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1483 Uppsatser om Water vapour transmission - Sida 51 av 99
Sådd av tallfrön med vattenryggsäck : en laboratoriestudie
Föryngring av skog är en nödvändig, men kostsam åtgärd och därför är det eftersträvansvärt att hitta en föryngringsmetod som är både kostnadseffektiv och ger en bra föryngring. Ett sätt att få en billigare föryngringsåtgärd är att använda frösådd. Vid en lyckad sådd gör det stora plantuppslaget att plantorna får bra förutsättningar för god kvalitet. Dessa plantor får dessutom bättre rotutveckling och stabilitet än planterade plantor. Användningen av skogssådd är dock begränsad av bl.a.
Rabies : en utmaning för Indien
This literature study describes the ways in which the spread of rabies can be prevented in India, what guidelines are set and also which methods have proved most effective.
Every year rabies causes the death of around 20 000 people in India, which makes the prevalence in the country the highest in the world. The main source for human infection is bite wounds from infected dogs. People and animals can be vaccinated both prophylactic and post-exposure prophylactic (PEP), despite this the disease continues to claim high number of victims. The majority of those dying are young men and children from the poorer part of the population. Knowledge among the Indian population on rabies and its transmission routes, wound care and vaccinations is very limited.
Flygplansavisningens miljöpåverkan vid svenska flygplatser
The aim of this thesis was to answer a number of questions about the environmental consequences of aircraft de-icing. A further aim was to suggest how the environmental consequences due to the release of de-icing fluids can be measured and reduced.The main impact of the aircraft de-icing on the environment is due to the large oxygen demand for the degradation of glycol based de-icing fluids which are released in the environment. The effect of the increase in oxygen demand depends on where the degradation occurs in the ecosystem. In a sensitive ecosystem, the large demand of oxygen could provide an anaerobic environment which would be harmful for many types of organisms.In order to reduce the negative effects of the applied de-icing fluid, there is some type of collection system at every regular airport in Sweden. The methods of collection can be divided into two general groups, hydrological isolation or vacuum sweeper trucks.
Safe retrieval of nutrients to improve food security
Safe retrieval of nutrients from human excreta to fertilize crops in order to gain adequate yields will increase food security and sustainability in agriculture areas with nutrient-poor fields. Safe and nutritious food will meet the dietary needs of the individual which promotes public health and the ability of an active life. Human excreta should be considered as a resource instead of being assumed as waste. Human faeces and urine is excellent fertilizers which may close the nutrient loop if utilized properly. However, sanitation of the excreta is required to prevent disease transmission by reducing the content of gastrointestinal pathogens such as bacteria, viruses and parasites.
The objective of this study was to in small scale evaluate the sanitation in a combined liquid compost and urea treatment by monitor the inactivation of bacteria and viruses at the combination three start temperatures, 45, 40 and 35 °C, and three additions of urea, 0.5, 0.75 and 1 % and reference, 0 % urea addition.
Hydrauliken i Ångersjöns fosforfällor : bestämning av flödesvägar och åtgärdsförslag för optimal fosforbindning vid avloppsrening med reaktiva filter
Discharge of untreated wastewater leads to unnaturally high levels of nitrogen and
phosphorus in rivers, lakes and the sea, which results in unbalanced ecosystems with
eutrophication and lack of oxygen. Part of the phosphorus in surface waters is coming from
on-site wastewater treatment from scattered households with unsatisfactory purification.
Blast furnace slag is a by-product from iron production, and has in laboratory trials showed good phosphorus binding capacity. To test blast furnace slag as a reactive filter media for phosphorus separation in a full scale experiment, a wastewater treatment plant has been built behind the picnic area at Ångersjön alongside the road E4 in central-eastern Sweden. The plant contains two parallel lines, one with blast furnaces slag and the other with Filtralite-P as phosphorus sorbent. Both filters have showed decreasing phosphorus purification effect with time in spite of a low wastewater load.
Underlag för bedömning av energibrunnar inom vattenskyddsområde
Denna rapport beskriver arbetet med utvecklingen av en ny modell för kaplanturbiner. Utvecklingen bygger på två kopplade differentialekvationer som under arbetets gång anpassats och implementerats i turbinmodellen.Modellen beskriver hur vattenflöde och turbinmoment påverkas av avvikelsen från den optimala kombineringskurvan för vinklarna på turbinens ledskena och löphjul, och är anpassad för ett referensaggregat med tillgängliga provdata. Även övriga enheter i vattenkraftaggregatet modelleras och sätts samman med frekvensregulator och elnät för att simulera aggregatets reglerstabilitet i önätsdrift.Verifieringen av turbinmodellen sker genom försök att återskapa de befintliga verkningsgradskurvorna med hjälp av modellen. Resultatet visar en god följning av de verkliga kurvformerna, dock med något lägre maximal verkningsgrad.Verifieringen av önätmodellen sker genom att prova stabiliteten i nätfrekvens och turbineffekt vid stegpålastningar. Resultatet ger en stabilare reglerstabilitet än i verkligheten, men uppfyller ändå förväntningarna på en fungerande modell.This report describes the development of a new kaplan turbine model.
Kan en standard för miljökommunikation förbättra miljöprestanda? : Ett examensarbete i samarbete med NQA Nordic AB
Mankind has always been communicating, it is almost impossible to not communicate. The communication tree has grown a new branch, the environmental communication branch, and an ISO standard, the ISO 14 063 Environmental communication- guidelines and examples was issued October 2006. The purpose of this thesis is commissioned by the managing director of NQA Nordic AB in order to examine and analyse how organisations communicate environmental issues today, and how big the need for ISO 14 063 actually is, and further more if there are needs and wishes to make ISO 14 063 a certifiable standard. The main conclusion is that the there is a need for the standard, but it is difficult to say in which form since the knowledge about the standard is far to low among the organisations examined in this thesis. Clarity and transparency as ISO 14 063 promotes are important ingredients in organisations? environmental work, so sure a standard for environmental communication can help improve environmental performance, for example through opening up for two-way communication and from that on take part of the stakeholders? opinions.This study is based on a literature study and a questionnaire survey where 70 organisations (in this case authorities, corporations and non-governmental organisations) randomly chosen from the seven criteria, which ISO 14 001 defines as the environment: land, water, air, flora, fauna, natural resources and man and his collaboration with those.
Är det möjligt att använda SCR-rening av rökgaserna vid inblandning av avfall i biobränslet?
Waste appears to be a low-cost fuel compared to biofuel. This Masters thesis was conducted for Vattenfall Utveckling AB and deals with how waste in the fuel affects the performance of a SCR-catalyst. Different mechanisms of deactivation were surveyed, focusing on the poisoning mechanism. A literature study was carried out, which was used as a reference when analysing the results.Small samples (9x2x2 cm, 64 pieces) cut out from a full-scale unused honeycomb catalyst were exposed up to 1500h in two different combustion plants, Johannes in Gävle (co-combustion) and Högdalen in Stockholm (waste-combustion). The activity was measured mainly at 300°C but also at 250, 350, 375 and 400°C.
Trafikverkets effektstyrningssystem - EFS 132 kV : Bidraget till minskade förluster
The technological legacy from the early electrification of the Swedish railroads has resulted in a power grid with a lower grid frequency than the national power grid from which it is fed. Energy transfer between these power grids with different frequencies requires substations, adapting the grid frequency for the rail road power grid. For this purpose, a feeding power grid has been built, stretching across the country from Boden in the north to Tälle/Häggvik in the south.Power transfer in the Swedish power grid results in voltage angle differences which increase with increasing loads and transfer distance. These voltage angle differences are transferred from the power feeding substations to the rail road power grid, will in some extent cause loss of energy due to unwanted power flows from north to south.To minimize the losses due to this phenomenon, a power management system called EFS 132 kV has been developed and implemented. The system minimizes the unwanted power flows and controls the desired power flow for a good distribution of loads between the power feeding substations.This thesis investigates the extent of the transmission losses avoided due to the EFS 132 kV that coordinates the idling angles to a common reference point.The results indicate that EFS 132 kV affects the power flow, especially between the northern substations through an improved load distribution.
Två metoder av finutsättning och dess noggrannheter
This report describes a study of two different methods to achive the best possible result in setting out apartment details. These two methods are the setting out of details with a measuring tape from baselines and the setting out procedure with an instrument (totalstation).Through our knowledge in surveying and mapping technology and help from a carpenter, this investigation has been implemented. The setting out using a tape has been performed by letting the carpenter to set out windows, bathroom and water- and drain-details from baselines and drawing. The setting out using a surveying instrument was carried out by means of a Trimble Total Station. These two methods have been compared in order to detect and show the difference that occurs.The report shows the investigation background story from the practice of Swedish Mätcenter in Karlstad.A result of differences in accuracy and time is described in the report, as well as their theoretical consequences.
"Och så levde de lyckliga i alla sina dagar" : En analys av den borgerliga diskursen i den östgötska folksagan
Fairy tales are commonly considered to be both timeless and classless. Since the 17th century, when most of the tales we have access to today were first collected and published, the idea that fairy tales are part of an oral tradition, and therefore more or less uninfluenced by academic and literary trends, have been dominant amongst researchers, critics and readers. This idea needs to be revaluated. Even if the tales might have their roots in an oral tradition the history of the fairy tale ?is not primarily a history of oral transmission, but rather a history of print?, as Elizabeth Wanning Harries puts it (Wanning Harries, 2001:4).
Kringtjänster för fastighetsmäklare
The amendment of a law which is expected to come may well have a significant impact on the Swedish real-estate broke market. The law change will probably have an effect in the number of ways real-estate brokers will compete as a result of the increasing variety of services offered. In order to gain competitive advantages brokers must be at the forefront in the development regarding the changing market. To do so requires that the company chooses an appropriate range of peripheral services that are profitable. The problem is to choose the ?right? services to convey. The purpose of this paper is to describe the services that are in demand for transmission and how the agents can work to meet the demand of this new market.
Föroreningstransport med dagvatten - Utveckling av reningsmoduler för modellverktyget Mike Urban SWQ (Storm Water Quality)
On a request from the water sewage plant Gryaab in Gothenburg a power quality survey was performed. The voltages and currents have continuously been sampled in the incoming 10 kV substation HSP01 from April-August 2008. Power quality measurements were also performed in Gryaabs other 10 kV substation HSP04 fed from HSP01 and at the terminals of the induction motor IN_PU4040 of 1.3 MW which controls one of the four large inflow pumps to the plant. The reason for the latter measurement was due to registered negative transients each time the motor was connected to the grid. The cause of the transients could be explained by the coupling in the substation, the ageing of the motor which could result in damage of the bearings or resonance in the motor circuit which amplifies high frequency harmonics.
?ÄNTLIGEN!?- En lysrörsarmatur för det egna hemmet
The aim of our study is to ascertain whether a hanging suspension fluorescentlamp for a private home environment is going to be attractive for a largeaudience. We want to open up for new uses of fluorescent lamps as lightsources.The main approach in this work is how to design a fixture with fluorescentlamps as a light source that will meet the requirements and requests of thehome environment could look like. At the same time we want to make a newimpression of how a fluorescent light source.Primarily we used a quantitative method, but this was rejected after a pilotstudy. Instead we used a qualitatively based method in the sense that weconducted a group interview as well as individual interviews.Based on data from the interviews and our preliminary work a prototype wasbuilt. This prototype is a fluorescent fixture equipped with 2x14W T5fluorescent lamps, dimmed separately.
Landvinning : scenarier för efterbehandling och gestaltning av Aitikgruvan, Gällivare
Open pit mining creates huge amounts of tailings and waste rock deposits. Due to it's content of sulphide minerals, predominantly pyrite (FeS2), there is a risk of oxidation and formation of acid water containing heavy metals, known as Acid Rock Drainage (ARD). To prevent the process of oxidation, the tailings and waste rock have to be reclaimed. The most commonly used methods of reclamation are a coverage of water or soil.
Mining also results in a large-scale interference in the landscape that will make an eternal change of its appearance.