scholarly journals Investigation and Analysis of the Catastrophic Failure of an Offshore Water Injector Well

2018 ◽  
Vol 203 ◽  
pp. 01002
Author(s):  
Ramesh Ramasamy
Keyword(s):  
Failure Mode ◽  
Catastrophic Failure ◽  
Offshore Water ◽  
Sequence Of Events

The catastrophic failure of an offshore water injector well is presented in this paper. The failure mode was determined from the final collapsed state of the conductor pipe which resulted in the surface Xmas tree and wellhead to drop vertically down onto the platform deck. Various inspections and assessments are carried out to determine the integrity of the well structure and compared against the original drilling records. Stability evaluations of the casing is also carried out to account for the loss of annular cement which resulted in loss of centralisation. The analyses conclude that various sequence of events have contributed towards the failure of this well. The lack of intermediate inspections and monitoring have resulted in uninhibited corrosion and pitting on the conductor pipe. Some considerations on the necessity of an effective inspections strategy and rationalisations of a robust integrity screening are also drawn.

scholarly journals Catastrophic failure of tripolar constrained liners due to backside wear: a novel failure mode

2018 ◽  
Vol 4 (3) ◽  
pp. 270-274 ◽  
Author(s):  
Christopher W. Jones ◽  
Michael-Alexander Malahias ◽  
Elexis Baral ◽  
Timothy Wright ◽  
Thomas P. Sculco ◽  
...  
Keyword(s):  
Failure Mode ◽  
Catastrophic Failure ◽  
Backside Wear

Transition angle, a novel concept for predicting the failure mode in orthotropic materials

2012 ◽  
Vol 227 (10) ◽  
pp. 2157-2164 ◽  
Author(s):  
Mahdi Fakoor ◽  
Roham Rafiee
Keyword(s):  
Failure Mode ◽  
Damage Zone ◽  
Laminated Composite ◽  
Theoretical Method ◽  
Orthotropic Materials ◽  
Fiber Direction ◽  
Catastrophic Failure ◽  
Fiber Fracture ◽  
Laminated Composite Materials ◽  
Novel Concept

In this article, transition angle, a new concept for predicting failure mode in orthotropic materials, has been proposed. This angle is introduced as a transition angle from fiber fracture mode to matrix one of orthotropic part. Theoretical calculation of this angle is performed using the concept of microcracks in crack tip damage zone. In order to ensure about the consistency of the proposed approach with the nature of the fracture phenomena in wood, the results obtained from theoretical method are put into contrast with those obtained from practical testing. Transition angle is usable in introducing a safe domain for an angle in loading vector to fiber direction at laminated composite materials and prevents catastrophic failure.

Designing a Control and Containment Device for Cradle-Mounted, Transverse-Actuated Swash Plates

2000 ◽  
Vol 123 (3) ◽  
pp. 447-455 ◽  
Author(s):  
Noah D. Manring
Keyword(s):  
Closed Form ◽  
Failure Mode ◽  
Low Pressure ◽  
Design Criterion ◽  
Catastrophic Failure ◽  
Successful Operation ◽  
Axial Piston Pumps ◽  
Swash Plate ◽  
Critical Components ◽  
Axial Piston

Many axial-piston pumps utilize a swash plate for regulating discharge flow. In this research, the required control and containment forces are examined for a cradle-mounted, transverse-actuated swash plate. These forces are described in closed-form for providing the designer with information that is necessary for sizing these critical components within the pump. In this research, it is shown that improper design of the containment device will cause the swash plate to dislocate itself from the cradle. In general, it is noted that this failure mode is severe and that it may even cause catastrophic failure of the pump. In summary, a design criterion is presented which describes the limits of successful operation during both high and low-pressure conditions. Design and operational changes are suggested for improving the adequacy of the swash-plate containment design.

scholarly journals An ISO 9001 based approach for the implementation of process FMEA in the Brazilian automotive industry

2015 ◽  
Vol 32 (6) ◽  
pp. 589-602 ◽  
Author(s):  
Dimas Campos de Aguiar ◽  
Valério Antonio Pamplona Salomon ◽  
Carlos Henrique Pereira Mello
Keyword(s):  
Failure Mode ◽  
Potential Effect ◽  
Process Approach ◽  
Raw Material ◽  
Iso 9001 ◽  
Multidisciplinary Teams ◽  
Complex Activity ◽  
Effect Analysis ◽  
Content Type ◽  
Sequence Of Events

Purpose – The purpose of this paper is to present a structured way for the definitions of the Process Failure Mode and Effect Analysis (FMEA) attributes, such as potential failure mode, potential cause and potential effect, in order to make it simpler to define the controls and scores. Design/methodology/approach – This study performs, through a case study in incoming inspection of raw material, the comparison of a conventional application of the Process FMEA with a proposal based on the concepts of process approach defined by ISO 9001. Findings – Even written in a form similar to a script, the application of Process FMEA is a very complex activity and, like most quality tools, before being applied, FMEA should be clearly understood by the team. One way to facilitate this understanding is considering the sequence of events in the failures analysis to understand their causes and effects, just as are the sequences of inputs and outputs in the definition of the process approach addressed in ISO 9001. Originality/value – This paper shows a simple way to better structure Process FMEA, facilitating meetings with multidisciplinary teams.

Fine Structural Changes in the Adenohypophyses of Rats Following Destruction of the Pituitary Stalk

1977 ◽  
Vol 35 ◽  
pp. 496-497
Author(s):  
K. Kovacs ◽  
E. Horvath ◽  
J. M. Bilbao ◽  
F. A. Laszlo ◽  
I. Domokos
Keyword(s):  
Structural Changes ◽  
Tissue Injury ◽  
Anterior Lobe ◽  
Uranyl Acetate ◽  
Male Rats ◽  
Pituitary Stalk ◽  
Sequence Of Events ◽  
Pituitary Glands ◽  
Electrolytic Lesions ◽  
Ultrathin Sections

Electrolytic lesions of the pituitary stalk in rats interrupt adenohypophysial blood flow and result in massive infarction of the anterior lobe. In order to obtain a deeper insight into the morphogenesis of tissue injury and to reveal the sequence of events, a fine structural investigation was undertaken on adenohypophyses of rats at various intervals following destruction of the pituitary stalk.The pituitary stalk was destroyed electrolytically, with a Horsley-Clarke apparatus on 27 male rats of the R-Amsterdam strain, weighing 180-200 g. Thirty minutes, 1,2,4,6 and 24 hours after surgery the animals were perfused with a glutaraldehyde-formalin solution. The skulls were then opened and the pituitary glands removed. The anterior lobes were fixed in glutaraldehyde-formalin solution, postfixed in osmium tetroxide and embedded in Durcupan. Ultrathin sections were stained with uranyl acetate and lead citrate and investigated with a Philips 300 electron microscope.

Analytical electron microscopy of grain boundaries in Al-Cu metallizations

1992 ◽  
Vol 50 (2) ◽  
pp. 1684-1685
Author(s):  
J. R. Michael ◽  
A. D. Romig ◽  
D. R. Frear
Keyword(s):  
Electron Microscopy ◽  
Integrated Circuits ◽  
Failure Mode ◽  
Current Density ◽  
Thermal History ◽  
Analytical Electron Microscopy ◽  
Cu Metallization ◽  
Analytical Electron ◽  
Interconnect Lines

Al with additions of Cu is commonly used as the conductor metallizations for integrated circuits, the Cu being added since it improves resistance to electromigration failure. As linewidths decrease to submicrometer dimensions, the current density carried by the interconnect increases dramatically and the probability of electromigration failure increases. To increase the robustness of the interconnect lines to this failure mode, an understanding of the mechanism by which Cu improves resistance to electromigration is needed. A number of theories have been proposed to account for role of Cu on electromigration behavior and many of the theories are dependent of the elemental Cu distribution in the interconnect line. However, there is an incomplete understanding of the distribution of Cu within the Al interconnect as a function of thermal history. In order to understand the role of Cu in reducing electromigration failures better, it is important to characterize the Cu distribution within the microstructure of the Al-Cu metallization.

Desmosomal distribution in the epidermis of a non-contracting human skin equivalent

1992 ◽  
Vol 50 (1) ◽  
pp. 896-897
Author(s):  
L.X. Oakford ◽  
S.D. Dimitrijevich ◽  
R. Gracy
Keyword(s):  
Human Skin ◽  
Basal Layer ◽  
Skin Equivalent ◽  
Tissue Component ◽  
Intact Skin ◽  
Similar Sequence ◽  
Sequence Of Events ◽  
Suprabasal Keratinocytes ◽  
Human Skin Equivalent

In intact skin the epidermal layer is a dynamic tissue component which is maintained by a basal layer of mitotically active cells. The protective upper epidermis, the stratum corneum, is generated by differentiation of the suprabasal keratinocytes which eventually desquamate as anuclear comeocytes. A similar sequence of events is observed in vitro in the non-contracting human skin equivalent (HSE) which was developed in this lab (1). As a part of the definition process for this model of living skin we are examining its ultrastructural features. Since desmosomes are important in maintaining cell-cell interactions in stratified epithelia their distribution in HSE was examined.

Albumin-Induced Endocytic Vacuoles in Tetrahymena Pyrijormis

1975 ◽  
Vol 33 ◽  
pp. 694-695
Author(s):  
L. J. Brenner ◽  
D. G. Osborne ◽  
B. L. Schumaker
Keyword(s):  
Electron Microscopy ◽  
Bovine Serum Albumin ◽  
Bovine Serum ◽  
Protein Concentration ◽  
Tetrahymena Pyriformis ◽  
Sequence Of Events ◽  
Cytoplasmic Bodies ◽  
Food Vacuoles ◽  
Mouse Ascites ◽  
Normal Human

Exposure of the ciliate, Tetrahymena pyriformis, strain WH6, to normal human or rabbit sera or mouse ascites fluids induces the formation of large cytoplasmic bodies. By electron microscopy these (LB) are observed to be membrane-bounded structures, generally spherical and varying in size (Fig. 1), which do not resemble the food vacuoles of cells grown in proteinaceous broth. The possibility exists that the large bodies represent endocytic vacuoles containing material concentrated from the highly nutritive proteins and lipoproteins of the sera or ascites fluids. Tetrahymena mixed with bovine serum albumin or ovalbumin solutions having about the same protein concentration (7g/100 ml) as serum form endocytic vacuoles which bear little resemblance to the serum-induced LB. The albumin-induced structures (Fig. 2) are irregular in shape, rarely spherical, and have contents which vary in density and consistency. In this paper an attempt is made to formulate the sequence of events which might occur in the formation of the albumin-induced vacuoles.

Amyloid β-peptide and Alzheimer's disease

2014 ◽  
Vol 56 ◽  
pp. 99-110 ◽  
Author(s):  
David Allsop ◽  
Jennifer Mayes
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Senile Plaques ◽  
Strong Support ◽  
Amyloid Β ◽  
Amyloid Β Peptide ◽  
Amyloid Cascade Hypothesis ◽  
Sequence Of Events ◽  
Aβ Amyloid ◽  
Amyloid Cascade

One of the hallmarks of AD (Alzheimer's disease) is the formation of senile plaques in the brain, which contain fibrils composed of Aβ (amyloid β-peptide). According to the ‘amyloid cascade’ hypothesis, the aggregation of Aβ initiates a sequence of events leading to the formation of neurofibrillary tangles, neurodegeneration, and on to the main symptom of dementia. However, emphasis has now shifted away from fibrillar forms of Aβ and towards smaller and more soluble ‘oligomers’ as the main culprit in AD. The present chapter commences with a brief introduction to the disease and its current treatment, and then focuses on the formation of Aβ from the APP (amyloid precursor protein), the genetics of early-onset AD, which has provided strong support for the amyloid cascade hypothesis, and then on the development of new drugs aimed at reducing the load of cerebral Aβ, which is still the main hope for providing a more effective treatment for AD in the future.

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