Sökresultat:
870 Uppsatser om Variable reduction - Sida 11 av 58
Dagvattendammars reningseffekt : påverkande faktorer och metodik för statistisk modellering
Storm water is defined as runoff from precipitation such as rain or snow. It is collected in sewage disposal systems and since it mainly originates from urban areas it can contain high levels of heavy metals, nutrients and oil etc. Polluted storm water is currently treated by different methods such as wet ponds, constructed wetlands and filter strips. This study investigates these methods, which in earlier studies have shown to give varying results regarding their treatment efficiency.This thesis has been written on commission of SWECO VIAK and was aimed at studying those parameters that may affect the treatment efficiency of nutrients and heavy metals in storm water treatment facilities (STF:s). Through literature studies the dominating treatment processes in ponds and wetlands were examined.
Miljöanpsassad metod för hjultvätt
In order to avoid harmful substances ending up at the municipal sewage treatment plants, it is important to purify the wastewater at the source. One such source is the wheel washers available in many tire garages which are used to wash the wheels on our vehicles when we change between summer and winter tires. It is important to wash the wheels before storage, to extend the tires lifetime. The purpose of this study is to find a green innovative solution for reduction of emissions of heavy metals at the source, so that the sludge from the sewage treatment plants can be used as fertilizer. The target is to find a wheel wash method which leads to compliance with the guidelines for car washers, and that also provides a better washing result than with the existing method.
Skattningar i gallringsskog med hjälp av flygburen laserskanning : beräkningar med massaslutenhet
This master?s thesis is a remote sensing study of an area-based method used to detect forest in need of thinning by use of laser data and field samples. Only pine-dominated forest has been included in the study and height limits were set to match empirical restrictions. The study area was in the municipality of Älvsbyn (Latitude 65° 40´ N, Longitude 21° 00´ E), in northern Sweden.The Swedish authority Lantmäteriet is currently laser scanning most parts of Sweden, providing new opportunities and applications. The primary aim of the national laser scanning is to create a new elevation model, useful in consequence analysis of climate changes.
Behandlingsvåtmarkers reningseffekt på aktiva läkemedelssubstanser under vinterförhållanden : En studie av fyra svenska våtmarker för avloppsrening
Pharmaceuticals that are found in marine ecosystems are a threatening environmental concern, which is known to harm both animal and plant life. One of the reasons for this problem is that the waste water treatment techniques are not optimized to clear waste water from its pharmaceuticals contain. In this master thesis four Swedish treatment wetlands were studied, and their ability to reduce numerous pharmaceuticals in waste water. The four treatment wetlands that were studied were those in Oxelösund, Trosa, Nynäshamn and Eskilstuna. Two ecotoxicological tests and chemical analysis were used.
Arbete och arbetstidi det postindustriella samhället : En jämförande attitydstudie mellan Sverigeoch USA med fokus på arbetstidsförkortning
Within the field of welfare research, few people take into account both the aspect of gender and class. Thetraditional class-oriented research has a one-dimensional perspective on gender and the feminist welfare researchrarely carry out large comparative studies. A multi-dimensional perspective on the construction ofgender and class would benefit from both the feminist and class welfare-oriented research, and contribute toincreasing the knowledge about the individual's experience and attitudes to work and work time. The aim ofthis paper is to examine the correlation of the intersectional relationship between sex / gender position andclass position with the attitudes and motives for working time reduction. Especially in, (1) the value in work,and (2) the attitude to a high number of working hours, as well as (3) its combined effect on the conflict betweenwork and family.
TOMO Hugglink
Tomo Hugglink (TOMO Skog) is an innovation for harvest and transport of biofuels. The system consists of a truck, a chipping unit and crane mounted on a link and a wood chip trailer. The system works in such a way that the chipping unit is disconnected and placed on the site and wood chips are loaded directly into the wood chip trailer.The aim of this study was:- To examine the performance of the TOMO Hugglink system under different conditions such as the size, placement and quality of the pile.- To calculate the cost per raw ton for two vehicle combinations at different transport distances and to examine the effect of a reduction in set-up time and an increase in load weight.- To identify possible improvements with the TOMO Hugglink system.A time study was conducted within the thesis work to make it possible to determine production and time consumption. In the subsequent economic analysis the cost per tone at different transport distances was calculated for two different lorry concepts. Furthermore the effect of a reduction in set-up time and an increase in load weight was calculated.Under current conditions the utilization of the chipper is low and only 29 % of the total system time is occupied by chipping.
Validation of Steins/Arla Foods method for lactate fermenting clostridia in milk
One of the most serious and economically important defects caused by clostridia in milk products is the late blowing of semi-hard cheeses.Clostridia occur naturally in soil and can contaminate milk through crops contaminated by dung and soil followed by a less successful silage process, that give them opportunity to grow unaerobically. When anaerobic conditions occur, such as storage of semi-hard cheese, they ferment lactic acid to butyric acid and the gases CO2 and H2.At the fusion of Arla and MD Foods, a series of changes were conducted on the MPN method for lactic acid fermentation for clostridia in milk. These changes resulted in an increased accuracy due to an increased number of test tubes and the change of media from MRCM to BBB, Bryant & Burkey Broth, that was thought to be more selective for Cl. tyrobutyricum, the organism mostly found in hard cheese. When the number of dairy farmers that were given quality reduction fines increased, the new method was suspected and a validation was conducted.The validation included inoculation of different clostridia and bacillus strains into BBB substrate and enzymatic testing of positive samples with Rapid ID 32A.
Effektivisering av kylsystem på Utö värdshus
Energy consumption is at present a major political issue, and numerous projects that comprise many nations are currently in process to increase energy efficiency and bring down energy dependency. As a member state of the EU, Sweden now faces the challenge of implementing substantial energy-saving measures until the year 2016. One of these measures is the project ?Green Islands? financed by the EU that intend on creating sustainable islands in areas around the Baltic Sea. The Archipelago Foundation leads the project that concerns the Stockholm archipelago, where focus has been placed upon decreasing energy usage in businesses and services on Utö among other islands.
Optimerad hygienisering vid kompostering av avloppsslam
The aim of this study was to in laboratory experiments investigate how addition of urea, ECOX and structural materials can optimize sanitization during composting of sewage sludge. Today we strive for a sustainable society and the importance of closing the nutrient loop increases. It has therefore become even more important to safely reuse plant nutrients from human excreta to agricultural land. Partly because it increases the sustainability of society as the world's supply of many nutrients are finite, partly because it promotes human health, both by reducing disease transmission and by increasing Agricultural production.
An untapped resource such as sewage sludge that is rich in nutrients and humus-forming materials could replace parts of the commercial fertilizers used in Sweden today. owever, sewage sludge contains undesirable substances such as heavy metals and drug residues, and pathogenic microorganisms.
Optimering av SNCR-system i en biobränsleeldad panna : möjligheter till minskade NOx-utsläpp för ENA Energi
Emission of nitrogen oxides as well as carbon monoxides is an inevitable result of combustion. A Swedish law "Law of environmental fee for emissions of nitrogen oxides as a result of energy production" (lagen om miljöavgift på utsläpp av kväveoxider vid energiproduktion (SFS 1990:613)) controls the emission of NOx from energy production by a system of fees. The system has resulted in a strong approach toward less emissions of NOx among the energy production plants. High emission levels, today exceeding 52 mg/MJsupplied fuel, leads to costs for energy production companies. This paper examines possibilities to reduce the emissions of NOx by optimization of the SNCR-technique in a biofuel fired heat and power plant.
Effektivare elanvändning på avfallskraftvärmeverk : Förslag till handlingsplan för minskad elanvändning på Renovas anläggning i Göteborg
This thesis has identified and studied measures to allow for reduced use of electricity in a waste incineration plant in western Sweden. The energy extracted from the waste at the powerplant is utilized and sold in form of electricity and heat. Technical and environmentally the combined heat and power plant is by today's standards among the leading waste incineration plants in the world. The owners are constantly striving to improve the efficiency of the waste incineration plant. They have seen the opportunities for savings in reducing internal usage of electricity.
Den positiva hälsovågen : En kvantitativ studie om hälsofrämjande arbete
The construction of buildings and paved surfaces changes the natural water balance.Precipitation generates surface runoff and storm water instead of infiltrating into the soil.Storm water has come to be considered as a major source of pollution in lakes and streams inthe vicinity of urban areas. Reduction of pollutants in storm water is a key action in order toprotect sensitive recipients and maintain high water quality. Storm water is traditionallytransported by storm sewers to the nearest recipient. In recent years the approach to stormwater management has changed; storm water should primarily be disposed of on site, throughlocal disposal of storm water, LOD. LOD is created by a combination of the function ofseveral smaller local facilities and the general sewer system.
Translationsnoggrannhet i läsningen mellan tRNA och mRNA : En analys av variationen i den maximala diskrimineringen d i initialselektion
The purpose of this thesis is to analyze the variation in the maximal discrimination of the interaction between cognate and a non-cognate codon and anti-codon (also called the d-value). The variation was analyzed with a multiple regression model with the d-value as the dependent variable and with the codon position and the different mRNA and tRNA bases as independent variables. The result of the analysis not only confirmed earlier studies that the maximal accuracy was highest in the second codon position and lowest in the third codon position but we also found significant relationships and interaction effects..
LIP : en effektivitetsstudie
Lokala investeringsprogram was a subsidy program which supported environmental reforms during the years 1998 to 2002. The subsidies were given to Swedish municipalities. Most of the evaluations of the subsidised projects have now been completed and included in a database.
The purpose with this thesis is to analyse whether the instrument has been effective with respect to carbon dioxide reductions and costs. These calculations have focused on subsidy and cost efficiency. The analysis has been compared with a previous report called "LIP ur ett samhällsekonomiskt perspektiv".
The result shows that the reduction cost for one kg CO2 has been almost one SEK, which is twice as high as the cost reported in a previous report, half a SEK.
Bakteriereduktion i diskmaskiner : Studie av olika metoder för att reducera bakterier
Bacteria are a problem that occurs naturally in dishwashers when the dish stands there dirty for an extended period of time. To get rid of the unpleasant smell that the bacteria is causing, the most common solution is to run a regular washingcycle which can cause problems for the environmentally-conscious consumers since this causes unnecessary energy waste and emissions of chemicals in the washwater. To solve the problem in a more environmentally-friendly way by directly attacking the bacteria with an appropriate bacterialreductionmethod can therefore be an attractive feature in a dishwasher. There are many different ways to treat surfaces that have been exposed to the bacteria. Some high-profile methods are UV-radiation, microwaves and oxidant (ozone) that all three have had success in reducing bacteria in different contexts.