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Author(s):  
Zhenbin Zhang ◽  
Oluleke Babayomi ◽  
Tomislav Dragicevic ◽  
Rasool Heydari ◽  
Cristian Garcia ◽  
...  

Author(s):  
Zhenbin Zhang ◽  
Oluleke Babayomi ◽  
Tomislav Dragicevic ◽  
Rasool Heydari ◽  
Cristian Garcia ◽  
...  

Minerals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1104
Author(s):  
Yazhou Hu ◽  
Lars E. Holmer ◽  
Yue Liang ◽  
Xiaolin Duan ◽  
Zhifei Zhang

Small Shelly Fossils (SSFs) from the Cambrian are widely distributed and well known across different paleocontinents of the world. However, middle Cambrian SSFs from North China Platform have only rarely been documented until now. In this paper, we presented the first report on SSFs from bioclastic and oolitic limestones of the Zhangxia and Hsuzhuang formations of Henan province, North China. The carbonate-hosted fauna includes brachiopods (Micromitra sp., M. modesta, Eoobolus sp., and Schizopholis sp.), helcionellids (Oelandiella accordionata and O. aliciae), hyolithids, Hyolithellus sp., Chancelloria eros, sponge spicules, echinoderm ossicles, and chancelloriid sclerites. In terms of preservation, the brachiopod shell valves of M. modesta appeared to be homogeneous, consisting of tightly packed phosphate grains. Eoobolus sp. is composed of primary layer and secondary baculate, both of which consist of tightly compacted phosphate grains. Schizopholis sp. has multiple-lamellar phosphatized microstructures that distinctly differ from the other brachiopods recovered from the Longwanggou section. A similar multiple-lamellar microstructure was also revealed in conchs of Hyolithellus, with tightly compacted phosphate grains. The argillaceous shell of Oelandiella accordionata and O. aliciae, and the calcitic inner molds of hyolith did not preserve any shell structure. The helcionellids O. accordionata and O. aliciae and the brachiopod M. modesta were reported for the first time from North China. The fauna is most similar to the middle Cambrian faunas of South Australia, in the brachiopod and mollusk components; it is also similar in composition of brachiopods and mollusks to coeval faunas from South China. The new fauna of SSFs in the Yiyang Longwanggou Section indicated that the Hsuzhuang and Zhangxia formations are late Drumian to middle Guzhuangian in age, most likely correlating with the Murrawong Creek Formation of South Australia.


Author(s):  
Itay Nudel ◽  
Ariel Pokhojaev ◽  
Yoli Bitterman ◽  
Nir Shpack ◽  
Luca Fiorenza ◽  
...  

Human dentin consists of a primary layer produced during tooth formation in early childhood and a second layer which first forms upon tooth eruption and continues throughout life, termed secondary dentin (SD). The effect of attrition on SD formation was considered to be confined to the area subjacent to attrition facets. However, due to a lack of three-dimensional methodologies to demonstrate the structure of the SD, this association could not be determined. Therefore, in the current study, we aimed to explore the thickening pattern of the SD in relation to the amount of occlusal and interproximal attrition. A total of 30 premolars (50–60 years of age) with varying attrition rates were evaluated using micro-computerized tomography. The results revealed thickening of the SD below the cementoenamel junction (CEJ), mostly in the mesial and distal aspects of the root (p < 0.05). The pattern of thickening under the tooth cervix, rather than in proximity to attrition facets, was consistent regardless of the attrition level. The amount of SD thickening mildly correlated with occlusal attrition (r = 0.577, p < 0.05) and not with interproximal attrition. The thickening of the SD below the CEJ coincided with previous finite element models, suggesting that this area is mostly subjected to stress due to occlusal loadings. Therefore, we suggest that the SD formation might serve as a compensatory mechanism aimed to strengthen tooth structure against deflection caused by mechanical loading. Our study suggests that occlusal forces may play a significant role in SD formation.


2020 ◽  
Vol 5 ◽  
Author(s):  
Kirsten Wolthuis ◽  
Gerard W. Bol ◽  
Alexander Minnaert ◽  
Marleen J. Janssen

The Layered Communication Model (LCM) consists of three layers of intersubjective development divided into different communicative behaviors per layer. Earlier research showed that the LCM can be used to describe the communication level between teachers and their students with congenital deafblindness (CDB). This study analyzed whether the LCM can also be used to monitor the development of LCM behaviors over time. Videos of eight student-teacher dyads recorded at the start of this study (baseline phase) and 5 months later (follow-up phase) were coded using 10-s partial interval coding. The presence of the communicative behaviors at the three layers of the LCM during baseline and follow-up were calculated and compared between dyads and phases. The results on the presence of LCM behaviors were in line with earlier research. The presence of primary layer behaviors was comparable between dyads, confirming that this is a basic communication layer. The differences found between dyads in the presence of secondary and tertiary layer behaviors shows that these can be used to determine a dyad's communicative level. Results also showed that the LCM can be used to monitor communication development. Small increases were found in the presence of LCM behaviors between baseline and follow-up for the primary layer behaviors, but larger increases were found for secondary and tertiary layer behaviors, showing that development can be monitored. In conclusion, this study again showed that the LCM can be used to describe a dyad's communicative level. We also found increases in the presence of certain behaviors between baseline and follow-up for all dyads, which shows that the LCM can also be used to monitor communication over time. More insight into the period between the analyzed phases is suggested to analyze what might have caused the increase in presence of behaviors. This would reveal more about the use of the LCM as a tool to improve communication development.


Author(s):  
Agneta Shashkova

This article is dedicated to features of the late period in the icon painting of Ivan S. Yizhakevych which coincides with the religion persecution in the USSR as well as features of the study of icons in functional churches.In this paper we have set out the complex analysis of nomadic icons “Blessed Virgin Mary and Baby Jesus” and “Christ Enthroned” from Pokrovsky church in Priorka in Kyiv. By means of the visual research using the concentrated visible light and macro photography technical, technological and painting features of the icon painting have been specified.Based on the study of the painting layer features of the author icon painting style of Mr. Yizhakevych and stylistic features that are typical for his late creative period between 1940 and 1960 have been analyzed.Based on the comparative analysis between the above icons and other icons painted by Mr. Yizhakevych we have specified the attribution and considered the possibility of author icon finishing painting in a given period in order to return brightness to faded areas and restore partially lost ones. The possibility of repainting of separate parts of icons in order to specify dimensions of separate fragments or change in the compositional position of figures is also studied.In this paper we have specified typical techniques of the author style of Ivan S. Yizhakevych used by him for the primary layer of icons and author renewal and the assumption has been made that his students had likely helped him in preparation activities and painted parts of painting that are secondary according to their composition. Based on the analysis of the painting technique and features of Mr. Yizhakevych’s style the assumption have been made that the non-author finishing painting had been made approximately between 1990 and 2000 during one of the thorough repairs of the church.In this paper it has been established that the latter non-author renewals had significantly damaged the appearance of both icons by adding the rude and unprofessional performance to their separate elements which is not typical for the artist; this fact causes major difficulties when considering these icons to be integral works of Ivan S. Yizhakevych.This paper is illustrated by pictures of icons “Blessed Virgin Mary and Baby Jesus” and “Christ Enthroned” as well as their schematic images including the analysis of author and non-author renewals.


2019 ◽  
Vol 53 (5) ◽  
pp. 482-487
Author(s):  
T. N. Smirnova ◽  
G. T. Ushatinskaya ◽  
E. A. Zhegallo ◽  
I. V. Panchenko

2019 ◽  
Vol 16 (4) ◽  
pp. 550-559 ◽  
Author(s):  
Abhinav Chadha ◽  
Mir Irfan Ul Haq ◽  
Ankush Raina ◽  
Rana Ratna Singh ◽  
Narendra Babu Penumarti ◽  
...  

Purpose This paper aims to explore the effect of bed temperature, primary layer thickness and infill pattern (rectilinear, honeycomb, triangular) on the mechanical properties of tensile strength and bending strength of 3D printed parts. Design/methodology/approach Samples in accordance to various ASTM standards were printed by fused deposition modelling (FDM) method by varying the various input paramaters such as bed temperature, primary layer thickness and infill pattern (rectilinear, honeycomb, triangular). Tensile and bending testing was carried out on the printed parts, and post to the testing, fractography has been carried out using scanning electron microscope. Findings With increase in bed temperature tensile strength and flexural strength first increases then decreases. With the increase in primary layer thickness, tensile strength and flexural strength increase. With regard to infill patterns, triangular and honeycomb exhibit better tensile strength and better flexural strength. Practical implications The 3D printing is increasingly becoming important for manufacturing of engineering parts, determining the process parameters which could result in better mechanical and physical properties shall certainly help designers and manufacturers globally. Originality/value This work elucidates the effect of various process parameters of FDM on tensile and flexural properties of the samples.


2018 ◽  
Vol 26 (1) ◽  
pp. 156-171
Author(s):  
Adi Fux ◽  
Pnina Soffer ◽  
Mor Peleg

Maintenance of computer-interpretable guidelines is complicated by evolving medical knowledge and by the requirement to customize content to local practice settings. We developed a framework to support knowledge engineers in customization and maintenance of computer-interpretable guidelines specified in the PROforma formalism. In our layered approach, the computer-interpretable guidelines containing the original clinical guideline serves as the primary layer and local customizations form secondary layers that adhere to its schema while augmenting it. Java code unifies the layers into a single enactable computer-interpretable guidelines. We performed a pilot experiment to verify the effectiveness of a layered framework. In this first attempt, we evaluated the hypothesis that the layered computer-interpretable guidelines framework supports knowledge engineers in maintenance of customized computer-interpretable guidelines. Participants who used the layered framework completed an update process of the primary knowledge in less time and made fewer errors as compared to those using the single-layer framework.


Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2867 ◽  
Author(s):  
Woon-Gyu Lee ◽  
Thai-Thanh Nguyen ◽  
Hyeong-Jun Yoo ◽  
Hak-Man Kim

Since the penetration of distributed energy resources (DERs) and energy storage systems (ESSs) into the microgrid (MG) system has increased significantly, the sudden disconnection of DERs and ESSs might affect the stability and reliability of the whole MG system. The low-voltage ride-through (LVRT) capability to maintain stable operation of the MG system should be considered. The main contribution of this study is to propose a distributed control, based on a dynamic consensus algorithm for LVRT operation of the MG system. The proposed control method is based on a hierarchical control that consists of primary and secondary layers. The primary layer is in charge of power regulation, while the secondary layer is responsible for the LVRT operation of the MG system. The droop controller is used in the primary layer to maintain power sharing among parallel-distributed generators in the MG system. The dynamic consensus algorithm is used in the secondary layer to control the accurate reactive power sharing and voltage restoration for LVRT operation. A comparison study on the proposed control method and centralized control method is presented in this study to show the effectiveness of the proposed controller. Different scenarios of communication failures are carried out to show the reliability of the proposed control method. The tested MG system and proposed controller are modeled in a MATLAB/Simulink environment to show the feasibility of the proposed control method.


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