scholarly journals Gabion as a coastal protection structure: a case study in Panjang Island Indonesia

2022 ◽  
Vol 955 (1) ◽  
pp. 012005
Author(s):  
H P Adi ◽  
S I Wahyudi ◽  
A Soebagyo
Keyword(s):  
Coastal Area ◽  
Small Island ◽  
Structure Stability ◽  
Coastal Protection ◽  
Soil Pressure ◽  
Structure Assessment ◽  
The Stability ◽  
A Minor ◽  
Coastal Damage

Abstract Panjang Island is a small island in Jepara, Indonesia which is very vulnerable to coastal damage due to crashing waves. Therefore, presence of coastal protection structure is essentially important. Gabion structure was constructed to protect this coastal area. Considering the age, the existing gabion structure needed assessment and analysis to ensure its performance in term of protecting the coastal area. This study aimed at assessing and analyzing the performance of the existing gabion structure. Data of the study were collected through observing the condition of the structure. Assessment was carried out by scaling 1 (minor) to 5 (severe damage). Results of the analysis showed that the value of stability to overturning was 3.96, while the stability to shearing was 2.07, the structure stability was in safe category. Soil pressure under the structure in σ max. was 0.39 kg/cm2, while σ min was 0.16 kg/cm2, which means safe. The condition of gabion as a coastal protection structure in section 1 was partially damaged with a moderate level of damage, in section 2, the damage was revealed to be a minor level of damage, while in section 3, the damage was in a minor level of damage.

scholarly journals Effective Coastal Adaptation Needs Accurate Hazard Assessment : A Case Study In Port Resolution, Tanna Island Vanuatu

2021 ◽  
Author(s):  
Faivre Faivre ◽  
Rodger Tomlinson ◽  
Daniel Ware ◽  
Saeed Shaeri ◽  
Wade Hadwen ◽  
...  
Keyword(s):  
Developing Countries ◽  
Hazard Assessment ◽  
Local Community ◽  
Small Island ◽  
Coastal Protection ◽  
Local Data ◽  
Coastal Adaptation ◽  
Adaptation Decision ◽  
Wave Models

Abstract Developing countries face risks from natural hazards that are being amplified by climate change. Selection of effective adaptation interventions to manage these risks requires a sufficiently accurate assessment of the coastal hazard at a given location. Yet challenges remain in terms of understanding local coastal risks given the coarseness of global wave models and the paucity of locally scaled data in most developing countries, including Small Island Developing States (SIDS) like Vanuatu. The aim of this paper was to examine the differences in hazard assessment and adaptation option selections arising from analyses using globally versus locally scaled data on coastal processes. As a case study, we focused on an eroding cliff face in Port Resolution on Tanna Island, Vanuatu, which is of concern to the local community and government authorities. The coastal process modelling revealed that the global wave data generated unrealistically high predictions of wave height within Port Resolution bay. Expensive engineering adaptations designed to provide coastal protection were therefore likely to fail in preventing ongoing cliff erosion. In this case, the best adaptation solution involves changing land use to revegetate and help stabilise the cliff top. Our case study highlights the importance of accurate hazard assessment, especially in data poor regions where extrapolation of global datasets and models in the absence of local data can result in poor adaptation decision making. Furthermore, the multidisciplinary approach applied here can be applied in other data-poor regions to strengthen analyses exploring the benefits of local adaptation interventions.

scholarly journals Analisa stabilitas struktur revetmen di Pantai Kedungu, Tabanan Bali

2017 ◽  
Vol 13 (1) ◽  
pp. 11-22
Author(s):  
Vivi Yovita Indriasari ◽  
Johan Risandi ◽  
Rudhi Akhwadhy
Keyword(s):  
Bearing Capacity ◽  
Local Community ◽  
Sand Dunes ◽  
Structure Design ◽  
Structure Stability ◽  
Coastal Protection ◽  
Incoming Wave ◽  
Local Residents ◽  
The Stability ◽  
Proper Condition

Study in Kedungu Beach which has a wide sand dunes and dense vegetation. This place is usually used for tourism by local residents. Causes of erosion is awave come in the form an angle, create longshore current, and litoral drif sediments. The condition is very alarming, because it erodes the amount of land owned by residents. Until now there is no goverment handling yet, only the efforts of the local community by building sea walls and currently also not in a proper condition. Based on the analysis of the data captured in the field and numerical modeling methods, resulting the methode to overcome the erotion problem, i.e. build coastal protection structures such as revetment, where the structure serves as an incoming wave damper and defend the coastline. The purpose of this paper is to provide an overview of the structure stability of revetment against coastal erosion.Stability analysis takes into account the stability of the rolling, sliding, and soil bearing capacity decrease. The dimension and design ofrevetment is secure from overturning (SF = 7.669 > 2); sliding (SF = 4.082>1,5) and bearing capacity support (17.498>3). From this analysis concluded that in the revetment structure design safe and can be applied in the study area. Analysis of the stability of the revetment structure is expected to reduce the level of damage to the building structure coast and surrounding buildings.

Tuning Transition Metal Carbides Activity by Surface Metal Alloying: Case Study on CO2 Capture and Activation

2018 ◽  
Author(s):  
Marti Lopez ◽  
Luke Broderick ◽  
John J Carey ◽  
Francesc Vines ◽  
Michael Nolan ◽  
...  
Keyword(s):  
Transition Metal ◽  
Co2 Capture ◽  
Density Functional ◽  
Deep Understanding ◽  
Metal Carbides ◽  
Transition Metal Carbides ◽  
Adsorption Sites ◽  
Surface Metal ◽  
A Minor

<div>CO2 is one of the main actors in the greenhouse effect and its removal from the atmosphere is becoming an urgent need. Thus, CO2 capture and storage (CCS) and CO2 capture and usage (CCU) technologies are intensively investigated as technologies to decrease the concentration</div><div>of atmospheric CO2. Both CCS and CCU require appropriate materials to adsorb/release and adsorb/activate CO2, respectively. Recently, it has been theoretically and experimentally shown that transition metal carbides (TMC) are able to capture, store, and activate CO2. To further improve the adsorption capacity of these materials, a deep understanding of the atomic level processes involved is essential. In the present work, we theoretically investigate the possible effects of surface metal doping of these TMCs by taking TiC as a textbook case and Cr, Hf, Mo, Nb, Ta, V, W, and Zr as dopants. Using periodic slab models with large</div><div>supercells and state-of-the-art density functional theory based calculations we show that CO2 adsorption is enhanced by doping with metals down a group but worsened along the d series. Adsorption sites, dispersion and coverage appear to play a minor, secondary constant effect. The dopant-induced adsorption enhancement is highly biased by the charge rearrangement at the surface. In all cases, CO2 activation is found but doping can shift the desorption temperature by up to 135 K.</div>

Structure, Stability and Water Adsorption on Ultra-Thin TiO2 Supported on TiN

2019 ◽  
Author(s):  
Jose Julio Gutierrez Moreno ◽  
Marco Fronzi ◽  
Pierre Lovera ◽  
alan O'Riordan ◽  
Mike J Ford ◽  
...  
Keyword(s):  
Density Functional ◽  
Water Adsorption ◽  
Chemical Potential ◽  
Energy Gap ◽  
Molecular Water ◽  
Structure Stability ◽  
Ambient Conditions ◽  
Rutile Structure ◽  
The Stability ◽  
The One

<p></p><p>Interfacial metal-oxide systems with ultrathin oxide layers are of high interest for their use in catalysis. In this study, we present a density functional theory (DFT) investigation of the structure of ultrathin rutile layers (one and two TiO<sub>2</sub> layers) supported on TiN and the stability of water on these interfacial structures. The rutile layers are stabilized on the TiN surface through the formation of interfacial Ti–O bonds. Charge transfer from the TiN substrate leads to the formation of reduced Ti<sup>3+</sup> cations in TiO<sub>2.</sub> The structure of the one-layer oxide slab is strongly distorted at the interface, while the thicker TiO<sub>2</sub> layer preserves the rutile structure. The energy cost for the formation of a single O vacancy in the one-layer oxide slab is only 0.5 eV with respect to the ideal interface. For the two-layer oxide slab, the introduction of several vacancies in an already non-stoichiometric system becomes progressively more favourable, which indicates the stability of the highly non-stoichiometric interfaces. Isolated water molecules dissociate when adsorbed at the TiO<sub>2</sub> layers. At higher coverages the preference is for molecular water adsorption. Our ab initio thermodynamics calculations show the fully water covered stoichiometric models as the most stable structure at typical ambient conditions. Interfacial models with multiple vacancies are most stable at low (reducing) oxygen chemical potential values. A water monolayer adsorbs dissociatively on the highly distorted 2-layer TiO<sub>1.75</sub>-TiN interface, where the Ti<sup>3+</sup> states lying above the top of the valence band contribute to a significant reduction of the energy gap compared to the stoichiometric TiO<sub>2</sub>-TiN model. Our results provide a guide for the design of novel interfacial systems containing ultrathin TiO<sub>2</sub> with potential application as photocatalytic water splitting devices.</p><p></p>

Polysaccharide Structures in the Outer Mucilage of Arabidopsis Seeds Visualized by AFM

2020 ◽  
Author(s):  
MAK Williams ◽  
V Cornuault ◽  
AH Irani ◽  
VV Symonds ◽  
J Malmström ◽  
...  
Keyword(s):  
Average Length ◽  
American Chemical Society ◽  
Md Simulations ◽  
Chemical Society ◽  
Side Chains ◽  
Rhamnogalacturonan I ◽  
Afm Imaging ◽  
Minor Population ◽  
The Stability ◽  
A Minor

© 2020 American Chemical Society. Evidence is presented that the polysaccharide rhamnogalacturonan I (RGI) can be biosynthesized in remarkably organized branched configurations and surprisingly long versions and can self-assemble into a plethora of structures. AFM imaging has been applied to study the outer mucilage obtained from wild-type (WT) and mutant (bxl1-3 and cesa5-1) Arabidopsis thaliana seeds. For WT mucilage, ordered, multichain structures of the polysaccharide RGI were observed, with a helical twist visible in favorable circumstances. Molecular dynamics (MD) simulations demonstrated the stability of several possible multichain complexes and the possibility of twisted fibril formation. For bxl1-3 seeds, the imaged polymers clearly showed the presence of side chains. These were surprisingly regular and well organized with an average length of ∼100 nm and a spacing of ∼50 nm. The heights of the side chains imaged were suggestive of single polysaccharide chains, while the backbone was on average 4 times this height and showed regular height variations along its length consistent with models of multichain fibrils examined in MD. Finally, in mucilage extracts from cesa5-1 seeds, a minor population of chains in excess of 30 μm long was observed.

DEVELOPMENT OF THE BASIC CRITERIA FOR RUSSIAN COASTS TYPIFICATION

2017 ◽  
Author(s):  
Рубен Косян ◽  
Ruben Kosyan ◽  
Viacheslav Krylenko ◽  
Viacheslav Krylenko
Keyword(s):  
Coastal Zone ◽  
Coastal Area ◽  
Economic Activity ◽  
Basic Information ◽  
Dynamic Features ◽  
Static State ◽  
Evolutionary Features ◽  
Coastal Features ◽  
The Stability

There are many types of coasts classifications that indicate main coastal features. As a rule, the "static" state of the coasts is considered regardless of their evolutionary features and ways to further transformation. Since the most part of the coastal zone studies aimed at ensuring of economic activity, it is clear that the classification of coast types should indicate total information required by the users. Accordingly, the coast classification should include the criterion, characterizing as dynamic features of the coast and the conditions and opportunities of economic activity. The coast classification, of course, should be based on geomorphological coast typification. Similar typification has been developed by leading scientists from Russia and can be used with minimal modifications. The authors propose to add to basic information (geomorphological type of coast) the evaluative part for each coast sector. It will include the estimation of the coast changes probability and the complexity of the coast stabilization for economic activity. This method will allow to assess the dynamics of specific coastal sections and the processes intensity and, as a result – the stability of the coastal area.

Extraction of strontium and barium salts by the nitrobenzene solution of dicarbolide in the presence of glymes

1985 ◽  
Vol 50 (3) ◽  
pp. 581-599 ◽  
Author(s):  
Petr Vaňura ◽  
Emanuel Makrlík
Keyword(s):  
Stability Constants ◽  
Organic Phase ◽  
Equilibrium Constants ◽  
Minor Role ◽  
Nitrobenzene Solution ◽  
Ligand Structure ◽  
Stability Constants Of Complexes ◽  
Separation Factors ◽  
The Stability ◽  
A Minor

Extraction of microamounts of Sr2+ and Ba2+ (henceforth M2+) from the aqueous solutions of perchloric acid (0.0125-1.02 mol/l) by means of the nitrobenzene solutions of dicarbolide (0.004-0.05 mol/l of H+{Co(C2B9H11)2}-) was studied in the presence of monoglyme (only Ba2+), diglyme, triglyme, and tetraglyme (CH3O-(CH2-CH2O)nCH3, where n = 1, 2, 3, 4). The distribution of glyme betweeen the aqueous and organic phases, the extraction of the protonized glyme molecule HL+ together with the extraction of M2+ ion and of the glyme complex with the M2+ ion, i.e., ML2+ (where L is the molecule of glyme), were found to be the dominating reactions in the systems under study. In the systems with tri- and tetraglymes the extraction of H+ and M2+ ions solvated with two glyme molecules, i.e., the formation of HL2+ and ML22+ species, can probably play a minor role. The values of the respective equilibrium constants, of the stability constants of complexes formed in the organic phase, and the theoretical separation factors αBa/Sr were determined. The effect of the ligand structure on the values of extraction and stability constants in the organic phase is discussed.

Applications of random graphs

2017 ◽  
Author(s):  
A.C.C. Coolen ◽  
A. Annibale ◽  
E.S. Roberts
Keyword(s):  
Social Networks ◽  
Random Graphs ◽  
Interaction Network ◽  
Power Grids ◽  
Protein Protein Interaction ◽  
Topological Features ◽  
First Case ◽  
The Stability ◽  
Protein Protein Interaction Network

This chapter reviews graph generation techniques in the context of applications. The first case study is power grids, where proposed strategies to prevent blackouts have been tested on tailored random graphs. The second case study is in social networks. Applications of random graphs to social networks are extremely wide ranging – the particular aspect looked at here is modelling the spread of disease on a social network – and how a particular construction based on projecting from a bipartite graph successfully captures some of the clustering observed in real social networks. The third case study is on null models of food webs, discussing the specific constraints relevant to this application, and the topological features which may contribute to the stability of an ecosystem. The final case study is taken from molecular biology, discussing the importance of unbiased graph sampling when considering if motifs are over-represented in a protein–protein interaction network.

Supplier Development at LG Electronics

2020 ◽  
Author(s):  
Hyojin Kim ◽  
Daesik Hur ◽  
Tobias Schoenherr
Keyword(s):  
Management Practice ◽  
Digital Technologies ◽  
Supply Management ◽  
Future Research ◽  
Supplier Development ◽  
Environmentally Conscious ◽  
Competitive Capabilities ◽  
The Stability ◽  
Buyer Firm

Supplier development has been a critical supply management practice since the 1990s. In many instances, it has even become imperative for buyer firms to support and prepare their supply bases for uncertain economic and market environments, socially and environmentally conscious customers, advances in digital technologies, and increasing competition. Yet, research that approaches supplier development with the objective to advance all these dimensions in an integrated fashion is scarce. This study fills this void by exploring how a buyer firm may address these emerging challenges in its supply base. Specifically, an in-depth case study of LG Electronics explores how the firm designs and operates multidimensional supplier development activities to foster the stability and sustainability of its supply base while enhancing its core suppliers’ competitive capabilities. This chapter illustrates how supplier development can be taken to the next level, presents implications for managerial practice, and outlines promising future research avenues.

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