•A framework is proposed for the quantitative causation analysis of grounding accidents in Arctic waters.•Potential risk factors are identified for grounding accidents in Arctic shipping.•The ...interdependency of the risk factors is reflected using the AcciMap model.•The critical risk factors are identified for quantitative analysis using the BN model.•RCOs are proposed for decreasing the risk of ship grounding in Arctic shipping.
The melting of Arctic Sea ice has significantly facilitated Arctic shipping. However, such increased shipping has brought about higher maritime accidents in Arctic waters, especially for grounding and fire/explosion accidents. The paper presents a framework for quantitative analysis of the causation of grounding accidents in Arctic shipping by developing an accident map (AcciMap) - Bayesian network (BN) model. First, the potential risk factors for grounding accidents in the Arctic shipping were identified according to 322 maritime accident investigation reports (MAIRs) - 299 global MAIRs of grounding accidents (including 5 in Arctic waters) and 23 MAIRs (except grounding accidents) in Arctic waters and related literature. Consequently, an AcciMap model is developed for describing the evolution of grounding accident scenarios and reflecting the interdependency of the identified risk factors. Then, a probabilistic model is proposed to evaluate the probability and severity of the grounding accident for presenting a convincing justification for risk control options (RCOs). The framework is applied for the quantitative analysis of a cruise ship grounding accident in Arctic waters. Results demonstrate (1) improved understanding of cruise ship grounding risk factors related to government supervision, shipping company management, technical and operational management, unsafe incidents and behaviors, and environmental conditions; (2) quantitative analysis of the evolution of grounding accident and better identification of the critical risk factors; (3) determination of RCOs for risk management in Arctic shipping.
Chronic kidney disease (CKD) is a global public health problem, and cardiovascular disease is the most common cause of death in patients with CKD. The incidence and prevalence of cardiovascular ...events during the early stages of CKD increases significantly with a decline in renal function. More than 50% of dialysis patients die from cardiovascular disease, including coronary heart disease, heart failure, arrhythmia, and sudden cardiac death. Therefore, developing effective methods to control risk factors and improve prognosis is the primary focus during the diagnosis and treatment of CKD. For example, the SPRINT study demonstrated that CKD drugs are effective in reducing cardiovascular and cerebrovascular events by controlling blood pressure. Uncontrolled blood pressure not only increases the risk of these events but also accelerates the progression of CKD. A co-crystal complex of sacubitril, which is a neprilysin inhibitor, and valsartan, which is an angiotensin receptor blockade, has the potential to be widely used against CKD. Sacubitril inhibits neprilysin, which further reduces the degradation of natriuretic peptides and enhances the beneficial effects of the natriuretic peptide system. In contrast, valsartan alone can block the angiotensin II-1 (AT1) receptor and therefore inhibit the renin–angiotensin–aldosterone system. These two components can act synergistically to relax blood vessels, prevent and reverse cardiovascular remodeling, and promote natriuresis. Recent studies have repeatedly confirmed that the first and so far the only angiotensin receptor–neprilysin inhibitor (ARNI) sacubitril/valsartan can reduce blood pressure more effectively than renin–angiotensin system inhibitors and improve the prognosis of heart failure in patients with CKD. Here, we propose clinical recommendations based on an expert consensus to guide ARNI-based therapeutics and reduce the occurrence of cardiovascular events in patients with CKD.
The oil tanker shipping market always presents periodicity following varied laws in different periods. However, most of the studies on the tanker freight rate market are short-term projections, while ...those on its long-term periodicity characteristics are mostly qualitative ones. In order to study the periodic variation law of the tanker market, this paper uses quantitative methods to figure out the cycle duration and amplitude of different scales of Aframax tanker's freight, and predicts the long-term variation trend of freight rate on that basis. This paper selects the one-year charter freight rate of Aframax tankers (110,000 DWT D/H) to comprehensively analyze the Aframax tanker freight market variation law, and further divides the cycle into three major categories. With the help of wavelet analysis, this paper quantifies the periodic volatility of the Aframax tanker shipping market, and figures out a quarterly cycle of 11.2 months, a short-term cycle of 3.7 years, and a medium-to-long-term cycle of 11.9 years. Based on the cycle characteristics, the paper predicts the market cycle trend to the next medium-to-long-term cycle and further to the year 2030, so as to offer some reference to oil tanker shipping market players for better decision-making.
•World maritime transportation is important to crude oil trade.•Periodic variation law of the tanker market is studied.•An wavelet analysis method is established for case of Aframax tanker shipping.•Historical data used in empirical research provides decision-making basis for stakeholders.
•Maritime accident data analysis provides decision-making basis for stakeholders.•Geospatial techniques and methods for maritime accident evaluation are developed.•Spatial patterns of global maritime ...accidents are explored.•Characteristics of global maritime accidents are found to be diverse in different regions.
Maritime safety has become one of the top concerns of the global maritime sector in recent years. This paper explores the spatial patterns and characteristics of maritime accidents on a global scale. Maritime accident data dating from 2003 to 2018 from the Marine Casualties and Incidents (MCI) module of the Global Integrated Shipping Information System (GISIS) was collected and manipulated and descriptive analyses were conducted subsequently to obtain the overall profile of global maritime accidents. Geospatial techniques of Kernel Density Estimation (KDE) and K-means clustering method were introduced and parameters specifically used in this study were identified. These geospatial techniques were utilized to a) create a number of KDE maps of global maritime accidents, and b) subdivide these accidents into six classes and profile characteristics of maritime accidents within each class. Maritime accidents are more likely to occur around the United Kingdom, Denmark, Singapore, and Shanghai of China. This may be due to the large cargo volume, the high density of routes, the poor geographical conditions of the sea area and the poor climate conditions in these areas. Distributions of maritime accidents by time, initial event, and ship type are found to be diverse in different accident classes.
•Investigating the port congestion under the COVID-19 pandemic in maritime supply chain.•Analyzing the port system and countermeasures for port congestion under the COVID-19 pandemic.•Establishing a ...container port congestion evaluation model combined with the SEIR model.•Studying and evaluating the effects of different port congestion governance countermeasures.
As the hub connecting global production and consumption, ports play a pivotal role in the global maritime supply chain system. The outbreak of the COVID-19 pandemic and its rapid global spread have caused significant port congestion, resulting in skyrocketing freight rates and posing a serious threat to the smooth operation of international trade. Based on the impact of the COVID-19 pandemic, we have developed a novel container port congestion evaluation model by integrating the classical SEIR model, using the system dynamics (SD) theory. In this study, we simulate the impact of different port congestion countermeasures using data from Ningbo Zhoushan Port. The results demonstrate that implementing smart regulations at a high level of epidemic prevention and control is the most efficient approach to swiftly eliminate port congestion. In addition, it is worth mentioning that in the scenarios with a low level of epidemic prevention and control, increasing port investment to optimize smart ports can yield even better effects. Furthermore, we have discussed the impact of factors such as the ratio of infected people, the number of contacted people, and epidemic prevention and control capacity on port congestion index. Hence, we propose that the implementation of advanced smart regulation systems can enhance port operational efficiency and effectively alleviate port congestion. Additionally, amidst the normalization of the COVID-19 pandemic, which has yet to disappear, it is crucial to maintain a vigilant approach to prevention and control to ensure the seamless operation of the port industry.
Regional container port operation plays a crucial role in international trade and economic development. Amid fierce competition, orderly running of regional ports is vital. The rank-size status of ...the regional container ports indicates the orderliness and distribution concentration of port system development and is the focus of port administrations and port operators. This paper introduces the rank-size distribution rule into studies on the development of regional container port systems and proves that Zipf's three-parameter model can effectively describe the evolvement of the rank-size system of regional container ports, taking the container port group in the Yangtze River Delta as an example. This paper finds that the regional container ports tend to become concentrated in high ranks during evolvement. Moreover, the macroeconomic environment has a great impact on the distribution concentration of regional container ports. Economic procyclicality can accelerate port concentration. On the other hand, economic counter-cyclicality will induce port decentralization. The results of this paper are conducive to port administrations and enterprises to gain a more comprehensive understanding of the development of regional container ports and to formulate the proper development plans. The results are also helpful for government departments to well design the development strategies for port and shipping development and better steer the benign development of regional container port groups.
The rapid growth of the global economy has boosted the shipping industry, but it has also increased energy consumption and exhaust emissions. Based on the system dynamics method, we construct a ...carbon abatement model of maritime supply chain, in which the interaction among company, economy, energy, environment, and policy is deeply analysed. The effect of various carbon abatement measures is simulated with a case study of Shanghai Port. The results prove that the shore power has tremendous potential for reducing emissions. Interestingly, the emission trading scheme has little effect on emission reduction. Conversely, it will increase CO
2
emissions because of the vicious circle of higher CO
2
production and decreased CO
2
treatment capability. Case 4 is the best alternative for reducing CO
2
emissions in maritime supply chain when combined measures are applied, regardless of the emission reduction effect or carbon emission intensity. Thus, it is most effective to mobilise all kinds of resources to reduce CO
2
emissions when conditions permit.
This paper proposes a novel B-spline interpolation based on
CL
points preprocessing algorithm and on
u
-
S
modeling, aiming to overcome the shortages of linear and circular interpolations. A B-spline ...toolpath trajectory is generated by fitting a given set of
CL
points.
CL
points are preprocessed by chord distance to reduce computation load, thus using fewer feature
CL
points to generate a B-spline toolpath trajectory. As for disadvantages due to parameter updating for B-spline interpolation, a fifth order polynomial based on
u
-
S
modeling is constructed to map the desired curve length
S
to the corresponding spline parameter
u
, cutting the real-time computation load. Simulation results are provided to verify the feasibility and effectiveness of the proposed interpolation algorithm.
Irradiation damage in P92 ferritic/martensitic steel irradiated by Ar+ ion beams to 7 and 12dpa at elevated temperatures of 290°C, 390°C and 550°C has been investigated by transmission electron ...microscopy, scanning electron microscopy and atomic force microscopy. The precipitate periphery (the matrix/carbide interface) was amorphized only at 290°C, while higher irradiation temperature could prevent the amorphization. The formation of the small re-precipitates occurred at 290°C after irradiation to 12dpa. With the increase of irradiation temperature and dose, the phenomenon of re-precipitation became more severe. The voids induced by irradiation were observed after irradiation to 7dpa at 550°C, showing that high irradiation temperature (≥ 550°C) was a crucial factor which promoted the irradiation swelling. Energy dispersive X-ray analysis revealed that segregation of Cr and W in the voids occurred under irradiation, which may influence mechanical properties of P92 F/M steel.
High density of small voids, about 2.5nm in diameter, was observed after irradiation to 12dpa at 550°C, which was shown in panel a (TEM micrograph). As shown in panel b (SEM image), a large number of nanometer-sized hillocks were formed in the surface irradiated at 550°C, and the mean size was ~30nm. The formation of the nanometer-sized hillocks might be due to the voids that appeared as shown in TEM images (panel a). High irradiation temperature (≥550°C) was a crucial factor for the formation of void swelling. Display omitted
► Small carbides re-precipitated in P92 matrix irradiated to 12dpa at 290°C. ► High density of voids was observed at 550°C. ► Segregation of Cr and W in voids occurred under irradiation.
The bromodomain is an evolutionarily conserved motif found in many transcriptional activators including p300 which contains an intrinsic histone acetyltransferase activity and is a general ...coactivator for many transcription factors. One mode of bromodomain action is to serve as a binding module to recognize specific acetyl-lysine residue of histones during chromatin remodeling and transcriptional activation. The function of p300 is required for diverse sets of gene expression. However, it is not known whether the p300 bromodomain is involved in the expression of all or only subset of p300-dependent genes. In this study, we examined the impact of either wild type or a bromo-deficient p300 on the expression of several p300-dependant genes. The effects of histone acetylation on the expression of these genes were also assessed by targeting histone deacetylase activities with an inhibitor approach. We show that the impact of these inhibitors on the transcriptional activation of p300-dependent genes are impaired in cells containing the bromo-deficient p300, indicating that the interplay of p300 and histone acetylation in p300-dependent gene transcription requires the bromodomain. We also observed an increase in the expression of bromo-deficient p300 at the level of transcription possibly to compensate for the loss of p300 function. However, the high level of bromo-deficient p300 is not able to maintain the basal level of histone acetylation. Thus, the bromodomain is important for p300 to maintain the basal level of histone acetylation and to induce the transcriptional activation of p300-dependent genes. Nevertheless, the requirement of bromodomain and histone acetylation in p300-dependent gene transcription is determined by a gene specific manner.
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