2,425 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
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
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
Seismological analysis of the Helium ionization zones in low- and moderate-mass stars
No full textThe region of the second ionization of helium in solar-like stars is a narrow subsurface layer whose thermodynamic properties are responsible for the presence of a characteristic signature in the oscillation frequencies of the p modes. Here, with the aim of detecting the acoustic depth of the second helium ionization zone, we consider two methods of analysing the signal generated in the oscillation frequencies by the sharp decrease in the first adiabatic exponent Γ1, which occurs where ionization takes place. The properties of the ionization zone, once determined by seismological means, may be used to put constraints on the structure of the stars, in particular on the envelope helium abundance...
Diarrhoeal diseases among adult population in an agricultural community Hanam province, Vietnam, with high wastewater and excreta re-use
No full textDespite the potential health risks of wastewater and excreta use as fertiliser in agriculture, it is still widespread in Vietnam. However, the importance of diarrheal risk in adults' associated with the combined exposures to both excreta and wastewater use in agriculture is largely unknown. This study was carried out to determine diarrhoeal incidence and associated risk factors among the adult population exposed to wastewater and excreta used in agriculture in Hanam province, Vietnam.; An open cohort of 867 adults, aged 16-65 years, was followed weekly for 12 months to determine the incidence of diarrhoea. A nested case-control study was used to assess the risk factors of diarrhoeal episodes. Two hundred and thirty-two pairs of cases and controls were identified and exposure information related to wastewater, human and animal excreta, personal hygiene practices, and food and water consumption was collected.; The incidence rate of reported diarrhoea was 0.28 episodes per person-years at risk. The risk factors for diarrhoeal diseases included direct contact with the Nhue River water (odds ratio [OR] = 2.4, attributable fraction [AF] 27%), local pond water (OR = 2.3, AF 14%), composting of human excreta for a duration less than 3 months (OR = 2.4, AF 51%), handling human excreta in field work (OR = 5.4, AF 7%), handling animal excreta in field work (OR = 3.3, AF 36%), lack of protective measures while working (OR = 6.9, AF 78%), never or rarely washing hands with soap (OR = 3.3, AF 51%), use of rainwater for drinking (OR = 5.4, AF 77%) and eating raw vegetables the day before (OR = 2.4, AF 12%).; Our study shows that professional exposure to wastewater and excreta during agricultural activities are significantly contributing to the risk of diarrhoea in adults. The highest attributable fractions were obtained for direct contact with Nhue River and local ponds, handling practices of human and animal excreta as fertilisers, lack of protective measures while working and poor personal hygiene practices, and unsafe food and water consumption were associated with the risk of diarrhoeal episodes in adults. Improve personal hygiene practices and use of relevant treated wastewater and excreta as the public health measures to reduce these exposures will be most effective and are urgently warranted
Reliability Analysis of Offshore Jacket Structures with Wave Load on Deck using the Model Correction Factor Method
No full textTraditionally deterministic push-over analyses are performed for steel-jacket offshore platforms in order to calculate RSR (Reserve Strength Ratio) values as the representative reliability measure for total collapse of the structure. In this paper reliability analyses are performed for total failure/collapse of jacket type platforms with wave in deck loads using the so-called Model Correction Factor Method (MCFM). A simple representative model for the RSR measure is developed and used in the MCFM technique. A realistic example is evaluated and it is seen that it is possible to perform probabilistic reliability analysis for collapse of a jacket type platform using the model correction factor method. The total number of deterministic, complex nonlinear analysis is typically as low as 10.Traditionally deterministic push-over analyses are performed for steel-jacket offshore platforms in order to calculate RSR (Reserve Strength Ratio) values as the representative reliability measure for total collapse of the structure. In this paper reliability analyses are performed for total failure/collapse of jacket type platforms with wave in deck loads using the so-called Model Correction Factor Method (MCFM). A simple representative model for the RSR measure is developed and used in the MCFM technique. A realistic example is evaluated and it is seen that it is possible to perform probabilistic reliability analysis for collapse of a jacket type platform using the model correction factor method. The total number of deterministic, complex nonlinear analysis is typically as low as 10
The Magneto-Optical Filter in Napoli: Perspectives and Test Observations
No full text"Solar Convection and Oscillations and their Relationship", F.Pijpers, J. Christensen-Dalsgaard and C.S. Rosenthal eds
Aesthetics of urban media façades
No full textThis paper sets out to develop and extend current literature on\ud
design practices for ambient media façades. It does this by\ud
bringing together theories of ambient media, computational\ud
aesthetics, and urban aesthetics. This unique theoretical\ud
combination has informed the design of several exemplars\ud
produced by the author, which are discussed as case studies
The policy of free healthcare for children under the age of 6 years in Vietnam: assessment of the uptake for children hospitalised with acute diarrhoea in Ho Chi Minh City.
No full textOBJECTIVE: To assess the proportion of, and reasons for, households not utilising the policy of free healthcare for children under 6 years of age (FCCU6) for hospitalisation with diarrhoea, and assess the risk of catastrophic expenditure for households that forgo FCCU6 and pay out of pocket. METHODS: Invoices detailing insurance information and charges incurred from 472 hospitalised diarrhoeal cases in one paediatric hospital in Ho Chi Minh City were retrieved. Hospital charges and the utilisation of elective services were analysed for patients utilising and not utilising FCCU6. Associations between socio-economic factors with non-utilisation of FCCU6 were evaluated. RESULTS: Overall, 29% of patients were FCCU6 non-users. The FCCU6 non-users paid a median hospital charge of 18.57-46.24), consuming no more than 1.4% of a medium-income household's annual income. Seventy per cent of low-income FCCU6 non-users utilised less-expensive elective services, whereas only 43% of medium income patients and 21% of high-income patients did (P = 0.036). Patients from larger households and those with a parent working in government were more likely to use FCCU6. CONCLUSIONS: The rate of FCCU6 non-usage in this study population was 29%. A significant proportion of those that did not use FCCU6 was from lower income households and may perceive a justifiable cost-benefit ratio when forgoing FCCU6. Although a single diarrhoeal hospitalisation is unlikely to induce a catastrophic expenditure, FCCU6 non-usage may disproportionately increase the risk of catastrophic expenditure for lower income households over multiple illnesses
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