Spilled gallstones mimicking a retroperitoneal sarcoma following laparoscopic cholecystectomy

Laparoscopic cholecystectomy has become a standard treatment of symptomatic gallstone disease. Although spilled gallstones are considered harmless, unretrieved gallstones can result in intra-abdominal abscess. We report a case of abscess formation due to spilled gallstones after laparoscopic cholecystectomy mimicking a retroperitoneal sarcoma on radiologic imaging. A 59-year-old male with a surgical history of a laparoscopic cholecystectomy complicated by gallstones spillage presented with a 1 mo history of constant right-sided abdominal pain and tenderness. Computed tomography and magnetic resonance imaging demonstrated a retroperitoneal sarcoma at the sub-hepatic space. On open exploration a 5 cm × 5 cm retroperitoneal mass was excised. The mass contained purulent material and gallstones. Final pathology revealed abscess formation and foreign body granuloma. Vigilance concerning the possibility of lost gallstones during laparoscopic cholecystectomy is important. If possible, every spilled gallstone during surgery should be retrieved to prevent this rare complication.

Modeling underwater transport of oil spilled from deepwater area in the South China Sea

Based on a Lagrangian integral technique and Lagrangian particle-tracking technique,a numerical model was developed to simulate the underwater transport of oil from a deepwater spill. This model comprises two submodels: a plume dynamics model and an advection-diffusion model. The former is used to simulate the stages dominated by the initial jet momentum and plume buoyancy of the spilled oil,while the latter is used to simulate the stage dominated by the ambient current and turbulence. The model validity was verified through comparisons of the model predictions with experimental data from several laboratory flume experiments and a field experiment. To demonstrate the capability of the model further,it was applied to the simulation of a hypothetical oil spill occurring at the seabed of a deepwater oil/gas field in the South China Sea. The results of the simulation would be useful for contingency planning with regard to the emergency response to an underwater oil spill.

CALCULATION FOR THE DISSOLVED QUANTITIES OF OIL SPILLED AT SEA

Laboratory and field experiments on the dissolution of oil showed that the quantity of the dissolvedoil component in the seawater depends on its solubility, concentration in the pertroleum, and theenvironmental conditions. The vertical oil concentration in calm sea decreases exponentially with depth.The vertical diffusion coefficients and dissolution constants of the N-pareffin from C12 to C21, totaliso-paraffin, cycle-paraffin and aromatic components in calm sea were calculated, and the oil dissolution in-to seawater was determined to be about 0.52% in 48 h for No. 0 light diesel oil.

A CFD Model to Evaluate Near-Surface Oil Spill from a Broken Loading Pipe in Shallow Coastal Waters

Oil spills continue to generate various issues and concerns regarding their effect and behavior in the marine environment,owing to the related potential for detrimental environmental,economic and social implications.It is essential to have a solid understanding of the ways in which oil interacts with the water and the coastal ecosystems that are located nearby.This study proposes a simplified model for predicting the plume-like transport behavior of heavy Bunker C fuel oil discharging downward from an acutely-angled broken pipeline located on the water surface.The results show that the spill overall profile is articulated in three major flow areas.The first,is the source field,i.e.,a region near the origin of the initial jet,followed by the intermediate or transport field,namely,the region where the jet oil flow transitions into an underwater oil plume flow and starts to move horizontally,and finally,the far-field,where the oil re-surface and spreads onto the shore at a significant distance from the spill site.The behavior of the oil in the intermediate field is investigated using a simplified injection-type oil spill model capable of mimicking the undersea trapping and lateral migration of an oil plume originating from a negatively buoyant jet spill.A rectangular domain with proper boundary conditions is used to implement the model.The Projection approach is used to discretize a modified version of the Navier-Stokes equations in two dimensions.A benchmark fluid flow issue is used to verify the model and the results indicate a reasonable relationship between specific gravity and depth as well as agreement with the aerial data and a vertical temperature profile plot.

Progress in metal oxide-based electrocatalysts for sustainable water splitting

Metal oxide-based electrocatalysts are promising alternatives to platinum group metals for water splitting due to their low cost,abundant raw materials,and impressive stability.This review covers recent progress in various metal oxides tailored for hydrogen and oxygen evolution reactions,discussing their crystal structure,composition,and surface modification influence on performance.Strategies like surface engineering,doping,and nanostructuring are evaluated for enhancing catalytic activity and stability.The key considerations for commercialization are highlighted,emphasizing ongoing research,innovation,and future scope to drive widespread adoption of water-splitting technology for a cleaner and sustainable future.

Oil Spill Risk Assessment of Offshore Pipeline in the Bohai Sea Under the Perspective of Ecological Protection

In recent decades,the exploration and development of marine oil and gas resources have increased significantly to meet the increasing energy demand of mankind.The Bohai Sea is a semi-closed continental sea that has a weak water exchange capacity and high ecological fragility.However,at present,more than 200 oil platforms have been built in the Bohai Sea,with more than 270 offshore oil pipelines having a length exceeding 1600 km.The oil spill pollution of offshore platforms has a great impact on the marine environment and ecosystems.Therefore,a comprehensive assessment of its risks is of great practical significance.This paper systematically constructs a comprehensive oil spill risk assessment model that combines the oil spill risk probability model and the ocean hydrodynamic model.This paper uses the Bohai Sea offshore pipeline as an example to assess its oil spill risk.The high-risk-value areas of the Bohai Sea offshore pipeline are mainly distributed at the bottom of Liaodong Bay,the bottom of Bohai Bay,near the Caofeidian area,and the northern part of the Yellow River Estuary.

Transport and behavior of marine oil spill containing polycyclic aromatic hydrocarbons in mesocosm experiments

Polycyclic aromatic hydrocarbons(PAHs)are one of the most important groups in oil,and re sponsible for major toxic and/or carcinogenic impact on humans and wildlife.It is important to understand the behavior of PAHs in marine environment after an oil-spill incident.However,interaction between petroleum PAHs and microbial communities in a marine environment remains unclear.Therefore,a series of mesocosm experiments were conducted.in which water-accommodated fraction(WAF)of oil was generated to simulate an oil-spill scenario and to analyze the transport and behavior of marine oil spill containing PAHs with and without dispersants.Results indicate that the application of dispersant could increase the concentration of total PAHs in water column due mainly to significant increase in the concentration of highmolecular weight(HMW)PAHs at a lower removal rate.At the end of the 7-day experiment,significant amount of HMW PAHs were accumulated in sediment.In general,the application of dispersant did not increase the sediment uptake of PAHs but increased the PAHs concentration in water column.

Parameterization Method of Wind Drift Factor Based on Deep Learning in the Oil Spill Model

Oil spill prediction is critical for reducing the detrimental impact of oil spills on marine ecosystems,and the wind strong-ly influences the performance of oil spill models.However,the wind drift factor is assumed to be constant or parameterized by linear regression and other methods in existing studies,which may limit the accuracy of the oil spill simulation.A parameterization method for wind drift factor(PMOWDF)based on deep learning,which can effectively extract the time-varying characteristics on a regional scale,is proposed in this paper.The method was adopted to forecast the oil spill in the East China Sea.The discrepancies between predicted positions and actual measurement locations of the drifters are obtained using seasonal statistical analysis.Results reveal that PMOWDF can improve the accuracy of oil spill simulation compared with the traditional method.Furthermore,the parameteriza-tion method is validated with satellite observations of the Sanchi oil spill in 2018.

The Mitigation Strategies for Managing the Potential Environmental Risks Posed by Oil and Gas Development on Mangrove Ecosystems in the Coastal Communities

Guyana is an oil-producing country vulnerable to potential oil spills and the environmental risks posed by oil and gas exploration and production activities. Despite the technologically advanced equipment employed by ExxonMobil Guyana and affiliates, an oil spill could occur due to accidents, equipment failures, or sabotages. The selected coastal communities as the study areas in Region 1 and Region 2 could be adversely affected, particularly the mangrove ecosystems. Potential oil spill pollution will adversely impact mangrove ecosystems in Region 1 and Region 2. Mangroves offer significant benefits to coastal communities, such as coastal defence and carbon sequestration, which puts Guyana on the world map. The research aimed to investigate the mitigation strategies to manage the potential environmental risks on mangrove ecosystems in the coastal communities of Region 1 and Region 2. It followed a qualitative approach and conducted semi-structured interviews with the Toshaos of the selected coastal communities. The data analysis strategy was thematic analysis using the Nvivo software. The major themes included legal and policy frameworks, oil spill response strategies, community-based involvement, and monitoring and enforcement of regulations. The significant results included reviewing and updating the regulatory framework for mangrove management and conservation;oil spills mitigation measures such as containment and shoreline protection and cleanup, cost recovery and compensation, and limited monitoring and law enforcement of mangrove management and conservation regulations by inter-agencies. The regulatory and institutional framework is outdated and needs to be amended. The agencies overseeing mangrove management and conservation have overlapping responsibilities and require more coordination. There should be greater collaboration among agencies for mangrove management and conservation and improved monitoring and enforcement programmes through institutional support.

The Environmental Risks Posed by the Oil and Gas Development and Its Potential Impacts on Mangrove Ecosystems and the Coastal Community’s Well-Being

Guyana is an oil-producing country with oil and gas exploration and production operations approximately 190 km offshore. The coastal communities selected as the study areas in Region 1 and Region 2 are adjacent to the coast and 5 to 10 km inshore. In the event of oil spills, Shell Beach Protected Areas and the other selected communities will be negatively impacted, particularly the mangrove ecosystems and the community’s well-being. The research aims to investigate the potential environmental risks posed by oil and gas exploration and production activities. It followed a qualitative approach and employed semi-structured interviews with the Toshaos of the coastal communities. The data analysis strategy was thematic analysis using the Nvivo software. The major themes included community assets, the importance of mangrove ecosystems, and the impacts of mangrove ecosystem damage through oil spills. Oil spill pollution will negatively impact mangrove ecosystems and the coastal community well-being in Region 1 and Region 2. The major results include damage to cultural artefacts, saltwater intrusion of major creeks, reduced fish catch levels, and agriculture products, which are the main economic activities in the selected communities. Consuming contaminated agriculture and marine products will lead to adverse health problems. Mangrove ecosystems provide considerable benefits to coastal community residents, including shields against river bank erosion, natural habitats for wildlife and source of income, shared traditions, social values, recreational facilities, and tourist attractions. These benefits contribute to the overall coastal community’s well-being. The mangrove forests must be protected and conserved to avoid environmental damage.

Application of Vegetation Indices for Detection and Monitoring Oil Spills in Ahoada West Local Government Area of Rivers State,Nigeria

The study evaluated the environmental effects of an oil spill in Joinkrama 4 and Akimima Ahoada West LGA,Rivers State,Nigeria,using various vegetation indices.Location data for the spill were obtained from the Nigeria Oil Spill Detection and Response Agency,and Landsat imagery was acquired from the United States Geological Survey.Three soil samples were collected from the affected area,and their analysis included measuring total petroleum hydrocarbons(TPH),total hydrocarbons(THC),and polycyclic aromatic hydrocarbons(PAH).The obtained data were processed with ArcGIS software,utilizing different vegetation indices such as the Normalized Difference Vegetation Index(NDVI),Atmospheric Resistant Vegetation Index(ARVI),Soil Adjusted Vegetation Index(SAVI),Green Short Wave Infrared(GSWIR),and Green Near Infrared(GNIR).Statistical analysis was performed using SPSS and Microsoft Excel.The results consistently indicated a negative impact on the environment resulting from the oil spill.A comparison of spectral reflectance values between the oil spill site and the non-oil spill site showed lower values at the oil spill site across all vegetation indices(NDVI 0.0665-0.2622,ARVI-0.0495-0.1268,SAVI 0.0333-0.1311,GSWIR-0.183-0.0517,GNIR-0.0104--0.1980),indicating damage to vegetation.Additionally,the study examined the correlation between vegetation indices and environmental parameters associated with the oil spill,revealing significant relationships with TPH,THC,and PAH.A t-test with a significance level of p<0.05 indicated significantly higher vegetation index values at the non-oil spill site compared to the oil spill site,suggesting a potential disparity in vegetation health between the two areas.Hence,this study emphasizes the harmful effect of oil spills on vegetation and highlights the importance of utilizing vegetation indices and spectral reflectance analysis to detect and monitor the impact of oil spills on vegetation.

Physico-Chemical Characteristics and Heavy Metals in Groundwater Bassambiri-Nembe, Bayelsa State, Nigeria

The study is focused on the post impact of oil spill contamination of groundwater in Bassambiri Nembe Bayelsa State. Groundwater samples were sampled from hand dug wells from eight stations including the control point for physico-chemical investigation using sterilized glass bottles. Standard methods were used for the analyses. The result of physico-chemical parameters analyzed shows that the values of the groundwater pH ranged between 5.90 - 6.35, electrical conductivity between 80.39 - 89.23 μS/cm, Salinity 23.3 - 28.69 mg/l, Turbidity 1.71 - 3.84 NTU, Biochemical Oxygen Demand (BOD) 1.12 - 1.36 mg/l, Alkalinity 8.56 - 12.12 mg/l, Total Hardness 11.8 - 14.47 mg/l and Temperature 26.1℃ - 27.3℃. Analysis of cations shows that Na ranged from 7.38 - 10.34 mg/l, K 0.26 - 0.49 mg/l, Calcium ion levels 2.56 - 3.59 mg/l and Mg 0.88 mg/l - 1.23 mg/l. The anions showed Potassium ion levels ranged from 0.01 mg/l - 0.02 mg/l, Chloride ion levels 12.29 mg/l - 15.88 mg/l, Fluoride ion levels 0.01 mg/l and Nitrates from 0.27 mg/l - 0.48 mg/l. Total Heterotopic Fungi population ranged from 15.26 - 48.55 Coliform Forming units/ml. The maximum permissible value of total coliforms in drinking water was exceeded. However, the Total Hydrocarbon Concentration (THC) across the groundwater sample points was less than 0.01 mg/l. The concentration of PAH and BTEX was 0.01 mg/l across the study area. The heavy metal concentrations in the groundwater samples were negligible with levels of 0.01 mg/l observed in the study area except for iron ranging from 0.20 - 0.56 mg/l levels above the WHO permissible limit. The physico-chemical parameters of groundwater indicate that they fall below WHO permissible limits. The cations and anions concentration indicate a stable and healthy water system which is relatively good. The groundwater system has high levels of iron in groundwater and bacterial contamination. Treatment is required to avoid acute and chronic iron overload resulting from consumption from drinking groundwater within the study area.

Value evaluation of ecological risk of marine chemical spills

The environmental risk of chemical spills near coastal zones threatens abundant marine ecological resources. By appraising the ecological damage value of the environmental risk of marine chemical spills, we can facilitate decision-making for the development of a coastal zone and establishment of economic policy on coastal zone management. In this study, the ecological effect of the environmental risk of a chemical spill in the Haicang chemical industrial park in Xiamen was identified, after which its impact was forecasted and its ecological damage value was assessed. The information generated in this study will be useful in future studies evaluating marine ecological compensation based on environmental risk analysis.

Laboratory investigation into the oil diffusion from submarine pipeline under water flow

A physical model test has been conducted to study the oil diffusion from the submarine pipeline under water flow.The crude oil in the flume is spilled from a leakage point of the pipeline and diffused from the seabed to the surface. By the non-contact optical measuring technology, an image acquisition and data analysis system is designed to explore the spilled mechanism and characteristic. The oil trajectory, velocity and the rising time to the surface are obtained through this system. The influence of the water flow and the spilled discharge on the behavior of the spilled oil are analyzed from both qualitative and quantitative perspectives. The sensitivity study of the characteristic physical quantities to various factors are presented afterward. The spilled oil under water is mainly distributed in the form of the scattered particles with different sizes. The rising process of the oil can be divided into three stages: full, dispersion and aggregation period. The spilled discharge is the primary factor affecting the rising time of the oil particles. In the rising process of the oil particles, the vertical velocity of the oil is mainly affected by the spilled discharge, and the transverse velocity is more dependent on the water velocity. The deviation of the transverse oil velocity is much larger than that of the rising time and the vertical oil velocity. The study can provide a theoretical reference for the prediction system of oil spill emergency.

Sorption Behaviours of Exfoliated Graphite

Exfoliated graphite (EG) is selected as a new kind of sorbent to sorb heavy oil spilled. In order to make use of EG more effectively, some basic experiments are performed to investigate its sorption properties, i.e. , specific sorption, height of saturation layer, sorption time constant. In the present experiments, A grade heavy oil is employed as a standard sorbate. It is concluded that 1) under the condition that the area of solid (filter bottom) liquid (heavy oil) interface is a constant, specific sorption usually decreases when the amount of EG filled or the apparent bulk density increase; however, the specific sorption initially increases when the apparent bulk density is too low and the amount of EG filled is too much; 2) under the condition that the apparent bulk density of EG filled is a constant, the sorption time constant tends to increase when the amount of EG filled increases; however, for a constant amount of EG filled, the sorption time constant will decrease when the apparent bulk density increases.

BP神经网络在船舶溢油损害评估中的应用

建立基于船舶溢油污染损害评估的BP神经网络,借助MATLAB语言对该网络进行训练和仿真,并对仿真结果进行误差分析,证明使用BP神经网络对船舶溢油污染损害评估的可行性和实用性。

考虑顾客有限理性的汽车租赁需求无约束估计方法

租车系统的预订数据不能代表顾客真实需求,库存控制导致供需不匹配,也会产生需求的“溢出”和“再现”。无约束估计多以短视型或策略型为假设,导致顾客的有限理性行为没有被充分考虑。以多价格等级车型的租赁需求为研究对象,基于顾客的有限理性形成租赁决策,用Logit模型分析顾客选择行为,结合前景理论的价值函数求得顾客效用,以分析需求转移行为,实现无约束估计。算例表明,多车型Spill改进模型能有效避免需求高估,并解释真实需求对收益的影响程度,存量控制收益提高了0.81%。

A review of numerical modeling research on the marine oil spill

Recently, as the oceanic activities are more and more frequently carried out, marine oil spill accidents bring to enormous harm to the economy and society in China, especially in the Offshore China. Marine oil spill is one kind of serious disasters which severely damages the marine environment. Aiming at the improvement of the emergency response system and response ability for the oil spill, the relative technologies on oil spill response are developed. This paper briefly introduces the developments and achievements of the oil spill numerical models, including the oil spill spreading model, the oil spill transport model, the oil particle model as well as the oil spill weathering model, which provide the theoretic criterions for the future work on the oil spill predicting and response.

Evaluation of diagnostic ratios of medium and serious weathered oils from five different oil sources

Laboratory experiments were conducted to simulate oil weathering process, a medium to long term weathering process for 210-d, using samples collected from five different oil resources. Based on relative deviation and repeatability limit analysis about indexes of these samples, the results show there had been significant changes in diagnostic ratios among the initial and weathered samples of different oils during this process. Changes of selected n-alkane diagnostic ratios of all oil samples displayed more obviously than diagnostic ratios of terpanes,steranes and PAHs in this process. Almost all selected diagnostic ratios of terpanes, steranes and PAHs can be efficiently used in tracking sources of hydrocarbon pollution, differentiating from the n-alkane diagnostic ratios.In these efficient diagnostic ratios, only four ratios maintained good stability in the weathering processes and are more suitable because their relative deviation（RSD） are lower than 5%.

一种新的快速局部不变特征算法

针对传统局部不变特征算子主方向提取不准确和匹配阶段过于耗时的问题,提出一种基于RI-LBP算子和混合spill树的快速局部不变特征算法。首先提出一种FAST-Difference算法,提取出模板图像和待匹配图像的稳定特征点,然后使用旋转不变的RI-LBP描述符计算特征向量,最后对特征向量集使用混合spill树进行匹配并使用RANSAC算法剔除误匹配点。RI-LBP算子自身的旋转不变性能够在一定程度上克服特征点主方向确定不准确的缺点,使特征描述符的提取更加稳定,并生成更简单的53维局部不变特征描述符。混合spill树相对于kd-tree省略了回溯过程,对于高维数据拥有更好的匹配效率。实验证明:该算法与SURF算法描述能力相近,旋转和光照条件下比SURF性能更优,并且匹配速度更快。