Ultrasonic effect on the photodegradation of 2,4-dichlorophenol wastewater

Kai-Yuan Cheng,Yung-Hsu Hsieh,Yi-Tze Tsai,Chen-Yu Chang,Ching-Yi Chang 대한환경공학회 2015 대한환경공학회 학술발표논문집 Vol.2015 No.10

The relationship between residential burglaries and urban environments in Taipei City: a data mining approach

Yi-Kai Juan,Wan-Hsuan Lin 서울시립대학교 도시과학연구원 2023 도시과학국제저널 Vol.27 No.1

Although the overall crime rate in Taiwan has shown a declining trend in recent years, the proportion of burglaries remains high. Most studies regarding the prevention of burglaries proceed from the perspectives of population composition or criminal psychology, and place focus on the internal spatial planning of buildings without mentioning the association between case locations and urban environments. In order to effectively prevent crime and improve the quality of life, this study utilized cases provided by the Taipei City Government Open Platform (Data. Taipei) to confirm the surrounding environmental factors and building data of burglary cases for data mining application. The proposed method consists of two phases: clustering and association rule mining. In the clustering phase, the key substructures of environmental information are collected; then characteristics in each cluster are analyzed based on the association rule. The results of analysis showed that the first group (Group 1) in the classification should give priority to improving the visibility of idle space and streets, while the second group (Group 2) should improve the efficiency of personnel surveillance and solve the problem of crowds caused by business activities. The third group (Group 3), which featured narrow lanes and insufficient street lamps on chaotic streets, should engage in overall planning and design. Some studies have found that the environmental characteristics of burglary cases in Taipei City are different from the characteristics of crime-saddled urban areas defined by international scholars. Such differences deserve further study. The findings of this study can serve as an environmental design model for future urban development.

Micro-scale PLA Fibrous Membranes for Adsorption of Cigarette Smoke

Yi-qing Gu,Zhe Wang,Ying Sun,Yi-Kai Wang,Zhi-juan Pan 한국섬유공학회 2018 Fibers and polymers Vol.19 No.3

Porous PLA fibrous membranes with different morphologies were successfully fabricated by varying the relative humidity. When the relative humidity was higher than 45 %, nanopores morphology appeared on the surface of PLA fibers. The micro-structures of PLA fibers and the packing densities and through-pore sizes of the PLA fibrous membranes were measured and found to greatly influence the smoke adsorption properties. The smoke adsorption was recorded in photos, and the process of how smoke adsorbed on the membranes was observed by SEM. The max removal efficiencies of nicotine, tar, water vapor, and carbon monoxide were 40.0 %, 36.9 %, 5.8 % and 13.6 % measured by a cigarette-smoking machine, and sensory evaluation was conducted to assess the practical application of fibrous membranes for smoke adsorption.

Facile Synthesis of In2S3 Modified Ag3PO4 Nanocomposites with Improved Photoelectrochemical Properties and Stabilities

Yi-Kai Zeng,Shenyu Bo,Jun-hui Wang,Bin Cui,Lei Zhu,Won-Chun Oh,Hao Gu 한국재료학회 2020 한국재료학회지 Vol.30 No.11

In this work, Ag3PO4/In2S3 nanocomposites with low loading of In2S3 (5-15 wt %) are fabricated by two step chemical precipitation approach. The microstructure, composition and improved photoelectrochemical properties of the asprepared composites are studied by X-ray diffraction pattern (XRD), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), photocurrent density, EIS and amperometric i-t curve analysis. It is found that most of In2S3 nanoparticles are deposited on the surfaces of Ag3PO4. The as-prepared Ag3PO4/ In2S3 composite (10 wt%) is selected and investigated by SEM and TEM, which exhibits special morphology consisting of lager size substrate (Ag3PO4), particles and some nanosheets (In2S3). The introduction of In2S3 is effective at improving the charge separation and transfer efficiency of Ag3PO4/In2S3, resulting in an enhancement of photoelectric behavior. The origin of the enhanced photoelectrochemical activity of the In2S3-modified Ag3PO4 may be due to the improved charge separation, photocurrent stability and oriented electrons transport pathways in environment and energy applications.

Decomposition of containing methyl tert-butyl ether wastewater using the gamma-ray/hydrogen peroxide process

Kai-Yuan Cheng,Yung-Hsu Hsieh,Yi-Tze Tsai,Ching-Yi Chang,Chen-Yu Chang 대한환경공학회 2015 대한환경공학회 학술발표논문집 Vol.2015 No.10

The Influence of Reconstruction Algorithm and Heart Rate on Coronary Artery Image Quality and Stenosis Detection at 64-Detector Cardiac CT

Yi-Ting Wang,Chung-Yi Yang,Jong-Kai Hsiao,Hon-Man Liu,Wen-Jen Lee,Yun Shen 대한영상의학회 2009 Korean Journal of Radiology Vol.10 No.3

Objective: We wanted to evaluate the impact of two reconstruction algorithms (halfscan and multisector) on the image quality and the accuracy of measuring the severity of coronary stenoses by using a pulsating cardiac phantom with different heart rates (HRs). Materials and Methods: Simulated coronary arteries with different stenotic severities (25, 50, 75%) and different luminal diameters (3, 4, 5 mm) were scanned with a fixed pitch of 0.16 and a 0.35 second gantry rotation time on a 64-slice multidetector CT. Both reconstruction algorithms (halfscan and multisector) were applied to HRs of 40-120 beats per minute (bpm) at 10 bpm intervals. Three experienced radiologists visually assessed the image quality and they manually measured the stenotic severity. Results: Fewer measurement errors occurred with multisector reconstruction (p = 0.05), a slower HR (p < 0.001) and a larger luminal diameter (p = 0.014); measurement errors were not related with the observers or the stenotic severity. There was no significant difference in measurements as for the reconstruction algorithms below an HR of 70 bpm. More nonassessable segments were visualized with halfscan reconstruction (p = 0.004) and higher HRs (p < 0.001). Halfscan reconstruction had better quality scores when the HR was below 60 bpm, while multisector reconstruction had better quality scores when the HR was above 90 bpm. For the HRs between 60 and 90 bpm, both reconstruction modes had similar quality scores. With excluding the nonassessable segments, both reconstruction algorithms achieved a similar mean measured stenotic severity and similar standard deviations. Conclusion: At a higher HR (above 90 bpm), multisector reconstruction had better temporal resolution, fewer nonassessable segments, better quality scores and better accuracy of measuring the stenotic severity in this phantom study. Objective: We wanted to evaluate the impact of two reconstruction algorithms (halfscan and multisector) on the image quality and the accuracy of measuring the severity of coronary stenoses by using a pulsating cardiac phantom with different heart rates (HRs). Materials and Methods: Simulated coronary arteries with different stenotic severities (25, 50, 75%) and different luminal diameters (3, 4, 5 mm) were scanned with a fixed pitch of 0.16 and a 0.35 second gantry rotation time on a 64-slice multidetector CT. Both reconstruction algorithms (halfscan and multisector) were applied to HRs of 40-120 beats per minute (bpm) at 10 bpm intervals. Three experienced radiologists visually assessed the image quality and they manually measured the stenotic severity. Results: Fewer measurement errors occurred with multisector reconstruction (p = 0.05), a slower HR (p < 0.001) and a larger luminal diameter (p = 0.014); measurement errors were not related with the observers or the stenotic severity. There was no significant difference in measurements as for the reconstruction algorithms below an HR of 70 bpm. More nonassessable segments were visualized with halfscan reconstruction (p = 0.004) and higher HRs (p < 0.001). Halfscan reconstruction had better quality scores when the HR was below 60 bpm, while multisector reconstruction had better quality scores when the HR was above 90 bpm. For the HRs between 60 and 90 bpm, both reconstruction modes had similar quality scores. With excluding the nonassessable segments, both reconstruction algorithms achieved a similar mean measured stenotic severity and similar standard deviations. Conclusion: At a higher HR (above 90 bpm), multisector reconstruction had better temporal resolution, fewer nonassessable segments, better quality scores and better accuracy of measuring the stenotic severity in this phantom study.

Electron Heating and Current Scaling in a Two-dimensional Electron System in Close Proximity to Nanoscale Scatterers

Yi-Ting Wang,Chun-Kai Yang,Sheng-Di Lin,Chi-Te Liang 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.10

We have performed magneto-transport measurements on a two-dimensional electron system(2DES) which is in close proximity to nanoscaled scatterers. Weak localization, as evidenced bynegative magnetoresistance, is observed. In this work, we use the extracted phase coherence rateas a thermometer to measure the electron’s effective temperature Te in our 2DES when a highdriving current I flows through the device. We find that Te / I0.52, consistent with 1/ep T2in two dimensions, where 1/ep is the electron-phonon scattering rate. However, the phase coherencerate 1/ T, with a very small offset, is consistent with zero-temperature dephasing. Mostimportantly, our experimental results are in agreement with the fact that at low temperatures, thedominant phase-breaking mechanism is electron-electron scattering, not electron-phonon scattering. Therefore we are able to investigate both electron-electron scattering and electron-phonon scatteringwhich are, in most cases, difficult to study independently in the linear region. Our data showthat the electron heating effect is a very powerful tool for studying semiconductor devices.

Preliminary Application of High-Definition CT Gemstone Spectral Imaging in Hand and Foot Tendons

Kai Deng,Cheng-Qi Zhang,Wei Li,Jun-Jun Wang,Xin-Yi Wang,Tao Pang,Guang-Li Wang,Cheng Liu 대한영상의학회 2012 Korean Journal of Radiology Vol.13 No.6

Objective: To assess the feasibility of visualizing hand and foot tendon anatomy and disorders by Gemstone Spectral Imaging (GSI) high-definition CT (HDCT). Materials and Methods: Thirty-five patients who suffered from hand or foot pain were scanned with GSI mode HDCT and MRI. Spectrum analysis was used to select the monochromatic images that provide the optimal contrast-to-noise ratio (CNR) for tendons. The image quality at the best selected monochromatic level and the conventional polychromatic images were compared. Tendon anatomy and disease were also analyzed at GSI and MRI. Results: The monochromatic images at about 65 keV (mean 65.09 ± 2.98) provided the optimal CNR for hand and foot tendons. The image quality at the optimal selected monochromatic level was superior to conventional polychromatic images (p = 0.005, p < 0.05). GSI was useful in visualizing hand and foot tendon anatomy and disorders. There were no statistical differences between GSI and MRI with regard to tendon thickening (χ2 = 0, p > 0.05), compression (χ2 = 0.5, p > 0.05), absence (χ2 = 0, p > 0.05) and rupture (χ2 = 0, p > 0.05). GSI was significantly less sensitive than MRI in displaying tendon adhesion (χ2 = 4.17, p < 0.05), degeneration (χ2 = 4.17, p < 0.05), and tendinous sheath disease (χ2 = 10.08, p < 0.05). Conclusion: GSI with monochromatic images at 65 keV displays clearly the most hand and foot tendon anatomy and disorders with image quality improved, as compared with conventional polychromatic images. It may be used solely or combined with MRI in clinical work, depending on individual patient disease condition. Objective: To assess the feasibility of visualizing hand and foot tendon anatomy and disorders by Gemstone Spectral Imaging (GSI) high-definition CT (HDCT). Materials and Methods: Thirty-five patients who suffered from hand or foot pain were scanned with GSI mode HDCT and MRI. Spectrum analysis was used to select the monochromatic images that provide the optimal contrast-to-noise ratio (CNR) for tendons. The image quality at the best selected monochromatic level and the conventional polychromatic images were compared. Tendon anatomy and disease were also analyzed at GSI and MRI. Results: The monochromatic images at about 65 keV (mean 65.09 ± 2.98) provided the optimal CNR for hand and foot tendons. The image quality at the optimal selected monochromatic level was superior to conventional polychromatic images (p = 0.005, p < 0.05). GSI was useful in visualizing hand and foot tendon anatomy and disorders. There were no statistical differences between GSI and MRI with regard to tendon thickening (χ2 = 0, p > 0.05), compression (χ2 = 0.5, p > 0.05), absence (χ2 = 0, p > 0.05) and rupture (χ2 = 0, p > 0.05). GSI was significantly less sensitive than MRI in displaying tendon adhesion (χ2 = 4.17, p < 0.05), degeneration (χ2 = 4.17, p < 0.05), and tendinous sheath disease (χ2 = 10.08, p < 0.05). Conclusion: GSI with monochromatic images at 65 keV displays clearly the most hand and foot tendon anatomy and disorders with image quality improved, as compared with conventional polychromatic images. It may be used solely or combined with MRI in clinical work, depending on individual patient disease condition.

[Poster Presentation] STUDIES ON STRUCTURAL FEATURES OF TRADITIONAL HANDMADE PAPER USING IMAGE ANALYZER

Kai-Tang Hu,Il-Rho Yi,Seon-Hwa Jeong,Tae-Ho Choi,Nam-Seok Cho 한국펄프·종이공학회 1999 한국펄프종이학회 기타 간행물 Vol.- No.-

A kind of image analysis system is used to investigate the structural features of the traditional handmade papers made from Kenaf and Abutilon. The screen mark on the paper was identified and analyzed. The dusts, shives and fiber bundles were manifested and calculated. The relationship between basis weight of the traditional paper and mean gray level of the image was discussed in detail. Some methods to express the formation of traditional handmade paper were studied.

EFFECT OF THE STRUCTURE OF ISOMERS OF MERCAPTOVALERIC ACID ON OPTICAL PROPERTIES OF CdTe QUANTUM DOTS

KAI-GUO MA,JIN-YI BAI,TAN FANG,Haiqing Guo 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2013 NANO Vol.8 No.5

4-Mercaptovaleric acid (4MVA) and 3-mercaptovaleric acid (3MVA), two branched isomers of 5-mercaptovaleric acid (MVA), were designed and synthesized. They were used as capping agents in the aqueous synthesis of CdTe quantum dots (QDs) by a modified hydrothermal method with sodium tellurite as Te source. Compared with MVA-CdTe, either 4MVA-QDs or 3MVA-QDs exhibited higher fluorescent quantum yield (QY) and sharper absorption peak, which confirmed the superiority of using branched mercapto acids in the aqueous synthesis of QDs for improved optical properties. The fluorescence of QDs capped with 4MVA was higher than that of QDs capped with 4-mercaptobutyric acid (MBA) but lower than that of QDs capped with 3-mercaptobutyric acid (3MBA), which further confirmed the advantage of designing methyl side group rather than methylene group in the main chain for desired optical properties. However, the lower fluorescence, less sharp absorption peak and faster growth rate of 3MVA-QDs than that of 3MBA-QDs indicated adverse effect of side group on the aqueous synthesis of QDs if the size of side group is very bulky. Our results are helpful for selecting and designing appropriate capping agents for QDs with excellent properties.