This master thesis covers the seasonal planning of a small scale hydropower system. The system in this study is owned and operated by Mälarenergi Vattenkraft AB. The total system consists of 4 different main rivers with 24 hydropower stations and several dams. The total installed power in the system is 43.75 MW. Most of the hydropower stations are regarded as small scale hydropower stations and thus entitled to green certificates.In this report the issue of planning is formulated as an optimization problem.

This report is the final result of the master thesis that have been done at  Sharpman Engineering. Sharpman Engineering is a small development and manufacturing company that produces and make drawings for everything from heavy duty log raft to aids for disabled people. The purpose have been to make one concept that make it easy for elderly and people having problem with knee- and back problem to stand up from a sitting position. The final result will the company have for further investigations and use for a pre-serial production with the goal to produce a new working product.To get an overview of what is on the market have a comprehensive survey has been done, followed by a survey on patent. This patent survey are for no intrusion on existing patents should occur and give new ideas.

Food is widely consumed and in 2011 an average American devoured approximately one ton of food. The production of these goods requires large amounts of energy and contributes to 22-31 % of all greenhouse gas emissions occurring in Europe. More than one third of the produced food is discarded instead of consumed, and food waste make up about 30 % of the waste generated by households. 60 % of this food waste could be avoided if the eatables were handled in a better way.Avoidable food waste arises partly because residues from food are not taken care of, and because the food is not stored in a way that optimise its durability. Residues arises part- ly because of the contradictory and complex demands of everyday life and are, because of our busy lifestyle, difficult to avoid.

The economic situation in the Swedish agricultural industry is currently experiencing a development towards larger units. This progress occurs simultaneously as farmers in cooperation more frequently make investments to decrease risk exposure and to improve the financial result. The purpose with this thesis is to study which advantages and problems a group of farmers experience after a common investment in a small-scale seed production. The aim with this investment is to increase the level of vertical integration in their respective agricultural firms and the results will be analyzed from an economic point of view. At present, the farmers are all seed producers with considerable cultivation areas.

The objective of this study was to make an inventory and a potential analysis of the organic beef production in the region of Gävleborg, Sweden. A survey was conducted, where a questionaire was sent to all farmers in the region who had environmental subsidies concerning organic cropping systems in 2001. In total, there were 701 farmers, of which 46 % participated in the study. Three slaughter houses were interviewed to get their pictures of the development of organic beef production. The study shows that there are potentials and interests in the region to increase the production of organic beef.

Assessing and measuring post-operative pain in all animals is a challenge, but doing it in small mammals, for example guinea pigs, presents an even larger difficulty. Validated pain scales developed for use in dogs in clinical practice are currently available, but no such scale has been widely accepted for use in guinea pigs in the veterinary setting. In this experimental study, six guinea pigs that had undergone surgery and anaesthesia were observed for behavioural changes that could be associated with pain. The six guinea pigs were also given pain scores with the use of Colorado State University Feline Acute Pain Scale (CSU-APSF), a scale which uses both behaviour when not handled, body tension and response to palpation to evaluate pain intensity. The six guinea pigs showed a number of different behaviours, for example rigid posture, fixed stare and ?wet dog response? (the body is vigourosly shaken), that could be associated with pain.

This master thesis has been performed at Vattenfall Power Consultant in Gothenburg and Trollhättan for Vattenfall Vattenkraft. In this report vacuum circuit breaker in small-scale hydropower stations with the rated power 4 MVA and below has been studied. Models of the stations are modeled and analyzed in PSCAD/EMTDC to study the high voltage transients that are created after current chopping with vacuum circuit breaker. Vacuum circuit breaker may chop the current before it reaches zero value, which means that high voltage transients can be created. The equipment of the stations can be destroyed by high voltage transients.The purpose of this thesis is to examine the use of vacuum circuit breaker in small-scale hydropower stations and the risk for high voltage transients from current chopping.According to the results there is a risk of high voltage transients after current chopping with small synchronous generators in stations with the operating voltages 0.4 kV and 3.6 kV.

An analysis of a specific application of anaerobic wastewater treatment at a pulp and board mill, Stora Enso Skoghall, was carried out. A literature study was done and effluent wastewater from CTMP pulp production was analyzed. The analysis consisted of a broad constituent analysis and an anaerobic treatment trial. Results from these test where used to calculate the treatment effectiveness and resulting energy potential at the mill.The literature study and constituent analysis showed that toxicity of the water to be treated, due to wood extractives and sulphur content, was of concern. Detoxification chemicals targeting these constituents where used in the anaerobic treatment trial.

It is essential to reuse- and recycles residues to decrease the amount of deposit materials and reach sustainable energy use. Two ways to work towards this is to recycle wood ashes to the forest as nutrient compensation and extract biogas from combustion of biomass.The aim with this study was to decide whether wood ashes that been used for biogas upgrading with accelerated carbonation also can be used as a nutrient compensation in the woods according to recommendations from the Swedish Forest Agency (Skogsstyrelsen).The ashes that were used in this study came from Johan Andersson who works at JTI in Uppsala, who also treated the ashes with biogas. The ashes have, in both untreated and treated condition, been analyzed in this study according to contents of elements, leaching properties, hardening properties and contents of crystalline phases, to evaluate what impact carbonation with biogas has on the ashes.The accelerated carbonation led to hardening of the ash, and decreased amount of CaO- and increased amount of CaCO3. The CO2-uptake also entails a dilution of the elements, and the content of nutrients and trace elements decreases. However the results show an indication of an uptake of S from the biogas to the ash, since the dilution had a smaller impact on S than the rest of the elements.

Each year, the coffee machines at Ericsson in Kista produce around 100 tons of ground coffee waste.The companies Coor Service Management, Löfbergs Lila and Selecta are all responsible for differentstages in the logistical chain in delivering coffee and, together with Ericsson, they want to increasetheir environmental benefit. The plan is to produce biogas through anaerobic digestion instead ofincinerating the coffee waste in a heating plant. The results are to be presented as different businesscases in which different biogas plants are compared with the reference case (heating plant),comparing costs and environmental impacts.There are two major environmental benefits from producing biogas; reduced carbon dioxideemissions from when fossile fule is replaced by carbon neutral biogas, and reduced emissions fromreturning digestate from the bio reactor to farmland instead of using industrial fertelizer.In order to determine the biogas potential in coffee waste, a couple of properties had to bedetermined in a laboratory. Properties such as the dry substance content, heating value, moisturecontent and ash content. The results show that 100 tons coffee waste could produce around 16 500Nm3 biogas which would contain 163 MWh.The biogas reactor and upgrade plant both need energy gas to function and uses around 14 MWh ofthe produced gas.

Subclinical mastitis (SCM) is a well-known problem in the dairy sector, where it causes severe economic losses mainly due to reduced milk production. This is a problem not only in the western world but also in developing countries. Surveys from different developing countries have shown a SCM prevalence of 52.4 ? 88.6 % at cow level and 26.7 ? 63.2 % at quarter-level. To combat mastitis is important to optimize the milk production of the cow.

This thesis is   focused on identifying and documenting all   electrical equipment, such as devices, power lines / cables, and connectors in the facility and also on presenting a brief   technical description and information of the systems around the reactors.   Furthermore there will be a brief description of LabVIEW - which is a   graphical programming language- and which devices / elements   are programmed. For further notification, I am not   responsible for the programming of the devices in LabVIEW   which I have only used as a tool in my work. The plant   for production of biogas consists of four reactors   of which the third reactor (Lakbädden)   is connected to another reactor (UASB)   where they cooperate with each other.   The reactors are used for producing   biogas in the form of methane gas.The reactors I and II are   connected to, various electrical devices as, flow meters, temperature   sensors, frequency converter and   more.

Global warming is a huge issue that humans have contributed to through over-exploitation of natural resources and extensive usage of fossil fuels. Now more than ever, we need to embrace a recycle thinking and reuse our waste, for example through producing biogas from our food waste. The purpose of this report was therefore to identify the energy usage and emissions resulting from the biogas chain which spans from Solna Stad to Uppsala Vatten. Furthermore, potential efficiency improvements were to be identified and proposed. This report focused mainly on the first part of the biogas chain that includes the collection of the food waste and the reloading process.

Avloppsreningsverket Sundet i Växjö har en rötningsanläggning som producerar biogas. Anläggningen består idag av två rötkammare och en maskin för avvattning som substratet går igenom efter rötningen. Substratet som används i rötningsprocessen är avloppsslam från Växjö. Planer finns på att utöka processen med en tredje reaktor i vilken det rötade slammet ska återrötas. Detta för att få ut mer biogas ur slammet.

Fossil fuels are affecting our climate negatively and there is a limited amount of them in the world, which leads to the importance of finding alternative fuels. One alternative is biogas, which is produced though a digestion process of different organic materials in a biogasreactor. Organic substrate that comes from farms has the biggest potential to increase the production of biogas in Sweden. Primarily crops from farms, but also waste products like manure are of great importance.Today there is a calculated theoretical potential for biogasproduction of 14TWh per year, which is around ten times larger than Sweden?s production today.