scholarly journals The Identification of Multiple Crystalline Zinc Soap Structures Using Infrared Spectroscopy

2020 ◽  
Vol 74 (12) ◽  
pp. 1505-1514 ◽  
Author(s):  
Joen Hermans ◽  
Kate Helwig
Keyword(s):  
Infrared Spectroscopy ◽  
Cross Section ◽  
Paint Layer ◽  
Stretch Vibration Band ◽  
Vibration Band ◽  
Widespread Application ◽  
Depth Analysis ◽  
Zinc Salts ◽  
Common Sign ◽  
Microscopy Data

The formation of crystalline zinc soaps (zinc salts of fatty acids) in oil paint layers is a common sign of paint degradation. In this study, we have used infrared spectroscopy to systematically identify differences in structure and composition of crystalline zinc soap phases, and report data analysis methods for structure attribution in challenging oil paint samples. Supported by reported crystal structures, it was possible to distinguish two distinct types of zinc soap geometry: a highly symmetrical packing for long-chain saturated soaps (type B) and an alternating packing for zinc soaps with short, unsaturated, or dicarboxylic chains (type A). These two types of packing can be identified by a single or split asymmetric COO stretch vibration band. With this new information, we studied the structure and composition of zinc soaps formed in a zinc white model paint and in a cross-section from the painting Equations in Space by Lawren Harris. Using non-negative matrix factorization, band integration and band position maps, it was possible to clearly identify zinc azelate in the model paint and map its spatial distribution. The same methods showed that the paint cross-section contained both types of zinc soap structure within the same paint layer, with the less symmetrical structure appearing only at the interface with the ground layer. The results give valuable information on the internal chemistry of oil paint layers, and the demonstrated methods can find widespread application for in-depth analysis of infrared microscopy data.

scholarly journals Comparative Study of Two Nanoindentation Approaches for Assessing Mechanical Properties of Ion-Irradiated Stainless Steel 316

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 719 ◽  
Author(s):  
Michael Saleh ◽  
Zain Zaidi ◽  
Christopher Hurt ◽  
Mihail Ionescu ◽  
Paul Munroe ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cross Section ◽  
Ion Irradiation ◽  
Thin Layers ◽  
Experimental Conditions ◽  
Irradiation Energy ◽  
Depth Analysis ◽  
Deformation Processes ◽  
Stainless Steel 316 ◽  
Hardness Values

Nanoindentation is a commonly used method to measure the hardness of surfaces with thin layers, and is especially useful in studying the change in mechanical properties of ion irradiated materials. This research compares two different methods of nanoindentation to study the changes in hardness resulting from ion irradiation of SS316 alloy. The samples were irradiated by He2+ ions at beam energies of 1, 2, and 3 MeV, respectively. The first method involves the indentation of the irradiated surface perpendicular to it using the continuous stiffness mode (CSM), while the second applies the indents on an oblique surface, accessing an inclined cross-section of the irradiated material. Finite element modelling has been used to further illuminate the deformation processes below the indents in the two methods. The hardness profiles obtained from the two nanoindentation methods reveal the differences in the outcomes and advantages of the respective procedures, and provide a useful guideline for their applicability to various experimental conditions. It is shown through an in depth analysis of the results that the ‘top-down’ method is preferable in the case when the ion irradiation energy, or, equivalently, the irradiated depth is small, due to its greater spatial resolution. However, the oblique cross section method is more suitable when the ion irradiation energy is >1 MeV, since it allows a more faithful measurement of hardness as a function of dose, as the plastic field is much smaller and more sensitive to local hardness values.

Triply Coupled Vibration Band Gaps in Periodic Thin-Walled Open Cross Section Beams

2005 ◽  
Author(s):  
Dianlong Yu ◽  
Yaozong Liu ◽  
Jing Qiu ◽  
Gang Wang ◽  
Jihong Wen
Keyword(s):  
Cross Section ◽  
Expansion Method ◽  
Band Gaps ◽  
Vibration Band ◽  
Coupled Vibration ◽  
Plane Wave Expansion Method ◽  
Filling Fraction ◽  
Thin Walled ◽  
Gap Width ◽  
Open Cross Section

Triply coupled vibration through periodic thin-walled open cross section nonsymmetrical beams composed of two kinds of material is studied in this paper. Based on the triply coupled vibration equation, plane wave expansion method for the thin-walled beams is provided. If the filling fraction keeps constant, the lattice is one of the factors that affect the normalized gap width. If the lattice and filling fraction keep constant, the Young’s modulus contrast plays a fundamental role for the band gap width, but not density contrast. Finally, the frequency response of a finite periodic binary beam is simulated with finite element method, which provides an attenuation of over 20dB in the frequency range of the band gaps. The findings will be significant in the application of phononic crystals.

scholarly journals Improving the laser engraving quality of padpainted and spray-painted mechatronic devices

2019 ◽  
Vol 299 ◽  
pp. 06004
Author(s):  
Ion Cristian Braga ◽  
Razvan Udroiu ◽  
Anisor Nedelcu
Keyword(s):  
Optical Microscopy ◽  
Cross Section ◽  
Cost Reduction ◽  
Paint Layer ◽  
Measuring Techniques ◽  
Ultrasonic Measuring ◽  
Coating Layers ◽  
The Cost ◽  
Different Thickness

Considering the cost reduction in automotive processes, in the case of mechatronic devices that use2-3 colours for symbols, a solution is to replace the multi-component molding injection with the painting of a white component substrate in different colours. However, combined painting techniques, namelypad-painting and spray-painting, can lead to many risks, especially when those symbols are obtained bylaser etching, so removing the final paint layer to let only the first coloured layer be visible. The paper's aim is to present the analysis and reduction of the variation due to the different thickness of the coating layers as well as their drying level by using the ultrasonic measuring techniques and the optical microscopy cross-section to reduce the over-adjusting of the engraving parameters and to improve the final quality of the symbols.

IR and Sims Study of Hydrogen Diffusion in RF Sputter Deposited Boron Doped a-Si:H and Undoped a-Ge:H

1989 ◽  
Vol 149 ◽  
Author(s):  
S. Mitra ◽  
X.-L. Wu ◽  
R. Shinar ◽  
J. Shinar
Keyword(s):  
Hydrogen Diffusion ◽  
Secondary Ion Mass Spectrometry ◽  
Stretch Vibration Band ◽  
Vibration Band ◽  
Boron Doped ◽  
Multiple Trapping ◽  
Stretch Vibration ◽  
Order Of Magnitude ◽  
Sputter Deposited ◽  
Secondary Ion

ABSTRACTSecondary ion mass spectrometry (SIMS) and IR measurements of long range deuterium motion in rf sputter deposited (rf sp) p-doped a-Si:H and undoped a-Ge:H are compared to recently published results on undoped rf sp a-Si:H, which exhibited strongly power-law time dependent diffusion constants (exponent α= 0.75±0.1) in films of as-deposited content of di-H and tri-H bonds (usually associated with microvoids) Ndo –4–5 at.%. In pdoped a-Si:H samples where Ndo-l.8–3.8at.%, the diffusion is much faster, but the exponent is similar. In undoped a-Ge:H exhibiting a stretch vibration band indicative of mono-H bonding only, the diffusion is about one order of magnitude faster than in undoped a-Si:H, and α = 0.23. The results are discussed in relation to both the multiple trapping (dispersive) and defect mediated diffusion models.

scholarly journals THE INTERPLAY BETWEEN EARTHEN LANDSCAPE HERITAGE AND SOCIO-POLITICAL DEVELOPMENTS IN THE NORTHERN WEI DYNASTY: A VIEW FROM ARCHAEOLOGY

2021 ◽  
Vol VIII-M-1-2021 ◽  
pp. 209-214
Author(s):  
Y. Zhao ◽  
C. Xu
Keyword(s):  
Landscape Archaeology ◽  
Cultural Development ◽  
Widespread Application ◽  
Archaeological Data ◽  
The Social ◽  
Depth Analysis ◽  
Northern Wei ◽  
Northern Wei Dynasty ◽  
Archaeological Excavations ◽  
Wei Dynasty

Abstract. In the past two decades, landscape archaeology has undergone a paradigm shift from traditional theoretical methods to being practically oriented, with the advent of the widespread application of philosophical theories (such as phenomenology, hermeneutics, and others) and the emerging new technologies in social sciences. Nevertheless, landscape archaeology has not been able to garner the attention it requires from Chinese archaeology, which fails to understand its significance behind the systematic regional survey methods. Rather, for a long time, the study of the man-land relationship has been considered to be a part of environmental archaeology. Besides, the landscape elements in archaeological excavations were often considered as mechanical interactions between people and the environment, resulting in a lack of holistic and systematic research on a selection of archaeological sites. The focus however has remained restricted to the earthen remains and relics in the archaeological process. The Northern Wei Dynasty was the first nomadic regime to control the Central Plains in the Chinese history and moved its capital three times for the purpose of sinicization. The recent archaeological excavations of the ancient city of Shengle, imperial palaces, tombs, sacrificial sites, gardens, Yinshan palaces, and the border defense facilities during the Shengle period of the Northern Wei Dynasty have revealed several phenomena and evidence of the cultural integration of the various ethnic groups. As mentioned earlier, the limitations in the research horizon have led to the in-depth analysis and research of archaeological relics and archaeological data during this period seeking the desired attention. This study considers landscape archaeology, anthropology, sociology, and history as the primary research methods pertinent to the above situation. It considers archaeological relics and archaeological data from the prosperous period as the research object and thoroughly analyses the relationship between the people and the earthen landscape relics, to reveal the social culture, the religious beliefs, the politics, and the military behind the integration of the multi-ethnic culture, along with the cognition of the natural environments, the social structures, and the religious spaces. Simultaneously, the analysis results would also endeavor to integrate the artifacts, the relics (space, structure, layout, and locational relationship), road grids, surrounding environment, and several other surface space elements to restore and reproduce the prosperous social and cultural situations scenes of the bygone period. The final outcome shall become a typical research case. By comparing and combing the archaeological discoveries of the Northern and the Southern Dynasties of China and the pertinent archaeological data, we could further understand and explain the multi-ethnic cultural development and evolution while providing an essential theoretical basis for the present social and cultural research on the Northern Wei Dynasty in China.

scholarly journals Towards routine study of hydrogenous materials using powder neutron diffraction

2014 ◽  
Vol 70 (a1) ◽  
pp. C1739-C1739
Author(s):  
Paul Henry
Keyword(s):  
Neutron Diffraction ◽  
Single Crystal ◽  
Cross Section ◽  
Materials Science ◽  
Incoherent Scattering ◽  
Scattering Cross Section ◽  
Incident Neutron ◽  
Widespread Application ◽  
Scattering Cross ◽  
Powder Neutron Diffraction

Hydrogen (1H) is an element that is ubiquitous in chemistry and materials science. Neutron diffraction is the preferred technique for studying 1H-containing compounds, but is complicated by the high incoherent scattering cross section, which also varies with wavelength. This variation of scattering cross section as a function of wavelength/energy and chemical environment is not well understood.[1-2] This is surprising as it is the largest contributing factor to the scattering properties used in single crystal and powder neutron diffraction experiments to calculate the optimal sample size for hydrogen containing compounds and the tabulated data are given for fixed neutron velocity of 2200 m s-1 (approximately 1.8 Å). The use and current limitations of certain current generation neutron diffraction instruments to probe 1H materials has recently been described.[3] Here, I present work to validate an empirical correction for the incoherent scattering cross section of 1H as a function of incident neutron wavelength in the range 0.5 - 10 Å using continuous source, monochromatic wavelength measurements. The practical use of this is that a, potentially quantitative, correction for all neutron diffraction data, including time-of-flight (TOF) from pulsed sources, as a function of scattering angle and neutron path length will become possible. Implementation of methodology that allows routine H position definition from easily synthesised material (i.e. non-isotopically enriched, and in polycrystalline or small single crystal (≤ 50 μm) form) for both TOF and monochromatic neutron instruments would be both of widespread application. Additionally, i will present work on an instrument concept for a pulsed monochromatic powder diffractometer for the ESS, which will be built in Lund by the end of the current decade. This diffractometer will aim to specialise in the data collection and analysis of hydrogenous materials using a combination of diffraction and inelastic techniques.

Doubly coupled vibration band gaps in periodic thin-walled open cross-section beams

2005 ◽  
Vol 14 (8) ◽  
pp. 1501-1506 ◽  
Author(s):  
Yu Dian-Long ◽  
Liu Yao-Zong ◽  
Qiu Jing ◽  
Wang Gang ◽  
Wen Ji-Hong
Keyword(s):  
Cross Section ◽  
Band Gaps ◽  
Vibration Band ◽  
Coupled Vibration ◽  
Thin Walled ◽  
Open Cross Section

scholarly journals Development of a Fast-Spectrum Self-Powered Neutron Detector for Molten Salt Experiments in the Versatile Test Reactor

2021 ◽  
Vol 253 ◽  
pp. 05006
Author(s):  
K. C. Goetz ◽  
S. M. Cetiner ◽  
C. Celik
Keyword(s):  
Cross Section ◽  
Neutron Detector ◽  
Nuclear Reactions ◽  
Neutron Cross Section ◽  
Nuclear Data ◽  
Data File ◽  
Fast Neutrons ◽  
Flux Monitor ◽  
Depth Analysis ◽  
Self Powered

The self-powered neutron detector (SPND) is a widely used flux monitor in thermal nuclear reactors. Although this is a mature technology, the current state of the art is tuned for a thermal neutron spectrum, so many of the devices currently in use lack sensitivity to fast neutrons. Because current in SPNDs is produced through nuclear reactions with the neutron flux inside a reactor, sensitivity in SPNDs is determined by the neutron cross section of the neutron-sensitive portion of the detector, termed the emitter. This neutron cross section drops by orders of magnitude between thermal and fast neutron energies for many emitters in currently used SPNDs, with a corresponding drop in current from the detector. This paper discusses efforts to develop a fast-spectrum self-powered neutron detector (FS-SPND) that is sensitive to neutrons with energies ranging from 0.025 eV up to 1 MeV. An in-depth analysis of Evaluated Nuclear Data File (ENDF)/B-VII.1 neutron-capture cross sections was performed, and four new materials were identified that are suitable emitter candidates for use in measuring fast neutrons. All four materials are stable mid-shell nuclei in the region between doubly magic 132Sn and 208Pb. Each candidate was simulated with the Geant4 Monte Carlo simulation toolkit to optimize overall detector efficiency.

scholarly journals Dark matter, fine-tuning and (g-2)_{\mu} in the pMSSM

2021 ◽  
Vol 11 (3) ◽  
Author(s):  
Melissa van Beekveld ◽  
Wim Beenakker ◽  
Marrit Schutten ◽  
Jeremy De Wit
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Cross Section ◽  
Direct Detection ◽  
Fine Tuning ◽  
Dark Matter Relic Density ◽  
Depth Analysis ◽  
Relic Density ◽  
The Right ◽  
First Time

In this paper we perform for the first time an in-depth analysis of the spectra in the phenomenological supersymmetric Standard Model that simultaneously offer an explanation for the (g-2)_{\mu}(g−2)μ discrepancy \Delta a_{\mu}Δaμ, result in the right dark-matter relic density \Omega_{DM} h^2ΩDMh2 and are minimally fine-tuned. The resulting spectra may be obtained from [1]. To discuss the experimental exclusion potential for our models, we analyse the resulting LHC phenomenology as well as the sensitivity of dark-matter direct detection experiments to these spectra. We find that the latter type of experiments with sensitivity to the spin-dependent dark-matter–nucleon scattering cross section \sigma_{SD,p}σSD,p will probe all of our found solutions.

THE KINETICS AND INFRARED SPECTROSCOPY OF C1 HYDROCARBONS ADSORBED ON CLEAN AND OXYGEN-MODIFIED Mo(100)

1999 ◽  
Vol 06 (01) ◽  
pp. 13-21 ◽  
Author(s):  
GEFEI WU ◽  
M. KALTCHEV ◽  
W. T. TYSOE
Keyword(s):  
Infrared Spectroscopy ◽  
Surface Chemistry ◽  
Cross Section ◽  
Infrared Spectra ◽  
Infrared Absorption ◽  
Spectroscopic Data ◽  
New Feature

The surface infrared spectra (700–2300 cm -1) of CH 3 I , CD 3 I , CH 2 I 2 and CD 2 I 2 adsorbed on Mo(100) at 80 K have been observed and assigned. The strongest infrared absorption of CH 3 I is the δs( CH 3) mode at 1236 cm -1, which shifts significantly on heating the surface to 135 K, yielding a new peak at 1106 cm -1 indicating the formation of a surface- CH 3 species. This new feature dominates the spectrum after annealing to 160 K and disappears at 235 K, where the TPD results show the desorption of methane. This chemistry was also studied on oxygen-covered Mo(100) with oxygen coverages of 1.0 and 1.5. These were not found to substantially affect the surface chemistry. When CH 2 I 2 is adsorbed on Mo(100), the ω( CH 2) mode at 1107 cm -1 is the strongest feature, and when one heats the sample to 135 K, a new peak appears at 1061 cm -1 which is ascribed to the formation of a surface- CH 2 I species. This peak disappears on heating at about 200 K, where previous ultraviolet-photoelectron-spectroscopic data showed the formation of a surface- C 1 species. No RAIRS data have been reported for adsorbed-methylene species, because of either a low-adsorption cross section or the lack of appropriate symmetry of these modes. The deuterated molecules show the same effects except that peaks are shifted as expected so that ν(H)/ν(D) ~1.35.

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