Dispersion Dynamics of Clustered Particles by Centrifugal Force

In this paper an approach is proposed to solve the problem of aggregation in nanomaterials through the mean of rotational separation aiming to quickly disperse clustered nanoparticles while not affecting their purity. If it is possible, this approach may replace the current mean of mechanical mixing, which may cause impurities issues. The hypothesis is that the centrifugal force due to rotational velocity acting on the nanoparticles can overcome the cohesive force between the nanoparticles, therefore dispersing the clustered nanoparticles. The experimental mean is to put different spheres connected by different types of glues imitating different nanoparticle clusters into centrifuges imitating the swivel plate. The results from both the theoretical model and the experiment show that for a cluster with a cohesive force of 1.75N, a rotational velocity of about 800rad./s is required to disperse the cluster. While for a cluster with a cohesive force of 0.25N and the same mass and position, a rotational velocity of about 150 rad./s is required to disperse the cluster. Except for the cohesive force, the mass and position of the nanoparticle on the swivel plate also have a large effect on the required rotational velocity. The observation of the physical mechanism of the dispersion has also shown that while using this way, the cluster is dispersed slowly with small parts separated from it. Therefore, this way can also eliminate re-clustering problems of nanoparticles.

Experimental Study on the Mechanical Property of Loess Mixed with Bentonite-HDTMA

Malan loess in the middle and lower reaches of the Yellow River after mixed with different bentonite and HDTMA ratios was selected to carry out shear and consolidation tests for discussing the influence of bentonite-HDTMA on the mechanical property of loess lining material in landfills. Studies have shown that, after mixing 6% to 14% bentonite, the cohesive force of modified loess is significantly increased, the friction angle is reduced and remains stable, and the shear strength is improved. The compressibility of materials slightly decreases with the increase of bentonite ratio. The addition of 2%–4% HDTMA weakens the increment for the cohesive force caused by bentonite, but the friction angle is effectively recovered. The compressibility of materials increases with the increase of HDTMA ratio. As the dry density increases, the shear strength of the modified loess increases, and the compressibility coefficient decreases. The mechanical property of loess lining material can be optimized by adding 6%–14% bentonite. The incorporation of 2%–4% HDTMA does not have a significant negative impact on the optimization effect of bentonite. From the perspective of the mechanical property, it is recommended that the dry density of modified loess is 1.70 g/cm3, the bentonite ratio is 10%–14%, and the HDTMA ratio is 2%–4%.

Research on Bonding Performance of Anchorage Caisson Foundation with Different Contact Surfaces and Grouting Bed

In view of the first domestic offshore suspension bridge with caisson foundation, this paper mainly studies the bonding properties between underwater pre-filled aggregate grouting bed and anchorage caisson foundation. Through the test, the cohesive force of adding ordinary concrete between the anchorage caisson foundation and the grouting bed, the cohesive force of adding paper base asphalt felt between the anchorage caisson foundation and the grouting bed, and the cohesive force of adding geotextile between the anchorage caisson foundation and the grouting bed are measured, respectively. When the contact surface is concrete and geotextile, the fracture form of the specimen was analyzed by numerical simulation, and the AE variation trend of the two specimens have been studied. The results of this article can provide references for other projects.

Numerical Simulation Study on Compression Characteristics of Gravelly Soil Mixture Based on Soft Servo Method

Because of complex mechanical properties and deformation mechanism, gravel soil mixture is an important medium of concern in the field of geotechnical engineering. Based on the continuous-discontinuous coupling algorithm formed by the structure shell elements and the particle discrete element method (PFC3D), the soft servo loading of the sample is realized, and the typical triaxial compression test data are used to calibrate mesoscale parameters. Furthermore, the numerical tests under different rock contents and confining pressure are carried out. The change rule of shear strength of mixed medium is discussed. It shows that the continuous-discontinuous coupling algorithm achieves a good effect in reflecting the deformation process. Under the mechanism of the flexible servo, the failure mode of the sample takes on drum-failure mode, and the internal of the damaged sample forms an obvious asymmetric X-shaped shear band. With the increase of stone content, the internal friction angle and cohesive force distribution of the sample have certain discreteness, but on the whole, the internal friction angle and cohesive force increase with the increase of stone content. The results can provide a reference for the parameter determination of mixed mediums such as gravel soil.

Cultural Diversity in Igbo Life: A Postcolonial Response to Chinua Achebe’s Arrow of God

In his book Chinua Achebe, David Caroll (1980) describes the novel Arrow of God as a fight for dominance both on the theological and political level, as well as in the framework of Igbo philosophy. In Critical Perspectives on Chinua Achebe (1990), famous Achebe critics C. L. Innes and Berth Lindforts consider Arrow of God as a novel with conflicting ideas and voices inside each community with the tensions and rivalries that make it alive and vital. Another profound scholar on Achebe Chinwe Christiana Okechukwu (2001) in Achebe the Orator: The Art of Persuasion in Chinua Achebe's Novels assesses Arrow of God, which depicts a community under imminent danger of cultural genocide unleashed by agents of Western imperialism who have recently arrived in the indigenous society. However, the author in this study attempts to see Arrow of God as a postcolonial response to cultural diversity that upholds its uniting and cohesive force in Nigerian Igbo life. The goal is to look at how Achebe, in response to misleading western discourses, develops a simplistic image and appreciation that persists in Igbo life and culture even as colonization takes hold. This paper also exhibits how the Igbo people share their hardships, uphold their age-old ideals, celebrate festivals, and even battle on disagreements. This study employs postcolonial theory to reconsider aspects of cultural diversity among the African Igbo people, which are threatened by the intervention of European colonialism in the name of religion, progress, and civilization.

German Musical Baroque, a mini European Union avant la lettre: the bassoon concerto

The German musical Baroque represents a sum of stylistic diversities, in which the European cultural values were merged with the national ones, resulting in a strongly individualized, but malleable style. The works dedicated to the bassoon by German composers are living evidence of aesthetic unity in the Baroque stylistic diversity, emphasizing the universality of music and its cohesive force. The analyzed concertos approach the aesthetics of each composer, through his relationship with Italian and French music, personalized in an expressive form of the German type: robust, in a clear, dynamic solid structure.

Study on the Mechanical Effect and Constitutive Model of Montmorillonite under the Action of Acid Rain: A Case Study on Montmorillonite-Quartz Remolded Soil

Clay minerals are the common insoluble cementing substances in soil. To study the mechanical effect of montmorillonite under the action of acid rain, the variation law and mechanism of the cohesive force and internal friction angle were discussed by immersing montmorillonite-quartz remolded soil in HNO3 solution with pH = 3. It was found that, under acidic conditions, the cohesive force increased after the first drop and subsequently decreased again, while the internal friction angle remained basically unchanged. Considering the vertical pressure of soil landslide, the change in the shear strength of cohesive soil under acid rain is consistent with the change in the cohesive force. The X-ray diffraction (XRD) results showed that the acid could erode the cement-montmorillonite, and no new substance was generated, which caused a decrease in cohesion. In addition, based on the microcementation nature of montmorillonite and the change mechanism of cohesion under acid rain, the cohesive force model of saturated montmorillonite-quartz remolded soil under acid rain was established. The change trend of calculated cohesion values was consistent with the one of measured values, and the error was small.