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Photocatalytic degradation of the dye sulforhodamine-B: A comparative study of different light sources

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Journal of Environmental Sciences 2007年第1期19卷 97-102页

作者： FANG Yan-fen HUANG Ying-ping LIU De-fu HUANG Yang GUO Wei david johnson Center for Ecologic and Environmental Science Three Gorges University Yichang 443000 China Department of Chemistry and Environment Sciences Ferrum College VA 24088 USA

The photocatalytic degradation of dye pollutant sulforhodamine-B （SRB） in aqueous titanium dioxide （TiO2） dispersions was examined under three lighting regimes： UV light （330 nm〈λ〈 380 nm）, sunlight, and visible light （λ〉450 nm）, all investigated at pH=2.5. Total organic carbon （TOC） and chemical oxygen demand （CODer） assays show that the degradation rate of SRB is much higher when irradiated with UV and sunlight compared with visible light. The temporal concentration changes of SRB illustrated a first-order reaction and the rate constant, k, is 0.197 min^-1, 0.152 min^-1, 0.027 min^-1, respectively, under the three lighting conditions. The final mineralized products were amine compounds identified by infrared spectrophotometry. When irradiated with visible light, the photocatalytic degradation rate could be improved by lowering the H2O2 concentration and inhibited by increasing the H2O2 concentration, but results contrary to the above were obtained when UV light was used for irradiation.

关键词： TiO2 photocatalytic degradation sulforhodamine-B (SRB)

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The Spin Torus Energy Model and Electricity

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Open Journal of Applied Sciences 2019年第6期9卷 451-479页

作者： david johnson Retired IT Lecturer Perth Australia

Defining the electron to be a toroidal form of concentrated energy rather than a monopole point-charge, such as used for the Orbital Nuclear Atomic Model (ONAM), leads to a subtly different explanation for electricity and the dynamic nature of electromagnetic fields. The Spin Torus Energy Model (STEM) is used to define the electron and positron, which are then used to explain the nature of electric and magnetic fields, electric current generation from battery and induction sources, capacitor charge and discharge, and superconductivity. STEM supports the notion that free positrons exist within matter, and are equal in importance to electrons: as ONAM makes no provision for positrons within matter, this assertion has wide ranging implications for atomic structure models and chemistry.

关键词： Electron Positron Bitron Electromagnetic Energy Chiral Torus Induction Electricity Electric Field Magnetic Field Electrostatic Charge Static Attraction Repulsion Capacitor Hole Superconductivity

Degradation of organic pollutants by a Co_3O_4 -graphite composite electrode in an electro-Fenton-like system

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Chinese Science Bulletin 2013年第19期58卷 2340-2346页

作者： LIU Shuan GU Yan WANG ShuLian ZHANG Yu FANG YanFen johnson david M HUANG YingPing Engineering Research Center of Eco-environment in Three Gorges Reservoir Region Ministry of EducationChina Three Gorges University Institute of Oceanology Chinese Academy of Sciences School of Natural Science & Mathematics Ferrum College

A novel composite electrode was constructed by pressing together Co3O4 and graphite and it was used as the cathode in an electro-Fenton-like (EFL) system. The poor electron transport characteristic of Co3O4 was overcome by incorporating graphite. In situ electro-catalytic generation of hydroxyl radicals (·OH) occurred at high current efficiencies from pH 2-10, extending the traditional Fenton reaction pH range. Cyclic voltammetry and AC impedance spectrometry were used to characterize the composite electrode. The ability of the EFL system to degrade organic compounds was investigated using sulforhodamine B (SRB) and 2,4-dichlorophenol (2,4-DCP) as probes. Decoloration of SRB (1.0×10-5 mol/L) was complete (100%) in 150 min and SRB was effectively degraded from pH 2-10. The decomposition of SRB was studied using Fourier transform infrared spectroscopy (FT-IR) and total organic carbon (TOC) analysis and results indicated that the final degradation products were carbon dioxide, carboxylic acids and amines. The EFL system also decomposed 2,4-DCP and the degradation was 98.6% in 240 min. Electro-catalytic degradation of SRB occurs by a ·OH mechanism. After 5 times reused, the degradation rate of SRB did not significantly slow down. The electrode shows excellent potential for use in advanced oxidation processes (AOPs) used to treat persistent organic pollutants (POPs) in wastewater.

关键词：污染物降解复合电极 L系统石墨傅里叶变换红外光谱 Fenton反应持久性有机污染物硫酸盐还原菌

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Independence Day

第二课堂(A) 2015年第7期 35-36页

作者： david johnson

导读:在中国,除了春节和中秋节等传统节日外,国庆节算是最重要的节日了。而在美国,除了感恩节和圣诞节等,7月4日的独立日也算得上最重要的节日。America celebrates July 4 as Independence Day because it was on July 4,1776,that mem... 详细信息

导读:在中国,除了春节和中秋节等传统节日外,国庆节算是最重要的节日了。而在美国,除了感恩节和圣诞节等,7月4日的独立日也算得上最重要的节日。America celebrates July 4 as Independence Day because it was on July 4,1776,that members of the Second Continental Congress,meeting in Philadelphia,signed the Declaration of Independence.

关键词： Hancock

A Sustainability Total Management Model Applied to the Product Life Cycle

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Management Studies 2017年第4期5卷 346-360页

作者： Anthony david johnson Seoul National University of Science and Technology Seoul S.Korea

In this worldwide consumer society the quest for new and more sophisticated products is ever present often leaving an unsustainable toll on the Earth＇s resources to the point where some commodities are reduced to levels of scarcity The growing challenge for product creators is to provide new products that have the least impact on the environment. The need for sustainable products is growing annually but often product creators are either unwilling to engage or are uninformed as to how to engage with the sustainable creation processes. There is a requirement for a cohesive management strategy that can both inform industrialists and provide the tools for the implementation of a sustainable approach to product design and the product life cycle. This paper reviews several publications and builds on previous work （johnson, Gibson, ＆ Barrans, 2011）, enhancing the commonly used Life Cycle Analysis （LCA） and creating a complete management strategy, which is the Sustainability Enhancement Program （SEP）. This incorporates ISO Standards as an operating platform. Embodied Energy （Ashby, 2012） is used as a metric by SEP so that the value of energy input within any product can be measured and reduced in the future product iterations.

关键词： sustainability Embodied Energy ISO 14001 ISO 14040 Environmental Management

Role of microbial dysbiosis in the pathogenesis of esophageal mucosal disease:A paradigm shift from acid to bacteria?

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World Journal of Gastroenterology 2021年第18期27卷 2054-2072页

作者： Steve M D'Souza Kevin Houston Lauren Keenan Byung Soo Yoo Parth J Parekh david a johnson Department of Internal Medicine Division of GastroenterologyEastern Virginia Medical SchoolNorfolkVA 23502United States

Genomic sequencing,bioinformatics,and initial speciation(e.g.,relative abundance)of the commensal microbiome have revolutionized the way we think about the“human”body in health and *** interactions between the gut bacteria and the immune system of the host play a key role in the pathogenesis of gastrointestinal diseases,including those impacting the *** relatively stable,there are a number of factors that may disrupt the delicate balance between the luminal esophageal microbiome(EM)and the *** changes are thought to be a product of age,diet,antibiotic and other medication use,oral hygiene,smoking,and/or expression of antibiotic products(bacteriocins)by other *** effects may lead to persistent dysbiosis which in turn increases the risk of local inflammation,systemic inflammation,and ultimately disease *** has suggested that the etiology of gastroesophageal reflux disease-related esophagitis includes a cytokine-mediated inflammatory component and is,therefore,not merely the result of esophageal mucosal exposure to corrosives(i.e.,acid).Emerging evidence also suggests that the EM plays a major role in the pathogenesis of disease by inciting an immunogenic response which ultimately propagates the inflammatory ***,we discuss the potential role for manipulating the EM as a therapeutic option for treating the root cause of various esophageal disease rather than just providing symptomatic relief(i.e.,acid suppression).

关键词： Microbiome Gastroesophageal reflux disease Probiotics Prebiotics Bacteriocins Dysbiosis Barrett’s esophagus Esophageal cancer Esophagitis Eosinophilic esophagitis

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德拉库拉：骇人听闻的真相

疯狂英语（初中天地） 2008年第10期 50-53页

作者： david johnson KC

一直以来,以吸血鬼为主角的文学和影视作品长盛不衰。这些恐怖但有着迷人魅力、似人非人的"生物"吸引着无数的读者和观众。随着"暮光之城"(The Twilight Saga)系列首部曲《暮色》(Twilight)中文版的推出,这股吸血鬼热潮更是有增无减。那... 详细信息

一直以来,以吸血鬼为主角的文学和影视作品长盛不衰。这些恐怖但有着迷人魅力、似人非人的"生物"吸引着无数的读者和观众。随着"暮光之城"(The Twilight Saga)系列首部曲《暮色》(Twilight)中文版的推出,这股吸血鬼热潮更是有增无减。那么,吸血鬼究竟是什么?历史上最广为人知的吸血鬼德拉库拉背后又藏着什么恐怖的真相?请看——

关键词：吸血鬼特兰西瓦尼亚罗马尼亚语民间传说修道院布拉姆

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