In-situ microcantilever bending of titanium revealing hydrogen-dislocation interactions

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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

Stress Corrosion Cracking in an Extruded Cu-Free Al-Zn-Mg Alloy

Stress corrosion cracking (SCC) in Cu-free Al-Zn-Mg (7xxx) aluminium alloys limits its use in many applications. In this work, we study in detail the microstructure of a peak and slightly overaged condition in an AA7003 alloy using transmission- and scanning electron microscopy in order to provide a comprehensive understanding of the microstructural features related to SCC. The SCC properties have been assessed using the double cantilever beam method and slow strain rate tensile tests. Grain boundary particles, precipitate free zones, and matrix precipitates have been studied. A difference in the SCC properties is established between the two ageing conditions. The dominating difference is the size and orientation of the hardening phases. Possible explanations correlating the microstructure and SCC properties are discussed.</jats:p

Role of cementite morphology on corrosion layer formation of high-strength carbon steels in sweet and sour environments

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Evaluation of microstructural and environmental effects on the hydrogen uptake and desorption in high-strength carbon steels: A thermal desorption spectroscopy study

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Salmon farming in the North: How do we regulate growth?

Source at https://framsenteret.no/fram-forum/Aquaculture has become a major part of global food production, and according to the UN Food and Agriculture Organization, it is now the fastest growing animal food-producing industry. In the North, further growth in salmon farming is expected. What mechanisms are in place to regulate this growth

Korrosjon av Stål i Ferskvann

Det er i dag en diskusjon gående om korrosjon og korrosjonsmonn på pæler som skal stå i Mjøsa. Mjøsa er ferskvann, og det gjelder pæler på lengder opp mot 100 meter, og ca 50 meter av pælen vil stå i ferskvannet. Det er tenkt at stålet i pælene kan være prosjektert som bærende konstruksjon, og dermed er det ikke krav om utstøping av pælene med betong, hvilket vil redusere både kostnader og klimafotavtrykk. Designlevetid er 100 år. I litteraturen rapporteres det om korrosjonshastigheter fra 1,8 mm til 7350 mm / 100 år. Hovedårsaken til den store spredningen er forskjeller i vanntemperatur, oksygeninnhold, forekomsten av bakterier som kan årsake korrosjon, vannets strømningshastighet og vannkvaliteten. Også i de relevante standardene spriker korrosjonsmonnet fra 1,4 mm til 20 mm for 100 års levetid. Dette blir diskutert i denne state-of-the-art studie.publishedVersio

Pristup procjeni zdravstvenoga rizika za ljude prilikom izgradnje gradskoga parka

A Human Health Risk Assessment (HHRA) was undertaken for a proposed park development “River Landing”, to be constructed along the north bank of the South Saskatchewan River in the City of Saskatoon, Saskatchewan, Canada. The purpose of the HHRA was to determine whether chemical constituents identified at the site, including polycyclic aromatic hydrocarbons (PAHs), petroleum hydrocarbons (PHCs), and toxic and heavy metals, would adversely affect the health of construction workers and potential park users. Although more traditional remediation options were considered, the risk assessment approach was chosen since it represented the best available technology. The HHRA was undertaken using protocols and methodologies proposed and readily accepted by the Canadian Council of Ministers of the Environment (CCME), Health Canada, and the United States Environmental Protection Agency (US EPA). Results of the risk assessment revealed that the magnitude and distribution of the chemicals at the site were such that extensive remediation was not required, and that the site could be developed without any significant restrictions on the proposed use. The assessment revealed that potential exposure to soil constituents would not result in adverse health risk to construction workers involved in park development or future park users.Napravljena je procjena zdravstvenoga rizika za ljude (izv. human health risk assessment, HHRA) za projekt gradskoga parka “River Landing” koji bi se trebao izgraditi duž sjeverne obale rijeke South Saskatchewan u Saskatoonu, saveznoj državi Saskatchewan u Kanadi. Svrha je procjene bila utvrditi mogu li kemijski spojevi zatečeni na gradilištu, uključujući policikličke aromatske ugljikovodike, naftne ugljikovodike te toksične i teške metale, štetno utjecati na zdravlje građevinskih radnika i korisnika parka. Premda je razmotrena i uporaba tradicionalnijih metoda sanacije, izabran je ovaj pristup procjeni rizika zbog toga što rabi najbolju dostupnu tehnologiju. Procjena rizika provedena je prema protokolima i metodama koje je odmah usvojio Kanadski savjet ministara za zaštitu okoliša (izv. Canadian Council of Ministers of the Environment, CCME), savezni ured za zdravlje Health Canada te Agencija za zaštitu okoliša Sjedinjenih Država (izv. United States Environmental Protection Agency, US EPA). Procjena rizika pokazala je da količina i rasprostranjenost kemikalija na gradilištu nisu takvi da zahtijevaju opsežniju sanaciju, te da se lokacija može izgraditi bez značajnih ograničenja u namjeni. Procjenom je također utvrđeno da eventualno izlaganje sastavnicama tla neće dovesti do štetnih posljedica za zdravlje građevinskih radnika koji rade na parku, a niti za buduće korisnike parka

Electroencephalographic field influence on calcium momentum waves

Macroscopic EEG fields can be an explicit top-down neocortical mechanism that directly drives bottom-up processes that describe memory, attention, and other neuronal processes. The top-down mechanism considered are macrocolumnar EEG firings in neocortex, as described by a statistical mechanics of neocortical interactions (SMNI), developed as a magnetic vector potential $\mathbf{A}$. The bottom-up process considered are $\mathrm{Ca}^{2+}$ waves prominent in synaptic and extracellular processes that are considered to greatly influence neuronal firings. Here, the complimentary effects are considered, i.e., the influence of $\mathbf{A}$ on $\mathrm{Ca}^{2+}$ momentum, $\mathbf{p}$. The canonical momentum of a charged particle in an electromagnetic field, $\mathbf{\Pi} = \mathbf{p} + q \mathbf{A}$ (SI units), is calculated, where the charge of $\mathrm{Ca}^{2+}$ is $q = - 2 e$, $e$ is the magnitude of the charge of an electron. Calculations demonstrate that macroscopic EEG $\mathbf{A}$ can be quite influential on the momentum $\mathbf{p}$ of $\mathrm{Ca}^{2+}$ ions, in both classical and quantum mechanics. Molecular scales of $\mathrm{Ca}^{2+}$ wave dynamics are coupled with $\mathbf{A}$ fields developed at macroscopic regional scales measured by coherent neuronal firing activity measured by scalp EEG. The project has three main aspects: fitting $\mathbf{A}$ models to EEG data as reported here, building tripartite models to develop $\mathbf{A}$ models, and studying long coherence times of $\mathrm{Ca}^{2+}$ waves in the presence of $\mathbf{A}$ due to coherent neuronal firings measured by scalp EEG. The SMNI model supports a mechanism wherein the $\mathbf{p} + q \mathbf{A}$ interaction at tripartite synapses, via a dynamic centering mechanism (DCM) to control background synaptic activity, acts to maintain short-term memory (STM) during states of selective attention.Comment: Final draft. http://ingber.com/smni14_eeg_ca.pdf may be updated more frequentl