability of the σ phase near the liquidus. The present results will help to design and process treatment of the Co-Cr-Fe-Ni based high entropy alloys.
33
Wang, Wenrui, Qi Sun, Dingzhi Wang, Junsong Hou, Wu Qi, Dongyue Li, and Lu Xie. "Microstructure and Mechanical Properties of the ((CoCrFeNi)95Nb5)100−xMox High-Entropy Alloy Coating Fabricated under Different Laser Power." Metals 11, no. 9 (September 17, 2021): 1477. http://dx.doi.org/10.3390/met11091477.
Full textAbstract:
In this paper, the ((CoCrFeNi)95Nb5)100−xMox (x = 1, 1.5 and 2) high-entropy alloy (HEA) coatings were fabricated on the substrate of 45# steel by laser cladding process under different laser beam power. The influence of laser beam power and molybdenum element content on the microstructure and microhardness of the HEA coatings was investigated. Results show that the HEA coatings were composed of face-centered cubic (FCC) phase and Laves phase, had low porosity, and bonded well to the substrate. The Mo1 coating is composed of cellular dendritic structures and columnar dendritic structures. With the increase of molybdenum element content, the columnar dendritic structures disappeared, the grains are refined, and the arrangement of grains is more compact. The volume fraction of the interdendritic phase under the laser beam power of 800 W was small and irregular. After the laser beam power was increased to 1000 W, the volume fraction of the interdendritic phase was increased. Under the laser beam power of 1200 W, the volume fraction of the interdendritic phase was small again. Therefore, the coatings fabricated under the laser beam power of 1000 W had a larger volume fraction of the interdendritic phase and higher microhardness. With the increase in molybdenum content, the grain changed from columnar dendrite to cellular dendrite, and the microhardness of the coating increased. The characteristics of the laser cladding process, the formation of Laves phase, and the fine grain strengthening lead to high microhardness of the coatings.
34
Basok, Borys, Borys Davydenko, and Anatoliy M. Pavlenko. "Numerical Network Modeling of Heat and Moisture Transfer through Capillary-Porous Building Materials." Materials 14, no. 8 (April 7, 2021): 1819. http://dx.doi.org/10.3390/ma14081819.
Full textAbstract:
The article presents the modeling of the dynamics of the vapor-gas mixture and heat and mass transfer (sorption-desorption) in the capillary structure of the porous medium. This approach is underpinned by the fact that the porous structure is represented by a system of linear microchannels oriented along the axes of a three-dimensional coordinate system. The equivalent diameter of these channels corresponds to the average pore diameter, and the ratio of the total pore volume to the volume of the entire porous material corresponds to its porosity. The entire channel area is modeled by a set of cubic elements with a certain humidity, moisture content, pressure and temperature. A simulation is carried out taking into account the difference in temperatures of each of the phases: solid, liquid and gas.
35
Shi, Zhenxue, and Shizhong Liu. "A Study on the Co-Content Optimization of the DD15 Single-Crystal Superalloy." Crystals 13, no. 3 (February 24, 2023): 389. http://dx.doi.org/10.3390/cryst13030389.
Full textAbstract:
The fourth-generation single-crystal superalloy DD15 with 6% Co, 9% Co and 12% Co was cast using the vacuum directionally solidified furnace, while other alloying element’s content remained unchanged. The long-term aging experiment was conducted at 1100 °C for 1000 h after standard heat treatment. The stress rupture tests of the alloy were conducted at 1100 °C/137 MPa and 1140 °C/137 Mpa. The influence of Co content on the microstructure and stress rupture properties of DD15 alloy had been investigated to optimize the Co content to obtain excellent comprehensive performance. The results showed that the primary dendrite arm spacing of the alloy decreases at first and increases afterwards, and the volume fraction of γ-γ′ eutectic decreases with the growth of Co content in the as-cast microstructures. The size, cubic degree and volume fraction of the γ′ phase of the alloy after standard heat treatment all decrease with the increase in Co content. The microstructure stability of the alloy is enhanced with the increase in Co content. No TCP phase was present in the alloy with 12% Co precipitate even after aging 1000 h. The stress rupture lives at two conditions, both reduced in different degrees with the increase in Co content. The effect of Co on the stress rupture life of the alloy improves with the increase in Co content or test temperature. The acicular TCP phase appeared in the 6% Co alloy and 9% Co alloy in the microstructure of the ruptured specimens with different Co contents. Moreover, the TCP phase content in the 6% Co alloy is much more than that in the 9% Co alloy. There is no TCP phase precipitation in the 12% Co alloy. At last, the relationship between microstructure stability, stress rupture properties and Co content of the alloy is discussed. The alloy containing 9% Co is the best choice considering the microstructure stability and stress rupture properties.
36
Trzciński, Grzegorz, Łukasz Tymendorf, and Paweł Kozakiewicz. "Parameters of Trucks and Loads in the Transport of Scots Pine Wood Biomass Depending on the Season and Moisture Content of the Load." Forests 12, no. 2 (February 15, 2021): 223. http://dx.doi.org/10.3390/f12020223.
Full textAbstract:
Transport of wood biomass is one of the key operations in forestry and in the wood industry. An important part is the transport of shredded wood, where the most common forms are chips and sawdust. The aim of the research was to present the variability of the total weight of trucks (gross vehicle weight, GVW), the weight of the empty trucks (tare), and loads of chips and sawdust in different periods of the year. Changes in specific parameters were analyzed: GVW; tare weight; trailer capacity; use of the trailer load capacity; bulk volume and bulk density of wood biomass loads; solid cubic meter (m3) and weight of 1m3 of the load; and load weight depending on the season, with simultaneous measurements of wood chips and sawdust moisture. More than 250 transports from four seasons of the year were analyzed in the research. It was found that the total weight of trucks (GVW) was at a comparable level, on average from 39.42 to 39.64 Mg with slight differences (with SD 0.29 and 0.39). The weight of empty trucks was 16.15 Mg for chip-bearing trucks and 15.93 Mg for sawdust-bearing trucks (with SD 0.604 and 0.526). The type of wood material has an influence on the transported volume. The average quantity of load in the bulk cubic meter was 64.783 m3 for wood chips (SD 3.127) and 70.465 m3 (SD 2.516) for sawdust. Over 30% differences in the volume of transported wood chips and approximately 18% for sawdust were observed. The use of the loading capacity of the trailer was on average 72.58% (SD 5.567) for the transport of wood chips and 77.42% (SD 3.019) for the transport of sawdust. The sawdust bulk density was from 0.3050 to 0.4265 Mg⋅m−3 for wood chips and 0.3200 to 0.3556 Mg⋅m−3 for sawdust. This parameter is significantly dependent on moisture content, and the determined correlation functions can be used for estimating and predicting bulk density. The abovementioned absolute moisture content of chips and sawdust also depends on the season, which also affects the selected parameters of wood biomass loads.
37
Karlovich, P. T., and W. C. Fonteno. "Effect of Soil Moisture Tension and Soil Water Content on the Growth of Chrysanthemum in 3 Container Media." Journal of the American Society for Horticultural Science 111, no. 2 (March 1986): 191–95. http://dx.doi.org/10.21273/jashs.111.2.191.
Full textAbstract:
Abstract No differences in final height, top fresh weight, top dry weight, or flower number were observed in Chrysanthemum morifolium Ramat. ‘Spice’ grown in 16.5-cm azalea pots when allowed to dry to soil moisture tensions of 5, 10, 20, or 30 kPa between waterings. Differences did occur in these parameters among the 3 tested media. Differences also occurred across all 3 media based on the volume of water remaining in the pot prior to watering. Plants growing in media containing more than 500 ml water just prior to irrigation had increased growth compared to plants in media containing less than 500 ml water. Cubic regression models were used to describe the percentage of moisture in the pot at soil moisture tensions between 0 and 30 kPa. The model may be used to predict container capacity and air space for most container sizes.
38
Mohapatra, Sudipta, Kyeong-Cheol Baek, and Min-Suk Oh. "Intercritically Annealed Medium-Manganese Steel: Insights into Microstructural and Microtextural Evolution, Strain Distribution, and Grain Boundary Characteristics." Materials 17, no. 11 (June 5, 2024): 2757. http://dx.doi.org/10.3390/ma17112757.
Full textAbstract:
Aluminum-incorporated medium-manganese steel (MMnS) has potential for lightweight transport applications owing to its impressive mechanical properties. Increasing the austenite volume fraction and making microstructural changes are key to manufacturing MMnS. However, the grain boundary character and strain distribution of intercritically annealed low-density MMnS have not been extensively scrutinized, and the effects of crystallographic texture orientation on tensile properties remain ambiguous. Therefore, in this study, the microstructure, microtexture, strain distribution, and grain boundary characteristics of a hot-rolled medium-Mn steel (Fe–0.2 C–4.3 Al–9.4 Mn (wt%)) were investigated after intercritical annealing (IA) at 750, 800, or 850 °C for 1 h. The results show that the 800 °C annealed sample exhibited the highest austenite volume fraction among the specimens (60%). The duplex microstructure comprised lath-type γ-austenite, fine α-ferrite, and coarse δ-ferrite. As the IA temperature increased, the body-centered cubic phase orientation shifted from <001> to <111>. At higher temperatures, the face-centered cubic phase was oriented in directions ranging from <101> to <111>, and the sums of the fractions of high-angle grain boundaries and coincidence–site–lattice special boundaries were significantly increased. The 800 °C annealed sample with a high austenite content and strong γ-fiber {111}//RD orientation demonstrated a noteworthy tensile strength (1095 MPa) and tensile elongation (30%).
39
Ji, D. H., X. J. Xiao, C. M. Zhang, X. L. Li, M. Z. Hu, and Y. Yin. "Regulatory band gap of vacancy at the B sites in CH3NH3Pb1−xI3 perovskite." Modern Physics Letters B 30, no. 23 (August 30, 2016): 1650294. http://dx.doi.org/10.1142/s0217984916502948.
Full textAbstract:
The structure, electronic structure, states density and optics properties of the orthorhombic CH3NH3Pb[Formula: see text]I3 perovskite with vacancy at the B sites are calculated by the CASTEP program. The calculated results indicate that the cell volume shrinks with the content of vacancy at the B sites increasing, and the structure has the large degree of distortion from the cubic structure. The band gaps are 1.656, 1.750, 3.077, 3.256 and 4.76 eV, corresponding to [Formula: see text], 0.25, 0.50, 0.75 and 1.00, respectively. As an application, the additional absorption peak can be obtained by CH3NH3Pb[Formula: see text]I3 perovskite doped vacancy at the B sites.
40
Ivannikov, Alexander Yurievich, Ivan Konstantinovich Grebennikov, Yulia Alexandrovna Klychevskikh, Anna Vladimirovna Mikhailova, Konstantin Victorovich Sergienko, Mikhail Alexandrovich Kaplan, Anton Sergeevich Lysenkov, and Mikhail Anatolievich Sevostyanov. "Fabrication, Microstructure, and Physico-Mechanical Properties of Fe–Cr–Ni–Mo–W High-Entropy Alloys from Elemental Powders." Metals 12, no. 10 (October 20, 2022): 1764. http://dx.doi.org/10.3390/met12101764.
Full textAbstract:
In this work, 35Fe30Cr20Ni10Mo5W (wt.%) and 30Fe30Cr20Ni10Mo10W (wt.%) high-entropy alloys were fabricated using a powder metallurgy route. Powder mixtures for a hot-pressure process were obtained by the mixing and mechanical alloying of elemental powders. Mechanical alloying was carried out for 1, 2.5, 5, and 10 h. X-ray phase analysis of the powder mixtures showed that with increasing time of mechanical alloying, Face-Centered Cubic (FCC), Body-Centered Cubic (BCC), and nickel–iron intermetallic phases were formed in the structure, and the volume content of molybdenum and tungsten decreased. The hot-pressing was carried out at a pressure of 30 MPa and a temperature of 1200 °C for 30 min. The maximum densities of 8.14 ± 0.02 and 8.40 ± 0.01 g/cm3 and compressive strengths of 2430 ± 30 MPa and 2460 ± 35 MPa for consolidated materials were achieved using powder mixtures after 10 h of mechanical milling, for compositions with 5 wt.% W and 10 wt.% W, respectively. The workpieces fabricated with a pressure-assisted sintering process from milled powders were found to consist of FCC, BCC, and sigma phases.
41
Messas, Tidjani, Djamel Achoura, Boutrid Abdelaziz, and Belgacem Mamen. "Experimental investigation on the mechanical behavior of concrete reinforced with Alfa plant fibers." Frattura ed Integrità Strutturale 16, no. 60 (March 25, 2022): 102–13. http://dx.doi.org/10.3221/igf-esis.60.08.
Full textAbstract:
Currently, the reinforcement of ordinary concrete with synthetic fibers poses ecological problems because the manufacturing process of these products is very polluting. Plant fiber composites are a new challenge for environmental protection. The present article aims to investigate the mechanical behavior of concrete reinforced with natural fibers, called alfa fibers. Compression and three-point bending tests have been performed on cubic and prismatic samples, respectively. Different fiber lengths (2.5, 5, and 8 cm) and content (0.6, 1.2, and 1.8%by volume) of alfa fibers have been used to examine their influence on the mechanical behavior of the fiber-reinforced concrete. The obtained results show that for a volume content of 1.2% of plant fibers of 5 cm length, the tensile strength of the reinforced concrete increases up to 54.41% compared to the ordinary concrete (BT). However, for content of 1.8% of fibers with 8 cm length, both the compressive and tensile strength of the reinforced concrete decrease slightly. At this level, an excess of both fiber content and their length produces the formation of voids within concrete. Moreover, such an excess made the hydration reaction slower. It is worth noticing that the orientation of fibers also plays a significant role in the nucleation and propagation of microcracks. The fibers arranged both horizontally and obliquely are more resistant to microcracking than those oriented in the loading direction.
42
Thürlová, Hana, and Filip Průša. "Influence of the Al Content on the Properties of Mechanically Alloyed CoCrFeNiMnXAl20−X High-Entropy Alloys." Materials 15, no. 22 (November 9, 2022): 7899. http://dx.doi.org/10.3390/ma15227899.
Full textAbstract:
The equiatomic CoCrFeNiMn alloy prepared by mechanical alloying and spark plasma sintering underwent partial substitution of Mn by Al (5, 10 and 15 at.%) to determine its influence on mechanical properties and thermal stability. It was discovered that the higher the Al content, the higher the volume fraction of the hard phase with primitive cubic (PC) crystallographic lattice, which increases the hardness and strength of the alloys. The most promising mechanical properties have been achieved in the CoCrFeNiMn5Al15 alloy reaching the compressive yield strength (CYS) of 2135 ± 21 MPa and the ultimate compressive strength (UCS) of 2496 ± 21 MPa. All the prepared alloys showed good thermal stability as they maintained or only slightly reduced their initial hardness during the 100 h annealing at 800 °C. Furthermore, the higher the Al content, the higher the resistance against high-temperature oxidation. The oxidic layer changed its composition from Mn-oxides (CoCrFeNiMn15Al15 alloy) to Al-based oxides with exceptional protective properties.
43
Garlea, E., V. O. Garlea, Hahn Choo, C. R. Hubbard, and Peter K. Liaw. "Neutron Incoherent Scattering Measurements on Hydrogen-Charged Zircaloy-4." Materials Science Forum 539-543 (March 2007): 1443–48. http://dx.doi.org/10.4028/www.scientific.net/msf.539-543.1443.
Full textAbstract:
Neutron incoherent scattering measurements were conducted on Zircaloy-4 round bars. The specimens were charged in a tube furnace at 430 °C, using a 12.5 vol. % hydrogen in an argon mixture for 30, 60, and 90 minutes at 13.8 kPa pressure. The volume-average neutron diffraction measurements showed the presence of the face-centered-cubic delta zirconium hydride (δ-ZrH2) phase in the hydrogenated specimens. The assessment of the background in the diffraction profiles due to the incoherent scattering from the hydrogen atoms was carried out by performing inelastic scans around zero energy transfer and at a fixed two-theta value for which there was only flat background and no coherent scattering. To estimate the relative amount of hydrogen in the Zircaloy-4 samples, the increase in incoherent scattering intensities with hydrogen content was calibrated using samples for which the hydrogen content was known. Measurement of the background scattering from locations within the round bar was also performed to map the distribution of hydrogen content.
44
Haryanta, Dwi, Fungki Sri Rejeki, and Endang Retno Wedowati. "INDEPENDENT COMPOST HOUSE AS A SUSTAINABLE URBAN ORGANIC WASTE MANAGEMENT MODEL." International Journal of Engagement and Empowerment (IJE2) 2, no. 3 (December 6, 2022): 259–72. http://dx.doi.org/10.53067/ije2.v2i3.78.
Full textAbstract:
Neighborhoods or urban villages do not have facilities to dispose of or process tree-changing waste carried out by residents, which is prone to causing social, environmental health, and aesthetic problems. Independent composting houses expect a solution in the form of a mass composting program but on a scale still affordable at the RW or district level. One composting process unit with a volume of one cubic meter is capable of processing three trucks of intermediate waste—the introduction project conducted in RW 02 Kalirungkut, Surabaya City. Residents ask to collect the chaffing waste at a point, and after 1-2 months, thresh. The composting equipment consists of an iron frame with one cubic meter volume and a cubic meter composting bag. Following the threshing, the dry leaves were collected and placed in the bag along with an activated EM4 solution starter. After all the components add, the bag zips up, the content does not mix, and it places in the incubator for three months. After the incubation period, the material will change color to blackish brown, the structure will become crumbly, and the temperature will be the same as the surrounding air temperature as a sign that the compost is ready to be harvested. The harvested compost is put in small bags weighing 15-20 kg, ready to be distributed to residents or sold to the general public. Residents can use the compost to grow fruits, vegetables, or ornamental/garden plants. The spirit of the residents of RW 02 Kalirungkut Surabaya City continues to be encouraged to continue the independent compost house program by monitoring, assisting, and providing incentives, especially in the distribution of excess compost used by residents
45
Dippong, Thomas, Erika Andrea Levei, Iosif Grigore Deac, Ioan Petean, and Oana Cadar. "Dependence of Structural, Morphological and Magnetic Properties of Manganese Ferrite on Ni-Mn Substitution." International Journal of Molecular Sciences 23, no. 6 (March 13, 2022): 3097. http://dx.doi.org/10.3390/ijms23063097.
Full textAbstract:
This paper presents the influence of Mn2+ substitution by Ni2+ on the structural, morphological and magnetic properties of Mn1−xNixFe2O4@SiO2 (x = 0, 0.25, 0.50, 0.75, 1.00) nanocomposites (NCs) obtained by a modified sol-gel method. The Fourier transform infrared spectra confirm the formation of a SiO2 matrix and ferrite, while the X-ray diffraction patterns show the presence of poorly crystalline ferrite at low annealing temperatures and highly crystalline mixed cubic spinel ferrite accompanied by secondary phases at high annealing temperatures. The lattice parameters gradually decrease, while the crystallite size, volume, and X-ray density of Mn1−xNixFe2O4@SiO2 NCs increase with increasing Ni content and follow Vegard’s law. The saturation magnetization, remanent magnetization, squareness, magnetic moment per formula unit, and anisotropy constant increase, while the coercivity decreases with increasing Ni content. These parameters are larger for the samples with the same chemical formula, annealed at higher temperatures. The NCs with high Ni content show superparamagnetic-like behavior, while the NCs with high Mn content display paramagnetic behavior.
46
Duan, Ai Jun, Hui Li Fan, Zhen Zhao, Gui Yuan Jiang, and Jian Liu. "Hydrodesulfurization Performances of NiMo Supported on Micro/Mesoporous Beta/MCM-48 Composite Catalyst." Advanced Materials Research 233-235 (May 2011): 827–32. http://dx.doi.org/10.4028/www.scientific.net/amr.233-235.827.
Full textAbstract:
Using CTAB as the mesostructure directing agent, a novel micro/mesoporous composite material of Beta-MCM-48 was synthesized and self-assembled from nanocrystal Beta solutions by two-step hydrothermal method in this study. The typical physico-chemical properties of material were characterized by the techniques and measurements of BET surface area, pore volume, pore size, XRD and TEM. Based on the characterization results, it could be found that BM48 composite simultaneously possessed BEA microporous structure and cubic Ia3d mesoporous structure, and the degree of mesoporous order was comparably uniform, which construct a suitable gradient of micro/mesopore structures and facilitated the diffusion of large size reactant molecules. The HDS performance in a microreactor indicated that NiMo/ABM48 series catalysts with different BM48 contents and various Mo loadings showed better hydrodesulfurization performances compared with the conventional NiMo/Al2O3catalyst, and the optimal content of BM48 in the supports was 20 m%, and the suitable loading of Mo in the catalyst was 15 m%. The best HDS efficiency reached 98.3% and the corresponding sulfur content in product was 23.02 µg•g-1, which met the sulfur regulation of Euro IV ultra clean diesel specification.
47
Chen, Xue-Fei, Chang-Qing Quan, and Chu-Jie Jiao. "Experimental Study of Chloride Resistance of Polypropylene Fiber Reinforced Concrete with Fly Ash and Modeling." Materials 14, no. 16 (August 6, 2021): 4417. http://dx.doi.org/10.3390/ma14164417.
Full textAbstract:
Herein, the paper reports an experimental investigation lasting one year on the chloride resistance of polypropylene fiber (PF) reinforced concrete with fly ash (FA). Four influential factors at four levels were studied, viz. water to binder ratio (w/b) (0.53, 0.34, 0.29, and 0.25), PF dosage (0%, 0.06%, 0.08%, and 0.1% in volume basis of the total volume of concrete), FA content (0%, 15%, 25%, and 35% in mass substitution ratio of cement) and concentration of NaCl solution (0%, 3%, 5%, and 7%). Dry–wet cyclic immersion and long-term soaking were taken into consideration in addition to the aforementioned factors. A L16(44) orthogonal table was used to sequence influencing factors and to determine the optimal combination. Results showed that 7% NaCl solution caused the highest chloride content in 0–5 mm depth, whilst the w/b ratio of 0.25 curbed the chloride penetration within 10 mm even for concrete subjected to dry–wet cyclic immersion for 360 d. Subsequently, a respond surface model (RSM) basing on polynomials was constructed to visually evaluate the effect of PF dosage and FA content. Results clarified that a cubic model was more precise and PF dosage and FA content turned out to have the positive facilitation to chloride resistance. The positive effect of PF however is not consistent and commensurate for concrete with varied fly ash content. Finally, a fuzzy logic based nonlinear model accommodating all seven influencing factors was verified to be proper and adaptive in predicting chloride content.
48
Thomas, Lutz, Gerald Jungschaffer, and Bruno Sprössler. "Improved Sludge Dewatering by Enzymatic Treatment." Water Science and Technology 28, no. 1 (July 1, 1993): 189–92. http://dx.doi.org/10.2166/wst.1993.0045.
Full textAbstract:
Nowadays West Germany produces 50 million cubic metres of liquid sludge per year. This tendency is still on the increase, whereas traditional means of utilisation, such as in agriculture, show a sharp decline. For this reason, about 60 - 70 % of the sludge has to be deposited at waste tips with a limited capacity. Therefore it is highly desirable to reduce the sludge volume as much as possible. By enzymatic hydrolsis it is possible to modify the hydrophilic, water-retaining organic compounds of the sludge in order to reduce its water content. Enzymes improve mechanical dewatering in common belt-type filter presses or decanters in combination with flocculation by means of special flocculating aids.
49
Yang, Jing, Yingwei Fei, Xiaojun Hu, Eran Greenberg, and Vitali B. Prakapenka. "Effect of Carbon on the Volume of Solid Iron at High Pressure: Implications for Carbon Substitution in Iron Structures and Carbon Content in the Earth’s Inner Core." Minerals 9, no. 12 (November 20, 2019): 720. http://dx.doi.org/10.3390/min9120720.
Full textAbstract:
Understanding the effect of carbon on the density of hcp (hexagonal-close-packed) Fe-C alloys is essential for modeling the carbon content in the Earth’s inner core. Previous studies have focused on the equations of state of iron carbides that may not be applicable to the solid inner core that may incorporate carbon as dissolved carbon in metallic iron. Carbon substitution in hcp-Fe and its effect on the density have never been experimentally studied. We investigated the compression behavior of Fe-C alloys with 0.31 and 1.37 wt % carbon, along with pure iron as a reference, by in-situ X-ray diffraction measurements up to 135 GPa for pure Fe, and 87 GPa for Fe-0.31C and 109 GPa for Fe-1.37C. The results show that the incorporation of carbon in hcp-Fe leads to the expansion of the lattice, contrary to the known effect in body-centered cubic (bcc)-Fe, suggesting a change in the substitution mechanism or local environment. The data on axial compressibility suggest that increasing carbon content could enhance seismic anisotropy in the Earth’s inner core. The new thermoelastic parameters allow us to develop a thermoelastic model to estimate the carbon content in the inner core when carbon is incorporated as dissolved carbon hcp-Fe. The required carbon contents to explain the density deficit of Earth’s inner core are 1.30 and 0.43 wt % at inner core boundary temperatures of 5000 K and 7000 K, respectively.
50
SAAD AKL, A. A., and M. ELHADI. "ESTIMATION OF CRYSTALLITE SIZE, LATTICE PARAMETER, INTERNAL STRAIN AND CRYSTAL IMPURIFICATION OF NANOCRYSTALLINE Al3Ni20Bx ALLOY BY WILLIAMSON-HALL METHOD." Journal of Ovonic Research 16, no. 5 (September 2020): 323–35. http://dx.doi.org/10.15251/jor.2020.165.323.
Full textAbstract:
Al3Ni20Bx alloys (0.06≤ x ≤0.12) nanocrystalline, AlNiB-NCys were synthesized by rapid solidification method in an arc-melt furnace or in an induction furnace. The effect of changing the addition ratio of boron on the crystallography, microstrural, crystal impurifications has been investigated for the Al3Ni20Bx ternary. The crystal structure of samples obtained using X-ray diffraction was examined. XRD analysis revealed that prepared samples have the polycrystalline nanometric face centered cubic structure. XRDLine profile analysis by Lorentzian and Gaussian distributions were used to study the microstructure and crystal imperfections of Al3Ni20Bx. Crystallite size and microstrain were estimated using Williamson-Hall plots for the major eight XRD peaks. The data obtained shows that when the metal content is increased, the lattice parameters and volume of unit cell are increased linearly with boron concentration increase. This behavior is believed to be associated with an increase in content B by up to 11% that is entered into the unit cell of the Al3Ni20Bx system.