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Abstract

Cumulative blasts are an important controlled blasting method used to control the propagation of cracks in the predetermined direction. However, traditional cumulative blasts are associated with long processing times and poor blasting effects. A simple blasting technology called bilateral cumulative tensile explosion (BCTE) is proposed in this paper. There are two application types where BCTE is used. The first application is used to control the stability of high-stress roadways in both Wangzhuang mine 6208 tailgate and Hongqinghe mine 3-1103 tailgate. The second application is used to replace the backfill body in gob-side entry retaining (GER) in Chengjiao mine 21404 panel, Jinfeng mine 011810 panel and Zhongxing mine 1200 panel. The first application type reveals that BCTE can significantly reduce the deformation of the surrounding rock and reduce the associated maintenance cost of the roadways. Whereas the second application type, the roadway deformations are smaller, the process is simpler, and the production costs are lower, which further promotes GER and is of significance towards conserving resources.
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Authors and Affiliations

Jun Yang
1
ORCID: ORCID
Binhui Liu
1
ORCID: ORCID
Wenhui Bian
1
ORCID: ORCID
Kuikui Chen
1
ORCID: ORCID
Hongyu Wang
1
ORCID: ORCID
Chen Cao
2
ORCID: ORCID

  1. China University of Mining and Technology, State Key Laboratory for Geomechanics and Deep Underground Engineering, Beijing 100083, China
  2. University of Wollongong, Mining & Environment Engineering, School of Civil, Wollongong, NSW 2522, Australia
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Abstract

Pipeline welding is an integral part of oil and gas exploration industries. Often the welded joint failures were due to lack of weld quality, improper heat treatment and even poor workmanship. Further, the use of new material in pipeline industry puts focus on a better understanding of qualifying requirements of welding for reducing the failures in future. This necessitates the need for development and design of suitable welding fluxes for joining these materials. In this paper an attempt is made to study the effects of submerged arc welding fluxes on weldability as well as structural integrity issues in pipeline steels. Physicochemical and thermophysical properties of submerged arc fluxes widely affects the mechanical behaviour of pipeline steels. This paper presents an overview of the role of welding parameters, flux composition, cooling rate, slag behaviour and physicochemical properties of slag on final welded joint properties such as tensile strength, impact toughness etc. during submerged arc welding.
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Authors and Affiliations

Lochan Sharma
1 2
ORCID: ORCID
Rahul Chhibber
3
ORCID: ORCID

  1. Chandigarh University, Institute of Engineering, Mechanical Engineering Department, Mohali-140413, Punjab, India
  2. University Centre for Research & Development, Chandigarh University, Mohali-140413, Punjab, India
  3. MED, IIT Jodhpur, India
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Abstract

The use of fractional-order calculus for system modeling is a good alternative to well-known classic integer-order methods, primarily due to the precision with which the modeled object may be mapped. In this study, we created integer and fractional discrete models of a real object – a highspeed brushless micro-motor. The accuracy of the models was verified and compared.

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Authors and Affiliations

M. Matusiak
M. Bąkała
R. Wojciechowski
P. Ostalczyk
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Abstract

The contributions of the members of the Department of Geochemistry, Mineralogy and Petrology, University of Warsaw, to the study of the chevkinite-group of minerals (CGM) are described. The range of research topics includes: (i) geochemical and mineralogical studies of natural occurrences of the group, and attempts to relate their chemical composition to host lithology; (ii) detailed analysis of the hydrothermal alteration of CGM in various settings, with the aim of understanding element redistribution and the potential implications for ore formation. An ongoing series of high P-T experiments is providing quantitative information on the pressures, temperatures and melt water conditions under which the alteration assemblages have formed. Various spectroscopic techniques are being used to determine the structure of the CGM and to identify cation distribution in the structures.
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Authors and Affiliations

Ray Macdonald
1 2
Bogusław Bagiński
1

  1. University of Warsaw, Faculty of Geology, Department of Geochemistry, Mineralogy and Petrology, Żwirki i Wigury 93, 02-089 Warszawa, Poland
  2. Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
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Abstract

Effect of annealing treatment on deep drawing behavior of hot-rolled Q235 carbon steel/410/304 stainless steel three-layer composite plate was investigated. Deep drawability of the unannealed composite plates exhibits a sharp difference for various contact surfaces with the die. The limit drawing ratio (LDR) of the composite plate with the carbon steel contacting the die is 1.75, while it is 1.83 with the stainless steel contacting the die due to the different mechanical responses to the tensile stress at the corner of the die. After annealing at 900°C for 2 h, however, the deep drawabilities of the composite plates both for various contact surfaces with the die are significantly improved and becomes almost identical, which are attributed to the stress relief, the enhanced ductility and the improved interface bonding strength of the hot-rolled component plates during annealing.
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Authors and Affiliations

Zehua Lv
1 2 3
Zhixiong Zhang
1 2 3
Jianchao Han
1 2 3
Tao Wang
1 2 3
ORCID: ORCID

  1. Taiyuan University of Technology, College of Mechanical and Vehicle Engineering, Taiyuan 030024, PR China
  2. Taiyuan University of Technology, Engineering Research Center of Advanced Metal Composites Forming Technology and Equipment, Ministry of Education, Taiyuan 030024, PR China
  3. Taiyuan University of Technology, Tyut-Uow Joint Research Centre, Taiyuan 030024, PR China
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Abstract

This paper proposes a method to optimize reinforcement layout of three-dimensional members under a state of complex stress and multiple load cases (MLCs). To simulate three-dimensional members, the spatial truss-like material model is adopted. Three families of truss-like members along orthotropic directions are embedded continuously in concrete. The optimal reinforcement layout design is obtained by optimizing the member densities and orientations. The optimal design of three-dimensional member is carried out by solving the problem of minimum volume of reinforcing bars with stress constraints. Firstly, the optimized reinforcement layout under each single load case (SLC) is obtained as per the fully stressed criterion. Second, on the basis of the previous results, an equivalent multi-case optimization is proposed by introducing the idea of stiffness envelope. Finally, according to the characteristics of the truss-like material, a closed and symmetrical surface is adopted to fit the maximum directional stiffness under all SLCs. It can be proved that the densities and orientations of truss-like members are the eigenvalues and eigenvectors of the surface coefficient matrix, respectively. Several three-dimensional members are used as examples to demonstrate the capability of the proposed method in finding the best reinforcement layout design of each reinforced concrete (RC) member and to verify its efficiency in application to real design problems.
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Authors and Affiliations

Hao Cui
1
ORCID: ORCID
Junjie Xia
1
ORCID: ORCID
Lang Wu
1
ORCID: ORCID
Min Xiao
1
ORCID: ORCID

  1. College of Civil Engineering and Architecture, Jiangxi Science and Technology Norma lUniversity, No.605 Fenglin Avenue, 330013, Nanchang, China
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Abstract

The article presents methods of evaluating energy consumption of water pumps. Pump characteristics during work at variable rotational speed and constant head are discussed. Characteristics of the upper slope of pump efficiency curve were determined for the cases of constant and variable growth of rotational speed The left-sided coefficient of pump efficiency correction was defined.
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Authors and Affiliations

Leszek Szychta
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Abstract

In this paper, we randomly select 75 sets data of calcium sulfate hemihydrate (CSH) content and initial setting time, and the traditional test method of CSH and analyses initial setting time was used by complexometric titration. So the close relationship between them was studied in depth, which classification fitting data to be analyzed by regression analysis. The result shows that this regression analysis method can accurately determine CSH content in modified industrial by-product gypsum. The determination method has the advantages of simplification and rapid operation. As well as, the XRF quantitative analytical method was used to test the CSH content, which verified the accuracy of regression analysis method. The results also show that this method has high accuracy, and can simplify the traditional experimental process. The method developed is easier and more convenient and has broad prospects in application.

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Authors and Affiliations

Bing Li
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Abstract

Daylight character in a space can be defined as the manner in which daylight permeates and is dispersed in that space. The architectural elements related to daylighting under investigation in this study were rooted in Iranian-Isfahani heritage, considered traditional Iranian architecture (from the 16th to early 20th century). The establishment of a classification system for daylighting systems holds significant utility. This study aims to delineate the architectural components present in Isfahani-style structures that facilitate the ingress of daylight, thereby enhancing the indoors.
The methodology employed in this research relies on subjective observation and photographic documentation. Based on the findings of this study, architectural daylighting elements can be organized into four distinct categories: Controllers, Scatterers, Filterers, and Modifiers. This classification system delineated these categories based on the observed order in their complexity (in terms of both quantity and quality of daylight treatment), function (pertaining to lighting, view-out, or shading), material characteristics (including transparency, roughness, and brightness), and their impact on daylighting (such as distribution, colour rendition, and intensity). Daylight Controllers encompassed elements like the hurno (skylight), the ravaq, the sabat, and the tabesh-band/sarsayeh/kharakpoush (shading devices), while daylight Scatterers encompassed the shabak, the rozan, the pachang (windows and doors), and the muqarnas (an ornamental feature of skylight). Daylight Filterers, representing more advanced elements when compared to the previous two categories, included the goljam (windows) and the jam-khaneh (skylights). The most intricate daylight manipulation elements were the daylight Modifiers, exemplified by the orosi (windows) and the roshandan (skylight)
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Authors and Affiliations

Mosleh Ahmadi
1
ORCID: ORCID
Natalia Sokół
1
ORCID: ORCID
Joanna Francuzik
1
ORCID: ORCID
Justyna Martyniuk-Pęczek
1
ORCID: ORCID

  1. Gdańsk University of Technology Faculty of Architecture and Urban Planning
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Abstract

This paper discusses the influence of different sign conventions for strains and stresses, i.e. the solid mechanics sign convention and the soil mechanics sign convention, on the form of governing partial differential equations (the static equilibrium equations and the continuity equation) used to describe the wave-induced cyclic response of a poro-elastic seabed due to propagation of a sinusoidal surface water-wave. Some selected analytical solutions, obtained by different authors and published in specialist literature in the form of complex functions describing the wave-induced pore-fluid pressure, effective normal stress and shear stress oscillations in the seabed, have been analysed and compared with each other mainly with respect to different sign conventions for stains and stresses and also with regard to different orientations of the positive vertical axis of the two-dimensional coordinate system and different directions of surface water-wave propagation. The performed analyses of the analytical solutions has indicated many inaccuracies, or even evident errors and exemplary mistakes of wrong-signed values of basic wave-induced response parameters (the shear stress in particular), thereby disqualifying these solutions and their final equations from practical engineering applications. Most of the mistakes found in the literature must be linked to authors’ lack of understanding and consistency in an uniform application of a certain sign convention for strains and stresses in the soil matrix at both stages of mathematical formulation of the governing problem and correct interpretation of equations of the final analytical solution. The present paper, based mostly on a thorough literature review, ought to draw attention and arouse interest among coastal scientists and engineers in proper identification and use of the existing analytical solutions to the wave-induced cyclic seabed response – solutions which differ very often in the applied sign convention for stresses in the soil matrix.
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Authors and Affiliations

Waldemar Magda
1
ORCID: ORCID

  1. Gdansk University of Technology, Faculty of Civil and Environmental Engineering, Department of Geotechnical and Hydraulic Engineering, 11/12 Gabriela Narutowicza Street, 80-233 Gdansk, Poland
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Abstract

Basing on isolated vertebrae, fossil fishes of the order Gadiformes have been first discovered in sediments of the La Meseta Formation (upper Eocene — ?lower Oligocene) on Seymour (Marambio) Island, West Antarctica. This is one of the oldest and the only locality with the Gadiformes skeletal remains in the Southern Hemisphere. Other poorly preserved centra have been determined as Teleostei (order incertae sedis).

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Authors and Affiliations

Anna Jerzmańska
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Abstract

The article directly and indirectly refers to anthropological and philosophical texts which strive to discover and present the gender factor as important in the light of the humanities. The author refers to “Literackie nie-nazywanie. Onomastykon polskiej prozy współczesnej” (Literary Not-naming. Onomasticon of the modern Polish prose) by Magdalena Graf and indicates the femininity factor as a relevant one also in onomastics.

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Authors and Affiliations

Katarzyna Skowronek
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Abstract

A simple analytical method is developed to estimate frequencies of longitudinal modes in closed hard-walled ducts with discontinuities in a cross-sectional area. The approach adopted is based on a general expression for the acoustic impedance for a plane wave motion in a duct and conditions of impedance continuity at duct discontinuities. Formulae for mode frequencies in a form of transcendental equations were found for one, two and three discontinuities in a duct cross-section. An accuracy of the method was checked by a comparison of analytic predictions with calculation data obtained by use of numerical implementation based on the forced oscillator method with a finite difference algorithm.

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Authors and Affiliations

Mirosław Meissner
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Abstract

The reviewed book is a new, expanded and modernized edition of the classical position of the book “Acoustics” published in 1954 and reprinted in 1986. The subtitle: “Sound Fields and Transducers” reflects well the nature of the changes in relation to the original. The chapters concerning sound fields and transducers have been added or significantly expanded and chapters on other subjects, such as noise control, hearing, and speech, have been removed. The chapter about acoustic measurements has been also removed, although some parts of it concerning reciprocity calibration of transducers would be compatible with the concept of the present version of the book. The book consists of 14 chapters. The chapters are divided into parts which are numbered consecutively, independently on numeration of chapters, and sections numbered within chapters. The book contains also three appendices. The scientific level of the book is high and it is designed for advanced readers, e.g., graduate students, and professionals who want to expand their knowledge.
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Authors and Affiliations

Andrzej Dobrucki
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Abstract

The paper presents the mathematical models of dual stator squirrel-cage induction motor, formulated in phase coordinate system and in general transformed space vector form. The two types of models of dual stator induction motor are considered. The control systems of field-oriented control (IFOC and DFOC) and direct torque control (DTC) of the dual stator induction motor have been described and discussed.

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Authors and Affiliations

Krzysztof Pieńkowski
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Abstract

The motivation of this work was to define the reburning potential of sewage sludge gasification gas (syngas). Numerical simulation of co-combustion process of syngas in hard coal-fired boiler has been done. All the calculations were performed using the Chemkin program. Plug-Flow Reactor model was used. The calculations were modelled using GRI-Mech 2.11 mechanism. The highest NO conversions are obtained at the temperature of about 1000-1200 K. The highest reduction efficiency was achieved for the molar flow ratio of syngas equal to 15%. The combustion of hard coal with sewage sludge - derived syngas reduces NO emissions and the amount of coal needed to produce electricity and heat. Advanced reburning, which is a more complicated process gives efficiency of up to 80%. The calculations show that the analyzed syngas can yield better results.

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Authors and Affiliations

Sebastian Werle
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Abstract

The study analyses application possibilities of filtration and thickening models in evaluation of papermaking suspension drainage rate. The authors proposed their own method to estimate the drainage rate on the basis of an existing Ergun capillary model of liquid flow through a granular material. The proposed model was less sensitive to porosity changes than the Ergun model. An empirical verification proved robustness of the proposed approach. Taking into account discrepancies in the published data concerning how the drainage velocity of papermaking suspension is defined, this study examines which of the commonly applied models matches experimental results the best.

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Authors and Affiliations

Piotr Przybysz
Czesław Kuncewicz
František Rieger
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Abstract

Samples of active coke, fresh and spent after cleaning flue gases from communal waste incinerators, were studied. The outer layers of both coke particles were separately removed by comminution mechanism in a spouted bed. Analyses included density, mercury porosimetry and adsorption. The remaining cores were examined to determine the degree of consumption of coke by adsorption of hazardous emissions (SO2, HCl, heavy metals) through its bed. The differences in contamination levels within the porous structure of the particles were estimated. The study demonstrated the effectiveness of active coke in the cleaning of flue gases.

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Authors and Affiliations

Bronisław Buczek
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Abstract

Cross layer cooperative protocol which exploits the benefits of physical layer cooperative communication, is one of the widely recognized MAC layer protocol design strategies for future wireless networks. This paper presents performance analysis of a cooperative mac and these performance parameters are compared those of the legacy IEEE 802.11 DCF MAC. Appropriate relay station selection is the main hurdle in designing efficient cooperative MAC protocol for wireless networks. This cooperative mac demonstrated that intermediate relay nodes themselves can initiate cooperation for relaying data frame to the receiver on behalf of the sender. This procedure makes the selection process of a “helper node” more distributed in nature as well as it contributes to increase throughput of a wireless network by reducing the overheads that are usually incurred in the helper selection process. It has been shown by thorough analytical analysis that the proposed cooperative MAC protocol offers higher throughput and lower frame transmission delay in both ideal and error prone wireless environment. These performance metrics are also evaluated while the wireless nodes are mobile as well.

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Authors and Affiliations

Md. Ruhul Amin
Md. Shohrab Hossain
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Abstract

The celebrated Polish avant‑garde artist Stanisław Ignacy Witkiewicz turned form arts to philosophy in the later years of his life. He was in contact with prominent Polish professional philosophers, e.g., T. Kotarbiński and R. Ingarden. He wrote a philosophi-cal treatise of his own and published several essays explaining his views, defending them in fiery polemical tracts. Although an autodidact himself, his erudition on recent philosophical topics, scientific trends and achievements was impressive. To his favorite philosophical ‘enemies’, as he was fond to say, belonged Bertrand Russell, along with other famous thinkers of that time, e.g., A. Whitehead, R. Carnap or L. Wittgenstein.
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Authors and Affiliations

Łukasz Kowalik
1
ORCID: ORCID

  1. Uniwersytet Warszawski, Wydział Filozofii, Redakcja „Przeglądu Filozoficz-nego”, ul. Krakowskie Przedmieście 3, 00-927 Warszawa
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Abstract

The main task for imagination in Roman Ingarden’s theory of literary work is to reconstruct fictional objects and their appearances, as well as to furnish details even not mentioned in the work but compatible with the schematic description contained in the work. Imagination, therefore, plays an essential role in the act of Ingardenian ‘concretization’, that is in an inner presentation of the written work by the mind of the reader. According to the program of anti‑psychologism, the imaginative activities do not belong to the literary work. In particular, the creative imagination of the author and the free inspirations experienced by a reader must not be regarded as part of the work. Ingarden understands imagination traditionally, as the ability of visualizing mental images. It is possible, however, to understand imagination in a different way, that may be called semiotic, when it becomes an art of giving meaning to fictitious, fantastical, metaphorical and symbolical sentences. Adopting such a conception of imagination reveals imaginative features in all the four levels of literary work indicated by Ingarden. In particular, the notorious Ingardenian ‘quasi‑judgment’ could be defined as the imaginative sentence.
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Authors and Affiliations

Łukasz Kowalik
1
ORCID: ORCID

  1. Uniwersytet Warszawski, Wydział Filozofii, ul. Krakowskie Przedmieście 3, 00-927 Warszawa
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Abstract

LABLITA-Suite. Resources for the acquisition of Italian as a second language – LABLITA-suite provides technology-enhanced learning resources for the acquisition of Italian L2. IMAGACT allows for mastering the semantic properties of action verbs in the early phases of language acquisition. The LABLITA corpus of Spoken Italian can be used for training learners for face to face conversations. RIDIRE and CORDIC provide corpus linguistic tools for accessing Italian phraseology, which is useful for enhancing writing capabilities in the various domains of language usage.

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Authors and Affiliations

Massimo Moneglia

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