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50 Uppsatser om Calcium carbonate - Sida 1 av 4
Studie och riskanalys av sulfidleror i Uppsala stad
Most of the city of Uppsala rests on postglacial clay with a varying content of sulphur. The sulphur occurs naturally in the clay in reduced form as sulphide and the clay is for that reason usually called ?sulphide clay?. Excavation during construction activities gives rise to large amounts of excavation material, of which the sulphide clay is a considerable part.When the clay is exposed to air and water, an oxidation of the sulphides occurs which may produce an acid leachate and the mobilisation of heavy metals bound in the clay or underlying material. The aim of the work has been to improve our understanding of the behaviour of sulphide clays and produce a basis for risk assessment in the future handling of excavation material with high sulphide content.
Hårdhetsvariation i grundvatten längs Badelundaåsen mellan Leksand och Avesta
Water hardness indicates the concentration of calcium and magnesium ions in water. Water with high concentrations of these ions is described as hard water and water with low concentrations is described as soft water. Water that is too hard or too soft can lead to technical and economical problems. In collaboration with Midvatten AB, groundwater hardness in the Badelunda esker between Leksand and Avesta has been mapped, and an attempt has been made to explain the variations. For this purpose, different GIS programs, such as ArcView, ArcInfo, IDIRISI, and one geochemical modelling program, PHREEQC, has been used.
Kemisk stabilisering av gruvavfall från Ljusnarsbergsfältet med mesakalk och avloppsslam : Chemical stabilization of mine waste with sewage sludge and calcium carbonate residues
Chemical stabilization of mine waste from Ljusnarsbergsfältet with sewage sludge and Calcium carbonate residuesMine waste from Ljusnarsbergsfältet in Kopparberg, Sweden, is considered to constitute a great risk for human health and the surrounding environment. Some of the waste rock consists of sulphide minerals. When sulphide minerals come into contact with dissolvedoxygen and precipitation, oxidation may occur resulting in acid mine drainage (AMD) and the release of heavy metals. The purpose of this study has been to characterise the waste material and try to chemically stabilize the waste rock with a mixture of sewage sludge and Calcium carbonate. The drawback of using organic matter is the risk that dissolved organic matter can act as complexing agents for heavy metals and in this way increase their mobility.
Analys av parathormon och joniserat kalcium i blod hos hund :
The calcium homeostasis in the body is normally strict regulated to be kept within very narrow limits. This regulation is due to the action of parathyroid hormone (PTH) which is synthesized in the chief cells of the parathyroid glands. In different diseases, the calcium homeostasis is disturbed and this could either be due to a dysfunction of the parathyroid gland itself, or it could have a completely different explanation. To investigate disturbed calciumhomeostasis, ionized calcium and PTH can be analyzed from a blood sample. There are a lot of different assays to measure PTH in humans.
Syntes av hydroxyapatit/ nanocellulosa kompositer
Cellulose nanocrystals (CNC) are great candidates for composite materials. The reasons why CNCs are such attractive materials for them are due to their great mechanical properties, high aspect ratio and low density. On the other hand, hydroxyapatite (HAp) is a kind of calcium phosphate and a main component of bones and teeth. The purpose of the present study is to make oriented nano-sized composites with CNC and HAp. Although some researchers carried out to make CNC composites with HAp for biomedical materials, nano-sized and oriented ones haven?t been achieved yet.
Mesatorrhalt
AbstractDegree thesis Solid content in Lime Mud By Andre Flodin Process operator program ? Umeå University 17/6 ? 2014 Pages: 21A thesis was made on Billerudkorsnäs production unit in Karlsborg where lime kiln in the causticising department of chemical recovery plant does not meet the required production. Causticising department is the final step in the chemical recycling unit. There, the filtered green liquor is mixed with lime to recover the cooking chemicals used in the pulp factory. The cooking liquid is called white liquor.
Kalciums och magnesiums inverkan på arsenikavdrivningen i virvelbäddsugnen : The influence of calcium and magnesium on the expellation of arsenic in the fluidized bed furnace
In the fluidized bed furnace at Rönnskärsverken, Skelleftehamn, sulphur-containing ore concentrates are roasted in order to remove about 50% of the sulphur in the incoming ore concentrate. This occurs in order to reach the goal of a matte containing 55% of copper in the following smelting process. At the same time as the ore concentrate is partially roasted pollutions as arsenic, antimony and bismuth are expelled. Earlier made thermodynamic calculations of equilibrium suggested that calcium and magnesium form stable compounds with arsenic and thereby inhibit expellation of arsenic in the fluidized bed furnace, an element that is undesired. The purpose of this thesis work was to gain knowledge of the mechanisms behind the formation of these stable arsenic compounds.
Utvärdering av en snabbtest för diagnostisering av hypokalcemi hos nötkreatur :
Clinical signs of hypocalcaemia in dairy cows are easily recognized, and a rapid response to treatment generally confirms the diagnosis in the field. However, clinical signs of other disorders in cows, such as toxemia, calving paralysis, or muscoskeletal injury, may mimic those associated with hypocalcaemia. Therefore, making a diagnosis of hypocalcaemia on the basis of clinical signs alone may be difficult. In ambulatory veterinary practices, cow-side tests are useful to make the diagnosis and prognosis easier.
Kruuse?s Kalcium Test is a cow-side test based on the principle that calcium ions are necessary for coagulation of blood, and that chelation with EDTA prevent coagulation.
Produktutveckling av koncept för isbanesystem
Today most ice rinks in Sweden use secondary refrigeration systems with a solution of calcium chloride and water as secondary refrigerant. Due to the large amount of energy such a system uses more efficient systems would be desired.An earlier study concluded in the possibilities of using carbon dioxide as secondary refrigerant with copper tubes as the loops in the ice rink. Since then 3 ice rink refrigeration systems has been built with carbon dioxide in copper tubes. Excluding the ones being direct involved in those projects there is still very little knowledge about how these system works. This study has been made primarily with the aim of adding to the knowledge concerning availability and cost and secondary to look at possibilities for improvement.A comparison between systems with carbon dioxide, calcium chloride respective ammonium solved in water has been made by using Decision Matrix.
Konsolidering av v?vsp?nda papperstapeter: analys och metodutveckling
Printed and painted wallpaper on a weaved fabric backing was a common way to decorate homes in Sweden during the eighteenth and nineteenth centuries. Not much is written about the craftsmanship in relation to the hanging of these wallpapers and even less about the conservation of the objects. Even so, many wall segments remain in situ and in museums and are more often than not in dire need of conservation such as deacidification and consolidation. These are composite objects, consisting of cellulose materials with different properties along with adhesives and paints. Analysis of the materials is required to ensure safe handling and choice of conservation materials, and to establish a treatment plan which will be executed in several steps.
This thesis aims to identify these steps and develop a method for conserving the wall segments with suitable materials, preferably without altering the source material to any significant degree.
Utvärdering av rörelsemönster hos öring (Salmo trutta) utifrån otolitmikrokemi
The classic view of trout (Salmo trutta) life history is that trout begins its life in freshwater, migrates to the ocean after about 1-4 years and then returns to freshwater to spawn. As trout fry have been caught at the mouth of the River Emån, near the Baltic Sea, researchers have speculated that some trout emigrate during their first year of life. The purpose of this study was to describe the variation in the length of time trout reside in freshwater before they migrate to the ocean for the first time. Another purpose was to investigate whether it was possible to discern where and how long the fish spent in freshwater and saltwater during different parts of their lives. Between 2007 and 2009, 23 adult trout were captured in the River Emån in southeastern Sweden.
Ledarskap & management i storskalig smågrisproduktion
This study has been done in order to map the supply of vegetarian and vegan food products in Sweden for business clients and consumers. A total of 665 food stuffs were found and classified into six categories. The biggest category was meat substitutes with 302 products and the second largest category was sandwich spreads with 150 different products. Within the remaining categories a varied number of products were found; 86 beverages, 64 cooking accessories, 34 milk free ice creams and 29 plant based yogurts. Of the meat substitutes were 28 only available for business clients.
Utbudet av vegetariska och veganska livsmedelsprodukter på den svenska marknaden : vilka produkter finns och hur är de berikade?
This study has been done in order to map the supply of vegetarian and vegan food products in Sweden for business clients and consumers. A total of 665 food stuffs were found and classified into six categories. The biggest category was meat substitutes with 302 products and the second largest category was sandwich spreads with 150 different products. Within the remaining categories a varied number of products were found; 86 beverages, 64 cooking accessories, 34 milk free ice creams and 29 plant based yogurts. Of the meat substitutes were 28 only available for business clients.
Societetsparken i Norrtälje : nulägesanalys och utvecklingsförslag
The short term effect of phosphorus in sewage sludge was investigated to establish howmuch of this a farmer can grant him- or herself, if using sewage sludge as a phosphorusfertilizer. Possible differences in plant availability between sludge phosphorus precipitatedby iron, aluminum or calcium integrations were studied in a sandy soil at two pH levels.The sludges were analyzed using pot and incubation trials. As the intention was to investigategrowth limitation due to phosphorus deficiency, a soil with low phosphorus supplywas chosen as well as a low phosphorus application rate. Sludge corresponding to 12kg phosphorus per hectare was applied. Treatments fertilized by sludge were compared totreatments where 0, 6 and 12 kg phosphorus per hectare from mineral fertilizer was applied.Every treatment was replicated six times.
Kemisk stabilisering av gruvavfall från Ljusnarsbergsfältet med mesakalk och avloppsslam
Mine waste from Ljusnarsbergsfältet in Kopparberg, Sweden, is considered to constitute a great risk for human health and the surrounding environment. Some of the waste rock consists of sulphide minerals. When sulphide minerals come into contact with dissolved oxygen and precipitation, oxidation may occur resulting in acid mine drainage (AMD) and the release of heavy metals. The purpose of this study has been to characterise the waste material and try to chemically stabilize the waste rock with a mixture of sewage sludge and Calcium carbonate. The drawback of using organic matter is the risk that dissolved organic matter can act as a complexing agent for heavy metals and in this way increase their mobility.