scholarly journals Regional Differences of Dental Microwear on the Occlusal Surface of an M2 from Neolithic Japan: A Case Study

2018 ◽  
Vol 18 (2) ◽  
pp. 61-64
Author(s):  
Teruyuki Hojo
Keyword(s):  
Regional Differences ◽  
Occlusal Surface ◽  
Coarse Grain ◽  
Dental Microwear ◽  
Small Areas ◽  
Grain Sizes ◽  
Tuberous Roots ◽  
Cast Specimen ◽  
Scanning Electron

Regional differences of dental microwear among four small areas on the heavily worn occlusal surface of a mandibular M2 of an adult male from Neolithic Japan were investigated using a scanning electron microscope (SEM). The M2 specimen was cast using a high-resolution epoxy resin under low pressure for SEM, and the cast specimen was sputter-coated with gold. Among the four regions of the M2, two (facets 3 and 9) showed higher proportions of pits (78.6% and 75.0%, respectively), and the two others (lingual marginal facet 7n, and the inner side of facet 7n) showed lower proportions of pits (5.6% and 33.3%, respectively). The two pitted regions seem to reflect the processing of hard foods, and the two other regions with higher frequencies of striations might reflect exposures to less gritty, softer foods. The variation of these pits and striations suggests that the Jomon subsisted on stone-processed hard foods, with coarse grain sizes of sand in foods that included tuberous roots, animal meats with bones, and clams. The analyses of regional differences of dental microwear will develop important ways to study tooth use and past diets.

scholarly journals Deep Learning Based Instance Segmentation of Titanium Dioxide Particles in the Form of Agglomerates in Scanning Electron Microscopy

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 968
Author(s):  
Paul Monchot ◽  
Loïc Coquelin ◽  
Khaled Guerroudj ◽  
Nicolas Feltin ◽  
Alexandra Delvallée ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Titanium Dioxide ◽  
Learning Community ◽  
Spherical Particles ◽  
Average Value ◽  
Size Characterization ◽  
Scanning Electron

The size characterization of particles present in the form of agglomerates in images measured by scanning electron microscopy (SEM) requires a powerful image segmentation tool in order to properly define the boundaries of each particle. In this work, we propose to use an algorithm from the deep statistical learning community, the Mask-RCNN, coupled with transfer learning to overcome the problem of generalization of the commonly used image processing methods such as watershed or active contour. Indeed, the adjustment of the parameters of these algorithms is almost systematically necessary and slows down the automation of the processing chain. The Mask-RCNN is adapted here to the case study and we present results obtained on titanium dioxide samples (non-spherical particles) with a level of performance evaluated by different metrics such as the DICE coefficient, which reaches an average value of 0.95 on the test images.

scholarly journals Effect of Annealing Process on the Mechanical Properties of X70 Pipeline Steel

2018 ◽  
Vol 186 ◽  
pp. 02001
Author(s):  
Teng-wei Zhu ◽  
Cheng-liang Miao ◽  
Zheng Cheng ◽  
Zhipeng Wang ◽  
Yang Cui ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Annealing Temperature ◽  
Pipeline Steel ◽  
Annealing Process ◽  
X70 Pipeline Steel ◽  
Grain Sizes ◽  
Scanning Electron

The influence of the mechanical properties of X70 pipeline steel under different annealing temperature was studied. The corresponding microstructure was investigated by the Field Emission Scanning Electron Microscopy. The results showed that the yield strength and the tensile strength both experienced from rise to decline with the increase of annealing temperature. The grain sizes were coarse and a large amount of cementite precipitated due to preserving temperature above 550 °, which induced matrix fragmentation and deteriorate the -10 ° DWTT Toughness. There were little changes on the microstructure and mechanical properties when the annealing temperature was under 500 °.

scholarly journals Effect of Grain Size on Carburization Characteristics of the High-Entropy Equiatomic CoCrFeMnNi Alloy

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7199
Author(s):  
Hyunbin Nam ◽  
Jeongwon Kim ◽  
Namkyu Kim ◽  
Sangwoo Song ◽  
Youngsang Na ◽  
...  
Keyword(s):  
Grain Size ◽  
Grain Boundaries ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Grain Sizes ◽  
Fine Grain ◽  
Cast Specimen ◽  
Vacuum Carburization ◽  
Cold Rolled ◽  
Face Centered

In this study, the carburization characteristics of cast and cold-rolled CoCrFeMnNi high-entropy alloys (HEAs) with various grain sizes were investigated. All specimens were prepared by vacuum carburization at 940 °C for 8 h. The carburized/diffused layer was mainly composed of face-centered cubic structures and Cr7C3 carbide precipitates. The carburized/diffused layer of the cold-rolled specimen with a fine grain size (~1 μm) was thicker (~400 μm) than that of the carburized cast specimen (~200 μm) with a coarse grain size (~1.1 mm). In all specimens, the carbides were formed primarily through grain boundaries, and their distribution varied with the grain sizes of the specimens. However, the carbide precipitates of the cast specimen were formed primarily at the grain boundaries and were unequally distributed in the specific grains. Owing to the non-uniform formation of carbides in the carburized cast specimen, the areas in the diffused layer exhibited various carbide densities and hardness distributions. Therefore, to improve the carburization efficiency of equiatomic CoCrFeMnNi HEAs, it is necessary to refine the grain sizes.

The Photoluminescence Spectra Research of SiC Thin Film under Different Sputtering Powers

2019 ◽  
Vol 295 ◽  
pp. 93-97
Author(s):  
Chang Zhao ◽  
Man Zhao ◽  
Su Ye Lv ◽  
Qing Jun Liu ◽  
Guang Jian Xing
Keyword(s):  
Thin Film ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Crystal Morphology ◽  
Growth Conditions ◽  
Photoluminescence Spectra ◽  
Experimental Conditions ◽  
Grain Sizes ◽  
Power Inputs ◽  
Scanning Electron

This study prepared an SiC thin film by using the ratio frequency magnetron sputtering method, investigated the effects of different sputtering powers on the SiC material and analysed the changes in crystal morphology and photoluminescence characteristics caused by changes in the growth conditions used. It was considered that there was 6H-SiC crystal morphologies in the SiC thin film under the experimental conditions prevailing in this study. The SiC morphologies with small grain sizes intermingled and therefore formed anSiC thin film. The analyses of the photoluminescence spectra and Scanning Electron Microscope indicated that the SiC thin film materials with preferable crystal compositions could be prepared under appropriate power inputs.

scholarly journals Limitations of Rural Tourism as an Economic Diversification and Regional Development Instrument. The Case Study of the Region of La Vera

2019 ◽  
Vol 11 (12) ◽  
pp. 3309 ◽  
Author(s):  
Francisco Javier Castellano-Álvarez ◽  
María de la Cruz del Río-Rama ◽  
José Álvarez-García ◽  
Amador Durán-Sánchez
Keyword(s):  
Regional Differences ◽  
Economic Diversification ◽  
Agricultural Employment ◽  
Rural Economies ◽  
Tourism Sector ◽  
Single European Act ◽  
The Common ◽  
European Regional Policy ◽  
European Regional

In the mid-1980s, at the same time as the Common Agricultural Policy (CAP) reforms resulted in a decrease in agricultural employment, the Single European Act transformed the reduction of regional differences into an objective of European regional policy. The LEADER Initiative and the PRODER Program were two of the instruments chosen by the European Commission to deal with the effects that these new challenges would have for the rural environment. This research studies the scope and limitations of these programs. For this, we analyzed their implementation, resorting to the case study of the region of La Vera, Extremadura (Spain). The results show that although the structure of these programs is consistent with the purpose of developing and diversifying rural economies, their application must overcome a number of risks, including an excessive concentration of investments in the tourism sector, which stands out from the rest. In addition to highlighting the limitations of tourism as an axis of development, this research detects some aspects that should be taken into account when implementing these programs.

scholarly journals Beyond standardized mortality ratios; some uses of smoothed age-specific mortality rates on small areas studies

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Jordi Perez-Panades ◽  
Paloma Botella-Rocamora ◽  
Miguel Angel Martinez-Beneito
Keyword(s):  
Life Expectancy ◽  
Age Groups ◽  
Dependence Structure ◽  
Risk Indicator ◽  
Small Areas ◽  
Life Expectancy At Birth ◽  
First Case ◽  
Wide Range ◽  
Standardized Mortality Ratios

Abstract Background Most epidemiological risk indicators strongly depend on the age composition of populations, which makes the direct comparison of raw (unstandardized) indicators misleading because of the different age structures of the spatial units of study. Age-standardized rates (ASR) are a common solution for overcoming this confusing effect. The main drawback of ASRs is that they depend on age-specific rates which, when working with small areas, are often based on very few, or no, observed cases for most age groups. A similar effect occurs with life expectancy at birth and many more epidemiological indicators, which makes standardized mortality ratios (SMR) the omnipresent risk indicator for small areas epidemiologic studies. Methods To deal with this issue, a multivariate smoothing model, the M-model, is proposed in order to fit the age-specific probabilities of death (PoDs) for each spatial unit, which assumes dependence between closer age groups and spatial units. This age–space dependence structure enables information to be transferred between neighboring consecutive age groups and neighboring areas, at the same time, providing more reliable age-specific PoDs estimates. Results Three case studies are presented to illustrate the wide range of applications that smoothed age specific PoDs have in practice . The first case study shows the application of the model to a geographical study of lung cancer mortality in women. This study illustrates the convenience of considering age–space interactions in geographical studies and to explore the different spatial risk patterns shown by the different age groups. Second, the model is also applied to the study of ischaemic heart disease mortality in women in two cities at the census tract level. Smoothed age-standardized rates are derived and compared for the census tracts of both cities, illustrating some advantages of this mortality indicator over traditional SMRs. In the latest case study, the model is applied to estimate smoothed life expectancy (LE), which is the most widely used synthetic indicator for characterizing overall mortality differences when (not so small) spatial units are considered. Conclusion Our age–space model is an appropriate and flexible proposal that provides more reliable estimates of the probabilities of death, which allow the calculation of enhanced epidemiological indicators (smoothed ASR, smoothed LE), thus providing alternatives to traditional SMR-based studies of small areas.

scholarly journals Regional Differences and Spatial Aggregation of Sustainable Transport Efficiency: A Case Study of China

2018 ◽  
Vol 10 (7) ◽  
pp. 2399 ◽  
Author(s):  
Fei Ma ◽  
Xiaodan Li ◽  
Qipeng Sun ◽  
Fei Liu ◽  
Wenlin Wang ◽  
...  
Keyword(s):  
Regional Differences ◽  
Spatial Aggregation ◽  
Sustainable Transport ◽  
Transport Efficiency
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