1,315 research outputs found

    FeS corrosion products formation and hydrogen uptake in a sour environment for quenched & tempered steel

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    Surface corrosion product formation is one of the important factors affecting the corrosion rate and hydrogen uptake in a H2S environment. However, it is still unclear how the base material composition will affect the corrosion products that are generated, and consequently their impact on the corrosion rate. In this paper, corrosion product formation and the impact of the Mo content of the base material on the composition of the corrosion products and hydrogen absorption in a sour environment was investigated. The corrosion layer was composed of a double layered mackinawite (FeS1−x) structure, which was enriched with molybdenum and chromium. The layers were formed via two different mechanisms, i.e., the inner layer was created via a general oxide film formation corrosion mechanism, whereas the upper layer was formed by a precipitation mechanism. The presence of this double corrosion layer had a large influence on the amount of diffusible hydrogen in the materials. This amount decreased as a function of contact time with the H2S saturated solution, while the corrosion rate of the materials shows no significant reduction. Therefore, the corrosion products are assumed to act as a physical barrier against hydrogen uptake. Mo addition caused a decrease in the maximal amount of diffusible hydrogen

    Evaluation of the effect of TiC precipitates on the hydrogen trapping capacity of Fe-C-Ti alloys

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    The present work evaluates the hydrogen trapping behavior of different laboratory cast generic Fe-C-Ti martensitic alloys. Titanium carbides were precipitated in the materials by well-designed heat treatments. A quenched and tempered martensitic matrix with final strength above 1000 MPa was aimed for and verified by means of hardness measurements. Tempering allowed generating precipitates with different characteristics in terms of coherency, size and distribution due to the secondary hardening effect, as was evaluated by transmission electron microscopy. The hydrogen trapping capacity of the TiC precipitates was investigated by thermal desorption spectroscopy, while melt extraction was performed to determine the amount of hydrogen present after cathodic hydrogen charging. Generally, it could be concluded that the incoherent particles in the quenched material were not able to trap hydrogen, whereas the quenched and tempered material trapped hydrogen at the interface of small probably coherent TiC.</jats:p

    T-ALL and thymocytes : a message of noncoding RNAs

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    In the last decade, the role for noncoding RNAs in disease was clearly established, starting with microRNAs and later expanded towards long noncoding RNAs. This was also the case for T cell acute lymphoblastic leukemia, which is a malignant blood disorder arising from oncogenic events during normal T cell development in the thymus. By studying the transcriptomic profile of protein-coding genes, several oncogenic events leading to T cell acute lymphoblastic leukemia (T-ALL) could be identified. In recent years, it became apparent that several of these oncogenes function via microRNAs and long noncoding RNAs. In this review, we give a detailed overview of the studies that describe the noncoding RNAome in T-ALL oncogenesis and normal T cell development

    Understanding the interaction between a steel microstructure and hydrogen

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    The present work provides an overview of the work on the interaction between hydrogen (H) and the steel&rsquo;s microstructure. Different techniques are used to evaluate the H-induced damage phenomena. The impact of H charging on multiphase high-strength steels, i.e., high-strength low-alloy (HSLA), transformation-induced plasticity (TRIP) and dual phase (DP) is first studied. The highest hydrogen embrittlement resistance is obtained for HSLA steel due to the presence of Ti- and Nb-based precipitates. Generic Fe-C lab-cast alloys consisting of a single phase, i.e., ferrite, bainite, pearlite or martensite, and with carbon contents of approximately 0, 0.2 and 0.4 wt %, are further considered to simplify the microstructure. Finally, the addition of carbides is investigated in lab-cast Fe-C-X alloys by adding a ternary carbide forming element to the Fe-C alloys. To understand the H/material interaction, a comparison of the available H trapping sites, the H pick-up level and the H diffusivity with the H-induced mechanical degradation or H-induced cracking is correlated with a thorough microstructural analysis

    Explicit Control Of Implicit Responses Simple Directives Can Alter IAT Performance

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    Research has begun to reveal the malleability of implicit prejudice. One measure of this construct, the race Implicit Association Test (IAT), represents a widely-used tool to assess individuals’ positive and negative associations with different racial groups. In two studies, we demonstrate the capacity of salient pressures to alter implicit racial responses. In Study 1, an enhancement of promoting pressures through an explicit instruction to stereotype was sufficient to increase pro-White bias on the IAT. In Study 2, an enhancement of inhibiting pressures through a simple instruction to avoid stereotyping was sufficient to reduce pro-White bias. Taken together, the studies suggest that implicit prejudice is amenable to voluntary control through the use of simple, direct means. (PsycINFO Database Record (c) 2013 APA, all rights reserved)(journal abstract

    Ask A Busy Person: Attentional Myopia And Helping

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    According to an oft-quoted piece of folk wisdom, if one wants something accomplished, the best person to ask is a busy person. We tested a version of this proposition in two studies. Study 1 exposed participants to a helping request in which cues promoting the relevant behavior were made more salient than those inhibiting it. Study 2 featured a request in which inhibiting cues were made more salient than cues promoting the behavior. In both studies, participants who were busied by high cognitive load showed more influence of the dominant behavioral pressure than did participants under minimal load. The results suggest that busy people can respond more to a helping appeal, but only when cues facilitating helping are more salient than those discouraging it

    Reducing Smoking Among Distracted Individuals: A Preliminary Investigation

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    INTRODUCTION: According to the attentional myopia model, salient cues that serve to inhibit behavior can be especially effective under conditions of limited attention. A small field study tested the implications of this model for smoking reduction. METHODS: Twenty-three undergraduate smokers were exposed to a prominent health warning for 2 5-day experimental phases, with phase order counterbalanced across participants. During one phase, participants simply viewed the warning at regular intervals. During the other phase, participants viewed the warning for the same duration but also simultaneously performed a distracting cognitive load task. RESULTS: Participants in the phase that combined a health warning with cognitive load reported smoking significantly fewer cigarettes and taking significantly fewer puffs of smoke as compared to a baseline comparison phase-a reduction in smoking not observed in the absence of cognitive load. CONCLUSIONS: Sources of attentional distraction may heighten the impact of salient smoking warnings, resulting in significant reductions in smoking
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