Effect of Mud Shedding on Riser Anti-Recoil Control at Emergency Disconnect

2012 ◽  
Author(s):  
Songcheng Li ◽  
Mike Campbell ◽  
Hugh Howells ◽  
Simeon Powell
Keyword(s):  
Sea Water ◽  
Housing System ◽  
Drilling Mud ◽  
Element Analysis ◽  
Before And After ◽  
Pressure Impact ◽  
Emergency Events ◽  
Mud Pressure ◽  
Mud Flow

With drilling capability extends to water depths up to 3000m, significantly increased is the risk associated with a failed riser recoil control in the event of an emergency riser disconnect due to loss of vessel station keeping. In deeper waters the tensioner system undertakes higher top tension due to the accumulation of riser length and mud weight. During emergency disconnect, the riser is disconnected between the blow-out preventer (BOP) and the lower marine riser package (LMRP), releasing the base tension and mud pressure. Impact between the top riser system and the diverter housing system should be avoided, and the clearance between the LMRP and BOP should be secured. Efforts have been continuously made in the industry to achieve a more accurate predict of the riser recoil response. The relevance of mud discharge to recoil control has been widely discussed but little quantitative data has been revealed in the literature. In this paper, effect of mud shedding on riser recoil response is discussed. The Herschel-Bulkley rheology model is utilized for mud flow and is considered the latest advance in the drilling industry. Water hammer theories with column separation are modified to account for mud discharge in laminar, transitional and turbulent flow regimes. As a case study herein, recoil response of a drilling riser attached to a dynamically positioned semi-submersible drilling vessel is assessed to present the mud discharge effect on riser anti-recoil control. At emergency events, the riser is disconnected above the BOP, which is located at a water depth of about 2150m for this study. Mud is generally preferred to be freely discharged during an emergency disconnect for ease of anti-recoil control and riser integrity. The density difference between drilling mud in the riser annulus and sea water outside the riser outer casing before disconnect induces a high pressure difference, which drives mud shedding at riser disconnect. Mud flow rate plays an important role in the speed control of the riser uplift. 3D finite element analysis is performed in time domain to simulate riser response before and after disconnect. 2HRECOIL software is integrated into ANSYS user programmable features to better model the riser response and mud discharge.

The Influence of Attitudes, Subjective, Norms, and Behavior Controls on Intention to Choose Islamic Banks With Islamic Religiosity as a Moderating Variable (Case Study at Bri Syariah Purwokerto Customers)

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Akhmad Khoyrun Najakh ◽  
Dwiwiyati Astogini ◽  
Sri Martini
Keyword(s):  
Behavioral Control ◽  
Sampling Technique ◽  
Subjective Norm ◽  
Subjective Norms ◽  
Islamic Banks ◽  
Control Behavior ◽  
Before And After ◽  
And Behavior ◽  
Number Of Customers

The purpose of this study was to analyze the influence of attitudes on the intention to choose Islamic banks, to analyze the effect of subjective norm on the intention to choose Islamic banks. to analyze the effect of the control behavior of the intention to choose the Islamic banks, to analyze the moderating influence of religiosity on the relationship attitudes, subjective norms and behavioral control of the intention to choose the Islamic banks . The method used is a survey with a sampling technique used purposive sampling with a sample size of this study was 100 respondents . Further analysis tools used in this study is multiple regression analysis using SPSS 16.0 software . Based on this study it can be concluded that the attitude does not affect to the intention of choose Bank BRISyariah. Subjective norm positive effect on intention choose Bank BRISyariah. Control behavior does not affect to the intention choose Bank BRISyariah. Relationship between Attitudes, Subjective Norms and Behavior Control with the intention to select Bank BRISyariah not moderated by religiosity.Based on these conclusions can be said that the Bank BRISyariah should improve understanding related to the subjective norm in order to increase the number of customers who use the services of Islamic Banking . Further research is recommended in order to follow up and develop this research to further explore the independent and dependent variables continued before and after behavioral intention or intention to perform a specific action .

Impact of merger on efficiency and productivity : a case study of commercial banks in Malaysia

1970 ◽  
Vol 5 (1) ◽  
pp. 77
Author(s):  
Mahadzir Ismail ◽  
Saliza Sulaiman ◽  
Hasni Abdul Rahim ◽  
Nordiana Nordin
Keyword(s):  
Efficiency Score ◽  
Malmquist Productivity Index ◽  
Productivity Index ◽  
Data Envelopment ◽  
Master Plan ◽  
Before And After ◽  
Domestic Banks ◽  
The Impact ◽  
Efficiency And Productivity

The Financial Master Plan (2001- 2010) aims to enhance the capacity of banking industry so that higher effic iency and productivity can be reaped in the future. This study seeks to determine the impact of merger on the efficiency and productivity ofcommercial banks in Malaysia for the period 1995 until 2005. The study uses a non-parametric approach, nam ely DEA (data envelopment analysis?) to estimate the efficiency scores and to construct the Malmquist productivity index. To enable this estimation, three bank inputs and outputs are used. Amongst the findings are those banks exhibit higher efficiency score after the merger and thefo reign banks are more efficient than the local banks. Productivity of the banks is calculated in both periods, before and after the merger: The results show that, it is the local banks that have improved the most after the merger. The main source of productivity is technical change or innovation. The findings support the existing policy of having larger domestic banks in term of size.

ANALISIS EFEKTIVITAS PROGRAM USAHA AGRIBISNIS PERDESAAN (PUAP) SERTA DAMPAKNYA TERHADAP TINGKAT PENDAPATAN PETANI (STUDI KASUS PADA GABUNGAN KELOMPOK TANI TELUK JAYA)

2014 ◽  
Vol 5 (2) ◽  
Author(s):  
Yudi Triyanto
Keyword(s):  
Poverty Alleviation ◽  
F Test ◽  
Income Levels ◽  
Before And After ◽  
Program Funding ◽  
Independent Variable ◽  
Farmer Income ◽  
Positive Effect ◽  
Group Association

Study the effectivity analysis of Program Usaha Agribisnis Perdesaan (PUAP) and its impact on farmer income levels (case study of the Teluk Jaya Farmers Group Association) aims to 1. knowing how large the effectivity of PUAP funds is for income levels in poverty alleviation in Teluk Desa Sentosa Panai Hulu Subdistrict, 2. to analyze and determine the level of income of Gapoktan Teluk Jaya Farming Business in Teluk Sentosa, Panai Hulu Subdistrict before and after receiving PUAP assistance. The results showed that the effectivity of PUAP program funding is very effective and good, it can be seen from the results of the F test of 12.406 with a significant level of 0.000 while the F value of the table is 2.051. When compared to the value of F test (12.406) > Ftable (2.051) at α 5%, it was concluded that simultaneously the effectivity variable and the PUAP program had a positive effect. The increase in income of the Teluk Jaya Farmers Group in Teluk Sentosa after receiving PUAP funds can be known from the t table for the effectivity variable of 2.663 and the PUAP program for 1.270 with a significant value for each independent variable (2.051); (0.073). Whereas for the t table value in the distribution statistics t table with the level of test α = 5% and df1 = 27 of 2,051. Based on the criteria that if the value is t count> t table); namely (2.663> 2,051) (1,270> 2,051) so that it can be concluded that the effectivity variable partially has a positive and significant effect on the income level.Keywords : effectivity variable,  income level, PUAP program

Obesity management through Ayurveda - A Case Study

2017 ◽  
Vol 2 (4) ◽  
Author(s):  
Dheeraj Kumar Tyagi ◽  
Shivakumar .
Keyword(s):  
Clinical Findings ◽  
Dietary Habit ◽  
Unhealthy Lifestyle ◽  
Lifestyle Management ◽  
Before And After ◽  
Effect Of Treatment ◽  
And Control

Lifestyle disorders are one of the biggest threats for the population living unhealthy lifestyle. Sthoulya (Obesity) is one such disorder which creates lot of physical as well as mental disorder to the sufferer. Due to changing lifestyle, comforts and dietary habit lots of individuals changed their life totally. Obesity is a growing disease in developed and developing countries. Prevalence is drastically hike in past few years. Ayurveda, the science of life with which we can manage and control lots of lifestyle disorders. Focusing on dietary and lifestyle management along with treatment, we can overcome the hazards of obesity which is growing in a uncontrolled manner. The available data is based on the clinical findings only. Aim and objective: To assess the effect of “Guru Cha Atarpanam Chikitsa” in the management of Sthoulya. Setting: Swastharakshana evam Yoga, OPD and IPD, SDMCAH, Hassan. Method: Udwarthana, Parisheka, Shamana Aushadhis, Ahara, and Vihara was followed within the treatment duration and effect of treatment was assessed before and after treatment, advised for follow up. Results: The treatment adopted is effective in the management of Sthoulya and to improve the quality of life.

scholarly journals Changes of Walking Activity During the First Cycle Phases of COVID-19 Pandemic: A Case Study of Seoul, Korea

2021 ◽  
pp. 193758672110265
Author(s):  
Youngjun Park ◽  
Haekwon Chung ◽  
Sohyun Park
Keyword(s):  
Public Health ◽  
Physical Inactivity ◽  
Voluntary Participation ◽  
Walking Activity ◽  
Significant Difference ◽  
Before And After ◽  
Acceleration And Deceleration ◽  
Preliminary Study ◽  
The Government

Aim: This study explores the changes in regular walking activities during the phases of the pandemic. Background: With the spread of COVID-19 transmission, people are refraining from going out, reducing their physical activity. In South Korea, COVID-19 broke out in the 4th week of 2020 and experienced the first cycle phases of the pandemic, such as outbreak, widespread, and decline. In response to the pandemic, the government encouraged voluntary participation in social distancing campaigns, and people reduced their outside activities. Methods: This article examines the decrease and increase of the Prevalence of Regular Walking (≥30 min of moderate walking a day, on ≥5 days a week) by the COVID-19 phases. This study is based on weekly walking data for 15 weeks in 2020, via the smartphone healthcare app, which is managed by 25 public health offices of the Seoul government. Results: According to the findings, the level of prevalence of regular walking (PRW) has a significant difference before and after the outbreak, and every interval of the four-stage COVID-19 phases, that is, pre-pandemic, initiation, acceleration, and deceleration. The level of PRW sharply decreased during initiation and acceleration intervals. In the deceleration interval of COVID-19, the PRW kept increasing, but it has not yet reached the same level as the previous year when the COVID-19 did not exist. Conclusions: As a preliminary study, this study explains empirically how COVID-19 changed PRW in Seoul. It would be helpful to enhance our understanding of the changes in physical inactivity in the pandemic period.

Temporal dynamics of encrusting communities during the Late Devonian: a case study from the Central Devonian Field, Russia

Paleobiology ◽  
2017 ◽  
Vol 43 (4) ◽  
pp. 550-568 ◽  
Author(s):  
Michał Zatoń ◽  
Tomasz Borszcz ◽  
Michał Rakociński
Keyword(s):  
Temporal Dynamics ◽  
Small Sample ◽  
Time Interval ◽  
Faunal Turnover ◽  
Central Devonian Field ◽  
Before And After ◽  
Substrate Size ◽  
Mass Extinction Event ◽  
Diversity Dynamics

AbstractIn this study we focused on the dynamics of encrusting assemblages preserved on brachiopod hosts collected from upper Frasnian and lower Famennian deposits of the Central Devonian Field, Russia. Because the encrusted brachiopods come from deposits bracketing the Frasnian/Famennian (F/F) boundary, the results also shed some light on ecological differences in encrusting communities before and after the Frasnian–Famennian (F-F) event. To explore the diversity dynamics of encrusting assemblages, we analyzed more than 1300 brachiopod valves (substrates) from two localities. Taxon accumulation plots and shareholder quorum subsampling (SQS) routines indicated that a reasonably small sample of brachiopod host valves (n=50) is sufficient to capture the majority of the encrusting genera recorded at a given site. The richness of encrusters per substrate declined simultaneously with the number of encrusting taxa in the lower Famennian, accompanied by a decrease in epibiont abundance, with a comparable decrease in mean encrustation intensity (percentage of bioclasts encrusted by one or more epibionts). Epibiont abundance and occupancy roughly mirror each other. Strikingly, few ecological characteristics are correlated with substrate size, possibly reflecting random settlement of larvae. Evenness, which is negatively correlated with substrate size, shows greater within-stage variability among samples than between Frasnian and Famennian intervals and may indicate the instability of early Famennian biocenoses following the faunal turnover. The occurrence distribution of encrusters points to nonrandom associations and exclusions among several encrusting taxa. However, abundance and occupancy of microconchids remained relatively stable throughout the sampled time interval. The notable decline in abundance (~60%) and relatively minor decline in diversity (~30%) suggest jointly that encrusting communities experienced ecological collapse rather than a major mass extinction event. The differences between the upper Frasnian and lower Famennian encrusting assemblages may thus record a turnover associated with the F-F event.

scholarly journals A Qualitative Case Study on Influencing Factors of Parents’ Child Abuse of North Korean Refugees in South Korea

Healthcare ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 49
Author(s):  
Wonjung Ryu ◽  
Hyerin Yang
Keyword(s):  
Child Abuse ◽  
South Korea ◽  
Influencing Factors ◽  
Acculturative Stress ◽  
North Korean Refugees ◽  
Korean Parents ◽  
Before And After ◽  
Maternal Parenting Stress ◽  
Past Experiences

The purpose of this study is to investigate the influencing factors of parental child abuse by North Korean refugees who are living in South Korea. In-depth interviews were conducted with five parents who escaped from North Korea. The study identified three categories of factors impacting child abuse: the weakening of family functions from past experiences before and after defection, the stress of adapting to the culture of an unfamiliar society, and low parenting self-efficacy. North Korean parents suffered from emotional and functional crises from past traumatic events and, at the same time, experienced additional acculturative stress as a “minority” after entering South Korea, even as they continued to deal with Maternal Parenting Stress. These complex factors have been shown to lead to child abuse in migrant societies. This study contemplated the context of child abuse through specific examples. The results could provide thoughtful insights into child abuse among migrants and refugee parents, and provide evidence-based intervention plans for its prevention.

scholarly journals Behavior of Offshore Pile in Calcareous Sand—Case Study

2021 ◽  
Vol 9 (8) ◽  
pp. 839
Author(s):  
Tarek N. Salem ◽  
Nadia M. Elkhawas ◽  
Ahmed M. Elnady
Keyword(s):  
Load Capacity ◽  
High Stress ◽  
Embedment Depth ◽  
Shear Stresses ◽  
Northern Coast ◽  
Compression Tests ◽  
Calcareous Sand ◽  
Element Analysis ◽  
Mixing Ratios

The erosion of limestone and calcarenite ridges that existed parallel to the Mediterranean shoreline forms the calcareous sand (CS) formation at the surface layer of Egypt's northern coast. The CS is often combined with broken shells which are considered geotechnically problematic due to their possible crushability and relatively high compressibility. In this research, CS samples collected from a site along the northern coast of Egypt are studied to better understand its behavior under normal and shear stresses. Reconstituted CS specimens with different ratios of broken shells (BS) are also investigated to study the effect of BS ratios on the soil mixture strength behavior. The strength is evaluated using laboratory direct-shear and one-dimensional compression tests (oedometer test). The CS specimens are not exposed to significant crushability even under relatively high-stress levels. In addition, a 3D finite element analysis (FEA) is presented in this paper to study the degradation offshore pile capacity in CS having different percentages of BS. The stress–strain results using oedometer tests are compared with a numerical model, and it gave identical matching for most cases. The effects of pile diameter and embedment depth parameters are then studied for the case study on the northern coast. Three different mixing ratios of CS and BS have been used, CS + 10% BS, CS + 30% BS, and CS + 50% BS, which resulted in a decrease of the ultimate vertical compression pile load capacity by 8.8%, 15%, and 16%, respectively.

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