Study on Melt Coolability and Water Ingression Through Melt Pool in Scaled Down Core Catcher—The Influence of Vessel Angle

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Ganesh V. ◽  
Parimal P. Kulkarni ◽  
Arun K. Nayak
Keyword(s):  
Temperature History ◽  
Bottom Plate ◽  
Transient Temperature ◽  
Test Evaluation ◽  
The Core ◽  
Melt Pool ◽  
Core Catcher ◽  
Post Test ◽  
History Of ◽  
Series Of Experiments

Abstract An ex-vessel core catcher is generally used in advanced reactors to mitigate core melt scenarios by stabilizing and cooling the corium for prolonged period by strategically flooding it. The side indirect cooling along with delayed top flooding of water ensures that the water interacts with the oxidic components only after melt inversion. However, water ingression either through the top of melt pool or through the crust–vessel gap may lead to unoxidized metal–water interaction in the melt leading to hydrogen production. To avoid this deleterious scenario, water ingression into the bulk of the melt is to be avoided. In this study, a series of experiments using a scaled down core catcher has been conducted to study the phenomena of melt coolability and water ingression by varying the bottom vessel angle of the core catcher. Three different angles of the bottom plate were considered: 10, 20, and 30 deg. The melt used was a corium simulant in the form of CaO–B2O3.The transient temperature history of melt pool, inside and outside vessel surface temperatures along with the post-test evaluation of the test section reveals that the bottom angle has an effect on water ingression and the resultant melt eruption at different locations. The tests conducted showed that the scaled down core catcher with 10-deg inclination of the bottom plate does not exhibit water ingression, whereas the 20- and 30-deg angle-scaled down core catchers showed water ingression and subsequent melt eruption.

Numerical and Experimental Model Studies on Thermal Hydraulic Behavior of FBR Internal Core Catcher Assembly

2006 ◽  
Author(s):  
Sanjay Kumar Das ◽  
Anil Kumar Sharma ◽  
A. Jasmin Sudha ◽  
G. Punitha ◽  
G. Lydia ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Source ◽  
Maximum Temperature ◽  
Model Studies ◽  
The Core ◽  
Core Catcher ◽  
Internal Core ◽  
Series Of Experiments ◽  
Retention Device ◽  
Good Agreement

Core Catcher is provided as an in-vessel core debris retention device to collect, support, cool and maintain in sub-critical configuration, the generated core debris from fuel melting due to certain postulated Beyond Design Basis Events (BDBE) for Fast Breeder Reactor (FBR). This also acts as a barrier to prevent settling of debris on main vessel and keeps its maximum temperature within acceptable creep range. Heat transfer by natural convection in the core catcher assembly has been assessed numerically and through water experiments using geometrically similar configuration. Resistive heating elements are used in experiment as heat source to simulate debris decay heat on core catcher. Series of experiments were carried out for two configurations referred as geometry A and geometry B. The later configuration showed enhanced natural convective heat transfer from the lower plenum of the vessel. Temperatures were monitored at critical positions and compared with numerical evaluation. Numerically evaluated flow fields and isotherms are compared with experimental data for specific steady state temperatures on heat source plate. Numerical results are found to be in good agreement with that obtained from experiments. The combined efforts of numerical and experimental work conclude core catcher assembly with geometry B to be more suitable.

Experimental Analysis of Journal Bearings Undergoing Oscillatory Motion

2007 ◽  
Author(s):  
Xiaobin Lu ◽  
Michael M. Khonsari
Keyword(s):  
Friction Coefficient ◽  
Thermal Field ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Oscillatory Motion ◽  
Temperature History ◽  
The Finite Element Method ◽  
History Of ◽  
Series Of Experiments ◽  
Good Agreement

A series of experiments is carried out on a grease-lubricated, heavy loaded journal bearing undergoing oscillatory motion to examine its thermal field. The history of temperature measurement and the friction coefficient are monitored. The finite element method is employed using ANSYS to simulate the temperature history with input of the friction coefficient result. Experiment and simulation show good agreement.

Thanato-Laboratorien. Theorien von Tod und Sterben und Elias Canettis Buch gegen den Tod

2020 ◽  
Vol 4 (1) ◽  
pp. 67-86
Author(s):  
Elisabeth Heyne
Keyword(s):  
Human Life ◽  
Death And Dying ◽  
Point Of View ◽  
Visual Images ◽  
Elias Canetti ◽  
History Of ◽  
Series Of Experiments ◽  
First Time ◽  
Textual Form ◽  
Or History

AbstractAlthough visual culture of the 21th century increasingly focuses on representation of death and dying, contemporary discourses still lack a language of death adequate to the event shown by pictures and visual images from an outside point of view. Following this observation, this article suggests a re-reading of 20th century author Elias Canetti. His lifelong notes have been edited and published posthumously for the first time in 2014. Thanks to this edition Canetti's short texts and aphorisms can be focused as a textual laboratory in which he tries to model a language of death on experimental practices of natural sciences. The miniature series of experiments address the problem of death, not representable in discourses of cultural studies, system theory or history of knowledge, and in doing so, Canetti creates liminal texts at the margins of western concepts of (human) life, science and established textual form.

THE CORE AND PERIPHERY OF THE CURRENT CULTURE OF ARTISTIC CREATION ABOUT THE GREAT PATRIOTIC WAR IN THE STUDENTS’ VIEWS

2020 ◽  
Vol 6 (3) ◽  
pp. 130-149
Author(s):  
Elena N. NARKHOVA ◽  
Dmitry Yu. NARKHOV
Keyword(s):  
Historical Memory ◽  
Soviet Period ◽  
Russian Society ◽  
Student Culture ◽  
The Core ◽  
Musical Works ◽  
Great Patriotic War ◽  
History Of ◽  
Current Student ◽  
Historical Periods

This article analyzes the degree of demand for works of art (films and television films and series, literary and musical works, works of monumental art) associated with the history of the Great Patriotic War among contemporary students. This research is based on the combination of two theories, which study the dynamics and statics of culture in the society — the theory of the nucleus and periphery by Yu. M. Lotman and the theory of actual culture by L. N. Kogan. The four waves of research (2005, 2010, 2015, 2020) by the Russian Society of Socio¬logists (ROS) have revealed a series of works in various genres on this topic in the core structure and on the periphery of the current student culture; this has also allowed tracing the dynamics of demand and the “movement” of these works in the sociocultural space. The authors introduce the concept of the archetype of the echo of war. The high student recognition of works of all historical periods (from wartime to the present day) is shown. A significant complex of works has been identified, forming two contours of the periphery. Attention is drawn to the artistic work of contemporary students as a way to preserve the historical memory of the Great Patriotic War. This article explains the necessity of preserving the layer of national culture in order to reproduce the national identity in the conditions of informational and ideological pluralism of the post-Soviet period. The authors note the differentiation of youth due to the conditions and specifics of socialization in the polysemantic sociocultural space.

Indexicality of Grammar: The Case of Japanese Transgender Speakers

2019 ◽  
Author(s):  
Hideko Abe
Keyword(s):  
Gender Identity ◽  
Gender Identity Disorder ◽  
Grammatical Gender ◽  
Core Structure ◽  
Subject Positions ◽  
Transgender Identity ◽  
The Core ◽  
History Of ◽  
History Of Scholarship ◽  
Grammatical Structures

This article discusses how the intersection of grammatical gender and social gender, entwined in the core structure of language, can be analyzed to understand the dynamic status of selfhood. After reviewing a history of scholarship that demonstrates this claim, the discussion analyzes the language practices of transgender individuals in Japan, where transgender identity is currently understood in terms of sei-dōitsusei-shōgai (gender identity disorder). Based on fieldwork conducted between 2011 and 2017, the analysis reveals how individuals identifying with sei-dōitsusei-shōgai negotiate subject positions by manipulating the specific indexical meanings attached to grammatical structures.

Boundary Condition Design to Heat a Moving Object at Uniform Transient Temperature Using Inverse Formulation

2004 ◽  
Vol 126 (3) ◽  
pp. 619-626 ◽  
Author(s):  
Hakan Ertu¨rk ◽  
Ofodike A. Ezekoye ◽  
John R. Howell
Keyword(s):  
Boundary Condition ◽  
Temperature Distribution ◽  
Design Problem ◽  
Manufacturing Industry ◽  
Three Dimensional ◽  
Chemical Deposition ◽  
Iterative Solution ◽  
Conveyor Belt ◽  
Temperature History ◽  
Transient Temperature

The boundary condition design of a three-dimensional furnace that heats an object moving along a conveyor belt of an assembly line is considered. A furnace of this type can be used by the manufacturing industry for applications such as industrial baking, curing of paint, annealing or manufacturing through chemical deposition. The object that is to be heated moves along the furnace as it is heated following a specified temperature history. The spatial temperature distribution on the object is kept isothermal through the whole process. The temperature distribution of the heaters of the furnace should be changed as the object moves so that the specified temperature history can be satisfied. The design problem is transient where a series of inverse problems are solved. The process furnace considered is in the shape of a rectangular tunnel where the heaters are located on the top and the design object moves along the bottom. The inverse design approach is used for the solution, which is advantageous over a traditional trial-and-error solution where an iterative solution is required for every position as the object moves. The inverse formulation of the design problem is ill-posed and involves a set of Fredholm equations of the first kind. The use of advanced solvers that are able to regularize the resulting system is essential. These include the conjugate gradient method, the truncated singular value decomposition or Tikhonov regularization, rather than an ordinary solver, like Gauss-Seidel or Gauss elimination.

scholarly journals Brain smart – Let's play safely: Evaluation of a concussion education program in schools

2021 ◽  
Vol 5 ◽  
pp. 205970022110244
Author(s):  
Katie Alison Falla ◽  
Sarah Randall ◽  
Carol DeMatteo
Keyword(s):  
School Board ◽  
Education Program ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Concussion Management ◽  
Chi Squared ◽  
Post Test ◽  
History Of ◽  
Concussion Knowledge ◽  
Concussion Education

Objectives There are two objectives for this paper. First, to determine effects of a concussion education program in a local school board in terms of concussion-specific knowledge in children and confidence in identifying and managing concussion in adults. Second, to identify differences and similarities in concussion knowledge between children who participate in sports and those who do not and between children with a history of one or more concussions and those without. Design A cross sectional survey regarding concussion knowledge was distributed randomly to students and adults at both pre- and posteducation timepoints. A concussion education program was disseminated across the school board for students between the distribution survey timepoints. Following the education program, adults and students completed their respective post-test surveys. Chi-squared tests in SPSS determined the significance of between-group differences. Results All 17 adults (100.0%) who had received concussion education recently reported confidence in their knowledge of concussion management, compared to 35.7% adults who had not received education for over a year (p = 0.020). For students, all of whom completed the concussion education training between the pre- and post-tests, there were no significant differences in concussion knowledge scores between athletes and non-athletes (either in or outside of school) or between those with a history of concussion and those without. There were no significant changes in concussion knowledge between the pre- and post-tests, except for one question. Conclusion Concussion education programs increase confidence of concussion management protocols in adults involved in sport, but they require improvements to better support knowledge amelioration, particularly for target groups that are at high risk of sustaining another injury.

A Three-Dimensional Finite Difference Solution for the Thermal Stresses in Railcar Wheels

1969 ◽  
Vol 91 (3) ◽  
pp. 891-896 ◽  
Author(s):  
G. E. Novak ◽  
B. J. Eck
Keyword(s):  
Computer Program ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
Transient Temperature ◽  
Shear Stresses ◽  
Radial Temperature ◽  
Closed Form Solutions ◽  
Brake Application ◽  
History Of ◽  
Thin Disks

A numerical solution is presented for both the transient temperature and three-dimensional stress distribution in a railcar wheel resulting from a simulated emergency brake application. A computer program has been written for generating thermoelastic solutions applicable to wheels of arbitrary contour with temperature variations in both axial and radial directions. The results include the effect of shear stresses caused by the axial-radial temperature gradients and the high degree of boundary irregularity associated with this type of problem. The program has been validated by computing thermoelastic solutions for thin disks and long cylinders; the computed values being in good agreement with the closed form solutions. Currently, the computer program is being extended to general stress solutions corresponding to the transient temperature distributions obtained by simulated drag brake applications. When this work is completed, it will be possible to synthesize the thermal history of a railcar wheel and investigate the effects of wheel geometry in relation to thermal fatigue.

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