<p>This thesis is based upon synthesis and structure determination of new transition metal oxo-halide compounds, which includes p-element cations that have a stereochemically active lone pair. A synthesis concept has been developed, which uses several different structural features to increase the possibility to yield a low-dimensional arrangement of transition metal cations. A total of 17 new compounds has been synthesised and their structures have been determined <i>via</i> single-crystal X-ray diffraction. The halides and the stereochemically active lone-pairs will typically act as terminating species segregating into regions of non-bonding volumes, which may take the form of 2D layers, 1D channels or Euclidean spheres. The transition metals that have been used for this work are copper, cobalt and iron. The Hard-Soft-Acid-Base principle has been utilized to match strong Lewis acids to strong Lewis bases and weak acids to weak bases. All compounds show tendencies towards low-dimensionality; they all have sheets of transition metal cations arranged into layers, where the layers most often are connected via weak dispersion forces.</p>

<p>In this work we have investigated the intercalation of electron-donors between NbS₂ slabs in Nb-based layer sulfides.</p><p>Two series of Sr substituted Nb-based misfit sulfides belonging to the 1.5Q/1H and 1Q/1H series of misfit layer compounds have been synthesised. For large lanthanides (Ln=La, Ce), only the 1Q/1H compounds formed whereas for smaller lanthanides and yttrium, both types of phases can be obtained. The crystal structure of misfit sulfide (Pr_0.55Sr_0.45S)_1.15NbS₂ has been refined using the composite approach. In the Q-slab, Pr-atoms are partly replaced by Sr with a random distribution over one cation position. The crystal structure of misfit sulfide [(Sm_1/3Sr_2/3S)_1.5]_1.15NbS₂ belonging to the 1.5Q/1H series have also been determined. The obtained results suggest a preferred occupancy of the cation positions in the slab where Sr atoms mainly occupy positions on the exterior of the slab while Sm atoms are in the center of the slab. The (La_1-xSr_xS)_1.15NbS₂ solid solution (0.1<x<0.9) has also been studied. It was found that the maximum value of Sr substitution is 40-50% and therefore, the minimal value of charge transfer to stabilize this structure type is about 0.6ē per Nb atom. </p><p>An attempt to synthesize Sr_xNbS₂ (0.1≤x≤0.5) intercalates was made but single phases were not obtained and increasing the temperature from 1000^оС to 1100^оС leads to the decomposition of these intercalates. Single crystals of Sr_0.22Nb_1.05S₂ and Sr_0.23NbS₂ were found and their structures were determined. The structures belong to two different types of packings with statistical distribution of Sr between layers.</p><p>A new superconducting sulfide, "EuNb₂S₅", was investigated by ED and HREM and its structure model consisting of Nb₇S₁₄ and (Eu₃S₄)₂ slabs alternating along the c-axis is suggested. An attempt to suggest a model for the structure of "SrNb₂S₅" by means of X-ray single crystal diffraction was made. The proposed structure consists of two types of slabs: a Nb₇S₁₄ and a [Sr₆(NbS₄)₂S] slab with niobium in tetrahedral coordination. It is shown that "SrNb₂S₅" and "EuNb₂S₅" are have similar structures.</p><p>For the first time, single crystals of the complex sulfide BaNb_0.9S₃ have also been studied by means of X-ray single crystal diffraction. The single crystal refinement and EDX analysis showed the existence of cation vacancies at the niobium position. BaNb_0.9S₃ has also been studied by ED and no superstructure was found which implies that and the vacancies are statistically distributed.</p><p>No improvement of the magnetic properties of the studied compounds was observed in comparison to NbS₂.</p>

<p>This thesis covers sampling and analytical procedures for isocyanates (R-NCO) and amines (R-NH₂), two kinds of chemicals frequently used in association with the polymeric material polyurethane (PUR). Exposure to isocyanates may result in respiratory disorders and dermal sensitisation, and they are one of the main causes of occupational asthma. Several of the aromatic diamines associated with PUR production are classified as suspected carcinogens. Hence, the presence of these chemicals in different exposure situations must be monitored. </p><p>In the context of determining isocyanates in air, the methodologies included derivatisation with the reagent di-<i>n</i>-butylamine (DBA) upon collection and subsequent determination using liquid chromatography (LC) and mass spectrometric detection (MS). A user-friendly solvent-free sampler for collection of airborne isocyanates was developed as an alternative to a more cumbersome impinger-filter sampling technique. The combination of the DBA reagent together with MS detection techniques revealed several new exposure situations for isocyanates, such as isocyanic acid during thermal degradation of PUR and urea-based resins. Further, a method for characterising isocyanates in technical products used in the production of PUR was developed. This enabled determination of isocyanates in air for which pure analytical standards are missing. Tandem MS (MS/MS) determination of isocyanates in air below 10^-6 of the threshold limit values was achieved.</p><p>As for the determination of amines, the analytical methods included derivatisation into pentafluoropropionic amide or ethyl carbamate ester derivatives and subsequent MS analysis. Several amines in biological fluids, as markers of exposure for either the amines themselves or the corresponding isocyanates, were determined by LC-MS/MS at amol level. In aqueous extraction solutions of flexible PUR foam products, toluene diamine and related compounds were found. </p><p>In conclusion, this thesis demonstrates the usefulness of well characterised analytical procedures and techniques for determination of hazardous compounds. Without reliable and robust methodologies there is a risk that exposure levels will be underestimated or, even worse, that relevant compounds will be completely missed.</p>

<p>This thesis is concerned with <i>in-situ</i> time-, temperature- and pressure-resolved synchrotron X-ray powder diffraction investigations of a variety of inorganic compounds with twodimensional layer structures and three-dimensional framework structures. In particular, phase stability, reaction kinetics, thermal expansion and compressibility at non-ambient conditions has been studied for 1) Phosphates with composition <i>M</i><i>IV</i>(HPO₄)₂·<i>n</i>H₂O (<i>M</i><i>IV</i> = Ti, Zr); 2) Pyrophosphates and pyrovanadates with composition<i> M</i><i>IV</i>X₂O₇(<i>M</i><i>IV</i> = Ti, Zr and X = P, V); 3) Molybdates with composition ZrMo₂O₈. The results are compiled in seven published papers and two manuscripts.</p><p>Reaction kinetics for the hydrothermal synthesis of α-Ti(HPO₄)₂·H₂O and intercalation of alkane diamines in α-Zr(HPO₄)₂·H₂O was studied using time-resolved experiments. In the high-temperature transformation of γ-Ti(PO₄)(H₂PO₄)·2H₂O to TiP₂O₇ three intermediate phases, γ'-Ti(PO₄)(H₂PO₄)·(2-x)H₂O, β-Ti(PO₄)(H₂PO₄) and Ti(PO₄)(H₂P₂O₇)_0.5 were found to crystallise at 323, 373 and 748 K, respectively. A new tetragonal three-dimensional phosphate phase called τ-Zr(HPO₄)₂ was prepared, and subsequently its structure was determined and refined using the Rietveld method. In the high-temperature transformation from τ-Zr(HPO₄)₂ to cubic α-ZrP₂O₇two new orthorhombic intermediate phases were found. The first intermediate phase, ρ-Zr(HPO₄)₂, forms at 598 K, and the second phase, β-ZrP₂O₇, at 688 K. Their respective structures were solved using direct methods and refined using the Rietveld method. <i>In-situ</i> high-pressure studies of τ-Zr(HPO₄)₂revealed two new phases, tetragonal ν-Zr(HPO₄)₂and orthorhombic ω-Zr(HPO₄)₂ that crystallise at 1.1 and 8.2 GPa. The structure of ν-Zr(HPO₄)₂ was solved and refined using the Rietveld method.</p><p>The high-pressure properties of the pyrophosphates ZrP₂O₇ and TiP₂O₇, and the pyrovanadate ZrV₂O₇were studied up to 40 GPa. Both pyrophosphates display smooth compression up to the highest pressures, while ZrV₂O₇ has a phase transformation at 1.38 GPa from cubic to pseudo-tetragonal β-ZrV₂O₇ and becomes X-ray amorphous at pressures above 4 GPa.</p><p>In-situ high-pressure studies of trigonal α-ZrMo₂O₈ revealed the existence of two new phases, monoclinic δ-ZrMo₂O₈and triclinic ε-ZrMo₂O₈ that crystallises at 1.1 and 2.5 GPa, respectively. The structure of δ-ZrMo₂O₈was solved by direct methods and refined using the Rietveld method.</p>

<p>In the work underlying this thesis solid-phase microextraction (SPME) was evaluated as a passive sampling technique for organophosphate triesters in indoor air. These compounds are used on a large scale as flame-retarding and plastizicing additives in a variety of materials and products, and have proven to be common pollutants in indoor air. The main objective of this work was to develop an accurate method for measuring the volatile fraction. Such a method can be used in combination with active sampling to obtain information regarding the vapour/particulate distribution in different indoor environments. SPME was investigated under both equilibrium and non-equilibrium conditions and parameters associated with these different conditions were estimated. </p><p>In <b>Paper I</b>, time-weighted average (TWA) SPME under dynamic conditions was investigated in order to obtain a fast air sampling method for organophosphate triesters. Among the investigated SPME coatings, the absorptive PDMS polymer had the highest affinity for the organophosphate triesters and was consequently used in all further work. Since the sampling rate is dependent on the agitation conditions, the linear airflow rates had to be carefully considered. Sampling periods as short as 1 hour were shown to be sufficient for measurements in the ng-μg m^-3 range when using a PDMS 100-μm fibre and a linear flow rate above 7 cm s^-1 over the fibre. </p><p>SPME under equilibrium conditions is rather time-consuming, even under dynamic conditions, for slowly partitioning compounds such as organophosphate triesters. Nevertheless, this method has some significant advantages. For instance, the limit of detection is much lower compared to 1 h TWA sampling. Furthermore, the sampling time can be ignored as long as equilibrium has been attained. In <b>Paper II</b>, SPME under equilibrium conditions was investigated and evaluated for organophosphate triester vapours. Since temperature and humidity are closely associated with the distribution constant a simple study of the effect of these parameters was performed. The obtained distribution constants were used to determine the air levels in a common indoor environment. SPME and parallel active sampling on filters yielded similar results, indicating that the detected compounds were almost entirely associated with the vapour phase</p><p>To apply dynamic SPME method in the field a sampler device, which enables controlled linear airflow rates to be applied, was constructed and evaluated (<b>Paper III</b>). This device was developed for application of SPME and active sampling in parallel.</p><p>A GC/PICI-MS/MS method was developed and used in combination with active sampling of organophosphate triesters in indoor air (<b>Paper IV</b>). The combination of MS/MS and the soft ionization achieved with methanol as reagent gas yielded high selectivity and detection limits comparable to those provided by GC with nitrogen-phosphorus detection (NPD). The method limit of detection, when sampling 1.5 m³ of air, was in the range 0.1-1.4 ng m^-3. In <b>Paper V</b>, the developed MS method was used in combination with SPME for indoor air measurements.</p><p>The levels detected in the investigated indoor environments range from a few ng to μg m^-3. Tris(2-chloropropyl) phosphate was detected at a concentration as high as 7 μg m^-3 in a newly rebuilt lecture room.</p>

<p>This thesis is focused on studies of substituted Hg-based superconducting copper oxides ((Hg_1-x<i>M</i>_x)Ba₂Ca_n-1Cu_nO2_n+2+δ). These compounds are promising objects of investigation, not only from a fundamental point of view but also because of their high values of superconducting transition temperature (<i>T</i>_c) and irreversibility field (<i>H</i>_irr).</p><p>The first part of the thesis is devoted to optimization of the synthesis procedure for Hg-based cuprates. The influence of different parameters (<i>T</i>,<i> t</i>, <i>p</i>(Hg),<i> p</i>(O₂)) on the synthesis of these compounds in sealed silica tubes was studied. Optimal conditions yielded samples containing up to 95% of HgBa₂Ca₂Cu₃O_8+δ (Hg-1223). The formation of solid solutions with the formula (Hg_1-xCu_x)Ba₂Ca₂Cu₃O_8+δ (where x <= 0.5) was also established. Another technique was developed, using LiF as a flux, for synthesis of samples containing up to 90% of the HgBa₂CaCu₂O_6+δ (Hg-1212) phase.</p><p>The second part concerns synthesis and studies of oxyfluorides using Hg-1212 and Hg-1223 as starting materials together with XeF₂ as a fluorinating agent. It was found that oxyfluorides of both phases have a parabolic dependence of T_c vs. <i>a</i> parameter as well as enhanced <i>T</i>_c values (Δ<i>T</i> ≈ 3-4 K) in comparison with optimally doped non-fluorinated analogues. The crystal structure of Hg-1223 oxyfluoride was studied by X-ray powder and neutron diffraction methods. It is suggested that chemical modification of the crystal structure leads to a decrease in Cu-O distance without noticeable change in Cu-O-Cu angle (in the (CuO₂) layers), which may be the significant factors influencing this <i>T</i>_c increase. Hg-1223 oxyfluoride was also studied under high pressure for first time. It was found that this compound has a record-high <i>T</i>_c value (≈ 166 K) at <i>P</i> ≈ 23 GPa.</p><p>The last part describes the investigation of substituted Hg-based superconductors in the series (Hg_0.9M_0.1)Ba₂CuO_4+δ {(Hg,<i>M</i>)-1201}, where <i>M</i> = Tl, Pb, W, Mo, Nb and V. A comprehensive study of these compounds by various methods (X-ray powder diffraction, EDX, IR-, EXAFS- and XANES -spectroscopy) indicated that the change of charge carrier doping level is a crucial factor determining the irreversibility line. (Hg_0.9Mo_0.1)Ba₂CuO_4+δ showed the most improved irreversibility line position among the (Hg,<i>M</i>)-1201 compounds studied in this series.</p>

<p>In this work the objective was to develop a method that would make it easier to quantitatively evaluate different quality parameters in pasta. This was done with the assistant of a texture analyzer from TexVol Instruments. The quality parameters that were investigated were hardness, resilience, elasticity and adhesiveness. Two different types of measurements were used to measure three different pasta brands. These were single cycle and hold until time. Before this was done the main parameters in the texture analyzer were tested and adjusted to suite the method. Most of the steps in the developed method worked satisfactorily but more studies have to be done to make the method useful in the daily work with pasta production and pasta development. With all tests in mind it could be said that the De Cecco pasta was the one with the best texture parameters. It had the highest hardness, elasticity and resilience and the lowest adhesiveness. The other two brands, Kungsörnen and Tomadini had lower but similar results. Further important studies to look into is if there`s a possibility to get a computer software that are more targeted on pasta measurement. Another important thing is if these pasta measurements can be done in a different way, perhaps just using a few spaghetti straws. It would also be interesting to study the protein network in an electron microscope because then it´s easier to understand what´s happening when pasta is prepared. Last but not least I think it´s important to do a organoleptic test to see if it´s possible to taste the measured results.</p> / <p>Detta examensarbete gick ut på att ta fram en metod med hjälp av en texturmätare där olika kvalitetsparametrar såsom hårdhet, elasticitet och spänst kunde mätas på pasta. Dessa mätningar gjordes på tre olika spaghettimärken. Dessa var Kungsörnen, Tomadini samt De Cecco. Mätningarna på de olika pastamärkena gjordes med hjälp av en texturmätare från TexVol som är ett svenskt företag. Deras olika instrument är främst framtagna för att fungera inom bageribranchen och köttindustrin. Detta gjorde att det var spännande att se om detta instrument även kunde användas med framgång för att mäta olika kvalitetsegenskaper på kokt pasta. Först gjordes mätningar på Kungsörnens spaghetti vid olika koktider. Dessa var mellan 5 och 14 minuter. Dessa mätningar gjordes främst för att se vad som händer med de olika kvalitetsegenskaperna från det att pastan är underkokt till kraftigt överkokt. Utifrån resultaten från dessa mätningar är det svårt att dra några tydliga slutsatser då de varierade kraftigt. Därefter gjordes mätningar på de tre olika pastamärkena med två olika mätmetoder, dels single cycle och dels hold until time. Med single cycle menas att proben(mätstången) går ner i pastan och sen direkt upp igen medan vid hold until time metoden så går proben ner för att sen stanna nere tills en förinställd tid passerat innan den går upp igen. På detta sätt kan olika kvalitetsegenskaper mätas med de olika mätmetoderna. För att dessa mätmetoder ska fungerar har olika parametrar på texturmätaren utvärderats och på detta sätt har en metod/tillvägagångssätt tagits fram. De flesta av stegen i denna metod verkar fungera bra men ett stort problem är att mätningarna skiljer sig mycket åt. Detta beror troligtvis på att pastan lägger sig olika inför varje mätning vilket gör att mätningarna blir långt ifrån identiska vilket leder till att resultaten blir svårtolkade. Vissa tendenser kan dock ändå ses. Om alla mätningar tags i beaktande kan det sägas att De Cecco pastan är den pasta av högst kvalité. De Cecco pastan är den som är mest "al dente", mest elastisk, mest spänst samt lägst klibbighet. Vad detta beror på är svårt att säga då det kan finnas många förklaringar som är mer eller mindre relevanta. En trolig förklaring kan vara att De Cecco pastan har ett högre proteininnehåll än de båda andra märkena. I litteraturen står det att ett högre proteininnehåll ger en bättre kokt pasta och detta verkar rimligt då protein nätverket blir starkare vilket håller ihop pastan på ett bättre sätt. En annan möjlig orsak kan vara att fördelningen av de olika proteinerna är bättre i De Cecco pastan än i de andra märkena vilket leder till en bättre kvalitet. De två andra, Kungsörnen och Tomadini hade snarlika resultat.</p><p>Vad som behöver göras för att denna metod eventuellt ska kunna användas i den dagliga produktionen av pasta och utveckling av ny pasta är att ta bort så många felkällor som möjligt så att standardavvikelsen i alla mätningar blir avsevärt mindre. Detta kan kanske avhjälpas av att ha en mjukvara som är mer anpassad till pastamätningar än den som var används nu som är anpassad till bageribranchen. En annan viktig sak kan vara att mäta på bara några få pasta strå till skillnad mot nuvarande "spaghettinystan". Ytterligare en intressant sak är att göra en organoleptisk undersökning av de olika pastamärkena för att se om de uppmätta resultaten är smakbara. Även att titta i elektronmikroskåp för att se de olika spaghettis proteinnätverk kan vara intressant för att få en förståelse för hur pastan ändrar sig under kokning.</p>

<p>Undersökningen syftar till att granska och jämföra elevkunskaper i de naturvetenskapliga ämnena biologi, fysik och kemi i årskurserna 5 och 9.  Kunskapstestet som använts i undersökningen har baserats på uppnåendemålen för årskurs 5 enligt gällande styrdokument, samt kunskapsmål upprättade av No nätverket i den för undersökningen aktuella kommunen.</p><p>Jämförelser görs också mellan elever med bakgrund i samma skolor, men som nu går i olika årskurser, samt mellan kön. Ytterligare ett syfte är att undersöka om skolstorlek har någon betydelse för elevers resultat.</p><p>Undersökningen visar att båda årskurserna har bäst testresultat i biologi. Likaså framkommer det att pojkarna i undersökningen inte har utvecklats lika mycket resultatmässigt som flickorna mellan årskurserna. I undersökningen framkom det också att skolstorlek inte har någon betydelse för elevernas resultat.</p>

Syftet med denna studie är att få större kunskap om NT-projektet, vilket är en kommunalsatsning på naturvetenskap och teknik, och om denna satsning gjort någon skillnad när det kommer till pedagogernas arbete med kemi i kommunens förskolor. Vidare kommer det också undersökas om de som arbetar med NT-projektet har någon särskild utbildning. Detta då det finns intresse att utvärdera NT-projektet och deras ”NT-lådor” samt införskaffa kunskap inom detta område inför framtida arbete inom kommunen ifråga. Kvalitativ- och kvantitativforskningsmetod har använts för att nå fram till frågeställningen. Jag har genomfört en kvalitativ intervju som var ostrukturerad. Ostrukturerade intervjuer liknar vanliga samtal och passar bäst i detta sammanhang då jag inte har stor kunskap när det kommer till NT-projektet. Jag har även genomfört en enkätundersökning som riktade sig till pedagogerna i tretton förskolor. Resultatet av intervjun ledde till en större inblick i NT-projektet och dess arbete.  Enkätundersökningens resultat visar på betydelsen av material, kunskap och tid, faktorer som uppfattas som bristfälliga i den pedagogiska verksamheten i dagsläget. / The purpose of this study is to gain a greater knowledge of the NT project, which is a local government investment in science and technology, and if this effort made ​​a difference when it comes to the teachers' work in chemistry in the municipal preschools. Furthermore, it will also examine whether those who work with NT project has any special training. There is an interest to evaluate NT-project and their "NT-boxes" and acquire knowledge in this area for future work within the community in question. Qualitative and quantitative research methods have been used to reach the issue. I conducted a qualitative interview that was unstructured. Unstructured interviews are similar to regular conversation and fits best in this context, this because I do not have great knowledge regarding the NT-project. I have also carried out a survey which was directed to the educators in thirteen preschools. The result of the interview led to a greater insight into the NT-project and its achievements. Questionnaire survey results show the importance of materials, knowledge and time, factors that are perceived as deficient in the preschool in the current situation.

The purpose of this investigation was to find out more about students’ spontaneous ideas about properties and transformations of matter. Examples of matter chosen are such which students know about from everyday life and focus is mainly on the questions if students know that all matter has weight and that matter is preserved in transformations. The method used is semi structured qualitative interviews with individual students. Different experiments were carried out together with the students who afterwards were interviewed. However, the students show varying answers and no generalizations can be done. However, when their conclusions from observations differ from their earlier experiences they trust their eyes. All students know that a human body has weight as well as a grain of dust. They also know that with addition of a colored substance in the water, the mass increases, but more hesitation exists when the additive is sugar. A couple of students are capable of discussing logically sometimes but not at all events. / Undersökningens syfte var att undersöka vad elever i årskurs tre har för spontana uppfattningar om materiens egenskaper och dess transformationer. Exempel på materia som valts är det eleverna känner till i vardagen och undersökningen har främst fokuserat på om eleverna dels vet att all materia väger något samt dels att materia är beständig och inte försvinner vid transformationer. Metoden som använts är semistrukturerade kvalitativa intervjuer med enskilda elever. Olika försök genomfördes tillsammans med eleverna som sedan intervjuades. Resultatet visar att eleverna varierar sina svar. Inga generella slutsatser kan dras. Dock kan man se att de grundar sina svar på det de ser och knyter sina föreställningar till sin vardag. När ögats uppfattning inte överensstämmer med erfarenheter litar flertalet elever på ögats observation. Alla elever vet att en människa väger liksom dammkorn. De vet också att vid tillsats av en färgad substans i vatten så ökar massan men fler oklarheter råder vid tillsats av socker. Ett par elever förmår resonera logiskt vid ett tillfälle men inte vid ett annat.