253 research outputs found
QXLA: Adding Upper Quantiles for the Studentized Range to Excel for Multiple Comparison Procedures
Microsoft Excel has some functionality in terms of basic statistics; however it lacks distribution functions built around the studentized range (Q). The developed Excel addin introduces two new user-defined functions, QDISTG and QINVG, based on the studentized range Q-distribution that expands the functionality of Excel for statistical analysis. A workbook example, demonstrating the Tukey, S-N-K, and REGWQ tests, has also been included. Compared with other options available, the method is fast with low error rates
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TREATMENT OF PLUTONIUM- AND URANIUM-CONTAMINATED OIL FROM ROCKY FLATS ENVIRONMENTAL TECHNOLOGY SITE
A removal method for plutonium and uranium has been tested at the Rocky Flats Environmental Technology Site (RFETS). This alternative treatment technology is applicable to U.S. Department of Energy (DOE) organics (mainly used pump oil) contaminated with actinides. In our studies, greater than 70% removal of the actinides was achieved. The technology is based on contacting the oil with a sorbent powder consisting of a surface modified mesoporous material. The SAMMS (Self-Assembled Monolayers on Mesoporous Support) technology was developed by the Pacific Northwest National Laboratory for removal and stabilization of RCRA (i.e., lead, mercury, cadmium, silver, etc.) and actinides in water and for removal of mercury from organic solvents [1, 2]. The SAMMS material is based on self-assembly of functionalized monolayers on mesoporous oxide surfaces. The unique mesoporous oxide support provides a high surface area, thereby enhancing the metal-loading capacity. The testing described in this report was conducted on a small scale but larger-scale testing of the technology has been performed on mercury-contaminated oil without difficulty [3]
Computer Model for Prediction of PCB Dechlorination and Biodegradation Endpoints,”
Mathematical modeling of polychlorinated biphenyl (PCB) transformation served as a means of predicting possible endpoints of bioremediation, thus allowing evaluation of several of the most common transformation patterns. Correlation between laboratory-observed and predicted endpoint data was, in some cases, as good as 0.98 (perfect correlation = 1.0)
Bio-Energy Production from Anaerobic Digestion of Animal and Farm Wastes
Track II: Transportation and BiofuelsIncludes audio file (20 min.)US produces annually huge amount of animal and farm wastes (e.g. only cow manure in amount of about 1.8 billion tons). These wastes can be valuable source of renewable energy besides overcoming the environmental problems caused by them such as greenhouse gas effect of methane emission of 22 times worse than carbon dioxide, surface and ground water contamination, odor, dust, ammonia leaching, etc. In this project we systematically studied the process, kinetics, microorganisms interaction and population, and the effects of design and operating parameters on reactor design and scale up of cow manure digestion for bioenergy production and for wastes treatment by developing and implementing advanced imaging, visualization and computational techniques such as computational fluid dynamics (CFD), novel multiple radioactive particles tracking technique (MRPT), novel dual source computed tomography (DSCT), and microbiology imaging techniques. New design and conditions of anaerobic digesters that can reduce significantly the inactive volume and improve the digesters performance have been identified and recommended. In addition, for the first time, the energy produced has been related to the energy introduced in order to maximize the energy output while minimizing the energy input through the mixing power consumed. It is hoped that the findings will be applied in the field to promote bioenergy production and eliminate major environmental pollution problems
Methane Production in a 100-L Upflow Bioreactor by Anaerobic Digestion of Farm Waste
Manure Waste from Dairy Farms Has Been Used for Methane Production for Decades, However, Problems Such as Digester Failure Are Routine. the Problem Has Been Investigated in Small Scale (1-2 L) Digesters in the Laboratory; However, Very Little Scale-Up to Intermediate Scales Are Available. We Report Production of Methane in a 100-L Digester and the Results of an Investigation into the Effect of Partial Mixing Induced by Gas Upflow/recirculation in the Digester. the Digester Was Operated for a Period of About 70 D (With 16-D Hydraulic Retention Time) with and Without the Mixing Induced by Gas Recirculation through an Internal Draft Tube. the Results Show a Clear Effect of Mixing on Digester Operation. Without Any Mixing, the Digester Performance Deteriorated within 30-50 D, Whereas with Mixing Continuous Production of Methane Was Observed. This Study Demonstrates the Importance of Mixing and its Critical Role in Design of Large-Scale Anaerobic Digesters. Copyright © 2006 by Humana Press Inc. All Rights of Any Nature Whatsoever Reserved
Mesophilic Digestion Kinetics of Manure Slurry
Anaerobic Digestion Kinetics Study of Cow Manure Was Performed at 35°C in Bench-Scale Gas-Lift Digesters (3.78 L Working Volume) at Eight Different Volatile Solids (VS) Loading Rates in the Range of 1.11-5.87 G L-1 Day-1. the Digesters Produced Methane at the Rates of 0.44-1.18 L L-1 Day-1, and the Methane Content of the Biogas Was Found to Increase with Longer Hydraulic Retention Time (HRT). based on the Experimental Observations, the Ultimate Methane Yield and the Specific Methane Productivity Were Estimated to Be 0.42 L CH4 (G vs. Loaded)-1 and 0.45 L CH4 (G vs. Consumed)-1, Respectively. Total and Dissolved Chemical Oxygen Demand (COD) Consumptions Were Calculated to Be 59-17% and 78-43% at 24.4-4.6 Days HRTs, respectively. Maximum Concentration of Volatile Fatty Acids in the Effluent Was Observed as 0.7 G L-1 at 4.6 Days HRT, While It Was Below Detection Limit at HRTs Longer Than 11 Days. the Observed Methane Production Rate Did Not Compare Well with the Predictions of Chen and Hashimoto\u27s [1] and Hill\u27s [2] Models using their Recommended Kinetic Parameters. However, under the Studied Experimental Conditions, the Predictions of Chen and Hashimoto\u27s [1] Model Compared Better to the Observed Data Than that of Hill\u27s [2] Model. the Nonlinear Regression Analysis of the Experimental Data Was Performed using a Derived Methane Production Rate Model, for a Completely Mixed Anaerobic Digester, Involving Contois Kinetics [3] with Endogenous Decay. the Best Fit Values for the Maximum Specific Growth Rate (Μm) and Dimensionless Kinetic Parameter (K) Were Estimated as 0.43 Day-1 and 0.89, Respectively. the Experimental Data Were Found to Be within 95% Confidence Interval of the Prediction of the Derived Methane Production Rate Model with the Sum of Residual Squared Error as 0.02. © Humana Press Inc. 2007
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Mercury separation from aqueous wastes
This project is providing an assessment of new sorbents for removing mercury from wastes at US Department of Energy sites. Four aqueous wastes were chosen for lab-scale testing; a high-salt, acidic waste currently stored at Idaho National Engineering Laboratory (INEL); a high-salt, alkaline waste stored at the Savannah River Site (SRS); a dilute lithium hydroxide solution stored at the Oak Ridge Y-12 Plant; and a low-salt, neutral groundwater generated at the Y-12 Plant. Eight adsorbents have been identified for testing, covering a wide range of cost and capability. Screening tests have been completed, which identified the most promising adsorbents for each waste stream. Batch isotherm tests have been completed using the most promising adsorbents, and column tests are in progress. Because of the wide range of waste compositions tested, no one adsorbent is effective in all of these waste streams. Based on loading capacity and compatibility with the waste solutions. the most effective adsorbents identified to date are SuperLig 618 for the INEL tank waste stimulant; Mersorb followed by lonac SR-3 for the SRS tank waste stimulant; Durasil 70 and Ionac SR-3) for the LIOH solution; and lonac SR-3 followed by lonac SR-4 and Mersorb for the Y-12 groundwater
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Reaching Part Per Trillion Clean-Up Criteria for Mercury in Water
In the last couple of years, emphasis on environmental mercury contamination and elimination of mercury use has increased. The U.S. Department of Energy has for many decades maintained a stockpile of elemental mercury for operations and, as a consequence of its routine use, spills have occurred. These historical spills have resulted in some contamination of water streams and soils. In this work we examine a newly developed technique for removal of mercury from contaminated groundwater. In this application the mercury concentration was approximately 2.3 parts per billion and the treatment criterion was 200 parts per trillion. Several forms of mercury species contributed to the contamination. The treatment technique developed for this water was to convert all forms of mercury, through a series of fast chemical reactions, to elemental mercury, which was air-stripped from the water. This paper presents preliminary laboratory work on the method
Circulating neurofilament light in ischemic stroke: temporal profile and outcome prediction
BACKGROUND AND PURPOSE: Neurofilament light chain (NfL) is a marker of neuroaxonal damage. We aimed to study associations between serum NfL (sNfL) concentrations at different time points after ischemic stroke and outcomes. // METHODS: We prospectively included ischemic stroke cases (n = 595, mean age 59 years, 64% males) and assessed outcomes by both the modified Rankin Scale (mRS) and the NIH stroke scale (NIHSS) at 3 months and by mRS at 2 years. In a subsample, long-term (7-year) outcomes were also assessed by both mRS and NIHSS. We used the ultrasensitive single-molecule array assay to measure sNfL in the acute phase (range 1-14, median 4 days), after 3 months and 7 years in cases and once in controls (n = 595). // RESULTS: Acute-phase sNfL increased by the time to blood-draw and highest concentrations were observed at 3 months post-stroke. High sNfL associated to stroke severity and poor outcomes, and both associations were strongest for 3-month sNfL. After adjusting for age, previous stroke, stroke severity, and day of blood draw, 3-month sNfL was significantly associated to both outcomes at all time points (p < 0.01 throughout). For all main etiological subtypes, both acute phase and 3-month sNfL were significantly higher than in controls, but the dynamics of sNfL differed by stroke subtype. // CONCLUSIONS: The results from this study inform on sNfL in ischemic stroke and subtypes over time, and show that sNfL predicts short- and long-term neurological and functional outcomes. Our findings suggest a potential utility of sNfL in ischemic stroke outcome prediction
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