Microencapsulation optimization of natural anthocyanins with maltodextrin, gum Arabic and gelatin

The barberry (Berberis vulgaris) extract which is a rich source of anthocyanins was used for spray drying encapsulation with three different wall materials, i.e., combination of maltodextrin and gum Arabic (MD + GA), maltodextrin and gelatin (MD + GE), and maltodextrin (MD). Response Surface Methodology (RSM) was applied for optimization of microencapsulation efficiency and physical properties of encapsulated powders considering wall material type as well as different ratios of core to wall materials as independent variables. Physical characteristics of spray-dried powders were investigated by further analyses of moisture content, hygroscopicity, degree of caking, solubility, bulk and absolute density, porosity, flowability and microstructural evaluation of encapsulated powders. Our results indicated that samples produced with MD + GA as wall materials represented the highest process efficiency and best powder quality; the optimum conditions of microencapsulation process for barberry anthocyanins were found to be the wall material content and anthocyanin load of 24.54 and 13.82, respectively. Under such conditions, the microencapsulation efficiency (ME) of anthocyanins could be as high as 92.83. © 2016 Elsevier B.V

Magneto-tunable terahertz absorption in single-layer graphene: A general approach

Terahertz (THz) anisotropic absorption in graphene could be significantly modified upon applying a static magnetic field on its ultra-fast 2D Dirac electrons. In general, by deriving the generalized Fresnel coefficients for monolayer graphene under applied magnetic field, relatively high anisotropic absorption for the incoming linearly polarized light with specific scattering angles could be achieved. We also prove that the light absorption of monolayer graphene corresponds well to its surface optical conductivity in the presence of a static magnetic field. Moreover, the temperature-dependent conductivity of graphene makes it possible to show that a step by step absorption feature would emerge at very low temperatures. We believe that these properties may be considered to be used in novel graphene-based THz application

Breaking a Chaotic Cryptographic Scheme Based on Composition Maps

Recently, a chaotic cryptographic scheme based on composition maps was proposed. This paper studies the security of the scheme and reports the following findings: 1) the scheme can be broken by a differential attack with $6+\lceil\log_L(MN)\rceil$ chosen-plaintext, where $MN$ is the size of plaintext and $L$ is the number of different elements in plain-text; 2) the scheme is not sensitive to the changes of plaintext; 3) the two composition maps do not work well as a secure and efficient random number source.Comment: 9 pages, 7 figure

MMS Observations of Plasma Heating Associated With FTE Growth

Upon formation, flux transfer events (FTEs) in the subsolar magnetosheath have been observed to grow in diameter, λ, while convecting along the magnetopause. Plasma pressure has also been found to decrease subâ adiabatically with increasing λ, indicating the presence of internal plasma acceleration and heating processes. Here, the Magnetospheric Multiscale (MMS) fields and plasma measurements are used to determine the relative roles of parallel electric fields, betatron, and Fermi processes in plasma heating inside an ensemble of 55 subsolar FTEs. Plasma heating is shown asymmetric inside FTEs. Parallel electric fields dominate (>75%) ion and electron heating at the leading edge of FTEs. At the trailing edge, betatron and Fermi processes overtake (>50%), resulting in ion cooling and electron heating, respectively. The observed strong net heatings inside FTEs are proportional to λâ 1/2. It is concluded that reconnectionâ driven heating continues inside FTEs far from the subsolar electron and ion diffusion regions.Plain Language SummaryEnergetic charged particles are observed in many space and astrophysical environments, including our solar system. However, the acceleration and heating mechanisms responsible for generating these energetic charged particles remain to be discovered. Simulations and in situ observations have shown that magnetic reconnection, a process through which magnetic field lines â reconnectâ and release magnetic energy, plays a major role in generating energetic charged particles. The primary sites for magnetic energy transfer to charged particle acceleration and heating are the twin exhaust regions that emanate from the reconnection Xâ line. However, the amount of kinetic energy gained by charged particles in the exhaust regions represents only a small fraction of the total energy released by magnetic reconnection. Here, the Magnetospheric Multiscale (MMS) multipoint fields and plasma measurements are used to determine the contributions of acceleration mechanisms operating inside flux transfer events (FTEs), which are formed in the reconnection exhaust regions. We observe that acceleration mechanisms contribute to the charged particles’ energy gain inside FTEs. We further reveal that while acceleration mechanisms are most significant inside smaller FTEs, they continue to accelerate charged particles inside larger FTEs. We conclude that magnetic reconnectionâ driven charged particle acceleration is longâ lasting and can take place far from the exhaust regions.Key PointsThe relative roles of parallel electric fields, betatron, and Fermi processes in plasma heating inside 55 subsolar FTEs are determinedParallel electric fields dominate plasma energization at FTEs’ leading edge. Betatron and Fermi processes overtake at FTEs’ trailing edgeMMS observations reveal strong plasma acceleration inside FTEs that is inversely proportional to the square root of FTE diameterPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152496/1/grl59844_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152496/2/grl59844-sup-0001-2019GL084843-SI.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152496/3/grl59844.pd

A Model for Leveraging the Tools of Personal knowledge Management 2.0 as the Next Generation of E-Learning

Assictant: In recent years a fundamental revolution has been seen in the education. This transformation is not only in the tools and methods, but in the concept and approach of education. One of these developments is in the transferring from teacher-centered methods into students-centered methods. In this transformation, personal knowledge management can be recognized as the coin of e-learning. Concurrent with this evolution in the methods, tools of teaching have been changed fundamentally from traditional teaching tools to e-learning and e-learning 2.0 (e-learning with Web 2.0 tools). This novel method has been studied in this research. At the first, personal knowledge management processes, Web 2.0 tools have been recognized and then the overlaps with the training have been studied. The suggested model has been composed of  these three areas, validated by the Delphi panel, and at last with chi-square test a survey has been done. 300 users of knowledge workers of online knowledge communities have been recognized and categorized; and knowledge workers 2.0 have been selected. In recognizing processes and tools of personal knowledge management, which can be used in e-learning, these knowledge workers answer the questions. On the other hand, 11 experts on Knowledge management (authors of ISI articles) in three rounds have been contributed in Delphi panel. The result of this study has been formed as a model for leveraging personal knowledge management tools in learning. This model includes the personal knowledge management 2.0 processes which can be used in learning. In addition, the best tools for each process have been identified in this model

MMS Multi-Point Analysis of FTE Evolution: Physical Characteristics and Dynamics

Previous studies have indicated that flux transfer events (FTEs) grow as they convect away from the reconnection site along the magnetopause. This increase in FTE diameter may occur via adiabatic expansion in response to decreasing external pressure away from the subsolar region or due to a continuous supply of magnetic flux and plasma to the FTEs’ outer layers by magnetic reconnection. Here we investigate an ensemble of 55 FTEs at the subsolar magnetopause using Magnetospheric Multiscale (MMS) multi-point measurements. The FTEs are initially modeled as quasi-force-free flux ropes in order to infer their geometry and the spacecraft trajectory relative to their central axis. The MMS observations reveal a radially-inward net force at the outer layers of FTEs which can accelerate plasmas and fields toward the FTE’s core region. Inside the FTEs, near the central axis, plasma density is found to decrease as the axial net force increases. It is interpreted that the axial net force accelerates plasmas along the axis in the region of compressing field lines. Statistical analysis of the MMS observations of the 55 FTEs indicates that plasma pressure, Pth, decreases with increasing FTE diameter, λ, as Pth,obsv - λ-0.24. Assuming that all 55 FTEs started out with similar diameters, this rate of plasma pressure decrease with increasing FTE diameter is at least an order of magnitude slower than the theoretical rate for adiabatic expansion (i.e., Pth,adiab. - λ-3.3), suggesting the presence of efficient plasma heating mechanisms, such as magnetic reconnection, to facilitate FTE growth.Key PointsThe forces inside FTEs observed by MMS suggest plasma acceleration toward and along the FTE’s central axis causing plasma to escapeThe roles of adiabatic expansion and reconnection in FTE growth are explored using MMS observationsThe observed sub-adiabatic decrease of plasma pressure as FTE size increases requires plasma heating mechanisms such as reconnectionPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151362/1/jgra55065_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151362/2/jgra55065.pd