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Abstract

The attractiveness of uncultivated (weedy) and cultivated strips (planted with a mixture of flowering plants) and the adjacent sugar beet crop to Carabidae was studied in 1999–2000 at the Experimental Research Station near Wrocław, Poland. Obtained results showed that greater plant abundance and their diversity on weedy strips had a positive effect on the number of carabid beetles. Also more carabid species were identified in uncultivated strips than in strips of mixture of Phacelia tanacetifolia, Coriandrum sativum and Sinapis alba. The lowest number of species was trapped in sugarbeet crop and bare soil. The most numerous species in all treatments were Pseudoophonus rufipes, Anchomenus dorsalis (Pont.), Poecilus cupres and the species of the Bembidion genera.

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Authors and Affiliations

Jacek P. Twardowski
Michał Hurej
Teresa Jaworska
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Abstract

It is well known that if plastic wastes are not well managed, it has a negative impact on the environment as well as on human health. In this study, recycling plastic waste in form of strips for stabilizing weak subgrade soil is proposed. For this purpose, a weak clay soil sample was mixed with 0.2%, 0.3%, and 0.4% of plastic strips by weight of soil, and the experimental results were compared to the control soil sample with 0% plastic. Laboratory tests on the Standard compaction test, Unconfined compression test (UCS), and California bearing ratio (CBR) were conducted according to the American Society for Testing and Materials (ASTM). The results of the study reveal that there are significant improvements in the strength of weak soil stabilized with plastic waste strips. Accordingly, the Standard Proctor test shows that there is a small increment in the maximum dry density of the soil when it is mixed with plastic strips. The result from the CBR test shows that there is a significant increment of CBR value with the plastic strip content. The unconfined compressive strength test also shows that increasing the percentage of plastic strips from 0 to 0.4% resulted in increased strength of soil by 138% with 2 cm length plastic strips. Therefore, this study recommends the application of plastic strips for improvement of the strength of soft clay for subgrade construction in civil engineering practice as an alternative weak soil stabilization method.
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Authors and Affiliations

Worku Firomsa Kabeta
1
ORCID: ORCID

  1. Gdansk University of Technology, Faculty of Civil and Environmental Engineering, Narutowicza11/12, 80-233 Gdansk, Poland
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Abstract

A wideband antenna with dual band characteristic at 5.33/14.3GHz with resonating frequencies for wireless applications is presented. The strategy of the design is to introduce multiband in antenna band. Bandwidth of the antenna increases by embedding annular ring on the radiating patch and four bands are achieved by introducing coupling gap between the patches. Surface current distribution is analyzed at different resonating frequencies for understanding the radiation mechanism and effect of annular ring. The antenna parameters such as return loss, radiation pattern, gain, VSWR and group delay are discussed. The impedance bandwidth of the proposed dual band antenna at lower resonant frequency is 12.7% (simulated) and 9.8 % (measured) whereas at upper resonant frequency is 15.3 % (simulated) and 13.97 % (measured).

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Authors and Affiliations

Karunesh Srivastava
Sweta Singh
Aditya Kumar Singh
Rajeev Singh
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Abstract

The structural system of a multiple strip-shaped pillar-roof is common in underground mine exploitation, and research on its mechanics and micro/macroeconomics is meaningful for utilizing strip-shaped pillar resources. A general model of the structural system of a multiple strip-shaped pillar-roof was established, the deformation mechanism of the model was analysed by material mechanics, and the deflection curve equations of the model were obtained. Based on the stress strain constitutive relation of the strip pillar and cusp catastrophe theory, the nonlinear dynamic instability mechanism of the structural system of a multiple strip-shaped pillar-roof was analysed, and the expressions of the pillar width for maintaining the stability of different types of structural systems were derived. The benefits of different structural systems were calculated using micro/macroeconomic theory, the type of the structural system was determined, and different recovery schemes were obtained. Theoretical application research was applied to a large manganese mine, and the results demonstrate that no pillar recovery was needed in 2016, a 9-m wide artificial pillar could be built to replace a pillar in 2017, and the construction of 14-m wide artificial pillars can be conducted in 2018.

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Authors and Affiliations

Qingfa Chen
Shiwei Wu
Fuyu Zhao
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Abstract

This article presents the results of an experimental study of cold rolling TRB strips of S235JR steel applying one grooved roll and another plain roll. The purpose of the study was to determine the possibility of rolling TRB strips with the technology studied, depending on the dimensions of the charge and the number of rolling passes. In addition, the possibility of reducing the magnitude of TRB strip curvature due to the introduction of asymmetry into the process was investigated. The effect of the rolling process and shape variation on the material’s hardening was evaluated by measuring hardness. Based on the results, it was determined that the greater the initial thickness of the charge, the higher the shape tolerances can be obtained. In addition, hardness variation was observed on the cross-section of TRB strips, which decreased with increasing values of plastic deformation. It has also been shown that it is possible to reduce the curvature of the TRB strip due to the use of double asymmetry.
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Authors and Affiliations

Bartosz Sułek
1 2
ORCID: ORCID
Janusz Krawczyk
3
ORCID: ORCID

  1. Łukasiewicz Research Network – Poznan Institute of Technology, 6 Ewarysta Estkowskiego Str, 61-755 Poznan, Poland
  2. AGH University of Krakow, Doctoral School, al. A. Mickiewicza 30, 30-059 Krakow, Poland
  3. AGH University of Krakow, Faculty of Metals Engineering and Computer Science, al. A. Mickiewicza 30, 30-059 Krakow, Poland
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Abstract

The column is one of the most significant structural elements, which is designed to support mainly the compressive load. Strengthening of existing reinforced concrete columns is required to enhance ductility and increase load capacity to sustain the overload as sometimes there may be a change in use. Ten rectangular concrete columns were constructed and tested. H/b ratio was kept constant and equals 6 for all columns The aim of this work is to study the behaviour and efficiency of RC columns strengthened with steel jackets subjected to axial load. An experimental study of the behaviour of ten strengthened concrete columns with slenderness ratio (t / b) equals 6 was carried out. Variables such as aspect ratio ( H / b), the volume of steel batten plates, and spacing of steel batten plates at centres ( S) were considered. The results showed that using this method of strengthening is very effective and an increase in the axial load capacity of the strengthened columns is obtained.
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Authors and Affiliations

Abd Rahman Mujahid Ahmed Ghoneim
1
ORCID: ORCID
Mahmoud Ahmed Mohamed Mohamed
1
ORCID: ORCID
Kader Haridy
2
ORCID: ORCID
Hazem Ahmed
2
ORCID: ORCID
Mohmmad Pyram
2
ORCID: ORCID
Abdu Khalf
2
ORCID: ORCID

  1. Assiut University, Faculty of Engineering, Civil Engineering Department, Assiut, P.O. Box 71515, Egypt
  2. Al-Azhar University, Faculty of Engineering-Qena, Civil Engineering Department, 83513, Egypt
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Abstract

The use of FRP materials as external reinforcement of masonry structures has been recognized as an effective and minimally invasive method ofwall strengthening. The available literature and research reports confirmthe positive effect of the strip-like arrangement of composites with a horizontal, diagonal and – as shown in the paper – vertical configuration. The problem here is the proper estimation of the benefits of such FRP reinforcement, namely determining the real increase in shear strength. The paper described selected calculation procedures that can be found in the available literature (proprietary solutions), as well as in the published guidelines for the design of masonry walls strengthening using FRP materials. The results of experimental tests of sheared masonry walls made of AAC blocks and strengthened using vertical strips of carbon and glass fibres are briefly presented. Finally, based on the presented formulae, the values of the theoretical shear force resulted from the FRP contribution were calculated and detailed discussed.
The comparison of the experimental and theoretical shear forces showed that only one of the presented calculation methods gave a high agreement of the results for both carbon and glass sheets. In addition, it was noticed that in two cases the effects of strengthening – depending on the material used – drastically differed, which was not observed in the research.
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Authors and Affiliations

Marta Kałuża
1
ORCID: ORCID

  1. Silesian University of Technology, Faculty of Civil Engineering, Akademicka 5, 44-100 Gliwice, Poland
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Abstract

Simulations are becoming one of the most important techniques supporting production preparation, even in those industrial sectors with atypical technological processes, such as in metallurgy, where there is a multiphase material flow. This is due to the fact that in the conditions of a market economy, enterprises have to solve more and more complex problems in a shorter time. On the basis of the existing production process and the knowledge of the flow characteristics in a given process, a model is built, which, when subjected to simulation tests, provides experimental results in the scope of the defined problem. The use of computer techniques also creates new possibilities for the rational use of the reserves inherent in each technological process. Taking into account the existing demand and the state of modern technology, the computer model can be a source of information for further analysis and decision-making processes supporting company management. At work a model of the logistic system was made on the example of a hot-rolled steel strip mill, on which simulation experiments were carried out to improve the effectiveness and efficiency of the analysis production line. The presented article aims to disseminate the idea of ??Industry 4.0 in Polish companies from the manufacturing industry sector, taking into account simulation techniques.
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Authors and Affiliations

Mariusz Niekurzak
1
Ewa Kubińska-Jabcoń
1

  1. AGH University of Science and Technology, Faculty of Management, Poland
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Abstract

Due to the increasing necessity of building on soils with insufficient bearing capacity, the development of methods for soil improvement is an important geotechnical engineering issue. One of the innovative methods of soil stabilisation is the use of nano-additives. The paper presents the influence of nanosilica on the bearing capacity under the footing under undrained conditions. For this purpose, a simple and quick unconfined compression test was used to evaluate the undrained shear strength of selected silty soil. Tests were conducted for soil without additives and with nanosilica contents of 1, 3 and 5%. All samples were compacted to the maximum dry density in a Proctor apparatus, and strength tests were conducted after 7 days of curing. The results clearly show an increase in undrained shear strength with increasing nanosilica content. Based on these data, a parametric analysis of the bearing capacity under the strip footing was performed for 4 variants of nanosilica content and for 9 loading cases. Thus, the impact of stabilisation in a practical engineering issue was presented. For all load cases the optimal dimensions of the foundation were determined. In addition, for the selected case, calculations were made for a fixed foundation dimension. All computations were performed in accordance with Eurocode 7 with GEO5 software.
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Authors and Affiliations

Matylda Tankiewicz
1
ORCID: ORCID
Jakub Mońka
1
ORCID: ORCID
Zofia Zieba
1
ORCID: ORCID

  1. Wrocław University of Environmental and Life Sciences, Department of Civil Engineering, Norwida 25, 50-375 Wrocław, Poland
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Abstract

The outcrop of the tsunami deposits, about 6 m thick, is located in the archaeological site Tel Askan in the Al Zhraa locality, southwest of the Gaza City. These deposits are unconformably underlain by sand dunes and sharply overlain by a palaeosol. They are pale gray sands mixed with volcanic ash and fine-grained deposits, and are intercalated with peat, few centimetres thick. The sand-sized grains are well rounded and well sorted, and consist mainly of quartz and subordinate of feldspar. Both macro- and microfossils were observed from tsunami deposits. Additionally, rip-up clasts and pottery shards were observed, indicating higher-flow regime. The potteries in tsunami deposits provide evidence for tsunami inundation at distance of about 1 km from the present shoreline.
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Bibliography

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Authors and Affiliations

Khalid Fathi Ubeid
1
ORCID: ORCID

  1. Department of Geology, Faculty of Science, Al Azhar University-Gaza, P.O. Box 1277, Gaza Strip, Palestine
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Abstract

Optical waveguides (WGs) are widely used as interconnects in integrated optical circuits both for telecommunication and sensing applications. There are different kind of optical WG designs that offers different guiding parameters, opening a vast number of possibilities. A silica-titania (SiO2:TiO2) rib WG is discussed and examined by a numerical analysis in this article with a great emphasis on the analysis of bending losses and optimization. A modal analysis for different basic parameters of the WG is presented with a detailed wavelength-based modal analysis. Various potential fabrication methods are discussed, however, a sol-gel method and dip-coating deposition technique are proposed for the low-cost development of such WGs. Moreover, an approach towards minimizing the bending losses by adding an upper cladding layer on the rib WG is presented and described.
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Authors and Affiliations

Muhammad Shahbaz
1
ORCID: ORCID
Łukasz Kozlowski
1
Muhammad A. Butt
1
ORCID: ORCID
Ryszard Piramidowicz
1
ORCID: ORCID

  1. Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warszawa, Poland
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Abstract

A simulation-based optimization approach to design of phase excitation tapers for linear phased antenna arrays is presented. The design optimization process is accelerated by means of Surrogate-Based Optimization (SBO); it uses a coarse-mesh surrogate of the array element for adjusting the array’s active reflection coefficient responses and a fast surrogate of the antenna array radiation pattern. The primary optimization objective is to minimize side-lobes in the principal plane of the radiation pattern while scanning the main beam. The optimization outcome is a set of element phase excitation tapers versus the scan angle. The design objectives are evaluated at the high fidelity level of description using simulations of the discrete electromagnetic model of the entire array so that the effects of element coupling and other possible interaction within the array structure are accounted for. At the same time, the optimization process is fast due to SBO. Performance and numerical cost of the approach are demonstrated by optimizing a 16-element linear array of microstrip antennas. Experimental verification has been carried out for a manufactured prototype of the optimized array. It demonstrates good agreement between the radiation patterns obtained from simulations and from physical measurements (the latter constructed through superposition of the measured element patterns).

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Authors and Affiliations

Sławomir Kozieł
Stanislav Ogurtsov
Adrian Bekasiewicz
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Abstract

The aim of this paper is to compare some geometric parameters and deflections of a sandwich meta-structure with its classic, three-layer counterpart. Both structures are composed of the same materials and have the same external dimensions and mass, but their middle layers (cores) are different. The core of the sandwich meta-structure is a new spatial structure itself, consisting of there-layer bars. The core of the classic sandwich structure is a layer of the continuum. To make the comparison more general and convincing, three geometrical parameters, i.e., ratio of interfacial contact (Ric), interlayer bonding factor (Ibf) and coefficient of impact sensitivity (Cis), were introduced and applied. Deflections of the structures, simply supported at the edges and loaded in the mid-span by a static force, have been measured and are presented in the paper. Potential advantages of the new meta-structure are briefly outlined.

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Authors and Affiliations

Stanisław Karczmarzyk

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Abstract

In order to study the failure mechanism and characteristics for strip coal pillars, a monitoring device for strip coal pillar uniaxial compression testing was developed. Compression tests of simulated strip coal pillars with different roof and floor rock types were conducted. Test results show that, with increasing roof and floor strength, compressive strength and elastic modulus of “roof-strip coal pillar-floor” combined specimens increase gradually. Strip coal pillar sample destruction occurs gradually from edge to the interior. First macroscopic failure occurs at the edge of the middle upper portion of the specimen, and then develops towards the corner. Energy accumulation and release cause discontinuous damage in the heterogeneous coal-mass, and the lateral displacement of strip coal pillar shows step and mutation characters. The brittleness and burst tendency of strip coal pillar under hard surrounding rocks are more obvious, stress growth rate decreases, and the rapid growth acoustic emission (AE) signal period can be regarded as a precursor for instability in the strip coal pillar. The above results have certain theoretical value for understanding the failure law and long-term stability of strip coal pillars.
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Authors and Affiliations

Xiao Qu
1
Shaojie Chen
1
Dawei Yin
Shiqi Liu

  1. Hohai University, China
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Abstract

Strip backfilling mining technology is of great significance for eliminating coal gangue, improving coal recovery rate, harmonizing the development between resources and environment in diggings. This paper firstly analyzed the roof control mechanism, the deformation and failure mechanism and characteristics of the filling body through theoretical analysis. Then, through numerical simulation combined with the geological conditions on site, a gangue strip filling scheme was designed for the 61303 working face of the 13th layer of the rear group coal of the Wennan Coal Mine in Shandong Province, and the filling scheme of filling 50 m and leaving 25 m was determined. Finally, an on-site engineering test was carried out on the 61303 working face. Through the analysis of the measured data of “three quantities” after the filling test, it can be seen that the test has achieved a good engineering application effect and verified the rationality of the filling scheme design. It solves the coal gangue problem, improves the resource recovery rate, and provides a reference for other similar mines.
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Authors and Affiliations

Wenbin Xing
1
ORCID: ORCID
Wanpeng Huang
1
ORCID: ORCID
Fan Feng
1
ORCID: ORCID

  1. Shandong University of Science and Technology, China
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Abstract

The aim of the study was to estimate the content of trace elements: zinc, cadmium, lead, molybdenum and nickel in products and wastes of coal treatment from Upper-Silesian Basin. Two analytical methods were applied: atomic absorption spectrometry (FAAS, ETAAS) and anodic (ASY) and adsorptive stripping voltammetry (AdSY). ASY is used to determine zinc, cadmium and lead; AdSY molybdenum and nickel, and FAAS and ETAAS to determine all elements. In the case of Zn, Ni, Mo, Pb and Cd determined by FAAS (ETAAS) the concentrations were practically the same as those obtained by ASY or AdSY.
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Authors and Affiliations

Krystyna Srogi
Mariusz Minkina
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Abstract

This communication proposes a compact 4-shaped monopole annular ring UWB antenna design. The proposed structure contains multiple radiating strips inside the annular ring, in the form of a 4-shaped and a 50Ω microstrip feed line. A tapered structure with a feed point is chosen to achieve wideband characteristics. The proposed model is printed on a low-priced FR4 substrate with a size of 0.180λ 0 × 0.225λ 0 (20 × 25mm 2). The proposed model achieves a fractional bandwidth of 133.74% in the 2.7 to 13.6 GHz range with S11<-10dB and covers the 3.1-10.6 GHz unlicensed band approved by FCC in 2002 and X-band applications. The antenna exhibits stable and Omni-directional radiation patterns in the operating frequency range. The analysis of the proposed monopole antenna using characteristic modes is performed to obtain a physical understanding of the radiation process occurring on the radiating antenna. The modal significance curves and the modal current distributions are used to analyze the radiating antenna using the first six characteristic modes. The measurement and simulation results show a good agreement.
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Authors and Affiliations

Bhaskara Rao Perli
1
A. Maheswara Rao
2

  1. Research Scholar, ECE Department, JNTUA, Anantapur, India
  2. ECE Department, PBRVITS, Kavali, India
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Abstract

The present paper describes a methodological framework developed to select a multi-label dataset transformation method in the context of supervised machine learning techniques. We explore the rectangular 2D strip-packing problem (2D-SPP), widely applied in industrial processes to cut sheet metals and paper rolls, where high-quality solutions can be found for more than one improvement heuristic, generating instances with multi-label behavior. To obtain single-label datasets, a total of five multi-label transformation methods are explored. 1000 instances were generated to represent different 2D-SPP variations found in real-world applications, labels for each instance represented by improvement heuristics were calculated, along with 19 predictors provided by problem characteristics. Finally, classification models were fitted to verify the accuracy of each multi-label transformation method. For the 2D-SPP, the single-label obtained using the exclusion method fit more accurate classification models compared to the other four multi-label transformation methods adopted.
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Authors and Affiliations

Neuenfeldt Júnior Alvaro
Matheus Francescatto
Gabriel Stieler
David Disconzi
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Abstract

Innovative procedure of microalloying continuous cast aluminum strip, thickness 10 mm, by Be, Zr and Mn using 3C Pechiney technology (no. 39762, P-377/76), and modifying the existing parameters for strip casting and crystallization was implemented under industrial conditions with two randomly selected batches 2×8 tones, without previous selection of standardized quality of aluminum, purity Al 99.5%, obtained by electrolysis. The application of microalloying and overall structural modification of the technology resulted in obtaining nanoscale, ultra-thin, compact oxide high-gloss film with uniform surface of continuous cast strip, instead of the usual thick and porous oxide film. The outcome of microalloying the obtained equiaxed fine-grained nano/micro structure was avoiding anisotropic and dendritic microstructure of the strip, and improving deformation and plastic properties of modified continuous cast strip subjected to the technology of plastic treatment by rolling until the desired foil thickness of 9 μm was obtained. The invention of microalloying and structural modification, including multiplying effect of several components, directly or indirectly, changed numerous structurally-sensitive properties. The obtained nano/micro structure of crystal grains with equiaxed structure resulted in the synergy of undesirable <111> and inevitable <100> and <110> textures. Numerous properties were significantly enhanced: elastic modulus was improved, and intensive presence of cracks in warm forming condition was prevented due to rapid increase of the number of grains to 10000 grains/cm2 in as-cast state.
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Authors and Affiliations

M.M. Purenović
1
J.M. Purenović
2
J.Č. Baralić
2

  1. University of Niš, Faculty of Sciences and Mathematics, Serbian Academy of Inventors and Scientists, Serbia
  2. University of Kragujevac, Faculty of Technical Sciences Cacak, Department of Physics and Materials, Serbia

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