Sökresultat:
47 Uppsatser om Calcium - Sida 3 av 4
Fosforavskiljning i reaktiva filter vid småskalig avloppsrening
An excessive input of nutrients to lakes and other water bodies has created a problem with eutrophication in Sweden. Untreated, or partially treated, domestic sewage is a major source for discharge of phosphorus (P), which is the nutrient most frequently responsible for eutrophication of most fresh waters and the Baltic Sea. The waste water can be cleaned by filter materials, which have a high P-retention ability and which after saturation may be used as fertilizers. Four potentially suitable filter materials were tested in batch- and column experiments in this study. In the batch experiments, the following materials were shaken with waste water in time series ranging from 5 seconds to 60 minutes: coarse (1-4 mm) and fine (0-2 mm) Polonite® (heated bedrock from Poland); Filtralite® (light expanded clay aggregates with limestone added before burning); water cooled blast furnace slag (BF-slag) and BF-slag mixed with 10% burned limestone.
Kalkningens påverkan på fosforlöslighet : skakförsök baserade på två svenska långliggande kalk- och fosforgödslingsförsök
Eutrophication is an environmental problem that affects more than ten percent of Swedish lakes. Excess nutrients increase the growth of algae, and cause major problems in the ecosystem through oxygen-free bottoms, fish kills, and at worst dead bottoms. Agriculture accounts for 44% of human emissions of phosphorus to lakes and rivers. Leaching occurs of particle bound phosphorus and of dissolved
phosphate. The amount of phosphate in the soil solution that may be leached is partly due to the prevailing pH in the soil solution.
The purpose of this study was to investigate how the relationship between phosphate solubility and pH was affected by liming.
The rabbit as an animal model in dental implant research : with special reference to bone augmenting materials
Dental implants that are integrated into the jaw bones are widely used to replace lost teeth in human beings. Tooth-loss is often related to loss of the surrounding alveolar bone. This can make implant placement difficult and a bone substituting material may be required. The standard method is to use a bone graft harvested from the patient which requires additional surgery than that needed for implant placement. Limitations in the amount of bone that can be harvested also pose a problem.
Methane emission from nitrate-treated tannin rich feed for cattle in Vietnam
In developing countries such as Vietnam the population consumes more animal products for example milk and meat than before which requires greater livestock production. Ruminants contributes to more methane emission which creates a dilemma between food production and its environmental impact. By feeding ruminants with nutritive crops which humans can not assimilate the animal performance will increase in terms of better growth and milk production without inpinging on food that can be consumed directly by humans. Increasing animal performance reduces methane emission in terms of amount of methane in kg-1 milk and meat which today is much greater in developing countries than developed countries. The aim of the study was to investigate tropical tannin-rich legumes for their potential as a feed supplement for ruminants made in vitro.
Effekt av olika kvävegödselmedel på utvecklingen av klumprotsjuka i salladskål (Brassica rapa ssp. pekinensis)
The price trend on rapeseed the latest years has led to an increasing interest to grow the crop among many farmers in Sweden. The price trend has resulted in more than a doubling of the oilseed area since the early 2000s. For many farmers it is an advantage to increase cultivation of rapeseed because of the high proportion of cereals in the crop rotation on many farms, but it is not just benefits. The risk of the fields being infected by clubroot increases within frequent rapeseed cultivation and it often leads to subtantial economic losses. Clubroot is caused by Plasmodiophora brassicae that is a soilborne pathogen in genus Protozoa and its resting spores can be found in the soil for up to 18 years.
The bioavailability of soluble oxalates in stir-fried silver beet leaves
The prevailing food and energy crisis of the world, due to the declining reserves of fossil energy and a never ending rise of consumption, forces us to look into new fields to supply our energy demand. The boom of bio energy is criticized, as food crops are used to provide biodiesel and ethanol and the volumes are ridiculously small to supply world demand. Algae are one of the world?s oldest life forms and exist in many different phyla, providing a great variety to choose from, for different purposes. Cultivating microalgae offer a way to produce energy at great volumes without competing with food production and at the same time the algae offer a way to use our expensive nutrients in a more efficient way, besides this the algae are carbon dioxide neutral since their carbon source can be supplied by the atmosphere and the additional energy required can be supplied by algal oil or other renewable sources.
Fodersammansättningens betydelse för tillväxt hos häst :
The aim of the present study was to investigate the effect on growth of foals on two different diets, either a forage-based diet or a diet containing approx. 40 % concentrate. The report also includes a review of the pertinent literature on the effects of diet on mares? milk and growth of horses. The hypothesis of the study was that a forage based diet will result in a similar growth pattern as a diet including more concentrates if the diets contain the same amount of energy, crude protein, lysine, Calcium and phosphorous.
Bioelectromagnetics for improved crop productivity : an introductory review with pilot study of pre-sowing treatment of tomato
Various electromagnetic (EM) treatments has been investigated for their potential in improving crop productivity over the past century. There is today an increasing amount of scientists advocating EM treatments as an organically compatible method for improving plant
growth and yield. However, failure to produce repeatable effects and defining causal mechanisms has made it a study of much controversy and debate. The subject requires indepth
interdisciplinary knowledge, making it inaccessible for the majority of biologists, horticulturists and growers. In this combined literature review and pilot study, these issues are addressed by providing a comprehensive introductory review of the topic plant
bioelectromagnetics and its potential horticultural usability.
Djuromvårdnad vid fång
Laminitis is a common but devastating condition, and affected horses are often euthanized or influenced a very long time. Many horses never return to their original capacity. Laminitis is often associated with severe pain and a long time of convalescence. Symthoms includes lameness, hoof hyperthermia, strenghthened digital pulse and pain. The horse often tries to move the body weight away from the forelegs which are often more severly affected than the hindlimbs.
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.
Faktorer som påverkar magnesiumabsorptionen i våmmen hos kor
In metabolism Mg plays an important role because it affects many cellular enzymes in the body. The energy metabolism and protein synthesis are dependent on Mg as an enzyme activator, Mg is also involved in the synthesis of RNA and DNA. Absorption of Mg primarily takes place over the ruminal epithelium in ruminants. The main storage of Mg is in the bones but that can only be reached if the cow is in great need of Calcium or phosphorus, it's a hormonal regulated process that induces catabolism of bones. Free and available sources of Mg are found in soft tissues and in the extra cellular fluids that includes cerebrospinal fluids and blood.
Utfodring av sällskapskanin. Vilka råd ger vi djurägarna?
The most suitable method to answer the issues of this study was to do a combined literature- and questionnaire study. The literature part of the study was based on Original Research articles, Review Articles and books with a list of reference literature after each chapter and the purpose was to answer the questions ?What feed items should be given to rabbits in different life stages? and ?Which problems may develop from an inadequate diet??
Two questionnaires were constructed. One was sent by e-mail to small animal veterinary hospitals to be answered anonymously by veterinary nurses. The other was linked to from two internet forums, that with rabbits as their focus.
Genetisk och immunologisk bakgrund till atopisk dermatit hos hund
Atopisk dermatit är en sjukdom som drabbar ungefär en tiondel av världens hundar. Sjukdomen ger som följd av allergenexponering symptom såsom klåda, hudlesioner och otitis externa. Patogenesen för atopisk dermatit är komplex och multifaktoriell. Målet med denna litteraturstudie var att undersöka hur genetiska och immunologiska faktorer bidrar till sjukdomens patogenes. En obalans i T-hjälpar-(Th)-svaret vid atopisk dermatit är allmänt accepterad.
Bildandet av kalciumoxalatstenar i hundens urinvägar : en genomgång av potentiella predisponerande faktorer
Urinsten, urolithiasis, är en relativt vanlig åkomma i hundens urinvägar. Stenarna är uppbyggda av olika mineraler och salter av vilka kalciumoxalat och struvit
(magnesiumammoniumfosfat) är de vanligaste, ensamma eller i kombination med andra ämnen. Stenarna återfinns framförallt i de nedre urinvägarna, det vill säga i urinblåsa och
urinrör. De kan ställa till stora problem genom obstruktion och svår smärta. De upptäcks vanligtvis genom röntgen och måste ofta avlägsnas kirurgiskt men risken för att nya stenar utvecklas är stor.
Askgödsling och dess lämplighet i torvmarksskogar tillhörande Sveaskog Förvaltnings AB : en litteraturstudie
During whole-tree harvesting, there is a risk that the soil will become impoverished of nutrients. To prevent this, nutrients are returned to the harvested site as wood ash. This action also reduces the risk of soil acidification. Nevertheless, the ash does not result in any increase of tree growth if it is added on mineral soils, which is where the measure is most commonly used in Sweden. Due to the lack of growth response, the interest from landowners is small, which is why ash amendment today is not done enough to compensate for the need.