Browsing by Author "Chang, Yu-Bin"

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A Self-Balancing Striping Scheme for NAND-Flash Storage Systems
(2008)
Chang, Yu-Bin
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Chang, Li-Pin
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資訊工程學系
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Department of Computer Science
To use multiple memory banks in parallel is a nature approach to boost the performance of flash-memory storage systems. However, realistic data-access localities unevenly load each memory bank and thus the benefits of parallelism is severely limited. In this work, we propose to encode popular data with redundancy by means of erasure codes. Load balancing is thus achieved by accessing only lightly loaded banks, because to retrieve a subset of data blocks and code blocks sufficiently reconstructs the requested data. The technical issues pertain to redundancy allocation, redundancy placement, and request scheduling. By experiments, we found that, by offering 10% extra redundant space, the read response time is largely improved by 30%.
Cultivation of microalgal Chlorella for biomass and lipid production using wastewater as nutrient resource
(2015-05-01)
Chiu, Sheng-Yi
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Kao, Chien-Ya
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Chen, Tsai-Yu
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Chang, Yu-Bin
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Kuo, Chiu-Mei
Using wastewater for microalgal cultures is beneficial for minimizing the use of freshwater, reducing the cost of nutrient addition, removing nitrogen and phosphorus from wastewater and producing microalgal biomass as bioresources for biofuel or high-value by-products. There are three main sources of wastewater, municipal (domestic), agricultural and industrial wastewater, which contain a variety of ingredients. Some components in the wastewater, such as nitrogen and phosphorus, are useful ingredients for microalgal cultures. In this review, the effects on the biomass and lipid production of microalgal Chlorella cultures using different kinds of wastewater were summarized. The use of the nutrients resource in wastewater for microalgal cultures was also reviewed. The effect of ammonium in wastewater on microalgal Chlorella growth was intensively discussed. In the end, limitations of wastewater-based of microalgal culture were commented in this review article. (C) 2014 Elsevier Ltd. All rights reserved.
Ferrofluid-assisted rapid and directional harvesting of marine microalgal Chlorella sp used for biodiesel production
(2017-11-01)
Ho, Shih-Hsin
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Chiu, Sheng-Yi
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Kao, Chien-Ya
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Chen, Tsai-Yu
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Chang, Yu-Bin
In this work, a novel harvesting strategy using ferrofluids coupled with flocculation as a magnetic directional harvesting system was developed, providing a fast and easy way to effectively collect microalgae with no further modifications made to the ferrofluids. With a ferrofluid dosage of 25 mg L-1, a high harvesting efficiency of 95-100% was achieved within 1 min. In addition, we successfully performed a wastewater recycling strategy coupled with a microalgal ferrofluid-harvesting dynamic flow-through system to harvest biomass of Chlorella sp. MTF-7 which could achieve over 80% of the maximum level after three repeated recycling cultivations. This work demonstrated the use of an integrated microalgal ferrofluid-harvesting dynamic flow-through system to develop a simple and effective strategy to enhance microalgal harvesting efficiency, along with wastewater recycling, in a marine microalgal Chlorella sp. MTF-7. (C) 2017 Elsevier Ltd. All rights reserved.
Simultaneous microalgal biomass production and CO2 fixation by cultivating Chlorella sp GD with aquaculture wastewater and boiler flue gas
(2016-12)
Kuo, Chiu-Mei
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Jian, Jhong-Fu
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Lin, Tsung-Hsien
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Chang, Yu-Bin
;
Wan, Xin-Hua
A microalgal strain, Chlorella sp. GD, cultivated in aquaculture wastewater (AW) aerated with boiler flue gas, was investigated. When AW from a grouper fish farm was supplemented with additional nutrients, the microalgal biomass productivity after 7 days of culture was 0.794 g L-1 d(-1). CO2 fixation efficiencies of the microalgal strains aerated with 0.05, 0.1, 0.2, and 0.3 vvm of boiler flue gas (containing approximately 8% CO2) were 53, 51, 38, and 30%, respectively. When the microalgal strain was cultured with boiler flue gas in nutrient-added AW, biomass productivity increased to 0.892 g L-1 d(-1). In semi-continuous cultures, average biomass productivities of the microalgal strain in 2-day, 3-day, and 4-day replacement cultures were 1.296, 0.985, and 0.944 g L-1 d(-1), respectively. These results demonstrate the potential of using Chlorella sp. GD cultivations in AW aerated with boiler flue gas for reusing water resources, reducing CO2 emission, and producing microalgal biomass. (C) 2016 Elsevier Ltd. All rights reserved.
Utilization of carbon dioxide in industrial flue gases for the cultivation of microalga Chlorella sp.
(2014-08-01)
Kao, Chien-Ya
;
Chen, Tsai-Yu
;
Chang, Yu-Bin
;
Chiu, Tzai-Wen
;
Lin, Hsiun-Yu
The biomass and lipid productivity of Chlorella sp. MTF-15 cultivated using aeration with flue gases from a coke oven, hot stove or power plant in a steel plant of the China Steel Corporation in Taiwan were investigated. Using the flue gas from the coke oven, hot stove or power plant for cultivation, the microalgal strain obtained a maximum specific growth rate and lipid production of (0.827 d(-1), 0.688 g L-1), (0.762 d(-1), 0.961 g L-1), and (0.728 d(-1), 0.792 g L-1), respectively. This study demonstrated that Chlorella sp. MTF-15 could efficiently utilize the CO2, NOX and SO2 present in the different flue gases. The results also showed that the growth potential, lipid production and fatty acid composition of the microalgal strain were dependent on the composition of the flue gas and on the operating strategy deployed. (C) 2014 Elsevier Ltd. All rights reserved.