scholarly journals To be or not to be local: a provenance study of archaeological ceramics from Shahr-i Sokhta, eastern Iran

2021 ◽  
Vol 13 (4) ◽  
Author(s):  
Negar Eftekhari ◽  
Parviz Holakooei ◽  
Elena Marrocchino ◽  
Carmela Vaccaro
Keyword(s):  
Compositional Data ◽  
Archaeological Site ◽  
Chemical Components ◽  
Fine Grained ◽  
Eastern Iran ◽  
Wide Range ◽  
The Matrix ◽  
Clay Matrix ◽  
Non Local ◽  
Spectroscopy Studies

AbstractFindings from the archaeological site of Shahr-i Sokhta in eastern Iran include a wide range of undecorated, monochrome, and polychrome ceramics with gray, red, and buff-colored bodies that date back to a period spanning from 3200 to 1800 B.C.E. Given the large number and variety of ceramics unearthed from Shahr-i Sokhta, the provenance of these wares has remained a subject of controversy. Based on compositional data obtained from quantitative wavelength dispersive X-ray fluorescence (WDXRF) spectroscopy studies and petrographic observations, findings from this study provide information that can be used to determine whether the ceramics from Shahr-i Sokhta were manufactured locally or were imported from elsewhere. We show here that the chemical components of a large group of ceramics with gray, red, and buff-colored bodies are similar to those found in local clay sources and kiln wasters, suggesting local production of these wares. However, one group of red and gray-colored wares demonstrated entirely different chemistry, suggesting a different origin. In support of the quantitative WDXRF data, petrofabric analysis of the first group of buff, gray, and red wares revealed poorly sorted basaltic clasts similar to those found randomly distributed in the matrix of local clays. By contrast, the non-local gray and red wares exhibited fine-grained clay bodies with sorted distribution of fine-grained quartz within the clay matrix.

scholarly journals Non-Local and Multi-Scale Mechanisms for Image Inpainting

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3281
Author(s):  
Xu He ◽  
Yong Yin
Keyword(s):  
Markov Random Fields ◽  
Receptive Fields ◽  
Image Inpainting ◽  
Long Distance ◽  
Visual Appearance ◽  
Fine Grained ◽  
Multi Scale ◽  
Non Local ◽  
Relationship Of

Recently, deep learning-based techniques have shown great power in image inpainting especially dealing with squared holes. However, they fail to generate plausible results inside the missing regions for irregular and large holes as there is a lack of understanding between missing regions and existing counterparts. To overcome this limitation, we combine two non-local mechanisms including a contextual attention module (CAM) and an implicit diversified Markov random fields (ID-MRF) loss with a multi-scale architecture which uses several dense fusion blocks (DFB) based on the dense combination of dilated convolution to guide the generative network to restore discontinuous and continuous large masked areas. To prevent color discrepancies and grid-like artifacts, we apply the ID-MRF loss to improve the visual appearance by comparing similarities of long-distance feature patches. To further capture the long-term relationship of different regions in large missing regions, we introduce the CAM. Although CAM has the ability to create plausible results via reconstructing refined features, it depends on initial predicted results. Hence, we employ the DFB to obtain larger and more effective receptive fields, which benefits to predict more precise and fine-grained information for CAM. Extensive experiments on two widely-used datasets demonstrate that our proposed framework significantly outperforms the state-of-the-art approaches both in quantity and quality.

scholarly journals Influence of Alumina Nanofibers Sintered by the Spark Plasma Method on Nickel Mechanical Properties

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 548 ◽  
Author(s):  
Leonid Agureev ◽  
Valeriy Kostikov ◽  
Zhanna Eremeeva ◽  
Svetlana Savushkina ◽  
Boris Ivanov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Strength Properties ◽  
Alumina Nanoparticles ◽  
Metal Powders ◽  
Wide Range ◽  
The Matrix ◽  
Spark Plasma ◽  
Average Size

The article presents the study of alumina nanoparticles’ (nanofibers) concentration effect on the strength properties of pure nickel. The samples were obtained by spark plasma sintering of previously mechanically activated metal powders. The dependence of the grain size and the relative density of compacts on the number of nanofibers was investigated. It was found that with an increase in the concentration of nanofibers, the average size of the matrix particles decreased. The effects of the nanoparticle concentration (0.01–0.1 wt.%) on the elastic modulus and tensile strength were determined for materials at 25 °C, 400 °C, and 750 °C. It was shown that with an increase in the concentration of nanofibers, a 10–40% increase in the elastic modulus and ultimate tensile strength occurred. A comparison of the mechanical properties of nickel in a wide range of temperatures, obtained in this work with materials made by various technologies, is carried out. A description of nanofibers’ mechanisms of influence on the structure and mechanical properties of nickel is given. The possible impact of impurity phases on the properties of nickel is estimated. The tendency of changes in the mechanical properties of nickel, depending on the concentration of nanofibers, is shown.

scholarly journals Estimating the number of usability problems affecting medical devices: modelling the discovery matrix

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Vincent Vandewalle ◽  
Alexandre Caron ◽  
Coralie Delettrez ◽  
Renaud Périchon ◽  
Sylvia Pelayo ◽  
...  
Keyword(s):  
Medical Devices ◽  
Market Access ◽  
Real Life ◽  
Usability Testing ◽  
Probability Of Detection ◽  
Usability Problems ◽  
Usability Problem ◽  
Wide Range ◽  
The Matrix ◽  
Problem Detection

Abstract Background Usability testing of medical devices are mandatory for market access. The testings’ goal is to identify usability problems that could cause harm to the user or limit the device’s effectiveness. In practice, human factor engineers study participants under actual conditions of use and list the problems encountered. This results in a binary discovery matrix in which each row corresponds to a participant, and each column corresponds to a usability problem. One of the main challenges in usability testing is estimating the total number of problems, in order to assess the completeness of the discovery process. Today’s margin-based methods fit the column sums to a binomial model of problem detection. However, the discovery matrix actually observed is truncated because of undiscovered problems, which corresponds to fitting the marginal sums without the zeros. Margin-based methods fail to overcome the bias related to truncation of the matrix. The objective of the present study was to develop and test a matrix-based method for estimating the total number of usability problems. Methods The matrix-based model was based on the full discovery matrix (including unobserved columns) and not solely on a summary of the data (e.g. the margins). This model also circumvents a drawback of margin-based methods by simultaneously estimating the model’s parameters and the total number of problems. Furthermore, the matrix-based method takes account of a heterogeneous probability of detection, which reflects a real-life setting. As suggested in the usability literature, we assumed that the probability of detection had a logit-normal distribution. Results We assessed the matrix-based method’s performance in a range of settings reflecting real-life usability testing and with heterogeneous probabilities of problem detection. In our simulations, the matrix-based method improved the estimation of the number of problems (in terms of bias, consistency, and coverage probability) in a wide range of settings. We also applied our method to five real datasets from usability testing. Conclusions Estimation models (and particularly matrix-based models) are of value in estimating and monitoring the detection process during usability testing. Matrix-based models have a solid mathematical grounding and, with a view to facilitating the decision-making process for both regulators and device manufacturers, should be incorporated into current standards.

Phytochemistry and Pharmacology of the Genus Pedicularis Used in Traditional Chinese Medicine

2014 ◽  
Vol 42 (05) ◽  
pp. 1071-1098 ◽  
Author(s):  
Mao-Xing Li ◽  
Xi-Rui He ◽  
Rui Tao ◽  
Xinyuan Cao
Keyword(s):  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
Chemical Constituents ◽  
Iridoid Glycosides ◽  
In Vivo Studies ◽  
Chemical Components ◽  
Wide Range ◽  
Phenylpropanoid Glycosides

In the present review, the literature data on the chemical constituents and biological investigations of the genus Pedicularis are summarized. Some species of Pedicularis have been widely applied in traditional Chinese medicine. A wide range of chemical components including iridoid glycosides, phenylpropanoid glycosides (PhGs), lignans glycosides, flavonoids, alkaloids and other compounds have been isolated and identified from the genus Pedicularis. In vitro and in vivo studies indicated some monomer compounds and extracts from the genus Pedicularis have been found to possess antitumor, hepatoprotective, anti-oxidative, antihaemolysis, antibacterial activity, fatigue relief of skeletal muscle, nootropic effect and other activities.

Ni Content Surface Layer Produced by Laser Surface Treatment on Amorphisable Cu Base Alloy

2010 ◽  
Vol 649 ◽  
pp. 101-106
Author(s):  
Mária Svéda ◽  
Dóra Janovszky ◽  
Kinga Tomolya ◽  
Jenő Sólyom ◽  
Zoltán Kálazi ◽  
...  
Keyword(s):  
Surface Layer ◽  
Surface Treatment ◽  
Laser Cladding ◽  
Base Alloy ◽  
Laser Surface ◽  
Laser Alloying ◽  
Laser Surface Treatment ◽  
Ni Content ◽  
Wide Range ◽  
The Matrix

The aim of our research was to comparatively examine Ni content surface layers on amorphisable Cu base alloy produced by different laser surface treatments. Laser surface treatment (LST) techniques, such as laser surface melting, laser alloying and laser cladding, provide a wide range of interesting solutions for the production of wear and corrosion resistant surfaces. [1,2] With LST techniques, the surface can be: i) coated with a layer of another material by laser cladding, ii) the composition of the matrix can be modified by laser alloying. [3] Two kinds of laser surface treatment technologies were used. In the case of coating-melting technology a Ni content surface layer was first developed by galvanization, and then the Ni content layer was melted together with the matrix. In the case of powder blowing technology Ni3Al powder was blown into the layer melted by laser beam and Argon gas. LST was performed using an impulse mode Nd:YAG laser. The laser power and the interaction time were 2 kW and 20÷60 ms. The characterization of the surface layer microstructure was performed by XRD, scanning electron microscopy and microhardness measurements.

Residual shear strength of fine-grained soils and soil–solid interfaces at low effective normal stresses

2015 ◽  
Vol 52 (2) ◽  
pp. 198-210 ◽  
Author(s):  
Hisham T. Eid ◽  
Ruslan S. Amarasinghe ◽  
Khaled H. Rabie ◽  
Dharma Wijewickreme
Keyword(s):  
Shear Strength ◽  
Large Strain ◽  
Laboratory Research ◽  
Normal Stresses ◽  
Interface Shear ◽  
Residual Shear Strength ◽  
Fine Grained ◽  
Solid Interface ◽  
Wide Range ◽  
Shear Area

A laboratory research program was undertaken to study the large-strain shear strength characteristics of fine-grained soils under low effective normal stresses (∼3–7 kPa). Soils that cover a wide range of plasticity and composition were utilized in the program. The interface shear strength of these soils against a number of solid surfaces having different roughness was also investigated at similar low effective normal stress levels. The findings contribute to advancing the knowledge of the parameters needed for the design of pipelines placed on sea beds and the stability analysis of shallow soil slopes. A Bromhead-type torsional ring-shear apparatus was modified to suit measuring soil–soil and soil–solid interface residual shear strengths at the low effective normal stresses. In consideration of increasing the accuracy of assessment and depicting the full-scale field behavior, the interface residual shear strengths were also measured using a macroscale interface direct shear device with a plan interface shear area of ∼3.0 m2. Correlations are developed to estimate the soil–soil and soil–solid interface residual shear strengths at low effective normal stresses. The correlations are compared with soil–soil and soil–solid interface drained residual shear strengths and correlations presented in the literature.

Dependence of Granular Matrix Demagnetizing Factor on the Matrix Relative Size

2015 ◽  
Vol 1083 ◽  
pp. 32-36 ◽  
Author(s):  
Alexander Sandulyak ◽  
Anna Sandulyak ◽  
Petr Shkatov
Keyword(s):  
Magnetic Permeability ◽  
Relative Size ◽  
Dramatic Effect ◽  
Comparative Estimate ◽  
Magnetic Filter ◽  
Wide Range ◽  
Demagnetizing Factor ◽  
The Matrix ◽  
Granular Matrix ◽  
Operating Units

We note that for a wide range of porous, especially granular, ferromagnetics used as matrices of magnetic filter-separators, there is still an issue of defining their demagnetizing factor N which has a dramatic effect on the values of average magnetic permeability of these operating units of filter-separators. The work aims at filling the existent gaps in the issue, we supply N values depending on the relative size of such magnets as well as a respective generalizing phenomenological dependence which is characterized by an exponential realtion between the demagnetizing factor and relative size radical. The established relation allows obtaining real values of magnetic permeability of a short filter matrix thus providing an unbiased comparative estimate of its technological workability.

Effect of Consolidation and Sintering Parameters on the Mechanical Responses of Nanocrystalline Al-Fe Alloy Processed by Mechanical Alloying

2015 ◽  
Vol 719-720 ◽  
pp. 87-90
Author(s):  
Muneer Baig ◽  
Hany Rizk Ammar ◽  
Asiful Hossain Seikh ◽  
Mohammad Asif Alam ◽  
Jabair Ali Mohammed
Keyword(s):  
Mechanical Alloying ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Compressive Loading ◽  
Rate Sensitivity ◽  
Testing Temperature ◽  
Fine Grained ◽  
Mechanical Responses ◽  
Wide Range ◽  
High Frequency Induction

In this investigation, bulk ultra-fine grained and nanocrystalline Al-2 wt.% Fe alloy was produced by mechanical alloying (MA). The powder was mechanically milled in an attritor for 3 hours and yielded an average crystal size of ~63 nm. The consolidation and sintering was performed using a high frequency induction sintering (HFIS) machine at a constant pressure of 50 MPa. The prepared bulk samples were subjected to uniaxial compressive loading over wide range of strain rates for large deformation. To evaluate the effect of sintering conditions and testing temperature on the strain rate sensitivity, strain rate jump experiments were performed at high temperature. The strain rate sensitivity of the processed alloy increased with an increase in temperature. The density of the bulk samples were found to be between 95 to 97%. The average Vickers micro hardness was found to be 132 Hv0.1.

scholarly journals Compressibility behaviour of remoulded, fine-grained soils and correlation with index properties

2000 ◽  
Vol 37 (3) ◽  
pp. 712-722 ◽  
Author(s):  
A Sridharan ◽  
H B Nagaraj
Keyword(s):  
Liquid Limit ◽  
Plasticity Index ◽  
Engineering Properties ◽  
Test Results ◽  
Index Properties ◽  
Initial Water ◽  
Fine Grained ◽  
Wide Range ◽  
The Relationship ◽  
Water Contents

Correlating engineering properties with index properties has assumed greater significance in the recent past in the field of geotechnical engineering. Although attempts have been made in the past to correlate compressibility with various index properties individually, all the properties affecting compressibility behaviour have not been considered together in any single study to examine which index property of the soil correlates best with compressibility behaviour, especially within a set of test results. In the present study, 10 soils covering a sufficiently wide range of liquid limit, plastic limit, and shrinkage limit were selected and conventional consolidation tests were carried out starting with their initial water contents almost equal to their respective liquid limits. The compressibility behaviour is vastly different for pairs of soils having nearly the same liquid limit, but different plasticity characteristics. The relationship between void ratio and consolidation pressure is more closely related to the shrinkage index (shrinkage index = liquid limit - shrinkage limit) than to the plasticity index. Wide variations are seen with the liquid limit. For the soils investigated, the compression index relates better with the shrinkage index than with the plasticity index or liquid limit.Key words: Atterberg limits, classification, clays, compressibility, laboratory tests.

scholarly journals Unravelling the impact of harvesting pressure on canopy-forming macroalgae

2016 ◽  
Vol 67 (1) ◽  
pp. 153 ◽  
Author(s):  
Doriane Stagnol ◽  
Renaud Michel ◽  
Dominique Davoult
Keyword(s):  
Habitat Characteristics ◽  
Spatiotemporal Variability ◽  
Macrobenthic Assemblages ◽  
Wide Range ◽  
The Matrix ◽  
Commercial Species ◽  
Canopy Removal ◽  
The Impact ◽  
Relevant Finding

Canopy-forming macroalgae create a specific surrounding habitat (the matrix) with their own ecological properties. Previous studies have shown a wide range of responses to canopy removal. Magnitude and strength of the effects of harvesting are thought to be context-dependent, with the macroalgal matrix that can either soften or exacerbate the impact of harvesting. We experimentally examined in situ the effect of harvesting on targeted commercial species, and how these potential impacts might vary in relation to its associated matrix. We found that patterns of recovery following the harvesting disturbance were variable and matrix specific, suggesting that local factors and surrounding habitat characteristics mediated the influence of harvesting. The greatest and longest effects of harvesting were observed for the targeted species that created a dominant and monospecific canopy on their site prior to the disturbance. Another relevant finding was the important natural spatiotemporal variability of macrobenthic assemblages associated with canopy-forming species, which raises concern about the ability to discriminate the natural variability from the disturbance impact. Finally, our results support the need to implement ecosystem-based management, assessing both the habitat conditions and ecological roles of targeted commercial species, in order to insure the sustainability of the resource.

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