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Vad har SEM för påverkan på SMF:s digitala marknadsföring : En fallstudie / What impact does SEM have on SME's digitalmarketing : A case studyElin, Jonsson, Ella, Dahllöf January 2021 (has links)
Research questions: 1. In what ways do SMEs embrace sökmotormarknadsföring that digital development has made possible? 2. What are the obstacles for SMEs to adopt sökmotormarknadsföring? Purpose: The purpose of the study is to find out how small to medium-sized companies adopt sökmotormarknadsföring to their marketing strategy. This also creates a better understanding of the obstacles that are experienced in connection with sökmotormarknadsföring. This is to identify the obstacles and help companies with knowledge to get past them. The study also aims to create an understanding of why companies choose not to work with this, despite the fact that it has been proven that it helps companies to be seen and increases brand awareness. Method: The essay is based on a qualitative study with interviews. A deductive approach is also applied. The target group is based on the selected respondents who through interviews lead to the purpose of the study. Conclusion: There are several similarities between how companies work with SEM and what obstacles there are to absorbing it. The prominent answer is that the companies would hire an external service that would handle the work for them, or have a combination of internal and external work, but get help with the expertise on the subject. Companies must be open to SEM in order to benefit from it and see the benefits of the strategy compared to a normal traditional marketing. The two most common factors why SMFs do not currently work with SEM are a lack of competence and financial resources. / Forskningsfrågor: 1. På vilka sätt tar SMF:s till sig sökmotormarknadsföringsom den digitala utvecklingenmöjliggjort? 2. Vad finns det för hinder för SMF:s att ta tillsig sökmotormarknadsföring? Syfte:Syftet med studien är att ta reda på vilkasätt som små- och medelstora företag tar tillsig sökmotormarknadsföring som den digitala utvecklingenmöjliggör. På så sätt skapas ävenbättre förståelse för vilka hinder som upplevs i sambandmed sökmotormarknadsföring. Dettaför att identifiera hinder samt hjälpa företag medkunskap för att ta sig förbi dem. Studienämnar även att skapa en förståelse för varför företagväljer att inte arbeta med detta, trots attdet är bevisat att det hjälper företag att synas samtökar varumärkeskännedomen. Metod:Uppsatsen grundas på en kvalitativ studie medintervjuer. Det tillämpas även endeduktiv ansats. Målgruppen baseras på de valda respondenternasom genom intervjuer lederfram till studiens syfte. Slutsats:Det finns flera likheter mellan hur företagenarbetar med SEM och vilka hinder somfinns för att ta till sig det. Det framträdande svaretär att företaget vill anlita en extern tjänstsom sköter arbetet åt dem eller ha en kombinationav internt och externt arbete. Slutligen gårdet att konstatera att företag måste vara öppna förta till sig SEM för att få nytta av det och sefördelarna med strategin jämfört med en vanlig traditionellmarknadsföring. Det tvåvanligaste faktorerna till att SMF:s inte arbetarmed SEM i dagsläget beror på bristen avkompetens och finansiella resurser.
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Mikroplaster i jord och sediment – utveckling av metodför provbehandling och analys / Micro Plastics in Soil and Sediment – Development of aMethod of Sample Treatment and AnalysisThuné, William January 2018 (has links)
Fenomenet mikroplaster har på senare tid blivit allt mer uppmärksammat i jord och sediment, varje dag kommer nya artiklar om mikroplasternas förekomst eller verkan. Intresset har ökat markant för mikroskopiska skräppartiklar i miljön. Mikroplast definieras som plastpartiklar mindre än 5 mm. Det har konstaterats ha en skadlig påverkan på organismer (Lassen et al., 2015). Det är ett stort miljöproblem som mikroplasterna skapar då det har visat sig ge skadliga effekter på vattenlevande organismer speciellt. Organismerna förväxlar mikroplaster med plankton och får i sig mikroplaster istället för föda. Det har inte gjorts större studier på hur marklevande organismer påverkas av dessa mikroplaster, men det misstänks även kunna innebära problem när slam sprids på åkermark. För att analysera mikroplaster måste dessa isoleras. Målet med detta arbete var att kunna separera dem från det övriga materialet. Detta gjordes genom att man tillsatte olika kemikalier vid olika temperaturer och förhållanden för att undersöka hur mikroplasterna påverkas av olika omständigheter. Provtagningen för sediment skedde på en och samma hamnbassäng som hade ett djup på 0 – 0,3 meter och jorden som undersöktes inköptes på Plantagen i Uppsala. Proverna delades upp i hanterbara mängder inför processen som bestod av olika steg. Det var känt sedan innan vilka kemikalier det rörde sig om, både när det gäller separationslösning och digereringsmedel. De vanligaste separationslösning var natriumklorid, kalciumklorid, zinkklorid och natriumjodid. I denna studie undersöktes dock bara natriumklorid och kalciumklorid, då både zinkklorid och natirumjodid visat sig påverka miljön negativt och eftersom det åtgår flera hundra gram salt per prov ansågs det inte nödvändigt att undersöka dessa två. Efter närmare undersökning så visade det sig att kalciumklorid hade bäst densitet på 1,4 g/cm3 vilket gjorde att oönskade partiklar sjönk till botten och de fyra vanligaste plasterna (PE, PET, PP och PVC) hade möjlighet att flyta upp till ytan. Med hjälp av separationskolonnen (se figur 2), som användes i denna studie, kunde den översta fasen enkelt dekanteras från övriga provet med hjälp av ventilen som delade upp kolonnen. Eftersom separationskolonnen inte kunde hantera stora provmängder undersöktes alternativa separationstekniker men eftersom dekanteringssteget är kritiskt så lämpade sig inte de andra alternativen. När det kommer till digereringsmedel så var det natriumhydroxid, salpetersyra och väteperoxid som undersöktes. Digereringsstegets uppgift är att lösa upp övrigt material i provmatrisen såsom organiskt material. Det var viktigt att testa en bas, en syra och ett oxidationsmedel för att veta hur plasterna reagerade. Vidare så kombinerades dessa digereringsmedel med olika temperaturer om 25 °C, 50 °C och 80 °C. I figur 3 visar diagrammet att väteperoxiden inte undersöktes vid 80 °C, det beror på att det är så pass mycket annat material i sediment och jord att riskerna var för höga, det är okänt hur häftiga reaktioner detta kan skapa. Det visade sig att salpetersyra vid 50 °C lämpade sig bäst för att lösa upp så mycket som möjligt av matrisen utan att påverka de fem vanligaste plasterna för vidare analys. Eftersom storleken på mikroplasterna sträcker sig över 0–5 mm filtrerades proverna genom tre filter. Ett grovt filter på 1 mm maskstorlek, ett filter på 100 μm och det minsta filtret på 10 μm. Den grövsta filtret kunde utvärderas visuellt med ögat och därifrån räkna antal plastpartiklar, filtret på 100 μm utvärderades under stereomikroskop och partiklarna som kunde tänkas vara plast plockades ut och sattes på en bit koltejp som fick genomgå en SEM-analys för att fastställa vilka partiklar som var plast. Sista och minsta filtret på 10 μm går igenom SEM-analysen direkt för att de är så pass små partiklar och genom att titta på sammansättningen av ämnen på enskild artikel kunde bedömningen göras ifall det var en plastpartikel, mineral eller organiskt material. / The phenomenon of micro plastics in soil and sediment has recently become more and more noticeable and every day new articles are published about the presence and effects of micro plastics. The interest has also increased significantly for micro plastic litter particles in the environment. The definition of micro plastic particles is that they are smaller than 5 mm in size. The finished and ongoing studies have shown that the micro plastics have a bad effect on the environment (Lassen et al., 2015). It has become a very big environmental problem that the micro plastics created as it has been shown to produce harmful effects on aquatic organism in particular. What happens is that the aquatic organism confuses micro plastics with plankton and they devour the micro plastics instead of food. Unfortunately, there is no major study when it comes to soil-based organism, but it can be said that they are also affected by this problem since micro plastics in soil and sediment is spread on arable land. To be able to analyze micro plastrics, these has to be isolated from other particles. This was done by adding different chemicals at different temperatures and conditions to investigate how the micro plastics are affected by different circumstances. The important part for the micro plastics is to stay true to its original form or shape even after going through different steps throughout the procedure. The sediment samples occurred from the same harbor basin that has a depth of 0 – 0.3 meters and the soil was purchased from Plantagen in Uppsala. The samples were divided into manageable amounts for the procedure to operate without complications. Studies have already shown that the chemicals that are best suited for both separation and digestive solution was sodium chloride, calcium chloride, zinc chloride and sodium iodide. In this study, however, only sodium chloride and calcium chloride were investigated, as both zinc chloride and sodium iodide did show a significant impact on the environment and furthermore required several grams of salt per sample thus they both got excluded from this study. After closer examination, it was clear that calcium chloride had the best density of 1.4 g/cm3 which was enough to separate the unwanted particles to fall to the bottom (sediment) and the four most common plastics e.g. PE, PET, PP and PVC, to float to the surface. The fractionating column (figure 2) used in this study, the top phase could easily be separated from the rest of the solution by closing the valve dividing the column. Since the fractionating column was unable to handle large number of samples, alternative separation techniques were investigated, but since the decantation step is critical, the other options were not fitted in this study. The next step in the procedure was digesting the rest of the materials in the matrix. The digestive agents, sodium hydroxide, nitric acid and hydrogen peroxide were investigated. The purpose of the digestion step was to dissolve other materials in the sample matrix e.g. organic material. It was important to investigate a base, an acid and an oxidant to really know how the micro plastic reacts. Furthermore, these digestives were combined with various temperature of 25 °C, 50 °C and 80 °C. The reason why hydrogen peroxide doesn’t have an 80 °C in the charts, figure 3, is because of the unknown reactions that could occur, since the samples of sediment and soil, contains a large amount of other materials. The decision was made to use nitric acid at 50 °C, it was most suitable for dissolving as much as possible without affecting the five most common plastics for further analysis. Since the size of micro plastics extends over 0 – 5 mm, the samples were filtered through three filters. A filter of 1 mm mesh size, a filter of 100 μ m and the smallest filter of 10 μ m. The biggest was easily evaluated by looking at the particles to decide which are plastics and not. The 100 μ m-filter was evaluated under stereo microscope and the particles that could be plastic were picked up and glued on a piece of carbon tape which then went through a SEM-analysis to determine which of these hand-picked particles were plastics and not. The final and smallest filter, 10 μm, passed through the SEM-analysis directly, these particles were too small to evaluate with the stereo microscope. By looking at the composition of the substances on a single particle, the assessment could be made if it was plastic, mineral or organic material. The important part with the evaluation made with the eye to identify which particle is plastic or not was by adding external stress, e.g. pressure, heat and other factors. It is known that plastics has a characteristic appearance, usually thread-shaped with a smooth surface. By gauging the, what we think is plastic, it could easy be decided if it’s a plastic or not. As we know, plastic has a trait of going back to its original state. If the particle caused by the external stress returned to its original form, it was considered a plastic, however if it remained deformed it was eliminated. The 100 μm is evaluated by stereo microscope and SEM-analysis, the particles that looks like plastic were picked up and glued on a carbon tape that was analyzed by the SEM-analysis. What made the SEM suitable for this study is that by looking at the composition of the substances on a single particle, the evaluation went quick by looking at the spectra. The smallest filter, 10 μm, was evaluated directly in the SEM-analysis. Using its electrons drawn to different particles of different composition, a spectrum could be produced and evaluated in the vase of a micro plastic or not, if the particle gave rise to carbon and oxygen alone onthe spectrum, it can be a micro plastic.
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Metamorfose no ventrículo de abelha: reconstrução por mitose ou diferenciação celular? / Bee midgut metamorphosis: reconstruction from mitosis or cell differentiation?Martins, Gustavo Ferreira 13 February 2004 (has links)
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Previous issue date: 2004-02-13 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / O tubo digestivo dos insetos pode ser dividido em intestino anterior, intestino médio ou ventrículo e intestino posterior, sendo o ventrículo de origem endodérmica e os intestinos anterior e posterior de origem ectodérmica. No ventrículo ocorre a secreção de enzimas digestivas e a absorção dos nutrientes. Os principais tipos celulares encontrados no ventrículo são as células digestivas, que secretam enzimas e absorvem nutrientes e as células regenerativas, que se diferenciam e originam os demais tipos celulares do epitélio do ventrículo. Durante a metamorfose das abelhas, o epitélio do ventrículo é substituído, e esta substituição ocorre às custas da diferenciação das células regenerativas larvais. O presente trabalho busca investigar as modificações ocorridas no epitélio do ventrículo da abelha Melipona quadrifasciata anthidioides durante o desenvolvimento pós-embrionário e se existe proliferação das células regenerativas durante a metamorfose do ventrículo, utilizando-se técnicas anatômicas, de imunofluorescência e imunoperoxidase com anticorpo anti BrdU. Foram analisadas larvas de diferentes idades, pré-pupas, pupas de operárias em diferentes fases de desenvolvimento: pupas de olhos brancos, olhos marrons, olhos pretos e operárias adultas. Os resultados revelaram que na larva ocorre proliferação de células regenerativas, o que pode ser comprovado pela observação de metáfases, culminando com o aumento do número de células regenerativas por ninho. Com o envelhecimento da larva o número e o tamanho dos ninhos de células regenerativas aumentam. A substituição do epitélio larval pelo epitélio do adulto ocorre a partir do segundo dia após o inicio da defecação. Neste período os ninhos de células regenerativas estão em contato, formando uma espécie de rede, lembrando um sincício pelo fato de não ter sido observado o limite celular. Concomintante à degeneração das células digestivas larvais ocorre a diferenciação das células regenerativas, formando as células digestivas do adulto. Células regenerativas BrdU positivas são observadas somente na fase de pré-pupa, 12 h após a injeção de BrdU, indicando que é durante esta fase que a população de células regenerativas aumenta. Pode-se entender a proliferação das células regenerativas como um processo compensatório, que repõe as células regenerativas que se diferenciam durante a metamorfose do ventrículo. Parece que a existência de proliferação de células regenerativas culmina no aumento da população de células regenerativas e não na formação de novas células digestivas. A hipótese de que células digestivas dos adultos se originam através da proliferação e posterior diferenciação das células regenerativas durante a metamorfose do ventrículo de M. quadrifasciata anthidioides pode ser rejeitada porque a proliferação das células regenerativas durante a pupação não seria suficiente para restabelecer os ninhos de células regenerativas e ao mesmo tempo formar novas células digestivas e pelo fato de que a população de células regenerativas existente durante o processo de defecação parece ser suficiente para promover a renovação do epitélio do ventrículo durante a metamorfose. / The digestive tract of insects can be divided into foregut, midgut and hindgut. Fore and hindgut have an ectodermic origin, while midgut is endodermic. Midgut is responsible for the enzyme secretion and nutrient absorption. The midgut epithelium is formed basically by the digestive cells, responsible for the enzyme secretion and nutrient absorption and for the small regenerative cells that are placed in nests scattered among the digestive cells. During midgut metamorphosis, the epithelium is substituted to attend adult's nutritional needs, and this substitution occurs due to larval regenerative cells differentiation. The present work focused on the midgut epithelial modifications during the post- embryonic development of the stingless bee Melipona quadrifasciata anthidioides. The presence of regenerative cells proliferation during midgut metamorphosis was also investigated, using anatomical and imunofluorescence techniques with antibody against BrdU. Were analyzed specimens at the following developmental stage: larvae of different ages, prepupae, White eyed, brown eyed and black eyed pupae and adult workers. Regenerative cell proliferation is easily detected during larval period by the presence of metaphase, which results in the regenerative cell number increasing. During larval aging the number and the size of the nests of regenerative cells also increases. Larval epithelium degeneration starts in the second day after defecation process had initiated. In this period the nests of regenerative cells are in contact and cell limit were not visualized, resembling a sincicium. The degeneration of the larval digestive cells and the regenerative cells differentiation into adult's digestive cells occurs at the same time. The BrdU positive regenerative cells are only observed in the prepupae period, 12 h after BrdU injection indicating that regenerative cell population increase during this period. Regenerative cell proliferation can be understood as a compensatory process, responsible for the regenerative cell replacing that are consumed during midgut epithelial renewing during metamorphosis. It probably assures the maintenance of the adult midgut epithelium. It seems that the regenerative cell proliferation culminates in the increase of the regenerative cells population and not in the formation of new digestive cells because the proliferation of regenerative cells would not be enough to reestablish the nests of regenerative cells and at the same time form new adult digestive cells. In this sense the hypothesis that digestive adult cells are originated through the regenerative cell proliferation and posterior differentiation during metamorphosis can be rejected. M. quadrifasciata anthidioides midgut
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UTILIZAÇÃO DE FARINHA DE CHIA (Salvia hispânica) NA ELABORAÇÃO DE PÃO SEM GLÚTEN SEM ADIÇÃO DE GOMA E GORDURA / THE USE OF CHIA (hispanic Salvia) FLOUR ON PREPARATION OF GLUTEN FREE BREAD WITHOUT GUM AND FATHuerta, Katira da Mota 12 March 2015 (has links)
Celiac disease is a permanent intolerance to gluten and its treatment is based in the total removal of these dietary proteins . The chia seed is highly nutritious because of the high content of protein, dietary fiber and essential fatty acids. In presence of water the seed exudes a transparent mucilaginous gel that has emulsifying properties, becoming it an excellent ingredient for use as a substitute for fats and starches in the baking industry. This work aimed to evaluate the effect chia flour (Salvia Hispanic L.) in the physical, microbiological, nutritional and sensory gluten-free breads prepared without addition of starch and fat. Chemical composition analysis were carried out at the flour and developed products. To determine the quality of the bread was developed analyzes of specific volume, mass rearing, cooking losses , water activity , texture, crust color and crumb . The count of yeasts and molds was held for five days of storage and the acceptability and purchase intent of the bread was evaluated by an affective test with 50 untrained volunteers. The chemical composition of the bread indicates that the presence of chia flour increases the nutritional value and provides the decrease in carbohydrate content . All the texture parameters were influenced by partial replacement of rice and soybean flour by chia flour. Also the color of the bread became darker and decreased the specific volume and the losses caused during cooking. Regarding sensory analysis, for bread prepared without gum , the formulation containing 2.5% of chia in replacement of rice and soy flour was the most accepted with values close to 5 score on the scale represented by " liked ". On the other hand, for bread prepared without fat all the treatments showed no significant difference for flavor and texture from the standard sample. Also, the treatment with 2.5% of chia flour showed purchase intention similar to the standard for both cases . The addition of chia flour on gluten-free breads without gum and fat resulted in a healthy food product alternative for celiac consumer. However we suggest more studies to improve the bread texture parameters. / A doença celíaca é uma intolerância permanente ao glúten e seu tratamento consiste basicamente na remoção total dessas proteínas da dieta. A chia é um grão altamente nutritivo devido ao seu elevado conteúdo de proteínas, fibra alimentar e ácidos graxos essenciais, em presença de água, ela exsuda um gel transparente mucilaginoso que possui propriedades emulsificantes, isso a torna um excelente ingrediente para ser utilizado como substituto de gorduras e gomas na indústria da panificação. Este trabalho teve como objetivo avaliar o efeito da farinha de chia (Salvia hispânica L.) na qualidade física, microbiológica, nutricional e sensorial de pães sem glúten elaborados sem adição de goma e gordura. Foram realizadas análises de composição química nas farinhas e nos produtos desenvolvidos. Para determinar a qualidade dos pães, foram desenvolvidas análises de volume específico, elevação da massa, perdas por cocção, atividade de água, textura, cor da crosta e miolo. A contagem de bolores e leveduras foi realizada durante cinco dias de estocagem e a aceitabilidade e intenção de compra dos pães foi avaliada através de um teste afetivo com 50 provadores não treinados. A composição centesimal dos pães indica que a farinha de chia quando adicionada a formulação aumenta o valor nutricional e diminui o teor de carboidratos. Todos os parâmetros de textura foram influenciados com a substituição parcial das farinhas de arroz e soja por farinha de chia, a cor dos pães tornou-se mais escura e houve diminuição do volume específico e das perdas ocasionadas durante a cocção. Com relação a análise sensorial, para os pães elaborados sem goma, a formulação que continha 2,5% de farinha de chia em substituição as farinhas de arroz e soja foi a mais aceita com valores próximos a 5, escore representado na escala por gostei , já para os pães elaborados sem gordura todos os tratamentos não apresentaram diferença significativa para sabor e textura com relação ao padrão. O tratamento com 2,5% de farinha de chia apresentou intenção de compra semelhante ao padrão para ambos os casos. A adição de farinha de chia na elaboração de pães sem glúten sem goma e gordura resultou em um produto que pode ser uma alternativa de alimento saudável para o consumidor celíaco, porém sugerem-se mais estudos que busquem a melhoria dos parâmetros de textura dos pães.
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Aplikace korelativní AFM/SEM mikroskopie / Application of correlative AFM/SEM microscopyHegrová, Veronika January 2019 (has links)
This thesis is dealing with application of Correlative Probe and Electron Microscopy. All measurements were carried out by atomic force microscope LiteScope which is designed especially to be combined with electron microscopes. Advantages of Correlative AFM/SEM Microscopy are demonstrated on selected samples from field of nanotechnology and material science. Application of the correlative imaging was proposed and then realized particularly in case of low-dimensional structures and thin films. Further, this thesis deals with the possibility of combining Correlative AFM/SEM Microscopy with other integrated techniques of an electron microscope such as Focused Ion Beam and Energy Dispersive X-rays Spectroscopy.
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Comparison of immunologic responses following intranasal and oral administration of a USDA-approved, live-attenuated Streptococcus equi vaccineDelph, Katherine January 1900 (has links)
Master of Science / Department of Clinical Science / Elizabeth Davis / Background: While there is a commercially-available vaccine for Streptococcus equi subsp. equi licensed for the intranasal route of administration, some equine practitioners are administering this vaccine orally despite a lack of evidence for its efficacy by this route of administration.
Objectives: To compare systemic and local immune responses following intranasal or oral administration of the USDA-approved, live-attenuated Streptococcus equi subspecies equi vaccine (Pinnacle IN®, Zoetis, Florham Park, New Jersey).
Study Design: Experimental, randomized clinical trial
Methods: Eight healthy horses with low Streptococcus equi M protein (SeM) titers (<1:1600) were randomly assigned to an intranasal or oral two-vaccine series. SeM-specific serum immunoglobulins G (IgG) and A (IgA) and nasal secretion IgA were assessed using a commercially-available ELISA (Equine Diagnostic Solutions, LLC, Lexington, Kentucky) and a novel magnetic microsphere assay utilizing fluorescence. A general linear mixed models approach was used for statistical data analysis.
Results: As expected, intranasal vaccinates showed substantial increases in both serum SeM-specific IgG and IgA levels post-vaccination (P=0.0006 and P=0.007, respectively). Oral vaccinates showed an increase in serum SeM-specific IgG post-vaccination (P=0.0150), though only one-third the magnitude of intranasal vaccinates. Oral vaccinates showed no evidence of change in SeM-specific IgA post-vaccination (P=0.15).
Main Limitations: Changes in mucosal antibody responses were not identified in this study which may be related to small change in antibody response, timing of sample collection, or method of nasal secretion collection.
Conclusions: Results indicate that intranasal or oral vaccine administration resulted in increased serum SeM-specific IgG, though the magnitude of response differed between routes.
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Synthesis and characterisation of delafossite CuFeO2 for solar energy applicationsForslund, Axel January 2016 (has links)
Delafossite CuFeO2 is an intrinsic p-type semiconductor with a band gap around 1.5 eV. Further, it is composed of relatively abundant, nontoxic elements, and therefor have potential to be an attractive material for solar energy harvesting.This work examines three routes to synthesise this material. The first includes a sol-gel deposition and then relies on solid state reaction above 650 degrees Celsius in inert gas atmosphere. In this work, no delafossite is obtained with this method.The second method is a hydrothermal route to make particles under hydrostatic pressure in an autoclave. Delafossite is obtained mixed with other phases.The third route includes aqueous precipitation similar to the second route, but a temperature of 70 degrees Celsius and ambient pressure is sufficient to produce a pure delafossite particle phase. It provides a robust and simple way to make delafossite CuFeO2 particles.The resulting particles are deposited and compressed on glass into thin films.The films have a band gap slightly below 1.5 eV and show some photoactivity in electrochemical measurements.
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Colloidal Self-Assembly of Multi-fluorescent Silsesquioxane MicroparticlesNeerudu Sreeramulu, Niharika 01 April 2016 (has links)
Self-assembly of colloidal microparticles is one of the strategies for making characteristic patterns. These versatile self-assemblies provide a route to elevate the efficiency of an electronic device. Silsesquioxane particles with various functionalities were synthesized by a modified Stöber condensation method. This thesis describes the synthesis of benzylchloride silsesquioxanes, benzylchloride-amine silsesquioxanes and amine-functionalized silsesquioxane particles with multi-fluorescent tags. The size and morphology of the particles were controlled by varying the concentration of base and anhydrous ethanol (solvent). The size distribution of particles was controlled by adjusting the molar ratios of organotrialkoxy silane, base, and ethanol concentrations. Through selective post-functionalization with fused arenes of anthracene and rhodamine, multifluorescent particles were obtained. Morphologies and optical properties of particles were characterized by TEM, SEM, fluorescence optical microscopy, and absorption and fluorescence spectroscopies. The composition of silsesquioxanes was confirmed by FTIR, thermogravimetric analysis, and elemental analysis. A versatile technique was developed for the self-assembly of particles on different polymer substrates by changing the colloidal suspension concentration and the polymer substrate.
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Effect of Temperature and Salt on Laboratory Growth of Vampirovibrio chlorellavorus and Killing of a Cultivated Chlorella HostLi, Xuehui January 2015 (has links)
Vampirovibrio chlorellavorus (Gromov et Mamkaeva, 1980) is a member of the phylum cyanobacteria that has been described as an obligate pathogen of several of the green microalga, Chlorella. It utilizes as yet unknown functions to access the contents of individual Chlorella sp. host cells, which results in cell death. Its presence in a cultivated Chlorella sorokiniana culture was first discovered using polymerase chain reaction (PCR) to amplify the 16S ribosomal DNA gene, followed by DNA sequencing. Its continued routine detection throughout much of the cultivation season suggested it was an endemic member of the phycosphere community in this open cultivation system, located in Tucson, Arizona. Ultimately, its presence resulted in rapid death of C. sorokiniana in open pond systems and reduced biomass harvest. PCR analysis of total DNA isolated from sand and soil layers removed from a nearby riverbed indicated that V. chlorellavorus resides naturally in the riverbed. The ability to manage this bacterial pathogen in cultivated Chlorella host species is hindered by the limited information available in the literature regarding the biological and genomic characteristics of V. chlorellavorus. The objective of this study was to identify environmental factors that trigger the apparent increased growth rate of V. chlorellavorus and rapid algal death during the cultivation cycle. In laboratory experiments, V. chlorellavorus was shown to cause death of C. sorokiniana when the temperature exceeded 28°C, whereas, algal death was not observed when the temperature was 24°C or lower, among the temperatures tested. Also, the bacterium was more pathogenic to C. sorokiniana, grown in open cultivation systems during the summer months, compared to the cooler season months. Futhermore, when C. sorokiniana and V. chlorellavorus were co-cultivated in the presence of sodium chloride ranging from 0-10 g per liter, the growth of the bacterium was not impeded to any extent that might suggest C. sorokiniana was rendered less susceptibility to pathogen attack. Future work involves examining more triggers and ways to inhibit V. chlorellavorus growth.
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THE CULTURE CONNECTION: TESTING A MODEL OF AFRICAN AMERICAN ATTITUDES TOWARD MENTAL HEALTH SERVICE UTILIZATIONSmith, Andrea Michelle 01 January 2009 (has links)
The purpose of the current study was to combine the factors previously determined to be related to African American help seeking into a single path model and, using structural equation modeling (SEM), determine the relative influence of each factor in the attitudes toward seeking mental health services (see Figure 2.2) among a community sample of African American adults from several metropolitan areas in the US. As such, SEM was utilized to compare the relative fit of two opposing models within this sample, one where a path from economic barriers to help-seeking attitudes was estimated freely and one where that path was constrained. Many have argued that for African Americans, economic constraints are barriers to seeking help. While existing literature fails to consistently support this contention, the current study does suggest that social status does carry significant weight in predicting attitudes toward seeking mental health services. Acculturation was not as strong of a predictor. Limitations , including the use of an abbreviated help-seeking scale, were discussed. In addition, implications for African Americans seeking services were also discussed.
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