The purpose of the study was to psychometrically evaluate the Revised Janis and Field Scale using the rasch model. The model is a measurement model often used to develop and improving composite measures. Quantitative content analysis was also used in the study. After the two analyses were conducted the problematic items were examined, where an interpretative perspective was applied to try to explain why some questions didn’t seem to work as intended. The other purpose of the study was to examine if emotional and cognitive components need to be treated as separate variables when studying self-esteem. The data collection was administrated at Karlstad University in April of 2014. In total 225 respondents participated in the survey, of whom 140 were women and 85 were men. Based on the rasch model, the instrument did not seem to measure self-esteem in an acceptable manner. There were also major problems with the content of the questions and how they were structured. It is concluded that the instrument should not be used for research purposes. Based on the analyses it was not possible to determine if it’s necessary to distinguish between emotional and cognitive components of self-esteem. It requires more analysis, based on more reliable instruments in the future. / Syftet med studien var att utvärdera mätinstrumentet Revised Janis and Field Scale med hjälp av psykometriska analyser baserat på raschmodellen. Raschmodellen är en mätmodell som används inom olika discipliner vid utveckling och granskning av mätinstrument. Därutöver genomfördes här även en kvantitativ innehållsanalys. När de två analyserna var genomförda granskades problematiska frågor, där ett tolkningsperspektiv anlades för att försöka förklara varför vissa frågor inte verkade fungera som avsett. Avsikten med studien var även att undersöka om emotionella och kognitiva beståndsdelar bör hanteras som separata variabler. Datainsamlingen ägde rum vid Karlstads universitet under april månad 2014. Totalt deltog 225 respondenter i undersökningen, 140 kvinnor respektive 85 män. Baserat på raschanalysen verkar inte instrumentet mäta självkänsla på ett godtagbart sätt. Därutöver finns problem med de ämnen som frågorna behandlar och hur frågorna samt svarsalternativen är formulerade. Bedömningen gjordes baserat på analyserna att instrumentet inte bör användas i vetenskapliga sammanhang. Avslutningsvis var det inte möjligt att bekräfta om det är nödvändigt att särskilja mellan emotionella och kognitiva beståndsdelar ur självkänslan utifrån de analyser som genomförts här. Det krävs att fler analyser genomförs i framtiden och att dessa bygger på mer stabila mätinstrument för att uppnå det syftet. / Self-esteem, The Self, Revised Janis and Field Scale, Rasch analysis

The estimation of evapotranspiration (ET), a key process within the Earth's surface water and energy balance, remains an important challenge for a wide range of disciplines such as surface hydrology, irrigation management and meteorology. However, notwithstanding the considerable progress recently made in our understanding of the physical and biological processes governing ET, the accurate quantification of ET is very tricky to achieve, even at a limited spatial scale. In this study, we combine field measurements with numerical experiments to tackle issues related to the quantification of ET and the associated uncertainties for a maize cropped field using two different approaches, i.e. the agro-hydrological modelling and the soil water balance approach. For the agro-hydrological modelling, we mainly focus on the estimation of field-scale soil water content and on the identification of root water uptake parameters. With regard to the field-scale soil water content, we put forward that the within-field variability is large and that the maize crop plays a non-negligible role in the development of the soil water content patterns both at the field and at the maize row scale. For deriving root water uptake parameters (RWUP), we develop and test two different approaches, i.e. the simplified soil water balance and the inverse modelling approach. Using numerical experiments, we show that the simplified soil water balance approach produces quite accurate RWUP. On the other hand, the inverse modelling approach is only successful for some soils and for some conditions due to instability and nonuniqueness issues. For the soil water balance approach, we show that the accuracy of the local ET estimate is strongly dependent on the estimation method used to derive the bottom fluxes and that the use of pedotransfer functions is of little interest. For field-scale ET estimates, we show that the variability of ET is large both at the field scale (due to the variable crop growth) and at the maize row scale (due to the maize row layout). To produce accurate field-scale ET estimates, we suggest to scale up maize row scale ET estimates using the concept of temporal stability or using a covariant such as the Leaf Area Index. The results of our study suggest that the estimation of water fluxes or associated state variables for a row cropped field requires a two-step upscaling strategy, from the local scale to the row, then from the row to the field scale.

This thesis is focused around improving soil moisture estimates of spatial variability and mean at the field scale, which are useful for many different applications. The objectives were: (1) examine soil moisture spatial patterns and variability within field scale, and (2) compare field-scale soil moisture determination methods. An observational study was conducted, in which soil moisture was monitored over a 500 m by 500 m area during two and a half growing seasons at a prairie pasture in central Saskatchewan. Analysis of the spatial patterns of root-zone soil moisture revealed two distinct spatial patterns representing wet (spring) and dry (fall) periods. The relationship between spatial variability and mean soil moisture was found to follow an unusual concave trend, where variability was smallest at mid-range moisture contents. These spatial variability characteristics are a result of differences in participation level. Some locations were non-participating having only small moisture changes over the growing season, while others were dynamic having large changes. At the pasture site, these participation differences are a result of high soil heterogeneity, which may be characteristic of Solonetzic soils. In the second part of this thesis, methods to determine mean field-scale root-zone soil moisture were evaluated. The cosmic-ray neutron probe has the most potential for providing field-scale measurements. However, these measurements are only representative of moisture in the top 20 cm of soil, and need to be scaled up in order to represent the entire root-zone (0–110 cm). The three scaling methods applied to obtain lower root-zone soil moisture were: (1) a single time stable location, (2) representative landscape unit, where a single monitoring profile for each vegetation type was used, and (3) modeling by exponential filter. The representative landscape unit approach estimated soil moisture changes well, but not volumetric water content. The time stability method performed the best, followed by the exponential filter. However, the exponential filter has more potential, as the time stability method is difficult to apply to other field sites; particularly those without existing soil moisture instrumentation, due to its calibration requirements. The findings of this thesis make a contribution to the large body of existing literature on soil moisture variability and scaling. Suggestions for future research are provided.

With the depletion of the existing reservoirs and the decline in oil discoveries during the last few decades, enhanced oil recovery (EOR) methods have gained a lot of attention. Among the various improved recovery methods, waterflooding is by far the most widely used. However, the presence of reservoir heterogeneity such as high permeability streaks often leads to premature breakthrough and poor sweep resulting in reduced oil recovery. This underscores the need for a prudent reservoir management, in terms of optimal production and injection rates, to maximize recovery. The increasing deployment of smart well completions and i-field has inspired many researchers to develop algorithms to optimize the production/injection rates along intervals of smart wells. However, the application of rate control for other EOR methods has been relatively few. This research aims to extend previous streamline-based rate optimization workflow to polymer flooding and CO2 flooding. The objective of the approach is to maximize sweep efficiency and minimize recycling of injected fluid (polymer/CO2) by delaying its breakthrough. This is achieved by equalizing the front arrival time at the producers using streamline time-of-flight. Arrival time is rescaled to allow for optimization after breakthrough of injected fluid. Additionally, we propose an accelerated production strategy to increase NPV over sweep efficiency maximization case. The optimization is performed under operational and facility constraints using a sequential quadratic programming approach. The geological uncertainty has been accounted via a stochastic optimization framework based on the combination of the expected value and variance of a performance measure from multiple realizations. Synthetic and field examples are used extensively to demonstrate the practical feasibility and robustness of our approach for application to EOR processes.

No description available.

Syftet med denna uppsats var att undersöka sociometerteorins sociologiska relevans, förenlighet med flerdimensionella och hierarkiska modeller av självbild samt mätinstrumentet Revised Janis and Field Scales mätegenskaper. En enkät administrerades till 225 studenter vid Karlstads universitet, varav 140 respondenter var kvinnor och 85 var män. Resultatet visar att principiell komponentanalys i huvudsak replikerar valideringsstudien från 1984 medan Raschanalys visar att mätinstrumentet har stora och allvarliga problem och behöver revideras innan användning eller kasseras. Vidare är den modell över självbilden som mätinstrumentet är avsett att fånga föråldrad och inaktuell. Resultatet visar även att sociometerteorin kan relateras till symbolisk interaktionism och därmed har en sociologisk relevans men att förenligheten med modeller över självbilden är begränsad till huruvida teorin kan anses beskriva mekanismen bakom den sociala självbilden. Diskussionen avhandlar självkänslans självuppfyllande profetia, att självhjälpsindustrin, media och allmänhet etiketterar företeelser som och tillskriver begreppet betydelse och relevans varpå det beforskas vidare trots att forskningsfältet verkar befinna sig i ett degenerativt tillstånd. Vidare diskuteras att självkänsla och självbild ej är utbytbara begrepp eftersom det senare begreppet har prediktiv validitet (dvs. har visats förutsäga andra utfall). Slutligen ges ett förslag att antingen rikta fokus mot att studera självmedkänsla, socialt stöd, socialt kapital, självbild och subjektivt välmående istället för det för närvarande fruktlösa självkänslabegreppet, eller att utveckla begreppet teoretiskt innan fler kvantitativa studier utförs. Ytterligare slutsatser och implikationer av uppsatsen diskuteras. / The purpose of this thesis was to investigate the sociometer theory’s sociological relevance, compatibility with multidimensional and hierarchical models of the self-concept and the measurement instrument Revised Janis and Field Scales measurement properties. A questionnaire was administered to 225 students at Karlstad University, of whom 140 respondents were female and 85 were male. The results shows that the principal components analysis in general replicates the validation study from 1984 while Rasch analysis demonstrates that the measurement instrument have major and severe problems and needs to be revised before use or discarded. Furthermore, the model of self-concept that the measurement instrument is intended to capture is outdated and obsolete. The results also shows that the sociometer theory can be related to symbolic interactionism and thus have a sociological relevance but that the compatibility with models of the self-concept is limited to whether the theory can be regarded as describing the mechanism behind the social self-concept. The discussion treats a self-fulfilling prophecy of self-esteem, that the self-help industry, media and public label phenomena as and ascribes the concept meaning and relevance whereon it is further researched despite that the research field seems to be in a degenerative state. Furthermore, self-esteem and self-concept are not interchangeable concepts since the latter concept has predictive validity (i.e. has been shown to predict other outcomes). Finally, a proposition is made to either direct focus at researching self-compassion, social support, social capital, self-concept and subjective well-being instead of the currently fruitless self-esteem concept, or to develop the concept theoretically before conducting more quantitative studies. Further conclusions and implications of the thesis are discussed.

In gas-condensate reservoirs, gas productivity declines due to the increasing accumulation of liquids in the near wellbore region as the bottom-hole pressure declines below the dew point pressure. This phenomenon occurs even in reservoirs containing lean gas-condensate fluid. Various methods were addressed to remediate the productivity decline, for example, fracturing, gas injection, solvent injection and chemical treatment. Among them, gas injection techniques have been used as options to prevent retrograde condensation by vaporizing condensate and/or by enhancing condensate recovery in gas-condensate reservoirs. It is of utmost importance that the behavior of liquid accumulation near the wellbore should be described properly as that provides a better understanding of the productivity decline due to the originated from impaired relative mobility of gas. In this research, several gas injection techniques were assessed by using compositional simulators. The feasibility of different methods such as periodic hot gas injection and gas reinjection using horizontal wells were assessed using different reservoir fluid and injection conditions. It is shown that both the temperature and composition of the injection fluids play a key role in the remediation of productivity and condensate recovery. The combined effect of these parameters were investigated and the resulting impact on gas and condensate production was calculated by numerical simulations in this study. Design parameters pertaining to field development and operations including well configuration and injection/production scheme were also investigated in this study along with the above parameters. Based on the results, guidelines on design issues relating gas injection parameters were suggested. The various simulation cases with different parameters helped with gaining insight into the strategy of gas injection techniques to remediate the gas productivity and condensate recovery. / text

Not many studies are currently devoted to the estimation of soil moisture from space-borne SAR data at the field scale. Superficial soil moisture is indeed generally estimated from SAR images at lower resolutions, rarely reaching the sub-kilometric scale. This is mainly due to the lack of in situ data, such as measured soil moisture and parameters indicative of the soil roughness and vegetation conditions. Moreover, when working at the kilometric scale, some hypothesis assumed while modelling the backscattered SAR signal over a vegetated area are more likely satisfied, whereas when working at higher resolutions such as the field scale, other interactions should be taken into account. Indeed, over a vegetated area the total backscattered SAR signal is usually modelled as the incoherent sum of the vegetation and the soil components, and only in the last years has been added a further contribution provoked from the presence of subsurface scatterers. In the present thesis, the just mentioned contributions are considered and modelled at the field scale for soil moisture estimation purposes. A long term Change Detection method is applied to copolarized Sentinel-1 data, with a focus on taking into account the component of the total backscattering coefficient due to the presence of subsurface scatterers, recently proposed in literature. By exploiting the strong relationships detected over the study area between the copolarized signal and the observed soil moisture, the inversion algorithm for soil moisture retrieval is adapted for considering the cases of dominant subsurface scattering mechanism. Moreover, the proper time scale of detection of subsurface scattering is identified at the field scale, providing helpful information for correcting retrieval algorithms based on SAR data also at lower spatial scales.

Rural areas of most developing nations are dependent on agriculture. In the most remote areas, sometimes referred to as the "less favored areas" (LFAs), the economic importance of agriculture is paramount. An important obstacle to development in these areas is that agriculture is at the mercy of nature, which may not be particularly friendly. These areas have remained remote due to natural shortcomings causing economic development to occur slower than more advantaged areas elsewhere. Cochabamba Department, in central Bolivia, is home to some of these LFAs. Most Cochabamban producers are located in the "high climatic risk" (CIP-WPA) Andean highlands. Farmers in LFAs surrounding Cochabamba city produce (among other things) potatoes for market and home consumption; the potato is the main source of food and income for most residents. Previous studies and anecdotal evidence have shown that Andean potato farmers may plant upwards of 10 varieties of potatoes on small amounts of land (Brush, 92). Because of the low rates of improved crop variety adoption in many LFA's, efforts are needed to understand farmer objectives and needs with respect to variety characteristics. The goal of this study is to determine how exposure to risk factors impacts potato planting decisions through demand for potato variety characteristics. The main source of data for this project is a survey of 145 farm households implemented during the last quarter of 2007 in 3 communities of Cochabamba. These data were used to estimate an econometric model that evaluated the role of household, regional and variety characteristics in farmer decision making. Decisions about planting each variety were modeled with a Tobit framework and estimated by the Heckman method (as suggested by Cameron and Trivedi), with the impact of individual variety characteristics restricted to be the same for each variety. Several hypotheses were confirmed such as the importance of yield, though many results were different than expected. Blight tolerance was found to be negatively correlated with selection, although most farmers report taking some kind of action to decrease damage from blight. Possible explanations for this negative correlation are discussed in this paper, and strategies for overcoming these obstacles are suggested. / Master of Science

The low salinity water injection technique (LSWI) has become one of the important research topics in the oil industry because of its possible advantages for improving oil recovery. Several mechanisms describing the LSWI process have been suggested in the literature; however, there is no consensus on a single main mechanism for the low salinity effect on oil recovery. As a result of the latter, there are few models for LSWI and especially for carbonates due to their heterogeneity and complexity. In this research, we proposed a systematic approach for modeling the LSWI effect on oil recovery from carbonates by proposing six different methods for history matching and three different LSWI models for the UTCHEM simulator, empirical, fundamental, and mechanistic LSWI models. The empirical LSWI model uses contact angle measurements and injected water salinity. The fundamental LSWI model captures the effect of LSWI through the trapping number. In the mechanistic LSWI model, we include the effect of different geochemical reactions through Gibbs free energy. Moreover, field-scale predictions of LSWI were performed and followed by a sensitivity analysis for the most influential design parameters using design of experiment (DoE). The LSWI technique was also optimized using the response surface methodology (RSM) where a response surface was built. Also, we moved a step further by investigating the combined effect of injecting low salinity water and carbon dioxide on oil recovery from carbonates through modeling of the process and numerical simulations using the UTCOMP simulator. The analysis showed that CO₂ is the main controller of the residual oil saturation whereas the low salinity water boosts the oil production rate by increasing the oil relative permeability through wettability alteration towards a more water-wet state. In addition, geochemical modeling of LSWI only and the combined effect of LSWI and CO₂ were performed using both UTCHEM and PHREEQC upon which the geochemical model in UTCHEM was modified and validated against PHREEQC. Based on the geochemical interpretation of the LSWI technique, we believe that wettability alteration is the main contributor to the LSWI effect on oil recovery from carbonates by anhydrite dissolution and surface charge change through pH exceeding the point of zero charge. / text