Yu-Tuan Chou

Optimization of Biohydrogen Production with Biomechatronics

Massive utilization of petroleum and natural gas caused fossil fuel shortages. Consequently, a large amount of carbon dioxide and other pollutants are produced and induced environmental impact. Hydrogen is considered a clean and alternative energy source. It contains relatively high amount of energy compared with other fuels and by-product is water. In this study, the combination of ultrasonic mechanical and biological effects is utilized to increase biohydrogen production from dark fermentation bacteria. The hydrogen production is affected by many process conditions. For obtaining the optimal result, experimental design is planned using the Taguchi Method. Four controlling factors, the ultrasonic frequency, energy, exposure time, and starch concentration, are considered to calculate the highest hydrogen production by the Taguchi Method. Under the best operating conditions, the biohydrogen production efficiency of dark fermentation increases by 19.11%. Results have shown that the combination of ultrasound and biological reactors for dark fermentation hydrogen production outperforms the traditional biohydrogen production method. The ultrasonic mechanical effects in this research always own different significances on biohydrogen production.

Fabrication Improvement of Cold Forging Hexagonal Nuts by Computational Analysis and Experiment Verification

Cold forging has played a critical role in fasteners and has been applied to the automobile industry, construction industry, aerospace industry, and living products so that cold forging presents the opportunities for manufacturing more products. By using computer simulation, this study attempts to analyze the process of creating machine parts, such as hexagonal nuts. The DEFORM-3D forming software is applied to analyze the process at various stages in the computer simulation, and the compression test is also used for the flow stress equation in order to compare the differences between the experimental results and the equation that is built into the computer simulation software. At the same time, the metallography and hardness of experiments are utilized to understand the cold forging characteristics of hexagonal nuts. The research results would benefit machinery businesses to realize the forging load and forming conditions at various stages before the fastener formation. In addition to planning proper die design and production, the quality of the produced hexagonal nuts would be more stable to promote industrial competitiveness.

Assessing the Hardness of Quenched Medium Steel Using an Ultrasonic Nondestructive Method

Developing new materials or improving their heat treatment techniques is key to industrial upgrades for increasing fastener product quality. Nowadays, high tensile strength bolts are heat-treated to achieve desired mechanical properties such as hardness, strength, toughness, and resistance to fatigue and wear. Ultrasound detection is one widely used nondestructive inspection technique. Based on the characteristics of wave transmission, the refraction, diffraction, and scattering of ultrasound wave velocity and attenuation in a material are governed by its grain boundary characteristics. In this study, C1045 middle carbon steel was heat-treated at various temperatures and then water-quenched, and the relationships among grain size, ultrasonic velocity, attenuation, and material hardness were then determined using two ultrasound sources. Our experimental results show that a smaller average grain size as well as higher hardness can be obtained from higher quenching temperatures. Faster acoustic velocities and slower attenuation coefficients are caused by higher material hardness. A scattering effect is more obvious for higher transducer frequencies. Our results demonstrate another nondestructive test that can assess the quenching process in the fastener industry.

Traffic Noise Propagating from Vibration of Railway Wagon

Traffic noise has become a serious environmental hazard as more cars are purchased and driven. To help objectively and subjectively reduce perceived noise load, methods to analyze traffic noise offer an important means of creating a design to reduce noise output from main sources and transmission routes. Acoustic analysis using BEASY and dynamic analysis using ANSYS are conducted to forecast noise at a distance of 15 m from a railway wagon travelling at 100 km/h. This noise is based on structural vibration only and it excludes other noise sources from the railway wagon. The simulation results demonstrate that the overall noise at 15 m from a railway wagon car is 85.1 dB(L) from linear energy weighting calculation and 72.9 dB(A) from the A-weighting calculation. In this study, noise level propagating from vibration of the railway wagon is measured or calculated using A-weighting filter to simulate the frequency response of the human ear. The study results can be useful to factories, companies, or organizations and can provide an important resource and help reduce traffic noise. This can be achieved by predetermining the test location and structure configuration and adapting local planning and thus preventing excessive traffic noise in residential areas.

Numerical Analysis of Indoor Sound Quality Evaluation Using Finite Element Method

Indoors sound field distribution is important to Room Acoustics, but the field suffers numerous problems, for example, multipath propagation and scattering owing to sound absorption by furniture and other aspects of decor. Generally, an ideal interior space must have a sound field with clear quality. This provides both the speaker and the listener with a pleasant conversational environment. This investigation uses the Finite Element Method to assess the acoustic distribution based on the indoor space and chamber volume. In this situation, a fixed sound source at different frequencies is used to simulate the acoustic characteristics of the indoor space. This method considers the furniture and decoration sound absorbing material and thus different sound absorption coefficients and configurations. The preliminary numerical simulation provides a method that can forecast the distribution of sound in an indoor room in complex situations. Consequently, it is possible to arrange interior furnishings and appliances to optimize acoustic distribution and environmental friendliness. Additionally, the analytical results can also be used to calculate the Reverberation Time and speech intelligibility for specified indoor space.

Improvement on acoustic characteristics of a small space using material selection

Purpose – Recently, the acoustic characteristics of indoor spaces have been perceived to be more important due to the economic development needs of societies. At the same time, container houses have gradually become more widely used in many applications because of their sustainability and ease of use. In spite of their convenience, these container units still need to foster pleasant and quiet sound environments. The paper aims to discuss these issues. Design/methodology/approach – In this paper, commercial software, designed by Ecotect Analysis, has been used to evaluate the sound characteristics of container houses. As a result, the decorated materials in such a small indoor space have been redesigned for the acoustic comfort of users based on the optimal reverberation time (RT). First, a three-dimensional model of the container house was constructed using the software’s default tools. Then, the indoor acoustic characteristics of various design conditions were obtained from the simulation process underta...

Educational Virtual Reality implementation on English for Tourism Purpose using knowledge-based engineering

Recently, effective language learning is an important issue, especially in English for a special purpose. The traditional learning method exists some disadvantages, lack student focused learning, emphasis on critical thinking, process oriented learning, emphasis on larger concepts or structures, interactivity, etc. For the rapid development, computer-assisted language learning (CALL) embraces a wide range of information and communications technology applications and approaches to teaching and learning languages, as well as Virtual Reality (VR) is often used for that purpose. Educational language VR is a well-developed in IT field, with many available hardware and software solutions. However, those solutions are made with lacking methodology and systematics. As a result, utilizing VR services and products for language learning are unique and lead to increased development complexity. This paper proposes an original methodology that can be used to build immersive VR applications dedicated to training English for Tourism Purpose (ETP) skills. The original concept is based on knowledge-based engineering (KBE). The methodology and tools oriented to knowledge based engineering-KBE applications (MOKA) is used to implement the standardized content. Three elements are established before building the VR content, description of the lifecycle for a KBE, representation of knowledge associated with the application using text and graphics and software tool that helps to apply the representation and the route map. The results represent a complete stage of the methodology and the tools execution. Feasibility of the methodology is shown with a simple case - 3 scenes of leader English, include, scenario plan, panoramic 360-degree scene, virtual characters of conversation partners, related conversational situations, prompting of instruction. The effective virtual reality platform and its ETP conversational situations and authentic scenes established in this study can provide a brand-new learning model for both educational content designers and learners. In this proposed innovative approach, the obtained effectiveness of preparation of educational VR solutions is not only applied in language learning, but also in other fields.

A hybrid approach on multi-objective route planning and assignment optimization for urban lorry transportation

In urban goods delivery, the service quality is affected by number of lorry, distance between two points, road blocking and assigned time of customers, etc. The lower efficiency of human power and delivery time are caused from poor route planning. A hybrid approach of route finding, which is involved in multi-objectives and lorry assignment, is developed for achieving the optimal delivery schedule and decreasing the transportation cost in this research. Two stages in this method are proposed. The first stage is the pre-assigned scheduling, which is dependent on customer requirement, time adjustment, and number of lorry. Next, the route planning is done by delivered location and transportation time as well as reducing the number of lorry. In this stage, the Google Map API is introduced to calculate the distance and time of two or more locations. Meanwhile, the optimal assignment can be obtained by group-based optimization process. To verify the feasibility of this approach, ten formal route planning are re-analyzed. The results show that the total delivery distance is reduced 34.1% and the transportation time is reduced 21.6%. Obviously, good promising for obtaining better delivery service quality is presented in this approach.

A study of high-strength bolts after dephosphoring

A wide variety of fasteners are produced, including those for the automobile industry, household electrical appliances industry, architectural engineering, and even the aviation industry. The effects of the high-tensile bolt dephosphoring process on the entire fastener manufacturing process and its organizational characteristics and mechanical properties are analyzed and discussed in this study. Our experimental results reveal that the bolt dephosphoring process must be completed before heat treatment, which can be confirmed with a dephosphoring reagent or metallographic observation. Once bolt heat treatment is completed, bolts without dephosphoring appear to be coated with δ ferrite (delta ferrite) composed of a phosphate coating and a phosphatizing coating, which are not easily removed. Heat treatment with phosphorus results in grain boundary segregation, causing embrittlement and a reduction in lattice bonding forces and resulting in a high risk of fracturing when bolts are used in high-temperature environments or undergo multiaxial stresses.