Experimental Runs (experimental + run)

Distribution by Scientific Domains


Selected Abstracts


Effect of surfactants and liquid hydrocarbons on gas hydrate formation rate and storage capacity

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 8 2003
Zhigao Sun
Abstract Hydrate formation rate plays an important role in making hydrates for the storage and transport of natural gas. Micellar surfactant solutions were found to increase gas hydrate formation rate and storage capacity. With the presence of surfactant, hydrate could form quickly in a quiescent system and the energy costs of hydrate formation reduced. Surfactants (an anionic surfactant, a non-ionic surfactant and their mixtures) and liquid hydrocarbons (cyclopentane and methylcyclohexane) were used to improve hydrate formation. The experiments of hydrate formation were carried out in the pressure range 3.69,6.82 MPa and the temperature range 274.05,277.55 K. The experimental pressures were kept constant during hydrate formation in each experimental run. The effect of anionic surfactant (sodium dodecyl sulphate (SDS)) on natural gas storage in hydrates is more pronounced compared to a non-ionic surfactant (dodecyl polysaccharide glycoside (DPG)). The induction time of hydrate formation was reduced with the presence of cyclopentane (CP). Cyclopentane and methylcyclohexane (MCH) could increase hydrate formation rate, but reduced hydrate storage capacity The higher methylcyclohexane concentration, the lower the hydrate storage capacity. Copyright © 2003 John Wiley & Sons, Ltd. [source]


Use of chemometric methodology in optimizing conditions for competitive binding partial filling affinity capillary electrophoresis

ELECTROPHORESIS, Issue 16 2008
Ruth E. Montes
Abstract This work expands the knowledge of the use of chemometric response surface methodology (RSM) in optimizing conditions for competitive binding partial filling ACE (PFACE). Specifically, RSM in the form of a Box,Behnken design was implemented in flow-through PFACE (FTPFACE) to effectively predict the significance of injection time, voltage, and neutral ligand (neutral arylsulfonamide) concentration, [Lo], on protein,neutral ligand binding. Statistical analysis results were used to create a model for response surface prediction via contour and surface plots at a given maximum response (,RMTR) to reach a targeted Kb,=,2.50×106,M,1. The adequacy of the model was then validated by experimental runs at the optimal predicted solution (injection time,=,2.3,min, voltage,=,11.6,kV, [Lo],=,1.4,,M). The achieved results greatly extend the usefulness of chemometrics in ACE and provide a valuable statistical tool for the study of other receptor,ligand combinations. [source]


Implementation of chemometric methodology in ACE: Predictive investigation of protein,ligand binding

ELECTROPHORESIS, Issue 16 2007
Grady Hanrahan
Abstract An ACE predictive investigation of protein,ligand binding using a highly effective chemometric response surface design technique is presented. Here, Kd was estimated using one noninteracting standard which relates to changes in the electrophoretic mobility of carbonic anhydrase B (CAB, EC 4.2.1.1) on complexation with the ligand 4-carboxybenzenesulfonamide (CBSA) present in the electrophoresis buffer. Experimental factors including injection time, capillary length, and applied voltage were selected and tested at three levels in a Box,Behnken design. Statistical analysis results were used to create a mathematical model for response surface prediction via contour and surface plots at a given target response (Kd,=,1.19×10,6,M). As expected, there were a number of predicted solutions that reached our target response based on the significance of each factor at appropriate levels. The adequacy of the model was validated by experimental runs with the predicted model solution (capillary length,=,47,cm, voltage,=,11,kV, injection time,=,0.01,min) presented in detail as an example. [source]


Biofilm Growth and Bed Fluidization in a Fluidized Bed Reactor Packed with Support Materials of Low Density,

ENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 2 2004
R.A. Saucedo-Terán
Abstract Support materials of low-density for fluidized bed reactors provide several operational advantages, including lower energy requirements and proper biofilm growth balance. The aim of this investigation was to study the extent of biofilm growth and bed fluidization in an experimental reactor, using polyester resin (,pr,=,1220,kg/m3) and vitrified expanded perlite (,vep,=,1710,kg/m3) as alternative support materials to conventional silica sand. A noteworthy amount of biofilm was observed to be attached to both support materials from the very beginning of the bioreactor operation. Nevertheless, there were significant variations in biofilm growth and activity over the course of the experimental trials. For both perlite and polyester beds, the highest biofilm mass and the highest total number of mesophilic bacteria were observed between the 7th and the 10th day, showing a steady state trend at the end of the experimental runs. The chemical oxygen demand (COD) removal levels were concomitant with biofilm mass and total mesophilic bacteria changes, although the polyester bed efficiency was slightly higher than that for the perlite bed. As expected, the polyester bed was fluidized at a lower re-circulation flow compared to the perlite bed. Reactor back-washing was not required for these support materials since biomass excess was adequately separated by means of a special internal device. The efficiencies of removal of organic matter achieved were acceptable (up to 78,%) despite the low volume of the support material (25,%) and the low hydraulic retention time (30,min). [source]


EXPERIMENTAL AND NEURAL NETWORK PREDICTION OF THE PERFORMANCE OF A SOLAR TUNNEL DRIER FOR DRYING JACKFRUIT BULBS AND LEATHER

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 6 2005
B.K. BALA
ABSTRACT This article presents the field performance of a solar tunnel drier for drying jackfruit bulbs and leather. The drier consists of a transparent plastic-covered flat-plate collector and a drying tunnel connected in series to supply hot air directly into the drying tunnel using two direct-current fans operated by a photovoltaic module. The drier has a loading capacity of 120,150 kg of fruits. Sixteen experimental runs were conducted for drying jackfruit bulbs and leather (eight runs each). The use of a solar tunnel drier led to a considerable reduction in drying time and dried products of better quality in comparison to products dried under the sun. A multilayered neural network approach was used to predict the performance of the solar tunnel drier. Using solar drying data of jackfruit bulbs and leather, the model has been trained using backpropagation algorithm. The prediction of the performance of the drier was found to be excellent after it was adequately trained. It can be used to predict the potential of the drier for different locations, and can also be used in a predictive optimal control algorithm. [source]


The effect of low-power microwaves on the growth of bacterial populations in a plug flow reactor

AICHE JOURNAL, Issue 5 2010
Renzo Carta
Abstract A plug flow reactor (PFR) which permits the growth of bacteria in a microwave environment is described. The apparatus is used to analyse the effect of microwave radiation at the frequency of 2.45 GHz and at 37°C on the growth rate of three bacterial species: Bacillus clausii, Pseudomonas aeruginosa, and Staphylococcus aureus. The growth constant is determined for reacting mixtures irradiated with microwaves of different powers ranging from 0 to 400 mW. Analyses show that (a) the apparatus is able to perform the experimental runs maintaining an aseptic environment; (b) under the microwave power levels examined in the present study, no effects are detected for the Bacillus clausii and Pseudomonas aeruginosa species, while for the Staphylococcus aureus species, a few small effects are found (a minimum value of the growth constant at 200 mW and an increase of the constant between 200 and 400 mW). © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source]


Experiments on sediment trap efficiency in reservoirs

LAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 1 2005
Horacio Toniolo
Abstract Sediment trap efficiency plays a key role in the effective operational life of reservoirs. This paper presents the results of five laboratory experiments on trap efficiency. An over-spilling condition and four gaps located at the downstream end of a reservoir were analysed in this study. The experimental design assumed a river carrying two phases of sediment flowing into a one-dimensional reservoir. The coarse sediment (sand) was deposited and formed a defined prograding delta. The fine sediment (mud) formed a dilute suspension of wash load in the river. As the river entered the reservoir, the muddy water plunged on the foreset, forming a turbidity current. The turbidity current deposits, in turn, formed a bottomset. Black coal slag and white glass beads were used to simulate sand and mud. Their specific densities were 2.6 and 2.5 for black coal and beads, respectively. The water surface elevation in the reservoir was approximately similar in all experiments. Neither the water nor sediment discharge conditions were changed during the experimental runs. Suspended sediment was sampled through seven siphons; six of these being components of a rake in which they were vertically stacked. The last siphon was positioned on the rake outlet. Sediment samples were taken three times, at approximately evenly spaced intervals in the experiments. Suspended sediment concentration and grain size distribution were calculated for each siphon. The bed sediment deposit was sampled after each experiment. Sediment trap efficiency in the reservoir was calculated. Experimental results show the maximum venting capacity (minimum trap efficiency) occurs under over-spilling conditions. [source]


Statistical optimization of medium components for extracellular protease production by an extreme haloarchaeon, Halobacterium sp.

LETTERS IN APPLIED MICROBIOLOGY, Issue 1 2009
SP1(1)
Abstract Aims:, Optimization of medium components for extracellular protease production by Halobacterium sp. SP1(1) using statistical approach. Methods and Results:, The significant factors influencing the protease production as screened by Plackett,Burman method were identified as soybean flour and FeCl3. Response surface methodology such as central composite design was applied for further optimization studies. The concentrations of medium components for higher protease production as optimized using this approach were (g l,1): NaCl, 250; KCl, 2; MgSO4, 10; tri-Na-citrate, 1·5; soybean flour, 10 and FeCl3, 0·16. This statistical optimization approach led to production of 69·44 ± 0·811 U ml,1 of protease. Conclusions:, Soybean flour and FeCl3 were identified as important factors controlling the production of extracellular protease by Halobacterium sp. SP1(1). The statistical approach was found to be very effective in optimizing the medium components in manageable number of experimental runs with overall 3·9-fold increase in extracellular protease production. Significance and Impact of the Study:, The present study is the first report on statistical optimization of medium components for production of haloarchaeal protease. The study also explored the possibility of using extracellular protease produced by Halobacterium sp. SP1(1) for various applications like antifouling coatings and fish sauce preparation using cheaper raw material. [source]


A petrogenetic model for the origin and compositional variation of the martian basaltic meteorites

METEORITICS & PLANETARY SCIENCE, Issue 12 2003
Lars E. BORG
The models are based on low to high pressure phase relationships estimated from experimental runs and estimates of the composition of silicate Mars from the literature. These models attempt to constrain the mechanisms by which the martian meteorites obtained their superchondritic CaO/Al2O3 ratios and their source regions obtained their parent/daughter (87Rb/86Sr, 147Sm/144Nd, and 176Lu/177Hf) ratios calculated from the initial Sr, Nd, and Hf isotopic compositions of the meteorites. High pressure experiments suggest that majoritic garnet is the liquidus phase for Mars relevant compositions at or above 12 GPa. Early crystallization of this phase from a martian magma ocean yields a liquid characterized by an elevated CaO/Al2O3 ratio and a high Mg#. Olivine-pyroxene-garnet-dominated cumulates that crystallize subsequently will also be characterized by superchondritic CaO/Al2O3 ratios. Melting of these cumulates yields liquids with major element compositions that are similar to calculated parental melts of the martian meteorites. Furthermore, crystallization models demonstrate that some of these cumulates have parent/daughter ratios that are similar to those calculated for the most incompatible-element-depleted source region (i.e., that of the meteorite Queen Alexandra [QUE] 94201). The incompatible-element abundances of the most depleted (QUE 94201-like) source region have also been calculated and provide an estimate of the composition of depleted martian mantle. The incompatible-element pattern of depleted martian mantle calculated here is very similar to the pattern estimated for depleted Earth's mantle. Melting the depleted martian mantle composition reproduces the abundances of many incompatible elements in the parental melt of QUE 94201 (e.g., Ba, Th, K, P, Hf, Zr, and heavy rare earth elements) fairly well but does not reproduce the abundances of Rb, U, Ta and light rare earth elements. The source regions for meteorites such as Shergotty are successfully modeled as mixtures of depleted martian mantle and a late stage liquid trapped in the magma ocean cumulate pile. Melting of this hybrid source yields liquids with major element abundances and incompatible-element patterns that are very similar to the Shergotty bulk rock. [source]


Extension of the exhaustive Gaussian approach for BER estimation in experimental direct-detection OFDM setups

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2010
Tiago M. F. Alves
Abstract An extension of the exhaustive Gaussian approach to estimate the bit error ratio from a set of experimental runs in direct-detection orthogonal frequency division multiplexing optical communication systems is proposed. The approach provides fast and accurate bit error ratio estimates avoiding the high amount of data required by direct error counting. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2772,2775, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25595 [source]


Industrial high pressure ethylene polymerization initiated by peroxide mixtures: A reduced mathematical model for parameter adjustment

POLYMER ENGINEERING & SCIENCE, Issue 5 2001
M. Asteasuain
We present a method for the adjustment of parameters in the mathematical modeling of industrial tubular reactors for high pressure polymerization of ethylene. We propose a reduced mathematical model for these reactors that aids in the task of model parameter update commonly done periodically in industrial plants. This reduced model was built from a detailed model for multiple peroxide and oxygen initiator systems we had developed before. Some of the assumptions in that rigorous model were reviewed in order to minimize computational effort. Good and faster predictions were obtained by assuming different constant jacket temperatures and pressures at each zone. Pressure pulse equations had to be included in the model. A simplification of the adjustment procedure is also proposed here. It consists in using only the reactions considered crucial for the description of this polymerization. The peroxide initiator and solvent mixtures were treated as fictitious unique initiator and solvent respectively. A procedure was established for the quick estimation of the kinetic parameters that represent initiator and solvent mixtures of different compositions. This resulted in a model that can be adjusted rapidly to predict the behavior of a specific industrial reactor. The reduced model was validated using experimental runs initiated by oxygen either alone or together with peroxide mixtures. [source]


Construction of quantitative proteome reference maps of mouse spleen and lymph node based on two-dimensional gel electrophoresis

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 13 2006
Yayoi Kimura
Abstract Quantitative features of the proteome are extremely useful for studying cellular processes at a molecular level. In this study, we attempted to construct quantitative reference proteome maps of the mouse spleen and lymph node based on 2-DE followed by protein identification using MS. We analyzed more than 1000,spots on the 2-DE images and consequently were able to determine that 919,spots were derived from 328,different genes. To obtain statistically reliable information of the protein levels from these 2-DE images, we measured the volumes of the respective spots on 2-DE images obtained by four to six independent experimental runs. These measurements were used to calculate the variability of the volumes of the respective spots on 2-DE following subcellular fractionation, which enabled us to discriminate differentially produced proteins from those within the range of intrinsic variability. More importantly, while the 2-DE data have been traditionally collected in a gel image-based manner, the resultant quantitative 2-DE data could be analyzed using the same procedure as that for mRNA expression profiles. This greatly assists in bridging the gap between the analyses of transcriptomes and proteomes and enables the integration of this data on the same informational platform. [source]


Cost-constrained G -efficient Response Surface Designs for Cuboidal Regions

QUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 2 2006
Youjin Park
Abstract In many industrial experiments there are restrictions on the resource (or cost) required for performing the runs in a response surface design. This will require practitioners to choose some subset of the candidate set of experimental runs. The appropriate selection of design points under resource constraints is an important aspect of multi-factor experimentation. A well-planned experiment should consist of factor-level combinations selected such that the resulting design will have desirable statistical properties but the resource constraints should not be violated or the experimental cost should be minimized. The resulting designs are referred to as cost-efficient designs. We use a genetic algorithm for constructing cost-constrained G -efficient second-order response surface designs over cuboidal regions when an experimental cost at a certain factor level is high and a resource constraint exists. Consideration of practical resource (or cost) restrictions and different cost structures will provide valuable information for planning effective and economical experiments when optimizing statistical design properties. Copyright © 2005 John Wiley & Sons, Ltd. [source]


Partition experimental designs for sequential processes: Part II,second-order models

QUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 5 2002
Leonard A. Perry
Abstract Second-order experimental designs are employed when an experimenter wishes to fit a second-order model to account for response curvature over the region of interest. Partition designs are utilized when the output quality or performance characteristics of a product depend not only on the effect of the factors in the current process, but the effects of factors from preceding processes. Standard experimental design methods are often difficult to apply to several sequential processes. We present an approach to building second-order response models for sequential processes with several design factors and multiple responses. The proposed design expands current experimental designs to incorporate two processes into one partitioned design. Potential advantages include a reduction in the time required to execute the experiment, a decrease in the number of experimental runs, and improved understanding of the process variables and their influence on the responses. Copyright © 2002 John Wiley & Sons, Ltd. [source]


Effect of seeding sludge type and hydrodynamic shear force on the aerobic sludge granulation in sequencing batch airlift reactors

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2009
K. Y. Koh
Abstract Two sequencing batch airlift reactors (SBARs) were operated simultaneously for two separate runs. In the first run, two different types of seeding sludge were cultivated in two separate reactors under the same superficial air velocity (SAV). In the second run, the same seeding sludge was cultivated in both reactors but under different SAV, i.e. 1.2 and 3.6 cm s,1. Both runs were carried out for a period of about 20 days, during which the chemical oxygen demand (COD) removal efficiency and morphology of sludge were examined. Batch tests using sodium acetate as the main carbon source were conducted to investigate the COD removal efficiency, and the morphologies of sludge were examined under light microscopy. Results showed that the COD removal efficiency improved with cultivation time. Morphological study showed that all cultivated sludge lost their filamentous species after a few days of cultivation, leaving behind communities of loosely packed pellet-like groups. Although the SAV recommended by other researchers was applied to the SBAR, granulation did not take place at the end of both experimental runs. It was suspected that the failure for aerobic sludge to granulate under the selected operating strategies and reactor configuration was partly due to the intrinsic traits of the sludge microbial community. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source]


Geomagnetic field effect on cardiovascular regulation

BIOELECTROMAGNETICS, Issue 2 2004
Juraj Gmitrov
Abstract The goal of the present research was try to explain the physiological mechanism for the influence of the geomagnetic field (GMF) disturbance, reflected by the indices of the geomagnetic activity (K, Kp, Ak, and Ap indices), on cardiovascular regulation. One hundred forty three experimental runs (one daily) comprising 50 min hemodynamic monitoring sequences were carried out in rabbits sedated by pentobarbital infusion (5 mg/kg/h). We examined the arterial baroreflex effects on the short term blood pressure and heart rate (HR) variabilities reflected by the standard deviation (SD) of the average values of the mean femoral arterial blood pressure (MAP) and the HR. Baroreflex sensitivity (BRS) was estimated from blood pressure/HR response to intravenous (i.v.) bolus injections of vasoconstrictor (phenylephrine) and vasodilator (nitroprusside) drugs. We found a significant negative correlation of increasing GMF disturbance (Kp) with BRS (P,=,0.008), HR SD (P,=0.022), and MAP SD (P,=,0.002) signifying the involvement of the arterial baroreflex mechanism. The abrupt change in geomagnetic disturbance from low (K,=,0) to high (K,=,4,5) values was associated with a significant increase in MAP (83,±,5 vs. 99,±,5 mm Hg, P,=,0.045) and myocardial oxygen consumption, measured by MAP and HR product (24100,±,1800 vs. 31000,±,2500 mm Hg,·,bpm, P,=,0.034), comprising an additional cardiovascular risk. Most likely, GMF affects brainstem and higher neural cardiovascular regulatory centers modulating blood pressure and HR variabilities associated with the arterial baroreflex. Bioelectromagnetics 25:92,101, 2004. © 2004 Wiley-Liss, Inc. [source]


A new efficient mixture screening design for optimization of media

BIOTECHNOLOGY PROGRESS, Issue 4 2009
Fred Rispoli
Abstract Screening ingredients for the optimization of media is an important first step to reduce the many potential ingredients down to the vital few components. In this study, we propose a new method of screening for mixture experiments called the centroid screening design. Comparison of the proposed design with Plackett-Burman, fractional factorial, simplex lattice design, and modified mixture design shows that the centroid screening design is the most efficient of all the designs in terms of the small number of experimental runs needed and for detecting high-order interaction among ingredients. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source]