322 research outputs found
A theoretical framework for steady-state rheometry in generic flow conditions
No full textWe introduce a general decomposition of the stress tensor for incompressible fluids in terms of its components on a tensorial basis adapted to the local flow conditions, which include extensional flows, simple shear flows, and any type of mixed flows. Such a basis is determined solely by the symmetric part of the velocity gradient and allows for a straightforward interpretation of the non-Newtonian response in any local flow conditions. In steady homogeneous flows, the material functions that represent the components of the stress on the adapted basis generalize and complete the classical set of viscometric functions used to characterize the response in simple shear flows. Such a general decomposition of the stress is effective in coherently organizing and interpreting rheological data from laboratory measurements and computational studies in nonviscometric steady flows of great importance for practical applications. The decomposition of the stress in terms with clearly distinct roles is also useful in developing constitutive models.journal articl
Shear Jamming and Fragility of Suspensions in a Continuum Model with Elastic Constraints
No full textUnder an applied traction, highly concentrated suspensions of solid particles in fluids can turn from a state in which they flow to a state in which they counteract the traction as an elastic solid: a shear-jammed state. Remarkably, the suspension can turn back to the flowing state simply by inverting the traction. A tensorial model is presented and tested in paradigmatic cases. We show that, to reproduce the phenomenology of shear jamming in generic geometries, it is necessary to link this effect to the elastic response supported by the suspension microstructure rather than to a divergence of the viscosity
Microstructure and thickening of dense suspensions under extensional and shear flows
No full textDense suspensions are non-Newtonian fluids that exhibit strong shear thickening and normal stress differences. Using numerical simulation of extensional and shear flows, we investigate how rheological properties are determined by the microstructure that is built under flows and by the interactions between particles. By imposing extensional and shear flows, we can assess the degree of flow-type dependence in regimes below and above thickening. Even when the flow-type dependence is hindered, non-dissipative responses, such as normal stress differences, are present and characterise the non-Newtonian behaviour of dense suspensions
Predictions of microstructure and stress in planar extensional flows of a dense viscous suspension
No full textWe consider extensional flows of a dense layer of spheres in a viscous fluid and employ force and torque balances to determine the trajectory of particle pairs that contribute to the stress. In doing this, we use Stokesian dynamics simulations to guide the choice of the near-contacting pairs that follow such a trajectory. We specify the boundary conditions on the representative trajectory, and determine the distribution of particles along it and how the stress depends on the microstructure and strain rate. We test the resulting predictions using the numerical simulations. Also, we show that the relation between the tensors of stress and strain rate involves the second and fourth moments of the particle distribution function
Normal stress differences in dense suspensions
No full textThe presence and the microscopic origin of normal stress differences in dense suspensions under simple shear flows are investigated by means of inertialess particle dynamics simulations, taking into account hydrodynamic lubrication and frictional contact forces. The synergic action of hydrodynamic and contact forces between the suspended particles is found to be the origin of negative contributions to the first normal stress difference , whereas positive values of observed at higher volume fractions near jamming are due to effects that cannot be accounted for in the hard-sphere limit. Furthermore, we found that the stress anisotropy induced by the planarity of the simple shear flow vanishes as the volume fraction approaches the jamming point for frictionless particles, while it remains finite for the case of frictional particles
Designs on “Old Seto” Porcelain
No full textIt is widely known that the porcelain ware called Ko (Old) Seto, produced in the Seto area around the thirteenth and fourteenth centuries, shows the influence of Sung China in its shapes and designs. It has not been studied thoroughly, however, how the Chinese inspiration was accepted. Believing that such studies will be valuable, the author has made some researches on the subject. The existing pieces of the Old Seto ware are numerous, and ornamental designs on them cover a wide variety. The author chose, as the basis of his researches, jars and vases which are believed to be genuine and typical, and studied designs which appear frequently on these.
As space does not allow discussions on all individual pieces, the author herein reports only the results of his researches. Designs on them include those imitating ornaments of Chinese Lung-ch‘üan celadon and Ching-tê-chên pale-white porcelain (ying-ching) of the Southern Sung period, and of the Korean Kōrai (Koryo) celadon ; Chinese- and Korean-style ones to which Japanese-style motifs are added, or which are modified into Japanese style, and those consisting of Japnese-style motifs only. Through these designs the author found that they attest to considerably creative, original ideas of Seto potters.
It is evident that the Old Seto pieces were made during the last part of the Kamakura Period, but the chronological order of individual specimens is hard to tell ; it is therefore impossible exactly to describe how these designs developed. Nevertheless they are very significant from the viewpoint of designs in Japanese ceramics, and in Japanese handicrafts in general.
Pre-historic and proto-historic earthenwares are left out here. There are a few examples of Heian Period pottery which have ornaments in line-engraving, but the Old Seto ware has no ornaments either similar to or apparently derived from them. Furthermore, pottery pieces with decorative patterns prior to the Kamakura Period are mostly in shapes imitating those of metal objects, and their patterns, also following metal examples, are hardly ones peculiar to pottery. Designs on the Old Seto ware, however, are desings characteristic of ceramics, and are diferent in character from earlier ones. It cannot be denied that the tradition of the Sué Type Pottery of the Heian Period carried on partly into the Old Seto, but in decorative designs the Old Seto potters, instead of following old tradition, chose imported continental-style ornaments which they improved with their original ideas and which were laden with the vigorous spirit of the Kamakura Period of the warriors' rule. It is notable, too, that designs on the Old Seto ware are the first examples of pottery designs in the true sense of the term in Japan.
Comparison of Old Seto ornaments with designs in other fields of decorative arts is interesting. In lacquer art, the Kamakura-bori imitated the effect of the Chinese carved lacquer just as the Old Seto copied continental designs, but it did not achieve notable development. Designs in maki-e lacquer and in metalwork were traditional cnes flavoured with the taste of the time. Those on mirror-backs also adhered to tradition, though only a very few of them imitated Chinese Han-style mirrors of the Sung Dynasty. The novel designs in Old Seto discussed above are remarkable achievements of the then newly-risen ceramic industry in the Seto area.journal articl
Navigating Digital Borders: Seto Community in the Virtual Territory of the VK Social Network
No full textReceived 30 September 2024. Accepted 5 March 2025. Published online 30 April 2025.The paper examines the digital geography of the virtual Seto community in the VK social network (also known as VKontakte), focusing on how dispersed Seto people in Russia and Estonia use digital spaces to communicate, as well as express, preserve, and promote their cultural identity. By applying a multi-sited ethnographic methodology, the research involves both online explorations and offline semi-structured interviews, with fieldwork conducted in the Pechory District. Using the network and territory approaches to digital ethnography, the study highlights how the VK serves as a digital territory where Setos, divided by distances and physical borders, connect, share cultural practices, and foster a sense of community. Special attention is given to the Seto traditions of leelo polyphonic singing and festive costumes, both of which serve as vital markers of ethnic identity in this digital landscape. Through content analysis of Seto personal profiles and public pages, the research reveals how social networks help maintain connections and how digital geographies are constantly shaped and reshaped by cultural exchanges. This study underscores the adaptability of online spaces in sustaining fragmented ethnic communities across physical distances.This work was supported by the Russian Science Foundation under Grant 23-78-10079, https://rscf.ru/project/23-78-10079/The author is grateful to the assistance of the Museum Reserve Izborsk, Manor Museum of the Seto people in the village of Sigovo, Pechory Museum of History, and the “Flax Province” Museum. The author is also highly appreciative of the valuable consultations and recommendations provided by Elena Variksoo, Tatiana Ogareva, Mare Piho, Malle Bogacheva, and Vera Fest
The experimental realism of William Dean Howells
No full textThe “experimental” in my title refers to Howells’s self-conscious development of a literary form that could give the most complete, deepest account of a reality characterized by the ordinary and even the banal. For the middle class, Howells’s perennial subject, the norm is to aspire to transcend, and the ordinary can appear elusive, even nonexistent. Of course, in political terms, a middle class culture considers everyone basically the same, this resemblance defining the ordinary. It is assumed that everyone shares the same economic goals, and the same desire for familial and individual success. Being ordinary is therefore a moral quality. This means, paradoxically, that ordinariness can only prove itself in exceptional individuals. To strive is virtuous, to fail is shameful; either way one’s ordinariness is subsumed to a greater drama. The drama at the center of middle class art is the plight of the exceptional individual demonstrating a Platonic ordinariness. It is hard to think of characters in novels who are not exceptional financially or morally. In Henry James’s The Portrait of a Lady and The Wings of the Dove finance and morality go together. The novels of Eliot, Dickens, even those of the French realists unfold stories in which ordinary characters, by some exceptional moral quality, try to transcend their economic and historical situations. Howells called this story romantic and insisted on writing about the most mundane aspects of ordinary life. His novels were not about the exceptional who rise above the crowd but about ordinary people who do not transcend but stay on the ground. Howells described this divide between moral ideals and actual economic circumstance as “the infernal juggle of the mind. ” This contradiction at the heart of everyday life was what he wanted to depict. His design of characters and plots, even his sentences, develop continuously into further complexity as they discover the tensions and self-betrayal inherent in middle class optimism. “Discover” is the key term: Howells wrote in order to find out the truth about ordinary life, and the more he discovered the more his novels tended toward disjunction. In resisting the urge to reaffirm middle class morals, he was having not only a political argument with the dominant ideology of late-nineteenth century America but a formal argument with the conventional novel. Down the critical years, Howells’s trust in the novel form to do its own work has been difficult to see because his way of demonstrating it was so unusual. To the extent that his form was un-transcendent, descriptive rather than theoretical, it has been unapparent. My dissertation is an attempt to make evident and describe the working of Howells’s unapparent form. I have used a method of analysis congruent with his practice. I proceed as he wrote, historically, by following the unfolding events of his style and form.Ph.D.Includes bibliographical referencesIncludes vitaby Brian Seto McGrat
Nuchequula nuchalis
No full textNuchequula nuchalis (Temminck & Schlegel, 1845): Figure 3E, F Equula nuchalis Temminck and Schlegel 1845: 126. Leiognathus nuchalis — Eguchi et al. 2008: 19. Nuchequula nuchalis — Chakrabarty and Sparks 2007: 18; Kimura et al. 2008b: 22; Senou 2013: 902; Fujiwara and Motomura 2016: 197. Diagnosis. This species is characterized by the following combination of characters: mouth protruding downwards; small slender teeth on both jaws; anterior dorsolateral surface of body completely naked; black blotch on nape (Senou 2013). Distribution. Nuchequula nuchalis is known from Japan, the western and southern coasts of Korean Peninsula, Taiwan, and the coast of China. In Japanese waters, this species is known from the western coast of Aomori Prefecture to the southern part of the western coast of Kyushu (Sea of Japan coast), the eastern coast of Aomori Prefecture to the southern part of eastern coast of Kyushu, Seto Inland Sea, and Okinawa Island (Pacific coast) (Senou 2013). Remarks. The record of Nuchequula nuchalis in this study is based on 8 specimens (40.8–116.4 mm SL) from Kadogawa Bay in November and December. However, this species is caught frequently with shallow set nets (<10 m depth) for commercial purposes in the bay (author. Wada, pers. comm.). In addition, our survey did not record this species with the other deeper set nets, although we collected it from estuaries in Miyazaki Prefecture out of the survey period (KPM-NI 41550–41553, Kita-gawa river, northern part of Miyazaki Prefecture; KPM-NI 41888–41891, Hitotsuse-gawa river and Tondahama Lagoon, central Miyazaki Prefecture). These records indicate that N. nuchalis inhabits estuaries and shallow areas of the coasts of Miyazaki Prefecture.Published as part of Miki, Ryohei, Murase, Atsunobu & Wada, Masaaki, 2018, A checklist of ponyfishes (Teleostei, Leiognathidae) from Miyazaki Prefecture, east coast of Kyushu, southern Japan, with range extensions of three tropical species, pp. 243-255 in Check List 14 (1) on page 249, DOI: 10.15560/14.1.24
Chemical composition of pond waters on the ilands located in the Seto Inland Sea
No full textFreshwater ponds are found on a number of islands located in the Seto Inland Sea. The author made observation of the chemical properties of pond water at some of the ponds located on the islands in the western part of the Seto Inland Sea. The primary purpose of this survey was to know the effect of the "sea breeze" from the chlorine contents of pond water. Some of the surveyed ponds were utilized for irrigation. Almost all the surveyed ponds were relatively shallow, and dissolved oxygen was poor in the bottom layer. Chlorine contents were considerably lower than expected. Other chemical compositions and their contents in each pond were not extraordinary; they were of the same order as the average values reported by Dr. S. YOSHIMURA for the lake waters of Japan. The results of the observation and water analysis are shown in Table I.
It seemed that all the surveyed ponds could be utilized for the culture of freshwater fishes
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