scholarly journals Deformations on the ship sections during fabrication: cause and remedies

2021 ◽  
Vol 44 ◽  
pp. 15-22
Author(s):  
Eisawy Mohamed ◽  
Renardo-Florin Teodor
Keyword(s):  
Production Cost ◽  
Deformation Characteristics ◽  
The Finite Element Method ◽  
Case Scenario ◽  
Worst Case ◽  
Turning Operations ◽  
Influencing Parameters ◽  
Steel Cutting ◽  
Process Material

During fabrication process, material deformations are likely to occur due to various factors such as heat during steel cutting, welding induced deformations, lifting and turning of ship sections, temporary stiffening and other possible modifications of ship sections. Lifting induced deformations is one of the major causes of deformations that highly affect the production cost and quality. The aim of this thesis is to outline the main causes of deformations that occur in ship sections during fabrication and to analyse in detail the lifting and turning operations of one ship section using the Finite Element Method (FEM). A strength check using the FEM has been performed on the selected ship section to investigate the deformations and stresses in two different cases with three different loading conditions. First, the section has been analysed without temporary stiffening in three load scenarios: lifting before turning, worst-case scenario during turning and lifting after turning. Similarly, the second case study has been analysed but with the temporary stiffening added according to the lifting plan. Various influencing parameters that determine the lifting plan has been investigated such as the sling angle which directly affects the deformation characteristics. It is observed that the addition of temporary stiffening is essential to minimize the deformations and to maintain the stress levels below the yield point.

Slavery in Brazil: A Case Study of Diamantina, Minas Gerais

1988 ◽  
Vol 45 (1) ◽  
pp. 47-59 ◽  
Author(s):  
Donald Ramos
Keyword(s):  
Urban Areas ◽  
Living Conditions ◽  
Case Scenario ◽  
Worst Case ◽  
Men And Women ◽  
Mortality And Morbidity ◽  
Diamond Mining ◽  
Large Numbers ◽  
Special Case

The study of slave mortality and morbidity in Brazil has been very difficult because of the extreme paucity of sources. Techniques which have been useful in studying the lives of free men and women seldom are useful for analyzing their slaves. The use of parish records such as baptism and death registers is not possible because of the custom of listing only the slave's first name and the unimaginative choice of names which resulted in large numbers of Joãos, Josés, Manuels, Antônios, Antonias, Joanas, and, of course, Marias. Equally important, the types of plantation records available to students of U.S. slavery have seldom been found for Brazil.This essay is an examination of an isolated slave register, which, for a series of idiosyncratic reasons, provides information permitting a glimpse at mortality and morbidity in a distinct and carefully controlled slave population. Because the slaves involved were used in diamond mining under horrendous conditions it is probable that the conclusions reached in this essay represent a worst case scenario. Rather than typical, this is a special case where work and living conditions were probably worse than in plantation zones and certainly worse than in urban areas. It is this situation which makes the conclusions of this essay quite startling.

scholarly journals IMPACT OF SEA LEVEL RISE ON THE ACCESSIBILITY OF COASTAL PORTS: A CASE STUDY OF THE PORT OF ZEEBRUGGE (BELGIUM)

2018 ◽  
pp. 107
Author(s):  
Gerasimos A. Kolokythas ◽  
Bart De Maerschalck ◽  
Joris Vanlede ◽  
Kai Chu
Keyword(s):  
Numerical Simulations ◽  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Zone ◽  
Current Situation ◽  
Reference Scenario ◽  
Case Scenario ◽  
Worst Case ◽  
Access Channel

The effect of sea level rise on the hydrodynamic flow in the Belgian coastal zone is investigated in the light of the nautical accessibility of the port of Zeebrugge in Belgium. To this end, numerical simulations are performed considering three different scenarios of sea level rise along with a reference scenario (current situation). Specifically, a moderate, a warm and a worst case scenario of sea level rise (SLR) equal to 60 cm, 90 cm and 200 cm by the year 2100, are considered. The main objective is to find out how the strong tidal currents, which are mainly directed transversely to the access channel and limit the access to the port to a certain tidal window, will be affected by the considered SLR scenarios.

Integrated pre-drill and real-time geomechanical modelling brings significant benefits to deepwater wildcat exploration drilling campaign – a case study

2017 ◽  
Vol 57 (2) ◽  
pp. 698
Author(s):  
M. Sadegh Asadi ◽  
Amitava Ghosh ◽  
Sanjeev Bordoloi ◽  
Michael Reese
Keyword(s):  
Real Time ◽  
Wellbore Stability ◽  
Model Parameters ◽  
Seismic Velocities ◽  
Real Time Monitoring ◽  
Case Scenario ◽  
Worst Case ◽  
Primary Input ◽  
Exploratory Wells

This case study demonstrates the significance of integrated pre-drill geomechanical modelling and real-time monitoring for drilling wildcat exploratory wells in the deepwater settings of an offshore field in South-East Asia. The key challenges in the area include deeper water depths (1.6 km), lack of relevant offset well information and a complex geological setting. In this project, the primary input data for the pre-drill geomechanical model were low resolution 2D seismic velocities derived from an un-calibrated velocity model and petrophysical data from an offset well located in shallow waters, 100 km away from the deepwater prospect. During pre-drill planning, a contingency casing plan was put in place to consider the uncertainties in the model and cover the worst-case scenario of high pore pressure (PP). To reduce the uncertainty during drilling, the well was monitored in real-time and the pre-drill predictions improved whenever new information or data became available. The objective was to have good data coverage to assist in real-time geomechanical modelling for operational decision making. Real-time wellbore stability monitoring was carried out by utilising all available drilling and logging data as well as logging while drilling (LWD), pressure measurements and seismic while drilling (SWD) velocities. Wellsite interpretation on cuttings, cavings and formation gases were also integrated into the model predictions. Based on real-time monitoring, pre-drill predictions and model parameters were continuously updated for the next planned section at the end of each section target depth (TD). Interactive real-time monitoring with continuous pre-drill model updates before drilling the subsequent sections helped to not only deepen the intermediate hole sections, but also to drill efficiently with proper mud weight management and without any significant wellbore instability issues. This integrated workflow helped to successfully drill two exploratory wells, with the major benefit of eliminating the contingency 6ʹʹ slim-hole section.

scholarly journals Risk Analysis of Quarantine Station Performance: A Case Study of the Importation of Equine Infectious Anemia Virus-Infected Horses into California

1998 ◽  
Vol 10 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Tim E. Carpenter ◽  
Michael D. McBride ◽  
David W. Hird
Keyword(s):  
Equine Infectious Anemia Virus ◽  
Computer Simulation Model ◽  
Case Scenario ◽  
Worst Case ◽  
Quarantine Station ◽  
Equine Infectious Anemia ◽  
Simulation Results ◽  
Anemia Virus ◽  
Importation Risk

We examined the risk of importing and mistakenly releasing equine infectious anemia virus (EIAV)-infected horses into California. A computer simulation model was constructed to evaluate current and alternative quarantine station procedures; 150,000 iterations were performed to simulate 15 different scenarios of 10,000 horses imported into the state over a 14-year period. Simulation results showed that under current conditions of low EIAV prevalence in exporting countries, increasing the quarantine period would not decrease the number of EIAV-infected horses mistakenly released from quarantine. In a worst case scenario of high EIAV prevalence in exporting countries, the model predicted 10 EIAV-infected horses would be imported, of these 1 or none would escape detection and would be released mistakenly if quarantine duration were 3 or 14 days, respectively. This model may be applied to other quarantine station situations for evaluating the importation risk for EIAV and other diseases.

Monitoring and Screening of Pipelines for Movement: A Fast and Cost-Effective Alternative for Pipeline Operators to Measure Drift in Pipelines

2019 ◽  
Author(s):  
Michael Schorr ◽  
Klaas Kole ◽  
Ferdinand Foessing
Keyword(s):  
Early Warning ◽  
Early Stage ◽  
Satellite Image ◽  
Mining Industry ◽  
Specific Area ◽  
Cost Effective ◽  
Heavy Rain ◽  
Case Scenario ◽  
Worst Case

Abstract For pipelines in the oil, gas, and mining industry, movement of pipelines is one of the main integrity hazards. This movement in most cases is caused by landslides instigated by heavy rain, earthquakes or volcanic activities. If the pipeline movement remains undetected at an early stage, it can lead to the need for costly repairs to prevent, remove, or repair potential or actual damage. Moreover, if the movements stay undetected for too long, these lines may fail and lead to catastrophic events. This paper will illustrate what a fast and cost-effective solution to avoid these threats at an early stage looks like and how it works. It will explain the process and demonstrate the full power of this technology on the basis of a case study. The standard solution for pipelines without a permanent position monitoring system at the time of installation includes the use of intelligent tools that are able to detect even the slightest changes in the trajectory. These inspection tools are quite expensive to run, especially when multiple screening runs are required throughout a year, e.g. before and after the rainy season or after a seismic event. Other monitoring solutions are either limited to only a specific area where the movement has already been detected at an earlier stage or lack the precision required to serve as an early warning system, such as LIDAR or satellite image comparison. Over the years, ROSEN has developed a technology that can bridge the gap between frequent measurements and cost-effective service. It is based on an electronic gyroscope that is commonly used in Inline Inspection tools but can also be installed in readily available cleaning tools. When first run in a pipeline, it records the whole pipeline trajectory, leaving no segment undocumented. The next step is to compare these recorded pipeline routing measurements with already existing trajectory baseline data, recorded earlier by any ILI tool with an optical gyro or similar. This comparison will reveal any deviation between both trajectories and precisely determine any pipeline movement. A case study will demonstrate how the comparison is achieved. When performing repetitive inspections, this screening comparison enables the operators to detect the onset of movements and monitor the progress of any known pipeline movement. It allows them to distinguish between stable areas from dynamic ground movements and keeps close track of changes in the pipe course. Through regular repetitions, any further development of the movement is tracked, and appropriate reactive measures can be scheduled in a timely manner. This new service provides a cost-effective and powerful early warning tool for geological pipeline integrity threats that can lead to loss of integrity, the asset, or — worst-case scenario — loss of life or environmental contamination, while at the same time, it reduces the necessity of pipeline intervention that will affect production.

scholarly journals Mixed farming diversification may be costly: southern Queensland case study

2017 ◽  
Vol 68 (4) ◽  
pp. 378 ◽  
Author(s):  
A. F. Zull ◽  
J. Owens ◽  
M. Bourgault ◽  
B. Johnson ◽  
G. Peck ◽  
...  
Keyword(s):  
Production Systems ◽  
Farming System ◽  
Order System ◽  
Case Scenario ◽  
Worst Case ◽  
Local Climate ◽  
Mixed Farming ◽  
The Right ◽  
Semi Arid

Many farmers in Australia and in other countries have a choice of crop or livestock production, and many choose a mixture of both, based on risk preference, personal interests, markets, land resources and local climate. Mixed farming can be a risk-spreading strategy, especially in highly variable climates, but the right scales of each enterprise within the mix may be critical to farm profitability. To investigate expected farm profits, the probability of breaking even, as well as the worst and best case scenarios, we used farm data and APSIM (Agricultural Production Systems Simulator) to simulate the production of a typical, semi-arid, mixed-farm in southern Queensland. Three farming system scenarios were investigated: I, livestock and more intensive cropping; II, current production system of livestock and minimal cropping; and III, livestock only. We found that the expected profits were in the order system I > system III > system II. The key reason for the lower profits of system II was the high overhead cost of capital to continue some cropping, with low annual cropping income. Under the worst case scenario, in years with low rainfall, system I had the greatest downside risk with far greater financial losses. Systems I and III had similar probabilities of breaking even, and higher than system II, which incurs cropping overheads and limited cropping returns. Therefore, system II was less desirable than either system I or III. This case study helps farmers and advisors of semi-arid mixed farming enterprises to be better informed when making decisions at the paddock and whole-farm level, in both the short and long term, with respect to profit and risk. The method used in this paper can be applied to other mixed farms, in Australia and elsewhere.

scholarly journals Hazard Assessment for a Glacier Lake Outburst Flood in the Mo Chu River Basin, Bhutan

2021 ◽  
Vol 11 (20) ◽  
pp. 9463
Author(s):  
Wilfried Hagg ◽  
Stefan Ram ◽  
Alexander Klaus ◽  
Simon Aschauer ◽  
Sinan Babernits ◽  
...  
Keyword(s):  
River Basin ◽  
Risk Mitigation ◽  
Residential Buildings ◽  
Outburst Flood ◽  
Case Scenario ◽  
Worst Case ◽  
Lake Volume ◽  
Flood Magnitude ◽  
Elevation Model

The frequency of glacier lake outbursts floods (GLOFs) is likely to increase with the ongoing glacier retreat, which produces new glacial lakes and enlarges existing ones. Here, we simulate the outburst of a potentially dangerous glacial lake in Bhutan by applying hydrodynamic modelling. Although the lake volume is known, several parameters connected to the dam breach and the routing of the flood are rough estimates or assumptions, which introduce uncertainties in the results. For this reason, we create an ensemble of nine outburst scenarios. The simulation of magnitude and timing of possible inundation depths is an important asset to prepare emergency action plans. For our case study in the Mo Chu River Basin, the results show that, even under the worst case scenario, little damage to residential buildings can be expected. However, such an outburst flood would probably destroy infrastructure and farmland and might even affect the operation of a hydroelectric powerplant more than 120 km downstream the lake. Our simulation efforts revealed that, by using a 30-m elevation model instead of a 5-m raster, flood magnitude and inundation areas are overestimated significantly, which highly suggests the use of high-resolution terrain data. These results may be a valuable input for risk mitigation efforts.

scholarly journals How should hospitals manage the backlog of patients awaiting surgery following the COVID-19 pandemic? A demand modelling simulation case study for carotid endarterectomy

2020 ◽  
Author(s):  
Guy Martin ◽  
Jonathan Clarke ◽  
Sheraz Markar ◽  
Alexander W Carter ◽  
Sam Mason ◽  
...  
Keyword(s):  
Carotid Endarterectomy ◽  
Quality Care ◽  
Surgical Care ◽  
Surgical Capacity ◽  
Case Scenario ◽  
Worst Case ◽  
Health Crisis ◽  
Demand Modelling ◽  
The Impact

Background The COVID-19 pandemic presents unparalleled challenges for the delivery of safe and effective care. In response, many health systems have chosen to restrict access to surgery and reallocate resources; the impact on the provision of surgical services has been profound, with huge numbers of patient now awaiting surgery at the risk of avoidable harm. The challenge now is how do hospitals transition from the current pandemic mode of operation back to business as usual, and ensure that all patients receive equitable, timely and high-quality surgical care during all phases of the public health crisis. Aims and Methods This case study takes carotid endarterectomy as a time-sensitive surgical procedure and simulates 400 compartmental demand modelling scenarios for managing surgical capacity in the UK for two years following the pandemic. Results A total of 7,69 patients will require carotid endarterectomy. In the worst-case scenario, if no additional capacity is provided on resumption of normal service, the waiting list may never be cleared, and no patient will receive surgery within the 2-week target; potentially leading to >1000 avoidable strokes. If surgical capacity is doubled after 1-month of resuming normal service, it will still take more than 6-months to clear the backlog, and 30.8% of patients will not undergo surgery within 2-weeks, with an average wait of 20.3 days for the proceeding 2 years. Conclusions This case study for carotid endarterectomy has shown that every healthcare system is going to have to make difficult decisions for balancing human and capital resources against the needs of patients. It has demonstrated that the timing and size of this effort will critically influence the ability of these systems to return to their baseline and continue to provide the highest quality care for all. The failure to sustainably increase surgical capacity early in the post-COVID-19 period will have significant long-term negative impacts on patients and is likely to result in avoidable harm.

A Case Study on Landslide-Generated Tsunami and Its Impact on the U.S. Atlantic Coast

2010 ◽  
Author(s):  
Hongqiang Zhou ◽  
Christopher W. Moore ◽  
Robert Weiss ◽  
Vasily V. Titov ◽  
Yong Wei
Keyword(s):  
Atlantic Coast ◽  
Catastrophic Failure ◽  
Case Scenario ◽  
The West ◽  
Worst Case ◽  
La Palma ◽  
Cumbre Vieja ◽  
The U.S ◽  
Numerical Approaches

Recent studies suggested that the potential eruption of Cumbre Vieja Valcano on La Palma Island may cause catastrophic failure of the west flank and generate a tsunami that threats the American coasts (e.g. Ward and Day, 2001; Lo̸vholt et al., 2008). In the present study, we revisit this problem with a credible worst case scenario and advanced numerical approaches.

scholarly journals Slope Stability in a Multi-Hazard Eruption Scenario (Santorini, Greece)

Geosciences ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 412
Author(s):  
Giovanni Forte ◽  
Melania De Falco ◽  
Nicoletta Santangelo ◽  
Antonio Santo
Keyword(s):  
Slope Stability ◽  
Volcanic Eruptions ◽  
Case Scenario ◽  
Worst Case ◽  
Aerial Photos ◽  
Cascading Effects ◽  
Critical Areas ◽  
Ash Fallout ◽  
Fallout Deposition

Under the European FP7 SNOWBALL project (2014–2017), the island of Santorini was used as a case study to validate a procedure to assess the possible multiple cascading effects caused by volcanic eruptions. From January 2011 to April 2012, the area was affected by low to moderate (Mw <3.2) seismic shaking, which caused concern regarding a possible volcanic eruption that ultimately failed to materialize. Assuming the worst-case scenario of a sub-Plinian eruption, this study provides insights into the approach adopted by the SNOWBALL project to identify the most critical areas (hot spots) for slope stability. Geological field surveys, thematic maps, and geomorphological data on aerial photos and landform interpretation were adopted to assess the static susceptibility. The eruption scenario is related to two different phenomena: a pre-eruption earthquake (Mw 5.2) and the subsequent ash fallout deposition following the prevailing winds. Landslide susceptibility in seismic conditions was assessed through the HAZUS approach and the estimate of Newmark displacements (u), while the critical areas for ash fallout mobilization were assessed adopting empirical relationships. The findings are summarized in a scenario map reporting the most critical areas and the infrastructures most vulnerable to such phenomena.

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