Martensitic stainless steel CA6NM has the potential to be utilized as a turbine blade material for geothermal power plants because of its superior mechanical properties. However, the turbine blade material for geothermal power plants must have not only superior mechanical properties but also excellent corrosion resistance. Therefore, in this study, CA6NM was modified by varying its molybdenum (Mo) and nitrogen (N) contents to improve its corrosion resistance in the geothermal environment. The Mo and N contents of CA6NMwere modified as follows: CA6NM1 with 1% Mo, CA6NM2 with 2% Mo, and CA6NM3 with 2% Mo and 0.1% N. Two temperature parameters, i.e., room temperature and 60°C, and two CO2gas parameters, i.e., presence and absence of CO2gas, were utilized in this study. To understand the corrosion behavior of modified CA6NM in geothermal brine, the electrochemical impedance spectroscopy (EIS) test was performed in simulated geothermal brine. The results of the EIS test showed that both Mo and N can increase the corrosion resistance of CA6NM in simulated geothermal brine at 60°C.

As touch mania sweeps across many applications, a large number of venders seek to upgrade to dual-touch if not to multi-touch features, but cannot justify the price of capacitive touchscreens. To get around this, other methods - both legacy and cutting edge – are available. The idea is to create inexpensive alternatives to capacitive touchscreens or retrofit dual-touch/multi-touch gestures to existing resistive-touchscreen designs, for example. This paper introduces a new scheme to detect any dual-touch on an analog resistive touchscreen. A 4-wire version was chosen due to the simplicity of its structure. Both linear and polynomial regression, was used to support the ability of detecting any position. Four screen sizes, 4.3-inch, 5.7-inch, 7-inch, and 10.2-inch, were explored. The findings revealed that resistance changes during touch can be utilized for detecting the coordinates of finger(s), for a single-touch and any dual-touch. The maximum error across all screen sizes, evaluated by RMSE, is under 3mm from the exact position on both the X and Y-axes.

Stormwater management is a topic of growing complexity. It includes all measures in mitigating stormwater runoff. Various studies have identified stormwater as a major carrier of various pollutants and other contaminants. The utmost motive behind the implementation of stormwater management strategies is to use a suite of Best Management Practices to reduce sediment load, nutrients and chemical pollutant loads in stormwater before they reach natural watercourses downstream. Mitigation of the flood threat is another objective. Mitigation measures have been implemented in many countries with the same objectives. The relevant factors to be considered when adopting stormwater management measures are the geophysical aspects such as the climate, hydrology, land, soil and topography, law and social factors as well as the technical and economic issues. The world is moving more towards green concepts in mitigating stormwater runoff. Some of these measures are Low Impact Designs, Sustainable Urban Drainage System (SUDS) and Water Sensitive Urban Design. SUDS are more attuned to the green concept. The primary goal of SUDS is to switch from pipe-engineered system to practices and systems that use and enhance natural processes, i.e. infiltration, evapotranspiration, filtration and re-use. While conventional drainage systems focus only on the stormwater quantity, SUDS pay attention to all three aspects of quantity, quality and amenity/biodiversity. These measures have their own advantages and shortcomings. This review targets the present the state of the art of SUDS and its importance in stormwater management.

Inundation of urban areas due to heavy rainfall more frequently occurs in many large cities all over the world. This is more evident now due to the impacts of climate change. The design rainfall storm pattern, an input used to design urban drainage systems, plays an important role for developing sufficient drainage capacity for big cities. There are few studies in Thailand focusing on the accuracy of the Chicago Design Storm, which has been widely used for decades, in estimation of the peak intensity of rainfall for drainage systems. This study aims to first examine the accuracy of the Chicago Design Storm using observed data. Second, the impacts of climate change on rainfall intensity and on the Chicago Design Storm were investigated. Bangkok and its vicinity were selected as study area. Rainfall storm data with 1-5 minutes records and 15 minute records were collected from the meteorological station at AIT over the past 21 years and from the rainfall station in Sukhumvit area of Bangkok for 15 years. The Gumbel distribution was used in a Frequency Analysis to establish IDF Curves. The CDS, Yen & Chow and Sifalda methods were used to synthesize a Design Storm Pattern. Comparison of results of these methods with the observed data revealed that the CDS has good agreement in shape, i.e. peak intensity and time to peak. The CDS is still recommended for use in practice. However, MAPE was also used to evaluate accuracy of the synthesized CDS in comparison with the observed data. It was found that the CDS should be modified to reduce its peak intensity. Moreover, the impact of climate was also investigated. The Equidistance Quantile-Matching Method was adopted to compute IDF curves to include the climate change impact. The Global Climate Model (GCM), and HasGEM2-ES with RCP4.5 were used to generate rainfall data for the next 25 years. The changes in IDF curves due to climate change were compared. With the changed IDF curves, the peak intensity of design storms increased by up to 25%. It is therefore recommended to account for the impacts of climate change on design storms.

This paper investigates how experiences from the deployment of the Solrød biogas plant in Denmark - a large scale centralized biogas plant - can assist future biogas technologies in achieving circular economic benefits. Departing from a theoretical understanding of a circular economy provided by the Ellen MacArthur Foundation, the paper analyzes three areas: 1) biogas production, 2) nitrogen, phosphorous & green house gas (GHG) emissions, and 3) re-cycle/cascade materials. It consequently elaborates on the environmental benefits obtained, in terms of CO2 emission from biogas production substituted for fossil fuels, improved water quality and hence reduced GHG emissions due to lower nitrogen effluents, and re-cycling of nutrients on farmland thereby recovering finite resources and improving crop yield. Economic spin-off effects are presented, including new jobs created in the local community. Learning from Solrød Biogas, this paper further proposes to include the following activities when planning for future biogas plants: waste-stream identification and coupling in the local community, measuring the value of digestate as a fertilizer, short distance to farmers delivering manure, and plant design adapted to the local energy market. Finally, the paper suggests how to qualify the circular economic concept based on the findings from the Solrød biogas plant. It is here concluded, that emphasis should be on cascading energy from biogas production by means of combined heat and power (CHP), district heating or process heat to industry. Besides this, cascades in the manufacturing chain must also be intensified, allowing a more efficient materials and energy utilization and re-cycling in this part of the production chain. This will consequently reduce the total quantity of waste being generated by manufacturing industries, and thus benefit re-cycling strategies that only capture and seek to re-use a limited fraction of the waste being generated from industry.

Safety in aviation impacts the overall success of the sector. It depends on the effectiveness and efficiency of safety management systems (SMSs), which contain diverse and complex elements. Thus, a quantitative methodology for aviation SMS in developing countries, capable of prioritising resources with incomplete information, is needed. Grey relational analysis (GRA) is the most appropriate tool for this situation. This study assessed an existing SMS and determined its critical elements in a developing country’s aviation industry. Questionnaires were framed from the SMS manual of the International Civil Aviation Organization and from previous literature. The robustness and the efficiency of the approach were tested with data obtained from airline operators in Nigeria. Assessment of SMSs was done among airline service providers ascertaining the important levels of SMS elements. GRA was then applied to this data to identify the most influential elements of an SMS. Several companies were examined. Company A needs for a focus on sharing safety information and sensitization techniques to enable SMSs to better permeate through all levels, making employees aware of their SMS roles and duties to pursue a better safety culture. Company B needs to focus on more in-depth safety information dissemination platforms and methods. Non-punitive reporting should be done and safety promotion, culture, training and education should be prioritised. Company A has a better safety record than B. Overall, from the grey model, 12 critical elements were found out of 22 revised SMS elements that affect SMS. The major critical component was the safety structure and regulation. This is needed to build long lasting and effective SMSs. The novelty of this work is its unique application of GRA for a developing country’s airline safety.