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Stockholm lies at the top in Europe in terms of population growth. It is growing from 30,000 to 40,000 residents each year and therefor puts high demands on the regions development. One of the governments reactions to this housing problem was to approve a bill that would simplify the regulatory framework in the planning and building act. It will among other permit owners of a one-or two family houses to build a 25  compliment housing without a building permit, so called attefallshus. In this final project, a small 25  house is designed. The house was designed to have thin exterior walls to maximize the indoor living space and also to fulfill all the Boverkets regulations for permanent housing. Vacuum Insulated panels were used as an insulation material in the envelope to achieve the extra thin exterior walls to maximize the living space. Various different simulations were done to simulate: Heat- and moisture transfer through the exterior walls, thermal bridges, energy calculations and the daylight factor inside the house. Additional calculations were done in Excel to compare the mean U-value calculated in simulations. The moisture transfer simulation did show that there should not be any moisture problems in the exterior walls. The mean U-value calculations in Excel and in the simulations showed values less than the limitations of Boverkets building regulations.

Bygg- samt fastighetsbranschen står för cirka 21% av koldioxidutsläppen i Sverige. Detta är ett problem som behöver lösas eftersom Sverige år 2017 antog ett klimatpolitiskt ramverk med målet att år 2045 inte ha några nettoutsläpp av växthusgaser till atmosfären. Ett ökat byggande i trä är en viktig del av lösningen för att nå målet om klimatneutralitet. Ett fastighetsbolag som håller på att bygga sitt första kontorshus i trä är Vasakronan, som kallas Magasin X. Det finns ett flertal utmaningar med att bygga flervåningshus i trä, dessa är bland annat fukt- och akustikproblem. Trä är ett fuktkänsligt material och om byggnaden skadas av fukt finns det en förhöjd risk för mögel som kan leda till hälsoproblem för framtida brukare av byggnaden. Gällande akustik, kan det bli lyhört, om inte hänsyn tas till materialets låga densitet. Detta examensarbete utfördes i samarbete med Vasakronan och har som syfte att identifiera drivkrafterna med att bygga flervåningshus i trä, identifiera kunskapsbrister samt identifiera förslag på lösningar inom fukt och akustik vid byggande av flervåningshus i trä. I detta examensarbete utfördes intervjuer samt observation som metoder. Observationen utfördes på en erfarenhetsträff angående byggprojektet Magasin X. Vid erfarenhetsträffen avhandlades utmaningar samt lösningar som uppkommit under projektet. Tematisk analys användes som metod för att analysera intervjuerna för att därmed besvara uppsatsens frågeställningar. Följande har identifierats som drivkrafter för att bygga flervåningshus i trä. För det första är det ett material som leder till lägre koldioxidutsläpp jämfört med betong. För det andra är det ett material som är lämpligt för industriellt byggande vilket innebär att det är lätt att tillverka byggdelar i fabrik. För det tredje är det ett material som bidrar med en bättre arbetsmiljö förde som arbetar med att uppföra byggnaden jämfört med vid uppförande av en byggnad av betong och stål. För det fjärde är det ett material som är lätt att kombinera med andra material och använda vid påbyggnader på grund av dess låga densitet. Den främsta anledningen till kunskapsbrister är begränsad erfarenhet att bygga flervåningshus i trä. Förslag på lösningar mot kunskapsbrister är att använda sig av aktiviteter som seminarium för att sprida kunskap inom ämnet, upprätta instruktioner och manualer vid användandet av nya byggmetoder. Dessutom är en lösning att bygga fler flervåningshus i trä för att ansamla erfarenhet och kunskap. Lösningar för att åtgärda fuktproblematik är att använda väderskydd på byggnaden, helklistrad plastfolie och tejp på bjälklaget samt vatten-dammsuga vid regn. Lösningar på akustikproblem är att installera installationsgolv eller installera ett tyngre övergolv med antingen betonggjutning eller spackel med stegljudsmatta. Om möjligt är väderskydd den mest effektiva åtgärden för att minska risken för fukt, dock är det en dyr lösning. Det finns dock andra åtgärder som inte är lika effektiva men billigare, som att använda plastfolie, presenningar och ställningar och tejp för att täcka bjälklag. Gällande akustiken har det dock det inte varit möjligt i denna studie att avgöra vilken akustisk lösningsom är att föredra. En drivkraft till att bygga flervåningshus i trä är att minska klimatpåverkan men för att upprätthålla ett hållbart skogsbruk är det viktigt att inte hugga ner för mycket träd. Därmed kan en hybridstomme vara ett bra alternativ för framtiden. / The construction and real estate industry accounts for a large share of carbon dioxide emissions in Sweden, about 21% of greenhouse gas emissions. This is a problem that needs to be solved because in 2017 Sweden adopted a climate policy framework with the goal that by 2045 there will be no net emissions of greenhouse gases into the atmosphere. Increased construction in wood is an important part of the solution to achieve the goal of climate neutrality. A real estate company that is building its first wooden office building is Vasakronan, which is called Magasin X. There are several challenges with building multi-storey houses in wood, these include moisture problems and acoustic problems. One factor is the risk of moisture as wood is a moisture-sensitive material and if the building is damaged by moisture, there is an increased risk of mold, which can lead to health problems for future users of the building. If the light density of the material is not considered, it might be inefficiently soundproof. This master thesis was carried out in collaboration with Vasakronan and aims to identify the driving forces in building multi-storey buildings in wood, identify lack of knowledge within building of multi-storey buildings in wood and identify and investigate solutions to solve issues with moisture and acoustics in the construction of multi-storey buildings in wood. In this thesis, interviews and observation were used as a method. The observation was carried out at an experience meeting regarding the construction project Magazine X. At the experience meeting, challenges and solutions that arose during the project were discussed. The thematic analysis was also used as a method for analyzing the interviews in order to answer the research questions. The following have been identified as driving forces for building multi-storey wooden buildings. First, it is a material that leads to lower carbon dioxide emissions compared to building in concrete. Secondly, it is a material that is suitable for industrial construction, which means that it is easy to manufacture building components in a factory. Thirdly, it is a material that contributes to a better working environment for those who work with the construction of the building compared to when constructing a building of concrete and steel. Fourth, it is a material that is easy to combine with other materials and use in extensions due to its low density. The main reason for lack of knowledge is lack of experience in building multi-storey wooden buildings. Suggestions for solutions to knowledge gaps are to use activities such as seminars to spread knowledge in the subject. Solutions to fix moisture problems are to use weather protection on the building, wet guard and tape on the framing of joists and soak up water in the risk of rain. Solutions to acoustic problems are to install installation floors or install a heavier top floor with either concrete casting or putty with sound insulation mat. If possible, weather protection is the most effective measure to reduce the risk of moisture, but it is an expensive solution. However, there are other measures that are not as effective but cheaper, such as using wet guard, tarpaulins and scaffolding and tape to cover framing of joists. It has not been possible to determine which acoustic solution is preferable. A driving force for building multi-storey wooden buildings is to reduce the climate impact, but in order to maintain sustainable forestry, it is important not to cut down too many trees. Thus, a hybrid frame can be a good alternative for the future.

<p>In recent years, numerous multistate foodborne outbreaks have been reported that are often associated with low moisture foods (LMFs). The survival of microorganisms in low moisture conditions has become one of the major concerns in the food industry. With the increasing number of recalls, it is necessary to ensure food safety by developing and validating the process parameters. Establishing a thermal process requires a detailed understanding of the inactivation kinetics of the target pathogen with respect to both the process (temperature, time, equipment) and the product conditions (water activity, composition). Along with the most widely used conventional thermal processing, there has been an increase in the demand for natural or minimally processed foods. As a result, many alternative non-thermal processing approaches that provide antimicrobial benefits while retaining the quality attributes of the food product are under investigation. This research focused on studying the inactivation kinetics of foodborne pathogens <em>Salmonella enteritidis</em> PT30 and <em>Cronobacter</em> <em>sakazakii</em> in powdered LMFs using both the thermal and non-thermal (cold plasma) processing technologies. The efficacy of a dielectric barrier discharge cold plasma equipment was tested against pathogens <em>Salmonella</em> <em>enteritidis</em> PT30 and <em>Cronobacter</em> <em>sakazakii</em> in LMFs at 70 kV, resulting in 3.8 log reduction in <em>Cronobacter</em>, and 4.41 log reduction in <em>Salmonella</em> after 5 min of cold plasma treatment in pea protein. The cellular damage to the pathogens was examined by transmission electron microscopy (TEM), and the reactive oxygen (ROS: OH, O) and nitrogen (RNS: N₂, N₂⁺) species were identified using optical emission spectroscopy. The RMSE for the model was found to be between 0.11 and 0.36 with the low standard error of the parameters (δ, n, and log N₀), which illustrated that the Weibull model was a good fit for the experimental inactivation data. </p> <p>In the thermal processing study, the inactivation kinetic parameters of these pathogens were estimated at 70, 80, and 90 °C at 0.11, 0.22, and 0.33 water activity in pea protein powder. The non-isothermal temperature profiles were simulated by building a two dimensional, axisymmetric heat transfer model of the test cell. The inactivation parameters D_ref, z_T, and z_aw were estimated in MATLAB by using a one-step non-linear regression analysis, which was a combination of the primary log-linear model with the secondary modified-Bigelow model. The model was found to be a good fit, showing lower root mean square error (RMSE) and residuals. Further, <em>Enterococcus</em> <em>faecium</em> was observed to have higher D-values at all the processing temperatures and water activity levels as compared to <em>Salmonella enteritidis</em> PT30 and <em>Cronobacter</em> <em>sakazakii</em>, which provides valuable evidence that <em>Enterococcus</em> <em>faecium</em> can be used as a surrogate microorganism for validating the thermal process for pea protein powder.</p>

Betong är ett av världens vanligaste byggmaterial och består av cement, ballast, vatten och eventuella tillsatser. Trots dess utbredda användning uppstår det ofta problem både vid gjutning och efter gjutning. För att motverka dessa problem behandlas betongen på olika sätt, bland annat genom fukthärdning vid gjutning. Fukthärdning medför att fukt hindras avgå från betongen under hydratationen. Har betongen inte tillräckligt med fukt finns det risk att hållfasthetstillväxten avstannar. Syftet med arbetet är att studera hur fukthärdning med en vattenbaserad membranhärdare med silikat påverkar uttorkning och hållfasthet för en betong med lågt vct. I arbetet jämförs fullständig fukthärdning med plast, fukthärdning med membranhärdare och betong som lufthärdas. Membranhärdaren som använts är en vattenbaserad membranhärdare med silikat och den använda betongen har ett vct på 0,38 och hållfasthetklass C45/55. Hållfasthetsutvecklingen hos betong startar så fort cement blandas med vatten och den kemiska reaktionen kallas hydratation. Vid hydratationen reagerar belit (C2S) och alit (C3S) som finns i cement med vatten och bildar bland annat kalciumsilikathydrat (C-S-H) vilket är den beståndsdel som ger betongen sin hållfasthet. Faktorerna som påverkar betongens hållfasthetsutveckling är bland annat fukttillgång, temperatur, cementtyp och vattencementtal. Direkt efter gjutning innehåller betong stora mängder fukt, både som fritt vatten och i form av vattenånga, som ska torka ut. Uttorkningen av betong tar lång tid och pågår tills den är i fuktjämvikt med omgivningen. Uttorkningshastigheten beror på olika faktorer som vct och tillsatser, även metod för fukthärdning kan påverka uttorkningstiden. För att besvara syftet har betongkuber gjutits som fukthärdats med antingen membranhärdare eller genom att plastats in, samt har vissa kuber lufthärdats. I vissa betongkuber placerades fuktmätare för mätning av relativ fuktighet. Övriga provkuber provtrycktes för bestämning av tryckhållfasthet. Resultatet visar att membranhärdaren medför en långsammare uttorkning jämfört med betong som inte fukthärdats, men kortare uttorkningstid jämfört med betong som plastats in. Gällande hållfastheten visar resultatet att de kuber som membranhärdats får högre medelhållfasthet än de kuber som inte fukthärdats, men lägre medelhållfasthet än de som plastats in. Diskussionen behandlar resultatet och felkällor som kan påverka resultatet, och andra saker som kan påverka resultatet. Hållfastheten för de kuber som inte fukthärdats påverkas av en stor avvikelse, till skillnad mot de kuber som fukthärdats. Detta medför en stor påverkan på medelhållfastheten. Slutsatsen från arbetet visar att det finns tendenser som visar på längre uttorkningstid jämfört med betong som inte fukthärdats, men betong som plastats in har längre uttorkningstid än membranhärdad med den använda membranhärdaren. Gällande hållfastheten syns inget tydligt samband mellan hållfasthet och membranhärdning och att det behövs fler provkuber som testas för ett pålitligt resultat. / Concrete is one of the most common building materials in the world, consisting of cement, aggregate, water and optional additives. Despite its widespread use, problem often arise. To counteract these issues, concrete is treated in various ways, such as moist curing after casting, as insufficient moisture during hydration can halt strength development. The aim of this study is to investigate how moist curing with a water-based membrane hardener containing silicate affects dehydration and strength for concrete with low water-tocement ratio (w/c). The study compares complete moist curing with plastic, moist curing with membrane hardener and uncured concrete. The membrane hardener used is a water- based membrane hardener with silicate, and the concrete used has a water-to-cement ratio of 0,38 and a strength class of C45/55. The development of strength in concrete begins as soon as cement is mixed with water, and this chemical reaction is called hydration. During hydration, belite (C2S) and alite (C3S) in the cement react with water and form, among other things, calcium silicate hydrate (C-S-H), which is the component that gives concrete its strength. Factors that affect the strength development of concrete include moisture availability, temperature, type of cement, and water-cement ratio. Immediately after casting, concrete contains large amounts of moisture, both as free water and in the form of water vapor, which needs to dry out. The drying of concrete takes a long time and continues until it reaches moisture equilibrium with the surrounding environment. The drying rate depends on various factors such as water-cement ratio and additives, and the method of moisture curing can also affect the drying time. To address the objective, concrete cubes were cast and cured using either a membrane curing compound or by being wrapped in plastic, while some cubes were air-cured. Moisture meters were placed in some of the concrete cubes to measure relative humidity. The remaining test cubes were subjected to compression testing to determine their compressive strength. The results indicate that the membrane hardener leads to slower drying compared to uncured concrete cubes, but shorter drying times compared to plastic sheet curing. Regarding strength, the results shows that that cubes treated with membrane hardener exhibit higher average compressive strength than uncured cubes but lower average compressive strength then the cubes moisture cured with plastic. The discussion addresses the results and potential sources of error, and other things that can affect the result. The significant deviation in strength for uncured cubes compared to those subjected to moist curing greatly impacts the average compressive strength. The conclusion suggests trends indicating longer drying times compared to uncured concrete cubes, moisture curing with plastic curing demonstrating longer drying times than membrane hardening with the specific membrane hardener used. Regarding strength, no clear correlation is observed between strength and membrane hardener, indicating the need for further testing with more specimens for reliable results.

The initial objective of this research project was to determine the feasibility of manufacturing carbon fiber-reinforced (CFR) composites with a matrix consisting of a phenylethynyl-terminated version of a thermoplastic poly(etherimide) termed PETU. Successful composite manufacture with 3,000 g/mol (3k) PETU led to a survey of CFR 3kPETU mechanical properties for comparison with other high-performance composites. Encouraging results led to a study of moisture sorption effects on CFR 3kPETU properties. The success of these initial studies spawned the large scale production of 2,500 g/mol (2.5k) PETU. Thermal characterization of neat and CFR 2.5kPETU via differential scanning calorimetry, dynamic mechanical thermal analysis, and parallel plate rheometry resulted in an understanding of the influence of cure time and temperature on reaction progress via both reaction kinetics and monitoring of the glass transition temperature. From the rheological characterization, a two-stage, dual-Arrhenius model was developed to successfully model isothermal complex viscosity over the range of processing temperatures. Neat 2.5kPETU and CFR 2.5kPETU specimens were exposed separately to elevated temperature environments of different moisture and different oxygen concentrations to evaluate the effects of moisture absorption, moisture desorption, and thermal oxidation on material properties. Moisture absorption took place in a 90 °C / 85% relative humidity environment followed by moisture desorption in a 90 °C / 10% relative humidity environment. Thermal-oxidative aging for up to 5000 hours took place at 204 204 °C in environments of four different oxygen partial pressures: 0.0 kPa, 2.84 kPa, 20.2 kPa, and 40.4 kPa. Following exposure to the different aging environments, the specimens were tested for retention of mechanical properties. In addition, moisture sorption properties were measured. Results from the moisture sorption studies on CFR 3kPETU and CFR 2.5kPETU suggest that fully cured composites will withstand moisture absorption and desorption with negligible effects on mechanical properties, whereas, lack of full cure allows moisture sorption to permanently damage the composites. Despite a lack of mass loss or visual evidence of degradation following thermal-oxidative aging, a decline in mechanical properties was observed with the reduction becoming greater with longer aging times and higher oxygen partial pressures. / Ph. D.

This investigation has attempted to show that soil and water conservation practices do increase the amount of soil moisture in five of Denton County, Texas soils: Denton clay, Durant clay, San Saba clay, Kirvin fine sandy loam, and Tabor fine sandy loam.

Few current modeling tools are designed to predict short-term, high-risk runoff from critical source areas (CSAs) in watersheds which are significant sources of non point source (NPS) pollution. This study couples the Soil and Water Assessment Tool-Variable Source Area (SWAT-VSA) model with the Climate Forecast System Reanalysis (CFSR) model and the Global Forecast System (GFS) model short-term weather forecast, to develop a CSA prediction tool designed to assist producers, landowners, and planners in identifying high-risk areas generating storm runoff and pollution. Short-term predictions for streamflow, runoff probability, and soil moisture levels were estimated in the South Fork of the Shenandoah river watershed in Virginia. In order to allow land managers access to the CSA predictions a free and open source software based web was developed. The forecast system consists of three primary components; (1) the model, which preprocesses the necessary hydrologic forcings, runs the watershed model, and outputs spatially distributed VSA forecasts; (2) a data management structure, which converts high resolution rasters into overlay web map tiles; and (3) the user interface component, a web page that allows the user, to interact with the processed output. The resulting framework satisfied most design requirements with free and open source software and scored better than similar tools in usability metrics. One of the potential problems is that the CSA model, utilizing physically based modeling techniques requires significant computational time to execute and process. Thus, as an alternative, a deep learning (DL) model was developed and trained on the process based model output. The DL model resulted in a 9% increase in predictive power compared to the physically based model and a ten-fold decrease in run time. Additionally, DL interpretation methods applicable beyond this study are described including hidden layer visualization and equation extractions describing a quantifiable amount of variance in hidden layer values. Finally, a large-scale analysis of soil phosphorus (P) levels was conducted in the Chesapeake Bay watershed, a current location of several short-term forecast tools. Based on Bayesian inference methodologies, 31 years of soil P history at the county scale were estimated, with the associated uncertainty for each estimate. These data will assist in the planning and implantation of short term forecast tools with P management goals. The short term modeling and communication tools developed in this work contribute to filling a gap in scientific tools aimed at improving water quality through informing land manager's decisions. / PHD / Water pollution in the United States costs billions of dollars every year. Surface water pollution is caused by excess nutrients and effects the value of fisheries, recreational activities, and commercial operations, and can even lead to health hazards such as dangerous algal blooms. A major source of water pollution is from agricultural activities such as fertilizing crops. This type of pollution is called non-point source, as there is no obvious point where excess nutrients from fertilizers or manure enters the water, such as a discharge pipe, instead the pollution flows over the land first and then into the waterways following the rainfall-runoff patterns. One way to prevent non-point source pollution from agricultural activities is to give farmers tools to optimize operations in a way that can help lower the chance that pollution will occur. Scientific models, like a weather forecast, can help, but there is a lack of tools made specifically for reducing water pollution that are available to farmers. This work focuses on creating a free to use, high resolution and rapid update forecast delivered over the internet, capable of informing agricultural management practices to reduce water pollution. Over the course of this study, published advances in watershed modeling were made filling gaps in existing forecast technology. The final product combines cutting edge watershed science, machine learning and statistical models, web mapping tools, and terabytes of data to meet design goals.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第25269号 / 工博第5228号 / 新制||工||1997(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 西村 文武, 教授 米田 稔, 教授 松田 知成 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

In this thesis, analyses of the moisture budget in the 5th ECMWF reanalysis (ERA5) and in phase 6 of the Coupled Model Intercomparison Project (CMIP6) historical simulations and future projections are leveraged to explore the maintenance and response to climate change of the hydroclimate in the Mediterranean region. Recent and future projected changes in the Mediterranean, a climate-change hot and dry spot. The transition toward a warmer and drier climate has substantial social and economic implications; hence, it is critical to invest in understanding the Mediterranean hydroclimate change over the coming decades. One of our goals is to complement previous work by further decomposing the mean flow into contributions by the zonal-mean flow, which is dominated by the mean meridional circulation, and by zonally anomalous circulations and/or moisture, namely the stationary eddies. In present-day climate, as depicted by ERA5, annual-mean net evaporation (negative P-E) over the ocean and net precipitation (positive P-E) over land are primarily due to submonthly transient eddies converging moisture originating from the sea into the surrounding land. Overall, total stationary eddies reinforce the transient tendency over the ocean but oppose it over land, with the zonal-mean meridional circulation exerting a minor drying tendency limited to the region's southernmost latitudes. These large-scale features are captured quite well in the ensemble-mean of ten CMIP6 models analyzed in this work. The same CMIP6 model subset is thus used to study the response of the Mediterranean hydroclimate at the end of the 21st century under the SSP5-8.5 scenario. According to the CMIP6 multi-model mean, the climatological annual mean P – E is projected to decrease drastically by the end of the 21st century, both over northern Mediterranean land regions as well as the sea. These changes are not due to the transient eddies, which exert an overall negative but weak tendency, but are driven by changes in the time-mean flow. Consistent with the mean climatological moisture budget, this drying arises from the zonally anomalous circulation term, that is, enhanced zonally anomalous descent and lower-level diverging wind patterns over the Mediterranean region. Our results highlight the importance of circulation changes within the Mediterranean region and their impacts on the hydrological cycle. However, the thermodynamic adjustment is never trivial in our region and is deserving of further investigation. In particular, we are exploring if and to what extent an extended scaling, which is based only on climatological quantities and changes in surface properties, performs better than the simple Clausius-Clapeyron scaling by including thermodynamic changes in advection. Our analyses indeed show that, both in the annual mean and through the seasonal cycle, the extended scaling better captures the full thermodynamic component, which, unlike the simple scaling, predicts a wettening over the ocean. While not fully accounting for the magnitude nor the extent of this wettening, the extended scaling outperforms the simple scaling. %Areas of better agreement also include the nearby land regions, including France and the Iberian Peninsula, where the extended scaling predicts a stronger drying. Throughout the target region, the differences between the two scalings primarily arise from the contribution of the terms involving the gradients of fractional changes in local relative humidity and near-surface temperature changes. Even if largely cancelling, these two terms give rise to a pattern grossly characterized by moistening over the ocean and drying over neighbouring regions. Overall, the results of this thesis highlight how changes in the hydrological cycle in the Mediterranean region result from a complex interplay between different mechanisms, arising from both thermodynamic and dynamical changes. In particular, our results emphasize how the overall drying tendency in the region is primarily due to zonally asymmetric circulation changes rather than by changes in the mean meridional circulation, and is augmented by changes in transient eddies and those arising through the simple thermodynamic wet-get-wetter mechanism, and is partly opposed over the ocean and reinforced over the land regions by thermodynamic changes in advection. By shedding light on all of the involved mechanisms, this work advances our understanding of the factors that make the Mediterranean region a climate-change hot and dry spot.