Long-life 3-axis satellite attitude sensing, phase 1

The purpose was to investigate the feasibility of new, moderate-cost, high reliability navigation sensors for high-altitude satellites, using stellar sources to obviate the use of gyroscopic devices. The primary investigation focused on the need for developing a star tracker model to replace an old star tracker which is still needed for current probe and satellite programs. One innovative element of the proposed star tracker was the design, development, and testing of technology components related to a phase scrambler plate. The purpose of the phase scrambler plate is to convert the impulse response of the optical system from a point image to a uniformly bright, square, angularly large, in-focus image of the star source. A collimated star source was built and tested. A breadboard star tracker with an 8 x 8 degree field of view was designed and built. It was tested in normal quad-cell mode (without the phase scrambler plate) and with the phase scrambler plate. Although the phase scrambler plate was crudely made, the performance of the star tracker breadboard was greatly improved using the phase scrambler plate, instead of system defocus. If further developed, the phase scrambler plate may be added as a low-cost retroconversion to any objective lens to greatly improve quad-cell or CCD array tracking; applications include star trackers, laser metrology, laser machining optics, and surveying instrumentation

Access to Primary Health Care and Health Outcomes: The Relationships between GP Characteristics and Mortality Rates

This paper analyses the impact of economic conditions and access to primary health care on health outcomes in Norway. Total mortality rates, grouped into four causes of death, were used as proxies for health, and the number of general practitioners (GPs) at the municipality level was used as the proxy for access to primary health care. Dynamic panel data models that allow for time persistence in mortality rates, incorporate municipal fixed effects, and treat both the number and types of GPs in a district as endogenous were estimated using municipality data from 1986 to 2001. We reject the significant relationship between mortality and the number of GPs per capita found in most previous studies. However, there is a significant effect of the composition of GPs, where an increase in the number of fee-for-service GPs reduces mortality rates when compared with GPs employed directly by the municipality.general practitioners (GPs); mortality; morbidity; simultaneity; endogeneity; municipalities; dynamic panel data models

A Low-key Social Insurance Reform - Treatment Effects for Back Pain Patients in Norway

This paper estimates treatment effects for back pain patients using observational data from a low-key social insurance reform in Norway. Using a latent variable model we estimate the average treatment effects (ATE), the average effect of treatment on the treated (TT), and the distribution of treatment effects for outpatient treatment at three different locations. To estimate these parameters and the distribution of treatment effects we use a discrete choice model with unobservables generated by a factor structure model. Distance to nearest hospital (in kilometers) is used as an instrument in estimating the different treatment effects. We find a positive effect of treatment of 6 percentage points on the probability of leaving sickness benefits after allowing for selection effects and full heterogeneity in treatment effects. We also find that there are sound arguments for increasing the outpatient program of treating back pain patients.Discrete Regression and Qualitative Choice Models; Discrete Regressors; Proportions; Project Evaluation; Social Discount Rate; General; Unemployment: Models; Duration; Incidence; and Job Search.

Does variation in GP practice matter for the length of sick leave? A multilevel analysis based on Norwegian GP—patient data

In many countries, the social insurance system is under pressure from an ageing population. An increasing number of people are on sickness benefits and disability pensions in Norway. The general practitioner (GP) is responsible for assessing work capacity and issuing certificates for sick leave based on an evaluation of the patient. Although many studies have analysed certified sickness absence and predictive factors, very few studies focus on the length of sick leave and no studies assess its variation between patients, GPs or geographical areas within a multilevel framework. This study aims to analyse factors explaining the variation in the length of certified sick leave and to disentangle patients, GPs and municipality sources of variation in sickness durations for the whole population of Norwegian workers in 2003. This study uses a unique Norwegian administrative data set that merges data from different sources. The study uses amatched patient—GP data set, and employs amultilevel random intercept model to separate out patient, GP and municipality-level explained and unexplained parts of the variation in the certified sickness durations. We find that all observed patient and GP characteristics are significantly associated with the length of sick leaves (LSL). However, 98% of the variation in the LSL is attributed to patient factors rather than influenced by variations in GP practice or differences in municipality-level characteristics. Medical diagnosis is an important observed factor explaining certified sickness durations. Low variations across GPs may imply that the gatekeeping role of Norwegian GPs is weak compared with their advocate role.general practitioners (GPs); length of sick leave; multilevel regression models; matched GP—patient data

Naturfagsamarbeid på tvers av tre skoleslag : barneskole, ungdomsskole og videregående skole

Masteroppgave i profesjonsretta naturfag - Nord universitet, 201

Health Status, Life Expectancy and Early Claiming of Pension

Prior to 2011, individual life expectancy played no role in the Norwegian old-age pension system. However, after the 2011 reform, life expectancy became a central factor for early pension take-up. Asymmetric information is crucial in most insurance markets, including the new pension system, where employees can flexible claim a public pension from the age of 62. Individuals who expect to live longer than the average for their birth cohort can maximize their pension wealth by deferring pension claiming, while those with a shorter life expectancy should draw their pension as early as possible. This raises concerns that adverse selection may pose a risk to the sustainability of the new pension system. To investigate this issue, we use chronic disease as a proxy for life expectancy and examine its relationship with employment and pension decisions. Our findings show that individuals with a chronic health condition are more likely to draw a pension and continue working when they reach 62 years of age compared to those without a chronic health condition. This suggests potential adverse selection issues in the pension system, although our results suggest small effects after adjusting for unobservables.publishedVersio

Sysselsettingseffekter av pensjonsreformen - avhenger de av helsetilstand.

Denne analysen undersøker om dårlig helse hindrer individer fra å kunne øke sitt arbeidstilbud slik pensjonsreformen la opp til. Vi analyserer effekten av reformen på arbeidsdeltakelse og avtalte timer i arbeid for mennesker med ulik helsetilstand før reformen. Utvalget består av individer som er i arbeid måneden før de fyller 59 år. Våre viktigste funn er at effekten synes å være uavhengig av helsetilstand, og det gjelder for begge kjønn: De med dårligst helse øker arbeidstilbudet minst like mye som de med best helse. Dette gjelder enten vi måler helsetilstand basert på antall fastlegebesøk eller på type helseproblem.publishedVersio

Gel Pills for Downhole Pressure Control during Oil and Gas Well Drilling

During drilling of petroleum or geothermal wells, unforeseen circumstances occasionally happen that require suspension of the operation. When the drilling fluid is left in a static condition, solid material like barite may settle out of the fluid. Consequently, the induced hydrostatic pressure that the fluid exerts onto the formation will be reduced, possibly leading to collapse of the borehole or influx of liquid or gas. A possible mitigation action is placement of a gel pill. This gel pill should preferably be able to let settled barite rest on top of it and still transmit the hydrostatic pressure to the well bottom. A bentonite-based gel pill is developed, preventing flow of higher density drilling fluid placed above it to bypass the gel pill. Its rheological behavior was characterized prior to functional testing. The designed gel pill develops sufficient gel structure to accommodate the settled barite. The performance of the gel was tested at vertical and 40° inclination from vertical. Both conventional settling and the Boycott effect were observed. The gel pill provided its intended functionality while barite was settling out of the drilling fluid on top of this gel pill. The barite was then resting on top of the gel pill. It is demonstrated that a purely viscous pill should not be used for separating a high density fluid from a lighter fluid underneath. However, a bentonite or laponite gel pill can be placed into a well for temporary prevention of such intermixing.publishedVersio

Risk assessment of “other substances” - L-cysteine and L-cystine. Opinion of the Panel on Nutrition, Dietetic Products, Novel Food and Allergy of the Norwegian Scientific Committee for Food Safety

publishedVersio