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Number of results: 60
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Abstract

The caving effect of the top coal caving is crucial for efficient mining. Using the Yushuling coal mine, Xinjiang province, China, as a case study, the coal and rock physical and mechanical parameters, such as the compressive, tensile, and shear strength values and hardness of the top coal and roof rock, were determined. The analysis of the effect of different factors on the blasting presplitting process was numerically simulated, and the optimal parameters of blast drilling were identified. Three presplit boreholes were implemented: in the workface, the workface’s advance area, and the two roadway roofs in the workface’s advance area. The optimal blasting drilling parameters and charge structure were designed. The field test results in the mine under study indicated that the top coal recovery rate of the 110501 fully mechanised top coal caving face was improved twice (from 40 to more than 80%), and an effective blasting presplitting was achieved. The proposed blasting presplitting method has an important guiding significance for fully mechanised top coal caving mining in Xinjiang and similar mining areas.
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Authors and Affiliations

Qiang Sun
1
ORCID: ORCID
Chengfang Shan
2
ORCID: ORCID
Zhongya Wu
1
ORCID: ORCID
Yunbo Wang
1
ORCID: ORCID

  1. China University of Mining and Technology, China
  2. Kuqa Yushuling Coal Mine Co., Ltd, Kuqa, Aksu, China
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Abstract

It has been acknowledged that two important rock aggregate properties are the Los Angeles abrasion value (LAAV) and magnesium sulphate soundness (M wl). However, the determination of these properties is relatively challenging due to special sampling requirements and tedious testing procedures. In this study, detailed laboratory studies were carried out to predict the LAAV and M wl for 25 different rock types located in NW Turkey. For this purpose, mineralogical, physical, mechanical, and aggregate properties were determined for each rock type. Strong predictive models were established based on gene expression programming (GEP) and artificial neural network (ANN) methodologies. The performance of the proposed models was evaluated using several statistical indicators, and the statistical analysis results demonstrated that the ANN-based proposed models with the correlation of determination (R2) value greater than 0.98 outperformed the other predictive models established in this study. Hence, the ANN-based predictive models can reliably be used to predict the LAAV and M wl for the investigated rock types. In addition, the suitability of the investigated rock types for use in bituminous paving mixtures was also evaluated based on the ASTM D692/D692M standard. Accordingly, most of the investigated rock types can be used in bituminous paving mixtures. In conclusion, it can be claimed that the proposed predictive models with their explicit mathematical formulations are believed to save time and provide practical knowledge for evaluating the suitability of the rock aggregates in pavement engineering design studies in NW Turkey.
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Authors and Affiliations

Ekin Köken
1
ORCID: ORCID

  1. Abdullah Gul University, Nanotechnology Engineering Department, 38100, Kayseri – Turkey
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Abstract

The article presents the results of research on the formation of the WF coefficient in coal excavations. The WF coefficient determines the share of the wet surface of the excavation sidewall. The wet part of the excavation sidewall is covered partly by the water film, which evaporates, lowering the temperature of this surface. This coefficient is one of the principal parameters used in forecasting the changes in temperature and humidity of the mine air occurring on the way of contact between the excavation sidewall and the flowing air. During the determination of the coefficient value, the criterion of equality of the actual and forecasted ratios of sensible heat to total heat was assumed in the research methodology. Values of the WF coefficient in the examined excavations generally vary within the range of 0,1-0,6, and they are mostly dependent on the parameters related to the period of ventilation.
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Authors and Affiliations

Marcin Smołka
1
ORCID: ORCID

  1. Central Mining Institute, Plac Gwarków 1, 40-166 Katowice, Poland
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Abstract

Slope Stability Analysis is one of the main aspects of Open-pit mine planning because the calculations regarding the stability of slopes are necessary to assess the stability of the open pit slopes together with the financial feasibility of the mining operations. This study was conducted to analyse the effect of groundwater on the shear strength properties of soft rock formations and determine the optimum overall slope angle for an open pit coal mine at Thar Coalfield, Pakistan. Computer modelling and analysis of the slope models were performed using Slide (v. 5.0) and Phase2 (v. 6.0) software. Integrated use of Limit Equilibrium based Probabilistic (LE-P) analysis and Finite Element Method (FEM) based shear strength reduction analysis was performed to determine the safe overall slope angle against circular failure. Several pit slope models were developed at different overall slope angles and pore-water pressure ratio (Ru) coefficients. Each model was initially analysed under dry conditions and then by incorporating the effect of pore-water pressure coefficients of Ru = 0.1, 0.2, and 0.3 (partially saturated); finally, the strata were considered to be fully saturated. It was concluded that at an overall slope angle of 29 degrees, the overall slope will remain stable under dry and saturated conditions for a critical safety factor of 1.3.
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Authors and Affiliations

Shafi Muhammad Pathan
1
ORCID: ORCID
Abdul Ghani Pathan
1
ORCID: ORCID
Fahad Irfan Siddiqui
1
ORCID: ORCID
Muhammad Burhan Memon
1
ORCID: ORCID
Mairaj Hyder Alias Aamir Soomro
1
ORCID: ORCID

  1. Mehran University of Engineering and Technology, Department of Mining Engineering, Jamshoro, Pakistan
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Abstract

In this study, the noise sources to which a coal miner, who works at the Kurul panel of Kilimli Colliery, Zonguldak, was exposed were investigated. These sources were positioned at different points from the surface to the workface. Noise levels were measured according to the working periods of the coal miners around the machines. The results were evaluated under the Turkish Noise Regulation. The critical exposure times in which the coal miners could work without the use of personal protective equipment were examined according to the noise values to which they were exposed. In addition, the personal noise exposure values of the machine operators (boring machine, electro-hydraulic drill, and pick hammer) were determined during the development works. Two different types of noise measurements, with a microphone at the ear level and inside the ear protector, were conducted. The results obtained when the microphone of the personal dosimeter was at ear level, were found to be 15 dBA higher than those when the microphone was inside the ear protector. As a result, the selection methods of ear protectors were analyzed. Recommendations were given for those working on the risky tasks at the panel.
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Authors and Affiliations

Ilknur Erol
1
ORCID: ORCID
Okan Su
2
ORCID: ORCID

  1. Çukurova University, Dept. of Mining Engineering, Adana, Türkiye
  2. Zonguldak Bülent Ecevit University, Dept. of Mining and Mineral Extraction, Zonguldak, Türkiye
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Abstract

The analysis of natural hazards, including gas-geodynamic phenomena, requires study of the basic physical processes that take place at each stage of an event. This paper focuses on analysing the transport of fragmented rock material during rock and gas outbursts. Our theoretical considerations and experiments have allowed us to specify and verify the significant forces acting on fragmented rock during its transport, thus determining the speed of grains of each grain class in the stream of expanding gas. The above study may serve as a preface to a wide-ranging quantitative and qualitative energy analysis of the movement of material ejected during Gas-geodynamic phenomena.
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Authors and Affiliations

Katarzyna Kozieł
1
ORCID: ORCID
Jakub Janus
1
ORCID: ORCID

  1. Strata Mechanics Research Institute of the Polish Academy of Science, 27 Reymonta Str., 30-059 Kraków, Poland
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Abstract

In longwall coal exploitation, problems with the proper functioning of the powered shield support often occur. In many cases, it results from the insufficient load-bearing capacity of the ground (floor) and the inability to achieve the set or yield pressure of the shield support. The improper functioning of the shield support may also result from its construction and the lack of optimisation to work effectively on a weak mine floor. This paper presents an attempt to optimise the operating conditions of the base of two-legged shield support based on the field observations and results of the PFC3D numerical calculation. In the framework of the numerical calculations, the impact of the width of the base and the location of the hydraulic legs on the working conditions of shield support on a weak floor were analysed.
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Authors and Affiliations

Sylwester Rajwa
1
ORCID: ORCID
Sven Bock
2
ORCID: ORCID

  1. Central Mining Institute (GIG), 1 Gwarków Sq., 40-166 Katowice, Poland
  2. DMT GmbH, Germany
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Abstract

In the Upper Silesian Coal Basin (Poland), numerous former workings have been left unprotected after the liquidation of mines in the 19th and the beginning of the 20th century. The workings have been located at low depths. The paper presents the results of strength tests of wood samples acquired from linings in former workings, and the obtained results have been compared to the results achieved in tests of samples of wood intended to be used in a reconstruction of a historic gallery. The tests consisted in determining the bending strength of wood in compliance with the applicable Polish standard. The results showed that the wood from historic mines was characterised by high variability of bending strength – usually much lower than that of the wood intended for construction. Too low bending strength of timber may result in caving in shallow excavation and lead to sinkhole creation on the surface.
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Authors and Affiliations

Piotr Strzałkowski
1
ORCID: ORCID
Grzegorz Dyduch
1
ORCID: ORCID

  1. Silesian University, Faculty of Mining, Safety Engineering and Industrial Automation, 2 Akademicka Str., 44-100 Gliwice, Poland
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Abstract

The article assesses the production capacity of the Polish Power System, taking into account the military operations in Ukraine and the related resource crisis. An analysis was made of how the war in Ukraine will affect the validity of Poland’s energy policy adopted a year ago. The sensitivity of the Polish Energy System to the import of energy resources from Russia was assessed as well as the possibilities of filling the gap caused by the lack of these raw materials were described and measures were proposed. It shows how electricity prices in the EU countries developed in the last year and what the energy mix of these countries looked like. Alternative scenarios for the transformation of the domestic system were discussed, including the coal – renewable energy – nuclear energy scenario, with the minimization of gas as a fuel of the transition period.
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Authors and Affiliations

Antoni Tajduś
1
ORCID: ORCID
Stanisław Tokarski
2
ORCID: ORCID

  1. University of Science and Technology (AGH), Al. Mickiewicza 30, 30-059 Krakow, Poland
  2. Central Mining Institute, 1 Gwarków Sq., 40-166 Katowice, Poland
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Abstract

The article presents the problem of selecting the correct type of limestone for producing paving stones used to renovate the surface of Mariacki Square in Krakow. Due to using up local limestone deposits, imported limestones began to be used. The first one was a Turkish limestone with the trade name Lotus Beige. Despite substantial physical and mechanical parameters (compressive strength 134 MPa, water absorption 0.26%), after several years of use, the paving stone cracked and, as a result, fell apart into smaller fragments. Hauteville limestone from France has been selected for the following reconstruction of the surface. This limestone in the air-dry state was characterised by even higher parameters, i.e. compressive strength of 157 MPa, flexural strength at 16.9 MPa, Bohme Abrasion test at 15275 mm3, and water absorption at 0.23%. The tests also showed absolute frost resistance and high resistance to thermal shock. Unfortunately, after several years of using the surface of Mariacki Square, cracks and flaking of the rock material have been observed in terms of some paving stones. These cracks appeared within the so-called stylolite seams, which are a natural feature of limestone. Despite a very strict selection of materials, unfortunately, problems with the surface’s durability could not be avoided.
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Authors and Affiliations

Joanna Hydzik-Wiśniewska
1
ORCID: ORCID
Elżbieta Hycnar
1
ORCID: ORCID

  1. AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow, Poland
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Abstract

The article presents an analysis of the impact of bending optical fibers with tilted Bragg gratings on their spectral parameters. This article proves that it is possible to a choose TFBG cladding mode and the optical spectrum range related to it that allows the best metrological properties to be obtained when measuring bend. The results contained in the paper explain why the minima in the spectral characteristics, corresponding only to some cladding modes, change their shape during TFBG bending, which is important for application of Bragg gratings as bending sensors. It has been presented that in the case of TFBG we are able to aggregate the knowledge obtained during experiment to the form of a physical model of the fiber bending sensor.
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Authors and Affiliations

Piotr Kisała
1

  1. Lublin University of Technology, Nadbystrzycka 38A, 20-618 Lublin, Poland
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Abstract

In order to guarantee the accuracy of turntable angle measurement, a real-time compensation method for turntable positioning precision based on harmonic analysis is proposed in this paper. Firstly, the principle and feasibility of the real-time compensation method are analysed, and a detailed description of harmonic compensation is provided herein. Secondly, we analyse the relationships between the surface number of the polygon with the compensation order of the harmonic function and its corresponding compensation accuracy. The effects of the iterations number and the data width on calculation accuracy in the coordinate rotation digital computer (CORDIC) algorithm are analysed and the quantization models of the approximation error and rounding error of the CORDIC algorithm are established. Then, the calculation of the harmonic error function and real-time compensation processes are implemented on a field programmable gate array (FPGA) chip. The resource occupation and time delay of the phase angle calculation and the harmonic component calculation are discussed separately. Finally, the validity of the harmonic compensation method is proven through comparing the compensation effect with that of linear interpolation and the polynomial compensation method. The influences of the compensation order, the iterations number and the data width on the compensation results are demonstrated by simulation. A test platform with a laboratory-made FPGA circuit is built to evaluate the effect of real-time compensation with the harmonic function and the positioning error compensation can be performed within 760 ns. The results confirmed the effectiveness of the harmonic compensation method, revealing an improvement of the positioning precision from 54.21″ to 1.63″, equivalent to 96.99% reduction in positioning error.
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Authors and Affiliations

Yi Zhou
1
Weibin Zhu
1
Yi Shu
1
Yao Huang
2 3
ORCID: ORCID
Wei Zou
3
Zi Xue
3

  1. China Jiliang University, School of Measurement and Testing Engineering, Hangzhou, 310018, China
  2. Zhejiang University, College of Optical Science and Engineering, State Key Laboratory of Modern Optical Instrumentation, Hangzhou 310027, China
  3. National Institute of Metrology, Beijing, 100029, China
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Abstract

In modern clinical practice in various areas of dentistry, there is a need to virtualize and determine the diagnostic parameters of the stomatognathic system (SS). The aim of this article is to provide an evaluation of correct SS structures based on a comparison of mappings in pantomography, lateral cephalometry, and volumetric tomography using bone and tooth anthropometric points. The digital measurements performed determine the applicability of the analyzed imaging techniques for clinical diagnostics by indicating discrepancies and errors in the evaluation of geometric parameters. They should verify the location of characteristic points, lines, angles, and planes in relation to spatial objects mapped on the 1:1 scale. The analyses performed confirm the appearance of bone and dental structure asymmetry in healthy patients.
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Authors and Affiliations

Wojciech Ryniewicz
1
Łukasz Bojko
2
Anna M. Ryniewicz
2

  1. Jagiellonian University Medical College, Faculty of Medicine, Dental Institute, Department of Dental Prosthodontics and Orthodontics, 4 Montelupich Street, 31-155 Krakow, Poland
  2. AGH University of Science and Technology, Faculty of Mechanical Engineering and Robotics, 30 Mickiewicza Ave., 30-059 Krakow
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Abstract

This paper proposes data-based fault detection methods for an electromechanical actuator (EMA) with a brushed DC motor. The jam and winding short faults are considered in the study as the most prominent EMA faults. The fault detection is based on evaluating the properties of the motor current, considering the basic electromechanical parameters of EMAs. The main advantages are a non-intrusive approach utilising a commonly accessible motor current measurement, simple configurability, and the ability to detect faults under varying operation modes of EMA, including changes of speed, load, or movement profiles. The proposed methods have been evaluated with a custom testing system, and the results have proven the performance of the proposed approach to detect faults under varying operating conditions in industrial applications.
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Authors and Affiliations

Ondřej Hanuš
1
Radislav Smid
1

  1. Czech Technical University in Prague, Faculty of Electrical Engineering, Department of Measurement, Technicka 2,166 27 Prague, Czech Republic
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Abstract

Current vision-based roughness measurement methods are classified into two main types: index design and deep learning. Among them, the computation procedure for constructing a roughness correlation index based on image data is relatively difficult, and the imaging environment criteria are stringent and not universally applicable. The roughness measurement method based on deep learning takes a long time to train the model, which is not conducive to achieving rapid online roughness measurement. To tackle with the problems mentioned above, a visual measurement method for surface roughness of milling workpieces based on broad learning system was proposed in this paper. The process began by capturing photos of the milling workpiece using a CCD camera in a normal lighting setting. Then, the train set was augmented with additional data to lower the quantity of data required by the model. Finally, the broad learning system was utilized to achieve the classification prediction of roughness. The experimental results showed that the roughness measurement method in this paper not only had a training speed incomparable to deep learning models, but also could automatically extract features and exhibited high recognition accuracy.
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Authors and Affiliations

Runji Fang
1
Huaian Yi
1
Shuai Wang
1
Yilun Niu
1

  1. School of Mechanical and Control Engineering, Guilin University of Technology, Guilin, 541006, People’s Republic of China
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Abstract

The current research work presents an investigation into use of the fitting coefficients resulting from the cubic curve fitting of the torque transducer calibration results in one direction to calculate the actual torque in the other torque direction with two methods: one is direct substitution with the nominal torque which gives a propagated linear relative interpolation error and the other is changing the sign of the second coefficient in the cubic function when using in the other torque direction. This proposed modification improves the absolute relative interpolation error by 5 to 16 times in the clockwise and counterclockwise directions based on the torque transducer’s classification.
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Authors and Affiliations

K.M. Khaled
1
Seif M. Osman
1

  1. National Institute of Standards (NIS), Force and Material Metrology Department, Tersa st., 11221 Giza, Egypt
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Abstract

Ultrasonic Non-Destructive Testing (NDT) is a powerful tool used for testing, verification, and inspection of material, especially for quality control and assurance. The key applications are the identification of flaws, cracks, irregularities, defects, and estimation of material thickness. The standard documents available for ultrasonic NDT are used as a guideline for the specifications and certification of the calibration reference standard block (RSB). The method for metrological characterization of the testing blocks is not specifically addressed in standard documents and is left to the wisdom of metrologists working in the ultrasonic calibration laboratories to adopt the suitable one. The ultrasonic flaw detector (UFD) is used most widely in ultrasonic NDT. The International Institute of Welding (IIW) V1 RSB standard is used as a reference to ascertain the functionalities of UFDs. In this article, we have proposed a new methodology for calibration of RSB and evaluation of associated measurement uncertainty along with influencing parameters. The proposed method conforms to the international standard ISO 2400:2012 and Indian standard IS 4904:2006 for validation purposes. According to these standards, the clauses for RSB e.g., dimension and quality of material have been examined. The expanded measurement uncertainty in thickness, ultrasonic longitudinal velocity, ultrasonic attenuation, parallelism and perpendicularity is ±0.068 mm, ±6.70 m/s, ±0.22 dB, and ±0.066 mm, respectively. The measurement uncertainty of these parameters is well within as per clauses stipulated in the standard documents except the ultrasonic longitudinal velocity for the IS standards.
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Authors and Affiliations

Kalpana Yadav
1 2
Sanjay Yadav
1 2
P.K. Dubey
1 2

  1. Pressure, Vacuum and Ultrasonic Metrology, Division of Physico-Mechanical Metrology, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012, India
  2. Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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Abstract

This article presents selected physical diagnostic methods used in otorhinolaryngology and results of their application. In addition to the applications of methods using the capabilities of selective sensors, selected methods of hybrid diagnostics were also presented – for assessment of parameters of respiratory processes, with polysomnography as an example of using both typical diagnostic methods dedicated to otolaryngology, as well as standard EEG and ECG methods. It has been shown that in some special cases of respiratory disorders, measurements of the air flow in the respiratory tract can be supplemented with pressure measurements in selected positions within the airways. The presented optical methods and diagnostic systems are very often used in the diagnosis of diseases not specific for otolaryngology occurring in the area of the head and neck. The presented material is the second part of the study discussing both standard and widely used diagnostic methods. All presented methods are dedicated to otolaryngology. This text is a continuation of the material published in No 4 of 2021 [1].
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Authors and Affiliations

Andrzej Zając
1
Andrzej Kukwa
2
Robert Barańska
3
Szymon Nitkiewicz
4 5
Edyta Zomkowska
6 7
Adam Rybak
8

  1. Military University of Technology, Warsaw, Institute of Optoelectronics, Kaliskiego St., 2, 00-908, Warsaw, Poland
  2. University of Warmia and Mazury, Olsztyn, Department and Clinic of Otorhinolaryngology, Head and Neck Diseases, Collegium Medicum, Warszawska St. 30, 10-082 Olsztyn, Poland
  3. AGH University of Science and Technology in Kraków, Department of Mechanics and Vibroacoustics, Mickiewicza St. 30, 30-059 Kraków, Poland
  4. University of Warmia and Mazury in Olsztyn, Department of Mechatronics, Faculty of Technical Science, Oczapowskiego St. 2, Olsztyn, Poland
  5. University of Warmia and Mazury in Olsztyn, Department of Neurosurgery, School of Medicine, Oczapowskiego St. 2, Olsztyn, Poland
  6. Clinic of Otorhinolaryngology, Head and Neck Surgery, University Hospital in Olsztyn, Warszawska St. 30, 10-082 Olsztyn, Poland
  7. University of Warmia and Mazury in Olsztyn, Department and Clinic of Otorhinolaryngology, Head and Neck Diseases, Collegium Medicum, Warszawska St. 30, 10-082 Olsztyn, Poland
  8. LABSOFT Sp. z o.o., Puławska St. 469, 02-844 Warsaw, Poland
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Abstract

The manufacturing and characterization of polymer nanocomposites is an active research trend nowadays. Nonetheless, statistical studies of polymer nanocomposites are not an easy task since they require several factors to consider, such as: large amount of samples manufactured from a standardized procedure and specialized equipment to address characterization tests in a repeatable fashion. In this manuscript, the experimental characterization of sensitivity, hysteresis error and drift error was carried out at multiple input voltages (����) for the following commercial brands of FSRs ( force sensing resistors): Interlink FSR402 and Peratech SP200-10 sensors. The quotient between the mean and the standard deviation was used to determine dispersion in the aforementioned metrics. It was found that a low mean value in an error metric is typically accompanied by a comparatively larger dispersion, and similarly, a large mean value for a given metric resulted in lower dispersion; this observation was held for both sensor brands under the entire range of input voltages. In regard to sensitivity, both sensors showed similar dispersion in sensitivity for the whole range of input voltages. Sensors’ characterization was carried out in a tailored test bench capable of handling up to 16 sensors simultaneously; this let us speed up the characterization process.
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Authors and Affiliations

Carlos Andrés Palacio Gómez
1
Leonel Paredes-Madrid
2
Andrés Orlando Garzon
2

  1. GIFAM Group, Universidad Antonio Nariño, Cra 7 No. 21-84, 150001 Tunja, Boyacá, Colombia
  2. Universidad Católica de Colombia, Faculty of Engineering, Carrera 13 # 47-30, Bogota, Colombia
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Abstract

International standards from IEC and IEEE regulate power grid parameters such as theRMSvalue, frequency, harmonic and interharmonic distortion, unbalance or the presence of transients, that are important to assure the quality of distributed power. Standard IEC 61000-4-30 suggests the zero crossing algorithm for the measurement of the power grid frequency, but also states that different algorithms can be used. This paper proposes a new algorithm, the Fractional Interpolated Discrete Fourier Transform, FracIpDFT, to estimate the power grid frequency, suitable for implementation in resource limited embedded measurement systems. It is based on the non-integer Goertzel algorithm followed by interpolation at non-integer multiples of the DFT frequency resolution. The proposed algorithm is validated and its performance compared with other algorithms through numerical simulations. Implementation details of the FracIpDFT in an ARM Cortex M4 processor are presented along with frequency measurement results performed with the proposed algorithm in the developed system.
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Authors and Affiliations

Nuno M. Rodrigues
1
Fernando M. Janeiro
2
Pedro M. Ramos
1

  1. Instituto de Telecomunicações, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
  2. Instituto de Telecomunicações, Universidade de Évora, 7000-671 Évora, Portugal
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Abstract

As the spherical hinge in the bridge swivel structure bears huge vertical pressure, the material and its structural load-bearing capacity are therefore highly-required. In the latest research, the ultrahigh performance concrete material is applied to the spherical hinge structure and the author of this article has conducted a detailed study on the mechanical properties and failure mechanism of this structure; however, there is still no real bridge application at present. In order to ensure the stability of the structure, based on an actual project, this research proposes a monitoring method for the stability of the UHPC spherical hinge horizontal rotation system, i.e., using theoretical calculations and numerical analysis methods. Besides, the mechanical characteristics of the bridge during the process of rotation are predicted, and the monitoring data of the stress of the UHPC spherical hinge, the bending moment of the pier bottom, as well as the acceleration time history of the cantilever beam end are made a comparison to judge whether the rotating posture of the structure is stable. The results show that UHPC spherical hinge features high strength and will not cause axial damage; also, the horizontal rotation system will not cause the unstability due to wind-induced vibration and structural self-excited vibration. Briefly concluded, the theoretical model is basically consistent with the measured data, i.e., the mechanical properties of the structure can be accurately predicted.
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Authors and Affiliations

Jiawei Wang
1
ORCID: ORCID
Bing Cao
1
ORCID: ORCID
Bo Huang
1
ORCID: ORCID

  1. Anhui Polytechnic University, School of Architecture and Civil Engineering, Wuhu City, Beijing Middle Road, China
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Abstract

The paste content in the self-compacting concrete is about 40% in unit volume. The rheological properties of paste directly determine the properties of self-compacting concrete. In this paper, the effect of silica fume (2, 3, 4, and 5%), limestone powder (5, 10 and 15%), and the viscosity modified admixture (2, 3, 4, 5, 6, and 7%) on the rheological properties were investigated. The effect of admixtures on shear thickening response was discussed based on the modified Bingham model. The results indicate that yield stress and plastic viscosity increased with increased silica fume and viscosity modified admixture replacement. The paste’s yield stress increases and then decreases with limestone powder replacement. The critical shear stress and minimum plastic viscosity are improved by silica fume and viscosity modifying admixture. The critical shear stress first increases and decreases as the limestone powder replacement increases. A reduction in the shear thickening response of paste was observed with silica fume and viscosity modified admixture replacement increase.
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Authors and Affiliations

He Liu
1
ORCID: ORCID
Guangchao Duan
1
ORCID: ORCID
Jingyi Zhang
2
ORCID: ORCID
Yanhai Yang
1
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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Abstract

Diverse strategies for identifying and finding the damages in structures have been continuously engaging to originators within the field. Due to the direct connection between the firmness, characteristic frequency, and mode shapes within the structure, the modular parameters may well be utilized for recognizing and finding the damages in structures. In current consider, a modern damage marker named Damage Localization Index (DLI) is applied, utilizing the mode shapes and their derivative. A finite element model of a frame with twenty and thirty components has been utilized, separately. The numerical model is confirmed based on experimental information. The indicator has been explored for the damaged components of a frame with one bay. The results have been compared with those of the well-known index CDF. To demonstrate the capability and exactness of the proposed method, the damages with low seriousness at different areas of the structures are explored. The results are investigated in noisy condition, considering 3% and 5% noise on modal data. The outcomes show the high level of accuracy of the proposed method for identifying the location of the damaged elements in frames.
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Authors and Affiliations

Mina Roodgar Nashta
1
ORCID: ORCID
Reza Taghipour
1
ORCID: ORCID
Mohsen Bozorgnasab
1
ORCID: ORCID
Hessam Mirgolbabaei
2
ORCID: ORCID

  1. Department of Civil Engineering, University of Mazandaran, Babolsar, Mazandaran, Iran
  2. Department of Mechanical and Industrial Engineering, University of Minnesota, Duluth, Minnesota, United States of America
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Abstract

It is often spoken and written about the use and benefits of BIM in the design, build, and exploitation phases. Based on an extensive analysis of scientific articles and practice, it has been noticed that, however, there is no comprehensive solution for the use of BIM at the stage of preparation for construction. And there is no relevant approach to the organization of construction though various software offers availability to calculate separate processes that are important for the organization of it. For example, based on the BIM model, determine the optimal place for the tower crane. But the problem is that such a local solution does not represent a comprehensive approach and does not represent apprehensive construction planning. It means, currently there is no method of planning, which will answer the questions: whether to choose a tower crane or a truck crane, where is the optimal place for unloading construction materials, considering the location of the crane, etc. Therefore, this article presents the vision and strategy of BIM development at the construction stage. The problem that should be solved now is the creation the strategy that will allow to improve the efficiency of construction works, adjusting them to the current situation in an optimal way. Therefore, the aim of the article is to combine separate ideas of BIM using in construction management as a whole and call scientists to discuss and supplement the topics of using BIM in construction management.
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Authors and Affiliations

Robertas Kontrimovic̆ius
1
ORCID: ORCID
Leonas Ustinovic̆ius
1
ORCID: ORCID
Czesław Miedziałowski
2
ORCID: ORCID
Mantas Vaišnoras
1
ORCID: ORCID

  1. Vilnius Gediminas Technical University, Faculty of Civil Engineering, Vilnius, Lithuania
  2. Bialystok University of Technology, Faculty of Civil Engineering and Environmental Sciences, Bialystok, Poland

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