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Number of results: 29
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Abstract

The Centro de Desarrollo Tecnológico del Gas developed a static expansion system to enable the calibration of medium and high vacuum pressure gauges in Colombia. The system can generate pressures between 0.1 Pa and 100 kPa. The characterization tests included the evaluation of pressure stability and desorption rate, a trueness test, and the analysis of the uncertainty budget of the calibration result. The pressure stability test was successfully completed and showed the positive effect of baking on the final pressure in the system. The trueness test allowed concluding that the calibration results with the system are comparable with those obtained with a reference meter traceable to a national metrology institute. The uncertainty budget analysis indicated the dominance of the pressure of the unit under calibration and of the initial pressure in the small tank in different pressure ranges on the uncertainty of the result. A comparison with a Monte Carlo simulation led to the conclusion that in this situation, the GUM (Guide to the Expression of Uncertainty in Measurement) method is not ideal for estimating the uncertainty of the results.
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Bibliography

[1] Khan,W., Hong, H. H., Satar, T., Ahmed, M., Khan, Z. A.,& Khan, M. Z. (2016). The KRISS primary vacuum gauge calibration standards:Areview. Journal of the Vacuum Society of Japan, 59(8), 222–235.
[2] Astrua, M., Mari, D., & Pasqualin, S. (2019). Improvement of INRiM static expansion system as vacuum primary standard between 10(-4) Pa and 1000 Pa. 19th International Congress of Metrology, 27007. https://doi.org/10.1051/metrology/201927007
[3] Semwal, P., Khan, Z., Dhanani, K. R., Pathan, F. S., George, S., Raval, D. C., Thankey, P. L., Paravastu, Y., & Himabindu, M. (2012). Spinning rotor gauge based vacuum gauge calibration system at the Institute for Plasma Research. Journal of Physics: Conference Series, 390, 012027. https://doi.org/10.1088/1742-6596/390/1/012027
[4] Bergoglio, M., & Calcatelli, A. (2004). Uncertainty evaluation of the IMGC-CNR static expansion system. Metrologia, 41, 278–284. https://doi.org/10.1088/0026-1394/41/4/009
[5] Greenwood, J. C. (2006). Simulation of the operation and characteristics of static expansion pressure standards. Vacuum, 80, 548–553. https://doi.org/10.1016/j.vacuum.2005.09.003
[6] Soriano Cardona, B., Torres Guzmán, J., & Santander Romero, L. (2001). Sistema de referencia nacional para la medición de vacío. Simposio de Metrología CENAM 2001, México.
[7] Bergoglio, M., Calcatelli, A., Marzola, L., & Rumiano, G. (1988). Primary pressure measurements down to 10(-6) Pa. Vacuum, 38(8–10), 887–891. https://doi.org/10.1016/0042-207X(88)90486-1
[8] Fedchak, J. A., Abbott, P. J., & Hendricks, J. H. (2018). Review Article: Recommended practice for calibrating vacuum gauges of the ionization type. Journal of Vacuum Science & Technology A, 36, 030802. https://doi.org/10.1116/1.5025060
[9] Torres Guzmán, J. C., Santander, L. A., & Jousten, K. (2005). Realization of the medium and high vacuum primary standard inCENAM,Mexico.Metrologia, 42(6), S157–S160. https://doi.org/10.1088/0026-1394/42/6/S01
[10] Jousten, K., Röhl, P., & Aranda Contreras, V. (1999). Volume ratio determination in static expansion systems by means of a spinning rotor gauge. Vacuum, 52(4), 491–499. https://doi.org/10.1016/S0042-207X(98)00337-6
[11] Herranz, D., Ruiz, S., & Medina, N. (2009). Volume ratio determination in static expansion systems by means of two pressure balances. XIX IMEKO World Congress, Fundamental and Applied Metrology, Portugal. https://www.imeko2009.it.pt/Papers/FP_280.pdf
[12] Phanakulwijit, S.,&Pitakarnnop, J. (2019). Establishment of Thailand’s national primary vacuum standard by a static expansion method. Journal of Physics: Conference Series, 1380, 012003. https://doi.org/10.1088/1742-6596/1380/1/012003
[13] Jitschin, W. (2002). High-accuracy calibration in the vacuum range 0.3 Pa to 4000 Pa using the primary standard of static gas expansion. Metrologia, 39(3), 249–261. https://doi.org/10.1088/0026-1394/39/3/2
[14] Kangi, R., Ongun, B., & Elkatmis, A. (2004). The new UME primary standard for pressure generation in the range from 9 × 10 -4 Pa to 103 Pa. Metrologia, 41(4), 251–256. https://doi.org/10.1088/ 0026-1394/41/4/005
[15] International Organization for Standardization. (2011). Vacuum gauges – Calibration by direct comparison with a reference gauge ISO Standard No. 3567:2011. https://www.iso.org/standard/59372.html
[16] Antsukova, A. I., Gorobei, V. N., Liubomirov, A. B., Pimenova, A. A.,&Chernyshenko, A. A. (2019). Calibration of measuring instruments of low absolute pressures. IOP Conference Series: Journal of Physics: Conference Series, 1313, 012002. https://doi.org/10.1088/1742-6596/1313/1/012002
[17] Ruiz González, S. (2011). Desarrollo de un nuevo patrón nacional de presión. Desde la columna de mercurio a patrones primarios de vacío [Doctoral dissertation, Universidad de Valladolid]. UVaDOC Repositorio Documental de la Universidad de Valladolid. https://doi.org/10.35376/10324/830
[18] Joint Committee for Guides in Metrology. (2008). Evaluation of measurement data – Guide to the expression of uncertainty in measurement (JCGM 100:2008). http://www.bipm.org/utils/common/ documents/jcgm/JCGM_100_2008_E.pdf
[19] Joint Committee for Guides in Metrology. (2008). Evaluation of measurement data – Supplement 1 to the “Guide to the expression of uncertainty in measurement” – Propagation of distributions using a Monte Carlo method (JCGM 101:2008). https://www.bipm.org/documents/20126/2071204/ JCGM_101_2008_E.pdf

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Authors and Affiliations

Jonathan Javier Duarte Franco
1
Carlos Mauricio Villamizar Mora
2
Carlos Eduardo García Sánchez
1

  1. Corporación Centro de Desarrollo Tecnológico del Gas, Grupo de Investigación en Fluidos y Energía, Carrera 23# 106-08, ZIP 680004, Bucaramanga, Colombia
  2. Universidad Industrial de Santander, Escuela de Ingeniería Mecánica, Grupo de Investigación en Energía y MedioAmbiente, Carrera 27 calle 9, ZIP 680002, Bucaramanga, Colombia
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Abstract

The reign of Bolesław I the Brave has for many years been very popular among historians and numismatists. The political history of his rule is at the centre of the research of the first one, and the history of his coinage of the latter. On the other hand, much less attention is paid to the fiscal and prestigious-symbolic contexts of the circulation of bullion, which at the turn of the 10th and 11th centuries consisted almost exclusively of imported coins and silver in a non-monetary form, mainly jewellery. This raises many questions: how did access to luxury goods affected the exercise of power? What equivalents and under what circumstances were foreign coins purchased? How did the desire to take control of the silver distribution networks between Meissen, Prague and Kiev in the first decades of the 11th century directed Bolesław’s expansion? Methodologically, the article combines the analysis of the hoards with the interpretation of written sources.
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Authors and Affiliations

Dariusz Adamczyk
1
ORCID: ORCID

  1. Deutsches Historisches Institut Warschau, Pałac Karnickich, Aleje Ujazdowskie 39, PL 00–540 Warsaw, Poland
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Abstract

Many open-pit mines are gradually converted to underground mining, the problem of roadway surrounding rock damage caused by expansive soft rock is becoming increasingly problematic. To study the seasonal evolution of expansive rock mass containing clay minerals, an underground mine transferred from an open-pit was selected as the experimental mine. The experimental results of SEM electron microscopy and X-ray diffraction confirmed that the surrounding rock of the main haulage roadway contains a large number of expansive clay minerals. The expansive grade of the main transport roadway’s surrounding rock could then be identified as the medium expansive rock mass, which has a large amount of exchangeable cation and strong water absorption capacity, based on the combined test results of dry saturated water absorption and free expansion deformation. The water swelling can cause the roadway to considerably deform, and then the surrounding rock will have strong rheological characteristics. From the research results in the text, the seasonal evolution law of the main haulage roadway in the experimental mine was obtained, and the deformation law of the expansive rock mass under different dry and wet conditions was revealed. The research results provide a reference for studying the stability evolution law of expansive soft rocks in underground mines.
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Authors and Affiliations

Hongdi Jing
1 2
ORCID: ORCID
Fuming Qu
3
ORCID: ORCID
Xiaobo Liu
3
ORCID: ORCID
Guangliang Zhang
4
Xingfan Zhang
1 2
Xinbo Ma
4

  1. Chinese Academy of Sciences, Shenyang Institute of Automation, Shenyang 110016, China
  2. Chinese Academy of Sciences, Institutes for Robotics and Intelligent Manufacturing, Shenyang110169, China
  3. University of Science and Technology Beijing, Beijing 100083, China
  4. Northeastern University, Shenyang 100083, China
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Abstract

In this work, a new supplementary formula was introduced to modify the Kerner model. This supplementary formula enable the Kerner model to predict the thermal expansion coefficient of multi-phase reinforced composites by normalization of the thermal expansion coefficient, bulk modulus, and shear modulus of the reinforcements. For comparison, the modified Kerner model as well as modified Schapery, the rule of mixtures, and Turner models were used to predict the thermal expansion coefficient of multi-phase reinforced composites 6092 Aluminum Alloy/silicon carbide/β-eucryptite. The results confirm the robustness of the modified Kerner model for predicting the thermal expansion coefficient of composites with multi-phase near-spherical inclusions. It may provide a fine selection to predict the thermal expansion coefficient of multi-phase reinforced metal matrix composites which cannot predict efficiently before.
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Authors and Affiliations

Shihao Zhang
1 2
ORCID: ORCID
Qinglin Hou
1
ORCID: ORCID
H.Y. Jiang
1 2
ORCID: ORCID

  1. Hunan University of Technology, School of Packaging and Materials Engineering, Zhuzhou 412007, China
  2. Hunan University of Technology, National & Local Joint Engineering Research Center for Advanced Packaging Material and Technology, Zhuzhou 412007, China
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Abstract

The main statement of the paper is that the post-truth is expanding at an unprecedented rate, continuously forcing itself into new areas of public life and permeating millions of minds. This phenomenon has not so far been satisfactorily explained by researchers of global-range social phenomena. The paper presents various definitions of post-truth and its interpretations. The argument revolves around what truth means and what it is threatened by, as well as the most important institution that is, by definition, concerned about the truth: the university. The article outlines the functions of the university and contemporary conditions of its functioning, including the threats to the preservation of its mission and axiological foundation: striving towards the truth. The idea of the university, created in Europe at the beginning of the second millennium, has shown to be strong and durable. It has adopted various organisational forms, depending on the period and region. The secret of the universities’ persistence and meaning cannot be considered apart from the history of the European civilisation. However, the phenomenon of post-truth expansion is the most serious threat to this institution. The expansion of post-truth also leads to changes in the quality of the public life, bringing about its degeneration, with considerable contributions of the numerous pathologies of the Internet, distribution of lies and surprisingly quickly growing acceptance of this phenomenon.

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Authors and Affiliations

Jerzy Wilkin
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Abstract

The topic of the article is a description of European urbonyms which fulfilled both political and commemorative roles in the past. The city names are presented in chronological order starting from ancient times to the 20th century. The ancient toponyms are related to the expansion of the Roman Empire, and the names of Roman emperors are used as a foundation for these toponyms. Such urbonyms created on the outskirts of the Roman Empire made reference to their new political allegiance and confirmed it. These naming practices therefore played an important role in the process of territorial expansion and the consolidation of political control. This naming model was also present in Byzantium, and became popular on the outskirts of medieval Ruthenia under the influence of the Byzantine Empire. The tradition of commemorating political rulers through toponyms stayed constant in the Eastern Slavic regions, and was continued by the Russian monarchy as well as the USSR. Such naming practices were initially used as a tool for the structural organisation of Kievan Rus’, and later to erase foreign names from these regions of Tsarist Russia. In Communist times, this tradition reaffirmed the new political reality through the use of surnames of political figures in toponyms. In the 20th century there was an increase in surnames featured in urbanonyms (the names of streets, squares, housing estates). This increase was meant to preserve the memory of remarkable individuals in society.

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Authors and Affiliations

Zofia Zierhofferowa
Karol Zierhoffer
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Abstract

Systematic attempts to maximise the efficiency of gas turbine units are achieved, among other possibilities, by increasing the temperature at the inlet to the expansion section. This requires additional technological solutions in advanced systems for cooling the blade rows with air extracted from the compressor section. This paper introduces a new mathematical model describing the expansion process of the working medium in the turbine stage with air film cooling. The model includes temperature and pressure losses caused by the mixing of cooling air in the path of hot exhaust gases. The improvement of the accuracy of the expansion process mathematical description, compared with the currently used models, is achieved by introducing an additional empirical coefficient estimating the distribution of the cooling air along the profile of the turbine blade. The new approach to determine the theoretical power of a cooled turbine stage is also presented. The model is based on the application of three conservation laws: mass, energy and momentum. The advantage of the proposed approach is the inclusion of variable thermodynamic parameters of the cooling medium. The results were compared with the simplified models used in the literature: separate Hartsel expansion, mainstream pressure, weighted-average pressure and fully reversible. The proposed model for expansion and the determination of theoretical power allows for accurate modelling of the performance of a cooled turbine stage under varying conditions.
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Authors and Affiliations

Paweł Trawiński
1

  1. Institute of Heat Engineering, Warsaw University of Technology, Nowowiejska 21/25, 00-665, Warsaw, Poland
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Abstract

The presence of noises in the vehicle cabin is an annoyance phenomenon which is significantly affected by the heating, ventilation, and air conditioning (HVAC) system. There are very limited studies reported on the specific type of noise characterisation and validation for both model and vehicle system levels. The present study developed a model of HVAC system that reflects the operation as in real vehicle, and the investigation of the HVAC components were carried out individually to determine which component contributes to the humming-type noise and vibration. The study was conducted under two conditions; idle speed of engine (850 rpm) and operating condition (850–1400 rpm). A ixed blower speed and fullface setting were applied throughout the experimental process. Three different sensors were used for the experiment, which are: accelerometer, tachometer, and microphone. From the results, the compressor and AC pipe components have contributed the most in generating the noise and vibration for both the model and vehicle systems. The findings also highlight that the humming-type noise and vibration were produced in the same operating frequency of 300–400 Hz and 100–300 Hz for idle and operating conditions, respectively, and this result was validated for both model and vehicle system levels.
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Authors and Affiliations

Mohd Hafiz Abdul Satar
1
Ahmad Zhafran Ahmad Mazlan
1
Muhd Hidayat Hamdan
1
Mohd Syazwan Md Isa
1
Muhd Abdul Rahman Paiman
2
Mohd Zukhairi Abd Ghapar
2

  1. The Vibration Lab, School of Mechanical Engineering, Universiti Sains Malaysia 14300 Nibong Tebal, Penang, Malaysia
  2. Testing & Development, Vehicle Development & Engineering, Proton Holdings Berhad, 40000 Shah Alam, Selangor, Malaysia
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Abstract

Heating, ventilation and air conditional (HVAC) system provides a cold ventilation for the comfort of the driver and passengers in a vehicle. However, the vibration induced by the HVAC contributes to a reasonable level of noise emission, and hissing is one of the critical noises. So far, the characterization of hissing noise from the vehicle is least to be reported compared to other type of noises. Hence, this paper investigates the occurrence of hissing noise from several HVAC components. A lab-scale HVAC system was developed to imitate the real-time operations of the vehicle HVAC system. Two engine conditions, namely as ambient and operating conditions, were tested at speed of 850 rpm and 850–1400 rpm, with the blower speed maintained constantly at one level. The result shows that the hissing noise from the labscale HVAC was produced at frequency range of 4000–6000 Hz. The finding also highlights that the main component contributors of noise emission are an evaporator and a thermal expansion valve. The validation with a real vehicle system showed a good consensus whereby the hissing noise was produced at the similar operating frequency ranges. Also, the hissing noise was found to be louder when in an operating condition which could be taken into consideration by the vehicle manufacturers to improve the HVAC design.
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Authors and Affiliations

Mohd Hafiz Abdul Satar
1
Ahmad Zhafran Ahmad Mazlan
1
Muhd Hidayat Hamdan
1
Mohd Syazwan Md Isa
1
Muhd Abdul Rahman Paiman
2
Mohd Zukhairi Abd Ghapar
2

  1. The Vibration Lab, School of Mechanical Engineering, Universiti Sains Malaysia 14300 Nibong Tebal, Penang, Malaysia
  2. Testing & Development, Vehicle Development & Engineering, Proton Holdings Berhad, 40000 Shah Alam, Selangor, Malaysia
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Abstract

Recent advances in the construction of speed of sound meters made high-accuracy routine measurements possible in laboratories non-specialized in physical acoustics. Reliable values of the isentropic compressibility can be obtained from speeds of sound and densities of liquids using the Laplace formula. Strict thermodynamic relationships connect the isentropic compressibility of a medium and its density as a function of temperature and pressure with the heat capacity. These relationships result from the principles of thermodynamics and require no approximations or molecular models. In this study, the heat capacities of twelve liquids: hydrocarbons, acetonitrile, and ionic liquids were calculated from the speeds and densities taken from the literature sources. The agreement of the calculation results with the reference heat capacities, either critical values or measured calorimetrically, was satisfactory. The relative uncertainty of the calculated heat capacities was rather conservatively estimated for 5%. If the measurement procedures were optimized for heat capacity determination, better results would be attained, with the uncertainty probably smaller than 1%. Thus, the speed-and-density method is a potential alternative to classical calorimetry.
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Authors and Affiliations

Sylwia Szpaczek
1
Wojciech Marczak
1

  1. Faculty of Science and Technology, Jan Długosz University, Czestochowa, Poland
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Abstract

The sodium expansion and creep strain of semi-graphitic cathodes are investigated using a modified Rapoport apparatus. To further understanding of the sodium and bath penetration damage processes, the impact of external stress fluence on the carbon cathode microstructure has been defined with XRD analysis, Raman spectroscopy and scanning electron microscope (SEM). Graphite atoms fracture into smaller fragments that are less directional than the pristine platelets, which allows for a possible filling of the cracks that thus develop by the sodium and bath during aluminum electrolysis. The average microcrystalline size (calculated by Raman spectroscopy) is reduced by the deformation. The decreased intensity and widened ‘G’ and ‘D’ peaks in the analysis indicate the poor order of the sheets along the stacking direction while the consistent layered graphite structure is sustained.

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Authors and Affiliations

Wei Wang
ORCID: ORCID
Weijie Chen
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Abstract

This study was carried out to evaluate the effect of steel slag (SS) as a by-product as an additive on the geotechnical properties of expansive soil. A series of laboratory tests were conducted on natural and stabilized soils. Steel slag (SS) was added at a rate of 0, 5, 10, 15, 20, and 25% to the soil. The conducted tests are consistency limits, specific gravity, grain size analysis, modified Proctor compaction, free swell, unconfined compression strength, and California Bearing Ratio. The Atterberg limit test result shows that the liquid limit decreases from 90.8 to 65.2%, the plastic limit decreases from 60.3 to 42.5%, and the plasticity index decreases from 30.5 to 22.7% as the steel slag of 25% was added to expansive soil. With 25% steel slag content, specific gravity increases from 2.67 to 3.05. The free swell value decreased from 104.6 to 58.2%. From the Standard Proctor compaction test, maximum dry density increases from 1.504 to 1.69 g/cm3 and optimum moisture content decreases from 19.77 to 12.01 %. Unconfined compressive strength tests reveal that the addition of steel slag of 25% to expansive soil increases the unconfined compressive strength of the soil from 94.3 to 260.6 kPa. The California Bearing Ratio test also shows that the addition of steel slag by 25% increases the California Bearing ratio value from 3.64 to 6.82%. Hence, steel slag was found to be successfully improving the geotechnical properties of expansive soil.
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Authors and Affiliations

Worku Firomsa Kabeta
1 2
ORCID: ORCID

  1. Gdansk University of Technology, Faculty of Civil and Environmental Engineering, Gabriela Narutowicza 11/12, 80-233, Gdansk, Poland
  2. Jimma University, Faculty of Civil and Environmental Engineering, Jimma saris, 378, Jimma, Ethiopia
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Abstract

An enormous number of structures and roads are put on expansive subgrade soils and may be exposed to the swelling and shrinkage risk. To prevent the expanding weight of the subgrade layer under loaded pavement, one of the following strategies may be utilized are geogrid layer. Reinforced pavement layers have been propagated in the field of civil engineering because of their profoundly adaptable and diversified use. In this study, axisymmetric models of pavement layers have been created by 2-D Plaxis software and all of these models included geogrid layers at various positions concentrated to research the impact of geogrid on the critical pavement responses. Geogrid was placed at the bottom of asphalt layer, bottom of base layer, tope and middle of the subgrade layer. All models are loaded with incremental contact pressure between 50 and 600 kPa. Analysis processes have been made for all models and the obtained investigation results show a significant effect on pavement behavior when the a geogrid layer was used under various tire pressures. Also, there is an increase in the bearing capacity of a model that includes geogrid at the top and middle of the subgrade layer by about 35% and the resistance of the asphalt layer to deformation and cracking failure was improved.
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Authors and Affiliations

Ghadah Ghassan Masood
1
ORCID: ORCID
Hadeel Ammar Mohammed
1
ORCID: ORCID
Hanan Adnan Hassan Afaj
1
ORCID: ORCID
Mohammed Yousif Fattah
2
ORCID: ORCID

  1. Lecturer, Highway and Transportation Department, Engineering College, Mustansiriyah University, Iraq, Baghdad
  2. Civil Engineering Department, University of Technology, Iraq
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Abstract

The article is devoted to study of the structure of the artistic expanse in Marina Tsvetaeva’s autobiographical essay Mother and Music. This structure is rich and complex; containing the following elements: concrete-geographical, spatial-physical, archetypal, emotional-psychological, sacred‑spiritual as well as others. Each of them, to one degree or another, reflects the peculiarities of the writer’s worldview, her creative manner, as well as her subjective attitude to the objective phenomena of surrounding reality. In the holistic context of this essay, the author contrasts two grandiose Universes – the mother’s world with her music and the daughter’s world with her poetry. The relativity and variability of the relevant spatial, psychological and other parameters emphasize the absoluteness of those eternal values of existence, on which the masterly organized system of Tsvetaeva’s prose is based.
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Authors and Affiliations

Ирина Бетко
1
ORCID: ORCID

  1. Uniwersytet Warmińsko‑Mazurski w Olsztynie
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Abstract

The thermal expansion of a ZrO2-20 mol% Gd2O3 pellet has been systematically investigated using a thermo-mechanical analyzer in the temperature range of 293-1773 K. Variations in the thermal expansion coefficient and density upon temperature change were calculated using the thermal expansion data. The average linear thermal expansion coefficient of the ZrO2-20 mol% Gd2O3 pellet was found to be 9.522 × 10–6 K–1 in the range of 298-1073 K. This value is smaller than that of ZrO2 and larger than that of Gd2O3. Further, with an increase in temperature to 1773 K, the density of ZrO2-20 mol% Gd2O3 pellet was found to decrease to 94.98 % of the initial density at 293 K.
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Authors and Affiliations

Kweonho Kang
1
ORCID: ORCID
Seok-Min Hong
1
ORCID: ORCID
Changhwa Lee
1
ORCID: ORCID
Yongjun Cho
1
ORCID: ORCID

  1. Korea Atomic Energy Research Institute, Daejeon, Republic of Korea
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Abstract

This study presents an analysis of the effect of the concentrated mass on the acoustic power and the resonant frequencies of a vibrating thin circular plate. The fluid-structure interactions and the acoustic wave radiation effect have been included. The eigenfunction expansion has been used to express the transverse displacement of the plate. The appropriate number of modes is determined approximately to achieve physically correct results. Then highly accurate results are obtained numerically. The radiated acoustic power has been used to determine the resonant frequencies. The introducing of the concentrated mass is justified by modelling the added mass of the moving component of the exciter.
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Authors and Affiliations

Wojciech P. Rdzanek
1
Krzysztof Szemela
1

  1. University of Rzeszow, College of Natural Sciences, Institute of Physics, Rzeszow, Poland
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Abstract

Recent years, the design of photonic crystal (PC) based optical devices is receiving keen interest in research and scientific community. In this paper, two dimensional (2D) PC based eight channel demultiplexer is proposed and designed and the functional characteristics of demultiplexer namely resonant wavelength, transmission efficiency, quality factor, spectral width, channel spacing and crosstalk are investigated. The demultiplexer is designed to drop the wavelength centred at 1537.6 nm, 1538.5 nm, 1539.4 nm, 1540.4 nm, 1541.2 nm, 1541.9 nm, 1542.6 nm and 1543.1 nm. The proposed demultiplexer is primarily composed of bus waveguide, drop waveguide and quasi square ring resonator. The quasi square ring resonator and square ring micro cavity (inner rods) are playing a vital role for a desired channel selection. The operating range of the devices is identified through a photonic band gap (PBG) which is obtained using a plane wave expansion (PWE) method. The functional characteristics of the proposed demultiplexer are attained using a 2D finite difference time domain (FDTD) method. The proposed device offers low crosstalk and high transmission efficiency with ultra-compact size, hence, it is highly desirable for DWDM applications.

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Authors and Affiliations

V. Kannaiyan
R. Savarimuthu
S.K. Dhamodharan
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Abstract

In this attempt, Two Dimensional Photonic Crystal (2DPC) Quasi Square Ring Resonator (QSRR) based four channel demultiplexer is proposed and designed for Wavelength Division Multiplexing systems. The performance parameters of the demultiplexer such as transmission efficiency, passband width, line spacing, Q factor and crosstalk are investigated. The proposed demultiplexer is composed of bus waveguide, drop waveguide and QSRR. In the proposed demultiplexer, the output ports are arranged separately in odd and even number, where an odd number of ports are located on the right side and even number of ports are located on the left side of the bus waveguide that are used to reduce the channel interference or crosstalk. Further, the refractive index of rods around the center rod is increased linearly one to another in order to improve the signal quality. The resonant wavelengths of the proposed demultiplexer are of 1521.1 nm, 1522.0 nm, 1523.2 nm and 1524.3 nm, respectively. The footprint of the device is of 180.96 μm2. Then, a four channel point to point network is designed and the proposed four channel demultiplexer is implemented by replacing a conventional demultiplexer. Finally, functional parameters of the network, namely, BER, receiver sensitivity and Q factor are estimated by varying the link distance. This attempt could create new dimensions of research in the domain of photonic networks.

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Authors and Affiliations

V. Kannaiyan
R. Savarimuthu
S.K. Dhamodharan
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Abstract

One of the main causes of damage to weirs regulating the flow of water in canals is local erosion of the bottom and banks. This is mainly due to the excessive kinetic energy of the stream flow and the uneven volumetric distribution of the water flow rate at the end of the strengthening. Due to this, 35–40% of hydraulic structures fail prematurely. The aim of the research was to determine the parameters of the spatial hydraulic jump arising behind the hydrotechnical structure and the rapid expansion of the cross-section. The research showed that the hydraulic jump with a curved cylinder in the plan is a spatial form and not only dissipates the energy of the stream, but also acts as a diffuser. With the stream expansion angle values in the range of 7–10°, a highly turbulent flow remains, which still has high kinetic energy at a distance from the end of the structure. At an angle of 25–27°, the flow is smooth, the velocity distribution is uniform across the width of the channel. In some cases, the forced expansion of the cross-section at the outflow of the weir favours the energy dissipation and uniform flow velocity distribution.
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Authors and Affiliations

Zhuzbay Kassymbekov
1
Abai Shinibaev
1
Galimzhan Kassymbekov
1

  1. Satbayev University, Satpayev Str., 22, Almaty, 050013, Kazakhstan
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Bibliography

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[2] S. John, “Strong localization of photons in certain disordered dielectric superlattices,” Physical Review Letters, vol. 58, no. 23, p. 2486, 1987.
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Authors and Affiliations

Mahesh V. Sonth
1
G. Srikanth
1
Pankaj Agrawal
1
B. Premalatha
2

  1. Department of Electronics and Communication Engineering, CMR Technical Campus, Hyderabad-501401, Telangana, India
  2. Department of Electronics and Communication Engineering, CMR College of Engineering & Technology, Hyderabad-501401,Telangana, India
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Abstract

Pot-cored coils are commonly used as probes in eddy current testing. In this paper, an analytical model of such a coil placed over a three-layer plate with a hole has been presented. The proposed solution enables the modelling of both magnetic and non-magnetic conductive plates that contain different types of hole, i.e. a through, a surface, an inner or a subsurface hole. The problem was solved by using the truncated region eigenfunction expansion (TREE) method. The analysis was carried out in a cylindrical coordinate system in which the solution domain was radially limited. With the employment of the filamentary coil, the expressions for the magnetic vector potential, and subsequently for the impedance of the cylindrical coil were obtained. The final formulas were presented in a closed form and then implemented in Matlab. The resistance and reactance values were compared with the results obtained in the experiment and using the finite element method in the Comsol Multiphysics package. In each of the cases, good agreement was obtained.

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Authors and Affiliations

G. Tytko
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Abstract

The following article can serve as yet another report from the workshop of an Etymological Dictionary of Arabic ( EtymArab).1 Work on a ‘zero version’ of such a dictionary has seen (slow but) steady progress since several years now. Taking the root √SLQ as an example, this contribution gives an idea about the high potential of such a project, but also shows its clear actual limits. The enormous spectrum of semantic values covered by √SLQ—one may distinguish more than thirty meanings that, at first sight, do not seem related to each other—provides a fine illustration of the complex composition of the modern as well as the classical lexicon. The current state of affairs in Arabic etymology allows us, to a certain degree, to ‘sort out things’ and bring some order into this confusing complexity. In many cases, however, research also remains ‘hanging in the air’.
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Authors and Affiliations

Stephan Guth
1
ORCID: ORCID

  1. University of Oslo, Norway
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Abstract

The properties of expansive concretes made of two types of cement: Portland cement CEM I and blast furnace slag cement CEM III were tested. The expansion of the concrete was caused by using an expansive admixture containing aluminium powder added in an amount of 0.5; 1 and 1.5% of cement mass. It was found that the compressive strength of concrete with CEM I decreased after using an expansive admixture in the amount of more than 0.5% of the cement mass. The compressive strength of concrete with CEM III decrease after addition of admixture in the entire range of dosages used. On the basis of electrochemical measurements, it was found no influence of an expansive admixture on corrosion of reinforcing steel. The use of an expansive admixture causes a slight increase in the effective diffusion coefficient of chloride ions in concrete.

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Authors and Affiliations

W. Jackiewicz-Rek
J. Kuziak
B. Jaworska
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Abstract

Self-Compacting Concrete (SCC) has been widely used in the filling layer of high-speed railways. The quality of the filling layer directly affects the durability, comfort, and safety of the track system. In this study, shrinkage characteristics and the creep behavior of SCC were investigated by compressive creep tests and shrinkage tests. They were performed on specimens with different loading levels with a calcium sulfoaluminate-based expansive agent (UEA) and viscosity modified admixture (VMA). Furthermore, based on the scanning electron microscope (SEM) morphology of hydration products and X-ray diffraction (XRD) analysis, the influence of admixtures on microstructure and mineral phases of SCC was analyzed.The results show that when concretes were loaded with the same stress level, the main factor influencing creep of SCC was the quantity and microstructure of amorphism and hydration crystal. The XRD and SEM result showed that UEA andVMAmake the creep and shrinkage of SCC reduce obviously as the cementitious system grow many crystals in hydration products. The creep of NC was less than SCC with identical compressive strength. At the same time, the addition of UEA can improve the ability to resist drying shrinkage.
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Authors and Affiliations

H. Liu
1
ORCID: ORCID
Guangchao Duan
1
ORCID: ORCID
Jingyi Zhang
2
ORCID: ORCID

  1. Shenyang Jianzhu University, School of Transportation and Geometics Engineering, No. 25 Hunnan Zhong Road, Hunnan District, 110168 Shenyang, China
  2. Shenyang Urban Construction University, School of Civil Engineering, No.380 Bai Ta Road, Hunnan District, 110167 Shenyang, China

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