scholarly journals Damaged warship stability tests based on ANEP-77: A case study for F-110

2017 ◽  
Vol 10 (20) ◽  
pp. 19
Author(s):  
José M. Riola ◽  
Rodrigo Pérez ◽  
Borja Rodríguez
Keyword(s):  
Environmental Conditions ◽  
Safety Assessment ◽  
Royal Navy ◽  
Stability Tests ◽  
Damage Scenarios ◽  
Damage Stability ◽  
Naval Ship ◽  
Safety Assessments ◽  
Core Part

Stability tests are a core part of a hydrodynamics warship design. The acquired knowledge from the hydrodynamics model basin will affect her lifespan. Particularly, a safety assessment of damaged ships, which considers environmental conditions such as waves and wind, is critical in future operations. Over the last decade, a significant amount of experience has been gained associated with predicting the capsize behavior of intact and damaged naval vessels, and the main objective of this paper is to provide insights into different relevant physical aspects to prevent the capsizing of damaged ships in waves following the Naval Ship Code (NSC) or ANEP-77 rules. Currently, the Royal Navy of Spain is developing the future F-110 frigate class and carried out model tests at Canal de Experiencias Hidrodinámicas de El Pardo (CEHIPAR) for optimizing the forms of body hulls. Among these dynamic experiences, the most critical are the damage stability tests. Although a safety criteria of damaged ships that considers environmental conditions such as waves and wind has not yet been developed, NATO and the European maritime classification societies have developed guidelines for safety assessments such as the ANEP-77. This code contains damage scenarios and environmental conditions. 

scholarly journals Recent Advances in Damage Stability Assessment with Application on a Container Vessel

2018 ◽  
Vol 2 (Special edition 2) ◽  
pp. 167-184
Author(s):  
Boris Tomić ◽  
Anton Turk ◽  
Bruno Čalić
Keyword(s):  
Recent Work ◽  
Safety Assessment ◽  
Design Procedure ◽  
Computer Programs ◽  
Assessment Criteria ◽  
Container Ship ◽  
Stability Assessment ◽  
Damage Scenarios ◽  
Damage Stability ◽  
Damage Condition

The paper reviews the design procedure and recent work published on the topic of the damage stability and the safety assessment criteria that is established accordingly. The available damage scenarios must be designed prior to the safety assessment of a damaged ship. Another aspect of the discussions is an opinion on some problematic aspects of the damage stability regulations with practical aspects presented in literature very sparse and the fact that different computer programs may give divers outcomes. A little review on the damage stability requirements with its new regulations is given. Stability assessment is performed on a selected container ship using the Maxsurf software for both the intact and damage condition of the vessel, while the parameters related to damage stability are identified and categorized when developing deterministic and probabilistic damage scenarios.

scholarly journals Better state pictures facilitating state machine characteristic conjecture

2021 ◽  
Author(s):  
Dang Duy Bui ◽  
Kazuhiro Ogata
Keyword(s):  
Virtual Machines ◽  
Mutual Exclusion ◽  
State Machine ◽  
Formal Proof ◽  
The State ◽  
Lessons Learned ◽  
Java Virtual Machines ◽  
Core Part ◽  
Proximity Principle

AbstractThe mutual exclusion protocol invented by Mellor-Crummey and Scott (called MCS protocol) is used to exemplify that state picture designs based on which the state machine graphical animation (SMGA) tool produces graphical animations should be better visualized. Variants of MCS protocol have been used in Java virtual machines and therefore the 2006 Edsger W. Dijkstra Prize in Distributed Computing went to their paper on MCS protocol. The new state picture design of a state machine formalizing MCS protocol is assessed based on Gestalt principles, more specifically proximity principle and similarity principle. We report on a core part of a formal verification case study in which the new state picture design and the SMGA tool largely contributed to the successful completion of the formal proof that MCS protocol enjoys the mutual exclusion property. The lessons learned acquired through our experiments are summarized as two groups of tips. The first group is some new tips on how to make state picture designs. The second one is some tips on how to conjecture state machine characteristics by using the SMGA tool. We also report on one more case study in which the state picture design has been made for the mutual exclusion protocol invented by Anderson (called Anderson protocol) and some characteristics of the protocol have been discovered based on the tips.

scholarly journals Ozone damage, detoxification and the role of isoprenoids – new impetus for integrated models

2016 ◽  
Vol 43 (4) ◽  
pp. 324 ◽  
Author(s):  
Supriya Tiwari ◽  
Rüdiger Grote ◽  
Galina Churkina ◽  
Tim Butler
Keyword(s):  
Stomatal Conductance ◽  
Environmental Conditions ◽  
Economic Losses ◽  
Plant Responses ◽  
Damage Scenarios ◽  
Biochemical Processes ◽  
Wide Range ◽  
Defence Responses ◽  
High Concentrations ◽  
The Impact

High concentrations of ozone (O3) can have significant impacts on the health and productivity of agricultural and forest ecosystems, leading to significant economic losses. In order to estimate this impact under a wide range of environmental conditions, the mechanisms of O3 impacts on physiological and biochemical processes have been intensively investigated. This includes the impact on stomatal conductance, the formation of reactive oxygen species and their effects on enzymes and membranes, as well as several induced and constitutive defence responses. This review summarises these processes, discusses their importance for O3 damage scenarios and assesses to which degree this knowledge is currently used in ecosystem models which are applied for impact analyses. We found that even in highly sophisticated models, feedbacks affecting regulation, detoxification capacity and vulnerability are generally not considered. This implies that O3 inflicted alterations in carbon and water balances cannot be sufficiently well described to cover immediate plant responses under changing environmental conditions. Therefore, we suggest conceptual models that link the depicted feedbacks to available process-based descriptions of stomatal conductance, photosynthesis and isoprenoid formation, particularly the linkage to isoprenoid models opens up new options for describing biosphere-atmosphere interactions.

Safety Assessment of Long Term Serviced Pressure Vessels: A Case Study of Typical Refining and Chemical Plants in China

2021 ◽  
Author(s):  
Zhiyuan Han ◽  
Guoshan Xie ◽  
Haiyi Jiang ◽  
Xiaowei Li
Keyword(s):  
Pressure Vessel ◽  
Safety Assessment ◽  
Failure Modes ◽  
Pressure Vessels ◽  
Time Dependent ◽  
Chemical Plants ◽  
Safety Specification ◽  
Detailed Assessment

Abstract The safety and risk of the long term serviced pressure vessels, especially which serviced more than 20 years, has become one of the most concerned issues in refining and chemical industry and government safety supervision in China. According to the Chinese pressure vessel safety specification TSG 21-2016 “Supervision Regulation on Safety Technology for Stationary Pressure Vessel”, if necessary, safety assessment should be performed for the pressure vessel which reaches the design service life or exceeds 20 years without a definite design life. However, the safety and risk conditions of most pressure vessels have little changes after long term serviced because their failure modes are time-independent. Thus the key problem is to identify the devices with the time-dependent failure modes and assess them based on the failure modes. This study provided a case study on 16 typical refining and chemical plants including 1870 pressure vessels serviced more than 20 years. The quantitative risk and damage mechanisms were calculated based on API 581, the time-dependent and time-independent failure modes were identified, and the typical pressure vessels were assessed based on API 579. Taking the high pressure hydrogenation plant as an example, this study gave the detailed assessment results and conclusions. The results and suggestions in this study are essential for the safety supervision and extending life of long term serviced pressure vessels in China.

Evaluating the Coupledness of the Aerodynamics and Hydrodynamics on the Estimation of Fatigue Damage Equivalent Load for a Floating Offshore Wind Platform

2018 ◽  
Author(s):  
Samuel Kanner ◽  
Bingbin Yu
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Environmental Conditions ◽  
Offshore Wind ◽  
Coupled Analysis ◽  
Offshore Wind Turbine ◽  
Wave Conditions ◽  
Equivalent Load ◽  
The Waves

In this research, the estimation of the fatigue life of a semi-submersible floating offshore wind platform is considered. In order to accurately estimate the fatigue life of a platform, coupled aerodynamic-hydrodynamic simulations are performed to obtain dynamic stress values. The simulations are performed at a multitude of representative environmental states, or “bins,” which can mimic the conditions the structure may endure at a given site, per ABS Floating Offshore Wind Turbine Installation guidelines. To accurately represent the variety of wind and wave conditions, the number of environmental states can be of the order of 103. Unlike other offshore structures, both the wind and wave conditions must be accounted for, which are generally considered independent parameters, drastically increasing the number of states. The stress timeseries from these simulations can be used to estimate the damage at a particular location on the structure by using commonly accepted methods, such as the rainflow counting algorithm. The damage due to either the winds or the waves can be estimated by using a frequency decomposition of the stress timeseries. In this paper, a similar decoupled approach is used to attempt to recover the damages induced from these coupled simulations. Although it is well-known that a coupled, aero-hydro analysis is necessary in order to accurately simulate the nonlinear rigid-body motions of the platform, it is less clear if the same statement could be made about the fatigue properties of the platform. In one approach, the fatigue damage equivalent load is calculated independently from both scatter diagrams of the waves and a rose diagram of the wind. De-coupled simulations are performed to estimate the response at an all-encompassing range of environmental conditions. A database of responses based on these environmental conditions is constructed. The likelihood of occurrence at a case-study site is used to compare the damage equivalent from the coupled simulations. The OC5 platform in the Borssele wind farm zone is used as a case-study and the damage equivalent load from the de-coupled methods are compared to those from the coupled analysis in order to assess these methodologies.

scholarly journals Socio-Environmental Condition Of Women At Prison: A Case Study Of Karachi Central Jail

2011 ◽  
Vol 5 (1) ◽  
pp. 65-77
Author(s):  
Dur-e-Shehwar Baloch ◽  
Parveen Shah ◽  
Misbah B Qureshi
Keyword(s):  
Qualitative Research ◽  
Data Collection ◽  
Environmental Conditions ◽  
Women Prisoners ◽  
Environmental Condition ◽  
Quantitative And Qualitative Research ◽  
Qualitative Research Methodology ◽  
Questionnaire Method ◽  
Condition Of Women

This paper proposed to discuss the socio-environmental conditions of women at prison in Karachi.1 Prison is kind of punishment in which people are physically restricted of a range of personal freedom. Besides this, in jail manual, women have been protected by different rules and regulations. This paper is an explanatory study based on quantitative and qualitative research methodology. The questionnaire method was used for the purpose of data collection. The study shows that the situation on ground and the conditions of women prisoners is not good. In Pakistan rules and laws are available however, they are not implemented. This paper also suggests measures and recommendations in order to overcome the unhealthy and unhygienic condition faced by women prisoners at Karachi Central Jail.

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