Sulfide Stress Corrosion Cracking Resistance of Modified ASTM A694 F60 Low Alloy Steel for Subsea Applications

The resistance to sulfide stress corrosion cracking (SSC) of modified ASTM A694 F60 low alloy steel, produced by two different manufacturers, was studied by four-point bend-testing. The two materials are named material A and material B in this report. Both materials were tested in two different environments with different severity, one ?sweet-transition region? test and one ?sour service? test. The test conditions were controlled by the H2S partial pressure (pH2S) and pH. These parameters were varied in the two tests. Resistance to SSC was investigated on the base materials and on the thermal weld-simulated and notched materials. The thermal weld simulation was performed to provide the intercritically reheated CGHAZ, leading to a microstructure containing hard constituents. The tests were performed in autoclaves at room temperature with a pressure of 10 bars.The microstructure and Vickers hardness (HV) of both base materials and the heat affected zones were studied as these parameters affect the SSC susceptibility. The hardness of material B is higher than for material A and are respectively 249±2 HV and 214±5 HV. The hardness of the heat affected zone of the two materials are similar, both peaking at the center at about 400 HV. The microstructure of base material A mainly consists of bainite and ferrite/pearlite while material B mainly consists of acicular ferrite and bainite. The microstructure of the intercritically reheated CGHAZ is characterized by bainite laths among large prior austenite grain boundaries. At the grain boundaries, M-A constituents have crown in a ?necklace? formation.The base materials did not reveal cracking in the sweet-transition test, however, localized corrosion caused by CO2 and H2S was found along the stressed side of the specimen. Base material B was more severely attacked than material A, based on the length and density of the corrosion pits. In the ?sour service? test, severe general and localized corrosion and cracking was observed in both base materials. The materials are therefore considered unsuitable for ?sour service? applications. In the HAZ specimens, of both material A and B, severe cracking was observed in both tests. The specimens were fully separated by cracking in the ?sour service? test. The welded materials are therefore considered highly susceptible to SSC when a notch exists in the intercritically reheated CGHAZ. The HAZ hardness is higher than the maximum hardness requirement for SSC resistance at 248 HV. It would therefore be beneficial to perform additional testing of the HAZ, with a hardness level within the requirements.The cracking appeared as transgranular and was often initiated at the prior austenite grain boundaries, near the M-A constituents in the HAZ

Dansk embryologikompendium

Kompendiet er først og fremst rettet mot medisinstudenter, men kan leses av alle med interesse for feltet eller ønske om en kort repetisjon av embryologien. Det er kortfattet og nærmest stikkordspreget, i A4-størrelse og paperback.publishedVersio

Hverdagsliv i en digital alder. Familieadministrering fra et kvinneperspektiv

Master i samfunnsvitenskap med fordypning i sosiologi - Nord universitet, 202

Sustained Maternal Hyperandrogenism During PCOS Pregnancy Reduced by Metformin in Non-obese Women Carrying a Male Fetus

Context Large, longitudinal studies on androgen levels in pregnant women with polycystic ovary syndrome (PCOS) are lacking. While metformin has a mild androgen-lowering effect in non-pregnant women with PCOS, its effects on maternal androgen levels in pregnancy are less well understood. Objective To describe androgen patterns in pregnant women with PCOS and in healthy control women, and to explore the potential effects of metformin on maternal androgen levels in PCOS. Design and Setting A post hoc analysis from a randomized, placebo-controlled, multicenter study carried out at 11 secondary care centers and a longitudinal single-center study on healthy pregnant women in Norway. Participants A total of 262 women with PCOS and 119 controls. Intervention The participants with PCOS were randomly assigned to metformin (2 g daily) or placebo, from first trimester to delivery. Main Outcome Measures Androstenedione (A4), testosterone (T), sex-hormone binding globulin (SHBG), and free testosterone index (FTI) at 4 time points in pregnancy. Results Women with PCOS versus healthy controls had higher A4, T, and FTI, and lower SHBG at all measured time points in pregnancy. In the overall cohort of women with PCOS, metformin had no effect on A4, T, SHBG, and FTI. In subgroup analyses, metformin reduced A4 (P = 0.019) in nonobese women. Metformin also reduced A4 (P = 0.036), T (P = 0.023), and SHBG (P = 0.010) levels through pregnancy in mothers with a male fetus. Conclusion Metformin had no effect on maternal androgens in PCOS pregnancies. In subgroup analyses, a modest androgen-lowering effect was observed in nonobese women with PCOS. In PCOS women carrying a male fetus, metformin exhibited an androgen-lowering effect.publishedVersio

Changes in serum cytokines throughout pregnancy in women with polycystic ovary syndrome

Context: Polycystic ovary syndrome (PCOS) is a common endocrine disorder associated with low-grade inflammation and increased incidence of pregnancy complications, but its influence on the maternal immune system in pregnancy is unknown. Longitudinal serum cytokine profiling is a sensitive measure of the complex immunological dynamics of pregnancy. Objective: This work aimed to determine the immunological dynamics of serum cytokines throughout pregnancy in women with PCOS and compare it to pregnancy in women without PCOS. Methods: A post hoc analysis was conducted of longitudinal serum samples from 2 randomized, placebo-controlled multicenter studies of pregnant women with PCOS and 2 studies of pregnant women without PCOS. Pregnant women with PCOS (n = 358) and without PCOS (n = 258, controls) provided 1752 serum samples from 4 time points in pregnancy (weeks 10, 19, 32, and 36). Main outcome measures included maternal serum levels of 22 cytokines and C-reactive protein (CRP) at 4 time points in pregnancy. Results: Women with PCOS showed marked immunological changes in serum cytokines throughout pregnancy. Compared to controls, women with PCOS showed higher levels of 17 cytokines and CRP at week 10 of pregnancy and a distinct cytokine development throughout pregnancy. The immunological dynamics in women with PCOS was significantly affected by maternal body mass index, smoking, and fetal sex. Conclusion: Pregnancy in women with PCOS was associated with a strong early mobilization of inflammatory and other serum cytokines persisting throughout pregnancy, indicating a more activated immune status. These findings provide a novel basis for further study of PCOS and pregnancy complications.Changes in serum cytokines throughout pregnancy in women with polycystic ovary syndromepublishedVersio

Cytokine Patterns in Maternal Serum From First Trimester to Term and Beyond

Pregnancy implies delicate immunological balance between two individuals, with constant changes and adaptions in response to maternal capacity and fetal demands. We performed cytokine profiling of 1149 longitudinal serum samples from 707 pregnant women to map immunological changes from first trimester to term and beyond. The serum levels of 22 cytokines and C-reactive protein (CRP) followed diverse but characteristic trajectories throughout pregnancy, consistent with staged immunological adaptions. Eotaxin showed a particularly robust decrease throughout pregnancy. A strong surge in cytokine levels developed when pregnancies progressed beyond term and the increase was amplified as labor approached. Maternal obesity, smoking and pregnancies with large fetuses showed sustained increase in distinct cytokines throughout pregnancy. Multiparous women had increased cytokine levels in the first trimester compared to nulliparous women with higher cytokine levels in the third trimester. Fetal sex affected first trimester cytokine levels with increased levels in pregnancies with a female fetus. These findings unravel important immunological dynamics of pregnancy, demonstrate how both maternal and fetal factors influence maternal systemic cytokines, and serve as a comprehensive reference for cytokine profiles in normal pregnancies.publishedVersio

Sulfide Stress Corrosion Cracking Resistance of Modified ASTM A694 F60 Low Alloy Steel for Subsea Applications

The resistance to sulfide stress corrosion cracking (SSC) of modified ASTM A694 F60 low alloy steel, produced by two different manufacturers, was studied by four-point bend-testing. The two materials are named material A and material B in this report. Both materials were tested in two different environments with different severity, one ?sweet-transition region? test and one ?sour service? test. The test conditions were controlled by the H2S partial pressure (pH2S) and pH. These parameters were varied in the two tests. Resistance to SSC was investigated on the base materials and on the thermal weld-simulated and notched materials. The thermal weld simulation was performed to provide the intercritically reheated CGHAZ, leading to a microstructure containing hard constituents. The tests were performed in autoclaves at room temperature with a pressure of 10 bars.The microstructure and Vickers hardness (HV) of both base materials and the heat affected zones were studied as these parameters affect the SSC susceptibility. The hardness of material B is higher than for material A and are respectively 249±2 HV and 214±5 HV. The hardness of the heat affected zone of the two materials are similar, both peaking at the center at about 400 HV. The microstructure of base material A mainly consists of bainite and ferrite/pearlite while material B mainly consists of acicular ferrite and bainite. The microstructure of the intercritically reheated CGHAZ is characterized by bainite laths among large prior austenite grain boundaries. At the grain boundaries, M-A constituents have crown in a ?necklace? formation.The base materials did not reveal cracking in the sweet-transition test, however, localized corrosion caused by CO2 and H2S was found along the stressed side of the specimen. Base material B was more severely attacked than material A, based on the length and density of the corrosion pits. In the ?sour service? test, severe general and localized corrosion and cracking was observed in both base materials. The materials are therefore considered unsuitable for ?sour service? applications. In the HAZ specimens, of both material A and B, severe cracking was observed in both tests. The specimens were fully separated by cracking in the ?sour service? test. The welded materials are therefore considered highly susceptible to SSC when a notch exists in the intercritically reheated CGHAZ. The HAZ hardness is higher than the maximum hardness requirement for SSC resistance at 248 HV. It would therefore be beneficial to perform additional testing of the HAZ, with a hardness level within the requirements.The cracking appeared as transgranular and was often initiated at the prior austenite grain boundaries, near the M-A constituents in the HAZ

Politiske konfliktlinjer og konservative partier - En komparativ studie av fire partier

En komparativ studie av fire konservative partier (Høyre, Det republikanske parti, Det konservative parti, og CDU/CSU), som baserer seg på partienes plasseringer på fire sentrale konfliktlinjer i samfunnsvitenskapen. Oppgavens analyseverktøy er partiprogram-data hentet fra MRG/CMP. Oppgavens tidsaspekt strekker seg fra 1945 til 2009. Oppgaven gir et innblikk i historien til de fire partiene, samt konservatisme som helhet. Hypotesene utledet går inn på de fire partienes plasseringer på hver av de fire konfliktlinjene opp mot hverandre. Det er også utledet hypoteser på de fire partienes plasseringer opp mot den respektive hovedkonkurrenten på venstresiden i en nasjonal kontekst. Resultater av analysene baserer seg på figurer og tabeller som illustrerer plasseringer, forskjeller, likheter, og tidstrender