bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mesenchymal stem cells – a historical overview
Authors: Stefańska Katarzyna , Bryl Rut , Moncrieff Lisa , Pinto Nelson , Shibli Jamil A. , Dyszkiewicz-Konwińska Marta 
Published: September 2020

Abstract
Mesenchymal stem cells are currently one of the most extensively studied topics in experimental medicine, given their unique properties in terms of immunomodulation, multiple factors secretion and homing to injured tissue sites. Such characteristics were proven to be invaluable in various disease management treatments, for example in cancer, tissue regeneration or immunologic/inflammatory-related disorders. MSCs were first isolated from bone marrow in 1960-1970’s and were characterized as cells with fibroblastoid shape and osteogenic potential, which form clonogenic colonies (CFU-F – colony-forming unit-fibroblast). Nowadays the term ‘mesenchymal stem cells’ is used in regards to all of the cells meeting minimal criteria published in 2006 by the International Society for Cellular Therapy, however the name ‘mesenchymal stromal cells’ has been suggested to be more appropriate. Regardless of the name controversy, these cells exhibit multilineage differentiation potential, self-renewal ability, adhere to plastic and express specific surface antigens. In 2011 the first commercial product based on MSCs was developed and many more are expected to emerge. This review focuses on a historical perspective concerning studies on MSCs, controversies regarding their name and their characteristics and clinical utilization.

Running title: The history of mesenchymal stem cells
In vitro antioxidant and antityrosinase activities of Manilkara kauki
Authors: Srisupap Sirinada , Chaicharoenpong Chanya 
Published: September 2020

Abstract

Manilkara kauki L. Dubard is a tropical plant in the genus Manilkara of family Sapotaceae. This study investigated the total phenolic and flavonoid contents, and antioxidant and antityrosinase activities in different parts of M. kauki (fruits, leaves, seeds, stem barks and woods) and in fractions of stem barks. The total phenolic and flavonoid contents of the methanol and aqueous crude extracts of different parts of M. kauki ranged from 10.87 to 176.56 mg GAE (gallic acid equivalents) per gram of crude extract and 14.33 to 821.67 mg QE (quercetin equivalents) per gram of crude extract, resp. Leaves and stem barks exhibited higher total phenolic and flavonoid contents and antioxidant and anti-tyrosinase activities than fruits, seeds and woods. Stem barks were sequentially extracted with n-hexane, ethyl acetate, methanol and water and then the fractionated extracts were subjected to antioxidant and antityrosinase activities testing. The ethyl acetate and methanol extracts of stem barks exhibited higher total phenolic and flavonoid contents and antioxidant and antityrosinase activities than the n-hexane and aqueous extracts. Moreover, ethyl acetate extract of M. kauki stem exhibited the highest antityrosinase activity. It may be a potential source of tyrosinase inhibitors for pharmaceutical and cosmetic applications.
Evaluation of yield and nitrogen utilisation with urease and nitrification inhibitors in sweet potato crop (Ipomoea batatas L.)
Authors: Kakabouki Ioanna , Togias Triantafyllos , Folina Antigoni Eleni , Karydogianni Stella , Zisi Charikleia , Bilalis Dimitrios 
Published: September 2020

Abstract
Sweet potato (Ipomoea batatas L.) is a new tuber crop grown in Greece. It constitutes an innovative dietary component for both humans and animals, due to its nutritional properties. The cultivation of sweet potato focuses on the growth of both tubers and plants. Nitrogen is considered an essential element for almost all crops. This study set out to compare the effect of nitrogen inhibitors on yield components of sweet potato. In the literature, it is stated that in sweet potato cultivation nitrogen mainly affects the plants’ growth such as the tuber's yield and some quality characteristics such as dry matter and protein content. To furthermore explore this particular area, field experiments took place in West Greece, during the years 2018 and 2019. Several urea combination treatments were used in the experimental process. The treatments were urea (46-0-0), urea with urease inhibitor (UI), urea with nitrification inhibitor (NI), urea with double inhibitors (UI + NI) and control (without fertilizer) in a randomised complete block design. Leaf area index (LAI) was significantly affected by the fertilizer marking the highest value of 5.35 under urea + UI + NI treatment. Marketable yield was profoundly affected by the fertilizer in the experimental years and ranged from 18,180 to 23,230 Kg · ha−1 whereas non-marketable yield was not affected by the fertilizer. A considerable impact of fertilizers was noticed on yield where the highest value was 30,923 Kg · ha−1 under urea + NI + UI treatment. The percentage of nitrogen on tubers and upper parts was significantly affected by the fertilizers. Nitrogen markers, such as nitrogen use efficiency (NUE), nitrogen harvest index and nitrogen agronomic efficiency (NAE), were used to evaluate nitrogen release. A significant positive correlation was noticed between marketable yield and NUE (0.774). Also, the significant increase in yield showed a positive correlation with NAE (0.727). For yield components of sweet potato, the highest values were observed in urea with double inhibitors treatment in both experimental years.
South-South migration and elections: evidence from post-apartheid South Africa
Authors: Bedasso Biniam E. , Jaupart Pascal 
Published: September 2020

Abstract
Little is known about the political consequences of immigration in Sub-Saharan Africa. In this paper, we estimate the effect of exposure to immigration on election outcomes in South Africa. Our analysis is based on municipality panel data and an instrumental variable (IV) strategy exploiting historical migrant settlement patterns. We find that local immigration concentration has a negative impact on the performance of the incumbent African National Congress, whereas support for the main opposition party, the Democratic Alliance, is found to increase in municipalities with a larger immigrant presence. These effects hold regardless of the skill levels of immigrants in a municipality. In terms of mechanisms, competition over jobs and local public services as well as ethnic diversity and cultural factors influence how immigration affects election outcomes. These findings are robust to a broad range of sensitivity checks. They provide evidence that immigration can be a politically salient issue in migrant-destination Sub-Saharan African countries. They also show that immigration can affect election results even in contexts where there is no single issue anti-migrant party.
Scientometric Analysis of Research Output from Brazil in Response to the Zika Crisis Using e-Lattes
Authors: Sampaio Ricardo Barros , de Abreu Batista Antônio , Ferreira Bruno Santos , Barreto Mauricio L. , Mena-Chalco Jesús P. 
Published: September 2020

Abstract

Purpose
This paper aims to test the use of e-Lattes to map the Brazilian scientific output in a recent research health subject: Zika Virus.

Design/methodology/approach
From a set of Lattes CVs of Zika researchers registered on the Lattes Platform, we used the e-Lattes to map the Brazilian scientific response to the Zika crisis.

Findings
Brazilian science articulated quickly during the public health emergency of international concern (PHEIC) due to the creation of mechanisms to streamline funding of scientific research.

Research limitations
We did not assess any dimension of research quality, including the scientific impact and societal value.

Practical implications
e-Lattes can provide useful guidelines for different stakeholders in research groups from Lattes CVs of members.

Originality/value
The information included in Lattes CVs permits us to assess science from a broader perspective taking into account not only scientific research production but also the training of human resources and scientific collaboration.
Russian Insecurities: How Fear Drives Perception in the Near Abroad
Authors: Kerrane Evan 
Published: September 2020

Abstract
Interpreting Russian actions in the Near Abroad relies on the perception of Russian intent, but all too often states fail to analyse how Moscow interprets Western objectives. While defensive realist theorists argue that states tend to seek only enough power to survive within the system, the U.S. 2017 National Security Strategy argues Moscow is a revisionist state, seeking a return to great power status. Increasing tensions among the actors in the region gives rise to potential misperception of intent. This article analyses state motivations under a defensive realist paradigm and addresses how Russian actions may emerge from a defensive perspective. Using a defensive realist framework, this article elevates Russian insecurities and fear of Western influence in the Near Abroad as the primary motivator of state action.
Effect of Heat Treatment Parameters on Mechanical Properties of Medium Carbon Steel
Authors: Blaoui M. M. , Zemri M. , Brahami A. 
Published: September 2020

Abstract
Engineering materials, mostly steel, are heat treated under controlled sequence of heating and cooling to alter their physical and mechanical properties to meet desired engineering applications. This paper presents a study of the influence of austenitization temperature, cooling rate, holding time and heating rate during the heat treatment on microstructure and mechanical properties (tensile strength, yield strength, elongation and hardness) of the C45 steel. Specimens undergoing different heat treatment lead to various mechanical properties which were determined using standard methods. Microstructural evolution was investigated by scanning electron microscopy (SEM). The results revealed that microstructure and hardenability of the C45 steel depends on cooling rate, austenitization temperature, holding time and heating rate.
Propagation and Reflection of Plane Waves in a Rotating Magneto-Elastic Fibre-Reinforced Semi Space with Surface Stress
Authors: Roy Indrajit , Acharya D. P. , Acharya Sourav 
Published: September 2020

Abstract
The present paper investigates the propagation of quasi longitudinal (qLD) and quasi transverse (qTD) waves in a magneto elastic fibre-reinforced rotating semi-infinite medium. Reflections of waves from the flat boundary with surface stress have been studied in details. The governing equations have been used to obtain the polynomial characteristic equation from which qLD and qTD wave velocities are found. It is observed that both the wave velocities depend upon the incident angle. After imposing the appropriate boundary conditions including surface stress the resultant amplitude ratios for the total displacements have been obtained. Numerically simulated results have been depicted graphically by displaying two and three dimensional graphs to highlight the influence of magnetic field, rotation, surface stress and fibre-reinforcing nature of the material medium on the propagation and reflection of plane waves.
Parameter's Optimization of Surface Plastic Deformation Corrosion-resistant Steel by Computer Simulation
Authors: Lasitsa Alexander M. , Churankin Vyacheslav G. , Derkach Valery V. 
Published: September 2020

Abstract
The knurling of corrosion-resistant steel 95X18 (the nearest analog is AISI 440B, AISI 440C, AISI A756, DIN-1.4125, SUS440C, Z100CD17) simulation with finite element method is investigated in the paper. Diagram stresses, strains and displacement are calculated by using CAE system SolidWorks. Dependence of strengthening area on processing tools geometry and loaded force are investigated. We proposed the algorithm of knurling parameters optimization by using a computer simulation. The correlation between simulation and experimental data was found.
Experimental Study of Temperature Influence on the Electrical Performance of Polycrystalline Photovoltaic Cell
Authors: Reteri Ahmed , Saib Hind , Chib Zahra 
Published: September 2020

Abstract
A thermal photovoltaic hybrid collector enables simultaneous electrical conversion of the solar radiation and recovery of heat absorbed by the cell. This energy cogeneration obviously yields the use of such systems which are very interesting in various fields. During the actual operation of the photovoltaic modules, the experimental characterization shows that the electrical efficiency decreases significantly with increasing temperature of the photovoltaic cells exposed to the sun. Our work focuses on an experimental study carried out in thermal transfer laboratory at the Faculty of Technology of the Tlemcen University, in order to analyze the effect of cell temperature, glazing on electrical performance, also the effect of the cooling of this cell.
Exact Thermomechanical Analysis of Functionally Graded (FG) Thick-Walled Spheres
Authors: Yildirim V. 
Published: September 2020

Abstract
The present study aims to provide a deeper understanding for the thermo-mechanical analysis of spheres made of non-homogeneous isotropic materials. To this end, Navier equations are solved analytically based on the spherically-symmetric plain-strain assumptions and closed-form formulas are proposed for the elastic fields in a simple-power-law graded spheres subjected to steady-state thermal and internal/external pressure loads. A comprehensive parametric study is then performed with both functionally-graded hypothetical and physical materials. Two benchmark examples are reconsidered with hypothetically chosen inhomogeneity indexes. Effects of inhomogeneity indexes are reviewed in these examples. Differently from the literature, thickness effects are also examined under separate and combined loads together with the thermo-mechanical behavioral differences in spheres and cylinders. Finally three physical metal-ceramic pairs are studied originally with appropriate inhomogeneity indexes which are defined as the inner surface is full ceramic and the outer surface is full metal. Results are presented in graphical and tabular forms.
Polarization of the Longitudinal Pochhammer–Chree Waves
Authors: Ilyashenko Alla V. , Kuznetsov Sergey V. 
Published: September 2020

Abstract
The exact solutions of the linear Pochhammer – Chree equation for propagating harmonic waves in a cylindrical rod, are analyzed. Spectral analysis of the matrix dispersion equation for longitudinal axially symmetric modes is performed. Analytical expressions for displacement fields are obtained. Variation of wave polarization on the free surface due to variation of Poisson’s ratio and circular frequency is analyzed. It is observed that at the phase speed coinciding with the bulk shear wave speed all the components of the displacement field vanish, meaning that no longitudinal axisymmetric Pochhammer – Chree wave can propagate at this phase speed.
Impact of Fiber Metal Laminates - Literature Research
Authors: Lisowski Bartłomiej 
Published: September 2020

Abstract
The paper refers the general idea of composite materials especially Fiber Metal Laminates (FMLs) with respect to low-velocity impact incidents. This phenomenon was characterized by basic parameters and energy dissipation mechanisms. Further considerations are matched with analytical procedures with reference to linearized spring-mass models, impact characteristics divided into energy correlations (global flexure, delamination, tensile fracture and petaling absorbed energies) and set of motion second order differential equations. Experimental tests were based on analytical solutions for different types of FML - GLARE type plates and were held in accordance to ASTM standards. The structure model reveals plenty of dependences related to strain rate effect, deflection represented by the correlations among plate and intender deformation, separate flexure characteristics for aluminium and composite, contact definition based on intender end-radius shape stress analysis supported by FSDT, von Karman strains as well as CLT. Failure criteria were conformed to layers specifications with respect to von Misses stress-strain criterion for aluminium matched with Tsai-Hill or Puck criterion for unidirectional laminate. At the final stage numerical simulation were made in FEM programs such as ABAQUS and ANSYS. Future prospects were based on the experiments held over 3D-fiberglass (3DFG) FMLs with magnesium alloy layers which covers more favorable mechanical properties than FMLs.
Mechanical Property Evaluation Aluminium 6061 Nickel Coated Cenosphere Composites
Authors: Ahamed A. , Prashanth T. 
Published: September 2020

Abstract
In recent years, among all the aluminium alloys, Al6061 is gaining much popularity as a matrix material to prepare MMCs owing to its excellent mechanical properties and good corrosion resistance. Fly ash cenospheres are primarily a by-product in power generation plants. Research is in progress to effectively use this byproduct to produce new usable and profitable materials as they pose major disposal and environmental problems. In the light of the above, the present investigation is aimed at development of metal coated cenosphere reinforced Al6061 composites and to characterize their mechanical properties. Al6061 nickel coated composites have been prepared by liquid metallurgy route by varying percentage of nickel coated cenospheres between 2–10% by weight in steps of 2%. Density, hardness and tensile behaviour of the composites is carried out. It is observed that there is an increase in the values of hardness, density of the composite with an increasing percentage of the nickel coated cenosphere reinforcements. There is also a notable increase in the tensile strength as well as reduction in ductility of the prepared composite. Fractographs to indicate the behaviour of the composites have also been depicted in the paper.
A Two Dimensional Axisymmetric Thermoelastic Diffusion Problem of Micropolar Porous Circular Plate with Dual Phase Lag Model
Authors: Kumar Rajneesh , Miglani Aseem , Rani Rekha 
Published: September 2020

Abstract
In the present work, we consider a two dimensional axisymmetric problem of micropolar porous circular plate with thermal and chemical potential sources in the context of the theory of dual phase lag generalized thermoelastic diffusion. The potential functions are used to analyze the problem. The Laplace and Hankel transforms techniques are used to find the expressions of displacements, microrotation, volume fraction field, temperature distribution, concentration and stresses in the transformed domain. The inversion of transforms based on Fourier expansion techniques is applied to obtain the results in the physical domain. The numerical results for resulting quantities are obtained and depicted graphically. Effect of porosity, LS theory and phase lag are presented on the resulting quantities. Some particular cases are also deduced.
Carbon Fibre Reinforced Wheel for Fuel Ultra–Efficient Vehicle
Authors: Wilczynski A. , Bartczak M. , Siczek K. , Kubiak P. 
Published: September 2020

Abstract
Due to municipal policies that are about to be legislated in many cities around the world, it may occur that habitants will be forced to commute in ultralight urban low-consuming cars. This paper covers the research concerning the innovative design, manufacturing method and the test of the wheel for such a vehicle. The design guidelines were as follows: elevated rigidity and durability, reduced weight and ease to adapt different types of hubs and powertrains. This was achieved by determining the forces acting on the wheel, examination of the characteristics of the possible materials and performing static finite element analysis simulations that were aimed to reveal stresses distribution and presumable failure points. Afterwards, the carbon fiber reinforced polymer disc wheel was manufactured and tested to compare the empirical deformations with the results of the simulations. The results proved that this type of wheel can be successfully used in ultralight passenger vehicle. The predicted weight reduction of such a wheel, in comparison to the wheels available on the market, may be about 40% due to using carbon fibre reinforced polymer and new, innovative solution - the magnesium hub, instead of aluminum, that is known to damp the vibration more efficiently and is easier to create a strong bond with the wheel.
Effect of Charpy Impact Test on Microstructure Properties of AISI4140 Steel
Authors: Chaouch Djamel , Sadok Ahmed , Bendaoudi Seif-Eddine , Chaouch Abdallah 
Published: September 2020

Abstract
In this paper, the mechanical properties and microstructures of AISI4140 low alloy steel under different tempering conditions are investigated. The samples are quenched, tempered to a martensite structure and loaded to fracture by means of Charpy machine according to standard test. Fractography analysis showed that the morphology fracture surface was changed by increasing tempering temperature. The variation of energy of Charpy impact fracture as a function of tempering temperature exhibits minimum values at 300 °C, which suggests the occurrence of temper embrittlement.
Verification of the Dynamic Modeling of 2-R Robot Actuated by (N) Equally Spaced Planet-Gears by Using SolidWorks and MATLAB/SIMULINK
Authors: Fernini Brahim , Temmar Mustapha , Kai Yoshihiro , Noor Muhamad M. 
Published: September 2020

Abstract
Industrial robots often use planetary gear system to have high joint torques; therefore, the influence of the rotary inertia of the number of the equally spaced planet-gears on the dynamical behavior of the robot is very important. The main objective of this paper is to develop the dynamic modeling of robot actuated by (n) equally spaced planet-gears in the case where the planet-carrier is fixed, no closed solution has been reported for this dynamic modeling, and to compare between the dynamic behavior of robot actuated by (n+1) and (n) equally spaced planet-gears for a same trajectory planning. The authors derive the explicit dynamic model for an elbow down of 2-R manipulator holding an external mass. Finally, the obtained simulation results by using Matlab/Simulink of the dynamic modeling are verified by modeling the same robot and using an advanced simulation via SolidWorks (2014).
Robotic machining in correlation with a 3D scanner
Authors: Kurc Krzysztof , Burghardt Andrzej , Szybicki Dariusz , Gierlak Piotri , Łabuński Wojciech , Muszyńska Magdalena , Giergiel Józef 
Published: September 2020

Abstract
The article presents an original method of communication and data exchange in a robotic machining station consisting of two robots, a positioner and a 3D optic scanner. The task of one of the robots, equipped with a 3D optic scanner, was to receive point cloud of a detail (mould) attached to the positioner table. After detail digitalisation, the received point cloud was adjusted to (compared with) a model detail in the form of a CAD file in the Atos Professional software. In the software, casting material excesses were received in places selected on the detail. Values of the excesses and their coordinates were saved in the script and sent to the robot controller using TCP/IP protocol. The other of robots, equipped with the force control addition and the option of obtaining various processing tools, received sent excess and its coordinates. The other robot adjusted the processing parameters to random excesses, the value of which was received from measurements of the optic scanner of the first robot.