2,212 research outputs found

    Effect of organic solvents on the separation of benzoic acids by capillary electrophoresis

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    The effect of organic modifiers on the separation of a number of closely related isomeric benzoic acids by capillary electrophoresis is described. It is shown that while a single modifier concentration cannot help resolve the entire electropherogram, organic modifiers do significantly enhance the resolution of parts of the separation system by comparison with 40 mmol l-1 phosphate buffer. The effects on separation and retention times are discussed in terms of the effects on electroosmotic flow and the electrophoretic mobilities of the charged solutes. The effects were found to be modifier specific, although the trends were in the same direction (ie., decreasing electroosmotic flow with increased percentage of organic modifier). The major influence is the manipulation of the electroosmotic mobility

    Heavy ion induced Single Event Phenomena (SEP) data for semiconductor devices from engineering testing

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    The accumulation of JPL data on Single Event Phenomena (SEP), from 1979 to August 1986, is presented in full report format. It is expected that every two years a supplement report will be issued for the follow-on period. This data for 135 devices expands on the abbreviated test data presented as part of Refs. (1) and (3) by including figures of Single Event Upset (SEU) cross sections as a function of beam Linear Energy Transfer (LET) when available. It also includes some of the data complied in the JPL computer in RADATA and the SPACERAD data bank. This volume encompasses bipolar and MOS (CMOS and MHNOS) device data as two broad categories for both upsets (bit-flips) and latchup. It also includes comments on less well known phenomena, such as transient upsets and permanent damage modes

    The Ursinus Weekly, December 19, 1902

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    Literary department: Poetry and philosophy • Immensee • A pipe dream • Philadelphia letter • Schaff Society • Among the colleges • National Civil Service Reform League • Alumni notes • Week in Congresshttps://digitalcommons.ursinus.edu/weekly/3068/thumbnail.jp

    Removal of carbamazepine and sulfamethoxazole by MBR under anoxic and aerobic conditions

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    This study reveals for the first time that near-anoxic conditions (dissolved oxygen, DO - 0.5 mg/L) can be a favorable operating regime for the removal of the persistent micropollutant carbamazepine by MBR treatment. The removal efficiencies of carbamazepine and sulfamethoxazole by an MBR were systematically examined and compared under near-anoxic (DO\u27 0.5 mg/L) and aerobic (DO\u3e 2 mg/L) conditions. Preliminary batch tests confirmed that sulfamethoxazole is amenable to both aerobic and anoxic biotransformation. However, carbamazepine-a known persistent compound-showed degradation only under an anoxic environment. In good agreement with the batch tests, during near-anoxic operation, under a high loading of 750 J.l8 /Ld, an exceptionally high removal (68 ± 10%) of carbamazepine was achieved. In contrast, low removal efficiency (12 ± 11%) of carbamazepine was observed during operation under aerobic conditions. On the other hand, an average removal efficiency of 65% of sulfamethoxazole was achieved irrespective of the DO concentrations

    Impact of humic acid fouling on membrane performance and transport of pharmaceutically active compounds in forward osmosis

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    The impact of humic acid fouling on the membrane transport of two pharmaceutically active compounds (PhACs) - namely carbamazepine and sulfamethoxazole - in forward osmosis (FO) was investigated. Deposition of humic acid onto the membrane surface was promoted by the complexation with calcium ions in the feed solution and the increase in ionic strength at the membrane surface due to the reverse transport of NaCl draw solute. The increase in the humic acid deposition on the membrane surface led to a substantial decrease in the membrane salt (NaCl) permeability coefficient but did not result in a significant decrease in the membrane pure water permeability coefficient. As the deposition of humic acid increased, the permeation of carbamazepine and sulfamethoxazole decreased, which correlated well with the decrease in the membrane salt (NaCl) permeability coefficient. It is hypothesized that the hydrated humic acid fouling layer hindered solute diffusion through the membrane pore and enhanced solute rejection by steric hindrance, but not the permeation of water molecules. The membrane water and salt (NaCl) permeability coefficients were fully restored by physical cleaning of the membrane, suggesting that humic acid did not penetrate into the membrane pores

    Water extraction from mixed liquor of an aerobic bioreactor by forward osmosis: membrane fouling and biomass characteristics assessment

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    This study investigated membrane fouling and biomass characteristics during water extraction from mixed liquor of an aerobic bioreactor by a submerged forward osmosis (FO) system. As the sludge concentration in the reactor increased from 0 to 20 g/L, fouling of the FO membrane increased but was much less severe than that of a reference microfiltration membrane. The results also indicate that aeration can be used to effectively control membrane fouling. By increasing the draw solute concentration, as expected, the initial water flux was increased. However, there appears to be a critical water flux above which severe membrane fouling was encountered. A short-term osmotic membrane bioreactor experiment showed build-up of salinity in the bioreactor due to the reverse draw solute transport and inorganic salts rejection by the FO membrane. Salinity build-up in the bioreactor reduced the permeate flux and sludge production, and at the same time, altered the biomass characteristics, leading to more soluble microbial products and less extracellular polymeric substances in the microbial mass. Additionally, the inhibitory effects of the increased salinity on biomass and the high rejection capacity of FO led to the build-up of ammonia and ortho-phosphate in the bioreactor

    General Aviation Trends in the European Market Memorandum Report

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    In 1969, as western Europe was becoming a common market, significant economic growth was projected. His Highness, The Aga Kahn requested that Economics Research Associates (ERA) perform a memorandum report and forecast the trends for private aviation potentials in Europe over the decade of the 1970s. The resulting report by ERA reviews the history of European aviation, current and future economic trends in the common European market area as these pertain to the growth of private aviation, advantages and disadvantages involved in noncommercial flying, and future trends in private aviation. Data was gathered from such sources as aviation publications, interviews with persons connected with private aviation, and market studies and projections of commercial organizations. The report includes the following sections: 1) introduction, 2) summary and conclusions, 3) the western European economy, 4) general aviation, 5) general aviation and future trends in aviation design, 6) impact of general aviation on tourism. The report includes four tables
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