Arc additive manufacturing of gradient hot forging die with shaped waterways

Under the working environment of high temperature and strong load impact,hot forging die is prone to failure which reduces the service life of die.Using arc additive manufacturing in the die cavity,a gradient material hot forging die with high precision,superior per-formance,and conformal cooling channels is developed.This improves the toughness of the die cavity and reduces the working temperature,thereby forming an isothermal field,which is an effective method to enhance the lifespan of the hot forging die.Three kinds of gradient flux-cored wires are designed for the surface of 5CrNiMo steel,and the microstructure and mechanical properties between gradient interfaces were studied.Based on the spatial curved structure of shaped waterways in the hot forging die cavity,a study was conducted on the strategy of partitioned forming for the manufacturing of the die with shaped waterways.In order to avoid interference with the arc gun,the hot for-ging die is divided into four regions,namely the transition region,upper,middle,and lower region,based on a combination of cavity depth and internal U-shaped and quadrilateral structures.The results show that the developed flux-cored wires have good moldability with straight sides of deposited metal under different process parameters and flat surface without cracks,pores and other defects.Under the same working conditions,the life of hot forging die formed by the gradient materials is more than multiple times that of the single material hot forging die,and the temperature gradient field of the shaped waterway die is 7℃/cm smaller than that of traditional straight waterway.

Modelling Dry Port Systems in the Framework of Inland Waterway Container Terminals

Overcoming the global sustainability challenges of logistics requires applying solutions that minimize the negative effects of logistics activities.The most efficient way of doing so is through intermodal transportation(IT).Current IT systems rely mostly on road,rail,and sea transport,not inland waterway transport.Developing dry port(DP)terminals has been proven as a sustainable means of promoting and utilizing IT in the hinterland of seaport container terminals.Conventional DP systems consolidate container flows from/to seaports and integrate road and rail transportation modes in the hinterland which improves the sustainability of the whole logistics system.In this article,to extend literature on the sustainable development of different categories of IT terminals,especially DPs,and their varying roles,we examine the possibility of developing DP terminals within the framework of inland waterway container terminals(IWCTs).Establishing combined road–rail–inland waterway transport for observed container flows is expected to make the IT systems sustainable.As such,this article is the first to address the modelling of such DP systems.After mathematically formulating the problem of modelling DP systems,which entailed determining the number and location of DP terminals for IWCTs,their capacity,and their allocation of container flows,we solved the problem with a hybrid metaheuristic model based on the Bee Colony Optimisation(BCO)algorithmand themeasurement of alternatives and ranking according to compromise solution(i.e.,MARCOS)multi-criteria decision-making method.The results from our case study of the Danube region suggest that planning and developingDP terminals in the framework of IWCTs can indeed be sustainable,as well as contribute to the development of logistics networks,the regionalisation of river ports,and the geographic expansion of their hinterlands.Thus,the main contributions of this article are in proposing a novel DP concept variant,mathematically formulating the problems of its modelling,and developing an encompassing hybrid metaheuristic approach for treating the complex nature of the problem adequately.

Analysis of Landscape Design of the Visual Aids to Navigation of Inland Waterway

The visual navigation marks are established purposely,which transfer information to the trained observer in order to navigate.The visual aids to navigation in freshwater could give aid to navigation.In addition,through its basic shape,appearance forms and colors,the landscape of navigation waterway is also displayed.The aids to navigation together with channel revetment and other surrounding landscape elements determine the landscape effect of the navigation waterway.Through analyzing the design of aids to navigation features,the design impact factors,the landscape design principles and methods of treatment are proposed in this research,in order to provide some references for the design of future visual aids to navigation.

Possibilities and challenges of expanding dimensions of waterway downstream of Three Gorges Dam

The waterway in the middle and lower reaches of the Yangtze River has long been known as the Golden Waterway and has served as an important link in the construction of the Yangtze River Economic Belt.Therefore,expanding its dimensions is a significant goal,particularly given the long-range cumulative erosion occurring downstream of the Three Gorges Dam (TGD),which has been concentrated in the dry river channel.With the regulation of the volume from upstream reservoirs and the TGD,the minimum discharge and water level of the river downstream are increasing,and creating favorable conditions for the increase of the depth of the waterway.The discharge compensation effect during the dry season offsets the decline in the water level of the river channel caused by the down-cutting of part of the riverbed,but the minimum navigable water level of the segment near the dam still shows a declining trend.In recent years,several waterway remediation projects have been implemented in the downstream reaches of the TGD and although the waterway depth and width have been increased,the channel dimensions are still insufficient in the Yichang-Anqing reach (with a total length of 1026 km),as compared to the upstream reservoir area and the deep water channel in the downstream tidal reaches.A comprehensive analysis of the water depth and the number and length of shoals in the waterway indicates that its dimensions can be increased to 4.5 m ×200 m and 6.0 m×200 m in the Yichang-Wuhan and Wuhan-Anqing reaches,respectively.This is also feasible given the remediation technologies currently available,but remediation projects need to be coordinated with those for flood prevention and ecological protection.

Heavy Metal Pollution and Ecological Risk Assessment in Sediments of Xiling Channel Inland Waterway of Guangdong Province

Using the sediment monitoring data of five sections of the Xiling Channel inland waterway of the Pearl River Delta,and using Nemerow composite index,the coefficient of variation,and the index of geoaccumulation( Igeo) and the potential ecological risk index,this paper analyzed and assessed the heavy metal pollution of sediments. The results indicate that Cr reached mild pollution;Cu had a large degree of variation,and the changes of Cr and Zn were significant with fluctuation;the enrichment of heavy metals decreased as follows: Cd > Cu > Cr > Zn> Pb > Ni > Hg > As;Cd had the highest degree of enrichment and belonged to moderate pollution;the ecological hazard of heavy metals was Cd > Hg > Cu > Pb > As > Cr > Ni > Zn,and Cd had the highest ecological hazard and was the main controlling factor of potential ecological risk. In conclusion,the sediments in Xiling Channel inland waterway were polluted by heavy metals to some extent,and cadmium was the main pollutant and had the largest potential ecological risk.

The Use of Hydrogen as a Fuel for Inland Waterway Units

Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing of large capital investment towards research and development of sustainable alternative energy sources. One of the most promising and abundant of these sources is hydrogen. Firstly, the use of current fossil fuels is. discussed focusing on the emissions and economic sides to emphasize the need for a new, cleaner and renewable fuel with particular reference to hydrogen as a suitable possible alternative. Hydrogen properties, production and storage methods are then reviewed along with its suitability from the economical point of view. Finally, a cost analysis for the use of hydrogen in internal combustion engines is carried out to illustrate the benefits of its use as a replacement for diesel. The outcome of this cost analysis shows that 98% of the capital expenditure is consumed by the equipment, and 68.3% of the total cost of the equipment is spent on the solar photovoltaic cells. The hydrogen plant is classified as a large investment project because of its high initial cost which is about 1 billion US$; but this is justified because hydrogen is produced in a totally green way. When hydrogen is used as a fuel, no harmful emissions are obtained.

Physical Modeling of Localized Scour for the Yangtze Estuary Waterway Improvement Project,Phase Ⅰ

In order to examine the effectiveness of engineering protection against localized scour in front of the south groin-group of the Yangtze Estuary Waterway Improvement Project, Phase I , an undistort-ed physical model on a geometric scale of 1:250 is built in this study, covering two groins and their adacent estuarine areas. By use of rinsing fix-bed model as well as localized mobile-bed model, the experiment is undertaken under bi-directional steady flow. According to the experimental results, waterway dredging leads to the increase in steram velocity, the increase being larger during the ebb than during the flood. Construction of the upstream groin has some influence on the flow patterns near the downstream groin. Localized scour in front of the groin-heads is controlled mainly by ebb flow. In the case of a riverbed composed entirely of silt, the depths of localized scour in front of the two groin- heads are 27 m and 29 m, respectively. In reality, the underneath sediment of the prototype riverbed is clay whose threshold velocity is much higher than the stream velocity in the Yangtze Estuary; therefore, the depths of localized scour will not be much larger than the thickness of the silt layer, i. e. 7.4 m and 4.7 m, respectively. The designed aprons covering the riverbed in fron of the groin-heads are very effective in scour control. Aprons of slightly smaller size can also fulfill the task of protection, but the area of localized scour increases significantly.

How Waterways, Glacial Melt Waters, and Earthquakes Re-aligned Ancient Rivers and Changed Illinois Borders

The borders of Illinois were established when Illinois became a state in 1818. The western border was delineated using the Mississippi River, and the Ohio River was used as the southern border. The eastern border was formed by the Ohio and Wabash Rivers plus the line along latitude 42030＇30＇＇ connecting the Wabash River to Lake Michigan. As initially proposed, the northern border of Illinois would have been 82 km （51 mi） to the south of the current longitude line of 87~31 ＇. This 2,160,000 ha （5,440,000 ac） addition to Illinois resulted in the territory having the required minimum of 40,000 people to qualify as a state. The northern border was moved to allow the linkage of the Great Lakes shipping route to the Illinois and Mississippi River navigation channels. Illinois thus gained a valuable shoreline on Lake Michigan and a location for a shipping port hub which became Chicago. Initially the transfer of goods between these waterways required a portage, but later a shipping canal was created to link the waterways. During the Civil War, Union forces used the connected waterway systems as a northern supply route to avoid the contested Ohio River.

A Study on Conversion of Marine Diesel Engines Using Blended Palm Oil for Inland Waterway Vessels in Vietnam

The climate change and limitation of natural resources becomes main obstacle for the global economical development. So, the Vietnamese Government is very much concerned with reduction of harmful gas discharging from the inland-water way ships. To overcome the problems, there are many counter-measures proposed such as： renovation of machinery and equipment, using re-creative energy and so on. The author＇s idea is to find a suitable method which can be applied on board of the inland-water ships to reduce discharging toxic gas by using blended palm oil as alternative fuel for marine diesel engines. Due to some disadvantages of the bended palm oil in comparison with traditional DO （diesel oil）, such as： low freezing point, high viscosity, low stability of blended fue, therefore somehow, the blended palm oil must be made a ship directly on board. With this idea, the author has designed and made agitate mixing equipment working on-line with fuel supply system of a diesel engine. The mixing equipment, then, has been tested at shore-side laboratory as well as on board ships. The research results showed that the fuel mixture （palm oil-DO） made by this mixing equipment is fully usable to replace traditional DO for marine diesel engines installed on board ships of inland water way in Vietnam. The Vietnamese Government accepted the research results as prerequisite to devise specific and practical action plans to reduce the pollution from the inland water way ships in coming years.

Numerical Simulation of Abnormal Wave Height Change Induced by Excavated Waterway with Boussinesq Equation

A nonlinear numerical model has been set up by use of Boussinesq Equation with finite difference method, and has been applied to the simulation of the abnormal change of wave height induced by excavated waterway. Numerical results demonstrate that the abnormal change of wave height is due to the adding of the reflected wave height induced by excavated waterway to the incident wave height. Because the angle between the incident wave and the axis of the waterway is smaller than the critical angle, the reflected wave produced by the waterway may propagate to the breakwater and may be added with the incident wave, then the abnormal change of wave height before the breakwater may be caused. So the wave reflection caused by the change of water depth cannot be neglected.

The study on a new technology of waterway information system

It is a lot limitations to survey and design waterway by the CAD technique, due to timely variation of hydrology and ecology in the complicated estuary area, such as Changjing River estuary. In this paper, the advantages of GIS technique is applied to manage and process the multi kind , multi scale and multi time hydrographic parameters, including water depth, current velocity, tidal, waves, wind speed, temperature and salinity etc., also to deal with different projection, different scale charts. Meanwhile, in the paper, combination techniques of GIS and CAD has been developed for unification of the charts for efficient management, two-way automatic carts conversion between GIS and CAD, automatic cutting and assemble of a number of Charts, flight path of the projection of spatial data and coordinate transformation. This new technique has been applied to survey and design waterway of Changing River estuary. The result shows that the combination technology of GIS and CAD has application potentiality in the waterway survey and design.

INFLUENCES OF THE FISH-MOUTH PROJECT AND THE GROINS ON THE FLOW AND SEDIMENT RATIO OF THE YANGTZE RIVER WATERWAY

A depth_integrated two_dimensional numerical model of current, salinity and sediment transport was proposed and calibrated by the observation data in the Yangtze River Estuary. It was then applied to investigate the flow and sediment ratio of the navigation channel, i.e. the North Channel of the Yangtze River Estuary,before and after the first phase waterway project is implemented. Particularly, the influences of groin length and the orientation of the submerged dam on the flow ratio and sediment load discharging into the North Channel were discussed. The numerical results demonstrate that less sediment load discharges into the navigation channel, which unburdens the waterway dredging, but in the meantime the flow ratio is also decreased. The flow and sediment ratio can be adjusted by changing layout and dimensions of the hydro_structures, such as the groin length, the top height, etc. The effect of the orientation of the submerged dam is more obvious than the groin lengh.

Study on the Improvement of Sea-Entering Waterway in the Changjiang Estuary

The Changjiang Estuary is the doorway of the Shanghai Harbour and the throat for the six provinces in the Changjiang River drainage area. However the minimum water depth of the waterway in the estuary is only about six meters, so that the development of the Shanghai Harbour and the utilization of water transportation on the Changjiang River have been greatly restrained. Since 1975, the depth of the sea-entering waterway of the Changjiang Estuary has been successfully increased by one meter. This article has made a comprehensive summing-up about the selection of waterways, the determination of the line for dredging and disposal of the dredged material, thus providing reference data for future work in increasing the depth of the waterway of the Changjiang Estuary and for controlling similar waterways of other estuaries.

Numerical Prediction of Hydrodynamic Forces on A Berthed Ship Induced by A Passing Ship in Different Waterway Geometries

An investigation has been conducted to quantify the effect of waterway geometry on the form and magnitude of forces and moment experienced by a berthed ship due to a passing ship.By using the dynamic mesh technique and solving the unsteady RANS equations in conjunction with a RNG k？ε turbulence model,numerical simulation of the three-dimensional unsteady viscous flow around a passing ship and a berthed ship in different waterway geometries is conducted,and the hydrodynamic forces and moment acting on the berthed ship are calculated.The proposed method is verified by comparing the numerical results with existing empirical curves and a selection of results from model scale experiments.The calculated interaction forces and moment are presented for six different waterway geometries.The magnitude of the peak values and the form of the forces and moment on the berthed ship for different cases are investigated to assess the effect of the waterway geometry.The results of present study can provide certain guidance on safe maneuvering of a ship passing by a berthed ship.

Linking Watershed Scales through Altered Waterways

Nested hierarchy theory advances the idea that rivers have a fractal dimension where processes at the catchment scale (>1 km) control processes at the reach or mesoscale (100 m) and microscale (1 - 10 m). Largely absent from this work is a mesoscale link to the larger and smaller scales. We used stream alteration classifications to provide this link. We used orthophotographs, land cover, and LiDAR derived terrain models to classify stream alterations within four watersheds. We compared phosphorus point data with watershed, sub-watershed, and 100-meter buffers around the point data. In the predominately urban watershed, the 100 m buffer scale correlated better with phosphorus levels. In the predominately agricultural watershed, the sub-watershed scale correlated with phosphorus levels better. We found adding the classification of the stream alteration type clarified anomalously low phosphorus levels.

Optimization of Waterway with Multiple Locks and Canals by Integration of Petri Net and Genetic Algorithm

This paper presents the possibilities of job optimization in waterway with multiple locks and canals, in order to increase the system productivity. Safe navigation in such complex waterway system is very demanding. Some of the problems that need to be solved are： How to control traffic in a way that vessels move in opposite directions; How to resolve possible conflicts in case that more vessels try to acquire particular lock at the same time; How to avoid possible deadlocks; How to ensure the vessel passage in the shortest possible time？ It is necessary to apply adequate control policy to avoid deadlocks and blocks the vessels＇ moving only in the case of dangerous situation. The motion of vessels can be described as the set of discrete events and states. Herein we propose deadlock avoidance algorithm for complex waterway system with multiple key resources and we use multiple re-entrant flowlines class of Petri net （MRF^PN）. The solution represents deadlock prevention supervisor in a sense that vessels are stopped only in a case of immediate dangerous situation in dense traffic. The goal of this paper is to find optimal, conflict and deadlock free job schedule in CWS. In this sense, the authors developed the algorithm which integrates MRF^PN with a genetic algorithm. The algorithm deals with multi-constrained scheduling problem with shared resources. The final goals are minimization the total travel time of vessels through the waterway system.

A 2D Mathematical Model for Sediment Transport by Waves and Tidal Currents

In this study, the combined actions of waves and tidal currents in estuarine and coastal areas are considered and a 2D mathematical model for sediment transport by waves and tidal currents has been established in orthogonal curvilinear coordinates. Non-equilibrium transport equations of suspended load and bed load are used in the model. The concept of background concentration is introduced, and the formula of sediment transport capacity of tidal currents for the Oujiang River estuary is obtained. The Dou Guoren formula is employed for the sediment transport capacity of waves. Sediment transport capacity in the form of mud and the intensity of back silting are calculated by use of Luo Zaosen＇ s formula. The calculated tidal stages are in good agreement with the field data, and the calculated velocities and flow directions of 46 vertical lines for 8 cross sections are also in good agreement with the measured data. On such a basis, simulations of back silting after excavation of the waterway with a sand bar under complicated boundary conditions in the navigation channel induced by suspended load, bed load and mud by waves and tidal currents are discussed.

LanePost:Lane-Based Optimal Routing Protocol for Delay-Tolerant Maritime Networks

Ship.to.ship, ship.to.shore radio links empowered by Wi Fi, Wi MAX etc have been recently exploited to build maritime multi.hop mesh networks to provide internet services to on.ship users. However, because of the mobility of the vessels/ships and the large inter.ship distances, nodes in the maritime network are frequently disconnected, forcing data communication in the maritime mesh networks to be opportunistic and delay.tolerant. In this paper, we present Lane Post, an optimization approach for maritime delay.tolerant routing protocol. We exploit the shipping lane information to predict the rendezvous opportunities of the ships to optimize the route selection in delay.tolerant routing. In particular, we show that when the shipping lane information is available, an opportunistic routing graph(ORG) for each ship can be constructed to predict its multi.hop data routing opportunities to the other ships or to the shore. Based on the ORG, we develop an optimal route protocol(i.e., Lane Post) for each ship to minimize its delay of multi.hop packet delivery via dynamic programming. We discussed the ways of collecting shipping lane information by centralized method or distributed method.The proposed Lane Post protocol was evaluated by ONE, an open.source delay.tolerant network simulator, which shows its dramatic performance improvement in terms of delay reduction compared to the state.of.the.art opportunistic routing protocols.

Tidal analysis in the venturi-shaped area between Zhenhai and Shenjiamen in the East China Sea

In order to better understand the general tidal features in the venturi-shaped area between Zhenhai and Shenjiamen in the northern coastal region of Zhejiang Province in the East China Sea, the tidal data were obtained from both the three permanent tide stations of Zhenhai, Dinghai and Shenjiamen, and four temporary tide stations of Mamu, Chuanshan, Guoju and Liuheng, along with the current speed being observed at Luotou Waterway. Results from harmonic analysis show that: (1) The area was dominated by shallow water tides with irregular semi-diurnal features, and the smallest tidal range occurred in the area near a crossing line between Zhenhai and Dinghai stations, indicating that a tidal node existed in the southern Hangzhou Bay; (2) Formulae, HS2/HM2 >0.4 and gM2-(gK1+gO1)=270° (where H and g are harmonic constants), could be used as judging criteria for high and low tidal level diurnal inequalities; (3) The duration difference between ebb and flood tides could be roughly assessed by the ratio of HM4 vs. HM2; and the larger the ratio is, the bigger the duration difference is. At the same time, the duration period could be assessed by 2gM2-gM4, the epoch difference between M2 and M4 tidal constituents. If 2gM2-gM4 <180°, then the ebb duration is longer than the flood duration; if 180°< 2gM2-gM4 <360°, the result is reversed; (4) Taking Dinghai station as a center point, the highest tidal levels and the average high tidal levels, as well as the average tidal ranges at all stations became higher and larger both southeastwards and northwestwards, while the lowest tidal levels and the average low tidal levels appeared to be lower both southeastwards and northwestwards; and (5) The tidal patterns were not all in line with the tidal current patterns. As a conclusion, the smallest tidal range occurred in the narrow part of the venturi-shaped area. Along the both sides of the area, the highest tidal level and tidal range became higher and larger, while the lowest tidal level became lower with the increase of the distance from the narrow throat area. This is somehow different from the theory that the tidal level increases gradually when it moves towards the top narrow area of a V-shaped bay or estuary.

Analysis and Countermeasures of a Lightning Accident Suffered by Hangjun 12

In the evening of October 17, 2012, the vessel Hangjun 12 of Changhang Wuhan Engineering Bureau was struck by lightning when working in Malaysia red ridge channel. In the lightning accident, the weather instrument of the ship was destroyed by the lightning to the ground, and the electronic information equipment in the vessel was influenced by induction lightning, which had damaged the electronic information system and elec- trical equipment. According to the Code for Design Protection of Structures against Lightning （ GB 50057-2010）, this lightning accident suffered by Hangjun 12 was analyzed theoretically from aspects of the protection scope of the two lightning reds, main measures against lightning electromag- netic impulse, and specific reasons for the lightning accident. Finally, some measures to prevent the ship from being struck by lightning were put forward, such as improving countermeasures against direct lightning flash, enhancing equipotential bonding and shielding measures and so forth.