Investigation of hydrogen embrittlement behavior in X65 pipeline steel under different hydrogen charging conditions

The hydrogen effect on a X65 carbon steel was investigated by tensile tests under both ex-situ and in-situ hydrogen charging conditions. The fractured samples were characterized and compared using a combination of scanning electron microscopy, electron backscattering diffraction, and energy-dispersive spectroscopy. The work highlights that the in-situ hydrogen charging is a necessity for investigation of hydrogen detrimental effects on the studied material, where a pronounced reduction in fracture elongation, the evolution of secondary cracks on gauge surface, and the corresponding brittle fractography were thoroughly characterized after in-situ testing. The reason resides in the rapid hydrogen outgassing effect, which was proved by Fick's law-based diffusion models. Then the interrupted tensile tests were performed to track the crack initiation and propagation behavior. The results show that the majority of cracks initiated at the interfaces of MnS and Al2O3 inclusions or between inclusions and matrix, which attributes to the elevated stress concentration around the inclusions. Moreover, the cracks were found to propagate along the {110} slip planes.publishedVersio

Development of UHPLC-MS/MS methods to quantify 25 antihypertensive drugs in serum in a cohort of patients treated for hypertension

We developed three ultra-high pressure liquid chromatography coupled to mass spectrometry detection (UHPLC-MS/MS) methods to quantify 25 antihypertensive drugs in serum samples. Patient-reported drug lists were collected, and drug concentrations were analysed in samples from 547 patients, half with uncontrolled hypertension, and all treated with ≥ 2 antihypertensive drugs. For sample preparation, serum was mixed with deuterated internal standards and acetonitrile and precipitated. Aliquots of the supernatant were injected on UHPLC-MSMS with a C18 reversed phase column. The mobile phase was 0.1 % HCOOH (formic acid) in water and 0.1 % HCOOH in acetonitrile (except in methanol for spironolactone/canrenone) at a flow rate of 0.4 mL/min. The calibrators and internal controls were prepared in Autonorm™. The calibration ranges were wide, and the models were linear or quadratic with squared correlation coefficients ≥ 0.97. The limits of detection and quantification, specificity, carry-over, and matrix effects were acceptable. The accuracy of the internal controls was in the range 85–121 %, and the intermediate precision for all drugs was 4–28 %. The patient-reported antihypertensive drug use and the detected serum drug concentrations were in accordance with that most frequently prescribed nationally. The percent non-detectable level was 5–10 % for bendroflumethiazide, doxazosin, nifedipine, and ramipril. Often the drug dose chosen was lower than the recommended maximum daily dose. We report the maximum (Cmax) and minimum (Cmin) drug concentrations after drug intake. The inter-individual pharmacokinetic variability at Cmin was 18-fold for hydrochlorothiazide, 22-fold for losartan carboxyl acid, 26-fold for amlodipine, 44-fold for candesartan, and 50-fold for valsartan. Our methods are suitable for measuring antihypertensive drugs in patient serum for therapy control.publishedVersio

Detection of Nonadherence to Antihypertensive Treatment by Measurements of Serum Drug Concentrations

Nonadherence to drugs is a challenge in hypertension treatment. We aimed to assess the prevalence of nonadherence by serum drug concentrations compared with 2 indirect methods and relate to the prescribed drug regimens in a nationwide multicenter study. Five hundred fifty patients with hypertension using ≥2 antihypertensive agents participated. We measured concentrations of 23 antihypertensive drugs using ultra high performance liquid chromatography tandem mass-spectrometry and compared with patients’ self-reports and investigators’ assessment based on structured interview. We identified 40 nonadherent patients (7.3%) using serum drug concentrations. They had higher office diastolic blood pressure (90 versus 83 mm Hg, P<0.01) and daytime diastolic blood pressure (85 versus 80 mm Hg, P<0.01) though systolic blood pressures did not differ significantly. They had more prescribed daily antihypertensive pills (2.5 versus 2.1 pills, P<0.01) and total daily pills (5.5 versus 4.4 pills, P=0.03). Prescription of fixed-dose combination pills were lower among the nonadherent patients identified by serum concentrations (45.0 versus 67.1%, P<0.01). Fifty-three patients self-reported nonadherence, while the investigators suspected 69 nonadherent patients. These groups showed no or few differences in drug regimens, respectively. In summary, we detected 7.3% prevalence of nonadherence by serum drug measurements in patients using ≥2 antihypertensive agents in a nationwide study; they had higher office and ambulatory diastolic blood pressures, higher number of prescribed daily pills, more daily antihypertensive pills, and less frequent prescriptions of fixed-dose combination pills. Indirect methods showed poor overlap with serum drugs concentrations and no or minimal medication differences. Thus, serum measurements of drugs were useful in detection and characterization of nonadherence to antihypertensive treatment.acceptedVersio

Kunnskapsdeling mellom generasjoner : en casestudie av eldre kunnskapsarbeidere

Formålet med studien er å få økt innsikt og forståelse for kunnskapsdeling mellom generasjoner i en kunnskapsbedrift, med spesielt fokus på eldre kunnskapsarbeidere. Vi har studert hvordan yngre og eldre opplever kunnskapsdeling, samt hva som påvirker eldre kunnskapsarbeidere til å dele kunnskap. Tidligere forskning på kunnskapsdeling fokuserer i liten grad på kunnskapsbedrifter, samt hvorvidt alder spiller en rolle. Utredningen er en kvalitativ casestudie med utgangspunkt i en mellomstor bedrift innen norsk romindustri. Vi finner at både yngre og eldre kunnskapsarbeidere har et positivt syn på kunnskapsdeling, og samtlige opplever kunnskapsdeling som viktig. Vår studie indikerer at eldre kunnskapsarbeidere har et mer langsiktig perspektiv på kunnskapsdeling enn yngre kunnskapsarbeidere. Tidligere forskning har i stor grad fokusert på motivasjon, men vår studie indikerer at eldre kunnskapsarbeidere allerede innehar svært høy motivasjon. I tillegg finner vi at seniorene, gjennom utstrakt erfaring innenfor sine felt, har gode evner til å dele kunnskap. Vi finner at mulighet er den begrensede faktoren for eldre kunnskapsarbeidere, og således avgjør graden av kunnskapsdeling som forekommer. Vi finner at eldre kunnskapsarbeidere kan oppleve utfordringer i forbindelse med å overlate ansvar til yngre medarbeidere, og at tydelig avklaring rundt seniors rolle i bedriften er avgjørende for at kunnskapsdeling mellom senior og yngre skal fungere godt. Vi finner at seniorene verdsetter å få slippe det administrative ansvaret som har fulgt med tidligere stillinger og heller få bruke tiden på spennende arbeidsoppgaver innenfor sitt fagfelt. I motsetning til hva tidligere forskning finner, indikerer vår studie at en flat organisasjonsstruktur kan hemme kunnskapsdeling. Vi finner at enkelte seniorer har et ønske om å opprettholde ekspertmakt, samt posisjon, i kunnskapshierarkiet. Det kan ha røtter tilbake til etableringsfasen og skyldes konkurranse- og enermentalitet. Vi finner også at sosiale relasjoner på tvers av avdelinger og generasjoner spiller en vesentlig rolle for hvorvidt kunnskapsdeling fungerer godt

«Clear, simple and concise» – a qualitative investigation of a group of students' attitudes towards and experiences with the 2012 orthography

Master's thesis in Literacy studiesSammendrag I denne kvalitative studien har jeg undersøkt noen videregående elevers holdninger til og erfaringer med den nye rettskrivinga i nynorsk. Studien tar utgangspunkt i at det i 2012 kom en ny rettskrivingsnormal for nynorsk, noe som medførte endringer i blant annet valgfrie former. Tidligere studier viser at elever ofte ikke kjenner til hvilke former de faktisk bruker eller at de ikke kjenner til valgfriheten som generelt finnes i nynorsk. Formålet med denne studien har vært å bygge videre på disse funnene, og belyse problemet med utgangspunkt i 2012-rettskrivinga. Problemstillingen har vært delt der disse fire forskningsspørsmålene har dannet utgangspunktet for analysen av datamaterialet: 1. Hvilke holdninger har elevene til nynorsk?, 2. Hvilke grunner har elevene for valg av former?, 3. Hvordan oppfatter elevene 2012-rettskrivinga? og 4. Hvilke formvalg og feil gjør elevene i tekstene, og hvordan kan disse ses i sammenheng med det informantene sier i intervjuene? Deltakerne har vært fem elever i sitt avgangsår på en videregående skole i Rogaland. Datainnsamlingen har jeg foretatt gjennom halvstrukturert intervju med informantene, i tillegg til at jeg har analysert en elevtekst (skoleoppgave) fra hver informant. Funnene fra intervjuene og elevtekstene har blitt analysert hver for seg, og i sammenheng, for å undersøke formvalg og feilmønstre og hvordan dette stemmer med det elevene selv oppgir. Et av hovedfunnene er at kun tre av de fem informantene har fått med seg at det kom en ny rettskriving i nynorsk i 2012, noe som kan tyde på at implementering av nye normer tar tid. Ifølge informantene har det vært lite fokus på dette i den nynorskundervisninga de har opplevd. Elevene har i utgangspunktet en positiv holdning til nynorsk, men oppfatter målformen som et skoleemne, og ikke noe de bruker til vanlig. Når det gjelder hvilke grunner de gir for valg av former, sier de fleste at de velger former ut fra talemålet eller ut fra et ønske om å skrive konservativ nynorsk. Det at de likevel ikke kjenner spesielt godt til valgfrie former, viser at elevene i praksis har en svært begrenset valgfrihet. Det viser seg dessuten at tilfeldigheter også spiller en rolle i informantenes valg av former. Det at elevene vil skrive konservativt og skille mellom nynorsk og bokmål, kan være en medvirkende årsak til noen feil av typen «overnynorsk». Dessuten forteller noen av informantene at de hører for seg en «indre stemme» når de skriver nynorsk, noe som kan medvirke til dialektfeil. Abstract In this qualitative study, I have investigated some upper secondary students’ attitudes towards and experiences with Norwegian Nynorsk. The point of departure of the study is the new 2012 official orthography for Nynorsk, which removed the hierarchy structure of optional spelling varieties, among other changes. Previous studies have shown that students often are unaware of the optional spelling varieties they use, or that they are unaware of the freedom of choice that exist in Norwegian Nynorsk. The aim of this study has been to elaborate upon these findings in the context of the 2012 official orthography. Four research questions have guided the analysis of the data: 1. Which attitudes do the students have towards Norwegian Nynorsk? 2. What are the students’ reasons for choices of optional spelling varieties? 3. How do the students perceive the 2012 official orthography? and 4. What spelling variety choices and mistakes do the students make in their texts, and what connections can be found between these and what they say in the interviews? The participants have been five students in their last year at an upper secondary school in Rogaland, Norway. I have conducted the data collection through semi-structured interviews with the informants. In addition, a text (school assignment) from each student has been analyzed. The findings from the interviews and from the texts have been analyzed both separately and together, in order to investigate choices of spelling varieties and mistake patterns, and how this relates to what the students report themselves. A main finding is that only three of the five informants are aware that a new official orthography of Norwegian Nynorsk was presented in 2012, which suggests that implementation of the new orthography takes some time. According to the informants, there has been little focus on this in their experiences with Norwegian Nynorsk education. The students appear to have a positive attitude towards Nynorsk. However, they regard it as a school subject and not as belonging to their everyday life. When asked about their reasons for their spelling choices, most of the informants say that they choose varieties belonging to their dialect, or that they want to write a conservative Nynorsk. The fact that most of them are mostly unaware of the optional spelling varieties shows that the students in practice has a limited freedom of choice. It is also apparent that coincidence is a significant factor in the students’ choices. The finding that the students wish to write conservatively and separate Norwegian Nynorsk and Norwegian Bokmål may be a contributing factor to some «over-Nynorsk» mistakes. An additional finding is that some of the informants report that they imagine an «inner voice» to guide their writing, which may contribute to some dialect mistakes

Identification and Characterization of Hydrogen Sulphide Producing Bacteria From Processing Plants for Salmon

Målet med denne oppgaven var å identifisere bakterier som produserte hydrogensulfid (H2S), fortrinnsvis Shewanella, fra prosesseringsanlegg for laks, og undersøke deres karakteristiske egenskaper med på fokus på forringelse av kvaliteten til fisk og fiskeprodukter. Bakterier som ble isolert fra prosesseringsanlegg for laks, og som produserte H2S, ble i hovedsak identifisert som Shewanella sp., etterfulgt av Aeromonas sp., og Morganella sp. Flere av bakteriestammene som ble undersøkt for karakteristiske egenskaper hadde potensiale for forringelse av kvaliteten til fisk og fiskeprodukter, med det var variasjon mellom stammene. Det ble også identifisert stammer av Shewanella som ikke produserte H2S på jernagar med L- cystein og tiosulfat som svovelkilder. Bakteriestammer av Shewanella som ikke produserte H2S på jernagar ble observert å ha mindre potensiale for kvalitetsforringelse enn stammer som produserte H2S på jernagar, men med noen unntak. Bakteriestammer av Shewanella viste stor diverisitet for ulike tester, og det var liten entydig sammenheng med fylogenetisk tilhørlighet. Det ble allikevel observert at flere bakteriestammer nært beslektet Shewanella putrefaciens, og bakteriestammer av Aeromonas sp., og Morganella sp., viste stort potensiale for kvalitetsforringelse da de vokste ved 4 °C, i 1 % NaCl, og produserte illeluktende odører som H2S og trimetylamin (TMA).The goal with this assignment was to identify bacteria that produced hydrogen sulphide (H2S), preferably Shewanella, from processing plants for salmon, and investigate their characteristic abilities regarding spoilage of fish and fish products. Bacteria isolated from processing plants for salmon, and that produced H2S, was mainly identified as Shewanella sp., followed by Aeromonas sp., and Morganella sp. Many of the bacteria strains that where investigated for characteristic abilities where shown to have spoilage potential, but it was variation between the strains. It was also identified strains of Shewanella that did not produce H2S on iron agar with L-cysteine and thiosulphate as sulfur sources. Shewanella strains that did not produce H2S on iron agar was observed to have less potential for spoilage than strains that did produce H2S, but with some exeptions. The Shewanella strains showed great diversity for different tests, and it was little unambiguous correlation with fylogenetic affiliation. It was still observed that several strains closely related to Shewanella putrefaciens, and strains of Aeromonas sp., and Morganella sp., showed most spoilage potential when they grew in 4 °C, in 1 % NaCl, and they produced foul odors like H2S and trimethylamine (TMA)M-MA

Improvements in Hypertension Care: Serum drug measurements to detect non-adherence to standard treatment and effects of renal denervation following directly observed therapy

As many as 40% of hypertensive patients are unable to reach their blood pressure target despite treatment with antihypertensive drugs. Over the last years, medication non-adherence have emerged as one of the most important causes of treatment failure. Largely depending on the method used in this assessment, the prevalence of non-adherence ranges from <10% to as much as 86% throughout different studies. Traditionally, most assessment methods have been indirect, i.e. patient self-assessment based on questionnaires, or physician-assessment wherein a doctor guesses whether a patient is adherent or not. These methods have proven to be less accurate, whereas direct methods, such as detection of antihypertensive drugs- or metabolites in biological fluids present as more accurate methods of non-adherence assessment. All 550 patients described in Paper I used ≥2 antihypertensive drugs and were referred/self-referred to a national hypertension study. They underwent thorough investigations including serum drug measurements of antihypertensive drugs. Furthermore, they were asked to complete a single, written question asking about their antihypertensive drug adherence. In addition, the physician assessed non-adherence based on a structured physician-patient interview. The results showed a prevalence of non-adherence of 7.3% based on the direct method. The indirect methods poorly overlapped and only two patients were identified as non-adherent by all three methods. A higher number of prescribed daily pills-, a higher number of prescribed antihypertensive pills-, and less prescription of combination pills were associated with non-adherence. Further, a lower patient age and non-caucasian ethnicity were associated with non-adherence. In the late 2000’s, renal denervation (RDN) was introduced as a potential treatment method for hypertension by introducing a catheter to the renal arteries and applying radiofrequency energy to ablate the sympathetic nerves within the adventitia of the artery wall. After the promising results from the first few studies, later randomized studied have shown the effect of RDN to be approximately equivalent to that of one antihypertensive drug. Although it is beyond doubt that RDN is able to reduce blood pressure, some patients seem to have a larger effect than others. Thus, it is important to find objective methods to identify these patients in advance. Additionally, long-term follow-up of patients who have undergone RDN is of importance to assess the safety- and efficacy of the procedure. The patients in Papers II and III were specifically referred to a renal denervation study, suspected of having treatment-resistant hypertension, i.e. using maximally tolerable doses of at least 3 antihypertensive drugs of which one had to be a diuretic. After witnessed intake of their prescribed drugs, patients underwent office- and ambulatory blood pressure measurements. Patients who remained hypertensive on the 24h ambulatory measurement were randomized to either RDN or drug adjustment assisted by hemodynamic monitoring. Paper II describes patients on long-term follow-up after three- and seven years. The two groups have similar blood pressure measurements on both visits, without any functional- or anatomical deterioration in renal function or any adverse events that could be attributed to the procedure. Paper III describes heart rate variability- and continuous blood pressure measurements during stress tests along with simultaneous sampling of catecholamines during an orthostatic stress test and a cold-pressor test. Before randomization, the two groups were similar in heart rate variability, continuous blood pressure measurements and catecholamine assessment, whereas at six months follow up the RDN group had a significantly lower adrenaline concentration immediately following the cold-pressor test. Thus, RDN seems to be able to reduce adrenaline reactivity

Treningsinduserte endringer i kroppssammensetning og muskelstyrke hos eldre og kvinner : en kontrollert randomisert studie

Aldring er assosiert med en gradvis nedgang i muskelmasse- og styrke. Formålet med denne studien var å undersøke i hvilken grad kroppssammensetning og muskelstyrke i eldre år ble påvirket av ulike treningsregimer i relasjon til kjønn. Metode: Totalt 138 friske, moderat aktive frivillige eldre (68- 92 år) ble via stratifisert randomisering, på bakgrunn av funksjonelle tester, fordelt til en av fire grupper: tradisjonell styrketrening (TST), funksjonell styrketrening (FST), utholdenhetstrening (UT) eller kontroll (KO). Alle treningsgruppene trente 3 ganger per uke i 12 uker. TST gjennomførte tung tradisjonell styrketrening med apparater og frie vekter (4-12RM). FST gjennomførte styrketrening med øvelser som simulerte tunge daglige aktiviteter f. eks: markløft med bruskasse (12-15RM). UT trente aerobics, stavgang og gikk tur. KO ble bedt om å opprettholde sitt daglige aktivitetsnivå. Kroppssammensetningen ble analysert med DXA før og etter treningsperioden. Resultater: Det var ingen forskjell mellom gruppen