Gas chromatography (GC) has been utilized for the study of enantiomer resolution of the atropisomers of PCBs, o,p´-DDD and o,p´-DDT. Different substituents and concentrations of cyclodextrin, capillary dimensions and type of stationary phase films have been investigated to achieve the resolution of as many of the atropisomers on one column as possible. The results indicated that the butyl substitution of 6-hydroxyl and the methyl substitution of 2- and 3-hydroxyl were the most promising for the enantiomeric separation. Using Capillary Electrophoresis (CE), the trimers and monomers of PM-β-CDs were compared for enantiomeric resolution, as well as comparing the cationic PMMA-β-CD with the anionic HS-β-CD. In these studies the trimer did not show an improved resolution for mepivacaine, when compared to the equimolar concentration of the monomer. The cationic CD gave increased resolution values for ibuprofen when compared to the anionic CD. A scheme for reversing enantiomeric elution order of both the basic propranolol and acidic ibuprofen is also presented, with the aim of facilitating the detection of impurities in a high sample loading. The detection of 1% of each enantiomer of propranolol, and 1% of R(-)-ibuprofen, was demonstrated, with elution prior to the tailing peak of the corresponding enantiomer. Dimethylacrylamide-coated capillaries were used in this work, and the stability of this coating was demonstrated, giving a highly reduced electroosmotic flow for up to six months. Enantiomeric baseline separations of omeprazole and 5-hydroxyomeprazole have also been achieved with both CE and Open Tubular Capillary Electrochromatography (OT-CEC) methods. With CE-UV, both a non-aqueous method (using HDMS-β-CD) and an aqueous method (using HS-β-CD) were used for enantiomeric resolution of the two racemates. Resolution of omeprazole was also achieved using CE-Electrospray Ionization-Mass Spectrometry (ESI-MS). In OT-CEC, avidin was immobilized on the inside surface of a fused silica capillary and was employed as chiral selector for the enantiomeric baseline resolution of omeprazole and 5-hydroxyomeprazole.

This thesis describes the host-guest chemistry between Cucurbit[7]uril (CB[7]) and CB[8] and a series of guests including bispyridinium cations, phenols and  napthalenes. These guests are bound to ruthenium polypyridine complexes or ruthenium based water oxidation catalysts (WOCs). The investigations are based upon utilizing the covalently linked photosensitizer and the electronic effects and chemical processes are investigated. / QC 20100927

Syftet med detta arbete var att skapa ett läromedel för undervisning i kemi och fysik. Den huvudsakliga utgångspunkten är tagen i läroplanens centrala innehåll för ämnena kemi och fysik i skolår 4-6. Målet har varit att aktiviteterna som finns beskrivna i läromedlet ska ge en helhetsbild och kombinera teori med praktiska uppgifter. Resultatet av vårt utvecklingsarbete mynnade ut i ett läromedel som består av lärarhandledning med tillhörande elevkompendium. I läromedlet finns praktiska aktiviteter som inte kräver någon specialutrustning eller speciell laborationssal. Aktiviteterna går att utföra i klassrummet med enkla och lättillgängliga vardagsmaterial. Läromedlet är utformat för undervisning på mellanstadiet men går naturligtvis att anpassas till tidigare eller senare år. / The purpose of this essay was to create a teaching aid for education in chemistry and physics. The main starting point is taken from the curriculum's central content for chemistry and physics in grades four through six. The aim was to create a teaching aid that combines theory with practical tasks. The teaching aid consists of a teaching guide with belonging student compendium. The practical activities described do not require any special equipment or laboratory rooms.  They can easily be performed inside the classroom with simple and accessible everyday items. The teaching aid is designed for education in grades four through six, but can of course be adapted for use in lower or higher grades.

Diss. Uppsala : Univ., 2003.

<p><strong>ABSTRACT</strong></p><p>The demand of healthier products is increasing, and more people are more interested of what they eat. Statistics show that the consumption of snacks is rising.</p><p>Hyperglycemia leads to an increased risk for complications in type II diabetes mellitus. Increased levels of postprandial plasma glucose may also lead to equal or maybe more harmful effects than fasting hyperglycemia. When the levels of postprandial plasma glucose are decreased, the development of cardiovascular complications is delayed, why it is important to lower the snacks consumption especially snacks that brings hunger quickly after they are eaten. Because of these factors, healthier products were developed in this study. The aim was to develop a wafer chocolate product that gives higher satiating effect and healthier blood glucose levels compared to one of Cloetta’s chocolate products. Two raw materials were used, a new carbohydrate and a new fat. The new carbohydrate is a healthier sugar alternative than sucrose, since it leads to lower and prolonged increase in blood glucose and insulin levels. The new fat is based on natural oil that is believed to be healthy, mainly due to its satiating effect. The effects of these two materials on blood glucose response and satiety were examined in two products. Furthermore, the products were made of fat reduced milk chocolate in which sucrose in the chocolate mass was 100 % replaced with the new carbohydrate, dietary fibre and fruit concentrate. Only one of the products contained the new fat. The products, together with Cloetta’s chocolate product were consumed by 17 healthy subjects. Blood glucose response and satiating effect after product intake were examined during a period of 3 days.</p><p>When blood glucose response was analyzed, a slight indication that the products were relatively healthier than placebo, due to placebo’s unhealthy fluctuations, was found. No clear differences regarding blood sugar maxima were found. Placebo showed, as expected, the highest blood glucose maxima and the largest incremental area under curve, but the maxima of the new fat-lacking product was less than half as high as that of the new fatcontaining product and the area was smaller too, which was not expected. The results regarding the hunger levels were not as expected either since the new fat-lacking product was most satiating while the new fatcontaining product was the least satiating. Despite that, 57 % of the subjects reported they would by such products in the future.</p><p>Several biases may have played a role in the results, for example whether or not subjects followed the criteria (e.g. lunch time, exercise), stress, worry, individual energy requirement and how serious and focused the subjects were. However, for further research, increasing the new fat content to 3 g, a bigger sized product, different filling, more subjects and more repeats of same measurements is recommended.</p><p> </p><p> </p> / <p> </p><p><strong><p>SVENSK SAMMANFATTNING</p></strong></p><p>Efterfrågan på hälsosammare produkter ökar, och fler människor blir mer intresserade av vad de äter. Statistik visar att konsumtionen av mellanmål ökar.</p><p>Hyperglykemi leder till en ökad risk för komplikationer i typ II-diabetiker. Ökade nivåer av postprandiell plasmaglukos kan leda till lika eller mer skadliga effekter än fastande hyperglykemi. När nivåerna av postprandiell plasmaglukos är lägre reduceras utvecklingen av kardiovaskulära komplikationer, därför är det viktigt att minska småätandet, speciellt av mellanmål som leder till hunger snart efter att de har ätits. På grund av dessa faktorer har hälsosammare produkter utvecklats i denna studie. Syftet var att utveckla en kexchokladprodukt som har högre mättnadseffekt samt hälsosammare blodsockernivåer jämfört med en av Cloettas chokladprodukter. Två produkter som alternativ till Cloettas chokladprodukter utvecklades. I dessa användes en ny kolhydrat och ett nytt fett. Den nya kolhydraten är ett hälsosammare sockeralternativ än sukros, då den leder till en lägre och förlängd ökning av blodglukos- och insulinnivåer. Det nya fettet är baserat på en naturlig olja som är hälsosam på grund av dess mättande effekt. Effekten av dessa två ämnen undersöktes. Vidare så gjordes de två produkterna av fettreducerad mjölkchoklad i vilken sukros i chokladmassan var 100 % ersatt med den nya kolhydraten, kostfiber samt fruktkoncentrat. endast en av produkterna innehöll det nya fettet. Produkterna, tillsammans med Cloettas chokladprodukt (placebo) konsumerades av 17 friska personer. Blodsockerresponsen och den mättande effekten efter produktintaget undersöktes under 3 timmars period per dag i totalt 3 dagar.</p><p>När blodglukosrespons analyserades hittades en svag indikation på att produkterna var relativt hälsosammare än placebo, på grund av de ohälsosamma fluktuationerna. Inga klara skillnader med avseende på blodsockermaxima hittades. Placebo visade, som väntat, det högsta blodglukosmaximum och den största arean under kurvan, men maximum för produkten utan det nya fettet var mindre än hälften så högt som det för produkten med det nya fettet och även arean under kurvan var mindre, vilket inte var förväntat. De upplevda hungernivåerna var inte heller som förväntat då produkten som saknar det nya fettet mättade flest personer medan produkten innehållande nya fettet mättade minst antal personer. Trots det så kunde 57 % av deltagarna tänka sig köpa sådana produkter i framtiden.</p><p>Flera faktorer kan ha påverkat resultatet, till exempel huruvida försökspersonerna följde kriterierna (t.ex. lunchtid, träning), stress, oro, individuella energibehov samt hur allvarliga och fokuserade personerna var när de angav hungernivåerna. För vidare studier rekommenderas ett högre innehåll av det nya fettet (3 g), en större produkt, annorlunda fruktbaserad fyllning och fler deltagare och flera upprepningar av samma mätningar.</p><p> </p>

According to the famous axiom known as Moore’s Law the number of transistors that can be etched on a given piece of silicon, and therefore the computing power, will double every 18 to 24 months. For the last 40 years Moore’s prediction has held true as computers have grown more and more powerful. However, around 2020 hardware manufac-turers will have reached the physical limits of silicon. A proposed solution to this dilemma is molecular electronics. Within this field researchers are attempting to develop individual organic molecules and metal complexes that can act as molecular equivalents of electronic components such as diodes, transistors and capacitors. By utilizing molecular electronics to construct the next generation of computers processors with 100,000 times as many components on the same surface area could potentially be created. We have synthesized a range of new pyridyl thienopyridine ligands and compared the electrochemical and photophysical properties of their corresponding Ru(II) complexes with that with the Ru(II) complexes of a variety of ligands based on 6-thiophen-2-yl-2,2´-bipyridine and 4-thiophen-2-yl-2,2´-bipyridine. While the electrochemistry of the Ru(II) complexes were similar to that of unsubstituted [Ru(bpy)3]2+, substantial differences in luminescence lifetimes were found. Our findings show that, due to steric interactions with the auxiliary bipy-ridyl ligands, luminescence is quenched in Ru(II) complexes that in-corporate the 6-thiophen-2-yl-2,2´-bipyridine motif, while it is on par with the luminescence of [Ru(bpy)3]2+ in the Ru(II) complexes of the pyridyl thienopyridine ligands. The luminescence of the Ru(II) com-plexes based on the 4-thiophen-2-yl-2,2´-bipyridine motif was en-hanced compared to [Ru(bpy)3]2+ which indicates that complexes of this category are the most favourable for energy/electron-transfer sys-tems. At the core of molecular electronics are the search for molecular ON/OFF switches. We have synthesized a reversible double cyclome-tallated switch based on the Ru(tpy) complex of 3,8-bis-(6-thiophen-2-yl-pyridin-2-yl)-[4,7]phenanthroline. Upon treatment with acid/base the complex can be switched between the cyclometallated and the S-bonded form. This prototype has potentially three different states which opens the path to systems based on ternary computer logic.

Syftet med studien är att undersöka hur pedagoger i förskolan talar om kemi, vilket besvaras genom forskningsfrågan “Vilka tolkningsrepertoarer gällande kemi framträder i pedagogernas tal?”. Studien tar avstamp i ett problemområde där det finns en brist av forskning gällande kemi i förskolan. Forskning som undersöker naturvetenskap i förskolan visar att pedagoger känner sig osäkra inom naturvetenskap och därmed undviker de naturvetenskapliga ämnena, inklusive kemi, i förskolan men å andra sidan visar forskning att pedagoger är positiva gentemot ämnet. Kemi i förskolan är av betydelse eftersom tidigare forskning belyser att ett naturvetenskapligt lärande i tidig ålder kan bidra till att underlätta för barnen i deras fortsatta skolgång. Med en socialkonstruktionistisk vetenskapsteoretisk utgångspunkt samt en inriktning på diskurspsykologi som metod har analysbegreppen varit retorik och funktion för att synliggöra tolkningsrepertoarer i pedagogernas uttalanden. Syfte och forskningsfråga har besvarats genom analyser av två fokusgruppsamtal med pedagoger i förskolan. I resultatet framträder tolkningsrepertoarer gällande svårigheter med konkretisering av kemi, kemi som underordnat andra ämnen samt pedagogernas roll som medupptäckare vid kemiundervisning. Det synliggörs en osäkerhet och en oro hos pedagogerna för att ses som okunniga samt oprofessionella av kollegorna men även hur de vill bevara sin goda relation genom att inte framställa sig som kunniga. Det tydliggörs hur de framställer sig som medupptäckare i kemiundervisning med barnen där pedagogerna själva menar att det inte krävs kunskap av dem för att skapa möjlighet till lärande. Det framkommer hur pedagogerna är omedvetna om när kemi uppkommer samt kan tillämpas i förskolans verksamhet.

During production of steel, slag is formed as a by-product. The process of steelmaking involves usage of additives such as chromium or vanadium as reactants to optimize and produce high quality steel. Vast amounts of slag are formed and there is a continuous search for applications that can make good use of the slag. Currently the use of slag in cleaning of metal polluted waters is researched and promising results has been found for many different types of slags. In this work two different AOD-slags has been used as sorbents for some selected elements (Zn, V, Cr, Mo, Pb, Li, Cd, Ba, Cu, Ni). The main difference between the two slags is the reducing agent that has been used, aluminium and silicon. This results in slags with different adsorption properties. The aluminium reduced slag show tendency for better adsorption capacities in general for the tested elements (Zn, V, Cr, Mo, Pb, Li, Cd, Ba, Cu, Ni), with a few exceptions. The buffering capacity of the materials were high, shown by the fact that final pH reached nearly 11.5 independent of the start pH (varied between 2 and 8). The adsorption process was rather quick and 24 minutes contact time was in most cases sufficient to reach equilibrium. For several of the elements e.g. Lithium, the maximum capacity of the slags was not reached even though a load of 3,07 mg Lithium was added per gram of slag.

The recycling industry which is efficiently functioning now has technical expertise, contented consumers, and resource availability and capital contributors. The potential inflow of new material into this existing system should be able to fulfill all the needs of the stakeholders involved in it. With most of the polymer wastes received from the polyethylene (PE) and polyethylene terephthalate (PET), they are available in abundant crossing the threshold quantity (Cornell, 2007) needed for the recycling process to be carried for every single polymer starting from the individual source separation till the granulation of pellets with active investment for the potential expectancy of returns in the recycling market targeting suitable consumers. Unlike other polymers like polyvinyl chloride and polypropylene (PP), biopolymers fail to fulfill the necessary criteria of being in threshold quantity to carry out the recycling process. With the very small inflow of biopolymers in the recycling industry, standalone recycling units for the same is not highly performed and appreciated. In addition to this, there are possible means and ways of the biopolymers getting infused into the conventional petrochemical polymers either through the mis-throws in manual sorting or in automated sorting. Though the studies so far don't have any substantial threatening effect over the biopolymer infusion, still it has its adversity affecting the industry by other means. The volumes of biopolymers are presently small and contamination of biopolymer in the plastic waste stream is presently not a problem. However, with increasing volumes of biopolymers, this can be a problem. Contamination could then be a future problem. This study investigates that problem and checks the truth to the claims of biopolymer infusion in the conventional post-consumer recycling systems affecting the quality of the recyclates. In order to investigate this, a biodegradable biopolymer (TPS &amp; PHA) will be mixed into a conventional polymer (PE, PP, PET) at various percentages. The mechanical and thermal properties are then measured as a function of the percentage biopolymer. In a second part of the project, the blend of conventional plastics and bioplastic is conditioned in humidity in order to simulate what will happen to a conventional polymer that has been contaminated with a biopolymer in a humid climate.

Polycyclic aromatic hydrocarbons (PAHs) are organic compounds that are composed by at least two aromatic rings. PAHs can be found in coal and petroleum, but can also be formed from incomplete combustion of for example fossil fuels, tobacco, wood and when smoking food. PAHs has been shown to cause several health risks such as carcinogenic effects, which led to that the U.S Environmental Protection Agency (U.S. EPA) selected 16 PAHs as priority pollutants. Those 16 PAHs is usually analysed when investigating PAH exposure. To analyze dermal exposure of PAHs a tape-stripping technique can be used. The tape-stripping method involves that a tape piece is placed on the skin to absorb the present PAHs and then the tape is removed and the PAHs can be extracted and cleaned-up from the tape. The aim of this study is to optimize a recently elaborated clean-up method for PAHs sampled by the tape-stripping technique. Also, to apply the method and measure the dermal exposure of 16 PAHs among soil remediation workers. Two clean-up methods were evaluated, Florisil SPE columns and deactivated silica (10%). Clean-up using Florisil columns were evaluated using 10 and 12 ml of n-hexane. For elution, poor recoveries were achieved for both elution volumes tested. On the other hand, tests using deactivated silica generated good recoveries for both elution solvents tested (i.e. 4 ml n-hexane:dichloromethane + 4 ml dichloromethane and 8 ml n-hexane). As for the elution solvents, no significant difference could be seen in the recoveries and the mixture of n-hexane and dichloromethane was used for the real samples. The dermal exposure of PAHs for the soil remediation workers were investigated using dermal tapes from the palm and neck of 18 soil remediation workers. Samples from the palm were sampled before and after a working day and there was a small difference between the total PAH concentration before and after a work-shift. For all categories of workers (office staff, machine operators and persons performing sampling) an increase in dermal concentration of PAHs could be observed for ten of the workers, but this increase were highest among the workers active in taking samples at the contaminated site. However, an increase in PAH exposure was not observed for all study participants and possible this is due to hand-washing after toilet visits. Overall, the concentrations of PAHs on the dermal samples from soil remediation workers were low, especially in comparison to other occupations such as chimney sweeps and pavers where PAH exposure is known to exist. The detected PAHs on the dermal tapes corresponded to PAH profiles in soil samples from the site.