This paper presents an experimental investigation on the behavior of interaction effect between two-bars on the bond between reinforcing bars and fiber reinforced concrete (FRC). This study contains two phases. The first phase included the studied bond behavior for specimens having a spacing between two-bars =25mm while the second phase focused on the study of bond behavior for specimens having a spacing between two-bars =50mm. The parameters considered are the variation in bar diameter and the effect of embedded lengths on bonding between two-steel bars and FRC. From the results of the experimental tests, the increase in the depth of embedded length, the ultimate load and the value of slip increased. The use of biggest bar diameter with the same embedded length increase both bond strength and toughness values. Further, behavior of specimens having a spacing between two-bars =25mm had the same behavior in resisting the influential loads during the test while for specimens having a spacing between two-bars =50mm, one of the bars slipped before the other at the initiating of loading and with the loading rate increased, the other reinforcing slipped.

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The massive accumulation of production and consumption waste at industrial enterprises speaks not only about the imperfection of production technologies and the irrational use of waste as secondary resources, but also about the presence of environmental problems. In this regard, research on the possibility of using waste in various industries is becoming increasingly relevant. The purpose of this work is to study the properties of slags of metallurgical production and to assess the possibility of their use as a filler of protective coatings for cast iron casting. The results of the conducted studies have shown that the main mineral of the KKC-1 and KKC-2 slags is cryptocrystalline granite. The average particle size of the initial slags KKC-1 and KKC-2 is 100.4 and 100.9 microns, respectively. The total slag surface was: for KKC-1 - 1393 cm2/cm3, for KKC-2 - 1452 cm2/cm3.After activation for 20 minutes, the average size of slag particles KKC-1 decreases to 8.1 µm, the total surface increased to 14272 cm2/cm3, slag KKC-2 - to 80.5 µm, the total surface increased to 2210 cm2/cm3. The activation time significantly affects the morphological characteristics of the particles. There were no significant differences between the samples during machining in the interval of 5-20 minutes. However, treatment for 20 minutes leads to a significant reduction in the size of the plate-shaped particles, while the surface of the particles after activation for 20 minutes is characterized by a much more developed surface. SEM studies of the KKC-2 sample before and after activation showed that there were no significant differences in the size and morphological characteristics of the particles after activation of the sample in the interval of 5-10 minutes. Thus, according to the research results, it can be concluded that it is possible to recommend the use of KKC-1 slag for coatings after its activation for 20 minutes in a planar centrifugal mill. KKC-2 slag can be used in formulations only after its activation in another way.

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The application of Box-Behnken Design for investigating the effects of treatment parameters including leak-off coefficient, pump rate, proppant concentration end of the job, and injection time, and parameters of the net pay thickness, and porosity of the reservoir on the production performance were discussed. Through analyzing the sensitivity of the positive factor influence from high to low on production performance, porosity was the highest factor one, then the pump rate (q, bpm), then the net pay thickness, the proppant concentration end of the job, and then the pumping time. In contrast, when the leak-off coefficient of the permeable thickness was increased from 0.003ft/min0.5 to 0.007ft/min0.5, the production performance was decreased because when the leak-off coefficient increases, the proppant distribution in the created fractures of the net pay thickness will be decreased, leading to poor proppant placement in the net pay thickness, causing to low fracture conductivity.

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Polycrystalline ER xY3-xFe5O12 nano-particleshave been prepared by conventional ceramic method. The structural parameters and Phase purity were investigated using X-ray diffractometer (XRD) and Scanning Electron Microscopy (SEM), which indicates the single-phase Er-YIG having well defined intensity peaks. The lattice constant was decreased from 12.290Ato 12.270A, in accordance with Vegard’s law and comparatively less than the reported results by Sol gel method due to increased heat treatment in conventional method. The crystallite size varies from 45.9nm-48.6nm with increase in Er-concentration relates to internal stresses caused by the addition of dopant which creates substitutional defects, that hinders the growth of the crystallite size. SEM micrograph was in support of XRD results with varied average grain size in the range of 4.21µm-3.85µm with increasing ER. The magnetic characteristics investigated by Vibrating Sample Magnetometer (VSM) confirmed the soft magnetic nature of all the samples. Decrease in saturation magnetization and increase in coercivity were observed with increase in ER doping. The Remanent magnetization was about (2 emu/g) for all the reported compositions.

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Marlis a general term that refers to any material, whether soil or rock-like, that contains 35-65 percent calcium carbonate and the rest of clay fraction (Al-Amoudi et al., 2010; Yong & Ouhadi, 2007) this formation is a rock-like when dry, never the less, it is a soft soil-like when moist. In general, high deformation and settlement are the main problems of Marl. In Amman-Jordan, the seasonal variations of water contents is the primary cause of deformability and failure problems of Marls. Mainly because most of the geotechnical studies are performed during the dry seasons, during which Marls show enhanced engineering properties. During the wet seasons, water percolates and all mechanical properties drastically deteriorate. Accordingly, several failures and excessive deformation incidents take place due to these seasonal cycles of wetting and drying. This research work is intended to investigate the mechanical properties of Amman Marls in a manner that enables overcoming the problems originated from the wetting seasonal variations, and the difficulty of obtaining intact samples that may reasonably represents the realistic conditions and properties of this formation Most of the formation in Amman consist of limestone and Marl. Marl a top soil strata in several parts in Amman is exposed to changing weather conditions of wetting and drying in the Greater Amman area. The bearing capacity of Marl is not consistent, and cannot be simply estimated when it is essentially changing in relation to its water content. In this study, deformability and strength characteristics of Marl are investigated by performing a series of field and laboratory tests including drilling and sampling, plate load test (PLT), unconfined compressive strength (UCS) test, seismic refraction and tomography (SRT), and multi-channel analysis of surface waves (MASW).

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This article discusses the signal delay during transmission over a fiber-optic communication line and ways to reduce group delays at high transmission speeds using Bragg gratings. The contradiction between the need to transmit signals over fiber-optic communication lines and the resulting dispersion and group delay gives rise to the problem of developing the necessary calculation of the parameters of Bragg grids. The aim of the study is to reduce the variance by determining the corresponding parameters of Bragg's lattice. There are a number of structures of fiber-optic Bragg gratings, for example, short-period and long-period gratings, slanted gratings, and alternating-period gratings with variable chirps. Variable-period gratings are used in optical networks, mainly to compensate for dispersion. The production of changeable-period (chirp) gratings consists of the narrowing and bending of the optical fiber during the application process and the linear stretching of the phase mask obtained by heating. In the production of the grid, chirp phase masks with a variable period are also used.

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For the design engineer, the material selection stage is crucial by the selected material must fulfill the properties specified in the design and other requirements such as economic, weight, and manufacturing constraints. For this reason, the use of robust materials selection methodologies becomes essential. This article compared 14 materials selection, taking into account seven criteria: the Ashby, characteristic magnitudes, and the database methods obtained the highest score. These three methods were applied to materials selection for a Skateboard table. The design properties Skateboard table were defined based on a bibliographic review. ANSYS Granta selector Software was used to determine some material properties and calculate commercial laminated materials’ properties in cases that do not have references. The Ashby methodology selected Stiffness-limited design at a minimum mass material index. Mass, thickness, and cost characteristic magnitudes were calculated by the method of characteristic magnitudes. The MatWeb online database was used to apply the selection by database method. The best material selected by the Ashby methodology from 4169 was longitudinal Bamboo. The characteristic magnitudes method selected a laminated material consisting of 5 maple sheets and 2 outer bamboo sheets from 5 materials. Database method did not obtain any material, but it resulted in a list of 90 possible materials starting from 155,000. Ashby’s method was the best one for this application since all design properties could be included.

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Several developers produce dysfunctional behaviour under time pressure (TP). It is believed that “situations and personality form two sides of a coin that cannot be separated from each other”. It is believed that different personality traits would produce different results under TP. There are numerous studies conducted in the past finding relations between different job roles & TP and personality. However, a lack of studies has been found in software development to measure the relationship between TP and the developer’s personality. Therefore, this study has set an objective to find out the relationship between software developer’s personality types (based on Myer-Briggs Type Indicator) and TP and their impact on software quality. The “completely randomized design” was used over 30 senior software engineering (SE) students for data collection. The experiment design contained six experimental rounds with different task complexity levels (i.e., easy, medium and hard) and TPs. Each even-numbered round (i.e., 2, 4, 6) was induced with TP, whereas odd rounds were without TP(NTP). McNemar test was used to find personality differences between groups. Moreover, a Genetic Algorithm (GA) was used under Rough Set Theory (RST) to develop the model. Model validation was performed by applying Naďve Bayes classifier and considering prediction accuracy, F1-score and Area under Curve (AUC)-Receiver Operation Characteristics (ROC) values. McNemar test results ensured that except round 1 and round 2, all rounds had a significant number of personality differences. Later, GA techniques returned 43 decision rules with 72.20% prediction accuracy. Based on the results, we can conclude that certain personality types can deal with TP effectively. For instance, intuiting, thinking and judging personality-based combinations can handle TP very well.

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