Dead Rise Research Articles

Seakeeping behavior of hexagonal catamaran hull form as an alternative geometry design of flat-sided hull vessel

The Flat-sided Hull Vessel was introduced to simplify and create an efficient ship production process by eliminating the fairing work, bending, and curved panel line assembly. The built process simplification is expected that the FSHV can be produced by the traditional boat yard. However, the flat hull concept has slightly increased resistance performance. Therefore, implementing a resistance reduction device is endorsed to improve the boat's performance. The focus of the research is to identify the influence of the flat hull concept on sea keeping behavior. The hexagonal catamaran hull form was developed on the dead rise angle, angle of attack, and stern angle variation. Furthermore, the response amplitude operator and the motion spectral density of heave, roll, and pitch motion were calculated. Otherwise, the sea keeping performance of the hexagonal catamaran is compared to the original rounded catamaran. The results show that the hexagonal catamaran hulls have better sea keeping performance in the Beam Sea. However, the conventional catamaran has demonstrated superiority over the hexagonal catamaran in the Bow Quartering and Head Sea conditions.

Tangible Black Joy and Beyond: An Interview with Isiah Lavender III

Tangible Black Joy and Beyond: An Interview with Isiah Lavender III Shelby L. Crosby (bio), Terrence Tucker (bio), and Isiah Lavender III (bio) We are excited to interview Dr. Isiah Lavender III for this special issue of CLAJ. Dr. Lavender is one of the most prolific scholars of Afrofuturism of the last decade. His interest in race and science fiction, shown in 2014’s Black and Brown Planets: The Politics of Race in Science Fiction and 2017’s DisOrienting Planets: Racial Representations of Asia in Science Fiction, has evolved into a significant interest in Afrofuturism, particularly in literature. His interest in Afrofuturism’s literary history and present contrasts Afrofuturism’s expansion into film, art, and music. Along with Afrofuturism Rising: The Literary Prehistory of a Movement and Literary Afrofuturism in Twenty-First Century (co-edited), his upcoming book Conversations with Nalo Hopkinson signals his interest in capturing and preserving the voices and experiences of some of the field’s most influential yet underappreciated voices. How do we define ourselves? How do others define us? These are the central questions that Isiah Lavender III answers in texts like Afrofuturism Rising and Literary Afrofuturism. Thinking about slave narratives as “laying bare a science-fictional American existence. Each of these black freedom fighters engenders the afrofuturist vista from antebellum America to the twenty-first century by creating a legacy of resistance.” It is this legacy of resistance, rooted in the “science-fictional American existence” that allows readers to understand the hope that lies within these narratives. Readers can also reimagine and redefine the notion of resistance in new terms, new words, and, perhaps, new worlds—new worlds that fugitive slaves had yet to imagine. As artists and scholars recover the voices and experiences that many have tried to erase, Lavender challenges us to consider that “Racism refuses to die even when the dead rise.” For him, the importance of Afrofuturism is not in happy endings or in easy solutions, but in the joy and possibility that lies in telling our own stories and continuing the search for the notions of freedom the fugitive slaves relentlessly pursued. 1. How far back can we trace the presence of Afrofuturism or Black Speculative Fiction in African American literature? Certainly, I think the presence of Afrofuturism can be seen in the spirituals and folktales prevalent in the black vernacular tradition of early America because songs and stories transported tired black bodies and black minds of the enslaved to more [End Page 175] hopeful places such as heaven. How could they not? For example, the spiritual “I Know Moon-Rise” engages outer space in evoking the moon and the stars, a physical actual heaven that Octavia E. Butler will extrapolate upon more than 200 years later in her great novel Parable of the Sower (1993), where the destiny of her imaginary religion, Earthseed, is to take root among the stars. Looking to the past to move into the future is surely Afrofuturist and absolutely related to the Akan concept of Sankofa first derived in Ghana. I do not think this concept occurred to the originator of the term Mark Dery when he invented the word in 1993 to frame a set of interviews with Samuel R. Delany Jr., Greg Tate, and Tricia Rose in the South Atlantic Quarterly. Dery did nominally have an African American future, technoculture, and prosthetic enhancement firmly in mind when he defined Afrofuturism, though that’s debatable since he used William Gibson’s orbital Rastas as an example. Delany brilliantly clapped back to this political error or cultural mis-step on Dery’s part with his skillful, even beautiful riff: You’ll forgive me if, as a black reader, I didn’t leap up to proclaim this passing presentation of a powerless and wholly nonoppositional set of black dropouts, by a Virginia-born white writer, as the coming of the black millennium in science fiction; but maybe that’s just a black thang…. (195) In short, Afrofuturism predates the founding of the United States from a skewed viewpoint even with the paradox of its being defined in the late twentieth century. I think the race of Dery himself has caused a bit of...

Codesign Case Study of a Planing Craft with Active Control Systems

This case study presents a novel insight into the design of a codesigned planing craft with an active control system (ACS), along with its potential advantages and disadvantages when compared with a traditionally designed vessel (i.e., a vessel whose geometry is first selected, and then its ACS is implemented). This work has three purposes:present tools a designer can use to codesign a planing craft with its ACS,use these tools to expand the design space and further explore the potential of codesign, andinvestigate the feasibility of having a planing craft with ACS designed to the codesign results found in 2) and compare it with a traditionally designed vessel. The vessel particulars that are numerically optimized are the beam, dead rise, longitudinal center of gravity (lcg), and two tuning parameters for the ACS's linear quadratic regulator. In the case study, the codesigned vessel had 4% lower drag at the design speed and Sea State (SS) 3, but on lower SS's it had drag savings of 10% and seakeeping improvements of around 40% for the investigated seakeeping metric. The case study suggests that although the codesigned vessel is technically feasible, it would require unconventional hull/deck design—a result which emphasizes the importance of considering the coupling between a planing craft and its ACS early in the concept design. 1. Introduction In search for a better performing planing craft, a naval architect could consider using an active control system (ACS) on their designs. Although they will encounter published research confirming performance improvements when an ACS is used (Wang 1985; Savitsky 2003; Xi & Sun 2006; Kays et al. 2009; Engle et al. 2011; Hughes & Weems 2011; Rijkens et al. 2011; Shimozono & Kays 2011; Rijkens 2013), literature addressing the concept design process of a planing craft that will have an ACS is, to the best of the authors' knowledge, limited only to the previous work by the authors (Castro-Feliciano et al. 2016, 2018). The work by Castro-Feliciano et al. (2016, 2018) suggests that the benefit from codesigning (as opposed to sequentially designing the vessel geometry and later adding an ACS) can be significant and should be the design methodology followed when designing a planing craft that will have an ACS.

О расчетах прочности и жесткости килеватых днищевых перекрытий и выборе доковых стоек поперечных переборок корабля

This paper explains how to calculate the correction factor for keel inertia moment due to the dead rise of grillage and how to consider bulkhead plating in calculation of dock strut response to keel cribbing. The solutions described in this study are different from the commonly used ones. New formulas have been obtained for taking into account inertia moment of grillages with dead rise, as well as for calculation of Euler stresses in dock struts, and their design algorithm has also been updated. The results offer more accurate calculations of grillages with dead rises and more accurate design of transverse bulkheads in terms of conventional beam models and methods of structural mechanics.

Analysis of waterjet-hull interaction and its impact on the propulsion performance of a four-waterjet-propelled ship

Waterjet-hull interaction has different effects on the propulsion performance of the outer and inner waterjets in ships propelled by four waterjets. The dead rise angle of the hull lines near the stern leads to different inflow characteristics in the capture areas of individual waterjets. To better understand these effects, self-propulsion tests were performed to investigate the thrust deduction fraction and energy/momentum velocity coefficients, and numerical simulations of unsteady multiphase flows were conducted using a discretised impeller/stator with dynamic overset grids. Results obtained indicate that the flow rates and gross thrust of inner waterjets were greater than those of the outer waterjets under the same rotational speeds, and that these differences gradually decreased with increases in the advanced speed. The hull had a stronger negative effect on the inflow of the outer waterjet because its energy/momentum velocity coefficients were smaller than those of the inner waterjets. Additionally, flow field analysis of the capture area verified the quality of the computations, and internal flow field analysis provided additional validation of observed results. It was found that the inlet-duct design and the presence of stabilizer fins caused different interaction behaviours, resulting in the propulsion performance discrepancies observed in four-waterjet systems.

When the dead rise: encountering resistant legacies of creative economy within an artist’s residency at a municipal cemetery

ABSTRACTRecent criticism of creative economies demonstrates tensions between programmes that support innovative cultural expression and community belonging, and those more oriented to instrumentally economic outcomes. While municipal planners recognize the link between cultural activity and enhanced quality of life, related budget support typically calls for quantifiable outcomes. Creative economy policies and projects are thus vulnerable to favouring more narrowly construed forms of economic growth. We explore the municipally embedded artist-in-residence (AiR) programme as a source of friction, complexity and inefficiency intentionally introduced into organizations constitutionally regulated to suppress exactly these kinds of excesses. In Deleuzian terms, the social machinery of neoliberal urban and economic development hesitates when it encounters the short-circuiting unpredictabilities of creative desire introduced by the embedded residency. The municipally embedded AiR is a residual apparatus of creative economy policy that can offer resistance to and even inoculation against easy alliances with neoliberal economic agendas. In the case of an embedded AiR in city cemeteries in Edmonton, Canada, the artist, working on the grounds, meeting visitors and holding workshops, uses now-obsolete photographic craft production to manipulate conventional memorial images and texts in unexpected conjunctions with experimental aesthetic expression and living stories. The physical presence of the residency also disrupts received categories to produce the cemetery as living public space rather than a setting with “holes to put the past in”. In this sense, the cemetery becomes accessible as newly encoded, sustainable cultural and recreational space with minimal civic investment. Calling up ghosts of challenged creative economy ideals, this AiR opens new forms of engagement between citizens, local history and urban nature as a complex adaptive system that incorporates both cultural values and commodity logic without primary emphasis on quantifiable outcomes.

The Dead Walk

Monsters have always enjoyed a significant presence in the human imagination, and religion was instrumental in replacing the physical horror they engendered with that of a moral threat. Zombies, however, are amoral – their motivation purely instinctive and arbitrary, yet they are, perhaps, the most loathed of all contemporary monsters. One explanation for this lies in the theory of the uncanny valley, proposed by robotics engineer Masahiro Mori. According to the theory, we reserve our greatest fears for those things which seem most human, yet are not – such as dead bodies. Such a reaction is most likely a survival mechanism to protect us from danger and disease – a mechanism even more essential when the dead rise up and walk. From their beginnings zombies have reflected western societies’ greatest fears – be they of revolutionary Haitians, women, or communists. In recent years the rise in the popularity of the zombie in films, books and television series reflects our fears for the planet, the economy, and of death itself

The “Nazi Detective” as Provider of Justice in Post-1990 British and German Crime Fiction: Philip Kerr's The Pale Criminal, Robert Harris's Fatherland, and Richard Birkefeld and Göran Hachmeister's Wer übrig bleibt, hat recht

The “Nazi Detective” as Provider of Justice in Post-1990 British and German Crime Fiction: Philip Kerr's <i>The Pale Criminal</i>, Robert Harris's <i>Fatherland</i>, and Richard Birkefeld and Göran Hachmeister's <i>Wer übrig bleibt, hat recht</i>

ON THE INFLUENCE OF BREAKING WAVE LOCAL GEOMETRY ON IMPULSIVE LOADS

In this paper, we study the wave impact process with a multi-fluid Navier-Stokes model (THETIS). Preliminary simulations have been conducted, first on a plunging wave generated by unstable Stokes initial condition, and second, involving a dam breaking bore impact. In both cases, a convergence study shows pressure peak results instability when using different meshes. This is due to the incapacity of the model to ensure, after a certain time of computation, the exact same surface profile at impact when simulating a specific case with different meshes. This instable numerical behavior is somehow similar to peak pressure instabilities observed in experiments. This similarity shows the critical role played by local free surface shape at impact on impulsive loads. When initializing the model with a specific interface right at impact, convergence is observed and the pressure peaks are correctly assessed by the code for moderate intensity impact. However, further improvements are still needed especially regarding the interface tracking technique to simulate the most violent impacts involving the weaker dead rise angles. The paper also encourages us to use numerical simulations preferably to study impact flow at local scale.

CFD Simulation for Displacement Deep-Vee Vessels on Resistance Influence Factor

Resistance influence factors of displacement type Deep-vee forms are analyzed with eight hull forms provided. The free surface viscous flow of these forms is calculated by air-water two phases RANS equations with RNG turbulence model and volume of fraction method. Total resistance, pressure distribution and wave profile of bow are presented. Some results can be taken as follows: while maintaining the same tonnage, L/B ratio and draft, the resistance performance of Deep-Vee vessels is excellent at high speed if a large transverse dead rise angle was located from 50%front midship to 25% backward midship; The resistance performance at a lesser L/B and draft is worse if the displacement and dead rise angle is the same; Furthermore, it can be improved by a cigar-shaped bulbous bow. The change of pressure distribution for cigar-shaped bulbous bow is more slightly than that of tobacco pipe-shaped bulbous bow.

Hypoventilation Due to Reinhalation in Infants With a Transport Ventilator

An infant of 5 kg of body weight was being ventilated with a conventional ventilator with a tidal volume of 40 mL and respiratory rate of 35 rpm, maintaining an expired CO2 of 37 mm Hg and a transcutaneous PCO2 of 43 mm Hg. For transfer, an Oxylog 3000 ventilator (Dräger, Lübeck, Germany) was set to intermittent positive-pressure ventilation mode with a tidal volume of 50 mL and the same respiratory frequency. After connecting, the expired CO2 increased rapidly to 75 mm Hg; the inspired CO2, to 27 mm Hg; and the transcutaneous PCO2, to 82 mm Hg, despite good chest expansion. The respirator was checked and found to be correct. On changing to the conventional ventilator, a rapid decrease was found in the expired CO2 and transcutaneous PCO2 values and the inspired CO2 fell to 0. The Oxylog 3000 ventilator should not be used for the transport of small children because the dead space rise to a significant reinhalation in these patients. Capnography and transcutaneous PCO2 are useful for the early detection of hypercapnia and the dead space during the transfer of pediatric patients.

The ambiguous boundary between genes and pseudogenes: the dead rise up, or do they?

Pseudogenes have long been considered to be 'dead', nonfunctional by-products of genome evolution. However, several lines of evidence now show that some pseudogenes are transcriptionally 'alive', and a few might even have biochemical roles. Therefore, the boundary between genes (often considered to be 'living') and pseudogenes (often considered to be 'dead') might be ambiguous and difficult to define. Here, we examine the evidence for and against pseudogene functionality, and we argue that the time is ripe for revising the definition of a pseudogene. Furthermore, we suggest a classification system to accommodate pseudogenes with various levels of functionality.

Comparison of measured and computed non-linear wave loads using a time domain method for an 86m catamaran

The time domain, Green function solution of the encountered wave response problem in spatially fixed co-ordinates for slender high speed hulls is used to show the effect of hull form on non-linear motion and load responses. It is found that the non-linear effect on motions is small for round bilge and SWATH type hulls, but is strong for a hard chine hull with significant dead rise angles. In particular, the frequency of maximum heave is significantly reduced in large seas. Non-linear effects on bending and shear are negligible for a round bilge design with wall sides at the water line. For a SWATH design, unsteady loads per unit wave height increase modestly by up to 13% as the wave height increases so as to expose broader immersed hull sections, but reduce again at the largest wave heights. For the hard chine design the bending and shear per unit wave height reduce by about 40% as wave height approaches the draught. Unsteady stress and encountered wave data measured on a 86m catamaran ferry give good agreement with predicted loads over a wide range of speed provided that the appropriate wave height is used in the computations.

Bow Flow Field with Spray Phenomena around a Planing Plate

A perturbational study is made of the bow flow field with spray phenomena around a planing plate with a small dead rise angle and a small trim angle in order to obtain the basis on the configuration of the wetted surface area. A hypothesis is proposed whereby the plate planes on a water surface deformed as a parabolic cylinder with transverse curvature near the bow, the deformation seems to be caused by the displacement effect. The hypothesis allows the assumption that a similarity flow changing the scale of transverse section as a square root of longitudinal length. The flow field is divided into three regions for the analysis. By analysing the bow near field, the spray root line is obtained as forming a parabola on the plate, so that good coincidence with an experimental result of pressure contour is shown with the help of the same flow near the spray root line as Wagner's local flow. The spray flow developing on the plate outside the spray root line is analyzed. The flow rate and thickness of the spray and the spray drag show good coincidence with an experimental result. The spray edge line is shown by assuming a lower bound of spray thickness.

Structural Response of Ships due to Stern Flare Slamming

Car ferries, pure car carriers and container ships may suffer from slamming on the stern flare because those ships require broad deck plane and the bottom of near the aft part becomes flat. In the present paper, a response of a container ship to stern flare slamming is studied using the numerical method which authors developed to analyze the dynamic response of ship hulls to the impulsive hydrodynamic force.The calculations are performed for the ship in following seas because an environment condition data suggests that a ship is operated in following seas as frequently as in head seas. Results obtained are as follows :1) When the wave length is equal to the ship length or shorter, there is a possibility of occurrence of severe stern flare slamming.2) It is recommended from a viewpoint of the strength that stern bottoms should have some degree of dead rise angle. Hydrodynamic impact force is not observed in the calculated result for the ship the stern bottom of which has 10° of dead rise angle.3) 4- and 5-node vibration have significant influence to the structural response of an aft part of ship as well as 2- and 3-node modes.

On the maximum pressure in the water impact of the wedge model

The present paper investigates theoretically the maximum pressure occurred in the water impact of the rigid wedge model. It is well known that Wagner's theory predicts the maximum pressure much higher than the experimental results by Chuang in case of small dead rise angle 4°, where air cushioning effects can be ignored. One of the reasons mentioned of such a discrepancy is error in measurement by a pressure gage of a finite diameter. It is not proved, however, that all the discrepancy can be attributed to the measurement error.The authors determine the wetted width by considering the splash width derived from the condition of energy balance and of the free surface under the assumption of self-similarity. The smaller value of the wetted width than Wagner's prediction is obtained and it shows a good agreement with the experiment by Bisplinghoff. &. Doherty.The present theory gives the lower maximum pressure than that predicted by Wagner, since the maximum pressure is approximately in proportion to the square of the wetted width ratio c/c' for small deadrise angle.It is concluded, therefore, that the maximum pressure is essentially lower than Wagner's prediction under the assumption of self-similarity in free surface.

When the Kingdom Comes Messianic Themes in Medieval Jewish Art

Students of medieval Christian art are all too familiar with Last Judgment scenes on the tympana of medieval Gothic cathedrals. The tympanum over the west portal of Bourges Cathedral is a good example in its awesome and dramatic depiction of the fate which awaited every Christian in the world to come. At the summit, Christ is seen enthroned on the seat of judgment, surrounded by angels, St. John and the Virgin. At the bottom, the resurrected dead rise from their tombs to appear before their judge. Below Christ is the chief actor in the drama of Judgment—St. Michael. With a balance suspended from his hand, he carefully weighs the deeds of every Christian to determine which soul is to be eternally damned to the tortures of hell on the left, and which is to enjoy the rewards of eternal bliss in paradise on the right. Such Christian representations need little explanation, but were I to ask how medieval Jewish art conceived the afterlife, my question might be met with some surprise, since it is common to find...