Rules of Classification Societies all around the world have made changes on design wave loads' value and fatigue influence factor modification due to the influence of springing and whipping on ultra-large containe...Rules of Classification Societies all around the world have made changes on design wave loads' value and fatigue influence factor modification due to the influence of springing and whipping on ultra-large containerships.The paper firstly introduced 3-D linear hydroelastic theory in frequency domain and 3-D nonlinear hydroelastic theory in time domain, considering large amplitude motion nonlinearity and slamming force due to the severe relative motion between ship hull and wave. Then the spectrum analysis method and time domain statistical analysis method were introduced, which can make fatigue analysis under a series of standard steps in frequency and time domain, respectively. Finally, discussions on the influence factor of springing and whipping on fatigue damages of 8500 TEU and 10000 TEU containerships with different loading states were made. The fatigue assessment of different position on the midship section was done on the basis of nominal stress. The fatigue damage due to whipping can be the same as the fatigue damage due to springing and even sometimes can be larger than the springing damage. Besides, some suggestions on calculating load case selection were made to minimize the quantity of work in frequency and time domain. Thus, tools for fatigue influence factor modification were provided to meet the demand of IACS-UR.展开更多
The desire to benefit from economy of scale is one of the major driving forces behind the continuous growth in ship sizes. However, models of new large ships need to be thoroughly investigated to determine the carrier...The desire to benefit from economy of scale is one of the major driving forces behind the continuous growth in ship sizes. However, models of new large ships need to be thoroughly investigated to determine the carrier's response in waves. In this work, experimental and numerical assessments of the motion and load response of a 550,000 DWT ore carrier are performed using prototype ships with softer stiffness, and towing tank tests are conducted using a segmented model with two schemes of softer stiffness. Numerical analyses are performed employing both rigid body and linear hydroelasticity theories using an in-house program and a comparison is then made between experimental and numerical results to establish the influence of stiffness on the ore carrier's springing response. Results show that softer stiffness models can be used when studying the springing response of ships in waves.展开更多
The Spring Festival,the oldest and most important traditional festival in Chinese culture,has been added to the United Nations Educational,Scientific and Cultural Organization(UNESCO)heritage list.On December 4,UNESCO...The Spring Festival,the oldest and most important traditional festival in Chinese culture,has been added to the United Nations Educational,Scientific and Cultural Organization(UNESCO)heritage list.On December 4,UNESCO announced its recognition of the Spring Festival,social practices celebrated by the Chinese people during the traditional lunisolar New Year,as an Intangible Cultural Heritage of Humanity during the 19th Session of the Intergovernmental Committee for Safeguarding Intangible Cultural Heritage in Asuncion,Paraguay.展开更多
The Spring Equinox,the fourth Chinese solar term out of 24,symbolizes hope,renewal and the promise of a bountiful harvest.As daylight begins to exceed nighttime and the Sun travels northward,it represents the awakenin...The Spring Equinox,the fourth Chinese solar term out of 24,symbolizes hope,renewal and the promise of a bountiful harvest.As daylight begins to exceed nighttime and the Sun travels northward,it represents the awakening of nature,growth,and new beginnings.展开更多
How delightful!Spring is bringing everything a new beginning.Grass is greening.Birds are singing.Buds are blooming.Bells,areringing.Children in the park areswinging.I'm so happy spring is springing,Spring is comi...How delightful!Spring is bringing everything a new beginning.Grass is greening.Birds are singing.Buds are blooming.Bells,areringing.Children in the park areswinging.I'm so happy spring is springing,Spring is coming.春姑娘悄悄向我们走来,挥一挥衣袖,万物复苏。ning鸟儿在歌唱,虫儿在鸣叫。草儿探着头,花儿羞答答地笑。Spring is springing.Everything is shining.你的世界里,还有哪些正在“进行时”?展开更多
Groundwater and surface water contamination by PTE(Potentially Toxic Elements)was assessed in Ruashi and Annexe municipalities of Lubumbashi city.Analyses of seventy water samples collected from six drilled wells,eigh...Groundwater and surface water contamination by PTE(Potentially Toxic Elements)was assessed in Ruashi and Annexe municipalities of Lubumbashi city.Analyses of seventy water samples collected from six drilled wells,eight spade-sunk wells,one river and one spring in both municipalities in 2017 and 2018 were carried out by ICP-SF-MS(Inductively Coupled Plasma-Sector Field Mass Spectrometry).Twenty PTEs including aluminum,arsenic,barium,bismuth,cadmium,cesium,chromium,cobalt,copper,iron,lead,manganese,molybdenum,nickel,strontium,thallium,tungsten,uranium,vanadium and zinc were detected at various concentrations in each one of the samples.Many samples had concentrations and mean concentrations of PTEs,such as aluminum,cadmium,copper,iron,lead,manganese,nickel and zinc,higher than the respective acceptable limits set for drinking water by the EU(European Union),the USEPA(United States Environmental Protection Agency),and the WHO(World Health Organization)standards.Most PTEs being deleterious to human health even at very low concentrations,people who use the groundwater and surface water to meet their water needs in both Ruashi and Annexe municipalities are at risk.展开更多
文摘Rules of Classification Societies all around the world have made changes on design wave loads' value and fatigue influence factor modification due to the influence of springing and whipping on ultra-large containerships.The paper firstly introduced 3-D linear hydroelastic theory in frequency domain and 3-D nonlinear hydroelastic theory in time domain, considering large amplitude motion nonlinearity and slamming force due to the severe relative motion between ship hull and wave. Then the spectrum analysis method and time domain statistical analysis method were introduced, which can make fatigue analysis under a series of standard steps in frequency and time domain, respectively. Finally, discussions on the influence factor of springing and whipping on fatigue damages of 8500 TEU and 10000 TEU containerships with different loading states were made. The fatigue assessment of different position on the midship section was done on the basis of nominal stress. The fatigue damage due to whipping can be the same as the fatigue damage due to springing and even sometimes can be larger than the springing damage. Besides, some suggestions on calculating load case selection were made to minimize the quantity of work in frequency and time domain. Thus, tools for fatigue influence factor modification were provided to meet the demand of IACS-UR.
基金Supported by the National Natural Science Foundation of China （Grant No. 51079034）, and the National Basic Research Program of China （Grant No. 2011CB013703）
文摘The desire to benefit from economy of scale is one of the major driving forces behind the continuous growth in ship sizes. However, models of new large ships need to be thoroughly investigated to determine the carrier's response in waves. In this work, experimental and numerical assessments of the motion and load response of a 550,000 DWT ore carrier are performed using prototype ships with softer stiffness, and towing tank tests are conducted using a segmented model with two schemes of softer stiffness. Numerical analyses are performed employing both rigid body and linear hydroelasticity theories using an in-house program and a comparison is then made between experimental and numerical results to establish the influence of stiffness on the ore carrier's springing response. Results show that softer stiffness models can be used when studying the springing response of ships in waves.
文摘The Spring Festival,the oldest and most important traditional festival in Chinese culture,has been added to the United Nations Educational,Scientific and Cultural Organization(UNESCO)heritage list.On December 4,UNESCO announced its recognition of the Spring Festival,social practices celebrated by the Chinese people during the traditional lunisolar New Year,as an Intangible Cultural Heritage of Humanity during the 19th Session of the Intergovernmental Committee for Safeguarding Intangible Cultural Heritage in Asuncion,Paraguay.
文摘The Spring Equinox,the fourth Chinese solar term out of 24,symbolizes hope,renewal and the promise of a bountiful harvest.As daylight begins to exceed nighttime and the Sun travels northward,it represents the awakening of nature,growth,and new beginnings.
文摘How delightful!Spring is bringing everything a new beginning.Grass is greening.Birds are singing.Buds are blooming.Bells,areringing.Children in the park areswinging.I'm so happy spring is springing,Spring is coming.春姑娘悄悄向我们走来,挥一挥衣袖,万物复苏。ning鸟儿在歌唱,虫儿在鸣叫。草儿探着头,花儿羞答答地笑。Spring is springing.Everything is shining.你的世界里,还有哪些正在“进行时”?
基金funding received from UNESCO-SIDA Project as well as Professor Martine Leermakers and Professor Willy Baeyens for their financial help to analyze the water samples in their laboratory at VUB.Acknowledgements
文摘Groundwater and surface water contamination by PTE(Potentially Toxic Elements)was assessed in Ruashi and Annexe municipalities of Lubumbashi city.Analyses of seventy water samples collected from six drilled wells,eight spade-sunk wells,one river and one spring in both municipalities in 2017 and 2018 were carried out by ICP-SF-MS(Inductively Coupled Plasma-Sector Field Mass Spectrometry).Twenty PTEs including aluminum,arsenic,barium,bismuth,cadmium,cesium,chromium,cobalt,copper,iron,lead,manganese,molybdenum,nickel,strontium,thallium,tungsten,uranium,vanadium and zinc were detected at various concentrations in each one of the samples.Many samples had concentrations and mean concentrations of PTEs,such as aluminum,cadmium,copper,iron,lead,manganese,nickel and zinc,higher than the respective acceptable limits set for drinking water by the EU(European Union),the USEPA(United States Environmental Protection Agency),and the WHO(World Health Organization)standards.Most PTEs being deleterious to human health even at very low concentrations,people who use the groundwater and surface water to meet their water needs in both Ruashi and Annexe municipalities are at risk.
