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10 Uppsatser om Peroxide - Sida 1 av 1

Jämförelse av metoder för peroxidbestämningar i bränslen : A comparison of methods for determination of peroxide content in fuel

New energy resources that can replace petroleum diesel are needed and biodiesel may be an excellent substitute. During storage and use, biodiesel can oxidize and form Peroxides, leading to degradation of the fuel. It is therefore important to determine the Peroxide content of the fuel. In this thesis the triphenylphosphine method, which involves GC-MS analysis has been compared to the standard iodometric method which involves titration with sodium thiosulfate. Working standards were made to see how well the iodometric method worked and also in order to make a calibration curve in GC-MS.

Behandling av lakvatten med kemiska oxidationsmedel för att delvis bryta ned oönskade organiska förening : en studie utförd vid Hovgårdens avfallsanläggning i Uppsala

A renewed application for environmental permit for the Hovgården landfill in Uppsala shall be submitted before December 2004, therefore the municipality of Uppsala needs improved knowledge of the contents, mostly organic compounds in the leachate and they also want to find a method to minimize the emissions of these compounds. The purpose of this study was to find a practical and economical method based on chemical oxidation using oxidants. The oxidants investigated are Fenton's reagent, hydrogen Peroxide, Oxypro, potassium permanganate and potassium persulfate. The study was made on untreated leachate and leachate that has been treated in an aerated dam followed by sedimentation dams collected from the Hovgården landfill, and alson on sludge water from sludge storage cells. The effects of the five oxidants have been established by analysing the UV absorbance at the wavelengths 253,7 nm and 260,0 nm at different pH values. The UV absorbance was used to indicate the amount of aromatic hydrocarbons in the water. Also analyses of iron and manganese were done after the experiments with potassium permanganate, hydrogen Peroxide and Fenton's reagent.

Experimentell studie av kinetiken vid peroxidblekning av pappersmassa

Vid TCF-blekning av pappersmassa är väteperoxid en av huvudkemikalierna. I dagsläget är det svårt att styra blekstegen. Operatörerna måste ta hänsyn till produktionstakt, blekbarheten på massan varierar och fördröjning i trender. PO-bleksteget på Södra Cell Värö har en ungefärlig uppehållstid på 4 timmar och det är först efter så lång tid som man kan se hur en förändring verkligen slår igenom. Överblekning kostar väldigt mycket i kemikalieåtgång och det är därför efterfrågat ett sätt att kunna styra och optimera peroxidblekningssteget.

Vaselin som kontroll vid försök med 1 % väteperoxidkräm i färska hudsår på häst

Wounds on horses are common and sometimes difficult to treat. The wounds are often big and could be discovered too late for primary sutures, which have to be applied within 8 hours from time of accident, before bacteria has been able to infiltrate the surrounding tissue. The healing is often complicated by delayed healing and wound infection with consequences like phlegmone, fistulation and proud flesh formation.To avoid these consequences, the traditional practice has been to administer systemic antibiotics alone, systemic antibiotics in combination with topical antibiotics or topical antibiotics alone. Because few antibiotics can be used in horses, is it important to household with the few substances that are available. In veterinary medicine today, the increasing resistance amongst pathogenic microbes such as MRSA presents a growing problem.

Utvärdering av avloppsvattenreningen vid Hallsta Pappersbruk : Kartläggning av inkommande avloppsvatten och optimering av driftparametrar

Hallsta paper mill uses large amounts of water during the pulp and paper making processes. The wastewater is treated in two separate activated sludge processes referred to as BIO 1 and BIO 2. The main aim is to reduce the organic substance content, measured as COD (Chemical Oxygen Demand) before the wastewater is released into the environment. Since the effluent produced is very rich in organic substances, the addition of nitrogen (N) and phosphorus (P) are necessary to give satisfactory treatment results. Problems with sludge bulking sometimes occur which lead to increased levels of suspended matter and nutrients in the effluent.

Optimering av blekeriet i CTMP-linjen vid Rottneros Bruk

At Rottneros pulp mill mechanical pulp is bleached with hydrogen Peroxide. The changes of bleaching chemicals that are used for different grades are taken from bleaching tables; however these tables are old and need to be updated. The purpose of this thesis was to be the basis of new documentation.In this thesis three pulps where studied with the aim to find the optimal bleaching chemical changes (total NaOH/VP-quote) for each pulp. The pulps were taken from the filter before the bleaching tower and the pulps were bleached in the lab. The most important pulp property in this study was the brightness and how that was influenced by the chemical dosages.

Interferences during analysis of polyphenols in fruit juices

One of the most commonly used methods for analysis of polyphenols is the Folin-Ciocalteu (FC) method, where the FC reagent has been reported to interfere with some substances in fruit juices. The interfering substance that is present in the highest amount in most fruit juices is ascorbic acid. In this study, the total phenolic content (TPC) of three fruit juices was analysed by the FC method as well as with an enzymatic method with hydrogen Peroxide oxidoreductase type II (HRP) for comparison. To investigate how the interfering ascorbic acid affects the TPC, juice samples were analysed after removal and addition, respectively, of ascorbic acid. The samples were analysed with HPLC both before and after the extraction phase of the FC method.

Comparison of Different Electrophoretic Methods for Haptoglobin Phenotyping and an Investigation in Patients with Abdominal Aortic Aneurysm

Haptoglobin is an acute phase protein with important biological role because of its capacity to bind to haemoglobin. Haptoglobin exists in three major genetic polymorphism types: Hp1-1, Hp2-1 and Hp2-2, the distribution of which has been associated with abdominal aortic aneurysm (AAA), an asymptomatic aortic disease common among men older than 65 years.    Five different electrophoretic methods were tested according to their ability to separate the haptoglobin phenotypes. The detection was based on a produced hemolysate of blood in which haemoglobin binds to haptoglobin thereby forming a complex that can be detected by specific haemoglobin staining using TMB-dihydrochloride and hydro Peroxide as substrate resulting in an azure-green color of the bands. Samples from 15 patients who had suffered surgery for not broken AAA, that is more than5.0 cmaortic diameter, and 15 samples from matched controls were analyzed.    Among the five tested electrophoretic methods best migration and separation was seen on the pre-cast agarosgel Hydragel HR on the instrument Hydrasys. The other four methods gave less successful results.

Driva tulpaner i näringslösning eller i jord :

The aim with this thesis is to make a comparison between forcing tulips in a hydroponic system and the forcing off tulips that have been planted in soil. The results are mostly based on interviews with six Dutch and one Swedish tulip forcer and the managing director at the Horticultural Research Centre, Proeftuin Zwaagdijke, in the Netherlands. There are benefits and disadvantages with both methods. Tulip bulbs planted in soil seem to get a brighter colour after forcing, compared with those forced ?in water?.

Kemisk karaktärisering samt nedbrytning av process- och avloppsvatten vid SCA Ortvikens pappersbruk

During pulp and papermaking process a huge amount of water is used. The wastewater contains a large amount of pollutants and has to be treated before it reaches the recipient. In March 2004 a new bleaching plant was started up at SCA Graphic Sundsvall AB, Ortviken?s paper mill using Peroxide. The production of bleached thermo mechanical pulp and thus the load to the wastewater plant increased.