bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electromagnetic analysis of fully superconducting motor for electric aircraft
Authors: Voccio John , Voccio Quinn 
Published: August 2020

Abstract
In order to reduce carbon emissions, there is considerable interest in all-electric aircraft for transportation. Fully superconductor motors will be required to meet the high specific weight requirements, which are >10 kW/kg for the NASA N3-X plane. This paper summarizes the results of electromagnetic analysis generated using the FEMM magnetics code, along with the Lua scripting language, to determine the optimum motor configuration for a 4 MW, 3000 rpm fan motor. In considering ac loss, the analysis assumes Bi-2212 stator windings and both iron-tooth and air-core designs are considered. The best selected case consists of an 8-pole configuration utilizing an armature current density of 100 A/mm2.
Simplex optimization of shield coil geometry for increasing magnetic shielding performance of air-core superconducting generator
Authors: Oh J M , Bang T K , Jang G H , Lee J I , Haran K S , Cho H W 
Published: August 2020

Abstract
This study deals with the simplex optimization of a shield coil geometry for improving the magnetic shielding performance of fully air-cored superconducting generators. The superconducting generator in this study has a 10 MW-3000 rpm class, fully air-cored, rotating armature structure designed for electric propulsion aircraft applications. The magnetic flux radiated to the outside of the machine is shielded by the shield coil, and the shielding performance is determined by the shape of the shield coil. In this study, the design of the shield coil is developed using simplex optimization to improve the shield performance. The shape optimization is conducted using the simplex optimal design method, and the validity of the designed shield coil is verified by comparing the shielding performance of the initial and the optimized models.
Estimation of Machine Parameters in Superconducting Transformer using Differential Evolution
Authors: Yonenaka T , Muraoka T , Ichiki Y , Otabe E S , Tokunaga Y 
Published: August 2020

Abstract
To analyze the inrush current in a superconducting transformer, the machine parameters for the transformer were estimated from the measured current using a search algorithm. To address the large rising edge error in estimations performed using a genetic algorithm (GA), a differential evolution (DE) was used in this study. As a result, the estimated time was reduced to about 1/10 that obtained with GA, and the evaluation value indicating the difference between the measured value and the estimated value was reduced to about 1/2. Thus, it was possible to estimate with higher accuracy by using DE.
An approach to development of the HTS magnet for SMES at JINR
Authors: Khodzhibagiyan H , Drobin V , Dorofeev G , Karpinskiy V , Shurygin A , Novikov M , Kashaev D , Zaslavskiy M , Kachlishvili G 
Published: August 2020

Abstract
Particle accelerator complex NICA (Nuclotron-based Ion Collider fAcility) comprises superconducting Booster and Nuclotron synchrotrons which magnets operating at pulse mode in opposite phase with period of about 4 seconds. Summary stored energy of Booster and Nuclotron magnets will vary from 1 to 2.6 MJ during the period. NICA power supply system can be significantly improved by Superconducting Magnetic Energy Storage (SMES) application that will help to move the energy back and force between Booster and Nuclotron. The useful energy at this SMES must be about 1.6 MJ so the maximum total SMES energy should be 3-5 MJ. SMES with this energy should have several Tesla magnetic fields to keep a reasonable size. SMES operating current can be not less than Booster and Nuclotron magnets current so it might be 10-12 kA. It is better to make such a SMES magnet from an HTS (high temperature superconductor) cable for the stability at 6-7 T and 4 s pulse mode. The SMES magnet is planned to be wound as a short solenoid (Brooks coil) of cables optimized for several coaxial sections. HTS cables with helical structure similar to well-known CORC (conductors on round core) cables are under the development at JINR. The HTS cabling technology is based on the same principle as Nuclotron type cable manufacturing technology. HTS tapes, cables and magnets experimental study and testing methods are being developed on the base of an existing test facility at LHEP. First HTS cable short sample with 6 HTS tapes was prepared and tested at 77 K in self-field. Its critical current is about 800 A that will allow achieve required operating currents of SMES magnet with a reasonable amount of HTS tapes in cables. Developments of high field high current fast cycling HTS magnets for accelerators are also being planned at JINR.
Theoretical and experimental investigation of R&W and W&R SMES coils wound with large-scale MgB2 Rutherford cables operated around liquid hydrogen temperature
Authors: Hira M , Yagai T , Takao T , Shintomi T , Makida Y , Hirano N , Komagome T , Tsukada K , Onji T , Arai Y , Ishihara A , Tomita M , Miyagi D , Tsuda M , Hamajima T 
Published: August 2020

Abstract
We have developed the system called Advanced Superconducting Power Conditioning System (ASPCS) composed of a Superconducting Magnetic Energy Storage (SMES), a fuel cell and a water electrolyzer for effective use of renewable energy such as wind and solar power generation. We have been investigating about the SMES coil using the large-scale Rutherford-type conductors made of commercially-available MgB2 wires. Due to strain sensitivity even before heat treatment for MgB2 production, the design for large-scale Rutherford cables both in the wind and react (W&R) method, and the react and wind (R&W) method applied to coil fabrication has to be done cautiously to prevent the degradation of the IC by the optimizing design parameters such as the twist pitch and the cable compaction. Especially for the R&W method using heat-treated wires, other factors like handling during the coil production process which affect the conductor and coil IC should be also considered. To evaluate the applied strains during the manufacturing process, we conducted theoretical investigation on the strains applied to individual filaments caused by wire-bending. We developed a test coil designed for the R&W method based on analyzing those factors. Furthermore, we measured the coil IC-B-T characteristics and compared to those of other test coils made by the W&R method.
Half-meter Scale Superconducting Magnetic Bearing for Cosmic Microwave Background Polarization Experiments
Authors: Sakurai Yuki , Ashton Peter , Kusaka Akito , Hill Charles A. , Kiuchi Kenji , Katayama Nobuhiko , Tajima Osamu 
Published: August 2020

Abstract
We report the development of a large-diameter superconducting magnetic bearing (SMB) used in a continuously rotating cryogenic half-wave plate (HWP) polarization modulator for cosmic microwave background (CMB) polarization experiments. A precise measurement of the CMB polarization will place tighter constrains on cosmic inflation, describing the rapid expansion of the early universe. The polarization modulator is a critical instrument for suppressing 1/f contamination, which is mainly caused by atmospheric noise, and for mitigating systematic uncertainties that arise when differencing orthogonal polarization detectors. To ensure a sufficient field of view and to reduce thermal emission, the polarization modulator must have a clear-aperture diameter of > 500 mm and must operate at cryogenic temperatures. We constructed a superconducting magnetic bearing (SMB) with an inner diameter of 550 mm, which is the largest used in any CMB polarization experiment to date. We tested the friction and stiffness of the bearing at liquid nitrogen temperatures. The measured total loss is 0.4 W and the spring constant is >105 N/m, which satisfies typical experimental requirements. Furthermore, we performed a performance test by changing the number of disk-shaped YBCO tiles, and then confirmed that the SMB performance was proportional to the YBCO volume.
Simulation of thrust magnetic bearings for levitation systems
Authors: Anischenko I.V. , Pokrovskii S.V. , Rudnev I.A. 
Published: August 2020

Abstract
This work presents the complex results of the FEM H-formulation modeling of the thrust magnetic bearing based on 2G HTS tapes. The simulated bearing consists of the HTS stator and PMs rotor. In the model we have used the magnetic and transport characteristics of industrial GdBa2Cu3O7-x superconductors and also took into account the thermal properties of each layer of high-temperature superconducting tape and the features of the layered structure of the whole stack. The numerical simulation was performed using the finite element method. The developed model feature is a direct magnetic assembly rotation simulation. Load characteristics and losses in the system at several operating temperatures were obtained. Comparison with the experimental results was done.
The Role of Design Characteristics of the Internal & External Spaces of Campus to Achieve Psychological Stability “Mosul University Campus as Case Study”
Authors: Mohammed Nasma Maan , Mohammed Anfal Azzam 
Published: August 2020

Abstract
The architect plays a great role in influencing the professors and students behavior of the constituent spaces of the architectural form he produces, since the occupation of this space needs to provide his biological, physical and psychological needs, thus positively affecting the performance of the users. The productivity of the individual increases, whether for work for adults or for students. The study dealt with the effect of shaping the architectural form of the buildings in general and the university buildings in particular in achieving psychological stability for professors and students to increase their positive influence and their chances of success as individuals in the society, and discussed the negative effects of these buildings on the professors and students as they design their lives and negative perception of architectural elements, principles and strategies. The researchers conducted some practical experiments regarding the role of each building on the inside of their users in terms of (space capacity or narrowness, high or low ceiling, shape and color of walls and ceiling, straight or curved architectural design lines, The value, as well as the shape and color of the furniture used). This role has been identified by distributing a questionnaire for each of the professors and students about the university building internal and external spaces at the University of Mosul, and collecting the data in special tables and then discussing the results. The architect who design and shape the architectural form of the university buildings must be well thought out as it directly affects (positively or negatively) on both of them of these configurations that he designed.
Hot Mix Asphalt Characteristics with Sugar Industry Waste Materials as Mineral Filler
Authors: Shareef Ranin Abd , Al-Hdabi Abbas 
Published: August 2020

Abstract
Recently, applying of the waste materials as mineral filler in hot asphalt mixture has many advantage for economic and environmental impacts and also used to improve the hot asphalt mixtures characteristics. In this research, sugar industry waste materials has been used as mineral filler to investigate the achievable prospects to improve hot asphalt mixture properties. The aim of this study is to evaluate the effect of adding Sugar Waste (SW) materials on the properties of hot mix asphalt in comparison with the State Commission of Roads and Bridges (SCRB, R9) requirements. Two groups of hot asphalt mixtures have been prepared, the first was with the Ordinary Portland Cement (OPC) as mineral filler i.e. (control mixture) and the second was prepared with SW materials (modified mixtures). These mixtures have been assessed based on different experimental tests which were Marshall Stability and Flow, Indirect Tensile Strength (ITS), Index of Retained Strength (IRS) and Long Term Aging (LTA). The results indicate that there is an improvement in the mixture properties; slight increase in Marshall Stability, an improvement in Indirect Tensile Strength, enhanced their Marshall stability after aging when tested in accordance to LTA. Furthermore, the modified mixtures comply with (SCRB, R9).
Finite element analysis of embankments on gypsiferous subgrade soil - stone column strengthened with geogrid
Authors: Mohammed Hadeel Ammar , Afaj Hanan A , Masood Ghadah Ghassan 
Published: August 2020

AbstractGypsum and anhydrite rocks are frequently found in numerous countries of the world in extensive deposits, the huge region in middle and west of Iraq is classified as a gypseous soil. Stone columns are non-time dependent foundation technique used to increase the structural stability and to reduce the structural deformations of soil. In the present study, the finite element method is used as a tool to utilized the effect of using stone columns with geogrid as reinforcing material for treatment gypsiferous subgrade soil under embankment during both construction and consolidation conditions. The results show that decreasing the stone column spacing leads to a considerable decrease in the settlement beneath the embankment, especially below the center line, reduction in the settlement of about 60% and when using geosynthetic material the reduction about 75%. Also, increases the excess pore water pressure immediately after the construction of each lift of the embankment and then falls with and without using geosynthetic material. The vertical stress in the gypsiferous subgrade soil increases at a very small rate especially in the early stages and decreases as stone columns spacing decreases.
Effect of longitudinal steel reinforcement ratio on deflection and ductility in reinforced concrete beams
Authors: Mansor Ahmed Abdullah , Mohammed Ahlam Sader , Salman Wissam D 
Published: August 2020

Abstract
This search report is an experimental result on load –deflection relationship of various ratios of longitudinal reinforcement for six simply supported reinforced concrete beams. All specimens’ dimensions are (200×300×1750mm) and they were tested under two-point loading. Concrete compressive strength was (37.0-40.7 MPa). The variables studied in this work were tensile steel ratio (0.46-3.0%), bar diameter (12, 16 and 25mm) and number of bars (2 or 3 bars). It is concluded that for low reinforcement values (ρ < 0.013), an increase in ρ is sharply reduced the ductility index μ

d
. However, this effect decreases with increase in ρ values. All beams exhibit insufficient displacement ductility (less than 3) when reinforced with ρ/ρ

b
> 0.4. The increase in longitudinal steel ratio using 2 bars is more significant than when using 3 bars in yield and ultimate strengths of specimens as well as the deflection values at yield load, but the deflection values have gradual decrease at the ultimate load as a result of ductility decrease. It was concluded that the increase in longitudinal reinforcement ratio causes an increase in yield and ultimate strength of beams, these increments are compatible with the steel ratio i.e. by increasing the ρ by 50% the strength is increased about this ratio. As well as, the decreasing in ductility compatible with increasing the ρ by 50% the ductility decreased in about 50% on average.
The Behavior of Polymer RC Columns Exposed to aggressive Soils
Authors: Rasheed L Sh , Salih Sh A , Hanash Z F 
Published: August 2020

Abstract
One of the most important properties about the durability of concrete is its resistance to sulfate attack. In this search, the effect of sulfate salts on reinforced polymer concrete columns was studied, the columns buried in two types of soil, sand and clay, in depth of 3 m, in one of the agricultural areas in the holy city of Karbala. The sandy soil comprised 10.609% of SO3, the clay soil 2.61%SO3. A compressive test for reinforced concrete columns, compressive test for concrete cubes and a tensile splitting test for concrete cylinders were applied, absorption, voids ratio and density also measured. A ratio of polymer / cement = 7.5% was found to reduce the compressive strength of polymer reinforced concrete columns buried in clay soil at ages 60, 150 and 240 days by 23.97, 20.28 and 24.96%. When buried in sandy soil, the decrease in strength was 31.12, 20.03 and 37.52 % respectively, in comparison to the reference column. From this it can be concluded that the use of a polymer (SBR) has negatively affected the strength of reinforced concrete columns after 150 days so is not recommended for use in concrete facilities which are subject to attack by sulfate salts.
Studying the influence of fiber reinforcement on the characteristics of roller compacted concrete used in airports with partial replacement of cement by cement kiln dust
Authors: Al-Tameemi Ali A , Alkelabi Ehsan A M 
Published: August 2020

AbstractRoller-compacted concrete is defined as that concrete of no-slump consistency in its’ unhardened state that is transported, placed, and compacted by roller compaction. The purpose of this research is to study the effect of using steel fiber reinforcement on the properties of roller compacted concrete in which, 5%, and 10% of the cementitious materials were replaced by cement kiln dust. Different contents of steel fibers were used to reinforce concrete which were compacted using a manually controlled roller device. The results showed that the compressive strength of the roller compacted concrete with 5% replacement of cementitious materials increased by 19, 25, 32, and 42%, when the concrete was reinforced using steel fibers amounts of 30, 50, 70, and 90 Kg per m3of concrete respectively. The corresponding increases in the flexural strength were (15, 34, 37, and 40%). Similar increases were recorded for specimens with 10% replacement. The research had confirmed the feasibility of using steel fiber reinforcement to enhance the properties of this kind of concrete to be used in airport pavements. Substitution of 5 to 10 % of the cementitious materials by cement kiln dust will save energy and contribute in decreasing the impact of pollutants on the environment.
Experimental investigations of the structural behaviour of simply support ferrocement-timber composite beams
Authors: Jaafer Abdulkhaliq A. , Hussein Karrar K. Abdul 
Published: August 2020

Abstract
An experimental study of simply supported ferrocement timber composite members is presented in this paper. An adhesively bonded connection is examined. Sikadur 31 thixotropic epoxy resin adhesive is used as a shear connector layer. The main purpose of the research is generating data and providing information about the structural behaviour of proposed ferrocement timber composite (FTC) beams. Several parameters studied including thickness, and width of timber beams, the number of wire mash layers of ferrocement slab and the presence and absence of a bonding layer of the shear connector and the effect of sag and hog bending moment. Ferrocement-timber composite (FTC) beams are a relatively new civil engineering solution and their behaviour should be investigated to develop relevant methods for calculating their resistance. The slip and the pinnacle load limit for connector were resolved tentatively in two push-out tests. The authors examined the stiffness and the strength of the connection used to join a ferrocement slab with a timber beam. These parameters are fundamental for planning composite beam, on the grounds that the conduct of a composite beam framework is relied upon the solidness and the quality of its associations. The composite beams specimens were subjected to a three-point loading test. Measurements also show that the connection could be considered perfect as the slip remains very little during the test (except at failure). Tests disclosed excellent loading capacity of the suggested beams relative to their weight. The use of epoxy resin can be providing appropriate bonding between the two layers. The energy absorption increases with increasing dimensions of timber. The maximum increase in load with increasing the depth of timber (72.5%) when the thickness of timber Change from (85 to 190) mm.
Review on Soil-Structure Interaction Problems
Authors: Daud Khalida A. 
Published: August 2020

Abstract
This work comprises a survey on former work on the response of structures resting on soil and method used in the analysis of problems. Several techniques were used earlier by other researchers, some of these based on closed form or series solutions and the other problems were solved using numerical technique (finite differences or finite elements). Beam, plate or 3D solid elements were used in the finite elements to model structural members whereas spring elements were used to model the soil. Also, the finite difference was used to formulate the problems of plates or beams placed on Winkler springs. Moreover, the series solution of the differential equations using Fourier series programmed in various computer languages was used in the previous studies to analysed such problems. The numerical analysis showed to be very effective in solving problems involving structures resting on the ground.
Cost and time reduction of concrete slabs construction by selecting the most economical structural design
Authors: Al Kulabi Ahmed K , Al Zahid Ali A 
Published: August 2020

AbstractIn construction industry, projects are usually completed in a budget more than what is estimated for, finished in a time more than the contracted time, not executed properly according to the specifications, and not constructed with the client satisfaction. The thing that causes lowering the profits of contractors, clients losing, time to market prolonging, and other consequences. Projects execution on or under the budgeted money requires valid practices, precise decisions, good strategies, and needs developing new techniques, such as cost reduction technique. Thus, this paper mainly aims to relieving part of the big concerns of those who specialized in construction media respecting construction cost overruns by determining the most economical structural design, which can be realized by studying, quantifying, analysing cost, and comparing a number of structural elements with different dimensions, different design combinations, and different materials proportions. Then, the optimum structural element, the element that meets the design requirements, comprises the least materials quantities, and costs least, was selected in case to achieve an economical construction.
Forecasting of monthly stochastic signal of urban water demand: Baghdad as a case study
Authors: Zubaidi Salah L. , Al-Bugharbee Hussein , Muhsin Yousif Raad , Hashim Khalid , Alkhaddar Rafid 
Published: August 2020

Abstract
Forecasting of municipal water demand is essential for the decision-making process in the water industry in particular for countries that suffered from water scarcity. An accurate prediction of water demand improves the water distribution systems’ performance. This study analyses the water consumption data of Baghdad city using a signal pre-treatment processing approach aiming at a stochastic signal extraction of such data. An autoregressive (AR) model is then applied to predict monthly water consumption. Our prediction model has been trained and tested using a water consumption data captured from Al-Wehda treatment plant between 2006 and 2015. The results reveal that applying signal pre-treatment method was an effective approach for detecting stochastics of our water consumption data, and the hybrid model was reliable for the prediction of water demand.