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Temperature Effects on Gas Sensing Properties of Electrodeposited chlorine Doped and Undoped n-Type Cuprous Oxide Thin Films

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Journal of Sensor Technology 2014年第3期4卷 119-126页

作者： Nayana Bandara Charith Jayathilaka Dhammika Dissanayaka Sumedha Jayanetti Department of Chemistry University of Colombo Colombo Sri Lanka Department of Physics University of Colombo Colombo Sri Lanka Department of Physics University of Colombo Colombo Sri Lanka Department of Physics Open University of Sri Lanka Nawala Sri Lanka Department of Physics University of Colombo Colombo Sri Lanka Department of Physics University of Kelaniya Kelaniya Sri Lanka

As one of the most widely used domestic fuels, the detection of possible leakages of Liquefied Petroleum (LP) gas from production plants, from cylinders during their storage, transport and usage is of utmost importance. This article discusses a study of the response of undoped and chlorine doped electrodeposited n-type Cuprous Oxide (Cu2O) films to of LP gas. Undoped n-type Cu2O films were fabricated in an electrolyte bath containing a solution of sodium acetate and cupric acetate whereas n-type chlorine doped Cu2O thin films were prepared by adding a 0.02 M cuprous chloride (CuCl2) into an electrolyte solution containing lactic acid, cupric sulfate and sodium hydroxide. The n-type conductivity of the deposited films was determined using spectral response measurements. The structural and morphological properties of the fabricated films were monitored using X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). Due to doping, the overall conductivity of the chlorine doped n-type Cu2O films increased by several orders of magnitude. The temperature dependent gas responses of both the undoped and chlorine doped n-type Cu2O thin films to the LP gas was monitored by measuring the electrical resistance (R), and using the contact probe method at a constant gas flow rate of 0.005 ml/s. Upon exposure to gases, both doped and undoped films showed a good response to the gas by increasing/decreasing the electrical resistance by ΔR. The undoped n-type Cu2O thin films showed a negative response (ΔR 2O thin films initially showed a positive response (ΔR > 0) to the LP gas which then reversed its sign to give a negative response which peaked at 52°C. The positive response shown by the chlorine doped Cu2O films vanished completely at 42°C.

关键词： Liquefied Petroleum Gas Electrodeposition Cu2O Thin Films chlorine Doped Undoped Gas Response

Effect of Inhabitation Mouthwash Solution Containing chlorine Dioxide (Pro Fresh<sup>®</sup>) on Oral Malodor

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Health 2015年第2期7卷 211-219页

作者： Masaki Sawa Senichi Suzuki Masakazu Azuma Tomoko Yoshizawa Kaiho Otomi Takuji Yamaguchi Hiroyuki Kobayashi Department of Hospital Administration Juntendo University Graduate School of Medicine Tokyo Japan Sawa Dental Office Aichi Japan Department of Emergency and Disaster Medicine Juntendo University Graduate School of Medicine Tokyo Japan Center for Advanced Kampo Medicine and Clinical Research Juntendo University Graduate School of Medicine Tokyo Japan

Recently, the interest in oral malodor has been grown and the number of people having trouble with oral malodor is increasing year by year. Generally, as the branch of medicine which deals with patients complaining about oral malodor, dentistry is mostly chosen. On the current situation, however, the dental office side typically finds it difficult to deal with several kinds of oral malodor which show no improvement even though cavities or periodontal disease is completely cured. Main components to cause oral malodor are volatile sulfur compounds (methyl mercaptan, dimethyl sulfide, hydrogen sulfide);in the present study, therefore, the effect of mouthwash solution containing chlorine dioxide to relieve oral malodor and increase saliva production was tested. The subjects were 92 patients (Control group: 2 males, 3 females, age;30.8 ± 4 years old, Mouthwash group: 28 males, 59 females, age: 36.9 ± 1.3 years old) who visited the hospital complaining about oral malodor. Intraoral gas, exhaled gas, the saliva production at rest, the ability for salivation and the buffering ability of saliva were examined twice, before the subjects used the mouthwash solution every day for one month. The simple chromatography oral chroma, which was insulated from the influence of temperature and humidity and also was able to measure with a high degree of accuracy, was used to measure odor as the device analysis method. The control group did not change in VSCs, saliva production and the buffering ability of saliva. After using mouthwash solution, the concentration of the 3 major components gas of intraoral gas and exhaled gas, i.e. methyl mercaptan, dimethyl sulfide, hydrogen sulfide, were all decreased. As for hydrogen sulfide, intraoral gas (from 225.8 ± 28.1 ppb to 41.1 ± 8.8 ppb) and exhaled gas (from 212.0 ± 50.4 ppb to 34.6 ± 16.6 ppb) was significantly decreased. Also, saliva production at rest (from 1.3 ± 0.1 ml to 1.7 ± 0.1 ml) and the ability to salivate (from 4.5 ± 0.3 ml to 5.1 ± 0.3 ml) were both significantly increased. As

关键词： chlorine Dioxide Oral Malodor Volatile Sulfur Compounds Intraoral Gas Exhaled Gas

The Determination of chlorine in Rocks and MineralS by Pyrohydrolytic Method

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Acta Geochimica 1985年第3期 291-296页

作者：张光宇刘远康 A student of Chengdu Geological College. Institute of Geochemistry Academia Sinica

In this paper a porccdute of pyrohydrolysis-spectrophotometric determination has been es-tablished for chlorine in rocks and minerals.The selection of accelerator and its requiredquantity,the time and temperature of sample decomposition and the influence of interferringelements and other factors are also discussed in detail.Because samples are usually fusedwith alkalis,higher blank is an insurmountable problem.However,with our procedure,theabove-mentioned drawback can be effectively overcome,and the determination of trace chlori-ne either in Igrge or in minor quantities of samples also is rather ideal.The determined re-suits indicate that the relative standard deviations are 8.7％ in the former and 4.5％ in thelatter case.This procedure is simple,rapid and well reproduceable.The detection limit ofthe method is 10ppm.The results obtained by our procedure are in good agreement with theproposed values from two reference samples in China(DZ ∑-1 and DZ∑-2)and one interna-tional geochemical reference Sample(RGM-1).This method has proved itself to be reliable.

关键词： overcome drawback quantities geochemical blank mentioned itself instead accelerator chlorine

Impact of chlorine, Temperature and Freezing Shock on the Survival Behavior of <i>Escherichia coli</i>O157:H7 on Ready-to-Eat Meats

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Food and Nutrition Sciences 2012年第4期3卷 530-538页

作者： Shiowshuh Sheen Cheng-An Hwang Vijay K. Juneja Food Safety and Intervention Technologies Research Unit USDA Agricultural Research Service Research Facility Eastern Regional Research Center Wyndmoor USA Residue Chemistry and Predictive Microbiology Research Unit USDA Agricultural Research Service Research Facility Eastern Regional Research Center Wyndmoor USA.

Foodborne pathogens continue to pose a potential food safety hazard in ready-to-eat (RTE) meat. chlorine is commonly used to sanitize processing equipment where Escherichia coli O157:H7 (Ec) may survive and contaminate food products. The objective of this study was to characterize the survival behavior of Ec with different stresses on RTE meats. A multi-strain cocktail of Ec was pre-treated with freezing shock for 15 - 20 h and/or chlorine (0, 25, and 50 ppm) for one hour, and then inoculated onto RTE meat surfaces to obtain about 3.0 log CFU/g. Samples were stored at three abuse temperatures (12℃, 18℃, and 24℃) and Ec was enumerated during the storage. The freezing shock impact was studied using the Ec cocktail stored in a freezer overnight followed by chlorine exposure for one hour. The lag phase and growth rate of Ec were estimated using DMFit (Combase, Baranyi’s model). Results indicated that Ec growth was suppressed by chlorine treatment. Freezing shock was found to have little impact in terms of lag time and growth rate. The lag phase of Ec after exposure to 0 ppm of chlorine (50.3 h) was shorter than that of Ec treated with 25 ppm (54.6 h) and 50 ppm (164.1 h) at 12℃. However, the lag phase decreased with an increase in temperature, e.g. at 25 ppm, lag times were 54.6, 51.1 and 48.9 h for 12℃, 18℃ and 24℃, respectively. Lag times increased with an increase in chlorine concentration. At 24℃, lag times were 15.8, 48.9, and 52.4 h for 0, 25, and 50 ppm, respectively. The growth rate increased with an increase in temperature for 0 and 25 ppm chlorine levels, but decreased at 50 ppm level. Growth rate and lag phase as a function of temperature and chlorine concentration can be described by polynomial models and modified Ratkowsky-type and Zwietering-type models. Results of this study will contribute to risk assessment of RTE meats.

关键词： chlorine Lag Time Growth Rate E. coli O157:H7 Modeling

Variable chlorine Decay Rate Modeling of the Matsapha Town Water Network Using EPANET Program

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Journal of Water Resource and Protection 2019年第1期11卷 37-52页

作者： Ababu T. Tiruneh Tesfamariam Y. Debessai Gabriel C. Bwembya Stanley J. Nkambule L. Zwane Department of Environmental Health Science University of Eswatini Kwaluseni Eswatini Department of Chemistry University of Eswatini Kwaluseni Eswatini

A variable chlorine decay rate modeling of the Matsapha town water network was developed based on initial chlorine dosages. The model was adequately described by a second order rate function of the chlorine decay rate with respect to the initial chlorine dose applied. Simulations of chlorine residuals within the Matsapha water distribution network were run using the EPANET 2.0 program at different initial chlorine dosages and using the variable decay rate as described by the second order model. The measurement results indicated that the use of constant decay rate tended to underestimate chlorine residuals leading to potentially excess dosages with the associated chemical cost and side effects. The error between the two rate models varied between 0% and 15%. It is suggested that the use of water quality simulation programs such as EPANET be enhanced through the extension programs that accommodate variable rate modeling of chlorine residuals within distribution systems.

关键词： Pipe Network EPANET chlorine Residual Bulk Decay Rate Water Quality chlorine Dose

Liquid chlorine Price Drops Drastically

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China Chemical Reporter 2008年第27期19卷 15-15页

Starting from mid-July the liquid chlorine market in China was sunk into a continuous reduction.In early September the price of liquid chlorine was between RMB 950-1300per ton in eastern

关键词： chlorine eastern Henan executed alkali Major getti

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Risk Assessment on the chlorine Leakage Dispersion

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Risk Assessment on the Chlorine Leakage Dispersion

Effect of CaO on retention of S, Cl, Br, As, Mn, V, Cr, Ni, Cu, Zn,W and Pb in bottom ashes from fluidized-bed coal combustion power station

2011 International Conference on Management Science and Intelligent Control(ICMSIC 2011)

作者： Dehong Zhou School of Environment and Civil Engineering Wuhan Institute of Technology Wuhan China

The chlorine is virulent chemical,it will lead to a significant and fatal accident in the event of leakage occurrence.According to the potential harm of the chlorine,this paper analyzes the risk of the chlorine leakage dispersion,chooses the Gauss model to calculate the chlorine leakage dispersion concentration and distance,and uses Matlab to simulate the chlorine leakage dispersion pictures.According to the risk analysis,we can grasp the concentration distribution and changing with the distance after the chlorine leakage,determine the safety distance for evacuation,obtain the relationships about concentration distribution with the atmospheric stability and other factors,we can also determine the scope of poisoning and injury.It can provide technical support for the enterprises and relevant departments to emergency response decision-making.

关键词： chlorine leakage risk analysis

来源： cnki会议评论

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Journal of Environmental Sciences 2014年第7期26卷 1429-1436页

作者： Lucie Bartonova Zdenek Klika Energy Units for Utilization of Non-Traditional Energy Sources Centre V?B-Technical University of Ostrava 708 33 Ostrava-Poruba Czech Republic Regional Material and Technology Research Centre VSB-Technical University of Ostrava 708 33 Ostrava-Poruba Czech Republic

This work was conducted to evaluate whether Ca-bearing additives used during coal combustion can also help with the retention of some other elements. This work was focused on the evaluation of bottom ashes collected during four full-scale combustion tests at an operating thermal fluidized-bed power station. Bottom ashes were preferred to fly ashes for the study to avoid interference from condensation processes usually occurring in the post-combustion zone. This work focused on the behaviors of S, Cl, Br, As, Mn, V, Cr, Ni, Cu,Zn, W, and Pb. Strong positive correlations with CaO content in bottom ashes were observed（for all four combustion tests） for S, As, Cl and Br（R = 0.917-0.999）. Strong inverse proportionality was calculated between the contents of Pb, Zn, Ni, Cr and Mn and CaO, so these elements showed association to materials other than Ca-bearing compounds（e.g., to aluminosilicates, organic matter, etc.）. Somewhat unclear behaviors were observed for W, Cu, and V. Their correlation coefficients were evaluated as statistically ＂not significant＂, i.e., these elements were not thought to be significantly associated with CaO. It was also discovered that major enrichment of CaO in the finest bottom ash fractions could be advantageously used for simple separation of elements strongly associated with these fractions, mainly S and As, but also Cl or Br. Removal of5% of the finest ash particles brings about a decrease in As concentration down to 77%-80% of its original bulk ash content, which can be conveniently used e.g., when high As content complicates further ash utilization.

关键词： Coal combustion Arsenic chlorine Bromine CaO Retention Fluidized-bed Trace elements

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Effects of O3/Cl2 disinfection on corrosion and opportunistic pathogens growth in drinking water distribution systems

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Journal of Environmental Sciences 2018年第11期30卷 38-46页

作者： Haibo Wang Chun Hu Suona Zhang Lizhong Liu Xueci Xing Key Laboratory of Drinking Water Science and Technology Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085 China Research Institute of Environmental Studies at Greater Bay School of Environmental Sciences and Engineering Guangzhou University Guangzhou 510006 China University of Chinese Academy of Sciences Beijing 100049 China

The effects of O3/Cl2 disinfection on corrosion and the growth of opportunistic pathogens in drinking water distribution systems were studied using annular reactors （ARs）. The corrosion process and most probable number （MPN） analysis indicated that the higher content of iron-oxidizing bacteria and iron-reducing bacteria in biofilms of the AR treated with O3/Cl2 induced higher Fe304 formation in corrosion scales. These corrosion scales became more stable than the ones that formed in the AR treated with Cl2 alone. O3/Cl2 disinfection inhibited corrosion and iron release efficiently by changing the content of corrosion-related bacteria. Moreover, ozone disinfection inactivated or damaged the opportunistic pathogens due to its strong oxidizing properties. The damaged bacteria resulting from initial ozone treatment were inactivated by the subsequent chlorine disinfection. Compared with the AR treated with Cl2 alone, the opportunistic pathogens M. auium and L. pneumophila were not detectable in effluents of the AR treated with O3/Cl2, and decreased to （4.60 ± 0.14） and （3.09 ± 0.12） loglo （gene copies/g corrosion scales） in biofilms, respectively. The amoeba counts were also lower in the AR treated with O3/Cl2. Therefore, O3/Cl2 disinfection can effectively control opportunistic pathogens in effluents and biofilms of an AR used as a model for a drinking water distribution system.

关键词： Ozone chlorine Corrosion Opportunistic pathogens Drinking water distribution systems

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