http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Chen Cheng-Lun,Huang Cong-Sheng 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.2
Phase shift full bridge DC/DC converter gains growing attention as the rapid development of electric vehicles, battery energy storage systems and microgrids. Comparing to conventional power converters, modern power converters are requested to meet dynamic load demands, high power conversion, effi ciency and, simultaneously, to achieve a wide range voltage output. The co-design of modern converter with wide range voltage output capability and voltage controller for the converter is technically challenging and still vacant in existing literatures. This paper provides a practical design demonstration to bridge the gap. After validations using IsSpice and MATLAB, a 750 watts phase shift full bridge DC/DC converter is implemented and a digital voltage controller is realized on a fi eld-programmable gate array (FPGA) chip alongside. This commercially ready prototype can provide a wide voltage output ranging from 0 to 50 V with excellent transient response, rendering 1% overshoot, less than 4.2 ms rise time and a maximum of 93.4% conversion effi ciency
Optimization of extraction process for bioactive compounds from Litsea cubeba fruits
Chih-Lun Cheng,Gui-Bing Hong 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.1
Response surface methodology (RSM) was applied to evaluate the extraction of active compounds from Litsea cubeba fruits. A central composite design (CCD) with five levels and three process parameters (extraction temperature, extraction time and ethanol concentration) was used to investigate the influence of the extraction temperature, extraction time and ethanol concentration on the multiple response variables (TPC, DPPH and ABTS assays). The results of the ANOVA analysis show that the quadratic term of the ethanol concentration was significant for all the response variables. The quadratic model was highly significant (P<0.05) for all the response variables. After optimizing for multi-response, the optimal conditions were determined as an extraction temperature of 42.3 oC, extraction time of 126.4min and ethanol concentration of 51%. Moreover, the extract of Litsea cubeba fruit attested possessing tyrosinase inhibitory activity, with an IC50 value of 5,720 μg mL−1. The second-order kinetic model represented the kinetic data very well. In addition, the obtained values of the effective diffusivities were in the range of 2.28-5.83×10−11m2s−1.
Resistance Reduction Scheme for Tower Grounding with Conductive Cement
Lun Li,Tian Xu,Pei Feng,Liu Xin,Jia Lulu,Deng Chenxing,Wang Xing,Lan Fen,Cheng Hongbo 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.3
The construction conditions of transmission lines are becoming more and more diffi cult. It is necessary to fi nd new ways to reduce the grounding resistance of poles and towers at high soil resistivity and small construction area. Conductive cement samples with graphite, stainless steel fi bers, and their mixtures as conductive phases materials were prepared, the resistivity, fl exural strength and compressive strength were tested, compared and analyzed. The graphite and stainless steel fi ber conductive cement with better comprehensive performance was selected out for tower grounding. The application schemes of conductive cement for tower grounding were designed and compared, the partial wrapping scheme was selected and its application methods under diff erent soil resistivity was analyzed. The analysis results can provide theoretical basis and guidance for the application of conductive cement in transmission tower grounding, the feasibility of scheme is proved by the fi eld application.
Cheng-hao Lee,Yanming Wang,Yiu-lun Tang,Chi-wai Kan 한국섬유공학회 2021 Fibers and polymers Vol.22 No.5
The colour quality assessment of reverse micelle-based (in octane or nonane medium) and conventional waterbaseddyed wool knitted fabric has been investigated using computer colour matching (CCM) approach. Both water-basedand non-aqueous based dyeing methods exhibited no chromatic shift from the reflectance curves and established goodlinearity in the construction of calibration curves. The linearity of both calibration curves in terms of R2 value played a criticalrole in CCM. The colour yield obtained from reverse micellar dyed fabric samples was higher than the colour yield valuesfrom wool knitted fabrics dyed in water bath under different dye percentages. The CCM predicted concentrations were ingood agreement to theoretical concentrations for both dyeing systems. To conclude, the results showed that reverse micellardyeing in octane and nonane is capable of generating reliable colour recipes. The relative unlevelness indices (RUI) obtainedfrom dyed wool knitted fabrics using reverse micellar approach reveal good to excellent levelness, which fulfills therequirements of the textile processing industry. TEM picture illustrated that reverse micelles are in nano-scale and this couldenhance the dyeing effect of wool with reactive dyes.
Yiu Lun Alan Tang,Cheng-hao Lee,Yanming Wang,Chi‑wai Kan 한국섬유공학회 2023 Fibers and polymers Vol.24 No.12
Feasibility and applicability of rhamnolipid (RL) microbial biosurfactant-based reverse micellar non-aqueous system in different solvent medium for dyeing of cotton fabrics was investigated. In this study, several solvents, including heptane, octane, nonane, decamethylcyclopentasiloxane (D5), and paraffin liquid (PL), were chosen as the dyeing medium for non-aqueous dyeing of cotton fabrics with fixed dyeing parameters. The dyeing properties of these RL reverse micellar dyed samples in different solvent medium were examined and compared with the conventional water-dyed samples in terms of color yield (K/Ssum value), CIE L*a*b* values, color levelness and reflectance. Most non-aqueous RL reverse micellar dyed samples exhibited better color yield than conventional water-dyed samples. The surface morphology of dyed cotton samples and the dye encapsulation morphology in different solvent medium were observed by SEM and TEM, respectively. Most non-aqueous dyed samples yielded good to excellent levelness comparable to water-dyed samples. However, poor levelness and bad levelness were found for D5-and PL-dyed samples. Further modification of dyeing parameters would be needed to obtain the best dyeing results for D5-dyed and PL-dyed samples.
Hsin-Lun Huang,Cheng-Tzu Liu,Ming-Chih Chou,Chien-Hui Ko,Chin-Kun Wang 한국식품영양과학회 2015 Journal of medicinal food Vol.18 No.6
Intestinal microflora and inflammation are associated with the risk of inflammatory bowel diseases. Noni (Morinda citrifolia L.) has various bioactivities, but its effect on colon health remains unknown. This study focused on the effects of fermented noni fruit extracts on colon microflora and inflammation of colon epithelial cells. The anti-inflammatory activities of ethanol and ethyl acetate extracts on Caco-2 cells were evaluated including interleukin-8 (IL-8) and cyclooxygenase-2 (COX-2). The growth of Lactobacillus and Bifidobacterium species was promoted by ethanol extract. Ethyl acetate extract decreased intracellular reactive oxygen species and significantly suppressed COX-2, IL-8, and prostaglandin E2 production and neutrophil chemotaxis by suppressing the translocation of the p65 subunit. Quercetin was the main contributor to the anti-inflammatory activity. The fermented noni fruit promoted probiotic growths and downregulated the intracellular oxidation and inflammation in Caco-2 cells. These results suggest that fermented noni fruit might protect against inflammatory diseases of the colon.
Electro-active polymer actuators employing sulfonated poly(styrene-ran-ethylene) as ionic membranes
Wang, Xuan-Lun,Oh, Il-Kwon,Cheng, Tai-Hong John Wiley Sons, Ltd. 2010 Polymer international Vol.59 No.3
<P>We first investigated sulfonated poly(styrene-ran-ethylene) (SPSE) as a novel ionic membrane for electro-active polymer actuators. SPSE is a newly developed hydrocarbon ionomer synthesized through a post-sulfonation procedure. The thermal, electrical, morphological and mechanical properties, as well as ion-exchange capacity, proton conductivity and water uptake were investigated and compared to a Nafion<SUP>®</SUP> counterpart. Tensile tests revealed that the SPSE membrane has good mechanical stiffness and strength while immersed in water. SPSE copolymers have good thermal stability and are easily processed for the production of membranes. In this study, SPSE actuators were fabricated according to traditional ionomeric polymer–metal composite preparation procedures and tailored to moderate dimensions. The bending responses of the SPSE actuators under both AC and DC electric excitations were investigated. The voltage–current behaviors of the actuators under AC excitation were also measured. The results showed that the SPSE actuators have good electromechanical performance with regard to tip displacement. Copyright © 2010 Society of Chemical Industry</P> <B>Graphic Abstract</B> <P>We investigated sulfonated poly(styrene-ran-ethylene) (SPSE) as a novel ionic membrane for electro-active polymer actuators. SPSE is a newly developed hydrocarbon ionomer synthesized through a post-sulfonation procedure. <img src='wiley_img_2010/09598103-2010-59-3-PI2775-gra001.gif' alt='wiley_img_2010/09598103-2010-59-3-PI2775-gra001'> </P>
Alan Yiu Lun Tang,Cheng-hao Lee,Yanming Wang,Chi‑wai Kan 한국섬유공학회 2023 Fibers and polymers Vol.24 No.2
The feasibility of computer colour matching (CCM) of rhamnolipid-based reverse micellar dyeing system on cotton fibre inoctane media has been investigated and compared with that of conventional water-based dyeing system. Calibration resultsconfirm that the calibration curves of both systems are linear in structure. Reflectance curves reveal that both water-dyedand RL octane-dyed standard and batch samples are identical in shape without any peak shift and alteration of colour properties. The actual colour matching results of RL octane reverse micellar dyeing system are close to theoretical predictionwith percentage difference less than 25%, verifying the applicability of CCM on RL reverse micellar dyeing system. RLoctane-dyed samples can achieve good to excellent levelness, washing and rubbing fastness, which are comparable to thatof water-dyed samples. Further experiments have been conducted to analyse the zeta-potential surface charge, particle sizedistribution and Raman spectra of RL. Volatile organic compound (VOC) detection and solvent recovery have also beenconducted. Experimental results reveal that the leakage of octane solvent is between 2 and 3 ppm which is at acceptably lowlevel whilst more than 98% of octane can be recovered for further use after the RL reverse micellar dyeing process, validatingthe environmental friendliness potential of the RL octane reverse micellar dyeing system.