scholarly journals The Impact of Submerged Breakwaters on Sediment Distribution along Marsh Boundaries

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1016 ◽  
Author(s):  
Iacopo Vona ◽  
Matthew Gray ◽  
William Nardin
Keyword(s):  
Salt Marsh ◽  
Sediment Transport ◽  
Wave Breaking ◽  
Sediment Trapping ◽  
Sediment Distribution ◽  
Design And Implementation ◽  
Study Results ◽  
Average Wave ◽  
The Impact

Human encroachment and development on coastlines have led to greater amounts of armoring of shorelines. Breakwaters are a common feature along coastlines, which are used to dampen wave energy and protect shorelines from flash floods or overwash events. Although common, their effects on sediment transport and marsh geomorphology are poorly understood. To address this gap, our study quantifies the effects of breakwaters on sediment transport and marsh evolution under different wave regimes using Delft3D-SWAN, a dynamic geomorphodynamic numerical model. Model configurations used the same numerical domain, but scenarios had different sediments, waves, tides, basin slopes and breakwater distances from the shoreline to explore how waves and tidal currents shape coastal margins. Model results suggested breakwaters were responsible for an average wave damping between 10–50%, proportional to the significant wave height across all modeled scenarios. Shear stress at the beginning of the marsh and the volume of sediment deposited at the end of the simulation (into the marsh behind the breakwater) increased on average between 20–40%, proportional to the slope and distance of the breakwater from the shoreline. Sediment trapping, defined as the ratio between the volume of sediment housed into the salt marsh behind and away from the breakwater, was found to be less than 1 from most model runs. Study results indicated that breakwaters are advantageous for wave breaking to protect shorelines from the wave’s energy, however, they might also be an obstacle for sediment transport, negatively affecting nourishment processes, and, consequently, impeded long-term salt marsh survival. Identifying a balance between waves dampening and shoreline nourishment should be considered in the design and implementation of these structures.

scholarly journals A májfunkció romlásának rizikófaktorai sikeres vesetranszplantációt követően

2019 ◽  
Vol 160 (5) ◽  
pp. 186-190
Author(s):  
Bernadett Borda ◽  
Attila Nemes ◽  
Csaba Lengyel ◽  
Tamás Várkonyi ◽  
Ferenc Rárosi ◽  
...  
Keyword(s):  
Liver Function ◽  
Immunosuppressive Therapy ◽  
Liver Enzymes ◽  
Graft Loss ◽  
Study Results ◽  
Allograft Function ◽  
The Difference ◽  
The Impact ◽  
The Relationship

Abstract: Introduction: Increase of liver function is one of the most common complications after kidney transplantation due to the use of immunosuppressive therapy and hyperlipidemia in addition to hepatitis C virus (HCV) infection. Method: Following the selection criteria (n = 59), the study is based on applied immunosuppressive therapy, baseline data of patients, further correlation between HCV and liver function deterioration. Patients were subjected to fasting laboratory examination to monitor serum electrolytes, uric acid and albumin levels. We looked at the effects of immunosuppressive therapy on the lipids (TG, TC, HDL, LDL) and liver enzymes (GOT, GPT, ALP, GGT). The analysis of the relationship between lipids and liver enzymes was also included in our study. Results: The data basics were not significantly different between the tacrolimus and the cyclosporine groups. In the laboratory results, Mg levels were significantly different between the two groups (p = 0.044). The impact of HCV on the liver function was significantly different on GGT (p = 0.008). We examed the lipids and liver function level between the tacrolimus and the patients receiving cyclosporine-based immunosuppression and the total cholesterol (p = 0.005) and GOT (p = 0.05) were significantly different between the two groups. Hyperlipidemia was associated with 26% of patients taking tacrolimus-based immunosuppression, and 89% of those receiving cyclosporine; the difference was significant (p = 0.002). Regarding the effect of hyperlipidemia on liver enzymes, ALP (p = 0.006) and GGT (p = 0.0001) were significantly higher. Conclusion: Increases in hepatic enzymes, ALT and GGT indicate the damage to hepatocytes. Beside the increase of liver function, which is the main risk factor in hepatitis on HCV soil, the applied immunosuppressive therapy and hyperlipidemia lead to degradation of allograft function and long-term graft loss. Orv hetil. 2019; 160(5): 186–190.

scholarly journals Open-Source Based Testbed for Multioperator 4G/5G Infrastructure Sharing in Virtual Environments

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Ricardo Marco Alaez ◽  
Jose M. Alcaraz Calero ◽  
Qi Wang ◽  
Fatna Belqasmi ◽  
May El Barachi ◽  
...  
Keyword(s):  
Open Source ◽  
Mobile Networks ◽  
Fourth Generation ◽  
Mobile Telecommunication ◽  
Significant Saving ◽  
Design And Implementation ◽  
Fifth Generation ◽  
The Impact ◽  
Telecommunication Operators

Fourth-Generation (4G) mobile networks are based on Long-Term Evolution (LTE) technologies and are being deployed worldwide, while research on further evolution towards the Fifth Generation (5G) has been recently initiated. 5G will be featured with advanced network infrastructure sharing capabilities among different operators. Therefore, an open-source implementation of 4G/5G networks with this capability is crucial to enable early research in this area. The main contribution of this paper is the design and implementation of such a 4G/5G open-source testbed to investigate multioperator infrastructure sharing capabilities executed in virtual architectures. The proposed design and implementation enable the virtualization and sharing of some of the components of the LTE architecture. A testbed has been implemented and validated with intensive empirical experiments conducted to validate the suitability of virtualizing LTE components in virtual infrastructures (i.e., infrastructures with multitenancy sharing capabilities). The impact of the proposed technologies can lead to significant saving of both capital and operational costs for mobile telecommunication operators.

3D numerical studies on stratification and mixing processes affecting fine sediment transport in the pre-dam of the Dhünn reservoir in Germany

2020 ◽  
Author(s):  
Wendy Gonzalez ◽  
Irina Klassen ◽  
Anne Jakobs ◽  
Frank Seidel
Keyword(s):  
Sediment Transport ◽  
Input Data ◽  
Measurement Data ◽  
Fine Sediment ◽  
Transport Processes ◽  
Transport Modeling ◽  
Wind Effects ◽  
Sediment Distribution ◽  
Vertical Diffusivity ◽  
The Impact

<p>Fine sediment transport processes and the thermodynamics in reservoirs are key processes governing the water quality of reservoirs. With regard to a sustainable sediment management of reservoirs, the prediction of sediment transport and deposition is becoming increasingly important.</p><p>The subject of the present work was the 3D numerical simulation of fine sediment transport in a reservoir taking into account stratification and mixing effects which in turn are caused by temperature gradients and wind effects. In order to understand and investigate the driving factors for stratification processes and their impact on fine sediment distribution, the great pre-dam of the Dhünn reservoir in Germany served as case study. The investigations were conducted in sensitivity analyses adopting a 3D sediment transport model with Delft 3D. The impact of various physical and numerical parameters on temperature and fine sediment transport modeling was examined: the number of vertical layers, the input data for the heat model (e.g. relative humidity, air temperature, cloud coverage, solar radiation), the vertical diffusivity and wind effects. The sensitivity studies showed that the input data for the heat model have a minor impact on the temperature and sediment transport modeling within the tested range of parameters. However, the vertical diffusivity and especially the inclusion of wind showed a greater influence on the simulated temperature and suspended sediment concentration gradients. The temperature modeling results by inclusion/exclusion of wind were qualitatively compared with temperature data from literature and with measurement data over a period of one month. Hereby, the simulations showed a good agreement with measurement data by exclusion of wind effects.</p><p>The results of the studies provide a solid basis for the development of further models in fields where fine sediment transport is affected by stratification processes and can also be very useful in terms of a better understanding of the interactions between temperature, wind and fine sediment transport.</p>

scholarly journals ESTUftRINE RESPONSE TO DREDGING IN THE TWEED RIVER, AUSTRALIA

1980 ◽  
Vol 1 (17) ◽  
pp. 96
Author(s):  
Bruce M. Druery
Keyword(s):  
Sediment Transport ◽  
Field Measurements ◽  
Gold Coast ◽  
Lower Estuary ◽  
Sediment Routing ◽  
Marine Sand ◽  
Tidal Hydraulics ◽  
The Impact ◽  
Hydraulic Processes

Between mid 1974 and mid 1975,760,000 m3 of sand was dredged from the bed of the Tweed River for the purpose of nourishing cyclone damaged beaches of the Gold Coast (Queensland). A comprehensive field data programme was established in 1976 to record the changes in the hydraulic processes of the Tweed River brought about by the dredging. The field measurements demonstrated that the dredged area was being infilled with sediments of both marine and estuarine origin. The dredging increased tidal ranges throughout the lower estuary, the effect being more pronounced at low water. Sediment bedload rates were estimated from detailed measurements of bedforms and used to calibrate a sediment transport formula. The formula was used in conjunction with a 1 Dim. numerical model of tidal hydraulics to simulate estuarine shoal dynamics by means of a simple sediment routing technique. The results showed that the dredging had altered the tidal hydrodynamics so as to enhance the ebb transport of sediment towards the dredged hole. In the long term it was found that the sediment transport switched to a weak net upstream movement of sediment. The detailed hydraulic mechanisms involved are discussed. The study demonstrates that the impact of dredging can be minimised by location upstream of the entrance plug of marine sand.

scholarly journals Response of tidal flow regime and sediment transport in North Male' Atoll, Maldives to coastal modification and sea level rise

2020 ◽  
Author(s):  
Shuaib Rasheed ◽  
Simon C. Warder ◽  
Yves Plancherel ◽  
Matthew D. Piggott
Keyword(s):  
Grain Size ◽  
Sediment Transport ◽  
Sea Level Rise ◽  
Sea Level ◽  
Land Reclamation ◽  
Tidal Flow ◽  
Sediment Grain Size ◽  
Sediment Distribution ◽  
Time Periods ◽  
The Impact

Abstract. Changes to coastlines and bathymetry alter tidal dynamics and associated sediment transport process, impacting upon a number of threats facing coastal regions, including flood risk and erosion. Especially vulnerable are coral atolls such as those that make up the Maldives archipelago which has undergone significant land reclamation in recent years and decades, and is also particularly exposed to sea level rise. Here we develop a tidal model of Male' Atoll, Maldives, and use it to assess potential changes to sediment grain size distributions under sea level rise and coastline alteration scenarios. The results indicate that the impact of coastline modification over the last two decades at the island scale is not limited to the immediate vicinity of the modified island, but can also significantly impact the sediment grain size distribution across the wider atoll basin. Additionally, the degree of change in sediment distribution which can be associated with sea level rise that is projected to occur over relatively long time periods is predicted to occur over far shorter time periods with coastline changes, highlighting the need to better understand, predict and mitigate the impact of land reclamation and other coastal modifications before conducting such activities.

scholarly journals Longitudinal study of the impact of three major regulations on the Korean pharmaceutical industry in the last 30 years

2022 ◽  
Vol 20 (1) ◽  
Author(s):  
Seung In Um ◽  
Uy Dong Sohn ◽  
Sun-Young Jung ◽  
Seung-Hun You ◽  
Changone Kim ◽  
...  
Keyword(s):  
Pharmaceutical Industry ◽  
Patent System ◽  
Sustainable Growth ◽  
New Drugs ◽  
Regulatory Policies ◽  
Study Results ◽  
Short Period ◽  
Before And After ◽  
The Impact

Abstract Background The pharmaceutical industry is heavily regulated. Partly for this reason, new drugs generally take over 10 years from the product development stage to market entry. Although regulations affect the pharmaceutical industry over a long period, previous studies investigating the impact of new regulatory policies have usually focused on the short period before and after implementing that policy. Therefore, the purpose of this study is to examine whether and how significantly regulatory policies affect long-term innovation in the pharmaceutical industry in Korea. Methods This study focused on three significant regulatory policies: the introduction of the product patent system, changes in the Good Manufacturing Practice (GMP) system, and the Drug Expenditure Rationalization Plan (DERP). The study used interrupted time series (ITS) analysis to investigate the long-term impacts of the policies before and after implementation. Results Our results show that introducing the product patent system in 1987 significantly increased the number of Korean patent applications. The effect of the revised GMP policies was also statistically significant, both before and after implementation and between pre-emptive companies and non-pre-emptive ones. However, due to the companies' negotiations with the regulatory authorities or the regulatory system that links drug approval and price evaluation, the DERP did not significantly delay new drug registration in Korea. Conclusion This study showed that the policies of the product patent system, GMP policies, and DERP regulations have significantly encouraged pharmaceutical companies to strive to meet regulatory requirements and promote innovation in Korea. The study suggests that it is necessary for companies to pre-emptively respond to systemic changes in development and production strategies to deal with regulatory changes and achieve sustainable growth. Also, our study results indicate that since government policies motivate the innovative system of the pharmaceutical industry, governmental authorities, when formulating pharmaceutical policies, need to consider the impact on the long-term innovation of the industry.

scholarly journals Functional Fc Gamma Receptor Gene Polymorphisms and Long-Term Kidney Allograft Survival

2021 ◽  
Vol 12 ◽  
Author(s):  
Markus Wahrmann ◽  
Bernd Döhler ◽  
Marie-Luise Arnold ◽  
Sabine Scherer ◽  
Katharina A. Mayer ◽  
...  
Keyword(s):  
Cox Model ◽  
Receptor Gene ◽  
Allograft Survival ◽  
Fc Gamma Receptor ◽  
Functional Polymorphisms ◽  
Gamma Receptor ◽  
Increased Risk ◽  
Study Results ◽  
The Impact

The functional Fc gamma receptor (FcγR) IIIA polymorphism FCGR3A-V/F158 was earlier suggested to determine the potential of donor-specific HLA antibodies to trigger microcirculation inflammation, a key lesion of antibody-mediated renal allograft rejection. Associations with long-term transplant outcomes, however, have not been evaluated to date. To clarify the impact of FCGR3A-V/F158 polymorphism on kidney transplant survival, we genotyped a cohort of 1,940 recipient/donor pairs. Analyzing 10-year death-censored allograft survival, we found no significant differences in relation to FCGR3A-V/F158. There was also no independent survival effect in a multivariable Cox model. Similarly, functional polymorphisms in two other activating FcγR, FCGR2A-H/R131 (FcγRIIA) and FCGR3B-NA1/NA2 (FcγRIIIB), were not associated with outcome. There were also no significant survival differences among patient subgroups at increased risk of rejection-related injury, such as pre-sensitized recipients (> 0% panel reactivity; n = 438) or recipients treated for rejection within the first year after transplantation (n = 229). Our study results suggest that the earlier shown association of FcγR polymorphism with microcirculation inflammation may not be strong enough to exert a meaningful effect on graft survival.

scholarly journals Long-term invasion dynamics of Spartina increase vegetation diversity and geomorphological resistance of salt marshes against sea level rise

2020 ◽  
Author(s):  
Dirk Granse ◽  
Sigrid Suchrow ◽  
Kai Jensen
Keyword(s):  
Salt Marsh ◽  
Species Diversity ◽  
Sea Level Rise ◽  
Sea Level ◽  
Salt Marshes ◽  
High Marsh ◽  
Marsh Vegetation ◽  
Vegetation Diversity ◽  
The Impact

AbstractThe cordgrass Spartina anglica C.E. Hubbard (Poaceae) is an invasive transformer in many salt marsh ecosystems worldwide. Relatively little is known about the capacity of Spartina to accelerate salt marsh succession and to protect salt marshes against sea level rise. We analyzed long-term changes in vegetation and elevation in mainland salt marshes of the European Wadden Sea in Schleswig-Holstein, Germany, to estimate the impact of non-native Spartina on the geomorphological resistance of salt marshes to sea level rise and on changes in species diversity. From 1989 to 2019, the Spartina-zone shifted and expanded upwards to elevations of the high marsh zone and Spartina increased in frequency in several salt marsh vegetation communities. At sites where Spartina dominated the vegetation already three decades ago, elevation and species diversity increased with a higher rate compared to sites lacking Spartina. The median change rates reached for elevation MHT +8.6 versus +1.5 mm per year, for species richness +3 versus $$\pm$$ ± 0 species per three decades, and for evenness +0.04 versus −0.08 per three decades, regarding plots with versus without former Spartina dominance, respectively. Invasion of salt marshes by Spartina and its continued, long-term presence were associated with increased elevation and species diversity in the face of sea level rise.

Negotiation Strategies and the Nature of Channel Relationships

1993 ◽  
Vol 30 (2) ◽  
pp. 183-203 ◽  
Author(s):  
Shankar Ganesan
Keyword(s):  
Problem Solving ◽  
Mail Survey ◽  
Situational Factors ◽  
Negotiation Strategies ◽  
Channel Relationships ◽  
Study Results ◽  
Problem Solving Strategy ◽  
Solving Strategy ◽  
The Impact

In recent years, retailers have placed greater emphasis on developing long-term relationships to obtain sustainable benefits on issues such as product quality, price, and markdown allowances. The author examines the impact of situational factors such as the time orientation of a relationship and the importance of the issues to be resolved on the use of various negotiation strategies (problem solving, compromise, and aggressive) in channel relationships. He also investigates the impact of different strategies on channel member outcomes and satisfaction. The data used to test the model were obtained in a mail survey of 124 retail buyers in six regional department store chains. The study results indicate that when retailers are long-term oriented, problem-solving and passive aggressive strategies are used for resolving conflicts on major issues. The use of problem-solving strategy to resolve major conflicts resulted in higher outcomes and greater satisfaction than either compromise or aggressive strategies. The findings also provide insights on the use of various negotiation strategies by retailers to resolve conflicts on important and relatively unimportant issues.

Preliminary Assessment of the Impact of Draining of Iraqi Marshes on Kuwait's Northern Marine Environment. Part I. Physical Manipulation

1999 ◽  
Vol 40 (7) ◽  
pp. 75-87 ◽  
Author(s):  
Abdul Nabi Al-Ghadban ◽  
T. Saeed ◽  
A. M. Al-Dousari ◽  
H. Al-Shemmari ◽  
M. Al-Mutairi
Keyword(s):  
Marine Environment ◽  
Negative Impact ◽  
Arabian Gulf ◽  
Preliminary Assessment ◽  
Sediment Distribution ◽  
Comparison Of The Results ◽  
The Impact ◽  
Water Depths ◽  
Physical Manipulation

Kuwait's northern marine area is considered to be the receiving basin for the influx of sediments and associated pollutants from the Shatt Al-Arab estuary. In recent years, Iraq has undertaken to drain the southern marshes, which acted as a sink for the sediment and its associated pollutants. The draining process is expected to significantly increase the rate of sedimentation and change the hydrodynamic regime of the northern Arabian Gulf. Thirty-three bottom sediment samples from the area likely to be impacted by the draining of the marshes were collected and studied in 1997-98. Locations of sampling stations were selected as close to an earlier study done in 1982. The recent marine sediments of the study area are subdivided into five textural classes: sandy clay, clay, silt, mud and sandy mud. The comparison of the results of this study with those of the 1982 study showed that finer sediments were deposited. Based on sediment distribution, characteristics of bottom sediments and the topographic nature of the study area, a north-south sediment transport from Shatt Al-Arab and the southern part of Iraq, affecting the marine environment of Kuwait, is inferred. Comparison of water depths of the 1956 and 1986 hydrographic maps, revealed that more deposition occurred in the northern area, and this was attributed to the draining process. In general, there were some indications of the negative impact of the draining of the marshes, however, long-term and more detailed studies are needed.

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