Ice Loading of Jack-Up Platforms

2005 ◽  
Author(s):  
Alexandra Weihrauch ◽  
Joachim Berger ◽  
Marc Bartels
Keyword(s):  
Shallow Water ◽  
Structural Integrity ◽  
High Mobility ◽  
The North ◽  
Detail Design ◽  
Broken Ice ◽  
The Stability ◽  
Jack Up ◽  
The Impact ◽  
Analytical Approaches

The use of drilling platforms for exploration drillings in ice-covered shallow water is expected to increase in the future. Jack-up platforms (JU) are regarded to be most suitable for exploration drillings due to their high mobility, their facile transportation and installation. Although having proved their capability for harsh environments, e.g. in the North Sea, jack-ups have neither been especially designed for nor have been operated frequently in icy waters. The problems associated with the operation of jack-ups in ice waters are related to structural integrity as well as to operational limitations. One objective of the research project MATRA-OSE was to check the design of JU for exploration and oil production in ice-covered, shallow-water areas. The global stability of JU as well as local and global loads acting on a three-legged jack-up drilling unit were investigated. The design loads were determined by analytical approaches. Different ice load cases were defined as the basis for the detail design. These load cases include local loads on single members of the platform legs like chords or braces as well as global loads, which may act on one individual leg or on several legs of the platform. Vertical forces, which result from a change of the water level (up-surge and down-surge) in case ice sheets are frozen to the platform legs were considered. Also the impact of ice being jammed between the platform legs was investigated. It has been found out that the most critical load case results from the ice being jammed between the platform legs. It should therefore be tried in practice to avoid the ice jamming by proper ice management, as the large ice loads calculated for this scenario may result in problems for the stability of a JU. Ice breakers could be used to pre break the ice and should try to clear the site from broken ice pieces before it starts to accumulate.

Submarine preservation of massive tabular ground ice by coastal retrogressive thaw slumps

2020 ◽  
Author(s):  
Brian Moorman
Keyword(s):  
Shallow Water ◽  
Thermal Conditions ◽  
Information Modeling ◽  
The Arctic ◽  
Ground Ice ◽  
Sedimentary Architecture ◽  
Coastal Retreat ◽  
The Stability ◽  
Ground Penetrating ◽  
The Impact

<p><span>Around the Arctic Ocean there are many stretches of coastline composed of ice-rich sediments. With the dramatic climatic, oceanic and terrestrial changes that are currently occurring, there is considerable concern over the stability of these coasts and how they are being altered. With the complexity that permafrost conditions add to the coastal setting, modelling erosion involves a more detailed understanding of the physical and thermal conditions as well as the sedimentological and wave action processes. This research examines the role that the shallow water energy balance plays in preserving sub-bottom massive ice as the coastline retreats and the implications it has for secondary subsea disturbance once the water depth increases.</span></p><p><span>The study area was Peninsula Point which is approximately 10 km west of Tuktoyaktuk, NWT, Canada. The massive ice and retrogressive thaw slumps at this location are some of the more dramatic examples of the impact of ice-rich permafrost on coastal processes in the Arctic. By mapping the area with satellite and aerial imagery and conducting repeat ground penetrating radar surveys (GPR) over a 30 year period, the long-term character of coastal retreat above, and below, the water line is revealed. In winter, the GPR was pulled behind a snowmobile along transects on land, across the shoreline and out onto the near shore area of the Beaufort Sea. This provided the stratigraphic continuity between the terrestrial and sub-sea settings. The GPR revealed the massive ice and sedimentary architecture, from which vertical and lateral relationships to the coastline were determined. The roles of erosion, re-sedimentation and shallow-water thermodynamics in the degradation and preservation of massive ground ice were revealed. Using this new information, modeling of the coastal retreat and sediment contributions to the ocean demonstrated a much more complex system than previously assumed.</span></p>

scholarly journals IMPLIKASI YURIDIS PERUBAHAN NAMA LAUT NATUNA UTARA TERHADAP ZONA EKOMONI EKSKLUSIF INDONESIA (ZEEI) DITINJAU DARI HUKUM INTERNASIONAL

2019 ◽  
Vol 18 (1) ◽  
pp. 40
Author(s):  
Rizky Hidayatullah ◽  
Chomariyah Chomariyah ◽  
Dita Birahayu
Keyword(s):  
South China Sea ◽  
Chinese Government ◽  
National Defense ◽  
Literature Study ◽  
Legal Research ◽  
Conceptual Approach ◽  
The North ◽  
External Impact ◽  
The Stability ◽  
The Impact

Indonesia changes the name of the sea in its Exclusive Economic Zone, which initially changed the name of the South China Sea to North Natuna Sea. The change in the name of the North Natuna Sea in Indonesia was protested by the Chinese government, given the abundant natural resources that made other countries especially China want to seize this region. Not only that, the North Natuna Sea is also one of the legal conflicts. The Indonesian government must increase awareness in terms of security and national defense in protecting sovereignty, especially in the North Natuna Sea. This study uses a normative juridical method and uses a legislative approach, a case approach, and a conceptual approach in this case literature study of library materials so that it can be called library legal research. The impact of the change in the name of the North Natuna Sea internally, the change in the map of Indonesia in the North Natuna Sea because this change can be implemented without external parties. External impact, Indonesia received recognition from other countries that the name of the Indonesian sea has changed its name. And efforts made by Indonesia to secure the stability of the North Natuna Sea.

scholarly journals Effect of Halabjah Earthquake on Al-Wand Earth Dam: Numerical Analysis

2021 ◽  
Vol 318 ◽  
pp. 01016
Author(s):  
Intisar H. Abbas ◽  
Maysam Th. Al-hadidi
Keyword(s):  
Numerical Modeling ◽  
Numerical Analysis ◽  
Natural Disaster ◽  
Seismic Activity ◽  
Earth Dam ◽  
The North ◽  
Porewater Pressure ◽  
The Stability ◽  
Earthquake Vibration ◽  
The Impact

The Halabja earthquake occurred on 12/11/2017 in Iraq, with a magnitude of 7.3 Mw, which happened in the Iraqi-Iranian borders. This earthquake killed and injured many people in the Kurdish region in the north of the country. There is no natural disaster more dangerous than earthquake, especially it occurs without warning, great attention must be paid to the impact of earthquakes on the soil and preparing for a wave of earthquakes. Numerical modeling using specific elements is considered a powerful tool to investigate the required behavior of structures in Geotechnical engineering, and the main objective of this is to assess the response of the Al-Wand dam to the Halabja earthquake, as this dam is located in an area that has been subjected to seismic activity recently. The modeling was done through the Geo-studio program, where the seepage was analyzed during the Al-wand dam using the Seep/w program. It was verified that the dam was safe against seepage failure and then moved to the QUAKE/W (a subprogram of GEOSTUDIO, which is used for liquefaction modeling of earthquakes and dynamic loading and determines the movement and increased pressures of pore water that arise due to earthquake vibration or sudden shock loads). The program was used to analyze the effect of the earthquake on the porewater pressure, effective stresses, and displacements. Also, it is not clear that the significant impact the earthquake has on these values. Finally, the Slope/w program was used to analyze the stability of the dam and to calculate the safety factor of the dam in two ways, and the results of the analysis show that the dam is considered safe under the influence of the tremor.

scholarly journals Vibration of effects in epidemiologic studies of alcohol consumption and breast cancer risk

2020 ◽  
Vol 49 (2) ◽  
pp. 608-618 ◽  
Author(s):  
Lingzhi Chu ◽  
John P A Ioannidis ◽  
Alex C Egilman ◽  
Vasilis Vasiliou ◽  
Joseph S Ross ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Observational Studies ◽  
Meta Analysis ◽  
Epidemiologic Studies ◽  
Relative Effect ◽  
Model Specification ◽  
Effect Estimate ◽  
The Stability ◽  
The Impact ◽  
Analytical Approaches

Abstract Background Different analytical approaches can influence the associations estimated in observational studies. We assessed the variability of effect estimates reported within and across observational studies evaluating the impact of alcohol on breast cancer. Methods We abstracted largest harmful, largest protective and smallest (closest to the null value of 1.0) relative risk estimates in studies included in a recent alcohol–breast cancer meta-analysis, and recorded how they differed based on five model specification characteristics, including exposure definition, exposure contrast levels, study populations, adjustment covariates and/or model approaches. For each study, we approximated vibration of effects by dividing the largest by the smallest effect estimate [i.e. ratio of odds ratio (ROR)]. Results Among 97 eligible studies, 85 (87.6%) reported both harmful and protective relative effect estimates for an alcohol–breast cancer relationship, which ranged from 1.1 to 17.9 and 0.0 to 1.0, respectively. The RORs comparing the largest and smallest estimates in value ranged from 1.0 to 106.2, with a median of 3.0 [interquartile range (IQR) 2.0–5.2]. One-third (35, 36.1%) of the RORs were based on extreme effect estimates with at least three different model specification characteristics; the vast majority (87, 89.7%) had different exposure definitions or contrast levels. Similar vibrations of effect were observed when only extreme estimates with differences based on study populations and/or adjustment covariates were compared. Conclusions Most observational studies evaluating the impact of alcohol on breast cancer report relative effect estimates for the same associations that diverge by >2-fold. Therefore, observational studies should estimate the vibration of effects to provide insight regarding the stability of findings.

Dietary Vitamin and Stability of Oral Anticoagulation: Proposal of a Diet with Constant Vitamin K1 Content

1997 ◽  
Vol 77 (03) ◽  
pp. 504-509 ◽  
Author(s):  
Sarah L Booth ◽  
Jacqueline M Charnley ◽  
James A Sadowski ◽  
Edward Saltzman ◽  
Edwin G Bovill ◽  
...  
Keyword(s):  
Dietary Intake ◽  
Vitamin K ◽  
High Performance ◽  
Case Reports ◽  
Food Composition ◽  
Dietary Guidelines ◽  
Dietary Vitamin ◽  
Vitamin K1 ◽  
The Stability ◽  
The Impact

SummaryCase reports cited in Medline or Biological Abstracts (1966-1996) were reviewed to evaluate the impact of vitamin K1 dietary intake on the stability of anticoagulant control in patients using coumarin derivatives. Reported nutrient-drug interactions cannot always be explained by the vitamin K1 content of the food items. However, metabolic data indicate that a consistent dietary intake of vitamin K is important to attain a daily equilibrium in vitamin K status. We report a diet that provides a stable intake of vitamin K1, equivalent to the current U.S. Recommended Dietary Allowance, using food composition data derived from high-performance liquid chromatography. Inconsistencies in the published literature indicate that prospective clinical studies should be undertaken to clarify the putative dietary vitamin K1-coumarin interaction. The dietary guidelines reported here may be used in such studies.

IMPACT OF GOVERNMENT DEBT ON FINANCIAL SECURITY OF UKRAINE

2017 ◽  
Author(s):  
Olena Pikaliuk ◽  
◽  
Dmitry Kovalenko ◽  
Keyword(s):  
Economic Development ◽  
Public Debt ◽  
Positive Impact ◽  
The State ◽  
Financial Security ◽  
State Budget ◽  
The Public ◽  
Debt Security ◽  
The Stability ◽  
The Impact

One of the main criteria for economic development is the size of the public debt and its dynamics. The article considers the impact of public debt on the financial security of Ukraine. The views of scientists on the essence of public debt and financial security of the state are substantiated. An analysis of the dynamics and structure of public debt of Ukraine for 2014-2019. It is proved that one of the main criteria for economic development is the size of public debt and its dynamics. State budget deficit, attracting and using loans to cover it have led to the formation and significant growth of public debt in Ukraine. The volume of public debt indicates an increase in the debt security of the state, which is a component of financial security. Therefore, the issue of the impact of public debt on the financial security of Ukraine is becoming increasingly relevant. The constant growth and large amounts of debt make it necessary to study it, which will have a positive impact on economic processes that will ensure the stability of the financial system and enhance its security.

Destabilizing the Structural Integrity of SARS-CoV2 Receptor Proteins by Curcumin Along with Hydroxychloroquine: An Insilco Approach for a Combination Therapy

2020 ◽  
Author(s):  
Akhileshwar Srivastava ◽  
Divya Singh
Keyword(s):  
Binding Energy ◽  
Combination Therapy ◽  
Receptor Binding ◽  
Structural Integrity ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Receptor Proteins ◽  
Main Protease ◽  
The Stability ◽  
Therapeutic Activities

Presently, an emerging disease (COVID-19) has been spreading across the world due to coronavirus (SARS-CoV2). For treatment of SARS-CoV2 infection, currently hydroxychloroquine has been suggested by researchers, but it has not been found enough effective against this virus. The present study based on in silico approaches was designed to enhance the therapeutic activities of hydroxychloroquine by using curcumin as an adjunct drug against SARS-CoV2 receptor proteins: main-protease and S1 receptor binding domain (RBD). The webserver (ANCHOR) showed the higher protein stability for both receptors with disordered score (<0.5). The molecular docking analysis revealed that the binding energy (-24.58 kcal/mol) of hydroxychloroquine was higher than curcumin (-20.47 kcal/mol) for receptor main-protease, whereas binding energy of curcumin (<a>-38.84</a> kcal/mol) had greater than hydroxychloroquine<a> (-35.87</a> kcal/mol) in case of S1 receptor binding domain. Therefore, this study suggested that the curcumin could be used as combination therapy along with hydroxychloroquine for disrupting the stability of SARS-CoV2 receptor proteins

Nachhaltigkeit im Wald – vor und hinter der Welle der Globalisierung | Sustainable Forest Management – In Front and Behind the Wave of Globalization

2000 ◽  
Vol 151 (12) ◽  
pp. 502-507
Author(s):  
Christian Küchli
Keyword(s):  
Forest Management ◽  
Cultural Landscape ◽  
Sustainable Forest Management ◽  
Essential Element ◽  
Specific Situation ◽  
The South ◽  
The North ◽  
Time Space ◽  
Starting Point ◽  
The Impact

Are there any common patterns in the transition processes from traditional and more or less sustainable forest management to exploitative use, which can regularly be observed both in central Europe and in the countries of the South (e.g. India or Indonesia)? Attempts were made with a time-space-model to typify those force fields, in which traditional sustainable forest management is undermined and is then transformed into a modern type of sustainable forest management. Although it is unlikely that the history of the North will become the future of the South, the glimpse into the northern past offers a useful starting point for the understanding of the current situation in the South, which in turn could stimulate the debate on development. For instance, the patterns which stand behind the conflicts on forest use in the Himalayas are very similar to the conflicts in the Alps. In the same way, the impact of socio-economic changes on the environment – key word ‹globalisation› – is often much the same. To recognize comparable patterns can be very valuable because it can act as a stimulant for the search of political, legal and technical solutions adapted to a specific situation. For the global community the realization of the way political-economic alliances work at the head of the ‹globalisationwave›can only signify to carry on trying to find a common language and understanding at the negotiation tables. On the lee side of the destructive breaker it is necessary to conserve and care for what survived. As it was the case in Switzerland these forest islands could once become the germination points for the genesis of a cultural landscape, where close-to-nature managed forests will constitute an essential element.

Healthcare System in the Arctic Zone of Russia. Known and Emerging Issues and Solutions to Them

2019 ◽  
pp. 3-20
Author(s):  
V.N. Leksin
Keyword(s):  
Metallurgical Industry ◽  
Healthcare Services ◽  
The Arctic ◽  
Russian Arctic ◽  
Arctic Zone ◽  
Shift Workers ◽  
The North ◽  
Medical Institutions ◽  
Emerging Issues ◽  
The Impact

The impact on healthcare organization on the territory of Russian Arctic of unique natural and climatic, demographic, ethnic, settlement and professional factors of influencing the health of population, constantly or temporarily living on this territory is studied. The necessity is substantiated of various forms and resource provision with healthcare services such real and potential patients of Arctic medical institutions, as representatives of indigenous small peoples of the North, workers of mining and metallurgical industry, military personnel, sailors and shift workers. In this connection a correction of a number of All-Russian normative acts is proposed.

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