INFLUENCE OF ACOUSTIC PRESSURE WAVE ON THE MOVEMENT OF THE UNDERWATER

The forced movement of the submarine under the action of an acoustic pressure wave at rectilinear and uniform movement of the device is analyzed. The analysis of the dynamics of translational movement of the hull under the action of an acoustic pressure wave in an ideal environment, which makes it possible to assess the physical properties of the environment and the elastic properties of the outer hull on the value of the maximum movement of the submarine. It is proved that if the total pressure pulse is limited, then the water particles will receive certain displacements and it can be expected that under these conditions the displacement of the submarine will be determined. The results of the analysis make it possible to conduct a comparative analysis of the translational movement of the submarine under the action of an acoustic pressure wave, taking into account the characteristics of the moving medium, more precisely, taking into account the viscosity of the real medium

Analysis of the Reverse Expansion Process in a Reciprocating Hybrid Power Machine with Two Suction Valves

The paper analyzes the existing design schemes of hybrid power machines with a coolant moving in the jacket space due to the vacuum at the suction and introduces a new design of a single-stage single-cylinder piston hybrid power machine with two suction valves, in which the forced movement of the coolant in the forward direction is provided due to the vacuum at the suction, and in the reverse direction due to the pressure drop of the compressed gas. The analysis of the reverse expansion process allowed us to determine the value of the reduced dead space, which directly affects the volumetric feed rate of the reciprocating compressor and the feed rate in general. The parametric analysis made it possible to determine the influence of the main design and operating parameters on the value of the reduced dead space and accordingly on the volumetric feed rate. The results obtained can be useful in the design and research of reciprocating hybrid power machines with the forced movement of the coolant.

Toward an expanded approach on Black mobilities

Mobilities scholars have shown how injustices may arise from forced movement or stillness. However, with notable exceptions, these studies tend to collapse analyses of race into a simplistic binary of immobility as an inherent characteristic of non-white people and the possibility of movement as only granted to white people. In this article, I call for an expanded approach that is inclusive of both the controlling forces of white supremacy and life-affirming resistance against and despite these constraints. Drawing from Black studies and Black Geographies, I argue for a more unified Black mobilities research agenda.

Designation speed of movement by language units in Russian and Persian languages

В статье анализируются языковые единицы, обозначающие темп движения в русском и персидском языках. Информация о темпе присутствует у большинства глаголов со значением движения. Анализ показывает, что языковые единицы в явном или скрытом виде обозначают перемещение субъекта и объекта с нормальным, быстрым и медленным темпом. В семантике глаголов, обозначающих перемещение с нормальным темпом, выделяется информация о стандартном положении в пространстве, отсутствии или наличии средств перемещения, добровольном перемещении, характеристике шагов (размеренность, выделенность) и т.д. Глаголы, обозначающие перемещение с медленным темпом, передают информацию о перемещении с трудом, о физическом недостатке, перемещении относительно опоры и т.д. Глаголы, обозначающие быстрый темп движения, сообщают о перемещении в направлении удаления от субъекта и о среде перемещения, намерении попасть в цель, скорости, принудительном перемещении, о намеренном погружении в жидкость, о полном отрыве от поверхности двух ног одновременно и т.д. In this work, the linguistic units denoting the pace of movement in Russian and Persian languages are subject to analysis. Information on the pace of movement is present in most verbs denoting movement. The analysis shows that linguistic units in explicit or latent form indicate the movement of the subject and the object with a normal, fast and slow pace. In the semantics of the verbs denoting moving at a normal pace, information is highlighted about the standard position in space, the absence of means of movement, the availability of means of movement, voluntary movement, characteristic steps (dimensionality, emphasis), etc. Verbs indicating movement at a slow pace transmit information about movement with difficulty, physical disability, movement relative to a support, etc. Verbs indicating a fast pace of movement report movement in the direction of moving away from the subject and the environment of movement, the intention to hit the target, speed, forced movement, intentional immersion in a liquid, complete separation from the surface of two legs at the same time, etc.

Assata’s escape as disincarceral practice

Often carceral studies tends to focus on the prison as a mode of stationary confinement, sometimes forgetting that its rationales and practices are based crucially in movement. This is especially true for black populations disproportionately affected by mass incarceration and intentionally disoriented to the causes and manifestations of the oscillation to which they are reduced. This article is concerned with the carceral landscape that emerges in the criminalization of black people and politics through the legal concept of vagrancy, and how, in turn, black surreptitious movement is used to contest incarceration. To do so, it argues that vagrancy paraphrases a suppression of black political practice, focusing on political prisoner Assata Shakur’s transnational escape to Cuba and its discursive omission in her autobiography. In tracing the transience of Shakur, the article forwards vagrancy as an elaboration of how anti-blackness materializes via carceral geographies by way of displacement, disorientation, and forced movement. It presents a reformulation of Shakur’s escape as disincarceration, which takes seriously the flight toward black liberation as one that is still meaningfully incomplete, elaborating the significance of a continual absconding from the field of representation that has been controlled and constituted by discursive and material hegemonies of race.

Confined in Waiting: Young Asylum Seekers Narrating In and Out of Temporary Shelter

This research considers the waiting and confinement experienced by young asylum seekers during and after their stay at a temporary shelter in Finland. The data for this research consists of interviews and ethnographic ‘hanging out’ with nine young asylum seekers throughout their asylum process. In order to generate new knowledge about the situated and fluid experiences of young adult asylum seekers’ confinement, this article focuses on four in-depth interviews with two young men, Kokab and Mahammed. They arrived in Finland in 2015, and are, at the time of writing this article, still waiting for their final asylum decisions. The results show, first, that while the time in the temporary shelter resembles physical, punitive confinement, it is also experienced as warm and social time. Second, the article argues that the confinement of young asylum seekers extends beyond the physical confinement, as they are for years confined in forced movement, indefinite waiting and othered as a number in the system.

Creating “them” and “us”

Purpose The purpose of this paper is to examine how the contemporary “refugee crisis” is being presented to children through picture books and teaching materials. It uses the concept of refugeedom as an approach that takes into account the multiple facets involved in the forced movement of people in the past and present and seeks to show the value of historical understandings in educational contexts when framing resources for teachers and students. Design/methodology/approach The paper examines a sample of high-profile English language picture books about children’s stories of forced displacement and the most prominent freely available teaching materials connected to the books. A critical discursive analysis of the books and educative guides considers the ways in which ideas and information about forced displacement is framed for child readers and children in primary school classrooms. The context for the authors’ interest in exploring these books and educational resources is that in response to the numbers of children who are part of the current “refugee crisis” alongside a public call for the “crisis” to be explained to children. Findings The paper argues that picture books open up spaces for children to explore refugeedom through experiences of forced movement and various factors involved in the contemporary “refugee crisis”. In contrast, in the teaching resources and some peritextual materials, the child in the classroom is addressed as entirely disconnected from children who are forcibly displaced, students in classrooms are positioned to learn from the refugee “other”. When links are made between students in classroom and children who have been forcibly displaced it is through activities that position students in classrooms to imagine themselves as forcibly displaced, or to suggest they act within a humanitarian framework of welcoming or helping refugees. The authors believe that if teaching resources were more directly informed by discipline specific tools of historical concepts, more nuanced approaches to past and present histories of forced movement could be considered and from that more fruitful learning opportunities created for all students. Practical implications This research provides ideas about how materials to support the use of picture books in educational settings could be developed to promote historical thinking and contextualisation around key social and political issues in the world today. It also makes the case for historians to be involved in the creation of teaching materials in a collaborative way so that academic insights can be brought to teachers and students at all levels of education. Originality/value The value of this research is to understand how children are positioned in reading and learning about forced displacement and query the impact of decontextualised approaches to learning. It argues for the critical interpretative value that historical understanding can bring to present day issues which are history in the making.

Optogenetics enables real-time spatiotemporal control over spiral wave dynamics in an excitable cardiac system

Propagation of non-linear waves is key to the functioning of diverse biological systems. Such waves can organize into spirals, rotating around a core, whose properties determine the overall wave dynamics. Theoretically, manipulation of a spiral wave core should lead to full spatiotemporal control over its dynamics. However, this theory lacks supportive evidence (even at a conceptual level), making it thus a long-standing hypothesis. Here, we propose a new phenomenological concept that involves artificially dragging spiral waves by their cores, to prove the aforementioned hypothesis in silico, with subsequent in vitro validation in optogenetically modified monolayers of rat atrial cardiomyocytes. We thereby connect previously established, but unrelated concepts of spiral wave attraction, anchoring and unpinning to demonstrate that core manipulation, through controlled displacement of heterogeneities in excitable media, allows forced movement of spiral waves along pre-defined trajectories. Consequently, we impose real-time spatiotemporal control over spiral wave dynamics in a biological system.