An Exact Method to Determine the Chain Axis Orientation Distribution in High Performance Fibers from a Single Inter-Chain Reflection

1988 ◽  
Vol 134 ◽  
Author(s):  
Ravi F. Saraf ◽  
T.J. Watson
Keyword(s):  
High Performance ◽  
Orientation Distribution ◽  
Inversion Method ◽  
Computation Method ◽  
Axis Orientation ◽  
Complete Chain ◽  
Orientation Function ◽  
Two Samples ◽  
Chain Axis ◽  
Oriented Polyethylene

ABSTRACTAn exact pole inversion method is used to calculate the complete chain-axis orientation distribution from a single inter-chain reflection. A brief outline of the formulation and computation method is given. This method is demonstrated by comparing the measured chain-axis distribution from a (002) reflection of oriented polyethylene samples, to the calculated distribution from (110) and (200) reflections of the same sample. The error in the Hermans Orientation function is less than 0.5% for the two samples tested.

MISORIENTATION DISTRIBUTION FUNCTION FOR CUBIC CRYSTALS

2019 ◽  
Vol 85 (5) ◽  
pp. 28-32
Author(s):  
A. S. Kolyanova ◽  
Y. N. Yaltsev
Keyword(s):  
Distribution Function ◽  
Grain Boundaries ◽  
Orientation Distribution ◽  
Recrystallization Annealing ◽  
Misorientation Distribution ◽  
Cubic Crystals ◽  
Special Boundaries ◽  
Pole Figures ◽  
Two Samples ◽  
Euler Space

A calculation method for obtaining the misorientation distribution function (MDF) for cubic crystals which can be used to estimate the presence or absence of special boundaries in the materials is presented. The calculation was carried out for two samples of Al-Mg-Si alloy subjected to various mechanical and thermal treatments: the first sample is subjected to rolling; the second sample is subjected to recrystallization annealing. MDF is calculated for each sample; the results are presented in the Euler space and in the angle-axis space. The novelty of the method consists in the possibility of gaining data on the grain boundaries from X-ray texture analysis without using electron microscopy. A calculation involving only mathematical operations on matrices was performed on the basis of the orientation distribution function restored from incomplete pole figures. It is shown that no special boundaries are observed in the deformed sample, whereas in the recrystallized alloy, special boundaries are detected at Ʃ = 23, 13, and 17. The shortcoming of the proposed method can be attributed to the lack of accurate data on grain boundaries, since all possible orientation in the polycrystal should be taken into account in MDF calculation.

scholarly journals Novel Mutations inMLH1andMSH2Genes in Mexican Patients with Lynch Syndrome

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Jose Miguel Moreno-Ortiz ◽  
María de la Luz Ayala-Madrigal ◽  
Jorge Román Corona-Rivera ◽  
Manuel Centeno-Flores ◽  
Víctor Maciel-Gutiérrez ◽  
...  
Keyword(s):  
Lynch Syndrome ◽  
High Performance ◽  
Autosomal Dominant ◽  
Immunohistochemical Analysis ◽  
Compound Heterozygous ◽  
Nuclear Staining ◽  
Dna Mismatch ◽  
Two Samples ◽  
Early Onset Colorectal Cancer ◽  
Mexican Patients

Background. Lynch Syndrome (LS) is characterized by germline mutations in the DNA mismatch repair (MMR) genesMLH1,MSH2,MSH6,andPMS2. This syndrome is inherited in an autosomal dominant pattern and is characterized by early onset colorectal cancer (CRC) and extracolonic tumors. The aim of this study was to identify mutations inMMRgenes in three Mexican patients with LS.Methods. Immunohistochemical analysis was performed as a prescreening method to identify absent protein expression. PCR, Denaturing High Performance Liquid Chromatography (dHPLC), and Sanger sequencing complemented the analysis.Results. Two samples showed the absence of nuclear staining for MLH1 and one sample showed loss of nuclear staining for MSH2. The mutations found inMLH1gene were c.2103+1G>C in intron 18 and compound heterozygous mutants c.1852_1854delAAG (p.K618del) and c.1852_1853delinsGC (p.K618A) in exon 16. In theMSH2gene, we identified mutation c.638dupT (p.L213fs) in exon 3.Conclusions. This is the first report of mutations in MMR genes in Mexican patients with LS and these appear to be novel.

scholarly journals Orientation analysis of pentacene molecules in organic field-effect transistor devices using polarization-dependent Raman spectroscopy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Bishwajeet Singh Bhardwaj ◽  
Takeshi Sugiyama ◽  
Naoko Namba ◽  
Takayuki Umakoshi ◽  
Takafumi Uemura ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Charge Carrier ◽  
Molecular Orientation ◽  
Field Effect ◽  
High Performance ◽  
Carrier Mobility ◽  
Field Effect Transistors ◽  
Charge Carrier Mobility ◽  
Orientation Distribution ◽  
High Resolution Technique

Abstract Pentacene, an organic molecule, is a promising material for high-performance field effect transistors due to its high charge carrier mobility in comparison to usual semiconductors. However, the charge carrier mobility is strongly dependent on the molecular orientation of pentacene in the active layer of the device, which is hard to investigate using standard techniques in a real device. Raman scattering, on the other hand, is a high-resolution technique that is sensitive to the molecular orientation. In this work, we investigated the orientation distribution of pentacene molecules in actual transistor devices by polarization-dependent Raman spectroscopy and correlated these results with the performance of the device. This study can be utilized to understand the distribution of molecular orientation of pentacene in various electronic devices and thus would help in further improving their performances.

The effect of management and employee perspectives of high-performance work systems on employees’ discretionary behaviour

2016 ◽  
Vol 45 (1) ◽  
pp. 121-141 ◽  
Author(s):  
Unai Elorza ◽  
Christopher Harris ◽  
Aitor Aritzeta ◽  
Nekane Balluerka
Keyword(s):  
Structural Equation ◽  
High Performance ◽  
Manufacturing Companies ◽  
Work Systems ◽  
Content Type ◽  
Organizational Contexts ◽  
Individual Level ◽  
High Performance Work Systems ◽  
Two Samples ◽  
The Relationship

Purpose – The purpose of this paper is to understand how management and employee perspectives of high-performance work systems (HPWS) relate to employee discretionary behaviour. In addition, the paper examines to what extent the relationship between employees’ perception of the HPWS and discretionary behaviour varies among different organizations/groups. Design/methodology/approach – Two samples were used in the study. The first sample included data from 51 managers and 1,023 employees from 26 manufacturing companies. The second sample included 52 managers and 6,382 employees from 42 manufacturing companies. Findings – The study shows that employee rated HPWS mediates the relationship between management rated HPWS and individual-level discretionary behaviour. Moreover, results showed that the effect of employee rated HPWS on discretionary behaviour varies among different organizations/groups. Practical implications – Results show that employee perceptions of the HPWS more strongly predict employees’ discretionary behaviour than management rated HPWS. Moreover, it shows that employees’ perceptions of the same HPWS, but operating in different organizational contexts exhibit different levels of discretionary behaviour. Originality/value – The study differentiates between management and employee perspectives of the HPWS. It also examines the variability of the relationship between HPWS and discretionary behaviour. Multilevel structural equation modelling is used to test the hypotheses.

Recent Advances in Morphology and Mechanical Properties of Rigid-Rod Molecular Composites

1989 ◽  
Vol 171 ◽  
Author(s):  
Stephen J. Krause ◽  
Wen-Fang Hwang
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Low Voltage ◽  
Orientation Distribution ◽  
Short Fiber ◽  
Chain Polymer ◽  
Structural Applications ◽  
Molecular Composites ◽  
Rigid Rod ◽  
Aromatic Heterocyclic

ABSTRACTRigid-rod molecular composites are a new class of high performance structural polymers which have high specific strength and modulus and also high thermal and environmental resistance. The concept of using a rigid-rod, extended chain polymer to reinforce a ductile polymer matrix at the molecular level has been demonstrated with morphological and mechanical property studies for aromatic heterocyclic systems, but new materials systems and processing techniques will be required to produce thermoplastic or thermoset molecular composites. Improved characterization and modeling will also be required. In this regard, new results on modeling of mechanical properties of molecular composites are presented and compared with experimental results. The Halpin-Tsai equations from ‘shear-lag’ theory of short fiber composites predict properties reasonably well when using the theoretical modulus of rigid-rod molecules in aromatic heterocyclic systems, but newer matrix systems will require consideration of matrix stiffness, desired rod aspect ratio, and rod orientation distribution. Application of traditional and newer morphological characterization techniques are discussed. The newer techniques include: Raman light scattering, high resolution and low voltage SEM, parallel EELS in TEM, synchrotron radiation in X-ray scattering, and ultrasound for integrity studies. The properties of molecular composites and macroscopic composites are compared and it is found that excellent potential exists for use of molecular composites in structural applications including engineering plastics, composite matrix resins, and as direct substitutes for fiber reinforced composites.

Crystallite Orientation Distribution in Biaxially Oriented Polyethylene

1968 ◽  
Vol 49 (4) ◽  
pp. 1532-1542 ◽  
Author(s):  
W. R. Krigbaum ◽  
T. Adachi ◽  
J. V. Dawkins
Keyword(s):  
Orientation Distribution ◽  
Crystallite Orientation ◽  
Oriented Polyethylene

scholarly journals On the aspect ratio of ’Oumuamua : less elongated shape for irregular surface properties

2020 ◽  
Vol 493 (2) ◽  
pp. 1546-1552 ◽  
Author(s):  
Allona Vazan ◽  
Re’em Sari
Keyword(s):  
Aspect Ratio ◽  
Light Curve ◽  
Surface Properties ◽  
Specular Reflection ◽  
Orientation Distribution ◽  
Brightness Variation ◽  
Spin Axis ◽  
Isotopic Spin ◽  
Axis Orientation ◽  
Surface Reflection

ABSTRACT The large brightness variation in the observed light curve of ’Oumuamua is probably related to its shape, i.e. to the ratio between its longest axis and its shortest axis (aspect ratio). Several approaches found the aspect ratio of ’Oumuamua to be unusually elongated. Moreover, the spin axis orientation has to be almost perpendicular to the observer in order to obtain such an extreme light curve, a configuration which is unlikely. However, interstellar ’Oumuamua may have different surface properties than we know in our Solar system. Therefore, in this work we widen the parameter space for surface properties beyond the asteroid-like models and study its effect on ’Oumuamua’s light curve. We calculate reflection from a rotating ellipsoidal object for four models: Lambertian reflection, specular reflection, single scattering diffusive, and backscatter . We then calculate the probability to obtain a light-curve ratio larger than the observed, as a function of the object’s aspect ratio, assuming an isotopic spin orientation distribution. We find the elongation of ’Oumuamua to be less extreme for the Lambertian and specular reflection models. Consequently, the probability to observe the light-curve ratio of ’Oumuamua given its unknown spin axis orientation is larger for those models. We conclude that different surface reflection properties may suggest alternatives to the extreme shape of ’Oumuamua , relieving the need for complicated formation scenario, extreme albedo variation, or unnatural origin. Although the models suggested here are for ideal ellipsoidal shape and ideal reflection method, the results emphasize the importance of surface properties for the derived aspect ratio.

A preliminary survey of zearalenone and other mycotoxins in Australian silage and pasture

2009 ◽  
Vol 49 (8) ◽  
pp. 696 ◽  
Author(s):  
K. F. M. Reed ◽  
D. D. Moore
Keyword(s):  
High Performance ◽  
Crude Protein ◽  
Protein Concentration ◽  
Nutritional Assessment ◽  
Preliminary Survey ◽  
Fusarium Spp ◽  
Eastern Australia ◽  
Two Samples ◽  
Feed Samples ◽  
Cattle And Sheep

The oestrogenic mycotoxin zearalenone can occur in pasture and fodder infected with various Fusarium spp., and at concentrations exceeding 1 mg/kg, it has been associated with a reduction in the fertility of grazing ruminants. Pasture and fodder samples collected in four small studies from cattle and sheep farms in south-eastern Australia were tested for zearalenone and other mycotoxins using high performance liquid chromatography. Zearalenone in winter pasture was detected (viz. >0.1 and up to 5.0 mg/kg DM) in 8 of 22 pastures; three exceeded the tolerance concentration, 1.0 mg/kg. Zearalenone was detected in 15 of 24 samples of silage that were submitted by farmers for nutritional assessment, but that were not suspected of toxicity; 12 were in the range 1.0–80 mg/kg. Zearalenone was correlated with crude protein concentration (r = 0.59, P < 0.05); it was high in legume-dominant compared with grass-dominant silage (P < 0.04). In a separate investigation of 28 feed samples submitted for mycotoxin screening by nutritionists/veterinarians, zearalenone was detected in 7 of 13 pastures, in two of two hays and 9 of 13 silages (6 of 28 exceeded 1 mg/kg). Deoxynivalenol was detected in 6 of 13 pastures, one of two hays and 10 of 13 silages. Deoxynivalenol was high (0.64–1.76 mg/kg) in five silages of excellent/average appearance. Ergovaline and lolitrem B were detected at above tolerable concentrations in four of eight perennial ryegrass-dominant samples examined. Aflatoxins, ochratoxin A and fumonisins were detected in some samples although the concentrations were low. Two samples contained either zearalenone and ergovaline, or zearalenone and deoxynivalenol, where both mycotoxins exceeded tolerable concentrations.

Determination of Fumonisins B1 and B2 in Herbal Tea and Medicinal Plants in Turkey by High-Performance Liquid Chromatography

2004 ◽  
Vol 67 (8) ◽  
pp. 1782-1786 ◽  
Author(s):  
GÜLDEN Z. OMURTAG ◽  
DUYGU YAZICIOĞILU
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Medicinal Plants ◽  
High Performance ◽  
Fumonisin B1 ◽  
Black Tea ◽  
Herbal Tea ◽  
Two Samples ◽  
Fumonisin B2

The purpose of this study was to measure the potential levels of fumonisin B1 (FB1) and fumonisin B2 (FB2) contamination in several herbal teas and medicinal plants that are consumed regularly in Turkey. FB1 and FB2 were detected using high-performance liquid chromatography with fluorescence detection after derivatization with o-phthaldialdehyde. A total of 115 commercially available herbal tea and medicinal plant samples were analyzed. The recoveries in black tea were 86.9 ± 8.42% for FB1 and 102 ± 6.80% for FB2 spiked with 1 μg/g of each analyte. Similarly, the mean recovery results in lime (linden) for FB1 and FB2 were 85.2 ± 9.76% and 78.6 ± 5.67%, respectively. The minimum detectable amounts for the o-phthaldialdehyde derivatives of FB1 and FB2 were 0.025 μg/g (1 ng injected) and 0.125 μg/g (5 ng), respectively. FB1 was detected in two samples (0.160 and 1.487 μg/g), and FB2 was detected in none of the samples.

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