Port Channels Research Articles

Retaining of dredging waste using geotextile tubes: analysis of the dewatering and undrained shear resistance of the sludge cake

The city of Rio Grande has its economy linked to coastal and port activities and has a port complex of high economic importance for the region. To maintain the depth of the port channels, periodic dredging operations are carried out, as occurred in the Port of Rio Grande between 2018 and 2020. Approximately 16 million m³ of sediments were removed from the channel and deposited in disposal zones. There has been an attempt to develop techniques that carry out the reuse and disposal of dredging waste more appropriately, seeking to minimize environmental impacts by avoiding inappropriate open-sea or onshore disposal. Within this context, this work aims to evaluate the potential of the retaining and dewatering process of dredging waste in geotextile tubs (linear geoforms, geobags e etc). This technique reduces the volume of dredged mud through desiccation and allows the geotextile tubs to be installed in sedimentation basins onshore or coastal protection structures. Thus, the present study evaluated the dewatering and filtration efficiency of these systems through tests of small bags. The advantages of adding flocculation polymer and the behavior of undrained shear strength over time of the retained cake were evaluated.

Impact of Port Shallowness (Clearance under the Ship’s Keel) on Shipping Safety, Energy Consumption and Sustainability of Green Ports

In a majority of ports, a ship’s speed is limited for reasons of navigational safety. At the same time, captains and port pilots choose the speed of the ship, but it cannot be higher than the speed allowed in the port. Therefore, the speed of the ship also depends on the experience of the masters and harbor pilots and the sailing conditions in specific situations. Choosing the optimal speed of the ship in the port, considering the hydrodynamic effect of shallow water and the controllability of the ship, can help reduce fuel consumption and ship emissions, which is important for the development of a sustainable port. In all cases, the safety of the shipping is the highest priority. The main objectives of this article are determining the optimal speed of ships in ports with low clearance under a ship’s hull, ensuring navigational safety, reducing fuel consumption and emissions, and creating a sustainable port. This article presents the methodology for calculating the optimal ship speed as the minimum controllable speed, fuel consumption and emission reduction, as well as its implications for sustainable and green maritime transport and port development. The methodology presented has been tested on real ships and using a calibrated simulator, navigating through port channels and port water’s restricted conditions.

Impact of Port Clearance on Ships Safety, Energy Consumption and Emissions

The safety of shipping, energy consumption and environmental impact in ports and port channels is very critical. One of the most important elements in the provision of safe navigation, energy consumption and emissions generation is the depth of ports so that under all conditions the hull of a ship does not touch the bottom of the channels or the bottom of the basin, as well as optimizing energy consumption and minimizing the environmental impact. The very high depth reserves in ports make it possible to ensure the safety of shipping, but at the same time require huge investments in the dredging and maintenance of a port’s channels and basins, which can have a negative impact on a port’s economic results. Optimizing the depth of port channels and basins is very important from an economic, maritime safety, energy saving and environmental point of view, as vessels navigating port channels and basins must not only keep their hulls off the bottom of the channel or basin, but also have good controllability, use minimal energy consumption and minimize their environmental impact. With good maneuverability, the number of and need for auxiliary vehicles (tugs) can be minimized. This article analyses the relationship between ships’ draught and port channels and basins depths, which influences the aspects of a ship’s controllability, in order to optimize the depths of port channels and basins and, at the same time, minimize energy consumption and environmental impact while preserving the necessary navigational safety.

Study on the Impact of Typhoon Maria (2018) on Suspended Sediment in Hangzhou Bay, China

Sediment transport in coastal waters has an important impact on the siltation of port channels and changes in the estuary ecological environment. The southeast coast of China is often hit by typhoons, which can affect the suspended sediment concentration (SSC) in coastal waters. In this study, we used Geostationary Ocean Color Imager (GOCI) data to analyze SSC variations in Hangzhou Bay during Typhoon Maria (2018), and the influencing factors were also analyzed. The results showed that: (1) During the typhoon’s transit, the SSC in Hangzhou Bay (HZB) increased by 200–800 mg/L, which was one-fold higher than the day before the typhoon. The variation of SSC on the south bank was noticeable, and the typhoon effect on SSC lasted for 2–3 days; (2) The wind speed and significant wave height (SWH) increased during the typhoon. In general, in the early stage of the typhoon, the SSC in HZB was affected by the wind, and in the interim and late period, SSC was influenced by the effect of wind and wave height; (3) Typhoon “Maria” accelerated the transport of sediment and land-based pollutants from land to sea; the effect of residual current and wind stress are the driving mechanisms for seaward sediment transport. However, mechanisms and driving factors of sediment transport in coast water are complex and diverse. The results of this study can help to understand the processes of riverbed erosion and deposition in Hangzhou Bay and adjacent waters. They are also significant for the study of nearshore hydrodynamic characteristics of typhoons and channel engineering.

A preliminary study of soft bottom benthic communities in an area affected by intense maritime traffic (Slovenian Sea, Northern Adriatic)

Maritime traffic and port activities pose several environmental and ecological problems in the marine environment. The purpose of this study was to provide baseline data for the future assessment of anthropogenic impacts related with port activities in Slovenian Sea (Northern Adriatic Sea). The macrobenthic communities near the port of Koper, as well as sites offshore were analysed. Results showed that the sites offshore were generally richer and more structured than sites inside the Port area. Those differences were explained partly by depth and sediment grain size. The ecological quality indicated by M-AMBI index resulted Good/High at all the sampling sites. However, the k-dominance curves indicated a disturbance at certain sites, in particular in the port channels. This work highlights the need for consistent monitoring programs to provide baseline data for future studies assessment of anthropogenic impacts.

RESEARCHES OF CHANGES OF THE COEFFICIENT OF A FILTRATION OF THE POROUS MEDIA AT THE DIFFERENT TYPES OF FORMATION OF A DEPOSIT. THE THEORETICAL ANALISIS AND PRACTICAL RECOMMENDATIONS FOR CALCULATIONS OF CLEARING FILTERS

On the basis of analogy betweem the laminar flow of a viscous liquid in a tube and a filtration in the porous media which submits to the linear law of resistance Dar-cy the formula for calculation of coefficient of a filtration at the combined form of adjournment of a deposit is obtained. Practical recommendations for a choiсе of theoretical and approximating experimental dependences for different types of formation of a deposit are given.
 Theoretical and applied studies of filtration of heterogeneous ridins in porous mediums with changing powers took away significant development in connection with solutions to the problems of water purification in the form of finely dispersed mineral and columnar particles and speeches. Changes in the power of porous media are observed in the history of various mechanical, physical-chemical and biological processes of mass transfer which are visible on the surface of the particles of the middle (surfase – the slurry type of the settlements of the siege after adsorption), or without the middle in the port channels (volume – the dispersed type of the settlement of the siege).
 With accumulated siege (the process of colmatation), a change in porosity and filtration coefficient is observed, and with inflows (the process of suffocation) – an increase in these important parameters of the porous medium.
 When filtering rich-phase and rich components sieges, it can be settled in a mixed (complex) form, like in plivkovy so in general. In case of filfiltration of rich-phase and rich-component native sediments, it can be settled in mixed (complex) forms – like in smelt, and in general forms. The type of the process of the siege of creation and indicated on the basis of laboratory data. To lie in the nursery area on the surface of the particles of interest, adhesive and sorption power of the particles of the medium, according to the type of encroachment, district, temperature and other char-acteristics of the porous medium and pore waters.

Maximum Safe Parameters of Ships in Complex Systems of Port Waterways

Context: From the perspective of marine traffic engineering, a system of port waterways is composed of a set of waterways (port areas), such as approach channels, port entrance, inner fairways (port channels, rivers, lakes), turning basins and port basins of various terminals. The sea waterway must be adjusted to the navigation of specific types of ships, characterized by length, breadth, draft and airdraft. The primary requirement for shipping in sea waterways is the safety of navigation. Each sea waterway has traffic restrictions for the ships using it. These restrictions are called conditions of sea waterway operation or conditions of ship operation in the sea waterway. Problem: There are a number of empirical, deterministic or probabilistic methods to determine the safe width of maneuvering areas on port waterways. The direct application of empirical methods to determine the conditions for the safe operation of ships on the complex waterway, such as the Świnoujście–Szczecin fairway, was impossible due to the complexity of the waterway and various restrictions on its individual parts. Method: The paper presents the assumptions and calculation procedure of a method allowing for the determination of maximum safe parameters of ships in existing complex waterways. Results: The proposed method was used in the preparation of port regulations for the dredged and widened Świnoujście–Szczecin waterway. The results of these calculations are presented as a practical application of the method. Conclusions: This article defines conditions for the safe operation of ships in complex port waterways systems and presents the methodology for determining maximum safe parameters of ships in existing complex port waterways systems.

Numerical simulation of observed flow phenomena in the supply and control ports and associated feed channels of a mini-vortex amplifier

The trajectory and reach of jets issuing from tangential control ports at the periphery of a vortex amplifier's swirl chamber depend largely on design geometry, size and pressures applied. Excessive control port pressure causes these jets to extend too far across the face of the radial supply ports, to impact on the opposing supply port wall whereupon, they bifurcate to create back diffusion of control port flow along the supply port channels. Flow through vortex amplifier geometry is simulated using a baseline Reynolds stress turbulence model with Computational Fluid Dynamics (CFX) automatic wall treatment. Anisotropic stress and vortex stretching in the swirl chamber and outlet have not prevented convergence (based on normalised vortex amplifier residuals). Known flow structures are reproduced. This paper is focussed on simulation close to pressures needed for bifurcation. Just before the point on an operating characteristic at which bifurcated tangential flow appears, the recirculation zone crossing most of the radial supply stretches to intermittently cut off the radial flow. The steady state results indicate asymmetry between the four ports, as smoke visualisation tests also imply. The transient results are sufficient to demonstrate time-dependent structures and suggest periodicity of flow structures. The model can be used to inform design and operability studies. Moreover, a curious near-wall structure of spinning flow not previously reported has been predicted close to the axis and hugging the swirl chamber wall opposite the outlet, at radii within the forced part of the Rankine vortex.

Periodic Trajectories Obtained With an Active Tractor Beam Using Azimuthal Polarization: Design of Particle Exchanger

We analytically calculate the forces generated on the near field by a focused azimuthally polarized Hermite-Gauss beam after passing a complex mask formed by two annular pupils. The resultant optical tractor beam shows two transport channels that move trapped objects upstream or downstream along the conveyor. From the analysis of the phase diagrams, we theoretically demonstrate that, depending on illumination inten- sity, the 3-D behavior of nanoparticles in this conveyor shows a limit cycle between trans- port channels. This limit cycle appears as a consequence of diffraction that produces spatially limited optical forces. We theoretically demonstrate the possibility of using the limit cycle to design a particle exchanger between channels.

Coastal microbial quality of surface sediments in different environments along the Italian coast.

In order to improve sediment handling following dredging operations, this study aims to statistically derive ranges of distribution for certain microbiological parameters, according to four environmental types inspired by Italian legislation on seaports: ports of international/national importance, ports of regional importance, port channels in brackish environments, and marine coastal areas. A national database was developed using microbiological data from technical reports available at the Italian Ministry of Environment and National Institute of Environmental Protection and Research (ISPRA) for the period 1990-2008. The parameters considered were total coliform bacteria, faecal coliform bacteria, Escherichia coli, enterococci, sulfite-reducing clostridia (SRC), total bacterial counts at 22 °C and at 37 °C, and fungi. The data were statistically analyzed: (1) to verify the correspondence with the identified environmental types and rank them according to the concentration gradient and (2) to describe the data distribution in order to obtain reference ranges typical for each parameter/environmental type. The four environmental types considered were clearly different for enterococci, SRC, and fungi, highlighting a correspondence with Italian legislation. For the remaining parameters, at least two environmental types were merged. In general, the less contaminated environments were small ports and relatively unimpacted coastal areas. The ranges defined for relatively clean coastal areas can be considered a target for other areas both from an environmental point of view and for the sediment management implications. These values could be used as a comparison in environmental surveys addressing marine or brackish sediment handling and may represent a future line of evidence for the assessment of overall sediment quality.

Application of theory of semi-Markov processes to determining distribution of probabilistic process of marine accidents resulting from collision of ships

ABSTRACT In this paper is presented possible application of the theory of semi-Markov processes to elaborating an eight-state model of the process of occurrence of serviceability state and unserviceability states of sea-going ships making critical manoeuvres during their entering and leaving the ports. In the analysis it was taken into account that sea-going ships are in service for a very long time t (t → ∞). The model was elaborated to determine the probability (P0) of correct execution of critical manoeuvres during ship’s entering and leaving the port as well as the probabilities Pj(j = 1, 2, 3, …, 7) of incorrect execution of critical manoeuvres by a ship, that leads to marine accidents. It was assumed that such accidents result from: ship’s grounding on port approaching fairway, collision with a ship on port approching fairway, collision with a pierhead during passing through port entrance, collision with a hydrotechnical structure during ship’s passing through port channels, collision with a port quay during coming alongside it and collision with a ship already moored to the quay. The probability (P0) was assumed a measure of safe execution of a critical manoeuvre. The probability characterizes possibility of avoiding any collision during ship’s entering and leaving the port. The probability Pa = 1 - P0 was assumed a measure of occurrence of a collsion and - consequently - marine accident. The probability Pa was interpreted as a sum of the probabilities Pj(j = 1, 2, 3, …, 7) of occurrence of all the selected events. In summing up the paper, attention was drawn to its merits which - in opinion of this author - are crucial for research on real process of accidents during entering the port and leaving it by sea-going ship in difficult navigation conditions.

化学組成および粒度分布に基づいた東京湾の底質分布

The deposition and transport of sediments should be managed properly in ports not only for the maintenance of port channels, but also from an environment perspective. Our focus in this study was to create maps of sediment spatial distributions in Tokyo Bay by using chemical composition. We collected sediments from 449 stations in the bay and analyzed particle-size distribution and chemical composition. Sediments were grouped by chemical compositions using k-means clustering and maps of the spatial distribution of sediments were drawn up. These maps enable determination of spatial distributions of sediments from each main river that enters the bay.

Multicriteria Analysis Evaluating Venice Port Development

The general aim of the International Maritime Organization (IMO) is the adoption of the highest practicable standards in matters concerning maritime safety, efficiency of navigation, prevention and control of environmental effects due to maritime traffic. The major environmental consequences investigated by IMO include air pollution, water pollution and the planning of ships’ waste reception and handling. However, in specific conditions (i.e. port channels or channels along historical sites) other effects should be taken into account, such as: the ships’ wake wash (that causes vibrations on the buildings, disruption to their foundations and corruption on the embankment system), the noise impact on neighboring residential areas (during mooring and ship loading/unloading operations) and emissions during the approaching phase. Furthermore, it is important to protect ports in particular geographical conditions. Ship movements near inhabited centers must be preserved from casualties and accidents involving ships, like collisions in the inner route or loose of load, engine failure, oil spill off (the 2009/18/EC Directive established the principles for investigating accidents). In some cases offshore ports could reduce some risks and environmental impacts. This research deals with the Venice Lagoon case study, where an offshore port (able to serve container, dry bulk and tanker ships) is under feasibility evaluation. Some of the benefits that could be obtained are: a reduced pollution, energy savings and lower environmental/infrastructural impacts. These issues will be investigated through the application of a Multicriteria Analysis model (MCA) to evaluate any benefit and/or disadvantage arising from the offshore terminal in deepsea waters, highlighting how several parameters (including safety) must be evaluated in justifying a massive investment as the offshore terminal. The goal of the research is to define a general methodology for the appraisal of huge infrastructure investments.

Uniportal video-assisted thoracic surgery for primary spontaneous pneumothorax using a single-incision laparoscopic surgery port: a feasible and safe procedure

Recent authors have pioneered the use of single-incision laparoscopic surgery (SILS) for umbilical cholecystectomy. The SILS approach has the potential of reducing the trauma of the surgical access and postoperative pain. Video-assisted thoracic surgery (VATS) greatly reduces patient postoperative pain compared with traditional thoracotomy incisions. The current trend is to use fewer working ports to reduce even more postoperative pain, chest wall paresthesia, and hospital stay. No reports have described using a SILS port in VATS. From September 2009 to March 2010, 13 patients had surgery for primary spontaneous pneumothorax. The patients underwent single-lung ventilation. A 2.5-cm-long incision was made at the sixth intercostal space in the median axillary line. The pleural space was entered by blunt dissection for placement of a single flexible port. A 5-mm 0° videothoracoscope, a roticulating grasper, and an endoGIA stapler were introduced through port channels. Apical lung blebs were stapled, and pleurodesis by pleural abrasion with Marlex mesh was performed. The study enrolled nine men (69.2%) and four women with a median age of 26.3years. No complications were recorded. The postoperative pain was mild for 10 patients (76.9%) and moderate for 3 patients. Mild chest wall paresthesia (numbness) was observed in three patients (23.07%). The postoperative hospital stay was 2.15days. Although the SILS port is for laparoscopic use, it allowed an adequate lineup of the instruments along the intercostal space and adequate instrument maneuverability for stapling and resecting of apical lung bullae or blebs. The procedure was accomplished successfully for 92.3% of the patients. This is the first report on the use of a SILS port in VATS. Further work and development of a proper thoracic single port are needed to define the uses and advantages of this uniportal technique.

Coastline and mudbank monitoring in French Guiana: contributions of radar and optical satellite imagery

The constant migration of mudbanks resulting from the sedimentary discharge of the Amazon River has an enormous impact on the French Guianese economy. Consequently, there is great local interest in finding tools that can be used in mapping and monitoring the mudbank migration with an acceptable level of reliability and a high frequency of measurement. This involves the ability to detect submarine mudbanks that interfere with access to port channels and impede navigation. Radar and optical satellite images of French Guiana acquired between 1997 and 2001 have been analysed to assess their utility in detecting mudbanks and monitoring coastline change. In the present study, the information derived from radar and optical satellite imagery was analysed with respect to tidal height. The influence of the radar incidence angle was considered, as well as the advantages of having multidate sequences when mapping coastal zones undergoing significant change. A comparative study between radar (European Remote Sensing Satellite (ERS) and RADARSAT) and optical (advanced spaceborne thermal emission and reflection radiometer (ASTER)) images was also conducted. The results show that low-angle radar is more suitable for detecting mudbanks, whereas high-angle radar is more appropriate for monitoring coastline change. Emerged mudbanks and mudbanks under a shallow layer of water (a few tens of centimetres at the most) are easily detectable in radar images. For high tidal levels, the optical images provide more information on the mudbanks than the radar images. Conversely, for low tidal levels, the information on the mudbanks is more detailed with radar imagery.

Import Orientations for Jor da nian-Based Companies

Abstract This pa per in ves ti gates the forces and fac tors that in flu -ence im p o r t o r i en t a t i o n s in Jor da n. It was found that or ga ni za tional buyers rate qual ity and price, rather than the coun try-of-or i gin, as the most im por tant prod uct at trib ute. The size of firms and their ex pe ri ence in import ing had min i mum im pact on im port ori en ta tions. Re sults in di cate that the or ga ni za tional buy ers in Jor dan are tra di tional in their use of promo tional tools and tend to pri mar ily rely on word-of-mouth and news papers for their in for ma tion con cern ing ex port ers and chan nels. The ar ti cle con cludes with a dis cus sion of the im pli ca tions for in ter na tional business.

Pollution and Eutrophication in the Venice Lagoon

To reduce the effect of the “high water”, which involves mainly the City of Venice, a project is underway to install barriers in the three port channels which connect the Venice lagoon to the Northern Adriatic Sea. To have a basis on which to gauge any observed effects in the water quality as a consequence of the reduction of the exchange of water between the lagoon and the open sea, a survey on the most polluted area of the lagoon was carried out over the period of a year. The following parameters were determined: pH, temperature, salinity, transparency, dissolved oxygen, ammoniacal nitrogen, orthophosphate, zinc and total coliforms. The results, compared to those obtained from previous studies, show that situation improved for ammoniacal nitrogen, zinc and coliforms and remained fairly constant for the other parameters. The inner zones of the lagoon are much more exposed to eutrophication as a consequence of a lower circulation of water and higher accumulation of nutrients. Release from sediments appears to play an important role in controlling the water quality in the shallow areas. Frequent algae blooms have been observed during spring and summer seasons. There is no evidence of an attenuation of eutrophic phenomena in recent years.