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Selected AbstractsVOL. 14 AUTHOR INDEXCLINICAL PSYCHOLOGY: SCIENCE AND PRACTICE, Issue 4 2007Article first published online: 13 NOV 200 No abstract is available for this article. [source] Exploratory behavior in mice selectively bred for developmental differences in aggressive behaviorDEVELOPMENTAL PSYCHOBIOLOGY, Issue 1 2008Kathryn E. Hood Abstract The development and expression of exploratory behavior was assessed in the Cairns lines of Institute for Cancer Research (ICR) mice that were selectively bred for differences in aggressive behavior, with a high-aggressive 900 line, low-aggressive 100 line, and control 500 line. Four paradigms were employed. Developmental changes were evident in the complex novel arena, with older males faster to contact a novel object, and ambulating more than young males. Within the control 500 line, older males showed longer latency to emerge from the home cage, and shorter latency to contact novel objects. In the 900 line, younger males showed this same pattern. R. B. Cairns proposed that line differences in aggressive behavior arise through alterations in developmental timing [Cairns et al. [1983] Life-span developmental psychology (Vol. 5). New York: Academic Press; Gariépy et al. [2001] Animal Behaviour 61: 933,947]. The early appearance of mature patterns of exploratory behavior in 900 line males supports this interpretation. The 900 line males also appear to be behaviorally inhibited in novel settings such as the light,dark box and the neohypophagia paradigm, compared to the 500 and 100 lines (Experiments 1, 2, and 4). Moreover, in the most complex apparatus, the novel arena, 900 line males were slowest to exit the home cage, and fastest to contact a novel object. The apparent contrast in these parameters of exploratory behavior is discussed in relation to T. C. Schneirla's [1965 Advances in the study of behavior (Vol. 1). New York: PN Academic] approach,withdrawal theory. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 50: 32,47, 2008. [source] Author Index (Vol. 120)ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 3 2006Article first published online: 11 AUG 200 No abstract is available for this article. [source] Author Index (Vol. 116)ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 3 2005Article first published online: 15 AUG 200 No abstract is available for this article. [source] Improving the Evaluation of Rural Development Policy Pour une meilleure évaluation de la politique de développement rural Die Evaluation der Politik zur Entwicklung des ländlichen Raums verbessernEUROCHOICES, Issue 1 2010David Blandford Summary Improving the Evaluation of Rural Development Policy A previous EuroChoices (Vol. 7, No. 1) compared and contrasted approaches to rural development policy in the EU and US. This Special Issue focuses on the evaluation of these policies, drawing on a workshop held in June 2009 at OECD Conference Center in Paris. Evaluation is an activity that runs parallel with policymaking and is capable of contributing to effectiveness and efficiency at all stages. Evaluators, wherever they work and whatever aspect of rural development is their focus, face some common technical problems. These include multiple (and often ill-defined) policy objectives, the choice of appropriate indicators (especially the need to distinguish between outputs and outcomes), how to establish baseline values, where to draw boundaries in terms of impact and time, and the identification of additionality and causality. Ensuring that lessons learned from evaluation are actually applied is problematic. Experiences covered in this Issue include the use of macro and case-study approaches, and various schemes (investment in human and social capital, and agri-environment and forestry). There is an inherent tension between using a common approach across countries and regions in the interests of comparability and the flexibility needed to capture all the relevant factors in the diverse situations in which rural development actions take place. Un précédent numéro de EuroChoices (Vol. 7, No. 1) comparait et mettait en regard les approches de l'Union européenne et des États-Unis en terme de politique de développement rural. Ce numéro spécial est consacréà l'évaluation de la politique et tire parti d'un atelier qui s'est tenu en juin 2009 au Centre de Conférences de l'OCDE à Paris. L'évaluation va de pair avec l'élaboration des politiques et peut contribuer à améliorer l'efficacité et l'efficience à tous les stades. Quels que soient leur affiliation et l'aspect du développement rural sur lequel ils se concentrent, les évaluateurs sont confrontés à certains problèmes techniques communs. Il s'agit des objectifs multiples (et souvent mal définis) de la politique, du choix d'indicateurs pertinents (en particulier la nécessité de faire la différence entre produit et résultat), de la manière d'établir des valeurs de référence, de la fixation de limites en terme d'incidence et de durée, et de l'identification des effets additifs et de la causalité. Il est difficile de s'assurer que les leçons tirées des évaluations sont effectivement retenues. Les expériences rapportées dans ce numéro comprennent des approches macroéconomiques ou fondées sur des études de cas, et couvrent différents programmes (investissements dans le capital social et humain, mesures agroenvironnementales, mesures forestières). Il existe une tension évidente entre l'utilisation d'une approche commune entre chaque pays et région, qui vise la comparabilité, et la flexibilité qui permet de prendre en compte l'ensemble des différents facteurs des situations variées dans lesquelles les mesures de développement rural sont appliquées. In einer vorherigen Ausgabe von EuroChoices (7:1) wurden Herangehensweisen an die Politik zur Entwicklung des ländlichen Raums in der EU und in den USA verglichen und diskutiert. Diese Sonderausgabe beschäftigt sich auf der Grundlage eines Workshops, der im Juni 2009 am OECD-Hauptsitz in Paris abgehalten wurde, mit Politikevaluation. Die Evaluation erfolgt parallel zur Politikgestaltung und kann in jeder Phase zur Steigerung von Wirksamkeit und Effizienz beitragen. Evaluatoren stehen einigen allgemeinen technischen Problemen gegenüber , ganz gleich, wo sie arbeiten und welchen Aspekten ländlicher Entwicklung sie sich widmen. Dazu zählen multiple (und oftmals unzureichend definierte) politische Ziele; die Auswahl von geeigneten Indikatoren (hier muss insbesondere zwischen Endprodukten und Ergebnissen unterschieden werden); die Frage, wie Ausgangswerte festzulegen und wo Grenzen im Hinblick auf Auswirkungen und den zeitlichen Rahmen zu setzen sind; sowie die Identifizierung von Additionalität und Kausalität. Es ist schwierig sicherzustellen, dass die Erkenntnisse aus der Evaluation auch umgesetzt werden. Die in dieser Ausgabe aufgegriffenen Erfahrungen berücksichtigen u.a. Makro- und Fallstudienansätze sowie verschiedene Maßnahmen (Investitionen in Human-/Sozialkapital sowie Agrarumwelt und Forstwirtschaft). Es besteht eine grundsätzliche Spannung zwischen einer im Interesse der Vergleichbarkeit einheitlichen länder- und regionenübergreifenden Herangehensweise und einer Flexibilität bei der Erfassung aller relevanten Faktoren in den verschiedenen Situationen, in denen ländliche Entwicklung stattfindet. [source] Disulfide bonds in merozoite surface protein 1 of the malaria parasite impede efficient antigen processing and affect the in vivo antibody responseEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 3 2004M. Hensmann Vol. 34(3) 2004, DOI 10.1002/eji.200324514 Due to a technical error, the wrong affiliations were given for C. Moss and V. Lindo. These are correct as given above. See original article http://dx.doi.org/10.1002/eji.200324514 [source] Correction: The natural killer cell-mediated killing of autologous dendritic cells is confined to a cellsubset expressing CD94/NKG2A, but lacking inhibitory killer Ig-like receptorsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 10 2003M. Della Chiesa Vol. 33(6) 2003, pp 1657-1666 The surname of the first author is Della Chiesa; thus the running title in the manuscript should have been given as M. Della Chiesa et al. [source] Correction: IL-10 is crucial for the transition from acute to chronic disease state during infection of mice with Schistosoma mansoniEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 8 2003C. H. Sadler Vol. 33(4) 2003, pp 880-888 Pages 882 (Fig. 2) and 883 (Fig. 5) The x-axis label in Fig. 2 should have the same sampling times post-infection as Fig. 1. The legend to Fig. 5 should be amended to read: blue nuclei, red collagen and yellow connective tissue or hepatic parenchyma. [source] Joseph J. Martocchio and Hui Liao (Eds.). (2009) Research in Personnel and Human Resources Management (Vol. 28).HUMAN RESOURCE MANAGEMENT, Issue 4 2010346 pages, CT: JAI Press, Stamford No abstract is available for this article. [source] Higher order finite element methods and multigrid solvers in a benchmark problem for the 3D Navier,Stokes equationsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 6 2002Volker John Abstract This paper presents a numerical study of the 3D flow around a cylinder which was defined as a benchmark problem for the steady state Navier,Stokes equations within the DFG high-priority research program flow simulation with high-performance computers by Schafer and Turek (Vol. 52, Vieweg: Braunschweig, 1996). The first part of the study is a comparison of several finite element discretizations with respect to the accuracy of the computed benchmark parameters. It turns out that boundary fitted higher order finite element methods are in general most accurate. Our numerical study improves the hitherto existing reference values for the benchmark parameters considerably. The second part of the study deals with efficient and robust solvers for the discrete saddle point problems. All considered solvers are based on coupled multigrid methods. The flexible GMRES method with a multiple discretization multigrid method proves to be the best solver. Copyright © 2002 John Wiley & Sons, Ltd. [source] Frictional behaviors during applications of lotions by use of a novel friction meter and evaluation of tactile feelingINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 4 2010A. Ishikubo Vol. 43, No.3 (2009) pp.171,176 A novel friction meter that allows us to measure normal force and friction force at the same time was developed, and the frictional behavior of cosmetics during application was investigated for an evaluation of a tactile feeling, permeability. As a result of measurements of four lotion samples by 15 panels, time courses of normal forces, friction forces and friction coefficients were different among the panels though they used the same samples. It was also found that the maximum value of differentiation in friction coefficient with better permeability feeling was larger than those with less permeability feeling. This suggests that relative changes in the time course of friction coefficients have an important influence on a tactile feeling, permeability. [source] The Consensus Conference and Combined-Integrated model of doctoral training in professional psychology, Overview of Part 1: Nature and scope of the Combined-Integrated modelJOURNAL OF CLINICAL PSYCHOLOGY, Issue 9 2004Craig N. Shealy This special series of articles on the Consensus Conference and Combined-Integrated (C-I) model of doctoral training in professional psychology consists of 13 articles in two successive volumes of the Journal of Clinical Psychology. Six articles are presented in Part 1 (Vol. 60, Issue 9), which collectively describe the "nature and scope" of the C-I model (e.g., historic and definitional issues; the potential advantages of this model; implications for the profession). In Part 2 of this special series (Vol. 60, Issue 10), articles 7 through 12 address the broader implications and potential applications of the C-I model within a range of professional and societal contexts (e.g., for interprofessional collaboration; the health care field; development of a global curriculum; the unified psychology movement; issues of assessment and professional identity; and higher education); article 13 provides a summary of the series as well as a discussion of future directions. As an overview, this paper provides the abstract for each of the articles in Part 1, and describes the various topics of the articles in Part 2. Taken together, the articles in this special series are designed to provide a coherent account of how and why the C-I model is timely and relevant, and therefore warrants serious consideration by the larger education and training community in professional psychology. © 2004 Wiley Periodicals, Inc. J Clin Psychol. [source] Toward an epistemology of WikipediaJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 10 2008Don Fallis Wikipedia (the "free online encyclopedia that anyone can edit") is having a huge impact on how a great many people gather information about the world. So, it is important for epistemologists and information scientists to ask whether people are likely to acquire knowledge as a result of having access to this information source. In other words, is Wikipedia having good epistemic consequences? After surveying the various concerns that have been raised about the reliability of Wikipedia, this article argues that the epistemic consequences of people using Wikipedia as a source of information are likely to be quite good. According to several empirical studies, the reliability of Wikipedia compares favorably to the reliability of traditional encyclopedias. Furthermore, the reliability of Wikipedia compares even more favorably to the reliability of those information sources that people would be likely to use if Wikipedia did not exist (viz., Web sites that are as freely and easily accessible as Wikipedia). In addition, Wikipedia has a number of other epistemic virtues (e.g., power, speed, and fecundity) that arguably outweigh any deficiency in terms of reliability. Even so, epistemologists and information scientists should certainly be trying to identify changes (or alternatives) to Wikipedia that will bring about even better epistemic consequences. This article suggests that to improve Wikipedia, we need to clarify what our epistemic values are and to better understand why Wikipedia works as well as it does. Somebody who reads Wikipedia is "rather in the position of a visitor to a public restroom," says Mr. McHenry, Britannica's former editor. "It may be obviously dirty, so that he knows to exercise great care, or it may seem fairly clean, so that he may be lulled into a false sense of security. What he certainly does not know is who has used the facilities before him." One wonders whether people like Mr. McHenry would prefer there to be no public lavatories at all. The Economist (Vol. 379, April 22, 2006, pp. 14,15) [source] Untersuchungen zur Herstellung siliziumkarbid-partikelverstärkter Aluminiumpulver durch Hochenergiekugelmahlen.MATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK, Issue 6 2010Fabrication of silicon carbide reinforced aluminium powders by high-energy ball-milling High-energy ball milling; Aluminium matrix composite; AA2017; SiC particle reinforcement; Microstructure Abstract Die Herstellung von Siliziumkarbid-Aluminium-Verbundpulver stellt die erste Stufe der pulvermetallurgischen Herstellungsroute für partikelverstärkte Aluminiumwerkstoffe dar. Der Prozess der Verbundpulverausbildung beim Mahlen in einer Hochenergiekugelmühle und der Einfluss von Prozessparametern werden anhand der Al-Legierung EN AW-2017 mit 10 und 15 Vol.-% Siliziumkarbidteilchen der Kornfraktion <2 ,m untersucht. Die Gefügeentwicklung des Pulvers wird materialografisch charakterisiert. Bestimmte Prozessparameter beeinflussen den Verbundpulverzustand zum Teil gegenläufig, so dass der erreichte Optimierungsstand als Kompromiss anzusehen ist. Lösungsvarianten für eine weitere Verbesserung werden aufgezeigt. The fabrication of aluminium silicon-carbide composite powder is the first step of the powder metallurgical production of particle-reinforced aluminium material. This paper deals with the production of silicon-carbide reinforced aluminium matrix (AA2017) composite powder through an high energy ball milling process by using simoloyer- and planetary high energy mills. The Stages of composite powder formation during the high-energy ball milling process will be shown by means of materialographic studies and by micro hardness. Major factors of influence as well as typical problems are discussed. [source] Erratum: Quantification of water diffusion and relaxation times of human U87 tumors in a mouse modelNMR IN BIOMEDICINE, Issue 2 2010Yanping Sun This paper (DOI: 10.1002/nbm.894) was published online on 22 September 2004 and was included in the October issue of that year (Vol. 17, no. 6, pp. 399,404). An error in the text has recently been discovered. The Experimental section on p. 400 should read as follows: For intracranial implantation, 1,×,105 U87 cells suspended in 10,µl of sterile phosphate-buffered saline (PBS) were injected into the right frontal hemisphere (3,mm anterior to the Bregma, 2,mm from the midline, and 3,mm deep) of all animals using a stereotactic fixation device (Stoelting, Wood Dale, IL, USA). [source] Nursing the Community, a Look Back at the 1984 Dialogue Between Virginia A. Henderson and Sherry L. ShamanskyPUBLIC HEALTH NURSING, Issue 4 2007Sarah E. Abrams ABSTRACT Dr. Sherry L. Shamansky, one of the founding editors of Public Health Nursing, interviewed renowned 20th-century leader, Virginia Avenal Henderson (1897,1996), then research associate emeritus at Yale University School of Nursing, about the nursing of "aggregates." Their discussion, originally published in Public Health Nursing, in 1984 (Vol. 1, No. 4), highlights Henderson's views about the scope of nursing, health care organization and funding, and perceived tension between direct care of the sick in the community and preventive activities directed toward communities or populations at risk. Readers familiar with Henderson's influential definition of nursing may find her responses to interview questions helpful in understanding her view of the opportunities and challenges faced by public or community health nurses of the time. [source] Effect of alkali metal hydroxides on the enantioseparation of amines using di- O -isopropylidene-keto- L -gulonic acid as the selector in NACE (vol. 27, issue 22, pp.ELECTROPHORESIS, Issue 24 20064469-4479) No abstract is available for this article. [source] Microscale fractionation facilitates detection of differentially expressed proteins in Alzheimer's disease brain samples (vol. 25, Issue 15, pp.ELECTROPHORESIS, Issue 18-19 20042557-2563) See original http://dx.doi.org/10.1002/elps.200406011 [source] Alcohol in Mayan Guatemala: consumption, distribution, production and composition of cuxaADDICTION, Issue 5 2009Fotis Kanteres ABSTRACT Aims To describe the consumption, distribution, production and chemical composition of alcohol, including cuxa (pronounced ,coo sha'), in Nahualá, a highland Mayan municipality in Guatemala. Cuxa is a sugarcane-derived spirit, in part produced clandestinely, that has been distributed in the community for several decades. Methods Key informant interviews with alcohol distributors and consumers, cuxa producers and health professionals, as well as analyses of questionnaires from a sample of 47 spouses who came to the local health centre for problems related to their husband's drinking. Sampling and chemical analysis of cuxa from 12 of 13 identified sales points in the head-town of Nahualá and its nearby settlements (10 km radius). Fieldwork was conducted between November 2007 and March 2008. Results Alcohol consumption was found to be integrated culturally in this community. The overall drinking culture was marked by irregular heavy drinking occasions, especially around market days, with substantial inebriation and health problems, especially among street inhabiting drinkers. Cuxa contributed to these problems, and cuxa drinking was socially stigmatized. Cuxa was produced both clandestinely and industrially, and sold legally by taverns and illegally by clandestine distributors. The alcoholic strength of the samples was typically between 17 and 19% vol.; clandestinely produced cuxa samples showed acetaldehyde contamination. Conclusions Measures should be taken to reduce the harm associated with alcohol in this community, including efforts to reduce acetaldehyde levels in cuxa. [source] Monotonic and Cyclic Deformation Behaviour of the SiC Particle-Reinforced Aluminium Matrix Composite AMC225xe,ADVANCED ENGINEERING MATERIALS, Issue 4 2010Marek Smaga The monotonic and cyclic deformation behaviour of the aluminium matrix composite AMC225xe , i.e., the aerospace grade aluminium alloy AA 2124 reinforced with 25,vol.-% ultrafine SiC particles , is characterised in detail on the basis of mechanical stress,strain hysteresis curves as well as temperature and electrical resistance measurements. A pronounced difference in plastic strain response is observed between tension and compression under monotonic and cyclic loading. In fully reversed stress-controlled constant amplitude tests, negative plastic mean strains developed. The cyclic deformation behaviour of AMC225xe is characterised by pronounced initial cyclic hardening. The endurance limit is reliably estimated in continuous load increase tests. In particular, electrical resistance data are used as input parameters for fatigue life calculations analogous to the Basquin equation. Microstructural details are investigated by light and scanning electron microscopy. [source] Microstructure and Properties of Pressureless Sintered HfB2 -Based Composites with Additions of ZrB2 or HfC,ADVANCED ENGINEERING MATERIALS, Issue 10 2007L. Silvestroni Ternary HfB2 -ZrB2 and HfB2 -HfC composites (see figure) with 20,vol.-% MoSi2 were produced from commercial powder and densified through pressureless sintering. Dense materials with fine microstructures were obtained at 1900,1950,°C. Flexural strength at 1500,°C confirmed the excellent stability of the composites at high temperature. [source] Cover Picture: Anisotropy and Dynamic Ranges in Effective Properties of Sheared Nematic Polymer Nanocomposites (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 12 2005Mater. Abstract Forest and co-workers report on p.,2029 that nematic polymer nanocomposite (NPNC) films can be processed in steady shear flows, which generate complex orientational distributions of the nanorod inclusions. Distribution functions for a benchmark NPNC (11,vol.-% of 1,nm,×,200,nm rods) are computed for a range of shear rates, yielding a bifurcation diagram with steady states at very low (logrolling) and high (flow-aligning) shear rates, and limit cycles (tumbling, wagging, kayaking) at intermediate shear rates. The orientational distributions dictate the effective conductivity tensor of the NPNC film, which is computed for all distribution functions, and extract the maximum principal conductivity enhancement (Emax, averaged in time for periodic distributions) relative to the matrix. The result is a "property bifurcation diagram" for NPNC films, which predicts an optimal shear rate that maximizes Emax. Nematic, or liquid-crystalline, polymer nanocomposites (NPNCs) are composed of large aspect ratio, rod-like or platelet, rigid macromolecules in a matrix or solvent, which itself may be aqueous or polymeric. NPNCs are engineered for high-performance material applications, ranging across mechanical, electrical, piezoelectric, thermal, and barrier properties. The rods or platelets possess enormous property contrasts relative to the solvent, yet the composite properties are strongly affected by the orientational distribution of the nanophase. Nematic polymer film processing flows are shear-dominated, for which orientational distributions are well known to be highly sensitive to shear rate and volume fraction of the nematogens, with unsteady response being the most expected outcome at typical low shear rates and volume fractions. The focus of this article is a determination of the ranges of anisotropy and dynamic fluctuations in effective properties arising from orientational probability distribution functions generated by steady shear of NPNC monodomains. We combine numerical databases for sheared monodomain distributions[1,2] of thin rod or platelet dispersions together with homogenization theory for low-volume-fraction spheroidal inclusions[3] to calculate effective conductivity tensors of steady and oscillatory sheared mesophases. We then extract maximum scalar conductivity enhancement and anisotropy for each type of sheared monodomain (flow-aligned, tumbling, kayaking, and chaotic). [source] Synthesis of Indium and Indium Oxide Nanoparticles from Indium Cyclopentadienyl Precursor and Their Application for Gas Sensing,ADVANCED FUNCTIONAL MATERIALS, Issue 7 2003K. Soulantica Abstract Decomposition of the organometallic precursor [In(,5 -C5H5)] in toluene in the presence of methanol (8 vol.-%) at room temperature leads to the immediate formation of aggregates of indium nanoparticles of 15,±,2 nm mean diameter. The aggregates are roughly spherical with a mean size of 400,±,40 nm. The particles were characterized by means of transmission electron and high-resolution transmission electron microscopies (TEM and HRTEM), and X-ray diffraction (XRD) studies indicate that the powder consists of the tetragonal phase of indium. The thermal oxidation in air of these nanoparticles yields well-crystallized nanoparticles of In2O3 with unchanged morphology (aggregates of nanoparticles of 16.6,±,2 nm mean diameter with aggregate mean size of 400,±,40 nm) and without any sign of coalescence. XRD pattern shows that the powder consists of the cubic phase of In2O3. The electrical conductivity measurements demonstrate that this material is highly sensitive to an oxidizing gas such as nitrogen dioxide and barely sensitive to a reducing gas such as carbon monoxide. Its association with SnO2 -based sensors allows the selective detection of carbon monoxide (30 ppm) and sub-ppm amounts of nitrogen dioxide (400 ppb) in a mixture at 21,°C and at a relative humidity of 60,%. [source] Percolative Mechanism of Aging in Zirconia-Containing Ceramics for Medical Applications,ADVANCED MATERIALS, Issue 6 2003C. Pecharromán For biomedical applications, zirconia-toughened alumina ceramics (see Figure) would be very appropriate materials, provided that the zirconia content is kept below the percolation threshold (upper limit of 16 vol.-% 3Y-TZP inside an alumina matrix). That the concept of a percolation threshold is relevant when talking about aging degradation, is demonstrated by comparing specular IR reflectance measurements with aging experiments. [source] Pilot Production of Hatchery-Reared Summer Flounder Paralichthys dentatus in a Marine Recirculating Aquaculture System: The Effects of Ration Level on Growth, Feed Conversion, and SurvivalJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2005Patrick M. Carroll Pilot-scale trials were conducted to evaluate growout performance of hatchery-reared summer flounder fingerlings in a state-of-the-art recirculating aquaculture system (RAS). The outdoor RAS consisted of four 4.57-m dia × 0.69-m deep (vol. =11.3 m3) covered, insulated tanks and associated water treatment components. Fingerlings (85.1 g mean initial weight) supplied by a commercial hatchery were stocked into two tanks at a density of 1,014 fish/tank (7.63 kg/m3). Fish were fed an extruded dry floating diet consisting of 50% protein and 12% lipid. The temperature was maintained between 20 C and 23 C and the salinity was 34 ppt. Under these conditions, growth, growth variation (CVwt), feed utilization, and survival of fish fed to 100% and 82% of a satiation rate were compared. Due to clear changes in growth patterns during the study, data was analyzed in three phases. During phase 1 (d 1,d 196), fish showed rapid growth, reaching a mean weight of 288 g ± 105 and 316 g ± 102, with a CVwt of 0.36 and 0.32 and FCR's of 1.38 and 1.36 in the subsatiation and satiation groups, respectively. During phase 2 (d 196,d 454), fish displayed slower growth reaching mean weights of 392 g ± 144 and 436 g ± 121, with a CVwt of 0.37 and 0.28, and increasing FCR's of 3.45 and 3.12 in the subsatiation and satiation groups, respectively. During phase 3 (d 454,d 614), fish showed little growth reaching mean weights of 399 g ± 153 and 440 g ± 129, with a CVwt of 0.38 and 0.29 in the subsatiation and satiation groups, respectively. Over the entire growout period (d 1,d 614), feed conversion ratios were 2.39 and 2.37 and survival was 75% and 81 % in the subsatiation and satiation treatments, respectively. The maximum biomass density reached during the study was 32.3 kg/m3. The satiation feed rate was superior to the 82% satiation rate, since it maximized growth rates, with no effect on FCR. The higher CVwt in the subsatiation group suggests increased competition for a restricted ration led to a slower growth with more growth variation. The decrease in growth in phases 2 and 3 was probably related to a high percentage of slower growing male fish in the population and the onset of sexual maturity. This study demonstrated that under commercial scale conditions, summer flounder can be successfully grown to a marketable size in a recirculating aquaculture system. Based on these results, it is recommended that a farmer feed at a satiation rate to minimize growout time. More research is needed to maintain high growth rates through marketable sizes through all-female production and/or inhibition of sexual maturity. [source] The Structure of Water in PEO-Based Segmented Block Copolymers and its Effect on Transition TemperaturesMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 9 2008Debby Husken Abstract The effect of water on block copolymers that contain hydrophilic PEO flexible segments is studied. The polyether phase consisted of either PEO or mixtures of PEO and hydrophobic PTMO, monodisperse crystallisable T6T6T was used as hard segments. Water absorption as a function of relative humidity and PEO content were studied. The PEO melting temperature and crystallinity were strongly reduced when the copolymer absorbed water, while the PTMO phase remained unaffected by its presence. Freezing water was present in the PEO-based copolymers when the PEO phase contained ,30 vol.-% water, its relative amount being almost independent of PEO concentration and molecular weight and the presence of hydrophobic PTMO segments. [source] Aggregation of Fillers Blended into Random Elastomeric Networks: Theory and Comparison with ExperimentsMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 16 2006Mustafa M. Demir Abstract Summary: A theoretical model describing aggregation of filler particles in amorphous elastomers is proposed. The model is based on a counting technique originally used in genome analysis to characterize the size and distribution of overlapping segments randomly placed on a DNA molecule. In the present model, the particles are first assumed to aggregate randomly upon mixing into the elastomer and their sizes are calculated. The sizes and distributions of aggregates are also studied in the presence of attractive interparticle forces. Results of the proposed model are compared with experimental data on silica-filled end-linked poly(dimethylsiloxane) networks. Comparison of the theory and experiment shows that the random aggregation assumption where no attractive forces exist between the particles is not valid and a significant attraction between the silica particles is needed in the theory to justify the experimental data obtained using atomic force microscopy. For filler content below 1.45 vol.-%, the model agrees, qualitatively, with experiment and shows the increase in cluster size with increasing amount of filler. It also explains the increase in the dispersion of aggregate sizes with increasing amount of filler. Clustering of the primary silica particles in an imaginary volume of poly(dimethylsiloxane) network. [source] Ultrafine Electrospun Polyamide-6 Fibers: Effects of Solvent System and Emitting Electrode Polarity on Morphology and Average Fiber DiameterMACROMOLECULAR MATERIALS & ENGINEERING, Issue 9 2005Pitt Supaphol Abstract Summary: In the present contribution, polyamide-6 (PA-6) solutions were prepared in various pure and mixed-solvent systems and later electrospun with the polarity of the emitting electrode being either positive or negative. The PA-6 concentration in the as-prepared solutions was fixed at 32% w/v. Some of the solution properties, i.e., shear viscosity, surface tension, and conductivity, were measured. Irrespective of the polarity of the emitting electrode, only the electrospinning of PA-6 solution in formic acid (85 wt.-% aqueous solution) produced uniform electrospun fibers, while solutions of PA-6 in m -cresol or sulfuric acid (either 20 or 40 wt.-% aqueous solution) did not. In the mixed-solvent systems, formic acid (85 wt.-% aqueous solution) was blended with m -cresol, sulfuric acid (either 20 or 40 wt.-% aqueous solution), acetic acid, or ethanol in the compositional range of 10,40 vol.-% (based on the amount of the minor solvent). Generally, the average fiber diameter increased with increasing amount of the minor solvent or liquid. Interestingly, the diameters of the fibers obtained under the negative electrode polarity were larger than those obtained under the positive one. Optical images of electrospun fibers from solutions of polyamide-6 in a mixed solvent of 85 wt.-% formic acid and 20 vol.-% m -cresol under positive (left) and negative (right) electrode polarity. [source] Electrical Response to Organic Vapor of Conductive Composites from Amorphous Polymer/Carbon Black Prepared by Polymerization FillingMACROMOLECULAR MATERIALS & ENGINEERING, Issue 2 2003Jun Rong Li Abstract In recent years, conductive polymer composites have found applications as gas sensors because of their sudden change in electric resistance of several orders of magnitude when the materials are exposed to certain solvent vapors. However, the composites having this function reported so far are mostly based on crystalline polymeric matrices, which factually sets a limit to materials selection. The present work prepares polystyrene/carbon black composites through polymerization filling and proves that the amorphous polymer composites can also serve as gas sensing materials. The composites' percolation threshold is much lower than that of the composites produced by dispersive mixing. In addition, high responsivity to some organic vapors coupled with sufficient reproducibility is acquired. The experimental data show that molecular weight and molecular weight distribution of the matrix polymer and conducting filler content exert great influence on the electrical response behavior of the composites. As a result, composites performance can be purposely tailored accordingly. Compared with the approaches of melt-blending and solution-blending, the current technique is characterized by many advantages, such as simplicity, low cost, and easy to be controlled. Effect of different organic solvent vapors on the electric resistance of PS/CB composites (CB content,=,10.35 vol.-%). [source] The Development of Proton Conducting Polymer Membranes for Fuel Cells Using Sulfonated Carbon NanofibresMACROMOLECULAR RAPID COMMUNICATIONS, Issue 3 2008Fabienne Barroso-Bujans Abstract This study describes a new strategy to improve the performance of PEMFCs by the addition of S/CNF. The presence of 2.08 vol.-% S/CNF increased the proton conductivity of a S/EPDM by one order of magnitude, which made it comparable to that of Nafion® 117, and without creating an electronic path. Furthermore, the filled membranes showed improved thermal stability and mechanical properties. [source] | ||||||||||||||||||||||||||||||||||||||||