bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transport of suspended sediment under the dam‐break flow on an inclined plane bed of arbitrary slope
Authors: Bohorquez P. , Fernandez‐Feria R. 
Published: November 2007

AbstractThe problem of transport of suspended sediment after the break of a dam on an inclined bed is considered. To that end we use the shallow‐water approximation for arbitrary, constant slopes of the bottom, taking into consideration the effect of friction. The numerical technique and the frictional model are validated by comparison with available experimental data and asymptotic analytical solutions, with special attention to the numerical solution near the wetting front. The transport of suspended sediment down the inclined bed is obtained and discussed as a function of the slope of the bed for different values of the parameters characterizing the sediment and its transport properties. For sufficiently large times we always find the formation of roll waves near the water front, which affects the transport of sediments significantly. These strong oscillations are accurately computed with the numerical method used. The relative importance of the bed load (to the suspended load) sediment transport is also discussed as a function of the size of the sediment particles and the slope of the bed for different models on the initiation of sediment suspension from bed load. We also check the dilute sediment approach and characterize the conditions for its failure. Finally, the results of the present simplified model are intended to be used as tests of more complex numerical models. Copyright © 2007 John Wiley & Sons, Ltd.
Lipase‐mediated methanolysis of soybean oils for biodiesel production
Authors: Chen Xin , Du Wei , Liu Dehua , Ding Fuxin 
Published: November 2007

AbstractBACKGROUND: Biodiesel is increasingly perceived as an important component of solutions to the important current issues of fossil fuel shortages and environmental pollution. Biocatalysis of soybean oils using soluble lipase offers an alternative approach to lipase‐catalyzed biodiesel production using immobilized enzyme or whole‐cell catalysis. The central composite design (CCD) of response surface methodology (RSM) was used here to evaluate the effects of enzyme concentration, temperature, molar ratio of methanol to oil and stirring rate on the yield of fatty methyl ester.RESULTS: Lipase NS81006 from a genetically modified Aspergillus oryzae was utilized as the catalyst for the transesterification of soybean oil for biodiesel production. The experimental data showed that enzyme concentration, molar ratio of methanol to oil and stirring rate had the most significant impact on the yield of fatty methyl ester; a quadratic polynomial equation was obtained for methyl ester yield by multiple regression analysis. The predicted biodiesel yield was 0.928 (w/w) under the optimal conditions and the subsequent verification experiments with biodiesel yield of 0.936 ± 0.014 (w/w) confirmed the validity of the predicted model.CONCLUSION: RSM and CCD were suitable techniques to optimize the transesterification of soybean oil for biodiesel production by soluble lipase NS81006. The related lipase NS81006 reuse stability, chemical or genetic modification, and transesterification mechanism should be taken into consideration. Copyright © 2007 Society of Chemical Industry
Start‐up and enrichment of a granular anammox SBR to treat high nitrogen load wastewaters
Authors: López Helio , Puig Sebastià , Ganigué Ramon , Ruscalleda Maël , Balaguer Maria D , Colprim Jesús 
Published: November 2007

AbstractBACKGROUND: Landfill leachate is characterized by low biodegradable organic matter that presents difficulties for the complete biological nitrogen removal usually performed by conventional biological nitrification/denitrification processes. To achieve this, the anaerobic ammonium oxidation (anammox) process is a promising biological treatment. This paper presents an anammox start‐up and enrichment methodology for treating high nitrogen load wastewaters using sequencing batch reactor (SBR) technology.RESULTS: The methodology is based on the gradual increase of the nitrite‐to‐ammonium molar ratio in the influent (from 0.76 to 1.32 mole NO2−‐N mole−1NH4+‐N) and on the exponential increase of the nitrogen loading rate (NLR, from 0.01 to 1.60 kg N m−3 d−1). 60 days after start‐up, anammox organisms were identified by polymerase chain reaction (PCR) technique as Candidatus Brocadia anammoxidans. After one year of operation, NLR had reached a value of 1.60 kg N m−3 d−1 with a nitrogen (ammonium plus nitrite) removal efficiency of 99.7%. The anammox biomass activity was verified by nitrogen mass balances with 1.32 ± 0.05 mole of nitrite removed per mole of ammonium removed and 0.23 ± 0.05 mole of nitrate produced per mole of ammonium removed. Also, enrichment of anammox bacteria was quantified by fluorescence in situ hybridization (FISH) analysis as 85.0 ± 1.8%.CONCLUSIONS: This paper provides a methodology for the enrichment of the anammox biomass in a SBR to treat high nitrogen loaded wastewaters. Copyright © 2007 Society of Chemical Industry
Electrochemical characteristics of titanium based biomaterials in artificial saliva
Authors: Mareci D. , Ungureanu G. , Aelenei D. M. , Rosca J. C. Mirza 
Published: November 2007

AbstractIn the last decade, new titanium alloys have been developed in different areas of dentistry, such as Ti6Al7Nb, Ti6Al2Nb1Ta1Nb, and Ti5Al2.5Fe. The aim of this study was to compare the Ti6Al7Nb, Ti6Al2Nb1Ta1Nb, Ti5Al2.5Fe, and Ti6Al4V alloys with the commercial titanium, regarding the corrosion resistance in artificial saliva. In the electrochemical estimations the polarization data are converted into instantaneous corrosion rate values (Icorr). The passivation properties were comparable for the four alloys. The EIS spectra are best fitted using an equivalent circuit (EC), which corresponds to the model of a two‐layer structure for the passive film. High impedance values (in the order of 106 Ω cm2) were obtained from medium to low frequencies for all materials suggesting high corrosion resistance in artificial saliva.The electrochemical and corrosion behavior of Ti6Al4V is not affected on substituting vanadium with niobium, iron, molybdenum, and tantalum.
Degradation processes in Al/SiCp/MgAl2O4 composites prepared from recycled aluminum with fly ash and rice hull ash
Authors: Pech‐Canul M. I. , Escalera‐Lozano R. , Pech‐Canul M. A. , Rendón‐Angeles J. C. , López‐Cuevas J. 
Published: November 2007

AbstractThe degradation characteristics of Al/SiCp/spinel composites prepared with fly ash (FA) and rice hull ash (RHA) under environmental conditions were investigated. Composite specimens were prepared with recycled aluminum via reactive infiltration in the temperature range 1050–1150 °C for 50–70 min and, in argon atmosphere at a pressure slightly above that of the atmospheric pressure. Results reveal that although both FA and RHA help in preventing SiCp dissolution and the subsequent chemical degradation of the composites, due to the interaction of native carbon in FA with liquid aluminum, FA‐composites are susceptible to corrosion via Al4C3. Moreover, this phase accelerates the degradation process and increases the damage severity. The primary corrosion mechanism in both types of composites is attributed to microgalvanic coupling between the intermetallic Mg2Si and the matrix. Accordingly, an appropriate control of the Si/(Si + Mg) molar ratio in the aluminum alloy hinders the Mg2Si corrosion mechanism in both types of composites and a proper FA calcination prevents chemical degradation in FA composites.
Synthesis and magnetic properties of novel polymeric complexes containing bithiazole rings
Authors: Lin Weihong , Sun Weilin , Shen Zhiquan 
Published: November 2007

AbstractA novel linear polymer (PFABT) containing bithiazole rings was synthesized by polycondensation of 2,2′‐diamino‐4,4′‐bithiazole (DABT) and formaldehyde. The complexes of PFABT with two transition metal ions (Fe2+, Cu2+) were prepared for the first time. The polymer was determined through FT‐IR, 1H‐NMR and elemental analysis (EA), and the complexes were characterized by FT‐IR. The magnetic behaviors of these complexes were measured as a function of magnetic field strength (0–50 kOe) at 4 K and as a function of temperature (4–300 K) under an applied magnetic field of 30 kOe. The results show that PFABT‐Cu2+ is a ferromagnet while PFABT‐Fe2+ is an anti‐ferromagnet. Copyright © 2007 John Wiley & Sons, Ltd.
Optical observation of discrete well width fluctuations in wide band gap III‐nitride quantum wells [phys. stat. sol. (b) 244, No. 5, 1727–1734 (2007)]
Authors: Haratizadeh H. , Monemar B. , Paskov Plamen P. , Holtz Per Olof , Valcheva E. , Iwaya M. , Kamiyama S. , Amano H. , Akasaki I. 
Published: November 2007

AbstractThe following author has to be removed from the list of authors in phys. stat. sol. (b) 244, 1727 (2007): Per Person, Linköping University, Sweden. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Today's Copernican flip: how putting collaborative learning at the hub of human evolution improves our chances of survival
Authors: Goerner Sally J. 
Published: November 2007

AbstractCivilization is reinventing itself, much as it did 500 years ago in the shift from medieval to modern patterns of society. This time, the modern, mechanistic, imperialistic approach to life is failing and a new, ‘collaborative learning species’ vision of humanity and ‘ecosystem’ view of Global Integral Civilization is rising to take its place. Systems science stands at the heart of a new, integral stage of science that supports this new stage of civilization, not only with empirical and methodological detail, but also with a solid foundation for the new cultural and economic understandings. The result is a Copernican flip in our scientific view of the world and a new Enlightenment movement beginning to gather force throughout the world. Yet, though the ideas, the technologies, the ennobling inspiration and even the popular desire for this new era already exist, so far they remain diffuse and disjoint—obscured, suffocated and intimidated beneath the powerful pressures of business as usual. Today's challenge is to use the new scientific framework to build the intellectual clarity, common‐cause unity and social infrastructure needed to achieve the next stage in human development by channelling these positive forces into a self‐sustaining, actively learning whole. Copyright © 2007 John Wiley & Sons, Ltd.
Fostering a sustainable learning society through knowledge‐based development
Authors: Laszlo Kathia Castro , Laszlo Alexander 
Published: November 2007

AbstractAccording to convention, there appears to be two main purposes of knowledge‐based development: economic prosperity and human development. This paper emphasizes the importance of the balance between these two purposes and suggests that they need to be complemented with an axiological framework grounded in a systemic and evolutionary perspective. Such a contextualization of development brings sustainability into focus and gives direction and meaning to related knowledge strategies. The notion of the knowledge economy has long been embraced as an attractive next stage of post‐industrial society. However, it remains grounded in an economic model that treats society and the biosphere as externalities. As a result, the knowledge economy appears as an improved but essentially unchanged paradigm of value exchange that continues to increase the gap between rich and poor, ignores the intrinsic value of living and life‐supporting systems and undermines the viability of the biosphere—as if human systems could live without it. A new framework for understanding development in a systemic and interconnected way—evolutionary development—is presented as the larger container within which knowledge strategies could make a significant difference in terms of the creation of value—not only financial, but also human, social and ecosystemic. The case of Monterrey, Mexico, as the host of the Universal Forum of Cultures in 2007 and as a place with the intention of becoming a knowledge city, is used to highlight the concrete opportunities to link the economic and human dimensions of knowledge‐based development for the creation of a sustainable learning society. Copyright © 2007 John Wiley & Sons, Ltd.
Reflexivity in social systems: the theories of George Soros
Authors: Umpleby Stuart 
Published: November 2007

AbstractGeorge Soros's reflexivity theory is quite compatible with second order cybernetics. Indeed his work shows how to apply ideas in second order cybernetics to economics, finance and political science. This paper briefly reviews three theories of reflexivity in cybernetics. It provides an introduction to Soros's version of reflexivity theory and reviews applications in economics and finance. Soros's approach to economics is based on different assumptions about information and about human behaviour. His approach to finance is more holistic than most current work in finance. He does not emphasize mathematical models but rather sees finance as a human player game with himself as a participant. The paper concludes that Soros's work is a very important contribution to and expansion of contemporary social science. Copyright © 2007 John Wiley & Sons, Ltd.
Testing friction and wear of the tribosystem piston ring and cylinder liner outside of engines
Authors: Woydt Mathias , Ebrecht Johannes 
Published: November 2007

AbstractAn OEM‐driven working group started in January 2004 to elaborate the philosophies, concepts and test procedures for testing piston ring and cylinder liner materials as well as engine oils outside of engines using the SRV (abbreviation for German: ‘Schwingung, Reibung, Verschleiß’; in English: ‘Oscillation, Friction, Wear’) test equipment. The different SRV test philosophies in use by OEMs are compiled. The working group focuses on (i) ASTM fuel economy sequence by ageing oils; (ii) friction and wear in the top‐dead‐centre region under mixed/boundary lubrication; (iii) extreme pressure load under mixed/boundary lubrication; and (iv) hydrodynamic friction. Tribological test results and precision data are presented. Copyright © 2007 John Wiley & Sons, Ltd.
Experimental manipulation of the timing of reproduction in the California vole
Authors: Lidicker William Z. 
Published: November 2007

SummaryThe potential role of food and water in determining 1) the timing of the normal breeding season in the California vole, and 2) two frequently occurring exceptions to this normal pattern, are explored by using experimentally manipulated enclosed populations. Hypotheses derived from field observations were tested in the enclosed populations by the manipulation of green food, dry food, water, and vole density. The results of three experiments involving five populations are reported. In all populations densities were maintained at near‐normal levels (475 to 1750 per ha).In all three experiments, it was shown that breeding was possible in the summer if sufficient food and water were available, although perhaps with reduced litter sizes and rates of growth and reproductive maturation of young. In two cases, severe weight losses and high mortality were induced by insufficient water. When water was provided, survivors recovered weight and reproductive competency in between five weeks and eight months. In three populations, starvation induced weight losses and mortality. In these cases recovery of the voles took only one month or less. In two of these last, the inadequate food situation was produced during the normally wet season by outbreaks of a European slug.It is concluded that available moisture is the most important factor in triggering both the end and beginning of the normal breeding season. Of course, inadequately fed mice do not breed at any season. Summer (dry season) breeding can occur when food and water conditions are adequate due to locally favorable conditions or very low population densities. Prolonged delays in growth and reproduction following the return of favorable conditions are most likely the consequence of chronic and severe water deprivation.
Effects of contagious distributions of parasitoid eggs per host and of sampling vagaries on Nicholson's area of discovery
Authors: Stinner R. E. , Lucas H. L. 
Published: November 2007

SummaryHassell andVarley described a negative relationship between the Nicholsonian area of discovery and parasitoid density that permits coexistence of two or more parasitoid species and yields stability. They ascribed the relationship to “mutual interference” among searching parasitoid adults, leading to a “decreased efficiency”. This matter has recently been studied in more detail byHassell and coworkers. Negative relationships can occur for several reasons. In the present paper it is shown that the negative relation occurs under certain assumptions about the way parasitoid eggs are distributed among hosts. Several “contagious” (or “clustered”) distributions were studied. Those assuming variation in host susceptibility or accessibility (negative binomial and added zeros distributions) yielded negative relations. Those assuming variation in parasitoid aggressiveness and fecundity (Neyman Type A distributions) yielded variable results depending on how the distributions of parasitoids per host and of eggs per parasitoid were combined. It was found that, when analyzing actual data, sampling fluctuations can introduce strong negative relations either with or without “contagion”. In all instances, the relation between area of discovery and parasitoid density is affected by host density and is, in general, not linear. The foregoing findings raise serious questions about the area of discovery concept. An alternative approach is suggested.
Dispersal distances of the Caribbean fruit fly, corn planthopper and Cuban May beetle
Authors: Wolfenbarger D. O. , Samol H. H. , Habeck D. H. 
Published: November 2007

SummaryAdults of the Caribbean fruit fly, Anastrepha suspensa (Loew), and Cuban May beetle, Phyllophaga bruneriChapin, were recovered at various distances from release sites. Corn planthopper, Peregrinus maidis (Ashmead), adults were numerous and more dead corn plants were found beside the grassy areas indicating that incidence of the disease was related to the insect abundance. Regression curves showed that rates of dispersion of insects or incidence of dead corn plants were related to distance.
Population dynamics of Malacosoma neustria testacea (Lepidoptera: Lasiocampidae): Stabilizing process in a field population
Authors: Shiga Masakazu 
Published: November 2007

SummaryStabilizing mechanism in population of Malacosoma neustria testacea was investigated in a central part of Japan based on eight year survey.Population fluctuation in each developmental stage in the experimental field was rather small, i.e., 5.9 times in egg and 85.0 times in female adult. Pupal weight negatively correlated with the densities of 5th instar larvae and prepupae (cocoons) and correlation coefficient was highly significant in females. Population density was stabilized by density‐dependent dispersal of female moths in preovipositional period. Comparison between fecundity of emerged moths and that of actually oviposited ones in the experimental field suggested that density‐dependent dispersal took place as the result of density‐dependent size variation, i. e., small‐sized female moths have higher flying ability. This hypothesis was supported by the experiment in which flying ability of newly emerged female moth was measured. Similar stabilizing mechanism is expected to occur in semelparous or pro‐ovigenic insects.
Nutritional management of patients with urea cycle disorders
Authors: Singh R. H. 
Published: November 2007

SummaryThe nutritional management of patients with urea cycle disorders (UCDs) involves restriction of dietary protein along with provision of adequate protein‐free energy, essential amino acid supplements, and vitamins and minerals in combination with nitrogen‐scavenging drugs. The present paper discusses nutrition therapy for a range of circumstances: during an acute hyperammonaemic episode and at hospital discharge; before, during, and after surgery; and for lifelong chronic management of UCDs.
Cowpea [Vigna unguiculata (L.) Walp.] core collection defined by geographical, agronomical and botanical descriptors
Authors: Mahalakshmi V. , Ng Q. , Lawson M. , Ortiz R. 
Published: November 2007

Cowpea is a drought-tolerant food legume grown in the savannah regions of the tropics and subtropics. The International Institute for Tropical Agriculture (IITA) holds the world collection of 15,003 cultivated cowpea from 89 countries in its genebank. In excess of 12,000 accessions were characterized for 28 agrobotanical descriptors. The entire collection was first stratified by country of origin and biological status. Land race accessions (10,227) with information on origin and characterization data were grouped using clustering procedures. The clustering analysis was based on Euclidean distances between and among accessions. Accessions within each country were then grouped hierarchically, according to their similarity. The number of clusters selected for countries varied from 2 to 20, depending on the size of collection for that country. A percentage number of accessions (5–25%) was chosen from each country, based on the size of the collection and its proximity to the centre of diversity. The number of accessions from each cluster in a country was then chosen randomly, based on the predetermined percentage. In countries where the numbers of accessions were few ( &lt; 10), the percentage chosen from those countries would be higher and may go up to 100% to ensure that at least one accession was chosen from every country. Accessions with no characterization information were treated as a group, and accessions were chosen randomly, based on their geographical distribution. In the process of selection, 200 accessions that are known to be resistant to pests and diseases and not originally chosen through the selection processes were, nevertheless, kept as part of the core collection. Following these procedures, a total of 1701 accessions of landraces were chosen from the entire collection. Using the same procedures, a subset of 225 accessions was chosen from 1422 advanced cultivars and breeding or research lines. A third subset of 130 accessions was chosen from 838 accessions that either lack information on origin or biological status, and six accessions of wild and weedy forms from the available 64 wild and weed accessions were added. Thus a core collection of 2062 accessions of cowpea was constituted. The diversity in the core collection was similar to that of the entire collection and correlated traits that may be linked were also preserved in the core collection. This core collection of cowpea provides an opportunity for further exploitation of the cowpea germplasm for improvement of this crop.