Post-run Analysis Research Articles

New trends in the analytical determination of emerging contaminants and their transformation products in environmental waters

Since the so-called emerging contaminants were established as a new group of pollutants of environmental concern, a great effort has been devoted to the knowledge of their distribution, fate and effects in the environment. After more than 20 years of work, a significant improvement in knowledge about these contaminants has been achieved, but there is still a large gap of information on the growing number of new potential contaminants that are appearing and especially of their unpredictable transformation products. Although the environmental problem arising from emerging contaminants must be addressed from an interdisciplinary point of view, it is obvious that analytical chemistry plays an important role as the first step of the study, as it allows establishing the presence of chemicals in the environment, estimate their concentration levels, identify sources and determine their degradation pathways. These tasks involve serious difficulties requiring different analytical solutions adjusted to purpose. Thus, the complexity of the matrices requires highly selective analytical methods; the large number and variety of compounds potentially present in the samples demands the application of wide scope methods; the low concentrations at which these contaminants are present in the samples require a high detection sensitivity, and high demands on the confirmation and high structural information are needed for the characterisation of unknowns. New developments on analytical instrumentation have been applied to solve these difficulties. Furthermore and not less important has been the development of new specific software packages intended for data acquisition and, in particular, for post-run analysis. Thus, the use of sophisticated software tools has allowed successful screening analysis, determining several hundreds of analytes, and assisted in the structural elucidation of unknown compounds in a timely manner.

Tribological Testing and Thermal Analysis of an Alkyl Sulfate Series of Ionic Liquids for Use as Aerospace Lubricants

Due to their low vapor pressures, low melting points, high boiling points, high radiation resistance, and high thermal stability, room-temperature ionic liquids (ILs) appear to be suitable candidates as new aerospace lubricants for the upcoming return to the Moon and eventual Mars missions and for air and rotorcraft applications. In this study, three ILs with the same cation, 1-butyl-3-methylimidazolium, but different sulfate anions were tested using an ultra-high vacuum spiral orbit tribometer (SOT) and their thermal properties were determined by thermogravimetric analysis (TGA). Specifically, 1-butyl-3-methylimidazolium methyl sulfate, 1-butyl-3-methylimidazolium ethyl sulfate, and 1-butyl-3-methylimidazolium octyl sulfate were tested. The SOT experiments revealed that the lifetimes of the three ILs decreased with increasing alkyl substituent length on the sulfate anion. Infrared and Raman spectra were taken to detect unused ILs and graphitic degradation products, respectively, on worn parts. Post-run spectroscopic analysis indicated residual degraded, but still usable, ILs in all runs, coupled with varying amounts of amorphous graphitic material produced as the final degradation product of all ILs. SOT testing indicated that these ILs have lower friction coefficients and lifetimes greater than those of two commonly used perfluoropolyalkylether (PFPE) space lubricants. TGA showed that the methyl sulfate IL had the highest thermal stability in air and nitrogen. The vapor pressure of the methyl sulfate IL is as at least as low as Fomblin 815Z at 20°C.

Interactive monitoring portal for fusion simulations

The Center for Simulation of RF Wave Interactions with Magnetohydrodynamics (SWIM) Project is a proto-Fusion Simulation Program (FSP) whose goal is to study high-performance fusion plasmas and perform comprehensive simulations that are essential to the development of fusion. SWIM team members are geographically distributed and utilize distributed supercomputers for computational simulations. Due to the highly distributed computational work environment, the SWIM team has the difficulty of monitoring code runs and discovering historical runs. To alleviate this difficulty a web-based monitoring portal has been developed and deployed.The monitoring portal tracks the progress of simulations and automatically collects metadata in real-time. This capability helps scientists to effectively utilize precious computer resources. Furthermore, the portal provides a web-based interface for post-run analysis, such as visualizing the results, logging the user comments, and rating the simulation quality. The user interface provides rapid discovery capability via multi-field searching and sorting.The development of the monitoring portal used open source software, such as Python, Django, MySQL, and Apache. It uses MDSplus for data management, Memcached for data caches, and OpenID for single sign-on security.This paper describes the software architecture, related technologies and deployment experiences of the monitoring portal.

Delegation-Based I/O Mechanism for High Performance Computing Systems

Massively parallel applications often require periodic data checkpointing for program restart and post-run data analysis. Although high performance computing systems provide massive parallelism and computing power to fulfill the crucial requirements of the scientific applications, the I/O tasks of high-end applications do not scale. Strict data consistency semantics adopted from traditional file systems are inadequate for homogeneous parallel computing platforms. For high performance parallel applications independent I/O is critical, particularly if checkpointing data are dynamically created or irregularly partitioned. In particular, parallel programs generating a large number of unrelated I/O accesses on large-scale systems often face serious I/O serializations introduced by lock contention and conflicts at file system layer. As these applications may not be able to utilize the I/O optimizations requiring process synchronization, they pose a great challenge for parallel I/O architecture and software designs. We propose an I/O mechanism to bridge the gap between scientific applications and parallel storage systems. A static file domain partitioning method is developed to align the I/O requests and produce a client-server mapping that minimizes the file lock acquisition costs and eliminates the lock contention. Our performance evaluations of production application I/O kernels demonstrate scalable performance and achieve high I/O bandwidths.

Photocathode behavior during high current running in the Cornell energy recovery linac photoinjector

The Cornell University energy recovery linac (ERL) photoinjector has recently demonstrated operation at 20 mA for approximately 8 hours, utilizing a multialkali photocathode deposited on a Si substrate. We describe the recipe for photocathode deposition, and will detail the parameters of the run. Post-run analysis of the photocathode indicates the presence of significant damage to the substrate, perhaps due to ion back-bombardment from the residual beam line gas. While the exact cause of the substrate damage remains unknown, we describe multiple surface characterization techniques (x-ray fluorescence spectroscopy, x-ray diffraction, atomic force, and scanning electron microscopy) used to study the interesting morphological and crystallographic features of the photocathode surface after its use for high current beam production. Finally, we present a simple model of crystal damage due to ion back-bombardment, which agrees qualitatively with the distribution of damage on the substrate surface.

Flow Cytometric Detection of Minimal Residual Disease In Acute Myeloid Leukemia – the Addition of hMICL and CD123 Add to Sensitivity and Applicability

AbstractAbstract 2719The outcome of acute myeloid leukemia (AML) is strongly correlated to the extent of minimal residual disease (MRD) at remission. Fusion transcripts, over-expressed genes and mutated genes have been employed in MRD quantification by RQ-PCR and are applicable for 30%–80% of all patients. More recently, flow cytometry (FCM) has been implemented as an additional tool for MRD detection employing strict gating criteria in detection of so-called leukemia associated aberrant immunophenotypes (LAIPs). In line with data from the Schuurhuis group we have identified human Myeloid Inhibitory C-type lectin (hMICL) as a candidate for AML marking at diagnosis and stable expression at relapse in a consecutive study of more than 150 patients. Importantly, we found expression of hMICL in the progenitor populations (defined as CD34+CD38- or CD117+CD38-) in AML cases. This contrasts to its absence on nearly all hematopoietic progenitors in healthy individuals and its lack of expression in acute lymphoblastic leukemia patients. Given that CD123 is also expressed in the vast majority of AML blasts at diagnosis and is characterized as a myeloid progenitor marker we hypothesized that the combination of hMICL and CD123 might serve as widely applicable MRD markers in AML and as such improve sensitivity for this approach. We performed a prospective study encompassing 38 patients with 74 follow up samples. Importantly, the assay was performed in strict parallel with other LAIPs, i.e. with no special provisions for the new markers. This FCM assay correlated strongly (88%) to available data from the most sensitive RQ-PCR marker of a series of molecular aberrations (p=0.37, McNemars chi^2 test), and that, the MRD detection and consequently reduced qualitative discordance resulted from a fourfold reduction of patients with FCM negative results but positive RQ-PCR result (table 1). The quantitative correlation coefficient between RQ-PCR and FCM increased from 0.46 to 0.7 by addition of hMICL and CD123 (figure 1).When sensitivities of the FCM assay were directly compared to those of validated RQ-PCR assays it was apparent that that of the FCM was inferior. However, it was still in the range in which it strongly predicted treatment failure. Undoubtedly, running more cells and samples and by employing more stringent gating and post-run analyses will further improve this strategy. However, given that treatment failures in AML are apparent by WT1 RQ-PCR with sensitivities at the 1; 1.000 range, the standard hMICL/CD123 assay should suffice in the vast majority of situations. We conclude that high-density expression of both hMICL and CD123 in the vast majority of AML cases at diagnosis and stable expression during the course of the disease combined with high sensitivity holds the potential for wide applicability and improved MRD monitoring by FCM using setup and interpretation not requiring special attention. This assay promises to be of great value in fast and efficient management of all AML patients. [Display omitted] Disclosure:No relevant conflicts of interest to declare.

INTEGRATING DISPARATE ANALYTICAL INSTRUMENTATION INTO AN AUTOMATED PROCESS CONTROL SYSTEM USED IN CELL CULTURE PROCESS DEVELOPMENT

Abstract This case study of a cell culture process development lab shows how various common analytical instruments were quickly and effectively integrated into a comprehensive process control and data management system. Streaming time-stamped results from these instruments directly into the process control system enabled automated real-time feedback and advanced characterizations of cell viability, instead of being limited to off-line, post-run analysis. Under the Ferm Works process control and data management software, drivers for instruments such as Cedex Cell Analyzer, YSI 2700 Biochemistry Analyzer, Bayer Blood Gas Analyzer and several other custom-made analytical instruments were easily added to the existing network of bioreactors and their hardware controllers (DCUs).

The Knoevenagel reaction: analysis and recycling of the ionic liquid medium

A study involving the scope of substrate in the Knoevenagel reaction in an IL medium has been conducted. Reactivity trends favor formation of the condensation product using electron deficient aryl aldehydes. Use of electron rich aldehydes and ketones lead to lower levels of conversion and no measurable amounts of condensation products, respectively. A recycling study confirmed that the reaction medium could be used multiple times affording, with each run, the desired condensation product 1a in excess of 90% conversion. Post-run analyses of the IL documented that the IL medium was unaltered upon reuse.

Near-IR imaging system for measuring temperatures in a low-NOx combustor

A system to measure temperatures O(1500K) in the fused quartz liner of a research combustor is discussed. A standard black/white charge-coupled device camera was used with an 800nm bandpass filter to thermally image high-emissivity paint strips on the inside and outside surfaces of the liner, a requirement for heat-flow model evaluations. Signals were viewed in real time with a framegrabber and simultaneously recorded to videotape for postrun analysis. This system is inexpensive compared to commercial mid- and long-wave IR thermal imagers and more sensitive to temperature differences through the use of bandpass filters for spectral selection of near-infrared wavelengths.

Steam Alternating Solvent Process: Lab Test and Simulation

Abstract A new heavy oil recovery process, the Steam Alternating Solvent (SAS) process, is studied by lab experiments and corresponding numerical simulation. The SAS process involves injecting steam and solvent alternately, using well configurations similar to those in the SAGD process. This process is designed to combine the advantages of the SAGD and VAPEX processes to minimize the energy input in heavy oil and bitumen recovery. Lab experiments were conducted using a 2D high-pressure/ high-temperature model. One baseline SAGD test and one SAS test were performed using an oil sample from Burnt Lake. A mixture of propane and methane was used as the solvent in the SAS test. The results showed that the energy input in the SAS process was 47% lower than that of the SAGD process for recovering the same amount of oil. The post-run analysis revealed that asphaltene precipitation occurred in the porous medium. Numerical history matching of the test data using Computer Modelling Group's STARS reservoir simulator captured the main features of the process. Introduction The main obstacle to producing oil from the large deposits of heavy oil and bitumen resources in northern Alberta is the high viscosity of these oils, usually over 10,000 mPa's at reservoir conditions. There are generally two types of methods for the reduction of oil viscosity. The first is to increase oil temperature by injecting a hot fluid, such as steam, into the reservoir, or by in situ combustion through the injection of oxygen-containing gas. The second method is to dilute the viscous oil by injecting low viscosity hydrocarbons (solvent). As the solvent dissolves and mixes with the viscous oil, the lower viscosity solvent-diluted oil can then be recovered. Two processes, Steam Assisted Gravity Drainage (SAGD) and Vapour Extraction (VAPEX), have been developed for the recovery of heavy oil and bitumen resources(1–3) based on the combination of the above viscosity reduction methods and horizontal well technology. The first has been successfully tested in the field and is moving to commercial scale application(4, 5). The second is presently in the initial field-testing stage(6). The advantage of the SAGD process is its relatively higher oil production rate. However, the higher production rate is associated with significant energy requirements, CO2 generation, and costly water treatment. The VAPEX process has the advantage of lower energy consumption, therefore, less CO2 generation. The major predicted drawback of the VAPEX process, however, is its relatively lower oil production rate. In the past several years, modifications, such as ES-SAGD(7) and SAGP(8), have been proposed to improve SAGD's energy efficiency. In the ES-SAGD process, a small amount of solvent with a boiling temperature matching the steam temperature is coinjected with steam to increase the oil production rate. In the SAGP process, non-condensable gas is co-injected with steam for the purpose of reducing heat loss to the overburden. Recent studies(9, 10) have indicated that the economics of a SAGD project are more sensitive to the energy consumption per unit of oil production than to the oil production rate.

Continuous Borehole-Curvature Estimates Based on Downhole Bending-Moment Measurements

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 90794, "Continuous Borehole-Curvature Estimates While Drilling Based on Downhole Bending-Moment Measurements," by G. Heisig, SPE, Baker Hughes Inteq; G. Cavallaro, Eni SpA Div. E&P; and P. Jogi, SPE, J. Hood, SPE, and I. Forstner, SPE, Baker Hughes Inteq, prepared for the 2004 SPE Annual Technical Conference and Exhibition, Houston, 26-29 September. A downhole bending-moment measurement combined with a simple mathematical model can provide a good estimate of well-bore curvature, matching results obtained from survey-data analysis well. The bending-moment measurement delivers well-bore-curvature information at a much higher resolution than the standard minimum-curvature method that assumes a constant curvature between survey stations. Introduction Any drilling bottomhole assembly (BHA) in a directional wellbore is subjected to bending moments caused by side forces acting on the BHA. These side forces may be caused by gravity, by dynamic effects, or by wall contacts of the BHA in curved wellbore sections. Mathematical models have been developed to predict the side forces, bending moments, and stresses that are introduced into a BHA by a given borehole-curvature profile, usually derived from measured survey data. The full-length paper discusses application of mathematical models to predict the borehole curvature from measured bending-moment data. The bending-moment data were acquired with a recently introduced drilling-dynamics tool in a variety of different applications and tool configurations including rotary-steerable systems (RSSs) and steerable-motor BHAs. The bending-moment data can be both transmitted to the surface while drilling and recorded in on-board memory for post-run processing and detailed analysis.

Brønsted acidic ionic liquids: the dependence on water of the Fischer esterification of acetic acid and ethanol

Initial studies involving the Fischer esterification of acetic acid utilizing task specific ionic liquid (TSIL) 1 and ethanol revealed an interesting trend when comparing overall conversions with the level of reuse. A rise in product yield was observed up to the third recycling of the ionic liquid (IL) medium. Post-run analyses revealed that the TSIL remained unchanged and the by-products of the reaction, acetic acid and water, were being retained. Use of TSILs in the Fischer esterification reaction was both high yielding and programmable if the proper ratio of both water and reagents to immobilized medium was observed.

Accelerating Assay Development Using Experimental Design and Integrated Liquid Handling

INTRODUCTION Molecular biologists developing assays face complex challenges inherent with the rate of new target identification and their adaptation to automation-ready assays. In addition, the exponential growth of compound libraries over the last several years has required that assays be miniaturized as a means of containing costs. Using AAO, the assay developer can take advantage of statistical design of experiment (a.k.a. DOE or experimental design) to create more robust, cost-effective assays. Making assays more robust for automated systems no longer has to be a bottleneck because AAO lets the scientist concentrate on the science, not the mundane tasks of pipetting or writing complex liquid handling methods. AAO combines the power of statistically designed experiments with the flexibility of the Biomek 2000 and post-run data collection and analysis. No longer is the DOE approach to assay development cumbersome and impractical.

Characterization of spray atomization of 3003 aluminum alloy during linear spray atomization and deposition

Linear spray atomization and deposition is an attractive technique to produce near-net-shape deposits, such as aluminum sheet and strip. In the present study, phase Doppler interferometry (PDI) was used in a backscatter mode to characterize, in situ, the droplet size and velocity distributions during linear spray atomization and deposition of a 3003 aluminum alloy. The PDI measurements were obtained along axes corresponding to the direction parallel to the nozzle slit and to the direction perpendicular to the slit. The PDI results delineate the temporal and spatial distribution of the droplet size and velocity during the metal spray. Both point and “line” measurements were obtained and are reported. The line measurements resulted from the integration of measurement made along a line scan obtained in real time (i.e., not ensemble averaged). Postrun analysis of the droplet size distribution using laser diffraction and sieving techniques is also reported. The PDI point measurements revealed that droplet size and velocity distribution were relatively invariant with time. The line measurements of droplet velocity showed that the droplet axial velocity exhibits a bimodal behavior, which becomes more apparent with increasing atomizing gas pressure, a result of droplet recirculation inside the spray chamber. In addition, the peak in the droplet axial velocity distribution increased as atomizing gas pressure increased. The line characterization also showed that the droplet size distribution became more homogeneous with increasing gas pressure, and that the distribution characteristic diameters of droplets decreased consistently with increasing gas pressure. Postrun characterization of the droplet size distribution of the entire metal spray using diffraction and sieving methods indicated that the mass (volume) median diameter D 50 and the Sauter mean diameter (SMD) D 32 decreased with increasing gas pressure in a manner consistent with PDI results.

Investigation of equilibria in solution. Determination of equilibrium constants with the HYPERQUAD suite of programs

A new suite of 10 programs concerned with equilibrium constants and solution equilibria is described. The suite includes data preparation programs, pretreatment programs, equilibrium constant refinement and post-run analysis. Data preparation is facilitated by a customized data editor. The pretreatment programs include manual trial and error data fitting, speciation diagrams, end-point determination, absorbance error determination, spectral baseline corrections, factor analysis and determination of molar absorbance spectra. Equilibrium constants can be determined from potentiometric data and/or spectrophotometric data. A new data structure is also described in which information on the model and on experimental measurements are kept in separate files.

Voltammetry with programmed baseline compensation

An instrument for repetitive voltammetric experiments has been designed, constructed and evaluated. The instrument is applicable as a detector for HPLC and FIA, process control and traditional experiments in unstired solutions. Special features include: multiple modes of voltammetry, real-time color-contour display of data, ability to change experimental parameters during a series of voltammograms, the storage on computer disk of all data points and parameters, ability to compensate background current on a point-by-point basis, and fast and convenient post-run data processing and analysis. The compensation of background currents, both capacitative and faradaic, results in flat baselines which allow increased current gain with improved peak definition and resolution from the ADC. Compensated baselines also allow operation at higher potentials and can be used to mask matrix impurities or even analytes added previously to the cell.

The use of differential measurements with a glucose biosensor for interference compensation during glucose determinations by flow injection analysis

A novel detection system for the determination of glucose in the presence of clinically important interferents, based on the use of dual sensors and flow-injection analysis (FIA), is described. The normalisation methodology involves measurement of the interference signal at a reference sensor; this signal can then be subtracted from the glucose sensor signal (post-run) to give a corrected measurement of the glucose concentration. The detection system consists of a thin layer cell with dual glassy carbon working electrodes. One electrode was surface modified to act asglucose biosensor by immobilisation of glucose oxidase (GOx) (from Aspergillus niger) with 1% glutaraldehyde and bovine serum albumin. The second electrode (glucose oxidase omitted) was utilised to measure the interference signal responding only to electroactive species present in the injected sample. A computer controlled multichannel potentiostat was used for potential application and current monitoring duties. The sensor responses were saved in ASCII format to facilitate post-run analysis in Microsoft Excel. Cyclic voltammetry (CV) was utilised to investigate the manner in which the interference signal contributed to the total signal obtained at the biosensor in the presence of glucose. The kinetic parameters Imax and the apparent Michaelis-Menten constant, K′m, were calculated for the sensor operating under flow-injection conditions.

Capacitive system for three-dimensional imaging of fluidized-bed density

The U.S. Department of Energy's Morgantown Energy Technology Center has been developing a capacitance imaging system (CIS) to support its fluidized-bed research programs. A second-generation system for capacitively imaging a cold, laboratory-scale, 15.24-cm diameter fluidized bed is described. The CIS acquires interelectrode, bed-crossing displacement current data to provide 193-pixel density values at four 2.54-cm vertically spaced levels and presents a three-dimensional density display at a rate of 30 maps per second in real time. The CIS also stores displacement current data at a rate of 60 density maps per level per second for post-run analysis. Different means of data processing are described that produce one method for real-time display and two methods for post-run analysis of data. The results of calibration and fluidization tests are presented, together with the errors associated with each of the methods for the known pixel densities in the calibration tests. Improvement in the calibration procedure to reduce these errors is proposed. Test results indicate the CIS would be a useful tool for research and monitoring operations in two-phase systems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A capacitive system for three-dimensional imaging of fluidized beds

A novel capacitance imaging system (CIS) has been developed which has unique capabilities for providing real-time, three-dimensional monitoring of fluidized-bed density. While the system was developed primarily to serve as a high-speed, density-imaging tool in fluidization research and development, it could also be used in other applications, such as pipeline transfer of solids, where multiphase dielectric material density changes are to be monitored. The CIS uses 16 evenly spaced, circumferentially located electrodes at each of four levels evenly spaced along the axis of a 6-in. diam fluidized bed as the density-sensing elements. The electronic system utilizes interelectrode displacement current values to obtain bed density estimates at each of the 49 pixels defined at each of the four levels. The system provides a real-time display of each of the four density maps at a rate of 30 maps per second at each level. The system also stores displacement current data, updated 100 times per second, for post-run analysis of bed behavior. The CIS capabilities are demonstrated for a plastic bead bed material. Density maps show the progression of a low-density region upward through a fluidized bed. Experimental use of the system by others produced values of bubble dimension and velocity that are consistent with values predicted by accepted theory.

Conditions for maximizing and inhibiting synthesis of glutathione in cultured rat lenses: An application of HPLC with radioisotope detection

This investigation was concerned with factors which would maximize and inhibit L-cyst(e)ine uptake and glutathione synthesis of rat lenses cultured for 24 hours in a medium containing [35S]-L-cystine. The lenticular protein-free extract was separated and quantified by use of HPLC equipment which included an in-line radioisotope detector coupled with extensive post-run computer analysis. Six thiols were assessed for their ability to increase the uptake of L-cyst(e)ine and its utilization for glutathione synthesis. The most successful was 2-mercaptoethanol, which increased the L-cyst(e)ine uptake 3.6-fold and glutathione synthesis 2.9-fold. This work demonstrated that the rate of glutathione synthesis was directly proportional to the rate of uptake of L-cyst(e)ine. An inhibitor of glutathione synthesis, buthionine sulfoximine, in a concentration range of 0.11-3 mM, decreased uptake of the [35S]-label by one-third. The 3.0 mM concentration inhibited glutathione synthesis 98.7% and decreased glutathione 51% in 24 hours. The data indicate that half the glutathione disappeared in 23 hours in these cultured rat lenses. Because determination of this value did not depend upon the variable rate of cysteine transport, the value may approximate the in vivo value.