Modulation of β-(BEDT-TTF)2PF6 crystal surface structure induced by charge redistribution in surface layers

1999 ◽  
Vol 433-435 ◽  
pp. 147-151 ◽  
Author(s):  
Masahiko Ishida ◽  
Takehiko Mori ◽  
Hidemi Shigekawa
Keyword(s):  
Surface Structure ◽  
Crystal Surface ◽  
Charge Redistribution ◽  
Surface Layers

Study of the Influence of Technological Factors on the Surface Structure of Aluminum 6000 Series Alloys Ingots

2020 ◽  
Vol 299 ◽  
pp. 938-942
Author(s):  
Leonid Moiseevich Gurevich ◽  
Dmitri Pronichev ◽  
Aleksey Serov
Keyword(s):  
Chemical Composition ◽  
Oxide Film ◽  
Surface Structure ◽  
The State ◽  
Ingot Surface ◽  
Surface Layers ◽  
Technological Factors ◽  
Light Color

The structure and chemical composition of the surface layers of aluminum 6000-series alloys after crystallization and homogenization annealing at 580 °C were investigated. It is shown that the state of the surface significantly depends on the presence of impurities in the coolant of the crystallizer, which deteriorate the continuity of the oxide film, which leads to the formation of light color of individual parts of the ingot surface.

Review of Factors Affecting the Quality of Architectural Concrete

2019 ◽  
Vol 808 ◽  
pp. 9-14
Author(s):  
Jan Sestak ◽  
Monika Utěšená ◽  
Radka Pernicova
Keyword(s):  
Surface Structure ◽  
Main Part ◽  
Quality Evaluation ◽  
Subject Area ◽  
Raw Material ◽  
Surface Layers ◽  
Conventional Concrete ◽  
Factors Affecting ◽  
The Subject

The paper deals with the properties, quality and durability of the exposed concrete. The main part of this paper are characteristic of architectural (sometimes called visible or naked) concrete and the criterion of the quality evaluation of the performed work. This is mainly the colour balance of the subject area, the quantity and the size of the pores, the quality of the raw material and the surface structure. Achieving the quality of architectural concrete is considerably more technologically demanding compared with conventional concrete. This is reflected also in its cost. In conclusion, the problems of surface layers of architectural concrete are summarized. Especially environments can cause faster degradation, reducing the lifetime of the whole construction, but also pointing to one of the main problems in construction, which is technological discipline.

Investigation of the Effect of Reducing the Thickness of Road Surfacing Layers Within the Tolerance Limits on the Reliability and Durability of Highways

2020 ◽  
pp. 43-57
Author(s):  
С. В. Гошовец
Keyword(s):  
Surface Structure ◽  
Layer Thickness ◽  
Negative Impact ◽  
Road Surface ◽  
Tolerance Limits ◽  
Surface Layers ◽  
Design Standards ◽  
Strength Criteria ◽  
The Road ◽  
Road Pavement

Состояние проблемы. Считается, что уменьшение толщины слоя в пределах допуска не оказывает существенного влияния на надежность и долговечность дорожной одежды. Так как конструкция дорожной одежды, как правило, состоит из нескольких слоев, можно предположить, что занижение толщины слоев в пределах допуска может оказать негативное влияние на прочность конструкции в целом. Применительно к отечественным нормам проектирования и строительства данное предположение остается не изученным. Результаты. Проведен анализ показателей, характеризующих толщину слоя, и практик назначения строительных допусков. Проанализированы исследования влияния допуска на надежность дорожной одежды и рекомендации по корректировке толщины слоев конструкции под влиянием допусков. Выполнены моделирование и расчет конструкций с учетом допусков. Выводы. Полученные результаты подтвердили предположение о том, что уменьшение толщины слоев дорожной одежды в пределах допусков негативно влияет на все критерии прочности. Предложено решение по устранению несогласованности между строительными допусками и нормами проектирования. Statement of the problem. Reducing the layer thickness within the tolerance is considered not to have a significant effect on the reliability and durability of the road surface structure. Since the construction of roadways usually consists of several layers, the assumption that understating the thickness of the layers within the tolerance can have a negative impact on the overall strength of the structure is not unreasonable. In relation to the domestic standards for the design and construction of this assumption has not yet been studied. Results. The analysis of indicators characterizing the layer thickness and practices for the purpose of construction tolerances, analysis of recommendations in the design standards for correcting the thickness of the layers of the structure due to the influence of tolerances, studies of the influence of tolerance on the reliability of road pavement, modeling and calculation of structures with allowances, suggestions are provided. Conclusions. The results confirmed the assumption that reducing the thickness of road surface layers within the tolerance limits negatively affects all the strength criteria. We have proposed a solution in order to eliminate inconsistencies between construction tolerances and design standards.

CRYSTAL SURFACE STRUCTURE OF THERMOPLASTIC POLYIMIDE: A POSSIBILITY OF CHAIN FOLDING

1993 ◽  
pp. 1353-1356
Author(s):  
Naoki Kobayashi ◽  
Shigenori Maeda ◽  
Shin Hosonuma ◽  
Kazushi Ohshima
Keyword(s):  
Surface Structure ◽  
Crystal Surface ◽  
Chain Folding

Dispersion of Electronic Surface Resonances and Crystal Surface Structure

1977 ◽  
Vol 38 (24) ◽  
pp. 1422-1425 ◽  
Author(s):  
E. G. McRae ◽  
J. M. Landwehr ◽  
C. W. Caldwell
Keyword(s):  
Surface Structure ◽  
Crystal Surface ◽  
Electronic Surface

Chemical, sorptive and morphological properties of montmorillonite treated with ammonium bifluoride (NH4HF2) solutions

Clay Minerals ◽  
1985 ◽  
Vol 20 (1) ◽  
pp. 81-92 ◽  
Author(s):  
J. Fijal ◽  
M. Zyla ◽  
M. Tokarz
Keyword(s):  
Electron Microscope ◽  
Chemical Composition ◽  
Crystal Surface ◽  
Bulk Sample ◽  
Morphological Properties ◽  
Surface Layers ◽  
Electron Microscopic ◽  
Ammonium Bifluoride

AbstractThe fluorination of montmorillonite by aqueous ammonium bifluoride solution (NH4HF2) has been investigated by chemical, sorptive, porosimetric and electron microscopic methods. Changes in the chemical composition of the montmorillonite during the fluorination were compared both in the crystal surface and in the bulk sample. The accumulation of fluorine was distinctly zonal, being present mainly in the surface layers. The electron microscope studies showed that the 300–400 nm thick macrodomains in the initial montmorillonite were cracked into small microdomains 20–30 nm in thickness, this resulting from disruption in the continuity of the octahedral sheets. These distinct changes in morphology of the montmorillonite aggregates particularly influenced the porosity and sorptive properties.

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