The Complexity of Abrasion Disaster Mitigation on Rupat Island

Abrasion disasters and environmental issues are strategic issues that are widely studied from various study perspectives, this article is the result of research conducted by researchers from the perspective of public administration. The Abrasion Disaster on Rupat Island is a disaster that can cause various social and economic impacts on the community. In 2019, the abrasion rate on Rupat Island reached 6-8 meters. Rupat Island is also one of the outer islands of Indonesia which borders with neighbouring countries, namely Malaysia and is included in the National Tourism Strategic Area (KSPN). Therefore, the abrasion disaster that occurred on Rupat Island, Bengkalis Regency must be managed in order to minimize the impact of theabrasion disaster that occurred. Abrasion disaster management can be done one of them by means of abrasion disaster management or efforts made to regulate the reduction of abrasiondisaster risk. The purpose research is to know abrasion disaster management actors in Rupat Bengkalis and determine what course the limitations in disaster management abrasion in Rupat Bengkalis. This type of research is qualitative research using data collection methods through interviews and documentation. The findings in this study is that the management effort abrasion disaster in Rupat actor countermeasures abrasion in Rupat not maximized This is caused by things still are limitations in disaster management is done. The value in this study is that disaster management actors at the regional and central levels cooperate with each other in order to maximize disaster management efforts

Deteksi Perubahan Garis Pantai Menggunakan Teknik Geospasial, Studi Kasus Kecamatan Tejakula

The coastal area in Tejakula Subdistrict has many potential benefits for local people and the development of the region. Regarding its economic perspective, marine biodiversity can be utilized for tourism development. In terms of culture and history, this area has many archaeological findings ranging from prehistory until the colonial period. However, the recent study from Balai Arkeologi Bali stated the objects were sunk into underwater at a depth of 1-2 meters due to the abrasion process. Therefore, this research discussed the changes of shoreline in the Tejakula Subdistrict area as a preliminary study to protect and preserve its potential values. This research, both in terms of economy, culture, and history. The calculation of shoreline changes is using the Digital Shoreline Analysis System (DSAS) application with Net Shoreline Movement (NSM) and End Point Rate (EPR) methods. The results showed that the coastal segment in Tejakula District experienced an abrasion change with an abrasion rate of 0.89 m/year based on the SPOT satellite image analysis and 0.17 m/year from Landsat satellite imagery.

BAYESIAN NETWORK FOR RISK ASSESSMENT OF ABRASION PROCESSES IN THE COASTAL AREA OF THE SEA OF AZOV

The coast of the Sea of Azov is characterized by a high population density and economic development. At the same time, a significant part of the sea coast is subject to abrasion. High coastal cliff retreat rates determine the relevance of assessing possible losses in this region. The aim of the work is to develop a model for assessing the risk of abrasion processes in the coastal zone of the Sea of Azov. Bayesian networks, which are often used to study coastal processes, were selected as a model toolkit. To assess the abrasion hazard in the coastal zone of the Sea of Azov, a network, consisting of two subnets, is proposed. The “Hazard Assessment” subnet describes the effect of exogenous factors on the abrasion rate. The “Risk Assessment” subnet is designed to determine the consequences (the magnitude of expected losses) of the abrasion process. The main attention is paid to the characteristics of the Bayesian network nodes. In the model, the risk from hazardous coastal processes is expressed in natural terms: the lost land area and the number of damaged facilities located on the coast. The Bayesian model is coupled with a geographic information system on base of the geospatial representation of the study region. An example of assessment the lost land area for a part of the Taganrog Bay coast is considered. Comparison of the losses estimates based on Bayesian network and average abrasion rate is given. Proposed probabilistic method provide additional information, enriching the decision-making process.

Experimental Investigation on Hydroabrasive Erosion of Steel Fiber UHPC and Rubber UHPC

Steel fiber ultrahigh performance concrete (UHPC) and rubber ultrahigh performance concrete (UHPC) adopt the methods of “rigidity overcomes rigidity” and “softness overcomes rigidity,” respectively, to resist the abrasion and cavitation erosion caused by water flow carrying large solid particles. The above two have been applied in engineering successfully, but there are differences in material properties, mechanical properties, and microstructures. In this study, we will analyze the difference of abrasion resistance performance of the above two kinds of UHPC, in terms of, for example, compressive strength, abrasion resistance strength, abrasion rate, and microstructure in different ages, so as to provide a new material and method. The results indicate that the steel fiber UHPC compressive strength is higher than that of rubber UHPC (containing 1% steel fiber), and the abrasion resistance performance of steel fiber UHPC is lower than that of rubber UHPC (containing 1% steel fiber) when the rubber content is 10% and 12.5%. With the increase of steel fiber content, the compressive strength of steel fiber UHPC is not significantly improved, and the influence of water-binder ratio (W/B) on UHPC is higher than that of steel fiber content. With the increase of rubber content, the rubber UHPC compressive strength decreases, abrasion resistance strength decreases, and abrasion rate increases. The cement paste-aggregate interface transition zone (ITZ) of steel fiber UHPC and rubber UHPC has few internal voids and high compactness; however, the ITZ of steel fiber UHPC is denser than that of rubber UHPC.

Performance Optimization of Original Aluminum Ash Coating

Aluminum ash is a kind of industrial solid waste. Original aluminum ash (OAA) can be prepared into original aluminum ash spray powder (OAASP) through hydrolysis treatment, and the original aluminum ash coating (OAAC) can be prepared on the surface of the substrate by plasma spraying. In order to optimize the performance of the OAAC, the OAASP was screened to select the appropriate particle size to improve the flowability of the powder. Then, the influence of the alumina content on coating performance was studied through comparative experiments. The micro morphology of the coating was analyzed, and the performance parameters of the coating were tested. The results show that the spray powder with a particle size of 120–150 mesh accounts for the largest proportion of OAASP, and its flowability is better than that of unsieved OAASP, which is suitable for coating preparation. The performance of the coating can be improved by adding high-purity alumina. When the Al2O3 addition is 50%, the porosity of the coating is 0.131%, the adhesive strength is 17.12 MPa, the microhardness is 713.36 HV, and the abrasion rate 10.31 mg/min. Compared with the coating without Al2O3, the porosity is decreased by 19.63%, the adhesive strength is increased by 5.35%, the microhardness is increased by 17.61%, and the abrasion rate is decreased by 19.83%. There are regions with different brightness on the surface of the coating with Al2O3. After semiquantitative analysis, the main phase in the bright region is Al2O3, and the main phases in the dark and gray regions are Al2O3, SiO2, and Fe3O4. The performance of the OAAC can be optimized by improving the flowability of the sprayed powder and increasing the alumina content.

A molecular dynamics-based investigation on tribological properties of functionalized graphene reinforced thermoplastic polyurethane nanocomposites

Tribo-mechanical properties of pure thermoplastic polyurethane and functionalized monolayer graphene-reinforced thermoplastic polyurethane polymer nanocomposites are investigated by molecular dynamics simulations. Initially, the mechanical properties of the thermoplastic polyurethane and functionalized monolayer graphene-reinforced thermoplastic polyurethane nanocomposites are measured by applying constant stain method. Subsequently, interfacial layer models are developed to apply confined shear on the iron layers to find out the coefficient of friction and the abrasion rate of pure thermoplastic polyurethane and functionalized monolayer graphene-reinforced thermoplastic polyurethane nanocomposites. The results imply that by the incorporation of 0.5 wt.% functionalized monolayer, graphene shows the increase of 20% in Young’s modulus, 15% in shear modulus and 6.66% in bulk modulus of pure thermoplastic polyurethane, respectively, which are in good agreement with the previous experimental studies. Maximum enhancement of mechanical properties can be obtained up to 3 wt.% addition of functionalized monolayer graphene addition in thermoplastic polyurethane matrix. Further, it is observed that 3 wt.% of functionalized monolayer graphene-reinforced thermoplastic polyurethane nanocomposite results in minimum coefficient of friction (0.42) and abrasion rate (19%) under constant normal load (5 kcal/mol/Å) and maximum sliding velocity (11 m/s). However, further reduction in minimum values of coefficient of friction and abrasion rate at 3 wt.% of functionalized monolayer graphene-reinforced thermoplastic polyurethane nanocomposites is seen under the minimum sliding velocity (1 m/s) considered with the same normal load condition. Finally, the inherent mechanisms for enhancement of tribo-mechanical properties in functionalized monolayer graphene-reinforced thermoplastic polyurethane nanocomposites are analysed by the atomic density profile, free volume and Connolly surface at the atomic level.

Study on Preparation of Aluminum Ash Coating Based on Plasma Spray

Ultimate aluminum ash (UAA) was used as the key raw material to prepare ultimate spray powder (USP) via water hydrolysis and ball milling, after which the coating was prepared by atmospheric plasma spray. The flowability of the USP was evaluated by the angle of repose; the process parameters of the coating were determined by orthogonal experiment, and the microstructure and properties of the coating were characterized. The results show that the ultimate spray powder after granulation has an angle of repose less than 40°, which meets the requirements of plasma spray. When the spray current is 600 A, the spray voltage is 55 V, the powder flow rate is 22 g/min, and the main air flow is 33 lspm, the prepared ultimate coating has the best comprehensive performance. The microhardness of the coating is 512 HV, which is about 1.5 times the hardness of the substrate; the abrasion rate is 18.53 × 10–3 g/min; the porosity is 0.17% and the average adhesive strength is 8.78 Mpa, which confirms the feasibility of using aluminum ash as a spray powder to prepare a coating.