Improving discharge uniformity of industrial-scale very high frequency plasma sources by launching a traveling wave

Hsin-Liang Chen,Yen-Cheng Tu,Cheng-Chang Hsieh,Deng-Lain Lin,Chin-Jung Chang,Keh-Chyang Leou 한국물리학회 2016 Current Applied Physics Vol.16 No.7

Very high frequency (VHF) PECVD has been demonstrated to be able to significantly increase the deposition rate without compromising the film quality for the manufacture of silicon heterojunction and silicon thin film solar cells. To further reduce the production costs by enhancing the throughput, larger electrode and higher frequency are often required at the same time. Nevertheless, raising frequency in large-area PECVD results in non-uniform discharge caused by the standing wave effect and deteriorates the processing uniformity. In this study, a technique that generates a traveling wave via superposing two specific standing waves launched simultaneously is proposed to resolve this issue. An industrial-scale linear plasma reactor with length and width of 125 and 10 cm, respectively, is adopted for experimental tests and two 80 MHz power supplies are utilized to separately control the standing waves. The experimental results show that the discharge gap is only partially covered by plasma discharge when only one standing wave is applied. However, as both standing waves are launched, the non-uniformity of plasma discharge can be effectively reduced to <±5%. In addition, numerical simulation is also conducted in this study to clarify whether the proposed technique can be applied to large-area rectangular PECVD (substrate size: 1.4 m 1.1 m). By arranging multiple feeding points on opposite sides of the powered electrode, the simulation results indicate the non-uniformity of electric field can be maintained within ±10%.

Influence of doping and annealing temperature on the structural and optical properties of Mg2SiO4:Eu3þ synthesized by combustion method

Hsin-Liang Chen,Yen-Cheng Tu,Cheng-Chang Hsieh 한국물리학회 2016 Current Applied Physics Vol.16 No.7

This paper presents the structural and optical properties of europium doped magnesium orthosilicate nanophosphor prepared by combustion method and further annealed at varying temperatures. The structural and optical properties were investigated by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscope (FESEM), High resolution Transmission electron microscope (HRTEM), Diffuse Reflectance Spectra (DRS) and Photoluminescence spectra (PL) together with decay time. The XRD results confirmed the phase formation of Mg2SiO4. FESEM and TEM results indicated spherical particles in nanometer size. Photoluminescence spectra of Mg2SiO4:Eu3þ nanophosphors exhibited five groups of peaks 5D0 / 7FJ (J ¼ 0, 1, 2, 3, 4) transitions. Intensity parameters (U2 U4) and other radiative properties such as radiative transition probability, total radiative transition probability, radiative life time, branching ratio and stimulated emission cross-section were calculated using Judd- Ofelt theory. The lifetime measurement indicates a decreasing trend up to 5 mol% of Eu3þ concentration.

The Relationship Between Night Shift Work and the Risk of Abnormal Thyroid-Stimulating Hormone: A Hospital-Based Nine-Year Follow-up Retrospective Cohort Study in Taiwan

Chen, Hsin-Hao,Chiu, Hsiao-Hui,Yeh, Tzu-Lin,Lin, Chi-Min,Huang, Hsin-Yi,Wu, Shang-Liang Occupational Safety and Health Research Institute 2021 Safety and health at work Vol.12 No.3

Background: Health-care providers typically undergo shift work and are subjected to increased stress. Night shift work may induce disturbed sleep cycles and circadian rhythm. The objective of this study was to explore if night shift workers (NSWs) show an increased risk of abnormal thyroid-stimulating hormone (TSH). Methods: We conducted a retrospective cohort study of 574 employees without thyroid disease and abnormal TSH at baseline who underwent annual check-ups between 2007 and 2016 in a medical center. NSWs were defined as those with working time schedules other than daytime hours. We calculated the incidence rate and estimated the adjusted hazard ratio (HR) for incident abnormal TSH and subclinical hypothyroidism compared with non-NSWs using a Cox regression model. Results: A total of 56 incident abnormal TSH cases and 39 subclinical hypothyroidism cases in NSWs were identified during 3000 person-years of follow-up. In models adjusted for age, sex, obesity, and working departments, we found no increased relative risk for incident abnormal TSH (HR: 0.72, 95% confidence interval: 0.33-1.60) or subclinical hypothyroidism (HR: 0.52, 95% confidence interval: 0.19-1.45) when comparing NSWs to non-NSWs; nor were incidence rates significantly different among exclusively medical employees after excluding administrative staff. Conclusion: In this hospital-based nine-year follow-up retrospective cohort study, NSWs were not associated with increased relative risk of incident abnormal TSH and subclinical hypothyroidism, in contrast to previous cross-sectional studies.

Intelligent LoRa-Based Positioning System

Jiann-Liang Chen,Hsin-Yun Chen,Yi-Wei Ma 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.9

The Location-Based Service (LBS) is one of the most well-known services on the Internet. Positioning is the primary association with LBS services. This study proposes an intelligent LoRa-based positioning system, called AI@LBS, to provide accurate location data. The fingerprint mechanism with the clustering algorithm in unsupervised learning filters out signal noise and improves computing stability and accuracy. In this study, data noise is filtered using the DBSCAN (Density-Based Spatial Clustering of Applications with Noise) algorithm, increasing the positioning accuracy from 95.37% to 97.38%. The problem of data imbalance is addressed using the SMOTE (Synthetic Minority Over-sampling Technique) technique, increasing the positioning accuracy from 97.38% to 99.17%. A field test in the NTUST campus (www.ntust.edu.tw) revealed that AI@LBS system can reduce average distance error to 0.48m.

Fermentation process development for hyaluronic acid production by Streptococcus zooepidemicus ATCC 39920

Shu-Jen Chen,Jia-Ling Chen,Wei-Chih Huang,Hsin-Liang Chen 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.2

The development of a fermentation strategy for hyaluronic acid (HA) production by Streptococcus zooepidemicus ATCC 39920 has been explored. The specific HA productivity (YP/X) was affected by the medium carbon-tonitrogen (C/N) ratio rather than the specific growth rate of cells. Accordingly, HA fermentation should be performed in a balanced medium with an optimum C/N ratio of 2 : 1 in a batch culture. To improve the performance of the batch culture, the operation conditions for the fill-and-draw culture were investigated. It was found that the timing of medium exchange is critical for successfully performing fill-and-draw operations. Since streptococcal cells at the stationary phase might lose the capacity of HA synthesis, the displacement of the medium in a fill-and-draw culture should be started at the late exponential growth phase.

Relationship Between Belief about Analgesics, Analgesic Adherence and Pain Experience in Taiwanese Cancer Outpatients

Liang, Shu-Yuan,Chen, Kang-Pan,Tsay, Shiow-Luan,Wu, Shu-Fang,Chuang, Yeu-Hui,Wang, Tsae-Jyy,Tung, Heng-Hsin,Cheng, Su-Fen Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.2

Social and behavioral scientists have proposed that a person's belief system crucially influences his or her behaviour, and therefore may affect outcomes of pain management. The purpose of this study was to explore the relationship between analgesic beliefs, analgesic adherence and pain experience amongst Taiwanese cancer outpatients. The cross-sectional study included 92 oncology outpatients in two teaching hospitals in the Taipei area of Taiwan. The research instruments included the Pain Opioid Analgesic Beliefs Scale-Cancer (POABS-CA), opioid adherence, and the Brief Pain Inventory-Chinese (BPI-Chinese). Beliefs about pain and opioids demonstrated a significant relationship with patients' opioid adherence (r = -0.30, p < 0.01). The more negative beliefs regarding opioids and pain the patient had, the worse their adherence to around the clock (ATC) analgesic regimen. However, there was no significant correlation between opioid belief and pain experience. As well, there were no significant relationships between adherence to opioid regimen and any of the measures of pain experience. The study highlights the potential importance of a patient's pain and opioid beliefs in adherence to pain medication.

Doxorubicin Promotes Migration and Invasion of Breast Cancer Cells through the Upregulation of the RhoA/MLC Pathway

Chien-Liang Liu,Ming-Jen Chen,Jiunn-Chang Lin,Chi-Hsin Lin,Wen-Chien Huang,Shih-Ping Cheng,Shan-Na Chen,Yuan-Ching Chang 한국유방암학회 2019 Journal of breast cancer Vol.22 No.2

Purpose: Cancer cells develop acquired resistance induced by chemotherapeutic drugs. In this study, we investigated the effects of brief treatment with cytotoxic drugs on the phenotype of breast cancer cells. Methods: Breast cancer cells MCF7 and BT-474 were briefly treated with paclitaxel or doxorubicin. Clonogenic, migration, and invasion assays were performed on the treated cells. Western blot analysis and RhoA activity assay were also performed. Results: Breast cancer cells when briefly treated with paclitaxel or doxorubicin showed reduced clonogenic ability. Doxorubicin, but not paclitaxel, augmented cell migration and invasion. The invasion-promoting effects of doxorubicin were lost when the two drugs were sequentially used in combination. Myosin light chain (MLC) 2 phosphorylation and RhoA activity were upregulated by doxorubicin and downregulated by paclitaxel. Pretreatment with RhoA inhibitors abolished the migration- and invasion-promoting effects of doxorubicin. Conclusion: Doxorubicin activates the RhoA/MLC pathway and enhances breast cancer cell migration and invasion. Therefore, this pathway might be explored as a therapeutic target to suppress anthracycline-enhanced tumor progression.

High-strength concrete deep beams with web openings strengthened by carbon fiber reinforced plastics

Wen-Yao Lu,Hsin-Wan Yu,Chun-Liang Chen,Shen-Lung Liu,Ting-Chou Che 사단법인 한국계산역학회 2015 Computers and Concrete, An International Journal Vol.15 No.1

The objective of this study is to examine the effect of carbon fiber reinforced polymer (CFRP) on the shear strengths of deep beams with web openings. A total of 18 high-strength concrete deep beams with web openings were tested. Twelve were externally wrapped with four layers of CFRP, six of them strengthened in the horizontal direction and the others in the vertical direction. The parameters of the configuration of CFRP, the sizes of the openings and the locations of the openings were covered in this study. The test results indicates the shear strengths of deep beams with openings sized 60×40 mm were about 16% higher than that with openings sized 68×68 mm. For deep beams with openings sized 60×40 mm, the lower the locations of openings the higher the shear strengths were. The test results also indicate the shear strengths of deep beams with web openings strengthened by CFRP wrapped in the vertical direction can be enhanced by about 10%. However, the shear strengths of deep beams with web openings strengthened by CFRP wrapped in the horizontal direction can only be enhanced by about 6%. The shear strengths of deep beam, with different size and location of web openings and strengthened by different configuration of CFRP can be reasonably predicted by the empirical formulas of Kong and Sharp.

GreenIoT Architecture for Internet of Things Applications

( Yi-wei Ma ),( Jiann-liang Chen ),( Yung-sheng Lee ),( Hsin-yi Chang ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.2

A power-saving mechanism for smartphone devices is developed by analyzing the features of data that are received from Internet of Things (IoT) sensors devices to optimize the data processing policies. In the proposed GreenIoT architecture for power-saving in IoT, the power saving and feedback mechanism are implemented in the IoT middleware. When the GreenIoT application in the power-saving IoT architecture is launched, IoT devices collect the sensor data and send them to the middleware. After the scanning module in the IoT middleware has received the data, the data are analyzed by a feature evaluation module and a threshold analysis module. Based on the analytical results, the policy decision module processes the data in the device or in the cloud computing environment. The feedback mechanism then records the power consumed and, based on the history of these records, dynamically adjusts the threshold value to increase accuracy. Two smart living applications, a biomedical application and a smart building application, are proposed. Comparisons of data processed in the cloud computing environment show that the power-saving mechanism with IoT architecture reduces the power consumed by these applications by 24% and 9.2%.

Tests of reinforced concrete deep beams

Wen-Yao Lu,Hsin-Tai Hsiao,Chun-Liang Chen,Shu-Min Huang,Ming-Che Lin 사단법인 한국계산역학회 2015 Computers and Concrete, An International Journal Vol.15 No.3

This study reports the test results of twelve reinforced concrete deep beams. The deep beams were tested with loads applied through and supported by columns. The main variables studied were the shear span-to-depth ratios, and the horizontal and vertical stirrups. The shear strengths can be effectively enhanced for deep beams reinforced with both horizontal and vertical stirrups. The test results indicate the shear strengths of deep beams increase with the decrease of the shear span-to-depth ratios. The normalized shear strengths of the deep beams did not increase proportionally with an increase in effective depth. An analytical method for predicting the shear strengths of deep beams is proposed in this study. The shear strengths predicted by the proposed method and the strut-and-tie model of the ACI Code are compared with available test results. The comparison shows the proposed method can predict the shear strengths of reinforced concrete deep beams more accurately than the strut-and-tie model of the ACI Code.