• Geomechanics and Engineering
• /
• v.18 no.1
• /
• pp.21-27
• /
• 2019

Rockburst disasters pose serious threat to mining safety and underground excavation, especially in China, resulting in massive life-wealth loss and even compulsive closed-down of some coal mines. To investigate the mechanism of rockbursts that occur under a state of static forces, a stress model with sidewall as prototype was developed and verified by a group of laboratory experiments and numerical simulations. In this model, roadway sidewall was simplified as a square plate with axial compression and end (horizontal) restraints. The stress field was solved via the Airy stress function. To track the "closeness degree" of the stress state approaching the yield limit, an unbalanced force F was defined based on the Mohr-Coulomb yield criterion. The distribution of the unbalanced force in the plane model indicated that only the friction angle above a critical value could cause the first failure on the coal in the deeper of the sidewall, inducing the occurrence of rockbursts. The laboratory tests reproduced the rockburst process, which was similar to the prediction from the theoretical model, numerical simulation and some disaster scenes.

• The Journal of Industrial Distribution & Business
• /
• v.12 no.9
• /
• pp.31-42
• /
• 2021

Purpose: After the reform and opening up, China's overall economic development has entered a new era. From mutual investment and trade transactions between domestic provinces and regions to investment and trade with foreign companies, the continuous supplement of investment funds makes the follow-up development of all aspects of economic development smoother and has played a strong impetus. effect. Foreign direct investment has many influences on the economic development of a country or region. Research design, data and methodology: This article uses the sample data of Shandong Province from 2011 to 2019 to analyze the foreign direct investment in Shandong Province by industry, region, method and other aspects, and study the relationship and influence between foreign direct investment and economic growth. Results: The results show that there is a relatively close relationship between foreign direct investment and economic growth, and it has played a role in promoting economic development in many aspects such as industrial structure, foreign trade, and employment. Conclusions: At the same time, corresponding suggestions are put forward based on the analysis and conclusions drawn.

• Advances in nano research
• /
• v.13 no.1
• /
• pp.29-45
• /
• 2022

The optimization for dynamic response associated with a cylindrical shell which is made of laminated composites embedded in a piezoelectric layer which is subjected to temperature rises and is resting on an elastic foundation is investigated for the first time. The first shear order theory (FSDT) is utilized in order to obtain the strain relations of the shell. Then, using the energy method, the equations of motions as well as boundary condition of the problem are attained. The formulation of this study together with the solution procedure which is a numerical solution method, differential quadrature method (DQM) is validated using other researches. This paper presents a thorough study on the parameters which impacts the vibration frequency of the laminated shell. The results of this paper shows that any type of laminated composite shell can reduce the vibration frequency providing that the angle related to layer are higher than 85 degrees. Also, in order to reduce the effect of temperature rises, the laminated composites instead of orthotropic one can be used.

• East Asian Journal of Business Economics (EAJBE)
• /
• v.11 no.1
• /
• pp.1-19
• /
• 2023

Purpose - In this study, we aimed to theorize blockchain-based social media platform users' commitment by examining the impact of their perceived justice of the token reward system. In addition, this study applied psychological ownership theory to verify the underlying mechanism between users' perceptions of justice and their commitment to the platforms. Research design, data, and methodology - To empirically test our conceptual framework in the study, we collected data through a web-based survey approach from the responses of 385 users who had experience with blockchain-based social media platforms. We employed a structural equation modeling approach to empirically test our proposed hypotheses. Result - The results indicated that distributive justice and informational justice have positive effects on user commitment. The results also showed that psychological ownership plays an important role in mediating the relationship between users' sense of distributive justice and commitment, and between procedural justice and commitment. The findings provided a better understanding of the sense of justice and user commitment in a blockchain-based social media environment. Conclusion - This study represents a preliminary attempt to theorize and empirically examine blockchain-based social media platform users' commitment. This study provided important contributions to the literature on how the effect of users' sense of justice in a reward system affects their commitment to blockchain-based social media platforms.

• Advances in nano research
• /
• v.12 no.2
• /
• pp.167-183
• /
• 2022

In this paper, the free and forced vibration analysis of rotating cantilever nanoscale cylindrical beams and tubes is investigated under the external dynamic load to examine the nonlocal effect. A couple of nonlocal strain gradient theories with different beams and tubes theories, involving the Euler-Bernoulli, Timoshenko, Reddy beam theory along with the higher-order tube theory, are assumed to the mathematic model of governing equations employing the Hamilton principle in order to derive the nonlocal governing equations related to the local and accurate nonlocal boundary conditions. The two-dimensional functional graded material (2D-FGM), made by the axially functionally graded (AFG) in conjunction with the porosity distribution in the radial direction, is considered material modeling. Finally, the derived Partial Differential Equations (PDE) are solved via a couple of the generalized differential quadrature element methods (GDQEM) with the Newmark-beta techniques for the time-dependent results. It is indicated that the boundary conditions equations play a crucial task in responding to nonlocal effects for the cantilever structures.

• Food Science of Animal Resources
• /
• v.43 no.1
• /
• pp.10-24
• /
• 2023

In this study, a antioxidant activity peptide fraction was separated and purified from metabolites of whey protein fermented by Lactobacillus rhamnosus B2-1. The fermentation sample was separated by macroporous resin D101 and Sephadex G-15. The collected fractions were tested for antioxidant and antitumor activities. In order to test the antioxidant activity of fractions, Hydroxyl (·OH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and Oxygen Radical Absorbance Capacity (ORAC) were used. The final purified peptide B11 showed highest ABTS and ·OH radical scavenging rate by 84.36±1.89% and 62.43±2.64%, respectively, and had an ORAC activity of 1,726.44±2.76 μM Trolox equivalent/g. Further, the inhibitory effect of B11 on the proliferation of LoVo human colon cancer cells, KB and Cal-27 human oral cancer cells were enhanced with increasing concentrations of B11. B11 contains 51.421% amino acids, with Glu and Asp being the major constituents. In this study, we obtained peptide fraction B11 with antioxidant activity, which is promising for development.

• Journal of Ginseng Research
• /
• v.46 no.2
• /
• pp.315-319
• /
• 2022

• Advances in nano research
• /
• v.15 no.3
• /
• pp.225-237
• /
• 2023

Combination of novel technologies with traditional physiotherapy in rehabilitation in injured athletes have shown to provide improved time of recovery. In specific, nanodrugs delivery systems are widely utilized as a counterpart to the physiotherapy in injuries in sports. In the present study, we focus on the common injuries in dance-sports, their recovery and the effect combination of nano-particle drug delivery with the physiotherapy practices. In this regard, a comprehensive review on the common injuries in dance sport is provided. Moreover, the researches on the effectiveness of the nano-particle drug delivery in therapy of such injuries and in similar cases are provided. The possibility of using combination of nano-particle drug delivery and physiotherapy is discussed in detail. Finally, using artificial intelligence methods, predictions on the recovery time and after-treatment side-effects is investigated. Artificial Neural Network (ANN) predictions suggested that using nano-particle drug delivery systems along with physiotherapy practices could provide shortened treatment time to recovery in comparison to conventional drugs. Moreover, the post-recover effects are less than the conventional methods.

• Steel and Composite Structures
• /
• v.50 no.4
• /
• pp.403-418
• /
• 2024

In this paper, vibration and energy absorption characteristics of a nanostructure which is composed of two embedded porous annular/circular nanoplates coupled by a viscoelastic substrate are investigated. The modified couple stress theory (MCST) and the Gurtin-Murdoch theory are applied to take into account the size and the surface effects, respectively. Furthermore, the structural damping effect is probed by the Kelvin-Voigt model and the mathematical model of the problem is developed by a new hyperbolic higher order shear deformation theory. The differential quadrature method (DQM) is employed to obtain the out-of-phase and in-phase frequencies of the structure in order to predict the dynamic response of it. The acquired results reveal that the vibration and energy absorption of the system depends on some factors such as porosity, surface stress effects, material length scale parameter, damping and spring constants of the viscoelastic foundation as well as geometrical parameters of annular/circular nanoplates. A bird's-eye view of the findings in the research paper offers a comprehensive understanding of the vibrational behavior and energy absorption capabilities of annular/circular porous nanoplates. The multidisciplinary approach and the inclusion of porosity make this study valuable for the development of innovative materials and applications in the field of nanoscience and engineering.

• The korean journal of orthodontics
• /
• v.54 no.2
• /
• pp.108-116
• /
• 2024

Objective: A three-dimensional-printed individual titanium plate was applied for maxillary protraction to eliminate side effects and obtain the maximum skeletal effect. This study aimed to explore the stress distribution characteristics of sutures during maxillary protraction using individual titanium plates in various directions and locations. Methods: A protraction force of 500 g per side was applied at forward and downward angles between 0° and 60° with respect to the Frankfort horizontal plane, after which the titanium plate was moved 2 and 4 mm upward and downward, respectively. Changes in sutures with multiple protraction directions and various miniplate heights were quantified to analyze their impact on the maxillofacial bone. Results: Protraction angle of 0-30° with respect to the Frankfort horizontal plane exhibited a tendency for counterclockwise rotation in the maxilla. At a 40° protraction angle, translational motion was observed in the maxilla, whereas protraction angles of 50-60° tended to induce clockwise rotation in the maxilla. Enhanced protraction efficiency at the lower edge of the pyriform aperture was associated with increased height of individual titanium plates. Conclusions: Various protraction directions are suitable for patients with different types of vertical bone surfaces. Furthermore, when the titanium plate was positioned lower, the protraction force exhibited an increase.