scholarly journals EVALUATION OF THE RELATIONSHIPS BETWEEN NAVIGATION CHANNEL DREDGING AND EROSION OF ADJACENT BEACHES IN SOUTHERN BRAZIL

2012 ◽  
Vol 1 (33) ◽  
pp. 106 ◽  
Author(s):  
Lucas Ferreira da Silveira ◽  
Lindino Benedet ◽  
Morjana Signorin ◽  
Rafael Bonanata
Keyword(s):  
Morphological Changes ◽  
Time Frame ◽  
Brazilian Coast ◽  
Coastal System ◽  
Direct Benefits ◽  
Navigation Channel ◽  
Severe Erosion ◽  
Increasing Demand ◽  
Maintenance Dredging ◽  
Benefit Cost

São Francisco do Sul Harbor, located in the Babitonga Bay, Santa Catarina, is one of the main containership harbors in Brazil and has been in operation since 1955. Due to the increasing demand for ships with greater size and draught, the navigation channel was dredged to 10 m depth in 1980 and has been gradually deepened to 13 m in recent years to accommodate Post-Panamax vessels. During the 30 years of dredging operations, more than 10 million m³ of sediments were removed from the coastal system and dumped into an offshore disposal area (about 15 m water depth), whilst the downdrift beach has experienced severe erosion. The downdrift municipality, Itapoá, recently filed a lawsuit against the Port claiming that harbor dredging has caused much of the erosion observed on its beaches. In order to evaluate the downdrift effects of dredging and maintaining the deep draft navigation channel across the ebb shoal of Babitonga Bay, the Delft3D model was used. The model was calibrated and validated with field data (water level and currents, waves and morphological changes). To evaluate channel impacts on adjacent beaches, 10 years morphology change simulations were conducted for pre-dredging scenario and scenarios of the navigation channel dredged at 10 m and 13 m depth, using the dredge and dump tool in Delft3D to maintain the deep draft channel along the simulation. A conceptual model of the sedimentary dynamics of the area was developed utilizing results from numerical modeling and field observations. It was observed in the results that dredging and maintaining the deep draft navigation channel over the last few decades have reduced the amount of sediment bypass by about 13 %. Channel dredging has therefore contributed to the erosion of the adjacent beaches, however other man-made interventions on this coastal system that contributed to the erosion problem were also identified (bay closure and tidal prism changes as well as jetties and other structures built updrift). Thus, it cannot be inferred that all the erosion of the downdrift beaches is due to the dredging activities. To mitigate for erosion effects of channel dredging, beneficial sediment disposal strategies were investigated. Strategies evaluated included beach disposal and ebb-shoal disposal of dredged materials. Beach disposal was the alternative that produced direct benefits to the downdrift beach while ebb-shoal disposal produced benefits that were not directly detected on the beach during the time frame evaluated here. Due to benefit-cost considerations, beach disposal was recommended for maintenance operations where dredging volume is greater than 400.000 m³ (about 50 % of the dredging maintenance operations exceed this threshold). For smaller maintenance dredging events, ebb shoal disposal was recommended. This work is the first of this nature in Brazil driven by legal disputes between downdrift beaches and Port authority and sets the precedent for future beneficial use of dredging materials along the Brazilian coast.

Assessing the Long-Term Planform Dynamics of Ganges-Jamuna Confluence With the Aid of Remote Sensing and GIS

2021 ◽  
Author(s):  
Nafis Sadik Khan ◽  
Sujit Kumar Roy ◽  
Md. Touhidur Rahman Mazumder ◽  
Swapan Talukdar ◽  
Javed Mallick
Keyword(s):  
Morphological Changes ◽  
Control Strategies ◽  
Satellite Image ◽  
Linear Structure ◽  
Time Frame ◽  
Morphological Alteration ◽  
Confluence Zone ◽  
Riverbank Erosion ◽  
The Ganges

Abstract The Ganges-Jamuna-Padma confluence is one of the world's most active confluences. The confluence of two of the world's greatest rivers, the Ganges and the Brahmaputra, makes this a globally significant site. Severe erosion along the banks has been caused by morphological changes in this region. Riverbank erosion is one of Bangladesh's most serious problems, as it necessitates costly intervention. Riverbank erosion in Bangladesh affects millions of people each year as a result of erosion in this confluence zone. As a result, it's critical to comprehend the confluence's morphological changing pattern. This study aims to quantify actual bank shifting around the confluence of the Ganges, Jamuna, and Padma in terms of shifting rate and area during a twenty-five-year period (1990-2015). To conduct this study the collected satellite image were geo-referenced and digitize bank lines from using ArcGIS program. The bank line is the linear structure that divides the river channel's outer border from the flood plains. The distance between the extreme margins of the left and right banks, including mid-channel sandbars, was measured to determine channel width variation. To assess the maturity of change, this time frame is subdivided into five phases, each lasting five years. In addition, the long-term shift from 1972 to 2015 is qualitatively noticeable. This morphological alteration was studied using LANDSAT satellite images. The research gives current and trustworthy information on the Ganga-Jamuna confluence's planform dynamics. This research will be useful in the planning and execution of drainage development plans and erosion control strategies in this critical confluence zone.

Investment Analysis of New Port Development Project As a Solution to Overload Problems in Long Ports

2019 ◽  
Vol 19 (2) ◽  
pp. 61-70
Author(s):  
Pandi Aditiya ◽  
Ahmad Herison ◽  
Ika Kustiani ◽  
Amril Ma’ruf Siregar
Keyword(s):  
Feasibility Study ◽  
Net Present Value ◽  
Payback Period ◽  
Development Project ◽  
Cost Ratio ◽  
Present Value ◽  
Port Development ◽  
Benefit Cost Ratio ◽  
Increasing Demand ◽  
Benefit Cost

The increasing demand for port services at the Panjang port causes high levels of ship queues. The solution to overcome this problem is to build a new port. However, this new port construction project has not yet conducted a feasibility study. The purpose of this study is to assess the feasibility of port development in the Panjang district of Bandar Lampung in terms of investment or financial aspects. The methods are Benefit-Cost Ratio, Net Present Value, Payback Period, and Internal Rate of Return. The results of the feasibility study of the most profitable investment are in the seventh scenario, the Net Present Value (NPV) of Rp. 463,292,122,605.34, the BCR result of 1.2959, the IRR yield of 12.11% and the Payback Period (PP) occur in the year to thirty-seventh with an economic age of 60 years. The conclusion is that the construction of a new port can be a solution to overcome the overload of Panjang port.

Numerical Modeling of Beach Morphological Change: A Case Study of Kaanapali Beach, Maui, Hawaii

2020 ◽  
Vol 03 (01n02) ◽  
pp. 2050002
Author(s):  
Ian Hardy ◽  
Zhenhua Huang ◽  
David Smith ◽  
Charles H. Fletcher
Keyword(s):  
Morphological Changes ◽  
Wave Model ◽  
Time Frame ◽  
Beach Profile ◽  
Spectral Wave Model ◽  
Wave Heights ◽  
Adcp Observations ◽  
Beach Survey ◽  
Profile Change

This case study reports results from field observations and numerical simulations of waves and morphological changes along a portion of Kaanapali Beach on West Maui, Hawaii, which is protected by a hard coral reef and experiences shoreline changes from season to season. The SWAN spectral wave model shows reasonable agreement with ADCP observations of wave-heights for the winter months. Simulated beach profile change over one-month time frame was able to reasonably capture the trend of beach face migration (accretion or erosion); the modeled shoreline also shows satisfactory agreement with beach survey data. This case study suggests that Delft3D is able to capture key features of sediment transport along a narrow beach protected by a fringing reef.

Tribological Characteristics of DLC-Coated Alumina at High Temperatures

2006 ◽  
Vol 128 (4) ◽  
pp. 711-717 ◽  
Author(s):  
K. Y. Lee ◽  
R. Wei
Keyword(s):  
High Temperature ◽  
Morphological Changes ◽  
Extreme Environments ◽  
Polymeric Materials ◽  
Film Coating ◽  
Wide Range ◽  
Before And After ◽  
Modification Technique ◽  
Increasing Demand ◽  
Coated Surfaces

Ceramic seals are widely used in many severe applications such as in corrosive, high temperature and highly loaded situations especially in hot chemical water-based extreme environments for automobile water pumps. Presently, polymeric materials are used as the counter part for alumina ceramic seals to reduce the ceramic-to-ceramic wear. As a result, leaks are very commonly observed from water pump during services. Consequently, it is needed to improve the surface properties of the ceramic seals using a surface modification technique such as a thin film coating process to meet the increasing demand of more stability, more durability, and lower friction of coefficient in those extreme environments. To meet these challenges, we have applied DLC (diamond-like carbon) coatings on alumina using a PIID (plasma immersion ion deposition) technique intended for seal applications. The DLC-coated specimens were tested under a wide range of temperature conditions, from room temperature up to 400°C, using a high temperature pin-on-disk tribo-tester. After that, the wear-tested specimens were analyzed using SEM with EDS to characterize the worn surfaces. Morphological changes of the DLC coated surfaces before and after the wear tests were studied. Under certain deposition conditions DLC performed very well up to 400°C. However, under other conditions, DLC failed catastrophically. In this paper we will present the friction and wear characteristics of the DLC-coated alumina. Finally, we will discuss the failure mode of DLC coatings.

scholarly journals NUMERICAL CALCULATION ON SHORELINE CONSERVATION IN MAJURO ATOLL, THE MARSHALL ISLANDS

2011 ◽  
Vol 1 (32) ◽  
pp. 94 ◽  
Author(s):  
Daisaku Sato ◽  
Hiromune Yokoki
Keyword(s):  
Morphological Changes ◽  
Beach Nourishment ◽  
Marshall Islands ◽  
Island Conservation ◽  
Severe Erosion ◽  
Effective Option ◽  
Conservation Result ◽  
Conservation Plan ◽  
Erosion And Accretion ◽  
Erosion Volume

Development of a numerical model for future estimation of morphological changes in Majuro atoll were carried out, and, at the same time, examination of beach nourishment for sustainable island conservation plan was examined by the developed model. Identified erosion and accretion area from calculated shoreline indicated that the northern tip of Laura and some areas in LongIsland had severe erosion until 100 years later as well as large accretion in northern part of the atoll. Three beach nourishment scenarios using eroded sediments, which were accreted in deep lagoon in northern part of atoll, were examined and they decreased 30% of accumulative erosion volume compared with the non-conservation result. This result shows that the beach nourishment is an effective option to sustainable island conservation plan in Majuro atoll.

scholarly journals Financial indicators to evaluate the economic performance of feedlot steers with different slaughter weights

2017 ◽  
Vol 47 (3) ◽  
Author(s):  
Edom de Avila Fabricio ◽  
Paulo Santana Pacheco ◽  
Fabiano Nunes Vaz ◽  
Daniel Batista Lemes ◽  
Angelina Camera ◽  
...  
Keyword(s):  
Net Present Value ◽  
Economic Feasibility ◽  
Financial Indicators ◽  
Internal Rate Of Return ◽  
Simple Linear Regression ◽  
Slaughter Weight ◽  
Feedlot Steers ◽  
Direct Benefits ◽  
Finishing Steers ◽  
Benefit Cost

ABSTRACT: The objective of this study was to evaluate various financial indicators, estimated deterministically (considering historical quotes twelve consecutive years - 2003 to 2014), on the economic feasibility of finishing steers commercialized with different weights, using the simulation technique. Performance data steers were simulated with average initial weight of 350kg, fed in feedlot and slaughtered with 410, 440, 470, 500, 530, 560 and 590kg. The feeding period varies from 46 to 185 days, respectively. Based in various economic indicators, the viability of the investment decreased linearly according to the increase in slaughter weight. The coefficient of simple linear regression and means from lowest to highest slaughter weight were, respectively: net present value (-0.538 and R$ 67.37, R$ 65.28, R$ 32.14, R$ -7.34, R$ 8.01, R$ -12.38, R$ -23.41); index benefit: cost (-0.0003 and R$ 1.042, R$ 1.039, R$ 1.014, R$ 1.006, R$ 1.003, R$ 0.995, R$ 0.991); additional return on investment (-0.009 and 1.38, 1.29, 0.35, 0.11, 0.05, -0.08, -0.13% per month); internal rate of return (-0.009 and 2.21, 2.10, 1.28, 0.80, 0.93, 0.78, 0.73% per month). Feedlot use as termination option to obtain the direct benefits of this technology is an alternative investment with low economic return.

Nakdong Estuary Barrage and Land Reclamation – Morphological Aspects

1984 ◽  
Vol 16 (1-2) ◽  
pp. 233-241 ◽  
Author(s):  
W D Eysink
Keyword(s):  
Land Reclamation ◽  
Morphological Changes ◽  
Ecological Impact ◽  
Flow Conditions ◽  
Cross Sectional ◽  
National Monument ◽  
Morphological Aspects ◽  
Maintenance Dredging ◽  
Time Required ◽  
Official Status

The construction of the barrage will change the flow conditions in the entire estuary which will interfere in the present equilibrium between channel dimensions and flow conditions. Consequently, morphological changes in the estuary have to be taken into account. Generally, the cross sectional area of a tidal channel shows a distinct relationship with a characteristic tidal prism passing that section. Also here such a relation could be found and was applied to predict the new equilibrium state of the estuary. Estimates of the time required for adaptation have been based on the total sediment volumes required for this and the future sediment transport pattern which must supply those volumes. The morphological study provided a basis for proper decisions on matters such as: selection of the barrage location, maintenance dredging and levee heights. It also gave the effects of the barrage on the tidal-flat area which, as an important bird habitat, has the official status of a national monument. In particular these effects and the aspects of maintenance dredging seaward of the barrage are discussed as they are major phenomena for the ecological impact of the barrage.

scholarly journals How Does the CO2 in Supercritical State Affect the Properties of Drug-Polymer Systems, Dissolution Performance and Characteristics of Tablets Containing Bicalutamide?

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2848
Author(s):  
Agata Antosik-Rogóż ◽  
Joanna Szafraniec-Szczęsny ◽  
Krzysztof Chmiel ◽  
Justyna Knapik-Kowalczuk ◽  
Mateusz Kurek ◽  
...  
Keyword(s):  
Particle Size ◽  
Binary Systems ◽  
Morphological Changes ◽  
Solid Dispersions ◽  
Drug Dissolution ◽  
Scanning Calorimetry ◽  
State Affect ◽  
Poorly Soluble ◽  
Increasing Demand ◽  
Size And Morphology

The increasing demand for novel drug formulations has caused the introduction of the supercritical fluid technology, CO2 in particular, into pharmaceutical technology as a method enabling the reduction of particle size and the formation of inclusion complexes and solid dispersions. In this paper, we describe the application of scCO2 in the preparation of binary systems containing poorly soluble antiandrogenic drug bicalutamide and polymeric excipients, either Macrogol 6000 or Poloxamer®407. The changes in the particle size and morphology were followed using scanning electron microscopy and laser diffraction measurements. Differential scanning calorimetry was applied to assess thermal properties, while X-ray powder diffractometry was used to determine the changes in the crystal structure of the systems. The dissolution of bicalutamide was also considered. Binary solid dispersions were further compressed, and the attributes of tablets were assessed. Tablets were analyzed directly after manufacturing and storage in climate chambers. The obtained results indicate that the use of supercritical CO2 led to the morphological changes of particles and the improvement of drug dissolution. The flowability of blends containing processed binary systems was poor; however, they were successfully compressed into tablets exhibiting enhanced drug release.

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