scholarly journals Biomimetic silica deposition promoted by sub-5 μm complexes of dicarboxylic acids/polyethyleneimine microballs: a new approach to tuning silica structures using messenger-like dicarboxylic acids

RSC Advances ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 435-443
Author(s):  
Daiki Soma ◽  
Ren-Hua Jin
Keyword(s):  
Dicarboxylic Acids ◽  
Surface Structures ◽  
Acid Base ◽  
New Approach ◽  
Silica Deposition

Acid–base complexes prepared from sub-5 μm polyethyleneimine microballs and dicarboxylic acids promoted silica deposition to give silica microballs with different morphological surface structures which were controlled by the structures of the acids.

scholarly journals An Evaluation of the use of Laser-Vibration Melting to Increase the Surface Roughness of Metal Objects

2015 ◽  
Vol 60 (1) ◽  
pp. 33-39 ◽  
Author(s):  
B. Grabas
Keyword(s):  
Surface Roughness ◽  
Laser Beam ◽  
Laser Power ◽  
Surface Structures ◽  
Scanning Velocity ◽  
New Approach ◽  
Practical Applications ◽  
Microscopic Evaluation ◽  
Heating Surfaces ◽  
Laser Beam Scanning

Abstract This paper presents preliminary, experimental results of a new, hybrid method of increasing the surface roughness of metal objects. In this new approach, metal objects are melted with a mobile laser beam while they are being rotated. A vibration generator provides circular vibrations with an amplitude of 3 mm, and the vibration plane is perpendicular to the moving laser beam. The melting tests were performed using flat carbon steel samples at a predetermined frequency of circular vibrations. The effects of laser power and laser beam scanning velocity on the melted shapes were studied. All laser melting procedures were performed at a vibration frequency of 105 Hz. The melted samples were subjected to microscopic evaluation and the Ra parameter, which characterises mean roughness, was measured using a profilometer. Melting metal samples with physically smooth surfaces (Ra = 0.21 µm) resulted in surface structures of varied roughness values, with Ra ranging from 5 µm to approximately 58 µm. The studies were undertaken to employ this technology for the purpose of passive heat exchange intensification of heating surfaces in practical applications.

THE CASE FOR ORDER-N METHODS IN LEED THEORY

1997 ◽  
Vol 04 (05) ◽  
pp. 901-905
Author(s):  
J. B. PENDRY
Keyword(s):  
Electron Diffraction ◽  
Point Source ◽  
Surface Structure ◽  
Time Evolution ◽  
Low Energy ◽  
Surface Structures ◽  
New Approach ◽  
Low Energy Electron Diffraction ◽  
Low Energy Electron ◽  
Moderate Complexity

Low energy electron diffraction experiments have superb sensitivity to surface structure, but rely on sophisticated theory for their interpretation. Advances in computer power, and developments in the theory itself, enable us to handle surface structures of moderate complexity. For future advances we must look to a completely new approach and the case is made for order-N methods which follow the time evolution of a point source of electrons to generate all beams for all angles of incidence and all energies in one shot.

Unified Approximations: A New Approach for Monoprotic Weak Acid-Base Equilibria

2004 ◽  
Vol 81 (9) ◽  
pp. 1367 ◽  
Author(s):  
Harry L. Pardue ◽  
Ihab N. Odeh ◽  
Teweldemedhin M. Tesfai
Keyword(s):  
Weak Acid ◽  
Acid Base ◽  
New Approach

scholarly journals Interaction between Dicarboxylic Acid and Sulfuric Acid-Base Clusters Enhances New Particle Formation

2018 ◽  
Author(s):  
Yun Lin ◽  
Yuemeng Ji ◽  
Yixin Li ◽  
Jeremiah Secrest ◽  
Wen Xu ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Organic Acids ◽  
Critical Nucleus ◽  
Dicarboxylic Acids ◽  
Particle Formation ◽  
Water Molecules ◽  
New Particle Formation ◽  
Acid Base ◽  
Covalent Bonds ◽  
Acid And Base

Abstract. Dicarboxylic acids are believed to stabilize pre-nucleation clusters and facilitate new particle formation in the atmosphere, but the detailed mechanism leading to the formation of multi-component critical nucleus involving organic acids, sulfuric acid (SA), base species, and water remains unclear. In this study, theoretical caculations are performed to elucidate the interactions between succinic acid (SUA) and clusters consisting of SA-ammonia (AM)/dimethylamine (DMA) in the presence of hydration of up to six water molecules. Formation of the hydrated SUA·SA·base clusters by adding one SUA molecule to the SA·base hydrates is energetically favorable. The addition of SUA to the SA·base hydrates either triggers proton transfer from SA to the base molecule, resulting in formation of new covalent bonds, or strengthens the pre-existing covalent bonds. The presence of SUA promotes hydration of the SA·AM and SA·AM·DMA clusters but dehydration of the SA·DMA clusters. At equilibrium, the uptake of SUA competes with the uptake of the second SA molecule to stabilize the SA·base clusters at atmospherically relevant concentrations. The clusters containing both the base and organic acid are capable of further binding with acid molecules to promote their subsequent growth. Our results indicate that the multi-component nucleation involving organic acids, sulfuric acid, and base species promotes new particle formation in the atmosphere, particularly under polluted conditions.

Hydrogen bonded supramolecular network in organic salts: crystal structures of acid–base salts of dicarboxylic acids and amines

CrystEngComm ◽  
2002 ◽  
Vol 4 (24) ◽  
pp. 135-142 ◽  
Author(s):  
Amar Ballabh ◽  
Darshak R. Trivedi ◽  
Parthasarathi Dastidar ◽  
Eringathodi Suresh
Keyword(s):  
Crystal Structures ◽  
Dicarboxylic Acids ◽  
Supramolecular Network ◽  
Acid Base ◽  
Organic Salts ◽  
Hydrogen Bonded

Ab initio determination of edge surface structures for dioctahedral 2:1 phyllosilicates: implications for acid-base for reactivity

2003 ◽  
Vol 51 (4) ◽  
pp. 359-371 ◽  
Author(s):  
Barry R. Bickmore ◽  
Kevin M. Rosso ◽  
Kathryn L. Nagy ◽  
Randall T. Cygan ◽  
Christopher J. Tadanier
Keyword(s):  
Ab Initio ◽  
Surface Structures ◽  
Acid Base ◽  
Edge Surface

New approach in the treatment of data from an acid–base potentiometric titration

2002 ◽  
Vol 375 (2) ◽  
pp. 217-222 ◽  
Author(s):  
Vania Maslarska ◽  
Jasmina Tencheva ◽  
Omortag Budevsky
Keyword(s):  
Potentiometric Titration ◽  
Acid Base ◽  
New Approach

The Influence of Surface Structure on the Interaction of Water with TiO2 (100)

1994 ◽  
Vol 357 ◽  
Author(s):  
Michael A. Henderson
Keyword(s):  
Surface Structure ◽  
Thermal Desorption ◽  
Surface Interaction ◽  
Surface Structures ◽  
Crystal Face ◽  
Acid Base ◽  
Unique Surface ◽  
The Way ◽  
Base Properties

AbstractThe influence of surface structure on the interaction of water with TiO2(100) (rutile) was investigated. Two unique surface structures of the (100) crystal face can be prepared by oxidation (the bulk-terminated surface) and by vacuum reduction (the {110}-microfaceted surface). Thermal desorption profiles, which measure of the strength of the adsorbate-surface interaction, indicate that submonolayer coverages of water are more stable on the bulk-terminated surface than on the {110}- microfaceted surface. Also, subtle differences exist in the way water interacts with 2-coordinate 02 sites on these two surfaces. The implications of these results are considered for the acid/base properties of microcrystalline particles.

scholarly journals Electrometric Determination Of Binary Mixtures In Food

2021 ◽  
Vol 03 (06) ◽  
pp. 8-13
Author(s):  
Narbek Sapaevich Palvanov ◽  
◽  
Mukhiddin Sultanovich Mekhmanov ◽  
Keyword(s):  
Aqueous Solutions ◽  
Binary Mixtures ◽  
Dicarboxylic Acids ◽  
Potentiometric Determination ◽  
Acid Base ◽  
Acid Base Titration

In this paper, the possibility of acid-base titration of binary mixtures of dicarboxylic acids in mixed and non-aqueous solutions is investigated. The possibility of titrimetric potentiometric determination of binary mixtures of dicarboxylic acids is shown.

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