294 research outputs found

    Method and apparatus for destroying organic compounds in fluid

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    An apparatus for the photocatalytic oxidation of organic contaminants in fluid includes a reactor and a photocatalyst affixed to support material. Preferably, the outer wall of the reactor is constructed of material transmissive of ultraviolet radiation. The support material preferably is transmissive of ultraviolet radiation. The support material can also be an adsorbent material. Also, a method for photocatalytic oxidation of organic contaminants in fluid. Also, a method for preparation of a supported photocatalyst. Also, a supported photocatalyst adapted for the photocatalytic oxidation of organic contaminants in fluid. Also, a method for preparing a photocatalyst adapted for the photocatalytic oxidation of organic contaminants in fluid.https://digitalcommons.mtu.edu/patents/1071/thumbnail.jp

    Regeneration of adsorbents using advanced oxidation

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    The present invention is a method of purifying fluid having organic material. The method comprises two operational steps. The first step includes passing the fluid through an adsorbent such that the organic material is substantially adsorbed by the adsorbent and the fluid is substantially purified. The second step includes destroying the adsorbed organic material on the adsorbent and regenerating the adsorbent in a form substantially free of adsorbed organic material.https://digitalcommons.mtu.edu/patents/1115/thumbnail.jp

    VRA Modeling, phase 1

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    The destruction of organic contaminants in waste water for closed systems, such as that of Space Station, is crucial due to the need for recycling the waste water. A co-current upflow bubble column using oxygen as the gas phase oxidant and packed with catalyst particles consisting of a noble metal on an alumina substrate is being developed for this process. The objective of this study is to develop a plug-flow model that will predict the performance of this three phase reactor system in destroying a multicomponent mixture of organic contaminants in water. Mass balances on a series of contaminants and oxygen in both the liquid and gas phases are used to develop this model. These mass balances incorporate the gas-to-liquid and liquid-to-particle mass transfer coefficients, the catalyst effectiveness factor, and intrinsic reaction rate. To validate this model, a bench scale reactor has been tested at Michigan Technological University at elevated pressures (50-83 psig,) and a temperature range of 200 to 290 F. Feeds consisting of five dilute solutions of ethanol (approx. 10 ppm), chlorobenzene (approx. 20 ppb), formaldehyde (approx. 100 ppb), dimethyl sulfoxide (DMSO approx. 300 ppb), and urea (approx. 20 ppm) in water were tested individually with an oxygen mass flow rate of 0.009 lb/h. The results from these individual tests were used to develop the kinetic parameter inputs necessary for the computer model. The computer simulated results are compared to the experimental data obtained for all 5 components run in a mixture on the differential test column for a range of reactor contact times

    Development of a Rational Modeling Approach for the Design, and Optimization of the Multifiltration Unit

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    This thesis includes the development and verification of an adsorption model for analysis and optimization of the adsorption processes within the International Space Station multifiltration beds. The fixed bed adsorption model includes multicomponent equilibrium and both external and intraparticle mass transfer resistances. Single solute isotherm parameters were used in the multicomponent equilibrium description to predict the competitive adsorption interactions occurring during the adsorption process. The multicomponent equilibrium description used the Fictive Component Analysis to describe adsorption in unknown background matrices. Multicomponent isotherms were used to validate the multicomponent equilibrium description. Column studies were used to develop and validate external and intraparticle mass transfer parameter correlations for compounds of interest. The fixed bed model was verified using a shower and handwash ersatz water which served as a surrogate to the actual shower and handwash wastewater

    WISE/NEOWISE Observations of Comet 103P/Hartley 2

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    We report results based on mid-infrared photometry of comet 103P/Hartley 2 taken during 2010 May 4-13 (when the comet was at a heliocentric distance of 2.3 AU, and an observer distance of 2.0 AU) by the Wide-field Infrared Survey Explorer. Photometry of the coma at 22 Ī¼m and data from the University of Hawaii 2.2 m telescope obtained on 2010 May 22 provide constraints on the dust particle size distribution, d log n/d log m, yielding power-law slope values of alpha = ā€“0.97 Ā± 0.10, steeper than that found for the inbound particle fluence during the Stardust encounter of comet 81P/Wild 2. The extracted nucleus signal at 12 Ī¼m is consistent with a body of average spherical radius of 0.6 Ā± 0.2 km (one standard deviation), assuming a beaming parameter of 1.2. The 4.6 Ī¼m band signal in excess of dust and nucleus reflected and thermal contributions may be attributed to carbon monoxide or carbon dioxide emission lines and provides limits and estimates of species production. Derived carbon dioxide coma production rates are 3.5(Ā± 0.9) Ɨ 10^(24) molecules per second. Analyses of the trail signal present in the stacked image with an effective exposure time of 158.4 s yields optical-depth values near 9 Ɨ 10^(ā€“10) at a delta mean anomaly of 0.2 deg trailing the comet nucleus, in both 12 and 22 Ī¼m bands. A minimum chi-squared analysis of the dust trail position yields a beta-parameter value of 1.0 Ɨ 10^(ā€“4), consistent with a derived mean trail-grain diameter of 1.1/Ļ cm for grains of Ļ g cm^(ā€“3) density. This leads to a total detected trail mass of at least 4 Ɨ 10^(10) Ļ kg

    The poverty of contractarian moral education

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    In A Theory of Moral Education, Michael Hand claims that a directive moral education that seeks to persuade children that a particular conception of contractarian morality is justified can be undertaken without falling foul of the requirement not to indoctrinate. In this article, we set out a series of challenges to Handā€™s argument. First, we argue that Handā€™s focus on ā€˜reasonable disagreementā€™ regarding the status of a moral conception is a red-herring in this conception. Second, we argue that the endorsement of moral contractarianism and the prohibition on indoctrination pull in different directions: if contractarianism is sound, then teachers or governments should be less worried about indoctrination than Hand suggests. Third, we argue that moral contractarianism is mistaken; teachers should look elsewhere for guidance on the moral norms and principles towards which they should direct their pupils

    Evaluating cutpoints for the MHI-5 and MCS using the GHQ-12: a comparison of five different methods

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    Background The Mental Health Inventory (MHI-5) and the Mental Health Component Summary score (MCS) derived from the Short Form 36 (SF-36) instrument are well validated and reliable scales. A drawback of their construction is that neither has a clinically validated cutpoint to define a case of common mental disorder (CMD). This paper aims to produce cutpoints for the MHI-5 and MCS by comparison with the General Health Questionnaire (GHQ-12). Methods Data were analysed from wave 9 of the British Household Panel Survey (2000), providing a sample size of 14,669 individuals. Receiver Operating Characteristic (ROC) curves were used to compare the scales and define cutpoints for the MHI-5 and MCS, using the following optimisation criteria: the Youden Index, the point closest to (0,1) on the ROC curve, minimising the misclassification rate, the minimax method, and prevalence matching. Results For the MHI-5, the Youden Index and the (0,1) methods both gave a cutpoint of 76, minimising the misclassification rate gave a cutpoint of 60 and the minimax method and prevalence matching gave a cutpoint of 68. For the MCS, the Youden Index and the (0,1) methods gave cutpoints of 51.7 and 52.1 respectively, minimising the error rate gave a cutpoint of 44.8 and both the minimax method and prevalence matching gave a cutpoint of 48.9. The correlation between the MHI-5 and the MCS was 0.88. Conclusion The Youden Index and (0,1) methods are most suitable for determining a cutpoint for the MHI-5, since they are least dependent on population prevalence. The choice of method is dependent on the intended application. The MHI-5 performs remarkably well against the longer MCS
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