Implementation of a new composting technology, serial self-turning reactor system, for municipal solid waste management in a small community in Thailand

“Serial Self-turning Reactors” (STR) is an innovative technology, which was developed to be an alternative organicwaste treatment for small communities in Thailand. It is a vertical-flow composting system which consists of a set of aerobicreactors sandwiched with a set of self-turning units. Combination of those components results to a high performance compostingwith capacity flexible. The pilot-scaled prototype of the new technology has been tested to ensure its effectiveness.This paper focuses on the implementation of STR technology. The study consisted of four parts: 1) selection of a targetcommunity and investigation of its current MSW practice, 2) preparation of a proposal which STR incorporated would andsubmit to the university’s administration for approval, 3) establishment of a demonstration plant and trial on actual practice,and 4) discussion and evaluation of the new technology in general and economical aspects. Thammasat University Rangsitcampus was selected to be the target community to approach the new technology. An improvement program, namely“Recycling and Composting Pretreatment Program” (RCPP) was proposed and implemented. Trial operation on plant-scaleperformed effectively with low running costs. An economic evaluation of STR was carried out to generalize the system

Experimental and Numerical Study on Cold-formed Steel Built-up Box Beams

In this paper, a study of flexural behavior of cold-formed steel built-up box beam which is commonly used in low rise and residential building is presented. Experimental investigation is conducted to understand about the failure mode and the load capacity of the beam in this study. Numerical analysis by using ABAQUS program was performed in order to verify with experimental result. In addition, influence of thickness, connection spacing, and web height and flange width to thickness ratio, affecting load capacity and buckling behavior of the beam, were discussed. The result shows that the finite element analysis can well predict the flexural strength of the beam and the thickness and connection spacing are the key factors to improve load capacity of the beam

Experimental and Numerical Investigation on Cold-formed Steel C Back-to-Back Beams

Investigation on flexural behavior of cold-formed steel (CFS) C back-to-back beam has been conducted in this study. In North American Specification for the Design of Cold-Formed Steel Structural Members, there is only the information on the spacing condition of C back-to-back beam. In the present experiment, twelve C back-to-back beam specimens with different connection spacing and cross-sectional dimension were tested under four-point loading. Bolts were used for connecting two C section beams. From the experimental result, the influence of the thickness and connection spacing of the C back-to-back beams were observed. Nonlinear finite element analysis of the beam specimens are performed, and compared with experimental result. It was found that the difference in ultimate load obtained from experimental and numerical result, are less than 30 percent

Models of municipal solid waste generation and collection costs applicable to all municipalities in Thailand

The aim of this paper is to identify and measure the variables which influence municipal solid waste (MSW) generation and collection costs in Thai municipality. The empirical analysis is based on the information derived from a survey conducted in a sample size of 570 municipalities across the country. The results from the MSW generation model indicate that the population density, the household size and the size of municipality are the significant determinant of waste generation. Meanwhile, with regards to the MSW collection cost model, the results showed some existence of positive in the volume of MSW collected, population density, the distance between the center of municipality to the disposal site the hazardous sorting and the size of municipality whereas, there were no evidence of the frequency of collection and the ratio of recycled material to waste generation on cost

Application of Mobile Mapping System to a Cable-Stayed Bridge in Thailand

Infrastructures must be inspected regularly to ensure serviceability and public safety. In the case of the Thailand expressway, 200 km of an elevated structure must be inspected once a year. Thailand expressway is an elevated reinforced concrete structure. Visual inspection for defects and structural movements such as excessive deflections, transverse movements, or settlements is a cumbersome process. Therefore, a mobile mapping 3D laser scanning (MLS) which is a high-resolution 3D laser scanner (Trimble MX-8) equipped on a vehicle, was introduced. Scanning was performed on live traffic on the expressway. From MLS, both the structure geometry and pavement point cloud data were obtained. A good agreement between elevations of the Rama XI bridge in Bangkok measured by point cloud data using MLS and by a real-time kinematic survey was obtained. The effect of mesh size on the output by MLS was investigated. It was found that a mesh size of 10 cm reduced the computational effort by 75% when compared to a mesh size of 5 cm. However, the International Roughness Index was reduced by 5%. International Roughness Index (IRI) estimated by MLS was close to the IRI values measured by the profilometer. However, a significant overestimation in the case of rutting depth was observed

Application of geographical information system to site selection of small run-of-river hydropower project by considering engineering/economic/environmental criteria and social impact

In the process of site selection of a small run-of-river hydropower project in Thailand, some problems are addressed as follows: the accessibility of the possible sites which are mostly located in rural and mountainous areas, the large amount of data required, and the lack of participation of the local people living nearby. In order to cope with these problems, this study proposes a new method to select feasible sites of small run-of-river hydropower projects by using Geographic Information System (GIS) technology. A combination of engineering, economic, and environmental criteria, as well as social impact is employed in this study. The selected study area is the upper Nan river basin situated in the north of Thailand. For the engineering criteria, the project locations are found by GIS in visual basic platform, and then economic evaluations of the selected projects are performed. Next, the environmental parameters are used to rank the projects by total weighted scores. Finally, a social impact study at the potential sites is conducted based on the public participation process, i.e. questionnaire survey and focus group discussions. The applicability of the proposed method is verified by the results of site selection of the small hydropower projects located on the Nan river basin in Thailand. This case study can be the model for the process of site selection of similar projects.Small run-of-river hydropower Geographic Information System Public participation Questionnaire survey Focus group Site selection

Experimental investigation on rectangular reinforced concrete beam subjected to bi-axial shear and torsion

This paper presents the experimental investigation on the failure mechanism and ultimate capacity of rectangular reinforced concrete beam under combined action of bi-axial shear accompanied with torsion through the test of four reinforced concrete members. The simple experimental set-up for a simply-supported beam under one point loading is introduced in this study by applying eccentric load to the tilted beam. This requires only one hydraulic jack to produce the complicated bi-axial shear and torsional loading. The main parameter is the magnitude of torsion induced to specimens which is relatively represented by the torsion-to-shear ratio. In addition, the influence of torsion on ultimate capacity of reinforced concrete with different ratio of two shears is investigated. From the experimental results, it is found that the increase in the magnitude of torsion about 69 percent drastically decreases bi-axial shear capacity as much as 12 to 39 percent according to the ratio of bi-axial shears. The experimental results are compared with the capacities calculated by the available interaction formula between uni-axial shear and torsion in the current design codes. The comparison indicates that the current design codes give quite conservative values of ultimate capacity

Material flows analysis of plastic in Thailand

A study of the plastics materials flow analysis in Thailand was aim to show the flow of plastic materials through production, consumption, and waste management based on the year 2013 and projection to the year 2020. This paper finds the plastic waste generation increasing steadily in line with population growth and increasing consumption. In addition, the simulation under waste management three scenarios includes the following: the business as usual, increasing recycled rate set on the National Solid Waste Management Master Plan (2016-2021) and increasing in rate of energy recovery by the Alternative Energy Development Plan 2015-2036. The plastic material flow analysis has shown that the implementation of the National Solid Waste Management Master Plan (2016-2021) or the Alternative Energy Development Plan 2015-2036 can reduce uncollected waste and improper waste disposal. Moreover, there is benefit by adding value from recycled materials and energy recovery

Improvement on design analyses of composite steel-concrete bridges using elaborate finite element methods

In this paper, three-dimensional finite element analysis of composite steel-concrete bridges is performed to simulate theactual bridge behavior. The accuracy of the model is verified against the results acquired from a field test. Thai trucks are loaded at possible locations of the bridge in order to obtain the maximum stresses on the bridge. The influences of concrete barriers, the displacement of bridge piers, and the Young’s modulus of concrete are then discussed, to reveal the actual behavior of the steel-concrete composite bridge. The reactions at the bearings on the bridge piers are also evaluated and discussed in this conjunction. Good agreement is obtained between the models and loading tests to show that the finite element model can aid engineers in design practices