The expansion of urban and suburban areas is a world-wide phenomena. One product of this development is a dramatic increase in impermeable surfaces and a consequent increase in stormwater runoff. Bioretention cells are one best management practice frequently used to mitigate the environmental impacts of urban stormwater runoff. To ensure that a bioretention cell will continue to perform adequately in the long term, it is imperative that the environmental conditions it will experience and their effect on its performance through time are considered during its design. Although bioretention cells are frequently used for stormwater management, very few quantitative data exist on how they perform through time and in varied physical environments. In regions with seasonal freeze-thaw cycles, it is important to understand the effects of freeze-thaw cycles on the infiltration rate of bioretention cell soil mixtures so that the integrity of the design will not be compromised by seasonal change. This project uses laboratory tests to investigate the effects of freeze-thaw cycles and sediment input on the infiltration capacity of three different bioretention cell soil mixtures. These results will provide an analog for long-term changes in bioretention cell infiltration rates due to freeze-thaw cycles, providing critical data on which soil mixture would be best implemented in geographic regions susceptible to freeze-thaw activity. Furthermore these results will inform design standards for bioretention cells to ensure their long-term performance.

Nedfrysning och upptining av spermatozoa används frekvent i andrologi-laboratoriet för assisterad reproduktionsteknik och bedömning av spermatozoa. I dagsläget finns det ingen standard hur nedfrysning och upptining av spermatozoa ska ske. I denna studie jämförs två olika processer; ”slow freeze” följt av upptining med G-IVFTM medium, vilken används på RMC Skånes Universitetssjukhus. Kryokonservering med ”pellets” följt av upptining med HTF + 10% HSA medium enligt Martínez-Soto J C m.fl. Två olika upptiningsmetoder används för varje process; först tinas spermatozoa i rumstemperatur i 10 minuter, följt av 10 minuter uppvärmning i 37 °C och precis innan analys tillsätts 37 °C medium. I den andra upptiningensmetoden tillsätts 37 °C medium till det frysta provet och förvaras i värmeskåp, 37 °C i 20 minuter. I studien analyseras effekterna av spermatozoa motilitet och vitalitet. Resultaten visar att med ”slow freeze” och G-IVFTM finns det ingen signifikant skillnad mellan upptiningsmetoderna för både motilitet, p-värde >0,05 och vitalitet, p-värde >0,05. I jämförelse med Martínez-Soto J C m.fl visades ingen skillnad mellan motilitet, p-värde >0,05. Studien visar en positiv effekt på vitalitet jämfört med Martínez-Soto J C m.fl studie, p-värde <0,01. Studien visar att användning av ”slow freeze” med G-IVFTM inte gör någon skillnad på motilitet men har en positiv signifikant påverkan på spermatozoa vitaliteten. Mer studier är nödvändiga för att stärka dessa resultat och överlag behövs mer studier inom området för att utveckla bättre metoder. / Freezing and thawing of spermatozoa are frequently used in the andrology laboratory for assisted reproduction techniques and assessment of spermatozoa. At present, there is no standard on how freezing and thawing of spermatozoa should occur. In this study two different processes are compared; “slow freeze” followed by thawing with G-IVFTM medium, which is used at RMC University Hospital. Cryopreservation with “pellets” followed by thawing with HTF + 10% HSA medium according to Martínez-Soto J C et al. Two different thawing methods are used for each process; first, the spermatozoa are thawed at room temperature for 10 minutes, followed by 10 minutes warming at 37 °C and just before analysis 37 °C medium is added. At the second thawing method, 37 °C medium is added to the sample and stored in a heating chamber, 37 °C for 20 minutes. The study analyzed the effects of spermatozoa motility and vitality. Results show that with “slow freeze” and G-IVFTM there is no significant difference between the two thawing methods for both motility, p-value >0,05 and vitality, p-value >0,05. Comparing with Martínez-Soto J C et al. no difference between motility was shown, p-value >0,05. The study shows a positive effect on vitality compared to Martínez-Soto J C et al, p-value <0,01. The study shows that the use of “slow freeze” with G-IVFTM does not make any difference in motility but has a significant positive effect on the spermatozoa vitality. More studies are necessary to strengthen these results. Overall more research is needed in the area to develop and find a common method.

Diplomová práce se zabývá přípravou 3D porézních kolagenových skafoldů metodou lyofilizace a jejich modifikací bioaktivními látkami. K modifikaci byly použity přírodní polysacharidy – chitosan, vápenatá oxidovaná celulóza a chitin/chitosan-glukanový komplex. Mechanické vlastnosti skafoldů byly upraveny síťováním pomocí karbodiimidů. Růstové faktory byly dodány formou destičkového lyzátu. Byl zkoumán vliv biologicky aktivních aditiv, siťovacího činidla a obohacení růstovými faktory na vlastnosti připravených skaffoldů a jejich bioaktivitu v tkáních živých organismů. Konkrétně byly studovány morfologické vlastnosti, struktura, porozita, botnání, stabilita, chemické složení, teplota denaturace a biologické vlastnosti. K charakterizaci byly použity metody rastrovací elektronová mikroskopie, infračervená spektroskopie, diferenční kompenzační kalorimetrie a konfokální mikroskop. Připravené kolagenové substráty obohaceny bioaktivním aditivem a destičkovým lyzátem mohou být využity v biomedicíně jako skafoldy pro růst buněk v systémech s nízkou mechanickou zátěží.

Orientador: Cassia Roberta Malacrida Mayer / Resumo: O Cerrado, segundo maior bioma brasileiro, possui uma rica flora e fauna dentre as savanas do mundo. O pequi (Caryocar brasiliense Camb.) é um fruto nativo desse bioma e apresenta muitos compostos bioativos como carotenoides, vitaminas A e E e compostos fenólicos que possuem ações anticarcinogênicas, antimicrobianas e antioxidantes. Esses compostos, no entanto, são sensíveis a exposição à luz e oxigênio. Para amenizar essa degradação podem ser utilizados métodos de encapsulação. A extração do óleo da polpa de pequi, por prensagem a frio, gera uma torta residual rica em compostos bioativos. Portanto, o objetivo do presente trabalho foi a encapsulação dos compostos fenólicos presentes na torta residual por meio da liofilização utilizando diferentes agentes encapsulantes (amido de mandioca modificado, goma arábica, maltodextrina e ovoalbumina). Para tanto foi obtido um extrato aquoso (1:6 m/v) da torta residual utilizando extração ultrassônica com os seguintes parâmetros: 240 W de potência, 50% de pulso e 10 minutos. Os materiais encapsulantes corresponderam a 20% do extrato. Inicialmente, o extrato foi misturado aos agentes encapsulantes puros com o intuito de verificar quais os melhores encapsulantes. Numa segunda etapa, foram utilizadas misturas de amido de mandioca modificado (AM) e maltodextrina (MD) para misturas nas proporções de 50% de AM e 50% de MD; 75% AM e 25% MD e 25% AM e 75% MD. Todas as amostras foram liofilizadas a -50 °C por 48 horas, originando pós de cor amar... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Cerrado, the second largest Brazilian biome, has a rich flora and fauna among the world’s savannas. Pequi (Caryocar Brasiliense Camb.) is a native fruit of this biome and has several bioactive compounds such as carotenoids, vitamins A and E and phenolic compounds that perform anticarcinogenic, antimicrobial and antioxidants actions. These compounds, however, are sensitive to light and oxygen exposure. To mitigate this degradation, encapsulation methods can be used. The oil extraction from pequi pulp, by cold pressing, generates a residual cake rich in bioactive compounds. Therefore, the objective of the present work was the encapsulation of the phenolic compounds present in the residual cake by freeze-drying using different encapsulating agents (modified cassava starch, Arabic gum, maltodextrin and ovoalbumin). For this, an aqueous extract (1:6 m/v) of the residual cake was obtained using ultrasonic extraction with the following parameters: 240 W of power, 50% of pulse and 10 minutes. The encapsulating materials corresponded to 20% of the extract. Initially, the extract was mixed with pure encapsulating in order to verify which are the best encapsulating. In second stage, modified cassava starch (AM) and maltodextrin (MD) were used for mixtures in the proportions of 50% AM and 50% MD; 75% AM and 25 MD and 25% AM and 75% MD. All samples were freezing drying at -50°C for 48 hours, resulting in yellowish powders, which were evaluated for physicochemical characteristics. Afte... (Complete abstract click electronic access below) / Mestre

As the new paradigm of data collection enabled by the advancements in wireless technology and digital electronics, small sensing devices have started to be used in everyday life. These devices are capable of sensing, computing, communicating, and forming a wireless sensor network (WSN) which is necessary to provide sensing services and to monitor various conditions. In addition to WSNs, the idea of Internet of Things (IoT) has started to draw more attention. IoT is defined as an interconnection between identifiable devices within the internet for sensing and monitoring processes. This dissertation addresses the development of wireless network and process control for two challenging IoT applications, namely smart agriculture and industrial lyophilization.<div><br><div>Smart agriculture refers to the concept of using modern technology to increase the quantity and quality of agricultural products. This dissertation presents a novel hybrid large-area IoT network by combining the low-power wide-area network (LPWAN) as well as ultra-low-power wireless personal area networks (WPAN) that delivers wide-area coverage while maintaining low-power operation. </div><div><br></div><div>Lyophilization is the process of removing water content from a material with the objective of increasing its stability and, hence, its shelf life. Continuous inline process tracking is imperative to a successful lyophilization process in industrial pharmaceuticals. To address this need, this dissertation presents two wireless sensing systems that are capable of monitoring lyophilization process with detailed design and demonstration<br></div></div>

Magnetic field-assisted freeze-casting was used to create porous B4C ceramic preforms. An optimum slurry consisted of a mixture of B4C powders with 6 wt.% Er2O3 powder in an H2O-PVA solution and was cooled at a rate of 1 °C/min from room temperature to -30 °C resulting in porous green state ceramic preform with vertical channels. The Er2O3 powder was added to improve the magnetic response of the slurry. The preform was then sublimated to remove H2O and then sintered. The sintered ceramic preform was then infiltrated in the most vertically aligned channel direction with molten Al (A356) metal through a vacuum-assisted pump to create the metal matrix composite (MMC). Finite element analysis simulations were used to analyze and predict the anisotropic effect of B4C channel alignment on mechanical properties. The mechanical properties of the composite were then experimentally found via compression testing, which was compared with rule-of-mixtures and finite element modeling simulations, to analyze the effect of anisotropy due to magnetic field-assisted freeze-casting. This study reinforces the viability of cost-effective magnetic field-assisted freeze-casting as a method to create highly directional ceramic preforms, which can be subsequently metal infiltrated to produce MMCs with highly anisotropic toughness.

The IronArc process is a novel process for a more sustainable production of liquid pig iron using electricity for heating and hydrocarbons for reduction. This thesis aims to facilitate its use by investigating possible refractory solutions and the gas blowing in the process which is done by a plasma generator. The process involves a slag with a high FeO content of 90 wt % and gangue content of approximately 5 wt % SiO2 and 5 wt % CaO. The interaction between such a slag and refractories of MgO, Al2O3, Cr2O3, SiC, ASZ,and C was investigated by high temperature experiments at 1700 K and by thermodynamic calculations in Thermo-calc and FactSage. In the high temperature experiments it was found that all of the studied refractory materials experienced signicant wear after 3 h, but the MgO-Al2O3 spinel refractories were the least affected. The thermodynamic calculations show fair agreement to the experiments, with the exception for the Cr2O3-spinel refractory which performed much worse than predicted by thermodynamic equilibrium calculations. It was concluded that the thermodynamic equilibrium calculations in Thermo-calc and Factsage can be used as an indicator for the stability of a refractory material, but with varying accuracy depending on the quality of the data in the database used. Since industrial refractory materials are not viable as refractory for the IronArc process a freeze-lining approach was evaluated by using CFD in ANSYS Fluent. The flow of a slag was simulated through two different designs of slag runner to investigate how well a freeze-lining protects the walls in a region with rapid flow and the cooling required to form and maintain said freeze-lining. It was found that the enthalpy porosity model in ANSYS Fluent in combination with the RSM turbulence model accurately predicts the thickness of a freeze lining when validated against experiments in the CaCl2-H2O system. For optimal protection of the refractory walls the reactor and runner should be designed to minimize the movement close to the walls as high near-wall turbulence will reduce the thickness and stability of the freeze-lining, leading to greater cooling requirements to maintain afreeze-lining. The IronArc process uses a plasma generator to supply heat to the reactor using electricity. By blowing gas and hydrocarbons through an electric arc, superheated gas is formed which when injected into the reactor provides both stirring and heating for the process. To study the behavior of the injected gas a simulation model was developed in OpenFOAM. The model for simulating gas blowing was tested in both incompressible and compressible simulations in the air-water system which were veried against an experimental study in the air-water system and found good agreement. The simulations of the plasma generator blowing were done in the compressible model to account for the high temperature and pressure present in the IronArc process. It was found that the stability of the gas blowing is dependent on the Froude number where low values cause an unstable and pulsating plume and higher values produce a more stable jet. It was also found that the empirical equation for penetration length is only valid for gas blowing with suciently high Froude numbers to produce a jetting behavior. It was found that the transition from pulsating to steady jetting in the IronArc system occurred around Froude numbers of 300 and higher values further increased the stability of the jet. For gas blowing below the transition region, the penetration length of the unstable and pulsating jet will be severely underpredicted by the empirical equation. This behavior must be considered when designing the gas blowing system for the IronArc process as the gas penetration length will signicantly influence the stirring in the reactor. Additionally, a pulsating and unstable jet produces large bubbles which risk coming in contact with the refractory walls which in previous studies has been shown to be very detrimental to the refractory lifetime. A decrease of the inlet diameter for the gas blowing increases the Froude number and the stability of the jet. By implementing the proposed refractory protection by freeze-lining and the small changes to the plasma generator inlet diameter the IronArc process can be developed into a promising industrial process capable of producing liquid pig iron in a more sustainable way. / Sammanfattning IronArc processen är en nytänkande metod för att producera flytande råjärn på ett mer hållbart sätt genom att använda elektricitet för uppvärmning och kolväten för reduktion. Denna avhandling ämnar att utvärdera möjliga metoder för att skydda infordingen i processen och undersöka gasblåsningen i processesen som görs med en plasma generator.   Ett av huvudstegen av IronArc processen är tillverkningen av en slagg med upp till 90 vikts % järnoxid samt 5 vikts % kiseldioxid och 5 vikts % kalciumoxid från gångarten. Interaktionen mellan en sådan slagg och olika infodringar baserade på MgO, Al2O3, Cr2O3, SiC, ASZ, och C undersöktes i högtemperaturexperiment vid 1700 K samt med termodynamiska beräknar i Thermo-calc och FactSage. Experimenten visade att alla de undersökta infodringsmaterialen bröts ned under de 3 timmar de var i kontakt med slaggen, men de två MgO-Al2O3 spinel baserade infodringarna visade högst motståndskraft mot slitaget. De termodynamiska beräkningarna överrensstämde bra med de experimentella resultaten för alla infodringsmaterial förutom den kromoxid baserade infodringen som bröts ned fullständigt trots att de termodynamiska beräkningarna påvisade viss stabilitet. Slutsatsen är att inget av de studerade infodringsmaterialen är bra anpassat för IronArc processen men att metoden som användes för de termodynamiska beräkningarna i Thermo-calc och FactSage kan användas för att ge en indikation om stabiliteten för olika infodringsmaterial i kontakt med slagg. Dock så kommer resultaten av de termodynamiska beräkningarna vara beroende av kvalitén av databasen som används för beräkningen.   Eftersom infodringsmaterialen inte kunde motstå slitaget från slaggen undersöktes en dynamisk infodring för slaggrännan i IronArc processen. Detta gjordes genom att simulera flödet och stelningen av slagg i flödesberäkningar i ANSYS Fluent i två olika typer av slaggrännor. Studien visade att enthalpy-porosity modellen för stelning samt RSM modellen för turbulens kunde förutspå stelningsförloppet i slaggrännan samt beskriva hur väl den dynamiska infodringen skyddar väggen och vilken kyleffekt som krävs för att bibehålla den. Denna modell validerades mot experimentella studier i CaCl2-H2O systemet med god överrensstämmelse. För optimalt skydd av väggarna i IronArc processen borde reaktorn och slaggrännan utformas så att flödet nära väggarna minimeras då ett turbulent flöde nära väggen är negativt för stabiliteten och tjockleken hos den dynamiska infodringen.   IronArc proceesen använder sig av en plasmagenerator för att förse processen med värme via elektricitet. Genom att blåsa gas och kolväten genom en ljusbåge värms gasblandningen och trycks in i reaktorn  vilket ger både värme och omrörning till processen. För att undersöka hur den varma gasen beter sig i reaktorn utvecklades en simuleringsmodell i OpenFOAM. Modellen utformades som både inkompressibel och kompressibel för blåsning av luft i vatten och jämfördes med experiment där gas blåstes i vatten. De båda modellerna överrensstämde bra med de experimentella resultaten och kunde därför användas för att studera gasflödet i IronArc processen. För simuleringen av IronArc processen valdes den kompressibla versionen av simuleringen då den tar hänsyn till de höga temperaturer och tryck som uppstår i reaktorn.   Simuleringarna visade att den inblåsta gasen kan ge en stabil gas-jet om Froude-talet för inblåset är tillräckligt högt. Om Froude-talet för gasblåsningen är för lågt så kommer gasen pulsera på ett instablit sätt och skapa stora bubblor som kommer i kontakt med infodringsmaterialet, vilket tidigare har påvisats orsaka ökat slitage på infodringsmaterialet. För IronArc processen krävdes ett Froude tal på ca 300 eller högre för att skapa en stabil jet av gas, där högre värden vidare ökar gas-jettens stabilitet. Studien visade också att den empiriska ekvationen som används för att beräkna penetrationslängden vid gasblåsning endast är korrekt om gasen är en stabil jet. Om ekvationen används för att beräkna penetrationslängden för gasblåsning med mindre än det krävda Froude talet kommer penetrationslängden kraftigt underskattas vilket kan medföra att fel beslut tas när en process utformas. Genom att minska diametern på dysan som används för gasblåsningen ökas Froude-talet och därmed stabiliteten av gasjetten, vilket gör den mer förutsägbar och bättre för processen.   För att vidare utveckla IronArc processen så bör den undersökta dynamiska infodringen samt de föreslagna modifieringarna till gasblåsningen användas. Då kan en lovande industriell process utformas som har möjlighet att producera flytande råjärn på ett mer hållbart sätt.    Keywords: IronArc, infodringsslitage, plasmagenerator, dynamisk infodring

This report aimed to investigate how chlorophyll-concentrations (Chl-a) in the water column and varved sediments were affected by changes in air temperature and precipitation and consequently how climate change will affect the sedimentation and productivity in boreal aquatic ecosystems. VRS (visible-reflectance-spectroscopy) was used to asses Chl-a and its derivates in sediment trap samples between 2002-2021 and in a series of freeze cores (1979-2021) from lake Nylandssjön, with annually laminated sediments. In order to evaluate how weather and climate change affected the sedimentation and productivity in the lake the results were compared with meteorological data from SMHI (Swedish Meteorological and Hydrological Institute) and Chl-a data from seperate depths in the water column. The results indicate that the majority of the yearly sedimentation occur either in May or June, where a higher cumulative amount of precipitation in May lead to a higher sedimentation rate in May (r=0,49; p=0,03). The amount of precipitation in spring also had a significant impact on the primary production in spring and summer (r=0,59; p=0,01; r=0,73; p=0,002). Water column Chl-a and spectrally inferred Chl-a in sediments show similar trends in concentrations with deeper water sampling, however, water column Chl-a displayed significant differences in values between various depths (p=0,0004). Consequently, climate change will much likely increase the productivity of boreal aquatic ecosystems within years and the amount of sedimentation that occurs between years due to higher temperatures. An increased amount of precipitation will also enhance the primary productivity and the transportation of allochthonous- and minerogenic material to the lake.

Gullies are significant contributors of sediment to streams in the southeastern USA. This study investigated gully erosion in the clay-rich soils of east Tennessee under a humid subtropical climate. The aims of this study were to (1) estimate long-term erosion rates for different gully geomorphic settings, (2) compare patterns of erosion for the different settings, and (3) model the response of gully erosion to freeze-thaw events. Erosion was measured weekly from June 2012 to August 2018 using 105 erosion pins distributed in gully channels, interfluves, and sidewalls. Erosion rates were estimated from average slopes of lines of best fit of pin lengths versus time. Maximum and minimum temperature was calculated daily using an on-site weather station and freeze-thaw events were identified. Gully erosion was modeled using antecedent freeze-thaw activity for the three geomorphic settings. Long-term erosion rates in channels, interfluves, and sidewalls were 2.5 mm/year, 20 mm/year, and 21 mm/year, respectively; however, week-by-week erosion was statistically different between the three settings, indicating different erosive drivers. Models of erosion with lagged freeze-thaw variables explained up to 34.8% of the variability in erosion variables; sidewall erosion was most highly related to freeze-thaw activity. Freeze-thaw in prior weeks was an important variable in all erosion models.

Microorganisms will play a significant role in the agricultural revolution in the coming decades and help meet the growing population's needs. Hence, understanding the impact of beneficial bacteria on crop development is key to the future of developing microbial products. The ability of PGPB to increase crop yields has been recently investigated in agriculture, as PGPB can support and protect plants under different stresses. Since PGPB interactions occur naturally, finding a method to apply beneficial bacteria while maintaining their efficiency and quality is a topic of interest. PGPB have been used as microbial inoculants, biofertilizers, and also as seed coatings. Preservation of microorganisms through desiccation has been used as the preferred method for long-term storage of microbial culture. The use of dry powders is favored over liquid cultures due to their ease of transportation and better quality control. For microbial preservation, freeze-drying has been defined as the most convenient and satisfactory preservation method for long-term storage. Freeze-drying is generally preferred over other drying techniques as it gives a high-quality dehydrated product. However, to reach a high-quality product, many parameters need to be monitored, such as bacterial cell concentration, growth medium, lyophilization buffer, rehydration, and duration of freeze-drying. In this research, SA190 was freeze-dried with 10% sucrose mixed with 5% trehalose as lyophilization buffer. Pseudomonas argentinensis SA190 was isolated from the root nodules of the desert plant Indigofera argentae in Saudi Arabia, specifically Jizan. The SA190 freeze-dried product was examined by several tests to assess the product viability and quality, such as accelerated test and water stability test. For future work, the effect of freeze-dried SA190 on plant growth and crop yield will be investigated. Moreover, optimization of the freeze-drying process, formulation, and packaging for commercial will be considered. In addition, bacterial strains isolated in DARWIN21 project with promising effects on plant growth, will be subjected to freeze-drying process.