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1
Uchiyama, Kandai, Sho Otsuka, and Seiji Nakagawa. "Effect of cortical activity enhancement on medial olivocochlear reflex." Journal of the Acoustical Society of America 154, no. 4_supplement (October 1, 2023): A239. http://dx.doi.org/10.1121/10.0023404.
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The medial olivocochlear reflex (MOCR) is reported to protects the inner ear from acoustic overexposure. It has been shown that MOCR by fluctuations in cognitive function, e.g., attention and expectation. However, the mechanism by which the cortical cognitive processing modulates MOCR has not been clarified. To investigate this mechanism, we compared the variability of cortical activity and MOCR after a mental calculation task that demands widespread cortical network activities. Cortical activity was assessed by measuring slow vertex response (SVR). Although MOCR strength and SVR amplitude did not change significantly after the calculation task, two measures had reverse dependence on the difficulty of the calculation task; A moderately difficult calculation task increased SVR amplitude while reduced MOCR strength. The results implicate that MOCR variations can be attributed to cortical activity changes. In addition, by simultaneously measuring MOCR and EEG during the calculation task, the time course of the effect of the cortical modulatory effect on MOCR was also examined.
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Ip, Chi F., William D. Hibler, and Gregory M. Flato. "On the effect of rheology on seasonal sea-ice simulations." Annals of Glaciology 15 (1991): 17–25. http://dx.doi.org/10.3189/1991aog15-1-17-25.
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A generalized numerical model which allows for a variety of non-linear rheologies is developed for the seasonal simulation of sea-ice circulation and thickness. The model is used to investigate the effects (such as the role of shear stress and the existence of a flow rule) of different rheologies on the ice-drift pattern and build-up in the Arctic Basin. Differences in local drift seem to be closely related to the amount of allowable shear stress. Similarities are found between the elliptical and square cases and between the Mohr-Coulomb and cavitating fluid cases. Comparisons between observed and simulated buoy drift are made for several buoy tracks in the Arctic Basin. Correlation coefficients to the observed buoy drift range from 0.83 for the cavitating fluid to 0.86 for the square rheology. The average ratio of buoy-drift distance to average model-drift distance for several buoys is 1.15 (square), 1.18 (elliptical), 1.30 (Mohr-Coulomb) and 1.40 (cavitating fluid).
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Ip, Chi F., William D. Hibler, and Gregory M. Flato. "On the effect of rheology on seasonal sea-ice simulations." Annals of Glaciology 15 (1991): 17–25. http://dx.doi.org/10.1017/s0260305500009496.
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A generalized numerical model which allows for a variety of non-linear rheologies is developed for the seasonal simulation of sea-ice circulation and thickness. The model is used to investigate the effects (such as the role of shear stress and the existence of a flow rule) of different rheologies on the ice-drift pattern and build-up in the Arctic Basin. Differences in local drift seem to be closely related to the amount of allowable shear stress. Similarities are found between the elliptical and square cases and between the Mohr-Coulomb and cavitating fluid cases. Comparisons between observed and simulated buoy drift are made for several buoy tracks in the Arctic Basin. Correlation coefficients to the observed buoy drift range from 0.83 for the cavitating fluid to 0.86 for the square rheology. The average ratio of buoy-drift distance to average model-drift distance for several buoys is 1.15 (square), 1.18 (elliptical), 1.30 (Mohr-Coulomb) and 1.40 (cavitating fluid).
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Volkova, N. V., M. I. Belousova, S. D. Tyurin, and E. D. Kupriyanova. "Selection of optimal conditions for the spectrophotometric determination of phosphorus in archaeological finds made of cast Iron using reducing agents - ascorbic acid and Mohr salt." Proceedings of the Southwest State University. Series: Engineering and Technology 14, no. 4 (December 13, 2024): 153–66. https://doi.org/10.21869/2223-1528-2024-14-4-153-166.
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Purpose of research. The aim of the work was to select conditions for the quantitative spectrophotometric determination of phosphorus in archaeological finds made of Iron using reducing agents - ascorbic acid and Mohr salt.Methods. A fragment of a cast-iron object discovered during archaeological excavations in the Salovsky settlement on the territory of the Penza region was chosen as the object of research. Reagent preparation and spectrophotometric analysis of phosphorus content were carried out in accordance with GOST 2604.4-87 Alloyed cast iron. Methods for the determination of phosphorus. To assess the reliability of the results, errors were identified according to the Smirnov criterion, and to assess the accuracy of the results, the variance, standard deviation and relative standard deviation of the determination of phosphorus content were calculated. To identify the effect of the reducing agent on the results of phosphorus determination, a one-factor analysis of variance was performed.Results. In the course of the work, the conditions for dissolving the samples were selected: the weight of the sample, the required volume of nitric acid, dilution of the samples, the volume of reagents for analysis. An experiment aimed at searching for a reducing agent of the yellow phosphorous-molybdenum complex has demonstrated satisfactory results when using the Mohr salt. The adequacy of replacing ascorbic acid with Mohr salt is proved by the close values of the phosphorus content in the studied samples: using the ascorbic acid reducing agent, the phosphorus content was (1.74.0.15)%, and using Mohr salt (1.72.0.24)%.Conclusion. The results obtained during the study allow us to conclude that the Mohr salt can be used as a reducing agent in the determination of phosphorus in the form of blue heteropolycomplex in iron alloys.
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Djebbar, R., S. B. Beale, and M. Sayed. "Numerical Study of Two-Phase Granular Flow for Process Equipment." Journal of Pressure Vessel Technology 122, no. 4 (February 1, 2000): 462–68. http://dx.doi.org/10.1115/1.1310366.
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This paper reports on a research program of modeling multi-phase granular flow. Both single-phase granular flow and two-phase liquid/granular flow in a pressure vessel were considered. For the latter case, detailed results based on a viscous/Mohr-Coulomb closure were compared to existing formulations. Idealized test cases indicated that the numerical procedure is sound. Subsequent simulations of two-phase flow using realistic geometries and boundary conditions showed that the pressure distribution in the solid phase is fundamentally different for the Mohr-Coulomb system than for the conventional system. The effect of the angle of internal friction, geometry, and other parameters is discussed. [S0094-9930(00)01204-X]
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Jiang, J. C., R. Baker, and T. Yamagami. "The effect of strength envelope nonlinearity on slope stability computations." Canadian Geotechnical Journal 40, no. 2 (April 1, 2003): 308–25. http://dx.doi.org/10.1139/t02-111.
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Engineering analysis of slope stability includes three separate but interrelated phases: (a) experimental strength measurements, (b) determination of a strength envelope that best fits the experimental results, and (c) formal limiting equilibrium analysis using the resulting strength envelopes. Studying the interrelations between these phases leads to an integrated approach to slope stability analysis. The present work uses a single experimental database that is fitted with both linear (MohrCoulomb) and nonlinear failure envelopes and investigates the effect of different forms of the failure criterion on slope stability computations for both 2D and 3D problems. It has been indicated that calculated minimum safety factors could be significantly overestimated by the linear approximation of a nonlinear strength envelope. The effect of neglecting strength envelope nonlinearity is more pronounced under 3D conditions than in a 2D simplification. As a result, the use of nonlinear failure criterions in slope stability analyses is recommended to account for the stress-dependent nature of the shear strength of soils.Key words: nonlinear strength envelope, MohrCoulomb failure criterion, limit equilibrium, critical slip surface, minimum factor of safety, three-dimensional stability analysis.
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Hakim, Abi Maulana, Samira Albati Kamaruddin, Andhika Sahadewa, Ramli Nazir, and Haris Eko Setyawan. "Effect of Grain Size Distribution on Shear Strength Characteristic of Random Fill Material at Keureuto Dam, Indonesia." Key Engineering Materials 970 (December 15, 2023): 151–56. http://dx.doi.org/10.4028/p-h30laq.
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Earth-fill dams are commonly constructed by composing different geomaterials to optimally utilize local natural resources. In Indonesia, random fill materials are frequently used as a major composition in dam construction. The term random fill material originated from its broad range of grain size. Grain size distribution influences shear strength characteristics of geomaterials. There are 2 shear strength equations to model the behavior of fill material, i.e., linear Mohr-Coulomb and non-linear power curve. Two series of large scale in situ direct shear tests were performed at Keureuto Dam, Indonesia. Sieve analysis tests were performed accordingly. The random fill material was composed of cobbles, gravel, and less than 25% of sand. The stress-displacement characteristics of random fill material indicated that plastic deformation occurred at shear strain of 1% to 4%. The shear failure was reached in shear displacements of 60 – 90 mm, equivalent to shear strain of 8% – 12 %. Stress-strain relationships showed a dilative behavior indicating the random fill was in a relatively dense form. The dilatancy tends to decrease as the normal stress increases. The linear Mohr-Coulomb failure criteria and non-linear power curve equation are suggested to characterize the shear strength of the random fill material. To obtain a realistic value of the non-cohesive strength parameter of granular material, the Mohr-Coulomb approach should be intercepted at zero. A relationship between secant friction angles for different normal stresses is presented. This angle tends to decrease at higher normal stresses.
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Wang, Yarlong. "The effect of a nonlinear Mohr–Coulomb criterion on borehole stresses and damage-zone estimate." Canadian Geotechnical Journal 31, no. 1 (February 1, 1994): 104–9. http://dx.doi.org/10.1139/t94-011.
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To investigate the possible error introduced by the assumption of a linear Mohr–Coulomb criterion on the stress distribution near a circular opening, a numerical approach is used to calculate both the damage-zone radius and the stresses near a circular opening. A general solution procedure for the stress calculation under a uniform far-field loading is presented and a closed-form solution for the near-opening stresses is given for a cohesionless medium. Based on the numerical results calculated, it is concluded that the linear assumption is acceptable for a strong rock with an unconfined compressive strength that is of similar magnitude to the far-field stress. However, the tangential stress calculated with this linear assumption may be overestimated, but the damage zone may be underestimated in weaker rock or soil such as an oil sand formation. Key words : Mohr–Coulomb criterion, circular opening, nonlinearity, oil sands, Gauss–Legendre method.
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Deng, Shuxin, Yonglai Zheng, Lipo Feng, Le Van Tuan, Cuizhou Yue, and Zhuorui Wu. "Analysis of plastic zones in surrounding rocks around a circular tunnel considering the effect of intermediate principal stress and heterogeneity." MATEC Web of Conferences 275 (2019): 03007. http://dx.doi.org/10.1051/matecconf/201927503007.
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Based on a modified Mohr-Coulomb criterion with a non-uniform coefficient, a calculation method of plastic zone boundary of surrounding rocks in a circular tunnel in non-uniform stress field is established. Both the effects of intermediate principal stress and heterogeneity are studied. With the increase of the intermediate principal stress, the plastic zone size of the surrounding rocks will decrease first and then increase. Lateral pressure coefficient has an effect on the shape of the plastic zone. With the increase of lateral pressure coefficient, the plastic zone gradually becomes uniform, and the failure of surrounding rock develops upward and downward from both sides. As non-uniform coefficient increases, the material is more uniform and the effect of intermediate principal stress on the plastic zone is less significant. If the effect of intermediate principal stress is not taken into account, the calculation results tend to be consistent with results calculated by the Mohr-Coulomb criterion, which are considered to be conservative.
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Liu, Yong, Jie Wang, Zhi Jun Zhang, and Rong Gui. "Effect on Tailing Dam Stability of Rainfall Infiltration." Advanced Materials Research 842 (November 2013): 777–81. http://dx.doi.org/10.4028/www.scientific.net/amr.842.777.
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Flow-deformation coupled unsaturated soil model is built based on rainfall infiltration condition and modified Mohr-Coulomb failure criterion according to modeling a tailing dam with ABAQUS software. A few conclusions are obtained by adopting proper hydraulic curve soil water characteristic curve and compared with actually measures data. Studies yields provide foundations for simulation analysis on tailing dam on the condition of rainfall infiltration.
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Yamini Anand, Mohd Abu Zaid. "Antioxidant Effect of Stevia Rebaudiana on Humanerythrocytes." Universities' Journal of Phytochemistry and Ayurvedic Heights 2, no. 29 (December 24, 2020): 26–31. http://dx.doi.org/10.51129/ujpah-2020-29-2(4).
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Abstract-The changing lifestyle and environment conditions have predisposed common man towards numerous diseases. Today most of the diseases are said to be caused by synthetic chemicals, toxic heavy metals, and the stress of modern living. It is also true that oxygen is essential for sustaining life but it is also dangerous to our existence. Oxygen is being viewed as playing a lead role in the generation of reactive intermediates, thereby causing cellular damage. Our body has the mechanism to handle free radicals and prevent its damaging effect, which involves the use of antioxidants as glutathione and antioxidant enzymes assuperoxidedismutase,catalase,glutathioneperoxidaseglutathionereductase, glutathione-S-transferase to counter these free radicals. When the redoxstatus of the body is overwhelmed by these radical species, this may result in variety of chronic diseases and even premature senility.The administration of natural antioxidant as food constitutes or therapeutic agents is looked-for to neutralize these reactive oxygen species and prevent or delay diseased condition caused by these reactive species. Most exogenous antioxidants come from raw vegetable fruits, spices, herbsandvariousmedicinalplants.Naturalantioxidants are always appreciated over synthetic ones because they lack toxic side effects. The present study deals with the effectsofStevia rebaudiana leaf extract on the statusantioxidant of RBC as evident by an in vitro dose-dependent decrease in the activity of erythrocytes superoxide dismutaseand catalase as compared to the normal control whereas at much higher concentration ofstevialeaf extract (100μg/ml)started to show a reversingtrendofitsprotectiveaction.
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Navale, Avinash V., Sagar D. Turkane, Kiran B. Ladhane, Chandresh H. Solanki, and Vishwas A. Sawant. "Analysis of Pile Group in Square Arrangement Embedded in Clayey Soil." Indian Journal Of Science And Technology 17, no. 45 (December 14, 2024): 4765–77. https://doi.org/10.17485/ijst/v17i45.2685.
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Objective: The purpose of this study is to simulate and compare the response of the 3 × 3 pile group, embedded in clay, subjected to static lateral load, in terms of lateral deflection when soil is represented by different elastoplastic yield criteria. The effect of geometrical and material parameters is also investigated. Methods: In the developed finite element formulation, 20 node isoparametric elements have been used to model piles and pile caps. Surrounding soil has been modeled using 8-node isoparametric elements. The code is being developed in FORTRAN 90. Findings: The parametric study revealed the impact of the constitutive model to represent soil, pile spacing, pile length, pile diameter, and soil properties on the lateral deflection of the pile group. Mohr-Coulomb criterion predicts the lowest lateral displacement and maximum bending moment. An increase in spacing-to-diameter ratio from 2 to 6 causes a decrease in pile displacement by 80.13% in Von Misses, 70.3% in Drucker-Prager outer, 76.68% in Drucker-Prager inner, and 56.62% in Mohr-Coulomb yield criteria. An increase in the elastic modulus of soil from 20000 kPa to 60000 kPa results in a reduction in lateral displacement by 43.12% and an increase in pile diameter from .6 m to 1.0 m causes a reduction in lateral displacement by 82.73% when Von Mises criterion is used. The change in length-to-diameter ratio from 10 to 25 reduces pile displacement by 23.91%. Novelty: Among the Von – Mises, Mohr-Coulomb, Drucker–Prager (outer), and Drucker–Prager (inner) criteria, the Mohr-Coulomb criterion predicts the lowest lateral response for the 3 × 3 pile group. However, as the s/D ratio increases from 2 to 6, the difference in response is minimized. A marginal difference is found at the L/D ratio of more than 15. Applications: The developed three-dimensional finite element software can be used by pile designers to predict the response of laterally loaded pile groups. Keywords: Lateral load, Pile group, Pile spacing, Von Misses criterion, Mohr-Coulomb criterion, Drucker-Prager criterion, Lateral pile deflection
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Ishizaka, Yuki, Sho Otsuka, and Seiji Nakagawa. "The effect of medial olivocochlear reflex enhancement associated with temporal expectation on listening performance in noise." Journal of the Acoustical Society of America 154, no. 4_supplement (October 1, 2023): A242. http://dx.doi.org/10.1121/10.0023419.
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The medial olivocochlear reflex (MOCR) is efferent feedback activated by acoustic stimulation and plays a role to improve signal detection in noise. We have reported that the MOCR and phase locking value (PLV) of delta oscillations showed a similar decreasing tendency with increasing jitter added to the preceding sound sequence. This suggests that the processing at the cortical regions is involved in the regularity -based enhancement of MOCR. Further, the dependency disappeared as the load of the interfered task increased, suggesting that the cortical predictive control of MOCR requires top-down attention to sounds. Considering the anti-masking effect of MOCR, MOCR enhancement with anticipation may improve listening performance in noise. We extended our previous experiments by measuring listening performance in noise and compared its dependence on the jitter size with MOCR strength and PLV of delta oscillation. In the low load condition, the three indices increased with decreasing the jitter. In the high load condition, by contrast, the dependency on the jitter size disappeared. The similarities of the indices in the dependency on jitter size and attention implicate that the cortical predictive control can facilitate the antimasking of MOCR, therefore improving the listening performance in noise.
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Sitorus, Pangeran Holong, and Sri Wulandari. "Pengaruh Perilaku Tinggi Muka Air Tanah dengan Variasi Kemiringan Lereng Terhadap Stabilitas Lereng Berbasis Pemodelan Numerik." Jurnal Teknik Sipil 29, no. 2 (August 18, 2022): 145–52. http://dx.doi.org/10.5614/jts.2022.29.2.5.
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Abstrak Masalah stabilitas lereng cukup umum dan tersebar luas di banyak proyek teknik sipil. Banyak kasus kelongsoran lereng alami yang disebabkan oleh faktor air, seperti air di permukaan maupun aliran air di dalam tanah. Tujuan dilakukannya penelitian ini untuk membuktikan pengaruh tinggi muka air tanah terhadap stabilitas lereng berbasis pemodelan numerik dengan meninjau nilai faktor keamanan lereng. Penelitian ini dilakukan dengan memodelkan tiga lereng dengan kemiringan yang berbeda menggunakan data tanah masing-masing sebagai Mohr-Coulomb Model dan Soft Soil Model dengan membuat variasi tinggi muka air tanah pada software Plaxis. Hasil yang didapat dari penelitian ini adalah adanya kenaikan nilai faktor keamanan Mohr-Coulomb Model sebesar 1,20 pada lereng Cipendawa, 0,97 pada lereng Semarang dan 1,36 pada lereng Tangerang Selatan sedangkan untuk Soft Soil Model terjadi kenaikan sebesar 1,07 pada lereng Cipendawa, 0,91 pada lereng Semarang dan 1,26 pada lereng Tangerang Selatan. Kenaikan nilai faktor keamanan ini ditinjau dari kondisi muka air tanah 0,5 meter sampai 5,5 meter. Adanya perubahan muka air tanah mempengaruhi nilai faktor keamanan dikarenakan tekanan air pori dapat menimbulkan gaya angkat dan dapat menurunkan kekuatan suatu massa tanah atau batuan penyusun lereng tersebut. Kata-kata Kunci: Muka air tanah, faktor keamanan, mohr-coulomb model, soft soil model. Abstract Slope stability problems are quite common and wide-spread in many civil engineering projects. Many cases of slope failure are caused by groundwater or underground water flow. The aim of this paper is to ensure the effect of groundwater level on slope stability based on numerical modeling by focusing on the value of the safety factor. This paper was conducted by modeling slopes from three different locations which have various angles of inclination using its soil data as Mohr-Coulomb Model and Soft Soil Model by varying the groundwater level in Plaxis. The results obtained from this study is an increment in safety factor value by 1,20 on the slope of Cipendawa, 0,97 on the slope of Semarang and 1,36 on the slope of South Tangerang using Mohr-Coulomb Model. The results generated from Soft Soil Model are safety factor value increment by 1,07 on Cipendawa, 0,91 on Semarang and 1,26 on South Tangerang. The increment of safety factor is being analyzed from the groundwater level fluctuations from 0.5 meters to 5.5 meters. The groundwater level fluctuation could affect the safety factor value because pore water pressure cause lifting and shall reduce the strength of soil mass of the slope. Keywords: Groundwater level, safety factor, mohr-coulomb model, soft soil model.
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Sort, J., J. Fornell, W. Li, S. Suriñach, and M. D. Baró. "Influence of the loading rate on the indentation response of Ti-based metallic glass." Journal of Materials Research 24, no. 3 (March 2009): 918–25. http://dx.doi.org/10.1557/jmr.2009.0117.
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The mechanical behavior of Ti-based metallic glass has been investigated by means of indentation experiments at different loading rates. Contrary to many crystalline materials, an increase of the loading rate causes a reduction of hardness, i.e., a mechanical softening. This effect is ascribed to deformation-induced creation of excess free volume, which is more pronounced for higher strain rates. The decrease of hardness is accompanied with an increase of the contact stiffness and a reduction of the reduced elastic modulus. Finite element simulations reveal that the mechanical response of this material can be described using the Mohr-Coulomb yield criterion. The changes in the nanoindentation curves with the increase of loading rate are well reproduced by decreasing the value of the Mohr-Coulomb cohesive stress. This result is consistent with the presumed enhancement of free volume.
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Kondratieva, Lydia, Anatoly Osokin, and Kirill Skvortsov. "Refinement of the Calculated Ground Resistance Value for the Volumetric Stress-Strain State." E3S Web of Conferences 371 (2023): 02014. http://dx.doi.org/10.1051/e3sconf/202337102014.
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Despite the fact that the Mohr-Coulomb theory of strength appeared more than a hundred years ago, many authors are still conducting research in accordance with the recommendations to find optimal solutions to practical problems. From the Coulomb-Mohr theory, a huge number of methods for solving applied problems were formed, for example, the initial critical load, which is useful for research in the article. This formula is no longer new, but despite this, it is still the object of research. The authors of this article consider the case of the assumption, applying it when issuing a formula for the initial critical load. Based on the initial critical load, a formula for the design soil resistance was obtained, which is still regulated by codes and standards in the field of design. The authors reflect the main ependencies that appear in the calculation of the stress-strain state in soil mechanics. Based on these dependencies, the amount of allowable stress is revealed, under which the condition of linear deformability will be satisfied. The authors have shown that the proposed formula for any stability parameters will correspond to the Mohr-Coulomb limit state condition. The conclusion of the article compares the effect of the formula obtained by the authors and the recipe of the formula obtained by N.P. Puzyrevsky.
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Kikuchi, Shoma, Yuki Ishizaka, Sho Otsuka, and Seiji Nakagawa. "Effects of orienting attention to a specific frequency on medial olivocochlear reflex - A study of dependence on target frequencies -." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 268, no. 2 (November 30, 2023): 5996–6000. http://dx.doi.org/10.3397/in_2023_0872.
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The medial olivocochlear bundle responds to acoustic stimuli and suppresses outer hair cell gain. This reflex response is called the medial olivocochlear reflex (MOCR) and improves signal detection in background noise, referred to anti-masking effect. Our previous study reported that orienting attention to moderate frequencies selectively increases MOCR near the attended frequency, and that the effects of attention to low and high frequencies are unlikely to appear in MOCR. The previous investigation was limited to the condition where participants kept orienting attention to the same frequency across trials. Here we examined the condition where participants switched attention to different frequencies trial by trial. During the measurements of MOCR, participants detected probe tones in background noise. The target frequency, 750, 1000, 1250, 1500, 2000 and 3000 Hz, was notified by a preceding cue frequency and varied across trials. When the target frequency was 1250 Hz, the MOCR strength tended to be attenuated at lower frequencies. In contrast, for any other target frequencies, MOCR didn't differ significantly from a non-attentional condition. The frequency range where attentional effect was observed was similar to our previous report. The similarity implicates that MOCR can covary with dynamically changing frequency-specific attention, which would help exerting antimasking effect flexibly.
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Ip, Bill, W. D. Hibler, and Greg Flato. "The Effect Of Rheology On Seasonal Sea-Ice Simulations." Annals of Glaciology 14 (1990): 340. http://dx.doi.org/10.3189/s0260305500009046.
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On the seasonal time scales relevant to numerical investigations of climate, the rheology used in large-scale sea ice models significantly affects the ice thickness build-up and ice velocity fields. Plastic rheologies with a normal flow rule have been used to-date in seasonal dynamic thermodynamic simulations. These rheologies have proved useful in simulating discontinuous slip near the coast while still supplying relatively robust velocity fields in the central Arctic Basin. However, as indicated by limited numerical sensitivity studies with different types of elliptical yield curves, the amount of shear strength significantly affects the ice build-up and can possibly cause a stoppage of the ice outflow through Fram Strait. In addition to the shear strength issue, there is also the possibility that non-normal flow rule rheologies, such as the Mohr Coulomb failure criterion used in soil mechanics, may cause somewhat different types of flow patterns, especially in the Fram Strait region. However, to date no seasonal simulations with such non-normal flow rule rheologies have been carried out.In order to investigate the role of different rheologies on the large-scale flow patterns in the Arctic Basin, a more general numerical scheme than that of Hibler (1979) is developed, which allows the simulation of the dynamic thermodynamic behavior of sea ice with a wide variety of different non linear rheologies. Using this numerical scheme, comparative simulations are carried out to seasonal equilibrium with several variations of the Mohr Coulomb rheology and compared to the more standard Elliptical yield curve results. In particular, the main control Mohr Coulomb case is a capped rheology in which the shear strength is taken to be proportional to the compressive stress. In this capped case only shear flow is allowed until a maximum allowable compressive stress is reached. This cap strength is parameterized to be a function of the ice thickness and compactness. For comparison, a simulation with a very large cap strength is also carried out, and an experiment with a similar compressive cap but much lower shear strength. Overall the results are analyzed to determine the sensitivity of the ice build-up to flow rule and shear strength magnitude. In addition special attention is given to the character of the flow and stoppage (if any) through Fram Strait.
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Ip, Bill, W. D. Hibler, and Greg Flato. "The Effect Of Rheology On Seasonal Sea-Ice Simulations." Annals of Glaciology 14 (1990): 340. http://dx.doi.org/10.1017/s0260305500009046.
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On the seasonal time scales relevant to numerical investigations of climate, the rheology used in large-scale sea ice models significantly affects the ice thickness build-up and ice velocity fields. Plastic rheologies with a normal flow rule have been used to-date in seasonal dynamic thermodynamic simulations. These rheologies have proved useful in simulating discontinuous slip near the coast while still supplying relatively robust velocity fields in the central Arctic Basin. However, as indicated by limited numerical sensitivity studies with different types of elliptical yield curves, the amount of shear strength significantly affects the ice build-up and can possibly cause a stoppage of the ice outflow through Fram Strait. In addition to the shear strength issue, there is also the possibility that non-normal flow rule rheologies, such as the Mohr Coulomb failure criterion used in soil mechanics, may cause somewhat different types of flow patterns, especially in the Fram Strait region. However, to date no seasonal simulations with such non-normal flow rule rheologies have been carried out. In order to investigate the role of different rheologies on the large-scale flow patterns in the Arctic Basin, a more general numerical scheme than that of Hibler (1979) is developed, which allows the simulation of the dynamic thermodynamic behavior of sea ice with a wide variety of different non linear rheologies. Using this numerical scheme, comparative simulations are carried out to seasonal equilibrium with several variations of the Mohr Coulomb rheology and compared to the more standard Elliptical yield curve results. In particular, the main control Mohr Coulomb case is a capped rheology in which the shear strength is taken to be proportional to the compressive stress. In this capped case only shear flow is allowed until a maximum allowable compressive stress is reached. This cap strength is parameterized to be a function of the ice thickness and compactness. For comparison, a simulation with a very large cap strength is also carried out, and an experiment with a similar compressive cap but much lower shear strength. Overall the results are analyzed to determine the sensitivity of the ice build-up to flow rule and shear strength magnitude. In addition special attention is given to the character of the flow and stoppage (if any) through Fram Strait.
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Abrehdary, M., and L. E. Sjöberg. "A New Moho Depth Model for Fennoscandia with Special Correction for the Glacial Isostatic Effect." Pure and Applied Geophysics 178, no. 3 (February 15, 2021): 877–88. http://dx.doi.org/10.1007/s00024-021-02672-8.
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AbstractIn this study, we present a new Moho depth model in Fennoscandia and its surroundings. The model is tailored from data sets of XGM2019e gravitationl field, Earth2014 topography and seismic crustal model CRUST1.0 using the Vening Meinesz-Moritz model based on isostatic theory to a resolution of 1° × 1°. To that end, the refined Bouguer gravity disturbance is determined by reducing the observed field for gravity effect of topography, density heterogeneities related to bathymetry, ice, sediments, and other crustal components. Moreover, stripping of non-isostatic effects of gravity signals from mass anomalies below the crust due to crustal thickening/thinning, thermal expansion of the mantle, Delayed Glacial Isostatic Adjustment (DGIA), i.e., the effect of future GIA, and plate flexure has also been performed. As Fennoscandia is a key area for GIA research, we particularly investigate the DGIA effect on the gravity disturbance and gravimetric Moho depth determination in this area. One may ask whether the DGIA effect is sufficiently well removed in the application of the general non-isostatic effects in such an area, and to answer this question, the Moho depth is determined both with and without specific removal of the DGIA effect prior to non-isostatic effect and Moho depth determinations. The numerical results yield that the RMS difference of the Moho depth from our model HVMD19 vs. the seismic CRUST19 and GRAD09 models are 3.8/4.2 km and 3.7/4.0 km when the above strategy for removing the DGIA effect is/is not applied, respectively, and the mean value differences are 1.2/1.4 km and 0.98/1.4 km, respectively. Hence, our study shows that the specific correction for the DGIA effect on gravity disturbance is slightly significant, resulting in individual changes in the gravimetric Moho depth up to − 1.3 km towards the seismic results. On the other hand, our study shows large discrepancies between gravimetric and seismic Moho models along the Norwegian coastline, which might be due to uncompensated non-isostatic effects caused by tectonic motions.
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LIAO, HONGJIAN, ZONGYUAN MA, and LIJUN SU. "CALCULATION OF THE ULTIMATE BEARING CAPACITY OF SOIL SLOPE BASED ON THE UNIFIED STRENGTH THEORY." International Journal of Modern Physics B 22, no. 31n32 (December 30, 2008): 5637–42. http://dx.doi.org/10.1142/s0217979208050930.
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At present, the failure criteria used in calculating the ultimate bearing capacity of soil slope are the Tresca and Mohr-Coulomb criteria. But the results are conservative and the potential strength of soil mass cannot be utilized sufficiently because these two criteria do not take into account the effect of the intermediate principal stress. In this paper the unified strength theory was used to analyze the ultimate bearing capacity of soil slope. The formula for calculating the ultimate bearing capacity of soil slope using the unified strength theory was established. At the end, a case history was analyzed and it indicated that the result of the unified strength theory is larger than that of the Mohr-Coulomb criterion. This indicates that calculation of ultimate bearing capacity of soil slope with the unified strength theory can sufficiently exploit the strength of material. Therefore, the calculation of ultimate bearing capacity of the soil slope based on the unified strength theory will be of great significance in future applications.
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Duris, Lukas, and Eva Hrubesova. "Numerical Simulation of the Interaction between Fibre Concrete Slab and Subsoil—The Impact of Selected Determining Factors." Sustainability 12, no. 23 (December 1, 2020): 10036. http://dx.doi.org/10.3390/su122310036.
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Shape and material optimization of building structures, including reducing the amount of concrete used, are very important aspects in sustainable construction. Numerical modelling is currently used very effectively to design optimized and sustainable structures, including their interaction with the surrounding rock environment. This paper is focused on the three selected factors of numerical modelling of fibre concrete slab and subsoil interaction: (1) the constitutive model of fibre concrete slab, (2) deformational and strength characteristics of subsoil, (3) effect of interface elements. The specialized geotechnical software Midas GTS NX, based on the finite element method, was used for the modelling of this task. Numerical results were compared with the experimental measurement of vertical displacements on the upper surface of slab. In the presented study, three constitutive models of slab recommended in MIDAS GTS NX code for modelling concrete behaviour (elastic, Mohr-Coulomb and Drucker-Prager) were applied. In addition, the sensitivity analysis with respect to the deformational and strength characteristics of subsoil was performed. The numerical study also presents the effect of the interface elements application on the slab behaviour. The numerical results of maximum vertical displacements based on the Drucker-Prager and elastic model underestimated both the experimental results and numerical results based on the Mohr-Coulomb model. From the qualitative point of view (shape of deflection curve), the numerical simulation showed the better agreement of the Mohr-Coulomb constitutive model with the experimental measurements in comparison with the other two investigated constitutive models. The performed parametric study documented that reduction of the strength and deformational characteristics of subsoil leads to the increase of maximum vertical displacements in the centre of slab, but the experimentally measured deflection curve, including uplift of slab and gapping occurrence between the slab and subsoil, was not achieved without the interface application.
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TOPÇU, Sadettin, and Evren SEYREK. "Numerical Analysis for Investigation of Hydraulic Fracturing Potential of the Rockfill Dam." Journal of Scientific Reports-A, no. 055 (December 31, 2023): 173–84. http://dx.doi.org/10.59313/jsr-a.1381469.
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Embankment dams may collapse because of internal erosion that develops in the crack developed in the upstream-downstream direction by hydraulic fracturing. It is known in the literature that many dams collapsed due to hydraulic fracturing. The hydraulic fracturing mechanism is defined as the propagation of an existing crack on the upstream face of the clay core under hydrostatic stresses or the formation of a new crack in low-stress zones by hydrostatic stress. The variety of materials and materials' mechanical properties generally affect the hydraulic fracturing potential. This study examined the effect of the deformation parameters (Elasticity modulus and Poisson ratio) of the impermeable curtain-function clay core material on the hydraulic fracturing potential. Normal Stress and Mohr-Coulomb methods were used to determine the hydraulic fracturing potential. The principal stress values required for these two methods were determined for the maximum cross-section of the clay-core rockfill type Çınarcık Dam by the finite element method. While the hydraulic fracturing potential is negligibly affected by the change of deformation parameters in the Normal Stress method, this effect is clearly seen in the Mohr-Coulomb method.
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Wang, Zhong-chang, Hai-tao Wang, and Qing Yang. "Analysis of localization of Mohr-Coulomb strength law with damage effect." Journal of Shanghai Jiaotong University (Science) 17, no. 5 (October 2012): 619–28. http://dx.doi.org/10.1007/s12204-012-1334-5.
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Hsu, Juishan, and Zijie Yu. "Impact of COVID-19 on Manufacturing Overhead Cost: A Case of an Electronic OEM Company in Guangdong, China." Highlights in Science, Engineering and Technology 72 (December 15, 2023): 705–13. http://dx.doi.org/10.54097/pmqaeg40.
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This research analyzes the data of the manufacturing overhead costs (MOHC) of a plant in an electronic OEM company (located in Guangdong, China) during and after the COVID-19 pandemic. A paired t-test and a multiple variable regression analysis are conducted. MOHC and other indications are visualized by time sequence diagrams to facilitate the identification of the difference between mid- and post-pandemic. Through diving deeper into the effect of COVID-19 on the MOHC, Unit MOHC, and shipment, the overall influence of COVID-19 on the entire electronic OEM industry can be inferred. It is concluded that COVID-19 has influenced MOHC, Unit MOHC, shipment, and employee size, which may bring forth a paradigm-shifting experience on how people view the influence of COVID-19 on the entire electronic OEM industry and pave the way for further research afterward. This paper fills the research gap by focusing on one plant in one company, avoiding the difference in MOHC among different companies and plants.
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Saeidi, Ali, Côme Cloutier, Abbas Kamalibandpey, and Alireza Shahbazi. "Evaluation of the Effect of Geomechanical Parameters and In Situ Stress on Tunnel Response Using Equivalent Mohr-Coulomb and Generalized Hoek-Brown Criteria." Geosciences 12, no. 7 (June 28, 2022): 262. http://dx.doi.org/10.3390/geosciences12070262.
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The generalized Hoek-Brown (GHB) failure criterion can estimate the rock mass parameters required for rock mechanics–related analyses such as numerical modeling in geomechanics. The determination of GHB parameters has been developed in the field of rock mechanics. Due to the wide use of the Mohr-Coulomb criterion and the lack of an existing relationship for determining its parameters for a rock mass, equivalent Mohr-Coulomb parameters (EMC) can be derived from the GHB. To determine the differences in the use of these two criteria, we analyzed the behavior of a deep circular tunnel in nine stress states for three metamorphic rocks recovered from the Canadian Shield from rock masses that present a very blocky structure. We carried out 241 simulations using the finite element code RS2 to assess the effect of the geological strength index (GSI), in situ stress, and rock type on the deviation of wall displacement, the number of yielded elements, and the differential stress obtained by the GHB and EMC parameters. A combination of low in situ stress and high GSI yielded similar results when using both failure criteria.
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Ekockaut, Joseph Arsène Bockou, Louis Ahouet, and Sylvain Ndinga Okina. "Comparative Study of the Influence of the Fish Coefficient and Young's Modulus with the Hardening Soil Model and The Mohr-Coulomb Model on the Behavior of Cable-Stayed Bridge Piles." Saudi Journal of Civil Engineering 9, no. 01 (January 22, 2025): 1–9. https://doi.org/10.36348/sjce.2025.v09i01.001.
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This article deals with the behavior of isolated piles subjected to two models used in geotechnics (Hardening Soil and Mohr Coulomb) under cyclic lateral loading and their head deformations compared to monotonic loading in sandy soil. The behavior of the cable-stayed bridge piers was predicted using PLAXIS 2D software, based on the results of in situ and laboratory geotechnical studies carried out by the control office for Building and Public Works (BCBTP). Numerical simulation is an alternative to the high cost of large-scale in situ and laboratory studies for describing the behavior of deep foundations. The results obtained show that piles subjected to lateral head loading cause a horizontal head displacement compared with the Hardening Soil and Mohr Coulomb models. Cyclic loading of a pile results in deformation of the soil mass at the surface. Lateral displacement increases with the first few cycles until it stabilizes, generating an irreversible residual displacement due to progressive soil plasticization. Lateral cyclic loading has a favorable influence on pile behavior under cyclic loading, due to the reversible effect on pile displacement.
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Jamos, Abdullah M., Blair Hosier, Shelby Davis, and Thomas C. Franklin. "The Role of the Medial Olivocochlear Reflex in Acceptable Noise Level in Adults." Journal of the American Academy of Audiology 32, no. 03 (March 2021): 137–43. http://dx.doi.org/10.1055/s-0040-1718705.
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Abstract Background The acceptable noise level (ANL) is a measurement used to quantify how much noise a person is willing to accept while listening to speech. ANL has been used to predict success with hearing aid use. However, physiological correlates of the ANL are poorly understood. One potential physiological correlate is the medial olivocochlear reflex (MOCR), which decreases the output of the cochlea and is thereby expected to increase noise tolerance. Purpose This study investigates the relationship between contralateral activation of the MOCR and tolerance of background noise. Research Design This study recruited 22 young adult participants with normal hearing. ANL was measured using the Arizona Travelogue recording under headphones presented at the most comfortable level (MCL) with and without multitalker babble noise. The MOCR strength was evaluated in all participants by measuring the cochlear microphonic (CM) with and without 40 dB sound pressure level contralateral broadband noise (CBBN). Data Analysis The CM observed in response to a 500-Hz tone was measured with and without CBBN, and changes in response to fast Fourier transform amplitude at 500 Hz were used as an indicator of the MOCR effect. The ANL was calculated by subtracting the maximum acceptable background noise level from the MCL. Participants were divided into two groups based on their ANL: low-ANL (ANL < 7 dB) and moderate-ANL (ANL ≥ 7 dB). An independent samples t-test was used to compare CM enhancement between low-ANL and moderate-ANL groups. Additionally, Pearson's correlation was used to investigate the relationship between the ANL and the MOCR effect on the CM. Results The results indicated that presentation of CBBN increased the CM amplitude, consistent with eliciting the MOCR. Participants in the low-ANL group had significantly larger CM enhancement than moderate-ANL participants. The results further revealed a significant correlation between the ANL and the MOCR effect on the CM. Conclusion This study suggests that a stronger MOCR, as assessed using CM enhancement, is associated with greater noise tolerance. This research provides a possible objective measure to predict background tolerance in patients and adds to our understanding about the MOCR function in humans.
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Jedrzejczak, W. Wiktor, Krzysztof Kochanek, Edyta Pilka, Małgorzata Pastucha, and Henryk Skarzynski. "Medial olivocochlear reflex reliability: The effects of averaging and presence of synchronized spontaneous otoacoustic emissions." Journal of the Acoustical Society of America 152, no. 4 (October 2022): 2150–59. http://dx.doi.org/10.1121/10.0014601.
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The medial olivocochlear reflex (MOCR), usually assessed by the inhibition of transiently evoked otoacoustic emissions (TEOAEs) with contralateral noise, is a very small effect. In understanding the origin of the MOCR, it is crucial to obtain data of the highest accuracy, i.e., with a high signal-to-noise ratio (SNR), which in turn largely depends on the number of signal averages. This study investigates how the reliability of MOCR measures is affected by the number of averages. At the same time, the effect of the presence of synchronized spontaneous otoacoustic emissions (SSOAEs) is taken into account, as it is known that this factor significantly affects TEOAE amplitudes and SNRs. Each recording session consisted of two series of four measurements, allowing comparison of MOCR magnitude based on 250, 500, 750, and 1000 averages. Reliability was based on comparing the two series. The results show that, for a good quality MOCR measure (i.e., intraclass correlation above 0.9), the required number of averages is at least double that obtainable from a standard TEOAE test (i.e., 500 compared to 250). Ears without SSOAEs needed a higher number of averages to reach a correlation of 0.9 than ears with SSOAEs.
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Zhang, Dong Dong, Jun Feng Zhou, Wei Guo Zhang, Cheng Bing Zhu, Rui Rui Sun, Li Jun Ji, and Ze Xian Wu. "The Finite Element Analysis of the Excavation on Adjacent Buildings Based on Mohr Coulomb Model." Advanced Materials Research 374-377 (October 2011): 2171–75. http://dx.doi.org/10.4028/www.scientific.net/amr.374-377.2171.
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The design and practice of a deep excavation in shanghai was presented. The FEM based on Mohr coulomb Model was adopted to analyze the deformation of the excavation and its effect on adjacent buildings. This method gives good prediction of both the deformation of the soil retaining structures and the settlement of the soils behind the wall after comparing with measured datas. Meanwhile, the method is suitable to deformation analysis of sensitive environment circumstance.
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Chu, Xi Hua, Qing Hui Jiang, and Bin Wang. "A Structural Failure Model for the Rock Mass with a Discontinuous Weak Structural Plane." Applied Mechanics and Materials 204-208 (October 2012): 135–38. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.135.
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A structural failure model is presented for the rock mass with a discontinuous weak structural plane. The present model takes into account the effect of weakening of both deformation and strength parameters. And it can degenerates into classical Mohr-Coulomb model or Jaeger model according to corresponding conditions. The numerical tests by Particle Flow Code demonstrate that the capability and performance of the proposed model in capturing behaviors of the mass rock.
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Zhang, Wu Mei, and Xing Huang. "Calculation for Earth Pressure of Cavity Expansion Considering Displacement." Applied Mechanics and Materials 580-583 (July 2014): 405–8. http://dx.doi.org/10.4028/www.scientific.net/amm.580-583.405.
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Most of the studies on cavity expansion are about the analytical solutions of the stress distribution, and not related to the effect of soil properties on earth pressure. Aiming at the problem, the change law of passive earth pressure is analyzed by using the Mohr-Coulomb model, and the formula of earth pressure is summarized. The error value of calculation and simulation is small that the formulas can be directly used in practical engineering.
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Stefanescu, E. R., M. Bursik, and A. K. Patra. "Effect of digital elevation model on Mohr-Coulomb geophysical flow model output." Natural Hazards 62, no. 2 (March 22, 2012): 635–56. http://dx.doi.org/10.1007/s11069-012-0103-y.
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Yang, Qian, Jun Xing Zhang, and Geng Ning Zhang. "Effect of the Inhomogeneity of a Substratum Soil on Longitudinal Settlements of a Shield Tunnel." Advanced Materials Research 568 (September 2012): 129–33. http://dx.doi.org/10.4028/www.scientific.net/amr.568.129.
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In this paper, we perform a 3D finite element analysis for the longitudinal settlement of a shield tunnel in soft soil, where a substratum soil contains a soft layer. The Mohr-Coulomb model is used for the substratum soil and soft layer. The longitudinal settlements are calculated for different elastic modulus and longitudinal length of the soft layer. The results show that a softer and longer layer will result in the larger settlement. It is also found that the maximum of the longitudinal settlements is linear function of the elastic modulus of the soft layer.
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Šliburytė, Laimona, and Giedrė Bankauskienė. "Prekės kilmės šalies efekto poveikis vartotojo požiūriui į prekę." Management of Organizations: Systematic Research 76 (2016): 133–47. http://dx.doi.org/10.7220/mosr.2335.8750.2016.76.9.
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Shen, Luming, Yuxing Liu, and Zhen Chen. "Bifurcation Analyses of Steel and Concrete with Rate-Dependent Properties Part Two: Bifurcation Analyses and Demonstration." Advances in Structural Engineering 4, no. 4 (October 2002): 225–32. http://dx.doi.org/10.1260/136943301320896705.
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Based on the continuum tangent stiffness tensors derived in part one for steel and concrete, bifurcation analyses of rate-dependent elasto-plasticity and elasto-damage are performed in (-(and (-(spaces of Mohr, respectively. Localization ellipse osculating Mohr's circle enables us to determine the critical state and failure angle. It is shown that strain rate has no effect on the failure angle, and that the parameters in rate-dependent damage model are restricted by the results of bifurcation analysis.
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Tian, Dongshuai, and Hong Zheng. "A Three-Dimensional Elastoplastic Constitutive Model for Geomaterials." Applied Sciences 13, no. 9 (May 6, 2023): 5746. http://dx.doi.org/10.3390/app13095746.
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The Mohr-Coulomb (M-C) failure criterion has been a popular choice for geotechnical analysis because of its simplicity and ease of use. The fact that the M-C criterion disregards the intermediate principal stress’s impact is a significant drawback. As a result, the M-C criterion is only applied to materials under biaxial stress. This paper presents a three-dimensional version of the M-C criterion. The proposed criterion, called the Generalized Mohr-Coulomb (GMC) criterion, considers the intermediate principal stress’s effect, in addition to inheriting the original M-C criterion’s benefits. We obtained the conditions that the strength parameters must satisfy when the GMC criterion fulfills the π plane’s convexity. The GMC criterion can better describe geotechnical materials’ strengths under general stress conditions. Based on an implicit algorithm, the user material subroutine (UMAT) of the three-dimensional GMC model was developed in ABAQUS using the Fortran programming language. The established elastoplastic model’s validity and the program’s accuracy were examined using numerical simulation. Finally, a numerical simulation of a three-dimensional tunnel excavation under various working conditions was performed. The calculation results from the GMC model are precise and have some engineering-related practical significance.
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Huynh, Cai Van, Nhung Dinh Tran, and Quyen Huynh. "Synergetic catalytic effect of molybdenium (Mo) and chromnium (Cr) ions on HZSM-5 support for isomerization of n-hexane by reaction without hydrogen." Science and Technology Development Journal 19, no. 4 (December 31, 2016): 83–94. http://dx.doi.org/10.32508/stdj.v19i4.707.
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Synergetic catalytic effect of molybdenium (Mo) and chromnium (Cr) ions on HZSM-5 support have been carried out. The catalyst of MoCr/HZSM-5 have been tested for iszomerization of n-hexane based on non-hydrogen reaction. The results showed that the catalytic synthesis by impregnating Mo and Cr on HZSM-5 support with the suitable amount ( Mo:10 %; Cr:3 %) did not change the basis structure of HZSM-5. The catalytic effect of Mo, Cr have been showed by catalytic testing results, for that the isoparaffin selectivity of MoCr/HZSM-5 is 46.5 % higher than in the case of Mo/HZSM-5 (43.56 %). The synergystic catalytic activity was clearly expressed by the dehydrogenation and hydrogenation role of Cr enhancing the stability of isomerization effect of Mo on MoCr/HZSM-5 catalyst for n-hexane’s isomerization reaction. Research results could be considered as the scienctific basis results for catalytic research applied to gasoline high quality production from the condensate feed by non-hydrogen technology in Vietnam.
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Pham, Hung Van, Huy Quang Dang, Lam Phuc Dao, and Long Khac Nguyen. "Study on arching effect in the embankment over pile - reinforced soft soil." Journal of Mining and Earth Sciences 61, HTCS6 (December 31, 2020): 19–25. http://dx.doi.org/10.46326/jmes.htcs2020.03.
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The paper employes 3D numerical modeling to analyze the soil arching mechanism within embankment by FLAC3D code, based on the finite difference method (FDM). To consider the pile group effect, the 3D mesh of four pile has been created. Related to the constitutive models, the embankment is used Mohr - Coulomb model, the soft soil is represented by modified Cam - clay model, and footing and piles are employed by elasticity model. The numerical results focus on the soil arching phenomena in terms of stress distribution on piles and soft soil, the stress concentration ratio and the stress reduction ratio. Additionally, the axial force along pile and the settlements of embankment, soft soil and pile are studied.
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Moradi, Golam, and Alireza Abbasnejad. "Experimental and numerical investigation of arching effect in sand using modified Mohr Coulomb." Geomechanics and Engineering 8, no. 6 (June 25, 2015): 829–44. http://dx.doi.org/10.12989/gae.2015.8.6.829.
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Zhao, Jun-hai, Yue Zhai, Lin Ji, and Xue-ying Wei. "Unified Solutions to the Limit Load of Thick-Walled Vessels." Journal of Pressure Vessel Technology 129, no. 4 (October 20, 2006): 670–75. http://dx.doi.org/10.1115/1.2767356.
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Unified solutions to the elastoplastic limit load of thick-walled cylindrical and spherical vessels under internal pressure are obtained in terms of the unified strength theory (UST) and the unified slip-line field theory (USLFT). The UST and the USLFT include or approximate an existing strength criterion or slip-line field theory by adopting a parameter b, which varies from 0 to 1. The theories can be used on pressure-sensitive materials, which have the strength difference (SD) effect. The solutions, based on the Tresca criterion, the von Mises criterion, the Mohr–Coulomb criterion, and the twin shear strength criterion, are special cases of the present unified solutions. The results based on the Mohr–Coulomb criterion (b=0) give the lower bound of the plastic limit load, while those according to the twin shear strength criterion (b=1) are the upper bound. The solution of the von Mises criterion is approximated by the linear function of the UST with a specific parameter (b≈0.5). Plastic limit solutions with respect to different yield criteria are illustrated and compared. The influences of the yield criterion as well as the ratio of the tensile strength to the compressive strength on the plastic limit loads are discussed.
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Han, Jia Ming, and San Qing Su. "Effect of Rainfall Infiltration on Loess Pitted Courtyard Cave Dwellings Stability." Advanced Materials Research 430-432 (January 2012): 1992–95. http://dx.doi.org/10.4028/www.scientific.net/amr.430-432.1992.
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Baishe villagers have inhabited loess pitted courtyard cave dwelling for hundreds of years in Sanyuan County of China.The sizes of local cave dwellings are mastered by field measurements, and variational regularity is summarized of average annual and monthly rainfall. By the soil routine and triaxial test, the physical and mechanical parameter is acquired with loess samples in different water content.At the same time, based on the literature datas, the relationship is established between rainfall and water content. Then, the definition of safety factor is given for loess cave dwellings in different depths, making use of the expressions of the surrounding rock loop stress and the Mohr - Coulomb intensity criterion. In the end,the variation of stability of loess cave dwelling could be analysed under different rainfall.
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Xun, Ju Sheng, Xiang Tian Xu, and Rui Qiang Bai. "Study on the Effects of the Rainwater Seepage on Slope Stability." Applied Mechanics and Materials 580-583 (July 2014): 729–32. http://dx.doi.org/10.4028/www.scientific.net/amm.580-583.729.
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The work condition of the highway, which is usually built in mountainous regions, is complex relative to the ordinary road. Slope instability accident caused by the seepage of rainwater usually occurred in the rainy season. The mechanism for seepage failure of slope was investigated by used the Mohr-Coulomb criterion and the principle of effective stress. The effect of rain intensity on slope stability was equivalently instead by the effect of moisture content on slope stability. The influence of moisture content on the safety factor of slope stability was further calculated according to the Bishop’s method. The degeneration of safety factor follow to the moisture content was presented in the percentage.
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Gardner, R., S. Piazolo, and N. Daczko. "Pinch and swell structures: evidence for brittle-viscous behaviour in the middle crust." Solid Earth Discussions 7, no. 2 (April 24, 2015): 1517–54. http://dx.doi.org/10.5194/sed-7-1517-2015.
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Abstract. The flow properties of middle to lower crustal rocks are commonly represented by viscous flow. However, examples of pinch and swell structures found in a mid-crustal high strain zone at St. Anne Point (Fiordland, New Zealand) suggest pinch and swell structures are initiated by brittle failure of the more competent layer in conjunction with material softening. On this basis we develop a flexible numerical model using brittle-viscous flow where Mohr–Coulomb failure is utilised to initiate pinch and swell structure development. Results show that pinch and swell structures develop in a competent layer in both Newtonian and non-Newtonian flow provided the competent layer has enough viscosity contrast and initially fails brittlely. The degree of material softening after initial failure is shown to impact pinch and swell characteristics with high rates of material softening causing the formation of thick necks between swells by limiting the successful localisation of strain. The flow regime and yielding characteristics of the matrix do not impact pinch and swell structure formation itself, so long as the matrix is less competent. To aid analysis of the structures and help derive the flow properties of rocks in the field, we define three stages of pinch and swell development and offer suggestions for measurements to be made in the field. Our study suggests that Mohr–Coulomb behaviour combined with viscous flow is an appropriate way to represent the heterogeneous rocks of the middle to lower crust. This type of mid-crustal rheological behaviour has significant influence on the localization of strain at all scales. For example, inclusion of Mohr–Coulomb brittle failure with viscous flow in just some mid-crustal layers within a crustal scale model will result in strain localisation throughout the whole crustal section allowing the development of through-going high strain structures from the upper crust into the middle and lower crust. This localization then has a significant effect on developing near-surface structures.
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Li, Jing Long, Shu Cai Li, and Shu Chen Li. "The Applications of Concrete Cut-Off Wall in the Reinforcement of the Earth Dam." Advanced Materials Research 150-151 (October 2010): 749–52. http://dx.doi.org/10.4028/www.scientific.net/amr.150-151.749.
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The concrete cutoff wall is a technology used in reinforcing sick dams more usually in recent years. In the text, the advanced FLAC3D method which is based on 3-D explicit finite difference method, is used to simulate a reinforcement of earth dam using concrete cutoff wall. Through the simulation, Mohr-Coulomb model, elastic model and Goodman element are used to analyse the distribution of the stress and the strain of the dam before and after reinforcement. Consequently, we can evaluate the unti-seepaging effect and raise the possible question.
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Žemgulienė, Jolanta. "Relationship Between Job Satisfaction and Employee Behavioral Intention Toward Work Performance: Mediation Effect of Communication Content." Management of Organizations: Systematic Research 63 (2012): 139–57. http://dx.doi.org/10.7220/mosr.1392.1142.2012.63.10.
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Zheng, Yonglai, and Shuxin Deng. "Failure Probability Model considering the Effect of Intermediate Principal Stress on Rock Strength." Mathematical Problems in Engineering 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/960973.
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A failure probability model is developed to describe the effect of the intermediate principal stress on rock strength. Each shear plane in rock samples is considered as a micro-unit. The strengths of these micro-units are assumed to match Weibull distribution. The macro strength of rock sample is a synthetic consideration of all directions’ probabilities. New model reproduces the typical phenomenon of intermediate principal stress effect that occurs in some true triaxial experiments. Based on the new model, a strength criterion is proposed and it can be regarded as a modified Mohr-Coulomb criterion with a uniformity coefficient. New strength criterion can quantitatively reflect the intermediate principal stress effect on rock strength and matches previously published experimental results better than common strength criteria.
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Jamos, Abdullah M., Mark E. Chertoff, Wafaa A. Kaf, and John A. Ferraro. "Medial Olivocochlear Reflex Effect on Cochlear Response in Humans: Elicitor Side and Level." Journal of the American Academy of Audiology 32, no. 06 (June 2021): 366–73. http://dx.doi.org/10.1055/s-0041-1728649.
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Abstract Background Understanding the functional differences between crossed and uncrossed medial olivocochlear (MOC) neurons has been of interest to researchers for decades. Previous reports revealed conflicting results about which MOC pathway, crossed or uncrossed, is stronger in humans. Both crossed and uncrossed MOC neurons synapse at the base of the outer hair cells (OHCs) in each ear. OHCs generate the cochlear microphonic, which is a major contributor to the cochlear response (CR) Purpose The current study investigated the effects of eliciting the crossed and uncrossed MOC reflex (MOCR) on CR in humans with three levels of noise. Research Design Normal-hearing, young adults (n = 16) participated in this study. The CR was recorded using 500 Hz tone-burst stimuli presented at 80 dB nHL. To examine the crossed and uncrossed MOCR, CR was recorded without and with continuous ipsilateral or contralateral broadband noise (BBN) at three levels (40, 50, and 60 dB SPL). Data Analysis Analysis of the CR was completed using the amplitude of the response extracted using fast Fourier transform. Statistical analysis was completed using repeated measures analysis of variance and post-hoc analysis. Results Compared with baseline, the presentation of BBN, specifically contralaterally, resulted in CR enhancement with no significant difference as a function of the three BBN levels. Greater enhancement of the CR amplitude was observed with contralateral than ipsilateral BBN elicitor. Conclusions The current findings suggest that a contralateral elicitor of the uncrossed MOC pathway results in a larger CR amplitude enhancement compared with an ipsilateral elicitor of the crossed MOC pathway, regardless of the elicitor level. Eliciting the MOCR appears to modulate the OHCs function. Furthermore, assessing the MOCR with the 500 Hz CR with BBN elicitors at moderate levels should separate its effects (i.e., increase response amplitude) from those associated with the middle ear muscle reflex (i.e., reduce response amplitude).
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Wang, Tao, and Ren Wang Liang. "Simulating Effect of Anchor Cable Pre-Tension to Supporting Structure." Advanced Materials Research 788 (September 2013): 525–29. http://dx.doi.org/10.4028/www.scientific.net/amr.788.525.
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Since the pre-stressed anchor technology became to be used from the beginning of twentieth century, it is widely used with the advantages of its good applicability, high cost performance, good looking appearance and easy green. Pre-stressed anchor achieves the purpose of actively controlling foundation pit deformation by exerting pre-stress on steel strand of its free section. This thesis chooses deep foundation pit engineering, adopt Mohr-Coulomb ideal soil body by finite difference software FLAC3D, and select different anchor pre-tension values to simulate. It combines Lizheng software to do numerical simulation and analytic study on pile-anchor supporting structure. This thesis compares results coming from the two kinds of software, and analyze the impact on row piles' body bending moment, pile top deformation, anchor cable axial force and foundation pit deformation when pre-tension changes.
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Zhang, Yu, Jin Liu, Te-Jia Fan, Chen-Yang Xu, Tian-Yi Meng, Yang Zhao, and An Su. "Earth Pressure of Three-Dimensional Stress States under Different Strength Criteria and Its Application." Advances in Materials Science and Engineering 2021 (September 15, 2021): 1–11. http://dx.doi.org/10.1155/2021/6035564.
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To solve the Earth pressure problems in practical engineering, such as retaining walls and foundation pits, we derive active and passive Earth pressure formulas in accordance with the relationship between intermediate principal stress and excavation under three-dimensional stress states. The formulas are derived on the basis of the Mohr–Coulomb, spatially mobilized plane (SMP), σ 3 SMP, Lade–Duncan, axisymmetric compression- (AC-) SMP strength, and generalized Mises (Gen-Mises) criteria and then extended to clay. We also compare the calculated Earth pressure with the measured data. Results indicate that the Earth pressure considering medium principal stress contribution under a three-dimensional stress state is consistent with the actual engineering. The calculated active Earth pressure in the Mohr–Coulomb strength criterion is larger, and the passive Earth pressure is smaller than the practical one because the intermediate principal stress effect is not considered. The calculated results of the SMP, σ 3 SMP, Lade–Duncan, AC-SMP strength, and Gen-Mises criteria are close to the measured data, among which the result of the Gen-Mises criterion is closer. The Earth pressure calculated using the Lade–Duncan criterion is no longer appropriate to describe the Earth pressure under medium principal stress condition in this study. The results of this study have theoretical significance for retaining structure design under a three-dimensional stress state.