uniform structure
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2022 ◽  
Author(s):  
Takumi Matsumoto ◽  
Ryuji Yamada ◽  
Satoshi Iizuka

Abstract New heat flow data corrected for climate change over the entire northeastern region of Japan were obtained using the temperature profile of the borehole of NIED High Sensitivity Seismograph Network (Hi-net). In addition, the crustal temperature structure was obtained by using a crustal structure model that takes into account the temperature dependence of thermal conductivity and the difference in heat generation due to lithology, using a crustal structure model that takes into account sedimentary layers rather than a uniform structure model with exposed bedrock at the surface. The results show that the crustal temperature structure in areas with thick sedimentary layers is improved compared to the previous model.


Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 63
Author(s):  
Paweł Sznajder ◽  
Bogdan Cichocki ◽  
Maria Ekiel-Jeżewska

We investigate qualitatively a uniform non-Brownian sedimenting suspension in a stationary state. As a base of our analysis we take the BBGKY hierarchy derived from the Liouville equation. We then show that assumption of the plasma-like screening relations can cancel some long-range terms in the hierarchy but it does not provide integrable solutions for correlation functions. This suggests breaking the translational symmetry of the system. Therefore a non-uniform structure can develop to suppress velocity fluctuations and make the range of correlations finite.


Author(s):  
Xiaonan Zhu ◽  
Fei Yang ◽  
Haoran Wang ◽  
Siyuan Zhao ◽  
Yifei Wu ◽  
...  

Abstract Intrinsic roughness of solid surfaces causes a series of inevitable shortcomings in the use of mechanical electrical contacts, among which one of the most fatal is the repulsive electrodynamic force arising from high currents. A large contact force coming from a heavy holding mechanism helps to suppress the repulsive effect whereas the mechanism consumes energy and remains to be challenging for a compact switching device. Here, a liquid metal (LM) bridge is introduced to wet solid electrodes to eliminate contact issues. Four instability patterns induced by the electromagnetic pinch effect are identified to characterize LM bridge’s response to high currents. Simulation results reveal that an inner vortex caused by uneven distributions of current density and electrodynamic volume force leads to the rupture of a necked LM bridge. With a uniform structure, a cylindrical LM bridge is proved to be robust with respect to an impulse current higher than 10 kA, exceeding a commercial compact relay by a factor of more than 10 in terms of current withstand performance. Our research facilitates compact and energy-saving switch equipment and has a potential to realize arbitrary desired levels of high current withstand without the use of a holding mechanism. This paper also offers deep insights into the high current applications of LM from the perspective of fluid related physical mechanisms.


2021 ◽  
Vol 4 (5) ◽  
pp. 1199-1218
Author(s):  
Evgeniya D. Zarubina

Minute books (pinkas) constitute one of the most valuable sources for studying the history of the Jewish communal institutions up to the 20th century. They comprise rich and diverse data on the everyday activities of the Jewish people. In the academic language, the word “pinkas” is applied not only to the communal minute books and minute books of the communal bodies but also to private minute books. The article deals with the development of this category of sources which evolved from private minute books dating back to at least the 11th century to the communal ones as well as the minute books of the communal bodies based on the dozen manuscript examples. These are mostly of European origin, however, with a few Eastern additions. This evolution process becomes visible as a result of the analysis of the manuscripts’ internal structure and composition. Special attention is paid to the techniques used to enforce this structure on codicological and paleographic levels. The data at hand suggest that at the beginning of the Modern period some of the minute books were shifted from private to the public domain. This was a response to the demand from the rapidly evolving communal institutions. To suit the widened audience of varying backgrounds the communal minute books compared to those for private use adopted a more uniform structure as well as with a set of “navigation” or referencing tools, such as captions written on margins. The early modern Italian communal minute books tend to be the most structured ones.


Author(s):  
Екатерина Анатольевна Богданова ◽  
Владимир Михайлович Скачков ◽  
Игорь Маратович Гиниятуллин ◽  
Данил Ильич Переверзев ◽  
Ксения Валерьевна Нефедова

В статье обсуждается возможность получения упрочненного композиционного материала с пористой структурой на основе наноструктурированного гидроксиапатита, синтезированного методом осаждения из раствора. Новый материал получен путем механохимичекого синтеза гидроксиапатита с армирующими добавками диоксида циркония и кремниевой кислоты. Синтезированные образцы аттестованы с использованием современных физико-химических методов анализа. Показано влияние качественного и количественного состава композита на протекание процессов спекания, пористость, прочностные характеристики, степень дисперсности и морфологию исследуемых образцов. Экспериментально установлено, что максимальными прочностными характеристиками и постоянным составом обладает образец Ca(PO)(OH) -15%SiO⋅nHO-5%ZrO. Композиционный материал обладает плотной равномерной структурой с высокой степенью кристалличности, с развитой пористостью, является перспективным материалом для дальнейших исследований с целью внедрения его в медицинскую практику. На разработанный композиционный материал подана заявка на патент. The article discusses the possibility of obtaining a hardened composite material with a porous structure based on nanostructured hydroxyapatite (HAP) synthesized by precipitation from a solution. The new material was obtained by the mechanochemical synthesis of HAP with reinforcing additives of zirconium dioxide and silicic acid. The synthesized samples are certified using modern physicochemical methods of analysis. The influence of the qualitative and quantitative composition of the composite on the sintering processes, porosity, strength characteristics, the degree of dispersion and morphology of the studied samples is shown. It has been experimentally established that the sample has the maximum strength characteristics and a constant composition of Ca(PO)(OH) -15%SiO⋅nHO-5%ZrO. The composite material has a dense uniform structure with a high degree of crystallinity, with a developed porosity, is a promising material for further research in order to introduce it into medical practice. A patent application has been filed for the developed composite material.


2021 ◽  
Vol 66 (6) ◽  
pp. 75-80
Author(s):  
N. Vorotynceva ◽  
M. Gaidukova

Purpose: Analysis the effectiveness of various methods of radiation studies for the detection of renal angiomyolipomas (RAMLs), including the diagnosis of Wunderlich syndrome. Material and methods: The analysis of the results of a comprehensive radiation study of the kidneys of 115 patients who were diagnosed with focal formation in primary renal ultrasound was carried out. Further, of those 115 people, 47 patients underwent MRI of the kidneys, 60 patients – CT and 8 patients complex MRI+CT, including contrast-enhanced vasculature. Results and discussion: Angiomyolipoma was detected by ultrasound in 38 (33.0 %) of 115 patients, and according to MRI and CT in total in 27 (23.5 %) patients. Coincidence of ultrasound findings and MRI and CT results was in 18 patients. Consequently, the sensitivity of ultrasound in the diagnosis of RAML was compared with MRI – 45 %; when compared with CT – 42.8 %, and specificity – 55 % and 57.1 %, respectively. Reliable signs of RAML in ultrasound were hyperechogenic homogeneous structure, clear smooth contours of the formation. The rounded form of education is statistically unreliable. Statistically significant characteristics of RAML in magnetic resonance imaging are heterogeneous structure, heterogeneous hyperintense MR-signal on T1 and heterogeneously hypointensity on T2-weighted images, always uniformly hypo-Fs for T1 / T2 Fs, with hypo clear boundary between education and renal parenchyma on T1 in the opp phase. Reliable signs of RAML with CT are non-uniform structure of education, with non-uniform x-ray density. Conclusion: Ultrasound diagnosis is necessary for screening kidney disease, while CT and MRI have greater sensitivity and specificity to determine the nature of focal formation. With the development of Wunderlich’s syndrome, a complex of radiological methods, including ultrasound, MRI and CT, allows to diagnose the cause of hemorrhage, as well as to obtain complete diagnostic information necessary for the surgeon to plan treatment.


2021 ◽  
Vol 23 (4) ◽  
pp. 111-124
Author(s):  
Vasiliy Fedorov ◽  
◽  
Aleksandr Rygin ◽  
Vasiliy Klimenov ◽  
Nikita Martyushev ◽  
...  

Introduction. As of today, additive technologies are among the most promising methods to manufacture various parts. They allow producing parts of complex shapes and provide their quality structure. The quality of the structure formed depends on numerous parameters: equipment type, its operation mode, materials, shielding medium, etc. Large international companies producing 3D-printers provide technological guidelines for working on it. Such guidelines include the information on the manufacturers of raw materials (printing powders), products their equipment can work with and the operation modes that should be used with such powders. These parameters should be investigated to use it on the domestic equipment developed within the framework of research programs and import substitution programs. The researchers and developers of 3D-printing equipment frequently run into a problem of using currently available raw materials for obtaining parts possessing minimal porosity, uniform structure and mechanical properties similar to that of at least cast blanks. One of the widely used materials for 3D-printing is stainless steel. It has high corrosion resistance, which reduces the requirements to the medium in which 3D printing is carried out. Manufactured stainless steel products have a good combination of strength and plastic characteristics. The aim of the study is to obtain stainless steel specimens possessing minimal number of micro- and macro-defects and uniform structure by the method of wire arc additive manufacturing using an electron-beam setup developed at Tomsk Polytechnic University. The methods to study the AISI 308LSi stainless steel 3D-printed specimens are as follows: XRD analysis, tomography, chemical analysis, metallographic analysis, microhardness testing. Results and discussion. It is established that the AISI 308LSi stainless steel specimens manufactured using the electron-beam 3D-printing setup contain no macro-defects in the bulk of the specimens. There are small microdefects represented by residual gas pores with the dimensions of no more than 5.2 μm. The microstructure of the specimens is formed close to that of coarse-grained cast austenite steels and consists of columnar grains of the γ-Fe austenite matrix and high-temperature ferrite. The interfaces between the wire layers are not pronounced; however, there are small differences in phase composition. Based on the analysis of the results obtained, it is established that the use of electron-beam 3D-printing for the manufacture of parts from AISI 308LSi steel gives a structure similar to cast austenitic steels. Macro-defects do not appear, and the number of gas pores is small.


2021 ◽  
pp. 108201322110418
Author(s):  
Maryam Pyro- Mossavi ◽  
Mahboobeh Kashiri ◽  
Yahya Maghsoudlou ◽  
Morteza Khomiri ◽  
Mehran Alami

Wheat filter flour is a by-product derived from the modern wheat milling process. In this study, the influence of plasticizer type (glycerol (G) and sorbitol (S)) and content (25, 35, and 45 g/100 g polymer) on the wheat filter flour-based film was evaluated. Regardless of plasticizer type, increasing the plasticizer content enhanced moisture content, water solubility, and water vapor permeability of film samples. The S-plasticized films presented the greatest tensile strength and the lowest EAB%. The scanning electron microscope observations confirmed the uniform structure of G-plasticized film. Moreover, antimicrobial and physico-mechanical properties of G-plasticized (25%) film were evaluated at the presence of carvacrol (5 and 10 g/100 g polymer). The considerable improvement was achieved in water affinity (14.2%) and flexibility (8.6%) by incorporating 10% carvacrol in G-plasticized films. The greatest inhibitory properties of active wheat filter flour films were observed against Aspergillus niger. By increasing the carvacrol concentration in film-forming solution, the inhibitory activity against Listeria monocytogenes and Escherichia coli in the liquid food model system was increased by 90.3% and 66.95%, respectively. Moreover, the active wheat filter flour-based film released a considerable insecticidal activity against Sitophilus granarius and Tribolium confusum. This work offers a novel utilization of wheat filter flour as an inexpensive blend polymer to manufacture multifunctional active film, which provides a promising approach for pest management besides enhancing the safety of products.


Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 8099
Author(s):  
Azrina Abd Aziz ◽  
Lila Iznita Izhar ◽  
Vijanth Sagayan Asirvadam ◽  
Tong Boon Tang ◽  
Azimah Ajam ◽  
...  

Collateral vessels play an important role in the restoration of blood flow to the ischemic tissues of stroke patients, and the quality of collateral flow has major impact on reducing treatment delay and increasing the success rate of reperfusion. Due to high spatial resolution and rapid scan time, advance imaging using the cone-beam computed tomography (CBCT) is gaining more attention over the conventional angiography in acute stroke diagnosis. Detecting collateral vessels from CBCT images is a challenging task due to the presence of noises and artifacts, small-size and non-uniform structure of vessels. This paper presents a technique to objectively identify collateral vessels from non-collateral vessels. In our technique, several filters are used on the CBCT images of stroke patients to remove noises and artifacts, then multiscale top-hat transformation method is implemented on the pre-processed images to further enhance the vessels. Next, we applied three types of feature extraction methods which are gray level co-occurrence matrix (GLCM), moment invariant, and shape to explore which feature is best to classify the collateral vessels. These features are then used by the support vector machine (SVM), random forest, decision tree, and K-nearest neighbors (KNN) classifiers to classify vessels. Finally, the performance of these classifiers is evaluated in terms of accuracy, sensitivity, precision, recall, F-Measure, and area under the receiver operating characteristics curve. Our results show that all classifiers achieve promising classification accuracy above 90% and able to detect the collateral and non-collateral vessels from images.


2021 ◽  
Vol 2086 (1) ◽  
pp. 012212
Author(s):  
M D Soldatenkova ◽  
A D Triznova ◽  
E M Baeva ◽  
P I Zolotov ◽  
A I Lomakin ◽  
...  

Abstract High-quality thin NbN films are very crucial for realizing quantum devices. Here, we investigated electrical transport and noise properties of a series of thin NbN films of various thicknesses grown on r-cut sapphire substrate using a DC magnetron sputtering technique. The films exhibit non-uniform thickness dependences for superconducting transition temperature (Te ) and normal-state resistivity. Morphological characterization of NbN samples of various thicknesses reveals uniform structure in thin films and granular structure in thick films. By measuring transport and noise properties in a normal state, we observe that the granular structure of NbN films does not have a strong effect on resistivity and does not cause an additional source of current noise.


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