Effect of a minor element with a large mixing enthalpy difference on the plasticity of amorphous alloys

2007 ◽  
Vol 22 (9) ◽  
pp. 2558-2564 ◽  
Author(s):  
Kyou-Hyun Kim ◽  
Hwi-Jun Kim ◽  
Jae-Chul Lee
Keyword(s):  
Phase Separation ◽  
Amorphous Alloys ◽  
Minor Element ◽  
Major Elements ◽  
Mixing Enthalpy ◽  
Additional Element ◽  
Enthalpy Difference ◽  
A Minor ◽  
Mixing Enthalpies

In this study, we investigated the role of a minor alloying element in improving the plasticity of amorphous alloys. The plasticity of the amorphous alloys, Cu60−xZr30Ti10Bex, was drastically improved with increasing amount of Be and reached a maximum of 23% at Cu53Zr30Ti10Be7. It was observed that an atomistic-scale phase separation existed within the alloy, which resulted from the large difference in mixing enthalpy between the binary pairs (Be–Cu, Be–Zr). This atomistic-scale phase separation resulted in an open structure in which atomic rearrangements in the form of the creation of free volume and crystallization were facilitated during deformation. Here we discuss the origin of the enhanced plasticity by clarifying the effect of an additional element, whose mixing enthalpies with the major elements are significantly different, on the structural change of the amorphous alloy.

Sulfides in Leg 37 drill core from the Mid-Atlantic Ridge

1977 ◽  
Vol 14 (4) ◽  
pp. 674-683 ◽  
Author(s):  
Wallace H. MacLean
Keyword(s):  
Deep Ocean ◽  
Minor Element ◽  
Major Elements ◽  
Drill Core ◽  
Minor Phase ◽  
Basalt Glass ◽  
Mid Atlantic Ridge ◽  
A Minor ◽  
Drill Holes ◽  
Good Agreement

Sulfides in 27 samples of drill core from four Leg 37 drill holes have been studied. Pyrite is the most abundant sulfide, averaging 0.39 ± 0.51% of basalt samples. Also present in basalt are sparse (0.0001%) and small (< 8 μm) magmatic globules of finely intergrown pyrrhotite, pentlandite, and chalcopyrite-iss, as well as a few globules composed of only one of these minerals. Larger and more abundant magmatic globules are present in gabbro and peridotite; pyrite is a minor phase in these rocks.Fe, Ni. Cu. and S are the major elements, and Co a minor element in the globules. Averaged Ni/Cu ratios for globules are: 3.3 (peridotite), 1.0 (gabbro). and 0.4 (basalt), the decrease in ratio indicating less normative olivine in the respective parent magmas when the globules were formed.Sulfides in globules in peridotite, and to a lesser extent in gabbro, form distinct grains free of inclusions, and appear to have equilibrated to below 300 °C. In basalt the minerals are finely intergrown and indicate quenching above about 600 °C, with local equilibration at lower temperatures.Three analyses of sulfur in basalt glass ranged from 930 to 1160 ppm, in good agreement with other analyses of deep-ocean basalts.

Design of a bulk amorphous alloy containing Cu–Zr with simultaneous improvement in glass-forming ability and plasticity

2007 ◽  
Vol 22 (2) ◽  
pp. 486-492 ◽  
Author(s):  
Seok-Woo Lee ◽  
Sang-Chul Lee ◽  
Yu-Chan Kim ◽  
E. Fleury ◽  
Jae-Chul Lee
Keyword(s):  
Amorphous Alloy ◽  
Amorphous Alloys ◽  
Glass Forming Ability ◽  
Bulk Amorphous Alloy ◽  
Mixing Enthalpy ◽  
High Plasticity ◽  
Atomic Packing ◽  
Bulk Amorphous Alloys ◽  
Glass Forming ◽  
Enthalpy Difference

We synthesized bulk amorphous alloy systems of Cu43Zr43Al7X7 (X = Be, Ag; numbers indicate at.%), with the objective of simultaneously enhancing the glass-forming ability (GFA) and the plasticity. The alloys not only exhibit high plasticity (∼7%, ∼8%), but also possess enhanced GFA (alloys with 12 and 8 mm diameter). The possible mechanisms underlying this enhanced GFA and plasticity exhibited by these alloys are discussed based on the atomic-packing state and atomistic-scale compositional separation associated with the mixing enthalpy difference. A strategy for designing bulk amorphous alloys with simultaneous improvement in the GFA and the plasticity is proposed from the viewpoint of atomic-packing state and atomistic-scale phase separation.

The Effect of Path Length and Display Size on Memory for Spatial Information

2012 ◽  
Vol 59 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Katherine Guérard ◽  
Sébastien Tremblay
Keyword(s):  
Path Length ◽  
Potential Role ◽  
Spatial Information ◽  
Recall Performance ◽  
Minor Role ◽  
Length Effect ◽  
Serial Memory ◽  
Fixed Reference ◽  
A Minor

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.

THE ROLE OF ANTHROPONYMS IN THE SEMANTIC FIELD OF ARTISTIC WORKS

2019 ◽  
Vol 2019 (29) ◽  
pp. 66-77
Author(s):  
Lidiya Derbenyova
Keyword(s):  
Literary Work ◽  
Main Theme ◽  
Semantic Field ◽  
New Meanings ◽  
Minor Part ◽  
The One ◽  
A Minor ◽  
And Storage ◽  
Horizon Of Expectations

The article explores the role of antropoetonyms in the reader’s “horizon of expectation” formation. As a kind of “text in the text”, antropoetonyms are concentrating a large amount of information on a minor part of the text, reflecting the main theme of the work. As a “text” this class of poetonyms performs a number of functions: transmission and storage of information, generation of new meanings, the function of “cultural memory”, which explains the readers’ “horizon of expectations”. In analyzing the context of the literary work we should consider the function of antropoetonyms in vertical context (the link between artistic and other texts, and the groundwork system of culture), as well as in the context of the horizontal one (times’ connection realized in the communication chain from the word to the text; the author’s intention). In this aspect, the role of antropoetonyms in the structure of the literary text is extremely significant because antropoetonyms convey an associative nature, generating a complex mechanism of allusions. It’s an open fact that they always transmit information about the preceding text and suggest a double decoding. On the one hand, the recipient decodes this information, on the other – accepts this as a sort of hidden, “secret” sense.

SATOUMI APPROACH FOR REALIZING SUSTAINABLE COASTAL USE IN A RIASTYPE BAY: A CASE OF SHIZUGAWA BAY IN SANRIKU COAST HIT BY THE HUGE TSUNAMI ON 11 MARCH 2011

2017 ◽  
Author(s):  
Teruhisa Komatsu ◽  
Teruhisa Komatsu ◽  
Shuji Sasa ◽  
Shuji Sasa ◽  
Shigeru Montani ◽  
...  
Keyword(s):  
Local Governments ◽  
Minor Element ◽  
Coupling Model ◽  
Sanriku Coast ◽  
High Productivity ◽  
Biological Coupling ◽  
Miyagi Prefecture ◽  
Human Use ◽  
A Minor ◽  
Aquaculture Facilities

Rias-type bays are one of the most common coasts in Japan where aquacultures have been active due to sheltered geological shape with a deep bottom. The huge tsunami hit Sanriku Coast consisting of open rias-type bays near the epicenter facing Pacific Ocean on 11 March 2011. For recovering Sanriku Coast, it is important to include sustainability in its program. Satoumi is defined as the human use and management of coastal seas for high productivity while maintaining high biodiversity. Therefore, we proposed Satoumi approach to an open rias-type bay, Shizugawa Bay, in southern Sanriku Coast. We conducted scientific researches on mapping of coastal habitats and aquaculture facilities, hydrography, and material flows of nutrients, a minor element (Fe) and organic matters in the bay including those from the rivers and from the offshore waters. At the same time, Committee for Shizugawa Bay Management of Fishermen’s Cooperative of Miyagi Prefecture decided to decrease in aquaculture facilities for sustainable development of aquaculture. Based on these data, a physical-biological coupling model was used for calculating the number of aquaculture facilities that are suitable not only for yields but also for environments. These researches were established on strong collaborations among a fishermen’s’ cooperative, local governments and scientists. Results of this practice may help to realize sustainable coastal use of a rias-type bay.

Effects of Myo-inositol Alone and in Combination with Seleno-Lmethionine on Cadmium-Induced Testicular Damage in Mice

2019 ◽  
Vol 12 (4) ◽  
pp. 311-323 ◽  
Author(s):  
Salvatore Benvenga ◽  
Antonio Micali ◽  
Giovanni Pallio ◽  
Roberto Vita ◽  
Consuelo Malta ◽  
...  
Keyword(s):  
Structural Changes ◽  
Natural Antioxidants ◽  
Minor Role ◽  
Positive Role ◽  
Testosterone Levels ◽  
Tnf Α ◽  
Testicular Lesions ◽  
A Minor ◽  
Immunohistochemical Analyses

Background: Cadmium (Cd) impairs gametogenesis and damages the blood-testis barrier. Objective: As the primary mechanism of Cd-induced damage is oxidative stress, the effects of two natural antioxidants, myo-inositol (MI) and seleno-L-methionine (Se), were evaluated in mice testes. Methods: Eighty-four male C57 BL/6J mice were divided into twelve groups: 0.9% NaCl (vehicle; 1 ml/kg/day i.p.); Se (0.2 mg/kg/day per os); Se (0.4 mg/kg/day per os); MI (360 mg/kg/day per os); MI plus Se (0.2 mg/kg/day); MI plus Se (0.4 mg/kg/day); CdCl2 (2 mg/kg/day i.p.) plus vehicle; CdCl2 plus MI; CdCl2 plus Se (0.2 mg/kg/day); CdCl2 plus Se (0.4 mg/kg/day); CdCl2 plus MI plus Se (0.2 mg/kg/day); and CdCl2 plus MI plus Se (0.4 mg/kg/day). After 14 days, testes were processed for biochemical, structural and immunohistochemical analyses. Results: CdCl2 increased iNOS and TNF-α expression and Malondialdehyde (MDA) levels, lowered glutathione (GSH) and testosterone, induced testicular lesions, and almost eliminated claudin-11 immunoreactivity. Se administration at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression, maintained GSH, MDA and testosterone levels, structural changes and low claudin-11 immunoreactivity. MI alone or associated with Se at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression and MDA levels, increased GSH and testosterone levels, ameliorated structural organization and increased claudin-11 patches number. Conclusion: We demonstrated a protective effect of MI, a minor role of Se and an evident positive role of the association between MI and Se on Cd-induced damages of the testis. MI alone or associated with Se might protect testes in subjects exposed to toxicants, at least to those with behavior similar to Cd.

scholarly journals Chlorine as a Discriminant Element to Establish the Provenance of Central Mediterranean Obsidians

2020 ◽  
Vol 6 (1) ◽  
pp. 454-476
Author(s):  
Franco Foresta Martin ◽  
Silvio G. Rotolo ◽  
Manuela Nazzari ◽  
Maria Luisa Carapezza
Keyword(s):  
Electron Microprobe ◽  
Minor Element ◽  
Igneous Rocks ◽  
Chlorine Concentration ◽  
Silicate Melts ◽  
Alkali Content ◽  
Central Mediterranean ◽  
A Minor

Abstract Chlorine is a minor element present in obsidians in quantities greater than in average igneous rocks. The chlorine concentration in obsidians is generally low, of the order of tenths of wt %, but it exhibits an appreciable differentiation among geological sources. Despite these characteristics, chlorine has rarely been taken into consideration as a possible indicator of obsidian provenance and it does not appear in the chemical analytical tables accompanying the geochemical characterisation of obsidian samples. In this work, after an overview of chlorine geochemistry and cycle, we present thirty-one new electron microprobe (EPMA) analyses, including Cl, of geologic obsidians sampled from the four sources of the Central Mediterranean, exploited in prehistoric times (Monte Arci, Palmarola, Lipari and Pantelleria). The results are compared with 175 new EPMA analyses, including Cl, of archaeological obsidians already characterised in previous work and of known provenance. As such it was possible to ascertain that each source has a characteristic chlorine concentration, showing the utility of its use in the studies of obsidian provenance. Furthermore, given that the solubility of chlorine in silicate melts is correlated to its alkali content, in particular sodium, we assessed the efficacy of simple binary graphs Cl vs Na2O to better constrain the provenance of the obsidian samples.

scholarly journals Deciphering the Role of π-Interactions in Polyelectrolyte Complexes Using Rationally Designed Peptides

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2074
Author(s):  
Sara Tabandeh ◽  
Cristina Elisabeth Lemus ◽  
Lorraine Leon
Keyword(s):  
Hydrogen Bonding ◽  
Phase Separation ◽  
Liquid Phase ◽  
Charge Density ◽  
Secondary Structures ◽  
Liquid Phase Separation ◽  
Polyelectrolyte Complexes ◽  
Π Interactions ◽  
Liquid Liquid Phase Separation

Electrostatic interactions, and specifically π-interactions play a significant role in the liquid-liquid phase separation of proteins and formation of membraneless organelles/or biological condensates. Sequence patterning of peptides allows creating protein-like structures and controlling the chemistry and interactions of the mimetic molecules. A library of oppositely charged polypeptides was designed and synthesized to investigate the role of π-interactions on phase separation and secondary structures of polyelectrolyte complexes. Phenylalanine was chosen as the π-containing residue and was used together with lysine or glutamic acid in the design of positively or negatively charged sequences. The effect of charge density and also the substitution of fluorine on the phenylalanine ring, known to disrupt π-interactions, were investigated. Characterization analysis using MALDI-TOF mass spectroscopy, H NMR, and circular dichroism (CD) confirmed the molecular structure and chiral pattern of peptide sequences. Despite an alternating sequence of chirality previously shown to promote liquid-liquid phase separation, complexes appeared as solid precipitates, suggesting strong interactions between the sequence pairs. The secondary structures of sequence pairs showed the formation of hydrogen-bonded structures with a β-sheet signal in FTIR spectroscopy. The presence of fluorine decreased hydrogen bonding due to its inhibitory effect on π-interactions. π-interactions resulted in enhanced stability of complexes against salt, and higher critical salt concentrations for complexes with more π-containing amino acids. Furthermore, UV-vis spectroscopy showed that sequences containing π-interactions and increased charge density encapsulated a small charged molecule with π-bonds with high efficiency. These findings highlight the interplay between ionic, hydrophobic, hydrogen bonding, and π-interactions in polyelectrolyte complex formation and enhance our understanding of phase separation phenomena in protein-like structures.

scholarly journals Membrane-associated phase separation: organization and function emerge from a two-dimensional milieu

2021 ◽  
Author(s):  
Jonathon A Ditlev
Keyword(s):  
Phase Separation ◽  
Cell Biology ◽  
Cellular Environment ◽  
Condensate Formation ◽  
Associated Proteins ◽  
Available Technology ◽  
And Function ◽  
Surrounding Membrane

Abstract Liquid‒liquid phase separation (LLPS) of biomolecules has emerged as an important mechanism that contributes to cellular organization. Phase separated biomolecular condensates, or membrane-less organelles, are compartments composed of specific biomolecules without a surrounding membrane in the nucleus and cytoplasm. LLPS also occurs at membranes, where both lipids and membrane-associated proteins can de-mix to form phase separated compartments. Investigation of these membrane-associated condensates using in vitro biochemical reconstitution and cell biology has provided key insights into the role of phase separation in membrane domain formation and function. However, these studies have generally been limited by available technology to study LLPS on model membranes and the complex cellular environment that regulates condensate formation, composition, and function. Here, I briefly review our current understanding of membrane-associated condensates, establish why LLPS can be advantageous for certain membrane-associated condensates, and offer a perspective for how these condensates may be studied in the future.

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