Formation and Protection of Fe-Cr Oxide Spinel During the Oxidation Process of Stainless Steels in LBE Environment

2009 ◽  
Author(s):  
Taide Tan ◽  
Yitung Chen
Keyword(s):  
Spinel Layer ◽  
Scale Removal ◽  
Chrome Oxide ◽  
Complex Process ◽  
Oxide Spinel ◽  
Mesoscopic Level ◽  
Cellular Automaton Method ◽  
Stochastic Cellular Automaton ◽  
Nuclear Coolant

The formation of the spinel of magnetite and chrome oxide, is a very complex process, especially with the scale removal effect in flowing lead bismuth eutectic (LBE) nuclear coolant. This paper studied the formation and the protection of the spinel of magnetite and chrome oxide on stainless steel, in different environments at a mesoscopic level. The role of the alloying element has been analyzed. The formation of the spinel of magnetite and chrome oxide and the scale removal effect are simulated using a stochastic cellular automaton method. The protection of this spinel layer to the structural materials has been analyzed.

The Influence of Chrome in the Oxidation Process of Steels in Flowing LBE

2009 ◽  
Author(s):  
Taide Tan ◽  
Yitung Chen
Keyword(s):  
Oxidation Process ◽  
Alloying Element ◽  
Mesoscopic Scale ◽  
Protective Oxide ◽  
Scale Removal ◽  
Chrome Oxide ◽  
Protective Oxide Film ◽  
Oxidation Model ◽  
Stochastic Cellular Automaton

The role of the alloying element has been analyzed during the oxidation process of stainless steels in the flowing lead bismuth eutectic (LBE) environment. The growth of the protective oxide film of steels has been studied at a mesoscopic scale. The influence of chrome has been studied using the developed stochastic cellular automaton mesoscopic oxidation model, considering the formation of the chrome oxide and magnetite. During the oxidation process, the scale removal effect has been taken into account as well.

Social Cohesion, Breaks, and Transformations in Italy, 535–600

2018 ◽  
Author(s):  
Walter Pohl
Keyword(s):  
The Political ◽  
Late Antique ◽  
Religious Context ◽  
Ancient Society ◽  
Complex Process ◽  
Term Change ◽  
Two Generations ◽  
Classical Culture

When the Gothic War began in Italy in 535, the country still conserved many features of classical culture and late antique administration. Much of that was lost in the political upheavals of the following decades. Building on Chris Wickham’s work, this contribution sketches an integrated perspective of these changes, attempting to relate the contingency of events to the logic of long-term change, discussing political options in relation to military and economic means, and asking in what ways the erosion of consensus may be understood in a cultural and religious context. What was the role of military entrepreneurs of more or less barbarian or Roman extraction in the distribution or destruction of resources? How did Christianity contribute to the transformation of ancient society? The old model of barbarian invasions can contribute little to understanding this complex process. It is remarkable that for two generations, all political strategies in Italy ultimately failed.

scholarly journals Consciousness, decision making, and volition: freedom beyond chance and necessity

2021 ◽  
Author(s):  
Hans Liljenström
Keyword(s):  
Decision Making ◽  
Free Will ◽  
Brain Activity ◽  
Brain Structures ◽  
Complex Process ◽  
Neural Information ◽  
Neural Information Processing ◽  
Stochastic Population Model ◽  
The Brain

AbstractWhat is the role of consciousness in volition and decision-making? Are our actions fully determined by brain activity preceding our decisions to act, or can consciousness instead affect the brain activity leading to action? This has been much debated in philosophy, but also in science since the famous experiments by Libet in the 1980s, where the current most common interpretation is that conscious free will is an illusion. It seems that the brain knows, up to several seconds in advance what “you” decide to do. These studies have, however, been criticized, and alternative interpretations of the experiments can be given, some of which are discussed in this paper. In an attempt to elucidate the processes involved in decision-making (DM), as an essential part of volition, we have developed a computational model of relevant brain structures and their neurodynamics. While DM is a complex process, we have particularly focused on the amygdala and orbitofrontal cortex (OFC) for its emotional, and the lateral prefrontal cortex (LPFC) for its cognitive aspects. In this paper, we present a stochastic population model representing the neural information processing of DM. Simulation results seem to confirm the notion that if decisions have to be made fast, emotional processes and aspects dominate, while rational processes are more time consuming and may result in a delayed decision. Finally, some limitations of current science and computational modeling will be discussed, hinting at a future development of science, where consciousness and free will may add to chance and necessity as explanation for what happens in the world.

scholarly journals Revisiting the Organic Template Model through the Microstructural Study of Shell Development in Pinctada margaritifera, the Polynesian Pearl Oyster

Minerals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 370 ◽  
Author(s):  
Jean-Pierre Cuif ◽  
Yannicke Dauphin ◽  
Gilles Luquet ◽  
Kadda Medjoubi ◽  
Andrea Somogyi ◽  
...  
Keyword(s):  
Pearl Oyster ◽  
Nacreous Layer ◽  
Prismatic Layer ◽  
Pinctada Margaritifera ◽  
Microstructural Study ◽  
Leading Role ◽  
Complex Process ◽  
Gathering Data

A top-down approach to the mineralized structures and developmental steps that can be separated in the shells of Pinctada margaritifera was carried out. Detailed characterizations show that each of the two major layers usually taken into account (the outer prismatic layer and the inner nacreous layer) is actually the result of a complex process during which the microstructural patterns were progressively established. From its early growing stages in the deeper part of the periostracal grove up to the formation of the most inner nacreous layers, this species provides a demonstrative case study illustrating the leading role of specifically secreted organic structures as determinants of the crystallographic properties of the shell-building units. Gathering data established at various observational scales ranging from morphology to the nanometer level, this study allows for a reexamination of the recent and current biomineralization models.

scholarly journals The genetics of amelogenesis imperfecta: a review of the literature

2005 ◽  
Vol 13 (3) ◽  
pp. 212-217 ◽  
Author(s):  
Maria Cristina Leme Godoy dos Santos ◽  
Sergio Roberto Peres Line
Keyword(s):  
Autosomal Recessive ◽  
Autosomal Dominant ◽  
Dental Enamel ◽  
Matrix Proteins ◽  
Specific Gene ◽  
Enamel Formation ◽  
Complex Process ◽  
Different Types ◽  
Kallikrein 4

A melogenesis imperfecta (AI) is a group of inherited defects of dental enamel formation that show both clinical and genetic heterogeneity. Enamel findings in AI are highly variable, ranging from deficient enamel formation to defects in the mineral and protein content. Enamel formation requires the expression of multiple genes that transcribes matrix proteins and proteinases needed to control the complex process of crystal growth and mineralization. The AI phenotypes depend on the specific gene involved, the location and type of mutation, and the corresponding putative change at the protein level. Different inheritance patterns such as X-linked, autosomal dominant and autosomal recessive types have been reported. Mutations in the amelogenin, enamelin, and kallikrein-4 genes have been demonstrated to result in different types of AI and a number of other genes critical to enamel formation have been identified and proposed as candidates for AI. The aim of this article was to present an evaluation of the literature regarding role of proteins and proteinases important to enamel formation and mutation associated with AI.

scholarly journals Tumor-Associated Macrophages (TAMs) in Colorectal Cancer (CRC): From Mechanism to Therapy and Prognosis

2021 ◽  
Vol 22 (16) ◽  
pp. 8470
Author(s):  
Hui Wang ◽  
Tian Tian ◽  
Jinhua Zhang
Keyword(s):  
Colorectal Cancer ◽  
Clinical Care ◽  
Inflammatory Cells ◽  
Genetic Alterations ◽  
Tumor Associated Macrophages ◽  
Invasion And Migration ◽  
Complex Process ◽  
Incidence And Mortality ◽  
And Migration

Colorectal cancer (CRC) is a malignant tumor in the digestive system whose incidence and mortality is high-ranking among tumors worldwide. The initiation and progression of CRC is a complex process involving genetic alterations in cancer cells and multiple factors from the surrounding tumor cell microenvironment. As accumulating evidence has shown, tumor-associated macrophages (TAMs)—as abundant and active infiltrated inflammatory cells in the tumor microenvironment (TME)—play a crucial role in CRC. This review focuses on the different mechanisms of TAM in CRC, including switching of phenotypical subtypes; promoting tumor proliferation, invasion, and migration; facilitating angiogenesis; mediating immunosuppression; regulating metabolism; and interacting with the microbiota. Although controversy remains in clinical evidence regarding the role of TAMs in CRC, clarifying their significance in therapy and the prognosis of CRC may shed new light on the optimization of TAM-centered approaches in clinical care.

scholarly journals Functions of Sleep

2021 ◽  
pp. 177-182
Author(s):  
E Miletínová ◽  
J Bušková
Keyword(s):  
Neuronal Development ◽  
Well Being ◽  
Main Function ◽  
Complex Issue ◽  
Complex Process ◽  
Scientific Papers ◽  
System Functioning ◽  
Function Of Sleep ◽  
The Individual

Sleep is essential component of life. Even though the research in this field develops constantly, there are still many aspects of this rather complex process that remains to be fully clarified. One of these aspects, reason why we actually sleep, is perhaps the most crucial. In this mini review we aim to address this question and discuss potential functions of sleep. Many recent scientific papers are currently available that covers similar topic. We tried to summarize these recent findings. There are certainly many ways how to approach this rather complex issue. Our article will specifically focus on role of sleep in neuronal development, synaptic plasticity, memory consolidation or mental health in general. Its role in immune system functioning will also be mentioned. Moreover, we will also consider more general functions of sleep, such as well-being of the organisms or securing survival of the individual. In conclusion, we will highlight possible main function of sleep.

Acceleration of Palatal Wound Healing in Smad3-deficient Mice

2009 ◽  
Vol 88 (8) ◽  
pp. 757-761 ◽  
Author(s):  
K. Jinno ◽  
T. Takahashi ◽  
K. Tsuchida ◽  
E. Tanaka ◽  
K. Moriyama
Keyword(s):  
Wound Healing ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Monocyte Chemoattractant Protein 1 ◽  
Inflammatory Protein ◽  
Complex Process ◽  
Dermal Cells ◽  
Macrophage Inflammatory Protein ◽  
Tgf Β1

Wound healing is a well-orchestrated complex process leading to the repair of injured tissues. It is suggested that transforming growth factor (TGF)-β/Smad3 signaling is involved in wound healing. The purpose of this study was to investigate the role of TGF-β/Smad3 signaling in palatal wound healing in Smad3-deficient (Smad3−/−) mice. Histological examination showed that wound closure was accelerated by the proliferation of epithelium and dermal cells in Smad3−/− mice compared with wild-type (WT) mice. Macrophage/monocyte infiltration at wounded regions in Smad3−/− mice was decreased in parallel with the diminished production of TGF-β1, monocyte chemoattractant protein-1, and macrophage inflammatory protein-1α compared with WT mice. Fibrocytes, expressing hematopoietic surface marker and fibroblast products, were recruited and produced α-smooth-muscle actin in WT mice, but were not observed in Smad3−/− mice. These results suggest that TGF-β/Smad3 signaling may play an important role in the regulation of palatal wound healing.

scholarly journals MicroRNAs as Haematopoiesis Regulators

2013 ◽  
Vol 2013 ◽  
pp. 1-20 ◽  
Author(s):  
Ram Babu Undi ◽  
Ravinder Kandi ◽  
Ravi Kumar Gutti
Keyword(s):  
Blood Cells ◽  
Erythroid Differentiation ◽  
Lymphocytic Leukemia ◽  
Myelogenous Leukemia ◽  
Aberrant Expression ◽  
Hematopoietic Stem ◽  
Complex Process ◽  
Development And Differentiation ◽  
Multiple Myelomas

The production of different types of blood cells including their formation, development, and differentiation is collectively known as haematopoiesis. Blood cells are divided into three lineages erythriod (erythrocytes), lymphoid (B and T cells), and myeloid (granulocytes, megakaryocytes, and macrophages). Haematopoiesis is a complex process regulated by several mechanisms including microRNAs (miRNAs). miRNAs are small RNAs which regulate the expression of a number of genes involved in commitment and differentiation of hematopoietic stem cells. Evidence shows that miRNAs play an important role in haematopoiesis; for example, myeloid and erythroid differentiation is blocked by the overexpression of miR-15a. miR-221, miR-222, and miR-24 inhibit the erythropoiesis, whereas miR-150 plays a role in B and T cell differentiation. miR-146 and miR-10a are downregulated in megakaryopoiesis. Aberrant expression of miRNAs was observed in hematological malignancies including chronic myelogenous leukemia, chronic lymphocytic leukemia, multiple myelomas, and B cell lymphomas. In this review we have focused on discussing the role of miRNA in haematopoiesis.

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