188,499 research outputs found
Feed and organic matter
No full textOrganic waste from fish production is conventionally measured as BOD5 (biological oxygen demand measured during 5 days) and COD (chemical oxygen demand (includes BOD5)). Organic waste is of particular concern for several reasons. The easily degradable part (BOD5) may have an immediate, negative impact on the receiving water body by reducing dissolved oxygen concentrations and increasing sedimentation. Within aquaculture systems, a high organic load may affect fish health and performance directly (e.g., gill disease) as well as indirectly (proliferation of pathogenic bacteria and parasites, reduction of dissolved oxygen concentrations, etc.). In recirculating aquaculture systems (RAS), a high organic load caused by limited water exchange may affect biofilter performance by favouring heterotrophic bacteria at the expense of autotrophic, nitrifying bacteria. Organic waste in RAS primarily originates from undigested feed, but also metabolic losses, mucus, dead tissue, feed waste and intake water may contribute. The nutrient composition of the feed affects the quantity and composition of the organic (undigested) waste, and including for example plant protein ingredients may affect the distribution between particulate and unsedimented (suspended and dissolved) organic waste. Quantifying aquaculture waste, including organic matter, nitrogen (N) and phosphorus (P), into different waste fractions (particulate and unsedimented) is essential for optimising the design of different treatment setups with specific cleaning objectives. A series of studies were carried out to measure the solid and unsedimented waste from juvenile rainbow trout (Oncorhynchus mykiss) fed three commonly applied commercial diets (Dalsgaard and Pedersen, 2011). Furthermore, it was hypothesized that particulate COD can be calculated from undigested nutrients. There were only minor differences between the diets. Generally, 48% of ingested N was recovered in the water and 7% in the solids. For phosphorus, 1% was recovered in the water and 43% in the solids. More COD was recovered as solids than as unsedimented waste, while it was opposite for BOD5. A BOD5/COD ratio of 0.5 was derived, indicating that unsedimented organic waste is characterized by easily degradable organic matter. In comparison, a solid BOD5/COD ratio of 0.2 indicated that this waste fraction contains high amounts of hard-to-degrade organic matter. The study confirmed that solid COD can be quite accurately calculated from the composition of undigested nutrient
The fear of bad smell: Health risk awareness related to using waste in agricultural production in Vietnam
No full textWaste watersWater reuseAgricultural productionFish farmingIrrigation waterPublic healthRisksSkin diseasesOrganic fertilizersWomen
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Understanding coverbal dimensional gestures in a virtual design environment
No full textSowa T, Wachsmuth I. Understanding coverbal dimensional gestures in a virtual design environment. In: Dalsgaard P, ed. Proceedings IDS'99 - Workshop on Interactive Dialogue in Multi-Modal Systems. Aalborg, Denmark: ESCA; 1999: 117-120
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Internettet som personaliseret og socialt medie
No full text De nye netbaserede digitale medier, der ofte går under betegnelsen social software eller Web 2.0, har ændret anvendelsen af internettet, og på få år er anvendelsen af disse medier blevet meget udbredt. Først og fremmest er e-mail og World Wide Web1 blevet taget bredt i brug og har dermed suppleret den traditionelle "push"-formidling med en "pull"-dimension, der muliggør, at interesserede kan opsøge informationerne, når og hvor de øsker det. Derudover er der de sidste par år fremkommet en række netbasrede teknologier, som muliggør social interaktion, aktiv deltagelse og egenproduktion. De mest udbredte teknologier er weblogs, wikier, sociale fælesskaber og sites til deling af digitale materialer (Freedman 2006; O'Reilly 2005; Dalsgaard 2006; Dalsgaard 2007). Disse teknologier har medført, at mediernes rolle har ændret sig.Spørgsmålet, som artiklen vil stille er, hvordan internettet kan fungere som vidensmedie. Hvad er potentialerne i internettet til at formidle og konstruere viden, og hvilke karakteristiske egenskaber har internettet som vidensmedie? Artiklen argumenterer for, at nye former for vidensdeling og vidensformidling kan opstå gennem personaliserede og sociale medier. Målet at identificere en række centrale egenskaber ved internettet i egenskab af personaliseret og socialt vidensmedie. Samtidig vil artiklen diskutere, hvordan internettet som vidensmedie muliggør, at uddannelsesinstitutioner og kulturinstitutioner kan udvide deres virke ud over deres fysiske rammer og deres hjemmesider. Artiklen afsluttes med en diskussion, der har til hensigt at pege i retning af, hvordan institutioner kan anvende digitale vidensmedier
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Edward P. Wimberly, ITC, July 2011
No full textThis video is a conversation with Dr. Edward P. Wimberly. Dr. Wimberly talks about his book, "No Shame in Wesley's Gospel: A Twenty-First Century Pastoral Gospel". Brad Ost, AUC Woodruff Library, is the interviewer
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