892 research outputs found
Growth, Development and Land-Use in a Simple Agrarian Economy with Endogeneous Population
The paper analyses the relation between demographic transformation, agricultural transformation and land-use pressure within a simple agrarian economy where population is treated both as a cause and consequence of economic changes. In this Malthusian-type of economy, population growth and food production are interrelated through two production activities. First, agricultural land and labour are tied up in production of agricultural products determining the current flow of consumption. Secondly, labour is used for converting the natural resource base in the form of wilderness, land into agricultural land. It is demonstrated that the economy can run into a poverty trap equilibrium which is the typical Malthusian situation. Alternatively, the equilibrium can be of a high income per capita type. Increasing returns to scale in food production together with an increasing amount of agricultural land, are the crucial factors behind this outcome. As increasing return to scale can be interpreted as if induced innovations take place, and can be seen in light of the presence of Boserup growth mechanisms.
EXPLOITING A LOCAL COMMON: EGOISTIC VS. ALTRUISTIC BEHAVIOR
The paper analyzes the exploitation of a local common where the behavior is steered by altruism rooted in social norms. The analysis is illustrated by using the Gordon-Schäfer model of a fishery. We start by reviewing the standard results when all exploiters are purely egoists; i.e., when own utility depends only on own profit. Under the assumption of identical harvesting efficiency for all owners, we then introduce social norms and find the consequences for the resource utilization and welfare under various degrees of altruism. It is demonstrated that more altruism generally leads to less harvesting effort, less economic overexploitation of the resource stock, and increased resource rent. In a next step, we open up for differences in harvesting technology. It is shown that a high degree of altruism, in addition to a large efficiency gap among the owners, restricts the possibility of an exploitation scheme where all owners participate in the harvesting activity. The possibility of a two-channel efficiency improvement as a result of more altruism is also demonstrated.Resource /Energy Economics and Policy,
A Pore-Scale Study on Cyclic Flows in Porous Underground Hydrogen Storage
A solution for energy storage is needed to balance supply and demand in future energy markets with an increased share of fluctuating renewable wind and solar energy. A key enabler is large-scale, seasonal energy storage, where porous underground formations are suitable storage solutions. An experimental pore-scale study was performed with the objective to investigate hydrogen flow, gas saturations, residual trapping and contact angles in porous media. Hydrogen injections were performed on a water saturated two- dimensional micromodel with pore network based on a natural sandstone relevant for underground hydrogen storage in an aquifer. The effect of capillary number on primary drainage and cyclic hydrogen injection was studied with a pore pressure of 40 bar and room temperature. An image segmentation algorithm was developed to extract gas sat- uration from microscope images of the pore space. A sensitivity analysis showed that the image segmentation algorithm had on average a relative uncertainty of 12%, pre- dominantly caused by water accumulations and uneven light source distribution. During primary drainage the hydrogen saturation increased for increasing capillary numbers. During imbibition the hydrogen saturation decreased until it stabilised at the residual gas saturation, where hydrogen was disconnected from the main flow, immobile and unable to recover. Static contact angles for primary drainage and imbibition varied between 19 to 71°. Local gas displacement through the field of view was observed during drainage and imbibition, resulting in fluctuating hydrogen saturation despite an expected increase for drainage and decrease for imbibition. Experiments showed that gas recovery should increase for higher capillary number, but a lower recovery was observed for the highest capillary number caused by local displacement through the field of view. Cyclic injections were performed at different capillary numbers and the development in hydrogen saturation was studied. Local gas displacements in and out of the field of view affected the end-point hydrogen saturation for each cycle. The end-point hydrogen satura- tion showed hysteresis where both gas development and end-points varied between cycles and repeated injections with equal capillary numbers. The gas saturation dependency on capillary number was weaker when gas was injected over several cycles. The relationship between increased gas saturation with increased capillary number was weaker for cyclic injections compared with primary drainage. Hydrogen loss during cyclic injection was studied by identifying the overlapping hydrogen distribution during drainage and imbibition. Trapped gas relative to initial gas satura- tion after drainage decreased with increasing capillary number. The results indicated increasing trapped gas with increasing cycles, but no clear trend was observed.Masteroppgave i energiENERGI399
Observations from the Hydrolysis of the Green Sea Urchin (Strongylocentrotus droebachiensis)
There is a large amount of coproduct generated by the sea urchin fisheries around the world as well as a growing interest in removing large quantities of undersize and low value sea urchins from barren areas in the northern Atlantic and Pacific coasts as well as other areas around the world. The authors believe there is scope to develop a hydrolysate product from this and this study gives preliminary observations on the characteristics of hydrolysate from the sea urchin Strongylocentrotus droebachiensis. The biochemical composition for S. droebachiensis is moisture 64.1%, protein 3.4%, oil 0.9%, and ash 29.8%. Amino acid composition, molecular weight distribution, lipid-class, and fatty acid composition are also presented. The authors suggest a sensory-panel mapping be undertaken on future sea urchin hydrolysates. Possible uses for the hydrolysate are unclear at this stage but the combination of amino acids and the relatively high levels of glycine, aspartic acid, and glutamic acid should be further investigated.Observations from the Hydrolysis of the Green Sea Urchin (Strongylocentrotus droebachiensis)publishedVersio
Institutional Work in a Palliative Unit: “There is Less Time for Patient Contact”
The encounter between divergent institutional logics may be challenging for
nurses, since they must balance different expectations in their daily
institutional work. These challenges increase when new reforms are
introduced. Our research question is: How do actors linked to a palliative care
unit experience the consequences of the Coordination reform in their daily
performance of care work? Our study is based on a qualitative study in a
palliative care unit in a nursing home where we interviewed patients, their
relatives, and nurses/department leaders. Our findings show that by
downgrading the professional logic because of the Coordination reform, the
focus is on efficiency and budget instead of proper healthcare. This is not
satisfactory for any of the actors in our study. We contribute to the research
on the reforming of the healthcare sector by focusing on how different actors
experienced day-to-day activities in a context where different institutional
logics were involved
An assessment of non-standardized tests of mathematical competence for Norwegian secondary school using Rasch analysis
International audienceDo non-standardized, publisher-provided tests for lower secondary school provide valid and reliable measures of mathematical competence? We analysed a sample of items pooled from tests accompanying three different Norwegian textbooks using Rasch analysis. The pooled sample of items was found to be sufficiently unidimensional for measuring function competence, with four strands of sub-competencies in accordance with theory. The competence associated with an increasing difficulty of items could be qualitatively characterised by shifts from a) identifying through constructing to reasoning about representations, b) using visual to using algebraic representations, and c) local to global interpretations of functions. While the individual tests differed substantially in the distribution of items across strands of mathematical competence, minor adjustments to the combined instrument were sufficient for providing a valid and reliable measure of mathematical competence
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