bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mathematical model of radio-frequency ion thruster with an additional magnetostatic field
Authors: Kanev S , Melnikov A , Nazarenko I , Khartov S 
Published: June 2020

Abstract
The paper presents an engineering simplified mathematical model for estimating integral characteristics of radio-frequency ion thrusters with an additional magnetostatic field. In addition to the integral characteristics calculation, the proposed model allows to obtain the distributions of some plasma local parameters in a gas-discharge chamber of thruster – atoms and charged particles concentrations, and temperature of electrons. In a calculation, axisymmetric geometry of main elements of a thruster structure is considered. Two approaches to taking into account the influence of an additional magnetic field on the distribution of charged particles concentration are implementing. Each of them allows to estimate integral characteristics of radio-frequency ion thrusters with acceptable accuracy. The comparison of the experimental data with simulation results showed that error of thruster’s parameters estimation does not exceed 20-25%, which is sufficient for preliminary designing of new radio-frequency ion thrusters models with an additional source of magnetostatic field.
Thin-film coating technologies on porous materials for chemical current sources
Authors: Sleptsov V V , Kulikov N K , Lwin Kyaw Zaw , Shchur P A , Govorov V A , Kukushkin D Yu 
Published: June 2020

AbstractThis paper investigates the technologies for the formation of the thin-film electrode material of the chemical current sources. To get the high specific energy density of the electrode we used the grinding of chemically active material (LiCoO2), which the most widely used for cathode materials of chemical current sources to deposit on the materialized carbon-based electrode materials. The tested results show that the specific energy density of the electrode reaches to 210 mAh/g, which is more than thick-film technologies can reach (150 mAh/g).
Experimental studies of scattering indicatrixes of radar absorbing materials
Authors: Snastin M , Dobychina E , Solod A 
Published: June 2020

Abstract
There is some kind of materials widely used in microwave engineering that known as radar absorbers. Whether it is the aircraft coating, the anechoic chamber interior or waveguide feed load. Anechoic chamber absorbers are typically characterized by reflectivity at normal incidence of electromagnetic wave. The study of the angular dependence of reflectivity for several absorber samples and the appraising of the impact of their combination on the anechoic chamber performance are the main aims of present work. For this purpose the experimental studies were carried out in an antenna measuring and computing complex based on the anechoic chamber. Obtained results may be useful in the anechoic chamber design and construction stages as well as the modernization of existing ones. It can also be used for modelling of the internal electromagnetic field distribution of indoor field test ranges.
A comparative statistical analysis of global trends in civil helicopter accidents in the U.S., the EU, and the CIS
Authors: Moon K , Yakovlev A A 
Published: June 2020

Abstract
With helicopter operations increasing worldwide for varying usage and purposes, it is important to identify changes in helicopter accident trends. This paper studies the trends in civilian helicopter accidents in the United States, the European Union, and the Commonwealth of Independent States, and evaluates helicopter flight safety. Comparative analysis was performed, focusing on statistics and accident reports from Federal Aviation Administration, International Helicopter Safety Foundation, United States Helicopter Safety Team, National Transportation Safety Board, European Union Aviation Safety Agency, and Interstate Aviation Committee. The overall helicopter accident trends by flight time, engine type, and phase of flight were considered. The differences among the groups were identified, and the flight safety of helicopter was compared with that of other types of aircraft. In conclusion, gas-turbine engine helicopters showed a significant increase in the number of accidents. Regarding phase of flight, takeoff, landing, maneuvering, and en-route reported the most number of accidents. This study emphasizes the need for more profound research on improving helicopter flight safety by analyzing the global trend of helicopter accidents.
Coastal navigation by a solar sail
Authors: Rodnikov A V 
Published: June 2020

Abstract
In this paper, we study relative motions of a light spacecraft equipped with a solar sail and tethered somehow to a heavy heliocentric orbital space station. One can say that such spacecraft realizes a kind of a coastal navigation. Formulating a model problem of the spacecraft motion, we state that if the sail can be oriented arbitrary then motions along a rectilinear tether are possible in both directions. Also, we present algorithm of the spacecraft relocation if it is joined with the station by a tether. This algorithm is based on the motion equations solutions that can be interpreted as perturbed motions of a simple pendulum.
Mechanical characteristics of short fiber composite samples located behind circle, rectangle, triangle obstacles
Authors: Kurkin E I , Spirina M O , Chertykovtseva V O , Zakhvatkin Ya V 
Published: June 2020

Abstract
The article investigates the influence of the weld line on the mechanical characteristics of flat samples on tensile strength according to ISO-527-2, cut from a plate with an obstacle, molded from polyamide-6, reinforced from 30% short glass fibers. There are considered circular, rectangular, triangular obstacles. Melt front, weld line location and reinforcing fiber orientation are calculated in Moldex3D. The stiffness and strength of the samples were predicted in ANSYS using an anisotropic nonlinear composite material model obtained in the Digimat by reverse engineering method. The transversely isotropic criterion of Tsai Hill in the first pseudo-grain failure statement was used for predict strength. The paper presents the influence of the weld line on the stress, deformation and first pseudo-grain failure strength criterion. The greatest contribution to the samples mechanical characteristics was made by the rectangular obstacle.
Pilot behavior in preview tracking task
Authors: Efremov A V , Tiaglik M S , Kh Irgaleev I 
Published: June 2020

Abstract
The influence of the input signal bandwidth and controlled element dynamics on the potential of the preview display for improving accuracy is considered. The pilot in the loop experiments in which the human operator tracked a program trajectory characterized by bandwidths of 0.2, 0.5, 1 rad/s were carried out with a number of simplified controlled element dynamics and with the predictive display/aircraft system dynamics. For the latter dynamics the experiments were performed for different preview times (from 0 up to 6 s) which allowed to define its optimal value.
Head-up display architecture development for perspective civil aircraft
Authors: Neretin E S , Dyachenko S A , Chufirin V A , Ilyashenko D M 
Published: June 2020

Abstract
Nowadays the civil aircraft head-up displays available on the market could not be easily integrated onboard due to architectural aspects. Particularly, these systems usually contain a dedicated computer unit performing the data processing to generate the appropriate image. This leads to increases in the overall avionics weight and size and limits the scope of head-up displays application in general. However, the mentioned characteristics could be improved by the usage of the integrated modular avionics concept for architecture design. According to that approach, the common hardware platform is used by different functional consumers to share computation resources. Thus, the required data processing function could be performed by the equipment already available onboard (without the need in additional hardware). The paper proposes the head-up display architecture for civil aircraft based on integrated modular avionics which significantly reduces the system’s weight and size compared to characteristics of existing analogous. Also, this way allows reducing the time expenses for aircraft development, testing and certification, as well as the vehicle operational cost.
Enhancements and Mechanisms of Nano Alumina (Al2O3) on Wear Resistance and Microstructure Characteristics of Concrete Pavement
Authors: Ahmed Dr. Nahla Yassoub , Alkhafaji Fatimah Fahem 
Published: June 2020

Abstract
Nano materials are being used in concrete technology to enhance performance grade sustainably of construction field works like rigid highway pavement. Nano materials like Nano Al2O3 are used as admixture for the cementitious materials to improve the mechanical and durability properties related to the physio-chemical reactions. The overall objective of this research is to evaluate the effects of Nano Al2O3 addition on the abrasion durability response of concrete pavement. These investigations are conducted to study different Nano Al2O3 contents (0.5, 1, 1.5, 2%) by weight of cement on the concrete strength and abrasion resistance by using the manufactured calibrated rotary cutter device for evaluation process and microstructure analysis by Scanning Electronic Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) tests. The compressive strength was tested at 28 days of curing and the results showed that the compressive strength of concrete increases up to 36% at 28 days by addition of 1% nano-alumina as a replacement of cement; Optimal content (1% by weight of cement) is found that appears better abrasion, durability abrasion performance and at the same time, achieves the main requirement of concrete highway pavement (strength and workability).
An improved life cycle for building secure software
Authors: abdulbaqi Huda Abdulaali , Mohialden Yasmin Makki , Alazawi Sundos Abdulameer , Elewe Adel Muhsin 
Published: June 2020

AbstractComputers advanced very fast technologically In recent times. This progress leads to high demand for more secure systems because sophisticated security problems have arisen. Since modern systems involve several areas of expertise, it is vital for the security engineer to follow an efficient and optimum approach and to take into consideration the mathematical and physical properties of the system. In the present study, the focus was placed on specific aspects of secure software building; the primary objective is to provide efficient and secure software in terms of resources and time. The designer should keep, as well, productivity, security and cost aspects in balance. Safe system requirements are continuously changing. Therefore, the designers should be aware of these changes. At the start of this research, the researchers distributed a survey about the security-engineering principles related to the life cycle of software engineering life and secure web systems. From the data acquired, the proposed method was developed and presented as a secure e-mail system built according to the engineering principles of software. The AHP (Analytic Hierarchy Process) technique correlated with composition operator have been used for finding the optimal concerns of software requirements and keep minimum maintenance and cost effect.
Converted Graphite to Carbon Nanotubes by Flame Method
Authors: Jassim M A , Yassin S A , Abdulrazzak F H , Al Mgheer T H , Alwan I , Al khazraji A H , Alkaim A F 
Published: June 2020

Abstract
Graphite converted to multi walled carbon nanotubes by a flame deposition method in the atmospheric pressure at 150.C. the process has included Combustion process of graphite in Oxygen/ Nitrogen gases without using catalyst by homemade reactors. The product was assembled on the upper part of the reactor were characterized using Raman spectroscopy, X-ray diffraction, photo- images and scanning electron microscopy SEM. The analysis shows that the combustion process succeeded to separate graphite sheets and forming a mixture of graphite nanotubes with graphene mixture after removing some Vander Walls forces. The work includes supposing mechanism for producing or convert planer graphite to the tubular structure of graphite or multi-walled carbon nanotubes.
Magnetic mesoporous silica material (Fe3O4@mSiO2) as adsorbent and delivery system for ciprofloxacin drug
Authors: hussein Enaas Abdul , Kareem Sameer H. 
Published: June 2020

Abstract
Magnetic mesoporous materials covered with mesoporous silica shells (Fe3O4@mSiO2) are the most promising material, which is fulfilling many applications especially for adsorption and delivering drugs system. The present research involves the preparation of magnetic nanoparticles Fe3O4 and mesoporous silica mSiO2 as coreshell materials using sol–gel method in the presence of amid propyl betaine surfactant as template. The surface texture, morphology and particle and crystalline size of the prepared adsorbent were characterized using SEM, TEM, XRD, and nitrogen adsorption–desorption techniques. The results show that the prepared adsorbent has surface area equal to 1670 m2/g, mesopores in range 2-10 nm with a high degree of ordering of the porous structure and has a crystalline size equal to 30.16 nm. The adsorption behavior of Ciprofloxacin drug from aqueous systems onto the adsorbent has been studied using a batch experiments method. The equilibrium of the process at temperature 293K was achieved within 120 min and 0.06 g of adsorbent dose. Adsorption isotherms were fitted with the Langmuir, Freundlich, Temkin, and Dubinin –Radushkevich models and the results show the Langmuir and Temkin model was best fitted, and the adsorption process is physical adsorption type. The kinetic data were analyzed and found to match well with pseudo-second order kinetic model. Ciprofloxacin drug loading and capacity of release of the Fe3O4@mSiO2 carrier was also studied.
Evaluation of the Properties of Sewage Water at Koueifieh Hospital-Benghazi, Libya
Authors: Alhaj H B , El-ajaily M M , Al-Mabrouk S H , Al-Noor N H , Al-Noor T H 
Published: June 2020

Abstract
The analytical parameters of wastewater gathered from ten stations have been studied by standard methods. The unpleasant odor was observed in all stations, in addition, the pH of the wastewater was measured to be in the range of 6.3-8, meanwhile, the electrical conductivity of the water was in the range of 2030-6450 μscm−1. The values of 3225, 406, (144-604), 5.84 and 130 ppm corresponded to maximum total dissolved solids, maximum biological oxygen demand, range of the chemical oxygen demand of the selected sites, maximum nitrate content and maximum sulfate content, respectively. The obtained analytical data showed variables in all used parameters in all stations, and most all of the studied parameters were higher in comparison with the permissible limit reported by World Health Organization or the Libyan National Center for Standardization and Metrology.
Determination and Identification of Nickel(II) Spectroscopy in Alloy Samples Using Chromogenic Reagent(HPEDN)
Authors: Raafid Esraa , Al-Da’amy Muneer A. , Kadhim Salih Hadi 
Published: June 2020

Abstract
A modern and easy procedure performed using the spectrophotometric method and estimating of Ni (II) in alloy samples. Using a ligand 1-((4-(1-(2-hydroxyphenylimino) ethyl)phenyl)diazenyl)naphthalene-2-ol (HPEDN) and a synthesis of the azo-schiff reaction by reaction p-aminoacetophenone with 2-naphtol in first step and reaction of product with 2-aminonaphthol, Ligand and its complex were identification by using UV-Vis. Spectrophotometry (326nm for ligand (HPEDN), 516nm for complex(Ni-HPEDN)), FT-IR, 1H-NMR, and 13C-NMR. The optimal conditions in the complex composition were studied at pH=9, temperature 25°C, and time 15min. The best concentration was found for Ligand (2×10−4 M), Under optimum conditions concentration ranged from (1.1-7.1) μg/mL of Nickel(II) were obeyed Beer‘s Low, with Molar Absorptivity 0.2648×104L.mol−1.cm−1. Limit of Detection(LOD) and Limit of Quantification(LOQ)were 0.3928 and 1.3082μg.mL−1 respectively. The stoichiometric composition of the chelate is 1:2 (Ni:HPEDN). This method is Sensitive, accurate and rapid spectrophotometric method. The results obtained were compared with flame atomic absorption spectrometry method and results are in conformity.
Extraction and determination of alpha-Cypermethrin in environmental samples from Kerbala city / Iraq and in its formulation using high performance liquid chromatography (HPLC).
Authors: Shaheed Ihsan M , Dhahir Saadiyah A 
Published: June 2020

Abstract
Synthetic perothroid, Alpha-cypermethrin (α-CY), was determined in both river water samples collected from different agriculture areas in Kerbala city / Iraq and in some of its formulation which include α-cypermethrin as an active gradient. The method is based on the development of the analysis using high performance liquid chromatography (HPLC) with ultraviolet detection. Dispersive liquid-liquid microextraction (DLLME) was also developed to extract α-cypermethrin from river water samples by using chloroform as extraction solvent and acetonitrile (ACN) as dispersant. A mixture of acetonitrile/methanol (50:50v/v) was optimized as a mobile phase and C18 column (250mmx4.6mm,5μm) was chosen as a stationary phase, at pH 7.0 and flow rate 0.5 mL.min−1. Linearity of calibration curve ranged from (0.1-70)μg mL−1 was applied. Limit of detection and limit of quantification are (0.047) and (0.157)μg.mL−1, respectively. Validation of this method was maintained for three concentration (0.5, 10 and 50) μg mL−1. Relative standard deviation were (0.823, 0.113 and 0.150) μg.mL−1, respectively for the three level of concentrations. Three spiked level were applied for recovery study (1.0, 5.0, and 10) μg.mL−1. Recovery ranged from (83.704 - 96.972%) for the three spiked level. The developed method could be provide an acceptable results for determination of α-cypermethrin in its formulation and river water samples.
Synthesis and biological evaluation of some imidazoline derivatives
Authors: Altameemi Hanaa A. , Askar Firyal W. , Nief Olfat A. 
Published: June 2020

Abstract
The group of imidazoline derivatives is an important class of compounds that possess broad biological activity. Many derivatives that have been efficiently synthesized form 4,5-dihydro-1H-imidazole s starting material to Synthesis of some new Schiff bases, 2-azetidinone and 4-thiazolidinone derivatives .The structures were characterized by FTIR and 1H-NMR spectra. All The synthesized compounds were evaluated for their antimicrobial activities against two kind of bacteria (gram +ve ) [ S .aureus, S.epidermi dis ] and (gram −ve ) [E.co li, Klebsiel lla spp] as well as fungi[C.albica ns] using the micro dilution procedure and compared with amoxicillin activity.
Designing and constructing a micro flow injection system (μFIA) for phosphate determination in soft drinks
Authors: Shafi Al-Jorani Y , Hussien Al-Sowdani K 
Published: June 2020

Abstract
Lab. made micro flow Injection system (μFIA) was designed which supplied with two microcontroller UNO and Mega types. These two microcontroller (Arduino) were provided with home- made software programs.The first one, type UNO used to control home- made mini peristaltic pump to drive reagents to detector. The other one was Mega type which was used as a data-logger to manipulate and recording the results as peak height corresponding the concentration by using Microsoft Excel 2010 program. The diameter of the tubes was 0.2mm i.d which used in all parts of manifolds The proposed μFIA manifold was used for phosphate determination in soft drinks samples which supplied from local market. The best conditions for the determination of phosphate by Murphy method was studied. linearity, detection limit, r.s.d% were 5-30 μg/ml,0.09 μg/ml and 0.48% respectively. The phosphate concentrations in the different soft drink samples were in the rang 250-825 μg/ml by using the standard addition method in order to eliminate all expected interferences. The home -made Semi- automated micro-flow injection analysis (μFIA) system was applied successfully for phosphate estimation with simple, high sensitive and accurate.
Common Fixed Point problem for Classes of Nonlinear Maps in Hilbert Space
Authors: Maibed Z H 
Published: June 2020

Abstract
in this article, we present a definition of k-generalized map independent of non-expansive map and give infinite families of non-expansive and k-generalized maps new iterative algorithms. Such algorithms are also studied in the Hilbert spaces as the potential to exist for asymptotic common fixed point.
Idempotent and Pure Gamma Subacts of Multiplication Gamma Acts
Authors: Abbas Mehdi S , Gubeir Samer A 
Published: June 2020

Abstract
The purpose of this article is to investigate pure gamma subacts of multiplication gamma acts and some related concepts. Some characterizations of pure gamma subacts are given. For this reason, we introduce the concept of idempotent gamma subacts and study some of its properties. Also, we discussed the relation among the pure, multiplication and idempotent gamma acts. Moreover, some result of pure gamma subacts of multiplication gamma acts are considered. Finally, we prove that the product of two pure gamma subacts is also pure.
Pre-Stability of Fixed Point
Authors: Haza Abedal-Hamza Mahdi , Sahi Ameer M. 
Published: June 2020

AbstractIn this paper, we introduced certain types of stability of the fixed points in discrete dynamical systems which are pre-stability, pre-c-stability, and pre-ic-stability. We studied the relationships among these types of stability, also the relationships among these types of stability and certain types of stability which are stability, c-stability, and ic-stability
Fully stable on Gamma Acts
Authors: Abbas Mehdi S , Saied Samir M 
Published: June 2020

Abstract
Let M be a Γ-monoid and A a unitary right MΓ-act. We have introduced and studied the notion of full stability on gamma acts. We say that A is fully stable if f(B)⊆ B, for each MΓ-subact B of A and MΓ- homomorphism f: B→A. This is equivalent to saying that f(aΓM) ⊆ aΓM for each element a in A. Many properties and characterizations of this class of gamma acts have been considered. In fact we show that full stability of MΓ-act A is equivalent to the following equivalent conditions (1) For each a∈A, (LA(RM(aΓM)))= aΓM. (2) For all a, b ∈ A and RM(aΓM) ⊆ RM(bΓM) implies that b ∈ aΓM. (3) For each a ∈ A, there is a Γ-compatible ρ on M such that (LA(ρ)) = aΓM. (4) [aΓM:bΓM]=[RM(bΓM): RM(aΓM)] for all a, b ∈ A where M is a commutative Γ-monoid. (5) Every MΓ-homomorphism from any essential MΓ-subact B of A into A satisfies f (B) ⊆ B and HomMΓ
(B,C) = HomMΓ
(B,C) = ϴ, for any MΓ-subacts B, C of A with zero intersection.
Performance simulation and design comparison of optical heterodyne temperature sensor based on Fiber Bragg Grating
Authors: Alattar Ammar S. , Kadhim Shehab A. , Mohammed Firas S. , Mahmood Aseel I. 
Published: June 2020

Abstract
In this work, an optical heterodyne temperature sensor system had been designed using Fiber Bragg Grating (FBG). Two techniques implemented. The first standard design uses dual laser diodes LDs as a laser sources that satisfy the condition of beat frequency range. The second new heterodyne optical system designed to get tunable source from single laser source using FBG, which is used as tunable element. By controlling the ambient temperature of the FBG, the wavelengths and their ranges can be controlled in way that satisfies the condition of beat frequency range. Mach-Zehnder interferometer (MZI) sensing technique had used with FBG element in both reference arm and sensing arm. Then the new modified heterodyne optical system had done by utilizing FBG in both reference arm and sensing arm with single source. A comparison study of results by using Optisystem software shows that, the modification of the second design provides better performance by increasing the wavelength shift and the sensitivity of the modified heterodyne temperature sensor.