bluuebunny/crossref_metadata_2025 huggingface dataset:
Rheological properties, oxidative stability and sensory evaluation of enzymatically synthesized medium‐ and long‐chain triacylglycerol‐based salad dressings
Authors: Koh Soo‐Peng , Arifin Norlelawati , Tan Chin‐Ping , Yusoff Mohd. Suria Affandi , Long Kamariah , Idris Nor Aini , Lai Oi‐Ming
Published: December 2008

The rheological properties of various oil‐based salad dressings were investigated. The shear rate‐shear stress study based on Power Law's model indicated pseudoplastic fluid behaviors of dressings prepared in this study. Soybean‐ and medium‐ and long‐chain triacylglycerols (MLCT)‐based dressings treated with different antioxidants showed similar rheological behaviors based on the changes in the storage modulus, loss modulus, viscosity profile and loss tangent in the frequency, amplitude and temperature sweep study. The time‐dependent study revealed similar thixotrophic properties between soybean‐ and MLCT‐based dressings. Addition of synthetic or natural antioxidants reduced the rate of oil deterioration in oil‐in‐water emulsion as a function of time. No significant differences (p >0.05) in hydrolytic reaction of all dressing systems were observed throughout the 3 months of storage at 20 °C. Quantitative descriptive analysis using trained panelists revealed no significant differences (p >0.05) either in salad oils or salad dressings except for MLCT‐based oils/dressings treated with oleoresin sage extracts, which showed darker and stronger odor intensity than other oil systems. Nevertheless, the overall quality of the physical appearance and organoleptic acceptability showed no significant differences (p >0.05) in all systems, indicating that MLCT‐based blends can be used as healthy functional oils to replace soybean oil in food dressing applications.
Oil chemical variation in walnut (Juglans regia L.) genotypes grown in Argentina
Authors: Martínez Marcela L. , Maestri Damián M.
Published: December 2008

Walnut (Juglans regia L.) oil (WO) from the varieties Chandler, Franquette, Hartley, Lara, Mayette, Serr, Sorrento and Tulare were studied in order to evaluate genotypical variations in fatty acid (FA) and volatile compositions, tocopherol content and oxidative parameters. Oil content was found to range between 71.4 and 73.9%. Oils obtained by pressing presented low acid (0.05–0.22% oleic acid), peroxide (0.05–0.47 meq O2/kg oil), K232, and K270 values, and moderate (247–365 µg/g oil) total tocopherol contents. Variations in unsaturated fatty acid contents were between 16.1 and 25.4% (oleic acid), 52.5 and 58.9% (linoleic acid), and 11.4 and 16.5% (linolenic acid). Oxidative stability (OS), as measured by the Rancimat method, was poor (2.64–3.44 h) and it correlated positively with oleic and negatively with linolenic acid contents. In contrast to their low OS, the antioxidant capacity evaluated through the 2,2‐diphenyl‐1‐picrylhydrazyl radical assay showed that the WO analyzed here have good radical‐scavenging activity. Tocopherols appear to be the most important contributors to this biochemical property. The findings connected with volatile composition showed a similar qualitative pattern where aldehydes were present at higher concentration. Most of them seem to come from unsaturated FA mainly through a chemical pathway.
Lipid damage in farmed rainbow trout (Oncorhynchus mykiss) after slaughtering and chilled storage
Authors: Ortiz Jaime , Palma Óscar , González Natalia , Aubourg Santiago P.
Published: December 2008

The flow ice system including ozone (OFI condition) was tested for slaughtering and storage (up to 16 days) of farmed rainbow trout (Oncorhynchus mykiss). Lipid damage analyses were carried out and compared to sensory acceptance and instrumental colour changes. Comparison to individuals processed with the flow ice system in the absence of ozone (FI condition) was undertaken. Rainbow trout slaughtered and chilled under FI and OFI conditions showed a low lipid damage development, according to lipid oxidation and hydrolysis events and lipid composition (polyunsaturated fatty acids, phospholipids and endogenous antioxidants) changes. Additionally, both icing conditions led to largely good quality and shelf life times and to the absence of changes in colour properties. It is concluded that flow ice as such, or including the presence of ozone, can be considered as ideal strategy to be employed as slaughtering and storage system during the commercialisation of the actual farmed species. The ozone presence has shown some profitable effects as leading to an extended shelf life time by quality retention of several sensory parameters; in contrast, some negligible negative effects could be observed on the secondary and tertiary lipid oxidation development. However, the oxidation values reached by individuals kept under OFI conditions cannot be considered as particularly high.
Lipidomic approaches to measuring isoprostanes and other markers of oxidative stress
Authors: Davies Sean S.
Published: December 2008

Oxidative stress shifts the normal physiological balance between the rate of formation and removal of reactive oxygen species (ROS) and leads to oxidative modification of a large number of macromolecules including lipids. Oxidative stress has been invoked as a potential mechanism in a wide variety of disease processes. One requirement for understanding the contribution of oxidative stress to disease is to quantitatively assess the resulting products during disease processes and potential interventions. ROS trigger a myriad of alterations in macromolecules, so that accurately measuring every possible alteration induced by oxidative stress is currently untenable. Therefore, quantifying specific products that are both representative of the formation of other products and that potentially directly participate in the disease process is a rational approach. This review focuses on one of the most commonly used biomarkers of oxidative stress, the F2‐isoprostanes, and then discusses the value of simultaneously measuring other related lipid peroxidation products.
Enzymatic interesterification of structured lipids containing conjugated linoleic acid with palm stearin for possible margarine production
Authors: Goli Sayed Amir Hossein , Sahri Miskandar Mat , Kadivar Mahdi
Published: December 2008

Structured lipids containing conjugated linoleic acid as a functional ingredient were blended with palm stearin in the ratios of 30 : 70, 40 : 60, 50 : 50, 60 : 40 and 70 : 30 (wt/wt). The blends were subjected to enzymatic interesterification by Candida antarctica lipase. After interesterification of the blends, changes in the physical properties of the products, including lower melting points and solid fat contents along with different melting behaviors, were evidenced. Analysis of triacylglycerols (TAG) of the interesterified blends showed a decrease in the concentration of high‐melting TAG. X‐ray diffraction analysis revealed, that all the reacted blends were predominantly in the β' crystal form. The mixture could be used for the formulation of margarines or other, similar products.
Synthesis of α,α′‐Disubstituted Linear Ethers by an Intermolecular Nicholas Reaction – Application to the Synthesis of (+)‐cis/(–)‐trans‐Lauthisan and (+)‐cis/(+)‐trans‐Obtusan
Authors: Ortega Nuria , Martín Tomás , Martín Víctor S.
Published: December 2008

A new and efficient methodology to prepare α,α′‐disubstituted linear ethers through an intermolecular Nicholas reaction (interNR) is described. cis‐2,8‐Disubstituted oxocanes, cis‐2,9‐disubstituted oxonanes, their trans isomers, and their parent unsaturated precursors were prepared from the corresponding Co2(CO)6–cycloalkynic ethers. Key steps in such syntheses were the ether linkage formation by interNR, RCM of the suitable acyclic dienyl ether, and montmorillonite K‐10 induced isomerization of the complexed cycloalkyne. By taking advantage of the developed methodology a short synthesis of (+)‐cis‐ and (–)‐trans‐lauthisan and (+)‐cis‐ and (+)‐trans‐obtusan are described. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Application of Tetrathiafulvalene‐Modified Carbon Nanotubes to Preparation of Integrated Mediating System for Bioelectrocatalytic Oxidation of Glucose
Authors: Kowalewska Barbara , Kulesza Pawel J.
Published: December 2008

Multiwalled carbon nanotubes (CNTs), that are modified with ultrathin layers of tetrathiafulvalene (TTF), were demonstrated to form a stable colloidal suspension. Such dispersion was exploited to fabricate an integrated mediating system (utilizing both highly conductive carbon nanostructures, CNTs, and a redox mediator, TTF) capable of facilitating electron transfers between the active sites of the enzyme (glucose oxidase) and the electrode surface. The resulting bioelectrocatalytic system produced sizeable glucose oxidation currents in phosphate buffer solution (pH 7.0). For comparison, the system utilizing TTF‐free (bare) CNTs and the glucose oxidase enzyme showed relatively much lower activity towards the glucose oxidation. Formation, electrocatalytic reactivity, durability, and morphology of proposed bioelectrocatalytic systems were examined using cyclic voltammetry, potential step techniques, rotating disk voltammetry and transmission electron microscopy. The whole concept of the preparation of CNT‐supported redox mediating systems is of potential utility to bioelectroanalytical chemistry.
Electroreductions on Silver‐Based Electrocatalysts: The Use of Ag Nanoparticles for CHCl3 to CH4 Conversion
Authors: Rondinini S. , Aricci G. , Krpetić Ž. , Locatelli C. , Minguzzi A. , Porta F. , Vertova A.
Published: December 2008

A preliminary investigation on a new class on electrocatalytic materials for the electroreduction of organic halides is presented and discussed. The electrocatalysts are based on silver nanoparticles (Ag_NP), ad hoc synthesised by chemical reduction of an aqueous silver salt in the presence of six different stabilising agents. The colloids are then supported on carbon powder (10% loading) for further characterisation and use. The electrocatalytic properties of the Ag_NP/carbon composites towards the dehalogenation of halocompounds are tested by cyclic voltammetry and by preparative electrolysis. The hydrodehalogenation of trichloromethane, extensively studied by this group, is selected as a model reaction, because of its relevance for the detoxification of wastes. The voltammetric characterisation is performed in an aqueous solution, supporting the composites on cavity microelectrodes. Gas‐diffusion electrodes (GDE) based on the most promising Ag_NP composite – and, for reference, on a commercial Ag/C oxygen reduction electrocatalyst – are then tested in an electrolytic process for the progressive conversion of gaseous trichloromethane to less chlorinated compounds, and ultimately to methane.
TBM Wienerwald Tunnel – Steps towards Successful Tunnelling
Authors: Zwittnig Gerald , Diewald Martin , Hechenblaickner Kurt
Published: December 2008

This article reports on incidents and measures which accompanied the implementation of the Wienerwald Tunnel project. The solutions found to problems that arose as work proceeded were important steps towards achieving a successful tunnelling process.
Action of Force on Rock Mass by Crack Water Pressure
Authors: Innerhofer Guntram
Published: December 2008

The formula of effective stress used in soil mechanics is adapted to the properties of rock mass by implementation of the wetting factor and the Saint‐Venant factor. The wetting factor defines the area over which a hydrostatic force can actually be developed, the Saint Venant factor defines the component of this force which is balanced by reduction of the effective stress in the crack zone. Here, the consequences of this concept are discussed with respect to uniaxial, plain stress and a continuum mechanical model. The effect of the concept is considered in relation to the state of stress in crack zones, and in the adjacent rock mass, and on the action of forces on the system. The development of crack propagation and of shear failure is discussed. The intention is to contribute towards a basic understanding of the complex effects of water pressure in rock masses, applicable to engineering practice.
San Francisco HEP Headrace Tunnel – TBM Success under the Presence of Pressurized Water in Faulty Deep Rock
Authors: de Oliveira Filho Afranio Alves , Belitardo Gustavo Teixeira , Büchi Ernst , Vigl Alois
Published: December 2008

The San Francisco Hydroelectric Project in Ecuador is utilizing hydropower from the Rio Pastaza in a 230 MW plant. 8.4 km of the 11.2 km long HRT have been excavated by a double shield (DS) TBM. After 4,950 m TBM excavation in metamorphic rock series of the Cordillera Real, the TBM was trapped by a block failure of the rock under high water ingress and the TBM shield was demolished. A rescue programme was undertaken immediately on the TBM in order to stabilize the region of the event, to get control about the water ingress, to make free and to repair the TBM and to continue excavation under controlled conditions. Concurrently an alternative rescue programme was investigated and started in order not to waste time if the rescue of the TBM should fail or if further events should occur. The TBM stoppage lasted for about five month and the rescue programme enabled the repair of the TBM and a controlled restart of the TBM without any accident. After the restart the TBM again reached a sufficient daily progress of more than 20 m/d and the tunnel could be finalized with success.
Liver damage underlying unexplained transaminase elevation in human immunodeficiency virus-1 mono-infected patients on antiretroviral therapy #
Authors: Ingiliz Patrick , Valantin Marc-Antoine , Duvivier Claudine , Medja Fadia , Dominguez Stephanie , Charlotte Frédéric , Tubiana Roland , Poynard Thierry , Katlama Christine , Lombès Anne , Benhamou Yves
Published: December 2008

Liver damage associated with chronic unexplained high serum transaminases in human immunodeficiency virus (HIV)-infected patients under combined antiretroviral therapy is unknown. Liver histology was prospectively investigated in patients presenting serum transaminase elevation for more than 6 months, after exclusion of alcohol abuse, hepatitis C virus (HCV) or hepatitis B virus (HBV) infection, autoimmune, and genetic liver diseases. In a subgroup of patients, liver mitochondrial activities were measured by spectrophotometry and mitochondrial DNA (mtDNA) by real-time polymerase chain reaction (PCR). Thirty patients were included with median values of alanine aminotransferase (ALT) levels: 80 U/L, age: 46 years, body mass index: 23 kg/m2, HIV RNA: 200 copies/mL, CD4 count: 365/mm3, duration of HIV infection: 13 years, and duration of treatment exposure: 118, 41, and 53 months for nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, and protease inhibitors, respectively. Histological anomalies were found in 22 of 30 patients. Steatosis was present in 18 patients, severe in nine patients, and associated with inflammation in 16 patients with a diagnosis of non-alcoholic steatohepatitis (NASH). Fibrosis was found in 18 patients, severe in six patients and associated with steatosis in 13 patients. Significant liver respiratory complex I defect, contrasting with high complex IV activity and normal mitochondrial DNA content, was observed in the group of patients compared with controls. The presence of NASH was correlated with high fasting glycemia and insulin levels, not with liver mitochondrial function or mitochondrial DNA content. Conclusions: HIV-infected patients on combined antiretroviral therapy with chronic transaminase elevation of unknown origin have a high rate of liver lesions, mostly consistent with NASH related to insulin resistance. (Hepatology 2008.)
Non‐linearities in the relation between the exchange rate and its fundamentals
Authors: Altavilla Carlo , De Grauwe Paul
Published: December 2008

We develop a simple theoretical model in which chartists and fundamentalists interact. The model predicts the existence of different regimes, and thus non‐linearities in the link between the exchange rate and its fundamentals. We test the model empirically by adopting a Markov‐switching vector error correction model. The results suggest the presence of non‐linear mean reversion in the nominal exchange rate process. The implications are that different sets of macroeconomic fundamentals act as driving forces of the exchange rates during different time periods. Copyright © 2008 John Wiley & Sons, Ltd.
Light‐Nutrient Influences on Biomass, Photosynthetic Potential and Composition of Suspended Algal Assemblages in the Middle Cape Fear River, USA
Authors: Dubbs Lindsay L. , Whalen Stephen C.
Published: December 2008

Dilution bioassays were conducted to evaluate the impact of nutrients on biomass (chlorophyll a), photosynthetic potential, and class composition of suspended algal assemblages in the middle Cape Fear River (USA). Ambient concentrations of dissolved inorganic nitrogen (DIN) and soluble reactive phosphorus (SRP) varied from 37.2 to 83.8 and from 1.0 to 7.1 μmol L–1. Experiments conducted at photosynthetic photon flux densities (PPFDs) similar to the mixed water column (< 1 to 5.3 E m–2d–1) showed no change in chlorophyll a, photosynthetic potential, or algal class composition at 15, 30, and 45% dilutions of DIN, SRP, or both. However, chlorophyll a and photosynthetic potential increased significantly in nutrient dilution bioassays conducted at PPFDs four‐fold above ambient, while the abundance of diatoms and Chrysophytes increased under elevated PPFD and ambient or elevated nutrients. Overall, the data indicate that irradiance is more important than nutrients in determining the size and class composition of suspended algal assemblages. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fiber technology for reliable repair of skeletal muscle
Authors: Franklin J. E. , Marler J. J. , Byrne M. T. , Melvin A. J. , Clarson S. J. , Melvin D. B.
Published: December 2008

Conventional soft‐tissue reclosure methods—sutures and staples—require substantial organized‐collagen content. Some tissues lack extensive intrinsic collagenous content. Wound disruption consequences range from newly closed abdominal wounds bursting open, to post‐cesarean wombs splitting at delivery, to heart valves loosening. Although sutures do approach the theoretical limit of normal force transfer‐cross‐sectional area times compressive strength, a different paradigm‐shear force transfer across the far greater surface attainable by fine fibers parallel to the potential disruptive force could exceed that theoretical limit. Capacity is now the product of frictional coefficient, existing tissue pressure, and contact area. Using a device comprising bundles of poly(ethylene terephthalate) fibers through tissue, we previously coupled muscles to devices and bones. Here we tested an analogous device for reclosing fascia‐stripped abdominal wall muscles. In 28 rabbits, fascia‐deprived rectus abdominus muscles were reclosed, using the experimental device or conventional sutures. Testing muscles from the 21 three‐week survivors, (with closure devices retained‐the usual clinical practice) demonstrated experimental failure strength which exceeded that of controls by 58%. Histologically, solid tissue elements did in‐grow between fibers for an extensive tissue‐prosthetic interface. Both histology and mechanical performance suggest the fiber technology presented herein surpasses conventional sutures in closure of collagen‐deficient tissues. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
A dissolution‐diffusion model for the TAXUS™ drug‐eluting stent with surface burst estimated from continuum percolation
Authors: Barocas Victor , Drasler William , Girton Tim , Guler Ismail , Knapp David , Moeller Jeff , Parsonage Edward
Published: December 2008

A two‐layer dissolution‐diffusion model is derived which incorporates a surface burst component that is estimated from continuum percolation models of overlapping Poisson distributed spheres. The model is shown to adequately describe the release properties of paclitaxel from a hydrophobic polymer matrix, including the surface burst and sustained release dependence on drug loading. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
The influence of thermal treatment on the mechanical characteristics of a PLLA coiled stent
Authors: Welch Tré R. , Eberhart Robert C. , Chuong Cheng‐Jen
Published: December 2008

We studied the effects of thermal treatment on the expansive characteristics of a coil‐within‐coil Poly(L‐lactic acid) (PLLA) fiber stent developed at our institution to improve its mechanical performance and reproducibility. Following fabrication, furled stents were thermally treated at 62°C for 25 min. The mechanical characteristics were measured compared with those of untreated stents when both were expanded via sequential balloon catheter pressure loading up to 12 atm. Treated stents reached full diameter at 3 atm and maintained that diameter despite further pressure increases. Using measurements of pressure, diameter, and axial length, we calculated the sequential mechanical work required to unfurl the stent. The mechanical work for complete unfurling of treated stents was significantly less than that required for untreated controls. Little axial dimensional change was observed for treated stents. Treated stents exhibited higher stiffness than controls at all pressure levels and also demonstrated higher resistance to external pressure‐induced collapse, as measured in a special apparatus developed in our laboratory. Differential scanning calorimetry measurements indicated higher crystallinity values for fibers used in treated stents compared with controls. SEM examination of striations revealed that treated stents underwent less twist than controls following balloon‐induced unfurling. The results indicate that, thermal treatment improves the reorientation and realignment of fiber crystalline structure, and favorably influences on the fiber stress‐strain behavior and the expansive mechanical characteristics of the PLLA fiber stents. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Scanning electron microscopic studies on surface microstructural features of some tissues of epizootic ulcerative syndrome‐affected Puntius ticto (Hamilton, 1822) from Southern Assam of India
Authors: Dey Sudip , Bhattacharyya S.P. , Chakraborty Rahul , Dutta A. , Kharbuli S.M.
Published: December 2008

Epizootic ulcerative syndrome (EUS)‐affected Puntius ticto exhibited a number of abnormalities in scale, gill, skin, and muscle at surface microstructural level. Lepidontal damage including breakage of individual lepidonts and complete loss of lepidontal assembly was evident in the scale. Disturbances in the gill included fusion of gill–lamella, distortion of lamellar surface, damage of primary and secondary gill lamella as well as breakage of gill racker. The skin of EUS‐affected Puntius ticto showed breakage of epidermal cell boundary, distortion, and loss of alignment of cells including lesions at places. Loss of alignment of muscles along with breakage and distortion of individual fibers was also evident. The similarities of these abnormalities in EUS‐affected Puntius ticto with those of pesticide and other pollutant toxicity reported in some fish is discussed with the help of relevant literature. Microsc. Res. Tech., 2009. © 2008 Wiley‐Liss, Inc.
Accurate shape from focus based on focus adjustment in optical microscopy
Authors: Shim Seong‐O , Malik Aamir Saeed , Choi Tae‐Sun
Published: December 2008

Optical microscopy allows a magnified view of the sample while decreasing the depth of focus. Although the acquired images from limited depth of field have both blurred and focused regions, they can provide depth information. The technique to estimate the depth and 3D shape of an object from the images of the same sample obtained at different focus settings is called shape from focus (SFF). In SFF, the measure of focus–sharpness–is the crucial part for final 3D shape estimation. The conventional methods compute sharpness by applying focus measure operator on each 2D image frame of the image sequence. However, such methods do not reflect the accurate focus levels in an image because the focus levels for curved objects require information from neighboring pixels in the adjacent frames too. To address this issue, we propose a new method based on focus adjustment which takes the values of the neighboring pixels from the adjacent image frames that have approximately the same initial depth as of the center pixel and then it re‐adjusts the center value accordingly. Experiments were conducted on synthetic and microscopic objects, and the results show that the proposed technique generates better shape and takes less computation time in comparison with previous SFF methods based on focused image surface (FIS) and dynamic programming. Microsc. Res. Tech., 2009. © 2008 Wiley‐Liss, Inc.
An assessment of present and future climate in the Mackenzie Delta and the near‐shore Beaufort Sea region of Canada
Authors: Bonsal Barrie R. , Kochtubajda Bohdan
Published: December 2008

Climate change is projected to significantly alter physical, biological, and socio‐economic systems, particularly in high latitudes. The Mackenzie Delta and near‐shore Beaufort Sea region of Canada is one such area that has already experienced considerable changes in climate and associated impacts. It has also been identified as highly sensitive due to recent oil and gas exploration and extraction. All Global Climate Models (GCMs) are projecting further changes to the Arctic climate, however, regional‐scale variations are not well documented. Using seven international GCMs, this study quantifies 18 future (2010–2039) temperature and precipitation projections over the Beaufort region on annual and seasonal scales. Several observed gridded temperature and precipitation datasets are also compared.

Observed climate comparisons reveal substantial variability, especially for precipitation. All future projections demonstrate temperature and for the most part, precipitation increases, however, there is a considerable range on both temporal and spatial scales. For temperature, autumn has the greatest change (+1.4 to + 3.3 °C), followed by winter (+1.2 to + 2.6 °C), spring (+0.8 to + 2.4 °C), and summer (+0.2 to + 1.6 °C). Spatially, the ocean warms more than the land during the cold season, and the eastern Beaufort is warmer than the western region. Future precipitation shows annual increases averaging between 4.8 and 10.7%. Unlike temperature, seasonal precipitation changes do not vary greatly although slight decreases are projected in some scenarios. Recent (1991–2005) temperature changes at Inuvik, Northwest Territories, indicate that Beaufort‐region warming is occurring faster than projected by the majority of GCMs. However, precipitation has not experienced these rapid changes. In terms of extremes, climate‐change projections revealed a substantial shift in the temperature distribution toward fewer very cold months and several more warm months. Extremely high monthly precipitation amounts are also projected to increase. This study can be considered an important step towards addressing future climate‐change impact assessments in Arctic regions. Copyright © 2008 Crown in the right of Canada. Published by John Wiley & Sons, Ltd.
Carcinoma of the colon: Margins of resection
Authors: Sternberg Ahud
Published: December 2008

Resection of colonic carcinoma with curative intent must encompass: (1) margins of bowel wall that are wider than the extent of microscopic intramural tumor spread beyond the macroscopic edge of the tumor; (2) lymphatic tissue draining the tumor and possibly containing cancer cells; (3) structures adhering to the tumor and possibly infiltrated by tumor cells. The minimal extent of resection that satisfies these requirements and possible benefits of extending the resection are reviewed. J. Surg. Oncol. 2008;98:603–606. © 2008 Wiley‐Liss, Inc.
Reevaluation of the rate constant for the reaction propene + NO3 by absolute rate determination
Authors: Picquet‐Varrault B. , Scarfogliero M. , Helal W. Ait , Doussin J‐F.
Published: December 2008

A rate constant for the reaction of NO3 with propene has been determined by an absolute rate technique at room temperature and atmospheric pressure. Experiments were performed in a Pyrex photoreactor coupled to two multiple reflection optical systems interfaced to a FTIR spectrometer and a UV–visible grating spectrometer. These two spectrometric devices allowed us a time‐resolved monitoring of propene and NO3 radicals. We propose the following rate constant: k = (6.4 ± l.l) × l0−15 cm3 molecule−1 s−1. This value is in good agreement with three published values but is about 30% lower than three other determinations and than the value recommended by frequently used bibliographic evaluations. As propene has been widely used as a reference compound in many other kinetic studies, implications of this reevaluation are briefly discussed. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 41: 73–81, 2009
Antagonism in (conventional anionic–gemini anionic) mixed micelle catalyzed oxidation of D‐fructose by alkaline chloramine‐T: A kinetic study
Authors: Kambo Neelu , Upadhyay Santosh K.
Published: December 2008

The catalytic effect of individual conventional anionic surfactant, namely, sodium lauryl sulfate (NaLS), anionic gemini surfactant, namely, sodium salt of bis(1‐dodecenyl succinamic acid) (NaBDS), and mixed surfactant (NaLS + NaBDS) on the rate of oxidation of D‐fructose by alkaline chloramine‐T has been investigated. The reaction always showed a first‐order dependence of rate with respect to each fructose, alkali, and chloramine‐T. The rate was proportional to (k′+k″ [surfactant]), where k′ and k″ are the rate constants in the absence and presence of the surfactant, respectively. The binding parameters have been evaluated. The observed catalytic effect of mixed micelle on the rate of oxidation was always less than the algebraic sum of the catalytic effect of two surfactants when they were taken separately, suggesting an antagonism (negative synergism) in mixed micelle. The antagonism has also been confirmed by determining critical micelle concentration and interaction parameter (βm) of mixed micelle under the experimental conditions of kinetics, that is, in alkaline medium. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 41: 123–132, 2009
Trajectories of fatigue in family caregivers of patients undergoing radiation therapy for prostate cancer
Authors: Fletcher Barbara A. Swore , Schumacher Karen L. , Dodd Marylin , Paul Steven M. , Cooper Bruce A. , Lee Kathryn , West Claudia , Aouizerat Bradley E. , Swift Patrick S. , Wara William , Miaskowski Christine
Published: December 2008

Predictors of and trajectories for evening and morning fatigue were evaluated in family caregivers of oncology patients using hierarchical linear modeling. Evening fatigue trajectory fit a quadratic model. Predictors included baseline sleep disturbances in family caregivers and baseline evening fatigue in patients. Morning fatigue trajectory fit a linear model. Predictors were baseline trait anxiety, levels of perceived family support, and baseline morning fatigue in patients. Findings suggest considerable inter‐individual variability in the trajectories of evening and morning fatigue. Evaluating family caregivers for sleep disturbance, anxiety, and poor family support, as well as high levels of patient fatigue, could identify those family caregivers at highest risk for sustained fatigue trajectories. © 2008 Wiley Periodicals, Inc. Res Nurs Health 32:125–139, 2009
How international nonprofits build brand equity
Authors: Laidler‐Kylander Nathalie , Simonin Bernard
Published: December 2008

This paper describes an empirical model of brand equity for international nonprofit organizations and offers nonprofit managers suggestions for the management of their brands. The main areas of interest include:

A review of the importance of branding for nonprofits, the lack of a brand equity models specifically for nonprofits, and the key differences between for‐profits and nonprofits.

A proposed nonprofit brand equity model, based on a grounded theory and system dynamics approach.

A series of specific managerial recommendations, for building nonprofit brand equity.

Copyright © 2008 John Wiley & Sons, Ltd.
The long‐term effects of housing assistance on work and welfare
Authors: Newman Sandra , Holupka C. Scott , Harkness Joseph
Published: December 2008

This paper examines the long‐term effect of project‐based housing assistance—public housing and private assisted housing—on work, earnings, and welfare receipt. We use the Panel Study of Income Dynamics–Assisted Housing Database to identify women ever living in project‐based assisted housing and to create comparison groups using propensity scores. Analyses show no evidence that moving into this type of assisted housing is associated with sustained reductions in employment rates, work hours, or earnings. Although welfare rates decline, they remain higher for assisted housing recipients compared with nonrecipients. Overall, these findings align with those of recent experimental and nonexperimental studies that include other forms of housing assistance and cover different time periods. © 2009 by the Association for Public Policy Analysis and Management.
Inequities in enforcement? Environmental justice and government performance
Authors: Konisky David M.
Published: December 2008

This paper examines whether state governments perform systematically less environmental enforcement of facilities in communities with higher minority and low‐income populations. Although this is an important claim made by environmental justice advocates, it has received little attention in the scholarly literature. Specifically, I analyze state regulatory enforcement of three U.S. pollution control laws—the Clean Air Act, the Clean Water Act, and the Resource Conservation and Recovery Act—over the period 1985–2000. To test for disparities in enforcement, I estimate a series of count models and find strong evidence across each of the three environmental laws that states perform less enforcement in poor counties, but little evidence of race‐based inequities. © 2009 by the Association for Public Policy Analysis and Management.
Institutional factors affecting biophysical outcomes in forest management
Authors: Coleman Eric A.
Published: December 2008

Although there is considerable interest in the impact of diverse policies affecting the biophysical outcomes in forests, gaining a substantial sample over time of forests under different institutional arrangements has been difficult. This article analyzes data from 46 forests located in six countries over time. In forests where policies have been adopted for conservation, active monitoring and sanctioning by locals is associated with positive forest conditions. Forests that allow user group harvesting, perhaps counterintuitively, are also shown to be associated with positive forest conditions. However, conditions in community‐managed forests are not statistically different from government‐ or privately managed forests. This implies that local communities can play an important role in achieving positive forest conditions but that full management responsibilities need not be given to achieve these results. © 2009 by the Association for Public Policy Analysis and Management.
Numerical study of transient natural convection in a cavity with multiple adiabatic blocks
Authors: Dalal Durga Charan , Pandit Swapan Kumar
Published: December 2008

This study deals with the solution of a problem of unsteady natural convection in a thermally driven square enclosure with four adiabatic square blocks placed inside. The governing equations are solved numerically using higher order compact schemes. Results are in good agreement with the established results for some special cases. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An immersed interface method for the Navier‐Stokes equations on irregular domains
Authors: Li Zhilin , Lai Ming‐Chih , Ito Kazufumi
Published: December 2008

An augmented method based on a Cartesian grid is proposed for the incompressible Navier Stokes equations on an irregular domain. The irregular domain is embedded into a rectangular one so that a fast Poisson solver can be used in the projection method. Unlike several methods suggested in the literature that set the force strengths as unknowns, which often results an ill‐conditioned linear system, we set the jump in the normal derivative of the velocity as the augmented variable. The new approach improve the condition number of the system for the augmented variable significantly. Using the immersed interface method, we achieve second order accuracy for the velocity. Numerical results and comparisons are given to validate the new method. Some interesting new numerical experiments results are also presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Discrete mechanics and control on Lie groupoids
Authors: Martínez Eduardo
Published: December 2008

The first order optimality conditions for discrete‐time optimal control problems defined on Lie groupoids are found, and they are expressed in terms of composability in a groupoid. Some examples are shown. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inversion of the X‐ray transform from limited angle parallel beam region of interest data with applications to electron tomography
Authors: Öktem Ozan , Quinto Eric Todd
Published: December 2008

We present a new local tomographic algorithm applicable to electron microscopy tomography. Our algorithm applies to the standard data acquisition method, single‐axis tilting, as well as for more arbitrary acquisition methods. Using microlocal analysis we put the reconstructions in a mathematical context, explaining which singularities are stably visible from the limited data given by the data collection protocol in the electron microscope. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Versions of inexact Kleinman‐Newton methods for Riccati equations
Authors: Hylla Timo , Sachs E. W.
Published: December 2008

Optimal control problems involving PDEs often lead in practice to the numerical computation of feedback laws for an optimal control. This is achieved through the solution of a Riccati equation which can be large scale, since the discretized problems are large scale and require special attention in their numerical solution. The Kleinman‐Newton method is a classical way to solve an algebraic Riccati equation. We look at two versions of an extension of this method to an inexact Newton method. It can be shown that these two implementable versions of Newton's method are identical in the exact case, but differ substantially for the inexact Newton method. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
New development of parallel robots and microrobots with three, four and five degrees of freedom
Authors: Plitea N. , Vidrean A. , Pisla D. , Pisla A. , Vaida C.
Published: December 2008

All over the world it can be noticed that product miniaturisation is a central theme in product development for different application areas. In robotics scientific research, one of the most important approaches is concerning the increase of the positioning accuracy by the use of parallel structures [3], [4], [5]. In this paper some variants of parallel robots and micro‐robots with three, four and five degrees of freedom are presented, which are used for manipulation within high precision assembling processes. The corresponding kinematic models have been developed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Riemann problems in FPU chains
Authors: Herrmann Michael , Rademacher Jens D.M.
Published: December 2008

We impose Riemann initial data to FPU chains and study the solutions on the hyperbolic macroscopic scale. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A fully variational strong discontinuity approach at finite strains
Authors: Radulovic Radan , Mosler Jörn
Published: December 2008

A novel, fully variational three‐dimensional finite element formulation for the modeling of locally embedded strong discontinuities at finite strains is presented. The proposed numerical model is based on the Enhanced Assumed Strain concept with an additive decomposition of the displacement gradient into a conforming and an enhanced part. The discontinuous component of the displacement field which is associated with the failure in the modeled structure is isolated in the enhanced part of the deformation gradient. In contrast to previous works, a variational constitutive update is used. The internal variables are determined by minimizing a pseudo‐elastic potential. The advantages of such a formulation are well known, e.g. the tangent stiffness matrix is symmetric, standard optimization algorithms can be applied and it represents a natural basis for error estimation and mesh adaption. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling the cerebral blood flow using a linear system approach
Authors: Reichold Johannes , Weber Bruno , Buck Alfred , Jenny Patrick
Published: December 2008

Cerebral blood flow (CBF) can be defined as the rate of delivery of arterial (nutritive) blood to the capillary beds of a particular mass of brain tissue. CBF assumes a fundamental role in homeostasis and neural activity as it regulates the supply of glucose and oxygen. A linear systems approach is employed to model CBF in a realistic vascular network. High‐resolution 3D data of the cerebral angioarchitecture in animal models acquired by Weber et al. [1] are utilized to create an analogous unstructured computational grid. Pressure boundary conditions are set at the large arteries and veins. Vessel properties such as diameter and curvature are represented by a corresponding transmissibility value. Vasodilation during neural activity or partial occlusion in cerebrovascular impairment are examples of localized changes in vessel attributes. It is investigated how these local alterations affect the global CBF. Among others, insights gained from the simulations are valuable for the correct interpretation of data acquired by magnetic resonance imaging modalities. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Edgeworthian economies
Authors: Finkenstädt Barbel , Pinto Alberto A. , Ferreira Miguel , Oliveira Bruno M.P.M.
Published: December 2008

We present a model of an Edgeworthian exchange economy where two goods are traded in a random meeting market place. The novelty of our model is that we associate a greediness factor to each participant which brings up a game alike the prisoner's dilemma into the usual Edgeworthian exchange economy. Along the time, random pairs of participants are chosen, and they trade or not according to their greediness. Furthermore, we let the greediness of the participants evolve along the trades according to one of the following rules: (a) the greediness of the participants decreases if they were able to trade and increases otherwise; (b) the greediness of the participants increases if they were able to trade and decreases otherwise. We observe that for rule (a) the greediness of each participant converges to one of two possible values, and that for rule (b) the greediness of all participants converges to a single value. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An Euler solver for the acoustic far‐field prediction of compressible jet flow
Authors: Keiderling Felix , Obrist Dominik , Müller Sebastian B. , Kleiser Leonhard
Published: December 2008

We report on a highly accurate Euler solver for predicting far‐field jet noise. The solver is based on a framework for Direct Numerical Simulation (DNS) / Large‐Eddy Simulation (LES) that provides the time‐dependent, noise‐generating flow field and the acoustic near‐field. The corresponding far‐field is then computed by solving the inviscid Euler equations in a conservative formulation which is discretized with compact finite differences. Numerical stability can be guaranteed by a spectrally selective filtering procedure developed in the context of subgrid‐scale modeling which is active only in the high wavenumber regime. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Propagation of localized bending deformations in microtubules
Authors: Tuszyński J. A. , Portet S. , Dixon J. M.
Published: December 2008

A continuum medium model is proposed describing a microtubule (MT) as an elastic rod. When the MT is subjected to a constant bending force, the dynamics of the angular deviation, with respect to the MT's rectilinear configuration, is governed by a Sine‐Gordon equation. Particular analytical solutions are kink and anti‐kink bending modes which may propagate at various speeds along the MT's length. Kinetic energies of these modes compare with thermal and ATP hydrolysis energies. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Existence of solutions for motion equations for an objective model of viscoelastic medium
Authors: Zvyagin Victor , Vorotnikov Dmitry
Published: December 2008

We consider the Dirichlet initial‐boundary value problem for the equations of motion of incompressible viscoelastic medium with objective rheological constitutive laws of Maxwell and Jeffreys kind. Several types of existence results are presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the effect of Kirkendall voids on solder joint reliability
Authors: Müller Wolfgang H. , Weinberg Kerstin , Böhme Thomas
Published: December 2008

A model for the theoretical description of Kirkendall voiding is presented based on vacancy diffusion and plastic deformation of spherical voids. We start with a phenomenological explanation of the Kirkendall phenomenon and discuss its consequences on microelectronic reliability. After that a constitutive model for void growth is introduced, which, for instances, can be used in order to predict the temporal development of a certain void distribution. We end this paper with exemplary numerical studies. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mixing symbolic and numerical approaches for the surface‐to‐surface intersection problem
Authors: Fioravanti Mario , Gonzalez‐Vega Laureano
Published: December 2008

This paper shows how the efficiency of the current methodologies applied to the surface‐to‐surface intersection problem can be improved by combining an algebraic/symbolic framework with efficient and robust numerical techniques. The algebraic/symbolic framework is used to translate the computation of resultants, subresultants, discriminants, etc. to one or several generalized eigenvalue problems and SVD computations. The framework requires only the values of the involved polynomials at some set of points, and it will guide the numerical computations, providing thus a certificate of the topological correctness of the output. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Packing cylinders on a cylinder with contact constraints
Authors: Goold Eric , Rakesh Leela
Published: December 2008

The problem of cylinder packing is investigated. The specific problem is to determine the maximum number of congruent cylinders that can be packed around a core cylinder of arbitrary dimensions. The constraint is that their circular face must keep in contact with the core cylinder and there may be no overlapping. Only right circular cylinders are considered. Mathematically, a lower and upper bound is determined. A quantitative result is also found using a modified genetic algorithm. The algorithm was found to reproduce the published results for the top and bottom circular faces of the core which reduces to the problem of packing congruent circles within a circle. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)