DOCSLIB.ORG

Inactivation Efficiency to Bacillus Subtilis and Escherichia Coli Bacterial Aerosols of Spraying Neutral Electrolyzed Water

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Inactivation Efficiency to Bacillus Subtilis and Escherichia Coli Bacterial Aerosols of Spraying Neutral Electrolyzed Water Journal of the Air & Waste Management Association ISSN: 1096-2247 (Print) 2162-2906 (Online) Journal homepage: http://www.tandfonline.com/loi/uawm20 Inactivation efficiency to Bacillus subtilis and Escherichia coli bacterial aerosols of spraying neutral electrolyzed water Chi-Yu Chuang , Shinhao Yang , Ming-Yih Chang , Hsiao-Chien Huang , Chin- Hsiang Luo , Po-Chen Hung & Wei Fang To cite this article: Chi-Yu Chuang , Shinhao Yang , Ming-Yih Chang , Hsiao-Chien Huang , Chin-Hsiang Luo , Po-Chen Hung & Wei Fang (2013) Inactivation efficiency to Bacillussubtilis and Escherichiacoli bacterial aerosols of spraying neutral electrolyzed water, Journal of the Air & Waste Management Association, 63:12, 1447-1456, DOI: 10.1080/10962247.2013.827604 To link to this article: https://doi.org/10.1080/10962247.2013.827604 Accepted author version posted online: 06 Aug 2013. Published online: 06 Aug 2013. Submit your article to this journal Article views: 598 Citing articles: 4 View citing articles Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=uawm20 TECHNICAL PAPER Inactivation efficiency to Bacillus subtilis and Escherichia coli bacterial aerosols of spraying neutral electrolyzed water ⁄ Chi-Yu Chuang,1 Shinhao Yang,2, Ming-Yih Chang,3 Hsiao-Chien Huang,2 Chin-Hsiang Luo,4 Po-Chen Hung,5 and Wei Fang1 1Department of Bio-Industrial Mechatronics Engineering, National Taiwan University, Taipei, Taiwan, Republic of China 2Center for General Education, Toko University, Taiwan, Republic of China 3Department of Biomechatronics Engineering, National Ilan University, Taiwan, Republic of China 4Department of Safety, Health and Environmental Engineering, Hungkuang University, Taiwan, Republic of China 5Institute of Occupational Safety and Health, Council of Labor Affairs, Taiwan, Republic of China ⁄ Please address correspondence to: Shinhao Yang, 51 University Rd., Sec. 2, Pu-tzu City, Chia Yi County 613, Taiwan, Republic of China; e-mail: [email protected] The main objective of this study is to apply neutral electrolyzed water (NEW) spraying to inactivate bioaerosols. We evaluated the inactivation efficiency of NEWapplied to inactivate two airborne bacterial Escherichia coli and Bacillus subtilis aerosols inside an environmental-controlled chamber in the study. Generated with electrolyzing 6.15 M sodium chloride brine, the NEW with free available chlorine (FAC) concentration 50, 100, and 200 ppm was pumped with an air pressure of 70 kg/cm2 through nozzle into the chamber to inactive E. coli and B. subtilis aerosols precontaminated air (initial counts of 3 Â 104 colony-forming units [CFU]/m3). Bacterial aerosols were collected and cultured from chamber before and after NEW spray. The air exchange rate (ACH, hrÀ1) of the chamber was set to simulate fresh air ventilating dilution of indoor environment. First-order concentration decaying coefficients (Ka, minÀ1) of both bacterial aerosols were measured as an index of NEW inactivation efficiency. The result shows that higher FAC concentration of NEW spray caused better inactivation efficiency. The Ka values under ACH 1.0 hrÀ1 were 0.537 and 0.598 for E. coli of FAC 50 and 100 ppm spraying, respectively. The Ka values of FAC 100 ppm and 200 ppm spraying for B. subtilis were 0.063 and 0.085 under ACH 1.0 hrÀ1, respectively. The results indicated that NEW spray is likely to be effective in inactivation of bacterial airborne contamination. Moreover, it is observed in the study that the increase of ventilation rate and the use of a larger orifice-size nozzle may facilitate the inactivation efficiency. Implications: Bacterial aerosols have been implicated in deterioration of air quality and occupational health. Effective, safe, and economic control technology is highly demanded, especially for agricultural and food industries. In the study, NEW mist spraying performed effectively in controlling E. coli and B. subtilis modeling bioaerosols contamination. The NEW revealed its potential as an alternative airborne disinfectant worth being discovered for improving the environmental quality in the future. Introduction were found in a swine confinement building investigation in Canada (Cormier et al., 1998; Cormier et al., 2000). There was Biological contamination in agricultural and 2.8 Â 104 CFU/m3 of respirable airborne microorganisms recov- food-processing facilities ered when Predicala et al. studied the bioaerosols concentration in the swine finishing barns (Predicala et al., 2002). An on-site Nowadays, indoor airborne biological contamination has survey in swine houses in Korea found 4 log CFU/m3 for total raised public health concerns worldwide (Douwes et al., 2003; airborne bacteria where air quality management is demanded Schenker et al., 1998). Exposure to high level of airborne bacter- (Kim et al., 2007). High density of bacterial aerosols and related ial aerosols in agricultural and food-processing facilities such as endotoxin exposure may lead to adverse health effect of poultry greenhouses and swine and poultry housing may cause adverse workers. The workers were reported to be high-prevalence health effects. This has become an important issue that led to groups for work-related eye, respiratory, and skin symptoms in intensive investigation in recent years (Lacey and Dutkiewicz, previous studies (Lacey and Dutkiewicz, 1994; Radon et al., 1994; Heederik and Sigsgaard, 2005; Mackiewicz et al., 1999). 2002; Heederik and Sigsgaard, 2005; Heederik et al., 2007). In High airborne bacterial aerosols concentrations (up to 105 greenhouse facilities, occupational asthma and rhinitis due to the colony-forming units [CFU]/m3) for nasal breathing exposure exposure to microorganisms and endotoxin during growth 1447 Journal of the Air & Waste Management Association, 63(12):1447–1456, 2013. Copyright © 2013 A&WMA. ISSN: 1096-2247 print DOI: 10.1080/10962247.2013.827604 1448 Chuang et al. / Journal of the Air & Waste Management Association 63 (2013) 1447–1456 seasons have been reported in various investigations (Adhikari NEW has been reported to pose creditable antimicrobial et al., 2010; Radon et al., 2002). High concentrations of bioaer- reactions against a variety of microorganisms in agricultural osols and endotoxin exposure of greenhouse workers harvesting and food industries. The performance of bactericidal efficiency cucumbers and tomatoes were detected in Denmark (Madsen of diluted NEW against E. coli O157:H7, Erwinia carotova, et al., 2009). The exposure to high-concentration bioaerosols can Salmonella enteritidis, and Listeria monocytogenes is at 1–2 also be identified in food facilities. More than 105 CFU/m3 of log units (Abadias et al., 2008). NEW was also revealed to be bacterial aerosols concentration in a noodle factory was effective sanitizer for reducing the presence of E. coli, observed in central Taiwan (Tsai and Liu, 2009). An investiga- L. monocytogenes, P. aeruginosa, and Staphylococcus aureus tion of a high-throughput chicken slaughter facility showed high on stainless-steel and glass surfaces with 6 log CFU/50 cm2 counts of E. coli, Bacillus cereus, Staphylococcus aureus, reduction (Deza, Araujo, and Garrido, 2005). Methicillin- Pseudomonas aeruginosa, and Salmonella spp. in the airborne resistant S. aureus (MRSA) and Acinetobacter baumannii were microbial levels; controlling measures are recommended before inoculated on the surface of ceramic tiles and was reduced by processing materials to prevent the spread of microorganisms 106.8-fold with electrolyzed water fogging treatment (Clark et al., downstream (Lues et al. 2007). 2006). Escherichia coli O157:H7 food-borne pathogenic strains were spot-inoculated on lettuce leaves and were significantly Inactivating mechanism of electrolyzed water on reduced by NEW (Pangloli and Hung, 2011). bacteria According to the investigation conducted by Monnin (Monnin, Lee, and Pascall, 2012), E. coli K12 and L. innocua Facing the air quality problem caused by airborne microor- were significantly sanitized from cutting boards by 4 log CFU/ ganisms in the agricultural and food facilities, researchers have 100 m2 with NEW. In field application, as an alternative for shown interest in the use of chemical technologies to reduce chemicals traditionally used for bactericidal purposes, electro- airborne bacteria without causing harmful effects to workers, lyzed water is gaining popularity due to its strong bactericidal food materials, and animals. Electrolyzed water is generated by effects when used on food and equipment surfaces and its electrolysis of saline brine in a cell within anodic and cathodic advantages such as safety and nonirritating response of mucous electrodes with or without ion-selective permeating membrane. membranes and skins. In addition, the electrolyzed water also The electrolyzed water contains high oxidation–reduction poten- has the advantages of being less toxic and causing less adverse tial (ORP) and free available chlorine (FAC) compounds (hypo- environmental impact than other chemical disinfectants (Graça chlorous acid HOCl, chlorine gas Cl2, and hypochlorite ion et al., 2011; Arevalos-Sánchez et al., 2012; McCarthy and OClÀ), resulting in strong antimicrobial activity (Huang et al., Burkhardt Iii, 2012; Guentzel et al., 2008; Zheng et al., 2012). 2008). Studies on disinfecting mechanisms found that electro- Despite the widely proven effectiveness bacterial contamina- lyzed water performs dehydrogenase activities on E. coli and tion on food products, food
Load more

Recommended publications
  • Separation Enhancement of Mechanical Filters by Adding Negative Air Ions
    132 Journal of Membrane and Separation Technology, 2016, 5, 132-139 Separation Enhancement of Mechanical Filters by Adding Negative Air Ions Shinhao Yang1, Yi-Chin Huang1, Chin-Hsiang Luo2,* and Chi-Yu Chuang3 1Center for General Education, Toko University, Chiayi 61363, Taiwan 2Department of Safety, Health and Environmental Engineering, Hungkuang University, Taichung 43302, Taiwan 3Department of Occupational Safety and Health, Chang Jung Christian University, Tainan 71101, Taiwan Abstract: The purpose of this work is to combine negative air ions (NAIs) and mechanical filters for removal of indoor suspended particulates. Various factors, including aerosol size (0.05-0.45 µm), face velocity (10 and 20 cm/s), species of aerosol (potassium chloride and dioctyl phthalate), relative humidity (30% and 70%), and concentrations of NAIs (2 × 104, 1 × 105, and 2 × 105 NAIs/cm3) were considered to evaluate their effects on the aerosol collection characteristics of filters. Results show that the aerosol penetration through the mechanical filter is higher than that through the mechanical filters cooperated with NAIs. This finding implies that the aerosol removal efficiency of mechanical filters can be improved by NAIs. Furthermore, the aerosol penetration through the mechanical filters increased with the aerosol size when NAIs were added. That is due to that the aerosol is easier to be charged when its size gets larger. The results also indicate the aerosol penetration decreased with the NAIs concentration increased. Reversely, aerosol penetration through the mechanical filters increased with the face velocity under the influence of NAIs. The aerosol penetration through the filter with NAIs was no affected with relative humidity.
    [Show full text]
  • Applying the Membrane-Less Electrolyzed Water Spraying for Inactivating Bioaerosols
    Aerosol and Air Quality Research, 13: 350–359, 2013 Copyright © Taiwan Association for Aerosol Research ISSN: 1680-8584 print / 2071-1409 online doi: 10.4209/aaqr.2012.05.0124 Applying the Membrane-Less Electrolyzed Water Spraying for Inactivating Bioaerosols Chi-Yu Chuang1, Shinhao Yang2*, Hsiao-Chien Huang2, Chin-Hsiang Luo3, Wei Fang1, Po-Chen Hung4, Pei-Ru Chung5 1 Department of Bio-Industrial Mechatronics Engineering, National Taiwan University, Taipei 10617, Taiwan 2 Center for General Education, Toko University, Chiayi 61363, Taiwan 3 Department of Safety, Health and Environmental Engineering, Hungkuang University, Taichung 43302, Taiwan 4 Institute of Occupational Safety and Health, Council of Labor Affairs, Taipei 10346, Taiwan 5 Union Safety Environment Technology Co., Ltd, Taipei 10458, Taiwan ABSTRACT The inactivating efficiency using membrane-less electrolyzed water (MLEW) spraying was evaluated against two airborne strains, Staphylococcus aureus and λ virus aerosols, in an indoor environment-simulated chamber. The air exchanged rate (ACH) of the chamber was controlled at 0.5 and 1.0 h–1. MLEW with a free available chlorine (FAC) concentrations of 50 and 100 ppm were pumped and sprayed into the chamber to treat microbial pre-contaminated air. Bioaerosols were collected and cultured from air before and after MLEW treatment. The first-order constant inactivation efficiency of the initial counts of 3 × 104 colony-forming units (CFU or PFU)/m3 for both microbial strains were observed. A higher FAC concentration of MLEW spraying resulted in greater inactivation efficiency. The inactivation coefficient under ACH 1.0 h–1 was 0.481 and 0.554 (min–1) for Staphylococcus aureus of FAC 50 and 100 ppm spraying.
    [Show full text]
  • Study in Taiwan - 7% Rich and Colorful Culture - 15% in Taiwan, Ancient Chinese Culture Is Uniquely Interwoven No.7 in the Fabric of Modern Society
    Le ar ni ng pl us a d v e n t u r e Study in Foundation for International Cooperation in Higher Education of Taiwan (FICHET) Address: Room 202, No.5, Lane 199, Kinghua Street, Taipei City, Taiwan 10650, R.O.C. Taiwan Website: www.fichet.org.tw Tel: +886-2-23222280 Fax: +886-2-23222528 Ministry of Education, R.O.C. Address: No.5, ZhongShan South Road, Taipei, Taiwan 10051, R.O.C. Website: www.edu.tw www.studyintaiwan.org S t u d y n i T a i w a n FICHET: Your all – inclusive information source for studying in Taiwan FICHET (The Foundation for International Cooperation in Higher Education of Taiwan) is a Non-Profit Organization founded in 2005. It currently has 114 member universities. Tel: +886-2-23222280 Fax: +886-2-23222528 E-mail: [email protected] www.fichet.org.tw 加工：封面全面上霧Ｐ 局部上亮光 Why Taiwan? International Students’ Perspectives / Reasons Why Taiwan?1 Why Taiwan? Taiwan has an outstanding higher education system that provides opportunities for international students to study a wide variety of subjects, ranging from Chinese language and history to tropical agriculture and forestry, genetic engineering, business, semi-conductors and more. Chinese culture holds education and scholarship in high regard, and nowhere is this truer than in Taiwan. In Taiwan you will experience a vibrant, modern society rooted in one of world’s most venerable cultures, and populated by some of the most friendly and hospitable people on the planet. A great education can lead to a great future. What are you waiting for? Come to Taiwan and fulfill your dreams.
    [Show full text]
  • Higher Plasma Pyridoxal Phosphate Is Associated with Increased Antioxidant Enzyme Activities in Critically Ill Surgical Patients
    Hindawi Publishing Corporation BioMed Research International Volume 2013, Article ID 572081, 7 pages http://dx.doi.org/10.1155/2013/572081 Clinical Study Higher Plasma Pyridoxal Phosphate Is Associated with Increased Antioxidant Enzyme Activities in Critically Ill Surgical Patients Chien-Hsiang Cheng,1 Shih-Chien Huang,2 Ting-Yu Chiang,3 Yueching Wong,4 and Yi-Chia Huang4 1 The Intensive Care Unit, Critical Care and Respiratory Therapy, Taichung Veterans General Hospital, Department of Nursing, HungKuang University, Taichung, Taiwan 2 Department of Nutritional Science, Toko University, Chiayi, Taiwan 3 Nutrition Section, Tung’s Taichung MetroHarbor Hospital, Taichung, Taiwan 4 School of Nutrition, Chung Shan Medical University, Department of Nutrition, Chung Shan Medical University Hospital, Taichung, Taiwan Correspondence should be addressed to Yi-Chia Huang; [email protected] Received 4 April 2013; Accepted 15 May 2013 Academic Editor: Stephen C. Land Copyright © 2013 Chien-Hsiang Cheng et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Critically ill patients experience severe stress, inflammation and clinical conditions which may increase the utilization and metabolic turnover of vitamin B-6 and may further increase their oxidative stress and compromise their antioxidant capacity. This study was conducted to examine the relationship between vitamin B-6 status (plasma and erythrocyte PLP) oxidative stress, and antioxidant capacities in critically ill surgical patients. Thirty-seven patients in surgical intensive care unit of Taichung Veterans General Hospital, Taiwan, were enrolled. The levels of plasma and erythrocyte PLP, serum malondialdehyde, total antioxidant capacity, and antioxidant enzyme activities (i.e., superoxide dismutase (SOD), glutathione S-transferase, and glutathione peroxidase) were determined on the 1st and 7th days of admission.
    [Show full text]
  • A Study on the Development of Advanced Faculty in Leisure and Sport for Higher Education Between 2006 and 2011
    A Study on the Development of Advanced Faculty in Leisure and Sport for Higher Education between 2006 and 2011 Cheng-Lung Wu, Department of Marine Sports and Recreation, National Penghu University of Science and Technology, Taiwan Yung-Chuan Tsai, Department of Recreation Sports & Health Promotion, Meiho University, Taiwan Yong Tang, Corresponding Author, Department of Aquatic Sport and Recreation, Taipei College of Maritime Technology, Taiwan ABSTRACT This study employed latent growth curve modeling to verify the growth on the number of full-time faculty in the department relevant to leisure and sports in higher educational institutions in Taiwan. The scope of this study covers the departments relevant to leisure and sport. The number of the full-time faculty in the department relevant to leisure and sport was treated as observed variable for the analysis of its growth. The results found that a goodness fit between the number of students recruited in the latent growth curve model and observed data and that the growth of the number of the faculty in the department relevant to leisure and sport was significantly different along with time and the increase of the number of classes in the department relevant to the leisure and sport. And, the number of the faculty in the department relevant to leisure and sport in between 2006 and 2011 was significantly impacted by the higher educational systems, traditional or vocational universities, both of the number in the beginning point and growth rate were significantly different. It revealed that the factor of traditional and vocational educational system did influence the number of full-time faculty.
    [Show full text]
  • The Rankings of Research Funding Among Universities in Taiwan
    Mar. 2010, Volume 7, No.3 (Serial No.64) US-China Education Review, ISSN 1548-6613, USA The rankings of research funding among universities in Taiwan WANG Ru-Jer (Department of Education, Graduate Institute of Educational Policy and Administration, National Taiwan Normal University, Taipei 106, Taiwan) Abstract: With the current trend that universities around the world have gradually stepped into higher education systems of popularization, there has been more diversity in universities; hence it has become necessary to increase the transparency of university governance. Since that university classification or university ranking is a powerful mechanism to demonstrate the diversity of an institute, the rankings of research funding have become desirable and also of great value. The main purpose of this study is to analyze the rankings of research funding among universities in Taiwan, and make relevant suggestions based on the findings. A secondary data analysis was conducted on the data obtained from the database of National Science Council, in order to develop the rankings of research funding among 164 universities in Taiwan. Based on the results, the conclusions are as follows: (1) The top three universities which won the funding of the National Science Council Research Project with the best overall strength were National Taiwan University, National Cheng Gung University, and National Chiao Tung University; (2) The top three universities which won the funding of the National Science Council Research Project with the best average faculty strength were National Tsing Hua University, National Chiao Tung University, and National Taiwan University. It is suggested that, when rating the strength of a university to win the research funding, both overall strength and average faculty strength should be considered to avoid the unfairness towards universities of smaller scale.
    [Show full text]
  • Fingerprint Analysis
    Quality Assessment and Origin Identication on Four Species of Curcumae Radix by HPLC Assay and Fingerprint Analysis Yu-Ling Ho HungKuang University Chi-Ren Liao Central Flagship Pharmacy Chun-Pin Kao Hsin Sheng College of Medical Care and Management Kun-Chang Wu China Medical University Shang-Chih Lai Tzu Chi University Yuan-Shiun Chang ( [email protected] ) China Medical University College of Chinese Medicine https://orcid.org/0000-0002-8149-2638 Research Article Keywords: Curcumae Radix, HPLC, assay, ngerprint, curcumin, desmethoxycurcumin, bisdesmethoxycurcumin, germacrone, curdione Posted Date: September 1st, 2021 DOI: https://doi.org/10.21203/rs.3.rs-838863/v1 License: This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License 1 Quality assessment and origin identification on four 2 species of Curcumae Radix by HPLC assay and 3 fingerprint analysis 4 5 Yu-Ling Ho 1, Chi-Ren Liao2, Chun-Pin Kao3, Kun-Chang 6 Wu4, Shang-Chih Lai5 and Yuan-Shiun Chang6, 7*, 7 8 Affiliation 9 1Department of Nursing, Hungkuang University, Taichung 43302, TAIWAN 10 2Central Flagship Pharmacy, 402, Wu Chuan Road, North Section, Taichung 40446, 11 TAIWAN 12 3Department of Nursing, Hsin Sheng College of Medical Care and Management, 13 Tao-Yuan 32544, TAIWAN 14 4Department of Pharmacy, College of Pharmacy, China Medical University, Taichung 15 40402, TAIWAN 16 5Department of Post-baccalaureate Chinese Medicine, Tzu Chi University, Hualien 17 97004, TAIWAN 18 6Department of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, 19 College of Chinese Medicine, China Medical University, Taichung 40402, TAIWAN 20 7Chinese Crude Drug Pharmacy, China Medical University Hospital, Taichung 40402, 21 TAIWAN 22 23 24 *Corresponding author 25 Prof.
    [Show full text]
  • Supplementary Materials Long-Term Surveillance of Antibiotic
    Supplementary Materials Long-Term Surveillance of Antibiotic Prescriptions and the Prevalence of Antimicrobial Resistance in Non- Fermenting Gram-Negative Bacilli Chia-Huei Chou 1,2,†, Yi-Ru Lai 3,†, Chih-Yu Chi 1,2, Mao-Wang Ho 1,2, Chao-Ling Chen 4, Wei-Chih Liao 2,5, Cheng-Mao Ho 6,7, Yu-An Chen 8,9, Chih-Yu Chen 5, Yu-Tzu Lin 2, Chia-Der Lin 2,10,* and Chih-Ho Lai 2,3,9,11,12,* 1 Departments of Infectious Disease, China Medical University Hospital, Taichung 40447, Taiwan; [email protected] (C.-H.C.); [email protected] (C.-Y.C.); [email protected] (M.-W.H.) 2 School of Medicine, Department of Medical Laboratory Science and Biotechnology, Graduate Institute of Biomedical Sciences, China Medical University, Taichung 40402, Taiwan; [email protected] (W.-C.L.); [email protected] (Y.-T.L.) 3 Graduate Institute of Biomedical Sciences, Department of Microbiology and Immunology, Chang Gung University, Taoyuan 33302, Taiwan; [email protected] 4 Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23284, USA; [email protected] 5 Department of Pulmonary and Critical Care Medicine, China Medical University Hospital, Taichung 40447, Taiwan; [email protected] (C.-Y.C.) 6 Department of Laboratory Medicine and Clinical Pathology, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung 42743, Taiwan; [email protected] (C.-M.H.) 7 Department of Nursing, Hungkuang University, Taichung 43302, Taiwan 8 Department of Life Sciences, National Chung Hsing University,
    [Show full text]
  • The Effect of Tertiary Education Expansion on Fertility: a Note on Identification
    DISCUSSION PAPER SERIES IZA DP No. 14672 ‘Bachelors’ and Babies: The Effect of Tertiary Education Expansion on Fertility Tushar Bharati Simon Chang Qing Li AUGUST 2021 DISCUSSION PAPER SERIES IZA DP No. 14672 ‘Bachelors’ and Babies: The Effect of Tertiary Education Expansion on Fertility Tushar Bharati Qing Li University of Western Australia Business Shanghai University School Simon Chang University of Western Australia Business School and IZA AUGUST 2021 Any opinions expressed in this paper are those of the author(s) and not those of IZA. Research published in this series may include views on policy, but IZA takes no institutional policy positions. The IZA research network is committed to the IZA Guiding Principles of Research Integrity. The IZA Institute of Labor Economics is an independent economic research institute that conducts research in labor economics and offers evidence-based policy advice on labor market issues. Supported by the Deutsche Post Foundation, IZA runs the world’s largest network of economists, whose research aims to provide answers to the global labor market challenges of our time. Our key objective is to build bridges between academic research, policymakers and society. IZA Discussion Papers often represent preliminary work and are circulated to encourage discussion. Citation of such a paper should account for its provisional character. A revised version may be available directly from the author. ISSN: 2365-9793 IZA – Institute of Labor Economics Schaumburg-Lippe-Straße 5–9 Phone: +49-228-3894-0 53113 Bonn, Germany
    [Show full text]
  • Biological Characteristics of the MG-63 Human Osteosarcoma Cells on Composite Tantalum Carbide/ Amorphous Carbon Films
    Biological Characteristics of the MG-63 Human Osteosarcoma Cells on Composite Tantalum Carbide/ Amorphous Carbon Films Yin-Yu Chang1, Heng-Li Huang2, Ya-Chi Chen3, Jui-Ting Hsu2, Tzong-Ming Shieh4, Ming-Tzu Tsai5* 1 Department of Mechanical and Computer-Aided Engineering, National Formosa University, Yunlin, Taiwan, 2 School of Dentistry, China Medical University, Taichung, Taiwan, 3 Department of Materials Science and Engineering, Mingdao University, Changhua, Taiwan, 4 Department of Dental Hygiene, China Medical University, Taichung, Taiwan, 5 Department of Biomedical Engineering, Hungkuang University, Taichung, Taiwan Abstract Tantalum (Ta) is a promising metal for biomedical implants or implant coating for orthopedic and dental applications because of its excellent corrosion resistance, fracture toughness, and biocompatibility. This study synthesizes biocompatible tantalum carbide (TaC) and TaC/amorphous carbon (a-C) coatings with different carbon contents by using a twin-gun magnetron sputtering system to improve their biological properties and explore potential surgical implant or device applications. The carbon content in the deposited coatings was regulated by controlling the magnetron power ratio of the pure graphite and Ta cathodes. The deposited TaC and TaC/a-C coatings exhibited better cell viability of human osteosarcoma cell line MG-63 than the uncoated Ti and Ta-coated samples. Inverted optical and confocal imaging was used to demonstrate the cell adhesion, distribution, and proliferation of each sample at different time points during the whole culture period. The results show that the TaC/a-C coating, which contained two metastable phases (TaC and a-C), was more biocompatible with MG-63 cells compared to the pure Ta coating.
    [Show full text]
  • Full-Scale Experiment Research for Performance Analysis of a Mechanical Smoke Exhaust System
    International Journal of the Physical Sciences Vol. 6(14), pp. 3524-3538, 18 July, 2011 Available online at http://www.academicjournals.org/IJPS DOI: 10.5897/IJPS11.006 ISSN 1992 - 1950 ©2011 Academic Journals Full Length Research Paper Full-scale experiment research for performance analysis of a mechanical smoke exhaust system Chung-Hwei Su 1*, Chin-Lung Chiang 2, Jo-Ming Tseng 3 and Yi-Pang CHIU 2 1Department of Fire Science, WuFeng University, No.117, Chian_Kuo Rd., Sec.2, Ming_Hsiung, Chiayi 621,Taiwan, R.O.C. 2Department of Safety, Health and Environmental Engineering, Hungkuang University, Taichung, 443, Taiwan, R.O.C. 3Department of Safety, Health and Environmental Engineering, Central Taiwan University of Science and Technology, 666, Buzih Road, Beitun District, Taichung, 40601, Taiwan, R.O.C. Accepted 16 May, 2011 This full-scale experiment studies the efficiency of a mechanical smoke exhaust system by using hot smoke testing. The mechanical smoke exhaust system consisted of an air-conditioning system in a ceiling and its linear return diffusers were used as a smoke vent. To measure the efficiency of the system, the study included measurements of the smoke descending rate, the diffusion of heat into the room, and the visibility. Simultaneously, the diffusions of the smoke scenes were recorded and visually inspected. In accordance with Taiwan’s regulatory body, the smoke exhaust flow rate was set at 1.0 CMM/m 2 as a reference. It was found that if the location of the smoke vent was established improperly, smoke turbulence was formed. The feasibility was assessed when the smoke exhaust flow rate was adjusted to 0.8 and 0.5 CMM/m 2.
    [Show full text]
  • Study-In-Taiwan.Pdf
    Table of Contents 1 Why Taiwan ? Study in Why Taiwan | 02 International Students’ Perspectives / Reason | 03 Taiwan! Getting to Know Taiwan Fascinating Taiwan | 08 2 History | 10 Climate | 10 Geography | 10 Culture | 11 Cuisine | 11 3 Campus Diary | 12 Studying in Taiwan The Educational System of Taiwan | 14 Choosing a School & Applying | 16 Knowing the Schools | 18 International Programs | 20 Visa & Arrival Information | 62 Scholarships | 64 Campus Diary | 68 4 Living in Taiwan FICHET: Your all – Accommodations | 70 Living cost | 70 Services | 72 inclusive information source Job Opportunities | 73 Campus Diary | 74 for studying in Taiwan FICHET (The Foundation for International Cooperation in Higher Education of Taiwan) Additional Information is TAIWAN?a Non-Profit Organization founded in 2005. It currently has 118 member universities. Useful Links | 76 Universities in Taiwan | 82 Chinese Language Centers | 88 ͙Why Taiwan? Tel: +886-2-23222280 Test of Chinese as a Foreign language (TOCFL) | 90 5 Fax: +886-2-23222528 International Students in Taiwan (Statistics) | 92 International Students’E-mail: [email protected] / Reasons www.fichet.org.tw ͙ The Reasons Why I Chose Taiwan Let’s listen to what international students say on “Why Taiwan?” Sharoon 1 Swaziland Why Taiwan? Identification Lungile Hlatshwayo Degree student Taiwan has an outstanding higher education system that provides opportunities for international students to Major Healthcare administration study a wide variety of subjects, ranging from Chinese language and history to tropical agriculture and forestry, genetic engineering, business, semi-conductors and more. Chinese culture holds education and scholarship in high Grade nd regard, and nowhere is this truer than in Taiwan.
    [Show full text]