Academic literature on the topic 'Contact between a shell and a round plate'

In the bodies of cylindrical apparatuses that operate under pressure, one of the weak elements is a flat bottom whose thickness is increased by 4…5 times in comparison with the wall thickness. This is due to the fact that the bottom is exposed to a more unfavorable bending deformation compared to the wall that «works» on stretching. In order to reduce specific metal consumption for the bottom, we propose the optimization of the shape of a radial cross-section by a rational redistribution of the material: to increase thickness of the bottom in the region of its contact with the wall and to significantly reduce it in the central zone. To describe a variable thickness of the bottom, we applied the Gauss equation with an arbitrary parameter that determines the intensity of change in the thickness in radial direction. We have obtained a general solution to the differential equation of the problem on bending a bottom at a given law of change in its thickness, which is represented using the hypergeometric Kummer’s functions. A technique for concretizing the resulting solution was proposed and implemented, based on the application of conditions of contact between a cylindrical shell and a bottom. The solution derived was used to minimize the mass of the bottom. We have designed a zone of transition from the bottom to the wall whose strength was verified by the method of finite elements under actual conditions

Background. Rhinosinusitis, affecting both maxillary and other sinuses, is a multidisciplinary issue which otolaryngologists, dentists, neurologists and ophthalmologists are constantly dealing with. There is a remarkable diagnostic value of anthropometric indicators of maxillary sinuses of people of different genders, using CT scan images of mature age patients. Purpose – establish a relationship between the shape of the maxillary sinuses and possible contacts of the tooth roots of the maxillary dental arch in healthy mature men and women. Materials and methods. The study was performed based on the results of 102 CBCT with normal maxillary sinuses variations in adults in the frontal and sagittal plane. The examinations were performed on Point 3D Combi 500 cone-beam tomograph. The paper belongs to the «description of case series» category whis is a type of study recognized by evidence based medicine and does not claim statistical significance of the results. Results and discussion. When examining the computer tomograms of men and women in the study group, it has been found out how the shape of the maxillary sinuses (MS) affects the contact of the tooth roots with the cortical plate and the mucous membrane of the maxillary sinuses. Six main shapes of the MS are defined: trapezoidal, square, round, oval, rectangular and triangular. In the frontal plane of CBCT, the most frequent contact with the MS cortical plate is observed in the triangular and rectangular shape of the MS, that is: in the MS rectangular shape it is in contact with the 15th, 25th tooth root in 13 people (56.5% of cases) and in the triangular shape – with the 15th, 25th tooth root in 17 people (56.5% of cases). Analyzing CBCT in the sagittal plane, the most frequent contact with the cortical plate of the left MS is observed in the MS triangular shape, namely – the sinus is in contact with the 25th tooth root in 38 people (59.4% of cases). In the sagittal plane of CBCT, the contact with the tooth roots was rarely observed in the MS square and round shape. In the MS square shape, the 13th and 14th tooth roots do not come into contact with its cortical plate, and, with the mucous membrane, there is no contact of all the roots of the teeth except the 16th, in 1 person only. Conclusions. The results of the study have made it possible to trace a number of patterns of influence of the maxillary sinus shape on the tooth roots contacting it. The contact of the MS cortical plate is most often observed with 16th and 26th tooth roots, while the MS mucous membrane – with 17th and 27th tooth roots of the upper jaw. It was found that in any shape of sinus in the frontal plane, no contact of the 13th, 23rd and 24th tooth roots of the maxillary dental arch with the mucous membrane of the maxillary sinus was detected. In the CBCT frontal plane, it has been found that the most frequent contact with the MS cortical plate is observed in triangular, trapezoidal and rectangular form of the MS, and the rarest one – in oval, square and round form of MS. The study has established that in the sagittal plane of CBCT the most frequent contact with the MS cortical plate is observed in the MS triangular shape, and the rarest – in the round one.

The study introduces a concept of contact stress analysis to the local stress calculation of plate and shell structures in pressure vessels. A new computational method for local stresses is proposed in the light of the contact between pad and shell and the compatibility at the pad edges due to the fillet weld. Using the developed program of the contact stress analysis of plates and shells, which is based on the flexibility mixed FEM, the authors have studied the contact stresses of a saddle support model and local stresses of a suspended tower structure which cannot be achieved with old methods. The theoretical calculations coincide well with the experimental results.

The article presents the results of a study of the contact zone of a thin-walled cylindrical shell located between two parallel rigid plates. The shell under consideration was located with various gaps from the rigid plate and was subsequently subjected to internal pressure. In the course of such a study, experimental, numerical and analytical estimates of the contact zone width were obtained depending on the discharge pressure. The obtained numerical and analytical estimates are tested with experiment. To study the width of the contact zone, depending on the gap, a testing workbench was used. The problem of numerical and analytical modelling was solved by the finite element analysis in the Ansys Workbench system. The solution to transcendental equation was found numerically using the Newton-Raphson method. As a result of experimental, numerical and analytical studies, results were obtained for a plane-oval shell with gaps of 0.5 mm, 1 mm and 2 mm, depending on the applied pressure.

The profitability of walnut cultivation and processing was investigated in the paper, both on small farms and large agricultural enterprises. The demand for walnuts in Ukraine and abroad was investigated. Theoretical studies of the dynamics of nut crop growth in the territory of our country were conducted. The tendency to increase domestic production of walnuts in the future is established. Among the most important areas of the organization of the process of purification of this raw material is noted the process of chopping (crushing) of its shell. Applying a constructive implementation of a vibrating machine «GMK-350» for the process of mechanical cleavage of the shell of a walnut were carried out studies of the influence of the working body (plate and spherical insert) on the technological and energy parameters of the process taking into account the quality of the processed product (the integrity of the core). The article analyzes the process of shelling of walnuts between the plate and the spherical insert. Graphical correlations between the size of the shell deformation and the dynamics of change of the driving force of change at different nut humidity and shell thickness are analyzed. The scheme of driving forces in the area of contact between the nut and the ring is drawn up and analyzed. The graphical dependences of the maximum crushing force on the bevel of the rings according to different shell thickness are presented; variations of the maximum crushing force depending on the humidity of the nuts for different thicknesses of the nut shell. It is established that, theoretically, the coefficient of friction increases as the angle of inclination of the ring increases. It is established that the crushing force of a walnut shell depends less on the friction coefficient and more on the contact surface.

Abstract. On the basis of the nonlinear plate-shell and piezoelectric theory, the governing equations of motion for axisymmetrical piezoelectric delaminated cylindrical shell under hygrothermal conditions were derived. The governing equation of transverse motion was modified by contact force and thus the penetration between two delaminated layers could be avoided. The whole problem was resolved by using the finite difference method. In calculation examples, the effects of delamination length, depth and amplitude of load on the nonlinear dynamic response of the axisymmetrical piezoelectric delaminated shell under hygrothermal conditions were discussed in detail.

Abstract: Heat transfer is one of the most important processes in many industries. For this a heat exchanger is used. There are many different types of heat exchanger available that are double tube heat exchanger, Shell and Tube heat exchanger, tube in tube heat exchanger, Plate heat exchanger, Finned heat exchanger etc. In heat exchanger a fluid is used to cool another fluid which is a higher temperature, this is done either with direct contact between the fluids or indirect contact between the fluids with a surface in between. Most common type of heat exchanger used in industries is Shell and Tube heat exchanger due to its dimension flexibility which is it dose not have any dimension limit to it. As most of the Shell and Tube heat exchanger in the industries are of long lengths and also they are equipped with only single pass of the tube and with either parallel flow or counter flow. They are also equipped with different types of baffle plate at different angles and placing. In this project we have done construction and performance on Shell and Tube heat exchanger which is made in compact size and which is also equipped with parallel flow and counter flow. We have given multiple passing of the tube throughout the shell which results in better cooling of water. The cooling medium used in this project is water at normal room temperature. Because of the compact size of this heat exchanger it can be used in small spaces with availability of water like in small scale industries. Keywords: Shell and tube heat exchanger, heat transfer, multiple pass, compact size, rotameter, valves

A numerical simulation model of heat flux sensors embedded in a flat plate is established. Each sensor has four thermal couples and is inserted into the specified hole. The problem is defined as a steady heat conduction problem with specified boundary conditions and solved by the finite element method. The results of the simulation case demonstrate that the maximum heat flux appears near the sensor shell. The average heat flux of the plate is much smaller than the maximum. Due to exiting of the contact heat resistance, the temperature of the sensor is much lower than that of the plate at horizontal surface. The maximum temperature difference appears on the bottom shell of the sensor. The maximum temperature difference between the simulation results and the experimental data at test points is 1.5 K. The model is verified and could be accepted for the further errors analysis.

Abstract With the development trend of automobile lightweight, the continuous casting process of automobile slab is more and more demanding. In this paper, the stress conditions and boundary conditions in the deoxidizer of the continuous casting process were analyzed, and a contact mechanics model was established between the cast slab and the copper plate. The deformation laws of the slab shell under different amplitude and frequency were simulated and analyzed, and the amplitude and frequency parameters that minimize the impact of slag marks on the slab shell were determined, providing a basis for selecting reasonable vibration parameters.

This book offers a comprehensive analysis of the evolution and development of arms control processes as an integral part of the Pakistan-India grand dialogue, which took place from 1988 to 2008 and it examines the larger political context and its impact on arms control processes. Nasir Mehmood prioritizes four types of political conflicts: Jammu and Kashmir, hostile domestic politics, dissimilar military doctrines, and China as a third party. Mehmood determines their connection and function in restricting arms control during three major rounds of broader security dialogue between Pakistan and India (1988-1994, 1997-1999, and 2004-2008). Through these major rounds of dialogue there are patterns of interaction within and across three sub-cases. This volume, which offers a systematic survey of bilateral arms control processes within the local settings and includes critical theoretical and policy insights, shall be of interest to students and scholars interested in security studies and international relations theory, with a focus on the strategic horizon of South Asia.

Nationalism: Past as Prologue began as a single volume being compiled by Ad Akande, a scholar from South Africa, who proposed it to me as co-author about two years ago. The original idea was to examine how the damaging roots of nationalism have been corroding political systems around the world, and creating dangerous obstacles for necessary international cooperation. Since I (Bruce E. Johansen) has written profusely about climate change (global warming, a.k.a. infrared forcing), I suggested a concerted effort in that direction. This is a worldwide existential threat that affects every living thing on Earth. It often compounds upon itself, so delays in reducing emissions of fossil fuels are shortening the amount of time remaining to eliminate the use of fossil fuels to preserve a livable planet. Nationalism often impedes solutions to this problem (among many others), as nations place their singular needs above the common good. Our initial proposal got around, and abstracts on many subjects arrived. Within a few weeks, we had enough good material for a 100,000-word book. The book then fattened to two moderate volumes and then to four two very hefty tomes. We tried several different titles as good submissions swelled. We also discovered that our best contributors were experts in their fields, which ranged the world. We settled on three stand-alone books:” 1/ nationalism and racial justice. Our first volume grew as the growth of Black Lives Matter following the brutal killing of George Floyd ignited protests over police brutality and other issues during 2020, following the police assassination of Floyd in Minneapolis. It is estimated that more people took part in protests of police brutality during the summer of 2020 than any other series of marches in United States history. This includes upheavals during the 1960s over racial issues and against the war in Southeast Asia (notably Vietnam). We choose a volume on racism because it is one of nationalism’s main motive forces. This volume provides a worldwide array of work on nationalism’s growth in various countries, usually by authors residing in them, or in the United States with ethnic ties to the nation being examined, often recent immigrants to the United States from them. Our roster of contributors comprises a small United Nations of insightful, well-written research and commentary from Indonesia, New Zealand, Australia, China, India, South Africa, France, Portugal, Estonia, Hungary, Russia, Poland, Kazakhstan, Georgia, and the United States. Volume 2 (this one) describes and analyzes nationalism, by country, around the world, except for the United States; and 3/material directly related to President Donald Trump, and the United States. The first volume is under consideration at the Texas A & M University Press. The other two are under contract to Nova Science Publishers (which includes social sciences). These three volumes may be used individually or as a set. Environmental material is taken up in appropriate places in each of the three books. * * * * * What became the United States of America has been strongly nationalist since the English of present-day Massachusetts and Jamestown first hit North America’s eastern shores. The country propelled itself across North America with the self-serving ideology of “manifest destiny” for four centuries before Donald Trump came along. Anyone who believes that a Trumpian affection for deportation of “illegals” is a new thing ought to take a look at immigration and deportation statistics in Adam Goodman’s The Deportation Machine: America’s Long History of Deporting Immigrants (Princeton University Press, 2020). Between 1920 and 2018, the United States deported 56.3 million people, compared with 51.7 million who were granted legal immigration status during the same dates. Nearly nine of ten deportees were Mexican (Nolan, 2020, 83). This kind of nationalism, has become an assassin of democracy as well as an impediment to solving global problems. Paul Krugman wrote in the New York Times (2019:A-25): that “In their 2018 book, How Democracies Die, the political scientists Steven Levitsky and Daniel Ziblatt documented how this process has played out in many countries, from Vladimir Putin’s Russia, to Recep Erdogan’s Turkey, to Viktor Orban’s Hungary. Add to these India’s Narendra Modi, China’s Xi Jinping, and the United States’ Donald Trump, among others. Bit by bit, the guardrails of democracy have been torn down, as institutions meant to serve the public became tools of ruling parties and self-serving ideologies, weaponized to punish and intimidate opposition parties’ opponents. On paper, these countries are still democracies; in practice, they have become one-party regimes….And it’s happening here [the United States] as we speak. If you are not worried about the future of American democracy, you aren’t paying attention” (Krugmam, 2019, A-25). We are reminded continuously that the late Carl Sagan, one of our most insightful scientific public intellectuals, had an interesting theory about highly developed civilizations. Given the number of stars and planets that must exist in the vast reaches of the universe, he said, there must be other highly developed and organized forms of life. Distance may keep us from making physical contact, but Sagan said that another reason we may never be on speaking terms with another intelligent race is (judging from our own example) could be their penchant for destroying themselves in relatively short order after reaching technological complexity. This book’s chapters, introduction, and conclusion examine the worldwide rise of partisan nationalism and the damage it has wrought on the worldwide pursuit of solutions for issues requiring worldwide scope, such scientific co-operation public health and others, mixing analysis of both. We use both historical description and analysis. This analysis concludes with a description of why we must avoid the isolating nature of nationalism that isolates people and encourages separation if we are to deal with issues of world-wide concern, and to maintain a sustainable, survivable Earth, placing the dominant political movement of our time against the Earth’s existential crises. Our contributors, all experts in their fields, each have assumed responsibility for a country, or two if they are related. This work entwines themes of worldwide concern with the political growth of nationalism because leaders with such a worldview are disinclined to co-operate internationally at a time when nations must find ways to solve common problems, such as the climate crisis. Inability to cooperate at this stage may doom everyone, eventually, to an overheated, stormy future plagued by droughts and deluges portending shortages of food and other essential commodities, meanwhile destroying large coastal urban areas because of rising sea levels. Future historians may look back at our time and wonder why as well as how our world succumbed to isolating nationalism at a time when time was so short for cooperative intervention which is crucial for survival of a sustainable earth. Pride in language and culture is salubrious to individuals’ sense of history and identity. Excess nationalism that prevents international co-operation on harmful worldwide maladies is quite another. As Pope Francis has pointed out: For all of our connectivity due to expansion of social media, ability to communicate can breed contempt as well as mutual trust. “For all our hyper-connectivity,” said Francis, “We witnessed a fragmentation that made it more difficult to resolve problems that affect us all” (Horowitz, 2020, A-12). The pope’s encyclical, titled “Brothers All,” also said: “The forces of myopic, extremist, resentful, and aggressive nationalism are on the rise.” The pope’s document also advocates support for migrants, as well as resistance to nationalist and tribal populism. Francis broadened his critique to the role of market capitalism, as well as nationalism has failed the peoples of the world when they need co-operation and solidarity in the face of the world-wide corona virus pandemic. Humankind needs to unite into “a new sense of the human family [Fratelli Tutti, “Brothers All”], that rejects war at all costs” (Pope, 2020, 6-A). Our journey takes us first to Russia, with the able eye and honed expertise of Richard D. Anderson, Jr. who teaches as UCLA and publishes on the subject of his chapter: “Putin, Russian identity, and Russia’s conduct at home and abroad.” Readers should find Dr. Anderson’s analysis fascinating because Vladimir Putin, the singular leader of Russian foreign and domestic policy these days (and perhaps for the rest of his life, given how malleable Russia’s Constitution has become) may be a short man physically, but has high ambitions. One of these involves restoring the old Russian (and Soviet) empire, which would involve re-subjugating a number of nations that broke off as the old order dissolved about 30 years ago. President (shall we say czar?) Putin also has international ambitions, notably by destabilizing the United States, where election meddling has become a specialty. The sight of Putin and U.S. president Donald Trump, two very rich men (Putin $70-$200 billion; Trump $2.5 billion), nuzzling in friendship would probably set Thomas Jefferson and Vladimir Lenin spinning in their graves. The road of history can take some unanticipated twists and turns. Consider Poland, from which we have an expert native analysis in chapter 2, Bartosz Hlebowicz, who is a Polish anthropologist and journalist. His piece is titled “Lawless and Unjust: How to Quickly Make Your Own Country a Puppet State Run by a Group of Hoodlums – the Hopeless Case of Poland (2015–2020).” When I visited Poland to teach and lecture twice between 2006 and 2008, most people seemed to be walking on air induced by freedom to conduct their own affairs to an unusual degree for a state usually squeezed between nationalists in Germany and Russia. What did the Poles then do in a couple of decades? Read Hlebowicz’ chapter and decide. It certainly isn’t soft-bellied liberalism. In Chapter 3, with Bruce E. Johansen, we visit China’s western provinces, the lands of Tibet as well as the Uighurs and other Muslims in the Xinjiang region, who would most assuredly resent being characterized as being possessed by the Chinese of the Han to the east. As a student of Native American history, I had never before thought of the Tibetans and Uighurs as Native peoples struggling against the Independence-minded peoples of a land that is called an adjunct of China on most of our maps. The random act of sitting next to a young woman on an Air India flight out of Hyderabad, bound for New Delhi taught me that the Tibetans had something to share with the Lakota, the Iroquois, and hundreds of other Native American states and nations in North America. Active resistance to Chinese rule lasted into the mid-nineteenth century, and continues today in a subversive manner, even in song, as I learned in 2018 when I acted as a foreign adjudicator on a Ph.D. dissertation by a Tibetan student at the University of Madras (in what is now in a city called Chennai), in southwestern India on resistance in song during Tibet’s recent history. Tibet is one of very few places on Earth where a young dissident can get shot to death for singing a song that troubles China’s Quest for Lebensraum. The situation in Xinjiang region, where close to a million Muslims have been interned in “reeducation” camps surrounded with brick walls and barbed wire. They sing, too. Come with us and hear the music. Back to Europe now, in Chapter 4, to Portugal and Spain, we find a break in the general pattern of nationalism. Portugal has been more progressive governmentally than most. Spain varies from a liberal majority to military coups, a pattern which has been exported to Latin America. A situation such as this can make use of the term “populism” problematic, because general usage in our time usually ties the word into a right-wing connotative straightjacket. “Populism” can be used to describe progressive (left-wing) insurgencies as well. José Pinto, who is native to Portugal and also researches and writes in Spanish as well as English, in “Populism in Portugal and Spain: a Real Neighbourhood?” provides insight into these historical paradoxes. Hungary shares some historical inclinations with Poland (above). Both emerged from Soviet dominance in an air of developing freedom and multicultural diversity after the Berlin Wall fell and the Soviet Union collapsed. Then, gradually at first, right wing-forces began to tighten up, stripping structures supporting popular freedom, from the courts, mass media, and other institutions. In Chapter 5, Bernard Tamas, in “From Youth Movement to Right-Liberal Wing Authoritarianism: The Rise of Fidesz and the Decline of Hungarian Democracy” puts the renewed growth of political and social repression into a context of worldwide nationalism. Tamas, an associate professor of political science at Valdosta State University, has been a postdoctoral fellow at Harvard University and a Fulbright scholar at the Central European University in Budapest, Hungary. His books include From Dissident to Party Politics: The Struggle for Democracy in Post-Communist Hungary (2007). Bear in mind that not everyone shares Orbán’s vision of what will make this nation great, again. On graffiti-covered walls in Budapest, Runes (traditional Hungarian script) has been found that read “Orbán is a motherfucker” (Mikanowski, 2019, 58). Also in Europe, in Chapter 6, Professor Ronan Le Coadic, of the University of Rennes, Rennes, France, in “Is There a Revival of French Nationalism?” Stating this title in the form of a question is quite appropriate because France’s nationalistic shift has built and ebbed several times during the last few decades. For a time after 2000, it came close to assuming the role of a substantial minority, only to ebb after that. In 2017, the candidate of the National Front reached the second round of the French presidential election. This was the second time this nationalist party reached the second round of the presidential election in the history of the Fifth Republic. In 2002, however, Jean-Marie Le Pen had only obtained 17.79% of the votes, while fifteen years later his daughter, Marine Le Pen, almost doubled her father's record, reaching 33.90% of the votes cast. Moreover, in the 2019 European elections, re-named Rassemblement National obtained the largest number of votes of all French political formations and can therefore boast of being "the leading party in France.” The brutality of oppressive nationalism may be expressed in personal relationships, such as child abuse. While Indonesia and Aotearoa [the Maoris’ name for New Zealand] hold very different ranks in the United Nations Human Development Programme assessments, where Indonesia is classified as a medium development country and Aotearoa New Zealand as a very high development country. In Chapter 7, “Domestic Violence Against Women in Indonesia and Aotearoa New Zealand: Making Sense of Differences and Similarities” co-authors, in Chapter 8, Mandy Morgan and Dr. Elli N. Hayati, from New Zealand and Indonesia respectively, found that despite their socio-economic differences, one in three women in each country experience physical or sexual intimate partner violence over their lifetime. In this chapter ther authors aim to deepen understandings of domestic violence through discussion of the socio-economic and demographic characteristics of theit countries to address domestic violence alongside studies of women’s attitudes to gender norms and experiences of intimate partner violence. One of the most surprising and upsetting scholarly journeys that a North American student may take involves Adolf Hitler’s comments on oppression of American Indians and Blacks as he imagined the construction of the Nazi state, a genesis of nationalism that is all but unknown in the United States of America, traced in this volume (Chapter 8) by co-editor Johansen. Beginning in Mein Kampf, during the 1920s, Hitler explicitly used the westward expansion of the United States across North America as a model and justification for Nazi conquest and anticipated colonization by Germans of what the Nazis called the “wild East” – the Slavic nations of Poland, the Baltic states, Ukraine, and Russia, most of which were under control of the Soviet Union. The Volga River (in Russia) was styled by Hitler as the Germans’ Mississippi, and covered wagons were readied for the German “manifest destiny” of imprisoning, eradicating, and replacing peoples the Nazis deemed inferior, all with direct references to events in North America during the previous century. At the same time, with no sense of contradiction, the Nazis partook of a long-standing German romanticism of Native Americans. One of Goebbels’ less propitious schemes was to confer honorary Aryan status on Native American tribes, in the hope that they would rise up against their oppressors. U.S. racial attitudes were “evidence [to the Nazis] that America was evolving in the right direction, despite its specious rhetoric about equality.” Ming Xie, originally from Beijing, in the People’s Republic of China, in Chapter 9, “News Coverage and Public Perceptions of the Social Credit System in China,” writes that The State Council of China in 2014 announced “that a nationwide social credit system would be established” in China. “Under this system, individuals, private companies, social organizations, and governmental agencies are assigned a score which will be calculated based on their trustworthiness and daily actions such as transaction history, professional conduct, obedience to law, corruption, tax evasion, and academic plagiarism.” The “nationalism” in this case is that of the state over the individual. China has 1.4 billion people; this system takes their measure for the purpose of state control. Once fully operational, control will be more subtle. People who are subject to it, through modern technology (most often smart phones) will prompt many people to self-censor. Orwell, modernized, might write: “Your smart phone is watching you.” Ming Xie holds two Ph.Ds, one in Public Administration from University of Nebraska at Omaha and another in Cultural Anthropology from the Chinese Academy of Social Sciences, Beijing, where she also worked for more than 10 years at a national think tank in the same institution. While there she summarized news from non-Chinese sources for senior members of the Chinese Communist Party. Ming is presently an assistant professor at the Department of Political Science and Criminal Justice, West Texas A&M University. In Chapter 10, analyzing native peoples and nationhood, Barbara Alice Mann, Professor of Honours at the University of Toledo, in “Divide, et Impera: The Self-Genocide Game” details ways in which European-American invaders deprive the conquered of their sense of nationhood as part of a subjugation system that amounts to genocide, rubbing out their languages and cultures -- and ultimately forcing the native peoples to assimilate on their own, for survival in a culture that is foreign to them. Mann is one of Native American Studies’ most acute critics of conquests’ contradictions, and an author who retrieves Native history with a powerful sense of voice and purpose, having authored roughly a dozen books and numerous book chapters, among many other works, who has traveled around the world lecturing and publishing on many subjects. Nalanda Roy and S. Mae Pedron in Chapter 11, “Understanding the Face of Humanity: The Rohingya Genocide.” describe one of the largest forced migrations in the history of the human race, the removal of 700,000 to 800,000 Muslims from Buddhist Myanmar to Bangladesh, which itself is already one of the most crowded and impoverished nations on Earth. With about 150 million people packed into an area the size of Nebraska and Iowa (population less than a tenth that of Bangladesh, a country that is losing land steadily to rising sea levels and erosion of the Ganges river delta. The Rohingyas’ refugee camp has been squeezed onto a gigantic, eroding, muddy slope that contains nearly no vegetation. However, Bangladesh is majority Muslim, so while the Rohingya may starve, they won’t be shot to death by marauding armies. Both authors of this exquisite (and excruciating) account teach at Georgia Southern University in Savannah, Georgia, Roy as an associate professor of International Studies and Asian politics, and Pedron as a graduate student; Roy originally hails from very eastern India, close to both Myanmar and Bangladesh, so he has special insight into the context of one of the most brutal genocides of our time, or any other. This is our case describing the problems that nationalism has and will pose for the sustainability of the Earth as our little blue-and-green orb becomes more crowded over time. The old ways, in which national arguments often end in devastating wars, are obsolete, given that the Earth and all the people, plants, and other animals that it sustains are faced with the existential threat of a climate crisis that within two centuries, more or less, will flood large parts of coastal cities, and endanger many species of plants and animals. To survive, we must listen to the Earth, and observe her travails, because they are increasingly our own.

Abstract Hanford stores millions of gallons of high-level waste in 27 carbon-steel double shell, underground tanks. A secondary shell surrounds the primary shell, where the bottom plate of the secondary shell rests on a channeled concrete pad. There have been instances of metal loss on the secondary shell bottom plates in contact with the concrete basemat where groundwater accumulation in the channels may have caused corrosion. In addition, uneven contact between the basemat and shell could create occluded areas where localized corrosion is possible. In previous studies, vapor corrosion inhibitors (VCIs) were tested for their ability to mitigate concrete-basemat side corrosion of the secondary shell bottom. The previous study indicated that VCIs are effective in mitigating corrosion in both immersed and vapor space conditions. However, the tanks being large with approximately 70-ft bottom, it is important to understand VCI distribution rate after VCIs are injected. Experiments were conducted with VCI injection in the groundwater along with coupons positioned at several locations with respect to the ground water. Coupons' potentials were monitored, and corrosion rate data were analyzed. It was determined that corrosion potential is a good indicator of VCI concentration in the simulated groundwater solution. The paper presents result and analysis of the experimental data.

Abstract Radioactive waste is stored in underground, carbon-steel double-shell tanks at the Department of Energy Hanford site. The double-shell tank design includes a secondary shell surrounding the primary shell, where the bottom plate of the secondary shell rests on a concrete pad that contain drainage channels. There have been instances of metal loss on the secondary shell bottom plates in contact with the concrete foundation where groundwater accumulation in the channels may have caused corrosion. In addition, uneven contact between the foundation and shell could create occluded areas where localized corrosion is potentially more severe. In previous studies, vapor corrosion inhibitors (VCIs) were tested for their ability to mitigate concrete-foundation-side, i.e., concrete-side, corrosion of the secondary shell bottom. The previous studies showed that VCIs are effective in mitigating corrosion for both immersed and vapor space conditions. However, even distribution of the VCIs throughout the 85-ft diameter bottom of the secondary shell could be a challenge. This study investigated the feasibility of nitrogen blanketing to mitigate concrete-side corrosion of the secondary shell. Laboratory experiments were conducted to quantify the nitrogen blanketing effect on corrosion mitigation. The experimental data showed that nitrogen blanketing is as effective as VCIs in mitigating the concrete-side corrosion of the double shell tanks. Experimental results associated with the two corrosion mitigation methods for their application on the Hanford double-shell tanks are presented.

Abstract Hanford stores millions of gallons of high-level waste storage site in 27 carbon-steel double shell, underground tanks (DSTs). A secondary shell surrounds the primary shell, where the bottom plate of the secondary shell rests on a channeled concrete pad. There have been instances of metal loss on the secondary shell bottom plates in contact with the concrete basemat where accumulation of the groundwater solution in the channels may have caused corrosion. In addition, uneven contact between the basemat and shell could create occluded areas where localized corrosion in form of crevice corrosion is possible. In previous studies, several commercially available vapor corrosion inhibitors (VCIs) were tested for their ability to mitigate concrete-basemat side corrosion of the secondary liner bottom. The previous studies involved use of disk coupons either immersed or placed in vapor space of the groundwater solution dosed with VCIs. Even though, VCIs have been found to be effective in mitigating corrosion on the disk coupons, it is not clear if VCIs can be sufficiently effective in mitigating the crevice corrosion. A study was conducted with disk coupons where each coupon’s disk surface was partially occluded using a crevice former. Several sets of the disk coupons were exposed to the groundwater solution for several months in three separate corrosion tests. Approximately half of the coupons were extracted after several months of exposure and analyzed for metal loss. The remaining sets of coupons were exposed for additional time to the commercially available VCIs by adding the VCIs to the ground water solutions in the tests. The remaining coupons were extracted after completion of the tests and analyzed for metal loss. Corrosion rate data of the pre-and post-VCI exposed coupons were compared to evaluate effectiveness of the VCIs for mitigating the crevice corrosion. The paper will present experimental data and results on effectiveness of VCIs in mitigating crevice corrosion on the bottom plates of the secondary shells.

The International Atomic Energy Agency requires that the transport of spent nuclear fuel in containers be able to handle certain loads in the axial, lateral and vertical direction under normal off-site handling scenarios. During transport, CANDU nuclear fuel bundles may experience axial impact loads due to possible sliding within a transport tube resulting in impact with the container wall. This paper presents a series of postulated fuel bundle impact scenarios in order to determine the enveloping dynamic g load that a bundle can experience before possible plastic deformation to the bundle fuel sheath. The IAEA load factors for envelope design are used as a reference to ramp the impact velocities and are not equivalent to the dynamic loads used in the analysis. Based on the transportation induced g loads outlined in the IAEA regulations for safe transport of spent fuel under normal handling conditions (IAEA 1985), these g loads are used to calculate a terminal velocity for the bundle whose motion impacts a rigid plate. One type of CANDU nuclear fuel bundle consists of 28 Zircaloy-4 fuel pencils loaded with Uranium Dioxide fuel pellets. The ends of the pencils are fitted with end caps and each end cap is spot welded to a Zircaloy-4 end plate at either end. The finite element model of the fuel bundle consists of 4-noded shell elements representing the fuel sheaths and end plates and 8-noded continuum elements representing the Uranium Dioxide pellets. For the purpose of the analysis, the fuel bundle is housed inside a transport tube, which limits the bundle lateral and vertical motion during impact rebound. The impact target is conservatively modelled as an infinitely rigid plate. Contact surfaces are modelled between the fuel bundle and transport tube, between the fuel bundle and impact plate and between each individual fuel pencil. Two bundle scenarios are considered. The first is a single fuel bundle impacting the plate and the second is two fuel bundles in series in a single transport tube impacting the plate. The second scenario considers the interaction between the two bundles during initial impact and rebound. The analysis covers these scenarios under various magnitudes of applied dynamic loading including 2g, 5g, and 8g. The objective is to determine at what applied load the fuel bundle will experience plastic damage to the fuel pencil sheath. This will effectively provide a bounding g load for CANDU spent fuel transport. The results of the analysis show that for a single bundle in a transport tube, a dynamic load of 8g results in plastic deformation of and the target are modeled using 4-noded shell elements. The pencil end caps are attached to the endplates using an area of common nodes (Fig. 3). Although the actual endcap to endplate connection is through a round spot-welded cross section, for modeling ease the interface is several fuel pencil sheaths. For the two-bundle case, a dynamic load of 8g does not result in any plastic deformation in the fuel pencil sheaths. Thus, a limiting dynamic load between 5g and 8g is determined for the fuel handling scenarios. This paper presents the methodology and models used in the analysis as well as the results of the simulations.

It is critical for principal bearing stiffness for actuators to be evaluated for robot applications. The bearing stiffness calculation can be obtained from Hertzian contact theory. From a design standpoint, given the bearing stiffness, the target stiffness of the actuator shell structure and output plate may be an order higher than that of the principal bearing. This paper evaluates and compares the relationship between the stiffness of the shell structure and principal bearing as well as between the stiffness of the output-plate and principal bearing. The principal bearing for the actuator could be the crossed roller bearing (CRB), four-point bearing (FPB), or a tapered roller bearing (TRB) because they best accommodate the combined radial, axial, and moment loads. Also, the bearing weight and assembled weight (shell structure + principal bearing + output-plate) required to obtain appropriate stiffness can be evaluated based on the stiffness of these adjacent structures which hold the principal bearing. Finally, the shortest possible force path passing through the principal bearing from the shell to the output plate makes it possible to maximize actuator stiffness and reduces other negative effects.

The elastic-plastic contact between a spherical shell and a rigid flat is analyzed using finite element analysis. The effect of spherical shell geometry and material properties on the onset of plastic deformation is determined by finding the critical normal load and the critical interference which correspond to the onset of plastic yielding. The location of initial plastic deformation is identified as a function of material properties and spherical shell geometry. This work provides the dimensionless critical load as a function of the shell parameter λ = (t/R)*(E/Y), where t, R, E and Y are the spherical shell thickness, radius, Young’s modulus and yield strength, respectively. The numerical results are compared with the solid sphere model based on Hertz’s contact theory and classical shell theory in the elastic regime. The behavior of a spherical shell contacting a rigid flat plate is a strong function of the shell parameter λ.

The rocking motion of tanks due to earthquakes causes the uplift and partial deformation of the tank bottom plate that has been considered to contribute to damage of various tanks. For analyzing the uplift displacement of the tank bottom plate numerically and precisely, this paper develops the analytical finite shell element, ring element and spring element partially attached to the ring element. These elements are defined as semi-analytical finite element models. Fourier series give their circumferential displacement function, while polynomial gives their radial displacement function. Applicability of a set of these elements to analyze the shell deformation and contact between the tank bottom plate and the foundation subjected to ground acceleration induced loads is verified. For evaluating analytical accuracy of the proposed method, numerical results are compared with other numerical ones.

For analyzing the uplift displacement of the tank bottom plate statically and precisely, this paper develops a shell element, ring element and spring element partially attached to the ring element. These elements are defined as a semi-analytical finite element. Moreover in analyzing uplift of the tank bottom plate precisely, the ring element can deal with effects of the large deformation, while the spring element enables to express the partial contact between the tank bottom plate and foundation. Dead load, hydro-pressure and inertia force due to earthquakes acceleration as well as dynamic pressure of fluid induced by bulging and rocking motions of the tank are applied statically. Comparison of results by the proposed method and that computed by the explicit FE Analysis reveals that the accurate uplift displacement is not obtained until all physical conditions involved in the tank rocking motion and the inward deformation of the tank shell is properly considered.

This investigation demonstrates the effect of the tank flexibility and plate thickness on the wheel/rail contact and the nonlinear dynamic behavior of railroad vehicles. To this end, a flexible tank is modeled using the finite element (FE) floating frame of reference formulation (FFR). The tank car finite element model is integrated with a three-dimensional railroad vehicle using computational non-linear multibody system (MBS) framework in which the wheel/rail interaction is formulated using a three-dimensional elastic contact formulation that allows for the wheel/rail separation. A triangular shell element is used to build the tank car and describe its deformation, The effect of the coupling between different modes of displacements is demonstrated by comparing the results of the simulations of the flexible and rigid tank car models. It is shown that there is a strong dynamic coupling between different modes of displacements of the tank car, the plate thickness, and the wheel/rail contact parameters. The effect of the flexibility and plate thickness of the tank car on the vehicle critical speed and dynamic characteristics are also examined.

The rocking motion of tanks due to earthquakes causes the large uplift deformation of the tank bottom plate that has been considered to contribute to the various damages of the tanks. For analyzing the uplift displacement of the tank bottom plate statically and precisely, this paper develops a shell element, ring element and spring element partially attached to the ring element. These elements are defined as a semi-analytical finite element. Fourier series give its circumferential displacement function, while the polynomial gives its radial displacement function. In addition, the ring element can deal with effects of the large deformation, while the spring element enables to express the partial contact between the tank bottom plate and foundation. On the other hand, the loads considered are dead load, hydro-pressure and inertia force due to earthquakes acceleration as well as dynamic pressure of fluid induced by bulging and rocking motion of the tank. The numerical analyses model of the LNG Storage Tank was created using the semi-analytical finite elements shown here, and the uplift displacement of the tank bottom plate accompanying the tank rocking motion was calculated with the static analyses. For evaluating analytical accuracy of the proposed method, numerical results of the proposed method are compared with that of the explicit FE Analysis.