Taiwan Association of Engineering and Technology Innovation: E-Journals
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Coal Fired Power Plant with Chemical Looping Combustion
Get PDFAround 54.7% of the total energy in India is produced from coal-fired power plants. In order to reduce the emission of CO2 into the atmosphere from these power plants, the effluent CO2 needs to be captured and sequestered or utilized. Chemical looping combustion (CLC) is an inherent CO2 capture technique in which coal is reacted with oxygen in the form of metal oxide instead of air and produces concentrated CO2 as a mixture of CO2 and steam. CO2 from this mixture can be easily separated and captured by condensing the steam. In this paper, a CLC integrated coal fired power plant with Fe2O3/Al2O3 as oxygen carrier was simulated using Aspen Plus ® simulation tool and the energy analysis was presented. High ash Indian coal was used in the present work. Results showed that CLC integrated coal fired power plant (CFPP) is more energy efficient with CO2 capture
Mechanical Properties of Dynamically Vulcanized Thermoplastic Polyurethane (TPU)/Polybutadiene Rubber (BR) Blends
Get PDFTo obtain thermoplastic polyurethane (TPU) with low hardness, dynamically vulcanized TPU/polybutadiene rubber(BR)(70/30) blends were prepared. The effect of dicumyl peroxide (DCP) content and stabilizers on the tensile strength and elongation at break of the dynamically vulcanized blends was examined. The tensile strength and elongation at break of the dynamically vulcanized blends decrease with increasing content of DCP. The addition of optimal content of stabilizer leads to the improvement of tensile strength and elongation at break of the blends. Also, the effect of sulfur cure systems and accelerators on the tensile strength and elongation of the blends was investigated. The tensile strength and elongation at break of all the dynamically vulcanized TPU/BR (70/30) blends using 1-step processing are not higher than those of simple TPU/BR (70/30) blends. However, the tensile strength and elongation of the dynamically vulcanized blends prepared at 8 min (mixing time) using 2-step processing are higher than those of the simple blends
Experimental Investigation on the Effect of Elevated Temperature on Compressive Strength of Concrete Containing Waste Glass Powder
Get PDFThis study examines the effect of elevated temperature on the strength of concrete containing glass powder (GWP) as Ordinary Portland cement replacement. The cement was partially replaced by 0, 15, 18, 21, 24, 27 and 30 % of GWP and samples were prepared at constant water-binder ratio of 0.5. The cube samples after curing in water for 90 days were exposed to 60, 150, 300 and 500°C temperatures increased at a heating rate of 10°C/min. Compressive strength values were measured on unheated samples and after air-cooling period of the heated samples. Scanning electron microscope (SEM) was carried out on selected samples to examine alterations in the matrix and interface. The results indicate a decrease in the compressive strength with increasing temperature, and significant alteration was observed in the concrete matrix and interface from the SEM analyses. However, the results indicate that concrete samples containing 21% GWP exhibit higher strength compared to control
Reversible Data Hiding over Facebook
Get PDFFacebook, the most popular Online Social Network (OSN), could be used as a platform to share secret messages through JPEG images online. However, due to the various lossy operations conducted over Facebook, the data embedded into the JPEG images can be easily destroyed, making the data extraction infeasible. More importantly, all these operations are carried out without users’ interference. In this paper, we first perform an in-depth investigation of the various lossy operations that Facebook applies to uploaded images. Based upon such prior knowledge, we propose a DCT-domain data hiding scheme that can effectively embed a large amount of data and successfully extract them out from the downloaded images, defeating the uncontrolled lossy operations. Compared with the state-of-the-art techniques, the proposed method offers much higher embedding capacity, and can extract the data successfully with very high probability. Furthermore, the restored image upon data extraction is of high quality, and the file size expansion is negligible. Extensive experimental results are provided to validate our findings
A Designed Enclosure Unit for Loop-Mediated Isothermal Amplification
Get PDFThe gene amplification technique is used in medical science and biotechnology popularly. The loop-mediated isothermal amplification (LAMP) is a nucleic acid amplification method that can be utilized in low-resource settings and does not require expensive or complex instruments. The annealing process of LAMP is performed at a constant temperature (around 65 °C) for an hour. From previous works, phase change materials (PCMs) have been applied for the latent heat energy storages due to their isothermal operation during phase transitions. The utilization of the melting temperature of the paraffin wax to maintain the suitable temperature for LAMP process is introduced in our study. To enhance the heat transfer inside the energy storage unit, several pin fins are constructed on the inner surface of the unit which is 50 mm × 50 mm × 50 mm in inner size. The influence of various numbers of pin fins on the temperature distribution is examined by the numerical simulation. The heat transfer inside the paraffin enclosure with fins is better than that without fin. It can be found that the temperature uniformity in the PCM inside the enclosure with fins shows much better. Though the numbers of the fin are increased, some transfer energy from the heat source remains at the enclosure wall and cannot penetrate into the PCM. The duration for all PCM melted from solid phase to liquid phase is over 10 minutes. In the future, the geometric parameters on the duration for phase transition of PCM inside the LAMP chamber will be investigated
Optimal Warranty Length and Selling Price to Maximize the Profit
Get PDFThis study focuses on the problem of determining the optimal coverage period and selling price of warranted products from the manufacturer’s perspective. We first consider how to maximize the profit per unit under the assumption that the product can be sold or the demand is independent of the warranty policy. Then we try to maximize the total profit for a planning period for the case where the demand for the product depends on the warranty coverage period and selling price. Since the warranty period and the selling price should be positively correlated, we first solve the profit maximization problem with the warranty depended demand under the constraint that the selling price is a linear function of the warranty coverage period (warranty based pricing). Furthermore, we investigate the case when such a constraint is removed (non-warranty-based pricing). Optimizing on two independent decision variables, the coverage period and the selling price, certainly improves the total profit. Under the two variable optimal conditions, it is observed that while the positive relationship between the optimal coverage period and the optimal price is confirmed, it is more complex than a linear one. We also find that the profit advantage for the non-warranty-based pricing over the warranty-based pricing is more significant for shorter coverage period. However, when the coverage period exceeds a threshold value, such a profit advantage becomes insignificant. The results of this study provide practitioners with useful insights in designing the profit optimal product warranty in highly competitive market
Synchronized Injection Molding Machine with Servomotors
Get PDFInjection Molding Machine (IMM) is one of the most important equipment in plastic industry. As a cyclic process, injection molding can be divided into three steps includes filling process, packing-holding process and cooling process, among which filling process and packing process are both most important phases for the quality of part, and the corresponding crucial process variables are injection velocity and packing pressure in filling and packing phases. Moreover the determining a suitable injection time, screw position and cavity pressure for transfer from injection velocity control to packing pressure control which is commonly called filling to packing switchover point is also critical for high quality part. This study is concerned with two research aspects: double servomotors synchronization control for injection unit, and filling to packing switchover methods. The simulation result of switching method based on injection time and ball screw position those are similar, and the result of switching method based on the cavity pressure that is better
Remote Monitoring of the Heart Condition of Athletes by Measuring the Cardiac Action Potential Propagation Time Using a Wireless Sensor Network
Get PDFHighly performing athletes are susceptible to cardiac damage of several kinds which may be irreversible. The monitoring of heart rate and ECG waveforms from such subjects by wireless sensor networks has been reported in health and sports care documents. However, a more decisive parameter for instant to instant changes would be the time of Cardiac Action Potential Propagation. This time, which can be between 15-20 ms would shoot suddenly in acute stress in highly performing athletes for short durations. Repeated incidents of such rising values will tend to cause irreversible damage to the heart. We developed the technique of measuring this time and reporting it through a wireless sensor network to monitoring station
Security Enhancement on Reconfiguring Coded Wavelength with Tunable Wavelength Filter Array Triggered Chaotic Sequences
Get PDFIn current study, the reconfigurable optical code-division multiple-access (OCDMA) scheme isimplemented that the chaos sequence is created non-linear time-variant sequence as secret key and then trigger tunable wavelength filter array as random wavelength allocation. In the encryption, the distribution of light carrier is designed and implemented by using tunable wavelength filter array triggered chaotic sequence. In addition, the arrayed waveguide grating (AWG) router is rewritten with maximal length code (M-sequence) to act as encoder. In the decryption, symmetric scheme and balanced photo-detector is presented and reconfigurable mechanism is followed the encryption synchronously either public or private channel. Hence, the multiple access interference (MAI) is cancelled completely while chaotic sequence is varied synchronously in transmitter and receiver. Compared to previous reconfigurable scheme by triggered register and switches after AWG router, the simulation results show that the secret key number of proposed cryptography is significantly increased to avoid eavesdropping attack in physical layer
Structural Analysis of Existing Multi-Speed Transmission Hubs of Bicycles
Get PDFThis paper presents the analysis of topological structure of multi-speed transmission hubs for bicycles. Three existing transmission hubs with 8-speed, 11-speed and 12-speed are introduced. The topological structure of each gear mechanism, which is the main body of a transmission hub, is analyzed. The degrees-of-freedom (DOF) of the transmission hub is calculated by the Kutzbach’s equation. The related clutching sequence table for each transmission hub is also listed