Fluorite: Illinois state mineral

Ope

Er vi på vei mot et boligkrakk? : en empirisk og komparativ analyse av boligmarkedet i forkant av boligkrakket 1987-1992 og i dag

Boligkrakket 1987-1992 var det største boligkrakket, målt i realpriser, i Norges historie. I denne avhandlingen har vi gjort en empirisk analyse av ulike faktorer som bidro til boligkrakket, og som har bidratt til den kraftige prisstigningen vi har hatt fram til i dag. Til å begynne med har vi gjort rede for definisjoner og teori som blir brukt videre i avhandlingen. Krisemodellen og kriseteorien til Hyman P. Minsky og Charles P. Kindleberger blir så gjort rede for. Modellen og teorien er gode verktøy for å forklare hvordan finansielle krakk og finansielle kriser oppstår. I den empiriske delen av oppgaven tar vi først for oss hvordan boligprisene har utviklet seg fra 1970-tallet og fram til i dag. Videre ser vi på hvordan viktige faktorer har drevet boligprisene til dagens nivå. Faktorene er valgt ut med grunnlag i Dag H. Jacobsen og Bjørn E. Naug sin boligprismodell. I den empiriske analysen gjør vi rede for analyseverktøy som HP-filteret, P/R- og P/Cverdier. Disse verktøyene blir brukt i store deler av analysen for å finne avvik fra trend og avvik fra fundamentale verdier. Analysen er delt opp etter de to tidsperiodene og bygget opp rundt Minskys modell og Kindlebergers teori. Funnene som blir gjort i analysen viser at både P/R- og P/C-verdiene i dag er på et betydelig høyere nivå enn de var forut for boligkrakket. Samtidig er ikke forholdet mellom faktiske og fundamentale P/R-verdier på et like høyt nivå. Vi ser også at utviklingen i forkant av boligkrakket passer særdeles godt inn i krisemodellen og kriseteorien til Minsky og Kindleberger. Videre ser vi i sammenligningen likheter mellom de to periodene. I periodene er det avvik fra fundamentale verdier og trend i boligprisene, og andre faktorer som boligprisveksten avhenger av. Samtidig ser vi en mer illevarslende utvikling i flere viktige faktorer i dag enn i forkant av boligkrakket. Med dette har vi derfor konkludert med at det eksisterer en aktivaboble i dagens boligmarked, og at vi kan få et boligkrakk i fremtiden.nhhma

Review of value and lean in complex product development

Approaches are being developed to improve complex product development from the perspective of value generation. However, the ideas and their relationships are still not fully articulated. We provide a structured literature review, with a primary but not exclusive focus on value ideas relating to lean in complex system product development. A framework organizes the concepts, methods, and their relationships. It clarifies the value delivery mechanism and could help to understand and thus improve value systems. Areas deserving further research attention are identified.We wish to thank the reviewers and editor for their valuable feedback, which helped to substantially improve early ver-sions of this articleThis is the accepted manuscript for a paper published in Systems Engineering Volume 18, Issue 2, pages 192–207, March 2015, DOI: 10.1002/sys.2129

Models and numerical methods for two-phase flow of CO2 in pipes

Key to the transport phase of carbon capture and storage (CCS) is understanding the behavior of liquid or supercritical CO2 in pipelines, and the consequences of cracks and pipe depressurization. It is therefore useful to develop mathematical models and numerical methods for two-phase flow of CO2 in pipes in order to better predict such behavior. Such developed tools can also be useful in fluid structure- interaction models. Key to simulating single or multiphase flows is the formulation of a flow model. Here, the homogeneous equilibrium model (HEM) has been used. Further, for a flow model such as HEM, closure conditions are needed, and in this thesis the Span- Wagner equation of state (EOS) has been used. This EOS is a Helmholtz function fitted to experimental data for CO2 properties, and so it is CO2-specific. When using the finite volume method to simulate fluid flow, a numerical flux func- tion is needed. In this thesis, the advection upstream splitting method (AUSM) family of schemes has been investigated and compared to the first ordered centered (FORCE) scheme in order to evaluate the performance of AUSM-schemes. AUSM+ up has been found to perform satisfactorily for three test cases. Due to the upstream nature of the scheme, it proved more accurate than the FORCE and Lax-Friedrichs schemes for a test case simulating the advection of a CO2 gas fraction in liquid. When compared to the results obtained by SINTEF Energy Research for a shock tube case and a depressurization case, AUSM+ up was found to reproduce all the expected solution features seen for the FORCE solution. For the shock tube case, slight differences in the evaluation of energy, temperature and velocity could be seen. Possible reasons for this could be that the solution is not grid-independent or that the flux splitting nature of AUSM schemes simply causes these variables to be evaluated slightly differently, possibly more accurately, compared to FORCE. When simulating the shock tube and the depressurization cases, the thermodynamic solver had problems evaluating the speed of sound correctly. This did not seem to affect the solution of state variables to a large degree. These problems occurred in regions where the thermodynamic solver evaluated certain cells to be liquid phase, whereas other cells were liquid with a fractional amount of gas. Such problems were not seen for FORCE and this is a drawback for AUSM+ up. A further drawback for AUSM+ up is that it requires parameter tuning, and the solution of the shock tube test case was parameter sensitive in order to obtain the correct solution. Another finding when comparing AUSM+ up and FORCE for the depressurization case was that the former has higher computational times for equal grid sizes. This increased computational cost is however well paid off by its better resolution compared with the FORCE scheme. The implementation of AUSM schemes proved complicated due to the need for parameter tuning, but the scheme performed satisfactorily for all test cases. The implementation of FORCE was comparably straightforward. Thus it could be worth investigating AUSM schemes that do not require parameter-tuning. Future work could also include implementing other flow models where one would avoid regions of oscillating speed of sound. Optimization of the AUSM+ up code is also a possible future task

“The pay is not worth it but it is excellent PD”: Australian teachers’ perspectives on doing large-scale marking

Anecdotally, teachers take up opportunities to mark large-scale assessments because they are told by colleagues that it is \u27good PD\u27. Assertions about the value of marking are passed along with little question. However, research into the benefits of participating as a marker in large-scale marking has not been conducted in the Australian context. This paper reports the results of an online survey of Australian teachers (N=43) about their participation in large-scale marking in order to examine whether the research that has been conducted internationally is likely to be generalisable to Australia. The responses to the survey are described and then compared with four main areas of benefit identified in the literature. It found that Australian teachers\u27 views of large-scale marking are similar to those of their international colleagues, and that teachers report a broad and varied range of benefits. Additionally, it was found that survey respondents identified a range of costs and drawbacks of marking that have not been reported in the literature, but that in spite of these the respondents would still recommend the experience to other teachers

The viability of simulated large-scale marking as professional development for preservice teachers

Judging the quality of student work is a core skill of a proficient teacher. This professional competency is often utilised by organisations that run large-scale marking operations when they recruit teachers as markers. These organisations and the teachers themselves often claim that large-scale marking is valuable professional development. This research aimed to determine whether professional learning outcomes similar to those reported by experienced teachers can be achieved for preservice teachers through participation in a live simulation of a large-scale marking operation. The research was conducted in three phases: an online survey of Australian teachers to establish that reports of benefit from other contexts are generalisable to Australia; a simulated marking experience for 22 preservice teachers at Edith Cowan University; and finally, follow-up interviews with seven of those participants after their first semester of teaching to establish to what extent their perceptions of the marking experience had changed. The research collected qualitative data through interviews and an online survey. Additionally, there was quantitative data collected during the marking simulation in the form of scores, and these were analysed with simple descriptive statistics, linear correlation, and a many-facet Rasch analysis to examine the severity or harshness of the novice markers. The analysis of the scoring was not done to examine the skill of the markers, but rather to evaluate the quality of the marker training in the simulation. It was found that the markers scored reliably, and so it was inferred that the simulation training was probably similar to authentic marker training. The research found that the benefits described by the simulation participants largely centred on increased confidence in marking and gaining experience of marking. These main benefits and several minor ones broadly aligned with benefits published in the literature. The perception of value in the simulated marking experience did not diminish after the preservice teachers had begun their work as teachers, and several reported using processes or concepts from the experience in their professional work. The research concluded that simulated marking sessions have applications in preservice teacher education. There were strong recommendations from participants that a practical marking experience such as the simulation become a mandatory part of initial teacher education courses

Floating Production in general, and a Parameter Study of a Flexible Riser for the Goliat FPSO in specific

A floating production system (FPS) consists of a floating structure, a mooring system, anchors and risers. Such systems enable production for larger ocean depths. Risers are vertical pipes used for transportation of production fluids between the seabed and the production unit. FPS and its components are presented and discussed in this thesis. Using an FPS entails certain challenges; risers, for instance, need other properties than for fixed structures, as they will hang from the floating unit, and must be able to absorb vessel movement. FPS is also a good option in remote areas with little infrastructure, as for the Barents Sea. When operating in arctic areas, additional challenges connected to the environment must be considered. In this thesis, challenges such as darkness, low temperatures and ice issues are identified and categorised. The Goliat field is the first operating field to start production of oil in arctic areas. At this field, a circular Floating Production, Storage and Offloading (FPSO) unit operates, and it is equipped with flexible risers. A model of this circular FPSO is modeled as a uniform cylinder with a draught of 32.2 metres. A 644 metre long steep wave flexible riser is modelled to span between the platform and the seabed in the 400 metre deep water. A parameter study is performed to investigate the influence on the riser response. The analyses are performed in RILFEX, a software utilized for static and dynamic analysis of slender marine structures. The varying parameters are the current profile, the riser diameter and the drag coefficient. An analysis for varying horizontal offset of the platform, relative to the riser's touch down point (TDP) on the seabed, is also performed. The platform position that results in lowest effective tension in the riser, is 250 metres away from TDP. For this case, the riser also has lowest response amplitude. Analyses are performed for three current profiles, uniform current, linear current and no current. It is found that by increasing the current, curvature near the riser top decreases. The case where linear current is applied, the largest tension in the riser occurs. Current variation also leads to change in the vertical displacement. For the case with no current, the riser top has a larger displacement in the negative z-direction, compared to the cases when current is applied. The next parameter subject to change is the diameter, and three cases were studied. For increasing diameter, the weight is also increased, and the additional buoyancy due to increased volume, does not even out the added weight. As a consequence, some results might be affected more by the weight change, rather than by the change of diameter. Regarding curvature and tension, the two risers with largest diameter and weight behaves similarly, compared to the smallest riser. The two largest diameters experience larger tension and have less curvature at the hangoff, which corresponds with the additional weight. The last parameter that was studied was the drag coefficient. For variation in diameter and drag, the displacement in vertical direction is only slightly affected near the riser top. As it is the riser properties that are changed, rather than external loading, the vessel motion is not significantly affected. The vertical displacement of the riser is affected more by change of riser properties at positions further from the vessel

Familial Occurrence of Multiple Sclerosis with Thyroid Disease and Systemic Lupus Erythematosus

Multiple sclerosis (MS) has some features which suggest it is an autoimmune disease. Autoimmune diseases frequently occur in families, and patients and families often have more than one type of autoimmune disease. However, there are few reports of MS occurring in patients or families with other autoimmune conditions. It is difficult to make a separate diagnosis of MS in a patient who has a systemic autoimmune disease such as systemic lupus erythematosus (SLE) or Sjogren's syndrome, because these diseases can affect the nervous system directly. However, it is possible to make independent diagnoses of MS and an autoimmune disease confined to another single organ in the same patient, or diagnoses of MS and SLE (or other autoimmune diseases) in different family members. Here we describe clinically definite MS in 2 sisters, one of whom had Graves' disease, and the other of whom had a daughter with SLE and with a high titre of anti-thyroid antibodies. Other female family members over 4 generations had histories of thyroid disease, MS and Addison's disease. Available family members were HLA typed. The MS patients were positive for HLA DR2. All but one of the affected family members were related to the proband on the maternal side, and all of these affected females shared an HLA haplotype. However, this haplotype was also present in unaffected individuals. Thus HLA type alone cannot account for the familial occurrence of these disorders. We conclude that, in this family, MS, like autoimmune thyroid disease and SLE, may be an autoimmune disease developing in genetically predisposed individuals

A comparative study of responses in planktonic food web structure and function in contrasting European coastal waters exposed to experimental nutrient addition

We quantify, compare, and generalize responses of experimental nutrient loadings (LN) on planktonic community structure and function in coastal waters. Data were derived from three mesocosm experiments undertaken in Baltic (BAL), Mediterranean (MED), and Norwegian (NOR) coastal waters. A planktonic model with seven functional compartments and 30-32 different carbon flows fit to all three experiments was used as a framework for flow-rate estimation and comparison. Flows were estimated on the basis of time series of measured biomass, some measured flows, and inverse modeling. Biomass and gross uptake rate of carbon of most groups increased linearly with increasing LN in the nutrient input range of 0-1 µmol N L-1 d-1 at all locations. The fate of the gross primary production (GPP) was similar in all systems. Autotrophic biomass varied by two orders of magnitude among locations, with the lowest biomass and response to nutrient addition in MED waters. The variation of GPP among sites was less than one order of magnitude. Mesozooplankton dominated by doliolids (Tunicata), but not those dominated by copepods, presumably exerted efficient control of the autotrophic biomass, thereby buffering responses of autotrophs to high nutrient input. Among the many factors that can modify the responses of autotrophs to nutrients, the time scale over which the enrichment is made and the precise mode of nutrient enrichment are important. We suggest a general concept that may contribute to a scientific basis for understanding and managing coastal eutrophicatio