bluuebunny/crossref_metadata_2025 huggingface dataset:
Solving the Multi-Period Disassembly-to-Order System Under Stochastic Yields, Limited Supply, and Quantity Discount
Authors: Massoud Amre Z. , Gupta Surendra M.
Published: September 2009

Our previous model [1] considered the disassembly-to-order (DTO) system where a variety of returned products were disassembled in order to satisfy the demand for specified number of components in a single period with limited supply and quantity discount. This paper extends the previous model by solving the problem in multiple periods. Lingo 11.0 and spreadsheet analysis are used to solve the problem under stochastic yields, limited supply, and quantity discount. The main objective of the model is to determine the optimal number of take-back end-of-life (EOL) products for the DTO system that maximizes the total profit. In order to meet the customer’s demand for the different components, a wide variety of products and subassemblies are considered for disassembly. Our model is further complicated because the operating conditions of the take-back EOL products are unknown. As a result, heuristic approach is used to transform the stochastic yields into deterministic equivalents. Additionally, several factors are considered before disassembling any product. When solved, the model provides an optimal ordering policy for the multi-period DTO system. An example is considered to illustrate the use of the model.
An Information-Theoretic Approach to Determine Important Attributes for Engineering Change Evaluation
Authors: Mehta Chandresh , Patil Lalit
Published: September 2009

A proposed Engineering Change (EC) can affect several lifecycle-wide components. Enterprises plan detailed evaluation of only those changes or effects that may have a significant impact. Using past knowledge of engineering changes can prove effective in determining whether an effect is significant. However, comparing ECs for every single attribute is a combinatorial problem, because an EC is composed of a large number of disparate and interdependent attributes. In this paper, we propose an information-theoretic approach to determine important attributes that should be compared to retrieve past ECs similar to the proposed change. Our approach accounts for unknown interdependencies between attributes of disparate datatypes. We believe that the method discussed in this paper will improve overall efficacy of the Engineering Change Management (ECM) process by facilitating fast and reliable evaluation of a proposed EC.
Numerical Investigation of the Effect of Fuel Recycling on the Susceptibility of a Direct Internal Methane Reforming SOFC to Carbon Deposition
Authors: Eveloy Valerie , Daoudi Merwan
Published: September 2009

There is considerable interest in developing solid oxide fuel cell (SOFCs) systems capable of operating directly on methane via direct internal reforming (DIR). However, a major barrier to DIR is the susceptibility of current state-of-the-art nickel based anodes to carbon deposition, particularly at low fuel humidification levels. Overcoming these difficulties will require improved anode designs and identification of suitable operating conditions. In this study, the potential effectiveness of partial fuel recycling in mitigating the risks of carbon deposits is investigated in a planar DIR-SOFC operated on humidified methane at inlet steam-to-carbon ratios (S:Cs) of 0.1 to 1. This is achieved using a detailed computational fluid dynamics (CFD) model which couples momentum, heat, mass and charge transport with electrochemical and chemical reactions. The model thermodynamically predicts the spatial extent of carbon deposits by accounting for both the cracking and Boudouard reactions, for several fuel humidification and recycling conditions. At temperatures close to 1173 K and for inlet fuel S:Cs of 0.5 to 1, 50% (mass %) fuel recycling is found to be an effective strategy against carbon deposition. For lower recycling ratios at the same fuel compositions, or lower S:C ratios (regardless of the recycling ratio), fuel recycling reduces the risk of coking, but does not eliminate it. The results suggest that partial fuel recycling could contribute to extend the operational range of DIR-SOFCs to lower S:C ratios (0.5 to 1.0) than typically considered, with reduced risks of carbon deposition, while reducing system cost and complexity in terms of steam production. For dry or weakly humidified fuels, additional mitigation strategies would be required.
Predicted Performance of an Integrated Solar Thermal and Photovoltaic System With Hybrid Turbine-Fuel Cell Cogeneration System With Cooling Loads
Authors: Kowalski Gregory J. , Zenouzi Mansour
Published: September 2009

A general approach, the HLRP technique, for determining the performance of a hybrid turbine-fuel cell cogeneration system with a renewable energy sources is presented for a domestic residence for a summer day with cooling loads. The use of the ratio of the thermal load to required power parameter (HLRP), which scales the energy systems, allows the performance to be quickly determined and preliminary carbon dioxide production rates and cost effects to be estimated. The present paper includes solar energy systems, thermal and photovoltaic, as renewable energy to illustrate the development of this technique and its integration with the hybrid fuel cell cogeneration system. The analysis focused on matching the transient characteristics of the power and thermal loads with those of the renewable energy system. The results demonstrate that for a typical summer day in the location studied there are not large variations in the energy utilization factors for the four different systems investigated. Surprisingly, the photovoltaic system produces the lowest first law performance and the largest amounts of carbon dioxide. This observation points out the complexity of these systems. The explanation illustrates that saving power production while increasing the use of the most inefficient device (the furnace) decreases the system performance. The information provided by the performance graphs is used to estimate costs for each system and to easily determine which system is the most efficient for satisfying energy requirements and reducing green house gas emissions. The results provide site planners and physical plant operators with initial information that can be used to design new facilities or effectively integrate large plant expansion that include renewable energy systems in a manner that will minimize energy requirements and reduce pollution effects.
Small-Scale, Green-Powered Hydrogen Generation System
Authors: Arruda David , Browne David , Thongkham Chris , Zenouzi Mansour
Published: September 2009

One of the major road blocks in the transition from the current oil economy to the future hydrogen fuel economy is the availability of low cost hydrogen fuel for the average consumer. Currently, the price per kilogram of hydrogen fuel is higher than the cost of an equivalent measure of gasoline and its availability is limited to large metropolitan areas. Both of these factors prevent hydrogen from being an attractive alternative to gasoline for most consumers. The goal of this project, in a senior thermal design course, is to design and construct a low-cost hydrogen generation system for residential hydrogen fuel production and storage. The system will be powered by renewable sources of energy; namely a micro-scale wind turbine and a solar panel. The power generated will be used to power a small-scale PEM electrolyzer to produce hydrogen gas that will then be stored at low pressure in a safe, metal hydride storage tank. This relatively low cost system will provide the average consumer with the ability to safely produce hydrogen fuel for use in residential fuel cells or fuel cell-powered vehicles, making hydrogen fuel an attractive alternative to fossil fuels.
Efficiency Experiments on Modified Dye Sensitized Solar Cells
Authors: Nguyen Crystal , Volpe Daniel , Wilson William , Zenouzi Mansour , Avent Jason
Published: September 2009

Dye Sensitized Solar Cells (DSSC) is a relatively new form of solar panels which use a photo reactive dye and electrolytic cell to capture sunlight and turn it into electricity. The efficiency of DSSCs is about 10% but they are much less expensive to produce than silicon solar cells. The carbon dioxide release from DSSC manufacture is much less than a silicon solar cell, so DSSCs pay back their greenhouse gas emissions rapidly, while many silicon panels may never pay back the pollution they require to manufacture. Because of greater efficiency, silicon solar cells still produce power more cheaply than DSSC. Slight improvements to efficiency or reduction in cost would make these solar panels a more cost effective solution for photovoltaic power. A standard DSSC was built and compared to a modified version using a graphite layer instead of platinum. Surprisingly, the graphite panel outperformed the platinum panel. This is thought to be a result of inexperienced manufacturing. Recommendations for improvements for the experiment are outlined.
Investigation of Porous Gas Diffusions Layer Modeling in PEM Fuel Cells
Authors: Shi Zhongying , Wang Xia
Published: September 2009

Darcy’s law, the Brinkman Equation and the modified N-S equation describe the momentum transport phenomena occurring in porous gas diffusion layer. This paper proposes to compare the differences in applying aforementioned models to describe the transport phenomena in porous gas diffusion layers, and evaluate their effects on the fuel cell performance. A two dimensional isothermal single phase PEM fuel cell model is developed, in which Darcy’s law, the Brinkman equation and the modified N-S equation are applied separately in porous electrodes. These three models show no visible effects on the fuel cell performance characterized by the polarization curves. The polarization curve shows a sharp potential drop when calculated by the pure diffusion model. Three values of GDL permeability are investigated here. The order of the magnitude of each term in the modified N-S equation is numerically evaluated. The inertial term is found much smaller than other terms, and can be dropped in the Navier-Stokes equation. Considering the boundary condition setting problem of Darcy’s law and the convergence problem of the modified N-S equation, the Brinkman equation is recommended by this paper to describe the momentum transport in porous electrodes.
Efficient coding in human auditory perception
Authors: Ming Vivienne L. , Holt Lori L.
Published: September 2009

Natural sounds possess characteristic statistical regularities. Recent research suggests that mammalian auditory processing maximizes information about these regularities in its internal representation while minimizing encoding cost [Smith, E. C. and Lewicki, M. S. (2006). Nature (London) 439, 978–982]. Evidence for this “efficient coding hypothesis” comes largely from neurophysiology and theoretical modeling [Olshausen, B. A., and Field, D. (2004). Curr. Opin. Neurobiol. 14, 481–487; DeWeese, M., et al. (2003). J. Neurosci. 23, 7940–7949; Klein, D. J., et al. (2003). EURASIP J. Appl. Signal Process. 7, 659–667]. The present research provides behavioral evidence for efficient coding in human auditory perception using six-channel noise-vocoded speech, which drastically limits spectral information and degrades recognition accuracy. Two experiments compared recognition accuracy of vocoder speech created using theoretically-motivated, efficient coding filterbanks derived from the statistical regularities of speech against recognition using standard cochleotopic (logarithmic) or linear filterbanks. Recognition of the speech created using efficient encoding filterbanks was significantly more accurate than either of the other classes. These findings suggest potential applications to cochlear implant design.
Modeling subjective evaluation of soundscape quality in urban open spaces: An artificial neural network approach
Authors: Yu Lei , Kang Jian
Published: September 2009

This research aims to explore the feasibility of using computer-based models to predict the soundscape quality evaluation of potential users in urban open spaces at the design stage. With the data from large scale field surveys in 19 urban open spaces across Europe and China, the importance of various physical, behavioral, social, demographical, and psychological factors for the soundscape evaluation has been statistically analyzed. Artificial neural network (ANN) models have then been explored at three levels. It has been shown that for both subjective sound level and acoustic comfort evaluation, a general model for all the case study sites is less feasible due to the complex physical and social environments in urban open spaces; models based on individual case study sites perform well but the application range is limited; and specific models for certain types of location/function would be reliable and practical. The performance of acoustic comfort models is considerably better than that of sound level models. Based on the ANN models, soundscape quality maps can be produced and this has been demonstrated with an example.
Experimental investigation on pore size effect on the linear viscoelastic properties of acoustic foams
Authors: Deverge Mickaël , Benyahia Lazhar , Sahraoui Sohbi
Published: September 2009

This paper presents linear viscoelastic measurement on a large frequency range (10−2–108 Hz) for cross-linked polymer open-cell foams of same density and different pore sizes. This large extension of frequency range is obtained by the validation of a frequency-temperature superposition principle, commonly used with polymers. At higher frequencies, the shear moduli are independent of the pore size. In acoustical insulation range (1 Hz–16 kHz), the shear moduli decreases with the foams’ pore size.
The Transmissibility and Control of Pandemic Influenza A (H1N1) Virus
Authors: Yang Yang , Sugimoto Jonathan D. , Halloran M. Elizabeth , Basta Nicole E. , Chao Dennis L. , Matrajt Laura , Potter Gail , Kenah Eben , Longini Ira M.
Published: September 2009

Flu's Tricky Tricks

After vaccination against influenza A virus, single-point mutations are selected in hemagglutinin (the virus molecule that binds to sialic acid molecules on the surface of host cells) that escape neutralization by polyclonal antibody responses.

Hensley
et al.

(p.
734
) have discovered that in mice these mutations increased the virus's avidity for sialic acid. Amino acid substitutions that occur during reiterations of immune escape and avidity modulation can thus drive antigenic variation. This constant evolution of influenza viruses requires us to change vaccine components annually, and, for equine influenza,

Park
et al.

(p.
726
) show that as the match between virus and vaccine strains drifts apart with time, the probability of becoming infected and the length of the infectious period increase to the point where outbreaks occur. Nevertheless, even imperfect vaccines may be of benefit to a population because increasing the proportion of vaccinated individuals can supply enough herd immunity to offset a poor antigenic match, especially if used in conjunction with antiviral drugs. For humans,

Yang
et al.

(p.
729
, published online 10 September) estimate that the rate of transmission within U.S. households puts influenza A 2009 H1N1 (the current pandemic “swine flu”) in the higher range of transmissibility, compared to past seasonal and pandemic strains. Thus, to achieve mitigation this fall, children should be the first recipients of vaccine, followed by adults—aiming overall for 70% coverage of the population.
Gold Run tephra: a Middle Pleistocene stratigraphic and paleoenvironmental marker across west-central Yukon Territory, Canada
Authors: Westgate J. A. , Preece S. J. , Froese D. G. , Telka A. M. , Storer J. E. , Pearce N. J.G. , Enkin R. J. , Jackson L. E. , LeBarge W. , Perkins W. T.
Published: September 2009

Gold Run tephra has been found at Thistle Creek, Sixtymile River, and the Klondike goldfields of west-central Yukon, Canada. It is a hornblende-bearing rhyolitic tephra with thicknesses of up to 10 cm at each site, suggesting a widespread distribution across interior Alaska and the Yukon Territory, given the long distance to the nearest volcanic centre. Old Crow, Flat Creek, and TA tephra beds are stratigraphically associated with Gold Run tephra at our study sites and have distinctive compositions. Gold Run tephra is not accommodated by the current classification scheme for late Cenozoic distal tephra beds in Alaska and the Yukon Territory — a scheme based on the physical and chemical attributes — so that its provenance is unknown. An early-Middle Pleistocene age is supported by a glass fission-track age of 0.74 ± 0.06 Ma, a normal remanent magnetic polarity for the enclosing loess, and the presence of a late Irvingtonian faunal assemblage in the associated organic-rich silts at Thistle Creek. Hence, Gold Run tephra was deposited during the very early part of the Brunhes Chron, at which time a shrub tundra environment prevailed across west-central Yukon.
Unnatural random mating policies select for younger age at maturity in hatchery Chinook salmon (Oncorhynchus tshawytscha) populations
Authors: Hankin David G. , Fitzgibbons Jacqueline , Chen Yaming
Published: September 2009

We explored the long-term consequences of three mating regimes ((1) completely random, (2) completely random but excluding jacks (age 2 males), and (3) male length ≥ female length) on age and sex structure of wild and hatchery populations of Chinook salmon ( Oncorhynchus tshawytscha ). Regimes similar to regimes 1 or 2 are used at most salmon hatcheries, whereas regime 3 emulates the outcomes of natural spawning behaviors that favor larger males. Inheritance of age at maturity is captured in age- and sex-structured models via matrices of age- and sex-specific conditional maturation probabilities that depend on age and sex of parents. In unexploited populations, regime 1 leads to substantial long-term selection for younger age at maturity, an effect that is somewhat reduced by regime 2, but greatly reduced under regime 3. Equilibrium age and sex structures for wild and hatchery populations under regime 3 are similar to those of natural populations, whereas mating regime 1 generates age structure that is greatly shifted toward younger ages and jacks. To prevent unintentional selection for younger age at maturity, we recommend that large-scale hatcheries replace unnatural completely random mating regimes with mating regimes that emulate the outcomes of natural spawning behaviors.
Effects of temperature change on demersal fishes in the California Current: a bioenergetics approach
Authors: Harvey Chris J.
Published: September 2009

Diverse fish assemblages should feature a range of biological and ecological responses to temperature change. Using preliminary bioenergetics models, I simulated growth and maturation of three California Current groundfish (yelloweye rockfish ( Sebastes ruberrimus ), sablefish ( Anoplopoma fimbria ), and spiny dogfish ( Squalus acanthias )) at fixed temperatures ranging from 5 °C to 11 °C. I examined three response variables (size at age 1 (W1), age at 50% maturity (τ50%), and total prey consumption (C)). Yelloweye rockfish responded most strongly for W1, which increased 496% as temperature increased from 5 °C to 11 °C. Spiny dogfish τ50%was highly sensitive, declining from >48 years at 5 °C to <13 years at 11 °C. Age-specific C was most responsive in yelloweye rockfish, increasing by more than fivefold over the range of temperatures, although sablefish likely have greater community-wide impact because their trophic level and absolute feeding rates are higher. Regime shifts, temperature anomalies, or global climate change may directly affect fish energy budgets, elicit range shifts, or produce complex ecological interactions. Studies like this will help managers to identify temperature-sensitive species and anticipate potential changes in populations and diverse communities.
Seasonal dispersion of Pacific halibut (Hippoglossus stenolepis) summering off British Columbia and the US Pacific Northwest evaluated via satellite archival tagging
Authors: Loher Timothy , Blood Calvin L.
Published: September 2009

Fisheries for eastern Pacific halibut ( Hippoglossus stenolepis ) occur over a 9-month season that is closed in winter to protect spawners. The industry has requested season extension, but conventional tag data suggest that 67% of Canada’s fishable biomass may comprise Alaskan spawning stock vulnerable to out-of-area interception. Seventy-eight halibut were tagged during summer in Canada and the US Pacific Northwest (USPNW) with archival tags programmed to report via satellite on 1 February, 15 February, and 1 March. Fifty-seven tags (44 Canadian and 13 USPNW) escaped recapture and reported on or near their scheduled reporting dates. Only 7% out-of-area dispersion was observed for Canadian-tagged halibut; light-based geolocations suggested that an additional 4% may have emigrated prior to February and then returned. Halibut that emigrated were located north of their tagging location. From the USPNW, 46% dispersion was observed. Eighty-nine percent of the tagged halibut displayed depth profiles consistent with migration to offshore spawning areas during the winter, and the majority (78%) were located on the continental slope (>200 m) immediately prior to tag reporting, suggesting locations on or near spawning grounds. There was no detectable difference in dispersion by date, but the mean central position of Canadian-tagged halibut shifted progressively farther southeast over time.
High-resolution infrared spectra of H2–Ne and D2–Ne van der Waals complexes This article is part of a Special Issue on Spectroscopy at the University of New Brunswick in honour of Colan Linton and Ron Lees.
Authors: McKellar A. R.W.
Published: September 2009

Spectra of weakly bound hydrogen–neon complexes have been studied in equilibrium gas mixtures at relatively high spectral resolution (0.05–0.12 cm–1) using a long-path (112 m), low-temperature (24 K) absorption cell and a Fourier transform infrared spectrometer. Most of the data cover the region of the H2 or D2 fundamental stretching vibrations in the mid-infrared (λ ∼2.4 or 3.3 μm), but results on the pure rotational S0 (0) band of D2–Ne in the far-infrared (λ ∼55 μm) are also included. The spectra are greatly improved compared to the only previous observation. The results serve as a stringent experimental constraint for testing and improving theoretical determinations of the potential-energy surface, which describes the intermolecular forces for the hydrogen–neon system.
Rotational transitions within the 21, 31, 41, and 61 states of formaldehyde H212C16O This article is part of a Special Issue on Spectroscopy at the University of New Brunswick in honour of Colan Linton and Ron Lees.
Authors: Margulès L. , Perrin A. , Janečkovà R. , Bailleux S. , Endres C. P. , Giesen T. F. , Schlemmer S.
Published: September 2009

This work, besides its fundamental interest, is motivated by the atmospheric and astrophysical importance of formaldehyde (H2CO). The goal of this study is to complete the already existing list of rotational transitions within the ground vibration state by a list of transitions within the four first excited 21, 31, 41, and 61 vibrational states, to help the detection of this species by microwave or millimetre wave techniques. For this purpose, the rotational spectra of H2CO in the 21, 31, 41, and 61 excited vibrational states have been investigated in Lille and Cologne in the millimetre region at 160–600 GHz and 850–903 GHz, respectively. The results of these millimetre wave measurements were combined with the 21, 31, 41, and 61 infrared energy levels, which were obtained from previous analysis of FTS spectra of the ν4 (out of plane bending mode), ν6 (CH2 rock mode), and ν3 (CH2 bending mode) bands recorded in the 10 µm region (D.C. Reuter, S. Nadler, S.J. Daunt, and J.W.C. Johns. J. Chem. Phys. 91, 646 (1989)) and more recently for the ν2 fundamental band (C=O stretching, located at 1746.009 cm–1) (F. Kwabia Tchana, A. Perrin, and N. Lacome. J. Mol. Spectrosc. 245, 141, (2007)). The energy level calculation of the 21, 31, 41, and 61 interacting states accounts for the various Coriolis-type resonances that perturb the energy levels of the 21, 31, 41, and 61 vibrational states as well as for the anharmonic resonances coupling the 21 and 31 energy levels, and in this way the microwave and infrared data could be reproduced within their associated experimental uncertainty. However, it is clear that the theoretical model used to account for the very large A-type Coriolis resonance linking the 41 and 61 energy levels of H2CO is only effective with poor physical meaning.
Temperature dependences for air-broadened Lorentz half-width and pressure shift coefficients in the 30013←00001 and 30012←00001 bands of CO2 near 1600 nm This article is part of a Special Issue on Spectroscopy at the University of New Brunswick in honour of Colan Linton and Ron Lees.
Authors: Predoi-Cross A. , McKellar A. R.W. , Benner D. Chris , Devi V. Malathy , Gamache R. R. , Miller C. E. , Toth R. A. , Brown L. R.
Published: September 2009

In this study, 39 high-resolution spectra of pure and air-broadened CO2 recorded at temperatures between 215 and 294 K were analyzed using a multispectrum nonlinear least-squares technique to determine temperature dependences of air-broadened Lorentz half-width and air-induced pressure shift coefficients for over 100 individual 12C16O2 transitions in the 30012←00001 (at 6348 cm–1) and 30013←00001 (at 6228 cm–1) bands. Data were recorded with two different Fourier transform spectrometers (Kitt Peak FTS at the National Solar Observatory in Arizona and the Bomem FTS at NRC, Ottawa), with absorption path lengths ranging between 25 and 121 m. The sample pressures varied between 11 torr (pure CO2) and 924 torr (CO2-air) with volume mixing ratios of CO2 in air between ∼1.5% and 11% (1 torr = 133.322 4 Pa). To minimize systematic errors and increase the accuracy of the retrieved parameters, a constrained multispectrum nonlinear least-squares fitting technique was used to include theoretical quantum mechanical expressions for the rovibrational energies and intensity parameters rather than retrieving the individual positions and intensities line by line. The results suggest no detectable vibrational dependence for the temperature dependences for the air-broadened Lorentz half-width coefficients and the air-induced pressure shift coefficients. The half-width coefficients and temperature dependence exponents were modeled using semiclassical calculations based upon the Robert–Bonamy formalism. A good agreement is seen between the measurements and theoretical calculations. Beyond |m| = 26, a simple scaling factor (0.96) has been applied to the calculated half-width coefficients to match the experimental measurements.
Theoretical study of electric moments, polarizabilities, and fine and hyperfine coupling constants of the B3Πg, C3Πu, A′5Σg+, and C″5Πu states of N2This article is part of a Special Issue on Spectroscopy at the University of New Brunswick in honour of Colan Linton and Ron Lees.This paper is dedicated to Professors Ronald M. Lees and Colan Linton from the Department of Physics, University of New Brunswick.
Authors: Bruna Pablo J. , Grein Friedrich
Published: September 2009

Several properties are calculated for the first time for the B3Πg, C3Πu, A′5Σg+, and C″5Πu states of N2, i.e., quadrupole (Θ) and hexadecapole (Φ) moments, static dipole polarizability (α), and hyperfine structure (hfs) data such as the electric field gradient (qii) and magnetic Frosch–Foley parameters (b, c, d). These quantities are evaluated with the density functional theory (DFT) method B3LYP/aug-cc-pVQZ. The variation with geometry is also considered for all parameters above. The B(σgπg) and C(σuπg) triplet Π states have similar values of the anisotropy P|2|(2) ∝ (Pxx − Pyy), with P = Θii, qii, or Tii (dipolar hfs tensor). The first-order spin-orbit coupling constant AΛ and the second-order electron-spin g-shift Δg⊥ are obtained with a 6-311+G(2d) basis and multireference configuration interaction (MRDCI) wave functions. Values of AΛ calculated for W3Δu and (B, C, C′, C″) Π states reproduce well the experimental data (C and C′ are two different minima of 13Πu). The variation of AΛ with R(N-N) is regular for all states studied, except for AΠ(13Πu), which changes abruptly between the C and C′ minima (from 38 to 2 cm−1). The Δg⊥ values — evaluated via sum over states expansions — are calculated for A′5Σg+ as well as A3Σu+ and B′3Σu−. The spin-rotation constant γΣ is derived via Curl’s equation γΣ = (−2B)Δg⊥. We find γΣ(A′) to be negative and to decrease steadily with vibrational excitation, in line with experimental observations. Both Δg⊥ and γΣ of A′5Σg+ are determined by the coupling of this weakly bound state with the strongly repulsive 15Πg state.
Constrained multispectrum analysis of CO2–Ar broadening at 6227 and 6348 cm–1 This article is part of a Special Issue on Spectroscopy at the University of New Brunswick in honour of Colan Linton and Ron Lees.
Authors: Benner D. Chris , Miller C. E. , Devi V. Malathy
Published: September 2009

We report the first extensive experimental measurements of Ar-broadened half-width and pressure-induced shift coefficients, speed dependence parameters, and line mixing coefficients for the 30013←00001 and 30012←00001 bands of 16O12C16O centered near 6227 and 6348 cm–1, respectively. These parameters were determined from 15 self-broadened and six Ar-broadened CO2 spectra recorded at room temperature with long absorption path lengths (25 to 121 m) using the McMath–Pierce Fourier transform spectrometer (FTS) at the National Solar Observatory. All 21 spectra were fit simultaneously using a multispectrum nonlinear least-squares technique. The line positions and line intensities were constrained to quantum mechanical expressions to obtain maximum accuracies in the retrieved parameters. Speed-dependent line shapes with line mixing (via the relaxation matrix formalism) were required to remove systematic errors in the fit residuals using only the Voigt profile. Remaining fit residuals were minimized by adjusting the half-width and pressure-induced shift coefficients of the overlapping 31113←01101 and 31112←01101 hot bands. We compare the Ar-broadening parameters with those recently determined for self- and air-broadening in the 30012←00001 and 30013←00001 bands and also with other Ar-broadening values from the literature, as appropriate.
Performance of helical piles in oil sand
Authors: Sakr Mohammed
Published: September 2009

The results of a comprehensive pile load-test program and observations from field monitoring of helical piles with either a single helix or double helixes installed in oil sand are presented in this paper. Eleven full-scale pile load tests were carried out including axial compression, uplift, and lateral load tests. The results of the full-scale load tests are used to develop a theoretical design model for helical piles installed in oil sand. Test results confirm that the helical pile is a viable deep foundation option for support of heavily loaded structures. The test results also demonstrated that circular-shaft helical piles can resist considerable lateral loads.
Studies on soil contamination due to used motor oil and its remediation
Authors: Singh S. K. , Srivastava R. K. , John Siby
Published: September 2009

An experimental program was undertaken to evaluate the changes in behaviour of soils due to interaction with used motor oil (U.M.O) followed by their remediation. Different types of soils classified as clay with low plasticity (CL), clay with high plasticity (CH), and poorly graded sand (SP) were used for the study. Laboratory studies were conducted on virgin (uncontaminated) soil samples and soil samples simulated to varying degrees of contamination (i.e., 3%, 6%, and 9% by dry weight of soil) to compare the geotechnical properties before and after contamination. The engineering properties altered due to contamination. Surfactant (sodium dodecyl sulphate (SDS)) enhanced washing was employed to decontaminate the soils. It was observed that the original geotechnical properties of soils could be almost restored (variation ranging from 0 to 12%) upon decontamination with SDS at an optimum dosage.
Overcoming data sparseness and parametric constraints in modeling of tree mortality: a new nonparametric Bayesian model
Authors: Metcalf C. Jessica E. , McMahon Sean M. , Clark James S.
Published: September 2009

Accurately describing patterns of tree mortality is central to understanding forest dynamics and is important for both management and ecological inference. However, for many tree species, annual survival of most individuals is high, so that mortality is rare and, therefore, difficult to estimate. Furthermore, tree mortality models have potentially complex suites of covariates. Here, we extend traditional and recent approaches to modeling tree mortality and propose a new nonparametric Bayesian method. Our model is constrained to both reflect and distinguish known relationships between mortality and its two key covariates, diameter and diameter increment growth, but it remains sufficiently flexible to capture a wide variety of patterns of mortality across these covariates. Our model also allows incorporation of outside information in the form of priors, so that increased mortality of large trees can always be formally modeled even when data are sparse. We present results for our nonparametric Bayesian mortality model for maple ( Acer spp.), holly ( Ilex spp.), sweet gum ( Liquidambar styraciflua L.), and tulip-poplar ( Liriodendron tulipifera L.) populations from North Carolina, USA.
DOES CHIRAL FERMION COUPLED TO A BACKGROUND DILATON FIELD PRESERVE INFORMATION?
Authors: RAHAMAN ANISUR
Published: September 2009

A model where chiral boson is coupled to a background dilaton field is considered to study the s-wave scattering of fermion by a background dilaton black hole. It is found that the scattering process of chiral fermion does not violate unitarity and information remains preserved. Faddevian anomaly plays a crucial role on the information scenario.
NEUTRAL CURRENTS IN ASU(4)L⊗U(1)YGAUGE MODEL WITH EXOTIC ELECTRIC CHARGES
Authors: PALCU ADRIAN
Published: September 2009

The weak currents with respect to the diagonal neutral bosons Z, Z′ and Z′′of a specific SU (4)L⊗ U (1)Ygauge model are computed in detail for all the fermion families involved therein. Our algebraical approach, which is based on the general method of solving gauge models with high symmetries proposed several years ago by Cotăescu, recovers in a nontrivial way all the Standard Model values for current couplings of the traditional leptons and quarks, and predicts plausible values for those of the exotic fermions in the model.
THE GammeV SUITE OF EXPERIMENTAL SEARCHES FOR AXION-LIKE PARTICLES
Authors: STEFFEN JASON H. , UPADHYE AMOL
Published: September 2009

We report on the design and results of the GammeV search for axion-like particles and for chameleon particles. We also discuss plans for an improved experiment to search for chameleon particles, one which is sensitive to both cosmological and power-law chameleon models. Plans for an improved axion-like particle search using coupled resonant cavities are also presented. This experiment will be more sensitive to axion-like particles than stellar astrophysical models or current helioscope experiments.
MICROSTRUCTURE AND MAGNETIC PROPERTIES CHANGE OF Fe3O4 NANOPARTICLES SYNTHESIZED UNDER MAGNETIC FIELDS AT ROOM TEMPERATURE
Authors: WANG JUN , XIA SIHUA , CAO SHIHE
Published: September 2009

Magnetite nanoparticles have been synthesized by a co-precipitation method under magnetic fields (0~1 T) at room temperature. The as-prepared samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and their microstructure analysis were evaluated on a Mössbauer spectrum. It was found that the Fe 3 O 4 samples produced under a magnetic field of 1 T had a much higher saturation magnetization (15.3 emu/g) than those produced under 0.6 T (7.56 emu/g) and 0 T magnetic fields (6.59 emu/g). This interesting result implies that magnetic fields can affect the growth of Fe 3 O 4 nanoparticles and further change the microstructure and crystallinity of Fe 3 O 4 nanoparticles. It is expected that this process could also be a promising technique to improve the magnetic properties of other magnetic materials.
APPLICATION OF HE'S PARAMETRIZED PERTURBATION METHOD FOR NONLINEAR HEAT DIFFUSION AND HEAT TRANSFER EQUATIONS
Authors: GANJI D. D. , JAMSHIDI N. , MOMENI M.
Published: September 2009

Perturbation methods depend on small parameters which are difficult to find for real-life nonlinear problems. He's parametrized perturbation method, which does not need small parameters, is one of the newest analytical methods to solve nonlinear equations. In this letter some nonlinear heat transfer equations are used as examples to illustrate the simple solution procedures of this method. Comparison of the results obtained by the new method with exact solutions reveals that the method is tremendously effective.
Contribution of different triggers to the gastric accommodation reflex in humans
Authors: Vanden Berghe Pieter , Janssen Pieter , Kindt Sebastien , Vos Rita , Tack Jan
Published: September 2009

Accommodation of the stomach consists of a vagally mediated relaxation of the proximal stomach, providing the meal with a reservoir. Our aim was to study whether, similar to other vagally mediated processes, the accommodation reflex is also determined by cephalic, oropharyngeal, gastric, and intestinal phases. Eleven healthy subjects underwent in randomized order five gastric barostat studies and two satiety drinking tests. In all studies, isobaric tone measurements (at minimal distending pressure + 2 mmHg) were performed 20 min before and 20 min after a nutrient stimulus. The stimuli included only visual and olfactory exposure to a meal (cephalic stimulation), taking liquid nutrient in the mouth without swallowing (sham feeding), ingestion of a 200-ml 300-kcal nutrient meal with blocked outflow to the pylorus (gastric retention), and meal infusion through a nasointestinal tube (duodenal instillation), or normal ingestion (control). During satiety testing, subjects ingested liquid nutrient at a fixed rate of 15 ml/min until maximum satiety, with an inflated or deflated intrapyloric balloon assembly. Progressively bigger gastric relaxatory responses were seen with cephalic stimulation (18 ± 19 ml), sham feeding (54 ± 21 ml), gastric retention (95 ± 47), duodenal instillation (144 ± 33), and control (232 ± 33 ml). The amount of nutrient ingested at maximum satiety was significantly lower with an inflated intrapyloric balloon (1,223 ± 103 vs. 1,392 ± 124 ml, P < 0.05). The accommodation reflex in humans lacks a cephalic phase, but it can be activated from the oropharynx, the stomach, and the duodenum. Blocking passage to the duodenum significantly decreases the amplitude of the accommodation reflex and induces early satiety.
Resveratrol attenuates mitochondrial oxidative stress in coronary arterial endothelial cells
Authors: Ungvari Zoltan , Labinskyy Nazar , Mukhopadhyay Partha , Pinto John T. , Bagi Zsolt , Ballabh Praveen , Zhang Cuihua , Pacher Pal , Csiszar Anna
Published: September 2009

The production of hyperglycemia-induced mitochondrial reactive oxygen species (mtROS) is a key event in the development of diabetic complications. Because resveratrol, a naturally occurring polyphenol, has been reported to confer vasoprotection, improving endothelial function and preventing complications of diabetes, we investigated the effect of resveratrol on mtROS production in cultured human coronary arterial endothelial cells (CAECs). The measurement of MitoSox fluorescence showed that resveratrol attenuates both steady-state and high glucose (30 mM)-induced mtROS production in CAECs, an effect that was prevented by the knockdown of the protein deacetylase silent information regulator 2/sirtuin 1 (SIRT1), an intracellular target of resveratrol. An overexpression of SIRT1 mimicked the effects of resveratrol, attenuating mtROS production. Similar results were obtained in CAECs transfected with mitochondria-targeted H2O2-sensitive HyPer-Mito fluorescent sensor. Amplex red assay showed that resveratrol and SIRT1 overexpression significantly reduced cellular H2O2 levels as well. Resveratrol upregulated MnSOD expression and increased cellular GSH content in a concentration-dependent manner (measured by HPLC coulometric analysis). These effects were attenuated by SIRT1 knockdown and mimicked by SIRT1 overexpression. We propose that resveratrol, via a pathway that involves the activation of SIRT1 and the upregulation of antioxidant defense mechanisms, attenuates mtROS production, suggesting the potential for new treatment approaches targeting endothelial mitochondria in metabolic diseases.
μ-Opioid receptor agonist injections into the presumed pre-Bötzinger complex and the surrounding region of awake goats do not alter eupneic breathing
Authors: Krause K. L. , Neumueller S. E. , Marshall B. D. , Kiner T. , Bonis J. M. , Pan L. G. , Qian B. , Forster H. V.
Published: September 2009

Opioids are clinically important in the alleviation of pain. An undesirable side effect of opioids is depression of breathing. Data from isolated preparations suggest this effect is due to attenuation of discharge activity of neurons in the pre-Bötzinger complex (preBötzC), a medullary area with respiratory rhythmogenic properties. The purpose of this study was to examine how [d-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin (DAMGO), a μ-opioid receptor agonist, affected breathing after injection into the presumed preBötzC of the adult awake goat. We hypothesized that DAMGO would cause breathing to decrease and become irregular when injected into the presumed preBötzC and the surrounding region of the conscious animal. We further hypothesized that ventilatory sensitivity to CO2and hypoxia would be blunted after the injection of DAMGO. Microtubules were bilaterally implanted into the presumed preBötzC of 10 adult female goats. After recovery from the surgery, DAMGO (0.5–10 μl, 1 nM–10 μM) was injected into the presumed preBötzC during the awake state. DAMGO had no effect on pulmonary ventilation [inspiratory minute ventilation (V̇i)], respiratory rhythm and pattern, the activation pattern of inspiratory and expiratory muscles, or arterial blood gases during eupneic breathing conditions ( P > 0.10). However, DAMGO attenuated ( P < 0.05) the evoked increase in breathing frequency when inspired CO2was increased, and DAMGO attenuated the V̇i response to reduction of inspired O2to 10.8% ( P < 0.05). We conclude that our data do not provide support for the concept that in awake mammals opioid depression of breathing is due to a directed action of opioids on preBötzC neurons.
Structural Characterization and Expression Analysis of the SERK/SERL Gene Family in Rice (Oryza sativa)
Authors: Singla Bhumica , Khurana Jitendra P. , Khurana Paramjit
Published: September 2009

Somatic embryogenesis (SE) is the developmental restructuring of somatic cells towards the embryogenic pathway and forms the basis of cellular totipotency in angiosperms. With the availability of full‐length cDNA sequences from Knowledge‐based Oryza Molecular Biological Encylopedia (KOME), we identified the leucine‐rich repeat receptor‐like kinase (LRR‐RLK) genes from rice (Oryza sativa), which also encompasses genes involved in regulating somatic embryogenesis. Eight out of eleven of the rice SERK and SERL (SERK-like) genes have the TIGR annotation as (putative) brassinosteroid insensitive 1‐associated receptor kinase (precursor). Real‐time polymerase chain reaction analysis was undertaken to quantify transcript levels of these 11 genes. Most of these genes were upregulated by brassinosteroids although only a few of these displayed auxin induction. The expression profile of these genes is nearly uniform in the zygotic embryogenic tissue, but the expression pattern is more complex in the somatic embryogenic tissue. It is likely that OsSERKs and OsSERLs may be involved in somatic embryogenesis and also perform a role in morphogenesis and various other plant developmental processes. Functional validation of these somatic embryogenesis receptor‐like kinase genes may help in elucidating their precise functions in regulating various facets of plant development.
Computational Methods for Multidimensional Neutron Diffusion Problems
Authors: Han Song , Dulla Sandra , Ravetto Piero
Published: September 2009

A neutronic module for the solution of two‐dimensional steady‐state
multigroup diffusion problems in nuclear reactor cores is developed. The module can produce
both direct fluxes as well as adjoints, that is, neutron importances. Different numerical schemes
are employed. A standard finite‐difference approach is firstly implemented, mainly to serve
as a reference for less computationally challenging schemes, such as nodal methods and
boundary element methods, which are considered in the second part of the work. The validation of the methods proposed is carried out by comparisons of results for reference structures. In particular a critical problem for a homogeneous reactor for which an analytical solution exists is considered as a benchmark. The computational module is then applied to a fast spectrum system, having physical characteristics similar to the proposed lead‐cooled ELSY project. The results show
the effectiveness of the numerical techniques presented. The flexibility and the possibility to
obtain neutron importances allow the use of the module for parametric studies, design assessments,
and integral parameter evaluations as well as for future sensitivity and perturbation
analyses and as a shape solver for time‐dependent procedures.
Aryl Hydrocarbon Receptor Expression Is Associated with a Family History of Upper Gastrointestinal Tract Cancer in a High-Risk Population Exposed to Aromatic Hydrocarbons
Authors: Roth Mark J. , Wei Wen-Qiang , Baer Jessica , Abnet Christian C. , Wang Guo-Qing , Sternberg Lawrence R. , Warner Andrew C. , Johnson Laura Lee , Lu Ning , Giffen Carol A. , Dawsey Sanford M. , Qiao You-Lin , Cherry James
Published: September 2009

Background: Polycyclic aromatic hydrocarbon (PAH) exposure is a risk factor for esophageal squamous cell carcinoma, and PAHs are ligands of the aryl hydrocarbon receptor (AhR). This study measured the expression of AhR and related genes in frozen esophageal cell samples from patients exposed to different levels of indoor air pollution, who did or did not have high-grade squamous dysplasia and who did or did not have a family history of upper gastrointestinal tract (UGI) cancer.

Methods: 147 samples were evaluated, including 23 (16%) from patients with high-grade dysplasia and 48 (33%) from patients without dysplasia who heated their homes with coal, without a chimney (a “high” indoor air pollution group), and 27 (18%) from patients with high-grade dysplasia and 49 (33%) from patients without dysplasia who did not heat their homes at all (a “low” indoor air pollution group). Sixty-four (44%) had a family history of UGI cancer. RNA was extracted and quantitative PCR analysis was done.

Results: AhR gene expression was detectable in 85 (58%) of the samples and was >9-fold higher in those with a family history of UGI cancer [median expression (interquartile range), −1,964 (−18,000, −610) versus −18,000 (−18,000, −1036); P = 0.02, Wilcoxon rank-sum test]. Heating status, dysplasia category, age, gender, and smoking were not associated with AhR expression (linear regression; all P values ≥ 0.1).

Conclusion: AhR expression was higher in patients with a family history of UGI cancer. Such individuals may be more susceptible to the deleterious effects of PAH exposure, including PAH-induced cancer. (Cancer Epidemiol Biomarkers Prev 2009;18(9):2391–6)