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2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jianlei Yang ◽  
Peng Li ◽  
Xuhui Zhang ◽  
Xiaobing Lu ◽  
Qing Li ◽  
...  

AbstractA series of experiments were conducted to investigate flow pattern transitions and concentration distribution during simultaneous pipe flow of oil–water two-phase flow through the horizontal and vertical sections. The flowing media applied were white mineral oil and distilled water. Superficial oil and water velocities were between 0 and 0.57 m/s. Flow pattern maps revealed that the horizontal and vertical sections of the pipe lead to different flow pattern characteristics under the same flow conditions. The original contributions of this work are that a transition mechanism for predicting the boundary between oil-in-water (O/W) flow and water-in-oil (W/O) in oil–water two-phase flow was obtained. The effects of input water cut, oil and water superficial velocities on the concentration distribution of the dispersed phase were studied. The empirical formulas for the phase holdup based on the drift-flux model were obtained. The predicted results agreed well with those of the experimental data, especially for the O/W flow pattern.


2021 ◽  
Vol 20 (1) ◽  
pp. 18-24
Author(s):  
Oleh Marchuk ◽  
Olga Antonyuk ◽  
Yuliya Marchuk ◽  
Denis Andriychuk ◽  
Volodymyr Marchuk

In 9-weeks prefetuses, urogenital complexes are located lower than in prefetuses of previous age groups. In the vertical sections of the urogenital cords, the paramesonephric ducts diff erentiate into the uterine tubes. Above the entrance to the pelvis, the urogenital cords pass obliquely in the vertical direction, at the level of which the paramesonephric ducts are connected, on both sides of which the mesonephric ducts are located. The primary kidneys are completely reduced in their upper two-thirds, the reduction of mesonephric cells in the lateral areas of the lower third of the kidneys begins. The caudal divisions of the paramesonephric ducts touch dorsally to the wall of the urogenital sinus, while the lower ends of the mesonephric ducts are in the thickness of the wall. The urogenital cords (mesonephric and paramesonephric ducts) protrude above the upper ends of the primary kidneys and below the permanent kidneys. The mesonephric and paramesonephric ducts are clearly demarcated by a layer of loosely spaced mesenchymal cells.In 10-weeks prefetuses, due to the connection of the lower vertical parts of the paramesonephric ducts, a common uterine- vaginal canal is formed, lined with pseudolayered epithelium. Mesonephric ducts retain their lumen in fragments.In 11-weeks prefetuses, the upper vertical sections of the urogenital cords, in connection with the reduction of the mesonephric ducts, contain mainly paramesonephric ducts, which are separated from each other by a loose layer of the mesenchyme. From these sections of paramesonephric ducts uterine tubes are formed. Oblique (middle) sections of the paramesonephric ducts with further development are transformed into intrauterine parts of the uterine tubes. The lower caudal sections of the paramesonephric ducts are transformed into the uterus and the upper two-thirds of the vagina.In 12-weeks prefetuses, the primary kidneys are almost completely reduced. Only single mesonephric tubules within their caudal area are determined. In parallel, there are intense processes of formation of internal female reproductive organs. The cranial ends of the uterine tubes expand, acquiring a funnel- shaped shape. The outer border of the infundibulum of the tube reminds a zigzag line, which is evidence of the beginning of the formation of the fi mbria of the uterine tube. The lumens of the mesonephric ducts are reduced to 6±0.1 μm, and in some parts of their walls are in contact with each other. Transformation of paramesonephric ducts into their derivatives (uterine tubes, uterus, upper part of the vagina) is accompanied by corresponding histological changes of their walls.


Geophysics ◽  
2021 ◽  
pp. 1-53
Author(s):  
Oluwaseun Joseph Aribido ◽  
Ghassan AlRegib ◽  
Yazeed Alaudah

We developed two machine learning frameworks that could assist in the automated litho-stratigraphic interpretation of seismic volumes without any manual hand labeling from an experienced seismic interpreter. The first framework is an unsupervised hierarchical clustering model to divide seismic images from a volume into certain number of clusters determined by the algorithm. The clustering framework uses a combination of density and hierarchical techniques to determine the size and homogeneity of the clusters. The second framework consists of a self-supervised deep learning framework to label regions of geological interest in seismic images. It projects the latent-space of an encoder-decoder architecture unto two orthogonal subspaces, from which it learns to delineate regions of interest in the seismic images. To demonstrate an application of both frameworks, a seismic volume was clustered into various contiguous clusters, from which four clusters were selected based on distinct seismic patterns: horizons, faults, salt domes and chaotic structures. Images from the selected clusters are used to train the encoder-decoder network. The output of the encoder-decoder network is a probability map of the possibility an amplitude reflection event belongs to an interesting geological structure. The structures are delineated using the probability map. The delineated images are further used to post-train a segmentation model to extend our results to full-vertical sections. The results on vertical sections show that we can factorize a seismic volume into its corresponding structural components. Lastly, we showed that our deep learning framework could be modeled as an attribute extractor and we compared our attribute result with various existing attributes in literature and demonstrate competitive performance with them.


2021 ◽  
Vol 10 (15) ◽  
pp. 3389
Author(s):  
Fusong Yuan ◽  
Shanshan Liang ◽  
Peijun Lyu

This study explored the effect of the light-off delay setting in a robotically controlled femtosecond laser on the taper and adaption of resin tooth preparations. Thirty resin teeth (divided into six equal groups) were studied under different light-off delay conditions. Tapers from six vertical sections of the teeth were measured and compared among the light-off delay groups. The mean taper decreased from 39.268° ± 4.530° to 25.393° ± 5.496° as the light-off delay increased (p < 0.05). The average distance between the occlusal surfaces of the scanned data and the predesigned preparation data decreased from 0.089 ± 0.005 to 0.013 ± 0.030 μm as the light-off delay increased (p < 0.05). The light-off delay of the femtosecond laser is correlated with the taper and adaption of automatic tooth preparations; this setting needs to be considered during automatic tooth preparation.


2021 ◽  
Author(s):  
Olivia Shears ◽  
Iris Möller ◽  
Tom Spencer ◽  
Ben Evans ◽  
Kate Royse

&lt;p&gt;Salt marsh ecosystems are important for supporting biodiversity, sequestering carbon and providing natural coastal protection. Evidence for their existing and potential future loss through marginal erosion is therefore of concern. However, the factors governing spatial variability in the rates of erosion at salt marsh margins &amp;#8211; including between creek banks within individual salt marsh sites &amp;#8211; remain relatively poorly understood. Accurate prediction of changes to the marsh edge, and thus marsh areal extent, requires more complete understanding of the dynamics and mechanisms occurring at exposed marsh fronts.&lt;/p&gt;&lt;p&gt;In this study, we present observations of the responses of vertical sections of marsh substrate exposed to tidal flat conditions, during a field experiment over a six-month period. Vertical sections were extracted from natural and restored sites at two salt marshes in the UK: Northey Island, eastern England, where sediment is fine-grained, and Hesketh Out Marsh West, north-west England, where sediment is typically sand/silt-dominated. The study specifically investigates the role of different sedimentology and downcore substrate properties, including lamination and rooting structures, on observed change in the exposed vertical sections. Images captured in the field are analysed using structure-from-motion photogrammetry and used to create 3-D models of surface change. This is coupled with laboratory testing of downcore sedimentary characteristics, such as particle size distribution and organic matter content.&lt;/p&gt;&lt;p&gt;The study finds that within-core and between-core variability in substrate response to erosive forcing appears to be partly related to variability in sedimentology. Sediment from sand-dominated layers, such as those found in the cores extracted from Hesketh Out Marsh West, was more rapidly and consistently (i.e. across the sediment cores) removed than clay-silt rich sediment. This grain-scale sediment removal resulted in specific morphological responses, whereby &amp;#8216;chunks&amp;#8217; of substrate were lost, creating cavity areas further exposed to hydrodynamic forcing. Intrinsic biophysical characteristics, including sediment type and the presence of vegetation structures, can impact vertical connectivity within salt marsh substrates. Observations of structural change in the vertical sections over the six-month study period suggest that reduced downcore connectivity in restored salt marsh substrates results in increased desiccation, cracking and bulk sediment removal. An improved understanding of how such intrinsic substrate properties impact marsh front dynamics will facilitate more accurate predictions of marsh evolution and potential ecosystem service provision under future conditions.&lt;/p&gt;


2021 ◽  
Author(s):  
Giuseppe Pucciarelli

&lt;p&gt;The topic of my work is a seismic tomography which has as object the investigation of Southern Tyrrhenian. This tomography has been obtained by means of inversion of teleseismic data to investigate subduction zones in the Southern Tyrrhenian oceanic back-arc basin. The subducting lithosphere has been mostly consumed along the Tyrrhenian-Apennine system has been consumed with the exception of the Calabrian arc sector. This kind of inversion could provide a good resolution to depth of 500-600 km, whereas previous local tomographies of Southern Tyrrhenian show results to depth of 250-300 km. The adopted database consists of 1929 teleseisms&amp;#160; recorded in period 1990-2012 by 122 southern Italian seismic station directly connected to ISC (International Seismological Centre). The software FMTT was employed for the inversion of these arrival times. I have implemented a grid of 0-500 km in depth, 7&amp;#176;E-20&amp;#176;E in longitude and 35&amp;#176;-48&amp;#176; in latitude, with a grid spacing of 50 km in depth, 0.8 degrees in longitude and 0.4 degrees in latitude. I have made 10 horizontal sections of final model from 50 km of depth to 500 km of depth, with an interval of 50 km of depth from each other. I have made 8 vertical sections, 4 NS vertical sections at fixed longitude and 4 WE vertical sections at fixed latitude. Finally, I have made 3 transversal sections. Summarising, the horizontal sections show an evolution of the high velocity body that represents the Ionian slab. It is visible both at depth of 50 km and at depth of 100 km, beneath the Calabrian arc and extends to northern Sicily beneath the Aeolian arc with a maximum of 0.6-0.8 km/s. At depth of 250 km, the tomography evidences a sort of &amp;#8220;transition&amp;#8221; due to the absence of the Southern Tyrrhenian HVA and the occurrence of a low velocity region with maximum of -0.5 km/s scattered between the Aeolian Islands and Calabria. In the depth interval from 250 km to 400 km, there are two impressive high velocity areas in northern Sicily and along southern Campania with a value of 0.3 km/s, separated by a low velocity area (LVA) along the Calabrian arc and the Aeolian Islands in the range [0.4 ; 0.6] km/s. Extensions of HVAs and LVAs previously mentioned have been estimated by means of vertical and transversal sections. This evidence could be interpreted as the effect of a three-dimensional circulation of astenospheric flow provoked by slab roll-back. A new evidence from the tomography is the presence of a LVA in the [250 ; 400] km depth interval with an extension of 100-150 km that practically splits the Tyrrhenian slab into two parts, in Neapolitan region and in the southern Calabria-northern Sicily region. The presence of this &amp;#8220;window slab&amp;#8221; could be interpreted as a tear in which unperturbed mantle insert itself.&lt;/p&gt;


Author(s):  
V. N. Shkura ◽  
◽  
A. S. Shtanko ◽  

Purpose: development and testing of a method for determining the size and moisture characteristics of moisture contours formed in the southern chernozems of the steppe type of soil formation during drip irrigation. Materials and methods. Experimental studies were carried out on light, medium and heavy loamy medium thick ordinary and southern chernozems. The vertical sections of humidification zones with a system of in-contour moisture isopleths were considered. As indicators determining the contour parameters, the following are considered: the content of physical clay in the moistened soil layer, the soil density and its lowest moisture capacity. Results. In the process of studying the experimental vertical sections of soil drip moistening zones, dependences characterizing the existing functional relationships between the contour geometric parameters and the characteristics of soil, phytosoil and technological conditions of their formation were determined. On the basis of the obtained experimental dependences, a method for calculating the contours linear dimensions and graphically constructing their outlines has been developed. The proposed method for contour predicting was tested on actual data on their sizes and moisture distribution in the inner-contour space, obtained by other researchers experimentally. Comparison of the experimental and predicted contours of drip moistening testifies to their qualitative similarity both in terms of the external outline and in terms of the location of isopleths with different levels of soil moisture inside the wetted zone. The calculated value of the irrigation rate differs from the actual one by 2.2 %. Conclusions. The proposed method for predicting the sizes of moisture contours and intra-contour isopleths, formed in chernozems of the steppe type of soil formation, was developed to the level of calculations using the author's computer program. An example of approbation of the proposed method indicates its acceptability for use in the crops drip irrigation design and operational practice.


Author(s):  
G. Kh. Murzakhanov ◽  
A. A. Barsukov ◽  
A. S. Semenov ◽  
A. V. Makshin

Article considered main stages of strength calculation of the steel gas pipeline under the Novodevichy Duker project. Specialists of the Moscow city Center used the basis of the finite element for calculation. The list of tasks consists of: 1. Strength calculation of the underground laying gas pipeline section. 2. The calculation of the stability of the two vertical sections. According to the results of strength calculation, specialists made the conclusion about ensuring the strength and stability of the considered section of the gas pipeline.


Author(s):  
Bùi Thế Vinh ◽  
Tran Phuong Duy

Section of weathering crust developed on the biotite granite (ankroet complex), distributed on high leveling surfaces 1400–1700 m of Miocene age (N1) at Trai Mat area and around Da Lat city. In terms of petrographic characteristics, this weathered shell section is full of zones: laterite, litoma, saprolite, and the original stone. On chemical-mineral characteristics: The results of synchronous processing of the results of chemical, thermal and jealous analysis ... on vertical sections shows, they belong to the form of fealsit formation (FeAlSi) with 4 types of shells: Fealsit / goethite-kaolinite-gibsit (FeAlSi / gt-kl-gb / N1), AlSiferit / (kaolinite-hydromica) -gibsit-goethit (AlSiFe / (kl-hmi) -gb-gt / N1), Sialit (actually receptors) / kaolinite-hydromica (SiAl / kl-hmi / N1) and Sialit (alkaline) / kaolinite rock-forming minerals (SiAl / kvtđ-kl / N1-Q). About microelements: concentrate in VPH compared to original stone: Cu: 1.8 – 3.3 times, Pb: 1 – 2 times, Mo: 0 – 2.83 times, most other elements were removed from the shell. Related minerals: Camp Mat, Da Lat Kaolin can be used as raw material for producing white bone tiles and birth materials. In this weathered shell section, there is a weathered shell of AlSiferite / (kaolinite-hydromica) -gibsit-goethite (AlSiFe / (kl-hmi) -gb-gt) which is a weathered clay-rich weathering product (gibsit up to 30 - 40%), developing on biotite granite at Mat camp - Da Lat area is often seen only in basalt weathering crust which is very rare in granite.  


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