•After over 50 years, research has failed to answer fundamental questions related to MIC.•Research has not provided tools for detection of MIC in the field.•There are no systematic programs to ...mitigate and prevent MIC.•Both require advancement of reliable and predictive MIC models.•It is suggested that proactive, integrated approaches be used for MIC prevention and mitigation.
Microbially influenced corrosion (MIC), is acknowledged to be the direct cause of catastrophic corrosion failures, with associated damage costs ranging to many billions of US$ annually. In spite of extensive research and numerous publications, fundamental questions relating to MIC remain unanswered. The following review provides an overview of current MIC research and stresses the lack of information related to MIC recognition, prediction and mitigation. The review establishes a link between management decisions and root causes. A holistic, proactive approach to MIC is suggested in which an entire system is considered, monitored and improved.
Abstract
Energy loss at a manhole which is at a junction of storm sewers or combined sewers is important for accurately estimating its discharge capacity. However, even in Japan, the energy loss at ...the manhole is usually ignored in designing sewers and flood inundation analysis. One of the reasons for the ignorance is difficulty to formulate the energy loss at the manhole because the number of variables which must be considered increases as the number of sewers connected to the manhole increases. The authors have formulated the energy loss of a four-way circular manhole with three inflow sewers and one outflow sewer at crossroad. The formula is applicable only to the equal flow rates in two opposite lateral inflow sewers. In this paper, a new formula for the energy losses is proposed based on experimental data on a four-way circular manhole with different flow rates on three inflow sewers. It shows that the energy losses calculated with it almost reproduce the measured ones.
One of the possible synthetic routes to pentoses is the formose reaction pathway from C1 and C2 carbon sources, but preferential ribose generation in a one-pot reaction without any control of ...conditions has not been reported. We have tested a one-pot pentose formation and analyzed the products and mechanism in the reaction, using
H-NMR and mass spectrometry. Hydroxyapatite (HAp), which consists of phosphate and calcium ions, worked continuously for cross-aldol reactions and Lobry de Bruyn-van Ekenstein transformations to yield ribose from formaldehyde and glycolaldehyde. The continuous reaction proceeds in one pot in hot water only in the presence of a HAp catalyst, without any fine pH control or any complicated condition control at each reaction step. Ribose production by HAp may be a reason why a pentose backbone was incorporated into nucleic acids in the prebiotic world.
This manuscript reports the consensus statements regarding recurrent ovarian cancer (ROC), reached at the fifth Ovarian Cancer Consensus Conference (OCCC), which was held in Tokyo, Japan, in November ...2015. Three important questions were identified: (i) What are the subgroups for clinical trials in ROC? The historical definition of using platinum-free interval (PFI) to categorise patients as having platinum-sensitive/resistant disease was replaced by therapy-free interval (TFI). TFI can be broken down into TFIp (PFI), TFInp (non-PFI) and TFIb (biological agent-free interval). Additional criteria to consider include histology, BRCA mutation status, number/type of previous therapies, outcome of prior surgery and patient reported symptoms. (ii) What are the control arms for clinical trials in ROC? When platinum is considered the best option, the control arm should be a platinum-based therapy with or without an anti-angiogenic agent or a poly (ADP-ribose) polymerase (PARP) inhibitor. If platinum is not considered the best option, the control arm could include a non-platinum drug, either as single agent or in combination. (iii) What are the endpoints for clinical trials in ROC? Overall survival (OS) is the preferred endpoint for patient cohorts with an expected median OS < or = 12 months. Progression-free survival (PFS) is an alternative, and it is the preferred endpoint when the expected median OS is > 12 months. However, PFS alone should not be the only endpoint and must be supported by additional endpoints including pre-defined patient reported outcomes (PROs), time to second subsequent therapy (TSST), or time until definitive deterioration of quality of life (TUDD).
The consensus statements regarding first-line therapies in women with ovarian cancer, reached at the Fifth Ovarian Cancer Consensus Conference held in Tokyo, Japan, in November 2015 are reported. ...Three topics were reviewed and the following statements are recommended: (i) Surgery: the subgroups that should be considered in first-line ovarian cancer clinical trials should be (a) patients undergoing primary debulking surgery and (b) patients receiving neo-adjuvant chemotherapy. The amount of residual disease following surgery should further stratify patients into those with absent gross residual disease and others. (ii) Control arms for chemotherapy: for advanced stage ovarian cancer the standard is intravenous 3-weekly carboplatin and paclitaxel. Acceptable alternatives, which should be stratified variables in trials when more than one regimen is offered, include weekly paclitaxel plus 3-weekly carboplatin, the addition of bevacizumab to 3-weekly carboplatin and paclitaxel, and intraperitoneal therapy. (iii) Trial Endpoints: overall survival is the preferred primary endpoint for first-line clinical trials with or without a maintenance component. Progression-free survival (PFS) is an alternative primary endpoint, but if PFS is chosen overall survival must be measured as a secondary endpoint and PFS must be supported by additional endpoints, including predefined patient reported outcomes and time to first or second subsequent therapy. For neoadjuvant therapy, additional ‘window of opportunity’ endpoints should be included.
In a previous study (Okamoto & Hiraga, 2022, https://doi.org/10.1029/2022jb024638), we concluded that diffusion creep and grain growth in polymineralic rocks proceed by a common diffusional ...mechanism. Here, we built on that finding and estimated lower mantle grain size and viscosity during a single mantle convection cycle dominated by diffusion creep. We approximated the lower mantle as a two‐phase material consisting of bridgmanite + ferropericlase and post‐perovskite + ferropericlase, depending on depth. We used previously reported self‐diffusivities for bridgmanite and post‐perovskite. We predict a bridgmanite grain‐size of tens to hundreds of microns shortly after the phase transition at ∼660 km depth. This size remains relatively constant until the mantle material enters the post‐perovskite zone, which is marked by significant grain growth up to ∼9 mm just prior to upwelling. This size is sufficient to prevent further grain growth until the mantle material reaches the top of the lower mantle. These grain sizes combined with the diffusivities yield viscosities that vary laterally and with depth. At a lateral temperature difference of up to 800 K in the lower mantle, fine‐grained cold downwelling mantle is almost as viscous as, or more likely to be softer than coarse‐grained hot upwelling mantle. The lateral viscosity variations cannot be more than 2 orders of magnitude, and we estimated viscosities of 1018–1020 Pa · s in the upper lower mantle, 5 × 1020–5 × 1022 Pa · s in the lower bridgmanite zone, and 1017–1019 Pa · s in the post‐perovskite zone, which compare well with the values estimated in previous geophysical modeling studies.
Plain Language Summary
We estimated lower mantle viscosity during a mantle convection cycle by assuming that the mantle flows by diffusion creep. Because diffusion creep is a grain‐size sensitive mechanism, grain size is a key parameter for determining mantle viscosity. We recently concluded that diffusion creep and grain growth in polymineralic rocks occur by the same diffusional mechanism. With previously reported self‐diffusivities for bridgmanite and post‐perovskite, we were able to estimate how the grain size of these minerals evolves after the ∼660‐km phase transition in downwelling mantle. Using these grain sizes and diffusivities, we were able to determine the mantle viscosity. We demonstrate that lower mantle viscosity has temporal and spatial variations induced by grain growth. At a lateral temperature difference of up to 800 K in the lower mantle, fine‐grained cold downwelling mantle is almost as viscous as, or more likely to be softer than coarse‐grained hot upwelling mantle. The estimated overall viscosity structure compares well with a one‐dimensional depth structure of the lower mantle viscosity estimated in previous geophysical modeling studies.
Key Points
We estimated lower mantle viscosity during a mantle convection cycle by assuming mantle flow with a diffusion creep mechanism
Our estimated viscosity structure agrees well with the viscosity structures predicted in previous geophysical models
Temperature and grain size dependence of diffusion creep suppresses lateral changes in the viscosity of the lower mantle
We conducted uniaxial compression and grain growth experiments on fine‐grained forsterite (Mg2SiO4) + 10 vol% periclase (MgO) aggregates. This aggregate is a unique polymineralic system in which all ...of the constituent elements in the secondary phase constitute the primary mineral phase, except for Si, which is the slowest diffusing species in the primary phase. Grain growth in polymineralic aggregates, where the presence of a secondary phase results in grain boundary pinning of the primary phase, proceeds via Ostwald ripening of the secondary phase. Grain growth and diffusion creep rates were analyzed, and both rates were found to be limited by the same grain‐boundary diffusivity. For periclase ripening, forsterite grains surrounding the periclase grains must be deformed, such that diffusion of Si as well as Mg and O is necessary for periclase ripening, similarly to diffusion creep of the aggregates. Most rocks are polymineralic and usually contain a silicate mineral as their main phase, in which Si is the slowest diffusing species. This leads to the prediction that a single diffusivity, which is Si diffusivity in most cases, determines the rates of grain growth and diffusion creep in much of the Earth's interior. The grain size, which is the result of grain growth, and the time it takes to achieve that size, indicate the diffusivity. Viscosity during diffusion creep is determined by these grain size and diffusivity values. We view these findings as a unique opportunity to estimate the viscosity from the Earth's crust to the lower mantle.
Plain Language Summary
To understand the rheological structure of the Earth's interior, we conducted compression and grain growth experiments on fine‐grained forsterite (Mg2SiO4) + 10 vol% periclase (MgO) aggregates. We showed that the same diffusional process controls grain growth and diffusion creep. The result reveals that deformation of the primary phase is necessary for grain growth (ripening) of the secondary phase in a polymineralic system. Most rocks are polymineralic and usually contain a silicate mineral as their main phase, in which Si is the slowest diffusing species. This leads to the prediction that a single diffusivity, which is Si diffusivity in most cases, determines the rates of grain growth and diffusion creep in much of the Earth's interior. The grain size, which is the result of grain growth, and the time it takes to achieve that size, indicate the diffusivity. We are able to estimate viscosity during diffusion creep by these grain size and diffusivity values.
Key Points
In a polymineralic system, deformation of the primary phase is necessary for grain growth (ripening) of the secondary phase
The same diffusional process controls grain growth and diffusion creep in polymineralic systems, especially of silicate
Grain size—time viscometer is presented
Mineral precipitation in an open fracture plays a crucial role in the evolution of fracture permeability in rocks, and the microstructural development and precipitation rates are closely linked to ...fluid composition, the kind of host rock as well as temperature and pressure. In this study, we develop a continuum thermodynamic model to understand polycrystalline growth of quartz aggregates from the rock surface. The adapted multiphase‐field model takes into consideration both the absolute growth rate as a function of the driving force of the reaction (free energy differences between solid and liquid phases), and the equilibrium crystal shape (Wulff shape). In addition, we realize the anisotropic shape of the quartz crystal by introducing relative growth rates of the facets. The missing parameters of the model, including surface energy and relative growth rates, are determined by detailed analysis of the crystal shapes and crystallographic orientation of polycrystalline quartz aggregates in veins synthesized in previous hydrothermal experiments. The growth simulations were carried out for a single crystal and for grain aggregates from a rock surface. The single crystal simulation reveals the importance of crystal facetting on the growth rate; for example, growth velocity in the c‐axis direction drops by a factor of ~9 when the faceting is complete. The textures produced by the polycrystal simulations are similar to those observed in the hydrothermal experiments, including the number of surviving grains and crystallographic preferred orientations as a function of the distance from the rock wall. Our model and the methods to define its parameters provide a basis for further investigation of fracture sealing under varying conditions.
Biodiesel or renewable diesel fuels are alternative fuels produced from vegetable oil and animal tallow that are being considered to help reduce the use of petroleum-based fuels and emissions of air ...pollutants including greenhouse gases. Here, we analyzed the gene expression of inflammatory marker responses and the cytochrome P450 1A1 (CYP1A1) enzyme after exposure to diesel and biodiesel emission samples generated from an in-use heavy-duty diesel vehicle. Particulate emission samples from petroleum-based California Air Resource Board (CARB)-certified ultralow sulfur diesel (CARB ULSD), biodiesel, and renewable hydro-treated diesel all induced inflammatory markers such as cyclooxygenase-2 (COX)-2 and interleukin (IL)-8 in human U937-derived macrophages and the expression of the xenobiotic metabolizing enzyme CYP1A1. Furthermore, the results indicate that the particle emissions from CARB ULSD and the alternative diesel fuel blends activate the aryl hydrocarbon receptor (AhR) and induce CYP1A1 in a dose- and AhR-dependent manner which was supported by the AhR luciferase reporter assay and gel shift analysis. Based on a per mile emissions with the model year 2000 heavy duty vehicle tested, the effects of the alternative diesel fuel blends emissions on the expression on inflammatory markers like IL-8 and COX-2 tend to be lower than emission samples derived from CARB ULSD fuel. The results will help to assess the potential benefits and toxicity from biofuel use as alternative fuels in modern technology diesel engines.
•Biodiesel or renewable diesel fuels induce inflammatory markers in macrophages.•Diesel and biodiesel emission samples induce cytochrome P450 1A1.•Emissions samples from diesel and the alternative diesel fuel blends activate the aryl hydrocarbon receptor.•Effects of the alternative diesel fuel blends emissions on the expression on inflammatory markers tend to be lower than emission samples derived from California ultra-low sulphur diesel fuel.
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