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This study aims to investigate the adoption of alternate wetting and drying (AWD) technique and provides the economic evaluation and determinants of AWD adoption in rice production in the Mekong Delta in Vietnam.

The study extends the drainage factor into the AWD score. The cost benefit analysis is utilized for the economic evaluation, and the Cragg model is applied to examine the determinants of AWD adoption.

The results indicate that there are significant differences in inputs such as water, seed, fertilizers and mechanization between the low and high levels of AWD adoption. The yields are significantly different at different adoption levels. The Cragg model found that irrigation infrastructure, AWD training and perceived ease of use of the technology are determinants of AWD adoption level. Collective pumping is considered as a major constraint in the AWD adoption.

The results provide managerial implications, with a focus on the effectiveness of inputs, the irrigation infrastructure and AWD training to promote the AWD adoption. Challenges of rice field flatness should be investigated in a further study.

The study contributes to existing literature by providing an empirical evidence for the large-scale adoption of AWD with a comprehensive economic evaluation, extending the drainage performance into the score to accurately reflect the water conservation and promoting the use of a more flexible modeling approach with the Cragg model.

To study the corrosion behavior of pipeline steel in coastal areas, a tidal seawater macro-cell corrosion device was built using a cycle soaking tank and a macro-cell corrosion facility to simulate the corrosion behavior of pipeline steel in a simulated coastal environment (dry and wet alternations during seawater-soil corrosion macro-cell processes).

The corrosion behaviors were studied via the weight loss method, electrochemical methods and morphological observations on corrosion.

The results show that during the initial stage of tidal seawater/soil macro-cell corrosion process of the X65 steel, the working electrode on the seawater side is the anode of the macro-battery. As corrosion progresses, the anode and the cathode of the macro-battery become inverted. As the area ratio and the dry – wet ratio increase, the time of anode and cathode inversion shortens. Galvanic current density decreases as the dry – wet ratio increases and increases as the area ratio increases. The corrosion process of macro-cell is affected by the reversal of anode and cathode. After the reversal of anode and cathode, the corrosion rate is mainly controlled by dry – wet alternating corrosion.

The corrosion behavior of a pipeline steel in a coastal environment was studied using a tidal seawater macro-cell corrosion device. The synergism effect between the tidal seawater and seawater-soil macro-cell on corrosion behavior was clarified.

It is now fairly well established that steel reinforcements need some additional protection and various types of coatings such as fusion‐bonded epoxy, galvanizing and cement slurry have been used. Evaluation of such coated rebars in aggressive marine conditions is done usually by conducting some accelerated corrosion tests. These accelerated corrosion tests cannot be truly representative of field conditions and they often give higher corrosion rates. Validity of such tests becomes questionable. In the present work, corrosion rates of cement slurry‐coated rebars, obtained by ASTM impressed voltage test, salt‐spray test, precracked cantilever model slab test, alternate wetting and drying test and macrocell corrosion test, have been compared with uncoated rebars. It is shown that for a passivating type of coating such as cement slurry, accelerated corrosion tests could be equally valid.

The aim of this paper is to construct a device that simulated the seawater splash zone, dynamic waterline zone (splash zone) and full immersion zone. Localized corrosion of 2A12 aluminum alloy long-scale specimen was studied.

Corrosion morphologies before and after the corrosion product removal were used to identify corrosion intensity at full seawater immersion zone, dynamic waterline zone (splash zone) and atmospheric zone. The average depth and diameter of corrosion pits in the three zones were evaluated by three-dimensional optical microscopy. The impact of wetting time of the atmospheric zone on the localized corrosion was investigated.

Corrosion pits were observed on the surface on day 4 for the wetted atmospheric zone (Case 1), and on the surface on day 8 for the alternant wet/dry atmospheric zone (Case 2). The corrosion product layer on the surface for Case 1 was partially broken down while the layer on the surface for Case 2 was intact. Average pitting depth and pitting diameters for Case 1 were more serious than that for Case 2.

The above findings revealed that the humidity of the atmospheric zone had great impact on the localized corrosion of aluminum alloy at the seawater splash zone.

In summary, it can be found that the current research on the simulation of natural atmospheric dry–wet alternating accelerated corrosion mainly focused on the study of electrochemical corrosion process and the study of corrosion rate; the micro-pre-corrosion mechanism of materials in this environment, especially for materials. The specific effects of fatigue and fracture performance still lack detailed research. Accordingly, this study aims to more realistically simulate the effect of natural atmospheric corrosion environment on the corrosion resistance and fatigue performance of aircraft skin.

In this study, the uniaxial strain control method was used to test the fatigue performance of pre-corrosion samples under simulated natural atmospheric corrosion using MTS809 tensile-torque composite fatigue machine. Scanning electron microscopy, X-ray energy spectrum analysis, atomic force microscopy and X-ray diffraction analysis were used. Fatigue fracture, corrosion morphology and corrosion products were analyzed.

The results show that the deep corrosion pit caused by pre-corrosion environment leads to multi-source initiation of crack; the fatigue life of pre-corroded sample decreases by about one-half, chloride ion invades the material and promotes intergranular corrosion; life prediction results show that the natural atmospheric corrosive environment mainly affects the plastic term in the Manson–Coffin formula resulting in a decrease in fatigue life.

Innovative experimental schemes and materials are used and the test temperature and relative humidity are strictly controlled. The corrosion failure mechanism of 2A70-T6 aluminum alloy under alternating wet and dry accelerated corrosion environment and its influence on fatigue behavior were obtained.

The purpose of this paper is to focus on the durability of underwater non-dispersible concrete in seawater environment.

In this paper, ten groups of underwater non-dispersible concrete mixtures were designed, and the anti-dispersibility and fluidity of the mixtures were tested.

The durability test analysis shows that different pouring methods have different effects on the durability of concrete. The durability of concrete poured on land is better than that poured in water. Different mineral admixtures have different effects on the durability of concrete: the frost resistance of the underwater non-dispersible concrete specimens with silica fume is the best; the impermeability and chloride ion permeability of the non-dispersible underwater concrete specimens with waterproofing agent are the best; and the alternation of wetting and drying has adverse effects on the durability indexes of the non-dispersible underwater concrete.

The durability of underwater non-dispersible concrete is tested and the results can be used for reference in engineering practice.

Researchers and policymakers are figuring out the adaptation technologies to cope with the changing climate. Adaptation strategies for crop production followed by the farmers at selected study locations had ranged from 6-30 per cent only, and this was mainly due to lack of awareness about the actual cost associated with adaptation and non-adaptation of these strategies.

Hence, this study aims to address the cost of adaptation for rice using joint probability distribution of rainfall and crop prices.

Cost of adaptation varied from INR2,389 to 4,395/ha for System of Rice Intensification (SRI); INR646 to 1,121/ha for alternate wetting and drying (AWD) and INR8,144 to 8,677/ha for well irrigation (WI), whereas expected cost for not using these technologies has ranged from INR6,976 to 9,172/ha for SRI; INR4,123 7,764/ha for AWD and INR10,825 to 17,270/ha for WI. Hence, promotion of the adaptation technologies itself will minimize the income losses to the farmers.

Even though, there are many ways for farmers (other than technology), to adapt to climate change (such as out-migration to cities, selling farm assets, focus on children’s education, etc.), this report, given the framework of the major research study undertaken, addresses only farm-level adaptation of the technologies to enhance farm income.

Public–private partnership in providing the technologies at cheaper costs, capacity building in handling the technologies and creating awareness about the technologies to minimize the expected cost of adaptation are suggested to improve the adoption level.

The research into the issue of maintainability of multi‐storey buildings in Sri Lanka is still in its adolescent stage. One of the critical building elements that requires immediate attention for maintainability is reinforced concrete flat roofs. They are often subjected to alternate drying and wetting cycles under tropical conditions, causing many defects and subsequent deterioration when proper detailing related to design, construction and maintenance actions are lacking. Therefore, the aim of this paper is focused on identifying problems and risks and proposing a model to enhance the maintainability of flat roofs.

The existing maintainability problems were collected from 50 multi‐storey buildings. The inherent risks of flat roofs' maintainability were identified and analyzed through their problem‐causing factors. A scoring system using artificial neural networks is developed to forecast the level of maintainability.

The paper found 721 maintainability problems of flat roofs and a further 12 maintainability risk conditions related to the flat roofs were elicited. The model showed the level of maintainability of a typical flat roof shown is only 51 percent. The risk factors are also prioritized to give guidance.

The paper provides useful information to the designers and users on maintainability problems related to flat roofs. Also it highlights important risk conditions in order to minimize these problems.

The purpose of this paper is to investigate the corrosion behaviors of 2A12 aluminum alloy in NaCl and EXCO solution, and establish the relationship between the corrosion depth and the time.

Alternate immersion corrosion test chamber was used to perform the corrosion test. The corrosion mediums were 3.5 percent NaCl solution and EXCO solution (NaCl 234 g/L, KNO3 50 g/L, 68 percent HNO3 6.8 mL/L). The surface morphology was studied using the digital microscope.

The average corrosion rate of aluminum alloy in NaCl solution decreased gradually at the initial stage and then went to a plateau value. The average corrosion rate of aluminum alloy in EXCO solution increased first, then showed a downward trend. The empirical function D=At B was verified.

The results could provide a reference for the establishment of accelerated environmental spectrum in the laboratory and give instructions on the application of aluminum alloy in alternated dry and wet environment.

Of the many new materials offered to industry in the last ten years, epoxy resins are some of the most versatile. They have excellent resistance to atmospheric and chemical attack, stability, and good mechanical and electrical properties. They are, therefore, particularly suitable for use in resisting corrosive conditions.