bluuebunny/crossref_metadata_2025 huggingface dataset:
Potential of Modified Corn Cob (Zea mays L.) and Petai Hull (Parkia hassk) as New Biosorbent for Removal of Lead Waste
Authors: Putri Fami Amalia , Hamadi Nur Fala , Lestari Ajeng Y.D. , Chafidz Achmad , Mutiara Tintin
Published: November 2018

Lead metal is one type of heavy metal that has high toxicity levels in the aquatic waste environment. The adsorption method is one of the alternatives in reducing heavy metal waste, by utilizing biosorbent. The purpose of this research is to study the process of making new biosorbent and to know the absorption of new biosorbent from corn cob (Zea mays L.) and petai hull (Parkia hassk) to dissolve lead metal waste (Pb). There are two types of biosorbents are ordinary (simplicia) biosorbents and modified biosorbents with nitric acid (HNO3). Synthetic waste is used in the form of Pb (II) metal ions from the Pb (NO3)2 solution using initial concentrations of 100, 200, 300, 400, and 500 mg / L. Biosorbents tested the concentration of metal ions with AAS and characterized using FTIR to determine functional groups. Maximum adsorption capacity was obtained by biosorbents D (simplicia) and H (HNO3) with Pb (II) adsorbed metal ion capacity of respectively 1.4175 mg/g and 2.230 mg/g at a concentration of 400 mg / l. The isotherm adsorption showed that the adsorption mechanism of Pb(II) ion fit for this study is seen from the values of R2 on C biosorbents is better with other adsorbents and respectively are followed Langmuir, Dubinin Radushkevich, Freundlich, and Langmuir isotherm adsorption.
A Study on the Fracture Mechanics of Support Structure of Excavation Puddle by LPG Explosion Using AUTODYN
Authors: Chae Chang Keun , Kim Eui Soo
Published: November 2018

Cutting iron bars using a gas cutting machine is indispensable inside puddles of pier foundations. However, gas explosive accidents constantly occur as a result of the leakage of gas. It is necessary to perform specialized and systematic evaluations on structural stability, such as internal stress of the support structure, because the structural stability dominates the explosion and the collapse possibility of the structure. In this study, a structure-fluid interaction analysis was performed using an explosion commercial program, 2D/3D AUTODYN, to apply engineering numerical analysis technology to analyze the fracture behavior. The structural stability of the supporting structure in puddles was evaluated.
Fabrication of the Anode Supported Solid Oxide Fuel Cells by Tape-Casting Process and Infiltration Method
Authors: Kwon Young Jin , Han Young Bae
Published: November 2018

The hydrogen is promising energy carrier due to its high energy density, convenient transportation, eternal sources in the earth and cleanness. Solid oxide fuel cells (SOFCs) have not been commercialized yet even though it has been studied for decades. The issues about solid oxide fuel cells are manufacturing process and electrochemical performance. Tape-casting process has an advantage of cost reduction for mass production. it is reported that infiltration improves electrochemical performance of SOFCs by enhancing the three phase boundary (TPB) and porosity. To fabricate the electrode with porous scaffold structure for infiltration, pore formers were added in the tape-casting slurry. In this study, four types of mixtures of several pore formers such as carbon black, graphite, poly methyl methacrylate and glassy carbon were estimated. Micro structure of each type is investigated through scanning electron microscope (SEM). The thickness of the unit cell manufactured by tape-casting is in the range of 200 - 250 μm. The fabricated unit cell with carbon black and glassy carbon shows the open circuit voltage 1.07 V at 800°C. As a result of the study, mixed ratio of pore formers was researched for Solid Oxide Fuel Cells manufacturing process applied by tape-casting and infiltration method.
Peculiarities of Productive Sediments Facies Analysis according to GWL Data
Authors: Aleksandrov Vadim , Kadyrov Marsel , Ponomarev Andrey , Drugov Denis , Zapevalov Vladimir
Published: November 2018

The research objective is to determine the genesis of productive sediments in the AS8, BS1, and YUS2 reservoirs and reveal the peculiarities of their forming. The identification of facies complexes in productive sediments was carried out with the help of facial and electrometric methods of investigation.
Assessment of Radial Drilling Feasibility at the Fields of the Orenburg Region
Authors: Aleksandrov Vadim , Kadyrov Marsel , Ponomarev Andrey , Golozubenko Vadim , Kopyrin Vladimir
Published: November 2018

The development and use of the radial drilling technology has been a controversial issue in the oil and gas industry for a long time. Nowadays, almost all big oil and gas producers deal with the question of its practical use at particular fields. The results of works carried out at carbonate reservoir units of the Orenburg Region were analyzed in the article. The ways to improve the existing technology of radial drilling were also offered. The research objective is to evaluate the technological efficiency of radial drilling application at the fields of the Volga-Ural oil and gas region with carbonate reservoir units. The results of radial drilling were characterized with the help of the detailed geological and field analysis and their quantitative evaluation was given.
Use of Diverter Compositions for Enhancing the Effectiveness of Oil Recovery from Productive Deposits
Authors: Aleksandrov Vadim , Galinskij Kirill , Ponomarev Andrey , Golozubenko Vadim , Sivkov Yuriy
Published: November 2018

One of the most important aspects in the activities of oil companies in the Western Siberia is to improve the effectiveness of water-flooding as the main method of impact on the formation. This is due to the fact that at the present time reservoirs of a complex structure with difficult to recover reserves prevail among newly introduced development objects, the extraction of which is extremely difficult using a simple method of water injection volumes regulation. First of all, this refers to reservoirs of Jurassic deposits, which are characterized by the most complex geological structure and porosity and permeability properties. A promising direction in improving the water-flooding system at such objects is the use of physical and chemical technologies to enhance the oil recovery of formations, and primarily, referring to the diverter technology. The research objective is to evaluate the effectiveness of using “hard” type diverter compositions to enhance oil recovery of formations. With the help of detailed oil-field analysis and field-geophysical studies, the nature of the development of oil reserves for Jurassic development sites has been assessed.
Using Borehole Seismic Data in Designing of Development and Further Exploration of Oil Fields
Authors: Aleksandrov Vadim , Kadyrov Marsel , Ponomarev Andrey , Drugov Denis , Neelova Evgeniya
Published: November 2018

Borehole seismology allows studying the specific features of the geological structure and physical properties of deposits in the borehole environment using waves of various kinds based on the analysis of characteristics of these waves, their rates propagation, attenuation, space polarization, and the nature of rock anisotropy. The research is intended to study the wave fields of various types of waves taking into account their dynamic, speed and polarization characteristics and the features of geological structure both in the vicinity to the borehole and laterally in the crosshole space. Using the borehole seismology method, the geological structure of reservoirs was specified; a prediction was given as to the development of enhanced reservoir units in the crosshole space.
Oil Recovery Factor Assessment Results for Sites of the Sredne-Ugutskoye Field
Authors: Aleksandrov Vadim , Kadyrov Marsel , Ponomarev Andrey , Drugov Denis , Neelova Evgeniya
Published: November 2018

Oil recovery factor (ORF) assessment for sites of the Sredne-Ugutskoye field was performed applying various methods. For this field, the ORF prognostic assessment applying the existing methodological approaches is very relevant, as well as the selection of the most appropriate and accurate ORF calculation methods, taking into account the specific features of the geological structure of formations and reservoirs. The research objective is to obtain an adequate assessment of the ORF for productive sites of the Sredne-Ugutskoye field. With the help of a whole group of methods (analogy, empirical-analytical and empirical-statistical methods), predictive calculations of the ORF value for a number of Jurassic-age development sites were performed.
Assessment of Bottomhole Formation Zone Results for the YUS11 Development Wells at the Fainsk Oil Field with the Application of Hydrocarbon Solvents and Acid Compounds
Authors: Aleksandrov Vadim , Kadyrov Marsel , Ponomarev Andrey , Drugov Denis , Zavatskij Mikhail
Published: November 2018

One of the acutest problems in the oil and gas industry is the efficient development of low-permeability reservoirs in Jurassic sediments. At that, the choice of efficient technologies can be made basing on the analysis of field-geological and laboratory data, as well as the analysis of previously conducted activities with account of facies genesis of reservoir rocks in the wells, where the geotechnical activities (GTA) are realized. The research objective is the assessment of bottomhole formation zone (BFZ) results for the YUS11 development wells at the Fainsk oil field with the application of hydrocarbon solvents and acid compounds. Using detailed field-geological analysis, the data obtained after the processing of a bottomhole formation area of the development wells with the application of hydrocarbon solvents and acid compounds was assessed.
Specific Features of the Geological Structure of the Formations YUS11 and YUS12 of the Sredne-Ugutskoye Oil Field and their Influence on the Effectiveness of Pay Zones Completion
Authors: Aleksandrov Vadim , Kadyrov Marsel , Ponomarev Andrey , Drugov Denis , Veduta Olga
Published: November 2018

The choice of the most effective technology for reservoir completion depends mainly on the conditions for the formation of its constituent deposits and the specific features of their geological structure. This circumstance makes it possible to predict the productivity of newly drilled wells, transferred to the pay zone, as well as to plan the necessary geological and technical interventions with maximum efficiency. The research objective is to assess the influence of specific features of the geological structure of the production zone on the effectiveness of pay zones completion. Facies maps for productive formations were constructed with the help of paleogeographic and facies methods of analysis; a detailed geological and routine analysis made it possible to numerically assess the tightness of the connection between the development indices and the geological and geophysical characteristics of the objects under investigation.
Studies on Applying Acid Compositions to Treat the Western Siberian Field Bottomhole Formation Zone
Authors: Nesterov Ivan , Kadyrov Marsel , Markov Alexander , Drugov Denis , Zapevalov Vladimir
Published: November 2018

Effective development of oil deposits includes the measures to restore and improve the porosity and permeability properties (PPP) of reservoir units, which inevitably deteriorate during the operation of the field. For this purpose, various technologies of bottomhole formation zone acid treatment (BFZAT) are used. These approaches are sufficiently developed and usually do not require additional laboratory adaptation. Specific requirements for technologies that include acid effect on the formation are required for interventions on low-permeability reservoirs (LPR), where the influence of the mineralogical composition of rocks and their porosity and permeability properties on the efficiency of BFZAT is the most significant. Therefore, during interventions development for LPR using acid methods, it is necessary to correctly assess the capabilities of a particular method (composition) in relation to specific conditions. This can be achieved by conducting standard laboratory tests (determination of rock carbonation and mass loss in 12% hydrochloric acid) and additional experiments to determine the mass of the secondary sediment, as well as the optimum reaction time at the formation temperature. The research objective is a laboratory research on the selection of acid compositions for bottomhole formation zone treatment for a number of low-permeability reservoirs in Western Siberia. Standard and special laboratory studies have allowed suggesting the most optimum acid compositions adapted to “rigid” formation conditions.
Characterization and Structure Analysis of the Anodic Film Formed on AZ31 Mg Alloy in KOH Alkaline Solution with Various Additives
Authors: Nishinaka K. , Salman S.A. , Kuroda K. , Okido M.
Published: November 2018

AZ31B Mg alloy was anodized under the current density of 20 mA cm-2 for 3.6 ks in KOH alkaline solutions contains 0.60 M KF, 0.09 M Na3PO4.12H2O, 0.45 M Al (OH)3 and 0.13 M KMnO4 at 298 °C. Pores structure anodic film was formed on magnesium alloy surface; the pours structure was also observed in the lower part of the anodic film. The anodic film consisted of MgO and MgAl2O4. The anodized film showed higher pitting potential from anodic polarization measurement in 0.1 M NaCl solution compared to non-anodized magnesium alloy specimen and leads to improve the corrosion resistance of anodized AZ31 magnesium alloy.
The Effect of the Structural Parameters of 3D Orthogonal Woven Composites on their Impact Responses under Different Modes of Impact
Authors: Midani Mohamad , Seyam Abde Fattah , Pankow Mark
Published: November 2018

Development of three-dimensional (3D) weaving technology introduced new and enhanced features to the 2D weaving technology. 3D Orthogonal Woven (3DOW) preforms have a through-thickness yarn component that significantly enhances the impact resistance and delamination resistance. In this study, a range of 3DOW E-glass preforms were woven using 3D weaving technology and then converted into composites, using vacuum assisted resin transfer molding technology. The composite samples had varying structural parameters, such as, number of Y-yarn layers, X-yarn pick density, Z-yarn interlacing pattern. The purpose was to study the effect of changing those structural parameters on the different impact responses of the 3DOW composites under different modes of impact, namely, tup, Izod and Charpy impact. The study indicated that, the number of Y-yarn layers, had the most significant effect on the total tup, Izod, and Charpy impact energies. The X-yarn pick density, had slight effect on the three modes of impact, while the Z-yarn weave design only had a slight significant effect on the tup and Charpy impact energy.
Cementing Line Configuration of Bioactive Engineered Zirconia Implants (In Vivo Histological Study)
Authors: Ahmed Dawlat Mostafa , Omar Samia Soliman
Published: November 2018

Background: Osseointegration of dental implant is a challenging issue for those who need to restore a missing tooth, a matter that necessitates wide range of research on different implant manufacturing, modification and bioactive coating materials.Aim of the study: Investigation of cementing line configuration around osseointegrated engineered nano-porous zirconia implants coated with bioactive autologous HA, platelet rich plasma (PRP) and bovine HA (Bio-oss) coatings in rabbit model.Materials and methods: Zirconia implants (cylinders 3.7 mm x 8 mm) were milled and sintered according to manufacturer recommendations. Then all specimens were treated with selective infiltration etching (SIE) to produce a nano-porous surface. Implants were surgically placed bilaterally in the femur distal heads of 20 male line V Spain white rabbits. Implants were divided equally into 4 groups (n=10): group (A) control (non-coated), group (B) autologous HA coated, group (C) PRP coated and group (D) Bio-Oss coated implants. Specimens were characterized with x-ray diffraction (XRD) analysis and mercury porosimetery. Histological examination was performed after six weeks of peri-implant healing period.Results: XRD patterns revealed the detection of hexagonal HA and (Y-TZP) tetragonal crystal phases for the HA coated surfaces. Mercury porosimetery revealed a significant reduction in total porosity percent after application of bioactive coating materials. The histological picture of osseiointegration and cementing line continuity in association with both of autologous HA and PRP were outstanding and satisfactory followed by that of Bio-Oss and all coated implants showed a noticeable difference from that of the control specimens that were surrounded by unsupported cementing line adjacent to newly formed bone with low density.Conclusions: Engineering of zirconia implant surface with bioactive coatings either HA or PRP to enhance its biological activity could be considered as reliable method to provide satisfactory osseiointegration.
Ballistic Impact Simulation of Proposed Bullet Proof Vest Made of TWIP Steel, Water and Polymer Sandwich Composite Using FE-SPH Coupled Technique
Authors: Nyanor Peter , Hamada Atef S. , Hassan Mohsen A.
Published: November 2018

The bullet-resistant vest (bullet proof vest) is an important accessory to absorb impact energy and stop bullets from penetrating the body. In the present work a sandwich composite structure was designed from different sequential layers of, twinning induced plastic (TWIP) steel, polypropylene – polyethylene (PP-PE) polymer and water for bullet proof vest application. Owing to the difficulty in experimentally testing materials for ballistic impact application, a finite element – smoothed particle hydrodynamic (FE-SPH) coupled simulation was applied for analyzing the impact characteristics of the proposed composite structure. Different structural layers of the composite are simulated to select the most effective thickness of steel/polymer/water layers in energy absorption and penetration prevention. The simulation results displayed that the optimum thickness of the layers are 2 mm steel/20 mm water/2 mm steel , which is able to stop a 9 mm bullet travelling at 360 m/s with less than 10 mm displacement of the inner surface of the composite. This composite is promising and has a great potential in fabrication of effective and light weight bullet proof vest with less expensive materials.
Mechanical Properties of a “Simple Panel Structure” Manufactured of an Ultra High Strength Stainless Steel
Authors: Kananen Markku , Järvenpää Antti , Jaskari Matias , Mäntyjärvi Kari
Published: November 2018

Corrugated core panels contain a formed, corrugated core bonded between two skin sheets. These panels are typically used in applications, where a low weight is required with integrity in stiffness. This paper demonstrates the mechanical properties of a simple panel structure (SPS), constructed using strips of work-hardened, austenitic stainless steel (ASS) grade 1.4310 (type 301) with the yield strength (YS) of ~1200 MPa. The 0.5 mm thick strips were formed into a C-shape and subsequently laser welded together by lap joints to form a SPS. The thickness of the SPS was 50 mm. The bending tests for the SPS were carried out transverse and 45-degrees related to the orientation of the web sheet. The results showed that the SPS, as loaded in the transverse direction, has about the same bending stiffness prior yielding as that of the previously tested 6 mm thick, low carbon S355 plain steel sheets, but the SPS is three times lighter than 6mm thick plain steel sheet. Compared with a corrugated core panel made of an annealed ferritic stainless steel (SS-panel) with the YS ~ 250 MPa, the weight of the both panels are roughly the same, but the bending resistance of the SPS is 45% higher. Experimental tests also verified that the benefit in the stiffness is quickly reduced if the load direction differs from transverse. In the 45-degrees loading direction, the SPS and the SS-panel had almost the same bending strength. On the other hand, the SPS and the SS-panel stiffnesses are much better than that of the carbon steel (the YS ~ 300 MPa) panel (CS-panel) in the both loading directions – the SPS being twice as stiff as the CS-panel.
Design and Manufacturing of a Non-Standard Chain Parts for a Scraper Chain Conveyor: A Case Study
Authors: Gamil Mohammed , El-Bitar Taher
Published: November 2018

This paper presents a complete case study for designing and manufacturing chain parts for scraper chain conveyor (SCC) for a real client (chicken’s dietary supplements company). The chain of the SCC is dilapidated due to joints and pins deterioration. The Productivity was reduced as a result of operating at low capacity load and repeated maintenance. The condition of chain was too worse and not able to be repaired. Furthermore, the chain was non-standardized. Therefore, a complete design is required to replace the damage parts of the chain. The design procedures are: (1) calculation of the expected loads that exert on the chain during operation, (2) selection of materials, (3) designing the different parts of the chain taking into account safety, assembly process and economic considerations. The final design was justified and validated. The SCC is working properly and safety under various load capacities.
Design for Additive Manufacturing in Extended DFMA Process
Authors: Mäntyjärvi Kari , Iso-Junno Terho , Niemi Henri , Mäkikangas Jarmo
Published: November 2018

As a new manufacturing method, Additive Manufacturing has begun to get a foothold in the manufacturing industry. The effective exploitation of the technology requires many times a re-design of the product or re-considering the manufacturing technology. Design for additive manufacturing differs considerably from design to other manufacturing methods, therefore design guidelines for additive manufacturing has been developed. The purpose of this paper is to present a new variant of the Design for Manufacturing and Assembly (DFMA) method which supports additive manufacturing.
DFAM Based Multi-Material 3D Printing Using Conductive and Flexible Filaments
Authors: Kutuniva Kari , Mäkikangas Jarmo , Mustakangas Aappo , Rautio Timo , Kumpula Jani , Mäntyjärvi Kari
Published: November 2018

The focus of this study was to test a low-cost level plastic printer in the multi-material printing application using principles of design for additive manufacturing (DFAM). Two sample structures were designed in the project. One of the main planning principles of the examples was to integrate multiple functions into one part and intelligently utilize a variety of materials and reduce parts count. The most common material used in the experiments was the basic PLA, which is widely used, easy-to-print and economical alternative. As special materials, electrically conductive PLA-based graphene filament and highly flexible polyurethane-based filament was used. The results show that multi-material printing is also possible with lower cost devices and it makes it easier for smart products to be manufactured cost-effectively. It has also been found that multi-material printing can be technically challenging and that further research and experiments in this subject are needed. In the future, the research topic will be even more interesting as equipment and materials will develop. This paper presents detailed printing parameters for all the materials used in the printing tests.
Effect of Gas Dilution Ratios and Substrate Temperature on the Structural Transition of a-Si/μc-Si Thin-Film Solar Cell Using PECVD
Authors: Abd El-Aaty Heba R. , Tobail Osama , Shoeib Madiha A. , El-Mahallawi Iman
Published: November 2018

Thin films of mixed amorphous/ microcrystalline-phases have been researched during the last decade, for manufacturing silicon solar cells. In this work the Plasma Enhanced Chemical Vapor Deposition PECVD process parameters; namely dilution ratios and substrate temperature, were controlled to build i-layer at low dilution ratios with moderate substrate temperatures. In this work an intrinsic layer was deposited on Indium Tin Oxide ITO glass by PECVD technique, with different dilution ratios of silane in hydrogen to study the transition from amorphous to microcrystalline phase. The Si:H thin film was evaluated by field emission scanning electron microscopy, x-ray diffraction and atomic force microscopy. The structural transition between a-Si:H to μc-Si:H achieved at dilution ratio 13.3 and substrate temperature 250°C with surface roughness 22.5 nm.
Indoor Radon Levels and Annual Effective Dose in Dwellings of Najran City, Saudi Arabia
Authors: Badran Heba M.
Published: November 2018

The main objective of this study is to assess the health hazard due to the indoor radon. CR-39 as time-integrated passive solid-state nuclear track detectors (SSNTDs) were used in the indoor radon measurements of Najran City, Saudi Arabia. CR-39 detectors were distributed in dwellings of different places of the city. The detectors were exposed in the dwellings for two months and then etched in NaOH 6.25 N solution at 70 ±1°C for 5 h. This study revealed that the radon concentration in the dwellings ranged from 15.03±1.9 to 70.48±3.3 Bq m-3 with an average of 34.00±14.0 Bq m-3. Comparison of indoor radon concentration measurements in the different floors showed that the radon concentration in ground floors was slightly higher than that in first floors. Results showed that there is no significant health risk from indoor radon concentration and annual effective dose in the study region.
Effect of Electrodes Material on the Performance of Batch Reactor Using Plasma Enhanced Technique for Wastewater Treatment
Authors: El-Gelil Gehad M. Abd , Mansour Moustapha S. , El Shazly Ahmed Hassan , Abou-Gabal Hanaa
Published: November 2018

The plasma degradation process of Eosin yellow aqueous solution utilizing AC corona discharge generated above liquid with a type of pin to plate by utilizing multiple needles electrodesis investigated the influence of electrodes material and effect of ferrous sulfate on decoloration and the kinetics of process are discussed. The AC corona discharge plasma was generated in the air gap between tip of needles and the water surface. The experimental results indicate that the decoloration rate increases with using stainless steel electrodes and with increasing the concentration of FeSO4. When dye concentration is 10 mg/L with pH of 3, the air gaps were 0.85 cm and the number of pins were 30, the decoloration rate went up to 97% in 60 min.
First Principles Study on Magnetic and Optical Properties of Single Layer CrSi2
Authors: Chen Shao Bo , Yao Kai Li , Huang Ping , Jiang Ze Lan , Lv Shi Lian , Luo Zheng Song
Published: November 2018

According to first-principle based on the density functional theory, the magnetic and optical properties of single layer CrSi2are calculated and analyzed by plane wave pseudo potential method. The band structure, density of state, optical absorption spectra, reflectivity and energy loss function of single layer CrSi2are obtained. The results show that single layer CrSi2has the properties of metal and magnetism. The calculations of optical properties of single layer CrSi2material deduce that it can absorb photons which belong to visible to ultraviolet region, even in far-infrared and far-ultraviolet regions. Single layer CrSi2has a good optical permeability to photon (with energy from 13 to 40eV), which shows that single layer CrSi2is suitable for optoelectronic devices, especially in infrared and vacuum ultraviolet detection applications.
Input Interface for all Spin Logic
Authors: Wang Sen , Cui Huan Qing , Yang Ying , Cai Li
Published: November 2018

We propose an input interface circuit that can provide input signals for the emerging all spin logic (ASL) devices. It consists of metal wires that are used for the transmission of electrical signals and magnetic tunnel junction that are used to transform electrical signals into input signals of ASL devices. The operation of input interface is validated by using a coupled spin-transport/magneto-dynamics model. A salient advantage of the proposed input interface is its ability to shorten the length of spin channel for spin transmission and avoid the complex fan-out structure when multiple identical input signals are needed. This input interface is especially useful for the design of large scale ASL circuits, in which many identical units are needed.
Spin Spatial Frequency Response of Atomic Magnetometer
Authors: Yin Ling Xiao , Chen Jing Ling
Published: November 2018

We describe a method for measuring the spin spatial frequency response in a Cs vapor cell by using a digital micro-mirror device (DMD) to modulate the pumping light both spatially and temporally. An equivalent space-alternative magnetic field is created by this way. The pumping light through the Cs vapor cell is measured and analyzed in spatial frequency domain. We obtain the spatial frequency response of the Cs vapor cell from 1.4 cm-1to 364.9 cm-1. The theoretical results of the spatial frequency response according to Fick's second diffusion law agree with the experimental results. This method provides an alternate approach for spatial characterization and three-dimensional imaging of spins.
Influence of the Thickness of Nonmagnetic Spacer on the Magnetic Properties of Fe/Cu Multilayered Nanowires
Authors: Wang Xi Zhi , Ma Liang Cai , Ma Ling , Lin Xue Ling
Published: November 2018

We present a systematic investigation on the equilibrium structure, stability and magnetic properties of one-dimensional Fe/Cu multilayered nanowires with different width of nonmagnetic Cu spacer using first-principles calculations. The multilayered nanowires preserve their FCC (001) directional lattice symmetry after structural optimization. It is found that the stability of Fe/Cu multilayered nanowires decreases with increasing concentration of nonmagnetic Cu layers. The calculated interlayer exchange coupling (IEC) is found to switch signs as the thickness of nonmagnetic Cu spacer increases in the nanowire, and the magnitude of the IEC value is found to decrease significantly with increasing the number of nonmagnetic Cu layers.
Mathematical Formula to Determine Geometrical Dimensions of Electrode Metal Droplets Transferred with Short Circuits
Authors: Il’yashchenko D.P. , Chinakhov D.A. , Kirichenko K.Yu. , Sydorets V.N.
Published: November 2018

A method is described to determine geometrical dimensions of electrode metal droplets depending on short circuit duration. It provides a quantitative evaluation of the electrode metal transfer and the energy impact on metal parts being welded. It is proved that using inverter power source decreases the size of droplets transferred to the welding pool by 24% in average if compared with a diode power source. It also reduces overheating of the droplets which improves efficiency of transferring chemical elements from the electrode to the weld metal.
Mechanisms Influencing the Formation of the Carbonized Layer Relief on the Polymer Surface after the Ion-Plasma Treatment Modeling
Authors: Belyaev A.Yu. , Svistkov A.L.
Published: November 2018

The work is devoted to the discussion of hypotheses that are put forward to explain the processes occurring during ion-plasma treatment of polyurethane. A carbonized layer forms on the surface of the polymer as a result of ion-plasma treatment. However this layer is not even. Wavy relief, the geometric features of which depend on the fluence (the number of ions entering the unit surface of the sample) and the energy of ions, is formed. It is shown that a simple explanation related to material heating and subsequent shrinkage does not allow explaining the cause of the phenomenon. The second hypothesis can be the pressure of the ion flow on the surface of the sample. It causes deformation and subsequent changes in the stress-strain state after the irradiation is stopped. Calculations show that this mechanism cannot explain the formation of the folded relief of the layer. A hypothesis, based on information about a significant material change, is expressed in the article. Polymer chains under ion-plasma treatment are broken into atoms. After striking ions move deep into the material causing the polymer to swell in the near-surface layer. This swelling can cause material to move close to the sample boundary and leads to the formation of a wavy surface.
Calculation and Experimental Technique for Determining the Damping Properties of Composite Materials
Authors: Koryagin Sergey I. , Sharkov O.V. , Velikanov Nikolay L.
Published: November 2018

Polymer coatings are widely used for effective vibration damping of sheet or hull structures of different engineering systems. The article presents a calculation and experimental technique that enables improved accuracy and validity of damping properties determination of polymer coatings. Mathematical models to determine the parameters of the experimental specimen having a homogenous strain state of the polymer coating are obtained. Experimentally confirmed that the use of coatings based on adhesive compositions such as "Sprut" increases by 18...28 times the damping capability in metal structures. An addition of fillers in adhesive compositions "Sprut" type in a proportion of 30...50% of its weight reduces by 2.4 times the damping properties of metal structures.
Numerical Modeling of Thermal Processes while Depositing Layers in Additive Production
Authors: Kuznetsov M.A. , Krampit M.A. , Kryukov Artem V. , Kust T.S. , Pavlov N.V.
Published: November 2018

The up to date industry tends to introduce additive technologies in all fields of production, since their use furthers manufacturing of sufficiently qualitative products in a quite quick and economical way.As a consequence, it is still a topical issue how to control quality of the output products.The paper reports on a numerical model of thermal processes in a substrate plate and in a product while depositing.Temperature distribution patterns and a penetration form of a substrate plate are considered for the entire process of deposition.
Acoustic Tomography of Composite Materials of the Through-Transition Method
Authors: Soldatov A.I. , Soldatov A.A. , Sorokin P.V. , Kostina M.A. , Shulgina Y.V.
Published: November 2018

The article presents the image of the testing area for the through-transition method with an acoustic array. Using linear acoustic array in through-transition method, a set of data from different angles is obtained. Using this data set and the back projection method, the test area imaging is obtained, which is represented by a set of small local areas. The number of initial projections passing through each local area is calculated. Furthermore, the density function is determined and the resulting function, that is encoded whether in color or grayscale, is displayed on the monitor screen.
Financial Attitudes and Behaviors of Internal Medicine and Internal Medicine–Pediatrics Residents
Authors: Wong Rachel , Ng Patricia , Bonino John , Gonzaga Alda Maria , Mieczkowski Alexandra E.
Published: November 2018

Background

Residents graduate from medical school with increasing levels of debt and also may possess poor financial knowledge and practices. Prior studies have assessed resident financial knowledge and interest in financial education, yet additional information regarding their attitudes about personal finance and financial planning could be essential for the development of relevant curricula.

Objective

We assessed baseline financial attitudes and planning behaviors of internal medicine and internal medicine–pediatrics residents in 3 geographically diverse academic programs.

Methods

A modified version of the Financial Industry Regulatory Authority National Financial Capability survey was administered anonymously to residents in 3 programs in spring 2017. Outcomes included levels of educational debt, positive financial planning behaviors, perception of finances and debt, and education about personal finance.

Results

Response rate was 62% (184 of 298). Rates of educational debt were high, with 81% (149 of 184) of respondents reporting educational debt, and the majority owing more than $100,000. Residents' financial practices were variable, and residents could be grouped into 1 of 3 categories—concerned-engaged, concerned-unengaged, and unconcerned-unengaged—based on their engagement with debt and financial management. Residents with high debt (> $250,000) had a bimodal distribution of respondents who strongly agreed and those who strongly disagreed they were concerned about debt.

Conclusions

Resident financial attitudes and practices are variable, ranging from highly engaged residents actively managing their financial wellness to unengaged residents who have low concern, despite high educational debt.
UV measurements at Marambio and Ushuaia during 2000–2010
Authors: Lakkala Kaisa , Redondas Alberto , Meinander Outi , Thölix Laura , Hamari Britta , Almansa Antonio Fernando , Carreno Virgilio , García Rosa Delia , Torres Carlos , Deferrari Guillermo , Ochoa Hector , Bernhard Germar , Sanchez Ricardo , de Leeuw Gerrit
Published: November 2018

Abstract. Solar ultraviolet (UV) irradiances were measured with NILU-UV
multichannel radiometers at Ushuaia (54∘ S) and Marambio
(64∘ S) between 2000 and 2013. The measurements were part of the
Antarctic NILU-UV network, which was started in cooperation between Spain,
Argentina and Finland. The erythemally weighted UV irradiance time series of
both stations were analysed for the
first time. The quality assurance procedures included a travelling reference
instrument to transfer the irradiance scale to the stations. The time series
were homogenized and high quality measurements were available for the period
2000–2010. During this period UV indices of 11 or more were measured on 5
and 35 days at Marambio and Ushuaia, respectively. At Marambio, the peak
daily maximum UV index of 12 and daily doses of around
7 kJ m−2 were measured in November
2007. The highest UV daily doses at both stations were typically around
6 kJ m−2 and occurred when the stations were inside the polar vortex,
resulting in very low total ozone amount. At both stations, daily doses in
late November could even exceed those in the summer. At Marambio, in some
years, also daily doses in October can be as high as those during the summer.
At Ushuaia, the peak daily maximum UV index of 13 was measured twice: in
November 2003 and 2009. Also during those days, the station of Ushuaia was
inside the polar vortex.
Global streamflow and flood response to stratospheric aerosol geoengineering
Authors: Wei Liren , Ji Duoying , Miao Chiyuan , Muri Helene , Moore John C.
Published: November 2018

Abstract. Flood risk is projected to increase under future warming climates due to an
enhanced hydrological cycle. Solar geoengineering is known to reduce
precipitation and slow down the hydrological cycle and may therefore be
expected to offset increased flood risk. We examine this hypothesis using
streamflow and river discharge responses to Representative Concentration
Pathway 4.5 (RCP4.5) and the Geoengineering Model Intercomparison Project (GeoMIP) G4
scenarios. Compared with RCP4.5, streamflow on the western sides of Eurasia
and North America is increased under G4, while the eastern sides see a
decrease. In the Southern Hemisphere, the northern parts of landmasses have
lower streamflow under G4, and streamflow of southern parts increases relative to RCP4.5.
We furthermore calculate changes in 30-, 50-, and 100-year flood return periods
relative to the historical (1960–1999) period under the RCP4.5 and G4
scenarios. Similar spatial patterns are produced for each return period,
although those under G4 are closer to historical values than under RCP4.5.
Hence, in general, solar geoengineering does appear to reduce flood risk in
most regions, but the overall effects are largely determined by this
large-scale geographic pattern. Although G4 stratospheric aerosol
geoengineering ameliorates the Amazon drying under RCP4.5, with a weak
increase in soil moisture, the decreased runoff and streamflow leads to an
increased flood return period under G4 compared with RCP4.5.
Solar and lunar tides in noctilucent clouds as determined by ground-based lidar
Authors: Fiedler Jens , Baumgarten Gerd
Published: November 2018

Abstract. Noctilucent clouds (NLCs) occur during summer from midlatitudes to high latitudes. They consist of
nanometer-sized ice particles in an altitude range from 80 to 90 km and are
sensitive to ambient temperature and water vapor content, which makes them a
suitable tracer for variability on all timescales. The data set acquired by
the ALOMAR Rayleigh–Mie–Raman (RMR) lidar covers 21 years and is
investigated regarding tidal signatures in NLCs. For the first time solar and
lunar tidal parameters in NLCs were determined simultaneously from the same
data. Several NLC parameters are subject to persistent mean variations
throughout the solar day as well as the lunar day. Variations with lunar time
are generally smaller compared to variations with solar time. NLC occurrence
frequency shows the most robust imprint of the lunar semidiurnal tide. Its
amplitude is about 50 % of the solar semidiurnal tide, which is
surprisingly large. Phase progressions of NLC occurrence frequency indicate
upward propagating solar tides. Below 84 km altitude the corresponding
vertical wavelengths are between 20 and 30 km. For the lunar semidiurnal
tide phase progressions vary symmetrically with respect to the maximum of the
NLC layer.
Is there an aerosol signature of chemical cloud processing?
Authors: Ervens Barbara , Sorooshian Armin , Aldhaif Abdulmonam M. , Shingler Taylor , Crosbie Ewan , Ziemba Luke , Campuzano-Jost Pedro , Jimenez Jose L. , Wisthaler Armin
Published: November 2018

Abstract. The formation of sulfate and secondary organic aerosol mass in the aqueous
phase (aqSOA) of cloud and fog droplets can significantly contribute to
ambient aerosol mass. While tracer compounds give evidence that
aqueous-phase processing occurred, they do not reveal the extent to which
particle properties have been modified in terms of mass, chemical
composition, hygroscopicity, and oxidation state. We analyze data from
several field experiments and model studies for six air mass types (urban,
biogenic, marine, wild fire biomass burning, agricultural biomass burning,
and background air) using aerosol size and composition measurements for
particles 13–850 nm in diameter. We focus on the trends of changes in
mass, hygroscopicity parameter κ, and oxygen-to-carbon (O ∕ C) ratio
due to chemical cloud processing. We find that the modification of these
parameters upon cloud processing is most evident in urban, marine, and
biogenic air masses, i.e., air masses that are more polluted than very clean
air (background air) but cleaner than heavily polluted plumes as encountered
during biomass burning. Based on these trends, we suggest that the mass
ratio (Rtot) of the potential aerosol sulfate and aqSOA mass to the
initial aerosol mass can be used to predict whether chemical cloud
processing will be detectable. Scenarios in which this ratio exceeds Rtot∼0.5
are the most likely ones in which clouds can significantly
change aerosol parameters. It should be noted that the absolute value of Rtot
depends on the considered size range of particles. Rtot is
dominated by the addition of sulfate (Rsulf) in all scenarios due to
the more efficient conversion of SO2 to sulfate compared to aqSOA
formation from organic gases. As the formation processes of aqSOA are still
poorly understood, the estimate of RaqSOA is likely associated with
large uncertainties. Comparison to Rtot values as calculated for
ambient data at different locations validates the applicability of the
concept to predict a chemical cloud-processing signature in selected air masses.
Impacts of temperature and soil characteristics on methane production and oxidation in Arctic tundra
Authors: Zheng Jianqiu , RoyChowdhury Taniya , Yang Ziming , Gu Baohua , Wullschleger Stan D. , Graham David E.
Published: November 2018

Abstract. Rapid warming of Arctic ecosystems accelerates microbial decomposition of
soil organic matter and leads to increased production of carbon dioxide
(CO2) and methane (CH4). CH4 oxidation potentially
mitigates CH4 emissions from permafrost regions, but it is still
highly uncertain whether soils in high-latitude ecosystems will function as a
net source or sink for CH4 in response to rising temperature and
associated hydrological changes. We investigated CH4 production and
oxidation potential in permafrost-affected soils from degraded ice-wedge
polygons on the Barrow Environmental Observatory, Utqiaġvik (Barrow),
Alaska, USA. Frozen soil cores from flat and high-centered polygons were
sectioned into organic, transitional, and permafrost layers, and incubated at
−2, +4 and +8 ∘C to determine potential CH4 production
and oxidation rates. Significant CH4 production was only observed
from the suboxic transition layer and permafrost of flat-centered polygon
soil. These two soil sections also exhibited highest CH4 oxidation
potentials. Organic soils from relatively dry surface layers had the lowest
CH4 oxidation potential compared to saturated transition layer and
permafrost, contradicting our original assumptions. Low methanogenesis rates
are due to low overall microbial activities measured as total anaerobic
respiration and the competing iron-reduction process. Our results suggest
that CH4 oxidation could offset CH4 production and limit
surface CH4 emissions, in response to elevated temperature, and thus
must be considered in model predictions of net CH4 fluxes in Arctic
polygonal tundra. Future changes in temperature and soil saturation
conditions are likely to divert electron flow to alternative electron
acceptors and significantly alter CH4 production, which should also
be considered in CH4 models.
The Mediterranean subsurface phytoplankton dynamics and their impact on Mediterranean bioregions
Authors: Palmiéri Julien , Dutay Jean-Claude , D'Ortenzio Fabrizio , Houpert Loïc , Mayot Nicolas , Bopp Laurent
Published: November 2018

Abstract. Ocean bioregions are generally defined using remotely-sensed sea surface chlorophyll fields, based on the assumption that surface chlorophyll is representative of euphotic layer phytoplankton biomass. Here we investigate the impact of subsurface phytoplankton dynamics on the characterisation of ocean bioregions. The Mediterranean Sea is known for its contrasting bioregimes despite its limited area, and represents an appropriate case for this study. We modelled this area using a high resolution regional dynamical model, NEMO-MED12, coupled to a biogeochemical model, PISCES, and focused our analysis on the bioregions derived from lower trophic levels. Validated by satellite and Biogeochemical-Argo float observations, our model shows that chlorophyll phenology can be significantly different when estimated from surface concentrations or integrated over the first 300 m deep layer. This was found in both low chlorophyll, oligotrophic bioregions as well as in high chlorophyll, bloom bioregions. The underlying reason for this difference is the importance of subsurface phytoplankton dynamics, in particular those associated with the Deep Chlorophyll Maximum (DCM) at the base of the upper mixed layer. Subsurface phytoplankton are found to significantly impact the bloom bioregions, while in oligotrophic regions, surface and subsurface chlorophyll are of similar importance. Consequently, our results show that surface chlorophyll is not representative of total phytoplankton biomass. Analysis of the DCM finds that its dynamics are extremely homogeneous throughout the Mediterranean Sea, and that it follows the annual cycle of solar radiation. In the most oligotrophic bioregion, the total phytoplankton biomass is almost constant along the year, implying that the summertime DCM biomass increase is not due to DCM photoacclimation, nor an increase of DCM production, but instead of the migration – with photoacclimation – of surface phytoplankton into the DCM.