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Sea-level variability and change along the Norwegian coast between 2003 and 2018 from satellite altimetry, tide gauges, and hydrography
No full textSea-level variations in coastal areas can differ significantly from those in the nearby open ocean. Monitoring coastal sea-level variations is therefore crucial to understand how climate variability can affect the densely populated coastal regions of the globe. In this paper, we study the sea-level variability along the coast of Norway by means of in situ records, satellite altimetry data, and a network of eight hydrographic stations over a period spanning 16 years (from 2003 to 2018). At first, we evaluate the performance of the ALES-reprocessed coastal altimetry dataset (1 Hz posting rate) by comparing it with the sea-level anomaly from tide gauges over a range of timescales, which include the long-term trend, the annual cycle, and the detrended and deseasoned sea-level anomaly. We find that coastal altimetry and conventional altimetry products perform similarly along the Norwegian coast. However, the agreement with tide gauges in terms of trends is on average 6 % better when we use the ALES coastal altimetry data. We later assess the steric contribution to the sea level along the Norwegian coast. While longer time series are necessary to evaluate the steric contribution to the sea-level trends, we find that the sea-level annual cycle is more affected by variations in temperature than in salinity and that both temperature and salinity give a comparable contribution to the detrended and deseasoned sea-level variability along the entire Norwegian coast. A conclusion from our study is that coastal regions poorly covered by tide gauges can benefit from our satellite-based approach to study and monitor sea-level change and variability
Derivative-free trust region optimization for robust well control under geological uncertainty
No full textA Derivative-Free Trust-Region (DFTR) algorithm is proposed to solve the robust well control optimization problem under geological uncertainty. Derivative-Free (DF) methods are often a practical alternative when gradients are not available or are unreliable due to cost function discontinuities, e.g., caused by enforcement of simulation-based constraints. However, the effectiveness of DF methods for solving realistic cases is heavily dependent on an efficient sampling strategy since cost function calculations often involve time-consuming reservoir simulations. The DFTR algorithm samples the cost function space around an incumbent solution and builds a quadratic polynomial model, valid within a bounded region (the trust-region). A minimization of the quadratic model guides the method in its search for descent. Because of the curvature information provided by the model-based routine, the trust-region approach is able to conduct a more efficient search compared to other sampling methods, e.g., direct-search approaches. DFTR is implemented within FieldOpt, an open-source framework for field development optimization, and is tested in the Olympus benchmark against two other types of methods commonly applied to production optimization: a direct-search (Asynchronous Parallel Pattern Search) and a population-based (Particle Swarm Optimization). Current results show that DFTR has improved performance compared to the model-free approaches. In particular, the method presented improved convergence, being capable to reach solutions with higher NPV requiring comparatively fewer iterations. This feature can be particularly attractive for practitioners who seek ways to improve production strategies while using an ensemble of full-fledged models, where good convergence properties are even more relevant
Rheological properties of Al2O3–CaO–SiO2 slags
No full textThe Al2O3–CaO–SiO2 ternary is a basic oxide system relevant for the Pedersen alumina production process and for aluminothermic silicon production with low environmental impact using secondary aluminium and silica raw materials. Rheological property is one of the most important properties for the above applications. A phenomenological viscosity model, inspired by the Calphad technique, has been proposed for the description of the rheological properties covering from homogenous liquid to heterogenous partial solidified Al2O3–CaO–SiO2 slags. The model has been developed by modification of the well-known Vogel-Fulcher-Tammann (VFT) formalism. Based on the phenomenological viscosity model, the effective diffusivity of slag can be evaluated. The relationships between cooling temperature rate, incubation time of solid precipitates as well as transition temperature have then been estimated. The model calculated the isothermal time-temperature-transformation (TTT) and the non-isothermal continuous-cooling-transformation (CCT) curves of CaAl2O4 and anorthite phases are in good agreement with the experimental observations
Frafall fra anoreksibehandling – en systematisk litteraturgjennomgang og kliniske implikasjoner
No full textBakgrunn: Opptil halvparten av pasientene som starter i behandling for anoreksi fullfører ikke, og forskning viser at de negative konsekvensene kan være store. Målsetning: Målet med denne systematiske litteraturgjennomgangen er å identifisere, systematisere og sammenfatte studier om frafall fra anoreksibehandling hos pasienter over 16 år. Problemstilling: Hvilke faktorer finner forskningslitteraturen er relatert til frafall fra behandling av anoreksi? Metode: Vi gjennomførte et systematisk litteratursøk i de to indeksdatabasene Web of Science Core Collection (Web of Science) og PsycINFO (OVID). Resultater: 18 studier ble inkludert, hvorav 17 av disse var kvantitative og èn var kvalitativ. Flertallet var kohortstudier som sammenlignet karakteristikker ved behandlingsstart hos pasienter som falt fra behandling med øvrige pasienter. For de fleste faktorene som ble undersøkt viste flertallet av studiene motstridende sammenhenger med frafall. Bare faktorer som handlet om terapiprosessen eller pasientenes egen opplevelse ga ikke motstridende funn, men det var bare henholdsvis en og to studier som undersøkte hver av disse. Konklusjon: Oppsummert finner vi ingen faktorer som gjennomgående kan predikere frafall fra anoreksibehandling. Resultatene tyder på at pasientenes opplevelse av behandling og god tidlig allianse ser ut til å ha en betydning når det gjelder å forebygge frafall. Videre forskning bør i større grad basere seg på kvalitative studier eller et teoretisk grunnlag om anoreksi når studier gjennomføres. Dette kan være nyttig for å forebygge at faktorer som tilsynelatende ikke henger sammen med frafall får for mye fokus
Risiko- og beskyttelsesfaktorer for omsorgstretthet og sekundærtraumatisering hos psykoterapeuter: en systematisk litteraturstudie
No full textDet er siden 1990-tallet lansert begreper som vikarierende traumatisering, sekundærtraumatisering og omsorgstretthet for å beskrive belastninger personer i hjelpeyrker kan oppleve som følge av sitt yrke. For å undersøke om det eksisterer risiko- eller beskyttelsesfaktorer for at psykoterapeuter kan utvikle sekundærtraumatisering eller omsorgstretthet, ble det gjennomført systematiske litteratursøk i databasene PsycINFO og MEDLINE. Funn fra 50 artikler ble gruppert som enten faktorer ved terapeuten, klienten eller arbeidsmiljøet. Funnene var blandede, men antyder at mening og sosial støtte er beskyttende faktorer, og at empati og administrative oppgaver er risikofaktorer. Det var overraskende at få studier omhandlet selvivaretakelsesstrategier, og korrelasjonene mellom demografiske faktorer som alder, kjønn, utdanning og arbeidserfaring med sekundærtraumatisering eller omsorgstretthet var ikke entydige. Uklar konseptualisering av begrepene, variasjon i benyttede måleverktøy og få longitudinelle eller eksperimentelle studier satte begrensninger for konklusjonsgrunnlaget. Implikasjoner av funnene diskuteres med utgangspunkt i terapeutfaktorer, klientfaktorer og arbeidsforholdet. Retning for videre forskning foreslås
Unique particle beams and energies at CERN applied to radiation testing of electronics
No full textThe radiation environment in space poses unique challenges to the successful operation of electronic components exposed to it. Hence, it is important to test the devices sufficiently before integrating them in space missions. Even better to do so already during their design phase. Likewise, radiation effects on electronics also represent reliability and availability threats for high-energy accelerator applications.
The work performed in the frame of this thesis focuses on the investigation of beams mimicking space and accelerator environments. Radiation such as Ultra-High Energy (UHE) heavy ions and Very High Energy (VHE) electrons play an important role in this context. Since UHE heavy ions are mostly present in the Galactic Cosmic Radiation (GCR) environment and electrons are mostly trapped around planets such as the Earth and Jupiter, their interaction with matter and the resulting radiation effects are of special interest.
Aspects such as nuclear fragmentation and energy deposition mechanisms are relevant when estimating the possible impact on electronic components of radiation present in space or on the ground. Hence, tests have been performed to study this response to the radiation exposure particle types in dedicated test facilities. During such experiments, the dosimetry and beam parameters must be in full control.
UHE heavy ion test campaigns and experiments with VHE electrons at CERN have served as an excellent opportunity to investigate the interaction with matter of various particle species and energies similar to the GCR and electron-rich environments in space, such as around Jupiter. Due to their high penetration depth, one of the advantages of UHE heavy ion beams at CERN is to test without decapsulation. Moreover, these beams offer the opportunity to work with particles of identical Linear Energy Transfer (LET) and energies to the ones in space. That is interesting, because on the contrary it is a well-established standard to perform radiation tests for space applications with low energy heavy ions.
With regards to high-energy electrons, the implications of an exponential increase in Single Event Effects (SEEs) connected to testing at a high instantaneous electron flux [1] and the resulting nuclear electron processes [2] need to be considered. These observations deserve to be characterised and understood, even if they might represent an experimental artefact.
For these reasons, the central research questions in this work are:
- Is testing with particles of the same LET, but different energy compared to the space environment representative enough?
- How can electron beams at CERN be used to test electronics for future space missions, which will be exposed to electron-rich environments? Are there non-linear effects related to high instantaneous intensities of electron fluxes by changing the charge density per pulse?
This work has contributed to the understanding of physical phenomena occurring in electronics caused by radiation present in space and in accelerators environments, such as fusion and nuclear fragmentation processes and energy deposition in different materials and volumes. Ground level experimental work in related particle beams, as well as Monte Carlo simulations tools like FLUKA have served for the investigations presented in this PhD thesis
On the person in personal health responsibility
No full textIn this paper, we start by comparing the two agents, Ann and Bob, who are involved in two car crashes. Whereas Ann crashes her car through no fault of her own, Bob crashes as a result of reckless driving. Unlike Ann, Bob is held criminally responsible, and the insurance company refuses to cover the car’s damages. Nonetheless, Ann and Bob both receive emergency hospital treatment that a third party covers, regardless of any assessment of personal responsibility. What warrants such apparent exceptionalism with respect to personal responsibility in the healthcare context? We turn our attention to an understudied aspect of the debate on personal health responsibility, namely, the conceptualisation of the person in need of emergency hospital treatment. Drawing on the research of Joshua Knobe and Shaun Nichols, we propose that a context-dependent conceptualisation of the person may help explain a reluctance to ascribe responsibility to the individual for negative health outcomes