Microstructural characteristics of SrTiO 3 nanoparticles: the role of capping ligand concentration

2016 ◽  
Vol 11 (5) ◽  
pp. 273-276 ◽  
Author(s):  
Uzma K.H. Bangi ◽  
Vipul M. Prakshale ◽  
WooJe Han ◽  
Hyung‐Ho Park ◽  
Noor Mahmad N. Maldar ◽  
...  
Keyword(s):  
Ligand Concentration ◽  
Microstructural Characteristics

Role of Bi and Ca Additions in Controlling the Microstructure of Sr-Modified 319 Alloys

2006 ◽  
Vol 519-521 ◽  
pp. 1257-1264 ◽  
Author(s):  
S. El Hadad ◽  
A.M. Samuel ◽  
F.H. Samuel ◽  
H.W. Doty ◽  
S. Valtierra
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Image Analysis ◽  
Mg Alloys ◽  
Microstructural Characteristics ◽  
Optical And Electron Microscopy ◽  
Modification Effect ◽  
Eutectic Si ◽  
Mg Addition

The role of bismuth (50 to 9000 ppm) and calcium (50 to 200 ppm) additions on the microstructural characteristics in Sr-modified 319 alloys (with/without 0.4 wt% Mg addition) were investigated using optical and electron microscopy, and image analysis. It was found that the modification effect of Sr continuously diminished with Bi addition up to ~3000 ppm Bi; further Bi addition led to the modification of the Si particles due to the presence of Bi. In the Ca-containing alloys, a coarse eutectic Si structure resulted with Ca additions of 50 ppm, due to the formation of Alx(Ca,Sr)Siy compounds. Increased Ca additions (up to 200 ppm) did not alter the Si particle size. The Alx(Ca,Sr)Siy phase particles appeared in rod-like form in the Sr-modified alloys and in plate-like form in the 319+0.4 wt% Mg alloys. MgO, Al2O3, and AlP particles appear to act as nucleants for the precipitation of the plate-like Alx(Ca,Sr)Siy phase.

scholarly journals The role of synthesis pathway on the microstructural characteristics of sulfur-carbon composites: X-ray imaging and electrochemistry in lithium battery

2020 ◽  
Vol 472 ◽  
pp. 228424 ◽  
Author(s):  
Daniele Di Lecce ◽  
Vittorio Marangon ◽  
Wenjia Du ◽  
Dan J.L. Brett ◽  
Paul R. Shearing ◽  
...  
Keyword(s):  
Lithium Battery ◽  
Carbon Composites ◽  
Microstructural Characteristics ◽  
X Ray ◽  
X Ray Imaging

scholarly journals Transforming Growth Factor β Depletion Is the Primary Determinant of Smad Signaling Kinetics

2009 ◽  
Vol 29 (9) ◽  
pp. 2443-2455 ◽  
Author(s):  
David C. Clarke ◽  
Meredith L. Brown ◽  
Richard A. Erickson ◽  
Yigong Shi ◽  
Xuedong Liu
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Ligand Concentration ◽  
Type Ii ◽  
Reversible Binding ◽  
Primary Determinant ◽  
Ligand Depletion ◽  
Dependent Mechanism

ABSTRACT A cell's decision to growth arrest, apoptose, or differentiate in response to transforming growth factor β (TGF-β) superfamily ligands depends on the ligand concentration. How cells sense the concentration of extracellular bioavailable TGF-β remains poorly understood. We therefore undertook a systematic quantitative analysis of how TGF-β ligand concentration is transduced into downstream phospho-Smad2 kinetics, and we found that the rate of TGF-β ligand depletion is the principal determinant of Smad signal duration. TGF-β depletion is caused by two mechanisms: (i) cellular uptake of TGF-β by a TGF-β type II receptor-dependent mechanism and (ii) reversible binding of TGF-β to the cell surface. Our results indicate that cells sense TGF-β dose by depleting TGF-β via constitutive TGF-β type II receptor trafficking processes. Our results also have implications for the role of the TGF-β type II receptor in disease, as tumor cells harboring TGF-β type II receptor mutations exhibit impaired TGF-β depletion, which may contribute to the overproduction of TGF-β and a consequently poor prognosis in cancer.

Microstructure and Recording Noise of Thin Film Longitudinal Media

1991 ◽  
Vol 232 ◽  
Author(s):  
Tadashi Yogi ◽  
Thao A. Nguyena ◽  
Steven E. Lambert ◽  
Grace L. Gorman ◽  
Gil Castillo
Keyword(s):  
Thin Film ◽  
Film Growth ◽  
Magnetic Layer ◽  
Deposition Condition ◽  
Growth Morphology ◽  
Microstructural Characteristics ◽  
Magnetic Layers ◽  
The Media ◽  
Sputtering Pressure

ABSTRACTThe magnetic and recording characteristics of Co-based thin film media are strongly influenced by microstructure. The media microstructural characteristics, in turn, depend on sputtering conditions of underlayers and magnetic layers. The role of Cr underlayer thickness and sputtering pressure have been reported previously. The present work examines the growth morphology and recording properties of a CoPtCr alloy on Cr underlayers where the deposition conditions such as sputtering pressure and rf bias were independently varied for the Cr underlayer and the magnetic layer. We find that the growth morphology of the magnetic layer is governed primarily by the deposition condition of the Cr underlayer. In particular, increased sputtering pressure for the Cr underlayer produces columnar morphology which induces isolation of the grains in the magnetic layer. This results in a significant reduction in the recording noise due to reduced intergrain exchange coupling. On the other hand, the application of ff bias during the deposition of the magnetic layer promotes more continuous magnetic grains, thereby increasing the recording noise. The observed trends in microstructure and recording noise can be understood qualitatively in terms of Thornton's microstructure diagram and the competition between micromorphological roughness and adatom mobility during the film growth.

Friction/Wear Behaviors of Magnetron Sputtered TiB2-C Composite Films on Ti6Al4V Alloy Substrate

2011 ◽  
Vol 189-193 ◽  
pp. 979-982
Author(s):  
Xiao Jing Xu ◽  
Xin Lan Sheng ◽  
Dan Chen ◽  
Xi Ling Xin ◽  
Kun Tian ◽  
...  
Keyword(s):  
Room Temperature ◽  
Composite Films ◽  
Ti6al4v Alloy ◽  
Wear Properties ◽  
Microstructural Characteristics ◽  
Carbon Doped ◽  
Alloy Substrate ◽  
Sic Films ◽  
Ball On Disc

The microstructure and friction/wear properties of TiB2-C (carbon-doped TiB2) films in TiB2-C/SiC double layer films (SiC films as interlayer) deposited on Ti6Al4V alloy substrate using magnetron sputtering technique at room temperature were investigated. The results show that the TiB2-C films exhibited the microstructural characteristics with nano-scale particles (domains), and the doped-carbon presented in manner of sp3 C-C and sp2 C-C bonds i.e. DLC (diamond-like carbon). The interface between the substrate and the SiC films and the interface between the SiC films and the TiB2-C composite films both showed good adhesion, with obvious element diffusions. As sliding against Si3N4 (silicon nitride) balls (2 mm in radius) using ball-on-disc type wear tester at room temperature under Kokubo simulation body fluid (SBF) and 50g load, the TiB2 -C composite films exhibited the friction coefficient of about 0.14 and the specific wear rate of 10.710-6 mm3 m−1 N−1. It is believed that the superior friction properties of the TiB2-C films are due to the role of the doped-carbon.

scholarly journals The role of microstructural characteristics of additively manufactured alloy 718 on tool wear in machining

2021 ◽  
pp. 103814
Author(s):  
Amir Malakizadi ◽  
Tina Hajali ◽  
Fiona Schulz ◽  
Stefan Cedergren ◽  
Joakim Ålgårdh ◽  
...  
Keyword(s):  
Tool Wear ◽  
Alloy 718 ◽  
Microstructural Characteristics

An efficient approach to modulate the coordination number of yttrium ions for diverse network formation

CrystEngComm ◽  
2019 ◽  
Vol 21 (28) ◽  
pp. 4136-4140 ◽  
Author(s):  
Jiwon Park ◽  
Jin Young Koo ◽  
Hee Cheul Choi
Keyword(s):  
Coordination Number ◽  
Network Formation ◽  
Ligand Concentration ◽  
Efficient Approach ◽  
Active Ligand

Hidden role of water! It acts as a key to determine the coordination number of yttrium by controlling the active ligand concentration.

Reductive nitrosylation of ferric carboxymethylated-cytochrome c

2017 ◽  
Vol 21 (01) ◽  
pp. 1-9 ◽  
Author(s):  
Paolo Ascenzi ◽  
Chiara Ciaccio ◽  
Giovanna De Simone ◽  
Roberto Santucci ◽  
Massimo Coletta
Keyword(s):  
Cytochrome C ◽  
Axial Ligand ◽  
Ligand Concentration ◽  
Anaerobic Conditions ◽  
Reductive Nitrosylation ◽  
Axial Bond ◽  
Kinetics Of ◽  
Mediated Reduction

Horse heart carboxymethylated-cyt[Formula: see text] (CM-cyt[Formula: see text] displays myoglobin-like properties due to the cleavage of the heme-Fe-Met80 axial bond. Here, reductive nitrosylation of CM-cyt[Formula: see text](III) between pH 8.5 and 9.5, at [Formula: see text] 20.0 C, is reported. Under anaerobic conditions, the addition of NO to CM-cyt[Formula: see text](III) leads to the transient formation of CM-cyt[Formula: see text](III)-NO in equilibrium with CM-cyt[Formula: see text](II)-NO[Formula: see text]. In turn, CM-cyt[Formula: see text](II)-NO[Formula: see text] is converted to CM-cyt[Formula: see text](II) by OH[Formula: see text]-based catalysis. Then, CM-cyt[Formula: see text](II) binds NO very rapidly leading to CM-cyt[Formula: see text](II)-NO. Kinetics of NO binding to CM-cyt[Formula: see text](III) is independent of the ligand concentration, [Formula: see text] values ranging between 3.6 ± 0.4 s[Formula: see text] and 7.1 ± 0.7 s[Formula: see text]. This indicates that the formation of the CM-cytc(III)-NO complex is rate-limited by the cleavage of the weak heme-Fe(III) distal bond (likely Lys79). The conversion of CM-cyt[Formula: see text](III)-NO to CM-cyt[Formula: see text](II)-NO is rate-limited by the OH[Formula: see text]-mediated reduction of CM-cyt[Formula: see text](II)-NO[Formula: see text] ([Formula: see text] (1.2 ± 0.1) × 103 M[Formula: see text].s[Formula: see text]. Lastly, the very fast nitrosylation of CM-cyt[Formula: see text](II) takes place, values of [Formula: see text] ranging between[Formula: see text]5.3 × 106 M[Formula: see text].s[Formula: see text] and 1.4 × 107 M[Formula: see text].s[Formula: see text]. These results indicate that CM-cyt[Formula: see text] behaves as the cardiolipin-cyt[Formula: see text] complex highlighting the role of the sixth axial ligand of the heme-Fe atom in the modulation of the metal-based reactivity.

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