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269 Uppsatser om Alkali silica reaction (ASR) - Sida 1 av 18

Modellering av svällande betong : Alkali-silikatreaktion (ASR) i en befintligturbininneslutning

För att bibehålla elnätet stabilt är det viktigt för elproducenterna attkunna möta samhällets behov av elkraft. Detta behov varierar beroendepå tid på dygnet och även av årstid. Att kunna samla energi då behovetär lågt, för att sedan utvinna och distribuera energi då behovet ökar ärdärför viktigt. Vattenkraft är en av de energikällor som är enklast attreglera. Denna energi är dessutom relativt miljövänlig.

Fällning av kisel från avloppsvatten vid Hellisheidarvirkjun - experimentell studie

This report is about the experiments with mixing of the separated water and the vacuum pump seal water at Hellisheiði power plant. This is done to prevent silica scaling and clogging in pipes and reinjection wells as well as eliminating vacuum pump seal water from the plant. The experiments were done in four stages: the first stage comprised of tests with different flows of separated water at 70°C, the second stage was carried out by mixing the separated water at 70°C and the seal water with different amounts of the seal water, the third and the fourth stages were like the first and second but with the separated water at 120°C. The results show that this method is good if the mixture is around 50/50 separated water and seal water, to control the silica scaling in the separated water and to be able to reinject the seal water with the separated water. This does not eliminate the silica scaling in all of the separated water because the amount of separated water is much more than the amount of seal water that comes from the plant. .

Skolsituationen för elever med betyget MVG i matematik : En fallstudie av fyra elever i grundskolans årskurs 9

This thesis has been focused around the Diels Alder reaction with the goal to design an enzyme catalyzed reaction pathway. To achieve this goal computer aided enzyme design was utilized. Common traditional methods of computational chemistry (B3LYP, MP2) do not do well when calculating reaction barriers or even reaction energies for the Diels Alder reaction. New calcu- lation methods were developed and tested. This was the focus of the first part of the thesis, by choosing a small system, extensive and heavy calculations could be done with CBS-QB3.

Uppbyggnad och reglering av en pumpstation till ett injektionssystem

I was assigned to the thesis as part of a project GMA AB (Ground Machinery Applications AB) is running. The project aims to develop a new method for injection of drilled holes in rock walls. Currently, the injections usually involve cement but the basic idea of the project is to replace cement with a supplement called Silica sol.Silica sol is known as a gelling liquid. The gel time is controlled by a mixing of saline. Depending on the amount saline that gets mixed in, the gel time varies.

Datorbaserad analys av enzymdesign för Diels-Alder  reaktioner

This thesis has been focused around the Diels Alder reaction with the goal to design an enzyme catalyzed reaction pathway. To achieve this goal computer aided enzyme design was utilized. Common traditional methods of computational chemistry (B3LYP, MP2) do not do well when calculating reaction barriers or even reaction energies for the Diels Alder reaction. New calcu- lation methods were developed and tested. This was the focus of the first part of the thesis, by choosing a small system, extensive and heavy calculations could be done with CBS-QB3.

Kisel som växtstärkande medel : en litteraturstudie

Sammanfattning Kisel (Si) är det näst vanligaste ämnet (drygt 25 %) i berggrunden. Bara en del av detta är tillgängligt som monokiselsyra, den form i vilken kisel är upptagbart för växter. Jordens kiselinnehåll är beroende av bergets vittring. Mycket höga halter av kisel återfinns i naturen i vulkaniska substrat (pimpsten innehåller drygt 66 % Si och scoria närmare 47 % Si), i diatomit (ett mineral bestående av resterna från encelliga kiselhaltiga alger, s.k. diatoméer) innehållande 66 % Si, scoria approximatly 47% Si), in diatomite (a mineral consisting of the remainings of single celled algae, diatoms containing < 40 % Si) and in some clays (30-60% Si).

Efterinjektering i Hallandsåstunneln. Analys av data från efterinjektering med cement och silica sol i den oinklädda delen av tunneln.

Social housing in Northern Europe and the importance of social and political consideration in planning. Focus of the essay lies on the "burning suburbs" of France, based on literature studies combined with a study visit to Les Minguettes outside of Lyon..

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.

Syrgasdelignifiering av magnesiumbaserad sulfitmassa med magnesiumbaserad alkali

Syftet med arbetet var att undersöka hur olika reaktionsbetingelser skulle påverka syrgasdelignifieringen av en sur sulfitmassa. De betingelser som undersöktes var utbyte, slut-pH, viskositet och kappatal. Massan som användes kom från Nordic Paper Seffle och alkalit som användes var magnesiumoxid. Syrgasdelignifiering av massan gjordes  i autoklaver i ett PEG bad där tid, temperatur och alkalisatser varierades.Resultaten visar att alla utbyten låg mellan 90-97% och att även de mest aggressiva betingelserna bara gav en viskositets reduktion på 260 enheter, motsvarande 19% av den totala viskositeten.Slut-pH för syrgasavluten hamnade mellan 6,5-9,4 beroende på alkalimängd och temperatur under delignifieringen. Slut-pH minskade när mängden alkali hölls konstant men temperaturen varierades mellan 110-140°C.Kappatalet för massan kunde effektivt reduceras från ett startvärde på 23,4 till ett slutvärde på under 5 med en temperatur på 140°C, alkalisats på 10 kg/ODT och en tid på två timmar utan större förluster av vare sig viskositet eller utbyte.En ovanligt resultat som upptäcktes under arbetet var att delignifieringen tappade i effektivitet med ökad alkalimängd och detta samband gällde vid alla betingelser.En teori om detta kan vara att jonstyrkan i lösningen gör att fibrerna i massan drar ihop sig och att syrgasen får svårare att reagera med ligninet..

Atopisk dermatit hos hund :

This student report is about canine atopic dermatitis It includes a description of the immunologic mechanisms and how the reaction affects the body. The symptoms are various, most common is pruritus, erythema and alopecia and directly associated with the immunologic reaction. The diagnostic process includes symptoms, physical findings, differential diagnosis, intradermal test and serological test. The options of treatment are several and vary for each patient. The report includes hyposensitization, medical treatment such as corticosteroids, antihistamin and cyclosporine, topical treatment, fatty acid supplements and environmental treatment. The prognosis is individual for each patient due to their different response to the treatment. It may take a while to find the right combination of treatments to achieve satisfactory control of the disease..

Är Marknaden Varse om Varsel? : En studie om den svenska kapitalmarknadens reaktion på varsel om uppsägning

The purpose of this study is to examine the capital market reaction generated by layoff announcements. The study takes place in Sweden and tests 138 news concerning layoffs which are categorized according to a content analysis. They are divided as: positive or negative news. The layoffs are also divided into three subgroups with varying sizes: 0,98 percent or less, between 0,99 and 4,49 percent or 4,5 percent or larger. The study uses an event study method to measure the reaction of the capital market.

Undersökning av slaggfasers alkaliupptagningsförmåga i LKAB´s experimentmasugn

Alkaliupptagningsförmåga samt slaggbildning under inverkan av varierande slaggbildare för kaolinbelagd MPBO, SPBO samt KPBA har studerats i följande examensarbete. Syftet med arbetet var att öka förståelsen för slaggbildningsmekanismerna samt att studera hur alkaliupptagningen varierar för de olika pelletsen. Utöver detta skall även inverkan av titaninjektionen, vilken genomfördes under delar av försöket, studeras. Korgprover samt driftdata från experimentmasugnen i kombination med analyser från svepelektronmikroskop ligger till grund för arbetet. Den ytbelagda MPBO pelleten visar på en ökad alkaliupptagning.

Låna på eget ansvar? Franska folkbibliotekarier om medieurval i samspel med låntagare

The aim of this master thesis is to examine which criteria are generally used to guide pub­lic librarians in their acquisitions' decision. The study went ahead in France, principally at La Bibliotheque municipale de Lyon. It also includes a view of some special library services in the social field.Twenty persons were interviewed and an attempt was made to divide their answers into three sections: acquisition routines and criteria for media purchase, how to receive the library visi­tors and their influence on the acquisitions, and, finally, the librarians' own opinions on the matter. One important question was whether censorship is applied and in that case, would it be a deliberately way of acting or rather a spontaneous reaction, more or less unconscious.Censorship in real or manifested through a self-preservative reaction turned out to be a factor closely dependant on the library's financial situation. Many librarians affirmed they would find useful some kind of a written practical library acquisition policy..

Personalnedskärningar och aktiepriser : En eventstudie av sambandet mellan personalnedskärningar och aktiepriser under perioden 2008-2012

Purpose: The purpose of this thesis is to investigate whether abnormal stock returns could be identified as a result of a layoff announcement during weak economy.Method: An event study methodology.Theory: Efficient market hypothesis, signal theory.Empirical results: Quantitative data from observations of stock prices in thirty two companies listed on the Nasdaq OMX Stockholm, in the period 2008 -2012.Conclusion: The results indicate that the market reaction was negative because there were negative abnormal returns on the Stockholm Stock Exchange during the period 2008-2012 in connection with the layoff announcements. The market reaction was milder when staff reductions were carried out as a result of a restructuring and stronger when staff reductions were carried out as part of a cost reduction program.The layoff announcements elicited different market reactions depending on the company's industry affiliation. The most negative reaction was in the Healthcare industry. Negative abnormal returns were lower in industries Industrials, Consumer Services and Consumer Goods. There were no abnormal returns for shares of companies in the industry Financials.

En proteomisk utvärdering av olika metoder för att samla uterussekret hos sto :

This study was performed in order to evaluate if the method of collecting uterine secretion by the tampon-method is representative for use in studies of uterine secretions in mares. Uterine secretion collected by tampon in six mares was compared with secretion collected by aspiration, regarded to be a native sample, at the Institution of Obstetrics and Gynaecology, SLU, Uppsala. Proteinanalysis was made at the Department of Farmaceutic Bioscience, toxicological unit, Uppsala University. Cytological smears and ultrasonography was used to assess if the tampon had caused an inflammatoric reaction that could influence the protein content of the samples. The results suggest that the tampon and aspirat method do not differ when it comes to proteinconcentration, but the distribution of proteins differ between these different collection methods. This difference could not likely be explained by means of proteins due to an inflammatory reaction from the tampon, since neither the cytological nor the ultrasonographical examination gave any indications of inflammation.

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